Bio

Chris Develder currently is associate professor with the research group IDLab1 in the Dept. of Information Technology (INTEC) at Ghent University - imec2, Ghent, Belgium. He received the MSc degree in computer science engineering and a PhD in electrical engineering from Ghent University (Ghent, Belgium), in Jul. 1999 and Dec. 2003 respectively (as a fellow of the Research Foundation, FWO). From Jan. 2004 to Aug. 2005, he worked for OPNET Technologies3, on (optical) network design and planning. In Sep. 2005, he re-joined INTEC as a postdoctoral researcher, and as a postdoctoral fellow of the FWO since Oct. 2006 (until 2012). In Oct. 2007 he obtained a part-time, and since Feb. 2010 a fulltime professorship at Ghent University. He has stayed as a research visitor at UC Davis (Jul.-Oct. 2007), CA, USA and at Columbia University, NY, USA (Jan. 2013 - Jun. 2015). He was and is involved in various national and European research projects (e.g., IST David, IST Phosphorus, IST E-Photon One, BONE, FP7 Alpha, FP7 Geysers, FP7 Increase, FP7 C-DAX).

Chris currently leads two research teams within IDLab, one on information retrieval and extraction, the other on smart grids. His research interests also still include optical networks (dimensioning, modeling, optimization, esp. for grid/cloud computing). He regularly serves as reviewer/TPC member for international journals and conferences (IEEE/OSA JLT, IEEE/OSA JOCN, IEEE/ACM Trans. Networking, Computer Networks, IEEE Network, IEEE JSAC, IEEE Commun. Mag., IEEE Trans. Smart Grid; IEEE Globecom, IEEE ICC, IEEE SmartGridComm, ECOC, ACM SIGIR, ACM CIKM, etc.). He is Senior Member of IEEE and Member of ACM.

1: IDLab is the integration of the former research groups DSLab, IBCN and MOSAIC.
2: Since Sep. 2016, the former research center iMinds has been officially merged into imec.
3: In Oct. 2012, OPNET was acquired by Riverbed.

Teaching

Master courses

M.Sc. in engineering • The Information Society and ICT • 2012 – present
M.Sc. in computer science engineering • Multimedia Networks • 2009 – 2014

Bachelor courses

B.Sc. in computer science engineering • Algorithms and Data Structures • 2010 – present

Talks

Upcoming/recent talks by Chris:

2016

inproceedings

C. Develder, N. Sadeghianpourhamami, M. Strobbe and N. Refa, "Quantifying flexibility in EV charging as DR potential: Analysis of two real-world data sets", in Proc. 7th IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2016), Sydney, Australia, 6-9 Nov. 2016, pp. 1-6.

inproceedings

visit

C. Develder, "Algorithms and communications for Smart Grids: Knowing and controlling power consumption" (Invited Presentation), University of British Columbia, Vancouver, BC, Canada, 19 Jul. 2016.

inproceedings

T. Wang, B. Jaumard, C. Develder, "Resilient backbone networks for multi-site data centers: Exploiting anycast (re)routing for multi-period traffic" (Invited Paper), in Proc. OSA Photonic Netw. Devices, Vancouver, BC, Canada, 18-20 Jul. 2016.

inproceedings

T. Wang, B. Jaumard, C. Develder, "Anycast (re)routing of multi-period traffic in dimensioning resilient backbone networks for multi-site data centers" (Invited Paper), in Proc. 18th Int. Conf. Transparent Optical Netw. (ICTON 2016), Trento, Italy, 10-14 Jul. 2016.

inproceedings

tutorial

C. Develder, H. Bontius, M. Hoefling, Y. Cao, P. Romano, M. Strobbe, W. Smith, L. Zanni, "Tutorial 4: Information-centric communication infrastructure for real-time state estimation of distribution networks using PMUs", in Proc. IEEE Int. Energy Conf. (Energycon 2016), Leuven, Belgium, 4 Apr. 2016.

2015

inproceedings

C. Develder, B. Jaumard, "Dimensioning backbone networks for multi-site data centers: Exploring the benefit of exploiting anycast routing for resilience" (Invited Paper), in IEEE Int. Workshop on Reliable Network Design and Modeling (RNDM 2015), Munich, Germany, 5-7 Oct. 2015.

inproceedings

C. Develder, "Dimensioning (optical) networks for cloud computing" (Invited Panelist), in 27th Int. Teletraffic Congress (ITC 27), Ghent, Belgium, 9-10 Sep. 2015.

visit

C. Develder, "Smart grid algorithms: Knowing and controlling power consumption" (Invited Presentation), Center for Urban Science and Progress (CUSP), NY, USA, 18 Jun. 2015.

visit

C. Develder, "Smart grid algorithms: Knowing and controlling power consumption" (Invited Presentation), UC Irvine, CA, USA, 5 Jun. 2015.

2014

inproceedings

C. Develder, "An information-centric approach for smart grid communications" (Invited Panelist), Panel Session on Internet of Energy, at IEEE Int. Conf. Smart Grid Commun. (SmartGridComm 2014), Venice, Italy, 4-6 Nov. 2014.

tutorial

C. Develder, "Charging electric vehicles in the smart grid" (Invited Lecture), at Groningen Energy Summer School 2014, Groningen, The Netherlands, 18-29 Aug. 2014.

inproceedings

M. Bui, T. Wang, B. Jaumard, D. Medhi, and C. Develder, "Time-varying resilient virtual network mapping for multi-location cloud data centers" (Invited Paper), in Proc. 16th Int. Conf. Transparent Optical Netw. (ICTON 2014), Graz, Austria, 6-10 Jul. 2014.

tutorial

B. Jaumard, M. Bui, C. Develder, "Resilient Optical Network Virtualization", Tutorial at 10th Int. Conf. on Design of Reliable Commun. Netw. (DRCN 2014), Ghent, Belgium, Mar. 31, 2014.

visit

C. Develder, et al., "Dimensioning (optical) networks for cloud computing" (Invited Presentation), Columbia University, New York, NY, USA, 23 Jan. 2014.

2013

visit

C. Develder, et al., "Dimensioning (optical) networks for cloud computing" (Invited Presentation), Concordia University, Montreal, QC, Canada, 26 Nov. 2013.

visit

C. Develder, et al., "Dimensioning (optical) networks for cloud computing" (Invited Presentation), Univ. Missouri - Kansas City, Kansas City, MO, USA, 7 Nov. 2013.

inproceedings

M. Bui, B. Jaumard, and C. Develder, "Anycast end-to-end resilience for cloud services over virtual optical networks" (Invited Paper), in Proc. 15th Int. Conf. Transparent Optical Netw. (ICTON 2013), Cartagena, Spain, 23-27 Jun. 2013.

visit

C. Develder, et al., "Distributed smart charging of electrical vehicles" (Invited Presentation), Bell Labs, Murray Hill, NJ, USA, 18 Jun. 2013.

2012

inproceedings

C. Develder, et al., "Power-saving strategies for optical grids/clouds" (Invited Presentation), at Colloquium EJC - ICT 2012, Lyon, France, 19-20 Nov. 2012.

inproceedings

C. Develder, J. Buysse, and B. Jaumard, "Designing resilient optical grids/clouds" (Invited Presentation), Workshop 2: What do we need to make an optical network robust against disasters?, at Photonics in Switching (PS 2012), Ajaccio, Corsica, France, 11 Sep. 2012.

inproceedings

B. Jaumard, A. Shaikh and C. Develder, "Selecting the best locations for data centers in resilient optical grid/cloud dimensioning" (Invited paper), in Proc. 14th Int. Conf. Transparent Optical Netw. (ICTON 2012), Coventry, UK, 2-5 Jul. 2012.

inproceedings

C. Develder, "Integrated simulation of power and communication networks for Smart Grids" (Invited Presentation), in EERA Smart Grids R&D Workshop, Milan, Italy, 26-28 Jun. 2012.

inproceedings

C. Develder, J. Buysse, M. De Leenheer, B. Jaumard and B. Dhoedt, "Resilient network dimensioning for optical grid/clouds using relocation" (Invited Paper), in Proc. Workshop on New Trends in Optical Networks Survivability at IEEE Int. Conf. on Commun. (ICC 2012), Ottawa, Ontario, Canada, 11 Jun. 2012.

2011

inproceedings

C. Develder, "Integrated simulation of power and communication networks for smart grid applications" (Invited Presentation), in IEEE Commun. Theory Workshop 2011 (CTW 2011), Sitges, Spain, 19-22 Jun. 2011.

inproceedings

C. Develder, J. Buysse, A. Shaikh, B. Jaumard, M. De Leenheer and B. Dhoedt, "Survivable optical grid dimensioning: anycast routing with server and network failure protection", in Proc. IEEE Int. Conf. Commun. (ICC 2011), Kyoto, Japan, 5-9 Jun. 2011.

Publications

See also my Google Scholar profile. If you have trouble obtaining a copy of one of the papers below, please get in touch via chris.develder@ugent.be.

Published papers

pubinproceedings

G. Bekoulis, J. Deleu, T. Demeester and C. Develder, "Reconstructing the house from the ad: Structured prediction on real estate classifieds", in Proc. 15th Conf. Eur. Chapter Assoc. Comput. Ling. (EACL 2017), Valencia, Spain, 3-7 Apr. 2017, pp. 1-5.

Reconstructing the house from the ad: Structured prediction on real estate classifieds

G. Bekoulis, J. Deleu, T. Demeester and C. Develder


in Proc. 15th Conf. Eur. Chapter Assoc. Comput. Ling. (EACL 2017), Valencia, Spain, 3-7 Apr. 2017, pp. 1-5.

In this paper, we address the (to the best of our knowledge) new problem of extracting a structured description of real estate properties from their natural language descriptions in classifieds. We survey and present several models to (a) identify important entities of a property (e.g., rooms) from classifieds and (b) structure them into a tree format, with the entities as nodes and edges representing a part-of relation. Experiments show that a graph-based system deriving the tree from an initially fully connected entity graph, outperforms a transition-based system starting from only the entity nodes, since it better reconstructs the tree.

Reconstructing the house from the ad: Structured prediction on real estate classifieds

G. Bekoulis, J. Deleu, T. Demeester and C. Develder


in Proc. 15th Conf. Eur. Chapter Assoc. Comput. Ling. (EACL 2017), Valencia, Spain, 3-7 Apr. 2017, pp. 1-5.

@inproceedings{Bekoulis2017EACL,
author = {Bekoulis, Giannis and Deleu, Johannes and Demeester, Thomas and Develder, Chris},
title = {Reconstructing the house from the ad: Structured prediction on real estate classifieds},
booktitle = {Proc. 15th Conf. Eur. Chapter Assoc. Comput. Ling. (EACL 2017)},
month = {3--7 Apr.},
year = {2017},
pages = {1--5},
address = {Valencia, Spain}
}

pubarticle

T. Wang, B. Jaumard and C. Develder, "Exploring the benefit of rerouting multi-period traffic to multi-site data centers" (Invited), IEEE/OSA J. Opt. Commun. Netw., 2017.

Exploring the benefit of rerouting multi-period traffic to multi-site data centers

T. Wang, B. Jaumard and C. Develder


IEEE/OSA J. Opt. Commun. Netw., 2017.

In cloud-like scenarios, demand is served at one of multiple possible data center (DC) destinations. Usually, which DC exactly is used can be freely chosen, which leads to an anycast routing problem. Furthermore, the demand volume is expected to change over time, e.g., following a diurnal pattern. Given that virtually all application domains today heavily rely on cloud-like services, it is important that the backbone networks connecting users to the DCs is resilient against failures. In this paper, we consider the problem of resiliently routing multi-period traffic: we need to find routes to both a primary DC and a backup DC (to be used in case of failure of the primary one, or the network connection towards it), and also account for synchronization traffic between primary and backup DCs. We formulate this as an optimization problem and adopt column generation, using a path formulation in two sub-problems: the (restricted) master problem (RMP) selects "configurations" to use for each demand in each of the time epochs it lasts, while the pricing problem (PP) constructs a new "configuration" that can lead to lower overall costs (which we express as the number of network resources, i.e., bandwidth, required to serve the demand). Here, a "configuration" is defined by the network paths followed from the demand source to each of the two selected DCs, as well as that of the synchronization traffic in between the DCs. Our decomposition allows for PPs to be solved in parallel, for which we quantitatively explore the reduction of the time required to solve the overall routing problem. The key question that we address with our model is an exploration of the potential benefits in rerouting traffic from one time epoch to the next: we compare several (re)routing strategies, allowing traffic that spans multiple time periods to (i) not be rerouted in different periods, (ii) only change the backup DC and routes, or (iii) freely change both primary and backup DC choices and routes towards them.

Exploring the benefit of rerouting multi-period traffic to multi-site data centers

T. Wang, B. Jaumard and C. Develder


IEEE/OSA J. Opt. Commun. Netw., 2017.

@article{Wang2017,
author = {Wang, Ting and Jaumard, Brigitte and Develder, Chris},
title = {Exploring the benefit of rerouting multi-period traffic to multi-site data centers},
journal = {IEEE/OSA J. Opt. Commun. Netw.},
year = {2017},
doi = {10.1364/JOCN.9.000C25}
}

pubinproceedings

C. Develder, N. Sadeghianpourhamami, M. Strobbe and N. Refa, "Quantifying flexibility in EV charging as DR potential: Analysis of two real-world data sets", in Proc. 7th IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2016), Sydney, Australia, 6-9 Nov. 2016, pp. 600-605.

Quantifying flexibility in EV charging as DR potential: Analysis of two real-world data sets

C. Develder, N. Sadeghianpourhamami, M. Strobbe and N. Refa


in Proc. 7th IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2016), Sydney, Australia, 6-9 Nov. 2016, pp. 600-605.

The increasing adoption of electric vehicles (EVs) presents both challenges and opportunities for the power grid, especially for distribution system operators (DSOs). The demand represented by EVs can be significant, but on the other hand, sojourn times of EVs could be longer than the time required to charge their batteries to the desired level (e.g., to cover the next trip). The latter observation means that the electrical load from EVs is characterized by a certain level of flexibility, which could be exploited for example in demand response (DR) approaches (e.g., to balance generation from renewable energy sources).
This paper analyzes two data sets, one from a charging-at- home field trial in Flanders (about 8.5k charging sessions) and another from a large-scale EV public charging pole deployment in The Netherlands (more than 1M sessions). We rigorously analyze the collected data and quantify aforementioned flexibility: (1) we characterize the EV charging behavior by clustering the arrival and departure time combinations, identifying three behaviors (charging near home, charging near work, and park to charge), (2) we fit statistical models for the sojourn time, and flexibility (i.e., non-charging idle time) for each type of observed behavior, and (3) quantify the the potential of DR exploitation as the maximal load that could be achieved by coordinating EV charging for a given time of day t, continuously until t + Delta.

Quantifying flexibility in EV charging as DR potential: Analysis of two real-world data sets

C. Develder, N. Sadeghianpourhamami, M. Strobbe and N. Refa


in Proc. 7th IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2016), Sydney, Australia, 6-9 Nov. 2016, pp. 600-605.

@inproceedings{Develder2016SGC,
author = {Develder, Chris and Sadeghianpourhamami, Nasrin and Strobbe, Matthias and Refa, Nazir},
title = {Quantifying flexibility in EV charging as DR potential: Analysis of two real-world data sets},
booktitle = {Proc. 7th IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2016)},
month = {6--9 Nov.},
year = {2016},
pages = {600--605},
address = {Sydney, Australia},
doi = {10.1109/SmartGridComm.2016.7778827}
}

pubinproceedings

L. Sterckx, C. Caragea, T. Demeester and C. Develder, "Supervised keyphrase extraction as positive unlabeled learning", in Proc. Conf. Empirical Methods in Natural Lang. Processing (EMNLP 2016), Austin, TX, USA, 1-5 Nov. 2016.

Supervised keyphrase extraction as positive unlabeled learning

L. Sterckx, C. Caragea, T. Demeester and C. Develder


in Proc. Conf. Empirical Methods in Natural Lang. Processing (EMNLP 2016), Austin, TX, USA, 1-5 Nov. 2016.

The problem of noisy and unbalanced train- ing data for supervised keyphrase extraction results from the subjectivity of keyphrase assignment, which we quantify by crowdsourcing keyphrases for news and fashion magazine articles with many annotators per document. We show that annotators exhibit substantial disagreement, meaning that single annotator data could lead to very different training sets for supervised keyphrase extractors. Thus, annotations from single authors or readers lead to noisy training data and poor extraction performance of the resulting supervised extractor. We provide a simple but effective solution to still work with such data by reweighting the importance of unlabeled candidate phrases in a two stage Positive Unlabeled Learning setting. We show that performance of trained keyphrase extractors approximates a classifier trained on articles labeled by multiple annotators, leading to higher average F1scores and better rankings of keyphrases. We apply this strategy to a variety of test collections from different backgrounds and show improvements over strong baseline models.

Supervised keyphrase extraction as positive unlabeled learning

L. Sterckx, C. Caragea, T. Demeester and C. Develder


in Proc. Conf. Empirical Methods in Natural Lang. Processing (EMNLP 2016), Austin, TX, USA, 1-5 Nov. 2016.

@inproceedings{sterckx2016emnlp,
author = {Sterckx, Lucas and Caragea, Cornelia and Demeester, Thomas and Develder, Chris},
title = {Supervised keyphrase extraction as positive unlabeled learning},
booktitle = {Proc. Conf. Empirical Methods in Natural Lang. Processing (EMNLP 2016)},
month = {1--5 Nov.},
year = {2016},
address = {Austin, TX, USA}
}

pubarticle

N. Sadeghianpourhamami, T. Demeester, D.F. Benoit, M. Strobbe and C. Develder, "Modeling and analysis of residential flexibility: Timing of white good usage", Appl. Energy, Vol. 179, Oct. 2016, pp. 790-805.

Modeling and analysis of residential flexibility: Timing of white good usage

N. Sadeghianpourhamami, T. Demeester, D.F. Benoit, M. Strobbe and C. Develder


Appl. Energy, Vol. 179, Oct. 2016, pp. 790-805.

Challenges that smart grids aim to address include the increasing fraction of supply by renewable energy sources, as well as plain rise of demand, e.g., by increased electrification of transportation. Part of the solution to these challenges lies in exploiting the opportunity to steer residential electricity consumption (e.g., for flattening the peak load or balancing the supply and demand in presence of the renewable energy production). To optimally exploit this opportunity, it is crucial to have insights on how flexible the residential demand is. Load flexibility is characterized by the amount of power, time of availability and duration of deferrable consumption. Residential flexibility however, is challenging to exploit due to the variation in types of customer loads and differences in appliance usage habits from one household to the other. Existing analyses of individual customer flexibility behavior in terms of timing are often based on inferences from surveys or customer load patterns (e.g., as observed through smart meter data): there is a high level of uncertainty about customer habits in offering the flexibility. Even though some of these studies rely on real world data, only few of them have quantitative data on actual flexible appliance usage, and none of them characterizes individual user behavior. In this paper, we address this gap and contribute with: (1) a new quantitative specification of flexibility, (2) two systematic methodologies for modeling individual customer behavior, (3) evaluation of the proposed models in terms of how accurately the data they generate corresponds with real world customer behavior, and (4) a basic analysis of factors influencing the flexibility behavior based on statistical tests. Experimental results for (2)–(4) are based on a unique dataset from a real-life field trial.

Modeling and analysis of residential flexibility: Timing of white good usage

N. Sadeghianpourhamami, T. Demeester, D.F. Benoit, M. Strobbe and C. Develder


Appl. Energy, Vol. 179, Oct. 2016, pp. 790-805.

@article{Sadeghianpourhamami2016APEN,
author = {Sadeghianpourhamami, Nasrin and Demeester, Thomas and Benoit, Dries F. and Strobbe, Matthias and Develder, Chris},
title = {Modeling and analysis of residential flexibility: Timing of white good usage},
journal = {Appl. Energy},
month = {Oct.},
year = {2016},
volume = {179},
pages = {790--805},
doi = {10.1016/j.apenergy.2016.07.012}
}

pubinproceedings

M.M. Shahriar Maswood, C. Develder, E. Madeira and D. Medhi, "Dynamic virtual network traffic engineering with energy efficiency in multi-location data center networks", in Proc. Int. Teletraffic Congress (ITC-28), Würzburg, 12-16 Sep. 2016, pp. 1-8.

Dynamic virtual network traffic engineering with energy efficiency in multi-location data center networks

M.M. Shahriar Maswood, C. Develder, E. Madeira and D. Medhi


in Proc. Int. Teletraffic Congress (ITC-28), Würzburg, 12-16 Sep. 2016, pp. 1-8.

For cloud enterprise customers that require services on demand, data centers must allocate and partition data center resources in a dynamic fashion. We consider the problem in which a request from an enterprise customer is mapped to a virtual network (VN) that is allocated requiring both bandwidth and compute resources by connecting it from an entry point of the datacenter to one or more servers, should this data center be selected from multiple geographically distributed data centers. We present a dynamic traffic engineering framework, for which we develop an optimization model based on a mixed-integer linear programming (MILP) formulation that a data center operator can use at each review point to optimally assign VN customers. Through a series of studies, we then present results on how different VN customers are treated in terms of request acceptance when each VN class has a different resource requirement. We found that a VN class with a low resource requirement has a low blocking even in heavy traffic, while the VN class with a high resource requirement faces a high service denial. On the other hand, cost for the VN with the highest resource requirement is not always the highest in the heavy traffic because of the significantly high service denial faced by this VN class.

Dynamic virtual network traffic engineering with energy efficiency in multi-location data center networks

M.M. Shahriar Maswood, C. Develder, E. Madeira and D. Medhi


in Proc. Int. Teletraffic Congress (ITC-28), Würzburg, 12-16 Sep. 2016, pp. 1-8.

@inproceedings{maswood2016,
author = {Shahriar Maswood, Mirza Mohd and Chris Develder and Edmundo Madeira and and Deep Medhi},
title = {Dynamic virtual network traffic engineering with energy efficiency in multi-location data center networks},
booktitle = {Proc. Int. Teletraffic Congress (ITC-28)},
month = {12--16 Sep.},
year = {2016},
pages = {1--8},
address = {Würzburg}
}

pubinproceedings

T. Wang, B. Jaumard and C. Develder, "Resilient backbone networks for multi-site data centers: Exploiting anycast (re)routing for multi-period traffic", in Proc. OSA Photonic Netw. Devices, Vancouver, BC, Canada, 18-20 Jul. 2016, pp. 1-3.

Resilient backbone networks for multi-site data centers: Exploiting anycast (re)routing for multi-period traffic

T. Wang, B. Jaumard and C. Develder


in Proc. OSA Photonic Netw. Devices, Vancouver, BC, Canada, 18-20 Jul. 2016, pp. 1-3.

Using column generation, we dimension networks interconnecting multi-site data centers (DCs), for multi-period traffic with anycast routing and resilience against single link/DC failures. We quantify (backup) resource savings from rerouting demands lasting multiple periods.

Resilient backbone networks for multi-site data centers: Exploiting anycast (re)routing for multi-period traffic

T. Wang, B. Jaumard and C. Develder


in Proc. OSA Photonic Netw. Devices, Vancouver, BC, Canada, 18-20 Jul. 2016, pp. 1-3.

@inproceedings{Develder2016PND,
author = {Wang, Ting and Jaumard, Brigitte and Develder, Chris},
title = {Resilient backbone networks for multi-site data centers: Exploiting anycast (re)routing for multi-period traffic},
booktitle = {Proc. OSA Photonic Netw. Devices},
month = {18--20 Jul.},
year = {2016},
pages = {1-3},
address = {Vancouver, BC, Canada},
doi = {10.1364/NETWORKS.2016.NeM3B.2}
}

pubinproceedings

T. Wang, B. Jaumard and C. Develder, "Anycast (re)routing of multi-period traffic in dimensioning resilient backbone networks for multi-site data centers" (Invited), in Proc. 18th Int. Conf. Transparent Optical Netw. (ICTON 2016), Trento, Italy, 10-14 Jul. 2016, pp. 1-6.

Anycast (re)routing of multi-period traffic in dimensioning resilient backbone networks for multi-site data centers

T. Wang, B. Jaumard and C. Develder


in Proc. 18th Int. Conf. Transparent Optical Netw. (ICTON 2016), Trento, Italy, 10-14 Jul. 2016, pp. 1-6.

We consider the problem of dimensioning resilient backbone networks for cloud-like scenarios where demand is to be served at one among several candidate data centers (DCs), and where that demand varies over time, which we assume to be slotted. We thus consider multi-period traffic, for which we need to find routes to both a primary DC and a backup DC (in case the primary, or the network connection towards it, fails) and account also for synchronization traffic (following its own routes) between the two chosen DCs. We propose a path formulation and adopt a column generation approach: the (restricted) master problem (RMP) selects “configurations” to use for each demand in each of the time periods, while pricing problems (PPs) construct new, potentially cost-reducing configurations for a given demand. Our model allows for several PPs to be solved in parallel, and we demonstrate the time savings achieved by doing so. We compare several anycast (re)routing strategies, where we allow traffic that spans multiple periods to either (i) not be rerouted in different periods, (ii) only change the backup DC and routes, or (iii) freely change both primary and backup DC choices and routes towards them.

Anycast (re)routing of multi-period traffic in dimensioning resilient backbone networks for multi-site data centers

T. Wang, B. Jaumard and C. Develder


in Proc. 18th Int. Conf. Transparent Optical Netw. (ICTON 2016), Trento, Italy, 10-14 Jul. 2016, pp. 1-6.

@inproceedings{Develder2016ICTON,
author = {Wang, Ting and Jaumard, Brigitte and Develder, Chris},
title = {Anycast (re)routing of multi-period traffic in dimensioning resilient backbone networks for multi-site data centers},
booktitle = {Proc. 18th Int. Conf. Transparent Optical Netw. (ICTON 2016)},
month = {10--14 Jul.},
year = {2016},
pages = {1--6},
address = {Trento, Italy},
doi = {10.1109/ICTON.2016.7550606}
}

pubarticle

N. Sluijs, T. Wauters, C. Develder, F. De Turck, P. Demeester and B. Dhoedt, "Using topology information for quality-aware peer-to-peer multilayer video streaming", Int. J. Commun. Syst., Jul. 2016, pp. 1620-1644.

Using topology information for quality-aware peer-to-peer multilayer video streaming

N. Sluijs, T. Wauters, C. Develder, F. De Turck, P. Demeester and B. Dhoedt


Int. J. Commun. Syst., Jul. 2016, pp. 1620-1644.

Due to increasing bandwidth capacities, the Internet has become a viable transport medium for a (live) video. Often, delivery of video streams relies on the client–server paradigm and therefore exhibits limited scalability. The Peer-to-Peer (P2P) network model is an attractive and scalable candidate to stream video content to end users. However, these P2P frameworks typically operate in a network agnostic mode. Introducing network topology information into these P2P frameworks offers opportunities to enhance the performance.
In this paper, we introduce a model to include network information when streaming a (multilayered) video in P2P frameworks. An important metric for video stream providers is the content quality perceived by end users. The optimization studied here aims at maximizing the number of users receiving a high quality video.
The paper addresses the optimization problem seen from the stream provider's viewpoint, having access to network topology information. An exact optimization approach is presented for benchmarking purposes and a heuristic approach to cope with realistic network sizes. In addition, we present an approach to decide the deployment location of peering functionality. The results show that our strategy significantly decreases the fraction of destinations receiving only the base layer, and by introducing extra peering functionality, network capacities are used more efficiently.

Using topology information for quality-aware peer-to-peer multilayer video streaming

N. Sluijs, T. Wauters, C. Develder, F. De Turck, P. Demeester and B. Dhoedt


Int. J. Commun. Syst., Jul. 2016, pp. 1620-1644.

@article{Sluijs2015,
author = {Sluijs, Niels and Wauters, Tim and Develder, Chris and De Turck, Filip and Demeester, Piet and Dhoedt, Bart},
title = {Using topology information for quality-aware peer-to-peer multilayer video streaming},
journal = {Int. J. Commun. Syst.},
month = {Jul.},
year = {2016},
pages = {1620--1644},
doi = {10.1002/dac.2919}
}

pubarticle

T. Demeester, R. Aly, D. Hiemstra, D. Nguyen and C. Develder, "Predicting relevance based on assessor disagreement: Analysis and practical applications for search evaluation", Inf. Retr., Vol. 19, No. 3, Jun. 2016, pp. 284-312.

Predicting relevance based on assessor disagreement: Analysis and practical applications for search evaluation

T. Demeester, R. Aly, D. Hiemstra, D. Nguyen and C. Develder


Inf. Retr., Vol. 19, No. 3, Jun. 2016, pp. 284-312.

Evaluation of search engines relies on assessments of search results for selected test queries, from which we would ideally like to draw conclusions in terms of relevance of the results for general (e.g., future, unknown) users. In practice however, most evaluation scenarios only allow us to conclusively determine the relevance towards the particular assessor that provided the judgments. A factor that cannot be ignored when extending conclusions made from assessors towards users, is the possible disagreement on relevance, assuming that a single gold truth label does not exist. This paper presents and analyzes the predicted relevance model (PRM), which allows predicting a particular result’s relevance for a random user, based on an observed assessment and knowledge on the average disagreement between assessors. With the PRM, existing evaluation metrics designed to measure binary assessor relevance, can be transformed into more robust and effectively graded measures that evaluate relevance towards a random user. It also leads to a principled way of quantifying multiple graded or categorical relevance levels for use as gains in established graded relevance measures, such as normalized discounted cumulative gain, which nowadays often use heuristic and data-independent gain values. Given a set of test topics with graded relevance judgments, the PRM allows evaluating systems on different scenarios, such as their capability of retrieving top results, or how well they are able to filter out non-relevant ones. Its use in actual evaluation scenarios is illustrated on several information retrieval test collections.

Predicting relevance based on assessor disagreement: Analysis and practical applications for search evaluation

T. Demeester, R. Aly, D. Hiemstra, D. Nguyen and C. Develder


Inf. Retr., Vol. 19, No. 3, Jun. 2016, pp. 284-312.

@article{Demeester2015IR,
author = {Demeester, Thomas and Aly, Robin and Hiemstra, Djoerd and Nguyen, Dong and Develder, Chris},
title = {Predicting relevance based on assessor disagreement: Analysis and practical applications for search evaluation},
journal = {Inf. Retr.},
month = {Jun.},
year = {2016},
volume = {19},
number = {3},
pages = {284--312},
doi = {10.1007/s10791-015-9275-x}
}

pubarticle

L. Sterckx, T. Demeester, J. Deleu and C. Develder, "Knowledge base population using semantic label propagation", Knowledge-Based Syst., 10 May 2016.

Knowledge base population using semantic label propagation

L. Sterckx, T. Demeester, J. Deleu and C. Develder


Knowledge-Based Syst., 10 May 2016.

Training relation extractors for the purpose of automated knowledge base population requires the availabil- ity of sufficient training data. The amount of manual labeling can be significantly reduced by applying distant supervision, which generates training data by aligning large text corpora with existing knowledge bases. This typically results in a highly noisy training set, where many training sentences do not express the intended relation. In this paper, we propose to combine distant supervision with minimal human supervi- sion by annotating features (in particular shortest dependency paths) rather than complete relation instances. Such feature labeling eliminates noise from the initial training set, resulting in a significant increase of pre- cision at the expense of recall. We further improve on this approach by introducing the Semantic Label Propagation (SLP) method, which uses the similarity between low-dimensional representations of candidate training instances to again extend the (filtered) training set in order to increase recall while maintaining high precision. Our strategy is evaluated on an established test collection designed for knowledge base popula- tion (KBP) from the TAC KBP English slot filling task. The experimental results show that SLP leads to substantial performance gains when compared to existing approaches while requiring an almost negligible human annotation effort.

Knowledge base population using semantic label propagation

L. Sterckx, T. Demeester, J. Deleu and C. Develder


Knowledge-Based Syst., 10 May 2016.

@article{Sterckx2016KBS,
author = {Lucas Sterckx and Thomas Demeester and Johannes Deleu and Chris Develder},
title = {Knowledge base population using semantic label propagation},
journal = {Knowledge-Based Syst.},
month = {10 May},
year = {2016},
doi = {10.1016/j.knosys.2016.05.015}
}

pubinproceedings

J. van der Herten, F. Depuydt, D. Deschrijver, M. Strobbe, C. Develder, T. Dhaene, R. Bruneliere and J.-W. Rombouts, "Energy flexibility assessment of an industrial coldstore process", in Proc. IEEE Int. Energy Conf. (Energycon 2016), Leuven, Belgium, 4-8 Apr. 2016.

Energy flexibility assessment of an industrial coldstore process

J. van der Herten, F. Depuydt, D. Deschrijver, M. Strobbe, C. Develder, T. Dhaene, R. Bruneliere and J.-W. Rombouts


in Proc. IEEE Int. Energy Conf. (Energycon 2016), Leuven, Belgium, 4-8 Apr. 2016.

Power-intensive industry plays a key role in balancing supply and demand in the energy grid: by offering flexible power, industry provides competitive alternatives to gas fired power plants and reduces the CO2 impact of grid balancing. Furthermore, operating costs can be reduced and grid operators can avoid technical failures. Recently, research has started to try and address the challenging question of determining the amount of power curtailment (i.e., how much power can be reduced for how long) without violating any process constraints. We consider several machine learning methods to assess the curtailment potential in a coldstore, based on historical data.

Energy flexibility assessment of an industrial coldstore process

J. van der Herten, F. Depuydt, D. Deschrijver, M. Strobbe, C. Develder, T. Dhaene, R. Bruneliere and J.-W. Rombouts


in Proc. IEEE Int. Energy Conf. (Energycon 2016), Leuven, Belgium, 4-8 Apr. 2016.

@inproceedings{vanderherten2016,
author = {van der Herten, Joachim and Depuydt, Frederick and Deschrijver, Dirk and Strobbe, Matthias and Develder, Chris and Dhaene, Tom and Bruneliere, Renaud and Rombouts, Jan-Willem},
title = {Energy flexibility assessment of an industrial coldstore process},
booktitle = {Proc. IEEE Int. Energy Conf. (Energycon 2016)},
month = {4--8 Apr.},
year = {2016},
address = {Leuven, Belgium},
doi = {10.1109/ENERGYCON.2016.7514032}
}

pubinproceedings

N. Sadeghianpourhamami, M. Strobbe and C. Develder, "Real-world user flexibility of energy consumption: Two-stage generative model construction", in Proc. 31st ACM/SIGAPP Symp. Applied Computing (SAC 2016), Pisa, Italy, 4-8 Apr. 2016. (Best poster award nomination)

Real-world user flexibility of energy consumption: Two-stage generative model construction

N. Sadeghianpourhamami, M. Strobbe and C. Develder


in Proc. 31st ACM/SIGAPP Symp. Applied Computing (SAC 2016), Pisa, Italy, 4-8 Apr. 2016.

Since the inception of smart grids, a substantial amount of research has focused on the development of scalable Demand Response (DR) approaches. For example, to flatten peak load, or to balance renewable energy production. A crucial assumption in DR is that at least some portion of the load is flexible, i.e., can be shifted in time. While the flexibility potential of smart devices has been analyzed extensively based on the device characteristics, little effort has been devoted to establishing potential factors in their owner’s behavior. In this paper, we focus on sharpening the analysis of flexibility in residential user load and contribute with: (1) a quantitative specification of such flexibility, (2) a systematic methodology to derive a generative model for user flexibility behavior from data, (3) application of the methodology on a real world data set from a field trial with smart appliances, and (4) analysis of factors determining that flexibility.

Real-world user flexibility of energy consumption: Two-stage generative model construction

N. Sadeghianpourhamami, M. Strobbe and C. Develder


in Proc. 31st ACM/SIGAPP Symp. Applied Computing (SAC 2016), Pisa, Italy, 4-8 Apr. 2016.

@inproceedings{sadeghianpourhamami2016,
author = {Sadeghianpourhamami, Nasrin and Strobbe, Matthias and Develder, Chris},
title = {Real-world user flexibility of energy consumption: Two-stage generative model construction},
booktitle = {Proc. 31st ACM/SIGAPP Symp. Applied Computing (SAC 2016)},
month = {4--8 Apr.},
year = {2016},
address = {Pisa, Italy},
doi = {10.1145/2851613.2853129}
}

pubinbook

C. Develder, M. Strobbe, K. De Craemer and G. Deconinck, "Charging electric vehicles in the smart grid", in "Smart grids from a global perspective", J. Scherpen, A. Beaulieu and J. de Wilde (Ed.), Springer, 16 Feb. 2016, pp. 147-161.

Charging electric vehicles in the smart grid
in: Smart grids from a global perspective

C. Develder, M. Strobbe, K. De Craemer and G. Deconinck


Springer, 16 Feb. 2016, pp. 147-161.

High level challenges that motivate the evolution towards smart grids include (i) the anticipated electrification of transportation, including electrical vehicles (EVs), and (ii) the increasing penetration of distributed renewable energy sources (DRES). This chapter will discuss how the extra grid load stemming from the EVs can be handled, including the context of reduced control over power generation in light of DRES adoption (especially solar and wind power). After a basic introduction to common EV charging technology, we give two illustrative examples of controlling EV charging: avoiding peaks, and balancing against renewable generation. We then qualitatively present possible demand response (DR) strategies to realize such control. Finally, we highlight the need for, and underlying principles of, (smart grid) simulation tools, e.g., to study the effectiveness of such DR mechanisms.

Charging electric vehicles in the smart grid
in: Smart grids from a global perspective

C. Develder, M. Strobbe, K. De Craemer and G. Deconinck


Springer, 16 Feb. 2016, pp. 147-161.

@inbook{Develder2016SGBook,
author = {Develder, Chris and Strobbe, Matthias and De Craemer, Klaas and Deconinck, Geert},
editor = {Scherpen, Jacquelien and Beaulieu, Anne and de Wilde, Jaap},
title = {Smart grids from a global perspective},
chapter = {Charging electric vehicles in the smart grid},
publisher = {Springer},
month = {16 Feb.},
year = {2016},
pages = {147--161},
doi = {10.1007/978-3-319-28077-6_10}
}

pubarticle

C. Colman-Meixner, C. Develder, M. Tornatore and B. Mukherjee, "A survey on resiliency techniques in cloud computing infrastructures and applications", IEEE Commun. Surv. Tutor., 18 Feb. 2016, pp. 1-38.

A survey on resiliency techniques in cloud computing infrastructures and applications

C. Colman-Meixner, C. Develder, M. Tornatore and B. Mukherjee


IEEE Commun. Surv. Tutor., 18 Feb. 2016, pp. 1-38.

Today’s businesses increasingly rely on cloud computing, which brings both great opportunities and challenges. One of the critical challenges is resiliency: disruptions due to failures (either accidental or because of disasters or attacks) may entail significant revenue losses (e.g., US$ 25.5 billion in 2010 for North America). Such failures may originate at any of the major components in a cloud architecture (and propagate to others): (i) the servers hosting the application, (ii) the network interconnecting them (on different scales, inside a data center, up to wide-area connections), or (iii) the application itself. We comprehensively survey a large body of work focusing on resilience of cloud computing, in each (or a combination) of the server, network, and application components.
First, we present the cloud computing architecture and its key concepts. We highlight both the infrastructure (servers, network) and application components. A key concept is virtualization of infrastructure (i.e., partitioning into logically separate units), and thus we detail the components in both physical and virtual layers. Before moving to the detailed resilience aspects, we provide a qualitative overview of the types of failures that may occur (from the perspective of the layered cloud architecture), and their consequences.
The second major part of the paper introduces and categorizes a large number of techniques for cloud computing infrastructure resiliency. This ranges from designing and operating the facilities, servers, networks, to their integration and virtualization (e.g., also including resilience of the middleware infrastructure).
The third part focuses on resilience in application design and development. We study how applications are designed, installed, and replicated to survive multiple physical failure scenarios as well as disaster failures.

A survey on resiliency techniques in cloud computing infrastructures and applications

C. Colman-Meixner, C. Develder, M. Tornatore and B. Mukherjee


IEEE Commun. Surv. Tutor., 18 Feb. 2016, pp. 1-38.

@article{ColmanMeixner2016,
author = {Colman-Meixner, Carlos and Develder, Chris and Tornatore, Massimo and Mukherjee, Biswanath},
title = {A survey on resiliency techniques in cloud computing infrastructures and applications},
journal = {IEEE Commun. Surv. Tutor.},
month = {18 Feb.},
year = {2016},
pages = {1--38},
doi = {10.1109/COMST.2016.2531104}
}

pubinproceedings

T. Wang, B. Jaumard and C. Develder, "A scalable model for multi-period virtual network mapping for resilient multi-site data centers" (Invited), in Proc. IEEE Int. Conf. Advanced Netw. and Telecommun. Sys. (ANTS 2015), Kolkata, India, 15-18 Dec. 2015.

A scalable model for multi-period virtual network mapping for resilient multi-site data centers (Invited)

T. Wang, B. Jaumard and C. Develder


in Proc. IEEE Int. Conf. Advanced Netw. and Telecommun. Sys. (ANTS 2015), Kolkata, India, 15-18 Dec. 2015.

In the currently dominant cloud computing paradigm, applications are being served in data centers (DCs) which are connected to high capacity optical networks. For cost efficiency reasons, in both DC and optical network domains, virtualization of the physical hardware is exploited. In a DC, it means that multiple so-called virtual machines (VMs) are being hosted on the same physical server. Similarly, the network is partitioned into separate virtual networks, thus providing isolation between distinct virtual network operators (VNOs). Thus, the problem of virtual network mapping arises: how to decide which physical resources to allocate for a particular virtual network? In this paper, we study that problem in the context of cloud computing with multiple DC sites. This introduces additional flexibility, due to the anycast routing principle: we have the freedom to decide at what particular DC location to serve a particular application. We can exploit this choice to minimize the required resources when solving the virtual network mapping problem. This paper builds on our earlier work and solves the resilient virtual network mapping problem that optimally decides on the mapping of both network and data center resources, considering time- varying traffic conditions and protecting against possible failures of both network and DC resources. Previously, we developed a model to solve the multi-period traffic case one step at a time: given the virtual network mapping in period t, we determine the (possibly changed) mapping for t + 1. Compared to that previous work, we now (i) define a truly multi-period model path formulation exploiting column generation, and (ii) demonstrate its scalability on a nation-wide network with traffic that varies across multiple periods.

A scalable model for multi-period virtual network mapping for resilient multi-site data centers (Invited)

T. Wang, B. Jaumard and C. Develder


in Proc. IEEE Int. Conf. Advanced Netw. and Telecommun. Sys. (ANTS 2015), Kolkata, India, 15-18 Dec. 2015.

@inproceedings{Wang2015ANTS,
author = {Wang, Ting and Jaumard, Brigitte and Develder, Chris},
title = {A scalable model for multi-period virtual network mapping for resilient multi-site data centers (Invited)},
booktitle = {Proc. IEEE Int. Conf. Advanced Netw. and Telecommun. Sys. (ANTS 2015)},
month = {15--18 Dec.},
year = {2015},
address = {Kolkata, India},
doi = {10.1109/ICTON.2015.7193343}
}

pubinproceedings

P. Barrio, L. Gravano and C. Develder, "Ranking deep web text collections for scalable information extraction", in Proc. 24th ACM Int. Conf. Information and Knowledge Management (CIKM 2015), Melbourne, Australia, 19-23 Oct. 2015.

Ranking deep web text collections for scalable information extraction

P. Barrio, L. Gravano and C. Develder


in Proc. 24th ACM Int. Conf. Information and Knowledge Management (CIKM 2015), Melbourne, Australia, 19-23 Oct. 2015.

Information extraction (IE) systems discover structured in- formation from natural language text, to enable much richer querying and data mining than possible directly over the unstructured text. Unfortunately, IE is generally a com- putationally expensive process, and hence improving its ef- ficiency, so that it scales over large volumes of text, is of critical importance. State-of-the-art approaches for scaling the IE process focus on one text collection at a time. These approaches prioritize the extraction effort by learning key- word queries to identify the “useful” documents for the IE task at hand, namely, those that lead to the extraction of structured “tuples.” These approaches, however, do not at- tempt to predict which text collections are useful for the IE task—and hence merit further processing—and which ones will not contribute any useful output—and hence should be ignored altogether, for efficiency. In this paper, we focus on an especially valuable family of text sources, the so-called deep web collections, whose (remote) contents are only ac- cessible via querying. Specifically, we introduce and study techniques for ranking deep web collections for an IE task, to prioritize the extraction effort by focusing on collections with substantial numbers of useful documents for the task. We study both (adaptations of) state-of-the-art resource selec- tion strategies for distributed information retrieval, as well as IE-specific approaches. Our large-scale experimental eval- uation over realistic deep web collections, and for several different IE tasks, shows the merits and limitations of the alternative families of approaches, and provides a roadmap for addressing this critically important building block for efficient, scalable information extraction.

Ranking deep web text collections for scalable information extraction

P. Barrio, L. Gravano and C. Develder


in Proc. 24th ACM Int. Conf. Information and Knowledge Management (CIKM 2015), Melbourne, Australia, 19-23 Oct. 2015.

@inproceedings{Barrio2015CIKM,
author = {Barrio, Pablo and Gravano, Luis and Develder, Chris},
title = {Ranking deep web text collections for scalable information extraction},
booktitle = {Proc. 24th ACM Int. Conf. Information and Knowledge Management (CIKM 2015)},
month = {19--23 Oct.},
year = {2015},
address = {Melbourne, Australia},
doi = {10.1145/2806416.2806581}
}

pubinproceedings

W.K. Chai, K.V. Katsaros, M. Strobbe, P. Romano, C. Ge, C. Develder, G. Pavlou and N. Wang, "Enabling Smart Grid Applications with ICN", in Proc. 2nd ACM Int. Conf. Information-Centric Networking (ICN 2015), San Francisco, CA, USA, 30 Sep. - 2 Oct. 2015, pp. 207-208.

Enabling Smart Grid Applications with ICN

W.K. Chai, K.V. Katsaros, M. Strobbe, P. Romano, C. Ge, C. Develder, G. Pavlou and N. Wang


in Proc. 2nd ACM Int. Conf. Information-Centric Networking (ICN 2015), San Francisco, CA, USA, 30 Sep. - 2 Oct. 2015, pp. 207-208.

We have harnessed the salient features of information-centric networking (ICN) and implemented a communication infrastructure, called C-DAX, for supporting smart grid applications. We will demonstrate the operations of C-DAX both in a laboratory setup and a real field trial that involves the deployment of C-DAX in a live electricity grid in the Netherlands. This demo will showcase the capabilities of C-DAX, highlighting how ICN satisfies stringent smart grid application requirements.

Enabling Smart Grid Applications with ICN

W.K. Chai, K.V. Katsaros, M. Strobbe, P. Romano, C. Ge, C. Develder, G. Pavlou and N. Wang


in Proc. 2nd ACM Int. Conf. Information-Centric Networking (ICN 2015), San Francisco, CA, USA, 30 Sep. - 2 Oct. 2015, pp. 207-208.

@inproceedings{Chai2015ICN,
author = {Chai, Wei Koong and Katsaros, Konstantinos V. and Strobbe, Matthias and Romano, Paolo and Ge, Chang and Develder, Chris and Pavlou, George and Wang, Ning},
title = {Enabling Smart Grid Applications with ICN},
booktitle = {Proc. 2nd ACM Int. Conf. Information-Centric Networking (ICN 2015)},
month = {30 Sep. -- 2 Oct.},
year = {2015},
pages = {207--208},
address = {San Francisco, CA, USA},
doi = {10.1145/2810156.2812610}
}

pubinproceedings

C. Develder and B. Jaumard, "Dimensioning backbone networks for multi-site data centers: Exploiting anycast routing for resilience" (Invited), in Proc. Int. Workshop on Reliable Netw. Design and Modeling (RNDM 2015), Munich, Germany, 5-7 Oct. 2015.

Dimensioning backbone networks for multi-site data centers: Exploiting anycast routing for resilience

C. Develder and B. Jaumard


in Proc. Int. Workshop on Reliable Netw. Design and Modeling (RNDM 2015), Munich, Germany, 5-7 Oct. 2015.

In the current era of big data, applications increasingly rely on powerful computing infrastructure residing in large data centers (DCs), typically adopting cloud computing technology. Clearly, this necessitates efficient and resilient networking infrastructure to connect the users of these applications with the data centers hosting them. In this paper, we focus on backbone network infrastructure on large geographical scales (i.e., the so-called wide area networks), which typical adopts optical network technology. In particular, we study the problem of dimensioning such backbone networks: what bandwidth should each of the links provide for the traffic, originating at known sources, to reach the data centers? And possibly even: how many such DCs should we deploy, and at what locations? More concretely, we summarize our recent work that essentially addresses the following fundamental research questions: (1) Does the anycast routing strategy influence the amount of required network resources? (2) Can we exploit anycast routing for resilience purposes, i.e., relocate to a different DC under failure conditions, to reduce resource capacity requirements? (3) Is it advantageous to change anycast request destinations from one DC location to the other, from one time period to the next, if service requests vary over time?

Dimensioning backbone networks for multi-site data centers: Exploiting anycast routing for resilience

C. Develder and B. Jaumard


in Proc. Int. Workshop on Reliable Netw. Design and Modeling (RNDM 2015), Munich, Germany, 5-7 Oct. 2015.

@inproceedings{Develder2015RNDM,
author = {Develder, Chris and Jaumard, Brigitte},
title = {Dimensioning backbone networks for multi-site data centers: Exploiting anycast routing for resilience},
booktitle = {Proc. Int. Workshop on Reliable Netw. Design and Modeling (RNDM 2015)},
month = {5--7 Oct.},
year = {2015},
address = {Munich, Germany},
doi = {10.1109/RNDM.2015.7324306}
}

pubinproceedings

H. Vandaele, J. Nelis, T. Verbelen and C. Develder, "Remote management of a large set of heterogeneous devices using existing IoT interoperability platforms", in Proc. EAI Int. Conf. Interoperability in IoT, Roma, Italy, 26-27 Oct. 2015.

Remote management of a large set of heterogeneous devices using existing IoT interoperability platforms

H. Vandaele, J. Nelis, T. Verbelen and C. Develder


in Proc. EAI Int. Conf. Interoperability in IoT, Roma, Italy, 26-27 Oct. 2015.

With the evolution of the Internet of Things, devices of many different technologies and manufacturers are being developed (e.g. for use cases ranging from home automation to smart cities). This creates chal- lenges regarding interoperability between these heterogeneous devices, as well as integrating them to enable innovative applications. Currently, several integration platforms already exist to integrate technologies in a local gateway (e.g. OpenHAB, Zodianet, etc.). Yet, the local set-up and configuration still is overly complex, especially for non-technical users. In this paper, we present a remote management platform that focuses on ease of configuration and installation. It allows monitoring, configu- ration, diagnostics and service provisioning without manual intervention of a technical person. The platform reacts on local changes such as the installation of a new device or state changes of discovered services. This information can then be used to install required plugins, generate alarms or take problem-solving actions.

Remote management of a large set of heterogeneous devices using existing IoT interoperability platforms

H. Vandaele, J. Nelis, T. Verbelen and C. Develder


in Proc. EAI Int. Conf. Interoperability in IoT, Roma, Italy, 26-27 Oct. 2015.

@inproceedings{Vandaele2015,
author = {Heleen Vandaele and Jelle Nelis and Tim Verbelen and Chris Develder},
title = {Remote management of a large set of heterogeneous devices using existing IoT interoperability platforms},
booktitle = {Proc. EAI Int. Conf. Interoperability in IoT},
month = {26--27 Oct.},
year = {2015},
address = {Roma, Italy}
}

pubinproceedings

G. Casier, J. Van Ooteghem, M. Strobbe, S. Verbrugge and C. Develder, "Evaluation of Belgian energy market models with demand response", in Proc. 54th FITCE Congress (FITCE 2015), Wroclaw, Poland, 1-3 Sep. 2015, pp. 1-6.

Evaluation of Belgian energy market models with demand response

G. Casier, J. Van Ooteghem, M. Strobbe, S. Verbrugge and C. Develder


in Proc. 54th FITCE Congress (FITCE 2015), Wroclaw, Poland, 1-3 Sep. 2015, pp. 1-6.

Energy markets worldwide are evolving towards smart grids. The value network of the current energy market will be subject to changing actors and roles in the evolution towards smart grids. There are several ways in which the market could respond to these changes, depending on who will take up newly emerging responsibilities. We consider the architecture of a large-scale pilot that was conducted within the Flemish Linear project and model the current energy market. Drawing upon the insights derived from the pilot and the current models, we propose several possible future market models that could take place when smart meters will be implemented and opportunities for demand response will emerge. Subsequently, the different models are evaluated by means of a PEST analysis.

Evaluation of Belgian energy market models with demand response

G. Casier, J. Van Ooteghem, M. Strobbe, S. Verbrugge and C. Develder


in Proc. 54th FITCE Congress (FITCE 2015), Wroclaw, Poland, 1-3 Sep. 2015, pp. 1-6.

@inproceedings{casier2015,
author = {Casier, Gregory and Van Ooteghem, Jan and Strobbe, Matthias and Verbrugge, Sofie and Develder, Chris},
title = {Evaluation of Belgian energy market models with demand response},
booktitle = {Proc. 54th FITCE Congress (FITCE 2015)},
month = {1--3 Sep.},
year = {2015},
pages = {1--6},
address = {Wroclaw, Poland}
}

pubarticle

K. Mets, F. Depuydt and C. Develder, "Two-stage load pattern clustering using fast wavelet transformation", IEEE Trans. Smart Grid, Vol. 7, No. 5, Jul. 2015, pp. 2250-2259.

Two-stage load pattern clustering using fast wavelet transformation

K. Mets, F. Depuydt and C. Develder


IEEE Trans. Smart Grid, Vol. 7, No. 5, Jul. 2015, pp. 2250-2259.

Smart grids collect large volumes of smart meter data in the form of time series or so-called load patterns. We outline the applications that benefit from analyzing this data (ranging from customer segmentation to operational system planning), and propose two-stage load pattern clustering. The first stage is performed per individual user and identifies the various typical daily power usage patterns (s)he exhibits. The second stage takes those typical user patterns as input, to group users that are similar. To improve scalability, we use fast wavelet transformation (FWT) of the time series data, which reduces the dimensionality of the feature space where the clustering algorithm operates in (i.e., from N data points in the time domain to log N). Another qualitative benefit of FWT is that patterns that are identical in shape but just differ in a (typically small) time shift still end up in the same cluster. Furthermore, we use g-means instead of k-means as the clustering algorithm. Our comprehensive set of experiments to analyzes the impact of using FWT vs. time-domain features, and g-means vs. k-means, to conclude that in terms of cluster quality metrics our system is comparable to state-of-the-art methods, while being more scalable (because of the dimensionality reduction).

Two-stage load pattern clustering using fast wavelet transformation

K. Mets, F. Depuydt and C. Develder


IEEE Trans. Smart Grid, Vol. 7, No. 5, Jul. 2015, pp. 2250-2259.

@article{Mets2015TSGcluster,
author = {Mets, Kevin and Depuydt, Frederick and Develder, Chris},
title = {Two-stage load pattern clustering using fast wavelet transformation},
journal = {IEEE Trans. Smart Grid},
month = {Jul.},
year = {2015},
volume = {7},
number = {5},
pages = {2250--2259},
doi = {10.1109/TSG.2015.2446935}
}

pubinproceedings

T. Wang, B. Jaumard and C. Develder, "A scalable model for multi-period virtual network mapping for resilient multi-site data centers" (Invited), in Proc. 17th Int. Conf. Transparent Optical Netw. (ICTON 2015), Budapest, Hungary, 5-9 Jul. 2015, pp. 1-8.

A scalable model for multi-period virtual network mapping for resilient multi-site data centers

T. Wang, B. Jaumard and C. Develder


in Proc. 17th Int. Conf. Transparent Optical Netw. (ICTON 2015), Budapest, Hungary, 5-9 Jul. 2015, pp. 1-8.

In the currently dominant cloud computing paradigm, applications are being served in data centers (DCs) which are connected to high capacity optical networks. For cost efficiency reasons, in both DC and optical network domains, virtualization of the physical hardware is exploited. In a DC, it means that multiple so-called virtual machines (VMs) are being hosted on the same physical server. Similarly, the network is partitioned into separate virtual networks, thus providing isolation between distinct virtual network operators (VNOs). Thus, the problem of virtual network mapping arises: how to decide which physical resources to allocate for a particular virtual network? In this paper, we study that problem in the context of cloud computing with multiple DC sites. This introduces additional flexibility, due to the anycast routing principle: we have the freedom to decide at what particular DC location to serve a particular application. We can exploit this choice to minimize the required resources when solving the virtual network mapping problem.
This paper builds on our earlier work and solves a resilient virtual network mapping problem that optimally decides on the mapping of both network and data center resources, considering time-varying traffic conditions and protecting against possible failures of both network and DC resources. We consider the so-called VNO resilience scheme: rerouting under failure conditions is provided in the virtual network layer. To minimize physical resource capacity requirements, we allow reuse of both network and DC resources: we can reuse the same resources for the rerouting under failure scenarios that are assumed not to occur simultaneously. Since we also protect against DC failures, we allocate backup DC resources, and account for synchronization between primary and backup DCs. To deal with the time variations in the volume and geographical pattern of the application traffic, we investigate the potential benefits (in terms of overall resource capacity requirements) of reconfiguring the virtual network mapping from one period to the next.
Previously, we developed a model to solve the multi-period traffic case one step at a time: given the virtual network mapping fore time t, we determine the (possibly changed) mapping for t + 1. Compared to that previous work, we now (i) define a truly multi-period model path formulation exploiting column generation, and (ii) demonstrate its scalability on a nation-wide network with hourly varying traffic.

A scalable model for multi-period virtual network mapping for resilient multi-site data centers

T. Wang, B. Jaumard and C. Develder


in Proc. 17th Int. Conf. Transparent Optical Netw. (ICTON 2015), Budapest, Hungary, 5-9 Jul. 2015, pp. 1-8.

@inproceedings{Wang2015ICTON,
author = {Wang, Ting and Jaumard, Brigitte and Develder, Chris},
title = {A scalable model for multi-period virtual network mapping for resilient multi-site data centers},
booktitle = {Proc. 17th Int. Conf. Transparent Optical Netw. (ICTON 2015)},
month = {5--9 Jul.},
year = {2015},
pages = {1--8},
address = {Budapest, Hungary},
doi = {10.1109/ICTON.2015.7193343}
}

pubinproceedings

L. Sterckx, T. Demeester, J. Deleu and C. Develder, "When topic models disagree: Keyphrase extraction with multiple topic models", in Proc. 24th Int. World Wide Web Conf. (WWW 2015), Florence, Italy, 18-22 May 2015, pp. 123-124.

When topic models disagree: Keyphrase extraction with multiple topic models

L. Sterckx, T. Demeester, J. Deleu and C. Develder


in Proc. 24th Int. World Wide Web Conf. (WWW 2015), Florence, Italy, 18-22 May 2015, pp. 123-124.

We explore how the unsupervised extraction of topic-related keywords benefits from combining multiple topic models. We show that averaging multiple topic models, inferred from different corpora, leads to more accurate keyphrases than when using a single topic model and other state-of-the-art techniques. The experiments confirm the intuitive idea that a prerequisite for the significant benefit of combining multiple models is that the models should be sufficiently different, i.e., they should provide distinct contexts in terms of topical word importance.

When topic models disagree: Keyphrase extraction with multiple topic models

L. Sterckx, T. Demeester, J. Deleu and C. Develder


in Proc. 24th Int. World Wide Web Conf. (WWW 2015), Florence, Italy, 18-22 May 2015, pp. 123-124.

@inproceedings{Sterckx2015WWWa,
author = {Lucas Sterckx and Thomas Demeester and Johannes Deleu and Chris Develder},
title = {When topic models disagree: Keyphrase extraction with multiple topic models},
booktitle = {Proc. 24th Int. World Wide Web Conf. (WWW 2015)},
month = {18--22 May},
year = {2015},
pages = {123--124},
address = {Florence, Italy},
doi = {10.1145/2740908.2742731}
}

pubinproceedings

L. Sterckx, T. Demeester, J. Deleu and C. Develder, "Topical word importance for fast keyphrase extraction", in Proc. 24th Int. World Wide Web Conf. (WWW 2015), Florence, Italy, 18-22 May 2015, pp. 121-122.

Topical word importance for fast keyphrase extraction

L. Sterckx, T. Demeester, J. Deleu and C. Develder


in Proc. 24th Int. World Wide Web Conf. (WWW 2015), Florence, Italy, 18-22 May 2015, pp. 121-122.

We propose an improvement on a state-of-the-art keyphrase extraction algorithm, Topical PageRank (TPR), incorporating topical information from topic models. While the original algorithm requires a random walk for each topic in the topic model being used, ours is independent of the topic model, computing but a single PageRank for each text regardless of the amount of topics in the model. This increases the speed drastically and enables it for use on large collections of text using vast topic models, while not altering performance of the original algorithm.

Topical word importance for fast keyphrase extraction

L. Sterckx, T. Demeester, J. Deleu and C. Develder


in Proc. 24th Int. World Wide Web Conf. (WWW 2015), Florence, Italy, 18-22 May 2015, pp. 121-122.

@inproceedings{Sterckx2015WWWb,
author = {Lucas Sterckx and Thomas Demeester and Johannes Deleu and Chris Develder},
title = {Topical word importance for fast keyphrase extraction},
booktitle = {Proc. 24th Int. World Wide Web Conf. (WWW 2015)},
month = {18--22 May},
year = {2015},
pages = {121--122},
address = {Florence, Italy},
doi = {10.1145/2740908.2742730}
}

pubarticle

W.K. Chai, N. Wang, K. Katsaros, G. Kamel, S. Melis, M. Hoefling, B. Vieira, P. Romano, S. Sarri, T. Tesfay, B. Yang, F. Heimgaertner, M. Pignati, M. Paolone, M. Menth, G. Pavlou, E. Poll, M. Mampaey, H. Bontius and C. Develder, "An information-centric communication infrastructure for real-time state estimation of active distribution networks", IEEE Trans. Smart Grid, Vol. 6, No. 4, Jul. 2015, pp. 2134-2146.

An information-centric communication infrastructure for real-time state estimation of active distribution networks

W.K. Chai, N. Wang, K. Katsaros, G. Kamel, S. Melis, M. Hoefling, B. Vieira, P. Romano, S. Sarri, T. Tesfay, B. Yang, F. Heimgaertner, M. Pignati, M. Paolone, M. Menth, G. Pavlou, E. Poll, M. Mampaey, H. Bontius and C. Develder


IEEE Trans. Smart Grid, Vol. 6, No. 4, Jul. 2015, pp. 2134-2146.

The evolution towards the emerging Active Distribution Networks (ADNs) can be realized via a Real-Time State Estimation (RTSE) application facilitated by the use of Phasor Measurement Units (PMUs). A critical challenge in PMU-based RTSE is the lack of a scalable and flexible communication infrastructure for the timely (i.e., sub-second) delivery of the high volume of synchronized and continuous synchrophasor measurements. We address this challenge by introducing a communication platform called C-DAX based on the information-centric networking (ICN) concept. With a topic-based publish-subscribe engine that decouples data producers and consumers in time and space, C-DAX enables efficient synchrophasor measurement delivery as well as flexible and scalable (re)configuration of PMU data communication for seamless full observability of power conditions in complex and dynamic scenarios. Based on the derived set of requirements for supporting PMU-based RTSE in ADNs, we design the ICN-based C-DAX communication platform, together with a joint optimized physical network resource provisioning strategy in order to enable the agile PMU data communications in near real-time. In this paper, C-DAX is validated via a prototype implementation deployed over a sample feeder as a proof-of-concept and evaluated through simulation-based experiments using a large set of real medium voltage grid topologies operating in the Netherlands.

An information-centric communication infrastructure for real-time state estimation of active distribution networks

W.K. Chai, N. Wang, K. Katsaros, G. Kamel, S. Melis, M. Hoefling, B. Vieira, P. Romano, S. Sarri, T. Tesfay, B. Yang, F. Heimgaertner, M. Pignati, M. Paolone, M. Menth, G. Pavlou, E. Poll, M. Mampaey, H. Bontius and C. Develder


IEEE Trans. Smart Grid, Vol. 6, No. 4, Jul. 2015, pp. 2134-2146.

@article{Chai2015TSG,
author = {Chai, Wei Koong and Wang, Ning and Katsaros, Konstantinos and Kamel, George and Melis, Stijn and Hoefling, Michael and Vieira, Barbara and Romano, Paolo and Sarri, Styliani and Tesfay, Teklemariam and Yang, Binxu and Heimgaertner, Florian and Pignati, Marco and Paolone, Mario and Menth, Michael and Pavlou, George and Poll, Erik and Mampaey, Marcel and Bontius, Herman and Develder, Chris},
title = {An information-centric communication infrastructure for real-time state estimation of active distribution networks},
journal = {IEEE Trans. Smart Grid},
month = {Jul.},
year = {2015},
volume = {6},
number = {4},
pages = {2134--2146},
doi = {10.1109/TSG.2015.2398840}
}

pubinproceedings

J. Nelis, H. Vandaele, M. Strobbe, A. Koning, F. De Turck and C. Develder, "Supporting development and management of smart office applications: a DYAMAND case study", in Proc. IFIP/IEEE Int. Symp. Integrated Netw. Management (IM 2015), Ottawa, Canada, 11-15 May 2015, pp. 1053-1058.

Supporting development and management of smart office applications: a DYAMAND case study

J. Nelis, H. Vandaele, M. Strobbe, A. Koning, F. De Turck and C. Develder


in Proc. IFIP/IEEE Int. Symp. Integrated Netw. Management (IM 2015), Ottawa, Canada, 11-15 May 2015, pp. 1053-1058.

To realize the Internet of Things (IoT) vision, tools are needed to ease the development and deployment of practical applications. Several standard bodies, companies, and ad-hoc consortia are proposing their own solution for inter-device com- munication. In this context, DYnamic, Adaptive MAnagement of Networks and Devices (DYAMAND) was presented in a previous publication to solve the interoperability issues introduced by the multitude of available technologies.
In this paper a DYAMAND case study is presented: in cooperation with a large company, a monitoring application was developed for flexible office spaces in order to reliably reorganize an office environment and give real-time feedback on the usage of meeting rooms. Three wireless sensor technologies were investigated to be used in the pilot. The solution was deployed in a "friendly user" setting at a research institute (iMinds) prior to deployment at the large company’s premises. Based on the findings of both installations, requirements for an application platform supporting development and management of smart (office) applications were listed. DYAMAND was used as the basis of the implementation. Although the local management of networked devices as provided by DYAMAND enables easier development of intelligent applications, a number of remote services discussed in this paper are needed to enable reliable and up-to-date support (of new technologies).

Supporting development and management of smart office applications: a DYAMAND case study

J. Nelis, H. Vandaele, M. Strobbe, A. Koning, F. De Turck and C. Develder


in Proc. IFIP/IEEE Int. Symp. Integrated Netw. Management (IM 2015), Ottawa, Canada, 11-15 May 2015, pp. 1053-1058.

@inproceedings{Nelis2015IM,
author = {Jelle Nelis and Heleen Vandaele and Matthias Strobbe and Arnoud Koning and De Turck, Fil and Chris Develder},
title = {Supporting development and management of smart office applications: a DYAMAND case study},
booktitle = {Proc. IFIP/IEEE Int. Symp. Integrated Netw. Management (IM 2015)},
month = {11--15 May},
year = {2015},
pages = {1053--1058},
address = {Ottawa, Canada},
doi = {10.1109/INM.2015.7140432}
}

pubinproceedings

M. Strobbe, K. Vanthournout, T. Verschueren, W. Cardinaels and C. Develder, "Deploying the ICT architecture of a residential demand response pilot", in Proc. IFIP/IEEE Int. Symp. Integrated Netw. Management (IM 2015), Ottawa, Canada, 11-15 May 2015, pp. 1041-1046.

Deploying the ICT architecture of a residential demand response pilot

M. Strobbe, K. Vanthournout, T. Verschueren, W. Cardinaels and C. Develder


in Proc. IFIP/IEEE Int. Symp. Integrated Netw. Management (IM 2015), Ottawa, Canada, 11-15 May 2015, pp. 1041-1046.

The Flemish project Linear was a large scale res- idential demand response pilot that aims to validate innovative smart grid technology building on the rollout of information and communication technologies in the power grid.
For this pilot a scalable, reliable and interoperable ICT infrastructure was set up, interconnecting 245 residential power grid customers with the backend systems of energy service providers (ESPs), flexibility aggregators, distribution system operators (DSOs) and balancing responsible parties (BRPs).
On top of this architecture several business cases were rolled out, which require the sharing of metering data and flexibility information, and demand response algorithms for the balancing of renewable energy and the mitigation of voltage and power issues in distribution grids.
The goal of the pilot is the assessment of the technical and economical feasibility of residential demand response in real life, and of the interaction with the end-consumer.
In this paper we focus on the practical experiences and lessons learnt during the deployment of the ICT technology for the pilot. This includes the real-time gathering of measurement data and real-time control of a wide range of smart appliances in the homes of the participants. We identified a number of critical issues that need to be addressed for a future full-scalle roll- out: (i) reliable in-house communication, (ii) interoperability of appliances, measurement equipment, backend systems, and business cases, and (iii) sufficient backend processing power for real-time analysis and control.

Deploying the ICT architecture of a residential demand response pilot

M. Strobbe, K. Vanthournout, T. Verschueren, W. Cardinaels and C. Develder


in Proc. IFIP/IEEE Int. Symp. Integrated Netw. Management (IM 2015), Ottawa, Canada, 11-15 May 2015, pp. 1041-1046.

@inproceedings{Strobbe2015IM,
author = {Matthias Strobbe and Koen Vanthournout and Tom Verschueren and Wim Cardinaels and Chris Develder},
title = {Deploying the ICT architecture of a residential demand response pilot},
booktitle = {Proc. IFIP/IEEE Int. Symp. Integrated Netw. Management (IM 2015)},
month = {11--15 May},
year = {2015},
pages = {1041--1046},
address = {Ottawa, Canada},
doi = {10.1109/INM.2015.7140430}
}

pubinproceedings

M. Feys, T. Demeester, B. Fortuna, J. Deleu and C. Develder, "On the robustness of event detection evaluation: A case study", in Proc. Forum for Information Retrieval Evaluation (FIRE 2014), Bangalore, India, 5-7 Dec. 2014.

On the robustness of event detection evaluation: A case study

M. Feys, T. Demeester, B. Fortuna, J. Deleu and C. Develder


in Proc. Forum for Information Retrieval Evaluation (FIRE 2014), Bangalore, India, 5-7 Dec. 2014.

Research on evaluation of IR systems has led to the insight that a robust evaluation strategy requires tests on a large number of events/queries. However, especially for event detection, the number of manually labeled events may be limited. In this paper we investigate how to optimize the evaluation strategy in those cases to maximize robustness. We also introduce two new vector space models for event detection that aim to incorporate bursty information of terms and compare these with existing models. Our experiments show that by using graded relevance levels we can reduce the impact of subjectivity and ambiguity of event detection evaluation. We also show that although user disagreement is significant, it has no real impact on the ranking of the results.

On the robustness of event detection evaluation: A case study

M. Feys, T. Demeester, B. Fortuna, J. Deleu and C. Develder


in Proc. Forum for Information Retrieval Evaluation (FIRE 2014), Bangalore, India, 5-7 Dec. 2014.

@inproceedings{Feys2014FIRE,
author = {Feys, Matthias and Demeester, Thomas and Fortuna, Blaz and Deleu, Johannes and Develder, Chris},
title = {On the robustness of event detection evaluation: A case study},
booktitle = {Proc. Forum for Information Retrieval Evaluation (FIRE 2014)},
month = {5--7 Dec.},
year = {2014},
address = {Bangalore, India}
}

pubinproceedings

L. Mertens, T. Demeester, J. Deleu, M. Feys and C. Develder, "Entity linking: Test collections revisited", in Proc. Forum for Information Retrieval Evaluation (FIRE 2014), Bangalore, India, 5-7 Dec. 2014.

Entity linking: Test collections revisited

L. Mertens, T. Demeester, J. Deleu, M. Feys and C. Develder


in Proc. Forum for Information Retrieval Evaluation (FIRE 2014), Bangalore, India, 5-7 Dec. 2014.

This paper analyzes two important conditions that are usually taken for granted in the evaluation of information retrieval systems: the test queries should be representative for the intended application scenario, and a sufficient amount of queries are needed to robustly assess system performance, as well as discern performance differ- ences between systems. Both issues have important consequences, as studied in this paper for the specific case of Entity Linking systems. We investigate two methods for automatic query generation, and show them to have a vast impact on evaluated system perfor- mance. We further demonstrate the effect a query set’s size has on its ability to faithfully distinguish systems, and propose a method for assessing the possible impact on system performance adding a specific number of queries to the set might have.

Entity linking: Test collections revisited

L. Mertens, T. Demeester, J. Deleu, M. Feys and C. Develder


in Proc. Forum for Information Retrieval Evaluation (FIRE 2014), Bangalore, India, 5-7 Dec. 2014.

@inproceedings{Mertens2014FIRE,
author = {Mertens, Laurent and Demeester, Thomas and Deleu, Johannes and Feys, Matthias and Develder, Chris},
title = {Entity linking: Test collections revisited},
booktitle = {Proc. Forum for Information Retrieval Evaluation (FIRE 2014)},
month = {5--7 Dec.},
year = {2014},
address = {Bangalore, India}
}

pubinproceedings

L. Sterckx, T. Demeester, J. Deleu and C. Develder, "Using semantic clustering and active learning for noise reduction in distant supervision", in Proc. 4th Workshop on Automated Knowledge Base Construction (AKBC 2014) at NIPS 2014, Montreal, Canada, 13 Dec. 2014.

Using semantic clustering and active learning for noise reduction in distant supervision

L. Sterckx, T. Demeester, J. Deleu and C. Develder


in Proc. 4th Workshop on Automated Knowledge Base Construction (AKBC 2014) at NIPS 2014, Montreal, Canada, 13 Dec. 2014.

The use of external databases to generate training data, also known as Distant Supervision, has become an effective way to train supervised relation extractors but this approach inherently suffers from noise. In this paper we propose a method for noise reduction in distantly supervised training data, using a discriminative classifier and semantic similarity between the contexts of the training examples. We describe an active learning strategy which exploits hierarchical clustering of the candidate training samples. To further improve the effectiveness of this approach, we study the use of several methods for dimensionality reduction of the training samples. We find that semantic clustering of training data combined with cluster-based active learning allows filtering the training data, hence facilitating the creation of a clean training set for relation extraction, at a reduced manual labeling cost.

Using semantic clustering and active learning for noise reduction in distant supervision

L. Sterckx, T. Demeester, J. Deleu and C. Develder


in Proc. 4th Workshop on Automated Knowledge Base Construction (AKBC 2014) at NIPS 2014, Montreal, Canada, 13 Dec. 2014.

@inproceedings{Sterckx2014AKBC,
author = {Sterckx, Lucas and Demeester, Thomas and Deleu, Johannes and Develder, Chris},
title = {Using semantic clustering and active learning for noise reduction in distant supervision},
booktitle = {Proc. 4th Workshop on Automated Knowledge Base Construction (AKBC 2014) at NIPS 2014},
month = {13 Dec.},
year = {2014},
address = {Montreal, Canada}
}

pubinproceedings

M. Feys, L. Sterckx, L. Mertens, J. Deleu, T. Demeester and C. Develder, "Ghent University-IBCN participation in TAC-KBP 2014 slot filling and cold start tasks", in Proc. 7th Text Analysis Conf. (TAC 2014), Gaithersburg, MD, USA, 17-18 Nov. 2014.

Ghent University-IBCN participation in TAC-KBP 2014 slot filling and cold start tasks

M. Feys, L. Sterckx, L. Mertens, J. Deleu, T. Demeester and C. Develder


in Proc. 7th Text Analysis Conf. (TAC 2014), Gaithersburg, MD, USA, 17-18 Nov. 2014.

This paper presents the system of the UGENT IBCN team for the TAC KBP 2014 slot filling and cold start (slot filling variant) tasks. This was the team’s first participation in both tasks. The slot filling system uses distant supervision to generate training data combined with a noise reduction step, and two different types of classifiers. We show that the noise reduction step significantly improves precision, and propose an application of word embeddings for slot filling.

Ghent University-IBCN participation in TAC-KBP 2014 slot filling and cold start tasks

M. Feys, L. Sterckx, L. Mertens, J. Deleu, T. Demeester and C. Develder


in Proc. 7th Text Analysis Conf. (TAC 2014), Gaithersburg, MD, USA, 17-18 Nov. 2014.

@inproceedings{Feys2014TAC,
author = {Feys, Matthias and Sterckx, Lucas and Mertens, Laurent and Deleu, Johannes and Demeester, Thomas and Develder, Chris},
title = {Ghent University-IBCN participation in TAC-KBP 2014 slot filling and cold start tasks},
booktitle = {Proc. 7th Text Analysis Conf. (TAC 2014)},
month = {17--18 Nov.},
year = {2014},
address = {Gaithersburg, MD, USA}
}

pubarticle

C. Develder, J. Buysse, B. Dhoedt and B. Jaumard, "Joint dimensioning of server and network infrastructure for resilient optical grids/clouds", IEEE/ACM Trans. Netw., Vol. 22, No. 5, Oct. 2014, pp. 1591-1606.

Joint dimensioning of server and network infrastructure for resilient optical grids/clouds

C. Develder, J. Buysse, B. Dhoedt and B. Jaumard


IEEE/ACM Trans. Netw., Vol. 22, No. 5, Oct. 2014, pp. 1591-1606.

We address the dimensioning of infrastructure, comprising both network and server resources, for large-scale decentralized distributed systems such as grids or clouds. We design the resulting grid/cloud to be resilient against network link or server failures. To this end, we exploit relocation: under failure conditions, a grid job or cloud virtual machine may be served at an alternate destination (i.e., different from the one under failure- free conditions). We thus consider grid/cloud requests to have a known origin, but assume a degree of freedom as to where they end up being served, which is the case for grid applications of the bag-of-tasks (BoT) type or hosted virtual machines in the cloud case. We present a generic methodology based on integer linear programming (ILP) that (1) chooses a given number of sites in a given network topology where to install server infrastructure, and (2) determines the amount of both network and server capacity to cater for both the failure free scenario and failures of links or nodes. For the latter, we consider either failure independent (FID) or failure dependent (FD) recovery. Case studies on European scale networks show that relocation allows considerable reduction of the total amount of network and server resources, especially in sparse topologies and for higher numbers of server sites. Adopting a failure dependent backup routing strategy does lead to lower resource dimensions, but only when we adopt relocation (especially for a high number of server sites): without exploiting relocation, potential savings of FD versus FID are not meaningful.

Joint dimensioning of server and network infrastructure for resilient optical grids/clouds

C. Develder, J. Buysse, B. Dhoedt and B. Jaumard


IEEE/ACM Trans. Netw., Vol. 22, No. 5, Oct. 2014, pp. 1591-1606.

@article{Develder2013TNET,
author = {Develder, Chris and Buysse, Jens and Dhoedt, Bart and Jaumard, Brigitte},
title = {Joint dimensioning of server and network infrastructure for resilient optical grids/clouds},
journal = {IEEE/ACM Trans. Netw.},
month = {Oct.},
year = {2014},
volume = {22},
number = {5},
pages = {1591--1606},
doi = {10.1109/TNET.2013.2283924}
}

pubinproceedings

M. Strobbe, K. Vanthournout, T. Verschueren, W. Cardinaels and C. Develder, "Large-scale residential demand response pilot ICT architecture", in Proc. 5th IEEE PES Innovative Smart Grid Technologies European Conf. (ISGT-EU 2014), Istanbul, Turkey, 12-15 Oct. 2014, pp. 1-6.

Large-scale residential demand response pilot ICT architecture

M. Strobbe, K. Vanthournout, T. Verschueren, W. Cardinaels and C. Develder


in Proc. 5th IEEE PES Innovative Smart Grid Technologies European Conf. (ISGT-EU 2014), Istanbul, Turkey, 12-15 Oct. 2014, pp. 1-6.

The Flemish project Linear is an example of an ongoing large scale residential demand response pilot that aims to validate innovative smart grid applications that exploit the rollout of information and communication technologies (ICT) in the power grid. In this paper, we discuss the design of such a scalable, reliable and interoperable ICT infrastructure that interconnects 245 residential power grid customers with the backend systems of various actors: e.g., energy service providers (ESPs), flexibility aggregators, distribution system operators (DSOs), balancing re- sponsible parties (BRPs). The use cases rolled out in Linear, built on top of our proposed ICT architecture, involve sharing both metering data and flexibility information (esp. for time shifting) of the households, and demand response (DR) algorithms for the balancing of renewable energy and the mitigation of voltage and power issues in distribution grids.

Large-scale residential demand response pilot ICT architecture

M. Strobbe, K. Vanthournout, T. Verschueren, W. Cardinaels and C. Develder


in Proc. 5th IEEE PES Innovative Smart Grid Technologies European Conf. (ISGT-EU 2014), Istanbul, Turkey, 12-15 Oct. 2014, pp. 1-6.

@inproceedings{Strobbe2014ISGTEU,
author = {Strobbe, Matthias and Vanthournout, Koen and Verschueren, Tom and Cardinaels, Wim and Develder, Chris},
title = {Large-scale residential demand response pilot ICT architecture},
booktitle = {Proc. 5th IEEE PES Innovative Smart Grid Technologies European Conf. (ISGT-EU 2014)},
month = {12--15 Oct.},
year = {2014},
pages = {1--6},
address = {Istanbul, Turkey},
doi = {10.1109/ISGTEurope.2014.7028760}
}

pubinproceedings

L. Van Halewyck, J. Verstraeten, M. Strobbe and C. Develder, "Economic evaluation of active network management alternatives for congestion avoidance - the DSO perspective", in Proc. 5th IEEE PES Innovative Smart Grid Technologies European Conf. (ISGT-EU 2014), Istanbul, Turkey, 12-15 Oct. 2014, pp. 1-6.

Economic evaluation of active network management alternatives for congestion avoidance - the DSO perspective

L. Van Halewyck, J. Verstraeten, M. Strobbe and C. Develder


in Proc. 5th IEEE PES Innovative Smart Grid Technologies European Conf. (ISGT-EU 2014), Istanbul, Turkey, 12-15 Oct. 2014, pp. 1-6.

The introduction of distributed renewable energy generators in the electricity grid implies a number of challenges for energy suppliers and utilities. One of these challenges is the increased risk for grid congestion issues due to the installation of large amounts of e.g. solar panels and wind turbines to the existing grid. As alternative to costly grid reinforcements several Active Network Management (ANM) techniques to mitigate this risk are researched, including (1) dynamic line rating and (2) demand side management. In this paper, we make an economic evaluation of those options from a Distribution System Operator (DSO) perspective. We discuss the aforementioned techniques and elaborate their business case for a specific use case in the MV-grid. Our calculations show that dynamic line rating can be considered as an alternative to network reinforcement, depending on the regulatory framework.

Economic evaluation of active network management alternatives for congestion avoidance - the DSO perspective

L. Van Halewyck, J. Verstraeten, M. Strobbe and C. Develder


in Proc. 5th IEEE PES Innovative Smart Grid Technologies European Conf. (ISGT-EU 2014), Istanbul, Turkey, 12-15 Oct. 2014, pp. 1-6.

@inproceedings{VanHalewyck2014ISGTEU,
author = {Van Halewyck, Lode and Verstraeten, Johan and Strobbe, Matthias and Develder, Chris},
title = {Economic evaluation of active network management alternatives for congestion avoidance - the DSO perspective},
booktitle = {Proc. 5th IEEE PES Innovative Smart Grid Technologies European Conf. (ISGT-EU 2014)},
month = {12--15 Oct.},
year = {2014},
pages = {1--6},
address = {Istanbul, Turkey},
doi = {10.1109/ISGTEurope.2014.7028941}
}

pubinproceedings

B. Fortuna, T. Demeester and C. Develder, "Towards large-scale event detection and extraction from news", in Proc. Large-scale Online Learning and Decision Making Workshop (LSOLDM 2014), Windsor, UK, 10-12 Sep. 2014.

Towards large-scale event detection and extraction from news

B. Fortuna, T. Demeester and C. Develder


in Proc. Large-scale Online Learning and Decision Making Workshop (LSOLDM 2014), Windsor, UK, 10-12 Sep. 2014.

Understanding and reasoning about textual data is one of the important topics in artificial intelligence and is being addressed by various research communities, ranging from knowledge representation, over natural language processing to text mining. Each community provides a different set of often overlapping intuitions, tools and methodologies for working with text.
Event processing from news and social media can be seen as a subtopic of text understanding [1, 2, 3, 4]. It comprises different tasks, including New and Retrospective Event Discovery, Event Type Classification and Event Template Extraction.
Research on event processing requires access to annotated data covering different tasks in the event processing pipeline. Over the last decades, several datasets have been created covering event discovery and event extraction, e.g., [5, 6, 7]. These datasets are rather limited in scope. For example, they contain articles from only few selected sources, or they contain a limited number of annotated events with a high selection bias (e.g., towards larger or well defined events like natural disasters or terrorism). Using such limited datasets to evaluate solutions for the event processing tasks may lead to favoring approaches that do not work well on real-world datasets. The main reasons for these limitations are (1) limited access to data resources and (2) the required and expensive manual annotations.
The main contributions we are working towards are (1) a systematic methodology for efficiently creating a large golden standard of manually annotated events over a large corpus of news articles with a realistic distribution over the covered topics and events, and (2) a resulting annotated corpus a resulting annotated corpus of 10,000 English general news articles embedded in 31 million news articles.

Towards large-scale event detection and extraction from news

B. Fortuna, T. Demeester and C. Develder


in Proc. Large-scale Online Learning and Decision Making Workshop (LSOLDM 2014), Windsor, UK, 10-12 Sep. 2014.

@inproceedings{Fortuna2014,
author = {Fortuna, Blaz and Demeester, Thomas and Develder, Chris},
title = {Towards large-scale event detection and extraction from news},
booktitle = {Proc. Large-scale Online Learning and Decision Making Workshop (LSOLDM 2014)},
month = {10--12 Sep.},
year = {2014},
address = {Windsor, UK}
}

pubarticle

H. Mohsenian-Rad, F. Granelli, R. Kui, C. Develder, L. Chen, T. Jiang and X. Liu, "Editorial: IEEE Communications Surveys & Tutorials Special Section on Energy and Smart Grid", IEEE Commun. Surv. Tutor., Vol. 16, No. 3, Sep. 2014, pp. 1687-1688.

Editorial: IEEE Communications Surveys & Tutorials Special Section on Energy and Smart Grid

H. Mohsenian-Rad, F. Granelli, R. Kui, C. Develder, L. Chen, T. Jiang and X. Liu


IEEE Commun. Surv. Tutor., Vol. 16, No. 3, Sep. 2014, pp. 1687-1688.

The aim of this special issue was to collect from academic and industrial players, tutorials and surveys related to the latest smart grid and energy related technologies and architectures. Contributions on major developments and updates on smart grid systems are considered. We received a total of 15 submissions from which five were finally accepted for this special issue. The papers span from smart grid communications to building energy efficiency, smart metering, information management, and co-simulation of power and communication systems. Each of the five article is briefly summarized.

Editorial: IEEE Communications Surveys & Tutorials Special Section on Energy and Smart Grid

H. Mohsenian-Rad, F. Granelli, R. Kui, C. Develder, L. Chen, T. Jiang and X. Liu


IEEE Commun. Surv. Tutor., Vol. 16, No. 3, Sep. 2014, pp. 1687-1688.

@article{MohsenianRad2014,
author = {Mohsenian-Rad, Hamed and Granelli, Fabrizio and Kui, Ren and Develder, Chris and Chen, Lijun and Jiang, Tao and Liu, Xue},
title = {Editorial: IEEE Communications Surveys & Tutorials Special Section on Energy and Smart Grid},
journal = {IEEE Commun. Surv. Tutor.},
month = {Sep.},
year = {2014},
volume = {16},
number = {3},
pages = {1687--1688},
doi = {10.1109/SURV.2014.042914.00001}
}

pubarticle

B. Vankeirsbilck, D. Verslype, N. Staelens, P. Simoens, C. Develder, P. Demeester, F. De Turck and B. Dhoedt, "Platform for real-time subjective assessment of interactive multimedia applications", Multimed. Tools Appl., Vol. 72, No. 1, Sep. 2014, pp. 749-775.

Platform for real-time subjective assessment of interactive multimedia applications

B. Vankeirsbilck, D. Verslype, N. Staelens, P. Simoens, C. Develder, P. Demeester, F. De Turck and B. Dhoedt


Multimed. Tools Appl., Vol. 72, No. 1, Sep. 2014, pp. 749-775.

With the advent of cloud computing and remote execution of interac- tive applications, there is a need for evaluating the Quality of Experience (QoE) and the influence on this QoE of network condition variations, media encoding parameter settings and related optimization algorithms. However, current QoE assessment focuses mainly on audiovisual quality in non-interactive applications, such as video-on-demand services. On the other hand, where experiments aim to quantify interactive quality, the focus is typically targeted at games, using an ad-hoc test setup to assess the impact of network variations on the playing experience. In this paper, we present a novel platform enabling the assessment of a broad range of interactive applications (e.g., thin client remote desktop systems, remotely rendered engineering applications, games). Dynamic reconfiguration of media encoding and decoding is built into the system, to allow dynamic adaptation of the media encoding to the network conditions and the application characteristics. Evaluating the influence of these automatic adaptations is a key asset of our approach. A range of possible use cases is discussed, as well as a performance study of our implementation, showing that the platform we built is capable of highly controllable subjective user assessment. Furthermore, we present results obtained by applying the platform for a subjective evaluation of an interactive multimedia application. Specifically, the influence of visual quality and frame rate on interactive QoE has been assessed for a remotely executed race game.

Platform for real-time subjective assessment of interactive multimedia applications

B. Vankeirsbilck, D. Verslype, N. Staelens, P. Simoens, C. Develder, P. Demeester, F. De Turck and B. Dhoedt


Multimed. Tools Appl., Vol. 72, No. 1, Sep. 2014, pp. 749-775.

@article{Vankeirsbilck2013MTA,
author = {Vankeirsbilck, Bert and Verslype, Dieter and Staelens, Nicolas and Simoens, Pieter and Develder, Chris and Demeester, Piet and De Turck, Filip and Dhoedt, Bart},
title = {Platform for real-time subjective assessment of interactive multimedia applications},
journal = {Multimed. Tools Appl.},
month = {Sep.},
year = {2014},
volume = {72},
number = {1},
pages = {749-775},
doi = {10.1007/s11042-013-1395-y}
}

pubarticle

S. Dooms, T. De Pessemier, D. Verslype, J. Nelis, J. De Meulenaere, W. Van den Broeck, L. Martens and C. Develder, "OMUS: an optimized multimedia service for the home environment", Multimed. Tools Appl., Vol. 72, No. 1, Sep. 2014, pp. 281-311.

OMUS: an optimized multimedia service for the home environment

S. Dooms, T. De Pessemier, D. Verslype, J. Nelis, J. De Meulenaere, W. Van den Broeck, L. Martens and C. Develder


Multimed. Tools Appl., Vol. 72, No. 1, Sep. 2014, pp. 281-311.

Media content in home environments is often scattered across multiple devices in the home network. As both the available multimedia devices in the home (e.g., smartphones, tablets, laptops, game consoles, etc.) and the available content (video and audio) is increasing, interconnecting desired content with available devices is becoming harder and home users are experiencing difficulties in selecting interesting content for their current context. In this paper, we start with an analysis of the home environment by means of a user study. Information handling problems are identified and requirements for a home information system formulated. To meet these requirements we propose the OMUS home information system which includes an optimized content aggregation framework, a hybrid group-based contextual recommender system, and an overall web-based user interface making both content and recommendations available for all devices across the home network. For the group recommendations we introduced distinct weights for each user and showed that by varying the weights, the coverage (i.e., items that can be returned by the recommender) considerably increases. Also the addition of genre filter functionality was proven to further boost the coverage. The OMUS system was evaluated by means of focus groups and by qualitative and quantitative performance assessment of individual parts of the system. The modularity of internal components and limited imposed hardware requirements implies flexibility as to how the OMUS system can be deployed (ranging from e.g., embedded in hardware devices or more software services based).

OMUS: an optimized multimedia service for the home environment

S. Dooms, T. De Pessemier, D. Verslype, J. Nelis, J. De Meulenaere, W. Van den Broeck, L. Martens and C. Develder


Multimed. Tools Appl., Vol. 72, No. 1, Sep. 2014, pp. 281-311.

@article{Dooms2013,
author = {Simon Dooms and De Pessemier, Toon and Verslype, Dieter and Nelis, Jelle and De Meulenaere, Jonas and Van den Broeck, Wendy and Martens, Luc and Develder, Chris},
title = {OMUS: an optimized multimedia service for the home environment},
journal = {Multimed. Tools Appl.},
month = {Sep.},
year = {2014},
volume = {72},
number = {1},
pages = {281--311},
doi = {10.1007/s11042-012-1347-y}
}

pubinproceedings

M. Bui, T. Wang, B. Jaumard, D. Medhi and C. Develder, "Time-varying resilient virtual network mapping for multi-location cloud data centers", in Proc. 16th Int. Conf. Transparent Optical Netw. (ICTON 2014), Graz, Austria, 6-10 Jul. 2014, pp. 1-8.

Time-varying resilient virtual network mapping for multi-location cloud data centers

M. Bui, T. Wang, B. Jaumard, D. Medhi and C. Develder


in Proc. 16th Int. Conf. Transparent Optical Netw. (ICTON 2014), Graz, Austria, 6-10 Jul. 2014, pp. 1-8.

Optical networks constitute a fundamental building block that has enabled the success of cloud computing. Vice versa, the concept of virtualization, a cornerstone of cloud computing, today also is applied in the networking field: physical network infrastructure is partitioned logically into separate virtual networks, thus providing isolation between distinct virtual network operators (VNOs). Thus, the problem of virtual network mapping has arisen: how to decide which physical resources to allocate for a particular virtual network? In a cloud context, not just network connectivity is required, but also data center (DC) resources, for computation and/or storage. Given the underlying anycast routing principle, the network operator has some freedom at what specific DC to allocate these resources.
In this paper, we solve a resilient virtual network mapping problem that optimally decides on the mapping of both network and data center resources, considering time-varying traffic conditions and protecting against possible failures of both network and DC resources. In terms of resilience, we consider the so-called VNO resilience scheme, where the rerouting under failure conditions is provided in the virtual network layer. To minimize physical resource capacity requirements, we allow reuse of both network and DC resources. Since we also protect against DC failures, we allocate backup DC resources, and account for synchronization between primary and backup DCs.
As optimization criteria, we not only consider overall network capacity minimization, but also aim to limit virtual network re-configurations from one time period to the next. We propose a scalable column-generation approach to solve the dynamic virtual network mapping problem, and demonstrate it in a case study on a nation-wide US backbone network.

Time-varying resilient virtual network mapping for multi-location cloud data centers

M. Bui, T. Wang, B. Jaumard, D. Medhi and C. Develder


in Proc. 16th Int. Conf. Transparent Optical Netw. (ICTON 2014), Graz, Austria, 6-10 Jul. 2014, pp. 1-8.

@inproceedings{Bui2014ICTON,
author = {Minh Bui and Ting Wang and Brigitte Jaumard and Deep Medhi and Chris Develder},
title = {Time-varying resilient virtual network mapping for multi-location cloud data centers},
booktitle = {Proc. 16th Int. Conf. Transparent Optical Netw. (ICTON 2014)},
month = {6--10 Jul.},
year = {2014},
pages = {1--8},
address = {Graz, Austria},
doi = {10.1109/ICTON.2014.6876287}
}

pubarticle

K. Mets, J. Aparicio and C. Develder, "Combining power and communication network simulation for cost-effective smart grid analysis", IEEE Commun. Surv. Tutor., Vol. 16, No. 3, Jul. 2014, pp. 1771-1796.

Combining power and communication network simulation for cost-effective smart grid analysis

K. Mets, J. Aparicio and C. Develder


IEEE Commun. Surv. Tutor., Vol. 16, No. 3, Jul. 2014, pp. 1771-1796.

Today's electricity grid is transitionaing to a so-called smart grid. The associated challenges and funding initiatives have spurred great efforts from the research community to propose innovative smart grid solutions. To assess the performance of possible solutions, simulation tools offer a cost effective and safe approach. In this paper we will provide a comprehensive overview of various tools and their characteristics, applicable in smart grid research: we will cover both the communication and associated ICT infrastructure, on top of the power grid. First, we discuss the motivation for the development of smart grid simulators, as well as their associated research questions and design challenges. Next, we discuss three types of simulators in the smart grid area: power system simulators, communication network simulators, and combined power and communication simulators. To summarize the findings from this survey, we classify the different simulators according to targeted use cases, simulation model level of detail, and architecture. To conclude, we discuss the use of standards and multi-agent based modeling in smart grid simulation.

Combining power and communication network simulation for cost-effective smart grid analysis

K. Mets, J. Aparicio and C. Develder


IEEE Commun. Surv. Tutor., Vol. 16, No. 3, Jul. 2014, pp. 1771-1796.

@article{Mets2014CST,
author = {Mets, Kevin and Aparicio, Juan and Develder, Chris},
title = {Combining power and communication network simulation for cost-effective smart grid analysis},
journal = {IEEE Commun. Surv. Tutor.},
month = {Jul.},
year = {2014},
volume = {16},
number = {3},
pages = {1771--1796},
doi = {10.1109/SURV.2014.021414.00116}
}

pubinproceedings

M. Bui, B. Jaumard and C. Develder, "Resilience options for provisioning anycast cloud services with virtual optical networks", in Proc. IEEE Int. Conf. on Commun. (ICC 2014), Sydney, Australia, 10-14 Jun. 2014.

Resilience options for provisioning anycast cloud services with virtual optical networks

M. Bui, B. Jaumard and C. Develder


in Proc. IEEE Int. Conf. on Commun. (ICC 2014), Sydney, Australia, 10-14 Jun. 2014.

Optical networks are crucial to support increasingly demanding cloud services. Delivering the requested quality of services (in particular latency) is key to successfully provisioning end-to-end services in clouds. Therefore, as for traditional optical network services, it is of utter importance to guarantee that clouds are resilient to any failure of either network infrastructure (links and/or nodes) or data centers. A crucial concept in establishing cloud services is that of network virtualization: the physical infrastructure is logically partitioned in separate virtual networks. To guarantee end-to-end resilience for cloud services in such a set-up, we need to simultaneously route the services and map the virtual network, in such a way that an alternate routing in case of physical resource failures is always available. Note that combined control of the network and data center resources is exploited, and the anycast routing concept applies: we can choose the data center to provide server resources requested by the customer to optimize resource usage and/or resiliency. This paper investigates the design of scalable optimization models to perform the virtual network mapping resiliently. We compare various resilience options, and analyze their compromise between bandwidth requirements and resiliency quality.

Resilience options for provisioning anycast cloud services with virtual optical networks

M. Bui, B. Jaumard and C. Develder


in Proc. IEEE Int. Conf. on Commun. (ICC 2014), Sydney, Australia, 10-14 Jun. 2014.

@inproceedings{Bui2014ICC,
author = {Bui, Minh and Jaumard, Brigitte and Develder, Chris},
title = {Resilience options for provisioning anycast cloud services with virtual optical networks},
booktitle = {Proc. IEEE Int. Conf. on Commun. (ICC 2014)},
month = {10--14 Jun.},
year = {2014},
address = {Sydney, Australia},
doi = {10.1109/ICC.2014.6883857}
}

pubinproceedings

M. Bui, B. Jaumard, I.B. Barla Harter and C. Develder, "Scalable algorithms for QoS-aware virtual network mapping for cloud services", in Proc. 18th Int. Conf. Optical Network Design and Modelling (ONDM 2014), Stockholm, Sweden, 19-22 May 2014.

Scalable algorithms for QoS-aware virtual network mapping for cloud services

M. Bui, B. Jaumard, I.B. Barla Harter and C. Develder


in Proc. 18th Int. Conf. Optical Network Design and Modelling (ONDM 2014), Stockholm, Sweden, 19-22 May 2014.

Both business and consumer applications increasingly depend on cloud solutions. Yet, many are still reluctant to move to cloud-based solutions, mainly due to concerns of service quality and reliability. Since cloud platforms depend both on IT resources (located in data centers, DCs) and network infrastructure connecting to it, both QoS and resilience should be offered with end-to-end guarantees up to and including the server resources. The latter currently is largely impeded by the fact that the network and cloud DC domains are typically operated by disjoint entities. Network virtualization, together with combined control of network and IT resources can solve that problem. In this paper, we formally state the combined network and IT provisioning problem in an integer linear programming (ILP) model, incorporating resilience as well as QoS in physical and virtual layers. We also provide a scalable column generation model, to address real world network sizes. We analyze the latter in extensive case studies, to answer the question at which layer to provision QoS and resilience in virtual networks for cloud services.

Scalable algorithms for QoS-aware virtual network mapping for cloud services

M. Bui, B. Jaumard, I.B. Barla Harter and C. Develder


in Proc. 18th Int. Conf. Optical Network Design and Modelling (ONDM 2014), Stockholm, Sweden, 19-22 May 2014.

@inproceedings{Bui2014ONDM,
author = {Bui, Minh and Jaumard, Brigitte and Barla Harter, Isil Burcu and Develder, Chris},
title = {Scalable algorithms for QoS-aware virtual network mapping for cloud services},
booktitle = {Proc. 18th Int. Conf. Optical Network Design and Modelling (ONDM 2014)},
month = {19-22 May},
year = {2014},
address = {Stockholm, Sweden}
}

pubinproceedings

L. Sterckx, T. Demeester, J. Deleu, L. Mertens and C. Develder, "Assessing quality of unsupervised topics in song lyrics", in Proc. 36th Eur. Conf. Information Retrieval (ECIR 2014), Amsterdam, The Netherlands, 13-16 Apr. 2014.

Assessing quality of unsupervised topics in song lyrics

L. Sterckx, T. Demeester, J. Deleu, L. Mertens and C. Develder


in Proc. 36th Eur. Conf. Information Retrieval (ECIR 2014), Amsterdam, The Netherlands, 13-16 Apr. 2014.

How useful are topic models based on song lyrics for ap- plications in music information retrieval? Unsupervised topic models on text corpora are often difficult to interpret. Based on a large collection of lyrics, we investigate how well automatically generated topics are related to manual topic annotations. We propose to use the kurtosis metric to align unsupervised topics with a reference model of supervised topics. This metric is well-suited for topic assessments, as it turns out to be more strongly correlated with manual topic quality scores than existing measures for semantic coherence. We also show how it can be used for a detailed graphical topic quality assessment.

Assessing quality of unsupervised topics in song lyrics

L. Sterckx, T. Demeester, J. Deleu, L. Mertens and C. Develder


in Proc. 36th Eur. Conf. Information Retrieval (ECIR 2014), Amsterdam, The Netherlands, 13-16 Apr. 2014.

@inproceedings{Sterckx2014ECIR,
author = {Sterckx, Lucas and Demeester, Thomas and Deleu, Johannes and Mertens, Laurent and Develder, Chris},
title = {Assessing quality of unsupervised topics in song lyrics},
booktitle = {Proc. 36th Eur. Conf. Information Retrieval (ECIR 2014)},
month = {13--16 Apr.},
year = {2014},
address = {Amsterdam, The Netherlands},
doi = {10.1007/978-3-319-06028-6_55}
}

pubinproceedings

S. Van Canneyt, M. Feys, S. Schockaert, T. Demeester, C. Develder and B. Dhoedt, "Detecting newsworthy topics in Twitter", in Proc. 2nd Workshop on Social News on the Web at WWW 2014 (SNOW 2014), Seoul, Korea, 8 Apr. 2014.

Detecting newsworthy topics in Twitter

S. Van Canneyt, M. Feys, S. Schockaert, T. Demeester, C. Develder and B. Dhoedt


in Proc. 2nd Workshop on Social News on the Web at WWW 2014 (SNOW 2014), Seoul, Korea, 8 Apr. 2014.

The task of the SNOW 2014 Data Challenge is to mine Twit- ter streams to provide journalists a set of headlines and complementary information that summarize the most newswor- thy topics for a number of given time intervals. We propose a 4-step approach to solve this. First, a classifier is trained to determine whether a Twitter user is likely to post tweets about newsworthy stories. Second, tweets posted by these users during the time interval of interest are clustered into topics. For this clustering, the cosine similarity between a boosted tf-idf representation of the tweets is used. Third, we use a classifier to estimate the confidence that the obtained topics are newsworthy. Finally, for each obtained newswor- thy topic, a descriptive headline is generated together with relevant keywords, tweets and pictures. Experimental re- sults show the effectiveness of the proposed methodology.

Detecting newsworthy topics in Twitter

S. Van Canneyt, M. Feys, S. Schockaert, T. Demeester, C. Develder and B. Dhoedt


in Proc. 2nd Workshop on Social News on the Web at WWW 2014 (SNOW 2014), Seoul, Korea, 8 Apr. 2014.

@inproceedings{vancanneyt2014snow,
author = {Van Canneyt, Steven and Feys, Matthias and Schockaert, Steven and Demeester, Thomas and Develder, Chris and Dhoedt, Bart},
title = {Detecting newsworthy topics in Twitter},
booktitle = {Proc. 2nd Workshop on Social News on the Web at WWW 2014 (SNOW 2014)},
month = {8 Apr.},
year = {2014},
address = {Seoul, Korea}
}

pubarticle

B. Belter, J. Rodriguez Martinez, J. Ignacio Aznar, J. Ferrer Riera, L.M. Contreras, M. Antoniak-Lewandowska, M. Biancani, J. Buysse, C. Develder, Y. Demchenko, P. Donadio, D. Simeonidou, R. Nejabati, S. Peng, L. Drzewiecki, E. Escalona, J.A. Garcia Espin, S. Gheorghiu, M. Ghijsen, J. Gutkowski, G. Landi, G. Carrozzo, D. Parniewicz, P. Robinson and S. Soudan, "The GEYSERS optical testbed: A platform for the integration, validation and demonstration of cloud-based infrastructure services", Computer Networks, Vol. 61, Mar. 2014, pp. 197-216.

The GEYSERS optical testbed: A platform for the integration, validation and demonstration of cloud-based infrastructure services

B. Belter, J. Rodriguez Martinez, J. Ignacio Aznar, J. Ferrer Riera, L.M. Contreras, M. Antoniak-Lewandowska, M. Biancani, J. Buysse, C. Develder, Y. Demchenko, P. Donadio, D. Simeonidou, R. Nejabati, S. Peng, L. Drzewiecki, E. Escalona, J.A. Garcia Espin, S. Gheorghiu, M. Ghijsen, J. Gutkowski, G. Landi, G. Carrozzo, D. Parniewicz, P. Robinson and S. Soudan


Computer Networks, Vol. 61, Mar. 2014, pp. 197-216.

Abstract The recent evolution of cloud services is leading to a new service transformation paradigm to accommodate network infrastructures in a cost-scalable way. In this transformation, the network constitutes the key to efficiently connect users to services and applications. In this paper we describe the deployment, validation and demonstration of the optical integrated testbed for the "GEneralized architecture for dYnamic infrastructure SERviceS" (GEYSERS) project to accommodate such cloud based Infrastructure Services. The GEYSERS testbed is composed of a set of local physical testbeds allocated in the facilities of the GEYSERS partners. It is built up based on the requirements specification, architecture definition and per-layer development that constitutes the whole GEYSERS ecosystem, and validates the procedures on the GEYSERS prototypes. The testbed includes optical devices (layer 1), switches (layer 2), and IT resources deployed in different local testbeds provided by the project partners and interconnected among them to compose the whole testbed layout. The main goal of the GEYSERS testbed is twofold. On one hand, it aims at providing a validation ground for the architecture, concepts and business models proposed by GEYSERS, sustained by two main paradigms: Infrastructure as a Service (IaaS) and the coupled provisioning of optical network and IT resources. On the other hand, it is used as a demonstration platform for testing the software prototypes within the project and to demonstrate to the research and business community the project approach and solutions. In this work, we discuss our experience in the deployment of the testbed and share the results and insights learned from our trials in the process. Additionally, the paper highlights the most relevant experiments carried out in the testbed, aimed at the validation of the overall GEYSERS architecture.

The GEYSERS optical testbed: A platform for the integration, validation and demonstration of cloud-based infrastructure services

B. Belter, J. Rodriguez Martinez, J. Ignacio Aznar, J. Ferrer Riera, L.M. Contreras, M. Antoniak-Lewandowska, M. Biancani, J. Buysse, C. Develder, Y. Demchenko, P. Donadio, D. Simeonidou, R. Nejabati, S. Peng, L. Drzewiecki, E. Escalona, J.A. Garcia Espin, S. Gheorghiu, M. Ghijsen, J. Gutkowski, G. Landi, G. Carrozzo, D. Parniewicz, P. Robinson and S. Soudan


Computer Networks, Vol. 61, Mar. 2014, pp. 197-216.

@article{Belter2014,
author = {Bartosz Belter and Rodriguez Martinez, Juan and Ignacio Aznar, José and Ferrer Riera, Jordi and Contreras, Luis M. and Monika Antoniak-Lewandowska and Matteo Biancani and Jens Buysse and Chris Develder and Yuri Demchenko and Pasquale Donadio and Dimitra Simeonidou and Reza Nejabati and Shuping Peng and Lukasz Drzewiecki and Eduard Escalona and Garcia Espin, Joan Antoni and Steluta Gheorghiu and Mattijs Ghijsen and Jakub Gutkowski and Giada Landi and Gino Carrozzo and Damian Parniewicz and Philip Robinson and Sebastien Soudan},
title = {The GEYSERS optical testbed: A platform for the integration, validation and demonstration of cloud-based infrastructure services},
journal = {Computer Networks},
month = {Mar.},
year = {2014},
volume = {61},
pages = {197--216},
doi = {10.1016/j.bjp.2013.12.031}
}

pubinproceedings

T. Demeester, R. Aly, D. Hiemstra, D. Nguyen, D. Trieschnigg and C. Develder, "Exploiting user disagreement for web search evaluation: An experimental approach", in Proc. 7th ACM Int. Conf. Web Search and Data Mining (WSDM 2014), New York, NY, USA, 24-28 Feb. 2014.

Exploiting user disagreement for web search evaluation: An experimental approach

T. Demeester, R. Aly, D. Hiemstra, D. Nguyen, D. Trieschnigg and C. Develder


in Proc. 7th ACM Int. Conf. Web Search and Data Mining (WSDM 2014), New York, NY, USA, 24-28 Feb. 2014.

In order to express a more nuanced notion of relevance as compared to binary judgments, graded relevance levels can be used for the evaluation of search results. Especially in Web search, users strongly prefer top results over less relevant results, and yet they often disagree on which are the top results for a given information need. This paper proposes a method to capture this user disagreement and integrate it into the evaluation procedure.
First, we present experiments that investigate the user disagreement. After that, a probabilistic model is proposed that results in a weighting of the relevance levels with a probabilistic interpretation. This is followed by a validity analysis, and an explanation of how to integrate the model with well-established evaluation metrics. Finally, we discuss a specific application of the model, in the estimation of suitable combined page and snippet relevance weights from Web search assessments.

Exploiting user disagreement for web search evaluation: An experimental approach

T. Demeester, R. Aly, D. Hiemstra, D. Nguyen, D. Trieschnigg and C. Develder


in Proc. 7th ACM Int. Conf. Web Search and Data Mining (WSDM 2014), New York, NY, USA, 24-28 Feb. 2014.

@inproceedings{Demeester2014WSDM,
author = {Demeester, Thomas and Robin Aly and Djoerd Hiemstra and Dong Nguyen and Dolf Trieschnigg and Chris Develder},
title = {Exploiting user disagreement for web search evaluation: An experimental approach},
booktitle = {Proc. 7th ACM Int. Conf. Web Search and Data Mining (WSDM 2014)},
month = {24--28 Feb.},
year = {2014},
address = {New York, NY, USA},
note = {Acceptance rate: 17% (64/376)},
doi = {10.1145/2556195.2556268}
}

pubinproceedings

J. Aparicio, J. Rosca, M. Mediger, A. Essl, K. Arzig and C. Develder, "Exploiting road traffic data for very short term load forecasting in smart grids", in Proc. 5th IEEE PES Conf. Innovative Smart Grid Technologies (ISGT 2014), Washington, DC, USA, 19-22 Feb. 2014.

Exploiting road traffic data for very short term load forecasting in smart grids

J. Aparicio, J. Rosca, M. Mediger, A. Essl, K. Arzig and C. Develder


in Proc. 5th IEEE PES Conf. Innovative Smart Grid Technologies (ISGT 2014), Washington, DC, USA, 19-22 Feb. 2014.

If accurate short term prediction of electricity consumption is available, the Smart Grid infrastructure can rapidly and reliably react to changing conditions. The economic importance of accurate predictions justifies research for more complex forecasting algorithms. This paper proposes road traffic data as a new input dimension that can help improve very short term load forecasting. We explore the dependencies between power demand and road traffic data and evaluate the predictive power of the added dimension compared with other common features, such as historical load and temperature profiles.

Exploiting road traffic data for very short term load forecasting in smart grids

J. Aparicio, J. Rosca, M. Mediger, A. Essl, K. Arzig and C. Develder


in Proc. 5th IEEE PES Conf. Innovative Smart Grid Technologies (ISGT 2014), Washington, DC, USA, 19-22 Feb. 2014.

@inproceedings{Aparicio2014ISGT,
author = {Juan Aparicio and Justinian Rosca and Markus Mediger and Alexander Essl and Klaus Arzig and Chris Develder},
title = {Exploiting road traffic data for very short term load forecasting in smart grids},
booktitle = {Proc. 5th IEEE PES Conf. Innovative Smart Grid Technologies (ISGT 2014)},
month = {19--22 Feb.},
year = {2014},
address = {Washington, DC, USA},
doi = {10.1109/ISGT.2014.6816498}
}

pubarticle

J. Buysse, M. De Leenheer, L.M. Contreras, J.I. Aznar, J.R. Martinez, G. Landi and C. Develder, "NCP+: an integrated network and IT control plane for cloud computing", Opt. Switch. and Netw., Vol. 11B, Jan. 2014, pp. 137-152.

NCP+: an integrated network and IT control plane for cloud computing

J. Buysse, M. De Leenheer, L.M. Contreras, J.I. Aznar, J.R. Martinez, G. Landi and C. Develder


Opt. Switch. and Netw., Vol. 11B, Jan. 2014, pp. 137-152.

Cloud computing, building on the idea of “computation as a public utility” is made possible by the increased network capabilities in terms of bandwidth and reduced latency. The cloud paradigm today sees adoption in many businesses given its advantages, not only from a customer point of view (e.g., universal access to the same applications across all company branches) but also from the application provider and network operator perspective (e.g., software updates no longer need to be distributed). To be able to offer cloud computing services efficiently, service providers need not just an infrastructure comprising both network and IT resources, but especially a control system that is able to orchestrate such integrated network and IT services. This paper offers a new proposal for such a system: an enhanced network control plane, the NCP+, which is based on a GMPLS control plane with a Hierarchical Path Computation Element (PCE) architecture able to jointly make network routing and IT server provisioning decisions. Indeed, in the assumed cloud paradigm, a user generally does not care what exact server the offered service is using, as long as its service requirements are met: thus the anycast principle applies. The paper discusses (i) the archi- tecture of the NCP+, (ii) two IT-aware aggregation mechanisms to be used in the hierarchical PCE approach and (iii) routing and scheduling algorithms for those aggregation mechanisms. We conclude this work with a thorough simulation analysis of the aggregation and routing/scheduling policies showing that Full Mesh aggregation where the domain topology is represented by a complete graph, although being less scalable in terms of computation time, is able to provision efficiently using the proposed load balancing routing and scheduling policy. However, for a scenario with stringent IT requirements, Star could be used in parallel for scenarios where end-to-end setup times are important.

NCP+: an integrated network and IT control plane for cloud computing

J. Buysse, M. De Leenheer, L.M. Contreras, J.I. Aznar, J.R. Martinez, G. Landi and C. Develder


Opt. Switch. and Netw., Vol. 11B, Jan. 2014, pp. 137-152.

@article{Buysse2013OSN,
author = {Buysse, Jens and De Leenheer, Marc and Contreras, Luis Miguel and Aznar, José Ignacio and Martinez, Juan Rodriguez and Landi, Giada and Develder, Chris},
title = {NCP+: an integrated network and IT control plane for cloud computing},
journal = {Opt. Switch. and Netw.},
month = {Jan.},
year = {2014},
volume = {11B},
pages = {137--152},
doi = {10.1016/j.osn.2013.09.002}
}

pubinbook

C. Develder, M. Tornatore, M.F. Habib and B. Jaumard, "Dimensioning resilient optical grid/cloud networks", in "Communication infrastructures for cloud computing", H.T. Mouftah and B. Kantarci (Ed.), IGI Global, Sep. 2013, pp. 73-106.

Dimensioning resilient optical grid/cloud networks
in: Communication infrastructures for cloud computing

C. Develder, M. Tornatore, M.F. Habib and B. Jaumard


IGI Global, Sep. 2013, pp. 73-106.

Optical networks play a crucial role in the provisioning of grid and cloud computing services. Their high bandwidth and low latency characteristics effectively enable universal users access to computational and storage resources that thus can be fully exploited without limiting performance penalties. Given the rising importance of such cloud/grid services hosted in (remote) data centers, the various users (ranging from academics, over enterprises, to non-professional consumers) are increasingly dependent on the network connecting these data centers that must be designed to ensure maximal service avail- ability, i.e., minimizing interruptions. In this chapter, the authors outline the challenges encompassing the design, i.e., dimensioning, of large-scale backbone (optical) networks interconnecting data centers. This amounts to extensions of the classical Routing and Wavelength Assignment (RWA) algorithms to so-called anycast RWA but also pertains to jointly dimensioning not just the network but also the data center resources (i.e., servers). The authors specifically focus on resiliency, given the criticality of the grid/cloud infrastructure in today’s businesses, and, for highly critical services, they also include specific design approaches to achieve disaster resiliency.

Dimensioning resilient optical grid/cloud networks
in: Communication infrastructures for cloud computing

C. Develder, M. Tornatore, M.F. Habib and B. Jaumard


IGI Global, Sep. 2013, pp. 73-106.

@inbook{Develder2013IGI,
author = {Develder, Chris and Tornatore, Massimo and Habib, M. Farhan and Jaumard, Brigitte},
editor = {Mouftah, Hussein T. and Kantarci, Burak},
title = {Communication infrastructures for cloud computing},
chapter = {Dimensioning resilient optical grid/cloud networks},
publisher = {IGI Global},
month = {Sep.},
year = {2013},
pages = {73--106},
note = {ISBN 978-1-4666-4524-0}
}

pubinproceedings

M. Bui, B. Jaumard and C. Develder, "Anycast end-to-end resilience for cloud services over virtual optical networks" (Invited), in Proc. 15th Int. Conf. Transparent Optical Netw. (ICTON 2013), Cartagena, Spain, 23-27 Jun. 2013.

Anycast end-to-end resilience for cloud services over virtual optical networks (Invited)

M. Bui, B. Jaumard and C. Develder


in Proc. 15th Int. Conf. Transparent Optical Netw. (ICTON 2013), Cartagena, Spain, 23-27 Jun. 2013.

Optical networks are crucial to support increasingly demanding cloud services. Delivering the requested quality of services (in particular latency) is key to successfully provisioning end-to-end services in clouds. Therefore, as for traditional optical network services, it is of utter importance to guarantee that clouds are resilient to any failure of either network infrastructure (links and/or nodes) or data centers. A crucial concept in establishing cloud services is that of network virtualization: the physical infrastructure is logically partitioned in separate virtual networks. Also, combined control of the network and data center (IT) resources is exploited. To guarantee end-to-end resilience for cloud services in such a set-up, we need to simultaneously route the services and map the virtual network, in such a way that an alternate routing is always available. Note that the anycast routing concept applies: assigning server resources requested by the customer to a particular (physical) datacenter can be done transparently. This paper investigates the design of scalable optimization models to perform the virtual network mapping resiliently, thus supporting resilient anycast cloud virtual networks. We compare the approach with the previous work considering classical protection schemes.

Anycast end-to-end resilience for cloud services over virtual optical networks (Invited)

M. Bui, B. Jaumard and C. Develder


in Proc. 15th Int. Conf. Transparent Optical Netw. (ICTON 2013), Cartagena, Spain, 23-27 Jun. 2013.

@inproceedings{Bui2013,
author = {Bui, Minh and Jaumard, Brigitte and Develder, Chris},
title = {Anycast end-to-end resilience for cloud services over virtual optical networks (Invited)},
booktitle = {Proc. 15th Int. Conf. Transparent Optical Netw. (ICTON 2013)},
month = {23--27 Jun.},
year = {2013},
address = {Cartagena, Spain},
doi = {10.1109/ICTON.2013.6603032}
}

pubinbook

T. Wauters, F. De Turck and C. Develder, "Overlay networks for smart grids", in "IEEE vision for smart grid communications: 2030 and beyond", S. Goel, S.F. Bush and D. Bakken (Ed.), IEEE Standards Association, May 2013, pp. 223-249.

Overlay networks for smart grids
in: IEEE vision for smart grid communications: 2030 and beyond

T. Wauters, F. De Turck and C. Develder


IEEE Standards Association, May 2013, pp. 223-249.

Smart Grid networks imply the overlaying of the power grid network with communication networks, to enable advanced coordination mechanisms. While the main drivers for Smart Grid projects might vary from region to region (e.g., increasing penetration of distributed renewable energy production in the European Union, need for enhanced reliability in the U.S.), the key differentiators of the next generation power grid stem from the massive amounts of data distributed throughout the grid, which must be used to optimally operate the grid. Thus, the basic functions that communication networks should provide can be summarized as: 1) data acquisition from a massive amount of measurement devices and 2) sending control signals to steer consumption/generation (e.g., demand-supply matching). The data acquisition part clearly involves gathering the smart meter data from the residential meters scattered across the distribution network. But it also implies collecting the information of so-called synchrophasors, generally known as phasor measurement units (PMUs), which are devices typically installed in the transmission network that combine precise measurements of currents and voltages with accurate time recording. Applications that can make use of these measurements (both in distribution and transmission networks) have varying requirements for real- time communications. Clearly, there is a need for (distributed) control mechanisms, which also imply specific network architectures.
An overlay network is a network built on the top of the underlying network. It relies on the infrastructure of the underlying network but only uses its basic services. Overlay networks themselves provide enhanced services optimized for the class of targeted applications. Smart Grid communications requires support of application-specific resource discovery, session control, routing, addressing, and other features in order to support services specifically designed for the Smart Grid operation. Smart Grid communications applications include data acquisition, operation of Smart Grid demand/response control mechanisms, synchrophasors, end-user energy management, etc.
Some overlay networks operators book infrastructure resources through service level agreements, and other overlay networks are designed to adapt to the environment and manage Quality of Experience to compensate for lack of Quality of Service. In this chapter, we discuss both of these types of overlay networks with emphasis on IP-based overlays that tend to use underlying infrastructure opportunistically, and do not rely on availability of adequate infrastructure resources.

Overlay networks for smart grids
in: IEEE vision for smart grid communications: 2030 and beyond

T. Wauters, F. De Turck and C. Develder


IEEE Standards Association, May 2013, pp. 223-249.

@inbook{Wauters2013SGV,
author = {Wauters, Tim and De Turck, Filip and Develder, Chris},
editor = {Goel, Sanjay and Bush, Stephen F. and Bakken, David},
title = {IEEE vision for smart grid communications: 2030 and beyond},
chapter = {Overlay networks for smart grids},
publisher = {IEEE Standards Association},
month = {May},
year = {2013},
pages = {223--249},
url = {http://www.techstreet.com/ieee/products/1858760}
}

pubinproceedings

M. Strobbe, T. Verschueren, S. Melis, D. Verslype, K. Mets, F. De Turck and C. Develder, "Design of a management infrastructure for smart grid pilot data processing and analysis", in Proc. IFIP/IEEE Int. Symp. Integrated Network Management (IM 2013), Ghent, Belgium, 27-31 May 2013, pp. 547-533.

Design of a management infrastructure for smart grid pilot data processing and analysis

M. Strobbe, T. Verschueren, S. Melis, D. Verslype, K. Mets, F. De Turck and C. Develder


in Proc. IFIP/IEEE Int. Symp. Integrated Network Management (IM 2013), Ghent, Belgium, 27-31 May 2013, pp. 547-533.

Future smart grids will combine power grid tech- nologies with information and communication technologies to enable a more efficient, reliable and sustainable energy produc- tion and distribution. To realize such a smart grid, large scale pilot projects are currently implemented and evaluated. Such pilot projects generate an excessive amount of data that needs to be processed: energy measurements, information on available flexibility from smart devices that can be shifted in time, control signals, dynamic prices, environmental data, etc. To validate and analyze the gathered data and adjust the running experiments in real-time, an optimized data management infrastructure is needed as well as comprehensive visualization tools.
In this paper we present a data management infrastructure optimized for the follow up of the large scale smart grid project called Linear. In this project a pilot in over 200 households is implemented to evaluate several business cases including the balancing of renewable energy supply and the mitigation of voltage and power issues in distribution grids. By decoupling the gathering of the incoming data, the processing and storage of the data, and the data visualization and analysis on different servers, each with their own, optimized database, we obtain an efficient system for validation of the generated data in the pilot, management of the deployed set-ups and follow-up of the ongoing experiments in real-time.

Design of a management infrastructure for smart grid pilot data processing and analysis

M. Strobbe, T. Verschueren, S. Melis, D. Verslype, K. Mets, F. De Turck and C. Develder


in Proc. IFIP/IEEE Int. Symp. Integrated Network Management (IM 2013), Ghent, Belgium, 27-31 May 2013, pp. 547-533.

@inproceedings{Strobbe2013IM,
author = {Strobbe, Matthias and Verschueren, Tom and Melis, Stijn and Verslype, Dieter and Mets, Kevin and De Turck, Filip and Develder, Chris},
title = {Design of a management infrastructure for smart grid pilot data processing and analysis},
booktitle = {Proc. IFIP/IEEE Int. Symp. Integrated Network Management (IM 2013)},
month = {27--31 May},
year = {2013},
pages = {547--533},
address = {Ghent, Belgium}
}

pubinproceedings

T. Demeester, D. Nguyen, D. Trieschnigg, C. Develder and D. Hiemstra, "Snippet-based relevance predictions for federated web search", in Proc. 35th Eur. Conf. Information Retrieval (ECIR 2013), Moscow, Russia, 24-27 Mar. 2013, pp. 697-700.

Snippet-based relevance predictions for federated web search

T. Demeester, D. Nguyen, D. Trieschnigg, C. Develder and D. Hiemstra


in Proc. 35th Eur. Conf. Information Retrieval (ECIR 2013), Moscow, Russia, 24-27 Mar. 2013, pp. 697-700.

How well can the relevance of a page be predicted, purely based on snippets? This would be highly useful in a Federated Web Search setting where caching large amounts of result snippets is more feasible than caching entire pages. The experiments reported in this pa- per make use of result snippets and pages from a diverse set of actual Web search engines. A linear classifier is trained to predict the snippet- based user estimate of page relevance, but also, to predict the actual page relevance, again based on snippets alone. The presented results confirm the validity of the proposed approach and provide promising insights into future result merging strategies for a Federated Web Search setting.

Snippet-based relevance predictions for federated web search

T. Demeester, D. Nguyen, D. Trieschnigg, C. Develder and D. Hiemstra


in Proc. 35th Eur. Conf. Information Retrieval (ECIR 2013), Moscow, Russia, 24-27 Mar. 2013, pp. 697-700.

@inproceedings{Demeester2013ECIR,
author = {Demeester, Thomas and Nguyen, Dong and Trieschnigg, Dolf and Develder, Chris and Hiemstra, Djoerd},
title = {Snippet-based relevance predictions for federated web search},
booktitle = {Proc. 35th Eur. Conf. Information Retrieval (ECIR 2013)},
month = {24--27 Mar.},
year = {2013},
pages = {697--700},
address = {Moscow, Russia},
doi = {10.1007/978-3-642-36973-5_63}
}

pubarticle

J. Buysse, K. Georgakilas, A. Tzanakaki, M. De Leenheer, B. Dhoedt and C. Develder, "Energy-efficient resource provisioning algorithms for optical clouds", IEEE/OSA J. Opt. Commun. Netw., Vol. 5, No. 3, Mar. 2013, pp. 226-239.

Energy-efficient resource provisioning algorithms for optical clouds

J. Buysse, K. Georgakilas, A. Tzanakaki, M. De Leenheer, B. Dhoedt and C. Develder


IEEE/OSA J. Opt. Commun. Netw., Vol. 5, No. 3, Mar. 2013, pp. 226-239.

Rising energy costs and climate change have led to an increased concern for energy efficiency (EE). As information and communication technology is responsible for about 4% of total energy consumption worldwide, it is essential to devise policies aimed at reducing it. In this paper, we propose a routing and scheduling algorithm for a cloud architecture that targets minimal total energy consumption by enabling switching off unused network and/or information technology (IT) resources, exploiting the cloud-specific anycast principle. A detailed energy model for the entire cloud infrastructure comprising a wide-area optical network and IT resources is provided. This model is used to make a single-step decision on which IT end points to use for a given request, including the routing of the network connection toward these end points. Our simulations quantitatively assess the EE algorithm’s potential energy savings but also assess the influence this may have on traditional quality-of-service parameters such as service blocking. Furthermore, we compare the one-step scheduling with traditional scheduling and routing schemes, which calculate the resource provisioning in a two-step approach (selecting first the destination IT end point and subsequently using unicast routing toward it). We show that depending on the offered infrastructure load, our proposed one-step calculation considerably lowers the total energy consumption (reduction up to 50%) compared to the traditional iterative scheduling and routing, especially in low- to medium-load scenarios, without any significant increase in the service blocking.

Energy-efficient resource provisioning algorithms for optical clouds

J. Buysse, K. Georgakilas, A. Tzanakaki, M. De Leenheer, B. Dhoedt and C. Develder


IEEE/OSA J. Opt. Commun. Netw., Vol. 5, No. 3, Mar. 2013, pp. 226-239.

@article{Buysse2013JOCN,
author = {Buysse, Jens and Georgakilas, Kostas and Tzanakaki, Anna and De Leenheer, Marc and Dhoedt, Bart and Develder, Chris},
title = {Energy-efficient resource provisioning algorithms for optical clouds},
journal = {IEEE/OSA J. Opt. Commun. Netw.},
month = {Mar.},
year = {2013},
volume = {5},
number = {3},
pages = {226--239},
doi = {10.1364/JOCN.5.000226}
}

pubinproceedings

T. Demeester, D. Nguyen, D. Trieschnigg, C. Develder and D. Hiemstra, "What snippets say about pages in federated web search", in Proc. 8th Asia Information Retrieval Soc. Conf. (AIRS 2012), Tianjin, China, 17-19 Dec. 2012.

What snippets say about pages in federated web search

T. Demeester, D. Nguyen, D. Trieschnigg, C. Develder and D. Hiemstra


in Proc. 8th Asia Information Retrieval Soc. Conf. (AIRS 2012), Tianjin, China, 17-19 Dec. 2012.

What is the likelihood that a Web page is considered relevant to a query, given the relevance assessment of the corresponding snippet? Using a new federated IR test collection that contains search results from over a hundred search engines on the internet, we are able to investigate such research questions from a global perspective. Our test collection covers the main Web search engines like Google, Yahoo!, and Bing, as well as a number of smaller search engines dedicated to multimedia, shopping, etc., and as such reflects a realistic Web environment.
Using a large set of relevance assessments, we are able to investigate the connection between snippet quality and page relevance. The dataset is strongly inhomogeneous, and although the assessors’ consistency is shown to be satisfying, care is required when comparing resources. To this end, a number of probabilistic quantities, based on snippet and page relevance, are introduced and evaluated.

What snippets say about pages in federated web search

T. Demeester, D. Nguyen, D. Trieschnigg, C. Develder and D. Hiemstra


in Proc. 8th Asia Information Retrieval Soc. Conf. (AIRS 2012), Tianjin, China, 17-19 Dec. 2012.

@inproceedings{Demeester2012AIRS,
author = {Demeester, Thomas and Dong Nguyen and Dolf Trieschnigg and Chris Develder and Djoerd Hiemstra},
title = {What snippets say about pages in federated web search},
booktitle = {Proc. 8th Asia Information Retrieval Soc. Conf. (AIRS 2012)},
month = {17--19 Dec.},
year = {2012},
address = {Tianjin, China},
doi = {10.1007/978-3-642-35341-3_21}
}

pubarticle

Comparison of intelligent charging algorithms for electric vehicles to reduce peak load and demand variability in a distribution grid

K. Mets, R. D'hulst and C. Develder


J. Commun. Netw., Vol. 14, No. 6, Dec. 2012, pp. 672-681.

A potential breakthrough of the electrification of the vehicle fleet will incur a steep rise in the load on the electrical power grid. To avoid huge grid investments, coordinated charging of those vehicles is a must. In this paper, we assess algorithms to schedule charging of plug-in (hybrid) electric vehicles as to minimize the additional peak load they might cause. We first introduce two approaches, one based on a classical optimization approach using quadratic programming, and a second one, market based coordination, which is a multi-agent system that uses bidding on a virtual market to reach an equilibrium price that matches demand and supply. We benchmark these two methods against each other, as well as to a baseline scenario of uncontrolled charging. Our simulation results covering a residential area with 63 households show that controlled charging reduces peak load, load variability, and deviations from the nominal grid voltage.

Comparison of intelligent charging algorithms for electric vehicles to reduce peak load and demand variability in a distribution grid

K. Mets, R. D'hulst and C. Develder


J. Commun. Netw., Vol. 14, No. 6, Dec. 2012, pp. 672-681.

@article{Mets2012JCN,
author = {Mets, Kevin and D'hulst, Reinhilde and Develder, Chris},
title = {Comparison of intelligent charging algorithms for electric vehicles to reduce peak load and demand variability in a distribution grid},
journal = {J. Commun. Netw.},
month = {Dec.},
year = {2012},
volume = {14},
number = {6},
pages = {672--681},
doi = {10.1109/JCN.2012.00033}
}

pubinproceedings

L. Mertens, T. Demeester, J. Deleu, P. Demeester and C. Develder, "UGent participation in the TAC 2012 entity-linking task", in Proc. 5th Text Analysis Conf. (TAC 2012), Gaithersburg, MD, USA, 14-15 Nov. 2012.

UGent participation in the TAC 2012 entity-linking task

L. Mertens, T. Demeester, J. Deleu, P. Demeester and C. Develder


in Proc. 5th Text Analysis Conf. (TAC 2012), Gaithersburg, MD, USA, 14-15 Nov. 2012.

This article describes in detail the system used by the UGent-IBCN team for participating in the Text Analysis Conference (TAC) 2012 Mono-Lingual Entity-Linking task. The pre- sented system is essentially rule-based, following a generic framework that is highly optimised for each label (i.e. with different rules for persons, organisations, and locations). The main contribution of this work is in identifying a number of label-specific issues and presenting simple heuristic solutions that yet allow building an efficient and effective system. These treated issues include resolving abbreviated organisation names, resolving popular nicknames, or taking into account American vs British spelling.

UGent participation in the TAC 2012 entity-linking task

L. Mertens, T. Demeester, J. Deleu, P. Demeester and C. Develder


in Proc. 5th Text Analysis Conf. (TAC 2012), Gaithersburg, MD, USA, 14-15 Nov. 2012.

@inproceedings{Mertens2012TAC,
author = {Mertens, Laurent and Demeester, Thomas and Deleu, Johannes and Demeester, Piet and Develder, Chris},
title = {UGent participation in the TAC 2012 entity-linking task},
booktitle = {Proc. 5th Text Analysis Conf. (TAC 2012)},
month = {14-15 Nov.},
year = {2012},
address = {Gaithersburg, MD, USA}
}

pubinproceedings

T.H. Van Duc, T. Demeester, J. Deleu and C. Develder, "UGent participation in the Microblog Track 2012", in Proc. Text Retrieval Conf. (TREC 2012), Gaithersburg, MD, 6-9 Nov. 2012.

UGent participation in the Microblog Track 2012

T.H. Van Duc, T. Demeester, J. Deleu and C. Develder


in Proc. Text Retrieval Conf. (TREC 2012), Gaithersburg, MD, 6-9 Nov. 2012.

In this paper, we describe the search system, developed at Ghent University for the TREC 2012 Microblog Track in order to rank Twitter messages or ‘tweets’ from a fixed corpus in response to a number of search requests. Our system ranks the tweets based on a Logistic Regression classifier trained with data from the Microblog Track 2011. The features used for training the classifier include local tweets features, but also, query expansion and tweet expansion features, based on external Web data, which appear to significantly improve results.

UGent participation in the Microblog Track 2012

T.H. Van Duc, T. Demeester, J. Deleu and C. Develder


in Proc. Text Retrieval Conf. (TREC 2012), Gaithersburg, MD, 6-9 Nov. 2012.

@inproceedings{VanDuc2012TREC,
author = {Van Duc, Thong Hoang and Demeester, Thomas and Deleu, Johannes and Develder, Chris},
title = {UGent participation in the Microblog Track 2012},
booktitle = {Proc. Text Retrieval Conf. (TREC 2012)},
month = {6--9 Nov.},
year = {2012},
address = {Gaithersburg, MD}
}

pubinproceedings

K. Mets, F. De Turck and C. Develder, "Distributed smart charging of electric vehicles for balancing wind energy", in Proc. 3rd IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2012), Tainan City, Taiwan, 5-8 Nov. 2012, pp. 133-138.

Distributed smart charging of electric vehicles for balancing wind energy

K. Mets, F. De Turck and C. Develder


in Proc. 3rd IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2012), Tainan City, Taiwan, 5-8 Nov. 2012, pp. 133-138.

To meet worldwide goals of reducing CO2 footprint, electricity production increasingly is stemming from so-called renewable sources. To cater for their volatile behavior, so-called demand response algorithms are required. In this paper, we focus particularly on how charging electrical vehicles (EV) can be coordinated to maximize green energy consumption. We present a distributed algorithm that minimizes imbalance costs, and the disutility experienced by consumers. Our approach is very much practical, as it respects privacy, while still obtaining near-optimal solutions, by limiting the information exchanged: i.e. consumers do not share their preferences, deadlines, etc. Coordination is achieved through the exchange of virtual prices associated with energy consumption at certain times.
We evaluate our approach in a case study comprising 100 electric vehicles over the course of 4 weeks, where renewable energy is supplied by a small scale wind turbine. Simulation results show that 68% of energy demand can be supplied by wind energy using our distributed algorithm, compared to 73% in a
theoretical optimum scenario, and only 40% in an uncoordinated business-as-usual (BAU) scenario. Also, the increased usage of renewable energy sources, i.e. wind power, results in a 45% reduction of CO2 emissions, using our distributed algorithm.

Distributed smart charging of electric vehicles for balancing wind energy

K. Mets, F. De Turck and C. Develder


in Proc. 3rd IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2012), Tainan City, Taiwan, 5-8 Nov. 2012, pp. 133-138.

@inproceedings{Mets2012SGC,
author = {Mets, Kevin and De Turck, Filip and Develder, Chris},
title = {Distributed smart charging of electric vehicles for balancing wind energy},
booktitle = {Proc. 3rd IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2012)},
month = {5-8 Nov.},
year = {2012},
pages = {133--138},
address = {Tainan City, Taiwan},
doi = {10.1109/SmartGridComm.2012.6485972}
}

pubinproceedings

J. Nelis, T. Verschueren, D. Verslype and C. Develder, "DYAMAND: DYnamic, Adaptive MAnagement of Networks and Devices", in Proc. 37th IEEE Conf. Local Computer Networks (LCN 2012), Clearwater, FL, USA, 22-25 Oct. 2012.

DYAMAND: DYnamic, Adaptive MAnagement of Networks and Devices

J. Nelis, T. Verschueren, D. Verslype and C. Develder


in Proc. 37th IEEE Conf. Local Computer Networks (LCN 2012), Clearwater, FL, USA, 22-25 Oct. 2012.

Consumer devices increasingly are “smart” and hence offer services that can interwork with and/or be controlled by others. However, the full exploitation of the inherent opportunities this offers, is hurdled by a number of potential limitations. First of all, the interface towards the device might be vendor and even device specific, implying that extra effort is needed to support a specific device. Standardization efforts try to avoid this problem, but within a certain standard ecosystem the level of interoperability can vary (i.e. devices carrying the same standard logo are not necessarily interoperable). Secondly, different application domains (e.g. multimedia vs. energy management) today have their own standards, thus limiting trans-sector innovation because of the additional effort required to integrate devices from traditionally different domains into novel applications. In this paper, we discuss the basic components of current so-called service discovery protocols (SDPs) and present our DYAMAND (DYnamic, Adaptive MAnagement of Networks and Devices) framework. We position this framework as a middleware layer between applications and discoverable/controllable devices, and hence aim to provide the necessary tool to overcome the (intra- and inter-domain) interoperability gaps previously sketched. Thus, we believe it can act as a catalyst enabling transsector innovation.

DYAMAND: DYnamic, Adaptive MAnagement of Networks and Devices

J. Nelis, T. Verschueren, D. Verslype and C. Develder


in Proc. 37th IEEE Conf. Local Computer Networks (LCN 2012), Clearwater, FL, USA, 22-25 Oct. 2012.

@inproceedings{Nelis2012,
author = {Nelis, Jelle and Verschueren, Tom and Verslype, Dieter and Develder, Chris},
title = {DYAMAND: DYnamic, Adaptive MAnagement of Networks and Devices},
booktitle = {Proc. 37th IEEE Conf. Local Computer Networks (LCN 2012)},
month = {22--25 Oct.},
year = {2012},
address = {Clearwater, FL, USA},
doi = {10.1109/LCN.2012.6423604}
}

pubinproceedings

W. Labeeuw, S. Claessens, K. Mets, C. Develder and G. Deconinck, "Infrastructure for collaborating data-researchers in a smart grid pilot", in Proc. 3rd IEEE PES Innovative Smart Grid Technologies Europe (ISGTEU 2012), Berlin, Germany, 14-17 Oct. 2012, pp. 1-8.

Infrastructure for collaborating data-researchers in a smart grid pilot

W. Labeeuw, S. Claessens, K. Mets, C. Develder and G. Deconinck


in Proc. 3rd IEEE PES Innovative Smart Grid Technologies Europe (ISGTEU 2012), Berlin, Germany, 14-17 Oct. 2012, pp. 1-8.

A large amount of stakeholders are often involved in Smart Grid projects. Each partner has its own way of storing, representing and accessing its data. An integrated data storage and a joint online analytical mining infrastructure is needed to limit the amount of duplicated work and to raise the overall security of the system. The proposed infrastructure is composed of standard application software and an in-house developed data analysis tool that allows researchers to add and share their own functionality without compromising security.

Infrastructure for collaborating data-researchers in a smart grid pilot

W. Labeeuw, S. Claessens, K. Mets, C. Develder and G. Deconinck


in Proc. 3rd IEEE PES Innovative Smart Grid Technologies Europe (ISGTEU 2012), Berlin, Germany, 14-17 Oct. 2012, pp. 1-8.

@inproceedings{Labeeuw2012,
author = {Wouter Labeeuw and Sven Claessens and Kevin Mets and Develder, Chris and Geert Deconinck},
title = {Infrastructure for collaborating data-researchers in a smart grid pilot},
booktitle = {Proc. 3rd IEEE PES Innovative Smart Grid Technologies Europe (ISGTEU 2012)},
month = {14--17 Oct.},
year = {2012},
pages = {1--8},
address = {Berlin, Germany},
doi = {10.1109/ISGTEurope.2012.6465728}
}

pubinproceedings

C. Develder, J. Buysse and B. Jaumard, "Designing resilient optical grids/clouds" (Invited), in Proc. Photonics in Switching (PS 2012), Ajaccio, Corse, France, 11 Sep. 2012.

Designing resilient optical grids/clouds (Invited)

C. Develder, J. Buysse and B. Jaumard


in Proc. Photonics in Switching (PS 2012), Ajaccio, Corse, France, 11 Sep. 2012.

We address the problem of dimensioning infrastructure, comprising both network and server resources, for large-scale decentralized distributed systems such as grids or clouds. We will provide an overview of our work in this area, and in particular focus on how to design the resulting grid/cloud to be resilient against network link and/or server site failures. To this end, we will exploit relocation: under failure conditions, a request may be sent to an alternate destination than the one under failure-free conditions.

Designing resilient optical grids/clouds (Invited)

C. Develder, J. Buysse and B. Jaumard


in Proc. Photonics in Switching (PS 2012), Ajaccio, Corse, France, 11 Sep. 2012.

@inproceedings{Develder2012PS,
author = {Develder, Chris and Buysse, Jens and Jaumard, Brigitte},
title = {Designing resilient optical grids/clouds (Invited)},
booktitle = {Proc. Photonics in Switching (PS 2012)},
month = {11 Sep.},
year = {2012},
address = {Ajaccio, Corse, France}
}

pubarticle

B. Vankeirsbilck, D. Verslype, N. Staelens, P. Simoens, C. Develder, B. Dhoedt, F. De Turck and P. Demeester, "Automatic fine-grained area detection for thin client systems", J. Netw. Comput. Appl., Vol. 35, No. 5, Sep. 2012, pp. 1620-1632.

Automatic fine-grained area detection for thin client systems

B. Vankeirsbilck, D. Verslype, N. Staelens, P. Simoens, C. Develder, B. Dhoedt, F. De Turck and P. Demeester


J. Netw. Comput. Appl., Vol. 35, No. 5, Sep. 2012, pp. 1620-1632.

The widespread availability of cloud infrastructures is fueling new interest in the thin client computing paradigm. However, current thin client protocols are not designed to handle new content types as often encountered in state-of-the-art applications (e.g. multimedia editing, gaming, multimedia playback). Conveying this content using traditional thin client protocols typically results in a combination of excessive resource usage and low visual quality. In this paper, we propose an approach where the content type can vary for different portions of the screen (e.g. combination of static text and video). Once the different content types have been detected, each of them can be encoded using the most appropriate algorithm. We present two algorithms for this runtime detection. The first algorithm is operating at the pixel level, thereby being independent of the actual thin client protocol used. The second algorithm assumes the presence of a rectangle-based thin client protocol (such as the popular VNC protocol), trading independence for improved performance. The appropriate parameter settings for these algorithms are experimentally determined. Furthermore, their influence is studied in detail in terms of detection accuracy, and the time to perform the algorithms is analysed. Accurate hints are derived within less than 10 ms, indicating the high potential of this approach for use in next generation thin client systems.

Automatic fine-grained area detection for thin client systems

B. Vankeirsbilck, D. Verslype, N. Staelens, P. Simoens, C. Develder, B. Dhoedt, F. De Turck and P. Demeester


J. Netw. Comput. Appl., Vol. 35, No. 5, Sep. 2012, pp. 1620-1632.

@article{Vankeirsbilck2012JCNA,
author = {Vankeirsbilck, Bert and Verslype, Dieter and Staelens, Nicolas and Simoens, Pieter and Develder, Chris and Dhoedt, Bart and De Turck, Filip and Demeester, Piet},
title = {Automatic fine-grained area detection for thin client systems},
journal = {J. Netw. Comput. Appl.},
month = {Sep.},
year = {2012},
volume = {35},
number = {5},
pages = {1620--1632},
doi = {10.1016/j.jnca.2012.03.007}
}

pubinproceedings

C. Develder, E. Varvarigos, A. Jukan and D. Simeonidou, "Topic 13: High performance network and communication", Springer-Verlag, in Proc. 18th Int. Euro-Par Conf. Parallel Processing (Euro-Par 2012), Rhodes Island, Greece, 27-31 Aug. 2012, pp. 700-700.

Topic 13: High performance network and communication

C. Develder, E. Varvarigos, A. Jukan and D. Simeonidou


Springer-Verlagin Proc. 18th Int. Euro-Par Conf. Parallel Processing (Euro-Par 2012), Rhodes Island, Greece, 27-31 Aug. 2012, pp. 700-700.

This topic on High-Performance Network and Communication is devoted to communication issues in scalable compute and storage systems, such as parallel computers, networks of workstations, and clusters. All aspects of communication in modern systems were solicited, including advances in the design, implementation, and evaluation of interconnection networks, network interfaces, system and storage area networks, on-chip interconnects, communication protocols, routing and communication algorithms, and communication aspects of parallel and distributed algorithms.

Topic 13: High performance network and communication

C. Develder, E. Varvarigos, A. Jukan and D. Simeonidou


Springer-Verlagin Proc. 18th Int. Euro-Par Conf. Parallel Processing (Euro-Par 2012), Rhodes Island, Greece, 27-31 Aug. 2012, pp. 700-700.

@inproceedings{Develder2012EuroPar,
author = {Develder, Chris and Varvarigos, Emmanouel and Jukan, Admela and Simeonidou, Dimitra},
title = {Topic 13: High performance network and communication},
booktitle = {Proc. 18th Int. Euro-Par Conf. Parallel Processing (Euro-Par 2012)},
publisher = {Springer-Verlag},
month = {27--31 Aug.},
year = {2012},
pages = {700--700},
address = {Rhodes Island, Greece},
doi = {10.1007/978-3-642-32820-6_69}
}

pubinproceedings

G. Landi, N. Ciulli, J. Buysse, K. Georgakilas, M. Anastasopoulos, A. Tzanakaki, C. Develder, E. Escalona, D. Parniewicz, A. Binczewski and B. Belter, "A network control plane architecture for on-demand co-provisioning of optical network and IT services", in Proc. Future Netw. Mobile Summit (FNMS 2012), Berlin, Germany, 4-6 Jul. 2012.

A network control plane architecture for on-demand co-provisioning of optical network and IT services

G. Landi, N. Ciulli, J. Buysse, K. Georgakilas, M. Anastasopoulos, A. Tzanakaki, C. Develder, E. Escalona, D. Parniewicz, A. Binczewski and B. Belter


in Proc. Future Netw. Mobile Summit (FNMS 2012), Berlin, Germany, 4-6 Jul. 2012.

The convergence between IT and optical network services is a fundamental step to support new emerging applications, typically distributed and with strict requirements in terms of performance and service reliability. The FP7 GEYSERS project has designed a new network architecture capable of joint and on-demand provisioning of ‘Optical Network + Any-IT’ resources for end-to-end service delivery. This service, referred to as Network + IT Provisioning Service (NIPS), is enabled through the cross-layer cooperation between the Service Middleware Layer (SML) and an enhanced Network Control Plane (NCP+) along the overall service lifecycle. This paper describes the GEYSERS NCP+ architecture that extends standard ASON/GMPLS and PCE solutions to operate over a virtual optical network infrastructure and offer on-demand provisioning of enhanced network transport services between virtual IT resources connected to the network edges. In the proposed architecture, some of the functionalities traditionally provided by the SML, like the selection of the IT end-points, are moved to the NCP+ side, allowing global optimization of the utilization of network and IT resources and of energy consumption. Simulation results are provided to evaluate the benefits of the combined computation of IT end-points and network paths, both in terms of reduced service blocking probability and utilization of the infrastructure resources.

A network control planearchitecture for on-demand co-provisioning of optical network and IT services

G. Landi, N. Ciulli, J. Buysse, K. Georgakilas, M. Anastasopoulos, A. Tzanakaki, C. Develder, E. Escalona, D. Parniewicz, A. Binczewski and B. Belter


in Proc. Future Netw. Mobile Summit (FNMS 2012), Berlin, Germany, 4-6 Jul. 2012.

@inproceedings{Landi2012FNMS,
author = {Landi, Giada and Ciulli, Nicola and Buysse, Jens and Georgakilas, Konstantinos and Anastasopoulos, Markos and Tzanakaki, Anna and Develder, Chris and Escalona, Eduard and Parniewicz, Damian and Binczewski, Artur and Belter, Bartosz},
title = {A Network Control Plane architecture for on-demand co-provisioning of optical network and IT services},
booktitle = {Proc. Future Netw. Mobile Summit (FNMS 2012)},
month = {4--6 Jul.},
year = {2012},
address = {Berlin, Germany}
}

pubinproceedings

B. Jaumard, A. Shaikh and C. Develder, "Selecting the best locations for data centers in resilient optical grid/cloud dimensioning" (Invited), in Proc. 14th Int. Conf. Transparent Optical Netw. (ICTON 2012), Coventry, UK, 2-5 Jul. 2012.

Selecting the best locations for data centers in resilient optical grid/cloud dimensioning (Invited Paper)

B. Jaumard, A. Shaikh and C. Develder


in Proc. 14th Int. Conf. Transparent Optical Netw. (ICTON 2012), Coventry, UK, 2-5 Jul. 2012.

For optical grid/cloud scenarios, the dimensioning problem comprises not only deciding on the network dimensions (i.e., link bandwidths), but also choosing appropriate locations to install server infrastructure (i.e., data centers), as well as determining the amount of required server resources (for storage and/or processing). Given that users of such grid/cloud systems in general do not care about the exact physical locations of the server resources, a degree of freedom arises in choosing for each of their requests the most appropriate server location. We will exploit this anycast routing principle (i.e., source of traffic is given, but destination can be chosen rather freely) also to provide resilience: traffic may be relocated to alternate destinations in case of network/server failures. In this study, we propose to jointly optimize the link dimensioning and the location of the servers in an optical grid/cloud, where the anycast principle is applied for resiliency against either link or server node failures. While the data center location problem has some resemblance with either the classical p-center or k-means location problems, the anycast principle makes it much more difficult due to the requirement of link disjoint paths for ensuring grid resiliency.

Selecting the best locations for data centers in resilient optical grid/cloud dimensioning (Invited Paper)

B. Jaumard, A. Shaikh and C. Develder


in Proc. 14th Int. Conf. Transparent Optical Netw. (ICTON 2012), Coventry, UK, 2-5 Jul. 2012.

@inproceedings{Jaumard2012ICTON,
author = {Jaumard, Brigitte and Shaikh, Ali and Develder, Chris},
title = {Selecting the best locations for data centers in resilient optical grid/cloud dimensioning (Invited Paper)},
booktitle = {Proc. 14th Int. Conf. Transparent Optical Netw. (ICTON 2012)},
month = {2--5 Jul.},
year = {2012},
address = {Coventry, UK},
doi = {10.1109/ICTON.2012.6253739}
}

pubinproceedings

J. Ferrer Riera, García-Espín, S. Figuerola, J. Buysse, M. De Leenheer, C. Develder and S. Peng, "Converged IT and optical network virtualisation: The last (clean-)step towards the future internet infrastructure management", in Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I 2012), Vilanova i la Geltru, Spain, 20-22 Jun. 2012.

Converged IT and optical network virtualisation: The last (clean-)step towards the future internet infrastructure management

J. Ferrer Riera, García-Espín, S. Figuerola, J. Buysse, M. De Leenheer, C. Develder and S. Peng


in Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I 2012), Vilanova i la Geltru, Spain, 20-22 Jun. 2012.

The last evolutions of the Internet bring the fact that all the emergence of novel applications, requirements, services, roles, and the challenges associated to them is being built on top of the same Internet that was designed for handling completely different elements. Converged, both Information Technology (IT) and optical network, infrastructure resource virtualisation is currently one of the most promising approaches to face the Future Internet challenges. The major research problem associated to infrastructure resource virtualisation is the virtual resource embedding problem. This article presents the grouped Virtual Infrastructure (VI) mapping approach, contextualised within the Generalised Architecture for Dynamic Infrastructure Services (GEYSERS) virtual infrastructure service provisioning framework. Our findings show that batched VI mapping strategy enhances the amount of virtual entities to be allocated on top of the physical substrate. The technological solution presented and the simulation of potential benefits show a novel Information and Communication Technology (ICT) infrastructure control and management solution that is able to accomodate the optimisation requirements for the Future Internet, such as cost, energy, availability, or flexibility, in coordination with application deployments and cloud service models.

Converged IT and optical network virtualisation: The last (clean-)step towards the future internet infrastructure management

J. Ferrer Riera, García-Espín, S. Figuerola, J. Buysse, M. De Leenheer, C. Develder and S. Peng


in Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I 2012), Vilanova i la Geltru, Spain, 20-22 Jun. 2012.

@inproceedings{FerrerRiera2012NOC,
author = {Ferrer Riera, Jordi and García-Espín and Sergi Figuerola and Jens Buysse and De Leenheer, Marc and Develder, Chris and Shuping Peng},
title = {Converged IT and optical network virtualisation: the last (clean-)step towards the future internet infrastructure management},
booktitle = {Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I 2012)},
month = {20--22 Jun.},
year = {2012},
address = {Vilanova i la Geltru, Spain},
doi = {10.1109/NOC.2012.6249916}
}

pubinproceedings

C. Develder, J. Buysse, M. De Leenheer, B. Jaumard and B. Dhoedt, "Resilient network dimensioning for optical grid/clouds using relocation" (Invited), in Proc. Workshop on New Trends in Optical Networks Survivability, at IEEE Int. Conf. on Commun. (ICC 2012), Ottawa, Ontario, Canada, 11 Jun. 2012.

Resilient network dimensioning for optical grid/clouds using relocation (Invited Paper)

C. Develder, J. Buysse, M. De Leenheer, B. Jaumard and B. Dhoedt


in Proc. Workshop on New Trends in Optical Networks Survivability, at IEEE Int. Conf. on Commun. (ICC 2012), Ottawa, Ontario, Canada, 11 Jun. 2012.

In this paper we address the problem of dimensioning infrastructure, comprising both network and server resources, for large-scale decentralized distributed systems such as grids or clouds. We will provide an overview of our work in this area, and in particular focus on how to design the resulting grid/cloud to be resilient against network link and/or server site failures. To this end, we will exploit relocation: under failure conditions, a request may be sent to an alternate destination than the one under failure-free conditions. We will provide a comprehensive overview of related work in this area, and focus in some detail on our own most recent work. The latter comprises a case study where traffic has a known origin, but we assume a degree of freedom as to where its end up being processed, which is typically the case for e.g., grid applications of the bag-of-tasks (BoT) type or for providing cloud services. In particular, we will provide in this paper a new integer linear programming (ILP) formulation to solve the resilient grid/cloud dimensioning problem using failure-dependent backup routes. Our algorithm will simultaneously decide on server and network capacity. We find that in the anycast routing problem we address, the benefit of using failure-dependent (FD) rerouting is limited compared to failure-independent (FID) backup routing. We confirm our earlier findings in terms of network capacity savings achieved by relocation compared to not exploiting relocation (order of 6--10% in the current case studies).

Resilient network dimensioning for optical grid/clouds using relocation (Invited Paper)

C. Develder, J. Buysse, M. De Leenheer, B. Jaumard and B. Dhoedt


in Proc. Workshop on New Trends in Optical Networks Survivability, at IEEE Int. Conf. on Commun. (ICC 2012), Ottawa, Ontario, Canada, 11 Jun. 2012.

@inproceedings{Develder2012ICC,
author = {Develder, Chris and Buysse, Jens and De Leenheer, Marc and Jaumard, Brigitte and Dhoedt, Bart},
title = {Resilient network dimensioning for optical grid/clouds using relocation (Invited Paper)},
booktitle = {Proc. Workshop on New Trends in Optical Networks Survivability, at IEEE Int. Conf. on Commun. (ICC 2012)},
month = {11 Jun.},
year = {2012},
address = {Ottawa, Ontario, Canada},
doi = {10.1109/ICC.2012.6364981}
}

pubinproceedings

J.A. García-Espín, J. Ferrer Riera, S. Figuerola, M. Ghijsen, Y. Demchemko, J. Buysse, M. De Leenheer, C. Develder, F. Anhalt and S. Soudan, "Logical infrastructure composition layer, the GEYSERS holistic approach for infrastructure virtualisation", in Proc. TERENA Networking Conference (TNC 2012), Reykjavík, Iceland, 21-24 May 2012.

Logical infrastructure composition layer, the GEYSERS holistic approach for infrastructure virtualisation

J.A. García-Espín, J. Ferrer Riera, S. Figuerola, M. Ghijsen, Y. Demchemko, J. Buysse, M. De Leenheer, C. Develder, F. Anhalt and S. Soudan


in Proc. TERENA Networking Conference (TNC 2012), Reykjavík, Iceland, 21-24 May 2012.

This article presents the Logical Infrastructure Composition Layer as a solution produced in the context of the European project GEYSERS for ICT infrastructure virtualisation in the Future Internet. The concepts behind this layer are based on infrastructure resources virtualisation, regardless of their nature (either IT or network); the Resources-Ownership-Roles-Actors model for virtualised resources access and the concept of the Virtual Infrastructure and its management attributes. This article provides an overview on them. After that, the work is focused on the Virtual-to-Physical Infrastructure mapping problem and different options to allocate Virtual Infrastructures over the same substrate. Finally we present the grouped VI mapping strategy and its analysis, depending on the utility function considered and the context conditions. Our findings show that batched VI mapping strategy enhances the amount of VIs to be allocated on the physical substrate. The technological solution and simulations on the potential benefits show a novel ICT infrastructure control and management solution that is able to accommodate the optimisation requirements for the Future Internet (cost, energy, availability, flexibility, etc.) in coordination with application deployments and cloud service models.

Logical infrastructure composition layer, the GEYSERS holistic approach for infrastructure virtualisation

J.A. García-Espín, J. Ferrer Riera, S. Figuerola, M. Ghijsen, Y. Demchemko, J. Buysse, M. De Leenheer, C. Develder, F. Anhalt and S. Soudan


in Proc. TERENA Networking Conference (TNC 2012), Reykjavík, Iceland, 21-24 May 2012.

@inproceedings{GarciaEspin2012TNC,
author = {García-Espín, Joan A. and Ferrer Riera, Jordi and Figuerola, Sergi and Mattijs Ghijsen and Yuri Demchemko and Buysse, Jens and De Leenheer, Marc and Develder, Chris and Fabienne Anhalt and Sébastien Soudan},
title = {Logical Infrastructure Composition Layer, the GEYSERS holistic approach for infrastructure virtualisation},
booktitle = {Proc. TERENA Networking Conference (TNC 2012)},
month = {21--24 May},
year = {2012},
address = {Reykjavík, Iceland}
}

pubinproceedings

M. Strobbe, T. Verschueren, K. Mets, S. Melis, C. Develder, F. De Turck, T. Pollet and S. Van de Veire, "Design and evaluation of an architecture for future smart grid service provisioning", in Proc. 4th IEEE/IFIP Int. Workshop on Management of the Future Internet (ManFI 2012), Maui, Hawaii, USA, 16 Apr. 2012, pp. 1203-1206.

Design and evaluation of an architecture for future smart grid service provisioning

M. Strobbe, T. Verschueren, K. Mets, S. Melis, C. Develder, F. De Turck, T. Pollet and S. Van de Veire


in Proc. 4th IEEE/IFIP Int. Workshop on Management of the Future Internet (ManFI 2012), Maui, Hawaii, USA, 16 Apr. 2012, pp. 1203-1206.

The current Internet evolves to a true Internet of Things where a plethora of heterogeneous devices are connected, communicate with each other and allow the deployment of new intelligent services, creating new ecosystems in diverse domains. One such a domain is the power grid. The increase of distributed renewable electricity generation, e.g. solar cells and wind turbines, requires new energy management systems where real-time measurements and communication between end users, suppliers and utilities are vital. To address this need, we propose a common service architecture that allows houses with renewable energy generation and smart energy devices to plug into a distributed energy management system, integrated with the public power grid. The presented architecture facilitates end-users to optimize their energy consumption, enables power network operators to better balance supply and demand, and creates a platform where new market players (e.g. ESCOs) can easily provide new services. This service architecture has been implemented and is currently evaluated in a field trial with 21 users, of which we present the initial results.

Design and evaluation of an architecture for future smart grid service provisioning

M. Strobbe, T. Verschueren, K. Mets, S. Melis, C. Develder, F. De Turck, T. Pollet and S. Van de Veire


in Proc. 4th IEEE/IFIP Int. Workshop on Management of the Future Internet (ManFI 2012), Maui, Hawaii, USA, 16 Apr. 2012, pp. 1203-1206.

@inproceedings{Strobbe2012ManFI,
author = {Strobbe, Matthias and Verschueren, Tom and Mets, Kevin and Melis, Stijn and Develder, Chris and De Turck, Filip and Pollet, Thierry and Van de Veire, Stijn},
title = {Design and evaluation of an architecture for future smart grid service provisioning},
booktitle = {Proc. 4th IEEE/IFIP Int. Workshop on Management of the Future Internet (ManFI 2012)},
month = {16 Apr.},
year = {2012},
pages = {1203--1206},
address = {Maui, Hawaii, USA},
doi = {10.1109/NOMS.2012.6212052}
}

pubinproceedings

K. Mets, M. Strobbe, T. Verschueren, T. Roelens, C. Develder and F. De Turck, "Distributed multi-agent algorithm for residential energy management in smart grids", in Proc. IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2012), Maui, Hawaii, USA, 16-20 Apr. 2012.

Distributed multi-agent algorithm for residential energy management in smart grids

K. Mets, M. Strobbe, T. Verschueren, T. Roelens, C. Develder and F. De Turck


in Proc. IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2012), Maui, Hawaii, USA, 16-20 Apr. 2012.

Distributed renewable power generators, such as solar cells and wind turbines are difficult to predict, making the demand-supply problem more complex than in the traditional energy production scenario. They also introduce bidirectional energy flows in the low-voltage power grid, possibly causing voltage violations and grid instabilities. In this article we describe a distributed algorithm for residential energy management in smart power grids. This algorithm consists of a market-oriented multi-agent system using virtual energy prices, levels of renewable energy in the real-time production mix, and historical price information, to achieve a shifting of loads to periods with a high production of renewable energy. Evaluations in our smart grid simulator for three scenarios show that the designed algorithm is capable of improving the self consumption of renewable energy in a residential area and reducing the average and peak loads for externally supplied power.

Distributed multi-agent algorithm for residential energy management in smart grids

K. Mets, M. Strobbe, T. Verschueren, T. Roelens, C. Develder and F. De Turck


in Proc. IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2012), Maui, Hawaii, USA, 16-20 Apr. 2012.

@inproceedings{Mets2012NOMS,
author = {Kevin Mets and Matthias Strobbe and Tom Verschueren and Thomas Roelens and Chris Develder and De Turck, Filip},
title = {Distributed multi-agent algorithm for residential energy management in smart grids},
booktitle = {Proc. IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2012)},
month = {16--20 Apr.},
year = {2012},
address = {Maui, Hawaii, USA},
doi = {10.1109/NOMS.2012.6211928}
}

pubinproceedings

M. Strobbe, K. Mets, M. Tahon, M. Tilman, F. Spiessens, J. Gheerardyn, K. De Craemer, S. Vandael, K. Geebelen, B. Lagaisse, B. Claessens and C. Develder, "Smart and secure charging of electric vehicles in public parking spaces", in Proc. 4th Int. Conf. Innovation for Sustainable Production (i-SUP 2012), Bruges, Belgium, 6-9 May 2012.

Smart and secure charging of electric vehicles in public parking spaces

M. Strobbe, K. Mets, M. Tahon, M. Tilman, F. Spiessens, J. Gheerardyn, K. De Craemer, S. Vandael, K. Geebelen, B. Lagaisse, B. Claessens and C. Develder


in Proc. 4th Int. Conf. Innovation for Sustainable Production (i-SUP 2012), Bruges, Belgium, 6-9 May 2012.

Governments worldwide are starting to give incentives to promote the use of (hybrid) electrical vehicles to achieve cleaner and more energy-efficient road transport with a low carbon footprint. Through tax/VAT reductions and free additional services — such as free parking, and/or battery charging or lower traffic congestion taxes — private users, public organizations and car fleet operators are stimulated to adopt the plug-in (hybrid) electrical vehicle (PHEV). This upcoming breakthrough of PHEVs will impose various challenges to the power grid, such as a significant increase of the load in residential areas and parking spaces as the limited range requires frequent charging. Another challenge is the seamless driver and car identification and fraud-sensitive measuring of the charged energy anywhere a car is charged. On the other hand new opportunities are created as these vehicles allow the storage of power on a wide scale, and typically offer some flexibility during the charging process which can be exploited by smart charging services to balance demand and supply or maximize the local consumption of renewable energy. In this paper we discuss the main actors involved in the charging of leased cars in public parking spaces. We present a novel service architecture and detail the security aspects. Furthermore we discuss how a market-based smart charging algorithm that is plugged into the architecture can exploit the flexibility of the parked cars to maximize the consumption of local generated wind energy. We conclude this paper with the presentation of a new business model for the smart charging of leased cars in public parking spaces, detailing the different actors and value flows.

Smart and secure charging of electric vehicles in public parking spaces

M. Strobbe, K. Mets, M. Tahon, M. Tilman, F. Spiessens, J. Gheerardyn, K. De Craemer, S. Vandael, K. Geebelen, B. Lagaisse, B. Claessens and C. Develder


in Proc. 4th Int. Conf. Innovation for Sustainable Production (i-SUP 2012), Bruges, Belgium, 6-9 May 2012.

@inproceedings{Strobbe2012iSUP,
author = {Strobbe, Matthias and Mets, Kevin and Tahon, M. and Tilman, M. and Spiessens, F. and Gheerardyn, J. and De Craemer, K. and Vandael, S. and Geebelen, K. and Lagaisse, B. and Claessens, B. and Develder, Chris},
title = {Smart and secure charging of electric vehicles in public parking spaces},
booktitle = {Proc. 4th Int. Conf. Innovation for Sustainable Production (i-SUP 2012)},
month = {6--9 May},
year = {2012},
address = {Bruges, Belgium}
}

pubarticle

C. Develder, M. De Leenheer, B. Dhoedt, M. Pickavet, D. Colle, F. De Turck and P. Demeester, "Optical networks for grid and cloud computing applications", Proc. IEEE, Vol. 100, No. 5, May 2012, pp. 1149-1167.

Optical networks for grid and cloud computing applications

C. Develder, M. De Leenheer, B. Dhoedt, M. Pickavet, D. Colle, F. De Turck and P. Demeester


Proc. IEEE, Vol. 100, No. 5, May 2012, pp. 1149-1167.

The evolution towards grid and cloud computing as observed for over a decennium illustrates the crucial role played by (optical) networks in supporting today’s applications. In this paper, we start from an overview of the challenging applications in both academic (further referred to as scientific), enterprise (business) and non-professional user (consumer) domains. They pose novel challenges, calling for efficient interworking of IT resources, for both processing and storage, as well as the network that interconnects them and provides access to their users. We outline those novel applications’ requirements, including sheer performance attributes (which will determine the quality as perceived by end users of the cloud applications), as well as the ability to adapt to changing demands (usually referred to as elasticity) and possible failures (i.e., resilience). In outlining the foundational concepts that provide the building blocks for grid/cloud solutions that meet the stringent application requirements we highlight, a prominent role is played by optical networking. The pieces of the solution studied in this respect span the optical transport layer as well as mechanisms located in higher layers (e.g., anycast routing, virtualization), and their interworking (e.g. through appropriate control plane extensions and middleware). Based on this study, we conclude by identifying challenges and research opportunities that can enable future-proof optical cloud systems (e.g., pushing the virtualization paradigms to optical networks).

Optical networks for grid and cloud computing applications

C. Develder, M. De Leenheer, B. Dhoedt, M. Pickavet, D. Colle, F. De Turck and P. Demeester


Proc. IEEE, Vol. 100, No. 5, May 2012, pp. 1149-1167.

@article{Develder2012ProcIEEE,
author = {Develder, Chris and De Leenheer, Marc and Dhoedt, Bart and Pickavet, Mario and Colle, Didier and De Turck, Filip and Demeester, Piet},
title = {Optical networks for grid and cloud computing applications},
journal = {Proc. IEEE},
month = {May},
year = {2012},
volume = {100},
number = {5},
pages = {1149--1167},
doi = {10.1109/JPROC.2011.2179629}
}

pubinproceedings

L. Mertens, T. Demeester, J. Deleu, C. Develder and P. Demeester, "Context-based person identification for news collections", in Proc. 12th Dutch-Belgian Information Retrieval Workshop (DIR 2012), Ghent, Belgium, 23-24 Feb. 2012, pp. 26-29.

Context-based person identification for news collections

L. Mertens, T. Demeester, J. Deleu, C. Develder and P. Demeester


in Proc. 12th Dutch-Belgian Information Retrieval Workshop (DIR 2012), Ghent, Belgium, 23-24 Feb. 2012, pp. 26-29.

In modern automated information extraction systems, Named Entity Disambiguation (NED) techniques are becoming increasingly important. The ambiguity of person names leads to a decrease in the output quality of search engines. This paper presents a two-stage rule-based NED model, based on a local and global context of the mentioned persons. A number of experiments with different scoring functions are reported, as well as a specific evaluation method to estimate the efficiency of the model on a real-life data collection in an unsupervised way.

Context-based person identification for news collections

L. Mertens, T. Demeester, J. Deleu, C. Develder and P. Demeester


in Proc. 12th Dutch-Belgian Information Retrieval Workshop (DIR 2012), Ghent, Belgium, 23-24 Feb. 2012, pp. 26-29.

@inproceedings{Mertens2012,
author = {Mertens, Laurent and Demeester, Thomas and Deleu, Johannes and Develder, Chris and Demeester, Piet},
title = {Context-based person identification for news collections},
booktitle = {Proc. 12th Dutch-Belgian Information Retrieval Workshop (DIR 2012)},
month = {23--24 Feb.},
year = {2012},
pages = {26--29},
address = {Ghent, Belgium}
}

pubinproceedings

T.H. Van Duc, T. Demeester, C. Develder and H. Shin, "Effectiveness of learning to rank for finding user similarity in social media", in Proc. 12th Dutch-Belgian Information Retrieval Workshop (DIR 2012), Ghent, Belgium, 23-24 Feb. 2012, pp. 30-33.

Effectiveness of learning to rank for finding user similarity in social media

T.H. Van Duc, T. Demeester, C. Develder and H. Shin


in Proc. 12th Dutch-Belgian Information Retrieval Workshop (DIR 2012), Ghent, Belgium, 23-24 Feb. 2012, pp. 30-33.

This paper focuses on an automatic and accurate approach for finding similar users in social networks. Many types of social networks could benefit from such techniques, but the focus in this paper is on online photo services. The similarity between users needs to be considered on two different levels, i.e., the semantic similarity (or correspondence in tagging behavior), and the similarity in terms of social relations. In recent work, heuristic formulas were introduced for the tag commonness (TC) and the link strength (LS), with an adaptive combination scheme to describe how relevant each of these similarity aspects are for particular users, in order to define the user similarity. This paper presents an experiment, where a Learning-to-Rank approach is used to find suitable combinations of TC and LS related parameter values, hence taking into account the proficiency of users to tag their photos, and their noticeability in the online community, in order to obtain an overall user similarity. The user experiments show that the results with this learning-to-rank approach are significantly better than with a former, heuristic, approach.

Effectiveness of learning to rank for finding user similarity in social media

T.H. Van Duc, T. Demeester, C. Develder and H. Shin


in Proc. 12th Dutch-Belgian Information Retrieval Workshop (DIR 2012), Ghent, Belgium, 23-24 Feb. 2012, pp. 30-33.

@inproceedings{VanDuc2012DIR,
author = {Van Duc, Thong Hoang and Demeester, Thomas and Develder, Chris and Shin, Hyoseop},
title = {Effectiveness of learning to rank for finding user similarity in social media},
booktitle = {Proc. 12th Dutch-Belgian Information Retrieval Workshop (DIR 2012)},
month = {23--24 Feb.},
year = {2012},
pages = {30--33},
address = {Ghent, Belgium}
}

pubinproceedings

M. De Leenheer, J. Buysse, C. Develder and B. Mukherjee, "Isolation and resource efficiency of virtual optical networks", in Proc. Int. Conf. Computing, Networking and Communications (ICNC 2012), Maui, Hawaii, USA, 30 Jan. - 2 Feb. 2012.

Isolation and resource efficiency of virtual optical networks

M. De Leenheer, J. Buysse, C. Develder and B. Mukherjee


in Proc. Int. Conf. Computing, Networking and Communications (ICNC 2012), Maui, Hawaii, USA, 30 Jan. - 2 Feb. 2012.

Virtualization of optical networking infrastructure is considered a fundamental technology in the future Internet. A key principle is that virtual networks are isolated to coexist on a shared physical substrate without interference. Although a very attractive proposition for virtual network operators and users, in this paper we demonstrate that realizing complete isolation by partitioning resources is wasteful. Therefore, we propose to group virtual network requests in clusters: within a cluster, bandwidth can be shared, whereas different cluster are properly isolated. Results indicate that intelligent isolation and design of virtual networks can lead to substantial savings of optical network resources compared to a fully isolated approach. Finally, we demonstrate the trade-off between network resource utilization and control plane scalability.

Isolation and resource efficiency of virtual optical networks

M. De Leenheer, J. Buysse, C. Develder and B. Mukherjee


in Proc. Int. Conf. Computing, Networking and Communications (ICNC 2012), Maui, Hawaii, USA, 30 Jan. - 2 Feb. 2012.

@inproceedings{DeLeenheer2012ICNC,
author = {De Leenheer, Marc and Jens Buysse and Chris Develder and Biswanath Mukherjee},
title = {Isolation and resource efficiency of virtual optical networks},
booktitle = {Proc. Int. Conf. Computing, Networking and Communications (ICNC 2012)},
month = {30 Jan. -- 2 Feb.},
year = {2012},
address = {Maui, Hawaii, USA},
doi = {10.1109/ICCNC.2012.6167543}
}

pubarticle

C. Develder, P. Lambert, W. Van Lancker, S. Moens, R. Van de Walle, J. Nelis, D. Verslype, S. Latré, N. Staelens, N. Vercammen, B. Vermeulen, B. Masschelein, T. Van Leeuwen, J.-F. Macq, K. Struyve, F. De Turck and B. Dhoedt, "Delivering scalable video with QoS to the home", Telecommun. Syst., Vol. 49, No. 1, Jan. 2012, pp. 129-148.

Delivering scalable video with QoS to the home

C. Develder, P. Lambert, W. Van Lancker, S. Moens, R. Van de Walle, J. Nelis, D. Verslype, S. Latré, N. Staelens, N. Vercammen, B. Vermeulen, B. Masschelein, T. Van Leeuwen, J.-F. Macq, K. Struyve, F. De Turck and B. Dhoedt


Telecommun. Syst., Vol. 49, No. 1, Jan. 2012, pp. 129-148.

User satisfaction is a key factor in the success of novel multimedia services. Yet, to enable service providers and network operators to control and maximize the quality (QoS, QoE) of delivered video streams, quite some challenges remain. In this paper, we particularly focus on three of them. First of all, objectively measuring video quality requires appropriate quality metrics and methods of assessing them in a real-time fashion. Secondly, the recent Scalable Video Coding (SVC) format opens opportunities for adapting video to the available (network) resources, yet the appropriate configuration of video encoding as well as real-time streaming adaptation are largely unaddressed research areas. Thirdly, while bandwidth reservation mechanisms in access/core networks do exist, service providers lack a means for guaranteeing QoS in the increasingly complex home networks (which they are not in full control of). In this paper we offer a broad view on these interrelated issues, by presenting the developments originating in a Flemish research project (including proof-of-concept demonstrations). From a developmental perspective, we propose an architecture combining a real-time video quality monitoring platform, on-the-fly adaptation (optimizing the video quality) and QoS reservation in a heterogeneous home network based on UPnP QoS v3. From a research perspective, we propose a new subjective test procedure that revealed user preference for temporal scalability over quality scalability. In addition, an extensive study on optimizing HD SVC encoding in IPTV scenarios with fluctuating bandwidth showed that under certain bandwidth constraints (prohibiting sufficient fidelity) spatial scalability is a better option than quality scalability.

Delivering scalable video with QoS to the home

C. Develder, P. Lambert, W. Van Lancker, S. Moens, R. Van de Walle, J. Nelis, D. Verslype, S. Latré, N. Staelens, N. Vercammen, B. Vermeulen, B. Masschelein, T. Van Leeuwen, J.-F. Macq, K. Struyve, F. De Turck and B. Dhoedt


Telecommun. Syst., Vol. 49, No. 1, Jan. 2012, pp. 129-148.

@article{Develder2010TSYS,
author = {Develder, Chris and Lambert, Peter and Van Lancker, Wim and Moens, Stefaan and Van de Walle, Rik and Nelis, Jelle and Verslype, Dieter and Latré, Steven and Staelens, Nicolas and Vercammen, Nick and Vermeulen, Brecht and Masschelein, Bart and Van Leeuwen, Tom and Macq, Jean-Francois and Struyve, Kris and De Turck, Filip and Dhoedt, Bart},
title = {Delivering scalable video with QoS to the home},
journal = {Telecommun. Syst.},
month = {Jan.},
year = {2012},
volume = {49},
number = {1},
pages = {129--148},
doi = {10.1007/s11235-010-9358-3}
}

pubinproceedings

J. Buysse, C. Cavdar, M. De Leenheer, B. Dhoedt and C. Develder, "Improving energy efficiency in optical cloud networks by exploiting anycast routing", in Proc. Asia Communications and Photonics Conf. (ACP 2011), Shanghai, China, 13-16 Nov. 2011.

Improving energy efficiency in optical cloud networks by exploiting anycast routing

J. Buysse, C. Cavdar, M. De Leenheer, B. Dhoedt and C. Develder


in Proc. Asia Communications and Photonics Conf. (ACP 2011), Shanghai, China, 13-16 Nov. 2011.

Exploiting anycast routing significantly reduces optical network and server energy usage. A case study shows that intelligently selecting destinations and routes thereto, while switching off unused (network) elements, cuts power consumption by around 20% and saves network resources by 29

Improving energy efficiency in optical cloud networks by exploiting anycast routing

J. Buysse, C. Cavdar, M. De Leenheer, B. Dhoedt and C. Develder


in Proc. Asia Communications and Photonics Conf. (ACP 2011), Shanghai, China, 13-16 Nov. 2011.

@inproceedings{Buysse2011ACP,
author = {Jens Buysse and Cicek Cavdar and De Leenheer, Marc and Bart Dhoedt and Chris Develder},
title = {Improving energy efficiency in optical cloud networks by exploiting anycast routing},
booktitle = {Proc. Asia Communications and Photonics Conf. (ACP 2011)},
month = {13--16 Nov.},
year = {2011},
address = {Shanghai, China},
doi = {10.1117/12.905436}
}

pubarticle

L. Brewka, P. Sköldström, J. Nelis, H. Wessing and C. Develder, "Automatic provisioning of end-to-end QoS into the home", IEEE Trans. Consumer Electronics, Vol. 57, No. 4, Nov. 2011, pp. 1670-1678.

Automatic provisioning of end-to-end QoS into the home

L. Brewka, P. Sköldström, J. Nelis, H. Wessing and C. Develder


IEEE Trans. Consumer Electronics, Vol. 57, No. 4, Nov. 2011, pp. 1670-1678.

Due to a growing number of high bandwidth applications today (such as HDTV), and an increasing amount of network and cloud based applications, service providers need to pay attention to QoS in their networks. We believe there is a need for an end-to-end approach reaching into the home as well. The Home Gateway (HG) as a key component of the home network is crucial for enabling the end-to-end solutions. UPnP-QoS has been proposed as an inhome solution for resource reservations. In this paper we assess a solution for automatic QoS reservations, on behalf of non-UPnP-QoS aware applications. Additionally we focus on an integrated end-to-end solution, combining GMPLS-based reservations in e.g., access/metro and UPnP-QoS based reservation in the home network.

Automatic provisioning of end-to-end QoS into the home

L. Brewka, P. Sköldström, J. Nelis, H. Wessing and C. Develder


IEEE Trans. Consumer Electronics, Vol. 57, No. 4, Nov. 2011, pp. 1670-1678.

@article{Brewka2011TCE,
author = {Brewka, Lukasz and Sköldström, Pontus and Nelis, Jelle and Wessing, Henrik and Develder, Chris},
title = {Automatic Provisioning of End-to-End QoS into the Home},
journal = {IEEE Trans. Consumer Electronics},
month = {Nov.},
year = {2011},
volume = {57},
number = {4},
pages = {1670--1678},
doi = {10.1109/TCE.2011.6131140}
}

pubinproceedings

K. Mets, T. Verschueren, F. De Turck and C. Develder, "Exploiting V2G to optimize residential energy consumption with electrical vehicle (dis)charging", in Proc. 1st Int. Workshop Smart Grid Modeling and Simulation (SGMS 2011) at IEEE SmartGridComm 2011, Brussels, Belgium, 17 Oct. 2011, pp. 7-12.

Exploiting V2G to optimize residential energy consumption with electrical vehicle (dis)charging

K. Mets, T. Verschueren, F. De Turck and C. Develder


in Proc. 1st Int. Workshop Smart Grid Modeling and Simulation (SGMS 2011) at IEEE SmartGridComm 2011, Brussels, Belgium, 17 Oct. 2011, pp. 7-12.

The potential breakthrough of pluggable (hybrid) electrical vehicles (PHEVs) will impose various challenges to the power grid, and esp. implies a significant increase of its load. Adequately dealing with such PHEVs is one of the challenges and opportunities for smart grids. In particular, intelligent control strategies for the charging process can significantly alleviate peak load increases that are to be expected from e.g. residential vehicle charging at home. In addition, the car batteries connected to the grid can also be exploited to deliver grid services, and in particular give stored energy back to the grid to help coping with peak demands stemming from e.g. household appliances. In this paper, we will address such so-called vehicle-to-grid (V2G) scenarios while considering the optimization of PHEV charging in a residential scenario. In particular, we will assess the optimal car battery (dis)charging scheduling to achieve peak shaving and reduction of the variability (over time) of the load of households connected to a local distribution grid. We compare (i) a business-as-usual (BAU) scenario, without any intelligent charging, (ii) intelligent local charging optimization without V2G, and (iii) charging optimization with V2G. To evaluate these scenarios, we make use of our simulation tool, based on OMNeT++, which combines ICT and power network models and incorporates a Matlab model that allows e.g. assessing voltage violations. In a case study on a three- feeder distribution network spanning 63 households, we observe that non-V2G optimized charging can reduce the peak demand compared to BAU with 64 If we apply V2G to the intelligent charging, we can further cut the non-V2G peak demand with 17% (i.e., achieve a peak load which is only 30% of BAU).

Exploiting V2G to optimize residential energy consumption with electrical vehicle (dis)charging

K. Mets, T. Verschueren, F. De Turck and C. Develder


in Proc. 1st Int. Workshop Smart Grid Modeling and Simulation (SGMS 2011) at IEEE SmartGridComm 2011, Brussels, Belgium, 17 Oct. 2011, pp. 7-12.

@inproceedings{Mets2011SGMS,
author = {Kevin Mets and Tom Verschueren and De Turck, Filip and Chris Develder},
title = {Exploiting V2G to Optimize Residential Energy Consumption with Electrical Vehicle (Dis)Charging},
booktitle = {Proc. 1st Int. Workshop Smart Grid Modeling and Simulation (SGMS 2011) at IEEE SmartGridComm 2011},
month = {17 Oct.},
year = {2011},
pages = {7--12},
address = {Brussels, Belgium},
doi = {10.1109/SGMS.2011.6089203}
}

pubinproceedings

T. Verschueren, K. Mets, B. Meersman, M. Strobbe, C. Develder and L. Vandevelde, "Assessment and mitigation of voltage violations by solar panels in a residential distribution grid", in Proc. 2nd IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2011), Brussels, Belgium, 17-20 Oct. 2011, pp. 540-545.

Assessment and mitigation of voltage violations by solar panels in a residential distribution grid

T. Verschueren, K. Mets, B. Meersman, M. Strobbe, C. Develder and L. Vandevelde


in Proc. 2nd IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2011), Brussels, Belgium, 17-20 Oct. 2011, pp. 540-545.

Distributed renewable electricity generators, such as solar cells and wind turbines introduce bidirectional energy flows in the low-voltage power grid, possibly causing voltage violations and grid instabilities. The current solution to this problem comprises automatically switching off some of the local generators resulting in a loss of green energy. In this paper we study the impact of different solar panel penetration levels in an residential area and the corresponding effects on the distribution feeder line. To mitigate these problems, we assess how effective it is to locally store excess energy in batteries. A case study on a residential feeder serving 63 houses shows that if 80% of them have photo-voltaic (PV) panels, 45% of them will be switched off, resulting in 482 kWh of PV-generated energy being lost. We show that providing a 9 kWh battery at each house can mitigate some voltage violations, and therefor allowing for more renewable energy to be used.

Assessment and mitigation of voltage violations by solar panels in a residential distribution grid

T. Verschueren, K. Mets, B. Meersman, M. Strobbe, C. Develder and L. Vandevelde


in Proc. 2nd IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2011), Brussels, Belgium, 17-20 Oct. 2011, pp. 540-545.

@inproceedings{Verschueren2011SGC,
author = {Tom Verschueren and Kevin Mets and Bart Meersman and Matthias Strobbe and Chris Develder and Lieven Vandevelde},
title = {Assessment and mitigation of voltage violations by solar panels in a residential distribution grid},
booktitle = {Proc. 2nd IEEE Int. Conf. Smart Grid Communications (SmartGridComm 2011)},
month = {17--20 Oct.},
year = {2011},
pages = {540--545},
address = {Brussels, Belgium},
doi = {10.1109/SmartGridComm.2011.6102381}
}

pubinproceedings

J. Nelis, D. Verslype and C. Develder, "Intelligent distributed multimedia collection: Content aggregation and integration", in Proc. 36th IEEE Conf. Local Computer Networks (LCN 2011), Bonn, Germany, 4-7 Oct. 2011, pp. 203-207.

Intelligent distributed multimedia collection: Content aggregation and integration

J. Nelis, D. Verslype and C. Develder


in Proc. 36th IEEE Conf. Local Computer Networks (LCN 2011), Bonn, Germany, 4-7 Oct. 2011, pp. 203-207.

People's multimedia content is spread around their home network and content services on the Internet, such as YouTube, Flickr, Facebook. In this paper we present a system that aggregates all the multimedia content of the end user and integrates it into a unified collection for the user's convenience. The system provides location transparency of multimedia content, content filtering on player compatibility and metadata completion to aid in improved usability. This effectively enables the user to rediscover his multimedia collection without any technical knowledge. A proof-of-concept implementation known as Intelligent Distributed Multimedia Collection (IDMC) has been made that is able to detect and browse UPnP MediaServer devices as well as collect information from YouTube. This implementation also contains a media player and is able to control UPnP MediaRenderer devices remotely. Furthermore, performance has been measured to assess different ways of iterating through a multimedia collection.

Intelligent distributed multimedia collection: Content aggregation and integration

J. Nelis, D. Verslype and C. Develder


in Proc. 36th IEEE Conf. Local Computer Networks (LCN 2011), Bonn, Germany, 4-7 Oct. 2011, pp. 203-207.

@inproceedings{Nelis2011,
author = {Nelis, Jelle and Verslype, Dieter and Develder, Chris},
title = {Intelligent distributed multimedia collection: Content aggregation and integration},
booktitle = {Proc. 36th IEEE Conf. Local Computer Networks (LCN 2011)},
month = {4--7 Oct.},
year = {2011},
pages = {203--207},
address = {Bonn, Germany},
doi = {10.1109/LCN.2011.6115189}
}

pubarticle

A. Shaikh, J. Buysse, B. Jaumard and C. Develder, "Anycast routing for survivable optical grids: Scalable solution methods and the impact of relocation", IEEE/OSA J. Opt. Commun. Netw., Vol. 3, No. 9, Sep. 2011, pp. 767-779.

Anycast routing for survivable optical grids: Scalable solution methods and the impact of relocation

A. Shaikh, J. Buysse, B. Jaumard and C. Develder


IEEE/OSA J. Opt. Commun. Netw., Vol. 3, No. 9, Sep. 2011, pp. 767-779.

In this paper, we address the issue of resiliency against single link network failures in optical grids and show how the anycast routing principle, which is typical of grids, can be exploited in providing efficient shared path protection. We investigate two different integer linear program models for the full anycast routing problem, deciding on the primary and backup server locations as well as on the lightpaths toward them. The first model is a classical integer linear programming (ILP) model, which lacks scalability. The second model is a large-scale optimization model which can be efficiently solved using column generation techniques. We also design two new heuristics: the first one is an improvement of a previously proposed one which, although providing near optimal solutions, lacks scalability, while the second one is highly scalable, at the expense of reduced accuracy. Numerical results are presented for three mesh networks with varying node degrees. They allow an illustration of the scalability of the newly proposed approaches. Apart from highlighting the difference in performance (i.e., scalability and optimality) among the algorithms, our case studies demonstrate the bandwidth savings that can be achieved by exploiting relocation rather than using a backup path to the original (failure-free) destination site. Numerical results for varying network topologies, as well as different numbers of server sites show that relocation allows bandwidth savings in the range of 7--21

Anycast routing for survivable optical grids: Scalable solution methods and the impact of relocation

A. Shaikh, J. Buysse, B. Jaumard and C. Develder


IEEE/OSA J. Opt. Commun. Netw., Vol. 3, No. 9, Sep. 2011, pp. 767-779.

@article{Shaikh2011JOCN,
author = {Shaikh, Ali and Buysse, Jens and Jaumard, Brigitte and Develder, Chris},
title = {Anycast routing for survivable optical grids: scalable solution methods and the impact of relocation},
journal = {IEEE/OSA J. Opt. Commun. Netw.},
month = {Sep.},
year = {2011},
volume = {3},
number = {9},
pages = {767--779},
doi = {10.1364/JOCN.3.000767}
}

pubarticle

J. Buysse, M. De Leenheer, B. Dhoedt and C. Develder, "Providing resiliency for optical grids by exploiting relocation: A dimensioning study based on ILP", Comput. Commun., Vol. 34, No. 12, Aug. 2011, pp. 1389-1398.

Providing resiliency for optical grids by exploiting relocation: A dimensioning study based on ILP

J. Buysse, M. De Leenheer, B. Dhoedt and C. Develder


Comput. Commun., Vol. 34, No. 12, Aug. 2011, pp. 1389-1398.

Grids use a form of distributed computing to tackle complex computational and data processing problems scientists are presented with today. When designing an (optical) network supporting grids, it is essential that it can overcome single network failures, for which several protection schemes have been devised in the past. In this work, we extend the existing Shared Path protection scheme by incorporating the anycast principle typical of grids: a user typically does not care on what specific server this job gets executed and is merely interested in its timely delivery of results. Therefore, in contrast with Classical Shared Path protection (CSP), we will not necessarily provide a backup path between the source and the original destination. Instead, we allow to relocate the job to another server location if we can thus provide a backup path which comprises less wavelengths than the one CSP would suggest. We assess the bandwidth savings enabled by relocation in a quantitative dimensioning case study on an European and an American network topology, exhibiting substantial savings of the number of required wavelengths (in the order of 11-50%, depending on network topology and server locations). We also investigate how relocation affects the computational load on the execution servers. The case study is based on solving a grid network dimensioning problem: we present Integer Linear Programming (ILP) formulations for both the traditional CSP and the new resilience scheme exploiting relocation (SPR). We also outline a strategy to deal with the anycast principle: assuming we are given just the origins and intensity of job arrivals, we derive a static (source,†destination)-based demand matrix. The latter is then used as input to solve the network dimensioning ILP for an optical circuit-switched WDM network.

Providing resiliency for optical grids by exploiting relocation: A dimensioning study based on ILP

J. Buysse, M. De Leenheer, B. Dhoedt and C. Develder


Comput. Commun., Vol. 34, No. 12, Aug. 2011, pp. 1389-1398.

@article{Buysse2011comcom,
author = {Buysse, Jens and De Leenheer, Marc and Dhoedt, Bart and Develder, Chris},
title = {Providing resiliency for optical grids by exploiting relocation: A dimensioning study based on ILP},
journal = {Comput. Commun.},
month = {Aug.},
year = {2011},
volume = {34},
number = {12},
pages = {1389--1398},
doi = {10.1016/j.comcom.2010.12.014}
}

pubinproceedings

J. Buysse, K. Georgakilas, A. Tzanakaki, M. De Leenheer, B. Dhoedt, P. Demeester and C. Develder, "Calculating the minimum bounds of energy consumption for cloud networks", in Proc. IEEE Int. Conf. Computer Commun. and Networks (ICCCN 2011), Maui, Hawaii, 31 Jul. - 4 Aug. 2011, pp. 1-7.

Calculating the minimum bounds of energy consumption for cloud networks

J. Buysse, K. Georgakilas, A. Tzanakaki, M. De Leenheer, B. Dhoedt, P. Demeester and C. Develder


in Proc. IEEE Int. Conf. Computer Commun. and Networks (ICCCN 2011), Maui, Hawaii, 31 Jul. - 4 Aug. 2011, pp. 1-7.

This paper is aiming at facilitating the energy-efficient operation of an integrated optical network and IT infrastructure. In this context we propose an energy-efficient routing algorithm for provisioning of IT services that originate from specific source sites and which need to be executed by suitable IT resources (e.g. data centers). The routing approach followed is anycast, since the requirement for the IT services is the delivery of results, while the exact location of the execution of the job can be freely chosen. In this scenario, energy efficiency is achieved by identifying the least energy consuming IT and network resources required to support the services, enabling the switching off of any unused network and IT resources. Our results show significant energy savings that can reach up to 55% compared to energy-unaware schemes, depending on the granularity with which a data center is able to switch on/off servers.

Calculating the minimum bounds of energy consumption for cloud networks

J. Buysse, K. Georgakilas, A. Tzanakaki, M. De Leenheer, B. Dhoedt, P. Demeester and C. Develder


in Proc. IEEE Int. Conf. Computer Commun. and Networks (ICCCN 2011), Maui, Hawaii, 31 Jul. - 4 Aug. 2011, pp. 1-7.

@inproceedings{Buysse2011ICCCN,
author = {Buysse, Jens and Georgakilas, Kostas and Tzanakaki, Anna and De Leenheer, Marc and Dhoedt, Bart and Demeester, Piet and Develder, Chris},
title = {Calculating the minimum bounds of energy consumption for cloud networks},
booktitle = {Proc. IEEE Int. Conf. Computer Commun. and Networks (ICCCN 2011)},
month = {31 Jul. -- 4 Aug.},
year = {2011},
pages = {1--7},
address = {Maui, Hawaii},
doi = {10.1109/ICCCN.2011.6005778}
}

pubinproceedings

A. Tzanakaki, M. Anastasopoulos, K. Georgakilas, J. Buysse, M. De Leenheer, C. Develder, S. Peng, R. Nejabati, E. Escalona, D. Simeonidou, N. Ciulli, G. Landi, M. Brogle, A. Manfredi, E. López, J. Ferrer Riera, J.A. Garcia-Espin, S. Figuerola, P. Donadio, G. Parladori and J. Jiménez, "Energy efficiency considerations in integrated IT and optical network resilient infrastructures" (Invited), in Proc. 13th Int. Conf. Transparent Optical Netw. (ICTON 2011), Stockholm, Sweden, 26-30 Jun. 2011, pp. 1-4.

Energy efficiency considerations in integrated IT and optical network resilient infrastructures (Invited)

A. Tzanakaki, M. Anastasopoulos, K. Georgakilas, J. Buysse, M. De Leenheer, C. Develder, S. Peng, R. Nejabati, E. Escalona, D. Simeonidou, N. Ciulli, G. Landi, M. Brogle, A. Manfredi, E. López, J. Ferrer Riera, J.A. Garcia-Espin, S. Figuerola, P. Donadio, G. Parladori and J. Jiménez


in Proc. 13th Int. Conf. Transparent Optical Netw. (ICTON 2011), Stockholm, Sweden, 26-30 Jun. 2011, pp. 1-4.

The European Integrated Project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services - is concentrating on infrastructures incorporating integrated optical network and IT resources in support of the Future Internet with special emphasis on cloud computing. More specifically GEYSERS proposes the concept of Virtual Infrastructures over one or more interconnected Physical Infrastructures comprising both network and IT resources. Taking into consideration the energy consumption levels associated with the ICT today and the expansion of the Internet in size and complexity, that incurring increased energy consumption of both IT and network resources, energy efficient infrastructure design becomes critical. To address this need, in the framework of GEYSERS, we propose energy efficient design of infrastructures incorporating integrated optical network and IT resources, supporting resilient end-to-end services. Our modeling results quantify significant energy savings of the proposed solution by jointly optimizing the allocation of both network and IT resources.

Energy efficiency considerations in integrated IT and optical network resilient infrastructures (Invited)

A. Tzanakaki, M. Anastasopoulos, K. Georgakilas, J. Buysse, M. De Leenheer, C. Develder, S. Peng, R. Nejabati, E. Escalona, D. Simeonidou, N. Ciulli, G. Landi, M. Brogle, A. Manfredi, E. López, J. Ferrer Riera, J.A. Garcia-Espin, S. Figuerola, P. Donadio, G. Parladori and J. Jiménez


in Proc. 13th Int. Conf. Transparent Optical Netw. (ICTON 2011), Stockholm, Sweden, 26-30 Jun. 2011, pp. 1-4.

@inproceedings{Tzanakaki2011ICTON,
author = {Anna Tzanakaki and Markos Anastasopoulos and Konstantinos Georgakilas and Jens Buysse and De Leenheer, Marc and Chris Develder and Shuping Peng and Reza Nejabati and Eduard Escalona and Dimitra Simeonidou and Nicola Ciulli and Giada Landi and Marc Brogle and Alessandro Manfredi and Ester López and Ferrer Riera, Jordi and Garcia-Espin, Joan A. and Sergi Figuerola and Pasquale Donadio and Giorgio Parladori and Javier Jiménez},
title = {Energy Efficiency Considerations in Integrated IT and Optical Network Resilient Infrastructures (Invited)},
booktitle = {Proc. 13th Int. Conf. Transparent Optical Netw. (ICTON 2011)},
month = {26--30 Jun.},
year = {2011},
pages = {1--4},
address = {Stockholm, Sweden},
doi = {10.1109/ICTON.2011.5971045}
}

pubinproceedings

E. Escalona, S. Peng, R. Nejabati, D. Simeonidou, J.A. García-Espín, J. Ferrer, S. Figuerola, G. Landi, N. Ciulli, J. Jimenez, B. Belter, Y. Demchenko, C. de Laat, X. Chen, A. Yukan, S. Soudan, P. Vicat-Blanc, J. Buysse, M. De Leenheer, C. Develder, A. Tzanakaki, P. Robinson, M. Brogle and T.M. Bohnert, "GEYSERS: A novel architecture for virtualization and co-provisioning of dynamic optical networks and IT services", in Proc. Future Netw. Mobile Summit (FNMS 2011), Warsaw, Poland, 15-17 Jun. 2011, pp. 1-8.

GEYSERS: A novel architecture for virtualization and co-provisioning of dynamic optical networks and IT services

E. Escalona, S. Peng, R. Nejabati, D. Simeonidou, J.A. García-Espín, J. Ferrer, S. Figuerola, G. Landi, N. Ciulli, J. Jimenez, B. Belter, Y. Demchenko, C. de Laat, X. Chen, A. Yukan, S. Soudan, P. Vicat-Blanc, J. Buysse, M. De Leenheer, C. Develder, A. Tzanakaki, P. Robinson, M. Brogle and T.M. Bohnert


in Proc. Future Netw. Mobile Summit (FNMS 2011), Warsaw, Poland, 15-17 Jun. 2011, pp. 1-8.

GEYSERS aims at defining an end-to-end network architecture that offers a novel planning, provisioning and operational framework for optical network and IT infrastructure providers and operators. In this framework, physical infrastructure resources (network and IT) are dynamically partitioned to virtual resources and then composed into a Virtual Infrastructure offered to operators as a service. The operator will be able to operate a virtual infrastructure with an enhanced Network Control Plane (NCP) able to offer coupled, optimized and dynamic on-demand Network and IT provisioning services (i.e., interconnections between multiple IT resources and end-users). The scope and novelty of the GEYSERS architecture is focused on the functional definition and description of two innovative layers, the enhanced Network Control Plane (NCP) and the Logical Infrastructure Composition Layer (LICL). The Service Middleware Layer (SML) and the physical layer (PHY) are part of the overall GEYSERS architecture but are based on existing developments that will be appropriately adapted or extended.

GEYSERS: A novel architecture for virtualization and co-provisioning of dynamic optical networks and IT services

E. Escalona, S. Peng, R. Nejabati, D. Simeonidou, J.A. García-Espín, J. Ferrer, S. Figuerola, G. Landi, N. Ciulli, J. Jimenez, B. Belter, Y. Demchenko, C. de Laat, X. Chen, A. Yukan, S. Soudan, P. Vicat-Blanc, J. Buysse, M. De Leenheer, C. Develder, A. Tzanakaki, P. Robinson, M. Brogle and T.M. Bohnert


in Proc. Future Netw. Mobile Summit (FNMS 2011), Warsaw, Poland, 15-17 Jun. 2011, pp. 1-8.

@inproceedings{Escalona2011,
author = {Eduard Escalona and Shuping Peng and Reza Nejabati and Dimitra Simeonidou and García-Espín, Joan A. and Jordi Ferrer and Sergi Figuerola and Giada Landi and Nicola Ciulli and Javier Jimenez and Bartosz Belter and Yuri Demchenko and Cees de Laat and Xiaomin Chen and Admela Yukan and Sebastien Soudan and Pascale Vicat-Blanc and Jens Buysse and De Leenheer, Marc and Chris Develder and Anna Tzanakaki and Philip Robinson and Marc Brogle and Bohnert, T. Michael},
title = {GEYSERS: A Novel Architecture for Virtualization and Co-Provisioning of Dynamic Optical Networks and IT Services},
booktitle = {Proc. Future Netw. Mobile Summit (FNMS 2011)},
month = {15--17 Jun.},
year = {2011},
pages = {1--8},
address = {Warsaw, Poland}
}

pubinproceedings

M. De Leenheer, J. Buysse, K. Mets, B. Dhoedt and C. Develder, "Design and implementation of a simulation environment for network virtualization", in Proc. 16th IEEE Int. Workshop Computer Aided Modeling, Analysis and Design of Commun. Links and Netw. (CAMAD 2011), Kyoto, Japan, 10-11 Jun. 2011, pp. 87-91.

Design and implementation of a simulation environment for network virtualization

M. De Leenheer, J. Buysse, K. Mets, B. Dhoedt and C. Develder


in Proc. 16th IEEE Int. Workshop Computer Aided Modeling, Analysis and Design of Commun. Links and Netw. (CAMAD 2011), Kyoto, Japan, 10-11 Jun. 2011, pp. 87-91.

Network virtualization has been proposed as a key enabler of the future internet, as it allows multiple networks to coexist on a shared physical infrastructure, and as such overcomes the difficulties in deploying novel technologies in the current Internet. However, much confusion still exists on the impact virtualization will have on performance, since we lack the necessary tools to study the behaviour of a virtualized network infrastructure. We report on the architecture and implementation of a simulation environment for virtualizing both (optical) network and IT infrastructures. We provide a detailed overview of the layered architecture, give insight in the design and implementation of the simulator, discuss potential use cases and finally include some preliminary results.

Design and implementation of a simulation environment for network virtualization

M. De Leenheer, J. Buysse, K. Mets, B. Dhoedt and C. Develder


in Proc. 16th IEEE Int. Workshop Computer Aided Modeling, Analysis and Design of Commun. Links and Netw. (CAMAD 2011), Kyoto, Japan, 10-11 Jun. 2011, pp. 87-91.

@inproceedings{DeLeenheer2011CAMAD,
author = {De Leenheer, Marc and Buysse, Jens and Mets, Kevin and Dhoedt, Bart and Develder, Chris},
title = {Design and implementation of a simulation environment for network virtualization},
booktitle = {Proc. 16th IEEE Int. Workshop Computer Aided Modeling, Analysis and Design of Commun. Links and Netw. (CAMAD 2011)},
month = {10--11 Jun.},
year = {2011},
pages = {87--91},
address = {Kyoto, Japan},
doi = {10.1109/CAMAD.2011.5941124}
}

pubinproceedings

K. Mets, T. Verschueren, C. Develder, T. Vandoorn and L. Vandevelde, "Integrated simulation of power and communication networks for smart grid applications", in Proc. 16th IEEE Int. Workshop Computer Aided Modeling, Analysis and Design of Commun. Links and Netw. (CAMAD 2011), Kyoto, Japan, 10-11 Jun. 2011, pp. 61-65.

Integrated simulation of power and communication networks for smart grid applications

K. Mets, T. Verschueren, C. Develder, T. Vandoorn and L. Vandevelde


in Proc. 16th IEEE Int. Workshop Computer Aided Modeling, Analysis and Design of Commun. Links and Netw. (CAMAD 2011), Kyoto, Japan, 10-11 Jun. 2011, pp. 61-65.

Innovative architectures, control mechanisms and network technologies are being proposed to realize the future smart grid. To assess their impact and effectiveness, simulation is key. Simulation in both areas of communication networks as well as power systems has been widely adopted. However, the coupling of those two worlds calls for tools able to address both. In this paper, we propose an innovative integrated framework that models and simulates both the communication network and power networks. We discuss the design and operation of the simulation environment, and illustrate this by means of a case study that employs it.

Integrated simulation of power and communication networks for smart grid applications

K. Mets, T. Verschueren, C. Develder, T. Vandoorn and L. Vandevelde


in Proc. 16th IEEE Int. Workshop Computer Aided Modeling, Analysis and Design of Commun. Links and Netw. (CAMAD 2011), Kyoto, Japan, 10-11 Jun. 2011, pp. 61-65.

@inproceedings{Mets2011CAMAD,
author = {Mets, Kevin and Verschueren, Tom and Develder, Chris and Vandoorn, Tine and Vandevelde, Lieven},
title = {Integrated simulation of power and communication networks for smart grid applications},
booktitle = {Proc. 16th IEEE Int. Workshop Computer Aided Modeling, Analysis and Design of Commun. Links and Netw. (CAMAD 2011)},
month = {10--11 Jun.},
year = {2011},
pages = {61--65},
address = {Kyoto, Japan},
doi = {10.1109/CAMAD.2011.5941119}
}

pubinproceedings

C. Develder, J. Buysse, A. Shaikh, B. Jaumard, M. De Leenheer and B. Dhoedt, "Survivable optical grid dimensioning: Anycast routing with server and network failure protection", in Proc. IEEE Int. Conf. Commun. (ICC 2011), Kyoto, Japan, 5-9 Jun. 2011.

Survivable optical grid dimensioning: Anycast routing with server and network failure protection

C. Develder, J. Buysse, A. Shaikh, B. Jaumard, M. De Leenheer and B. Dhoedt


in Proc. IEEE Int. Conf. Commun. (ICC 2011), Kyoto, Japan, 5-9 Jun. 2011.

Grids can efficiently deal with challenging computational and data processing tasks which cutting edge science is generating today. So-called e-Science grids cope with these complex tasks by deploying geographically distributed server infrastructure, interconnected by high speed networks. The latter benefit from optical technology, offering low latencies and high bandwidths, thus giving rise to so-called optical grids or lambda grids.
In this paper, we address the dimensioning problem of such grids: how to decide how much server infrastructure to deploy, at which locations in a given topology, the amount of network capacity to provide and which routes to follow along them. Compared to earlier work, we propose an integrated solution solving these questions in an integrated way, i.e., we jointly optimize network and server capacity, and
incorporate resiliency against both network and server failures. Assuming we are given the amount of resource reservation requests arriving at each network node (where a resource reservation implies
to reserve both processing capacity at a server site, and a network connection towards it), we solve the problem of first choosing a predetermined number of server locations to use, and subsequently determine the routes to follow while minimizing resource requirements. In a case study on a meshed European network comprising 28 nodes and 41 links, we show that compared to classical (i.e. without relocation) shared path protection against link failures only, we can offer resilience against both single link and network failures by adding about 55% extra server capacity, and 26% extra wavelengths.

Survivable optical grid dimensioning: Anycast routing with server and network failure protection

C. Develder, J. Buysse, A. Shaikh, B. Jaumard, M. De Leenheer and B. Dhoedt


in Proc. IEEE Int. Conf. Commun. (ICC 2011), Kyoto, Japan, 5-9 Jun. 2011.

@inproceedings{Develder2011ICC,
author = {Develder, Chris and Buysse, Jens and Shaikh, Ali and Jaumard, Brigitte and De Leenheer, Marc and Dhoedt, Bart},
title = {Survivable optical grid dimensioning: Anycast routing with server and network failure protection},
booktitle = {Proc. IEEE Int. Conf. Commun. (ICC 2011)},
month = {5--9 Jun.},
year = {2011},
address = {Kyoto, Japan},
doi = {10.1109/icc.2011.5963385}
}

pubinproceedings

K. Mets, T. Verschueren, F. De Turck and C. Develder, "Evaluation of multiple design options for smart charging algorithms", in Proc. 2nd IEEE ICC Int. Workshop on Smart Grid Commun., Kyoto, Japan, 5 Jun. 2011.

Evaluation of multiple design options for smart charging algorithms

K. Mets, T. Verschueren, F. De Turck and C. Develder


in Proc. 2nd IEEE ICC Int. Workshop on Smart Grid Commun., Kyoto, Japan, 5 Jun. 2011.

We evaluate the impact of limitations that may exist in actual implementations of plugin electrical vehicle chargers (e.g. no controllable charging current) on smart charging algorithms. We use quadratic programming to control and coordinate the charging of multiple vehicles in order to reduce the peak load and load profile variability observed by a distribution grid transformer. Simulation results are presented for a section of a residential distribution grid comprising 150 households.

Evaluation of multiple design options for smart charging algorithms

K. Mets, T. Verschueren, F. De Turck and C. Develder


in Proc. 2nd IEEE ICC Int. Workshop on Smart Grid Commun., Kyoto, Japan, 5 Jun. 2011.

@inproceedings{Mets2011ICC,
author = {Mets, Kevin and Verschueren, Tom and De Turck, Filip and Develder, Chris},
title = {Evaluation of multiple design options for smart charging algorithms},
booktitle = {Proc. 2nd IEEE ICC Int. Workshop on Smart Grid Commun.},
month = {5 Jun.},
year = {2011},
address = {Kyoto, Japan},
doi = {10.1109/iccw.2011.5963579}
}

pubinproceedings

P. Vicat-Blanc, S. Figuerola, X. Chen, G. Landi, E. Escalona, C. Develder, A. Tzanakaki, Y. Demchenko, J.A. García-Espín, J. Ferrer, E. López, S. Soudan, J. Buysse, A. Jukan, N. Ciulli, M. Brogle, L. van Laarhoven, B. Belter, F. Anhalt, R. Nejabati, D. Simeonidou, C. Ngo, C. de Laat, M. Biancani, M. Roth, P. Donadio, J. Jiménez, M. Antoniak-Lewandowska and A. Gumaste, "Bringing optical networks to the cloud: An architecture for a sustainable future internet", in Proc. Future Internet Assembly (FIA 2011), Budapest, Hungary, 15-17 May 2011, pp. 307-320.

Bringing optical networks to the cloud: An architecture for a sustainable future internet

P. Vicat-Blanc, S. Figuerola, X. Chen, G. Landi, E. Escalona, C. Develder, A. Tzanakaki, Y. Demchenko, J.A. García-Espín, J. Ferrer, E. López, S. Soudan, J. Buysse, A. Jukan, N. Ciulli, M. Brogle, L. van Laarhoven, B. Belter, F. Anhalt, R. Nejabati, D. Simeonidou, C. Ngo, C. de Laat, M. Biancani, M. Roth, P. Donadio, J. Jiménez, M. Antoniak-Lewandowska and A. Gumaste


in Proc. Future Internet Assembly (FIA 2011), Budapest, Hungary, 15-17 May 2011, pp. 307-320.

Over the years, the Internet has become a central tool for society. The extent of its growth and usage raises critical issues associated with its design principles that need to be addressed before it reaches its limits. Many emerging applications have increasing requirements in terms of bandwidth, QoS and manageability. Moreover, applications such as Cloud computing and 3D-video streaming require optimization and combined provisioning of different infrastructure resources and services that include both network and IT resources. Demands become more and more sporadic and variable, making dynamic provisioning highly needed. As a huge energy consumer, the Internet also needs to be energyconscious. Applications critical for society and business (e.g., health, finance) or for real-time communication demand a highly reliable, robust and secure Internet. Finally, the future Internet needs to support sustainable business models, in order to drive innovation, competition, and research. Combining optical network technology with Cloud technology is key to addressing the future Internet/Cloud challenges. In this context, we propose an integrated approach: realizing the convergence of the IT- and optical-network-provisioning models will help bring revenues to all the actors involved in the value chain. Premium advanced network and IT managed services integrated with the vanilla Internet will ensure a sustainable future Internet/Cloud enabling demanding and ubiquitous applications to coexist.

Bringing optical networks to the cloud: An architecture for a sustainable future internet

P. Vicat-Blanc, S. Figuerola, X. Chen, G. Landi, E. Escalona, C. Develder, A. Tzanakaki, Y. Demchenko, J.A. García-Espín, J. Ferrer, E. López, S. Soudan, J. Buysse, A. Jukan, N. Ciulli, M. Brogle, L. van Laarhoven, B. Belter, F. Anhalt, R. Nejabati, D. Simeonidou, C. Ngo, C. de Laat, M. Biancani, M. Roth, P. Donadio, J. Jiménez, M. Antoniak-Lewandowska and A. Gumaste


in Proc. Future Internet Assembly (FIA 2011), Budapest, Hungary, 15-17 May 2011, pp. 307-320.

@inproceedings{VicatBlanc2011,
author = {Vicat-Blanc, Pascale and Figuerola, Sergi and Chen, Xiaomin and Landi, Giada and Escalona, Eduard and Develder, Chris and Tzanakaki, Anna and Demchenko, Yuri and García-Espín, Joan A. and Ferrer, Jordi and López, Ester and Soudan, Sébastien and Buysse, Jens and Jukan, Admela and Ciulli, Nicola and Brogle, Marc and van Laarhoven, Luc and Belter, Bartosz and Anhalt, Fabienne and Nejabati, Reza and Simeonidou, Dimitra and Ngo, Canh and de Laat, Cees and Biancani, Matteo and Roth, Michael and Donadio, Pasquale and Jiménez, Javier and Antoniak-Lewandowska, Monika and Gumaste, Ashwin},
title = {Bringing Optical Networks to the Cloud: an Architecture for a Sustainable future Internet},
booktitle = {Proc. Future Internet Assembly (FIA 2011)},
month = {15--17 May},
year = {2011},
pages = {307--320},
address = {Budapest, Hungary},
doi = {10.1007/978-3-642-20898-0_22}
}

pubinproceedings

A. Tzanakaki, M. Anastasopoulos, K. Georgakilas, J. Buysse, M. De Leenheer, C. Develder, S. Peng, R. Nejabati, E. Escalona, D. Simeonidou, N. Ciulli, G. Landi, M. Brogle, A. Manfredi, E. López, J. Ferrer Riera, J. García-Espín, P. Donaldio, G. Parladori and J. Jiménez, "Energy efficiency in integrated IT and optical network infrastructures: The GEYSERS approach", in Proc. IEEE Infocom Workshop on Green Commun. Netw., Shanghai, China, 15 Apr. 2011, pp. 343-348.

Energy efficiency in integrated IT and optical network infrastructures: The GEYSERS approach

A. Tzanakaki, M. Anastasopoulos, K. Georgakilas, J. Buysse, M. De Leenheer, C. Develder, S. Peng, R. Nejabati, E. Escalona, D. Simeonidou, N. Ciulli, G. Landi, M. Brogle, A. Manfredi, E. López, J. Ferrer Riera, J. García-Espín, P. Donaldio, G. Parladori and J. Jiménez


in Proc. IEEE Infocom Workshop on Green Commun. Netw., Shanghai, China, 15 Apr. 2011, pp. 343-348.

In this paper we propose energy efficient design and operation of infrastructures incorporating integrated optical network and IT resources. For the first time we quantify significant energy savings of a complete solution jointly optimizing the allocation and provisioning of both network and IT resources. Our approach involves virtualization of the infrastructure resources and it is proposed and developed in the framework of the European project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services.

Energy efficiency in integrated IT and optical network infrastructures: The GEYSERS approach

A. Tzanakaki, M. Anastasopoulos, K. Georgakilas, J. Buysse, M. De Leenheer, C. Develder, S. Peng, R. Nejabati, E. Escalona, D. Simeonidou, N. Ciulli, G. Landi, M. Brogle, A. Manfredi, E. López, J. Ferrer Riera, J. García-Espín, P. Donaldio, G. Parladori and J. Jiménez


in Proc. IEEE Infocom Workshop on Green Commun. Netw., Shanghai, China, 15 Apr. 2011, pp. 343-348.

@inproceedings{Tzanakaki2011Infocom,
author = {Anna Tzanakaki and Markos Anastasopoulos and Konstantinos Georgakilas and Jens Buysse and De Leenheer, Marc and Develder, Chris and Shuping Peng and Reza Nejabati and Eduard Escalona and Dimitra Simeonidou and Nicola Ciulli and Giada Landi and Marc Brogle and Alessandro Manfredi and Ester López and Ferrer Riera, Jordi and García-Espín, Jordi and Donaldio, Pasquale and Parladori, Giorgio and Javier Jiménez},
title = {Energy efficiency in integrated IT and optical network infrastructures: The {GEYSERS} approach},
booktitle = {Proc. IEEE Infocom Workshop on Green Commun. Netw.},
month = {15 Apr.},
year = {2011},
pages = {343--348},
address = {Shanghai, China},
doi = {10.1109/INFCOMW.2011.5928835}
}

pubinproceedings

A. Willner, J. Ferrer Riera, J.A. Garcia-Espin, S. Figuerola, M. De Leenheer and C. Develder, "An analytical model of the service provisioning time within the Harmony network service plane", in Proc. 2nd IEEE Int. Workshop on Management of Emerging Networks and Services (MENS 2010), Miami, FL, USA, 10 Dec. 2010, pp. 514-518.

An analytical model of the service provisioning time within the Harmony network service plane

A. Willner, J. Ferrer Riera, J.A. Garcia-Espin, S. Figuerola, M. De Leenheer and C. Develder


in Proc. 2nd IEEE Int. Workshop on Management of Emerging Networks and Services (MENS 2010), Miami, FL, USA, 10 Dec. 2010, pp. 514-518.

Grid computing aims at offering standardized access to heterogeneous and distributed resources for scientific communities. However, in order to support emerging next generation Grid applications with specific Quality of Service requirements, the interconnecting networks have also been considered as first-class allocable Grid resources and have been also taken into account for the co-scheduling process. In the last few years, a number of network resource provisioning systems were developed, however, without providing specific analysis on the scalability of potential architectural design alternatives. Our approach is to formulate a fundamental analytical model to evaluate the expected service provisioning time using different architectures as a function of the involved transport domains. To validate our results, we have used measurements obtained from the European IST-FP6 Phosphorus project testbed. The main contribution is to provide an instrument to obtain reference values to support architectural design decisions even in an early stage of the development phase.

An analytical model of the service provisioning time within the Harmony network service plane

A. Willner, J. Ferrer Riera, J.A. Garcia-Espin, S. Figuerola, M. De Leenheer and C. Develder


in Proc. 2nd IEEE Int. Workshop on Management of Emerging Networks and Services (MENS 2010), Miami, FL, USA, 10 Dec. 2010, pp. 514-518.

@inproceedings{Willner2010,
author = {Alexander Willner and Ferrer Riera, Jordi and Garcia-Espin, Joan A. and Sergi Figuerola and De Leenheer, Marc and Develder, Chris},
title = {An analytical model of the service provisioning time within the Harmony network service plane},
booktitle = {Proc. 2nd IEEE Int. Workshop on Management of Emerging Networks and Services (MENS 2010)},
month = {10 Dec.},
year = {2010},
pages = {514--518},
address = {Miami, FL, USA},
doi = {10.1109/GLOCOMW.2010.5700373}
}

pubinproceedings

B. Jaumard, J. Buysse, A. Shaikh, M. De Leenheer and C. Develder, "Column generation for dimensioning resilient optical grid networks with relocation", in Proc. IEEE Global Telecommun. Conf. (Globecom 2010), Miami, FL, USA, 6-10 Dec. 2010, pp. 1-6.

Column generation for dimensioning resilient optical grid networks with relocation

B. Jaumard, J. Buysse, A. Shaikh, M. De Leenheer and C. Develder


in Proc. IEEE Global Telecommun. Conf. (Globecom 2010), Miami, FL, USA, 6-10 Dec. 2010, pp. 1-6.

Nowadays, the Quality of Service (QoS) in Optical Grids has become a key issue. An important QoS factor is resiliency, namely the ability to survive from certain network failures. Although several traditional network protection schemes were devised in the past, they are not optimized for Optical Grids. In an earlier work, we proposed relocation strategies providing backup paths to alternate destinations, exploiting the anycast routing principle of grids. To show the advantage of relocation (compared to traditional network protection) in terms of reduced network capacity, we formulated the network dimensioning problem as an Integer Linear Program (ILP). Yet, its solution exhibited very poor scalability and appeared not practical for reasonably large scale case studies. Therefore, we propose a novel formulation for the relocation protection scheme, using column generation (CG). This approach decomposes the original ILP into two parts, specifically a Restricted Master Problem (RMP) and a Pricing Problem (PP) which are iteratively and alternatively solved until the optimality condition is satisfied. Such a CG decomposition has a significant impact on the complexity of the model, leading to a significant improvement over previous ILPs in term of scalability and running times. We demonstrate that the CG method is highly scalable and generates nearly optimal solutions using case studies with up to 300 connections, showing it to be highly competitive with a previously proposed heuristic. We also perform some comparisons of the anycast scheme with the classical shared path protection on larger network instances.

Column generation for dimensioning resilient optical grid networks with relocation

B. Jaumard, J. Buysse, A. Shaikh, M. De Leenheer and C. Develder


in Proc. IEEE Global Telecommun. Conf. (Globecom 2010), Miami, FL, USA, 6-10 Dec. 2010, pp. 1-6.

@inproceedings{Jaumard2010,
author = {Jaumard, Brigitte and Buysse, Jens and Shaikh, Ali and De Leenheer, Marc and Develder, Chris},
title = {Column Generation for Dimensioning Resilient Optical Grid Networks with Relocation},
booktitle = {Proc. IEEE Global Telecommun. Conf. (Globecom 2010)},
month = {6--10 Dec.},
year = {2010},
pages = {1--6},
address = {Miami, FL, USA},
doi = {10.1109/GLOCOM.2010.5684026}
}

pubinproceedings

J. Nelis, D. Verslype, C. Develder, L. Brewka, H. Wessing and L. Dittmann, "Bandwidth reservations in home networks: Performance assessment of UPnP-QoS v3", in Proc. 35th IEEE Conf. Local Computer Networks (LCN 2010), Denver, CO, USA, 11-14 Oct. 2010, pp. 276-279.

Bandwidth reservations in home networks: Performance assessment of UPnP-QoS v3

J. Nelis, D. Verslype, C. Develder, L. Brewka, H. Wessing and L. Dittmann


in Proc. 35th IEEE Conf. Local Computer Networks (LCN 2010), Denver, CO, USA, 11-14 Oct. 2010, pp. 276-279.

In order for service providers to provide their users high quality services in the home network, Quality of Service (QoS) provisioning is needed to protect premium services. In this paper, we describe how a Universal Plug-and-Play (UPnP) based home network architecture solves this problem in a heterogeneous home network. We outline how it both relieves the end user from troublesome configuration and still offers control to the service provider. We particularly present performance assessment results for UPnP-QoS v3, based on a fully operational experimental implementation. The quantitative measurement results are further used in extensive simulations demonstrating acceptable response times and clear QoS admission differentiation.

Bandwidth reservations in home networks: Performance assessment of UPnP-QoS v3

J. Nelis, D. Verslype, C. Develder, L. Brewka, H. Wessing and L. Dittmann


in Proc. 35th IEEE Conf. Local Computer Networks (LCN 2010), Denver, CO, USA, 11-14 Oct. 2010, pp. 276-279.

@inproceedings{Nelis2010,
author = {Nelis, Jelle and Verslype, Dieter and Develder, Chris and Brewka, Lukasz and Wessing, Henrik and Dittmann, Lars},
title = {Bandwidth reservations in home networks: Performance assessment of UPnP-QoS v3},
booktitle = {Proc. 35th IEEE Conf. Local Computer Networks (LCN 2010)},
month = {11--14 Oct.},
year = {2010},
pages = {276--279},
address = {Denver, CO, USA},
doi = {10.1109/LCN.2010.5735720}
}

pubarticle

W. Vereecken, L. Deboosere, P. Simoens, B. Vermeulen, D. Colle, C. Develder, M. Pickavet, B. Dhoedt and P. Demeester, "Power efficiency of thin clients", Eur. Trans. Telecomm., Vol. 21, No. 6, Oct. 2010, pp. 479-490.

Power efficiency of thin clients

W. Vereecken, L. Deboosere, P. Simoens, B. Vermeulen, D. Colle, C. Develder, M. Pickavet, B. Dhoedt and P. Demeester


Eur. Trans. Telecomm., Vol. 21, No. 6, Oct. 2010, pp. 479-490.

Worldwide, awareness for energy consumption is rising because of global energy production limits as well as because of environmental concerns. As the energy fraction currently consumed by ICT-related equipment is substantial (about 8 per cent of electricity consumption worldwide in the use phase) and the growth rate in this particular sector is spectacular, in the ICT sector, adequate solutions are needed to allow sustainable growth. In this paper we aim at reducing power consumption of desktop applications by applying a thin client approach and we analyse the conditions necessary. To this end, estimates on power consumptions in typical desktop scenarios and analogous thin client settings are made and analysed. The paper concludes with an experimental study on currently available equipment, to translate the generic conclusions into their current implications and trade-offs.

Power efficiency of thin clients

W. Vereecken, L. Deboosere, P. Simoens, B. Vermeulen, D. Colle, C. Develder, M. Pickavet, B. Dhoedt and P. Demeester


Eur. Trans. Telecomm., Vol. 21, No. 6, Oct. 2010, pp. 479-490.

@article{Vereecken2010ETT,
author = {Willem Vereecken and Lien Deboosere and Pieter Simoens and Brecht Vermeulen and Didier Colle and Chris Develder and Mario Pickavet and Bart Dhoedt and Piet Demeester},
title = {Power efficiency of thin clients},
journal = {Eur. Trans. Telecomm.},
month = {Oct.},
year = {2010},
volume = {21},
number = {6},
pages = {479--490},
doi = {10.1002/ett.1431}
}

pubinproceedings

B. Vankeirsbilck, J. Nelis, D. Verslype, C. Develder, T. Van Leeuwen and B. Dhoedt, "Integrating personal media and digital TV with QoS guarantees using virtualized set-top boxes: Architecture and performance measurements", in Proc. 35th IEEE Conf. Local Computer Networks (LCN 2010), Denver, CO, USA, 11-14 Oct. 2010, pp. 504-511.

Integrating personal media and digital TV with QoS guarantees using virtualized set-top boxes: Architecture and performance measurements

B. Vankeirsbilck, J. Nelis, D. Verslype, C. Develder, T. Van Leeuwen and B. Dhoedt


in Proc. 35th IEEE Conf. Local Computer Networks (LCN 2010), Denver, CO, USA, 11-14 Oct. 2010, pp. 504-511.

Nowadays, users consume a lot of functionality in their home coming from a service provider located in the Internet. While the home network is typically shielded off as much as possible from the `outside world', the supplied services could be greatly extended if it was possible to use local information. In this article, an extended service is presented that integrates the user's multimedia content, scattered over multiple devices in the home network, into the Electronic Program Guide (EPG) of the Digital TV. We propose to virtualize the set-top box, by migrating all functionality except user interfacing to the service provider infrastructure. The media in the home network is discovered through standard Universal Plug and Play (UPnP), of which the QoS functionality is exploited to ensure high quality playback over the home network, that basically is out of the control of the service provider. The performance of the subsystems are analysed.

Integrating personal media and digital TV with QoS guarantees using virtualized set-top boxes: Architecture and performance measurements

B. Vankeirsbilck, J. Nelis, D. Verslype, C. Develder, T. Van Leeuwen and B. Dhoedt


in Proc. 35th IEEE Conf. Local Computer Networks (LCN 2010), Denver, CO, USA, 11-14 Oct. 2010, pp. 504-511.

@inproceedings{Vankeirsbilck2010LCN,
author = {Vankeirsbilck, Bert and Nelis, Jelle and Verslype, Dieter and Develder, Chris and Van Leeuwen, Tom and Dhoedt, Bart},
title = {Integrating personal media and digital TV with QoS guarantees using virtualized set-top boxes: Architecture and performance measurements},
booktitle = {Proc. 35th IEEE Conf. Local Computer Networks (LCN 2010)},
month = {11--14 Oct.},
year = {2010},
pages = {504--511},
address = {Denver, CO, USA},
doi = {10.1109/LCN.2010.5735763}
}

pubarticle

W. Haerick, T. Wauters, C. Develder, F. De Turck and B. Dhoedt, "Transparent resource sharing framework for internet services on handheld devices", Ann. Telecommun., Springer Paris, Vol. 65, No. 7-8, Aug. 2010, pp. 419-432.

Transparent resource sharing framework for internet services on handheld devices

W. Haerick, T. Wauters, C. Develder, F. De Turck and B. Dhoedt


Ann. Telecommun.Springer Paris, Vol. 65, No. 7-8, Aug. 2010, pp. 419-432.

Handheld devices have limited processing power and a short battery lifetime. As a result, computationally intensive applications cannot run appropriately or cause the device to run out of battery too early. Additionally, Internet-based service providers targeting these mobile devices lack information to estimate the remaining battery autonomy and have no view on the availability of idle resources in the neighborhood of the handheld device. These battery-related issues create an opportunity for Internet providers to broaden their role and start managing energy aspects of battery-driven mobile devices inside the home. In this paper, we propose an energy-aware resource-sharing framework that enables Internet access providers to delegate (a part of) a client application from a handheld device to idle resources in the LAN, in a transparent way for the end-user. The key component is the resource sharing service, hosted on the LAN gateway, which can be remotely queried and managed by the Internet access provider. The service includes a battery model to predict the remaining battery lifetime. We describe the concept of resource-sharing-as-a-service that allows users of handheld devices to subscribe to the resource sharing service. In a proof-of-concept, we evaluate the delay to offload a client application to an idle computer and study the impact on battery autonomy as a function of the CPU cycles that can be offloaded.

Transparent resource sharing framework for internet services on handheld devices

W. Haerick, T. Wauters, C. Develder, F. De Turck and B. Dhoedt


Ann. Telecommun.Springer Paris, Vol. 65, No. 7-8, Aug. 2010, pp. 419-432.

@article{Haerick2010,
author = {Haerick, Wouter and Wauters, Tim and Develder, Chris and De Turck, Filip and Dhoedt, Bart},
title = {Transparent resource sharing framework for internet services on handheld devices},
journal = {Ann. Telecommun.},
publisher = {Springer Paris},
month = {Aug.},
year = {2010},
volume = {65},
number = {7--8},
pages = {419--432},
doi = {10.1007/s12243-010-0168-0}
}

pubinproceedings

P. Leroux, K. Vanhecke, K. Roobroeck, C. Develder and F. De Turck, "Experimental characterization of an open out-of-home MHP-based DVR service", in Adjunct Proc. 8th Eur. Conf. Interactive TV and Video (EuroITV 2010 Workshops), Tampere, Finland, 9-11 Jun. 2010.

Experimental characterization of an open out-of-home MHP-based DVR service

P. Leroux, K. Vanhecke, K. Roobroeck, C. Develder and F. De Turck


in Adjunct Proc. 8th Eur. Conf. Interactive TV and Video (EuroITV 2010 Workshops), Tampere, Finland, 9-11 Jun. 2010.

MHP (Multimedia Home Platform) is an open standard for interactive TV middleware that was designed by the Digital Video Broadcasting (DVB) alliance and is found on many commercially deployed set-top boxes (STBs). In this paper, a detailed system architecture is presented which enables customers of digital television providers to use their MHP-based DVR from an out-of-home location through their mobile phone. Building further on the openness of the MHP platform, special focus was on the overall scalability, security and extensibility of the system and the efficient and fast communication between mobile phone and set-top box. Technical challenges are imposed by the limited hardware resources that are available on most of the currently deployed STBs and by the delays that are introduced by the mobile communication networks. In order to characterise the system's performance, extensive throughput and scala bility tests were performed on commercial DVRs. It is shown that the overall system performance meets the prede ned requirements even under heavy load

Experimental characterization of an open out-of-home MHP-based DVR service

P. Leroux, K. Vanhecke, K. Roobroeck, C. Develder and F. De Turck


in Adjunct Proc. 8th Eur. Conf. Interactive TV and Video (EuroITV 2010 Workshops), Tampere, Finland, 9-11 Jun. 2010.

@inproceedings{Leroux2010,
author = {Leroux, Philip and Vanhecke, Kris and Roobroeck, Klaas and Develder, Chris and De Turck, Filip},
title = {Experimental characterization of an open out-of-home MHP-based DVR service},
booktitle = {Adjunct Proc. 8th Eur. Conf. Interactive TV and Video (EuroITV 2010 Workshops)},
month = {9--11 Jun.},
year = {2010},
address = {Tampere, Finland}
}

pubinproceedings

B. Vankeirsbilck, C. Develder, T. Van Leeuwen, D. Verslype and B. Dhoedt, "DLNA interworking for virtualized set-top-boxes", in Proc. 8th Eur. Conf. Interactive TV and Video (EuroITV 2010), Tampere, Finland, 9-11 Jun. 2010.

DLNA interworking for virtualized set-top-boxes

B. Vankeirsbilck, C. Develder, T. Van Leeuwen, D. Verslype and B. Dhoedt


in Proc. 8th Eur. Conf. Interactive TV and Video (EuroITV 2010), Tampere, Finland, 9-11 Jun. 2010.

This paper proposes and evaluates a server centered approach to integrating personal content, residing in the user’s home network, in the Electronic Program Guide (EPG) of digital broadcast television. With this approach, a server located
outside the home of the user takes the integration work for its
account, leaving the set-top-box to only handle the interaction
with the user. We compare this approach to the situation in
which the set-top-box executes the EPG. The benefits of the
server centered approach are mainly simplification of the set-top-
box leading to less maintenance, reduced energy
consumption and lower cost while the functionality is boosted as
it could connect in the same way to other services in-home and
on the Internet. Another key benefit is that the central service
can be easily upgraded without changing anything to the STB
itself. We show that the overhead of sending the descriptions of
the in-home content to the server is limited. The delay perceived
by the user is limited to a typical value of 100 ms. The upstream
bandwidth used for sending descriptions of in-home content to
the integration server takes on average 100 Bytes per item,
thanks to fairly simple compression techniques.

DLNA interworking for virtualized set-top-boxes

B. Vankeirsbilck, C. Develder, T. Van Leeuwen, D. Verslype and B. Dhoedt


in Proc. 8th Eur. Conf. Interactive TV and Video (EuroITV 2010), Tampere, Finland, 9-11 Jun. 2010.

@inproceedings{Vankeirsbilck2010EuroITV,
author = {Vankeirsbilck, Bert and Develder, Chris and Van Leeuwen, Tom and Verslype, Dieter and Dhoedt, Bart},
title = {DLNA interworking for virtualized set-top-boxes},
booktitle = {Proc. 8th Eur. Conf. Interactive TV and Video (EuroITV 2010)},
month = {9--11 Jun.},
year = {2010},
address = {Tampere, Finland},
doi = {10.1145/1809777.1809829}
}

pubarticle

B. Van Houdt, C. Develder, J.F. Pérez, M. Pickavet and B. Dhoedt, "Mean field calculation for optical grid dimensioning", IEEE/OSA J. Opt. Commun. Netw., Vol. 2, No. 6, Jun. 2010, pp. 355-367.

Mean field calculation for optical grid dimensioning

B. Van Houdt, C. Develder, J.F. Pérez, M. Pickavet and B. Dhoedt


IEEE/OSA J. Opt. Commun. Netw., Vol. 2, No. 6, Jun. 2010, pp. 355-367.

For traditional optical network dimensioning, a plethora of algorithms exists to design the amount of network resources required to accommodate a given amount of traffic, expressed as a (source, destination)-based traffic matrix. In optical Grid dimensioning, however, the anycast principle applies: Grid users do not really care where exactly their tasks (Grid jobs) end up being executed. Thus, the destination of traffic is not known beforehand and traditional dimensioning algorithms are not applicable. In this paper we propose a mean field calculation method to analytically derive the traffic matrix for given job arrival intensities at the originating Grid sites (the sources). We also indicate how it can be integrated in a stepwise dimensioning approach to compute not only the amount of network resources, but also Grid resources (computational and/or storage). Hence it forms part of a solution for Grid dimensioning: determining how many servers to provide, where to place them, and which network to install for interconnecting server sites and users generating Grid jobs.

Mean field calculation for optical grid dimensioning

B. Van Houdt, C. Develder, J.F. Pérez, M. Pickavet and B. Dhoedt


IEEE/OSA J. Opt. Commun. Netw., Vol. 2, No. 6, Jun. 2010, pp. 355-367.

@article{VanHoudt2010,
author = {Van Houdt, Benny and Develder, Chris and Pérez, Juan F. and Pickavet, Mario and Dhoedt, Bart},
title = {Mean field calculation for optical grid dimensioning},
journal = {IEEE/OSA J. Opt. Commun. Netw.},
month = {Jun.},
year = {2010},
volume = {2},
number = {6},
pages = {355--367},
doi = {10.1364/JOCN.2.000355}
}

pubinproceedings

C. Develder, W. Haerick, K. Mets and F. De Turck, "Smart Grids and the role of ICT", in Proc. IEEE Smart Grid Comms Workshop, at IEEE Int. Conf. on Commun. (ICC 2010), Cape Town, South Africa, 23 May 2010.

Smart Grids and the role of ICT

C. Develder, W. Haerick, K. Mets and F. De Turck


in Proc. IEEE Smart Grid Comms Workshop, at IEEE Int. Conf. on Commun. (ICC 2010), Cape Town, South Africa, 23 May 2010.

Smart Grids and the role of ICT

C. Develder, W. Haerick, K. Mets and F. De Turck


in Proc. IEEE Smart Grid Comms Workshop, at IEEE Int. Conf. on Commun. (ICC 2010), Cape Town, South Africa, 23 May 2010.

@inproceedings{Develder2010SGC,
author = {Develder, Chris and Haerick, Wouter and Mets, Kevin and De Turck, Filip},
title = {Smart Grids and the role of ICT},
booktitle = {Proc. IEEE Smart Grid Comms Workshop, at IEEE Int. Conf. on Commun. (ICC 2010)},
month = {23 May},
year = {2010},
address = {Cape Town, South Africa}
}

pubinproceedings

J. Buysse, C. Develder, M. De Leenheer and B. Dhoedt, "ILP and scalable heuristics for dimensioning resilient optical grids", in Proc. 14th INFORMS Telecommun. Conf., Montreal, Canada, 5-9 May 2010.

ILP and scalable heuristics for dimensioning resilient optical grids

J. Buysse, C. Develder, M. De Leenheer and B. Dhoedt


in Proc. 14th INFORMS Telecommun. Conf., Montreal, Canada, 5-9 May 2010.

We present a study on resiliency against single link failures in optical grids and demonstrate how the Grid-specific any cast principle can be exploited to reduce network capacity requirements when adopting shared path protection. Since grid users usually do not care about the location their jobs end up being executed, we take advantage of relocation to alternate backup sites in case of failures. We solve the resulting routing-and-wavelength-assignment (RWA) problem optimally using Integer Linear Programming (ILP), extending earlier preliminary work. We also present a new, scalable heuristic to demonstrate that in a realistic case study (29 node European network, up to 150 connections) exploiting relocation results in about 20% less wavelength capacity compared to traditional shared path protection. An important aspect of network deployment is the ability to survive from certain network failures. To deal with those, a network operator can opt to provide so-called network protection. We compare two protection schemes where to protect a connection path from one point to another, a back-up path is reserved (for use when the primary fails). In case of so-called shared path protection, each primary path has a backup path where wavelengths can be shared between several back-up paths, as long as their corresponding primary light paths do not overlap. We have extended this shared path protection algorithm in a Grid context, where the any cast principle prevails: in general, multiple processing locations exist in a Grid network and any of those is an equal candidate for processing users' jobs (hence there is no a priori fixed destination of a particular job). Thus, instead of reserving a back-up path to the original destination determined by the Grid scheduler, we may relocate the job to another, possibly closer resource and thereby reduce overall network capacity. We evaluate the classical shared path protection (CSP) method and the shared path protection with relocation (SPR) scheme from a network dimensioning perspective by an Integer Linear Program (ILP). We start from a demand vector stating for each source node in the network a number of connections to be established between it and some resource. Hence we are free to determine not only the resource to serve as a backup, but also the best primary resource. We model the protection schemes as a minimum multi-commodity flow problem with according demand-and flow conservation constraints. We extend the CSP formulation to a SPR formulation by allowing the primary-and backup resources to differ. As demonstrated in [1] we show that these ILPs can only render us solutions for rather small network topologies where the demand has to stay relatively small. In these limited-scale cases, we found that SPR attains a network load reduction (NLR) (the number of necessary wavelengths to establish the desired protected connections) of about 20% compared to CSP.

ILP and scalable heuristics for dimensioning resilient optical grids

J. Buysse, C. Develder, M. De Leenheer and B. Dhoedt


in Proc. 14th INFORMS Telecommun. Conf., Montreal, Canada, 5-9 May 2010.

@inproceedings{Buysse2010INFORMS,
author = {Buysse, Jens and Develder, Chris and De Leenheer, Marc and Dhoedt, Bart},
title = {ILP and scalable heuristics for dimensioning resilient optical grids},
booktitle = {Proc. 14th INFORMS Telecommun. Conf.},
month = {5--9 May},
year = {2010},
address = {Montreal, Canada},
note = {Abstract only}
}

pubinproceedings

K. Mets, W. Haerick and C. Develder, "A simulator for the control network of smart grid architectures", Vol. 3, in Proc. 2nd Int. Conf. Innovation for Sustainable Production (i-SUP 2010), Bruges, Belgium, 18-21 Apr. 2010, pp. 50-54.

A simulator for the control network of smart grid architectures

K. Mets, W. Haerick and C. Develder


, Vol. 3in Proc. 2nd Int. Conf. Innovation for Sustainable Production (i-SUP 2010), Bruges, Belgium, 18-21 Apr. 2010, pp. 50-54.

We present an extensible simulation framework that has been developed to facilitate research on smart data exchange in power grids. Smart grids integrate traditional power grid technologies and information and communication technologies to generate, transport, distribute and consume energy in a more efficient manner. The framework not only incorporates the main power grid characteristics, but also explicitly models the communication network and control entities. Thus we enable the study of realistic implementation approaches to coordination mechanisms for smart grid applications. These coordination mechanisms are required for example to balance demand and supply, especially considering energy originating from renewable energy sources. We illustrate the design of the simulator with a use case in which the integration of electric vehicles in the distribution grid is managed.

A simulator for the control network of smart grid architectures

K. Mets, W. Haerick and C. Develder


, Vol. 3in Proc. 2nd Int. Conf. Innovation for Sustainable Production (i-SUP 2010), Bruges, Belgium, 18-21 Apr. 2010, pp. 50-54.

@inproceedings{Mets2010iSUP,
author = {Mets, Kevin and Haerick, Wouter and Develder, Chris},
title = {A simulator for the control network of smart grid architectures},
booktitle = {Proc. 2nd Int. Conf. Innovation for Sustainable Production (i-SUP 2010)},
month = {18--21 Apr.},
year = {2010},
volume = {3},
pages = {50--54},
address = {Bruges, Belgium}
}

pubinproceedings

K. Mets, T. Verschueren, W. Haerick, C. Develder and F. De Turck, "Optimizing smart energy control strategies for plug-in hybrid electric vehicle charging", in Proc. 1st IFIP/IEEE Int. Workshop on Management of Smart Grids, at 2010 IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2010), Osaka, Japan, 19-23 Apr. 2010, pp. 293-299.

Optimizing smart energy control strategies for plug-in hybrid electric vehicle charging

K. Mets, T. Verschueren, W. Haerick, C. Develder and F. De Turck


in Proc. 1st IFIP/IEEE Int. Workshop on Management of Smart Grids, at 2010 IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2010), Osaka, Japan, 19-23 Apr. 2010, pp. 293-299.

The electrification of the vehicle fleet will result in an additional load on the power grid. Adequately dealing with such pluggable (hybrid) electrical vehicles (PHEV) forms part of the challenges and opportunities in the evolution towards Smart Grids. In this paper, we investigate the potential benefits of using control mechanisms, that could be offered by a Home Energy control box, in optimizing energy consumption stemming from PHEV charging in a residential use case. We present smart energy control strategies based on quadratic programming for charging PHEVs, aiming to minimize the peak load and flatten the overall load profile. We compare two strategies, and benchmark them against a business-as-usual scenario assuming full charging starting upon plugging in the PHEV. The first, local strategy only uses information at the home where the PHEV is charged: as a result the charging is optimized for local loads. The local strategy is compared to a global iterative strategy which controls the charging of multiple vehicles based on global load information over a residential area. Both strategies control the duration and rate of charging and result in charging schedules for each vehicle. We present quantitative simulation results over a set of 150 homes, and discuss the strategies in terms of complexity and performance (esp. resulting energy consumption), as well as their requirements concerning infrastructure and communication.

Optimizing smart energy control strategies for plug-in hybrid electric vehicle charging

K. Mets, T. Verschueren, W. Haerick, C. Develder and F. De Turck


in Proc. 1st IFIP/IEEE Int. Workshop on Management of Smart Grids, at 2010 IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2010), Osaka, Japan, 19-23 Apr. 2010, pp. 293-299.

@inproceedings{Mets2010NOMS,
author = {Mets, Kevin and Verschueren, Tom and Haerick, Wouter and Develder, Chris and De Turck, Filip},
title = {Optimizing smart energy control strategies for plug-in hybrid electric vehicle charging},
booktitle = {Proc. 1st IFIP/IEEE Int. Workshop on Management of Smart Grids, at 2010 IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2010)},
month = {19--23 Apr.},
year = {2010},
pages = {293--299},
address = {Osaka, Japan},
doi = {10.1109/NOMSW.2010.5486561}
}

pubinproceedings

T. Verschueren, K. Mets, W. Haerick, C. Develder, F. De Turck and T. Pollet, "Architectures for smart end-user services in the power grid", in Proc. 1st IFIP/IEEE Int. Workshop on Management of Smart Grids, at 2010 IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2010), Osaka, Japan, 19-23 Apr. 2010, pp. 316-322.

Architectures for smart end-user services in the power grid

T. Verschueren, K. Mets, W. Haerick, C. Develder, F. De Turck and T. Pollet


in Proc. 1st IFIP/IEEE Int. Workshop on Management of Smart Grids, at 2010 IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2010), Osaka, Japan, 19-23 Apr. 2010, pp. 316-322.

The increase of distributed renewable electricity generators, such as solar cells and wind turbines, requires a new energy management system. These distributed generators introduce bidirectional energy flows in the low-voltage power grid, requiring novel coordination mechanisms to balance local supply and demand. Closed solutions exist for energy management on the level of individual homes. However, no service architectures have been defined that allow the growing number of end-users to interact with the other power consumers and generators and to get involved in more rational energy consumption patterns using intuitive applications. We therefore present a common service architecture that allows houses with renewable energy generation and smart energy devices to plug into a distributed energy management system, integrated with the public power grid. Next to the technical details, we focus on the usability aspects of the end-user applications in order to contribute to high service adoption and optimal user involvement. The presented architecture facilitates end-users to reduce net energy consumption, enables power grid providers to better balance supply and demand, and allows new actors to join with new services. We present a novel simulator that allows to evaluate both the power grid and data communication aspects, and illustrate a 22% reduction of the peak load by deploying a central coordinator inside the home gateway of an end-user.

Architectures for smart end-user services in the power grid

T. Verschueren, K. Mets, W. Haerick, C. Develder, F. De Turck and T. Pollet


in Proc. 1st IFIP/IEEE Int. Workshop on Management of Smart Grids, at 2010 IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2010), Osaka, Japan, 19-23 Apr. 2010, pp. 316-322.

@inproceedings{Verschueren2010NOMS,
author = {Verschueren, Tom and Mets, Kevin and Haerick, Wouter and Develder, Chris and De Turck, Filip and Pollet, Thierry},
title = {Architectures for smart end-user services in the power grid},
booktitle = {Proc. 1st IFIP/IEEE Int. Workshop on Management of Smart Grids, at 2010 IEEE/IFIP Netw. Operations and Management Symp. (NOMS 2010)},
month = {19--23 Apr.},
year = {2010},
pages = {316--322},
address = {Osaka, Japan},
doi = {10.1109/NOMSW.2010.5486557}
}

pubinproceedings

E. Peeters, C. Develder, J. Das, J. Driesen and R. Belmans, "LINEAR: towards a breakthrough of smart grids in Flanders", Vol. 3, in Proc. 2nd Int. Conf. Innovation for Sustainable Production (i-SUP 2010), Bruges, Belgium, 18-21 Apr. 2010, pp. 3-6.

LINEAR: towards a breakthrough of smart grids in Flanders

E. Peeters, C. Develder, J. Das, J. Driesen and R. Belmans


in Proc. 2nd Int. Conf. Innovation for Sustainable Production (i-SUP 2010), Bruges, Belgium, 18-21 Apr. 2010, pp. 3-6.

Smart grids refer to electricity networks that enable a more efficient (both economical and energetic), reliable and sustainable energy production and distribution. Such networks integrate innovative tools, technologies, products and services throughout the value chain — starting from production through transmission, distribution and supply completely to the devices and installations of the consumers — by the use of monitoring, communication and control technologies. Smart grids support bidirectional real-time exchange of both energy and information. As a result the end users have access to more accurate and timely information regarding their energy consumption and to several options regarding different tariff structures, which enables demand side integration and an improvement of the energy-efficiency. To implement the new structure for sustainable energy supply on a large scale in Flanders by 2020 (and beyond), a transition is necessary with short term action points, that are however based on a mid and long term strategy. The “breakthrough” project Linear (Local Intelligent Networks and Energy Active Regions) is a first crucial step in this transition towards Smart Grids. The project focuses on the realization of a technological and implementation breakthrough by innovative technological research and a large scale pilot in a residential area. All this in close collaboration with industrial partners and associated Flemish innovation platforms. The project has a budget of 9,5 M€ for the research institutes (ESAT/Electa-KULeuven, IBBT, VITO and IMEC) during a period of 5 years starting from may 2009. Besides this, the industrial partners invest a budget of more than 32 M€. This paper presents an overview of the project, with a focus on its specific short and long term goals and objectives.

LINEAR: towards a breakthrough of smart grids in Flanders

E. Peeters, C. Develder, J. Das, J. Driesen and R. Belmans


in Proc. 2nd Int. Conf. Innovation for Sustainable Production (i-SUP 2010), Bruges, Belgium, 18-21 Apr. 2010, pp. 3-6.

@inproceedings{Peeters2010,
author = {Peeters, Eefje and Develder, Chris and Das, J. and Driesen, Johan and Belmans, Ronnie},
title = {LINEAR: towards a breakthrough of smart grids in Flanders},
booktitle = {Proc. 2nd Int. Conf. Innovation for Sustainable Production (i-SUP 2010)},
month = {18--21 Apr.},
year = {2010},
volume = {3},
pages = {3--6},
address = {Bruges, Belgium}
}

pubarticle

B. Boone, S. Van Hoecke, G. Van Seghbroeck, N. Jonckheere, V. Jonckers, F. De Turck, C. Develder and B. Dhoedt, "SALSA: QoS-aware load balancing for autonomous service brokering", J. Syst. Softw., Vol. 83, No. 3, Mar. 2010, pp. 446-456.

SALSA: QoS-aware load balancing for autonomous service brokering

B. Boone, S. Van Hoecke, G. Van Seghbroeck, N. Jonckheere, V. Jonckers, F. De Turck, C. Develder and B. Dhoedt


J. Syst. Softw., Vol. 83, No. 3, Mar. 2010, pp. 446-456.

The evolution towards #Software##as##a##Service#, facilitated by various web service technologies, has led to applications composed of a number of service building blocks. These applications are dynamically composed by web service brokers, but rely critically on proper functioning of each of the composing subparts which is not entirely under control of the applications themselves. The problem at hand for the provider of the service is to guarantee non-functional requirements such as service access and performance to each customer. To this end, the service provider typically divides the load of incoming service requests across the available server infrastructure. In this paper we describe an adaptive load balancing strategy called SALSA (Simulated Annealing Load Spreading Algorithm), which is able to guarantee for different customer priorities, such as default and premium customers, that the services are handled in a given time and this without the need to adapt the servers executing the service logic themselves. It will be shown that by using SALSA, web service brokers are able to autonomously meet SLAs, without a priori over-dimensioning resources. This will be done by taking into account a real time view of the requests by measuring the Poisson arrival rates at that moment and selectively drop some requests from default customers. This way the web servers' load is reduced in order to guarantee the service time for premium customers and provide best effort to default customers. We compared the results of SALSA with weighted round-robin (WRR), nowadays the most used load balancing strategy, and it was shown that the SALSA algorithm requires slightly more processing than WRR but is able to offer guarantees -contrary to WRR- by dynamically adapting its load balancing strategy.

SALSA: QoS-aware load balancing for autonomous service brokering

B. Boone, S. Van Hoecke, G. Van Seghbroeck, N. Jonckheere, V. Jonckers, F. De Turck, C. Develder and B. Dhoedt


J. Syst. Softw., Vol. 83, No. 3, Mar. 2010, pp. 446-456.

@article{Boone2010,
author = {Boone, Bas and Van Hoecke, Sofie and Van Seghbroeck, Gregory and Jonckheere, Niels and Jonckers, Viviane and De Turck, Filip and Develder, Chris and Dhoedt, Bart},
title = {SALSA: QoS-aware load balancing for autonomous service brokering},
journal = {J. Syst. Softw.},
month = {Mar.},
year = {2010},
volume = {83},
number = {3},
pages = {446--456},
doi = {10.1016/j.jss.2009.09.033}
}

pubinproceedings

J. Buysse, M. De Leenheer, B. Dhoedt and C. Develder, "On the impact of relocation on network dimensions in resilient optical grids", in Proc. 14th Int. Conf. on Optical Network Design and Modelling (ONDM 2010), Kyoto, Japan, 31 Jan.-3 Feb. 2010.

On the impact of relocation on network dimensions in resilient optical grids

J. Buysse, M. De Leenheer, B. Dhoedt and C. Develder


in Proc. 14th Int. Conf. on Optical Network Design and Modelling (ONDM 2010), Kyoto, Japan, 31 Jan.-3 Feb. 2010.

Optical networks, with their high bandwidths and low latencies, are excellent to support Grid applications, esp. those arising in so-called eScience applications. In this paper, we consider the resulting so-called optical grids. We address the issue of resiliency against network failures and show how the Grid-specific anycast principle can be exploited in providing shared protection. Since in Grid scenarios users generally allow the Grid system to decide upon the location where jobs are executed, we exploit relocation to alternate backup sites in case of failures. We provide integer linear programming (ILP) solutions to the resulting routing and wavelength assignment problems, as well as a scalable heuristic. A case study on a European network topology shows that this relocation allows savings in the order of 16% of total wavelength capacity compared to traditional shared path protection.

On the impact of relocation on network dimensions in resilient optical grids

J. Buysse, M. De Leenheer, B. Dhoedt and C. Develder


in Proc. 14th Int. Conf. on Optical Network Design and Modelling (ONDM 2010), Kyoto, Japan, 31 Jan.-3 Feb. 2010.

@inproceedings{Buysse2010ONDM,
author = {Jens Buysse and De Leenheer, Marc and Bart Dhoedt and Chris Develder},
title = {On the impact of relocation on network dimensions in resilient optical grids},
booktitle = {Proc. 14th Int. Conf. on Optical Network Design and Modelling (ONDM 2010)},
month = {31 Jan.--3 Feb.},
year = {2010},
address = {Kyoto, Japan},
note = {Travel Grant Award},
doi = {10.1109/ONDM.2010.5431591}
}

pubarticle

T. Stevens, T. Wauters, C. Develder, F. De Turck, B. Dhoedt and P. Demeester, "Analysis of an anycast based overlay system for scalable service discovery and execution", Comput. Netw., Vol. 54, No. 1, Jan. 2010, pp. 97-111.

Analysis of an anycast based overlay system for scalable service discovery and execution

T. Stevens, T. Wauters, C. Develder, F. De Turck, B. Dhoedt and P. Demeester


Comput. Netw., Vol. 54, No. 1, Jan. 2010, pp. 97-111.

Support for anycast in the IP network layer allows one source node to contact a single member out of a group of destination nodes configured with the same IP address. Due to the stateless nature of the IP protocol, subsequent packets from the same source node targeted at the same anycast group may arrive at different group members. Consequently, native IP anycast cannot be applied directly to support distributed session-based services. For this reason, an anycast overlay architecture combining the transparency offered by native anycast with support for stateful communications has been proposed. In this paper, we investigate the operational impact of deploying this overlay architecture. Performance evaluation of a data plane prototype implementation for an anycast overlay node shows that high throughput and small latency can be achieved. Additionally, we show how threshold-based update triggering, in combination with an appropriate inter-proxy update strategy, delivers control plane accuracy with minimal network overhead.

Analysis of an anycast based overlay system for scalable service discovery and execution

T. Stevens, T. Wauters, C. Develder, F. De Turck, B. Dhoedt and P. Demeester


Comput. Netw., Vol. 54, No. 1, Jan. 2010, pp. 97-111.

@article{Stevens2010,
author = {Tim Stevens and Tim Wauters and Chris Develder and De Turck, Filip and Bart Dhoedt and Piet Demeester},
title = {Analysis of an anycast based overlay system for scalable service discovery and execution},
journal = {Comput. Netw.},
month = {Jan.},
year = {2010},
volume = {54},
number = {1},
pages = {97--111},
doi = {10.1016/j.comnet.2009.08.008}
}

pubinproceedings

W. Haerick, J. Nelis, D. Verslype, C. Develder, F. De Turck and B. Dhoedt, "Trust as differentiator for value-adding home service providers", in Proc. 1st Int. Workshop on Comput.Trust for Self-Adaptive Systems (SelfTrust 2009), part of ComputationWorld 2009, Athens, Greece, 15-20 Nov. 2009, pp. 693-700.

Trust as differentiator for value-adding home service providers

W. Haerick, J. Nelis, D. Verslype, C. Develder, F. De Turck and B. Dhoedt


in Proc. 1st Int. Workshop on Comput.Trust for Self-Adaptive Systems (SelfTrust 2009), part of ComputationWorld 2009, Athens, Greece, 15-20 Nov. 2009, pp. 693-700.

The openness of OSGi home service delivery platforms enables a service provider to deploy new services which aggregate services from other providers. Without security measures, each service provider is able to probe the home network, modify the configurations of other services, and (ab)use these services in favor of their own services. Premium service providers however prefer to protect their value-added services in an attempt to differentiate with low-cost or free Internet-based service providers. The common home technologies however lack fine-grained security support and do not allow to configure trust-based service adaptation. In this paper, we propose an intelligent residential gateway, with three security components that facilitate trust-based service adaptation in a multi provider environment. Using XACML policies, the collaboration between service components can remotely be modified. Legacy services can be protected and collaboration of services can be made dependent on the outcome of any other service. We compare OSGi virtualisation, embedded OSGi security and security-as-a-service. The latter allows for fine-grained access control on method-level. In a proof-of-concept implementation, we evaluate the performance overhead of transparent service authentication and three policy administration approaches. The results illustrate a minimal overhead to add trust-based service collaboration to any(legacy) service.

Trust as differentiator for value-adding home service providers

W. Haerick, J. Nelis, D. Verslype, C. Develder, F. De Turck and B. Dhoedt


in Proc. 1st Int. Workshop on Comput.Trust for Self-Adaptive Systems (SelfTrust 2009), part of ComputationWorld 2009, Athens, Greece, 15-20 Nov. 2009, pp. 693-700.

@inproceedings{Haerick2009ComputationWorld,
author = {Haerick, Wouter and Nelis, Jelle and Verslype, Dieter and Develder, Chris and De Turck, Filip and Dhoedt, Bart},
title = {Trust as differentiator for value-adding home service providers},
booktitle = {Proc. 1st Int. Workshop on Comput.Trust for Self-Adaptive Systems (SelfTrust 2009), part of ComputationWorld 2009},
month = {15--20 Nov.},
year = {2009},
pages = {693--700},
address = {Athens, Greece},
doi = {10.1109/ComputationWorld.2009.108}
}

pubinproceedings

K. Mets, J. Nelis, D. Verslype, P. Leroux, W. Haerick, F. De Turck and C. Develder, "Design of a context aware multimedia management system for home environments", in Proc. 1st Int. Conf. on Adaptive and Self-adaptive Systems and Applications (Adaptive 2009), part of ComputationWorld 2009, Athens, Greece, 15-20 Nov. 2009, pp. 49-54.

Design of a context aware multimedia management system for home environments

K. Mets, J. Nelis, D. Verslype, P. Leroux, W. Haerick, F. De Turck and C. Develder


in Proc. 1st Int. Conf. on Adaptive and Self-adaptive Systems and Applications (Adaptive 2009), part of ComputationWorld 2009, Athens, Greece, 15-20 Nov. 2009, pp. 49-54.

We present the design, implementation and performanceanalysis of a multimedia management system for homeenvironments. It enables comprehensive access and controlof media that is distributed over multiple devices. Basedon automatic discovery of the media servers and renderers(i.e. audio or display devices) through UPnP, our applicationintegrates all content in a single view (merging contentand/or removing duplicate items). The application is tailoredto a mobile platform and features a context aware platformto automatically select the nearest display device. Adaptivecontent filtering can be applied to restrict the list to content supported by this device. Performance measurements on a proof of concept implementation are presented.

Design of a context aware multimedia management system for home environments

K. Mets, J. Nelis, D. Verslype, P. Leroux, W. Haerick, F. De Turck and C. Develder


in Proc. 1st Int. Conf. on Adaptive and Self-adaptive Systems and Applications (Adaptive 2009), part of ComputationWorld 2009, Athens, Greece, 15-20 Nov. 2009, pp. 49-54.

@inproceedings{Mets2009ComputationWorld,
author = {Mets, K. and Nelis, J. and Verslype, D. and Leroux, P. and Haerick, W. and De Turck, F. and Develder, C.},
title = {Design of a context aware multimedia management system for home environments},
booktitle = {Proc. 1st Int. Conf. on Adaptive and Self-adaptive Systems and Applications (Adaptive 2009), part of ComputationWorld 2009},
month = {15--20 Nov.},
year = {2009},
pages = {49--54},
address = {Athens, Greece},
doi = {10.1109/ComputationWorld.2009.111}
}

pubinproceedings

D. Verslype, J. Nelis, T. Verschueren, W. Haerick, F. De Turck and C. Develder, "Framework for ubiquitous discovery and access to home services", in Proc. 1st Int. Conf. on Advanced Service Computing (Service Computation 2009), part of ComputationWorld 2009, Athens, Greece, 15-20 Nov. 2009, pp. 398-403.

Framework for ubiquitous discovery and access to home services

D. Verslype, J. Nelis, T. Verschueren, W. Haerick, F. De Turck and C. Develder


in Proc. 1st Int. Conf. on Advanced Service Computing (Service Computation 2009), part of ComputationWorld 2009, Athens, Greece, 15-20 Nov. 2009, pp. 398-403.

To relieve the end user of the configuration burdenthat arises when new devices are installed in the (home)network, service discovery protocols (SDP) have been devised. These enable automatic discovery of the services these devices offer. Yet, the existing SDPs are not compatible or interoperable. In this paper, we propose a framework that automatically translates between the various SDPs. We also solve the problem of current SDPs that only enable discovery within a single local (sub)network. Through a remote access component, we enable sharing of the services between multiple home networks. Hence we realize sharing of services over the boundaries of SDPs and home networks. Results of performance measurements on a proof-of-concept implementation illustrate that the frameworkoperates transparently to the various SDPs: translation has no significant impact on response times compared to native SDP services.

Framework for ubiquitous discovery and access to home services

D. Verslype, J. Nelis, T. Verschueren, W. Haerick, F. De Turck and C. Develder


in Proc. 1st Int. Conf. on Advanced Service Computing (Service Computation 2009), part of ComputationWorld 2009, Athens, Greece, 15-20 Nov. 2009, pp. 398-403.

@inproceedings{Verslype2009ComputationWorld,
author = {Dieter Verslype and Jelle Nelis and Tom Verschueren and Wouter Haerick and De Turck, Filip and Develder, Chris},
title = {Framework for ubiquitous discovery and access to home services},
booktitle = {Proc. 1st Int. Conf. on Advanced Service Computing (Service Computation 2009), part of ComputationWorld 2009},
month = {15--20 Nov.},
year = {2009},
pages = {398--403},
address = {Athens, Greece},
doi = {10.1109/ComputationWorld.2009.109}
}

pubinproceedings

J. Buysse, M. De Leenheer, B. Dhoedt and C. Develder, "Exploiting relocation to reduce network dimensions of resilient optical Grids", in Proc. 7th Int. Workshop Design of Reliable Commun. Netw. (DRCN 2009), Washington, D.C., USA, 25-28 Oct. 2009, pp. 100-106.

Exploiting relocation to reduce network dimensions of resilient optical Grids

J. Buysse, M. De Leenheer, B. Dhoedt and C. Develder


in Proc. 7th Int. Workshop Design of Reliable Commun. Netw. (DRCN 2009), Washington, D.C., USA, 25-28 Oct. 2009, pp. 100-106.

Optical Grids are widely deployed to solve complex problems we are facing today. An important aspect of the supporting network is resiliency i.e. the ability to overcome network failures. In contrast to classical network protection schemes, we will not necessarily provide a back-up path between the source and the original destination. Instead, we will try to relocate the job to another server location if this means that we can provide a backup path which comprises less wavelengths than the one the traditional scheme would suggest. This relocation can be backed up by the Grid specific anycast principle: a user generally does not care where his job is executed and is only interested in its results. We present ILP formulations for both resilience schemes and we evaluate them in a case study on an European network topology.

Exploiting relocation to reduce network dimensions of resilient optical Grids

J. Buysse, M. De Leenheer, B. Dhoedt and C. Develder


in Proc. 7th Int. Workshop Design of Reliable Commun. Netw. (DRCN 2009), Washington, D.C., USA, 25-28 Oct. 2009, pp. 100-106.

@inproceedings{Buysse2009DRCN,
author = {Buysse, Jens and De Leenheer, Marc and Dhoedt, Bart and Develder, Chris},
title = {Exploiting relocation to reduce network dimensions of resilient optical Grids},
booktitle = {Proc. 7th Int. Workshop Design of Reliable Commun. Netw. (DRCN 2009)},
month = {25--28 Oct.},
year = {2009},
pages = {100--106},
address = {Washington, D.C., USA},
doi = {10.1109/DRCN.2009.5340020}
}

pubinproceedings

G. Zervas, R. Nejabati, D. Simeonidou, C. Rafaelli, M. Savi, C. Develder, M. De Leenheer, D. Colle, N. Ciulli, G. Carrozzo and M. Schiano, "Programmable multi-granular optical networks: Requirements and architecture", in Proc. 6th Int. Conf. on Broadband Commun., Netw. and Systems (Broadnets 2009), Madrid, Spain, 14-17 Sep. 2009.

Programmable multi-granular optical networks: Requirements and architecture

G. Zervas, R. Nejabati, D. Simeonidou, C. Rafaelli, M. Savi, C. Develder, M. De Leenheer, D. Colle, N. Ciulli, G. Carrozzo and M. Schiano


in Proc. 6th Int. Conf. on Broadband Commun., Netw. and Systems (Broadnets 2009), Madrid, Spain, 14-17 Sep. 2009.

This paper presents a programmable multi-granular optical cross connect (MG-OXC) and network architecture deployable in multi-service and multi-provider networks. The concept of programmable MG-OXC is introduced to provide a way of utilizing multiple switching/transport granularities to efficiently support the emerging traffic demands in both core and metro networks. For this reason, the supported bandwidth granularities include full lambdas, sub- and super-lambdas and multiple transport formats such as bursts, flows and packets. The programmability is envisaged by a software/hardware platform that simplifies network control, re-planning at the logical level and end-to-end service transparency, by translating the technology-specific information to technology independent services in an abstracted and logical manner.

Programmable multi-granular optical networks: Requirements and architecture

G. Zervas, R. Nejabati, D. Simeonidou, C. Rafaelli, M. Savi, C. Develder, M. De Leenheer, D. Colle, N. Ciulli, G. Carrozzo and M. Schiano


in Proc. 6th Int. Conf. on Broadband Commun., Netw. and Systems (Broadnets 2009), Madrid, Spain, 14-17 Sep. 2009.

@inproceedings{Zervas2009Broadnets,
author = {Georgios Zervas and Reza Nejabati and Dimitra Simeonidou and Carla Rafaelli and Michele Savi and Chris Develder and De Leenheer, Marc and Didier Colle and Nicola Ciulli and Gino Carrozzo and Marco Schiano},
title = {Programmable multi-granular optical networks: Requirements and architecture},
booktitle = {Proc. 6th Int. Conf. on Broadband Commun., Netw. and Systems (Broadnets 2009)},
month = {14--17 Sep.},
year = {2009},
address = {Madrid, Spain},
doi = {10.4108/ICST.BROADNETS2009.7402}
}

pubinproceedings

W. Vereecken, L. Deboosere, P. Simoens, B. Vermeulen, D. Colle, C. Develder, M. Pickavet, B. Dhoedt and P. Demeester, "Energy efficiency in thin client solutions", in Proc. 1st Int. ICST Workshop on Green Grids, co-located with GridNets 2009, Athens, Greece, 8 Sep. 2009.

Energy efficiency in thin client solutions

W. Vereecken, L. Deboosere, P. Simoens, B. Vermeulen, D. Colle, C. Develder, M. Pickavet, B. Dhoedt and P. Demeester


in Proc. 1st Int. ICST Workshop on Green Grids, co-located with GridNets 2009, Athens, Greece, 8 Sep. 2009.

In current society it is becoming more and more important to take energy efficiency considerations into account when designing solutions. In ICT, virtualisation is being regarded as a way to increase energy efficiency. This paper analyses the energy saving opportunities of the thin client paradigm.

Energy efficiency in thin client solutions

W. Vereecken, L. Deboosere, P. Simoens, B. Vermeulen, D. Colle, C. Develder, M. Pickavet, B. Dhoedt and P. Demeester


in Proc. 1st Int. ICST Workshop on Green Grids, co-located with GridNets 2009, Athens, Greece, 8 Sep. 2009.

@inproceedings{Vereecken2009GreenGrids,
author = {Willem Vereecken and Lien Deboosere and Pieter Simoens and Brecht Vermeulen and Didier Colle and Chris Develder and Mario Pickavet and Bart Dhoedt and Piet Demeester},
title = {Energy efficiency in thin client solutions},
booktitle = {Proc. 1st Int. ICST Workshop on Green Grids, co-located with GridNets 2009},
month = {8 Sep.},
year = {2009},
address = {Athens, Greece},
doi = {10.1007/978-3-642-11733-6_12}
}

pubarticle

T. Stevens, M. De Leenheer, C. Develder, B. Dhoedt, K. Christodoulopoulos, P. Kokkinos and E. Varvarigos, "Multi-cost job routing and scheduling in grid networks", Futur. Gener. Comp. Syst., Vol. 25, No. 8, Sep. 2009, pp. 912-925.

Multi-cost job routing and scheduling in grid networks

T. Stevens, M. De Leenheer, C. Develder, B. Dhoedt, K. Christodoulopoulos, P. Kokkinos and E. Varvarigos


Futur. Gener. Comp. Syst., Vol. 25, No. 8, Sep. 2009, pp. 912-925.

A key problem in Grid networks is how to efficiently manage the available infrastructure, in order to satisfy user requirements and maximize resource utilization. This is in large part influenced by the algorithms responsible for the routing of data and the scheduling of tasks. In this paper, we present several multi-cost algorithms for the joint scheduling of the communication and computation resources that will be used by a Grid task. We propose a multi-cost scheme of polynomial complexity that performs immediate reservations and selects the computation resource to execute the task and determines the path to route the input data. Furthermore, we introduce multi-cost algorithms that perform advance reservations and thus also find the starting times for the data transmission and the task execution. We initially present an optimal scheme of non-polynomial complexity and by appropriately pruning the set of candidate paths we also give a heuristic algorithm of polynomial complexity. Our performance results indicate that in a Grid network in which tasks are either CPU- or data-intensive (or both), it is beneficial for the scheduling algorithm to jointly consider the computational and communication problems. A comparison between immediate and advance reservation schemes shows the trade-offs with respect to task blocking probability, end-to-end delay and the complexity of the algorithms.

Multi-cost job routing and scheduling in grid networks

T. Stevens, M. De Leenheer, C. Develder, B. Dhoedt, K. Christodoulopoulos, P. Kokkinos and E. Varvarigos


Futur. Gener. Comp. Syst., Vol. 25, No. 8, Sep. 2009, pp. 912-925.

@article{Stevens2009FGCS,
author = {T. Stevens and De Leenheer, Marc and Develder, Chris and B. Dhoedt and K. Christodoulopoulos and P. Kokkinos and E. Varvarigos},
title = {Multi-cost job routing and scheduling in grid networks},
journal = {Futur. Gener. Comp. Syst.},
month = {Sep.},
year = {2009},
volume = {25},
number = {8},
pages = {912--925},
doi = {10.1016/j.future.2008.08.004}
}

pubinproceedings

M. De Leenheer, J. Buysse, C. Develder, B. Dhoedt and P. Demeester, "Deflection routing in anycast-based OBS grids", in Proc. Int. Workshop on Optical Burst/Packet Switching (WOBS), in conjunction with Broadnets 2009, Madrid, Spain, 14 Sep. 2009.

Deflection routing in anycast-based OBS grids

M. De Leenheer, J. Buysse, C. Develder, B. Dhoedt and P. Demeester


in Proc. Int. Workshop on Optical Burst/Packet Switching (WOBS), in conjunction with Broadnets 2009, Madrid, Spain, 14 Sep. 2009.

Deflection routing is a much-studied contention resolution technique in the context of Optical Burst/Packet Switching networks, as it promises to improve burst blocking performance and may reduce or even eliminate buffer requirements. An OBSbased Grid is frequently based on anycast routing, which holds even greater potential to use the deflection technique for succesful delivery of Grid jobs. As such, we propose an extension to deflection routing whereby jobs are rescheduled, to improve job blocking probabilities under various traffic parameters. We present a case study and perform simulation analysis to demonstrate the effectiveness of our proposal.

Deflection routing in anycast-based OBS grids

M. De Leenheer, J. Buysse, C. Develder, B. Dhoedt and P. Demeester


in Proc. Int. Workshop on Optical Burst/Packet Switching (WOBS), in conjunction with Broadnets 2009, Madrid, Spain, 14 Sep. 2009.

@inproceedings{DeLeenheer2009WOBS,
author = {De Leenheer, Marc and Jens Buysse and Chris Develder and Bart Dhoedt and Piet Demeester},
title = {Deflection routing in anycast-based OBS grids},
booktitle = {Proc. Int. Workshop on Optical Burst/Packet Switching (WOBS), in conjunction with Broadnets 2009},
month = {14 Sep.},
year = {2009},
address = {Madrid, Spain},
doi = {10.4108/ICST.BROADNETS2009.7831}
}

pubinproceedings

C.T.A.M. de Laat, C. Develder, A. Jukan and J. Mambretti, "High performance networks: Introduction", in Proc. 15th Int. Euro-Par Conf. Parallel Processing (Euro-Par 2009), Delft, The Netherlands, 25-28 Aug. 2009, pp. 1013-1014.

High performance networks: Introduction

C.T.A.M. de Laat, C. Develder, A. Jukan and J. Mambretti


in Proc. 15th Int. Euro-Par Conf. Parallel Processing (Euro-Par 2009), Delft, The Netherlands, 25-28 Aug. 2009, pp. 1013-1014.

his topic is devoted to communication issues in scalable compute and storage systems, such as parallel computers, networks of workstations, and clusters. All aspects of communication in modern systems were solicited, including advances in the design, implementation, and evaluation of interconnection networks, network interfaces, system and storage area networks, on-chip interconnects, communication protocols, routing and communication algorithms, and communication aspects of parallel and distributed algorithms. In total 15 papers were submitted to this topic of which we selected the 7 strongest papers. We grouped the papers in two sessions of 3 papers each and one paper was selected for the best paper session. We noted a number of papers dealing with changing topologies, stability and forwarding convergence in source routing based cluster interconnect network architectures. We grouped these for the first session. The authors of the paper titled: “Implementing a Change Assimilation Mechanism for Source Routing Interconnects” propose a mechanism that can obtain the new topology, and compute and distribute a new set of fabric paths to the source routed network end points to minimize the impact on the forwarding service. The article entitled “Dependability Analysis of a Fault-tolerant Network Reconfiguration Strateg” reports on a case study analyzing the effects of network size, mean time to node failure, mean time to node repair, mean time to network repair and coverage of the failure when using a 2D mesh network with a fault-tolerant mechanism (similar to the one used in the BlueGene/L system), that is able to remove rows and/or columns in the presence of failures. The last paper in this session: “RecTOR: A New and Efficient Method for Dynamic Network Reconfiguration” presents a new dynamic reconfiguration method, that ensures deadlock-freedom during the reconfiguration without causing performance degradation such as increased latency or decreased throughput. The second session groups 3 papers presenting methods, protocols and architectures that enhance capacities in the Networks. The paper titled: “NIC-assisted Cache-Efficient Receive Stack for Message Passing over Ethernet” presents the addition of multiqueue support in the Open-MX receive stack so that all incoming packets for the same process are treated on the same core. It then introduces the idea of binding the target end process near its dedicated receive queue. In general this multiqueue receive stack performs better than the original single queue stack, especially on large communication patterns where multiple processes are involved and manual binding is difficult. The authors of: “A Multipath Fault-Tolerant Routing Method for High-Speed Interconnection Networks” focus on the problem of fault tolerance for high-speed interconnection networks by designing a fault tolerant routing method. The goal was to solve a certain number of link and node failures, considering its impact, and occurrence probability. Their experiments show that their method allows applications to successfully finalize their execution in the presence of several faults, with an average performance value of 97% with respect to the fault-free scenarios. The paper: “Hardware implementation study of the Self-Clocked Fair Queuing Credit Aware (SCFQ-CA) and Deficit Round Robin Credit Aware (DRR-CA) scheduling algorithms” proposes specific implementations of the two schedulers taking into account the characteristics of current high-performance networks. A comparison is presented on the complexity of these two algorithms in terms of silicon area and computation delay. Finally we selected one paper for the special paper session: “A Case Study of Communication Optimizations on 3D Mesh Interconnects”. In this paper the authors present topology aware mapping as a technique to optimize communication on 3-dimensional mesh interconnects and hence improve performance. Results are presented for OpenAtom on up to 16,384 processors of Blue Gene/L, 8,192 processors of Blue Gene/P and 2,048 processors of Cray XT3.

High performance networks: Introduction

C.T.A.M. de Laat, C. Develder, A. Jukan and J. Mambretti


in Proc. 15th Int. Euro-Par Conf. Parallel Processing (Euro-Par 2009), Delft, The Netherlands, 25-28 Aug. 2009, pp. 1013-1014.

@inproceedings{DeLaat2009,
author = {de Laat, Cees T. A. M. and Chris Develder and Admela Jukan and Joe Mambretti},
title = {High performance networks: Introduction},
booktitle = {Proc. 15th Int. Euro-Par Conf. Parallel Processing (Euro-Par 2009)},
month = {25--28 Aug.},
year = {2009},
pages = {1013--1014},
address = {Delft, The Netherlands},
doi = {10.1007/978-3-642-03869-3_93}
}

pubinproceedings

C. Develder, J. Buysse, M. De Leenheer and B. Dhoedt, "Dimensioning resilient optical grids", in Proc. 5th Reliability Issues in Next Gen. Optical Netw. Workshop (RONEXT), co-located with 11th Int. Conf. on Transparent Optical Netw. (ICTON), Island of São Miguel, Azores, Portugal, 28 Jun.-2 Jul. 2009.

Dimensioning resilient optical grids

C. Develder, J. Buysse, M. De Leenheer and B. Dhoedt


in Proc. 5th Reliability Issues in Next Gen. Optical Netw. Workshop (RONEXT), co-located with 11th Int. Conf. on Transparent Optical Netw. (ICTON), Island of São Miguel, Azores, Portugal, 28 Jun.-2 Jul. 2009.

An important problem in optical networking is to dimension the network: given the amount of traffic to carry, determine the required amount of network resources (wavelengths). In traditional scenarios, the traffic is specified in terms of a source-destination based traffic matrix. In an optical Grid scenario however, the anycast principle applies: users submit jobs, and generally do not care where exactly they end up being executed. This complicates dimensioning, since the destination of traffic is not known beforehand (in contrast to the assumptions in traditional dimensioning algorithms). On the other hand, this flexibility in choosing a destination opens opportunities to save on backup network resources: to protect against failures, we can opt to redirect jobs to another location (i.e. exploit relocation). In this paper we (i) outline how to derive a traffic matrix in a stepwise grid dimensioning approach, and (ii) present an assessment of potential network resource savings in resilient network dimensioning by exploiting relocation.

Dimensioning resilient optical grids

C. Develder, J. Buysse, M. De Leenheer and B. Dhoedt


in Proc. 5th Reliability Issues in Next Gen. Optical Netw. Workshop (RONEXT), co-located with 11th Int. Conf. on Transparent Optical Netw. (ICTON), Island of São Miguel, Azores, Portugal, 28 Jun.-2 Jul. 2009.

@inproceedings{Develder2009ICTON,
author = {Chris Develder and Jens Buysse and De Leenheer, Marc and Bart Dhoedt},
title = {Dimensioning resilient optical grids},
booktitle = {Proc. 5th Reliability Issues in Next Gen. Optical Netw. Workshop (RONEXT), co-located with 11th Int. Conf. on Transparent Optical Netw. (ICTON)},
month = {28 Jun.--2 Jul.},
year = {2009},
address = {Island of São Miguel, Azores, Portugal},
doi = {10.1109/ICTON.2009.5185140}
}

pubinproceedings

M. De Leenheer, J. Buysse, C. Develder, B. Dhoedt and P. Demeester, "Design of multi-granular optical networks", in Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I), Valladolid, Spain, 10-12 Jun. 2009, pp. 107-114.

Design of multi-granular optical networks

M. De Leenheer, J. Buysse, C. Develder, B. Dhoedt and P. Demeester


in Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I), Valladolid, Spain, 10-12 Jun. 2009, pp. 107-114.

Recent years have demonstrated the limited scalability of electronic switching to realize transport networks. In response, all-optical switching has been identified as a candidate solution to enable high-capacity networking in the future. One of the fundamental challenges is to efficiently support a wide range of traffic patterns, and thus emerges the need for equipment that is both practical and economical to construct and deploy. We have previously proposed the use of multi-granular optical cross-connects (MG-OXC), which support switching on both the wavelength and sub-wavelength level. To this end, the MG-OXCs are equipped with cheap, highly scalable slow switching fabrics, as well as a small number of expensive fast switching ports. This work summarizes our earlier work to demonstrate that a small number of fast switching ports suffice to support a wide range of traffic requirements, and that multi-granular optical switching can offer cost-benefits on a network-wide scale.

Design of multi-granular optical networks

M. De Leenheer, J. Buysse, C. Develder, B. Dhoedt and P. Demeester


in Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I), Valladolid, Spain, 10-12 Jun. 2009, pp. 107-114.

@inproceedings{DeLeenheer2009NOC,
author = {De Leenheer, M and Buysse, J and Develder, C and Dhoedt, B and Demeester, P},
title = {Design of multi-granular optical networks},
booktitle = {Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I)},
month = {10--12 Jun.},
year = {2009},
pages = {107--114},
address = {Valladolid, Spain}
}

pubinproceedings

M. Pickavet, W. Vereecken, S. Demeyer, P. Audenaert, D. Colle, C. Develder and P. Demeester, "Contribution and role of network architectures in the footprint reduction of ICT", in Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I 2009), Valladolid, Spain, 9-12 Jun. 2009.

Contribution and role of network architectures in the footprint reduction of ICT

M. Pickavet, W. Vereecken, S. Demeyer, P. Audenaert, D. Colle, C. Develder and P. Demeester


in Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I 2009), Valladolid, Spain, 9-12 Jun. 2009.

Contribution and role of network architectures in the footprint reduction of ICT

M. Pickavet, W. Vereecken, S. Demeyer, P. Audenaert, D. Colle, C. Develder and P. Demeester


in Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I 2009), Valladolid, Spain, 9-12 Jun. 2009.

@inproceedings{Pickavet2009NOC,
author = {Mario Pickavet and Willem Vereecken and Sofie Demeyer and Pieter Audenaert and Didier Colle and Chris Develder and Piet Demeester},
title = {Contribution and role of network architectures in the footprint reduction of ICT},
booktitle = {Proc. Eur. Conf. on Netw. and Optical Commun., in conjunction with 4th Conf. on Optical Cabling and Infrastructure (NOC/OC&I 2009)},
month = {9--12 Jun.},
year = {2009},
address = {Valladolid, Spain}
}

pubarticle

C. Develder, B. Mukherjee, B. Dhoedt and P. Demeester, "On dimensioning optical grids and the impact of scheduling", Photonic Netw. Commun., Vol. 17, No. 3, Jun. 2009, pp. 255-265.

On dimensioning optical grids and the impact of scheduling

C. Develder, B. Mukherjee, B. Dhoedt and P. Demeester


Photonic Netw. Commun., Vol. 17, No. 3, Jun. 2009, pp. 255-265.

When deploying Grid infrastructure, the problem of dimensioning arises: how many servers to provide, where to place them, and which network to install for interconnecting server sites and users generating Grid jobs? In contrast to classical optical network design problems, it is typical of optical Grids that the destination of traffic (jobs) is not known beforehand. This leads to so-called anycast routing of jobs. For network dimensioning, this implies the absence of a clearly defined (source, destination)-based traffic matrix, since only the origin of Grid jobs (and their data) is known, but not their destination. The latter depends not only on the state of Grid resources, including network, storage, and computational resources, but also the Grid scheduling algorithm used. We present a phased solution approach to dimension all these resources, and use it to evaluate various scheduling algorithms in two European network case studies. Results show that the Grid scheduling algorithm has a substantial impact on the required network capacity. This capacity can be minimized by appropriately choosing a (reasonably small) number of server site locations: an optimal balance can be found, in between the single server site case requiring a lot of network traffic to this single location, and an overly fragmented distribution of server capacity over too many sites without much statistical multiplexing opportunities, and hence a relatively large probability of not finding free servers at nearby sites.

On dimensioning optical grids and the impact of scheduling

C. Develder, B. Mukherjee, B. Dhoedt and P. Demeester


Photonic Netw. Commun., Vol. 17, No. 3, Jun. 2009, pp. 255-265.

@article{Develder2009PNET,
author = {Chris Develder and Biswanath Mukherjee and Bart Dhoedt and Piet Demeester},
title = {On dimensioning optical grids and the impact of scheduling},
journal = {Photonic Netw. Commun.},
month = {Jun.},
year = {2009},
volume = {17},
number = {3},
pages = {255--265},
doi = {10.1007/s11107-008-0160-z}
}

pubarticle

G.S. Zervas, M. De Leenheer, L. Sadeghioon, D. Klonidis, Y. Qin, R. Nejabati, D. Simeonidou, C. Develder, B. Dhoedt and P. Demeester, "Multi-granular optical cross-connect: Design, analysis, and demonstration", IEEE/OSA J. Opt. Commun. Netw., Vol. 1, No. 1, Jun. 2009, pp. 69-84.

Multi-granular optical cross-connect: Design, analysis, and demonstration

G.S. Zervas, M. De Leenheer, L. Sadeghioon, D. Klonidis, Y. Qin, R. Nejabati, D. Simeonidou, C. Develder, B. Dhoedt and P. Demeester


IEEE/OSA J. Opt. Commun. Netw., Vol. 1, No. 1, Jun. 2009, pp. 69-84.

A fundamental issue in all-optical switching is to offer efficient and cost-effective transport services for a wide range of bandwidth granularities. This paper presents multi-granular optical cross-connect (MG-OXC) architectures that combine slow (ms regime) and fast (ns regime) switch elements, in order to support optical circuit switching (OCS), optical burst switching (OBS), and even optical packet switching (OPS). The MG-OXC architectures are designed to provide a cost-effective approach, while offering the flexibility and reconfigurability to deal with dynamic requirements of different applications. All proposed MG-OXC designs are analyzed and compared in terms of dimensionality, flexibility/reconfigurability, and scalability. Furthermore, node level simulations are conducted to evaluate the performance of MG-OXCs under different traffic regimes. Finally, the feasibility of the proposed architectures is demonstrated on an application-aware, multi-bit-rate (10 and 40 Gbps), end-to-end OBS testbed.

Multi-granular optical cross-connect: Design, analysis, and demonstration

G.S. Zervas, M. De Leenheer, L. Sadeghioon, D. Klonidis, Y. Qin, R. Nejabati, D. Simeonidou, C. Develder, B. Dhoedt and P. Demeester


IEEE/OSA J. Opt. Commun. Netw., Vol. 1, No. 1, Jun. 2009, pp. 69-84.

@article{Zervas2009JOCN,
author = {Zervas, G. S. and De Leenheer, M. and Sadeghioon, L. and Klonidis, D. and Qin, Yixuan and Nejabati, R. and Simeonidou, D. and Develder, C. and Dhoedt, B. and Demeester, P.},
title = {Multi-granular optical cross-connect: Design, analysis, and demonstration},
journal = {IEEE/OSA J. Opt. Commun. Netw.},
month = {Jun.},
year = {2009},
volume = {1},
number = {1},
pages = {69--84},
doi = {10.1364/JOCN.1.000069}
}

pubinproceedings

J. Buysse, M. De Leenheer, C. Develder, B. Dhoedt and P. Demeester, "Cost-effective burst-over-circuit-switching in a hybrid optical network", in Proc. 5th Int. Conf. Networking and Services (ICNS 2009), Valencia, Spain, 20-25 Apr. 2009, pp. 499-504.

Cost-effective burst-over-circuit-switching in a hybrid optical network

J. Buysse, M. De Leenheer, C. Develder, B. Dhoedt and P. Demeester


in Proc. 5th Int. Conf. Networking and Services (ICNS 2009), Valencia, Spain, 20-25 Apr. 2009, pp. 499-504.

All optical switching has been proposed as a candidate to allow high capacity networking in the future. Currently, Optical Circuit Switching has been widely deployed, although this approach is potentially bandwidth-inefficient for small granularity flows and needs relatively long set-up times. Research is being done into Optical Packet Switching (OPS) and Optical Burst Switching (OBS), but these kinds of architectures are not yet able to be deployed due to the large network cost they impose. This paper tries to combine the benefits from OCS and OBS, by investigating a hybrid switching technique called burst-over-circuit switching (BoCS) where both OBS and OCS are used at a specific part in the network. First, a short summary will be provided, categorising existing hybrid ideas. Then, a simulation study will evaluate how well BoCS performs compared to pure OBS or OCS and finally the feasibility of the proposed method will be investigated by a network cost analysis.

Cost-effective burst-over-circuit-switching in a hybrid optical network

J. Buysse, M. De Leenheer, C. Develder, B. Dhoedt and P. Demeester


in Proc. 5th Int. Conf. Networking and Services (ICNS 2009), Valencia, Spain, 20-25 Apr. 2009, pp. 499-504.

@inproceedings{Buysse2009ICNS,
author = {Buysse, Jens and De Leenheer, Marc and Develder, Chris and Dhoedt, Bart and Demeester, Piet},
title = {Cost-effective burst-over-circuit-switching in a hybrid optical network},
booktitle = {Proc. 5th Int. Conf. Networking and Services (ICNS 2009)},
month = {20--25 Apr.},
year = {2009},
pages = {499--504},
address = {Valencia, Spain},
doi = {10.1109/ICNS.2009.12}
}

pubarticle

M. De Leenheer, C. Develder, J. Buysse, B. Dhoedt and P. Demeester, "Performance analysis and dimensioning of multi-granular optical networks", Opt. Switch. and Netw., Vol. 6, No. 2, Apr. 2009, pp. 88-98.

Performance analysis and dimensioning of multi-granular optical networks

M. De Leenheer, C. Develder, J. Buysse, B. Dhoedt and P. Demeester


Opt. Switch. and Netw., Vol. 6, No. 2, Apr. 2009, pp. 88-98.

Recent years have demonstrated the limited scalability of electronic switching to realize transport networks. In response, all-optical switching has been identified as a candidate solution to enable high-capacity networking in the future. One of the fundamental challenges is to efficiently support a wide range of traffic patterns, and thus emerges the need for equipment that is both practical and economical to construct and deploy. We have previously proposed the use of multi-granular optical cross-connects (MG-OXC), which support switching on both the wavelength and sub-wavelength level. To this end, the MG-OXCs are equipped with cheap, highly scalable slow switching fabrics, as well as a small number of expensive fast switching ports. The goal of this work is two-fold: first to demonstrate that a small number of fast switching ports suffices to support a wide range of traffic requirements, and second that multi-granular optical switching can offer cost-benefits on a network-wide scale. The first objective is studied through simulation analysis of a single switching node, and results indicate that a limited number of fast switching ports can significantly improve burst blocking performance over slow only switches. Furthermore, under certain circumstances, the MG-OXC can even approach the performance of a fast only switch design. Secondly, we introduce an Integer Linear Programming model for the total network installation cost, and our evaluation indicates that multi-granular optical switching can be a cost-effective solution on the network level, in comparison to slow only or fast only approaches. Furthermore, we can achieve reduced costs of individual OXC nodes, which allows us to minimize scalability problems corresponding to emerging fast switching fabrics.

Performance analysis and dimensioning of multi-granular optical networks

M. De Leenheer, C. Develder, J. Buysse, B. Dhoedt and P. Demeester


Opt. Switch. and Netw., Vol. 6, No. 2, Apr. 2009, pp. 88-98.

@article{DeLeenheer2009OSN,
author = {De Leenheer, Marc and Chris Develder and Jens Buysse and Bart Dhoedt and Piet Demeester},
title = {Performance analysis and dimensioning of multi-granular optical networks},
journal = {Opt. Switch. and Netw.},
month = {Apr.},
year = {2009},
volume = {6},
number = {2},
pages = {88--98},
doi = {10.1016/j.osn.2009.02.006}
}

pubinproceedings

M. Pickavet, W. Vereecken, S. Demeyer, P. Audenaert, B. Vermeulen, C. Develder, B. Dhoedt and P. Demeester, "Worldwide energy needs for ICT: The rise of power-aware networking", in Proc. 2nd Int. Symp. Advanced Netw. and Telecommun. Sys. (ANTS 2008), Mumbai, India, 15-17 Dec. 2008.

Worldwide energy needs for ICT: The rise of power-aware networking

M. Pickavet, W. Vereecken, S. Demeyer, P. Audenaert, B. Vermeulen, C. Develder, B. Dhoedt and P. Demeester


in Proc. 2nd Int. Symp. Advanced Netw. and Telecommun. Sys. (ANTS 2008), Mumbai, India, 15-17 Dec. 2008.

As Information and Communication Technology (ICT) is becoming more and more wide-spread and pervasive in our daily life, it is important to get a realistic overview of the worldwide impact of ICT on the environment in general and on energy and electricity needs in particular. This paper reports on a detailed study to estimate this impact today and to predict how this will evolve in the future. From this survey, important conclusions for the future of ICT industry and the Internet will be drawn, and challenges and research directives will be deduced.

Worldwide energy needs for ICT: The rise of power-aware networking

M. Pickavet, W. Vereecken, S. Demeyer, P. Audenaert, B. Vermeulen, C. Develder, B. Dhoedt and P. Demeester


in Proc. 2nd Int. Symp. Advanced Netw. and Telecommun. Sys. (ANTS 2008), Mumbai, India, 15-17 Dec. 2008.

@inproceedings{Pickavet2008ANTS,
author = {Mario Pickavet and Willem Vereecken and Sofie Demeyer and Pieter Audenaert and Brecht Vermeulen and Chris Develder and Bart Dhoedt and Piet Demeester},
title = {Worldwide energy needs for ICT: The rise of power-aware networking},
booktitle = {Proc. 2nd Int. Symp. Advanced Netw. and Telecommun. Sys. (ANTS 2008)},
month = {15--17 Dec.},
year = {2008},
address = {Mumbai, India},
doi = {10.1109/ANTS.2008.4937762}
}

pubinproceedings

W. Vereecken, W. Haerick, C. Develder, D. Colle, B. Vermeulen, M. Pickavet, B. Dhoedt and P. Demeester, "Power consumption of mobile and wireless thin clients", in Proc. World Wireless Research Forum: Meeting 21 (WWRF 21), Stockholm, Sweden, 13-15 Oct. 2008, pp. 1-4.

Power consumption of mobile and wireless thin clients

W. Vereecken, W. Haerick, C. Develder, D. Colle, B. Vermeulen, M. Pickavet, B. Dhoedt and P. Demeester


in Proc. World Wireless Research Forum: Meeting 21 (WWRF 21), Stockholm, Sweden, 13-15 Oct. 2008, pp. 1-4.

The thin client paradigm is regarded as a solution for running complex applications on mobile devices. In light of the current attention for energy efficiency it is important to review the power consumption of the thin client paradigm. We build an analytical model to estimate this power consumption and use experimental data to review these estimates. This is done for UMTS and wifi technology.

Power consumption of mobile and wireless thin clients

W. Vereecken, W. Haerick, C. Develder, D. Colle, B. Vermeulen, M. Pickavet, B. Dhoedt and P. Demeester


in Proc. World Wireless Research Forum: Meeting 21 (WWRF 21), Stockholm, Sweden, 13-15 Oct. 2008, pp. 1-4.

@inproceedings{Vereecken2008,
author = {Vereecken, Willem and Haerick, Wouter and Develder, Chris and Colle, Didier and Vermeulen, Brecht and Pickavet, Mario and Dhoedt, Bart and Demeester, Piet},
title = {Power consumption of mobile and wireless thin clients},
booktitle = {Proc. World Wireless Research Forum: Meeting 21 (WWRF 21)},
month = {13--15 Oct.},
year = {2008},
pages = {1--4},
address = {Stockholm, Sweden},
url = {http://www.wwrf.ch/library.html}
}

pubinproceedings

C. Develder, M. Pickavet, B. Dhoedt and P. Demeester, "A power-saving strategy for grids", in Proc. 2nd Int. Conf. on Networks for Grid Applications (GridNets 2008), Bejing, China, 8-10 Oct. 2008.

A power-saving strategy for grids

C. Develder, M. Pickavet, B. Dhoedt and P. Demeester


in Proc. 2nd Int. Conf. on Networks for Grid Applications (GridNets 2008), Bejing, China, 8-10 Oct. 2008.

In light of recently stirred energy consumption concerns, we investigate the opportunities for power consumption reduction in Grids. Considering real life Grid traces, we note considerable fluctuations in load. We consider a peak load dimensioning strategy to derive how much servers to install in computational Grids. In lower loaded periods, there is a potential to save energy by dynamically powering on/off servers to address the actual demand for computational capacity. An appropriate scheduling and power-saving scheme can, under such lower-load conditions, considerably reduce energy consumption. The price paid is that some jobs are executed at sites more remote than closer powered-down ones. Yet, the resulting penalty in consumed bandwidth is rather limited and is expected not to cancel the power consumption advantage.

A power-saving strategy for grids

C. Develder, M. Pickavet, B. Dhoedt and P. Demeester


in Proc. 2nd Int. Conf. on Networks for Grid Applications (GridNets 2008), Bejing, China, 8-10 Oct. 2008.

@inproceedings{Develder2008GridNets,
author = {Chris Develder and Mario Pickavet and Bart Dhoedt and Piet Demeester},
title = {A power-saving strategy for grids},
booktitle = {Proc. 2nd Int. Conf. on Networks for Grid Applications (GridNets 2008)},
month = {8--10 Oct.},
year = {2008},
address = {Bejing, China}
}

pubinproceedings

M. De Leenheer, C. Develder, B. Dhoedt and P. Demeester, "Dimensioning of multi-granular optical networks", in Proc. 34th European Conf. on Optical Commun. (ECOC 2008), Brussels, Belgium, 21-25 Sep. 2008.

Dimensioning of multi-granular optical networks

M. De Leenheer, C. Develder, B. Dhoedt and P. Demeester


in Proc. 34th European Conf. on Optical Commun. (ECOC 2008), Brussels, Belgium, 21-25 Sep. 2008.

We present an ILP model for dimensioning optical networks that support wavelength and sub-wavelength switching. Results indicate significant reductions in cost and node-complexity with such multi-granular networks.

Dimensioning of multi-granular optical networks

M. De Leenheer, C. Develder, B. Dhoedt and P. Demeester


in Proc. 34th European Conf. on Optical Commun. (ECOC 2008), Brussels, Belgium, 21-25 Sep. 2008.

@inproceedings{DeLeenheer2008ECOC,
author = {De Leenheer, M. and Develder, C. and Dhoedt, B. and Demeester, P.},
title = {Dimensioning of multi-granular optical networks},
booktitle = {Proc. 34th European Conf. on Optical Commun. (ECOC 2008)},
month = {21--25 Sep.},
year = {2008},
address = {Brussels, Belgium},
doi = {10.1109/ECOC.2008.4729521}
}

pubinproceedings

M. De Leenheer, C. Develder, J. Buysse, B. Dhoedt and P. Demeester, "Dimensioning of combined OBS/OCS networks", in Proc. 5th Int. Conf. on Broadband Communications, Networks and Systems (Broadnets 2008), London, UK, 8-11 Sep. 2008, pp. 126-130.

Dimensioning of combined OBS/OCS networks

M. De Leenheer, C. Develder, J. Buysse, B. Dhoedt and P. Demeester


in Proc. 5th Int. Conf. on Broadband Communications, Networks and Systems (Broadnets 2008), London, UK, 8-11 Sep. 2008, pp. 126-130.

To cope with ever-increasing traffic demands in transport networks, all-optical switching is currently perceived as a potential solution to remove bottlenecks caused by optoelectronic conversions. An effective realization of this concept must support a wide range of traffic patterns, while remaining feasible to construct and deploy both in an economical and practical sense. In this paper, we propose the use of multi-granular optical cross-connects (MG-OXC), which support switching on both the wavelength and sub-wavelength level. To this end, the MG-OXCs are equipped with cheap, highly scalable slow switching fabrics, as well as a small number of expensive fast switching ports. The main goal of this work is to motivate the use of multi-granular switching, as this can reduce total network installation costs. To this end, we introduce an Integer Linear Programming model, and our evaluation demonstrates that multi-granular optical switching can be a cost-effective solution on the network level, in comparison to slow only or fast only approaches. Furthermore, we can achieve reduced costs of individual OXC nodes, which allows us to minimize scalability problems corresponding to emerging fast switching fabrics.

Dimensioning of combined OBS/OCS networks

M. De Leenheer, C. Develder, J. Buysse, B. Dhoedt and P. Demeester


in Proc. 5th Int. Conf. on Broadband Communications, Networks and Systems (Broadnets 2008), London, UK, 8-11 Sep. 2008, pp. 126-130.

@inproceedings{DeLeenheer2008Broadnets,
author = {De Leenheer, M. and Develder, C. and Buysse, J. and Dhoedt, B. and Demeester, P.},
title = {Dimensioning of combined OBS/OCS networks},
booktitle = {Proc. 5th Int. Conf. on Broadband Communications, Networks and Systems (Broadnets 2008)},
month = {8--11 Sep.},
year = {2008},
pages = {126--130},
address = {London, UK},
doi = {10.1109/BROADNETS.2008.4769055}
}

pubinproceedings

C. Develder, M. De Leenheer, T. Stevens, B. Dhoedt, G. Markidis and A. Tzanakaki, "Scalable impairment-aware anycast routing in multi-domain optical grid networks", Vol. 3, in Proc. 10th Int. Conf. on Transparent Optical Networks (ICTON 2008), Athens, Greece, 22-26 Jun. 2008, pp. 150-153.

Scalable impairment-aware anycast routing in multi-domain optical grid networks

C. Develder, M. De Leenheer, T. Stevens, B. Dhoedt, G. Markidis and A. Tzanakaki


, Vol. 3in Proc. 10th Int. Conf. on Transparent Optical Networks (ICTON 2008), Athens, Greece, 22-26 Jun. 2008, pp. 150-153.

In optical grid networks, the main challenge is to account for not only network parameters, but also for resource availability. Anycast routing has previously been proposed as an effective solution to provide job scheduling services in optical grids, offering a generic interface to access grid resources and services. The main weakness of this approach is its limited scalability, especially in a multi-domain scenario. This paper proposes a novel anycast proxy architecture, which extends the anycast principle to a multi-domain scenario. The main purpose of the architecture is to perform aggregation of resource and network states, and as such improve computational scalability and reduce control plane traffic. Furthermore, the architecture has the desirable properties of allowing Grid domains to maintain their autonomy and hide internal configuration details from other domains. Finally, we propose an impairment-aware anycast routing algorithm that incorporates the main physical layer characteristics of large-scale optical networks into its path computation process. By integrating the proposed routing scheme into the introduced architecture we demonstrate significant network performance improvements.

Scalable impairment-aware anycast routing in multi-domain optical grid networks

C. Develder, M. De Leenheer, T. Stevens, B. Dhoedt, G. Markidis and A. Tzanakaki


, Vol. 3in Proc. 10th Int. Conf. on Transparent Optical Networks (ICTON 2008), Athens, Greece, 22-26 Jun. 2008, pp. 150-153.

@inproceedings{Develder2008ICTON,
author = {Develder, C. and De Leenheer, M. and Stevens, T. and Dhoedt, B. and Markidis, G. and Tzanakaki, A.},
title = {Scalable impairment-aware anycast routing in multi-domain optical grid networks},
booktitle = {Proc. 10th Int. Conf. on Transparent Optical Networks (ICTON 2008)},
month = {22--26 Jun.},
year = {2008},
volume = {3},
pages = {150--153},
address = {Athens, Greece},
doi = {10.1109/ICTON.2008.4598677}
}

pubinproceedings

M. De Leenheer, C. Develder, J. Vermeir, J. Buysse, F. De Turck, B. Dhoedt and P. Demeester, "Performance analysis of a hybrid optical switch", in Proc. Int. Conf. on Optical Network Design and Modelling (ONDM 2008), Catalonia, Spain, 12-14 Mar. 2008, pp. 37-42.

Performance analysis of a hybrid optical switch

M. De Leenheer, C. Develder, J. Vermeir, J. Buysse, F. De Turck, B. Dhoedt and P. Demeester


in Proc. Int. Conf. on Optical Network Design and Modelling (ONDM 2008), Catalonia, Spain, 12-14 Mar. 2008, pp. 37-42.

To cope with ever-increasing traffic demands in transport networks, all-optical switching is currently perceived as a solution to remove bottlenecks imposed by O/E/O conversions during data transfer. The successful realization of this concept is in large part dependent on the optical switch, which must support a wide range of traffic patterns, while remaining feasible to build both in an economical and practical sense. In this paper, we show a generic design for a hybrid optical switch composed of both slow and fast switching fabrics, and present a performance analysis to provide deeper insight in its behaviour. To this end, we propose and evaluate scheduling algorithms required at the edge of the network to map traffic on the different portions of the core switch, and present a simulation analysis covering a wide range of traffic parameters and switch design choices. These results show the effectiveness of the hybrid switch in catering for short-lived circuits (bursts) by only a limited amount of costly high-speed switching components.

Performance analysis of a hybrid optical switch

M. De Leenheer, C. Develder, J. Vermeir, J. Buysse, F. De Turck, B. Dhoedt and P. Demeester


in Proc. Int. Conf. on Optical Network Design and Modelling (ONDM 2008), Catalonia, Spain, 12-14 Mar. 2008, pp. 37-42.

@inproceedings{DeLeenheer2008ONDM,
author = {De Leenheer, M. and Develder, C. and Vermeir, J. and Buysse, J. and De Turck, F. and Dhoedt, B. and Demeester, P.},
title = {Performance analysis of a hybrid optical switch},
booktitle = {Proc. Int. Conf. on Optical Network Design and Modelling (ONDM 2008)},
month = {12-14 Mar.},
year = {2008},
pages = {37--42},
address = {Catalonia, Spain},
doi = {10.1109/ONDM.2008.4578401}
}

pubarticle

T. Stevens, M. De Leenheer, C. Develder, F. De Turck, B. Dhoedt and P. Demeester, "ASTAS: Architecture for scalable and transparent anycast services", J. Commun. Netw., Vol. 9, No. 4, Dec. 2007, pp. 1229-2370.

ASTAS: Architecture for scalable and transparent anycast services

T. Stevens, M. De Leenheer, C. Develder, F. De Turck, B. Dhoedt and P. Demeester


J. Commun. Netw., Vol. 9, No. 4, Dec. 2007, pp. 1229-2370.

Native information provider (IP) anycast suffers from routing scalability issues and the lack of stateful communication support. For this reason, we propose architecture for scalable and transparent anycast services (ASTAS), a proxy-based architecture that provides support for stateful anycast communications, while retaining the transparency offered by native anycast. Dynamic resource assignment for each initiated session guarantees that a connection is established with the most suitable target server, based on network and server conditions. Traffic engineering in the overlay can be realized in an effective way due to the dissemination of aggregated state information in the anycast overlay.
To minimize the total deployment cost for ASTAS architectures, we propose optimized proxy placement and path finding heuristics based on look-ahead information gathered in network nodes. Contrary to a regular integer linear program (ILP) formulation, these heuristics allow to optimize proxy placement in large networks. A use case on a European reference network illustrates that lower proxy costs enable proxy deployment closer to the end-users, resulting in a reduced network load.

ASTAS: Architecture for scalable and transparent anycast services

T. Stevens, M. De Leenheer, C. Develder, F. De Turck, B. Dhoedt and P. Demeester


J. Commun. Netw., Vol. 9, No. 4, Dec. 2007, pp. 1229-2370.

@article{Stevens2007JCN,
author = {Stevens, Tim and De Leenheer, Marc and Develder, Chris and De Turck, Filip and Dhoedt, Bart and Demeester, Piet},
title = {ASTAS: Architecture for scalable and transparent anycast services},
journal = {J. Commun. Netw.},
month = {Dec.},
year = {2007},
volume = {9},
number = {4},
pages = {1229--2370},
doi = {10.1109/JCN.2007.6182881}
}

pubinproceedings

T. Stevens, J. Vermeir, M. De Leenheer, C. Develder, F. De Turck, B. Dhoedt and P. Demeester, "Distributed service provisioning using stateful anycast communications", in Proc. 32nd IEEE Conf. on Local Computer Networks (LCN 2007), Dublin, Ireland, 15-18 Oct. 2007, pp. 165-174.

Distributed service provisioning using stateful anycast communications

T. Stevens, J. Vermeir, M. De Leenheer, C. Develder, F. De Turck, B. Dhoedt and P. Demeester


in Proc. 32nd IEEE Conf. on Local Computer Networks (LCN 2007), Dublin, Ireland, 15-18 Oct. 2007, pp. 165-174.

Notwithstanding IP anycast's introduction in Internet standards dates back to 1993 and its more recent adoption in IPv6 standards, its use in production environments is limited to date. This is mainly because native IP anycast lacks routing scalability and does not support session-based communications, thereby limiting its applicability to single request-response services such as DNS. For this reason, we propose a transparent anycast overlay architecture that retains the strengths of native anycast and neutralizes above-mentioned limitations. The resulting proxy infrastructure unleashes the power of anycast by opening up new opportunities for transparent distributed service provisioning. Taking into account user demands, available resources, network overhead and anycast infrastructure costs, we provide near- optimal heuristics for the placement of proxy nodes and dimensioning the infrastructure in large networks. We show that even modest overlay infrastructures, consisting of a small number of proxy routers, provide an effective stateful anycast solution where the detour via the proxy routers is negligible in terms of extra network load. Furthermore, simulation results illustrate that server state aggregation in the proxy nodes lessens control plane overhead, which contributes significantly to service robustness.

Distributed service provisioning using stateful anycast communication

T. Stevens, J. Vermeir, M. De Leenheer, C. Develder, F. De Turck, B. Dhoedt and P. Demeester


in Proc. 32nd IEEE Conf. on Local Computer Networks (LCN 2007), Dublin, Ireland, 15-18 Oct. 2007, pp. 165-174.

@inproceedings{Stevens2007LCN,
author = {Stevens, T. and Vermeir, J. and De Leenheer, M. and Develder, C. and De Turck, F. and Dhoedt, B. and Demeester, P. },
title = {Distributed service provisioning using stateful anycast communication},
booktitle = {Proc. 32nd IEEE Conf. on Local Computer Networks (LCN 2007)},
month = {15--18 Oct.},
year = {2007},
pages = {165--174},
address = {Dublin, Ireland},
doi = {10.1109/LCN.2007.26}
}

pubinproceedings

C. Develder, M. De Leenheer, B. Dhoedt and P. Demeester, "Evaluation of optical grid scheduling through dimensioning", in Proc. 33rd European Conf. and Exhibition on Optical Commun. (ECOC 2007), Berlin, Germany, 16-20 Sep. 2007.

Evaluation of optical grid scheduling through dimensioning

C. Develder, M. De Leenheer, B. Dhoedt and P. Demeester


in Proc. 33rd European Conf. and Exhibition on Optical Commun. (ECOC 2007), Berlin, Germany, 16-20 Sep. 2007.

Evaluation of optical grid scheduling through dimensioning

C. Develder, M. De Leenheer, B. Dhoedt and P. Demeester


in Proc. 33rd European Conf. and Exhibition on Optical Commun. (ECOC 2007), Berlin, Germany, 16-20 Sep. 2007.

@inproceedings{Develder2007ECOC,
author = {Chris Develder and De Leenheer, Marc and Bart Dhoedt and Piet Demeester},
title = {Evaluation of Optical Grid Scheduling through Dimensioning},
booktitle = {Proc. 33rd European Conf. and Exhibition on Optical Commun. (ECOC 2007)},
month = {16--20 Sep.},
year = {2007},
address = {Berlin, Germany}
}

pubinproceedings

M. De Leenheer, C. Develder, T. Stevens, B. Dhoedt, M. Pickavet and P. Demeester, "Design and control of optical grid networks" (Invited), in Proc. 4th Int. Conf. on Broadband Networks (Broadnets 2007), Raleigh, NC, 10-14 Sep. 2007, pp. 107-115.

Design and control of optical grid networks (Invited)

M. De Leenheer, C. Develder, T. Stevens, B. Dhoedt, M. Pickavet and P. Demeester


in Proc. 4th Int. Conf. on Broadband Networks (Broadnets 2007), Raleigh, NC, 10-14 Sep. 2007, pp. 107-115.

Grid computing aims to realize a high-performance computing environment, while increasing the usage efficiency of installed resources. This puts considerable constraints on the network technology, and ultimately has led to the development of Grids over optical networks. In this paper, we investigate the fundamental question of how to optimize the performance of such Grid networks. We start with an analysis of different architectural approaches (and their respective technological choices) to integrate Grid computing with optical networks. This results in models and algorithms to design optical Grid networks, and we show the importance to combine both dimensioning (offline) and scheduling (online) in the design phase of such systems. Finally, the concept of anycast routing is introduced and motivated. Both exact and heuristic algorithms are proposed, and their performance in terms of blocking probability and latency is presented.

Design and control of optical grid networks (Invited)

M. De Leenheer, C. Develder, T. Stevens, B. Dhoedt, M. Pickavet and P. Demeester


in Proc. 4th Int. Conf. on Broadband Networks (Broadnets 2007), Raleigh, NC, 10-14 Sep. 2007, pp. 107-115.

@inproceedings{DeLeenheer2007BroadNets,
author = {De Leenheer, Marc and Chris Develder and Tim Stevens and Bart Dhoedt and Mario Pickavet and Piet Demeester},
title = {Design and control of optical Grid networks (Invited)},
booktitle = {Proc. 4th Int. Conf. on Broadband Networks (Broadnets 2007)},
month = { 10--14 Sep. },
year = {2007},
pages = {107--115},
address = {Raleigh, NC},
doi = {10.1109/BROADNETS.2007.4550413}
}

pubinproceedings

C. Develder, M. De Leenheer, T. Stevens, B. Dhoedt, F. De Turck and P. Demeester, "Scheduling in optical grids: A dimensioning point of view", in Proc. Conf. on the Optical Internet - Australian Conference on Optical Fibre Technology (COIN-ACOFT), Melbourne, Australia, 24-27 Jun. 2007.

Scheduling in optical grids: A dimensioning point of view

C. Develder, M. De Leenheer, T. Stevens, B. Dhoedt, F. De Turck and P. Demeester


in Proc. Conf. on the Optical Internet - Australian Conference on Optical Fibre Technology (COIN-ACOFT), Melbourne, Australia, 24-27 Jun. 2007.

Scheduling in optical grids: A dimensioning point of view

C. Develder, M. De Leenheer, T. Stevens, B. Dhoedt, F. De Turck and P. Demeester


in Proc. Conf. on the Optical Internet - Australian Conference on Optical Fibre Technology (COIN-ACOFT), Melbourne, Australia, 24-27 Jun. 2007.

@inproceedings{Develder2007COIN,
author = {Develder, Chris and De Leenheer, Marc and Stevens, Tim and Dhoedt, Bart and De Turck, Filip and Demeester, Piet},
title = {Scheduling in optical grids: a dimensioning point of view},
booktitle = {Proc. Conf. on the Optical Internet - Australian Conference on Optical Fibre Technology (COIN-ACOFT)},
month = {24--27 Jun.},
year = {2007},
address = {Melbourne, Australia}
}

pubinproceedings

M. De Leenheer, C. Develder, F. De Turck, B. Dhoedt and P. Demeester, "Erlang reduced load model for optical burst switched grids", in Proc. 3rd Int. Conf. Networking and Services (ICNS 2007), Athens, Greece, 19-25 Jun. 2007.

Erlang reduced load model for optical burst switched grids

M. De Leenheer, C. Develder, F. De Turck, B. Dhoedt and P. Demeester


in Proc. 3rd Int. Conf. Networking and Services (ICNS 2007), Athens, Greece, 19-25 Jun. 2007.

This paper presents an Erlang reduced load model to analyze optical burst switched grid networks. The model allows the evaluation of job blocking probabilities, in which blocking occurs in both the transport network and the resources where jobs are processed. Additionally, a novel routing strategy is introduced to improve the usage efficiency of the existing infrastructure. Simulation analysis is used to confirm the validity and accuracy of the model, and the effectiveness of the novel routing strategy is shown for grids over OBS.

Erlang reduced load model for optical burst switched grids

M. De Leenheer, C. Develder, F. De Turck, B. Dhoedt and P. Demeester


in Proc. 3rd Int. Conf. Networking and Services (ICNS 2007), Athens, Greece, 19-25 Jun. 2007.

@inproceedings{DeLeenheer2007ICNS,
author = {De Leenheer, Marc and Chris Develder and De Turck, Filip and Bart Dhoedt and Piet Demeester},
title = {Erlang reduced load model for optical burst switched grids},
booktitle = {Proc. 3rd Int. Conf. Networking and Services (ICNS 2007)},
month = {19--25 Jun.},
year = {2007},
address = {Athens, Greece},
doi = {10.1109/ICNS.2007.62}
}

pubinproceedings

K. Christodoulopoulos, E. Varvarigos, C. Develder, M. De Leenheer and B. Dhoedt, "Job demand models for optical grid research", in Proc. 11th Int. IFIP TC6 Conf. on Optical Netw. Design and Modeling (ONDM2007), Athens, Greece, 29-31 May 2007, pp. 127-136.

Job demand models for optical grid research

K. Christodoulopoulos, E. Varvarigos, C. Develder, M. De Leenheer and B. Dhoedt


in Proc. 11th Int. IFIP TC6 Conf. on Optical Netw. Design and Modeling (ONDM2007), Athens, Greece, 29-31 May 2007, pp. 127-136.

This paper presents results from the IST Phosphorus project that studies and implements an optical Grid test-bed. A significant part of this project addresses scheduling and routing algorithms and dimensioning problems of optical grids. Given the high costs involved in setting up actual hardware implementations, simulations are a viable alternative. In this paper we present an initial study which proposes models that reflect real-world grid application traffic characteristics, appropriate for simulation purposes. We detail several such models and the corresponding process to extract the model parameters from real grid log traces, and verify that synthetically generated jobs provide a realistic approximation of the real-world grid job submission process.

Job demand models for optical grid research

K. Christodoulopoulos, E. Varvarigos, C. Develder, M. De Leenheer and B. Dhoedt


in Proc. 11th Int. IFIP TC6 Conf. on Optical Netw. Design and Modeling (ONDM2007), Athens, Greece, 29-31 May 2007, pp. 127-136.

@inproceedings{Christodoulopoulos2007,
author = {Konstantinos Christodoulopoulos and Emmanouel Varvarigos and Chris Develder and Marc De Leenheer and Bart Dhoedt},
title = {Job demand models for optical grid research},
booktitle = {Proc. 11th Int. IFIP TC6 Conf. on Optical Netw. Design and Modeling (ONDM2007)},
month = {29--31 May},
year = {2007},
pages = {127--136},
address = {Athens, Greece},
doi = {10.1007/978-3-540-72731-6_15}
}

pubinproceedings

P. Demeester, M. De Leenheer, C. Develder, J. Vermeir, T. Stevens, F. De Turck and B. Dhoedt, "Optical grid networks" (Invited), in Proc. 11th Int. IFIP TC6 Conf. on Optical Netw. Design and Modeling (ONDM2007), Athens, Greece, 29-31 May 2007, pp. 127-136.

Optical grid networks (Invited)

P. Demeester, M. De Leenheer, C. Develder, J. Vermeir, T. Stevens, F. De Turck and B. Dhoedt


in Proc. 11th Int. IFIP TC6 Conf. on Optical Netw. Design and Modeling (ONDM2007), Athens, Greece, 29-31 May 2007, pp. 127-136.

Optical grid networks (Invited)

P. Demeester, M. De Leenheer, C. Develder, J. Vermeir, T. Stevens, F. De Turck and B. Dhoedt


in Proc. 11th Int. IFIP TC6 Conf. on Optical Netw. Design and Modeling (ONDM2007), Athens, Greece, 29-31 May 2007, pp. 127-136.

@inproceedings{Demeester2007,
author = {Demeester, Piet and De Leenheer, Marc and Develder, Chris and Vermeir, J. and Stevens, Tim and De Turck, Filip and Dhoedt, Bart},
title = {Optical grid networks (Invited)},
booktitle = {Proc. 11th Int. IFIP TC6 Conf. on Optical Netw. Design and Modeling (ONDM2007)},
month = {29--31 May},
year = {2007},
pages = {127--136},
address = {Athens, Greece}
}

pubinproceedings

T. Stevens, M. de Leenheer, C. Develder, F. de Turck, B. Dhoedt and P. Demeester, "Anycast routing algorithms for effective job scheduling in optical grids", in Proc. European Conf. on Optical Commun. (ECOC 2006), Cannes, France, 24-28 Sep. 2006, pp. 1-2.

Anycast routing algorithms for effective job scheduling in optical grids

T. Stevens, M. de Leenheer, C. Develder, F. de Turck, B. Dhoedt and P. Demeester


in Proc. European Conf. on Optical Commun. (ECOC 2006), Cannes, France, 24-28 Sep. 2006, pp. 1-2.

Effective job scheduling in optical grids requires concurrent optimisation of resource and network path selection. To enable this functionality, practical anycast routing algorithms are proposed, and simulation analysis is used to compare their performance to a pseudo-optimal bound and to several heuristics.

Anycast routing algorithms for effective job scheduling in optical grids

T. Stevens, M. de Leenheer, C. Develder, F. de Turck, B. Dhoedt and P. Demeester


in Proc. European Conf. on Optical Commun. (ECOC 2006), Cannes, France, 24-28 Sep. 2006, pp. 1-2.

@inproceedings{Stevens2006ECOC,
author = {Stevens, Tim and de Leenheer, Marc and Develder, Chris and de Turck, Filip and Dhoedt, Bart and Demeester, Piet},
title = {Anycast routing algorithms for effective job scheduling in optical grids},
booktitle = {Proc. European Conf. on Optical Commun. (ECOC 2006)},
month = {24--28 Sep.},
year = {2006},
pages = {1--2},
address = {Cannes, France},
doi = {10.1109/ECOC.2006.4801318}
}

pubinproceedings

C. Develder, M. De Leenheer, T. Stevens, J. Baert, P. Thysebaert, F. De Turck, B. Dhoedt and P. Demeester, "Delivering the grid promise with optical burst switching " (Invited), in Proc. Int. Workshop on Optical Burst/Packet Switching (WOBPS East 2006), at the Joint Int. Conf. on Optical INternet and Next Generation Netwerks (COIN-NGN 2006), Jeju, South Korea, 9-13 Jul. 2006.

Delivering the grid promise with optical burst switching (Invited)

C. Develder, M. De Leenheer, T. Stevens, J. Baert, P. Thysebaert, F. De Turck, B. Dhoedt and P. Demeester


in Proc. Int. Workshop on Optical Burst/Packet Switching (WOBPS East 2006), at the Joint Int. Conf. on Optical INternet and Next Generation Netwerks (COIN-NGN 2006), Jeju, South Korea, 9-13 Jul. 2006.

Delivering the grid promise with optical burst switching (Invited)

C. Develder, M. De Leenheer, T. Stevens, J. Baert, P. Thysebaert, F. De Turck, B. Dhoedt and P. Demeester


in Proc. Int. Workshop on Optical Burst/Packet Switching (WOBPS East 2006), at the Joint Int. Conf. on Optical INternet and Next Generation Netwerks (COIN-NGN 2006), Jeju, South Korea, 9-13 Jul. 2006.

@inproceedings{Develder2006,
author = {Develder, Chris and De Leenheer, Marc and Stevens, Tim and Baert, Jurgen and Thysebaert, Pieter and De Turck, Filip and Dhoedt, Bart and Demeester, Piet},
title = {Delivering the grid promise with optical burst switching (Invited)},
booktitle = {Proc. Int. Workshop on Optical Burst/Packet Switching (WOBPS East 2006), at the Joint Int. Conf. on Optical INternet and Next Generation Netwerks (COIN-NGN 2006)},
month = {9--13 Jul.},
year = {2006},
address = {Jeju, South Korea}
}

pubinproceedings

J. Cheyns, D. Colle, C. Develder, E. Van Breusegem, M. Pickavet and P. Demeester, "Upgrade scenarios for OPS networks", in Proc. 9th Conf. on Optical Network Design and Modelling (ONDM 2005), Milan, Italy, 7-9 Feb. 2005, pp. 27-39.

Upgrade scenarios for OPS networks

J. Cheyns, D. Colle, C. Develder, E. Van Breusegem, M. Pickavet and P. Demeester


in Proc. 9th Conf. on Optical Network Design and Modelling (ONDM 2005), Milan, Italy, 7-9 Feb. 2005, pp. 27-39.

Upgrade scenarios for OPS networks

J. Cheyns, D. Colle, C. Develder, E. Van Breusegem, M. Pickavet and P. Demeester


in Proc. 9th Conf. on Optical Network Design and Modelling (ONDM 2005), Milan, Italy, 7-9 Feb. 2005, pp. 27-39.

@inproceedings{Cheyns2005ONDM,
author = {Jan Cheyns and Didier Colle and Chris Develder and Van Breusegem, Erik and Mario Pickavet and Piet Demeester},
title = {Upgrade scenarios for OPS networks},
booktitle = {Proc. 9th Conf. on Optical Network Design and Modelling (ONDM 2005)},
month = {7--9 Feb.},
year = {2005},
pages = {27--39},
address = {Milan, Italy},
doi = {10.1109/ONDM.2005.1426983}
}

pubarticle

C. Develder, A. Stavdas, A. Bianco, Davide, H. Lonsethagen, J.-P. Gimenez, R. Van Caenegem, S. Sygletos, F. Neri, J. Sole-Pareta, M. Pickavet, N. Le Sauze and P. Demeester, "Benchmarking and viability assessment of optical packet switching for metro networks", IEEE J. Lightwave Technol., Vol. 22, No. 11, Nov. 2004, pp. 2435-2451.

Benchmarking and viability assessment of optical packet switching for metro networks

C. Develder, A. Stavdas, A. Bianco, Davide, H. Lonsethagen, J.-P. Gimenez, R. Van Caenegem, S. Sygletos, F. Neri, J. Sole-Pareta, M. Pickavet, N. Le Sauze and P. Demeester


IEEE J. Lightwave Technol., Vol. 22, No. 11, Nov. 2004, pp. 2435-2451.

Optical packet switching (OPS) has been proposed as a strong candidate for future metro networks. This paper assesses the viability of an OPS-based ring architecture as proposed within the research project DAVID (Data And Voice Integration on DWDM), funded by the European Commission through the Information Society Technologies (IST) framework. Its feasibility is discussed from a physical-layer point of view, and its limitations in size are explored. Through dimensioning studies, we show that the proposed OPS architecture is competitive with respect to alternative metropolitan area network (MAN) approaches, including synchronous digital hierarchy, resilient packet rings (RPR), and star-based Ethernet. Finally, the proposed OPS architectures are discussed from a logical performance point of view, and a high-quality scheduling algorithm to control the packet-switching operations in the rings is explained.

Benchmarking and viability assessment of optical packet switching for metro networks

C. Develder, A. Stavdas, A. Bianco, Davide, H. Lonsethagen, J.-P. Gimenez, R. Van Caenegem, S. Sygletos, F. Neri, J. Sole-Pareta, M. Pickavet, N. Le Sauze and P. Demeester


IEEE J. Lightwave Technol., Vol. 22, No. 11, Nov. 2004, pp. 2435-2451.

@article{Develder2004JLT,
author = {Chris Develder and Alexander Stavdas and Andrea Bianco and Davide and H. Lonsethagen and J.P.F.-P. Gimenez and Van Caenegem, Ruth and S. Sygletos and Fabio Neri and J. Sole-Pareta and Mario Pickavet and Le Sauze, Nicolas and Piet Demeester},
title = {Benchmarking and viability assessment of optical packet switching for metro networks},
journal = {IEEE J. Lightwave Technol.},
month = {Nov.},
year = {2004},
volume = {22},
number = {11},
pages = {2435--2451},
doi = {10.1109/JLT.2004.836773}
}

pubarticle

F. Callegati, C. Develder, W. Cerroni, M. Pickavet and P. Demeester, "Scheduling algorithms for a slotted packet switch with either fixed or variable length packets", Photonic Netw. Commun., Vol. 8, No. 2, Sep. 2004, pp. 163-176.

Scheduling algorithms for a slotted packet switch with either fixed or variable length packets

F. Callegati, C. Develder, W. Cerroni, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 8, No. 2, Sep. 2004, pp. 163-176.

Scheduling algorithms for a slotted packet switch with either fixed or variable length packets

F. Callegati, C. Develder, W. Cerroni, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 8, No. 2, Sep. 2004, pp. 163-176.

@article{Callegati2004PNET,
author = {Callegati, Franco and Develder, Chris and Cerroni, Walter and Pickavet, Mario and Demeester, Piet},
title = {Scheduling algorithms for a slotted packet switch with either fixed or variable length packets},
journal = {Photonic Netw. Commun.},
month = {Sep.},
year = {2004},
volume = {8},
number = {2},
pages = {163--176},
doi = {10.1023/B:PNET.0000033976.33668.65}
}

pubarticle

C. Develder, B. Van Houdt, C. Blondia, M. Pickavet and P. Demeester, "Analytical MMAP-based bounds for packet loss in optical packet switching with recirculating FDL buffers", Photonic Netw. Commun., Vol. 8, No. 2, Sep. 2004, pp. 149-161.

Analytical MMAP-based bounds for packet loss in optical packet switching with recirculating FDL buffers

C. Develder, B. Van Houdt, C. Blondia, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 8, No. 2, Sep. 2004, pp. 149-161.

Analytical MMAP-based bounds for packet loss in optical packet switching with recirculating FDL buffers

C. Develder, B. Van Houdt, C. Blondia, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 8, No. 2, Sep. 2004, pp. 149-161.

@article{Develder2004PNET,
author = {Develder, Chris and Van Houdt, Benny and Blondia, Chris and Pickavet, Mario and Demeester, Piet},
title = {Analytical MMAP-based bounds for packet loss in optical packet switching with recirculating FDL buffers},
journal = {Photonic Netw. Commun.},
month = {Sep.},
year = {2004},
volume = {8},
number = {2},
pages = {149--161},
doi = {10.1023/B:PNET.0000033975.88406.28}
}

pubarticle

E. Baert, C. Develder, M. Pickavet and P. Demeester, "Routing strategies to minimize packet loss in an optical packet switched network with recirculating FDL buffers", Photonic Netw. Commun., Vol. 7, No. 2, Mar. 2004, pp. 279-300.

Routing strategies to minimize packet loss in an optical packet switched network with recirculating FDL buffers

E. Baert, C. Develder, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 7, No. 2, Mar. 2004, pp. 279-300.

Routing strategies to minimize packet loss in an optical packet switched network with recirculating FDL buffers

E. Baert, C. Develder, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 7, No. 2, Mar. 2004, pp. 279-300.

@article{Baert2004PNET,
author = {Baert, Elise and Develder, Chris and Pickavet, Mario and Demeester, Piet},
title = {Routing strategies to minimize packet loss in an optical packet switched network with recirculating FDL buffers},
journal = {Photonic Netw. Commun.},
month = {Mar.},
year = {2004},
volume = {7},
number = {2},
pages = {279--300},
doi = {10.1023/B:PNET.0000026892.02534.ad}
}

pubinproceedings

J. Cheyns, C. Develder, D. Colle, E. Van Breusegem and P. Demeester, "Cost efficient upgrading of OPS nodes", IFIP Int. Federation For Information Processing, in Proc. IFIP TC6/WG6.10 1st Optical Networks and Technologies Conf. (OpNeTec 2004), Pisa, Italy, 18-20 Feb. 2004, pp. 71-78.

Cost efficient upgrading of OPS nodes

J. Cheyns, C. Develder, D. Colle, E. Van Breusegem and P. Demeester


, IFIP Int. Federation For Information Processingin Proc. IFIP TC6/WG6.10 1st Optical Networks and Technologies Conf. (OpNeTec 2004), Pisa, Italy, 18-20 Feb. 2004, pp. 71-78.

We come back on a technique to build modular switch nodes. This approach allows for a more cost effective expansion of OPS nodes. We give two example designs, showing that the method is useful only for Broadcast & Select OPS nodes when taking price decrease in function of time into account.

Cost efficient upgrading of OPS nodes

J. Cheyns, C. Develder, D. Colle, E. Van Breusegem and P. Demeester


, IFIP Int. Federation For Information Processingin Proc. IFIP TC6/WG6.10 1st Optical Networks and Technologies Conf. (OpNeTec 2004), Pisa, Italy, 18-20 Feb. 2004, pp. 71-78.

@inproceedings{Cheyns2004OpNeTec,
author = {Cheyns, Jan and Develder, Chris and Colle, Didier and Van Breusegem, Eric and Demeester, Piet},
title = {Cost efficient upgrading of OPS nodes},
booktitle = {Proc. IFIP TC6/WG6.10 1st Optical Networks and Technologies Conf. (OpNeTec 2004)},
month = {18--20 Feb.},
year = {2004},
pages = {71--78},
address = {Pisa, Italy},
doi = {10.1007/0-387-23178-1_8}
}

pubinproceedings

J. Cheyns, E. Van Breusegem, D. Develder, Chris adn Colle, M. Pickavet and P. Demeester, "Evaluating cost functions for OPS node architectures / A packaging driven approach", in Proc. 8th IFIP Working Conf. on Optical Network Design and Modelling (ONDM 2004), Ghent, Belgium, 2-4 Feb. 2004, pp. 37-56.

Evaluating cost functions for OPS node architectures / A packaging driven approach

J. Cheyns, E. Van Breusegem, D. Develder, Chris adn Colle, M. Pickavet and P. Demeester


in Proc. 8th IFIP Working Conf. on Optical Network Design and Modelling (ONDM 2004), Ghent, Belgium, 2-4 Feb. 2004, pp. 37-56.

Evaluating cost functions for OPS node architectures / A packaging driven approach

J. Cheyns, E. Van Breusegem, D. Develder, Chris adn Colle, M. Pickavet and P. Demeester


in Proc. 8th IFIP Working Conf. on Optical Network Design and Modelling (ONDM 2004), Ghent, Belgium, 2-4 Feb. 2004, pp. 37-56.

@inproceedings{Cheyns2004,
author = {Cheyns, Jan and Van Breusegem, Eric and Develder, Chris adn Colle, Didier and Pickavet, Mario and Demeester, Piet},
title = {Evaluating cost functions for OPS node architectures / A packaging driven approach},
booktitle = {Proc. 8th IFIP Working Conf. on Optical Network Design and Modelling (ONDM 2004)},
month = {2--4 Feb.},
year = {2004},
pages = {37--56},
address = {Ghent, Belgium}
}

pubinproceedings

R. Van Caenegem, C. Develder, E. Baert, D. Colle, M. Pickavet and P. Demeester, "Architectures for OPS metro rings: Comparing active versus passive nodes / A dimensioning point of view", in Proc. 8th IFIP Working Conf. on Optical Network Design and Modelling (ONDM 2004), Ghent, Belgium, 2-4 Feb. 2004, pp. 101-120.

Architectures for OPS metro rings: Comparing active versus passive nodes / A dimensioning point of view

R. Van Caenegem, C. Develder, E. Baert, D. Colle, M. Pickavet and P. Demeester


in Proc. 8th IFIP Working Conf. on Optical Network Design and Modelling (ONDM 2004), Ghent, Belgium, 2-4 Feb. 2004, pp. 101-120.

Architectures for OPS metro rings: Comparing active versus passive nodes / A dimensioning point of view

R. Van Caenegem, C. Develder, E. Baert, D. Colle, M. Pickavet and P. Demeester


in Proc. 8th IFIP Working Conf. on Optical Network Design and Modelling (ONDM 2004), Ghent, Belgium, 2-4 Feb. 2004, pp. 101-120.

@inproceedings{VanCaenegem2004,
author = {Van Caenegem, R. and Develder, Chris and Baert, Elise and Colle, Didier and Pickavet, Mario and Demeester, Piet},
title = {Architectures for OPS metro rings: Comparing active versus passive nodes / A dimensioning point of view},
booktitle = {Proc. 8th IFIP Working Conf. on Optical Network Design and Modelling (ONDM 2004)},
month = {2--4 Feb.},
year = {2004},
pages = {101--120},
address = {Ghent, Belgium}
}

pubarticle

J. Cheyns, C. Develder, E. Van Breusegem, D. Colle, F. De Turck, P. Lagasse, M. Pickavet and P. Demeester, "Clos lives on in optical packet switching", IEEE Commun. Mag., Vol. 42, No. 2, Feb. 2004, pp. 114-121.

Clos lives on in optical packet switching

J. Cheyns, C. Develder, E. Van Breusegem, D. Colle, F. De Turck, P. Lagasse, M. Pickavet and P. Demeester


IEEE Commun. Mag., Vol. 42, No. 2, Feb. 2004, pp. 114-121.

While the technological evolution since C. Clos's seminal article (see Bell Sys. Tech. J., vol.32, p.406-24, 1953) on multistage switch architectures has been huge, his work and ideas still live on. We discuss node architectures for optical packet switching and show how the multistage approach proposed by Clos can be adopted to solve scalability issues and construct switches with large port counts. As in the old days, the driving factors behind the introduction of multistage concepts also include economic issues: compared to a single-stage architecture, the number of components to realize the switching fabric is reduced.

Clos lives on in optical packet switching

J. Cheyns, C. Develder, E. Van Breusegem, D. Colle, F. De Turck, P. Lagasse, M. Pickavet and P. Demeester


IEEE Commun. Mag., Vol. 42, No. 2, Feb. 2004, pp. 114-121.

@article{Cheyns2004Commag,
author = {Cheyns, J. and Develder, C. and Van Breusegem, E. and Colle, D. and De Turck, F. and Lagasse, P. and Pickavet, M. and Demeester, P.},
title = {Clos lives on in optical packet switching},
journal = {IEEE Commun. Mag.},
month = {Feb.},
year = {2004},
volume = {42},
number = {2},
pages = {114--121},
doi = {10.1109/MCOM.2003.1267109}
}

pubinproceedings

C. Develder, J. Cheyns, M. Pickavet and P. Demeester, "Service differentiation mechanisms for variable length packets in an optical switch with recirculating FDL buffer", in Proc. Photonics in Switching (PS 2003), Versailles, France, 28 Sep.-2 Oct. 2003, pp. 92-94 (paper PS.Mo.C8).

Service differentiation mechanisms for variable length packets in an optical switch with recirculating FDL buffer

C. Develder, J. Cheyns, M. Pickavet and P. Demeester


in Proc. Photonics in Switching (PS 2003), Versailles, France, 28 Sep.-2 Oct. 2003, pp. 92-94 (paper PS.Mo.C8).

Service differentiation mechanisms for variable length packets in an optical switch with recirculating FDL buffer

C. Develder, J. Cheyns, M. Pickavet and P. Demeester


in Proc. Photonics in Switching (PS 2003), Versailles, France, 28 Sep.-2 Oct. 2003, pp. 92-94 (paper PS.Mo.C8).

@inproceedings{Develder2003PS,
author = {Develder, Chris and Cheyns, Jan and Pickavet, Mario and Demeester, Piet},
title = {Service differentiation mechanisms for variable length packets in an optical switch with recirculating FDL buffer},
booktitle = {Proc. Photonics in Switching (PS 2003)},
month = {28 Sep.--2 Oct.},
year = {2003},
pages = {92--94 (paper PS.Mo.C8)},
address = {Versailles, France}
}

pubinproceedings

C. Develder, J. Cheyns, J. Van Breusegem, E. Baert, D. Colle, M. Pickavet and P. Demeester, "Architectures for optical packet and burst switches" (Invited), in Proc. 29th Eur. Conf. Optical Commun. (ECOC 2003), Rimini, Italy, 21-25 Sep. 2003, pp. 376-377 (paper We.1.4.4).

Architectures for optical packet and burst switches (Invited)

C. Develder, J. Cheyns, J. Van Breusegem, E. Baert, D. Colle, M. Pickavet and P. Demeester


in Proc. 29th Eur. Conf. Optical Commun. (ECOC 2003), Rimini, Italy, 21-25 Sep. 2003, pp. 376-377 (paper We.1.4.4).

Architectures for optical packet and burst switches (Invited)

C. Develder, J. Cheyns, J. Van Breusegem, E. Baert, D. Colle, M. Pickavet and P. Demeester


in Proc. 29th Eur. Conf. Optical Commun. (ECOC 2003), Rimini, Italy, 21-25 Sep. 2003, pp. 376-377 (paper We.1.4.4).

@inproceedings{Develder2003ECOCb,
author = {Develder, Chris and Cheyns, Jan and Van Breusegem, Jan and Baert, Elise and Colle, Didier and Pickavet, Mario and Demeester, Piet},
title = {Architectures for optical packet and burst switches (Invited)},
booktitle = {Proc. 29th Eur. Conf. Optical Commun. (ECOC 2003)},
month = {21--25 Sep.},
year = {2003},
pages = {376--377 (paper We.1.4.4)},
address = {Rimini, Italy}
}

pubinproceedings

C. Develder, R. Van Caenegem, E. Baert, M. Pickavet and P. Demeester, "Active versus passive OPS architectures for metro rings: A network dimensioning point of view", Vol. 1, in Proc. 29th Eur. Conf. Optical Commun. (ECOC 2003), Rimini, Italy, 21-25 Sep. 2003, pp. 100-103 (paper Mo.4.4.1).

Active versus passive OPS architectures for metro rings: A network dimensioning point of view

C. Develder, R. Van Caenegem, E. Baert, M. Pickavet and P. Demeester


, Vol. 1in Proc. 29th Eur. Conf. Optical Commun. (ECOC 2003), Rimini, Italy, 21-25 Sep. 2003, pp. 100-103 (paper Mo.4.4.1).

Active versus passive OPS architectures for metro rings: A network dimensioning point of view

C. Develder, R. Van Caenegem, E. Baert, M. Pickavet and P. Demeester


, Vol. 1in Proc. 29th Eur. Conf. Optical Commun. (ECOC 2003), Rimini, Italy, 21-25 Sep. 2003, pp. 100-103 (paper Mo.4.4.1).

@inproceedings{Develder2003ECOCa,
author = {Develder, Chris and Van Caenegem, Ruth and Baert, Elise and Pickavet, Mario and Demeester, Piet},
title = {Active versus passive OPS architectures for metro rings: A network dimensioning point of view},
booktitle = {Proc. 29th Eur. Conf. Optical Commun. (ECOC 2003)},
month = {21--25 Sep.},
year = {2003},
volume = {1},
pages = {100--103 (paper Mo.4.4.1)},
address = {Rimini, Italy}
}

pubarticle

L. Dittmann, C. Develder, D. Chiaroni, F. Neri, F. Callegati, W. Koerber, A. Stavdas, M. Renaud, A. Rafel, J. Sole-Pareta, W. Cerroni, N. Leligou, L. Dembeck, B. Mortensen, M. Pickavet, N. Le Sauze, M. Mahony, B. Berde and G. Eilenberger, "The European IST project DAVID: A viable approach toward optical packet switching", IEEE J. Sel. Areas Commun., Vol. 21, No. 7, Sep. 2003, pp. 1026-1040.

The European IST project DAVID: A viable approach toward optical packet switching

L. Dittmann, C. Develder, D. Chiaroni, F. Neri, F. Callegati, W. Koerber, A. Stavdas, M. Renaud, A. Rafel, J. Sole-Pareta, W. Cerroni, N. Leligou, L. Dembeck, B. Mortensen, M. Pickavet, N. Le Sauze, M. Mahony, B. Berde and G. Eilenberger


IEEE J. Sel. Areas Commun., Vol. 21, No. 7, Sep. 2003, pp. 1026-1040.

In this paper, promising technologies and a network architecture are presented for future optical packet switched networks. The overall network concept is presented and the major choices are highlighted and compared with alternative solutions. Both long and shorter term approaches are considered, as well as both the wide-area network and multiple-area networks parts of the network. The results presented in this paper were developed in the frame of the research project DAVID (Data And Voice Integration over DWDM) project, funded by the European Commission through the IST-framework.

The European IST project DAVID: A viable approach toward optical packet switching

L. Dittmann, C. Develder, D. Chiaroni, F. Neri, F. Callegati, W. Koerber, A. Stavdas, M. Renaud, A. Rafel, J. Sole-Pareta, W. Cerroni, N. Leligou, L. Dembeck, B. Mortensen, M. Pickavet, N. Le Sauze, M. Mahony, B. Berde and G. Eilenberger


IEEE J. Sel. Areas Commun., Vol. 21, No. 7, Sep. 2003, pp. 1026-1040.

@article{Dittmann2003,
author = {Dittmann, L. and Develder, C. and Chiaroni, D. and Neri, F. and Callegati, F. and Koerber, W. and Stavdas, A. and Renaud, M. and Rafel, A. and Sole-Pareta, J. and Cerroni, W. and Leligou, N. and Dembeck, L. and Mortensen, B. and Pickavet, M. and Le Sauze, N. and Mahony, M. and Berde, B. and Eilenberger, G. },
title = {The European IST project DAVID: A viable approach toward optical packet switching},
journal = {IEEE J. Sel. Areas Commun.},
month = {Sep.},
year = {2003},
volume = {21},
number = {7},
pages = {1026--1040},
doi = {10.1109/JSAC.2003.816388}
}

pubinproceedings

C. Develder, M. Pickavet and P. Demeester, "On trains and wagons: Switching variable length packets in a slotted OPS network", in Proc. Conf. on Optical Internet / Australian Conf. on Optical Fibre Technology (COIN/ACOFT 2003), Melbourne, Australia, 13-16 Jul. 2003, pp. 233-236 (paper TuA2-6).

On trains and wagons: Switching variable length packets in a slotted OPS network

C. Develder, M. Pickavet and P. Demeester


in Proc. Conf. on Optical Internet / Australian Conf. on Optical Fibre Technology (COIN/ACOFT 2003), Melbourne, Australia, 13-16 Jul. 2003, pp. 233-236 (paper TuA2-6).

On trains and wagons: Switching variable length packets in a slotted OPS network

C. Develder, M. Pickavet and P. Demeester


in Proc. Conf. on Optical Internet / Australian Conf. on Optical Fibre Technology (COIN/ACOFT 2003), Melbourne, Australia, 13-16 Jul. 2003, pp. 233-236 (paper TuA2-6).

@inproceedings{Develder2003COIN,
author = {Develder, Chris and Pickavet, Mario and Demeester, Piet},
title = {On trains and wagons: Switching variable length packets in a slotted OPS network},
booktitle = {Proc. Conf. on Optical Internet / Australian Conf. on Optical Fibre Technology (COIN/ACOFT 2003)},
month = {13--16 Jul.},
year = {2003},
pages = {233--236 (paper TuA2-6)},
address = {Melbourne, Australia}
}

pubinproceedings

D. Colle, J. Cheyns, C. Develder, E. Van Breusegem, A. Ackaert, M. Pickavet and P. Demeester, "GMPLS extensions for supporting advanced optical networking technologies", Vol. 1, in Proc. 5th Int. Conf. on Transparent Optical Networks (ICTON 2003), Warsaw, Poland, 29 Jun.-3 Jul. 2003, pp. 170-173.

GMPLS extensions for supporting advanced optical networking technologies

D. Colle, J. Cheyns, C. Develder, E. Van Breusegem, A. Ackaert, M. Pickavet and P. Demeester


, Vol. 1in Proc. 5th Int. Conf. on Transparent Optical Networks (ICTON 2003), Warsaw, Poland, 29 Jun.-3 Jul. 2003, pp. 170-173.

In response to the need for higher flexibility in optical networks, a generalised multiprotocol label switching (GMPLS) protocol suite is currently under standardisation. However, in these standards a label switched path (LSP) hierarchy is defined that only considers circuit-switched optical networks. The paper aims at broadening the scope of this hierarchy to more advanced optical networking technologies.

GMPLS extensions for supporting advanced optical networking technologies

D. Colle, J. Cheyns, C. Develder, E. Van Breusegem, A. Ackaert, M. Pickavet and P. Demeester


, Vol. 1in Proc. 5th Int. Conf. on Transparent Optical Networks (ICTON 2003), Warsaw, Poland, 29 Jun.-3 Jul. 2003, pp. 170-173.

@inproceedings{Colle2003ICTON,
author = {Colle, D. and Cheyns, J. and Develder, C. and Van Breusegem, E. and Ackaert, A. and Pickavet, M. and Demeester, P.},
title = {GMPLS extensions for supporting advanced optical networking technologies},
booktitle = {Proc. 5th Int. Conf. on Transparent Optical Networks (ICTON 2003)},
month = {29 Jun.--3 Jul.},
year = {2003},
volume = {1},
pages = {170--173},
address = {Warsaw, Poland},
doi = {10.1109/ICTON.2003.1264604}
}

pubinproceedings

S. Bjornstad, M. Nord, D.R. Hjelme, N. Stol, C. Develder, J. Cheyns, E. Van Breusegem, E. Baert, D. Colle, M. Pickavet, P. Demeester, F. Callegati, W. Cerroni, C. Raffaelli, P. Zaffoni, M. Lackovic, C.M. Gauger, D. Careglio, G. Junyent, M. Klinkowski, M. Marciniak and M. Kowalewski, "Optical burst and packet switching: Node and network design, contention resolution and quality of service", Vol. 2, in Proc. 7th Int. Conf. on Telecommunications (ConTEL 2003), Zagreb, Croatia, 11-13 Jun. 2003, pp. 775-782.

Optical burst and packet switching: Node and network design, contention resolution and quality of service

S. Bjornstad, M. Nord, D.R. Hjelme, N. Stol, C. Develder, J. Cheyns, E. Van Breusegem, E. Baert, D. Colle, M. Pickavet, P. Demeester, F. Callegati, W. Cerroni, C. Raffaelli, P. Zaffoni, M. Lackovic, C.M. Gauger, D. Careglio, G. Junyent, M. Klinkowski, M. Marciniak and M. Kowalewski


in Proc. 7th Int. Conf. on Telecommunications (ConTEL 2003), Zagreb, Croatia, 11-13 Jun. 2003, Vol. 2, pp. 775-782.

Future network should be able to efficiently serve packet-based networks, such as the Internet. In this paper, based on results from COST 266, we explore characteristics of optical burst switching (OBS) and optical packet switching (OPS). Both node design and metropolitan area network (MAN) are discussed. A unique joint comparative performance evaluation of contention resolution in OBS and OPS are presented, as well as methods of quality of service (QoS) differentiation in OBS/OPS networks, and their performance.

Optical burst and packet switching: Node and network design, contention resolution and quality of service

S. Bjornstad, M. Nord, D.R. Hjelme, N. Stol, C. Develder, J. Cheyns, E. Van Breusegem, E. Baert, D. Colle, M. Pickavet, P. Demeester, F. Callegati, W. Cerroni, C. Raffaelli, P. Zaffoni, M. Lackovic, C.M. Gauger, D. Careglio, G. Junyent, M. Klinkowski, M. Marciniak and M. Kowalewski


in Proc. 7th Int. Conf. on Telecommunications (ConTEL 2003), Zagreb, Croatia, 11-13 Jun. 2003, Vol. 2, pp. 775-782.

@inproceedings{Bjornstad2003,
author = {Bjornstad, S. and Nord, M. and Hjelme, D. R. and Stol, N. and Develder, C. and Cheyns, J. and Van Breusegem, E. and Baert, E. and Colle, D. and Pickavet, M. and Demeester, P. and Callegati, F. and Cerroni, W. and Raffaelli, C. and Zaffoni, P. and Lackovic, M. and Gauger, C. M. and Careglio, D. and Junyent, G. and Klinkowski, M. and Marciniak, M. and Kowalewski, M.},
title = {Optical burst and packet switching: Node and network design, contention resolution and quality of service},
booktitle = {Proc. 7th Int. Conf. on Telecommunications (ConTEL 2003)},
month = {11--13 Jun.},
year = {2003},
volume = {2},
pages = {775--782},
address = {Zagreb, Croatia},
doi = {10.1109/CONTEL.2003.1215913}
}

pubinproceedings

J. Cheyns, E. Van Breusegem, C. Develder, A. Ackaert, M. Pickavet and P. Demeester, "Performance improvement of an internally blocking optical packet/burst switch", in Proc. IEEE Int. Conf. on Commun. (ICC 2003), Anchorage, AK, USA, 11-13 May 2003, Vol. 2, pp. 1304-1308.

Performance improvement of an internally blocking optical packet/burst switch

J. Cheyns, E. Van Breusegem, C. Develder, A. Ackaert, M. Pickavet and P. Demeester


in Proc. IEEE Int. Conf. on Commun. (ICC 2003), Anchorage, AK, USA, 11-13 May 2003, Vol. 2, pp. 1304-1308.

Optical packet/burst switching is considered a promising technique to improve the performance of optical networks. Key components in these technologies are the optical switching nodes. Some of these node architectures suffer from internal blocking. Synchronous operation allows overcoming most of the problems introduced by this internal blocking. However, in asynchronous networks internal blocking can have a more pronounced effect. In this paper, we propose a windowing technique to improve the performance of internally blocking optical switching nodes in asynchronous operation. Simulations will show significant improvements can be made.

Performance improvement of an internally blocking optical packet/burst switch

J. Cheyns, E. Van Breusegem, C. Develder, A. Ackaert, M. Pickavet and P. Demeester


in Proc. IEEE Int. Conf. on Commun. (ICC 2003), Anchorage, AK, USA, 11-13 May 2003, Vol. 2, pp. 1304-1308.

@inproceedings{Cheyns2003ICC,
author = {Cheyns, J. and Van Breusegem, E. and Develder, C. and Ackaert, A. and Pickavet, M. and Demeester, P.},
title = {Performance improvement of an internally blocking optical packet/burst switch},
booktitle = {Proc. IEEE Int. Conf. on Commun. (ICC 2003)},
month = {11--13 May},
year = {2003},
volume = {2},
pages = {1304--1308},
address = {Anchorage, AK, USA},
doi = {10.1109/ICC.2003.1204594}
}

pubinproceedings

C. Develder, J. Cheyns, M. Pickavet and P. Demeester, "Multistage architectures for optical packet switching using SOA-based broadcast-and-select switches", in Proc. Optical Fiber Commun./National Fiber Optic Engineers Conf. (OFC/NFOEC 2003), Atlanta, GA, USA, 23-28 Feb. 2003, Vol. 2, pp. 794-795.

Multistage architectures for optical packet switching using SOA-based broadcast-and-select switches

C. Develder, J. Cheyns, M. Pickavet and P. Demeester


in Proc. Optical Fiber Commun./National Fiber Optic Engineers Conf. (OFC/NFOEC 2003), Atlanta, GA, USA, 23-28 Feb. 2003, Vol. 2, pp. 794-795.

Optical packet/burst switches can be scaled to high port counts using multistage architectures. To reduce the number of switching elements in SOA-based broadcast-and-select architectures, we deploy only a few stages while exploiting the WDM dimension.

Multistage architectures for optical packet switching using SOA-based broadcast-and-select switches

C. Develder, J. Cheyns, M. Pickavet and P. Demeester


in Proc. Optical Fiber Commun./National Fiber Optic Engineers Conf. (OFC/NFOEC 2003), Atlanta, GA, USA, 23-28 Feb. 2003, Vol. 2, pp. 794-795.

@inproceedings{Develder2003OFC,
author = {Develder, C. and Cheyns, J. and Pickavet, M. and Demeester, P. },
title = {Multistage architectures for optical packet switching using SOA-based broadcast-and-select switches},
booktitle = {Proc. Optical Fiber Commun./National Fiber Optic Engineers Conf. (OFC/NFOEC 2003)},
month = {23--28 Feb.},
year = {2003},
volume = {2},
pages = {794--795},
address = {Atlanta, GA, USA},
doi = {10.1109/OFC.2003.1248577}
}

pubarticle

J. Cheyns, C. Develder, E. Van Breusegem, E. Baert, A. Ackaert, M. Pickavet and P. Demeester, "Routing in an AWG based optical packet switch", Photonic Netw. Commun., Vol. 5, No. 1, Jan. 2003, pp. 69-80.

Routing in an AWG based optical packet switch

J. Cheyns, C. Develder, E. Van Breusegem, E. Baert, A. Ackaert, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 5, No. 1, Jan. 2003, pp. 69-80.

Routing in an AWG based optical packet switch

J. Cheyns, C. Develder, E. Van Breusegem, E. Baert, A. Ackaert, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 5, No. 1, Jan. 2003, pp. 69-80.

@article{Cheyns2003PNET,
author = {Cheyns, Jan and Develder, Chris and Van Breusegem, Erik and Baert, Elise and Ackaert, Ann and Pickavet, Mario and Demeester, Piet},
title = {Routing in an AWG based optical packet switch},
journal = {Photonic Netw. Commun.},
month = {Jan.},
year = {2003},
volume = {5},
number = {1},
pages = {69--80},
doi = {10.1023/A:1021005913665}
}

pubinproceedings

P. Demeester, A. Ackaert, E. Baert, J. Cheyns, S. De Maesschalck, C. Develder, A. Groebbens, M. Pickavet, E. Van Breusegem and S. Verbrugge, "Optical networking: Basic concepts and recent evolutions" (Invited), in Proc. 28th European Conf. on Optical Commun. (ECOC 2002), Copenhagen, Denmark, 8-12 Sep. 2002.

Optical networking: Basic concepts and recent evolutions (Invited)

P. Demeester, A. Ackaert, E. Baert, J. Cheyns, S. De Maesschalck, C. Develder, A. Groebbens, M. Pickavet, E. Van Breusegem and S. Verbrugge


in Proc. 28th European Conf. on Optical Commun. (ECOC 2002), Copenhagen, Denmark, 8-12 Sep. 2002.

Optical networking: Basic concepts and recent evolutions (Invited)

P. Demeester, A. Ackaert, E. Baert, J. Cheyns, S. De Maesschalck, C. Develder, A. Groebbens, M. Pickavet, E. Van Breusegem and S. Verbrugge


in Proc. 28th European Conf. on Optical Commun. (ECOC 2002), Copenhagen, Denmark, 8-12 Sep. 2002.

@inproceedings{Demeester2002,
author = {Demeester, Piet and Ackaert, A. and Baert, Elise and Cheyns, Jan and De Maesschalck, Sophie and Develder, Chris and Groebbens, Adelbert and Pickavet, Mario and Van Breusegem, Eric and Verbrugge, Sofie},
title = {Optical networking: Basic concepts and recent evolutions (Invited)},
booktitle = {Proc. 28th European Conf. on Optical Commun. (ECOC 2002)},
month = {8--12 Sep.},
year = {2002},
address = {Copenhagen, Denmark}
}

pubinproceedings

C. Develder, M. Pickavet and P. Demeester, "Choosing an appropriate buffer strategy for an optical packet switch with a feed-back FDL buffer", in Proc. 28th European Conf. on Optical Commun. (ECOC 2002), Copenhagen, Denmark, 8-12 Sep. 2002.

Choosing an appropriate buffer strategy for an optical packet switch with a feed-back FDL buffer

C. Develder, M. Pickavet and P. Demeester


in Proc. 28th European Conf. on Optical Commun. (ECOC 2002), Copenhagen, Denmark, 8-12 Sep. 2002.

For an optical packet switch with a feed-back buffer consisting of Fibre Delay Lines (FDLs), we compare buffer configurations and strategies. We focus on achieved Packet Loss Ratio (PLR) for memoryless, bursty and self-similar traffic types.

Choosing an appropriate buffer strategy for an optical packet switch with a feed-back FDL buffer

C. Develder, M. Pickavet and P. Demeester


in Proc. 28th European Conf. on Optical Commun. (ECOC 2002), Copenhagen, Denmark, 8-12 Sep. 2002.

@inproceedings{Develder2002ECOC,
author = {Chris Develder and Mario Pickavet and Piet Demeester},
title = {Choosing an appropriate buffer strategy for an optical packet switch with a feed-back FDL buffer},
booktitle = {Proc. 28th European Conf. on Optical Commun. (ECOC 2002)},
month = {8--12 Sep.},
year = {2002},
volume = {3},
address = {Copenhagen, Denmark},
note = {paper 8.5.4}
}

pubinproceedings

C. Develder, M. Pickavet and P. Demeester, "Strategies for an FDL based feed-back buffer for an optical packet switch with QoS differentiation", in Proc. Conf. on Optical Internet (COIN2002), Jeju Island, South Korea, 21-25 Jul. 2002, pp. 114-116 (paper COIN.TuD1).

Strategies for an FDL based feed-back buffer for an optical packet switch with QoS differentiation

C. Develder, M. Pickavet and P. Demeester


in Proc. Conf. on Optical Internet (COIN2002), Jeju Island, South Korea, 21-25 Jul. 2002, pp. 114-116 (paper COIN.TuD1).

Strategies for an FDL based feed-back buffer for an optical packet switch with QoS differentiation

C. Develder, M. Pickavet and P. Demeester


in Proc. Conf. on Optical Internet (COIN2002), Jeju Island, South Korea, 21-25 Jul. 2002, pp. 114-116 (paper COIN.TuD1).

@inproceedings{Develder2002COIN,
author = {Develder, Chris and Pickavet, Mario and Demeester, Piet},
title = {Strategies for an FDL based feed-back buffer for an optical packet switch with QoS differentiation},
booktitle = {Proc. Conf. on Optical Internet (COIN2002)},
month = {21--25 Jul.},
year = {2002},
pages = {114--116 (paper COIN.TuD1)},
address = {Jeju Island, South Korea}
}

pubinproceedings

C. Develder, J. Cheyns, E. Van Breusegem, E. Baert, A. Ackaert, M. Pickavet and P. Demeester, "Node architectures for optical packet and burst switching" (Invited), in Proc. Photonics in Switching (PS 2002), Jeju Island, South Korea, 21-25 Jul. 2002, pp. 104-106 (paper PS.WeA1).

Node architectures for optical packet and burst switching (Invited)

C. Develder, J. Cheyns, E. Van Breusegem, E. Baert, A. Ackaert, M. Pickavet and P. Demeester


in Proc. Photonics in Switching (PS 2002), Jeju Island, South Korea, 21-25 Jul. 2002, pp. 104-106 (paper PS.WeA1).

Node architectures for optical packet and burst switching (Invited)

C. Develder, J. Cheyns, E. Van Breusegem, E. Baert, A. Ackaert, M. Pickavet and P. Demeester


in Proc. Photonics in Switching (PS 2002), Jeju Island, South Korea, 21-25 Jul. 2002, pp. 104-106 (paper PS.WeA1).

@inproceedings{Develder2002PS,
author = {Develder, Chris and Cheyns, Jan and Van Breusegem, Eric and Baert, Elise and Ackaert, A. and Pickavet, Mario and Demeester, Piet},
title = {Node architectures for optical packet and burst switching (Invited)},
booktitle = {Proc. Photonics in Switching (PS 2002)},
month = {21--25 Jul.},
year = {2002},
pages = {104--106 (paper PS.WeA1)},
address = {Jeju Island, South Korea}
}

pubarticle

C. Develder, D. Colle, S. De Maesschalck, M. Pickavet and P. Demeester, "Influence of GMPLS recovery mechanisms on TCP performance", Photonic Netw. Commun., Vol. 4, No. 3-4, Jul.-Dec. 2002, pp. 321-345.

Influence of GMPLS recovery mechanisms on TCP performance

C. Develder, D. Colle, S. De Maesschalck, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 4, No. 3-4, Jul.-Dec. 2002, pp. 321-345.

Influence of GMPLS recovery mechanisms on TCP performance

C. Develder, D. Colle, S. De Maesschalck, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 4, No. 3-4, Jul.-Dec. 2002, pp. 321-345.

@article{Develder2002PNET,
author = {Develder, Chris and Colle, Didier and De Maesschalck, Sophie and Pickavet, Mario and Demeester, Piet},
title = {Influence of GMPLS recovery mechanisms on TCP performance},
journal = {Photonic Netw. Commun.},
month = {Jul.--Dec.},
year = {2002},
volume = {4},
number = {3--4},
pages = {321--345},
doi = {10.1023/A:1016064014931}
}

pubinproceedings

M. Pickavet, C. Develder, E. Baert and P. Demeester, "AI techniques for planning telecommunication networks", in Proc. Int. Conf. Artificial Intelligence (IC-AI 2002), Las Vegas, NV, USA, 24-27 Jun. 2002.

AI techniques for planning telecommunication networks

M. Pickavet, C. Develder, E. Baert and P. Demeester


in Proc. Int. Conf. Artificial Intelligence (IC-AI 2002), Las Vegas, NV, USA, 24-27 Jun. 2002.

AI techniques for planning telecommunication networks

M. Pickavet, C. Develder, E. Baert and P. Demeester


in Proc. Int. Conf. Artificial Intelligence (IC-AI 2002), Las Vegas, NV, USA, 24-27 Jun. 2002.

@inproceedings{Pickavet2002a,
author = {Pickavet, Mario and Develder, Chris and Baert, Elise and Demeester, Piet},
title = {AI techniques for planning telecommunication networks},
booktitle = {Proc. Int. Conf. Artificial Intelligence (IC-AI 2002)},
month = {24--27 Jun.},
year = {2002},
address = {Las Vegas, NV, USA}
}

pubinproceedings

M. Pickavet, A. Ackaert, E. Baert, J. Cheyns, D. Colle, S. De Maesschalck, P. Demeester, C. Develder, I. Lievens, E. Van Breusegem, S. Verbrugge and Q. Yan, "Design of communication networks using heuristics" (Invited), in Book of abstracts of "Arbeitskreis Mathematik in Forschung und Praxis", 23rd Symp. on Mathematik in der Telekommunikation, Duisburg, Germany, 18-19 Mar. 2002.

Design of communication networks using heuristics (Invited)

M. Pickavet, A. Ackaert, E. Baert, J. Cheyns, D. Colle, S. De Maesschalck, P. Demeester, C. Develder, I. Lievens, E. Van Breusegem, S. Verbrugge and Q. Yan


in Book of abstracts of "Arbeitskreis Mathematik in Forschung und Praxis", 23rd Symp. on Mathematik in der Telekommunikation, Duisburg, Germany, 18-19 Mar. 2002.

Design of communication networks using heuristics (Invited)

M. Pickavet, A. Ackaert, E. Baert, J. Cheyns, D. Colle, S. De Maesschalck, P. Demeester, C. Develder, I. Lievens, E. Van Breusegem, S. Verbrugge and Q. Yan


in Book of abstracts of "Arbeitskreis Mathematik in Forschung und Praxis", 23rd Symp. on Mathematik in der Telekommunikation, Duisburg, Germany, 18-19 Mar. 2002.

@inproceedings{Pickavet2002,
author = {Pickavet, Mario and Ackaert, A. and Baert, Elise and Cheyns, Jan and Colle, Didier and De Maesschalck, Sophie and Demeester, Piet and Develder, Chris and Lievens, Ilse and Van Breusegem, Eric and Verbrugge, Sofie and Yan, Qian},
title = {Design of communication networks using heuristics (Invited)},
booktitle = {Book of abstracts of "Arbeitskreis Mathematik in Forschung und Praxis", 23rd Symp. on Mathematik in der Telekommunikation},
month = {18--19 Mar.},
year = {2002},
address = {Duisburg, Germany}
}

pubinproceedings

C. Develder, M. Pickavet and P. Demeester, "Assessment of packet loss for an optical packet router with recirculating buffer", in Proc. 6th IFIP Working Conf. on Optical Netw. Design and Modelling (ONDM2002), Torino, Italy, 4-6 Feb. 2002.

Assessment of packet loss for an optical packet router with recirculating buffer

C. Develder, M. Pickavet and P. Demeester


in Proc. 6th IFIP Working Conf. on Optical Netw. Design and Modelling (ONDM2002), Torino, Italy, 4-6 Feb. 2002.

Assessment of packet loss for an optical packet router with recirculating buffer

C. Develder, M. Pickavet and P. Demeester


in Proc. 6th IFIP Working Conf. on Optical Netw. Design and Modelling (ONDM2002), Torino, Italy, 4-6 Feb. 2002.

@inproceedings{Develder2002ONDM,
author = {Develder, Chris and Pickavet, Mario and Demeester, Piet},
title = {Assessment of packet loss for an optical packet router with recirculating buffer},
booktitle = {Proc. 6th IFIP Working Conf. on Optical Netw. Design and Modelling (ONDM2002)},
month = {4--6 Feb.},
year = {2002},
address = {Torino, Italy}
}

pubarticle

D. Colle, S. De Maesschalck, C. Develder, P. Van Heuven, A. Groebbens, J. Cheyns, I. Lievens, M. Pickavet, P. Lagasse and P. Demeester, "Data-centric optical networks and their survivability", IEEE J. Sel. Areas Commun., Vol. 20, No. 1, Jan. 2002, pp. 6-20.

Data-centric optical networks and their survivability

D. Colle, S. De Maesschalck, C. Develder, P. Van Heuven, A. Groebbens, J. Cheyns, I. Lievens, M. Pickavet, P. Lagasse and P. Demeester


IEEE J. Sel. Areas Commun., Vol. 20, No. 1, Jan. 2002, pp. 6-20.

The explosive growth of data traffic-for example, due to the popularity of the Internet-poses important emerging network requirements on today's telecommunication networks. This paper describes how core networks will evolve to optical transport networks (OTNs), which are optimized for the transport of data traffic, resulting in an IP-directly-over-OTN paradigm. Special attention is paid to the survivability of such data-centric optical networks. This becomes increasingly crucial since more and more traffic is multiplexed onto a single fiber (e.g., 160×10 Gb/s), implying that a single cable cut can affect incredible large traffic volumes. In particular, this paper is tackling multilayer survivability problems, since a data- centric optical network consists of at least an IP and optical layer. In practice, this means that the questions "in which layer or layers should survivability be provided?" and "if multiple layers are chosen for this purpose, then how should this functionality in these layers be coordinated?" have to be answered. In addition to a theoretical study, some case studies are presented in order to illustrate the relevance of the described issues and to help in strategic planning decisions. Two case studies are studying the problem from a capacity viewpoint. Another case study presents simulations from a timing/throughput performance viewpoint

Data-centric optical networks and their survivability

D. Colle, S. De Maesschalck, C. Develder, P. Van Heuven, A. Groebbens, J. Cheyns, I. Lievens, M. Pickavet, P. Lagasse and P. Demeester


IEEE J. Sel. Areas Commun., Vol. 20, No. 1, Jan. 2002, pp. 6-20.

@article{Colle2002Jsac,
author = {D. Colle and De Maesschalck, Sophie and Develder, Chris and Van Heuven, Pim and A. Groebbens and J. Cheyns and I. Lievens and M. Pickavet and P. Lagasse and P. Demeester},
title = {Data-centric optical networks and their survivability},
journal = {IEEE J. Sel. Areas Commun.},
month = {Jan.},
year = {2002},
volume = {20},
number = {1},
pages = {6--20},
doi = {10.1109/49.974658}
}

pubarticle

S. De Maesschalck, D. Colle, A. Groebbens, C. Develder, A. Lievens, P. Lagasse, M. Pickavet, P. Demeester, F. Saluta and M. Quagliatti, "Intelligent optical networking for multilayer survivability", IEEE Commun. Mag., Vol. 40, No. 1, Jan. 2002, pp. 42-49.

Intelligent optical networking for multilayer survivability

S. De Maesschalck, D. Colle, A. Groebbens, C. Develder, A. Lievens, P. Lagasse, M. Pickavet, P. Demeester, F. Saluta and M. Quagliatti


IEEE Commun. Mag., Vol. 40, No. 1, Jan. 2002, pp. 42-49.

In recent years, telecommunication networks have faced explosive (IP) traffic growth. As traffic keeps growing, network reliability gains more and more importance. This article investigates to which extent switched connections and fast connection provisioning, typical for intelligent optical networks (IONs), can be used to provide resilience in an IP-over-optical multilayer network scenario. This solution, based on transport network flexibility, is compared with more traditional static multilayer resilience schemes in terms of cost (capacity) requirements and operational (dis)advantages

Intelligent optical networking for multilayer survivability

S. De Maesschalck, D. Colle, A. Groebbens, C. Develder, A. Lievens, P. Lagasse, M. Pickavet, P. Demeester, F. Saluta and M. Quagliatti


IEEE Commun. Mag., Vol. 40, No. 1, Jan. 2002, pp. 42-49.

@article{DeMaesschalck2002Commag,
author = {De Maesschalck, S. and Colle, D. and Groebbens, A. and Develder, C. and Lievens, A. and Lagasse, P. and Pickavet, M. and Demeester, P. and Saluta, F. and Quagliatti, M.},
title = {Intelligent optical networking for multilayer survivability},
journal = {IEEE Commun. Mag.},
month = {Jan.},
year = {2002},
volume = {40},
number = {1},
pages = {42--49},
doi = {10.1109/35.978048}
}

pubinproceedings

D. Colle, S. De Maesschalck, C. Develder, A. Groebbens, M. Pickavet and P. Demeester, "Design and dimensioning issues in survivable data-centric optical networks" (Invited), in Proc. 1st COST270 Workshop on Reliability of Optical Netw., Systems and Components, Dubendorf, Switzerland, 12-13 Dec. 2001.

Design and dimensioning issues in survivable data-centric optical networks (Invited)

D. Colle, S. De Maesschalck, C. Develder, A. Groebbens, M. Pickavet and P. Demeester


in Proc. 1st COST270 Workshop on Reliability of Optical Netw., Systems and Components, Dubendorf, Switzerland, 12-13 Dec. 2001.

Design and dimensioning issues in survivable data-centric optical networks (Invited)

D. Colle, S. De Maesschalck, C. Develder, A. Groebbens, M. Pickavet and P. Demeester


in Proc. 1st COST270 Workshop on Reliability of Optical Netw., Systems and Components, Dubendorf, Switzerland, 12-13 Dec. 2001.

@inproceedings{Colle2001a,
author = {Colle, Didier and De Maesschalck, Sophie and Develder, Chris and Groebbens, Adelbert and Pickavet, Mario and Demeester, Piet},
title = {Design and dimensioning issues in survivable data-centric optical networks (Invited)},
booktitle = {Proc. 1st COST270 Workshop on Reliability of Optical Netw., Systems and Components},
month = {12--13 Dec.},
year = {2001},
address = {Dubendorf, Switzerland}
}

pubinproceedings

A. Groebbens, D. Colle, C. Develder, S. De Maesschalck, M. Pickavet and P. Demeester, "Use of backup trees to improve resource efficiency of MPLambdaS protection mechanisms", in Proc. 3rd Int. Workshop on Design of Reliable Commun. Netw. (DRCN 2001), Budapest, Hungary, 7-10 Oct. 2001, pp. 152-159.

Use of backup trees to improve resource efficiency of MPLambdaS protection mechanisms

A. Groebbens, D. Colle, C. Develder, S. De Maesschalck, M. Pickavet and P. Demeester


in Proc. 3rd Int. Workshop on Design of Reliable Commun. Netw. (DRCN 2001), Budapest, Hungary, 7-10 Oct. 2001, pp. 152-159.

Use of backup trees to improve resource efficiency of MPLambdaS protection mechanisms

A. Groebbens, D. Colle, C. Develder, S. De Maesschalck, M. Pickavet and P. Demeester


in Proc. 3rd Int. Workshop on Design of Reliable Commun. Netw. (DRCN 2001), Budapest, Hungary, 7-10 Oct. 2001, pp. 152-159.

@inproceedings{Groebbens2001,
author = {Groebbens, Adelbert and Colle, Didier and Develder, Chris and De Maesschalck, Sophie and Pickavet, Mario and Demeester, Piet},
title = {Use of backup trees to improve resource efficiency of MPLambdaS protection mechanisms},
booktitle = {Proc. 3rd Int. Workshop on Design of Reliable Commun. Netw. (DRCN 2001)},
month = {7--10 Oct.},
year = {2001},
pages = {152--159},
address = {Budapest, Hungary}
}

pubinproceedings

C. Develder, D. Colle, P. Van Heuven, S. Van den Berghe, M. Pickavet and P. Demeester, "Influence of recovery time on TCP behaviour", in Proc. MPLS World Congress, Paris, France, 6-9 Feb. 2001.

Influence of recovery time on TCP behaviour

C. Develder, D. Colle, P. Van Heuven, S. Van den Berghe, M. Pickavet and P. Demeester


in Proc. MPLS World Congress, Paris, France, 6-9 Feb. 2001.

Influence of recovery time on TCP behaviour

C. Develder, D. Colle, P. Van Heuven, S. Van den Berghe, M. Pickavet and P. Demeester


in Proc. MPLS World Congress, Paris, France, 6-9 Feb. 2001.

@inproceedings{Develder2001,
author = {Develder, Chris and Colle, Didier and Van Heuven, Pim and Van den Berghe, Steven and Pickavet, Mario and Demeester, Piet},
title = {Influence of recovery time on TCP behaviour},
booktitle = {Proc. MPLS World Congress},
month = {6--9 Feb.},
year = {2001},
address = {Paris, France}
}

pubinproceedings

D. Colle, C. Develder, P. Van Heuven, S. De Maesschalck, A. Groebbens, M. Pickavet and P. Demeester, "Resilience in IP-over-WDM networks" (Invited), in Proc. 5th Working Conf. on Optical Netw. Design and Modelling (ONDM 2001), Vienna, Austria, 5-7 Feb. 2001.

Resilience in IP-over-WDM networks (Invited)

D. Colle, C. Develder, P. Van Heuven, S. De Maesschalck, A. Groebbens, M. Pickavet and P. Demeester


in Proc. 5th Working Conf. on Optical Netw. Design and Modelling (ONDM 2001), Vienna, Austria, 5-7 Feb. 2001.

Resilience in IP-over-WDM networks (Invited)

D. Colle, C. Develder, P. Van Heuven, S. De Maesschalck, A. Groebbens, M. Pickavet and P. Demeester


in Proc. 5th Working Conf. on Optical Netw. Design and Modelling (ONDM 2001), Vienna, Austria, 5-7 Feb. 2001.

@inproceedings{Colle2001,
author = {Colle, Didier and Develder, Chris and Van Heuven, Pim and De Maesschalck, Sophie and Groebbens, Adelbert and Pickavet, Mario and Demeester, Piet},
title = {Resilience in IP-over-WDM networks (Invited)},
booktitle = {Proc. 5th Working Conf. on Optical Netw. Design and Modelling (ONDM 2001)},
month = {5--7 Feb.},
year = {2001},
address = {Vienna, Austria}
}

pubarticle

D. Colle, P. Van Heuven, C. Develder, S. Van den Berghe, I. Lievens, M. Pickavet and P. Demeester, "MPLS recovery mechanisms for IP-over-WDM networks", Photonic Netw. Commun., Vol. 3, No. 1-2, Jan. 2001, pp. 23-40.

MPLS recovery mechanisms for IP-over-WDM networks

D. Colle, P. Van Heuven, C. Develder, S. Van den Berghe, I. Lievens, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 3, No. 1-2, Jan. 2001, pp. 23-40.

MPLS recovery mechanisms for IP-over-WDM networks

D. Colle, P. Van Heuven, C. Develder, S. Van den Berghe, I. Lievens, M. Pickavet and P. Demeester


Photonic Netw. Commun., Vol. 3, No. 1-2, Jan. 2001, pp. 23-40.

@article{Colle2001PNET,
author = {Colle, Didier and Van Heuven, Pim and Develder, Chris and Van den Berghe, Steven and Lievens, Ilse and Pickavet, Mario and Demeester, Piet},
title = {MPLS recovery mechanisms for IP-over-WDM networks},
journal = {Photonic Netw. Commun.},
month = {Jan.},
year = {2001},
volume = {3},
number = {1--2},
pages = {23--40},
doi = {10.1023/A:1011479509986}
}

pubinproceedings

P. Demeester, D. Colle, S. De Maesschalck, C. Develder, M. Pickavet and P. Van Heuven, "Resilience in IP-over-WDM based multilayer networks" (Invited), in Proc. Optical Networks, Götheborg, Sweden, 7 Dec. 2000.

Resilience in IP-over-WDM based multilayer networks (Invited)

P. Demeester, D. Colle, S. De Maesschalck, C. Develder, M. Pickavet and P. Van Heuven


in Proc. Optical Networks, Götheborg, Sweden, 7 Dec. 2000.

Resilience in IP-over-WDM based multilayer networks (Invited)

P. Demeester, D. Colle, S. De Maesschalck, C. Develder, M. Pickavet and P. Van Heuven


in Proc. Optical Networks, Götheborg, Sweden, 7 Dec. 2000.

@inproceedings{Demeester2000a,
author = {Demeester, Piet and Colle, Didier and De Maesschalck, Sophie and Develder, Chris and Pickavet, Mario and Van Heuven, Pim},
title = {Resilience in IP-over-WDM based multilayer networks (Invited)},
booktitle = {Proc. Optical Networks},
month = {7 Dec.},
year = {2000},
address = {Götheborg, Sweden}
}

pubinproceedings

D. Colle, C. Develder, P. Van Heuven, M. Pickavet, P. Demeester, L. Raptis, G. Chatzilias, C. Mas, Y. Manolessos, J. Comellas, A. Rafel, J. Prat, J. Sol'e-Pareta, S. Moyano, J.and Brunazzi, S. Rotolo, R. Stankiewicz and A. Gladish, "Recovery techniques for IP-over-WDM networks" (Invited), in Proc. IP over DWDM Conf., Paris, France, 27-30 Nov. 2000.

Recovery techniques for IP-over-WDM networks (Invited)

D. Colle, C. Develder, P. Van Heuven, M. Pickavet, P. Demeester, L. Raptis, G. Chatzilias, C. Mas, Y. Manolessos, J. Comellas, A. Rafel, J. Prat, J. Sol'e-Pareta, S. Moyano, J.and Brunazzi, S. Rotolo, R. Stankiewicz and A. Gladish


in Proc. IP over DWDM Conf., Paris, France, 27-30 Nov. 2000.

Recovery techniques for IP-over-WDM networks (Invited)

D. Colle, C. Develder, P. Van Heuven, M. Pickavet, P. Demeester, L. Raptis, G. Chatzilias, C. Mas, Y. Manolessos, J. Comellas, A. Rafel, J. Prat, J. Sol'e-Pareta, S. Moyano, J.and Brunazzi, S. Rotolo, R. Stankiewicz and A. Gladish


in Proc. IP over DWDM Conf., Paris, France, 27-30 Nov. 2000.

@inproceedings{Colle2000a,
author = {Colle, Didier and Develder, Chris and Van Heuven, Pim and Pickavet, Mario and Demeester, Piet and Raptis, L. and Chatzilias, G. and Mas, C. and Manolessos, Y.I. and Comellas, J. and Rafel, A. and Prat, J. and Sol'e-Pareta, J. and Moyano, J.and Brunazzi, S. and Rotolo, S. and Stankiewicz, R. and Gladish, Andreas},
title = {Recovery techniques for IP-over-WDM networks (Invited)},
booktitle = {Proc. IP over DWDM Conf.},
month = {27--30 Nov.},
year = {2000},
address = {Paris, France}
}

pubinproceedings

D. Colle, P. Van Heuven, A. Groebbens, C. Develder, M. Pickavet and P. Demeester, "Dimensioning IP-over-WDM networks", in Proc. IP over DWDM Conf., Paris, France, 27-30 Nov. 2000.

Dimensioning IP-over-WDM networks

D. Colle, P. Van Heuven, A. Groebbens, C. Develder, M. Pickavet and P. Demeester


in Proc. IP over DWDM Conf., Paris, France, 27-30 Nov. 2000.

Dimensioning IP-over-WDM networks

D. Colle, P. Van Heuven, A. Groebbens, C. Develder, M. Pickavet and P. Demeester


in Proc. IP over DWDM Conf., Paris, France, 27-30 Nov. 2000.

@inproceedings{Colle2000b,
author = {Colle, Didier and Van Heuven, Pim and Groebbens, Adelbert and Develder, Chris and Pickavet, Mario and Demeester, Piet},
title = {Dimensioning IP-over-WDM networks},
booktitle = {Proc. IP over DWDM Conf.},
month = {27--30 Nov.},
year = {2000},
address = {Paris, France}
}

pubinproceedings

P. Demeester, D. Colle, S. De Maesschalck, C. Develder, M. Pickavet and P. Van Heuven, "Resilience in IP over WDM based multilayer networks" (Invited), in Proc. 26th Eur. Conf. Optical Commun. (ECOC 2000), Munich, Germany, 3-7 Sep. 2000.

Resilience in IP over WDM based multilayer networks (Invited)

P. Demeester, D. Colle, S. De Maesschalck, C. Develder, M. Pickavet and P. Van Heuven


in Proc. 26th Eur. Conf. Optical Commun. (ECOC 2000), Munich, Germany, 3-7 Sep. 2000.

Resilience in IP over WDM based multilayer networks (Invited)

P. Demeester, D. Colle, S. De Maesschalck, C. Develder, M. Pickavet and P. Van Heuven


in Proc. 26th Eur. Conf. Optical Commun. (ECOC 2000), Munich, Germany, 3-7 Sep. 2000.

@inproceedings{Demeester2000,
author = {Demeester, Piet and Colle, Didier and De Maesschalck, Sophie and Develder, Chris and Pickavet, Mario and Van Heuven, Pim},
title = {Resilience in IP over WDM based multilayer networks (Invited)},
booktitle = {Proc. 26th Eur. Conf. Optical Commun. (ECOC 2000)},
month = {3--7 Sep.},
year = {2000},
address = {Munich, Germany}
}

Students & Staff

I am always willing to discuss with prospective PhD students whose research interests match with mine. Feel free to go through some of our team's recent papers to get a grasp of what our research deals with, before contacting me. Also, note that I take the liberty to ignore generic emails that do not show a genuine interest in and understanding about the research area.

Information Retrieval &
Extraction (IR/IE) Team

Postdoc


PhD Students


Project Staff

Johannes Deleu

Smart Grids Team

Postdoc


PhD Students

Nasrin Sadeghianpourhamami

PhD Alumni

Marc De Leenheer (graduated 12/2008; currently with ON.LAB, CA, USA)
Wouter Haerick (graduated 11/2009; currently FUSION business developer with Ghent University, Belgium)
Jens Buysse (graduated 04/2013; currently lector at Hogeschool Gent, Belgium)
Kevin Mets (graduated 03/2015; currently data scientist at Sentiance, Belgium)

Contact Details

IDLab, Dept. of Information Technology
Ghent University - imec
Technologiepark Zwijnaarde 15
9052 Gent, Belgium

Phone: +32 9 3314961 (secretary: +32 9 3314900)
Phone: +32 486 944 227 (mobile)
Email: chris.develder@ugent.be