Ongoing R&D projects

within

Telecommunications and Computer Networks Division / TKRN

 

 

(PhD / University Projects; August 2008):

 

 

 

 

 

     PROJECT  I.   (PhD-Dissertations & University Project):

 

        Project Title:

                                 

“Fault-tolerance and Adaption in Audio / Video Communications via Best Effort Networks”

 

 project related to topics :

 

Distributed Multimedia Platforms, Network Architecture, Internet / Intranets, Mobile Computing, Network Management, Quality of Service (QoS), Media Communications, MPEG, H.26x, VoIP, IP-TV

 

        People Involved:

 

PD Dr. Klaus-D. Heidtmann, Dr. Jürgen Wolf *), Prof. Dr. Bernd E. Wolfinger (University of Hamburg; *) also: HanseNet Telekommunikation GmbH, Hamburg)

 

        Goals of the project:

 

Best effort networks – such as the conventional Internet, WLANs or various other wireless networks – typically are not able to satisfy any quality of service (QoS) guarantees regarding (minimum) packet throughput, (maximum) packet delay or delay jitter. Therefore, these networks have to be modified in order to be able to support real-time communications. In this project we elaborate new techniques for fault-tolerance and adaptation which allow one to accept some deficiencies in network quality (e.g. packet losses).  The techniques which we have been investigating and analyzing are either part of some dedicated middleware or they are directly supported by the distributed applications. In case of audio / video communications, which has been the focus of our studies up to now, we are analyzing, in detail, techniques such as FEC, adaptive video encoding, information dispersal, traffic smoothing as well as combinations of these techniques [Wolfinger, Zaddach 2001]. Both, quantitative and qualitative assessments of the improvement in video quality are focal points of our research [Heidtmann, Kerse, Suchanek et al. 2001], [Heidtmann, Kiritz, Norgall 2008], [Kiritz 2007], [Norgall 2005]. 

 

        Project-related Publications:

        

[Heidtmann, Kerse, Suchanek et al. 2001] Heidtmann K., Kerse J., Suchanek T., Wolfinger B.E., Zaddach M., “Fehlertolerante Videokommunikation über verlustbehaftete Paketvermittlungsnetze“, GI-Fachtagung "Kommunikation in Verteilten Systemen" KiVS 2001, Hamburg, February 2001, Springer-Verlag, 2001

 

[Heidtmann, Kiritz, Norgall 2008] Heidtmann K., Kiritz M., Norgall J., Traffic Characterization and Fault Tolerance of H.264/AVC Encoded Video Streams for QoS-Management in Computer Networks, International Conf. on Information Systems Architectures and Technology, ISAT'2008, Szklarska Poreba, Poland, September 2008

 

[Kiritz 2007] Kiritz M., “Untersuchung der Fehlerrobustheit H.264/AVC-kodierter Videoströme bei simulierten Übertragungsverlusten“, MMBnet 2007, 4th GI/ITG-Workshop, Hamburg 2007, 150-159

 

[Norgall 2005] Norgall, J., “Lastanalyse zur Modellierung H.264/AVC-kodierter Videoströme“, Proc. 3rd GI/ITG Workshop MMBnet 2005, Hamburg 2005, pp. 111-118

 

[Wolfinger, Zaddach 2001] Wolfinger B.E., Zaddach M., “Techniques to Improve Quality-of-Service in Video Communications via Best Effort Networks“, IEEE International Conf. on Networking, ICN '01, Colmar, July 2001

 

 

 

 

PROJECT  II.   (PhD-Dissertations & University Project):

 

        Project Title:

                                 

“Load-adaptive Resource and Quality-of-Service Management for Real-time Communications in Local-area and Mobile Networks”

 

 project related to topics :

Resource Allocation & Redistribution, WLANs, Quality-of-Service (QoS) Management, Real-Time Communications, Distributed Multimedia Applications

 

        People Involved:

 

Stephan Heckmüller, Dr. Jürgen Wolf *), Prof. Dr. Bernd E. Wolfinger (University of Hamburg; *) also: HanseNet Telekommunikation GmbH, Hamburg)

 

        Goals of the project:

 

This project focuses on problems such as :

 

         Efficient management of communication resources required for a provisioning of application-specific QoS guarantees;

         Measurement and characterization of actual resource requirements resulting from dynamic variations in the offered load during audio/video communications;

         Load-adaptive resource redistributions in order to increase network utilization and performance of best-effort traffic.

 

        Project-related Publications:

        

[Heckmüller 2007] Heckmüller S., “Bereitstellung von Dienstgüte für aggregierte Multimediaströme in lokalen ‚Broadcast’-Netzen“, GI/ITG-Fachtagung "Kommunikation in Verteilten Systemen" KiVS 2007, Bern, February 26 - March 2, 2007 (Award: "Best Diploma Thesis 2006")

 

[Wolf 2007] Wolf J., “Lastadaptive Betriebsmittelverwaltung und Dienstgütemanagement für verteilte Echtzeitanwendungen in lokalen und drahtlosen Netzen“, Dissertation, Department Informatik, Universität Hamburg, 2007, erschienen in: Wolfinger B.E. (Hrsg.), Berichte aus dem Forschungsschwerpunkt Telekommunikation und Rechnernetze, Band 6, Shaker-Verlag, Aachen, 2007

 

[Wolf, Heckmüller, Wolfinger 2005] Wolf J., Heckmüller S., Wolfinger B.E., Dynamic Resource Reservation and QoS Management in IEEE 802.11e Networks, International Symp. on Performance Evaluation of Computer and Telecommunication Systems (SPECTS), July 24-28, Philadelphia, PA, USA, 2005 pp. 149-161

 

[Wolfinger, Wolf, Le Grand 2005] Wolfinger B.E., Wolf J., Le Grand G., Improving Node Behaviour in a QoS Control Environment by Means of Load-dependent Resource Redistributions in LANs, Internat. Journal of Communication Systems, Wiley, Vol. 18, Issue 4, May 2005, pp. 373-394

 

 

 

 

 

      PROJECT  III.   (PhD-Dissertations & University Project):

 

        Project Title:

                                 

“Traffic Engineering and Performance Engineering for Service-Integrated Networks with Real-Time Communications”

 

 project related to topics :

Performance Management, Traffic Engineering, Traffic Characterization, Load Measurement, Load Modeling, Load Transformation, Load Generators

 

        People Involved:

 

         Stephan Heckmüller, Andrey Kolesnikov, Prof. Dr. Bernd E. Wolfinger, Prof. Dr. Jing Cong *)  (University of Hamburg; *) meanwhile: Dong Hua University, Shanghai, PR China)

 

        Goals of the project:

                This long term project tries to approach various aspects of ”Traffic Engineering” [Wolfinger, Kühn 2002] including:

         Load measurement at different interfaces of a protocol / service hierarchy within service-integrated networks focussing on video traffic (MPEG-1/ -2, H.261, H. 263) on one hand and on UDP / IP traffic on the other hand [Gaitzsch 2007a], [Gaitzsch 2007b], [Heidtmann, Kiritz, Norgall 2008];

         Load modeling based on measurements covering again video traffic as well as packet traffic [Wolfinger, Zaddach, Heidtmann, Bai 2002];

         Load prediction by means of modeling load transformation processes [Zaddach 2001], [Zaddach, Wolfinger, Krämer, Heidtmann 2002], [Heckmüller, Wolfinger 2007a], [Heckmüller, Wolfinger 2007b];

         Construction of load generators for synthetic load in LANs, in wireless networks or in (interconnected) networks such as the Internet [Cong 2006], [Cong, Kolesnikov 2005], [Cong, Wolfinger 2006], [Kolesnikov 2007], [Kolesnikov 2008], [Schwengel 2007].

 

        Project-related Publications:

        

 [Cong 2006] Cong J., Load Specification and Load Generation for Multimedia Traffic Load in Computer Networks, Ph.D. Dissertation, Department Informatik, Universität Hamburg, 2006, published in: Wolfinger B.E. (ed.), Berichte aus dem Forschungsschwerpunkt Telekommunikation und Rechnernetze, Band 5, Shaker-Verlag, Aachen, 2006

 

[Cong, Kolesnikov 2005] Cong J., Kolesnikov A., A Methodology for Load Generation Based on a Formal Load Specification Technique, 3rd GI/ITG-Workshop MMBnet 2005, Hamburg 2005, pp. 71-82

 

[Cong, Wolfinger 2006] Cong J., Wolfinger B.E., A Unified Load Generator Based on Formal Load Specification and Load Transformation, ValueTools 2006, First Intern. IEEE Conf. on Performance Evaluation Methodologies and Tools, Pisa, October 2006

 

[Gaitzsch 2007a] Gaitzsch M., “Benutzerorientierte Leistungs- und Verfügbarkeitsbewertung von Internetdiensten am Beispiel des Portals hamburg.de“, GI/ITG-Fachtagung "Kommunikation in Verteilten Systemen" KiVS 2007, Bern CH, February 26 - March 2, 2007 (Award: "Best Diploma Thesis 2005") (a)

 

[Gaitzsch 2007b] Gaitzsch M., “Benutzerorientierte Leistungs- und Verfügbarkeitsbewertung von Internetdiensten“, VDM Verlag Dr. Müller, 2007 (b)

 

[Heckmüller, Wolfinger 2007a] Heckmüller S., Wolfinger B.E., “Load Transformations of Markovian Arrival Processes“,14th International Conf. on “Analytical and Stochastic Modelling Techniques and Applications” ASMTA 2007, Prag, June 2007 (a)

 

[Heckmüller, Wolfinger 2007b] Heckmüller S., Wolfinger B.E., “Modellierung verlustinduzierender Lasttransformationen für markovsche Ankunftsprozesse“, MMBnet 2007, 4th GI/ITG-Workshop, Hamburg 2007, 36-49 (b)

 

 [Heidtmann, Kiritz, Norgall 2008] Heidtmann K., Kiritz M., Norgall J., Traffic Characterization and Fault Tolerance of H.264/AVC Encoded Video Streams for QoS-Management in Computer Networks, International Conf. on Information Systems Architectures and Technology, ISAT'2008, Szklarska Poreba, Poland, September 2008

 

[Kolesnikov 2007] Kolesnikov A., Konzeption und Entwicklung eines echtzeitfähigen Lastgenerators für Multimedia-Verkehrsströme in IP-basierten Rechnernetzen, MMBnet 2007, 4th GI/ITG-Workshop, Hamburg 2007, 124-137

 

[Kolesnikov 2008] Kolesnikov A., “ Konzeption und Entwicklung eines echtzeitfähigen Lastgenerators für Multimedia-Verkehrsströme in IP-basierten Rechnernetzen“, Workshop Echtzeit 2008, Boppard, November 2008

 

[Schwengel 2007] Schwengel M., Verteilte Lastgenerierung – Architekturen, Realisierungen und Fallstudien, VDM Verlag Dr. Müller, 2007

 

 [Wolfinger, Kühn 2002] Wolfinger B.E., Kühn P.J. (eds.), Special Issue “Internet Traffic Engineering“, Praxis der Informationsverarbeitung und Kommunikation (PIK), 24. Jg., Heft 2, June 2002

 

[Wolfinger, Zaddach, Heidtmann, Bai 2002] Wolfinger B.E., Zaddach M., Heidtmann K., Bai G., “Analytical Modeling of Primary and Secondary Load as Induced by Video Applications Using UDP/IP“, Computer Communications Journal, Vol. 25, Issue 11-12, July 2002, 1094-1102

 

[Zaddach 2001] Zaddach M., “Modellierung, Charakterisierung und Transformation von Videoverkehrslasten“, Ph.D. Dissertation, Department Informatik, Univ. Hamburg, 2001, published in: Wolfinger B.E. (ed.), Berichte aus dem Forschungsschwerpunkt Telekommunikation und Rechnernetze, Band 2, Shaker-Verlag, Aachen 2001

 

[Zaddach, Wolfinger, Krämer, Heidtmann 2002] Zaddach M., Wolfinger B.E., Krämer N., Heidtmann K., “Lasttransformation und ihre Einsatzmöglichkeiten zur Verkehrsprognose in Intranets und im Internet“, Praxis der Informationsverarbeitung und Kommunikation (PIK), 24. Jg., Heft 2, 2002, 73-81

                          

 

 

 

 

      PROJECT  IV.   (PhD-Dissertations & University Project):

 

        Project Title:

                                 

“Analytical and Simulation Models and Tools to Study the Performance and Reliability of Communication Systems, Computer Networks and Distributed Applications”

 

 project related to topics :

Performance & Reliability Evaluation, Network Models, Simulation & Emulation Tools, BMAP Models, Model Validation, Internet, Wireless Networks, Multimedia Applications

 

        People Involved:

 

         Stephan Heckmüller*), PD Dr. Klaus-D. Heidtmann*), Prof. Dr. Bernd E. Wolfinger*), Thomas Begin**), Dr. Bruno Baynat**), Prof. Dr. Serge Fdida**) (*) University of Hamburg; **) LIP6, Université P. et M. Curie, Paris)

 

        Goals of the project:

 

This project comprises research in the following areas :

 

         Analytical, simulation and hybrid performance and reliability models for mobile networks, the Internet and for distributed applications;

         Development and application of modeling, emulation and performance/reliability evaluation tools for computer networks (e.g. mobile networks, Internet), supporting media communications;

         Functional modeling of measured system behavior of communication networks;

         Usage of networks models to perform detailed model-based QoS evaluation studies for real-time communications;  

         Model validations by means of performance measurements in existing networks.

 

        Project-related Publications:

          

[Begin, Brandwajn, Baynat, Wolfinger, Fdida 2007a] Begin T., Brandwajn A., Baynat B., Wolfinger B.E., Fdida S., ”Towards an Automatic Modeling Tool for Observed System Behavior”, European Performance Engineering Workshop EPEW 2007, Berlin, 27./28. September 2007 (a)

[Begin, Brandwajn, Baynat, Wolfinger, Fdida 2007b]  Begin T., Brandwajn A., Baynat B., Wolfinger B.E., Fdida S., ”High-level Approach to Modeling of Observed System Behavior”, PERFORMANCE 2007, IFIP WG 7.3 Intern. Symp. on Computer Performance, Modeling, Measurements, and Evaluation, Köln, 2.-5. Oct. 2007 (b)

[Begin, Brandwajn, Baynat, Wolfinger, Fdida 2007c] Begin T., Brandwajn A., Baynat B., Wolfinger B.E., Fdida S., ”High-level Approach to Modeling of Observed System Behavior”, SIGMETRICS Performance Evaluation Review, Vol. 35, No. 3; Dec. 2007, 34-36 (c)

[Gaitzsch 2007] Gaitzsch M., “Benutzerorientierte Leistungs- und Verfügbarkeitsbewertung von Internetdiensten“, VDM Verlag Dr. Müller, 2007

[Heckmüller, Wolfinger 2007] Heckmüller S., Wolfinger B.E., “Modellierung verlustinduzierender Lasttransformationen für markovsche Ankunftsprozesse“, MMBnet 2007, 4th GI/ITG-Workshop, Hamburg 2007, 36-49

[Heckmüller, Wolfinger 2008a] Heckmüller S., Wolfinger B.E., “Using Load Transformations to Predict the Impact of Packet Fragmentation and Losses on Markovian Arrival Processes”, 15th International Conf. on Analytical and Stochastic Modelling Techniques and Applications; ASMTA'08, Nicosia, Cyprus, June 2008 (a)

[Heckmüller, Wolfinger 2008b] Heckmüller S., Wolfinger B.E., “Analytical Modeling of Token Bucket Based Load Transformations”, International Symp. on Performance Evaluation of Computer and Telecommunication Systems, SPECTS 2008, Edinburgh, June 2008 (b)

[Heckmüller, Spork, Wolfinger 2008] Heckmüller S., Spork M., Wolfinger B.E., “Load Transformations of Markovian Arrival Processes: Methods and Tool Support”, 3rd International Workshop on Tools for solving Structured Markov Chains, SMCTools 2008, Athen, Greece, October 2008

[Scherpe 2006] Scherpe C., ”Emulation gekoppelter Rechnernetze mit lastabhängigem Verzögerungs- und Verlustverhalten - Architekturkonzepte, prototypische Realisierung und Fallstudien, Dissertation”, Department Informatik, Universität Hamburg, 2006, published in: Wolfinger B.E. (Hrsg.), Berichte aus dem Forschungsschwerpunkt Telekommunikation und Rechnernetze, Band 4, Shaker-Verlag, Aachen, 2006

[Scherpe, Brehmer, Wolfinger 2005] Scherpe C., Brehmer I., Wolfinger B.E., ”IP-basierte Emulation von gekoppelten Rechnernetzen”, MMBnet 2005, 3rd GI/ITG Workshop, Hamburg 2005, pp. 61- 70

[Ziviani, Wolfinger, de Rezende, Duarte, Fdida 2005] Ziviani A., Wolfinger B.E., de Rezende J.F., Duarte O.C.M.B., Fdida S., ”Joint Adoption of QoS Schemes for MPEG Streams”, Multimedia Tools and Applications, Kluwer Academic Publ., 2005