Past Projects

Projects 2007

TOPIC
NAME
REPORTS
1
Supporting Always Best Connectivity through efficient session management in converged networks
 

Description: Always Best Connectivity refers to the capability offered by the converged network to the mobile user of being connected « anytime, anywhere, anyway ». These requirements will be handled by the converged Core Network which controls the session signalling. This project will define session management in such a network and will investigate the functional details of the session management process in a converged Core Network architecture in order to best support Always Best Connectivity of the mobile user.

Representative Work
[1]3GPP System Architecture Evolution: Report on Technical Options and Conclusions
[2] “Why Session Management Matters”
http://www.lightreading.com/document.asp?doc_id=92478

Sofia Christoforou

Report

Presentation

2
Overload (Congestion) Control in Wireless Sensor Networks.
 

Description: A wireless sensor network is constrained by computation capability, memory space, communication bandwidth, and above all, energy supply. We consider the operation of a network in overload situations, that is, when the incoming traffic is outside the feasibility region determined by the network topology. Unpredictability in traffic load variations, link capacity fluctuations, topology modifications, node failures or various types of intentional misbehaviour may lead a network to overload conditions. A smooth and balanced system response in those stressful situations is essential for effective crisis management in the network. However, the important problem of overload (congestion) control in wireless sensor network is largely open. This project aims to look deeper into the overload problem by trying to specify the actual symptoms and the causes of overload in such networks. Additionally, the project is intended to present an overview of the related work in this field.

Representative Work
[1] C. –Y .Wan, S. B. Eisenman and A. T. Campbell, “CODA: Congestion Detection and Avoidance in Sensor Networks,” in Proceedings of ACM SenSys'03, Los Angeles , USA , 5-7 November, 2003.
[2] L. Georgiadis and L. Tassiulas, “Most Balanced Overload Response in Sensor Networks,” in Proceedings of International Symposium on Information Theory (ISIT), September 2005, pp. 553-557.
[3] Proceedings of the 2nd International Conference on Embedded Networked Sensor Systems, ACM SenSys 2004, November 2004, pp. 134-147

Panagiota Koullourou

Report

Presentation

3
Robustness and Resilience in Communication Networks from Complex Systems Perspective
 

Description:Communication networks become increasingly larger and have ever more components and information flow as the network increases at a fast pace. Mastering their complexity - the high level of interdependence between their often very heterogeneous components - becomes a major hurdle threatening to slow down the information revolution. Designing, controlling, modeling and monitoring behavior of such networks are fundamental challenges that should be addressed. We need new paradigms as we are rapidly moving from systems based on closed hierarchical structures to open and distributed, networked organizations. Recent studies of complex systems as they occur in nature, society or even engineering - whether these are living organisms, animal societies, ecosystems, markets, cultural groupings, or the Internet - suggest that we can learn lessons from these systems on how to design and control a new generation of complex communication networks. This project aims to investigate some characteristics of complex systems with respect to robustness (error tolerance) and resilience and subject these characteristics to communication system modelling, taking into consideration recent studies and results.

Representative Work
[1] R. Albert, H. Jeong and A.-L. Barabasi, “Error and attack tolerance of complex networks,” Nature 406, 378-482 (2000).
[2] R. Albert, and A.-L. Barabasi, “Statistical mechanics of complex networks,” Reviews of Modern Physics, Vol. 74, January 2002.

Pantelitsa Fotiou

Report

Presentation

4
Biologically Inspired Mechanisms for Adaptive and Robust Self-Organization in Wireless Sensor Networks
 

Description: New emerging networking technologies (ad-hoc networks, sensor networks) have a quite different structure and requirements from the traditional networks. Some basic characteristics of those networks involve different levels of QoS provisioning, fault tolerance, constrained lifetime and scalability. The only solution to meet the above characteristics seems to be that nodes must be equipped with adaptability to the current network status for controlling congestion. Towards this direction, the biologically inspired approach is promising since it is known that it has the excellent feature of adaptability to environmental changes. This project aims to investigate biologically inspired approaches that can be implemented in those new types of networks by focusing our attention primarily on the adaptability, robustness, and self-organization properties of a biological system.

Representative Work
[1 ]F. Dressler, B. Kruger, G. Fuchs and R. German “Self-Organization in Sensor Networks using Bio-Inspired Mechanisms,” Proceedings of 18th ACM/GI/ITG International Conference on Architecture of Computing Systems - System Aspects in Organic and Pervasive Computing (ARCS'05): Workshop Self-Organization and Emergence, Innsbruck, Austria, March 2005, pp. 139-144.
[2] F. Dressler, “Efficient and Scalable Communication in Autonomous Networking using Bio-inspired Mechanisms - An Overview,” Informatica - An International Journal of Computing and Informatics, vol. 29 (2), July 2005, pp. 183-188.

Marios Koutroullos

Report

Presentation

5
Performance Evaluation of Video Streaming over MIPv6
 

Description: Mobile IPv6 (MIPv6) protocol is aimed to provide transparent host mobility within IPv6. The main idea of the protocol is to enable a Mobile Node to move from one network to another without the need of changing its IPv6 address. Handover performance control is a vital part in the end-to-end delay and packet loss control for the QoS provisioning of real time services. This project aims to study video streaming performance in such a network in a scenario without client mobility and then demonstrates how the user mobility affects performance. In addition, it aims to compare the handoff latency of different approaches and combinations, as currently discussed within the IETF (MIPv6, FMIPv6 and HMIPv6) and tests how the handoff latency affects the QoS of real time applications . The overall project will be implemented using the network infrastructure of the Network Research Lab.

Representative Work
[1] Hannes Hartenstein , Marco Liebsch, Xavier Perez Costa, Ralf Schmitz, A MIPv6, FMIPv6 and HMIPv6 handover latency study: analytical approach , pp. 100-105, June 17-19, 2002, IST Mobile & Wireless Telecommunications Summit 2002, Thessaloniki, Greece.
[2] Xavier Perez-Costa , Marc Torrent-Moreno , Hannes Hartenstein, A Performance Comparison of Mobile IPv6, Hierarchical Mobile IPv6, Fast Handovers for Mobile IPv6 and their Combination , ACM SIGMOBILE Mobile Computing and Communications Review , Volume 7,  Issue 4   Pages: 5 – 19,Year of Publication: 2003 ,ISSN:1559-1662
[3] G. Bai, C. Williamson, “The Effects of Mobility on Wireless Media Streaming Performance”, P roceedings of Wireless Networks and Emerging Technologies (WNET) , Banff, AB, July 2004

Zinon Zinonos

Report

Presentation