Overlays in highly dynamic environments: design, performance and applications - MOBBESKAJP

 

Academic coordinator: Viktoria Fodor, Communication Networks (LCN)

Project leader: Dan Jurca, ACCESS postdoc

Other project members:

Bastiaan Kleijn, Sound and Image Processing  (SIP),

Erik Aurell, Supriya Krishnamurthy and Petter Holme, Computational Biology (CB), Gunnar Karlsson and György Dán (LCN)

Summary

The challenges addressed in MOBBESKAJP are to construct overlays and to control data transmission for voice, video and data communication between autonomous mobile units (cell phones) or in heterogeneous wired/wireless networks with many mobile users, also considering the extreme case of intermittent connectivity. Besides a lowering of costs to end customers, the results of the project are expected to find use in e.g. ad hoc networks in emergences.

The project will cover the following topics: i) analysing the characteristics of the relevant networking scenarios; ii) designing overlay topologies for voice, video and data communication between mobile units and designing self-configuring, self-maintaining and self-healing mechanisms for such overlays, iii) designing communication/routing strategies, source coding and traffic control solutions suitable for peer-to-peer communication. The project will perform theoretical work and aims at testing some of the proposed solutions with an end-system prototype. The project members represent three laboratories at KTH and have expertise in the areas of complex systems, teletraffic theory, and audio and video coding.

Deliverables

1. “Overlays for highly dynamic environments” (LCN,CB)

We define the overlay properties that allow efficient content retrieval and media distribution in very dynamic networks. Then, we propose distributed algorithms for constructing and maintaining such overlays.

 

2. “Structured overlays for content localization in dynamic networks” (CB,LCN)

We evaluate how solutions designed for fixed networks perform in more dynamic environments, where peers holding the content leave the overlay frequently, and the underlying physical network changes due to peer mobility. We define storing and replication rules to keep the content present and easy to access.

 

3. “Multiple-description coding in the context of overlay networks” (SIP,LCN)

We evaluate how multiple-description coding (MDC) can be applied in networks where the stream is distributed through an application layer overlay, where nodes can not restore missing information but can generate redundant information.

 

Status per mid 2008

• Author:     Viktoria Fodor, Ilias Chatzidrossos
  Title:    Playback delay in mesh-based peer-to-peer systems with random packet forwarding
  In:    IEEE Future Multimedia Networks
  Date:    September 2008
  The paper provides mathematical models to describe the performance of peer-to-peer streaming systems with random packet forwarding.
• Author:     György Dán, Viktória Fodor
  Title:    Delay Bounds and Scalability in Overlay Multicast
  In:    in Proc. of IFIP Networking
  Date:    May 2008
  The paper derives general delay-playback continuity bounds for peer-to-peer streaming systems that can be applied to assess the performance of various proposed approaches.

• Author:     György Dán
  Title:    Cooperative Caching and Relaying Strategies for Peer-to-peer Content Delivery
  In:    Proc. of IPTPS
  Date:    February 2008
  The paper proposes and evaluates distributed caching strategies to limit the transit traffic generated by peer-to-peer networks.

• Author: Ólafur Ragnar Helgason, Gunnar Karlsson

Title: On the Effect of Cooperation in Wireless Content Distribution

In: IEEE/IFIP WONS 2008

Date: January 2008

Analytic evaluation of content distribution strategies in sparse ad hoc networks

• Author: Supriya Krishnamurthy, Sameh El-Ansary, Erik Aurell and Seif Haridi

Title: An Analytical Study of a Structured Overlay in the Presence of Dynamic Membership

Journal: IEEE/ACM Transations on Networking, Volume 16, Number 4, August 2008, pages 814-825.

Date: August 2008

The paper presents an analytical study of dynamic membership (aka churn) in structured peer-to-peer networks.

• Author: Franck Legendre, Vincent Lenders, Martin May, Gunnar Karlsson

Title: Narrowcasting: An Empirical Performance Evaluation Study

In: ACM MOBICOM CHANTS Workshop

Date: September 2008

Experimental evaluation of content distribution strategies in sparse ad hoc networks

• Author: Franck Legendre, Vincent Lenders, Martin May, Gunnar Karlsson

Title: The Limits of Theory: Pragmatic Challenges in Mobile Ad Hoc Systems

In: IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

Date: September 2008

Note: Invited Paper

System aspects for wireless content distribution

• Author: Vladimir Vukadinovic, Gunnar Karlsson

Title: Multicast Scheduling with Resource Fairness Constraints

Journal: Kluwer Wireless Networks

Date: February 2008

Scheduling for joint unicast and multicast for wireless content distribution