Multimedia Broadcast/Multicast Service (MBMS) offers rich content distribution such as video, audio streaming and file sharing etc. through the UMTS cellular networks. However, due to the dynamic nature of the wireless channels, packet loss is inevitable even when complicated anti-error source or channel coding schemes are implemented in the system. Retransmission based solutions suffer from the well known feedback implosion problem.

Given that more and more mobile devices are equipped with multiple wireless interfaces (e.g., 3G cellular networks, local WLAN, and/or bluetooth), we propose to recover the cellular packet loss using the local WLAN networks, which we refer to as Cooperative Peer-to-Peer Repair (CPR). Our CPR solution is batch based, which means users first receive a batch of packets, after that, they begin to repair the batch of packet collaboratively. The key requirement of the CPR protocol is that the repairing process must be finished before the users receive the next batch of packets.

Our research focus on:

• Designing a fully distributed protocol Distributed CPR (DCPR) that dynamically discovers network topology, exchanges content availability with peers, and schedules peer-to-peer repair transmissions.
• Designing a Network Coding based CPR (NC-CPR) solution.
• Optimizing NC-CPR specifically for video streaming in a rate-distortion manner by imposing coding structure.

People

Publications

• (Leo) X. Liu, G. Cheung, and C-N. Chuah, "Structured Network Coding and Cooperative Local Peer0to-Peer Repair for MBMS Video Streaming," to appear in IEEE International Workshop on Multimedia Signal Processing (MMSP), October 2008. [pdf]

• S. Raza, G. Cheung, and C-N. Chuah, "DICoR: Distributed Interference-Aware Cooperative Repair of Multimedia Broadcast Losses," to appear in IEEE BroadNets, September 2008. [pdf]

• (Leo) X. Liu, G. Cheung, and C-N. Chuah, "Rate-distortion Optimized Network Coding for Cooperative Video Stream Repair in Wireless Peer-to-Peer Networks," IEEE Workshop on Mobile Video Delivery (MoViD), June 2008. [pdf]

• (Leo) X. Liu, S. Raza, C-N. Chuah, and G. Cheung, "Network Coding Based Cooperative Peer-to-Peer Repair in Wireless Ad-Hoc Networks," IEEE ICC, June 2008. [pdf]

• S. Raza, D. Li, C-N. Chuah, and G. Cheung, "Cooperative Peer-to-Peer Repair for Wireless Multimedia Broadcast," IEEE International Conference on Multimedia & Expo (ICME), July 2007. [pdf]

• G. Cheung, D. Li, and C-N. Chuah, "On the Complexity of Cooperative Peer-to-peer Repair for Wireless Broadcasting," IEEE Communications Letters, 2006. [pdf]

Acknowledgement

This project is supported by Hewlett Packard.