A wide range of end-to-end channel coding techniques have been used in support of packet video applications over the Internet and other packet networks. Traditional end-to-end Forward-Error-Correction (FEC) techniques do not scale well though, and especially for large networks due to the large number of packet losses at deep nodes of the underlying distribution tree. Meanwhile, emerging network paradigms, such as overlay, peer-to-peer, and ad-hoc wireless networks, open the door for new approaches of delivering real-time video to a large number of receivers while maintaining high level of reliability and throughput. Under this research project, a new framework, Network Channel Coding (NCC), that exploits emerging networking paradigms, such as peer-to-peer and overlay networks, are investigated and developed. This research optimizes NCC for generic network applications with emphasis on optimizing packet-video applications, their overall quality, and their throughput to a large number of receivers. In particular, optimum solutions for embedding and distributing channel coding functions within arbitrary network topologies (i.e., arbitrary graphs) are being investigated, analyzed, and designed. NCC optimization is being developed using cost-minimization under a rate-distortion (RD) like framework that maximizes throughput while minimizing the NCC overhead throughout the network. This framework reveals key theoretical limits and corresponding optimum NCC solutions that can be achieved for maximum-throughput and minimum-distortion packet video applications. Furthermore, practical and distributed NCC algorithms are being developed. Although general in nature, these distributed NCC algorithms are well suited for packet video over peer-to-peer and ad-hoc wireless systems. Furthermore, novel extensions in emerging areas, such as LDPC codes, cross-layer communications, and network (source) coding, are being explored and developed in the context of the optimization NCC framework.
