Efficient Uplink Bandwidth Utilization in P2P-TV Streaming Systems

Peer-to-Peer streaming systems (or P2P-TV) have been studied in the literature for some time, and they are becoming popular among users as well. P2P- TV systems target the real time delivery of a video stream, therefore posing different challenges compared to more traditional P2P applications like the better known file sharing P2P application. In this paper, we focus on mesh based systems in which the peers form a generic overlay topology upon which peers exchange small "chunks" of video. In particular, we study the signaling mechanisms that must be in place to trade chunks and to match the demand from other peers in a quick and efficient way, by automatically adapting a peer service rate to its upload capacity. The goal is to maximize peer upload capacity utilization, while avoiding forming long transmission queue, therefore minimizing the chunk delivery time, a crucial parameter for P2P-TV systems. Our results show that the proposed solution achieves several desirable goals: i) it limits the overhead due to signaling messages, ii) it achieves a fair resource utilization, making peers contribute proportionally to their bandwidth, iii) it improves system performance, reducing loss probability and chunk delivery delay with respect to mechanisms with non adaptive number of contacted peers.