Streaming layered video over P2P networks

Peer-to-Peer streaming has been increasingly deployed recently. This comes out from its ability to convey the stream over the IP network to a large number of end-users (or peers). However, due to the heterogeneous nature among the peers, some of them will not be capable to relay or upload the original stream because of bandwidth limitations. Different internet connections these days can be initiated from different devices such as 3G mobile phones or WiFi-connected PDAs. Most of the existing P2P streaming systems are based on video coding techniques which cannot cope with this level of heterogeneity at network and terminal level. Layered video coding techniques are being introduced in simple streaming scenarios, due to their ability to deliver streams at different scales (temporal, spatial and SNR). This eases transmission in case of limited bandwidth as the devices can pick and decode the minimum bit rate base layer. Layered coding is preferred over single-layer coding for its flexibility to be transmitted over heterogeneous networks. In this paper we take a step further and analyze layered video in the context of P2P. We study such an approach in combination with simple cross-layer optimization techniques, comparing the resulting performance with a state-of-the-art P2P TV platform. We identify considerable benefits in terms latency, jitter, throughput, and packet loss