Level-Based Peer-to-Peer Live Streaming with Rateless Codes

We propose a peer-to-peer system for streaming user-generated live video. Peers are arranged in levels so that video is delivered at about the same time to all peers in the same level, and peers in a higher level watch the video before those in a lower level. We encode the video bit stream with rate less codes and use trees to transmit the encoded symbols. Trees are constructed to minimize the transmission rate for the source while maximizing the number of served peers and guaranteeing on-time delivery and reliability at the peers. We formulate this objective as a height bounded spanning forest problem with nodal capacity constraint and compute a solution using a heuristic polynomial-time algorithm. We conduct ns-2 simulations to study the trade-off between used bandwidth and video quality for various packet loss rates and link latencies.