Towards Low-Redundancy Push-Pull P2P Live Streaming

P2P live streaming systems are developed in two major approaches: tree-push versus mesh-pull. The hybrid push-pull streaming, as an emerging and promising approach, offers a good tradeoff between traffic overhead and system throughput. In this paper, we demonstrate that video redundancy is a large contributor of the traffic overhead in push-pull systems. To reduce the traffic overhead, we propose simple but effective sub-stream scheduling and re-scheduling mechanisms, implemented in a push-pull streaming prototype called Low-redundancy Streaming (LStreaming). To demonstrate its effectiveness on reducing the traffic overhead, we conduct both simulation and prototype experiments and compare the proposed LStreaming with random mesh-pull and GridMedia. The simulation results show that LStreaming significantly reduces the total traffic overhead, i.e., up to 33% and 37% reduction compared with mesh-pull and GridMedia in dynamic P2P environments, respectively. LStreaming also achieves the throughput, more close to the optimal value than the other two schemes, and sustains a better video playback quality. The prototype experiments show that LStreaming is practical and achieves the expected performance.