The Research Of Multi-source Cooperation Techniques In P2P Media Streaming System

In the recent years, with unexpected speed P2P media streaming service has token up the markets of traditional media streaming service. P2P media streaming is what we use P2P technique in media streaming system. In P2P media streaming system, large amount of peers can use their own capacities to reduce severs'load and relieve backbone networks'pressure. It also copes with the scalable problem of mass intercurrent customers which traditional media streaming systems always have. Multi-source technique is one of the important parts in unstructured P2P media streaming technique. Owing that one peer's upload rate can not meet the demand of the playback, P2P media streaming system has to schedule more than one source peers to cooperate for one request peer. That's what we called multi-source technique. which mainly includes 3 aspects: data assignment algorithm, peer selection algorithm and admission control algorithm.In this paper, our researches are concentrated on data assignment algorithm and peer selection algorithm for a P2P media streaming system. And our innovative works includes: (1) dynamical data assignment algorithm and (2) semi-mature peer complete selection algorithm.For data assignment algorithm, we firstly analyze the limitation of present data assignment algorithm. Then we propose the dynamical data assignment algorithm (DDA) which can be used under practical network circumstance. And we run DDA in a P2P media streaming system developed by ourselves. Test tells us that in 94% of the service time DDA can make the total utility of fluctuant active peers'above the playback rate, which can provide consecutive and stable streaming service.For peer selection algorithm, we firstly analyze the defect of present peer selection algorithm FAST, which would miss large part of the semi-mature peers. Then we propose semi-mature peer complete selection algorithm (SPCS). And we validated the superiority by experiments, and result shows that in early time, the average initial delay of SPCS is 15% lower than that of FAST. If there are VCR operations, the system could be more effective.In the end of this paper, we introduce the macro architecture of our P2P media streaming system VShow. And detailedly explains the design of module of logical function layer we have developed in order to improve our QoS by using more effective algorithm in the next phase.