Research And Application On Media Streaming Over Peer To Peer Networks

Nowadays, the media streaming technologies which based on the C/S mode are enduring the embarrassment with some problems, such as excessive server loads and the bottleneck bandwidth. Compared with the conventional Client/Server mode, the Peer-to-Peer (P2P) technology has some advantages, including lower bandwidth and resource requirements, and a much less maintenance cost. This technology could adapt to heterogeneous network well, for its low deployment cost and good compatibility. Therefore, it is a good idea to integrate the two technologies. And the combination technology which uses in the remote video education could not only enhance the quality of server, but also make full utilization of end-peer's resources.Motivated by improving high quality real-time video in remote education system, this thesis studies the P2P media streaming technologies, and analyzes some representative P2P media streaming model. Based on P2P technology, a remote video education module has been designed and implemented. There are three main issues applied to this system to solve the problems about the overlay network topology, the system recovery time and the data transmission delay. Firstly, a new topology for the P2P overlay network which based on the tree of hierarchical structure is put forwarded. Nodes' degrees in this topology are restricted for achieving balance in a multi-cast tree. This solution could balance the load of the underlying overlay network within one multi-cast tree by avoiding excessive one peer's loads. Secondly, the proactive recovery strategy is proposed for reducing the system recovery delay. When a node joins the system, the proactive strategy will choose a candidate father for it. Finally, aiming to solve many-to-one data scheduling issue in the system, a new scheduling strategy which integrates a self-adaptive scheduling strategy with timeout urgent scheduling strategy is introduced. When a peer request data from partners, this strategy can adjust partners' capability of serving data and bandwidth based on partners' historical scheduling records in a self-adaptive way.In this thesis, the simulation results verify the P2P overlay network which has the capability to maintain the balance topology, a shorter system recovery time will gain in the proactive strategy once the node's father leaves, and a self-adaptive scheduling strategy with timeout urgent scheduling strategy will remain low server load and reduce the data transmission delay between peer pair. Finally, how to apply the P2P media streaming system to the remote video education is discussed to provide a real learner-centered Web-based education circumstance for remote students. And the realization ideals, methods and the system architecture are given in detail.