Network Coding Based P2P Media Streaming Technoligy

Compared to media streaming systems which are based on the Client/Server framework, in P2P network, each client receives data and forwards it to others at the same time. Large numbers of clients resource ignored before can be effectively used. The burden on the server will be relieved and the server can provide better quality of service for a great deal of users at the same time. So P2P media streaming technique developed fleetly in recent years.Firstly, the thesis summarized the P2P media streaming techniques and layered coding technology. Then, start-up delay and playback quality were introduced as two indicators from which we pointed out the shortage of the existing P2P streaming systems. To improve the performance of the peer-to-peer (P2P) system, data transmission scheme based on random network coding is presented. It includes the preprocessing of streaming media data in peer node, the encoding and decoding of data block, the data scheduling algorithm in peer nodes, the policy of network coding operate with layered coding and subscribing mechanism. In this design, layered coded data was also coded through network coding before transmitted to the receiving peer, and the receiving peer could decide whether the transmitting peer should send the enhancement layer data, and this method could improve the playback quality and reduce the start-up delay.According to the result of comparison simulations, under the changing network situation, compared with the original peer-to-peer system, the proposed scheme can improve the start-up time of the system and the playback quality of the receiving peer.