Research On Bittorrent-based Peer To Peer Media Streamin Scheduling Mechanism

BitTorrent is a typical representative of the P2P protocol for large-scale contentdistribution rapidly. But the content-distribution mechanisms will lead to download mediapieces out of order and it is not suitable for time-sensitive multimedia streaming files. Inview of BitTorrent protocol and P2P streaming media system have some similarities, suchas sub-slice mechanism and mesh topology. Therefore, the mechanism of files distributionrapid of BitTorrent is introduced to the multimedia streaming, and it has an importantsignificance that the mechanism provides fast data transmission for every node in thesystem. On the basis of comprehensive analysis for the current research in this area, thispaper has further deep research on the problems of data scheduling and TFT incentives.The material contents are as follows.First, aimed at the problem that BitTorrent protocol can make up for the play and startdelay of the P2P streaming media on demand system, in this paper, we propose a requestscheduling mechanism between nodes and server. Streaming media system based on themechanism, each request is different from the request of the pieces emergency, the requestqueue is set on Tracker server in order to filter and respond to the request of the highemergency node. In addition, the restrict window algorithm was proposed in the system.Finally, the distributed address allocation algorithm is adapted by requesting node to selectthe best neighbors.Secondly, aimed at the TFT policy of BitTorrent protocol is not suitable for streamingmedia system, in this paper, we proposed a block-based TFT incentives policy and amethod of data service processing on the basis of BitTorrent. A node integrates theneighbor node contribution to the system and the data block different between theservice-node upload and download node though the improvement of the original TFTpolicy. Then the node decides to provide upload service for which neighbor nodes and itachieve low start delay. On the data service, the priority of the request pieces determinesthe service time.Finally, the algorithms proposed in this paper are simulated on the General Peer-to-Peer Simulator. It compares with other streaming media system from continuousplayback、start up delay、seek delay and response time respectively.