Cluster Based P2p Three-tier Mobile Streaming Media System

With the increasing popularity of internet, the rapid development of wireless network technology and information transmission technology, wireless information network steps into the time of multimedia communications. In addition to the development of network information, the improvement of mobile device's performance provides a good environment to compute, encode and cache mobile multimedia data which guarantees the quality of multimedia clients. The developments of network technology and high performance mobile terminal guarantee the quality of multimedia and promote its application in production and life.The transmission of mobile multimedia needs higher transmission bandwidth, proper resources and stability network environment. In currently mobile multimedia systems, resources are stored in proxy server, when clients request resource, multimedia data is directly transmitted from proxy server to the client. As the number of mobile terminal requests rapid growth, in existing mobile multimedia systems, due to the pressure of server and limited bandwidth, the problems of playback jitter, play time extension and even couldn't respond customer requests are appeared at the client-side. So mobile streaming system faced the most important issue is to architecture an outstanding mobile multimedia system to provide a stable network environment so as to ensure service quality.In this paper, we analyze the features of existing mobile streaming media system and the clients' problem of lack resources which is caused by server's stress too heavy and bandwidth's limit when users requests increasing. Then we analyze the development and the advantages of P2P technology, meanwhile investigate the feasibility of the P2P technology applied in mobile streaming media system. In the premise of complying with the mobile streaming media system's design rules, considering fully using the resources which are cached in local mobile terminal devices and using P2P technology among the mobile devices with good performance, a cluster based P2P three-tier mobile streaming media system is proposed, and mean while cluster-based P2P client request scheduling policy is also proposed.The cluster based P2P three-tier mobile streaming media system (CTMM) is based on the existing proxy-based server streaming media system. The proposed system is by cluster-node selection strategy to select the mobile nodes with excellent performance to form self-organization cluster. The multimedia resources cached in cluster-node can be offered to other request nodes. According this method, local cluster-nodes form the lower P2P services provider. The framework constructs the layer of lower P2P services provider which is between the existing two-tier proxy-based mobile streaming media system's global service provider layer and service requests layer. Nodes in the lower P2P services provider layer increase the locality application of mobile streaming media data content. The proposed cluster based P2P three-tier mobile streaming media system can reduce bandwidth consumption of mobile streaming media, effectively ease the pressure of the backbone network, reduce the request rejection rate, and significantly reduces the time of transmission delay and playback jitter.