The Research Of Several Technologies In VoD System Based On P2P

Video On Demand (VoD), with the Video Server (VS) storing the video programs and other multimedia information, provides the clients with interactive video service through the transmission network and Consumer Premises Equipment (CPE). Of all the parts, VS is the core of the VoD, its stability and performance decided the performance of the whole system.The internet has grown rapidly in recent years. One reason is that the bandwidth of the network, Both bone network and the local access network, is becoming larger and larger, which provide necessary infrastructure for broadband applications;The other reason is that more and more people prefer to access information interactively. Both of them provide a good condition for the development of the VoD technology. At the same time, the growing demand of the users proposes new requirements for the VoD technology.There are some problems in current VoD systems:the volume is limited, once the volume reaches its limitation, VoD systems can't provide service for new request; Lack of load balance; large bandwidth requirement. The P2P (Peer-to-Peer) technology has made a great development recently. Unlike classical C/S (Client/Server) system, every node in the P2P network is both client and server, so it can improve the efficiency of resource sharing.The paper makes some research about the technology of the VoD system based on P2P, which consists of two fields:Membership management and caching strategy. In the membership management, by introducing the SMALL-WORLD theory to the classical membership management-SCAMP algorithm, the paper proposes SSCAMP algorithm which may make a improvement of the efficiency of resource search by using a structured treatment to the stochastic algorithm. Through the analysis of SSCAMP, the paper shows that the algorithm may improve the efficiency of resource discovery.Then the paper conducts a study on the P2P net-coding and the caching strategy. The paper proposes a variable sub-block strategy to meet the popularity of the resource which base on the technology of P2P net-coding. Through relevant analysis, the paper shows the caching strategy is feasible.At last, the paper shows the system design and the simulation of the caching strategy of the VoD system. The simulation studies of sub-block available that is affected by the sub-block size and the resource popularity. Through the simulate results, the paper shows the improvement by the different sub-block size in performance of different popularity.