Design And Research Of The P2P Based Video-on-Demand System

In present,with the development of the Internet,how to provide high efficient and reliable video services for users is an important topic.Based on the traditional Client/Server service architecture,problems of the high cost and unsatisfying user experience cannot be ignored.Researches and industries take more attention on how to provide low cost service without affecting the user experience.With the proposing of the Peer-to-Peer(P2P)network,it gives a new direction to design the video service system.More and more researches use P2 P technologies to design their video service systems.The basic idea of these systems is to utilize the idle resources of users and share content between users to accelerate the service process,and the server stress can be significantly reduced,which leads to the decreasing cost of service providers.In order to achieve this effect,how to design the architecture to support the autonomous management of users and how to utilize the user resources to enhance the service performance are two important questions.In this thesis,we design a P2 P based Video-on-Demand(Vo D)system and propose a virtual node based collaboration algorithm for the content scheduling,by which the service performance and resource utilization can be promoted,and the service stress is obviously reduced.The main works of this thesis are following: 1.The related work of living streaming and Vo D systems are analyzed.And different algorithms are discussed.2.A multi-layer based P2 P Vo D system is designed.Based on logic functions,this system is designed as three layers,including the overlay layer,the scheduling layer and the playing layer.In the overlay layer,we use Mesh network to organize the users' nodes,which can support the autonomous management of nodes and information exchange between nodes.In addition,this layer also collect the network information,which is used to support the scheduling layer periodically.Based on the feedback between different layers,it has the opportunity to optimize the overlay and neighborhood relationship of nodes,and promote the service performance.We also discuss the possible ways about how to utilize the user resource to improve the service performance,and point out our future work.3.A virtual node based P2 P collaboration model is proposed.In this approach,the virtual node can be generated from the node that has idle resources.The virtual node is used to pre-fetch the data block that causes the high server stress.When a user asks for that data block,the virtual node can be seen as a temp server,which is involved in scheduling process.From the simulation,it shows that this algorithm can obviously improve the performance of Vo D system,and reduce the service cost.