Research On Peer-to-peer Streaming Systems Based On Transcoding Strategy

With the rapid development of communication and multimedia technology, theresearch and application of Streaming System are getting more and more popularcurrently. Peer-to-peer streaming systems utilize upload bandwidth and storage capacityof the user nodes to relieve server load and assist server sharing the multimedia datainto the network, which greatly improves the performance and scale of the system.Presently, peer-to-peer streaming systems are mainly designed for traditional PC.With the diversification, mobility and personalized development of terminal equipment,networkarchitecture and user needs, current designs cannot meet the demand ofsupporting and optimization for the sharing of the same program with different qualityand format data. To solve thisproblem, this thesis proposes and studies several kinds ofpeer-to-peer streaming system based on transcoding. It describes the scenes and designsof each system, and optimizes the performance of server load and the utilization of usersupload bandwidth by mathematical modelsand algorithms, and compares with existingsystems by simulation experiments and mathematical analysis. Then, the thesisdiscusses and designs the minimum server load and optimal streaming rate allocationalgorithm of the peer-to-peer streaming system based on transcoding, as well asanalyzesthe performance under dynamic scenario, and proposes an adaptive algorithm.The main content of this thesisfollowing:First, briefly introducethe preliminarystudyofpeer-to-peer streaming system:peer-to-peer file sharing system. The thesis reviews the developing period ofpeer-to-peer streaming system, summarizes the main researches of this area, classifiesexisting designs and current frontier and hot issues.Second, the thesis proposes an Efficient Peer-to-peer Streaming System based onTranscoding (EPSST) in order to cope with some current problems and challenges.Using computational resource of user nodes, EPSST achieves transcoding the format orrate of multimedia data, in order to adapt different terminals, different software orhardware conditions, different network environments, and offer pervasive andpersonalized service. The thesis describes the composition and principle of EPSST.Compared with several current designs, the thesis discusses the functions and advantages of EPSST in terms of the adaptation, the supporting of multimedia datatypes, the structure of overlay network, the server load and the upload bandwidthutilization of user nodes.Third, the thesis proposes a system named Mobile and Fixed Node CooperatingEPSST (MFNC-EPSST) and a system named Multiple Mobile and Fixed NodeCooperating EPSST (MMFNC-EPSST)on the basis of EPSST to meet the growing ofmobile Internet. The thesis describes the basic structure of MFNC-EPSST andMMFNC-EPSST, and builds the system models. Based on system models, itproposesthe algorithms of path selection and bandwidth allocation to built overlay network,which is in order to achieve efficient upload bandwidth utilization of users, and lowerserver load. To verify the effectiveness of the design,the thesis also does samesimulation experments to compare the proposed system with current ones.Fourth, specific to the scenario of media distribution in multicast domain, based onEPSST system, the thesis proposes Bridge of Multicast Domain EPSST (BMD-EPSST).According to the different design requirements and complicacy, two basic organizationmodes and algorithms are proposed for BMD-EPSST.It also does some simulationexperiments to compare the proposed system with current ones.Fifth, the thesis discusses the minimum server load based on EPSST, and proposesOptimal Streaming Rate Allocation Algorithm (OSRAA) to achieve the minimum. Thethesissummarizes the similarities and differences of OSRAA and path selection andbandwidth allocation algorithms in proposed systems,and, based on simulationexperiment and mathematical model, compares the performance of server load in thesystem implementing OSRAA with existing designs, andanalysis the superiority.Sixth, the proposed systems and algorithms are analyzed in dynamic scenario.Simulation experiments give the adapted bandwidth setting of server. To balance theuploaded bandwidth and sever load in dynamic scenario, Encoding Rate AdaptiveAlgorithm (ERAA) is proposed to enable the equilibrium among multimedia quality,system scale and server load. Simulation experiments verify the effectiveness of ERAA.Finally, the thesis makes a conclusion of above research and presents directions forfuture research.