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Research, The Key Strategy Of Bittorrent-based Streaming Media On Demand

Posted on:2011-11-20Degree:MasterType:Thesis
Country:ChinaCandidate:P H LiuFull Text:PDF
GTID:2208360308967008Subject:Computer software and theory
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With development of the broadband network and information technology, streaming media applications become increasingly wide range of experience from the first to share MP3 music files to video live and video-on-demand (VoD) development process. Users can switch between different channels, but can not control the progress of play in live video services, so they just cache and transmission data in a small range before and after the play time. While in the video-on-demand services, users are free to choose not only interested video files, and can control the playback progress. It requires the network to store and transmit large amounts of streaming media data, taking up a huge amount of bandwidth resources. The traditional C/S mode with the server and bandwidth bottlenecks, obviously can not meet the video-on-demand services. In the VoD systems using P2P technology, every user shares a huge amount of bandwidth and storage requirements of multimedia, and transmission quality is usually changed for the better with the increased number of users. Using P2P to solve the problems in VoD has become a hot issue of the current study. Video-on-demand services have real-time, interactive, strict QoS requirements and data of play in the order,and nodes in P2P network has dynamic, heterogeneous, distributed characters. P2P streaming media applications also face node management, data scheduling, cache management and other challenges.In this thesis, we research the existing streaming media technology and P2P networks and apply the BitTorrent file distribution protocol to the P2P video-on-demand system. We discuss the feasibility and limitations of BitTorrent when it is applied to VoD services. Against the limitations of BitTorrent, we present improved and optimized algorithms in this thsis, and analyze them. It mainly includes three aspects: First, a time-based neighbor peer selection algorithm to improve the probability of peer downloading the new fragment from the peers connected to .Second, taking into account the clip playback time constraints and the rarity of the data, we propose double-window piece selection strategy to ensure that the emergency data download efficiency, achieving a balance between the system efficiency and start delay as well as continuity index. Third, we propose improved TFT algorithm to make full use of the upload bandwidth, and provide more shared services. We designed and implemented a system BTStream integrated the above-mentioned optimized algorithms and discuss Tracker server and the client's functional design. Finally, the system performance is analyzed, including the start delay, continuity index, and bandwidth utilization.
Keywords/Search Tags:P2P, BitTorrent, VoD, neighbor peer selection, piece selection
PDF Full Text Request
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