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Research On Content Distribution Technology Of Video-on-demand Service

Posted on:2013-01-30Degree:DoctorType:Dissertation
Country:ChinaCandidate:H F GuoFull Text:PDF
GTID:1118330371974915Subject:Computer software and theory
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VoD (Video-on-Demand) supporting interactive operations betters the traditional passive information service, with its characters of rich-content, easy to operate and convenient to fetch. VoD has boomed recently and is becoming the main way of streaming delivery. However, with the growing user scale, huge volume multimedia data and high dynamic of user, the existing content delivery solutions cannot satisfy the interactivity requirement. The large-scale application of VoD remains to be restricted by the dynamic of users with popular P2P technology. Driven by this demand, it is becoming more and more important to improve the quality and efficiency of content delivery and design high quality VoD with low cost to large-scale users.Based on the features of real-time, peer cooperation, asynchronous request, interactivities, the key technologies of Video-on-Demand content distribution are studied intensively from the following several aspects:(1) A novel VoD content distribution service model with collaboration of P2P and Cloud.(2) Effective, quick, accurate, service location mechanism;(3) Cache management scheme which can improve the cooperation of peers and develop the system capacity by analyze user's interests locality (called spatial locality);(4) A usefulness estimation model for video clips, which improves the cache hit ratio, satisfies user's requirement of fluent video playback after VCR operations;(5) The interplay model of VoD application and cloud platform. The major contributions are as following.The high dynamics of VoD users restrict the quick streaming delivery with P2P. In chapter â…¢, a novel VoD service model (CAPMedia) combining P2P and Cloud is proposed, which includes P2P-assisted peers, cloud-assisted peers, and source servers. In order to address the organization of peers, the neighbor management with Double linked list betters the performance of changeable neighbors; meanwhile, it gives a clue about stable peers'selection policy. The peer management scheme, which is based on the interest similarity and geography-aware features, improves the cooperation of peers and increased system capacity effectively. In addition, the video structure and performance evaluation model are discussed.Efficient service location is a key issue in VoD system, the existing schemes mainly focused on user's uniform access pattern. In this paper, we formalized the indexing model, carefully analyzed the issues affecting VoD performance, and proposed the optimum solution with greedy scheme. Then a novel adaptive indexing structure is proposed, called DSplay, which is based on user's arbitrary behaviors, DSplay groups users according to user's real-time request. It can reflect user's request pattern and chunk popularity without any history records. The simulation validates the high service location efficiency, especially in supporting unpredictable non-uniform user access pattern.Pre-fetching is a key issue in VoD service, with the growing computer storage and bandwidth capacity, it would be an ideal service model which fetches the video requested in future with idle bandwidth. A novel pre-fetching scheme with peer leaving behavior, neighbor-assisted, popularity-aware, is proposed to futher reduce the latency. It is not nessesary to predict the user behavior which is differs from the existing prefetching schemes. The knowledge extracted from DSplay is used to study a popularity-aware pre-fetching mechanism, then a neighbor assisted optimized model is presented by formal analysis. Moreover, a pre-fetching policy allowing user pre-fetch the video clips which are high related with target clips and are stored by neighbors, is discussed. It improves the sharing efficiency and bandwidth utility with supporting users' continuous playback efficiently.When users' mutual sharing cannot support enough capacity for requests due to users'access time locality, dynamic behaviors and other Internet applications, the scalability of system is threatened. It will bring high cost by deploying servers. How to take advantage of reliability, excellent storage and computing ability of cloud with CAPMeida to support VoD application is studied in chapter VI. Based on the analysis of the necessity and feasibility, the interplay between VoD and cloud is designed. Chunk migration policy with peer lifetime and popularity is designed and a cost evaluation model is formalized. Finally, the simulation results show the efficiency of integration of P2P and Cloud.This work is supported by National "863" Project (2008AA01A315),2011 Specialized Research Fund for the Doctoral Program of Higher Education, under grant of "Research of Key Technology of P2P VoD Based on Cloud"(20114101110007) and2011Innovative Talent Project of Department of Henan education, under grant of "Research on key Technology of P2P VoD"(2011HASTIT003).
Keywords/Search Tags:VoD, P2P, content distribution, prefetching mechanism, chunkcorrelation, cloud service
PDF Full Text Request
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