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计算机工程

• 多媒体技术及应用 • 上一篇    下一篇

基于用户行为特征的SVC 分片调度算法

唐朝伟1,张 希1,王雪锋1,周 旭2,宋俊平2   

  1. (1. 重庆大学通信工程学院,重庆400030; 2. 中国科学院声学研究所高性能网络实验室,北京100190)
  • 收稿日期:2014-03-05 出版日期:2015-02-15 发布日期:2015-02-13
  • 作者简介:唐朝伟(1966 - ),男,教授、博士后,主研方向:网络多媒体技术;张 希(通讯作者)、王雪锋,硕士;周 旭,副研究员、博士; 宋俊平,博士。
  • 基金资助:
    国家科技重大专项基金资助项目(2011ZX03005-004-02);国家自然科学青年基金资助项目(61102076)。

SVC Fragment Schedule Algorithm Based on User Behavior Characteristic

TANG Chaowei 1,ZHANG Xi 1,WANG Xuefeng 1,ZHOU Xu 2,SONG Junping 2   

  1. (1. College of Communication Engineering,Chongqing University,Chongqing 400030,China; 2. High Performance Network Lab,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China)
  • Received:2014-03-05 Online:2015-02-15 Published:2015-02-13

摘要: 针对异构环境中网络和终端的复杂性,以及用户随机搜索行为造成的视频点播服务中播放进度的突变性,提出一种异构环境中基于用户行为特征的可扩展视频编码分片调度算法。设计2 类调度窗口,即根据当前播放时刻保证顺序播放数据持续功能的播放窗口和依据服从Weibull 分布的用户随机搜索行为设计的加入数据预取机制的锚点窗口。对播放窗口和第一个锚点窗口采用逐层调度策略,以保证数据的及时性,其余锚点窗口使用rarestfirst策略,以平衡整个系统的分片分布。在OverSim 平台上的仿真结果表明,与现有的逐层调度算法和权值调度算法相比,该算法在发生用户随机搜索行为的应用场景中能提高节点分片调度性能,缩短响应时延,降低服务器负载,提高用户观看视频的质量和流畅度。

关键词: 异构环境, 用户行为, 分片调度, 锚点窗口, 对等网络, 可扩展视频编码

Abstract: In view of the complexity of the network and terminal in heterogeneous environment,and the mutability of playback progress in the video-on-demand service that is caused by user random seeking,an Scalable Video Coding (SVC) fragment schedule algorithm based on user behavior characteristic is proposed. In the proposed algorithm,two types of windows are designed. One is playback window based on current playtime to ensure order data continues,the other one is anchor window designed with data prefetching,which is based on user random seeking following the Weibull distribution. The Layer-by-Layer(LL) schedule strategy is utilized in playback window and the first anchor window to ensure the timeliness of data,and the rarest-first strategy is used in the other anchor windows to balance the fragment distribution of the whole system. Simulation results in OverSim show that,compared with current LL schedule algorithm and weighted schedule algorithm,the proposed algorithm can improv the fragment scheduling performance,shortens the response time delay,reduces the server load,and improves the quality and fluency of the user in watching video.

Key words: heterogeneous environment, user behavior, fragment schedule, anchor window, Peer-to-Peer Network (PPN), Scalable Video Coding(SVC)

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