中国邮电高校学报(英文) ›› 2011, Vol. 18 ›› Issue (5): 76-86.doi: 10.1016/S1005-8885(10)60107-0

• Networks • 上一篇    下一篇

Model of downloading strategy from peers and server for saving server bandwidth in P2P VoD system

危婷1,邓光青1,陈常嘉1,朱巍2   

  1. 1. 北京交通大学
    2. PPLive上海聚力传媒技术有限公司
  • 收稿日期:2011-03-28 修回日期:2011-06-07 出版日期:2011-10-31 发布日期:2011-10-13
  • 通讯作者: 危婷 E-mail:teresa04111007@gmail.com
  • 基金资助:

    中国自然科学基金:基于测量的流媒体发布建模和分析;中国自然科学基金:支持自治和丰富选择策略的因特网基础路由研究;中国科技部973项目:一体化网络的普适服务的体系理论和结构

Model of downloading strategy from peers and server for saving server bandwidth in P2P VoD system

  1. School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100044, China
  • Received:2011-03-28 Revised:2011-06-07 Online:2011-10-31 Published:2011-10-13
  • Contact: School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100044, China E-mail:teresa04111007@gmail.com

摘要:

In peer-to-peer (P2P) video on demand (VoD) system, once the P2P downloading rate cannot satisfy the need of playback, server is quickly referred to for help in providing enough bandwidth. Thus the switch of downloading from other peers (P2P) and server (HTTP) exists. This paper uses the proportion of P2P downloading amount (PPDA) during the video watching process to measure server load. This article is interested in finding a better strategy or switch rule between P2P and HTTP downloading for saving server bandwidth. The authors suggest and model a kind of switch rule based on local buffer amount, using mathematical theory of Brownian motion. It can effectively alleviate the impact of P2P rate fluctuation, reduce the switch times and improve the PPDA by at least 3%–5% on the basis of the former switch rule, which means substantial cost can be saved. Particularly the PPDA is related with the ratio of playback bit rate to the HTTP downloading rate which means the PPDA can be restricted by controlling the ratio in the real-world system. Though the result comes from constant bit rate (CBR) video supposition, it provides perspective and method for variable bit rate (VBR) application, and valuable insights for the future development of P2P VoD system.

关键词:

P2P, VoD, downloading, server load

Abstract:

In peer-to-peer (P2P) video on demand (VoD) system, once the P2P downloading rate cannot satisfy the need of playback, server is quickly referred to for help in providing enough bandwidth. Thus the switch of downloading from other peers (P2P) and server (HTTP) exists. This paper uses the proportion of P2P downloading amount (PPDA) during the video watching process to measure server load. This article is interested in finding a better strategy or switch rule between P2P and HTTP downloading for saving server bandwidth. The authors suggest and model a kind of switch rule based on local buffer amount, using mathematical theory of Brownian motion. It can effectively alleviate the impact of P2P rate fluctuation, reduce the switch times and improve the PPDA by at least 3%–5% on the basis of the former switch rule, which means substantial cost can be saved. Particularly the PPDA is related with the ratio of playback bit rate to the HTTP downloading rate which means the PPDA can be restricted by controlling the ratio in the real-world system. Though the result comes from constant bit rate (CBR) video supposition, it provides perspective and method for variable bit rate (VBR) application, and valuable insights for the future development of P2P VoD system.

Key words:

P2P, VoD, downloading, server load