移动对等直播流媒体系统的服务质量保证机制研究

摘要

With the development of mobile networks and smart mobile terminals, researches on mobile P2P live streaming systems become popular. However, extending the P2P live streaming system faces two obstacles: one is the differentiated services and the other is the Quality of Service (QoS) during the domain-across movement of mobile terminals . In the paper, an adaptive multi-rate streaming service method is proposed to deal with the differences between mobile terminals and PCs. Multiple sub-streams of one stream with different rates are distributed in one P2P distribution topology. Clients buffer all or part of sub-streams according to their situations and abilities. They can adaptively change their buffer and the playing sub-stream according to the variation of the network environment, and provide differentiated services for their neighbors. Meanwhile, a cross-domain mobile QoS mechanism containing data pre-buffering and temporary-storing is proposed. Experimental results demonstrate the efficiency of the ways presented for the QoS in the Mobile P2P Live Streaming System.%随着移动网络及移动智能终端的发展和日益普及,移动对等(P2P)网络流媒体方面的研究已成为当前的热点.然而,P2P流媒体的移动化面临两大问题,一是流媒体的差异化服务,二是终端移动过程中的服务质量保证.针对终端的差异性,本文提出了自适应多码率服务的思想,在一个P2P节目流拓扑中,发布多个子流,用户根据自己的网络状况和能力,缓冲全部或者部分子流,并根据网络环境的变化,动态地改变自身缓冲和播放的流,为邻居节点提供差异化的服务；同时提出了一种跨域移动服务质量保证机制,包括数据预缓存、数据暂存等策略.实验证明上述方法能有效提高移动对等直播流媒体系统的服务质量.