服务感知的移动P2P流媒体系统视频片调度算法

Service-aware Chunk Scheduling Algorithm for Mobile P2P Streaming

与有线网络相比,目前移动互联网的带宽普遍较低。这种情况下,如果移动P2P流媒体系统中用户节点上行带宽的利用率不高,将会极大地加重视频源服务器的负载,增加播放延时。为了充分地利用移动节点的上行带宽,缩短播放延时,文中提出了服务感知的视频片调度算法,它由请求算法和服务算法两部分组成。请求节点会根据最近的服务状况动态地调整请求的片数,减少服务拥塞的发生。服务节点会根据请求的优先级合理地安排上传顺序,提高服务的效率。仿真结果表明,该算法很好地适应了移动网络带宽低的情况,能够提高上行带宽的利用率,缩短播放延时。

Compared to the wired netework,the mobile internet has limited bandwidth.In this environment,the bandwidth utilization of user nodes＇ uplink greatly affects on the burden of video-source server in a mobile P2P streaming system,thus increasing the playback lag.In order to make full use of the uplink bandwidth of mobile node and shorten playback lag,this paper proposes service-aware video chunk scheduling algorithms including the request algorithm and the service algorithm.Requesting nodes dynamically adjust chunk number of each request according to the latest service status,which will decrease the occurrence of service congestion.Serving nodes reasonably arrange the upload order according to the request priority,which improves the service efficiency.Simulation results demonstrate that the service-aware algorithms adapt well to the mobile environment with low bandwidth,and can not only enhance the utilization of uplink bandwidth but also reduce the playback lag.