一种分层P2 P流媒体系统重叠网的构建策略

基于Peer-to-Peer(P2P)技术的流媒体应用具有部署效率高及可扩展性好等突出优势。而采用分层视频编码技术的P2P流媒体系统把原视频流分解为多个视频层数据进行分发,让节点能够选择与自己带宽资源相匹配的视频质量,使其很好地适应节点的异构性。但是各分层视频数据传输的路径存在较大差异,使重叠网构建策略面临更大的挑战。因此定义了基于分层视频编码技术环境下的P2P流媒体重叠网络构建问题,并证明该问题是一个NP难问题。提出了一种构建重叠网的集中启发式算法,同时还提出了一种基于视频组(Streaming Group)的分布式重叠网络构建策略。通过大规模网络仿真实验验证了基于该分布式重叠网构建策略的分层流媒体系统具备低服务器带宽占用、高数据获取率等优点。

Overlay Construction Policy in Layered P2P Streaming System

Peer-to-Peer(P2P)based streaming applications hold the advantages of high efficient deployment abilitsy and high scalability. Layered video coding based P2P streaming system splits the source video into multiple layer of video data and distributes these streaming data, which makes peer can select the playback duality according to its bandwidth resource. I}his kind of streaming system is more accommodative to the heterogeneity of peers. However, difference distribution overlay path of different layer of streaming data also leads to challenges of overlay construction in layered P2P streaming system. This paper formulated the overlay construction issue in layered P2P streaming environment, which is a NP-hard problem, and put forward a centralized heuristic algorithm, then designed a streaming group based distributed overlay construction policy. Large scale network simulation shows that this overlay construction mechanism has the characteristics of comparatively low bandwidth consumption at streaming server and high streaming acquisition ratio.