Abstract: A platform of P2P（Peer-to-Peer） video on demand in wireless mesh networks is established. The four factors which influence video quality are tested on the platform, including encoding and decoding method in application layer, encoding rate, inter-flow interference introduced by P2P mechanism and hop counts. The experiments results show that H.264 encoding is more appropriate for wireless mesh networks and encoding rate must not be greater than network connection speed in order to gain high quality. P2P video quality does not decrease along with network performance when the packet loss rate is smaller than 10%. P2P mechanism introduces 3 dB gain than non-P2P mechanism before the 1,000 th frame, but this advantage vanishes after the 1 000 th frame because of inter-flow interference. The transmission capacity decrease as hop count increases, but this rule is not suitable for P2P video performance.

Key words: Peer to Peer, wireless mesh networks, performance evaluation

摘要： 通过搭建基于无线Mesh网络的P2P流媒体点播测试平台，对影响无线Mesh网络中P2P流媒体性能的流媒体编解码方式、编码速率、数据转发路径的选择和跳数四个因素进行了测试。实验结果表明，采用H.264编解码标准更适合无线Mesh网络中流媒体的传输；编码速率必须不大于网络连接速率才能获得高视频质量；P2P技术可以抵抗10%的丢包对视频质量的影响，比采用非P2P技术在视频的前1 000帧视频质量平均高出3 dB；由于P2P技术带来的流间干扰的影响使得1 000帧以后视频质量下降了6 dB，严重影响了流媒体性能；无线Mesh网络的传输能力随着跳数的增加而减弱，但是流媒体质量并未随着跳数的增加而降低。

关键词: P2P, 无线Mesh网络, 性能评估