无线网络视频感知机会网络编码协议及其仿真研究

Simulation Study of Video-Aware Opportunistic Network Coding Protocol over Wireless Networks

提出一种无线网络视频感知的机会网络编码协议(VONC)。该协议根据视频流数据包的重要程度以及无线网络的链路状况,用效用增益函数来评估每个数据包对视频质量的贡献程度,而后根据其效用增益值的大小,采用多优先级的调度机制接入信道,以提高网络视频传输质量。另一方面,针对视频流传输过程中的拥塞问题,提出拥塞感知的流控制机制(CFC),与上述网络编码体系协同工作,以提高高优先级数据包成功传输概率。有针对性地设计了一系列仿真实验。结果表明,VONC能够有效提高重要视频帧的可解码率,网络视频传输质量得到显著改善。

A video-aware opportunistic network coding protocol （VONC） over wireless networks was proposed. The main idea was to use utility gain function to assess comprehensively the contribution of each video packet to streaming quality, according to both the importance of video packet and the wireless link condition. Multi-priority channel access mechanism based on the contribution was used to improve the video transmission quality. In addition, against the congestion of video transmission, congestion-aware flow control （CFC） mechanism was added on the base of the network coding. When congestion occured, CFC took the initiative to discard low-priority packets to improve successful transmission probability of high-priority data packets. Finally, a series of experiments were designed and conducted. The simulation experiments demonstrate that VONC can effectively improve the decoding rate of important video frames, and thus, the quality of video transmission is enhanced.