Abstract: Live video is one special category in video service for its real-time feature. Providing on-line live video service based on named data networking (NDN) rather than TCP/IP architecture and delivering content over satellite broadcasting can achieve the high quality service in large scale with relatively low cost. However, the long propagation delay of satellite link can lead to the problem of redundant data transmission (RDT) in live video broadcasting over satellite based on NDN. RDT will waste valuable communication and computation resource of satellite link. To solve this problem and further improve the application efficiency, this paper proposes an extended approach built on NDN, namely delay pending interest table (DPIT). The experimental results show that the DPIT mechanism can greatly reduce the influence of RDT problem and improve the efficiency of live video application over satellite broadcasting based on NDN.

Key words: Internet live video, satellite, broadcasting, named data networking (NDN)

摘要： 视频直播实时性强，应用广泛，是视频服务中的一种特殊应用。基于命名数据网络（named data networking，NDN）而非传统端到端的TCP/IP体系结构提供网络视频直播，并通过卫星广播进行内容分发，可以以相对较低的通信开销提供大范围高质量服务。然而，由于卫星链路传播延迟较高，基于NDN的卫星广播视频直播应用在内容分发过程中会出现冗余数据传输（redundant data transmission，RDT）现象。RDT将造成卫星链路通信计算资源的浪费，影响应用效率。为了解决该问题，进一步提升应用效率，在NDN的基础上进行改进，提出了容迟未决信息表（delay pending interest table，DPIT）。实验结果表明，DPIT可以有效降低RDT问题造成的影响，提升基于NDN组网卫星的广播视频直播应用效率。

关键词: 网络视频直播, 卫星, 广播, 命名数据网络（NDN）