摘要
针对TCP重传易导致延时抖动大、降低流媒体播放质量的问题,提出了使用TCP传输实时视频时,播放质量不受TCP重传影响的必要条件,即视频帧发送延时、播放缓冲区延时与网络往返时间需要满足一定的关系式。建立了视频帧发送延时的预测模型,该模型通过输入视频帧长度、丢包率、网络往返时间、TCP拥塞窗口大小与TCP超时重传时间,预测视频帧的发送延时。NS2模拟结果表明,可以通过发送延时的预测值来判断视频帧是否适合采用TCP传输。
Aimed to larger end-to-end delays and jitters and worse playing quality posed by the TCP retransmission for the multimedia streaming transmitting via Internet using TCP, this paper proposed the necessary conditions to overcome effect on video playing quality caused by TCP retransmission, such as the formula describing the relationship between video frame sending-delays, play out buffer delays and round trip time （RTT）. It presented a prediction model to predict the video frame sending-delays with input parameters as video frame lengths, network loss ratio, RTT, TCP congestion window size, and TCP retransmission timeout （RTO）. Experiments using NS2 simulator show that the prediction value of video frame sending-delays can be used to determine whether it is feasible for a video frame to be transsmitted using TCP protocol.
出处
《计算机应用研究》
CSCD
北大核心
2010年第6期2239-2242,共4页
Application Research of Computers
基金
国家杰出青年科学基金资助项目(60425310)
香港城市大学战略发展计划资助项目(7002102
7002214)
关键词
传输控制协议
实时视频
延时
预测
TCP（transmission control protocol）
real-time video
delay
prediction
