基于视频发送端速率控制的QoS技术研究

基于尽力而为的网络模式不能提供QoS保证,网络拥塞和分组丢失不可避免。在端到端视频单播结构下,论文提出了一个发送端速率控制框架SRCF,在此框架下首先利用RTCP报文中的字段提出了一种网络参数测量方法,然后设计了一个自适应速率算法SRCA,SRCA利用已得到的网络传输延迟和分组丢失率参数作为初始参数,来调整编码速率,达到充分利用带宽的目的,避免了视频质量由于调整参数带来的剧烈抖动。仿真结果表明,该算法在网络出现一定拥塞的条件下,能跟踪带宽的变化,网络和媒体QoS能保证视频质量较好。

Research on Guarantee Technology of Video Stream's QoS Based on Sender Rate Control

The best effort service of current Internet can not offer any Quality of Service(QoS)guarantees to real-time traffic.Congestion and packet loss are unavoidable.In this paper,a layered end-to-end unicast Internet video streaming architecture is presented.Sender Rate Control Framework(SRCF)is designed in video transmission layer.Under the frame -work,using the RTCP packet segment ,addressing the measurement of network parameters at first,then designing a Sender Rate Control Algorithm(SRCA)scheme ,which employs the parameters of network transmission delay and packet loss setting of SRCA to adjust the encode rate and obtain useful bandwidth.That avoids the quality jitter of video streaming.Finally,some experimental results are presented to demonstrate the effectiveness scheme to the quality of video streaming and track the changer of bandwidth.