Internet上基于两端的流媒体QoS控制

QOS CONTROL BASED ON TWO ENDS FOR STREAMING MEDIA ON INTERNET

在Internet这类无法可靠保证服务质量QoS的网络环境中,拥塞和带宽的不足成为流媒体应用的主要瓶颈,所以,流媒体应用的关键是QoS控制机制。QoS控制大致分为两大类:基于路由和基于两端。基于两端的QoS控制技术的基本思想是:网络状况好的时候多传些数据增强播放质量,网络状况不好的时候则只传输能够达到基本播放效果的数据。即QoS技术能够动态地调节传输数据量的多少。主要分析和介绍了相关的流媒体编码技术、基于客户端的QoS控制和基于服务器端的QoS控制技术。

In a certain environment of networks without reliable quality of service（QoS） assurance such as Internet, bandwidth and congestion are inadquate to be the main bottleneck of streaming media application. So on Internet the key for its application is QoS control mechanism. There are approximately two kinds of QoS control： based on Router and based on two ends. For two-end-based QoS control technology, the basic thought is that the quality of playing is strengthened through more data transmitting on good condition of network whereas acceptable playing effect is just achieved through adequate data transmitting on the contrary, that is, the QoS technology is able to dynamically adjust the data volume transmitted. Corresponding encoding of streaming media, QoS control based on client-side and technology of QoS control based on server-side are mainly introduced and analysed in this paper.