基于RTP协议和MPEG－4可扩展编码的非均匀QoS控制机制

1 引言随着IP网络、ATM网络和无线网络上传输的多媒体实时数据量不断增加,网络资源增长的相对滞后和需求之间的矛盾日益突出,尤其是局部拥塞的频繁出现,而传统的路由器通常不提供拥塞控制,因而对基于传输两端进行QoS控制的要求也越来越迫切。和QoS控制同样重要的是流媒体协议与编码,而且两者是QoS控制的基础。本文将MPEG-4可扩展编码的自适应能力和灵活性作为提高QoS控制能力的前提,选择当前实时传输领域最重要的PTP协议作为协

Unequal QoS Control Mechanism Based on RTP and MPEG-4 Scalable Coding

Since the significance of each layer in scalable coding is different, making use of this characteristic can rea-sonably use such resources as bandwidth, processing and caching by deploying varied QoS control strategies for differ-ent layers. This paper presents an idea of unequal QoS control and the implementation mechanism at two ends oftransmission based on RTP and MPEG-4 scalable coding, redefines the sequence number field of RTP header and ex-tends the RTP header. These can not only realize unequal bandwidth pre-allocation and unequal error protection, butalso rapidly and precisely estimate the delay jitter and packet loss ratio.