一种新的变比特率 MPEG 视频的多漏桶管制

New Method of Multiple Buckets Policing of Variable Bit Rate MPEG Video

研究如何对在ＡＴＭ网络中传输变比特率的ＭＰＥＧ视频流进行管制．提出了一种ＡＴＭ环境下基于变比特率ＭＰＥＧ编码特征Ｉ、Ｂ、Ｐ帧的多漏桶管制方法．与一般的漏桶方法相比，此方法能较准确地表征变比特率ＭＰＥＧ视频的业务特征，提高网络资源的利用率．实验结果表明，在相同的令牌池大小或业务负荷时，多漏桶模型的信元丢失率更低，因而多漏桶监控较为准确，可更有效地利用网络的缓冲和带宽资源．多漏桶模型可以通过改变各漏桶的相对大小来改变各帧信元的丢失分布，以此获得更好的主客观质量．

The article focuses on how to monitor and police the transportion of variable bit rate (VBR) video over ATM networks. The article presents a method of multiple buckets policing in ATM environment, which is based on VBR MPEG codec characteristics of I, B, P frame. Comparing to general bucket method, it presents MPEG video characteristics more precisely and can improve the utilization of resource greatly. The simulations show that, with the same size of the token pool or traffic load, the cell loss rate of multiple buckets model is lower. Thus the multiple buckets policing is more precise and can efficiently utilize the buffer and bandwidth resources. Moreover, a general bucket model and the other existed variants do not distinguish frame types of video. Its loss distribution is not controllable. Multiple buckets model is different. It can change loss distribution by altering the relative size of every bucket and obtain better subjective and objective quality.