A performance study of loss priorities for MPEG video traffic

We study the performance of a loss priority mechanism for MPEG-coded video traffic. This mechanism, known as partial buffer sharing (PBS), is implemented at an ATM multiplexer. The input to the multiplexer consists of several MPEG streams which are derived from the frame-size trace of a full-motion movie. Each stream contains three types of frames: I, P, and B. The significance of the information carried in MPEG frames differs according to the frame type; with I frames being more important than P and B frames. Hence, PBS with two priority classes is used to reduce the cell loss rate for I frames at the expense of higher loss rates for P and B frames. It is observed that the cell loss rates for the two priority classes are greatly influenced by the level of synchronization among the video streams