A TIMESTAMP-SENSITIVE SCHEDULING ALGORITHM FOR MPEG-II MULTIPLEXERS IN CATV NETWORKS

To achieve smooth display of MPEG-II programs in the residential cable TV networks, we present a timestamp-sensitive scheduling algorithm fo r MPEG-II multiplexers. The deadline-driven scheduler maintains, for e ach program stream, a counter and a timestamp to record and determine how many Transport Stream (TS) packets should be transmitted before th e current scheduling cycle ends. The decoding timestamp (DTS) of TS pa ckets is used to update the counter in order to prevent deadline viola tion. This algorithm is compared numerically with the timestamp-insens itive algorithm which runs constant-bit-rate (CBR) scheduling. The tra ce-driven simulation shows that the deadline violation of our timestam p-sensitive scheduling is much lower than CBR's and well controlled fo r programs with various degrees of burstiness. We also show that the a lgorithm can be further improved by adding a scheme to prevent buffer underflow and overflow at multiplexers and set-top-boxes, respectively .