Traffic characterization and bandwidth allocation for MPEG-2 VER video traffic

In this paper, starting from a long sample (about one hour) of the movie ''The Sheltering in the Sky'', coded according to the MPEG-2 standard with 2 different quantization steps, we study the characteristic of this traffic to identify efficient network bandwidth-allocation policies. In the first part of the paper we evaluate the efficiency that can be obtained by maintaining a constant quality, i.e., VER coding with a constant quantization step. Results obtained indicate that traffic with constant quality cad be transmitted with a suitable quality of service only if the network utilization is very low, i.e., 25-30%. As the network low utilization is caused by rare high-rate periods lasting few seconds, we propose to reduce the codec quantization step during these periods, Simulative results show that the two quantization steps approach significantly increases the utilization while maintaining the quality of the video signal at the highest value for most of the time, e.g., a 50% of the network utilization with the highest quality for the 99.7% of the time.