The Impact of Synchronising MPEG Stream on Bandwidth Allocation

An encoded video traac is a correlated and bursty traac with high value of peak to mean ratio (burstiness). For asynchronous transfer mode (ATM) networks, the challenge of QoS guarantees is to allocate an eeective bandwidth for each video connection and a tradeoo should be achieved between improving the network utilisation and providing QoS guarantees. The allocated bandwidth could be based on either deterministic multiplexing or statistical multiplexing. For eecient traac management in a high speed network, it is important to know the basic characteristics of multimedia traac. This paper presents a simple algorithm to deene and characterise VBR MPEG streams based on the amount of activity within each stream. This information is used to study the network utilisation when multiple streams are multiplexed. An allocation bandwidth approach based on a deterministic model for multiplexed VBR MPEG streams is presented. We then describe an arrangement for the multiplexed VBR MPEG streams. Furthermore, we show the impact of such arrangements on the allocated bandwidth. As a result, we show that it is possible to improve the network utilisation with statistical multiplexing even in the case of providing deterministic QoS guarantees. Finally, we explore the impact of the stream activity (amount of scene changes within MPEG stream) on the allocated bandwidth and the network multiplexing gain.