On the Characteristics of Variable Bit–Rate Video

Video might constitute a sizeable part of the traffic in future broadband networks. It is consequently important to consider the requirements of video and its characteristics in order to properly design and dimension the networks. Despite a massive amount of research on video source models and multiplexing performance, there are few results that are applicable to real sources and networks. For instance, most of the models consider only unregulated video coders, ignoring the fact that regulation is possible as long as it does not lead to objectionable quality variations. Moreover, most of these models cannot be verified by on–line measurement which makes them less useful for call–acceptance control. The purpose of this paper is to review the characteristics that may be expected from variable bit–rate video. This will be done in the context of ATM traffic classes and their associated admission controls.