QoS Control and Adaptation in Distributed Multimedia Systems

Abstract. Presently, many distributed multimedia systems adapt to their changing environments and Quality of Service (QoS) requirements by exchanging control and feedback data between servers and clients. In order to realize a more flexible adaptation to QoS in distributed multimedia systems, this paper seeks to present a new approach, based on distributed software agents located in both network nodes and end-systems. By having a good knowledge of local resources at each component, and with their capabilities to communicate in order to share their knowledge, the distributed software agents can alleviate the major fluctuations in QoS, by providing load balancing and resource sharing between the competing connections. In order to show the feasibility of our active adaptation approach, simulations have been conducted to adapt a delay sensitive flow such as distributed interactive virtual environment. We have performed our evaluations for short and long range (i.e. self-similar) traffic patterns. Preliminary results show a viable system, which exhibits a smooth and noticeable improvement in perceptual QoS during a heavy loaded network. In addition, our results indicate that the network and the application have more to benefit from the algorithm, when the traffic exhibits long range dependence behavior.