MARM: An agent-based adaptive QoS management framework

For distributed multimedia applications, the development of adaptive QoS (q uality of service) management mechanisms is needed to guarantee various and changeable end-to-end QoS requirements. In this paper, we propose an adapt ive QoS management framework based an multi-agent systems. In this framewor k,QoS management mechanisms are divided into two phases, the flow establish ment and renegotiation phase and the media-transfer phase. An adaptation to system resource changes and various user requirements is accomplished by d irect or indirect collaborations of the agents in each phase. In the flow e stablishment and renegotiation phase, application agents deter mine optimal resource allocation with QoS negotiations to maximize the total users util ity. In the media-transfer phase, stream agents collaborate to adjust each stream QoS reactively. In addition, personal agents help a novice user to s pecify stream QoS without any a priori knowledge of QoS. To make the interw orking of agents tractable, a QoS mapping mechanism is needed to translate the QoS parameters from level to level. since the expression of QoS differs from level to level. As an example of multimedia application based on the proposed framework, a one-way video system is designed. The experimental re sults of computer simulation show the validity of the proposed framework.