Dynamic QoS Management for Flexible Multimedia Applications

Many multimedia applications exhibit QoS flexibility, as they support certain quality degradation. In the end, increasing or decreasing the QoS level results in increasing or decreasing the resources demanded by the applications, which may be useful for overcoming system overload. In this context, the present paper, based on previous work of authors, proposes a model-based and multi-agent based approach for the management of QoS flexibility in multimedia applications founded on a suitable management of system resources. More precisely, it describes a modeling approach to capture the QoS flexibility demands, mapping them to resource demands. At runtime, a multi-agent based middleware allows the best QoS level of the running applications by adjusting their demand of system resources, i.e. their QoS level, to the resource availability at a concrete time. This proposal has been evaluated through a video-surveillance application.