Improving the delivery of multimedia services using an adaptive filtering strategy

In this paper, we present an adaptive filtering strategy for improving the delivery of multimedia services with guaranteed quality of service (QoS) on an end-to-end basis. Multimedia content is downloaded along an integrated wired/wireless network from media servers to mobile end-users. The proposed strategy assures that the network resources (e.g. capacities, buffer) are efficiently utilized and the QoS requirements (e.g. delay bandwidth) of two different classes of end-users are always respected as traffic flows in downstream. This objective is achieved by filtering, in each node of the network, the amount as well as type of content downloaded such that possible congestion episodes are avoided and the downloading speed of content is maintained. According to the proposed strategy, filters are able to select the bit-rate values required to download traffic by adaptively scaling the coding rate and, if necessary, transcoding media streams. The action performed by each filter is controlled by an optimization function that is implemented in our proposed resource manager. Simulation results demonstrate that the filtering strategy has significantly decreased the call-blocking rate while maintaining users QoS requirements and maximizing network capabilities.