Optimal Bandwidth-Buffer Tradeoff for VBR Media Transmission over the Relay-Server

In a client-server system, the minimum bandwidth required to transmit a pre-recorded VBR media can be computed in O(n). As the frame number n is usually very large, this resource management procedure is not suitable for online computation. Although an O(nlogn) algorithm has been proposed to characterize the bandwidth-buffer tradeoff for the optimal resource management (a native algorithm takes O(n)), this algorithm is not suitable for a general network system with additional relay-server. In this paper, we extend the problem model to consider the relay-server between client and server. This proposed model is good for scalable multimedia and fault-tolerance. Besides, the additional buffer in relay-server can be utilized to further smooth traffic and support more requests. In this paper, an O(nlogn) algorithm is proposed to decide the optimal bandwidth-buffer tradeoff for the relay-server. Based on the pre-computed tradeoff function, we can simply design a good QoS control procedure to allocate the suitable bandwidth for the available buffer size.