Quality of service and call admission control for adaptive multimedia services in wireless/mobile networks

Multimedia services with Quality of Service (QoS) have become very demanded in wireless/mobile networks. Call admission control (CAC) is vital for these services partially due to the network´s limited capacity. In this paper, we propose a call admission control framework for adaptive multimedia services in a wireless/mobile network, where the bandwidth of an ongoing call is time-varying during its lifetime. A call is degraded if the assigned bandwidth is below its request bandwidth. We introduce a new QoS parameter: degraded area size (DAS). It stands for the normalized mean product of the proportion of a calls degraded time and the degree of degradation. Based on DAS, we present a CAC model to show how to guarantee DAS. We also introduce a bandwidth reallocation algorithm to adjust calls bandwidth in a cell. Simulation results are compared with those from non adaptive multimedia services and show that the performance of our method is better