Call admission control using the moving pattern of mobile user for mobile multimedia networks

In this paper, a call admission control mechanism is proposed to provide a consistent QoS guarantee for multimedia traffic on a mobile computing environment. Each cell can reserve fractional bandwidth for handoff calls to its adjacent cells. It is important to determine the right amount of bandwidth reserved for handoff calls because the blocking probability of new calls may increase if the amount of reserved bandwidth is more than necessary. An adaptive bandwidth reservation based on a mobility graph and a 2-tier cell structure is proposed to determine the amount of bandwidth to be reserved in the cell and to control dynamically its amount according to network conditions. We also propose a call admission control based on this bandwidth reservation and "next-cell prediction" scheme using a mobility graph. In order to evaluate the performance of our call admission control mechanism, we measure metrics such as blocking probability of new calls, dropping probability of handoff calls, and bandwidth utilization. The simulation results show that the performance of our mechanism is superior to that of existing mechanisms such as NR-CAT2, FR-CAT2, and AR-CAT2.