An enhanced distributed call admission control for wireless systems

Call admission control (CAC) is one of the key elements to provide quality of service (QoS) guarantee in wireless mobile networks. A good CAC scheme should efficiently support handoffs and maintain a high utilization of the scarce radio resource while it should also be simple for implementation. Since the traditional guard channel policy is not optimal for a hard constrained handoff dropping probability, new CAC algorithms have been studied in the literature. Among them, the distributed call admission control seems to be simpler and more efficient with regards to the above requirements. However, there are some problems in the original scheme which make the implementation complex and lead to performance degradation. In this paper, we will first discuss simplifications to the original scheme, and then further enhance the modified scheme by considering the difference of mobility support requirement between high and low mobility users. The simulation results show that the enhanced scheme gives better performance