Call admission control for multi-service mobile networks with bandwidth asymmetry between uplink and downlink

In multi-service mobile networks, asymmetric bandwidth allocation has been proposed to satisfy the requirements of the asymmetric traffic load introduced by some data applications. However, it is difficult to promptly adjust bandwidth allocation on the uplink and downlink according to the traffic load dynamics. Superfluous real-time (RT) calls or non-real-time (NRT) calls might be accepted. This may lead to a low bandwidth utilization. In this paper, we propose and evaluate a new call admission control (CAC) scheme to address the problems caused by the mismatch of bandwidth allocation and traffic changes. By determining the admissible bandwidth region for the NRT calls, the proposed scheme prevents the calls from overusing the bandwidth resources. Thus the bandwidth utilization is improved and the blocking probability of the high priority calls can be guaranteed at a low level. The simulation results demonstrate that the proposed CAC scheme can achieve better performance compared to the existing schemes, even those performing well in multi-service mobile networks with asymmetric bandwidth allocation.