Call admission control algorithm based on dynamic bandwidth reservation and bandwidth degradation

A call admission control scheme, named MCBDA-CAC, is proposed for wireless/mobile network based on dynamic bandwidth reservation and bandwidth degradation algorithm (BDA). MCBDA-CAC adjusts the reservation bandwidth for handoff calls in terms of the results of admitting handoff calls, confines handoff dropping probability (HDP) under a predefined threshold, and decreases call blocking probability (CBP) as low as possible. In addition, based on the estimation of the bandwidth demand in the next time interval, different BDA trigger modes are adopted to achieve the tradeoff between the system operation complexity and bandwidth utilization ratio. The proposed BDA takes many factors into account, such as service priority, fairness, call duration time, bandwidth fluctuation, and degradation call number ratio. To guarantee the fairness and to limit bandwidth fluctuation, two QoS parameters, named bandwidth satisfactory degree and bandwidth fluctuation degree, are proposed. The performance simulation shows that during 2000 simulation intervals, the average HDP of MCBDA-CAC is higher slightly than that of the similar schemes, but is still confined within the threshold. In addition, the average CBP and the average BDA trigger numbers are all lower than those of the similar schemes.