Dynamic call admission control scheme for QoS priority handoff in multimedia cellular systems
A dynamic call admission control (CAC) and its associated resource reservation (RR) schemes are proposed in this research based on the guard channel (GC) concept for a wireless cellular system supporting multiple quality of service (QoS) classes. The proposed CAC policy selects the resource access threshold according to the estimated number of incoming call requests of different QoS classes. The amount of resources to be reserved is dynamically adjusted by considering neighboring-cell higher-priority calls, which are likely to handoff. The rationale behind our proposed dynamic CAC and RR scheme is to make an efficient resource reservation for priority calls by considering potential handoff calls in the neighboring cells, based on their signal to noise ratio (SNR) information and the traffic profile for each mobile. A comprehensive service model is developed, which includes not only mobile terminals' bandwidth requirements but also their different levels of priority, rate adaptivity as well as their mobility. Simulations are conducted by OPNET to study the performance of our proposed scheme in terms of cost function and system utilization under different traffic conditions.