Optimal CAC Policy in Multimedia Wireless Networks with Reservation Channel Schemes

In this paper, we investigate the call admission control (CAC) policy of a single cell in multimedia wireless networks with reservation channel scheme (RCS) for different classes of calls. Arrival process of each class of calls is assumed to be a Poisson process, the service time of each call is exponentially distributed. Admitting a call would bring a reward. However, if the reserved channels for the arriving call are all occupied, connecting this arriving call in the system will also bring a call holding cost per unit time. In order to achieve the maximum expected reward, we establish a discounted semi Markov decision process (SMDP) model and then derive the optimal policy for admitting or rejecting the arriving calls. We verify that the optimal CAC policy is a control limit policy if the cost functions have some special properties. Simulation result is consistence with the numerical result from our theoretic analysis.