Modeling hierarchical microcell/macrocell PCS architecture

In a personal communications services (PCS) network, heavy traffic areas may be covered by microcells which overlay with macrocells. We propose an analytic model to study the performance of the microcell/macrocell PCS architecture. Our model assumes that a PCS subscriber has a general residual time distribution in a microcell, and the macrocell residual time distribution is derived based on the microcell residual time distribution. A five-step iterative algorithm is used to compute the overflow traffic from a microcell to its overlay macrocell. Then the call incompletion probability is computed by a macrocell model based on the overflow traffic. Our study indicates that the variance of the microcell residual time distribution and the number of microcells covered by a macrocell have significant effects on the call incompletion probability.