Performance modeling and analysis of hierarchical wireless communications networks with overflow and take-back traffic

Hierarchical structuring of cellular systems is an effective way to address the problem of continuing growth in traffic volume from users with varying degrees of mobility in wireless networks. Overflow and take-back strategies integrate the two tiers (microcell and macrocell) smoothly, within which both microcells and macrocells serve as a secondary resource to each other, taking into account the different mobility classes the subscribers belong to. We develop an analytical model based on MMPP (Markov modulated Poisson processes) to evaluate the performance of such hierarchical systems. We obtain the probability of call loss and forced termination for calls in progress and we contrast them to those from systems with incremental traffic handling capabilities in overflow and take-back.