Analysis of a distributed CDMA channel access control protocol using embedded processes

We present and analyse a distributed channel access control protocol in a direct sequence CDMA network. In this protocol, every channel is available for use in every cell and channel access decisions are made by the mobiles based on information broadcast from the base stations. This is different from the access strategies which have appeared in the literature where call requests are processed solely by the base stations. Narrainen and Takawira (see IEEE Military Commun. Conf., Virginia, USA, p.384-8, 1996) analysed the distributed protocol using a M/M//spl infin/ queuing model. A drawback of this model is its failure to accurately represent the protocol for small values of channel access update intervals. In this paper, we present an enhanced analytical model based on semi-Markov embedded processes. The performance of the network is also determined through simulation of a 30 cell network. We model closed-loop power control and include propagation effects such as path loss with distance, log-normal shadowing, and Rayleigh fading. Teletraffic performance is computed in terms of call blocking, probability of forced termination, and grade of service.