System Level Model for Wireless Channel Unreliability in CDMA Mobile Cellular Networks

In this paper, a new system level approach for modeling wireless channel unreliability in CDMA cellular systems is proposed. The analysis takes into account call connection types (i.e., soft handoff or single base station) and their respective link reliabilities, which according to some measurements in real cellular networks reported in the literature can adequately be modeled by considering a Poisson call interruption process. This is turn results in significant simplifications of system level analysis. Then, with the proposed interruption modeling, an elegant teletraffic analysis for the performance evaluation of mobile cellular CDMA networks considering both wireless link unreliability and resource insufficiency is developed. Realistic mobility conditions are taken into account by characterizing users´ mobility parameters by means of a smooth random mobility model. Novel mathematical expressions for the new call blocking, handoff failure, and forced termination probabilities are then derived. Graph theory and Mason´s rule are employed for the derivation of the forced termination probability.