Evaluation of a call admission control scheme in W-CDMA cellular networks

Abstract

In this paper, we evaluate a call admission control (CAC) scheme suitable for W-CDMA cellular networks accommodating multiple service-classes. In such networks, the distinction between the new and the handoff traffic is very important. A simple CAC scheme can distinguish the calls between the two traffic types by setting different thresholds for call admission. This simple CAC scheme is evaluated in respect of blocking probabilities of both new and handoff calls. To this end, we formulate an aggregate Markov chain, which describes both the new-call and handoff-call arrival processes, under the assumption that they are both Poisson processes. Based on this Markov chain we derive recurrent and computationally efficient formulas for the calculation of the system state probabilities. Consequently, we calculate the new-call and handoff-call blocking probabilities. The analytical results are verified through simulation and found to be absolutely satisfactory.