Performance Analysis of the Guard Channel Scheme with Self-Similar Call Arrivals in Wireless Mobile Networks

Call admission control plays a significant role in the provisioning of differentiated Quality-of-Service (QoS) to new calls and handover calls in wireless mobile networks. Due to its cost-effectiveness, the Guard Channel (GC) call admission control scheme has been widely deployed. Existing studies on modelling and analysis of this scheme have been usually focused on the working conditions where both new and handover calls are modelled by traditional Markovian arrival processes (e.g., Poisson processes). However, many recent measurement studies have revealed that realistic network traffic exhibits statistically self-similar nature, which is significantly different from the properties of the traditional Markovian traffic. Therefore, the existing performance models of the GC-based call admission scheme are no longer adequate to capture the self-similar call arrivals. To fill this gap, this paper presents a novel analytical model for the GC-based call admission control scheme in the presence of self-similar new call and handover call arrivals. We derive the blocking probability of new calls and the dropping probability of handover calls and validate the accuracy of the developed model through comparison between analytical and simulation results. The model is then used to investigate the optimal number of guard channels required in wireless networks such that the loss probabilities of new calls and handover calls meet their corresponding QoS requirements.