Performance Analysis and Estimation of Call Admission Control Parameters in Wireless Integrated Voice and Data Networks

We propose an admission control policy for wireless multimedia networks that is based on the well known threshold-based guard channel method. The new scheme deals with two different types of traffic classes; namely: voice and data. We assume two different thresholds, one for each traffic class. In addition, we propose to buffer the handoff data calls if no free channels are available rather than rejecting them. For handoff voice calls, we propose two methods, namely: a blocking method and a preemptive method. For the blocking method, we reject the handoff voice calls if no channels are available. For the preemptive method, an ongoing data call can be buffered and its channel allocated to the handoff voice call. We study the effect of the thresholds, buffer size and the application of the proposed methods on call blocking probabilities. It is shown that the new call blocking probabilities are only affected by the threshold values. Meanwhile, the data handoff blocking probability exhibited great improvement. For handoff voice calls, when the blocking method is applied, the blocking probability value increases slightly with the increase of buffer size. Meanwhile, for the preemptive method, the handoff voice call blocking probability significantly decreases as the buffer size increases. Based on these results, we develop an algorithm that uses the proposed policy to estimate the appropriate thresholds and buffer size which meet the required call blocking probabilities for each traffic type.