Differentiated Connection Admission Control Strategy for Wireless VoIP Networks with Adaptive Modulation Coding

In this paper, a differentiated connection admission control (CAC) strategy for VoIP traffic-based wireless networks with Adaptive Modulation Coding (AMC) is proposed and mathematically analyzed. The service area is divided into different disjoint coverage zones according to the AMC strategy. The aim of the proposed CAC strategy is to regulate and restrain the admission of most resource demanding VoIP sessions (those with lower bit transmission rate). To this end, the number of sessions in a given coverage zone is weighted by a factor whose value depends on the allowed bit transmission rate of that zone. A joint connection and packet level analysis is developed to evaluate the performance of the proposed differentiated CAC strategy. Maximum achieved Erlang capacity for different bit transmission rates ratios and proportion of users in the different coverage zones is evaluated. Numerical results show that with the proposed differentiated CAC strategy, Erlang capacity increases up to 8% relative to CAC without admission differentiation.