Connection admission control strategy for wireless VoIP networks using different codecs and/or codec mode-sets

In this paper, a differentiated call admission control (CAC) strategy for VoIP traffic-based wireless networks using different codecs and/or codec mode-sets is proposed and mathematically analyzed. The aim of this strategy is to regulate and restrain the admission of most resource demanding VoIP sessions (those with a larger packet size requirement). To this end, upon the arrival of new VoIP session requests, the number of VoIP sessions using a given codec and/or codec mode-set is weighted by a factor whose value depends on the data rate transmission requirement of that codec and/or codec mode-set. A joint connection and packet level analysis is formulated to assess the performance of the proposed CAC strategy. Maximum achieved Erlang capacity for different data rate transmission requirement ratios and proportion of users using each codec and/or codec mode-set is evaluated. Numerical results show that system performance is improved with the proposed CAC strategy.