Simplified joint call and packet level teletraffic analysis of CAC strategies for VoIP traffic in wireless networks

In this paper, a simplified joint call and packet level teletraffic analysis method for performance evaluation of call admission control (CAC) strategies for voice over IP (VoIP) traffic over wireless access networks is proposed. The admission criterion of new sessions of the considered CAC strategies is based on either the total number of sessions or the number of active sessions. Arrivals and completions of VoIP sessions, on/off activity detection, and periodic and constant length packet generation of individual VoIP active sessions are modeled. Packet buffering, adaptive modulation coding, and proportional fair sharing scheduling are also considered. Our proposed analysis is based on the quantized queue and cross-level linked decomposition mechanisms that we introduce in this paper to drastically simplify the mathematical and computational procedures with no major impact on the accuracy of the results. The developed analysis allows evaluating the performance of the CAC strategies in terms of the most relevant QoS metrics of VoIP traffic at both call and packet level and, at the same time, mathematical and computational complexity are reduced with no major impact on the accuracy of numerical results.