Performance Evaluation of IMS-Based Push-to-Talk Service over Multiple Wireless Access Networks

This paper evaluates the performance of IMS-Based PoC service over three typical wireless access environment, such as GPRS, UMTS/WCDMA and WLAN/802.11. The contributions of this paper are: developing a NS2-based simulation platform with multiple wireless access environments which can be taken as a general platform for study; proposing a series-connected M/M/l queuing model to simulate the call processing delay of IMS entities; simulating and analyzing the call establishment delay of PoC sessions over GPRS, UMTS/WCDMA and WLAN. The simulation results can conduct the deployment of the real PoC system and evaluate the feasibility of performance optimization schemes for both network and services.