Comparison of Session Establishment Schemes over IMS in Mobile Environment

The existing session establishment scenario of IP multimedia subsystem (IMS) suffers from triangular routing for a certain period of time when an end SIP user or terminal is mobile. In this paper, the performance of three possible session establishment scenarios in a mobile environment is investigated by using an analytical model. The model is developed based on the expressions of cost functions, which may represent system delay and overhead involved in sessions establishment. Some numerical results are demonstrated which provides useful insights into the system behavior. Finally, a decision algorithm is demonstrated in this article to select the optimal session set up option