Delay Performance of Session Establishment Signaling in IP Multimedia Subsystem

In this paper we investigate and analyze SIP delay during the session establishment signaling process in the IMS system. The delay for end-to-end link scenarios such as WiMAX-to-WiMAX, UMTSto-UMTS, UMTS-to-WiMAX and vice versa are examined. For the analysis, we consider three types of delays: transmission delay, processing delay and queuing delay. The results show that the main delay of session establishment signaling process is due to the processing delay. In addition, the lower channel rate in the UMTS network as well as IMS service rate has significant impact to the session establishment signaling delay.