An analysis of session setup time in internet multimedia subsystem (IMS) with EV-DO (rev. a) wireless links

All-IP wireless networking infrastructures, such as those based on Internet Multimedia Subsystem (IMS), are becoming increasingly important due to the variety of applications they support, which include Voice over IP (VoIP) and real-time streaming multimedia. These applications are imposing specific requirements on network and wireless systems in terms of session (call) setup time. Call setup time is particularly important for interactive applications, such as gaming and push-totalk communication, where the user experience of time that takes to start or join a session directly translates in user perception of QoS. In this paper, we present a comprehensive approach to analyze the call set up time in IMS systems deploying Session Initiation Protocol (SIP) for signaling and CDMA2000 Evolution Data Only Rev. A (EV-DO-A) standard for wireless link transmission. Our model is based on practical assumptions for the system design parameters, including radio link delays, IMS processing and signaling properties. We derive important numerical results and present methods to improve the call setup time. Finally, we discuss directions for further research.