This paper analyzes the session setup delay in the IP multimedia subsystem (IMS) with the CDMA2000 evolution data only rev. A (EV-DO rev. A) standard for wireless transmission. Session setup delay is particularly critical for interactive multimedia applications, such as gaming, push-to-X and voice over IP (VoIP), as it directly translates in user perception of service quality. Keeping signaling delay low, however, is a challenge in IMS due to the text-based nature of the session initiation protocol (SIP) for signaling, and, more significantly, due to the lossy and capacity constrained wireless links. To address this challenge, we analyze the session setup delay end-to-end, by taking into account key system properties across all layers, ranging from radio links to IMS signaling architecture. We present a model for cross-layer performance analysis and simulation, which includes the statistical properties of the EV-DO (rev. A) wireless channel, and also takes into consideration the properties of transport protocols (TCP, UDP) and SIP signaling (message size and compression). By means of analysis and simulations, we study the setup delay performance of a generic, multi-operator IMS communication scenario between two mobile users. We describe how session setup delay can be estimated and reduced in realistic IMS settings and we propose architecture alternatives to the basic IMS scenario. The results derived from this study show that the proposed methods can incrementally lead to a lower setup delay and less sensitivity to the radio transmission quality and frame error rate compared to the base IMS scenario

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.

This paper analyzes the signaling efficiency for multimedia call (session) establishment in all-IP wireless networking infrastructures based on the Internet Multimedia Subsystem (IMS) standard framework and CDMA2000 Evolution Data Only Rev. A (EV-DOrA) standard for wireless link transmission. We present a comprehensive, bottom up analysis of signaling delay for setting up multimedia sessions and we evaluate system architecture alternatives to reduce it. Call setup time is particularly critical for interactive applications, such as gaming, push-to-X and Voice over IP (VoIP), where user experience of time that takes to start or join a session directly translates in user perception of service quality. Our analysis takes into account a large set of system design parameters across all layers, ranging from radio link properties to IMS processing and specific characteristics of the Session Initiation Protocol (SIP). For an example signaling flow between two mobile users, we derive an important set of numerical results for call set up time under various IMS design scenarios that consider effects of SIP compression efficiency, choice of transport protocols (TCP, UDP) and radio link quality. Based on the results obtained, we propose and discuss new methods to improve the signaling efficiency and to reduce the call setup time.