The SIP-based IP Multimedia Subsystem (IMS), while recently introduced, has become one of the primary distinguishing features of the next generation of mobile telecommunication systems. IMS allows mobile operators to offer advanced value-added services – like VoIP, so-called push-to-media, video, interactive gaming, and mobile banking – to their customers timely and efficiently. Google’s plans to enter the wireless world open up a world of possibilities for offering customers and businesses advanced services such as targeted location-based services and advertisements through the IMS framework.
Deploying IMS, however, is a non-trivial task. The core challenge for the telecom industry has been and will be the integration of the current radio access network (RAN) and IP transport infrastructure with the IMS domain. Within standardization bodies, efforts are underway to address the issues for call setup and mobility signaling, while developing unified user profile management and Quality of Service (QoS) architectures. The real goal is a standardized, IMS-centric, end-to-end unified signaling architecture.
To this end, this presentation provides an overview of IMS and QoS signaling over integrated RAN and IMS domains. By using an exemplary family media service, aspects and specifics of the end-to-end QoS invocation, control and policy enforcement, including roaming scenarios, are demonstrated. Based on laboratory measurements performed at Sprint-Nextel aided with simulations, the Post Dial Delay (PDD) delay is evaluated and some practical recommendations for delay reduction are presented. The presentation will conclude with discussion of open issues and viable solutions. This presentation should be of interest to Googlers who work on mobile related projects and intend to have a big picture of next generation mobile systems such as application development, and service and system integration with wireless operators.