Enabling network based presence aggregation using IMS

IP multimedia subsystems (IMS) and presence are the biggest buzzwords in the telecom industry today. Almost all major service providers are strategizing and planning roll out of IMS compliant network and value added services, to provide rich user experience. Moving to the hyper connected world, users have to manage multiple identities, corresponding to each connection, spread across multiple networks. Multimedia services are envisioned to be delivered seamlessly across the multiple devices of the same user. Current implementations around Presence agent aggregating presence information have limitations due to user identities spreading across multiple access devices. This limited the power of rich presence and mostly application tends to use presence aggregation around enterprise applications like email, calendars and Instant Messengers. With the advent of IMS technology, we can foresee a world exploring the benefits of presence from different networks, with presence being aggregated at the network rather than presence agents. IMS architecture eases the aggregation of presence from multiple sources and technologies. The access agnostic IMS architecture also promises one unified identity for a user spread across multiple devices and media types and thus making communication user centric. This paper details how IMS architecture can be envisioned to provide network based presence aggregation and demonstrates how the presence aggregation can be used to implement complex new services. It reports how a personpsilas availability across multiple devices and networks can be traced out with a single identity in IMS world and how the IMS network nodes interwork for this scenario.