Enhancing the Scalability of IMS-Based Presence Service for LBS Applications

Because of recent advances in both client devices and wireless communications, industry has started to look at the potentially relevant market of Location Based Services (LBSs). IP Multimedia Subsystem (IMS) and IMS-based presence service are putting together and standardizing the needed support for location data dissemination in industry-level LBS applications. However, the deployment of presence-based LBSs is still very challenging since frequent location updates have to be timely delivered to the (potentially many) subscribed LBS applications. The paper proposes a novel presence service solution with two original extensions to address the above challenging scalability issues: a load-balancing model working at both IMS infrastructure and service levels; a novel component to automatically de/activate new IMS infrastructure/presence service nodes by need, also by dynamically redistributing the incoming load. The prototype of this enhanced IMS presence service, fully-compliant with existing IMS standards, has been deployed and validated in our university campus wireless infrastructure: the reported performance results show improved scalability and limited load-balancing costs.