Understanding and enhancing the scalability of IMS-based services for Wireless Local Networks

The increasing request for mobile multimedia services have motivated relevant standardization efforts, such as the IP multimedia system (IMS) to support session control, mobility, and interoperability in all-IP next generation wireless networks. Notwithstanding their increasing diffusion, IMS solutions still exhibit limited support for service scalability, especially for data intensive services such as mobility management, presence, and instant messaging, by omitting clear design guidelines and techniques to (re-)distribute incoming load dynamically. The contribution of this paper is twofold. First, it thoroughly analyzes the state-of-the-art literature in the field to clarify all main IMS scalability issues. Second, it proposes a novel and widely applicable architecture of solution based on three original guidelines: data-centric session management; differentiated management of intra-/inter-domain communications; service-aware load-balancing at both infrastructure and service levels. Preliminary performance results collected in the IMS-enabled wireless infrastructure at our campus demonstrate the effectiveness of the proposal.