An IMS Vertical Handoff Solution to Dynamically Adapt Mobile Multimedia Services

Recent advances in wireless client devices and multimedia communications have motivated relevant standardization efforts, such as the IP Multimedia System (IMS) to support session control, mobility, and interoperability in all-IP next generation networks. Notwithstanding the central relevance of IMS for novel mobile multimedia services, IMS-based solutions still exhibit limited support for service continuity during handoffs, by omitting ad-vanced techniques to reduce/eliminate handoff delays and quality degrada-tions, especially during vertical handoffs. We propose an original solution for service continuity and dynamic multimedia content tailoring based on the primary design guideline of exploiting terminal-based decentralized handoff predictions to proactively activate application-level management operations (flow quality downscaling). The proposal is fully compliant with standard IMS and exploits infrastructure media gateways to execute content tailoring actions, without requiring heavy client-side adaptation operations. The reported experimental results point out that our solution can avoid streaming playout interruptions and significantly increase user-perceived service quality, without negative effects on handoff delay.