PRIME: Pre-registration for IMS Mobility Enhancement

The Next Generation Mobile Network (NGMN) is expected to include integration of wireless technologies. In NGMN multimedia services are provided through the IP Multimedia Subsystem (IMS). Recently IMS has been enhanced to ensure session continuity when roaming among different wireless technologies. However achieving seamless mobility which is one of the goals of NGMN is still a challenge. In this paper we propose the PRIME mechanism which reduces handover delay and makes seamless mobility achievable. We evaluate the performance of the proposed method by simulating a WiMAX to LTE handover. The results show that in a typical handover the PRIME mechanism reduces the connection preparation delay by 70%.