Distance tracking scheme for seamless handover in IMS-based systems with UMTS access network
This paper proposes a fast and seamless handover scheme for systems based on IP Multimedia Subsystem (IMS) architectural framework with Universal Mobile Telecommunications System (UMTS) access network. In the scheme the location, direction and movement pattern of a Mobile Node (MN) in a network cell are proactively tracked in order to determine the exact moment to trigger the pre-handover process with one of the adjacent cells considering MN’s direction before the execution of Layer 2 handover. The performance of the proposed scheme was evaluated by comparing it with the traditional handover scheme and the evaluation shows that the traditional handover scheme introduced a handover delay of about 675.5 ms, whereas the proposed scheme introduced handover delay of about 96.25 ms, which is less than 100 ms, hence the handover delay introduced by the proposed scheme fall within the specified range of best class service for voice traffic and streaming media over IP networks.
Keywords: IMS, Handover delay, Distance Tracking, pre-handover, UMTS