Handoff Mechanisms in Cellular IP: Enhancement into the Indirect Handoff Mechanism

Mobile IP is now the standard for supporting mobility in IP networks. It provides seamless mobility by hiding the change of IP address when a mobile host moves between IP subnets. Nevertheless, Mobile IP is not designed to support fast handoff and seamless mobility in handoff-intensive environments. Several micro-mobility protocols have been proposed to support host mobility with frequent handoffs within a domain without interaction with the Mobile IP enabled internet. Cellular IP, HAWAII and HFA are some of the popular IP micro-mobility protocols. Cellular IP complements Mobile IP with support for fast, seamless and local handoff control, and IP paging. In this paper a modification to the existing indirect handoff mechanism in Cellular IP is proposed and subsequently assessed by simulation. The approach proposed in this paper, called Enhanced Indirect Handoff, constitutes a new way to handoff to the new base station where the handoff is initiated along the old base station, resulting in reduced handoff delay and hence reduced packet loss.