Step-HMIP: A Hierarchical Foreign Agents Model for Mobile IP

Two significant performance problems exist in the current Mobile IP. First, the tunneling scheme of the Mobile IP introduces a triangle routing problem. Packets between corresponding node (CN) and mobile node (MN) are routed through a non-optimal triangle route. Second, the frequent handoffs between cellular base stations would aggravate network traffic overhead and cause in-flight packets loss during handoff. This paper proposes a hierarchical foreign agents model for Mobile IP. This model introduces a new entity, the Gateway Mobility Agent (GMA),to provide route optimization and smooth handoffs. Simulation results show that without modifying home agent, stationary corresponding node, such as the Web server and FTP server, and upper layer protocols, this model can achieve substantial performance improvement in term of route length,registration overhead, and data transmission rate during handoffs at a low cost.