Dynamic Location Control for Mobile Nodes

Mobile IP is the proposed standard of IP based protocol for mobile internetworking. Mobile nodes register with their home agents for location updates as they roam across IP subnets. IP datagrams for mobile nodes are routed rst to their home agents before being tunneled to mobile nodes through their current foreign agents. This paper investigates dynamic location control for mobile nodes and introduces a routing agent for a mobile node between its home agent and the current foreign agent. To the home agent, the routing agent represents the logical location of a mobile node that is close, but not necessarily identical, to the physical location indicated by the foreign agent. To the mobile node, the routing agent handles registration requests for local movements on behalf of the home agent. This approach has two distinctive advantages. First, the logical location provided by the routing agent allows exible and dynamic control over location updates. It shields local movements of mobile nodes from the home agent and from correspondent nodes that maintain location caches for mobile nodes. Second, the proximicity between the routing agent and the foreign agent reduces the time for registrations and the handoo delay. Our simulation results show signiicant improvements in TCP/IP performance over wireless networks.