Design and performance evaluation of an improved mobile IP protocol

Mobile IP is one of the dominating protocols that provide the mobility support in the Internet. However, even with some proposed optimization techniques, there is still space for improving the performance. In this paper, we present a novel mailbox-based scheme to further improve the performance. In this scheme, each mobile node migrating to a foreign network is associated with a mailbox. A sender sends packets to the receiver's mailbox, which will in turn forward them to the destination. During handoff, a mobile node can decide whether to move its mailbox and report the handoff to the home agent, or simply to report the handoff to the mailbox. In this way, the scheme is adaptive and can be made to reduce the workload on the home agent and minimize the total cost of message delivery and mobility management. To evaluate the performance of the proposed scheme, we develop a performance model considering two walk models for mobile nodes, based on which the cost function is derived. We also propose an iterative algorithm for deriving an optimal point where the cost function reaches its minimum. The results show that our new scheme can outperform mobile IP route optimization with smooth handoff extension, no matter how many packets are to be received during each migration.