An Improvement of Handoff Latency by Virtual MAPs for HMIPv6

The Hierarchical Mobile IP have been introduced as the way of constructing efficient wireless networks. But, in case the HMIPv6 is applied to the actual networks, it has problems that the load unbalance and overload to the MAP might be brought out because of the difference between the theoretical structure and the structure of actual network. In this paper, the scheme adopting the virtual MAP to the HMIPv6 is proposed. This solves the problems mentioned above and reduces handover delay time. The virtual MAP is the one of the routers located between the MN and actual MAP. In order to approve the scheme, the handoff latency of the standard HMIPv6 and the proposed HMIPv6 with virtual MAP are analyzed, respectively. The analytical results show that the proposed scheme improves the handoff latency. Experiments are performed to evaluate the handoff latency in terms of the amount of transmission packets under various conditions. The simulation results show that the proposed scheme is more effective than the standard HMIPv6 scheme.