Research On Improved Hierarchical Mobile IPv6 Handoff Strategy

In Hierarchical Mobile IPv6(HMIPv6),Router load has a great impact on the processing efficiency of the network and network resources managemen,and HMIPv6 still uses the DAD mechanism which is used in Mobile IPv6(MIPv6),it costs a lot of time when MN configures address.So,How to make the load of the network more balanced,and reduce the delay caused by DAD operation are of great research significance to improve the switch performance of HMIPv6.Firstly,this paper describes the MIPv6 protocol,and introduces three schemes which were put forward to improve the performance of MIPv6,and HMIPv6 is introduced especially.Secondly,this paper presents a HMIPv6 handover scheme based on DHCP technology.We open up a module in AR and MAP to realize the function of DHCP server in DHCP technology.When MN moves in the same MAP domain,AR distributes Link Care-of Address(LCoA)to MN directly;when MN moves between the MAP domains,AR and MAP distribute LCoA and Rigional Care-of Address to MN respectively,so that the time of configuring address and DAD operation is leaved out,reducing the handover delay of MN.When MN removes from the current AR and MAP management scope,it will send message to the AR and MAP to release LCoA and RCoA,avoid wasting address due to the address lease term is not reached.Thirdly,this paper presents a MAP selection scheme based on load balancing.In this scheme,when the load of the router in the path is greater than the threshold value,the data packet will be discarded,thus reducing the congestion in the network.When MN enters a new network,it will select the route whose load is smallest according to the real-time measurement,and then register the source MAP.So MN will select MAP in different layers according to the load of route,thus some MAP will not become the bottleneck of the entire network,making MAP load in the whole network more balanced.At last,we conduct the experiment to simulate the proposed schemes by using Network Simulator Version 2(NS2).The result of the experiment shows that,compared with HMIPv6,the handover delay of the HMIPv6 scheme based on DHCP is smaller;then,the paper analyzes the MAP selection scheme based on load balance from two aspects:signaling cost and MAP load.The result of the simulation experiment shows that,compared with the MAP selection scheme based on distance and the MAP selection scheme based on speed,the new scheme can make the load of MAP in the network more balanced.