The Research On Handover In Multi-level HMIPv6 Networks

The handover of the mobile nodes(MNs)from one access router(AR)to another AR will bring high signaling loads,high handover delay and high rate of packets loss.Most of current researches in Hierarchical Mobile IPv6(HMIPv6)mainly focus on the Mobile Anchor Point(MAP)network which is single-level,but the multi-level topology will bring many problems such as complex configure process,low network extensibility,high MAP loads.The paper studies on the MN's handover in the HMIPv6 network,proposes a handoff optimization method for the multi-level MAP topology which is based on HMIPv6.Firstly,in the design of address allocation algorithm,the paper proposes an algorithm which is based on the predicted address allocation.The nodes in the network based on the predicted address allocation can be allocated different states by predicted address allocation.MNs,ARs and MAPs in HMIPv6 can be allocated different addresses by the address allocation algorithm which is based on predicted address allocation,the algorithm doesn't need the duplicate address detection(DAD)to verify the uniqueness of the address in the network,so it can reduce the handover delay and the rate of packets loss.In the multi-level HMIPv6 network,the algorithm can allocate new status for new MAP or AR,so it can improve the expansibility of the network.Secondly,in the design of MAP selection algorithm,the paper proposes an algorithm based on the region.The algorithm is divided into two stages,first MAP selection and second MAP selection.MN's first MAP selection predicts the MN's movement by the location information,and selects the lower level MAP on the basis of reducing the frequency of handover between the MAPs.MN's second MAP selection is based on the residence time in different MAPs.MN can select the most suitable MAP,and the MAP load can be distributed reasonably through the algorithm.At the same time,the paper optimizes the handover in the second MAP selection to reduce the handover delay and the rate of packet loss.Finally,the proposed algorithms are simulated in the simulation platform called Network Simulator Version 2(NS2),and the simulation results are analyzed.The results show that the proposed algorithms can reduce the handover delay and the rate of packets loss,the MAP load can be distributed reasonably through the MAP selection.