Research On Improved HMIPv6 Handover Based On Prepared Allocation Care-of Address Pool

Hierarchical Mobile IPv6 is a new protocol based on Mobile IPv6.It introduces the mobile anchor point aiming to reduce the BU message which mobile node sends to home agent. On the other hand, it also increases the handover latency when mobile moves through the mobile anchor point. As a result, the problem of HMIPv6 long handover latency becomes more and more prominent along with the development of real-time service. Aiming at above situation, we at first analyzed the reasons of HMIPv6 long handover latency and proposed an improved HMIPv6 protocol called Prepared Allocation-HMIPv6.There are several aspects of the improved protocol.First, configure Care-of Address in advance.Care-of Address contains two parts:one is the information of access router prefix, and the other is mobile node interface ID. we have two ways to achieve pre-configure Co A. Mobile node can pre-acquire the information of access router prefix, and on the other hand, access router can pre-attain the mobile node interface. The traditional method is the first one, but we plan to complete CoA configuration and detection by candidate access router according to the second one.Second, duplicate address detection in advance.In order not to reduce the important degree of duplicate address detection, we propose the scheme that candidate access router instead of mobile node make out duplicate address detection, rather than ignore duplicate address detection to reduce handover latency just like in previous schemes.Third, candidate for access router.We select candidate access router form limited neighbor access routers according to popular network topology nowadays. On the other hand, we combine the factors of mobile node moving trend and QoS with simple formula to fix the optimal candidate access router.Forth, store pre-configure CoAs.Access routers in PA-HMIPv6 protocol set up CoA pool to maintain the pre-configure CoAs and deal with the CoAs until mobile node apply to the access router.We will emphasize the two vital handover quantity indexes which are handover latency and data loss rate in the following scheme. We also provide a contrast for HMIPv6 protocol and PA-HMIPv6 which is based on NS2 platform. As the experimental results show that PA-HMIPv6 protocol presents more prominently in the respects of handover latency and data loss rate than HMIPv6 protocol.