Mobile Ipv6 Handoff Technology

Recent years, our life has been undergoing major changes with the evolution of information network, such as Internet. The Internet has become an indispensably part of people's everyday life, and people want to obtain the Internet service wherever they are. So the mobile IP group, belonging to Internet Engineering Task Force (IETF), proposed the mobile IP standard drafts in 1992. During the last ten years, many researchers have been working on these drafts for improvement and have made the wireless technique more and more mature. When a mobile host at one LAN, it can receive almost all the users' data. But, when a user moves between two access routers, it will have to perform transitory disconnection with one access router, and cannot receive data from router. IETF prompted many handover mechanism standards, based on which the researcher proposed many improved mechanisms. One of their aims is to improve the QoS during handover, which is also our goal.We analyzed five popular handover mechanisms comprehensively, which are fast handover mechanism, smooth handover mechanism, hierarchical MIPv6 management module, the combination of hierarchical MIPv6 management module and fast handover mechanism (F-HMIPv6). All these handover mechanisms have their own particularities, however, none of them supports the QoS and buffer management expect the smooth handover mechanism. So when there is a transitory disconnection during handover, the QoS would be affected greatly.We shall propose an improved mobile IPv6 handover mechanism to overcome the disadvantage of these handover mechanisms, and analyze our improved mechanism together with simulation. We shall add buffer management based on the F-HMIPv6, and the buffer is added at MAP, so that the data could be buffered for the mobile host while it is doing the link layer handover. After the link layer handover, MAP forwards the data to mobile host via tunneling. Simulation results show that our improved mechanism can hold the merit of F-HMIPv6—low delay. It also can reduce the UDP packet loss and improve the TCP throughput. So our handover mechanism can improve the performance of system.