Research On Handoff Efficiency Of Mobile IPv6 Facing Internet Application For Passenger Train

IPv4 has some defects such as address space severe deficiency, insufficient mobility support and so on. Luckily, IPv6 solves these problems. It is sure that IPv6 is destined to become the core protocol of Next Generation Internet (NGI). Mobile IPv6 is an important part of IPv6 which can provide Internet users with mobility support within much more larger area, for example, for moving vehicle and passenger train. However, Mobile IPv6 has some challenges such as big handoff latency and big lost packet rate when handoffs. At home and abroad, many researchers have been doing many researches on these problems extensively and deeply so as to resolve them. But most of them are based on network simulation whereas seldom use experiment or engineer method. Although network simulation is very important which can give us some important suggestions to see the essence, it doesn't know the exact influence of every factor which affects simulation result under complicated situation. Research with experiment method just can overcome the defect. So this thesis does some researches on handoff performance of Mobile IPv6 under environment of passenger train with this method.First of all, basic terms and principle of Mobile IPv6 are introduced. Then Mobile IPv6 is compared with Mobile IPv4 which is a protocol of solving node mobility in IPv4. It shows the superiority of Mobile IPv6 from nine points of view, such as route optimization and ingress filter.Secondly, moving passenger train is selected as the research environment of Mobile IPv6. According to characteristics of passenger train, network model and handoff model and handoff pattern are proposed which are suitable for researching the handoff performance of Mobile IPv6. Then, handoff latency of Mobile IPv6 under this environment is analyzed qualitatively and mathematical expectation of layer IP handoff latency is gained. Following a testbed of MIPL (Mobile IPv6 for Linux) 2.0 is set up according to the network model of passenger train and experiment design is introduced. Based on this testbed, three handoff patterns of passenger train are simulated. And a series of experiment researches about Mobile IPv6 handoff performance are performed from channel and ESSID and IPsec. Moreover, some valuable conclusions and handoff latency distribution of all patterns are gained by experiment study.In the end, combining the result of theoretic analysis and problems discovered in experiment, some methods are proposed to improve the handoff performance of Mobile IPv6 under environment of passenger train, such as movement detection method besed on forecast information and duplicate address detection method based on probability.