The Research On Handover In Mobile IPv6

The core of next generation network is the IPv6 protocol. As an important part of IPv6 protocol, Mobile IPv6 protocol which developed by IETF has meet the people connecting to the Internet anytime and any place, do not replace the IP address and uninterrupted communication. However, with the development of multi-media real-time business (such as VOIP), mobile IPv6 can not satisfy with the real-time business needs of handover delay, especially in registered address and duplicate address detection, the time-consuming is serious. So it is a major impediment to application of protocol. IETF and many researchers have putting forward some schemes and the typical of schemes are HMIPv6 and FMIPv6 protocol. These schemes have improved the delay of handover in mobile IPv6 in some way, but there are also some problems for these schemes. So the performance of Mobile IPv6 in handover has to research more deeply.Based on the delay analysis of Mobile IPv6 handover, HMIPv6 and FMIPv6 handover, we combined with their advantages and problems, the scheme which is named handover in hierarchical mobile IPv6 Based on the Fast DAD mechanism in visual domain was proposed. In order to improve the handover performance and reduce the delay of handover, the paper has made the following tasks:1. we have analyzed deeply to process of the mobile IPv6 protocol handover, and point out the delay which the various steps have brought;2. We have analyzed handover process of the Mobile IPv6 protocol and improved protocol (such as HMIPv6 protocol, FMIPv6 Protocol), and pointed out that the design ideas, the improve methods and the problems for these protocol. We have analyzed deeply for direction of improved the handover delay;3. Based on the analysis and summing up, we have proposed the scheme named handover in hierarchical mobile IPv6 Based on the Fast DAD mechanism in visual domain. By introducing the concept of virtual domain based on HMIPv6, we defined MAP and neighbor MAP which were defined in HMIPv6 protocol in the same domain, and make servers in visual domain which ware defined in this paper replace mobile node to do DAD operations in handover process. When the mobile node moved in the network, there is no need to duplicate address detection, as moved in the same domain. The scheme have solved problem which needs to passive waiting in the traditional duplicate addresses detection, this is the innovation in this paper;4. In the means of experiment, NS2 simulation platform was used in this paper. NS2 is an open source, free simulation platform. Researchers can easily use it for network protocol development, and the modules are rich, almost involved in all network technology. Thus, NS2 is the network simulation software which academic community has widely used currently. In Published papers for network technology each year, the NS2 simulation results were also generally recognized by the academic community. Due to the existing version of NS2 is lack of mobile IPv6 and HMIPv6 simulation modules, so this paper use NS2 wireless extension module Mobiwan to simulate the mobile IPv6, and adding all the features of HMIPv6 and fast DAD function by modifying the C + + code of Mobiwan module, constructed a HMIPv6 simulation platform. Through this platform, we have simulated scheme in this paper. Because of the complexity of NS2 platform, and the document was incomplete, a large quantity of code, this is a lot of workload in this paper.NS2 is an open source simulation platform; there are many protocol modules in NS2 platform. But the mobile IPv6 protocol is a new protocol, so the NS2 standard version does not join the protocol. If the researcher want to research mobile IPv6 and HMIPv6 protocol, they must spend a great deal of time and energy to build the module and write code, so that the research for mobile IPv6 will been slow. In this paper, we build a HMIPv6 module when the scheme was simulated, this module can be good for the HMIPv6 simulation. Therefore, this platform can produce a positive effect for future research and speed up the research of mobile IPv6 protocol.After NS2 simulation, the final simulation results in this paper are as follows: For HMIPv6, the mobile node move between the domain increased by more duplicate address detection delay and registration delay compare with move in domain, this can be known from Table 1: T_AD=T_BH-T_IH=2130ms-1012ms=1118ms (1.1)T_AD is the increased delay, T_BH is the delay of between-domain and T_IH is the delay of inter-domain.For the scheme in this paper, due to optimize the delay of duplicate address detection, so the mobile node move between domains compare with move in domain has increased registration delay (this paper named TR), it can be known from Table 1: T_R=T_BV-T_IV=308ms-187ms=121ms (1.2)T_R is the registration delay, T_BV is the delay of between-domain and T_IV is the delay of inter-domain.Therefore, the delay of duplicate address detection T_DAD as follows: T_DAD=T_AD-T_R=1118ms-121ms=997ms (1.3)From the above data, we can see that the scheme which was proposed in this paper compared with the HMIPv6 handover delay have reduced 997ms, the rate of reduction is 98.5%. The scheme have great reduced handover delay and improved the quality of QoS of handover,it optimized the mobile IPv6 protocol.Next generation network will be an all-IP, multi-network integration network; the data and Internet business will be the dominant. As part of next generation networks, mobile networks will carry real-time voice, mobile multimedia, mobile e-commerce and other business. So roaming, applications and terminals will be more complex, mobile IPv6 will be the key of these services be realized. For the initial stage of mobile IPv6 protocol, there are many excellent characteristics, but there are still many problems for many researchers to study and do a large number of improvements. As one of the members, we have proposed the scheme for improving the handover and will played a significant role in promoting for .development and application of mobile IPv6.