Research On Seamless Handoff Of HMIPv6 Achitecture

With the increasingly wide spread of mobile devices such as PAD, laptops and mobile phones, more and more Internet service will be provided to mobile users through wireless network. People wish to maintain continual Internet access, communication and network service quality as good as fixed network access as well. Mobile IP technology provides mobility support without need to change node's IP address whereas mobile IPv6 furtherly explores and solves issues inherent in mobile IPv4. However, according to current mobile IPv6 specification(RFC3775)published by IETF, when mobile node accesses foreign network, it should firstly register with its home agent and begins to register to correnspondent node after receiving bingding acknowledgement sent by its home agent. In addition, mobile node needs to register to each correspondent node in turn. So, when mobile node moves often or it's far from agent and correspondent node, lots of registration packages will be generated, thereby leading to longer handoff dealy, severe package loss and communication throughput's reduction. How to improve mobile node's handoff performance becomes one of the key problems of MIPv6's development. IETF had proposed several solutions in terms of delay and generally could be boiled down to two categories: one is reducing the amounts of registration packages with help of hiberarchy; the other is reduding the delay caused by address configuration by means of pre-configuration.But HMIPv6 still needs to be improved in many aspects. This paper firstly extentively explores handoff mechanism adopted in Mobile IPv6, HMIPv6 and analysizes performance of several currently common handoff methods in detail, identifying repective strongness and weakness. Then this paper proposes one seamless handoff solution in HMIPv6 architecture with reference to HMIPv6 fast handoff solution. Its feasibility and innovation has been proved with simulaton test utilizing NS-2 package. Our solution maintains framework of hiberarchy handoff solution, only expands its functionality entity's function, thus furtherly reduces handoff delay and package loss rate.