| Mobile IPv6(MIPv6) is a protocol defined by RFC3775which allows MN to remain reachable while moving around in the IPv6Internet. But it has a relative long handoff latency which is often unacceptable to the real-time traffic such as Voice over IP when comes to handover. The Internet Engineering Task Force (IETF) has proposed a set of protocols based on the mobile IPv6to reduce the handoff latency, such as Fast Handovers for Mobile IPv6(FMIPv6) and the hierarchical mobile IPv6(HMIPv6).FMIPv6enables MN quickly detect its movement to a new subnet by providing the new access point (AP) and the associated subnet prefix information when MN still keeps connection with current subnet. Thus handover latency will be reduced remarkably in FMIPv6. The key concept of HMIPv6is to locally handle handovers by the usage of an entity called mobility anchor point (MAP) to reduce the amount of signaling between the Mobile Node (MN), its Correspondent Node (CN), and its Home Agent (HA). HMIPv6performs well in micro handoff but shows insufficient when comes to macro handoff. Moreover, HMIPv6only chooses the farthest available MAP in the network as the forwarding agent and keeps unchanged regardless of the network structure, which may lead to problems such as load balance and overload to the MAP especially when the number of MN is quite large. Hence it is crucial to select an appropriate MAP so as to improve the flexibility and scalability of the network, moreover, HMIPv6macro handoff still needs to be modified in order to achieve seamless handoff. In the paper, more attention is paid to the HMIPv6macro handoff.Hierarchical Mobile IPv6(HMIPv6) has been introduced as a way of constructing efficient wireless networks. But due to its choice of the fixed farthest available MAP as forwarding agent which may bring problems such as load balance or overload to the MAP in network with multiple MAPs, besides, HMIPv6still can’t meet requirements of seamless handover. In this paper, we first construct a new topology model and give a detailed introduction on it through studying of HMIPv6macro handoff. then we adopt a more flexible and scalable method of MAP selection to alleviate the problems aforementioned and utilize fast handover mechanism with serial duplicate address detection (SDAD) to improve the handover performance especially when the macro handoff occurred. Afterwards, theoretical analysis is provided to evaluate performance of our proposed scheme. At last, simulation results are given to validate that our proposed scheme is more superior and effective than the standard HMIPv6scheme.PMIPv6protocol is intended for providing network-based IP mobility management support to a mobile node, without requiring the participation of the mobile node in any IP mobility related signaling. The mobility entities in the network will track the mobile node’s movements and will initiate the mobility signaling and set up the required routing state.Here we use the same method to improve the performance of HPMIPv6MPLS (Multiprotocol Label Switching) protocol proposes an network architecture for fast packet switching and routing., provides a means to map IP addresses to simple, fixed-length labels used by different packet-forwarding and packet-switching technologies. Independent of the layer-2and layer-3protocols such as ATM and IP. And it interfaces to existing routing and switching protocols, such as IP, ATM, Frame Relay, Resource Reservation Protocol (RSVP) and Open Shortest Path First (OSPF), etc.In MPLS, data transmission occurs on Label-Switched Paths (LSPs). LSPs are a sequence of labels at each node along the path from the source to the destination. High-speed switching of data is possible because the fixed-length labels are inserted at the very beginning of the packet or cell and can be used by hardware to switch packets quickly between links. MPLS and MIP can both help reducing the time latency of packet forwarding in different aspects, so the integration of them will be the inevitable requirement of the next generetion network backbone. |
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