| With the development of current Internet, IPv4 will be replaced gradually by IPv6 for its limited addresses. Technological advances on mobile communications and wireless access raise the requirement of providing network services for mobile hosts. Thus, Mobile IPv6 (MIPv6) was proposed to enable mobile hosts to remain reachable while moving around in the IPv6 Internet. However, communication quality of MIPv6 degrades because of its high signaling overhead and its long handover delay. On the other hand, MIPv6 should provide Quality of Service (QoS) and multicast for mobile nodes because more and more multimedia information including voice, image and video are transmitted over Internet now.In this paper, we study three key techniques of MIPv6, including mobility management, QoS guarantee and multicast provisioning. The main research work and conclusions are as follows:(1) Based on the analysis of inter-domain registration cost of the mobile node in "Hierarchical Mobile IPv6" (HMIPv6), we proposed a mobility and traffic based "Mobility Anchor Point" (MAP) selection algorithm (MTMS). To make good use of the capability of higher MAP, a dynamic adjustment mechanism for MTMS was introduced. Theoretical analysis and simulation results showed that the inter-domain registration cost of MTMS was lower than the traditional mobility based MAP selection algorithm and dynamic adjustment mechanism improves the performance of MTMS further.(2) Based on the performance comparison in inter-domain registration cost of HMIPv6 and MIPv6, we suggested that a mobile node should choose a suitable protocol according to its "Combined Measure". Then an adaptive three-level mobility management framework (ATLMM) was proposed. In ATLMM, a mobile node may register with either a higher/lower MAP or home agent according to its mobility and traffic characteristics. Simulation results showed that ATLMM not only provided adaptive protocol selection for mobile nodes, but also decreased the overall inter-domain registration cost.(3) Existing mobile "Resourse reSerVation Protocol" (RSVP) extensions were discussed from four aspects: management of resource reservation, re-establishment of reservation path, design of mobile agent and integration of RSVP and mobility management. Based on the discussion, we proposed FMRSVP protocol to provide QoS guarantee for the mobile nodes under "Fast Handover for Mobile IPv6" (FMIPv6). FMRSVP makes use of FMIPv6 internal handover signaling to transfer QoS requirements of the mobile nodes, utilizes fast handover mechanism to reduce the amount and duration of passive reservations, and identifies crossover router toreduce reservation delay. Markov process was used for theoretical analysis and the results showed that FMRSVP achieved better performance than traditional mobile RSVP extension. We also proposed F-HMRSVP protocol to provide QoS guarantee for intra-domain and inter-domain handover process of the mobile nodes in "Fast Handover for Hierarchical Mobile IPv6" (F-HMIPv6). Simulation results showed that FMRSVP and F-HMRSVP both achieved good performance in reservation signaling cost, reservation delay, and bandwidth requirements.(4) Based on the analysis of the limitations of existing mobile multicast protocols when applied into real mobile networks, we proposed a mobility based dynamic multicast agent protocol (MDMAP), which introduces "domain multicast agent" (DMA) and "subnet multicast agent" (SMA) to provide multicast service for the mobile nodes. In MDMAP, DMAs are classified into several levels. The service areas of different DMAs are overlapped so that "single point of failure" can be avoided. The DMA discovery protocol reflects changes of network topology and the mobility based DMA selection algorithm reduces the frequency of tree reconstruction of high-speed mobile nodes. Simulation results showed that MDMAP achieved good performance in the frequency of tree reconstruction, and the delivery delay and cost of multicast datagrams.
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