Research On Handover, QoS And Other Key Technologies Of Mobile IPv6

Mobile IPv6 (MIPv6) is a protocol proposed by IETF to provide support to mobile users for seamless roaming on the Internet. Mobile IPv6 is presently a hot research subject in mobile communication, and will play an important role in the wireless communication system of future. However, MIPv6 is still immature in the handover technology such as high handover signaling overhead and long handover delay. Besides, with the rapid development of multimedia on the internet-video, voice, image, etc., support of Quality of Service (QoS) and multicast for MIPv6 network is also concerned by people. Therefore, research on handover technology, QoS assurance mechanism and multicast technology of MIPv6 not only has great theoretical significance, but also enjoys good prospect in application.This dissertation expounds the research background and current situation of MIPv6 and analyzes the advantages and disadvantages of its handover technology. Based on this, this dissertation concentrates on the handover technology, QoS and multicast in MIPv6 and proposes corresponding solutions. The main achievements are as follows:(1) A dynamic domain based handover scheme for mobile IPv6 is proposed, for Mobile anchor point (MAP) may become a single point or network bottlenecks because anchor point domain is unchanged in HMIPv6. In this scheme, mobile nodes (MN) could dynamically select mobile anchor point, so any access point (AP) could become its MAP and each MAP domain is dynamic. If a MN only changes its current position in a MAP domain, it only needs to register its on-link care-of address with the MAP rather than the home agent (HA) and corresponding node (CN). In addition, this scheme proposes a method of changing acceptation threshold dynamically which is based on the saturation of MAP. It reduces the congestion probability of MAP and makes the load balance on every node.(2) A QoS context transfer scheme for MIPv6 is proposed in the QoS assurance mechanism. This scheme could guarantee the quality of service (QoS) for real-time applications when Mobile Node performs handover. Because this method adopts the fast handover for hierarchical MIPv6 architecture, the signaling overhead and handover delay is reduced. Meanwhile, the scheme could reduce the delay caused by forwarding process after Mobile Node is switched and QoS is reestablished by reinitiating QoS signal, thereby reducing the QoS disruption. Performance analysis and simulations show that this scheme can reduce the delay and jitter obviously and can perform better especially in ping-pong movement, consequently realizing smooth handover. Besides, a PMIPv6 protocol with QoS assurance mechanism is proposed for the problem that MN may not support any kind of mobility management protocol. This protocol makes the handover simpler, faster and doesn’t need the MN participate in IP layer, and can effectively guarantee the QoS requirements of real-time business. Simulations show that the proposed protocol could meet the needs of real-time applications, because it reduces the delay and overhead of handover obviously, and has lower packet loss ratio.(3) A mobility prediction-based fast and hierarchical mobile multicast architecture is proposed on the basis of the analysis of the limitations in existing mobile multicast protocols when they are applied into real mobile networks. This scheme could configure the handover information before multicast handover by mobility prediction, and could reduce handover delay and subsequent packet loss rate with improved FMIPv6 handover method when mobile nodes are playing handover. In addition, it isolates the subnet movements from outside, and reduces the frequency of rebuilding multicast tree because of mobile nodes’movements by using a hierarchical architecture.Finally, a summary of the dissertation is made and some problems remained to be further researched are discussed.