Mobility Management For Mobile IPv6

In order to meet the requirements of wireless communication users and improve the quality of service, many domestic and foreign researchers are devoting in studying how to reduce the handover delay to ensure the communication quality.In this paper, several typical fast handover methods are introduced based on plenty of domestic and foreign references about handover latency. It also analyzed the shortcomings and the merits about the handover latency of these methods respectively. Based on these analysis of the exsiting fast handover method, two flow-based fast handover methods are proposed. In flow-based fast handover method for Hierarchical Mobile IPv6, it efficiently combines the benefits of flow-based idea and hierarchical structure. In this scheme, it utilized the flow state information to judge whether the node, which the BU message is passing by, is a cross-over router. If it is the cross-over router, a temporary tunnel is established between the cross-over router and the new location of mobile node. Then the traffic flow sent by corresponding node is redirected to the new location of mobile node and has no need to wait until the registration is finished, thus reduces the handover delay of downstream. At the same time, it utilized MAP to separate the movement of mobile node into macro-mobility and micro-mobility. Because the movement is within the same domain, the mobile node only needs to register to MAP, thus shortens the registration cost and reduces the handover latency of upstream. In flow-based fast handover method for mobile IPv6 network with route optimization, it utilizes the flow state information to judge whether it is a cross-over router. If it is, the cross-over router intercepts the Binding Update message, modifies its binding cache, then sends a Binding Acknowledge message to Mobile node. Thus the packets between corresponding node and mobile node can be delivered directly to the other end through route optimization and the delay time of the downstream and upstream traffic can both be minimized .Then using the NS2 simulator, the topology structure of network is established and the two methods is simulated. The results of simulation show that the new proposed flow-based methods have the minimized handover delay time than that of standard handover, hierarchical handover, respectively.