The Research And Implementation Of Fast Handoff And Registration Authentication Of Mobile IP In WLAN

With the mature and wide use of wireless LAN, it has been available for wireless nodes to roam everywhere. When a mobile node moves from one IP subnet to another, it is unable to access Internet for acquiring network service. At present, Mobile IP technique has been widely considered as the best network layer solution for realizing mobility in IP networks. Therefore, it is very important to combine Mobile IP and WLAN technique. Mobile IP technique realizes the mobile connections on network layer, but when processing handoff, a mobile node is unable to send or receive IP packets. The length of this disruption is considered critical because it can directly affect the performance of communications. Also Mobile IP technique brings potential secure problems, one of which is registration suffering denial of service attacks and replay attacks. Handoff and security are critical aspects of research of Mobile IP.On the background above, this thesis has focused on the research of fast improved design to Mobile IP-based handoff and registration authentication in WLAN. Based on these works, a Mobile IP prototype has been designed and implemented. This thesis specific research and implementation includes:Analyzing the implementation of Mobile IP functional entities, which include home agent, foreign agent and mobile node, furthermore, analyzing the handoff process, latency based on Mobile IP, and data link layer triggers and the acquiring methods available in WLAN.Abandoning the movement detection mechanism which relies on the periodic broadcasting agent advertisements, and using data link layer triggers in WLAN to detect movement; speeding up acquiring agent advertisements with agent advertisements buffer mechanism and actively sending an agent solicitation; designing and implementing a movement detection algorithm, namely hinted eager cell switching.Redesigning the regional registration, in which adds three mechanisms consisting registration of foreign agents in a visted domain, selection of crossover foreign agent and fast reply to regional registration requests, furthermore, implementing fast regional registration under multiple-tier foreign agents'architecture.