The Optimization Of Smooth Handoff Of Mobile IP

The function of Mobile IP is that the network nodes can keep connection withInternet while moving and at the same time the nodes can receive and send datapackets correctly.Handoff technique is the key technique of supporting mobility. Theimprovement on handoff can enhance effectively the communicative performanceof the mobile nodes. In order to lessen the packet loss during handoff, the conceptof smooth handoff was come out. The prominent improvement of smooth handoffis as follow: set buffer for the mobile nodes in the foreign agent. After handoff, theprevious agent transmitted packets in buffer to the new agent of the mobile nodeimmediately, so the loss of the data packet was limited.Although smooth handoff reduces effectively the loss rate of the packets, itwill cause communication delay. It is disadvantage to the performance of TCP andUDP and other applications based on them.In order to improve the performance of handoff of mobile IP,this paper givesan idea to optimize the smooth handoff. The basic idea of the optimized scheme is:when mobile node detect that it is enter a new network, it register with newforeign agent, and request the new foreign agent send information to its previousforeign agent to inform its move information. Once the previous agent receives theinformation, it sends those packets that buffered for the mobile node to the newforeign agent through tunnel. New foreign agent relays those packets come fromprevious agent without the register reply from mobile node's home agent. Whichshort the period during which mobile node cannot communicate with other node.Thus minimize the handoff delay.Build model on NS simulator and test the main parameters of the improvementplan. The result manifests that the idea given in this paper can improve theproblem of communication-delay and so on.