Research Of Mobile IP's Fast Handoff Performance

With the rapid development of Internet and IP technique, the demand of data service have exceeded traditional voice service. In order to support perfect mobile data service to mobile users, traditional Internet designed to static host need to support mobility. Mobile IP is a key technology in mobile communications,it involves location registration, identification and handoff management, etc.Until now, Mobile IP is the only standard to support Internet host mobility. Mobile IP provide IP mobility solution and make it possible for mobile node to communicate with a permanent IP to access any link. But when mobile node moves between two foreign agents, it had to handoff to ensure normal communications. As the result of high move frequency, mobile node may not finish home registration in time, the data packets send to mobile node will be lost. If mobile node spend long time to handoff, such as the current handoff procedure has not finished and mobile node moves to another foreign agent, a new handoff occurs, there will made more latency and packets lost.In order to solve mobile IP handoff problem, a fast handoff scheme is proposed, this scheme introduce a Hierarchical and Forwarding mobile IP scheme, which uses hierarchical mobility management in intra-domain and forwarding mechanism in inter-domain. It reduces the registration delay, an aspect of handoff delay, and acquires intra-domain and inter-domain fast handoff and improves handoff performance.It also proposed a Predictive Neighbor-Unicast Mobile IP (PNU-MIP) scheme. Compare to Unicast's delay and the cost of multicast, PNU-MIP reduce the latency and data packets lost in Handoff procedure. It uses mobility prediction and connection prediction to predict which Base Station mobile node will move to, so the new BS agents will buffer packets in advance and forward them to mobile node, which reduce the latency and data packets lost in Handoff procedure, effectively improve mobile IP's QoS. Mobile IP gives us a hierarchical management, Gateway foreign agents of different domain cooperate and make mobile node handoff localization, but the size of the domain is not clear in hierarchical management. If GFA is too large, too much data traffic will bound for GFA, which leads a great burden to GFA. If GFA is too small, too much registration signaling will bound for HA, which causes a unbearable delay. Here we offer a method to optimize the size of domain.