Optimization of Fast Handover in Hierarchical MobileIPv6 Networks

Fast handover protocol provides seamless handover in mobile IPv6 networks by reducing handover latency. One assumption in fast handover is that the MN (Mobile Node) or the network could know or predict the new AR (Access Router) before data transport from the previous AR to the MN is disrupted. In order to achieve this capability, the complexity of predicting the new AR and the diversity of the wireless link technologies should be considered. While it is difficult to know or predict the new AR exactly, a better solution is required to find a reasonable set of candidate ARs (i.e., neighbor ARs) that are likely to be the new AR after a handover. This paper introduces a NF-MHIPv6, It includes the concepts of Proxy Mobile IP for creation of CoA (Care of Address) and DAD (Duplicate Address Detection). In this protocol, the MN can handover without receiving any information about the new AR and this eliminates difficulties to know or predict exactly the new AR which is not specified in standard fast handover scheme. It decouples layer-2 and layer-3 handover and efficiently reduces handover latency through the minimized number of wireless signaling messages and pre-DAD. It also saves periods of service disruption and prevents packet loss in the case of ping-pong movement of the high-speed MN. The performance of the proposed mechanism is evaluated by simulations under variable conditions.