Fast Handover Based on Mobile IPv6 for Wireless LAN

Mobile networking technology is progressing to support the requirements of today’s new class of Internet users who roam about with sophisticated mobile computers and digital wireless data communication devices. Host mobility requires change in the routing protocol so that packets for a moving host can be delivered to their correct destination. Mobile IP (Internet Protocol) allows a mobile node to send and receive packets with its home IP address, regardless of the IP address of its current point of attachment in the Internet. Since Mobile IP induces the handover latency due to mobility management operations, fast handover algorithms have been studied to reduce the latency. Normal and fast handover procedures for Wireless LAN are introduced and compared each other. We propose an overall procedure that manages the layer 2 (L2: link layer) and layer 3 (L3: network layer) handovers simultaneously. Two types of the L2 triggers in Wireless LAN system are introduced: prehandover-trigger and link-state-trigger. Two criteria are defined to analyze the performance of the triggers: handover timeliness and handover accuracy. The fast handover reduces route reestablishment delay by 80 ~ 90 % and total handover delay by 20 ~ 25 % compared to the normal handover.