(WLAN) services. It is widely believed that WLANs will become a major portion of the fourth-
generation cellular system. The seamless handoff problem in WLANs is a very important
design issue to support the new astounding and amazing applications in WLANs,
particularly for a user in a mobile vehicle. The entire delay time of a handoff is divided into
probe, authentication, and reassociation delay times. Because the probe delay occupies …