A system facilitates handover of a wireless transmit and receive unit
(WTRU) between a cellular network and a wireless local area network
(WLAN). The WLAN communicates with a cellular network. A location of the
WTRU is determined. The coverage areas of the WLAN and cellular network
are determined. The WTRU is informed of the existence of the WLAN when
the WTRU approaches the coverage area of the WLAN. The WTRU is handed
over from the cellular network to the WLAN when the WTRU is in the
coverage area of the WLAN and vice versa.