A method includes a wireless transmit/receive unit (WTRU) receiving a network information message via a cellular network while the WTRU is in either a first mode or a second mode. The message includes a neighbor cell list that identifies a plurality of wireless access networks available for handoff, including a first network based on a first wireless access technology and a second network based on a second wireless access technology different than the first wireless access technology. When in the first mode, the WTRU performs physical measurements only on signals transmitted from the wireless access networks identified in the neighbor cell list, selects one of the networks for handover; and initiates a handover procedure with the selected network. When in the second mode, the WTRU selects one of the wireless access networks identified in the neighbor cell list using the received information related to the wireless access network.