A method, system and mobile station for handing off communications from a cellular radio access network, such as a code division multiple access (CDMA) radio access network, to an unlicensed mobile access network (UMAN) are provided. The handoff may be effected by a signaling sequence between the mobile station, an unlicensed network controller of the UMAN, a base station controller of the cellular radio access network and the core network. In this signaling sequence, the UMAN may be identified in various manners, such as by means of an otherwise unassigned pilot PN offset or by means of a band class and an invalid frequency.