A method, system and apparatus for internetworking WWAN and WLAN are disclosed. More specifically, a method, system, and apparatus for a mobile station to sense and select a WLAN or a WWAN are disclosed. A mobile station may communicate according to an 802.xx wireless local area network air interface protocol via WLAN logic or according to a wireless wide area network air interface protocol via WWAN logic. The mobile station detects RF energy in the 802.xx spectrum and, in response to the energy detection, determines whether there is an 802.xx WLAN capable of servicing the mobile station by performing a scanning operation. If there is an 802.xx WLAN capable of servicing the mobile station, the mobile station selects the WLAN logic so that it may communicate via an air interface. Under some embodiments, WWAN has information identifying the areas in which capable WLANs operate and the WWAN provisions the mobile station with at least a subset of such information. The mobile station uses such area-identifying information to determine whether to perform the RF energy detection operation. The information may be cell ids, or GPS information.