1. A computer-implemented method performed on a mobile device, the method comprising: receiving an identifier of a wireless access gateway, the identifier associated with a first application program, the first application program to be invoked in a first subsystem of the mobile device when the mobile device is located within a wireless communication range of the wireless access gateway; registering the identifier to a second application program, the second application program to be executed in a second subsystem of the mobile device; monitoring a current location of the mobile device using the second application program, including determining, using the identifier, that the mobile device is located within the wireless communication range of the wireless access gateway; and notifying the first subsystem of the mobile device that the mobile device is located within the wireless communication range of the wireless access gateway.