A method of wireless communication between a base station and a mobile station may entail scanning a first entry of a preferred roaming list for a first base station channel, transmitting a downlink signal from the base station to the mobile station; determining that the downlink signal to the mobile station from the base station has not been received, scanning the preferred roaming list for a second base station, identifying that the second base station does not exist on the preferred roaming list, and inquiring whether a vehicle ignition is off upon determining that the second base station does not exist. Moreover, the method may entail determining that the vehicle ignition is on, and return an excluded channel of a base station to the preferred roaming list and determine that the vehicle ignition is off and invoke a sleep mode of the digital control module.