Patent ID: 7689325

Claim:
A method of controlling communications between a message transmission facility and a vehicle having a first wireless module that receives messages from said facility by way of a cell communication network and a second wireless module that receives messages from said facility by way of a satellite communication network, the method comprising the steps of: establishing an initial communication receiving mode at turn-off of said vehicle by passing a software token to a selected one of said first and second wireless modules; detecting an available communication signal strength for the selected wireless module, and passing said software token from the selected wireless module to the other of said first and second wireless modules if said available communication signal strength is less than a threshold; transmitting a message from said facility to said first and second wireless modules; and identifying which of said wireless modules possesses said software token and periodically activating the identified wireless module to check for messages transmitted from said facility assigning a current budget to said software token, said current budget having an initial value indicative of a power consumption allowance for a period of inactivity following the turn-off of said vehicle; reducing the value of said current budget based on a power consumption of the wireless module that possesses said software token; and discontinuing the periodic activation of the identified wireless module when said current budget has been reduced to a reference value.