Patent ID: 8755848

Claim:
A mobile communications device, comprising: a processor configured to establish a network connection with a server via a first network using a first network technology; and a transceiver, in communication with the processor, configured to transmit a system check message to the server to determine if an incoming call request for the mobile communications device has been received at the server; wherein the processor is further configured to receive a predetermined time interval input from a user, to set the predetermined time interval according to the received user input, to maintain the mobile communications device in a sleep mode for the predetermined time interval and, upon expiration of the predetermined time interval, to change the mobile communications device from the sleep mode of operation to an active mode of operation to transmit the system check message without transmitting other intervening communication to the server; wherein the processor is configured to determine whether the incoming call request has been received at the server based on a response to the system check message; and wherein, if the processor determines that the response is not received, the mobile communications device is configured to establish a connection with a second network using a second network technology based at least in part upon an initial registration with the second network prior to entering the sleep mode, the second network technology being different from the first network technology.