Patent ID: 8818367

Claim:
A mobile communication device, comprising: a wireless module performing wireless transceiving to and from a first service network and a second service network; and a controller module transmitting a first request message for a Mobility Management (MM) procedure to the first service network via the wireless module, receiving a first rejection message with a first MM back-off timer corresponding to the first request message from the first service network via the wireless module, starting the first MM back-off timer for the first service network in response to the first rejection message, transmitting a second request message for the MM procedure to the second service network via the wireless module, receiving a second rejection message with a second MM back-off timer from the second service network via the wireless module, and in response to the second rejection message, keeping the first MM back-off timer running for the first service network when it is not yet expired and starting the second MM back-off timer for the second service network, wherein the controller module is coupled to a subscriber identity card, and further stores statuses of the first and second MM back-off timers in the subscriber identity card periodically before the mobile communication device is powered off, or stores the statuses of the first and second MM back-off timers in the subscriber identity card in response to the mobile communication device being powered off.