Patent ID: 8761713
Filing Date: 2014-06-24
Classification: H04W,Y02D

Abstract:
1. A method for receiving emergency broadcast information at a subscriber station, comprising: periodically waking up from a sleep state to check a paging channel during at least one control channel cycle of a broadcast service; checking the paging channel, during a first set of one or more time slots of the control channel cycle and during the wake-up, for unicast information; checking the paging channel, during a second set of one or more time slots of the control channel cycle and during the wake-up, for emergency broadcast information, wherein the second set of time slots is adjacent in time to the first set of time slots; receiving the emergency broadcast information on the paging channel in the second set of time slots of the control channel cycle, before reentering the sleep mode, wherein the emergency broadcast information is received from the same network that is checked for the unicast information; computing a short-term key from a pseudo-random number and a broadcast access key; and decrypting the received emergency broadcast information using the short-term key.