APPARATUS AND METHOD FOR DERIVING A RANDOM REFERENCE NUMBER FROM PAGING AND ORIGINATING SIGNALS

摘要

PURPOSE: A method and associated apparatus for deriving a random reference value from a paging signal transmitted between a network station and a user terminal of a radio telephonic communication system, such as a satellite cellular communication system are disclosed. CONSTITUTION: When communication is to be initiated, a paging signals transmitted by a network station (12) to a user terminal (24). When the user terminal (24) detects the paging signal, a random reference value is derived from a portion of the paging signal, and response signal, responsive to the random reference value is generated and transmitted to the network station (12). When the network station receives the response signal, it compares it to an expected response value to authenticate the user terminal (24).