Apparatus and method for deriving a standard random number from the paging signal and outgoing signal

摘要

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 radiotelephonic communication system, such as a satellite-cellular communication system. When communication is to be initiated, a paging signal is transmitted by a network station to a user terminal. When the user terminal 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. When the network station receives the response signal, it compares it to an expected response value to authenticate the user terminal.