Abstract: A system for the authorization of wireless telephone communications establishes two sets of authorized telephone numbers. A first set of authorized telephone numbers are supplied by the customer, and the second set of authorized numbers are derived from customer bills paid by the customer. The system analyzes transmission characteristics from an unauthenticated cellular telephone and attempts to verify its authenticity based on the transmission characteristic by analyzing the transmission characteristic with respect to stored reference waveforms for the authentic wireless telephone. However, the results of this signature analysis if negative may be overridden if the telephone number dialed by the unauthenticated cellular telephone matches a telephone number in either the first or second sets of authorized telephone numbers. The system also includes a technique for modifying the reference waveforms to compensate for changes in the transmission characteristic.

Abstract: A system and method for the detection of fraudulent use of a wireless telephone system includes a fingerprint analyzer that identifies an unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint of the unauthenticated wireless telephone. The system maintains a valid destination list specific for each authorized wireless telephone. Each valid destination list contains destinations considered to be valid for that particular authorized wireless telephone. When an unauthenticated wireless telephone transmits a call request containing a destination, the system classifies the call as valid when the destination is in the valid destination list for the authorized wireless telephone regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as fraudulent. The system may bypass or terminate the fingerprint analysis, or simply ignore the result of the fingerprint analysis by the fingerprint analyzer.