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AssigneeAmerican Telephone and Telegraph Company, AT&T Technologies, Inc.
InventorsRonald E. Anglikowski, Nissin Habib, Arden B. Wright
Estimating the term…
A security system for cordless telephones prevents unauthorized telephone lls over telephone lines. The system includes a base unit and a cordless handset unit which must share common information for proper operation. To prevent an unauthorized user in possession of a handset unit from easily matching a security code stored in the base unit and thereby obtain dial tone therefrom, the security code in the base unit is transferred to the handset unit while the handset unit is in a mating cradle in the base unit. Transfer circuits in the base unit and the handset unit respectively transmit and receive the security code and also an operating frequency channel over a direct-current charging path provided for charging of a battery in the handset unit whenever the handset unit is returned to the cradle.
A security arrangement for preventing unauthorized placing of telephone calls in a cordless telephone system over telephones lines associated with the system, the system including a base unit for connection to the telephone lines and for transmitting to and receiving signals from a remote unit associated with the base unit, the remote unit also transmitting to and receiving signals from the base unit, and the base unit being activatiable by the remote unit to cause dial tone to be transmitted to the remote unit for placing a telephone call therefrom, the security arrangement comprising:
A method of preventing unauthorized placing of telephone calls in a cordless telephone system over telephone lines associated with the system, the system including a base unit for connection to the telephone lines and for transmitting to and receiving signals from a remote unit associated with the base unit, the remote unit also transmitting to and receiving signals from the base unit, and the base unit being activatiable by the remote unit to cause dial tone to be transmitted to the remote unit for placing a telephone call therefrom, the method comprising the steps of:
Dependencies are inferred from the claim text.