Security arrangement for cordless telephone system
First Claim
1. 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:
- means for storing a predetermined signal code in the base unit for preventing the base unit from responding to an unauthorized remote unit;
means located in the base unit for transmitting and in the associated remote unit for receiving the predetermined signal code over an electrical path established when the remote unit is brought in electrical contact with the base unit, the electrical contact being made entirely by a direct current charging path used for charging a battery in the remote unit, the remote unit storing the signal code for transmission back to the base unit when located remote from the base unit and requesting dial tone therefrom;
comparison means in the base unit for comparing the predetermined signal code stored therein with the signal code received from a remote unit requesting dial tone; and
activation means in the base unit responsive to the comparison means, the activation means causing dial tone to be transmitted to the remote unit requesting dial tone when the signal code received from the remote unit is equivalent to the predetermined signal code stored in the base unit.
3 Assignments
0 Petitions
Accused Products
Abstract
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.
46 Citations
17 Claims
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1. 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:
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means for storing a predetermined signal code in the base unit for preventing the base unit from responding to an unauthorized remote unit; means located in the base unit for transmitting and in the associated remote unit for receiving the predetermined signal code over an electrical path established when the remote unit is brought in electrical contact with the base unit, the electrical contact being made entirely by a direct current charging path used for charging a battery in the remote unit, the remote unit storing the signal code for transmission back to the base unit when located remote from the base unit and requesting dial tone therefrom; comparison means in the base unit for comparing the predetermined signal code stored therein with the signal code received from a remote unit requesting dial tone; and activation means in the base unit responsive to the comparison means, the activation means causing dial tone to be transmitted to the remote unit requesting dial tone when the signal code received from the remote unit is equivalent to the predetermined signal code stored in the base unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. 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:
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storing a predetermined signal code in the base unit for preventing the base unit from responding to an unauthorized remote unit; transmitting the predetermined signal code from the base unit and receiving the predetermined signal code in the associated remote unit over an electrical path established when the remote unit is brought in electrical contact with the base unit, and wherein the transmitting and receiving steps further comprise in combination the step of bringing into electrical contact the remote unit and the base unit entirely over a direct current charging path used for charging a battery in the remote unit; storing the signal code by the remote unit for transmission back to the base unit when the remote unit is located remoted from the base unit and requesting dial tone therefrom; comparing the predetermined signal code stored in the base unit with the signal code received from a remote unit requesting dial tone; and activating the base unit when the signal code received from the remote unit is found by the comparing step to be equivalent to the predetermined signal code stored in the base unit. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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Specification