Cordless telephone
First Claim
1. A cordless telephone, comprising:
- a base unit connectable to a telephone network line for receiving and transmitting message signals therethrough;
a handset unit selectively mountable upon and separable from said base unit;
said base unit and said handset unit each including means for transmitting an identifying code signal over electromagnetic waves and means for receiving said transmitted identifying code signal;
said base unit including first memory means, first detecting means for generating a first detected output upon the mounting of said handset unit upon said base unit, means for automatically generating a counted value in response to said first detected output and a predetermined time associated therewith, and first means for storing said counted value as a new identifying code signal in said first memory means, said means for transmitting thereupon transmitting said new identifying code signal to said handset unit;
said handset unit including second memory means, second detecting means for generating a second detected output upon the mounting of said handset unit upon said base unit, and second means for storing said new identifying code signal in said second memory means in response to said second detected output;
said base and said handset unit each further including identity detecting means for detecting when a received identifying code signal is identical to an identifying code signal stored in said first and second memory means, respectively, and means for establishing a communication channel between said base and handset units only when identity is detected.
1 Assignment
0 Petitions
Accused Products
Abstract
A cordless telephone includes a base unit and a handset unit. When the handset unit is mounted on the base unit, an identifying code is automatically generated and stored in both units. Thereafter, when an incoming or outgoing telephone call is initiated, the two stored identifying codes are compared, and the telephone call proceeds only if the two identifying codes are identical. The new identifying code is generated as a counted value in accordance with a predetermined time following the mounting of the handset unit of the base unit. By having the predetermined time vary from telephone to telephone, the identifying codes will also vary, eliminating crosstalk interference and the risk of wiretapping.
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Citations
23 Claims
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1. A cordless telephone, comprising:
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a base unit connectable to a telephone network line for receiving and transmitting message signals therethrough; a handset unit selectively mountable upon and separable from said base unit; said base unit and said handset unit each including means for transmitting an identifying code signal over electromagnetic waves and means for receiving said transmitted identifying code signal; said base unit including first memory means, first detecting means for generating a first detected output upon the mounting of said handset unit upon said base unit, means for automatically generating a counted value in response to said first detected output and a predetermined time associated therewith, and first means for storing said counted value as a new identifying code signal in said first memory means, said means for transmitting thereupon transmitting said new identifying code signal to said handset unit; said handset unit including second memory means, second detecting means for generating a second detected output upon the mounting of said handset unit upon said base unit, and second means for storing said new identifying code signal in said second memory means in response to said second detected output; said base and said handset unit each further including identity detecting means for detecting when a received identifying code signal is identical to an identifying code signal stored in said first and second memory means, respectively, and means for establishing a communication channel between said base and handset units only when identity is detected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification