Single channel subscriber carrier system
AssigneeBrand-Rex Company
InventorsGary Eisenhauer, Frank Simokat
Life of this patent
Estimating the term…
Abstract
There is provided an improved subscriber carrier system which enables the transmission of both voice frequencies and carrier frequencies by a common line without the need for a battery at the subscriber carrier terminal to supply power for the subscriber carrier electronics. A high voltage power supply is utilized to supply power, both for the voice frequency terminal and the subscriber carrier terminal. Loop supervision circuitry is isolated from the power supply. Ringing signals are detected and regenerated at a frequency to pass through the isolation circuit.
Claims23
An electrical circuit for use with a telephone system having voice frequency and station carrier channels, said system comprising:
- a pair of metallic conductors;
- a first subscriber terminal circuit including means for transmitting and receiving information on voice frequencies;
- a second subscriber terminal circuit including means for modulating a carrier signal with a first voice signal provided by said second subscriber circuit and transmitting a resultant first modulated carrier signal over said pair of metallic conductors and means for receiving a second modulated carrier signal from said pair of metallic conductors and demodulating said second modulated signal to yield a second voice signal;
- a first central office terminal circuit including means for transmitting and receiving information on voice frequencies and first supervision means for generating line supervision signals and transmitting information corresponding to said line supervision signals over said pair of metallic conductors;
- a second central office terminal circuit including means for modulating a carrier signal with said second voice signal to produce said second modulated carrier signal and transmitting said second modulated carrier signal over said pair of metallic conductors and means for receiving said first modulated carrier signal from said pair of metallic conductors and demodulating said first modulated carrier signal to yield said first voice signal;
- a power supply means coupled to said pair of metallic conductors and to said first and second subscriber circuits for operating said first and second subscriber circuits;
- and
- means for isolating said first supervision means of said first central office terminal circuit from said power supply to prevent said power supply from interfering with said line supervision information.
An electrical circuit for use with a telephone system having voice frequency and station carrier channels, said circuit comprising:
- a first subscriber terminal circuit adapted to transmit and receive information on voice frequencies;
- a second subscriber terminal circuit adapted to transmit and receive information on carrier frequencies;
- said second subscriber circuit including means interfaced to said first subscriber circuit for modulating voice frequencies with a carrier signal to transmit the carrier signal and means for demodulating carrier signals to convert said carrier signals to voice frequencies;
- a first central office terminal circuit adapted to transmit and receive information on voice frequencies;
- a second central office terminal circuit adapted to transmit and receive information on carrier frequencies;
- said second central office circuit including means interfaced to said first office terminal circuit for modulating voice frequencies with a carrier signal to transmit the carrier signal and means for demodulating carrier signals to convert said carrier signals to voice frequencies;
- a pair of metallic conductors connecting said second subscriber terminal circuit to said second central office terminal circuit, said conductors transmitting carrier signals and loop supervision information;
- a DC power supply connected to said first and second subscriber circuits for operating said first and second subscriber circuits;
- and
- means for isolating a portion of said first central office terminal circuit which generates low frequency loop supervision signals corresponding to said loop supervision information from said DC current of said power supply so that said DC current does not interfere with normal loop supervision.
Dependencies are inferred from the claim text.