Method and apparatus for transmitting auxiliary channel over digital communications system
US4079203A · kind A · utility
12Cited by
4References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 30, 1977 |
| Grant date | Mar 14, 1978 |
| Priority date | — |
| Expiry date | Mar 30, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L5/26
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An auxiliary channel, for example, an engineering orderwire, is derived on n existing time-division multiplex carrier system by modulating the pulse repetition rate of the digital bitstream. The modulating signal itself may be an analog or a digital signal. The modulator and demodulator both include a first-in, first-out shift register acting as a buffer, and the desired modulation is effected by varying the rate at which the digital information is fed out of the FIFO buffer at the transmitting end of the carrier system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.