Remote terminal channel unit for telephone transmission lines
US5422950A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 1994 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Jul 28, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/40
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An automatic loss compensation for use in a two to four wire hybrid converter in a telephone system. Many hybrid converters provide a substantially fixed gain for receive signals that are provided to the customer loop telephone line and for transmit signals that are provided to the digital carrier transmission line. The compensation circuit includes a measurement circuit, controller, and receive and transmit amplifier. The measurement circuit determines the length of the customer loop telephone line and provides a length signal. The controller receives the length signal and categorizes the length as being within one of a plurality of segments. The controller appropriately varies the amplification and phase of the receive signal, which is then combined with an inverted transmit signal, in order to substantially reduce reflected signals from the transmission line and transmission line termination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.