Power line carrier multi telephone extension system for full duplex conferencing and intercom between telephones
US4523307A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1982 |
| Grant date | Jun 11, 1985 |
| Priority date | — |
| Expiry date | Nov 30, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2203/5437
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In a power line carrier telephone extension system for transmitting electrical signals between the telephone line and an extension telephone over the AC electric power line available at a telephone subscriber's premises, that includes a main station for processing signals between the subscriber's telephone line and power lines and two or more extension telephones of the system that plug into the power line, means that provides for two or more of the system telephones to communicate without going on the telephone line (Intercom), even while another system telephone is engaged in an outside telephone call and means are further provided for all telephones of the system to conference in Intercom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.