Patent · US Expired

Power line carrier telephone extension system for full duplex conferencing between telephones and having telephone call hold capability

US4514594A · kind A · utility

87Cited by
14References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 30, 1982
Grant dateApr 30, 1985
Priority date
Expiry dateSep 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 one or more extension telephones 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 one or more extension telephones of the system that plugs into the power line, all of which can place calls to the telephone line, answer calls from the telephone line and conference together in full duplex communication, means at the extension telephones for initiating a telephone line hold signal that is transmitted over the power line to the main station where the hold signal is detected and initiates connecting a hold impedance across the telephone line.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.