Key telephone system
US4554413A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1984 |
| Grant date | Nov 19, 1985 |
| Priority date | — |
| Expiry date | May 31, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/005
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A key telephone system uses four wires for transmission of voice and audio signals to and from the telephone stations and other components which are part of the system. A plurality of telephone stations are provided, each having a two wire audio input port, a separate two wire audio output port, and a data port. Communcation paths are established through a crosspoint matrix. The matrix includes a first group of addressable crosspoint switches for coupling selected transmit signal paths to selected first link points. A second group of such switches is provided for coupling selected receive signal paths to selected second link points. A third group of such switches couples selected first link points to selected second link points. A link searching routine determines which links are available for effecting communication paths. A minimizing function shares communication paths among common signals when possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.