Muliple highway time division multiplexed PABX communication system
US4140877A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1977 |
| Grant date | Feb 20, 1979 |
| Priority date | — |
| Expiry date | Apr 19, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/025
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A communication switching system of PABX uses a number of time division multiplexed send and receive highway pairs each servicing a plurality of peripheral devices or ports providing two-way communication with the outside world by means of associated telephones, trunk line interfaces, or similar apparatus. All highway pairs are multiplexed in accordance with the same time division format and the maximum number of two-way peripheral devices serviced by each highway pair is dependent on the number of time slots of the format assigned for audio communication. Each peripheral device transmits on a given audio time slot of its send highway. Switching to establish communication paths between peripheral devices is achieved in part by receiving means in each peripheral device responsive to command signals transmitted on command time slots on the associated receive highway instructing each peripheral device on which audio time slots of its receive highway to receive. A further part of the switching is provided by a plurality of highway switches in the common equipment which, under processor control, may forward the signal appearing in any given audio time slot of a send highway to the corre…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.