Centrally controlled electronic telephone system having a customer memory for storing information on two or more different subscriber stations and peripheral equipment-specific information
US4105874A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 1, 1977 |
| Grant date | Aug 8, 1978 |
| Priority date | — |
| Expiry date | Mar 1, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S379/914
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An electronic telephone switching system is described having peripheral units including a plurality of subscriber and line circuits, a plurality of trunk and tie line circuits, at least one attendant line circuit, a plurality of signaling tone receivers, and a plurality of link control circuits. Switching is carried out by a one wire speech path switching matrix and a one wire tone switching matrix. The system is centrally controlled and includes a central processing unit, a program memory, a scratch pad memory and a customer memory. Information, commands and addresses are communicated between the peripheral units and the central control and within the central control via bus lines. The bus lines between the peripheral units and the central control transmit data with lower rise time pulses than the bus lines interconnecting the coponents of the central control. Each electronic crosspoint switch has a two terminal conducting path and a control terminal for controlling the state of conduction of the conducting path. Different conducting path terminals of the speech path matrix and tone path matrix crosspoint switches are operated by the same peripheral link unit. The matrix coordinat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.