Programmable port sense and control signal preprocessor for a central office switching system
US4385206A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1980 |
| Grant date | May 24, 1983 |
| Priority date | — |
| Expiry date | Dec 16, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q11/0407
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A community office switching system includes a three-level hierarchy of distributed processors operating in parallel with one another to control the operation of a central office matrix switch network interconnecting 1,920 ports. At the highest level, a stored-program call control processor controls call progression, establishing paths through the matrix switch network. At the second level, a series of special-purpose, stored-program, port control processors each service 960 ports, sensing and transmitting supervisory signals and communicating the occurrence of significant port events to the call control processor. Each port event control processor dedicates approximately 32 microseconds out of every 32 milliseconds to each of the 960 ports in time-multiplexed fashion, and hence no port can ever be locked out at the port-control-processor level. One from a series of stored programs is executed to service each port precisely one every 32 milliseconds. At the lowest level, a digital filtering processor, associated with each port control processor, samples some signals from each port once every millisecond, filters the sampled signals to give one filtered sample every four millisecond…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.