Apparatus for controlling and indicating the integrity of the connection of telephone subscribers to a switching system
US4331843A · kind A · utility
7Cited by
1References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1980 |
| Grant date | May 25, 1982 |
| Priority date | — |
| Expiry date | Dec 29, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/303
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A system is shown for automatically detecting the integrity of telephone subscriber's line connection to a four wire switching system via a hybrid network.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.