Class of line identifier apparatus and method therefor
US4086439A · kind A · utility
Inventors
Key dates
| Filing date | Dec 17, 1976 |
| Grant date | Apr 25, 1978 |
| Priority date | — |
| Expiry date | Dec 17, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/64
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An apparatus identifying a class of called telephone lines by extending an identity signal back over the called line to a calling central operator or control. The identifier apparatus includes a signal identity generator connected to the called line, a signal decoder located at a calling central control such as an operator cordboard or traffic service position (TSPS), and a time-out for deactivating the generator after a predetermined time period has elapsed. A method is also set forth where a uniquely coded signal is extended over the communication line to an operator when an "OFF HOOK" condition appears from the called line to warn the operator that the called line is not authorized to receive collect calls.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.