PBX telephone call control system
US4747124A · kind A · utility
98Cited by
10References
13Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 6, 1985 |
| Grant date | May 24, 1988 |
| Priority date | — |
| Expiry date | May 6, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/58
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A PBX telephone call control system is disclosed. The system provides a line interface unit connection between a plurality of subscriber line extensions and a private branch exchange (PBX or Centrex equipped) switching equipment. The call control system appears to the PBX like any other telephone extension within the office environment and provides the user with more features in conjunction with the pre-existing PBX equipment, providing expanded capabilities at a reasonable expense.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.