Highway expansion apparatus for key telephone system and operation method thereof
US7139375B2 · kind B2 · utility
0Cited by
10References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 23, 2002 |
| Grant date | Nov 21, 2006 |
| Priority date | — |
| Expiry date | Sep 8, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/02
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In a highway expansion apparatus for a key telephone system and an operation method thereof, by connecting a MPB (main process board) of a master system with a system LMU (ink module unit) of an expansion system through a cable and generating a highway to be provided from the MPB to the expansion system, a highway of the key telephone system can be expanded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.