Digital line card having universal port for upgrading electronic messaging system
US5479498A · kind A · utility
29Cited by
16References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1993 |
| Grant date | Dec 26, 1995 |
| Priority date | — |
| Expiry date | Jun 11, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S379/902
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A digital line card is provided for use in an electronic messaging system for enabling the receipt of voice and text or image data over a single communications port. The digital line card includes a digital signal processing integrated circuit, a microprocessor and a random access memory component for storing coding schemes employed by the digital signal processing integrated circuit. The digital line card is programmed to detect the presence of dual-tone multifrequency command signals in the incoming data stream, and to switch between voice and data processing responsive to the command signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.