Call progress capability for a switched channel data service unit
US4995076A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1990 |
| Grant date | Feb 19, 1991 |
| Priority date | — |
| Expiry date | Feb 9, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q1/39
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A means is provided within an interface to data terminal equipment for obtaining call progress information. The call progress information provides relevant data as to the progress of a call initiated by the data terminal equipment. The interface is designed to be used in a portion of the telephone network that lacks byte alignment. Such portions of the telephone network do not currently receive call progress tones. The interface is preferably a data service unit that includes a receiving means processor and a display means. The data service unit interprets signals sent from the DDA/OCU that encode the progress or absence of call progress tones sent from the destination node of an initiated call.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.