Modem mode matching method with PBX dial-in
US5199071A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 10, 1990 |
| Grant date | Mar 30, 1993 |
| Priority date | — |
| Expiry date | Jul 10, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/06
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for matching operation modes of modems for connection of terminals to a telephone line, i.e., matching operation forms determined by a communication speed, a coding format, a synchronizing format, etc., on both the calling and answering sides of the telephone line. When the answering side detects an extension specifying signal sent from the calling side, an operation mode of a modem corresponding to the extension specifying signal is used to select the specified operation mode from among a plurality of operation modes for modem circuits equipped on the answering side, for matching the operation mode of the answering side modem with that on the calling side. The answering side modem has a function of detecting a push-button dial signal serving as the extension specifying signal, and a function of providing the plurality of operation modes for the modem and optionally changing the operation mode upon an instruction from an answering side terminal. The answering side terminal determines the correlation between the extension specifying signal from the calling side and the operation mode of the calling side modem. A calling terminal sets a call using a telephone n…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.