System and method for automatically selecting the mode of communication between a plurality of modems
US5796808A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 1997 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Jan 9, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L5/1438
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system is provided for automatically selecting the mode of communication between a plurality of multi-mode modems. A calling modem and an answering modem are disposed for intercommunication across an established communication link of a telephone network. The calling modem transmits a continuous calling signal across the established link, and the answering modem detects the calling signal and analyzes the calling signal to determine the configuration of the calling modem. In response, the answering modem generates and transmits an answering signal across the established link. The calling modem detects and analyzes the answering signal to determine the configuration of the answering modem. Finally, the system determines whether the established link passes through a PSTN, and if so, transmits a 2100 hertz tone across the established link. Otherwise, the system proceeds directly to the a modem training sequence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.