Method for controlling modem
US6295313A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1998 |
| Grant date | Sep 25, 2001 |
| Priority date | — |
| Expiry date | Jul 29, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/50
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
When the present modem control apparatus detects that the receive level of a probing signal in phase 2 of the pre-communication procedure or a tone signal with a specific frequency in phase 2 of the pre-communication procedure is lower than a prescribed value, it sets the transmission rate of the control channel to a low rate of 1200 bps. In this case, the modem control apparatus sets the transmission rate to 1200 bps through a prescribed bit of the MPh signal in the communication control procedure and performs the setting that will not permit communications with the answer modem at different transmission rates, through the second prescribed bit of said MPh signal, and notifies those settings to the answer modem, thus carrying out communications at a lower transmission rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.