High speed modem
US4924456A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 1988 |
| Grant date | May 8, 1990 |
| Priority date | — |
| Expiry date | Aug 29, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/50
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A modem is disclosed having a data transmission protocol involving lower-speed, full-duplex operation during the connect sequence with a remote modem and an automatic switch to higher-speed, half-duplex operation for data transfer. Further, the modem data transmission involves transparently changing between lower-speed, interactive operation and higher-speed operation based upon data transmission demands. The operation is controlled by a processor monitoring the contents of a transmit data buffer and providing a mode control command to the modem transmitter. The modem also adapts its speed to the quality of the telephone line by fallback or fallforward to a different speed based upon predetermined data frame retransmission criteria.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.