Transparent error detection in half duplex modems
US4744092A · kind A · utility
4Cited by
3References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 5, 1985 |
| Grant date | May 10, 1988 |
| Priority date | — |
| Expiry date | Jul 5, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L5/16
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A modem is operated in a half-duplex mode having various elements which are trained on data and which are locked up while data is not exchanged, thereby eliminating the need for a preamble. A preamble is used if the period between successive transmissions exceeds a preselected threshold. In addition, a parity encoder is used to calculate a parity word for each transmission, said parity word being inserted in the first baud period of the next transmission. This first baud period is usually empty because data signals have not been received yet from the corresponding data transmission equipment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.