Collision avoiding system and protocol for a two path multiple access digital communications system
US4532626A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1982 |
| Grant date | Jul 30, 1985 |
| Priority date | — |
| Expiry date | Jul 19, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/417
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In order to control the transfer of packets of information among a plurality of stations, e.g., digital computers, the instant communications system, station and protocol contemplate first and second oppositely directed signal paths. At least two stations are coupled to both the first and the second signal paths. A station includes arrangements for reading one signal from the first path and for writing another signal on the first path. The one signal is read from the first path by an arrangement which electrically precedes the arrangement for writing the other signal on the first path. A similar read arrangement is electrically preceding a write arrangement on the second path. If the station has a packet to transmit, it can overwrite a busy control field of the one signal packet on either path. Having read the one signal on the path, a logical interpretation may be made within the station as to whether the path is busy or is not busy. If the path is not busy, the packet may be written on the path by overwriting any signal thereon. If the path is busy, the station may defer the writing until the path is detected as not busy through a busy control field. The packets flow down the pat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.