Reconfigurable collision avoiding system, station and protocol for a two path multiple access digital communications system
US4542502A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1983 |
| Grant date | Sep 17, 1985 |
| Priority date | — |
| Expiry date | Dec 30, 2003 |
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 (and writing) signals from (and on) each of the two paths. Signals are read from either path by an arrangement which electrically precedes the arrangement for writing signals on the path. If the station has a packet to transmit, it can overwrite a busy control field of a packet on either path. Also having read a packet signal from 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 e.g. by reading a busy control field of another packet. Here the two paths are coupled to form two ring structures so the packets flow down the path to a destination station. Eventually all packets will …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.