Control mechanism for a ring communication system
US4566098A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1984 |
| Grant date | Jan 21, 1986 |
| Priority date | — |
| Expiry date | May 14, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/43
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The invention provides a ring communication network having an improved error recovery mechanism. The system uses a token or toggle signal which does not have an inherent control value but one that requires the values of a contiguous pair thereof to control access to the transmission medium of the system. A station recognizes that the ring is idle if the present value of the toggle signal is the same as the value of the toggle signal in the previous frame. Conversely, a station recognizes that the ring is busy if the present value of the toggle signal is different from the value of the toggle signal in the previous frame. A station that detects an idle toggle signal and wishes to transmit data on the communication ring changes the value of the toggle signal to that which corresponds to a busy status and transmits its data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.