Active T-coupler for fiber optic local networks which permits collision detection
US4233589A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1979 |
| Grant date | Nov 11, 1980 |
| Priority date | — |
| Expiry date | May 25, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/413
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An active T-coupler for fiber optic local networks which permits collision detection wherein two input 36, 44 optical fibers are coupled to photodetectors 360, 440, respectively. Two output 34, 46 optical fibers are coupled to receive light from light sources 340, 460. Driving sources 340, 460 are gate circuits 342, 462, which function in a manner similar to an OR gate, via driver circuits 341, 461. These OR gates receive electrical signals from the host station or an input light fiber detector. Further, the input detectors 360, 440 provide electrical signals to the driving OR gates 342, 462 to pass the signal on, i.e. repeat, or drive OR gate 370 to transmit the signal to the host station. Thus the coupler can act as an optical repeater or transmit originally generated light signals in either the forward or reverse directions. Further, the host station can monitor the electrical signals from the input detectors to detect the occurrence of a data collision while transmitting and thereby react appropriately.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.