Optical protection switch employing an interference filter
US6266168A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1997 |
| Grant date | Jul 24, 2001 |
| Priority date | — |
| Expiry date | Dec 19, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/0279
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A protection facility is provided for use in an optical communications node that communicates with another optical communications node via first and second bidirectional communications paths respectively serving as a service path and protection path, in which a filter filters signals respectively received over the service and protection paths and generates a main signal and a complementary signal for each of the paths. A control unit then generates a Loss of Signal (LOS_A) indication for the service path if a SUM signal or DIFF signal respectively derived as a function of a sum of the main and complementary signals generated for the service path and difference between the main and complementary signals generated for the service path is less than a respective threshold value. A switch then invokes protection switching responsive to the presence of the LOS_A indication.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.