Method and system for detecting optical faults in a network fiber link
US6285475A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 29, 1995 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | Dec 29, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q2011/0081
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and system for detecting optical faults by tapping a portion of a data signal from along a fiber network link at an optical switching site or node. The tapped data signal is evaluated to determine whether an optical fault exists along the fiber link. In this way, optical faults such as a fiber failure, cable cut, or nodal LTE failure occurring within a network path, are isolated to a specific fiber span or link. Network switch controllers can then take full advantage of optical switches provided between spans in an all-optical core network to restore end-to-end path communication. In one embodiment, a presence detector simply evaluates the magnitude of the tapped signal to determine an optical fault. In a second embodiment, a protocol analyzer evaluates selected bits or fields of the protocol used in the tapped data signal to determine an optical fault. Finally, in a third embodiment, a sub-carrier modulation signal is added to the high rate data signal prior to transport over the link. The subcarrier signal is significantly lower in both frequency and amplitude than the main data signal so as to not impact reliable reception of the main data signal. A low-pass filter tune…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.