Monitoring individual fibers of an optical cable for intrusion
US7706641B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 2006 |
| Grant date | Apr 27, 2010 |
| Priority date | — |
| Expiry date | Dec 31, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/85
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Some or all of the optical fibers of a single-mode or multi-mode cable are monitored for intrusion by transmitting through the fibers a signal which can be analyzed for changes in its characteristics which are indicative of movement as a prelude to an intrusion event. To avoid independent monitors of all of the fibers, in some cases the same light signal is looped through a plurality of the fibers in series by passive jumpers. Switches can be used to disconnect out those fibers which are compromised. As an alternative a plurality of separate monitoring signals can be provided each associated with its own sensor where unique combinations of the signals are transmitted through separate fibers allowing a higher number of fibers to be monitored than the number of signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.