In-service monitoring of a fiberoptic network

Patent metadata

Field	Value
Publication number	US-9571189-B2
Application number	US-201615061300-A
Country	US
Kind code	B2
Filing date	Mar 4, 2016
Priority date	Oct 23, 2013
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

An optical fiber breakage point may be located by coupling to the optical fiber an out-of-band optical test signal modulated at a periodic modulation pattern. A distance to the breakage point may be determined from a difference between modulation patterns of transmitted and received test signals.

First claim

What is claimed is:

1. A system comprising:
a controller configured to:
determine a magnitude of a returning optical test signal;
determine a modulation frequency offset of the returning optical test signal relative to a current value of a periodically swept modulation frequency; and
detect fault information in a fiberoptic link based on a comparison of at least one of:
the determined magnitude of the returning optical test signal and a reference magnitude of an optical test signal redirected by a wavelength-selective reflector; or
a comparison between the determined modulation frequency offset of the returning optical test signal to a reference modulation frequency offset of the optical test signal.

2. The system of claim 1 , further comprising:
a photodetector to detect the returning optical test signal.

3. The system of claim 1 , where the controller is further configured to:
detect, based on the determined modulation frequency offset of the returning optical test signal being less than the reference modulation frequency offset of the optical test signal, that there is a break in the fiberoptic link.

4. The system of claim 1 , where the controller is further configured to:
detect, based on the determined magnitude of the returning optical test signal being less than the reference magnitude of the optical test signal, that there is a deterioration in the fiberoptic link.

5. The system of claim 1 , where the wavelength-selective reflector is optically coupled to the fiberoptic link.

6. The system of claim 1 , where
the wavelength-selective reflector is configured to redirect the optical test signal at a first wavelength, and
the first wavelength is a test wavelength.

7. The system of claim 6 , where the wavelength-selective reflector is configured to propagate an information signal, at a second wavelength, to an antenna.

8. The system of claim 1 , where
the returning optical test signal is a first returning optical test signal,
the fiberoptic link is a first fiberoptic link, and
controller is further configured to:
determine a magnitude of a second returning optical test signal;
determine a modulation frequency offset of the second returning optical test signal relative to a current value of a periodically swept modulation frequency; and
detect fault information in a second fiberoptic link.

9. The system of claim 8 , where the controller, when detecting the fault information in the second fiberoptic link, is configured to:
detect the fault information in the second fiberoptic link, based on a comparison of at least one of:
the determined magnitude of the second returning optical test signal and the reference magnitude of the optical test signal; or
a comparison between the determined modulation frequency offset of the second returning optical test signal to a reference modulation frequency offset of the optical test signal.

10. The system of claim 1 , where the returning optical test signal is based on a test signal that is modulated at the periodically swept modulation frequency.

11. A method comprising:
determining, by a controller, a magnitude of a returning optical test signal;
determining, by the controller, a modulation frequency offset of the returning optical test signal relative to a current value of a periodically swept modulation frequency; and
detecting, by the controller, fault information in a fiberoptic link based on a comparison of at least one of:
the determined magnitude of the returning optical test signal and a reference magnitude of an optical test signal redirected by a wavelength-selective reflector; or
a comparison between the determined modulation frequency offset of the returning optical test signal to a reference modulation frequency offset of the optical test signal.

12. The method of claim 11 , further comprising:
detecting the returning optical test signal.

13. The method of claim 11 , further comprising:
detecting, based on the determined modulation frequency offset of the returning optical test signal being less than the reference modulation frequency offset of the optical test signal, that there is a break in the fiberoptic link.

14. The method of claim 11 , further comprising:
detecting, based on the determined magnitude of the returning optical test signal being less than the reference magnitude of the optical test signal, that there is a deterioration in the fiberoptic link.

15. The method of claim 11 , where the wavelength-selective reflector is optically coupled to the fiberoptic link.

16. The method of claim 11 , where
the wavelength-selective reflector is configured to redirect the optical test signal at a first wavelength, and
the first wavelength is a test wavelength.

17. The method of claim 16 , further comprising:
propagating an information signal, at a second wavelength, to an antenna.

18. The method of claim 11 , where
the returning optical test signal is a first returning optical test signal,
the fiberoptic link is a first fiberoptic link, and
the method further comprises:
determining a magnitude of a second returning optical test signal;
determining a modulation frequency offset of the second returning optical test signal relative to a current value of a periodically swept modulation frequency; and
detecting fault information in a second fiberoptic link.

19. The method of claim 18 , where detecting the fault information in the second fiberoptic link includes:
detecting the fault information in the second fiberoptic link, based on a comparison of at least one of:
the determined magnitude of the second returning optical test signal and the reference magnitude of the optical test signal; or
a comparison between the determined modulation frequency offset of the second returning optical test signal to a reference modulation frequency offset of the optical test signal.

20. The method of claim 11 , where the returning optical test signal is based on a test signal that is modulated at the periodically swept modulation frequency.

Assignees

• Lumentum Operations Llc

Inventors

• Lin Yuan
• Kim Brian Sungwan
• Parry John

Classifications

• H04B10/071 Primary

  using a reflected signal, e.g. using optical time domain reflectometers [OTDR] · CPC title

• H04B10/548

  Phase or frequency modulation · CPC title

• H04B10/07957 Primary

  Monitoring or measuring wavelength · CPC title