In-service monitoring of a fiberoptic network
View Patent ↗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.
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.