Systems and methods for optical dark section conditioning

Patent metadata

Field	Value
Publication number	US-9252913-B2
Application number	US-201313887942-A
Country	US
Kind code	B2
Filing date	May 6, 2013
Priority date	May 6, 2013
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

Embodiments of the disclosure are directed to optical dark section conditioning. An embodiment generates at least one of a broadband noise or signal at the head end of a section for a first module of the section; and operates all other modules of the section in gain control mode.

First claim

What is claimed is:

1. A method for optical dark section conditioning, comprising:
responsive to determining that a section is dark, wherein a dark section comprises connected fiber spans that are functional with no traffic carrying channels present, generating at least one of a broadband noise and a signal at a head end of the section, by a first module of the section; and
operating all other modules of the section in gain control mode.

2. The method of claim 1 , further comprising closing all per channel actuators at a head end optical add drop multiplexer (OADM) node.

3. The method of claim 2 , further comprising closing down pixels in a wavelength selective switch.

4. The method of claim 2 , further comprising changing a per channel or a group multiplexer variable optical attenuator to an approximate maximum attenuation.

5. The method of claim 1 , further comprising masking an alarm raised by a first amplifier at the head of the section.

6. The method of claim 1 , wherein the target gain for the other modules is based on a span loss of a preceding span, as determined by an optical supervisory channel.

7. The method of claim 1 , wherein the gain for the other modules is substantially based on prior results.

8. The method of claim 1 , further comprising setting gain targets for all modules in gain control mode.

9. The method of claim 1 , wherein a section head optical controller waits a predetermined amount of time in order to allow a first amplifier to achieve its output power target prior to setting the other modules in the section in gain control mode.

10. An apparatus for optical dark section conditioning, comprising:
logic configured to, responsive to a determination that a section is dark, wherein a dark section comprises connected fiber spans that are functional with no traffic carrying channels present, generate at least one of a broadband noise and a signal at a head end of the section by a first module of the section; and
logic configured to operate all other modules of the section in gain control mode.

11. The apparatus of claim 10 , further comprising logic configured to close all per channel actuators at a head end optical add drop multiplexer node.

12. The apparatus of claim 11 , further comprising logic configured to close down pixels in a wavelength selective switch.

13. The apparatus of claim 11 , further comprising logic configured to change a per channel or a group multiplexer variable optical attenuator to an approximate maximum attenuation.

14. The apparatus of claim 10 , further comprising logic configured to mask an alarm raised by the first amplifier.

15. The apparatus of claim 10 , wherein the target gain for the other modules is based on a span loss of a preceding span reported by an optical supervisory channel.

16. The apparatus of claim 10 , wherein the gain for the other modules is substantially based on prior results.

17. The apparatus of claim 10 , further comprising logic configured to set gain targets for all modules in gain control mode.

18. The apparatus of claim 10 , wherein the section head optical controller waits a predetermined amount of time in order to allow a first amplifier to achieve its output power target prior to setting all other modules in the section in gain control mode.

19. An apparatus for optical dark section conditioning, comprising:
a processor configured to
responsive to a determination that a section is dark, wherein a dark section comprises connected fiber spans that are functional with no traffic carrying channels present, generate at least one of a broadband noise and a signal at a head end of the section by a first module of the section; and
cause all other modules of the section to operate in gain control mode.

20. The apparatus of claim 19 , wherein the processor is configured to perform optical dark section conditioning on more than one dark section.

21. The apparatus of claim 20 , wherein the more than one dark section comprises at least one of the following:
a route and select based network architecture and a broadcast and select-based architecture.

22. The apparatus of claim 20 , wherein the processor is configured to perform optical dark section conditioning on a section that comprises at least one Raman amplifier.

23. The apparatus of claim 19 , wherein at least one of the modules has a back-reflector photodiode on an output port to detect back-reflection coming into the port.

24. The apparatus of claim 19 , wherein the processor is configured to reduce output power in order not to damage the modules.

25. A non-transitory computer-readable medium storing instructions executable by a processor for optical dark section conditioning, comprising:
at least one instruction to generate, responsive to a determination that a section is dark, wherein a dark section comprises connected fiber spans that are functional with no traffic carrying channels present, at least one of a broadband noise and a signal at a head end of the section by a first module of the section; and
at least one instruction to operate all other modules of the section in gain control mode.

26. The apparatus non-transitory computer-readable medium of claim 25 , further comprising at least one instruction to perform optical dark section conditioning on more than one dark section.

27. The non-transitory computer-readable medium of claim 25 , wherein the more than one dark section comprises at least one of the following:
a route and select based network architecture and a broadcast and select-based architecture.

28. The non-transitory computer-readable medium of claim 25 , performs further comprising at least one instruction to perform optical dark section conditioning on a section that comprises at least one Raman amplifier.

29. The non-transitory computer-readable medium of claim 25 , wherein at least one of the modules has a back-reflector photodiode on an output port to detect back-reflection coming into the port.

30. The non-transitory computer-readable medium of claim 25 , further comprising at least one instruction to reduce output power in order not to damage the modules.

31. A method for optical dark section conditioning, comprising:
disabling an automatic shutoff mode for a first amplifier in a dark section comprising connected fiber spans that are functional with no traffic carrying channels present;
setting the first amplifier in power control mode;
setting an estimated power target to bring a second amplifier in the section out of shutoff mode, wherein the second amplifier is the next amplifier in the set after the first amplifier; and
setting all remaining amplifiers in the section in gain control mode.

32. The method of claim 1 , further comprising detecting a fault in the section while the section is dark based on the optical dark section conditioning.

33. The apparatus of claim 10 , further comprising logic configured to detect a fault in the section while the section is dark based on the optical dark section conditioning.

Assignees

• Ciena Corp

Inventors

• Al Sayeed Choudhury A
• Miedema David
• Berg Loren S
• Bownass Dave C

Classifications

• H04J14/0221

  Power control, e.g. to keep the total optical power constant · CPC title

• H04J14/0289 Primary

  Optical multiplex section protection · CPC title

• H04J14/0202

  Arrangements therefor · CPC title

• H04B10/2935

  with a cascade of amplifiers · CPC title

• H04B10/0777 Primary

  Monitoring line amplifier or line repeater equipment · CPC title