Optical switch with path continuity monitoring for optical protection switching

Patent metadata

Field	Value
Publication number	US-10826601-B2
Application number	US-201916248882-A
Country	US
Kind code	B2
Filing date	Jan 16, 2019
Priority date	Jan 16, 2019
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

An Optical Protection Switch (OPS) includes a splitter connected to a transmitted input and a path continuity monitor transmitter and configured to output the transmitted input with a path continuity monitor signal to two paths; a switch connected to a receiver output and configured to provide one of two receiver inputs each from one of the two paths based on a setting of the switch; and one or more path continuity monitor receivers connected to the two receiver inputs and configured to detect a corresponding path continuity monitor signal from a complementary OPS, wherein the setting of the switch is set based upon the received path continuity monitor signals. The one or more path continuity monitor receivers each have a narrow optical bandwidth relative to an overall optical bandwidth of the transmitted input.

First claim

What is claimed is:

1. An Optical Protection Switch (OPS) comprising:
a splitter connected to a transmitted input and a path continuity monitor transmitter and configured to receive a path continuity monitor signal from the path continuity monitor transmitter and the transmitted input and to output the transmitted input with the path continuity monitor signal to two paths;
a switch connected to a receiver output and configured to provide one of two receiver inputs each from one of the two paths based on a setting of the switch; and
two path continuity monitor receivers each connected to a corresponding receiver input of the two receiver inputs and configured to detect a corresponding path continuity monitor signal split from a complementary path continuity monitor transmitter associated with a complementary OPS,
wherein the setting of the switch is based on data detected by one or more of the two path continuity monitor receivers on the corresponding path continuity monitor signal.

2. The Optical Protection Switch (OPS) of claim 1 , wherein the two path continuity monitor receivers each have a narrow optical bandwidth relative to an overall optical bandwidth of the transmitted input.

3. The Optical Protection Switch (OPS) of claim 2 , wherein the two path continuity monitor receivers include a narrowband optical filter, thereby lowering noise contribution to overall received power.

4. The Optical Protection Switch (OPS) of claim 1 , wherein the two path continuity monitor receivers are each configured to receive data, and wherein the data received by the two path continuity monitor receivers is tied directly into the switch for control thereof.

5. The Optical Protection Switch (OPS) of claim 1 , wherein the path continuity monitor signal is at a wavelength within a gain bandwidth of an optical amplifier but outside of data-bearing channels.

6. The Optical Protection Switch (OPS) of claim 1 , wherein the setting of the switch is set to switch based on a detected loss of the corresponding path continuity monitor signal.

7. The Optical Protection Switch (OPS) of claim 1 , wherein the path continuity monitor transmitter and the two path continuity monitor receivers are configured to carry data on associated wavelengths with the complementary OPS.

8. The Optical Protection Switch (OPS) of claim 7 , wherein, subsequent to a switch, the path continuity monitor transmitter is configured to communicate the switch to the complementary OPS for synchronization of paths using an in-band communication signal.

9. The Optical Protection Switch (OPS) of claim 1 , further comprising an optical filter on the transmitted input to block an upstream path continuity monitor signal.

10. The Optical Protection Switch (OPS) of claim 9 , wherein in a nested configuration N−1 OPS pairs are provided for protection of N fiber paths.

11. The Optical Protection Switch (OPS) of claim 9 , wherein the OPS is in an outer stage of a nested configuration, and wherein the one or more path continuity monitor receivers are configured to receive a path continuity monitor signal from inner stages of the nested configuration.

12. The Optical Protection Switch (OPS) of claim 9 , wherein a corresponding path continuity monitor signal for each stage in a nested configuration has unique modulation or frequencies for identification thereof.

13. A method of optical protection switching with an Optical Protection Switch (OPS) comprising:
in the OPS which includes a splitter on a transmit side that receives a path continuity monitor signal from the a continuity monitor transmitter and a transmitted input and splits the path continuity monitor signal and the transmitted input to both a first fiber path and a second fiber path and a receive switch on a receive side with the receive switch set to only one of the first fiber path and the second fiber path, receiving corresponding split path continuity monitor signals two path continuity monitor receivers from a complementary OPS; and
based on data detected by one or more of the two path continuity monitor receivers on the corresponding path continuity monitor signal, causing a switch of the receive switch.

14. The method of claim 13 , wherein the two path continuity monitor receivers each have a narrow optical bandwidth relative to an overall optical bandwidth of the transmitted input.

15. The method of claim 13 , wherein the two path continuity monitor receivers are each configured to receive data, and wherein the data received by the two path continuity monitor receivers is tied directly into the switch for control thereof.

16. The method of claim 13 , wherein each of the split path continuity monitor signals is at a wavelength within a gain bandwidth of an optical amplifier but outside of data-bearing channels.

17. The method of claim 13 , further comprising:
subsequent to a switch based on a loss of a path continuity signal, communicating the receive switch state to the complementary OPS for synchronization of paths.

18. The method of claim 13 , further comprising:
utilizing an optical filter on a transmitted input to block an upstream path continuity monitor signal in a nested configuration.

19. A nested Optical Protection Switch (OPS) system comprising:
N−1 OPS pairs providing protection for N fiber paths, and each OPS including
a splitter connected to a transmitted input and a path continuity monitor transmitter and configured to receive a path continuity monitor signal from the path continuity monitor transmitter and the transmitted input and to output the transmitted input with the path continuity monitor signal to two paths, wherein any upstream path continuity monitor signal is blocked on the transmitter input;
a switch connected to a receiver output and configured to provide one of two receiver inputs each from one of the two paths based on a setting of the switch; and
two path continuity monitor receivers, each connected to one of the receiver inputs and configured to detect a corresponding path continuity monitor signal split from a complementary path continuity monitor transmitter associated with a complementary OPS,
wherein the setting of the switch is set based on data detected by one or more of the two path continuity monitor receivers on the corresponding path continuity monitor signal.

20. The nested Optical Protection Switch (OPS) system of claim 19 , wherein the corresponding path continuity monitor signal is formed from a single source with unique modulated signals sent from the single source over each of the N fiber paths for identification thereof.

Assignees

• Ciena Corp

Inventors

• Bhatnagar Vipul
• Chedore Paul
• Al Sayeed Choudhury A
• Kohlert Scott
• Bownass David C

Classifications

• H04Q11/0062

  Network aspects · CPC title

• H04Q2011/0088

  Signalling aspects · CPC title

• H04J14/0275

  using an optical service channel · CPC title

• H04Q2011/0081

  Fault tolerance; Redundancy; Recovery; Reconfigurability · CPC title

• H04J14/0291

  Shared protection at the optical multiplex section (1:1, n:m) · CPC title