Optical path fault recovery

• US 10,469,161 B2
• Filed: 06/28/2017
• Issued: 11/05/2019
• Est. Priority Date: 01/17/2014
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Martinelli, Giovanni, Vasseur, Jean-Philippe, Galimberti, Gabriele M.
• Primary Examiner(s): Alagheband, Abbas H
• Application Number:
  US15/636,401
• Publication Number:
  US 20170302371A1
• Time in Patent Office: 860 Days
• Field of Search: 398 5, 398 2, 398 25, 398 34, 398 45, 398 59
• CPC Class Codes: H04B 10/038 using bypasses
• CPC Class Codes: H04J 14/0221 Power control, e.g. to keep the total optical power constant
• CPC Class Codes: H04J 14/0293 Optical channel protection
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/247 using M:N active or standby paths
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0011 using wavelength conversion
• CPC Class Codes: H04Q 2011/0016 using wavelength multiplexing or demultiplexing
• CPC Class Codes: H04Q 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability

Abstract

The embodiments disclosed herein provide fast recovery of a network signal path by, in the event of a failure or unacceptable degradation in a signal in the original network path, diverting the optical signal passing through the network to a preselected bypass optical path which is maintained in a warm or operational state. The optical elements on the bypass optical path are available network resources which may, during part or all of the time the bypass path is designated for a node in the primary optical path, be in use to transmit other optical signals in the network. By maintaining the resources in the designated bypass path in a warm or operating state, fast rerouting and recovery of an interrupted signal is possible.

Claims

1. A method of protecting integrity of an optical signal transmitted via an optical path in an optical network upon a failure or degradation in the optical path, comprising:

selecting an operational node in a primary optical path in the optical network having the optical signal passing therethrough;

selecting, for the operational node, a bypass optical path to be used in response to a failure or interruption of the operational node;

maintaining at least one device in the selected bypass optical path in a warm state during operation of the operational node where the at least one device transmits an optical signal without carrying data, and has sufficient availability to carry a bypassed optical signal therethrough.

2. The method of claim 1, wherein, upon the failure of the operational node, redirecting the optical signal to the bypass optical path.

3. The method of claim 2, wherein the optical signal comprises a first wavelength, and the bypass optical path comprises a device that is tuned to a second wavelength that is different than the first wavelength.

4. The method of claim 3, wherein redirecting the optical signal includes regenerating the optical signal of the second wavelength.

5. The method of claim 4, wherein regenerating the optical signal occurs in the primary optical path.

6. The method of claim 4, wherein regenerating the optical signal occurs in the bypass optical path.

7. The method of claim 2, wherein the at least one device is a regenerator.

8. An optical network path, comprising:

a primary path having a plurality of optical nodes interconnected by fiber;

a preselected bypass path for at least one of the plurality of optical nodes of the primary path, the bypass path including at least one node device therein, the node device having available bandwidth to carry a bypassed optical signal, and the node device is maintained in a warm state during at least a portion of a transmission of an optical signal through the primary path, wherein, in the warm state, the node device is configured to transmit an optical signal without carrying data;

wherein

the bypass path connects to the primary path at locations upstream and downstream of the at least one of the plurality of optical nodes of the primary path for which the bypass path is preselected.

9. The optical network path of claim 8, wherein the bypass path includes at least two optical nodes connected in series, and wherein at least two of the at least two optical nodes have a regenerator associated therewith.

10. The optical network path of claim 8, wherein the primary path includes node devices upstream and downstream of the locations thereof of interconnection with the primary path, and

at least one of the node devices upstream of the locations of interconnection with the bypass path, and at least one of the node devices downstream of the locations of interconnection with the bypass path include a regenerator associated therewith.

11. The optical network path of claim 8, wherein the optical network path, when rerouted through the bypass path, includes at least two regenerators associated therewith.

12. The optical network path of claim 8, wherein the node device is not dedicated to carry the bypassed optical signal.