# US 11,310,572 B2 · Multi layer protection control for coherent DWDM networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,310,572 B2 - Document ID: US11310572B2 - Status: Granted - Kind: B2 - Application number: 17/126,403 - Filed: 2020-12-18 - Published: 2022-01-20 - Granted: 2022-04-19 - Earliest claimed: 2020-07-15 - Assignees: Infinera Corporation - Applicants: Infinera Corp. - Inventors: Kapil Juneja; Amit Satbhaiya; Rajan Rao - Web page: https://patentgrep.com/patent/US11310572B2 ## CPC - H04J 14/0295: {Shared protection at the optical channel (1:1, n:m)} - H04Q 11/0062: {Network aspects} - H04B 10/032: using working and protection systems {(H04J14/0287 takes precedence)} - H04J 14/02122: {Colourless, directionless or contentionless [CDC] arrangements} - H04J 14/0227: {Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation} - H04J 14/0283: {WDM ring architectures} - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W) - H04B: TRANSMISSION ## Abstract A terminal node, an optical network and/or a method are described in which a first processor of a first optical protection switching module having a first optical switch, and a second processor of a second optical protection switching module having a second optical switch coordinate switching of the first optical switch and the second optical switch upon detection of a first failure by the first processor, or the detection of a second failure by the second processor. The first processor monitors optical signals received by a first line port to determine a first failure in a first working path at a first layer (e.g., physical layer) within an optical communication model. The second processor monitors the optical signals received by another line port to determine a second failure in the first working path at a second layer (e.g., optical layer) within the optical communication model. ## Claims ### Claim 1 A terminal node, comprising: a first optical protection switching module including a first line port connected to a first working path, a second line port connected to a first protection path, an system port, and a first processor monitoring optical signals received by the first line port to determine a first failure in the first working path at a first layer within an optical communication model, the first optical protection switching module including a first optical switch coupled to the first line port to receive first optical signals from the first working path and the second line port to receive second optical signals from the first protection path for selectively switching optical signals from the first line port or the second line port to the system port; a second optical protection switching module having a third line port receiving optical signals from the system port of the first optical protection switching module, and a second processor monitoring the optical signals received by the third line port to determine a second failure in the first working path at a second layer within the optical communication model, the second optical protection switching module having a second optical switch controlled by the second processor; and wherein the first processor and the second processor coordinate switching of the first optical switch and the second optical switch upon detection of the first failure by the first processor, or the detection of the second failure by the second processor. ### Claim 2 (depends on 1) The terminal node of claim 1, wherein the second processor is configured with a holdover period such that upon detection of the second failure, the second processor switches the second optical switch after confirming the presence of the second failure after the passage of the holdover period. ### Claim 3 (depends on 2) The terminal node of claim 2, wherein first optical switch has a first optical switch settling time being a time period for the first optical switch to switch from the first line port to the second line port, and wherein the holdover period is a predetermined period of time greater than the first optical switch settling time. ### Claim 4 (depends on 1) The terminal node of claim 1, wherein the first layer is a physical layer, and the second layer is an optical layer. ### Claim 5 (depends on 1) The terminal node of claim 1, wherein the first failure is an optical loss of signal. ### Claim 6 (depends on 1) The terminal node of claim 1, wherein the second failure is a loss of frame. ### Claim 7 An optical network, comprising: an optical fiber having a first end and a second end; a first node comprising a first optical protection switching module including a first line port connected to a first working path, a second line port connected to a first protection path, an system port supplying optical signals to the first end of the optical fiber, and a first processor monitoring optical signals received by the first line port to determine a first failure in the first working path at a first layer within an optical communication model, the first optical protection switching module including a first optical switch coupled to the first line port to receive first optical signals from the first working path and the second line port to receive second optical signals from the first protection path for selectively switching optical signals from the first line port or the second line port to the system port; a second node including a second optical protection switching module having a third line port receiving optical signals from the system port of the first optical protection switching module from the second end of the optical fiber, and a second processor monitoring the optical signals received by the third line port to determine a second failure in the first working path at a second layer within the optical communication model, the second optical protection switching module having a second optical switch controlled by the second processor; and wherein the first processor and the second processor coordinate switching of the first optical switch and the second optical switch upon detection of the first failure by the first processor, or the detection of the second failure by the second processor. ### Claim 8 (depends on 7) The optical network of claim 7, wherein the second processor is configured with a holdover period such that upon detection of the second failure, the second processor switches the second optical switch after confirming the presence of the second failure after the passage of the holdover period. ### Claim 9 (depends on 7) The optical network of claim 7, wherein the first processor coordinates switching of the second optical switch with the second processor by causing the first node to include an OTSP status with the optical signal and the second processor configures a holdover period based at least in part on the OTSP status such that, upon detection of the second failure, the second processor switches the second optical switch after confirming the presence of the second failure after the passage of the holdover period. ### Claim 10 (depends on 9) The optical network of claim 9, wherein first optical switch has a first optical switch settling time being a time period for the first optical switch to switch from the first line port to the second line port, and wherein the holdover period is a predetermined period of time greater than the first optical switch settling time. ### Claim 11 (depends on 9) The optical network of claim 9, wherein the second processor causes the first node to include the OTSP status with the optical signal by causing an optical supervisory channel to include the OTSP status. ### Claim 12 (depends on 7) The optical network of claim 7, wherein the first failure is an optical loss of signal. ### Claim 13 (depends on 7) The optical network of claim 7, wherein the second failure is a loss of frame. ### Claim 14 A node, comprising: a first optical protection switching module including a first line port connected to a first working path, a second line port connected to a first protection path, a system port, and a first processor monitoring optical signals received by the first line port to determine a first failure in the first working path at a first layer within an optical communication model, the first optical protection switching module including a first optical switch coupled to the first line port to receive first optical signals from the first working path and the second line port to receive second optical signals from the first protection path for selectively switching optical signals from the first line port or the second line port to the system port; a second optical protection switching module having a third line port receiving optical signals from the system port of the first optical protection switching module, and a second processor monitoring the optical signals received by the third line port to determine a second failure in the first working path at a second layer within the optical communication model, the second optical protection switching module having a second optical switch controlled by the second processor; and wherein the first processor and the second processor are preconfigured to coordinate switching of the first optical switch and the second optical switch upon detection of the first failure by the first processor, or the detection of the second failure by the second processor. ### Claim 15 (depends on 14) The node of claim 14, wherein the second processor is configured with a holdover period such that upon detection of the second failure, the second processor switches the second optical switch after confirming the presence of the second failure after the passage of the holdover period. ### Claim 16 (depends on 15) The node of claim 15, wherein first optical switch has a first optical switch settling time being a time period for the first optical switch to switch from the first line port to the second line port, and wherein the holdover period is a predetermined period of time greater than the first optical switch settling time. ### Claim 17 (depends on 14) The node of claim 14, wherein the first layer is a physical layer, and the second layer is an optical layer. ### Claim 18 (depends on 14) The node of claim 14, wherein the first failure is an optical loss of signal. ### Claim 19 (depends on 14) The node of claim 14, wherein the second failure is a loss of frame.