Single span calibration in a multi-span optical line system
Systems and methods include, responsive for a requirement to calibrate a single span in a multi-span optical line system where the single span includes a from-end node and a to-end node, determining no other upstream node in the multi-span optical multiplex section is currently calibrating or faulted; responsive to no other upstream node currently calibrating or faulted, calibrating the from-end node with a new target launch power into a fiber associated with the single span; and calibrating the to-end node keeping target launch power into a fiber associated with an immediate downstream span from the single span uninterrupted from a previous calibration. The to-end node and the from-end node are each (1) an intermediate line amplifier or (2) a terminal node and an intermediate line amplifier, in the multi-span optical line system.
1 . A method comprising steps of:
responsive for a requirement to calibrate a single span in a multi-span optical multiplex section where the single span includes a from-end node and a to-end node, determining no other upstream node in the multi-span optical multiplex section is currently calibrating or faulted;
responsive to no other upstream node currently calibrating or faulted, calibrating the from-end node with a new target launch power into a fiber associated with the single span; and
calibrating the to-end node keeping target launch power into a fiber associated with an immediate downstream span from the single span uninterrupted from a previous calibration,
wherein the keeping target launch power into a fiber associated with an immediate downstream span includes using a baseline line-out power profile taken on a line-out port from a previous calibration.
2 . The method of claim 1 , wherein the to-end node and the from-end node are each one of (1) an intermediate line amplifier and (2) a terminal node and an intermediate line amplifier, in the multi-span optical line system.
3 . The method of claim 1 , wherein the calibrating the from-end node includes setting the new target launch power based on provisioned or discovered characteristics of the single span.
4 . The method of claim 3 , wherein the characteristics include any of fiber type, span loss, inclusion or exclusion of Raman amplification, and span length.
5 . The method of claim 1 , wherein the calibrating the to-end node includes setting all actuators at the to-end node to the baseline line-out power profile, such that the calibration of the single span does not disrupt any downstream spans.
6 . The method of claim 1 , wherein the calibrating the from-end node and the calibrating the to-end node includes performing Raman gain calibration if present.
7 . The method of claim 1 , wherein the calibrating the from-end node and the calibrating the to-end node includes setting target gain and gain tilt for any Erbium Doped Fiber Amplifiers (EDFAs), running gain-calibration and setting target-gain for Raman amplifiers if present, and setting loss for Variable Optical Attenuators (VOAs).
8 . The method of claim 1 , wherein the calibrating the from-end node and the calibrating the to-end node includes setting Dynamic Gain Flattening Filter (DGFF) attenuation based on cumulative gain-ripples coming from upstream spans.
9 . The method of claim 1 , wherein the requirement to calibrate the single span includes a plurality of discrete or continuous spans in the multi-span optical multiplex section, and wherein the steps include
sequencing a calibration of the plurality of discrete or continuous spans in the multi-span optical multiplex section.
10 . The method of claim 1 , wherein the requirement is one of a user-initiated calibration, subsequent to an Optical Line Fail (OLF) recovery, a change in fiber type or fiber characteristics, a change in span loss, and a change in Raman amplification.
11 . A non-transitory computer-readable medium comprising instructions that, when executed, cause a processing device to perform steps of:
responsive for a requirement to calibrate a single span in a multi-span optical multiplex section where the single span includes a from-end node and a to-end node, determining no other upstream node in the multi-span optical multiplex section is currently calibrating or faulted;
responsive to no other upstream node currently calibrating or faulted, calibrating the from-end node with a new target launch power into a fiber associated with the single span; and
calibrating the to-end node keeping target launch power into a fiber associated with an immediate downstream span from the single span uninterrupted from a previous calibration,
wherein the keeping target launch power into a fiber associated with an immediate downstream span includes using a baseline line-out power profile taken on a line-out port from a previous calibration.
12 . The non-transitory computer-readable medium of claim 11 , wherein the to-end node and the from-end node are each one of (1) an intermediate line amplifier and (2) a terminal node and an intermediate line amplifier, in the multi-span optical line system.
13 . The non-transitory computer-readable medium of claim 11 , wherein the calibrating the from-end node includes setting the new target launch power based on provisioned or discovered characteristics of the single span.
14 . The non-transitory computer-readable medium of claim 11 , wherein the calibrating the to-end node includes setting all actuators at the to-end node to the baseline line-out power profile, such that the calibration of the single span does not disrupt any downstream spans.
15 . The non-transitory computer-readable medium of claim 11 , wherein the calibrating the from-end node and the calibrating the to-end node includes performing Raman gain calibration if present.
16 . The non-transitory computer-readable medium of claim 11 , wherein the calibrating the from-end node and the calibrating the to-end node includes setting target gain and gain tilt for any Erbium Doped Fiber Amplifiers (EDFAs), running gain-calibration and setting target-gain for Raman amplifiers if present, and setting loss for Variable Optical Attenuators (VOAs).
17 . The non-transitory computer-readable medium of claim 11 , wherein the calibrating the from-end node and the calibrating the to-end node includes setting Dynamic Gain Flattening Filter (DGFF) attenuation based on cumulative gain-ripples coming from upstream spans.
18 . The non-transitory computer-readable medium of claim 11 , wherein the requirement to calibrate the single span includes a plurality of discrete or continuous spans in the multi-span optical multiplex section, and wherein the steps include
sequencing a calibration of the plurality of discrete or continuous spans in the multi-span optical multiplex section.