Differentiation of power and channel count changes in optically amplified links

1. A method comprising:

measuring a first parameter from a first signal received at a node;

measuring a second parameter from a second signal received at the node;

comparing the first parameter to a third parameter and the second parameter to a fourth parameter; and

identifying a type of system perturbation based on the comparisons,

wherein the first parameter is a power measurement of the first signal, wherein the third parameter is a baseline power measurement (Pb sig ) of the first signal, wherein the second parameter is a power measurement of the second signal, and wherein the fourth parameter is a baseline power measurement (Pb OSC ) of the second signal.

2. The method of claim 1 , wherein the first signal is an optical signal comprising a plurality of wavelengths and wherein the second signal is an optical service channel.

3. The method of claim 1 , wherein a wavelength count change is identified if the comparison of the first signal power level to Pb sig indicates a change in the first signal power level and the comparison of the second signal power level to Pb OSC indicates substantially no change in the second signal power level.

4. The method of claim 1 , wherein a wavelength count change is identified if the comparison of the first signal power level to Pb sig indicates a change in the first signal power level and the comparison of the second signal power level to Pb OSC indicates an opposite change in the second signal power level.

5. The method of claim 1 , further comprising:

establishing a new output power for an optical amplifier in the node, based on the first parameter, in response to a wavelength count change being identified as the type of system perturbation; and

operating the optical amplifier in the node according to the established new output power.

6. The method of claim 1 , wherein a passive loss is identified if the comparison of the first parameter to the third parameter indicates a change in the first signal power level and the comparison of the second parameter to the third parameter indicates a substantially similar change in the second signal power level.

7. The method of claim 6 , further comprising:

operating an optical amplifier in the node to maintain a previously established constant output power, in response to the comparison of the first parameter and the third parameter being substantially the same.

8. The method of claim 1 , further comprising:

setting a threshold for determining a change in at least one of the comparisons.

9. An optical amplifier node comprising:

signal power detection logic configured to measure a first parameter from a first signal received at a node, and configured to measure a second parameter from a second signal received at the node;

comparison logic configured to compare the first parameter with a third parameter and the second parameter with a fourth parameter; and

identification logic configured to identify a type of system perturbation based on the comparisons,

wherein the identification logic is configured to identify a passive loss if the comparison of the first parameter and the third parameter indicates a change in the input power level of the first signal and the comparison of the second parameter and the fourth parameter indicates a substantially similar change in the input power level of the second signal.

10. The optical amplifier node of claim 9 , further comprising:

amplifier operation logic configured to operate an optical amplifier at the node based on the type of system perturbation identified.

11. The optical amplifier node of claim 10 , wherein the identification logic is configured to identify a wavelength count change, if the comparison of the first parameter and the third parameter indicates a change in the input power level of the first signal and the comparison of the second parameter and the fourth parameter indicates no change in the input power level of the second signal.

12. The optical amplifier node of claim 11 , wherein the amplifier operation logic is configured to establish a new constant power output level for the optical amplifier in response to the wavelength count change being identified as the type of system perturbation and based on the first parameter to maintain a constant power per channel.

13. The optical amplifier node of claim 9 , wherein the amplifier operation logic is configured to operate the optical amplifier in a constant power mode to maintain a previously established constant power output, in response to the first parameter and the third parameter being substantially the same.

14. An optical amplifier node comprising:

signal power processing logic configured to obtain a measurement of a first parameter associated with a first signal received at a node, configured to obtain a measurement of a second parameter associated with a second signal received at the node, and configured to compare the first parameter with a third parameter and the second parameter with a fourth parameter; and

identification logic configured to identify a type of system perturbation based on the comparisons, wherein the identification logic is configured to identify a passive loss if the comparison of the first parameter and the third parameter indicates a change in the input power level of the first signal and the comparison of the second parameter and the fourth parameter indicates a substantially similar change in the input power level of the second signal.