Conditions for the MCA board of the BWS 1600G to determine a wavelength loss and report the CHAN_LOS alarm

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Question:
What is the condition for the MCA board to report the CHAN_LOS alarm when wavelength monitoring configurations are correct?
CHAN_LOS
Answer:
The MCA board determines a wavelength loss when it detects the following wavelength conditions:
1. The optical power is lower than -40 dBm.
2. The optical power is greater than 5 dBm.
3. A wavelength exceeds the standard wavelength by ±0.14 nm.
4. The signal-to-noise ratio is smaller than 7.5 dB.
5. If the difference between the maximum and minimum optical power is greater than 10 dB, the MCA board determines that the wavelength with the minimum optical power is lost.

Other related questions:
Wavelength scanning results of MCA boards on BWS 1600G
Generally, the SNR AFEC is around 15. If center wavelength deviation is detected, an alarm is generated.

Nominal single-wavelength input optical power for OA boards on BWS 1600G?
Suggestion: What is the nominal single-wavelength input optical power is determined for OA boards of the BWS 1600G? Answer: Strictly speaking, there is no definition of nominal single-wavelength optical power for OA boards. The optical power is determined as follows: To increase the signal-to-noise ratio, the incident optical power and receive optical power must reach the maximum as possible. A 400G OAU board is used as an example. The maximum incident optical power is 20 dBm and 40 wavelengths are supported. Therefore, the maximum single-wavelength output optical power is 4 dBm. The BA gain is 19 dB, and therefore the single-wavelength input optical power of the BA board is defined to -15 dBm. A VOA and DCM need to be added between PA and BA boards, the minimum VOA attenuation is 3 dB, and the maximum DCM attenuation is 12 dBm. Therefore, the minimum single-wavelength output optical power of the PA board is as follows: -15 + 12 + 3 = 0 (dBm). The C-band gain is 20 dB and the L-band gain is 19 dB, and therefore the maximum single-wavelength input optical power of the PA board is -19 dBm. The attenuation of the maximum span is 36 dB, and therefore the minimum single-wavelength input optical power of the PA board is as follows: 4 - 36 = 32 (dBm). Varying with span reaches, the single-wavelength input optical power of the PA board ranges from -32 dBm to -19 dBm. The gain of a PA board embedded with a Raman amplifier (OAU_R) is 10 dB, and therefore the single-wavelength input optical power is -9 dBm.

Trigger conditions of the CHAN_LOS alarm on OTN equipment
The possible causes are as follows: 1. A monitored wavelength is not received actually. 2. The laser on the related board at the peer-end site is off. 3. Optical power variations of the monitored wavelengths are too large. 4. The multiplexing or amplifier unit connected to the MCA board has an overly large attenuation value. 5. The OTU board in the upstream direction of the MCA board is faulty. 6. The MCA board that reports the alarm is faulty.

Whether an SSE7LWFT01 board on a BWS 1600G supports wavelength tunable optical modules
In the board name, T indicates tunable wavelengths. The SSE7LWFT01 board supports wavelength tunable optical modules.

Command used to configure the wavelength of BWS 1600G
Run the :cfg-set-wavelenexp command to configure the wavelength of BWS 1600G.

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