WDM Commissioning Guide-A

HUAWEI TECHNOLOGIES CO., LTD.

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Huawei Confidential

Security Level: internal use only23/4/7

Jiang Luyong 17748

WDM Commissioning Guide

HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential

Forward

Based on the WDM commission, we develop this course. The aim of this course is to help engineers grasp the deployment and commission of WDM products.


Guideline The content of this course is

organized according to OptiX BWS 1600G Debugging and Commissioning Guide.

Before study this course, recommend you to study OptiX BWS 1600G Debugging and Commissioning Guide.

The emphases and difficulty of this course is the optical power Commissioning.


References OptiX BWS 1600G Backbone

DWDM Optical Transmission System Commissioning Guide

OptiX BWS 1600G Backbone DWDM Optical Transmission System Configuration Guide

OptiX BWS 1600G Debugging


Objectives

Upon completion of this course, you will be able to:

Know the operation steps of WDM commission

Understand the characteristic of WDM commission

Master the methods to WDM commission


Contents

Preparation for Commission Commission Requirement and

Method System Commission


Contents Preparation for

Commission Document Preparation Tools Preparation Commission Precaution


Preparation for Commission Document Preparation

Engineering Design Documents, include networking diagram, amplifier configuration diagram, card layout of a cabinet, wavelength distribution diagram, Optical fiber connecting diagram of a cabinet;

Engineering Survey Report: height of antistatic floor and cabling rack in the DWDM equipment room, mounting locations of the equipment in the equipment room, locations of the ODF cabinets on the line side and service side, and routing of fibers as well.

Contract information: know the engineering division, the requirement of equipment function and feature, especially the requirement of commission.

Testing record table: according to the engineering, prepare the testing record table before commission.


Preparation for Commission Tools Preparation

Instrument: Optical spectrum analyzer, optical power meter, Tesgine2500; SDH analyzer, SmartBits meter, and other meter with special service;

Accessories: Fiber jumper used for debugging (two separately for FC/PC-FC/PC,

LC/PC-LC/PC and LC/PC-FC/PC); fixed attenuator (3dB, 5dB, 10dB and 15dB), flange used for

debugging Cassette cleaner or lens tissue used to clean the end faces of fibers. As for important deployment or extension project, we must prepare

Fiber microscope.


Preparation for Commission Commissioning Precautions

Before commissioning, the installation engineer must work out the hardware quality check report. The installation engineer must ensure that the quality of the installation project does not affect later commissioning. In particular, pay attention to how the installation engineer test the installed fibers.

The instruments involved in testing need to be calibrated. The instruments that need to be grounded must be well grounded.

The error introduced by the accessories involved in testing (including fiber jumpers and flange) must be calculated in the test values.

Fibers must be cleaned during the system commissioning process. When you clean the fibers, you must use the special fiber cleaner, and use the fiber microscope to check whether the fiber interface is clean. Use lint-free wipes or (cassette cleaner) to clean the fiber jumper interface. Use the compressed air dedusting agent to clean the female connector.

All paths must be involved in the system commissioning. You need to commission all wavelengths that transmit optical power, to ensure that all paths that are initially configured are in the optimum status.

Record the commissioning data in details (optical amplifier unit, input and output optical power of the OTU).


Question Question:

1. If there are problems with the center wavelengths of multiple OTU boards that we test, what is the most probable problem?

2. Do we need to clean fibers during the WDM system commissioning process?

Answer:

1. The instrument is faulty or is not calibrated. 2. Fibers must be cleaned.


Summary

In this chapter, we have learned:

Document Preparation Tools Preparation Commission Precaution


Contents

Preparation for Commission Commission Requirement and

Method System Commission


Content

Commission Requirement and Method

Optical amplifier unit Optical Transponder Unit Other units


Commission Requirement and Method for Optical Amplifier Unit

1. Commissioning Requirement for Optical Amplifier Unit Optical power

Adjust the average optical power level of input and output wavelengths to or close to the one-channel standard input and output optical power.

Adjust the number of wavelengths that are greater than the average one-channel optical power to be equal to the number of wavelengths that are smaller than the average one-channel optical power.

Adjust the flatness of each one-channel optical power, so that the OSNR of the receive end is flat and meets the design requirement. If the optical power flatness meets the index requirement, the optical power flatness can be sacrificed to guarantee the signal noise ratio.

Definition of one-channel standard optical power The one-channel standard optical power means that one channel should be adjusted to a

value that guarantees the optimum performance. This value is generated based on the OSNR and non-linear balance and is the maximum input and output one-channel optical power that an optical amplifier unit allows.

OSNR requires higher optical power. The higher the optical power, the better the OSNR. Excessive optical power can result in non-linear impact. The lower the input optical power,

the smaller the non-linear impact. The one-channel standard optical power can be calculated based on the maximum optical

power index.


1. Commissioning Requirement for Optical Amplifier Unit Calculation of one-channel standard optical power for optical amplifier unit

Suppose the one-channel standard optical power is S (mW), 10lgS (dBm). Suppose the maximum number of add or drop wavelengths is N for the optical amplifier

unit and the optical power of each wavelength is the same, then Total optical power 10lgNS=10lgS+10lgN ＝ maximum input and output optical power The one-channel standard input and output optical power 10lgS ＝ maximum input and

output optical power - 10lgN, where N is the number of input wavelengths when the optical amplifier unit supports full wavelengths.

For example, the input optical power range of an optical amplifier unit is -32 to -3 dBm and the maximum output optical power is 20 dBm

When the optical amplifier unit supports 40 wavelengths, the one-channel standard input optical power is -3 - 10lg40 ＝ -19dBm

When the optical amplifier unit supports 40 wavelengths, the one-channel standard output optical power is 20-10lg40 ＝ 4dBm

Question: is the number of wavelengths when the system supports full wavelengths equals to the number of wavelengths when the optical amplifier unit supports full wavelengths?

No. For some WDM systems, the number of wavelengths when the optical amplifier unit supports full wavelengths is not equal to the number of wavelengths when the system supports full wavelengths. For example, the C+L band 80-channel system and the C+L band 160-channel system.




Board name

Module

Minimum input optical power (dBm)

Maximum input optical power (dBm)

Input/Outputsingle-wavelength standard power (dBm)10-wavelength

Input/Output single-wavelength nominal optical power (dBm)32-wavelength



Gain (dB)

Maximum output optical power for full wavelength (dBm)

E3OAUC01A/B/C/D(C band)

/ -32 0 / -15/5 -16/4 -19/1 20-33 20


/ -32 -3 / -18/2 -19/1 -22/-2 20-33 17


/ -32 -6 / -21/5 -22/4 -25/1 26-32 20

E3OAUC03E(C band)

/ -32 -4 / -19/5 -20/4 -23/1 24-36 20

1.Commission Requirement and Method for Optical amplifier unit


Board name

Module

Minimum input optical power (dBm)

Maximum input optical power (dBm)

Input/Outputsingle-wavelength standard power (dBm)10-wavelength




Gain (dB)

Maximum output optical power for full wavelength (dBm)

E3OAUC05A(C band)

/ -32 0 / -15/8 -16/7 -19/4 23-36 23

E3OBUC03A/C(C band)

/ -24 -3 / -18/5 -19/4 -22/1 20.5-25.5 20

E3OBUC05A(C band) / -24 0 -15/8 -16/7 -19/4 20.5-25.5 23E3OPUC03C(C band) / -32 -8 / -23/0 -24/-1 -27/-4 20.5-25.5 15Notes: here take the E3OAU/OBU/OPU for example, other boards such as E4/C6 and so on,

the principle is the same.

Commission Requirement and Method for Optical amplifier unit 1.Commission Requirement and Method for Optical amplifier unit


2. Flatness Requirement in Commissioning One-Channel Optical Power

Flatness requirement of one-channel optical power Adjust the optical power of each wavelength to fall inside the range (-2 dB to 2 dB) of

average one-channel optical power. Under special conditions (RAMAN/ROP/ULH has worse OSNR), the index requirement also apply.

If the optical power flatness meet the index requirement, the optical power flatness can be sacrificed to guarantee the flatness of OSNR (or BER).

Method of adjusting one-channel optical power flatness “adjust the transmit end based on the receive end”―monitor the receive end and

adjust the transmit end to ensure optical power flatness at the receive end. The purpose of adjusting the optical power flatness of each wavelength is to ensure that

the OSNR of the receive end is flat and meets the design requirement. If the designed OSNR is not met, the OSNR and flatness need to be further adjusted.

Before an optical amplifier unit is adjusted, ensure that the attenuator of each wavelength has enough tunable range. Set the initial value according to tunable range.

Notes 1. Currently, you can adjust the optical power flatness of each wavelength only when

each wavelength has a tunable attenuator. If not in the case, you can only check, but cannot adjust the flatness of transmitted optical power.

2. After you adjust the one-channel average optical power of an optical amplifier unit, consider to adjust the optical power flatness of each wavelength at the receive end.



3. Method of Commissioning One-Channel Optical Power One-channel input optical power

If the one-channel average input optical power before you add an attenuator is higher than the one-channel standard input optical power, adjust the variable optical attenuator (VOA) to enable the one-channel average input optical power to reach the standard.

If the one-channel average input optical power cannot reach the one-channel standard input optical power, remove the VOA at the input end of the amplifier. In this way, the one-channel average input optical power remains the maximum optical power.

One-channel output optical power Do not adjust the output optical power for optical amplifier units except the

OAU. The one-channel optical power that is output based on fixed gain is the standard optical power.

For the E2OAU, set an EVOA to enable the one-channel output optical power to reach the standard.

If the E3OAU and the C6OAU has an EVOA, set gain ＝ one-channel standard output optical power － adjusted one-channel average input optical power

For the OAU that does not have an EVOA, adjust the VOA of TDC/RDC to enable the one-channel average output optical power to reach the standard.



3. Method of Commissioning One-Channel Optical Power Sample E3OAU commissioning

The input optical power of the E3OAUC03E ranges from － 32 dBm to － 4 dBm, the gain ranges from 24 to 36, and the maximum output optical power is 20 dBm. The E3OAU is used in the OptiX 1600G III model system. If the tested one-channel average input optical power before you add a VOA is －15 dBm, how do you commission the system? If the value is － 25 dBm, how do you commission the system?

PA BA

TDC RDC MON

OUTINEDFA

PIN

VOA

splitter

1

5

2 43VOA

Note: Some OAUs do not have an EVOA. You need to add an MVOA

externally.



3. Method of Commissioning One-Channel Optical Power Sample E3OAU commissioning

The OptiX 1600G III model system is a 40x10G system. The calculated one-channel standard input optical power is － 20 dBm and the output optical power is +4 dBm.

If the one-channel average input optical power before you add a VOA is － 15 dBm, adjust the VOA to enable the one-channel average input optical power to reach

the standard. In this case, the one-channel average input optical power ＝－ 20 dBm, the gain is ＝ 4 － ( － 20) ＝ 24dB.

If the one-channel average input optical power before you add a VOA is － 25 dBm, remove the VOA to enable the one-channel average input optical power to reach

the largest value. In this case, the one-channel average input optical power ＝－25 dBm, the gain is ＝ 4 － ( － 25) ＝ 29dB.

Method of commissioning an OAU without EVOA adjust the VOA to enable the one-channel average input optical power to reach

the standard. Adjust the MVOA to enable the one-channel average output optical power to reach the standard (+4 dBm).



3. Method of Commissioning One-Channel Optical Power Sample E3OBU commissioning

The input optical power of the E3OBUC03 ranges from － 24 dBm to － 3 dBm, the gain is 23 dB, and the maximum output optical power is 20 dBm. The E3OBU is used in the 1600G III model system. If the tested one-channel average input optical power before you add a VOA is － 14dBm, how do you commission the system?

The OptiX 1600G III model system is a 40x10G system. The calculated one-channel standard input optical power － 19 dBm and +4 dBm.

Adjust the VOA to enable the one-channel average input optical power to reach the standard. In this case, the one-channel average input optical power ＝－ 19dBm, and the tested one-channel average output optical power is +4 dBm.

INBA OUT21

OBU diagramVOA



4. Method of Commissioning Total Optical Power Total input optical power

If the total input optical power before you add a VOA is higher than the total standard optical power, adjust the VOA to enable the total input optical power to reach the standard. In this case, the one-channel average input optical power ＝ one-channel standard input optical power.

If the total input optical power cannot reach the total standard input optical power, remove the VOA at the input end of the amplifier, to enable the total input optical power to remain the maximum optical power.

Total output optical power Do not adjust the output optical power for optical amplifier units except the

OAU. The optical power that is output based on fixed gain is the standard optical power.

For the E2OAU, adjust the EVOA to enable the total output optical power to reach the standard.

If the E3OAU and C6OAU has an EVOA, set the gain to enable the total output optical power reach the standard.

For the OAU that does not have an EVOA, adjust the VOA of TDC/RDC to enable the total output optical power to reach the standard.



4. Method of Commissioning Total Optical Power Definition of standard total optical power

The standard total optical power refers to the total optical power when you adjust one channel to reach the standard one-channel optical power.

Calculation of total standard optical power Total standard optical power = one-channel standard optical

power++10lgn+offset The definition of the one-channel standard optical power is the

same as what is described in previous pages n is the number of wavelengths contained in the signal that

accesses an amplifier Offset is the optical power compensation that is added for noise

impact when you use the optical power meter to commission a system. The smaller the number of wavelengths, the lower is OSNR, the larger the compensation value.



4. Method of Commissioning Total Optical Power Theoretical calculation of total optical power

Noise optical power = 10lgN1 = 10lg (40 x 8 x N) = 10lgS (output/input average one-channel optical power of the optical amplifier unit) － 10lgS/N (local OSNR) + 10 x lg8 + 10 x lg40. N1 is the total noise optical power, N is 0.1 nm noise optical power. OSNR defines the noise as 0.1 nm.

Signal optical power = 10LgS1 = 10lgnS = 10lgS (output/input average one-channel optical power of the optical amplifier unit) + 10lgn. n is the current number of wavelengths, S1 is the total signal optical power, and S is the one-channel signal optical power.

Total optical power = 10lg (S1 + N1) offset = 10lg (S1+N1) － 10lgS1 = 10lg (1 + N1/S1), N1=40 x 8 x N, S1=nS offset ＝ 10lg (1 + (40 x 8/n) x N/S) Note: This method can be used to verify the total optical power that is

calculated by using the previous method.



4. Method of Commissioning Total Optical Power Sample offset computation

For example, the one-channel standard output optical power of an optical amplifier unit is adjusted to +4 dBm. The OSNR is 22 dB. Totally there are two wavelengths. What is the total standard output optical power that should be commissioned?

OSNR = 10lgS/N = 22 dB N/S = 0.0063 offset = 10lg (1 +(40 x 8/n) x N/S) = 10lg (1 + (40 x 8/2) x 0.0063) = 3 dB offset is irrelevant to the input and output optical power, but is relevant to OSNR,

amplification range of an optical amplifier unit (for example, 320 nm, 1529 nm-1561 nm, 40 channel x 0.8 nm) and the number of current add/drop wavelengths.

The wavelength range is a fixed parameter for the optical amplifier unit. The higher OSNR, the less offset. The more wavelengths, the less offset.

For 10 channels, offset = 10lg (1+(40 x 8/n) x N/S) = 10lg (1+ (40 x 8/10) x 0.0063) = 0.8 dB



4. Method of Commissioning Total Optical Power Sample E3OAU commissioning

The input optical power of the E3OAUC03E ranges from － 32 to － 4 dBm. The gain ranges from 24 to 36. The maximum output optical power is 20 dBm. The E3OAUC03E is used in the OptiX 1600G III model system and has four wavelengths totally. If the tested total input optical power before you add a VOA is － 9 dBm, how do you commission the system? If the value is－ 20 dBm, how do you commission the system?

PA BA

TDC RDC MON

OUTINEDFA

PIN

VOA

splitter

1

5

2 43VOA

Note: Some OAUs do not have an EVOA.



4. Method of Commissioning Total Optical Power Sample E3OAU commissioning

The OptiX 1600G III model system is a 40x10G system. The calculated one-channel standard input optical power is － 20 dBm and +4 dBm. The empiric value of offset is approximately 1 dB and 1.5 dB. The total standard input and output optical power that are calculated are － 13 dBm and 11.5 dBm. The value can be more correct if the OSNR calculation tool is used.

If the one-channel average input optical power before you add a VOA is － 9 dBm,

you can adjust the VOA to enable the total input optical power to reach the standard value － 13 dBm.

the one-channel average optical power is calculated as the one-channel standard optical power － 20 dBm.

you can set gain = 4 － ( － 20) = 24 dB, and then query the total output optical power and the value is approximately 11.5 dBm.



4. Method of Commissioning Total Optical Power If the total input optical power before you add a VOA is － 20 dBm,

you can remove the VOA to enable the maximum input optical power to be －

20 dBm. the one-channel average input optical power = － 20 － 1 － 10lg4= － 27 dBm. you can set gain = 4 － ( － 27) = 31 dB. After you set the gain, the output

optical power is 11.5 dBm. Limitation of this commissioning method

The offset value is incorrect. As a result, commissioning may be incorrect. You can estimate the offset compensation value by means of OSNR and the

OSNR can be estimated by using the OSNR calculation tool. If the one-channel optical power deviation is large, the estimated offset may

be largely different.



5. Improved Commissioning Method of Total Optical Power Commissioning method by adjusting optical power by attenuation

A. As the OSNR of the input optical power of the optical amplifier unit at the OTM at the initial end is small, you can directly use it to calculate the total standard input optical power = one-channel standard optical power + 10lgN, where N is the number of wavelengths.

B. Adjust the total standard input optical power of the optical amplifier unit in the downstream direction = queried total optical power of the optical amplifier unit in the upstream direction － (one-channel standard optical power of the optical amplifier unit in the upstream direction －one-channel standard input optical power of the optical amplifier unit in the downstream direction). Adjust the VOA to enable the total input optical power in the downstream direction to be the total standard input optical power. If you fail to adjust the value to the standard value, remove the VOA to enable the input optical power to remain the maximum value. Then, you can query the total input optical power in the downstream direction.



5. Improved Commissioning Method of Total Optical Power Commissioning method by adjusting optical power by attenuation

C. The adjusted one-channel input optical power of the optical amplifier unit in the downstream direction = one-channel standard output optical power in the upstream direction － (queried total output optical power of the optical amplifier unit in the upstream direction － queried total input optical power of the optical amplifier unit in the downstream direction)

D. Set gain for the OAU in the downstream direction = one-channel standard output optical power of the optical amplifier unit in the downstream direction － adjusted one-channel input optical power of the optical amplifier unit in the downstream direction = (one-channel standard output optical power of the optical amplifier unit in the downstream direction － one-channel standard optical power in the upstream direction) + (queried total output optical power of the optical amplifier unit in the upstream － queried total input optical power of the optical amplifier unit in the downstream direction).



5. Improved Commissioning Method of Total Optical Power Sample E3OAU commissioning as what is described in the previous page

Query or test that the total output optical power in the upstream direction is 11 dBm.

You should adjust the total standard input optical power = 11 － (4 －( － 20)) = － 13 dBm If the total input optical power before you add a VOA is － 9 dBm,

you can adjust the VOA to enable the total input optical power to reach the standard. The total input optical power is － 13 dBm.

the adjusted one-channel input optical power of the optical amplifier unit in the downstream direction = 4 － (11 － ( － 13)) = － 20 dBm

you can set gain = 4 － ( － 20) = 24 dB you can use the total output optical power as a reference to adjust the

optical power of the optical amplifier unit in the downstream direction.



5. Improved Commissioning Method of Total Optical Power If the total input optical power before you add a VOA is － 20 dBm,

you can remove the VOA. The total input optical power = － 20 dBm the adjusted one-channel input optical power of the optical amplifier unit

in the downstream direction = 4 － (11 － ( － 20)) = － 27 dBm you can set gain = 4 － ( － 27) = 31 dB. You can use the total output

optical power as a reference to adjust the optical power of the optical amplifier unit in the downstream direction.

Difference with the previous commissioning method of total optical power The way of obtaining the standard total optical power is different. The method of calculating the one-channel optical power is different.



One-channel optical power

Total optical power Improved method of total optical power

Instrument Optical spectrum Analyzer

Optical power meter Optical power meter

Duration Long Short ShortCost High Low LowCorrectness High Low MediumImpact of earlier stage commissioning on later stage commissioning

Affected. If earlier stage commissioning is not correctly performed, re-commissioning should be performed on a per-station basis.

Affected. If earlier stage commissioning is not correctly performed, re-commissioning should be performed on a per-station basis.

Not affected. Re-commissioning is performed only for the stations where commissioning is not correctly performed.

Support for bidirectional commissioning on a per-station basis

Not supported Not supported Supported



6. Commissioning Requirement on Optical Power of Raman Amplifier Requirements

The switch gain of a Raman amplifier ≥ 10 dB The gain flatness of each channel should fall inside the 3 dB range. RPC has two pump and RPA has three pump. Amplification is the result of the

functioning of all pump. When the gain is guaranteed, set the pump optical power to a lower value for security.

The working current cannot exceeds the threshold. Before you turn on a pump laser, you need to enable IPA for the purpose of security.

The T2000 disables IPA. You must enable IPA to turn on the pump laser.

Fiber Type(by standard)

P1(power of pump group

1)

P2(power of pump group 2)

G.652/ G.655 24.0 dBm 24.0 dBmG.653 23.0 dBm 22.5 dBm



6. Commissioning Requirement and Method on Optical Power of Raman Amplifier Method of commissioning optical power of Raman amplifier – gain

1. After you connect fibers, when you have not turned on a pump laser, use the optical spectrum analyzer to monitor the MON port on a Raman amplifier and test the optical power of a one-channel signal.

2. Set the pump optical power to a recommended value. You need to set it for two pump groups.

3. Turn on the two groups of pump lasers and read the optical power of the one-channel signal by using the optical spectrum analyzer.

4. Compare the optical power of the one-channel signal when the pump laser is on and that when the pump laser is off, and calculate the switch gain.

5. If the switch gain is less than 10 dB, you can moderately increase the two groups of output pump optical power by 0.1 dB at a time, until the minimum channel switch gain is large than 10 dB.

Note: As you must enable IPA by using the T2000, a direct test on SYS enables IPA and shuts down the Raman pump. As a result, you cannot commission the optical power of the Raman amplifier.

Notes: The working current threshold crossing alarm indicates that you set a high value for the

pump optical power and need to set it to a lower value. The pump optical power that you set cannot generate this alarm. If this alarm is generated and the gain cannot reach the value of 10 dB, you need to shut down the laser and check or replace fibers.



6. Commissioning Requirement and Method on Optical Power of Raman Amplifier Method of commissioning optical power of Raman amplifier – gain flatness

1. After you adjust the switch gain to meet the value of 10 dB, compare the gain flatness of each channel and check whether they fall inside the range of 3 dB. If so, usually you need not adjust the gain flatness.

2. If the gain flatness of each channel exceeds 3 dB, or wavelengths concentrate on a wavelength, and you cannot correctly verify whether the gain spectrum is flat, you need to use ASE spectrum to verify it.

3. After you stop the signals at the transmit end, keep the same pump settings, and turn on the pump laser. Use the optical spectrum analyzer to test the SYS port. The test result is the ASE spectrum.

4. Compare the two wave peaks of 1535 nm and 1560 nm wavelengths in ASE spectrum. See if the optical power of the wave peak of the 1535 nm wavelength is approximately 1.2 dB (0.7 dB to 1.7 dB ) higher than that of the 1560 nm wavelength. If the compared value falls inside this range, you need not adjust the gain flatness.

Note 1: Generally, you need not adjust the gain flatness. This method of adjusting gain flatness cannot be performed by using the T2000 because stopping signals at the transmit end turns off the pump of the Raman board.

Note 2: For the purpose of security, you must use the T2000 to enable IPA before you can turn on the laser. Hence, when you turn on the laser, you must set the IPA auxiliary detection of Raman, to ensure that IPA does not shut down the laser during testing.



6. Commissioning Requirement and Method on Optical Power of Raman Amplifier Method of commissioning optical power of Raman amplifier – gain flatness

1529. 58nm处归零

- 2. 5

- 2

- 1. 5

- 1

- 0. 5

0

0. 5

1

1525 1530 1535 1540 1545 1550 1555 1560 1565

增益谱形ASE谱形

△ 1

△ 2

△ 2 △ 1 0. 7dB－＝

Zero at 1529.58nm

Gain spectrumASE spectrum



6. Commissioning Requirement and Method on Optical Power of Raman Amplifier Method of commissioning optical power of Raman – gain flatness

5. If the optical power of the wave peak of the 1535 nm wavelength is 1.7 dB higher than that of the 1560 nm wavelength, decrease the pump optical power of pump laser group 1 by 0.1 dB and increase the pump optical power of pump laser group 2 by 0.1 dB, until the optical power difference meets the requirement.

6. If the optical power of the wave peak of the 1535 nm wavelength is less than 0.7 dB higher than that of the 1560 nm wavelength, increase the pump optical power of pump laser group 1 by 0.1 dB and decrease the pump optical power of pump laser group 2 by 0.1 dB, until the optical power difference meets the requirement.

7. After you adjust the gain flatness, you need to re-test the switch gain. If the switch gain of all channels cannot be large than 10 dB, you need to re-adjust the switch gain in the way as described previously.

Note: Adjusting the pump optical power of pump laser group 1 changes the optical power of the 1535 nm wavelength. Adjusting the pump optical power of pump laser group 2 changes the optical power of the 1560 nm wavelength.



6. Commissioning Requirement on Optical Power of Raman Amplifier

Raman line requirements The Raman amplifier has a high requirement on the near-end line fiber loss. There

should be no connector in the circumference of 0 km to 20 km except at one end of the ODF. The two ends of fibers at all connection points must be fusion spliced.

Before you use a Raman amplifier, you must use OTDR to test the fibers on the line. It is recommended that the additional loss of the single-point loss event of fibers and cables in the line should meet the following criteria: the single-point additional loss is less than 0.1 dB (G652) or 0.2 dB (G655) in the circumference of 0 km to 10 km; the single-point additional loss is less than 0.2 dB (G652) or 0.4 dB (G655) in the circumference of 10 km to 20 km; the single-point additional loss is less than 0.4 dB in the circumference of 20 km to 30 km; the single-point additional loss is less than 1 dB in the circumference of 30 km to 40 km; the single-point additional loss is less than 2 dB in the circumference of more than 40 km. In addition, the single-point return loss cannot be less than 40 dB.

The fiber connector must be clean. If a spot appears on the fiber connector, the connector may easily be blown out.

The bending radius of a fiber jumper should be more than 4 cm. A large bending radius can blow out the fiber jump.



6. Commissioning Requirement on Optical Power of Raman Amplifier

Commissioning precautions The negative output optical power of a Raman amplifier can be 27 dBm. When you

insert and remove a fiber end, ensure that the laser is off as the laser exposure can cause permanent eye damage.

Currently, Raman amplifiers use backward pump structure. Strong pump lights are accessed to fibers through the input end (line) instead of the output end (SYS).

The Raman amplifier (all amplifier units on release 5.0 NEs) provides the automatic restart function after the laser is off for five minutes. This function must be disabled for Raman amplifiers and HBA high optical power units on the field.

For the purpose of security, you must set IPA by using the latest version of the T2000 before you can turn on the Raman pump lights.

Do not add non-fiber equipment and units, such as an attenuator and fiber jumper, at the input end of SSE1RPA/C.

Use the special APC fiber connector. If you use the PC fiber connector, great reflection can blow out the fiber connector.



7. Commissioning Requirement on Optical Power In the Event of No Amplifier (e.g. CWDM)

Commissioning Requirement on Optical Power In the Event of No Amplification (e.g. CWDM)

You need not commission the optical power in the line for the wavelengths that do not pass the amplifier, and need not ensure the optical power flatness of each wavelength in the line.

If an amplifier is not installed at the local transmit end but one is installed at the opposite receive end, you need to adjust the flatness of launched optical power of each wavelength to a high value as much as possible.

If an amplifier is not installed at the local receive end, you need not use a VOA to adjust the optical power of the dropped wavelengths in the line.

CWDM has no amplifier as CWDM has wide wavelength frequency that results in a high cost to install an amplifier.



Questions Questions

1. The maximum output optical power of an amplifier is 23 dBm. For a 40-channel system, what is the one-channel standard output optical power?

2. What are the main operations for commissioning an amplifier? 3. In the methods of commissioning one-channel optical power, is the one-

channel optical power method refers to the method of testing the optical power of an optical amplifier unit by using the optical power meter in the case of one channel? Is the method refers to the method of querying the optical power of an optical amplifier unit in the case of one channel?

4. Set gain = actual gain of the optical amplifier unit = output optical power of the optical amplifier unit － input optical power of the optical amplifier unit. Is it correct? Set gain = average actual gain of the optical power of current one-channel signal = average one-channel output optical power － average one-channel input optical power. Is it correct?


Summary

In this chapter, we have learned: The commission requirement of OA Three commission methods for OA Example for OA Commission


Contents




1. Commissioning Requirement for OTU Basic commissioning requirements

The input optical power of the OTU must meet the requirement of “receiver sensitivity+3 to overload point － 5”.

The received optical power of the OTU should be in the level of the middle value between the overload point and the sensitivity.

Multiple types of OTU boards should be normalized whenever possible for easy management.

The bit error rate before error correction of an OTU should be less than -7. The value that is less than -11 is better.

Method Test the received optical power of the OTU, and add, change or remove a fixed

optical attenuator according to the requirements on the optical power. Notes

During commissioning, it is forbidden that the optical power that exceeds the overload point is accessed into the receive interface on the OTU. Otherwise, the optical module may be blown out. Exercise caution when you use the OTDR.

When you use the OTDR, you should disconnect the fiber on the opposite ODF. Though the optical power that the OTDR tests is small, the optical power of a pulse signal can transiently be up to 20 dBm. If the optical power that exceeds the overload point is accessed into the local equipment by mistake or the fiber on the opposite ODF is not disconnected, the optical module is easily blown out.

Commission Requirement and Method for OTU


1. Commissioning Requirement for OTU Commissioning requirements on special OTU

The boards (the last letter of a board name is s) that support Super WDM and the same type of boards that do not support Super WDM have inconsistent transmitted waveform due to inconsistent transmitting modules and coding methods. The boards that support Super WDM has a better OSNR tolerance and can be interconnected with the same type of boards that do not support Super WDM. The way of commissioning the optical power for the boards that support Super WDM is the same as the way of commissioning the optical power of other OTU boards. When you use an optical spectrum analyzer to test the optical power, use the special instrument, such as Aglint86145B. The signal peak bandwidth that you need to set is 0.5 nm and the noise RES bandwidth is 0.1 nm.

The way of commissioning the optical power for the OTU boards with FEC/AFEC is the same as the way of commissioning the optical power for the OTU boards without FEC. Be aware that the OTU boards without FEC cannot be interconnected with the OTU boards with FEC/AFEC. The designed OSNR tolerance for the OTU boards without FEC and that for the OTU boards with FEC/AFEC are better.



1. Commissioning Requirement for OTU Commissioning requirements on special OTU

There is no difference in the commissioning requirements and methods for 10G OTU and 2.5G OTU boards. But, the dispersion tolerance that you configure for 10G OTU boards is smaller than that you configure for 2.5G OTU boards. Hence, you need to add DCM for dispersion compensation.

The way of commissioning the optical power for the OTU boards that support GE services is the same as the way of commissioning the optical power for the OTU boards that support SDH services. You need to use smartbits to test bit errors. In addition, set the same auto-negotiation mode for both ends.

The way of commissioning the optical power for the OTU board at the 50 GHz spacing is the same as the way of commissioning the optical power for the OTU board at the 100 GHz spacing. The 50G CRZ signal cannot be directly tested by using the optical spectrum analyzer. Only the integral test method can be used.

The way of commissioning the optical power for the OTU boards with the optical tunable transponder is the same as the way of commissioning the optical power for other OTU boards. You can use the T2000 to set wavelengths.




OTU

2.5GPIN:7dB

7CLIENT

OTU

10GPIN:7dB

7CLIENT

OTU

2.5GAPD:15dB

15CLIENT

OTU

10GAPD:10dB

10CLIENT

OTU

Multi-mode:

CLIENT

RX OUTSingle-mode:

M40&MB2/MR2

M40&MB2/MR2

M40&MB2/MR2

M40&MB2/MR2

M40&MB2/MR2

The configuration rules of the optical attenuators on the client-side optical interfaces on the OTU refer to the notes of this slide.



IN TX

D

4

0

OTUAPD:15dB15 CLIENT

OTUPIN:7dB

CLIENT

OTUAPD:15dB

15

OTUPIN:7dB

OTU

OTU

RX OUT

IN OUT

M

4

0OAU

7

7

2

2

As for WDM side in 1600G OTM, the configuration rules of the optical attenuators are as follows:An Optical Amplifier Unit is required for pass-through wavelengths added currently or in the future. Fixed attenuators are not needed between OA and D40, while they are required on receiving port of OTU at WDM side: 15 dB is added for APD and 7 dB is for PIN..As for WDM side in 6100 OTM, a tunable attenuator is needed on each pass-through wavelength as well as on added wavelength.



OTU in BWS 1600GReceiver

sensitivity (dBm)

Receiver overload

(dBm)

Output optical

power(dBm)

The scope of Input optical power (dBm)

LWCLWC1

DWDM Side ORP:-18 ORP:0 -10~0 -12~-6ORA:-28 ORA:-9 -10~0 -22~-16

Client side

I-16 ORP:-18 ORP:-3 -10~-3 -14~-8S-16.1 ORP:-18 ORP:0 -5~0 -12~-6L-16.1 ORA:-27 ORA:-9 -2~3 -22~-16L-16.2 ORA:-28 ORA:-9 -2~3 -22~-16

LWFLWFS

DWDM Side

100GHz ORP:-14 ORP:0 -5~0 -10~-650GHz ORP:-14 ORP:-1 -5~0 -10~-6CRZ ORP:-16 ORP:0 -5~0 -12~-6

Client side

I-64.1 ORP:-11 ORP:0 -6~-1 -8~-4I-64.2 ORP:-14 ORP:0 -5~-1 -10~-6S-64.2b ORP:-14 ORP:0 -1~2 -10~-6S-64.2a ORA:-18 ORA:-8 -1~2 -15~-11


Contents




Commission Requirement and Method for Other Boards1. Optical Supervisory Channel processing board (SC1/SC2/TC1/TC2)

Commission requirements To meet the requirement of processing the supervisory information, you need to set the

local clock of the SCC on an NE as the clock source of the entire network. The communication between the OSC/OTC and the SCC of other NEs must be synchronous with the clock.

The received optical power should not be close to the over loading point. The OSC processing board inside the site should be connected with 15dBm attenuation.

Orderwire settings Orderwire settings, conference call ring releasing, express orderwire

Output Optical Power

Output Optical Central Wavelength

Receiver Sensitivity

Overloaded Optical Power

-7–0dBm 1500nm–1520nm -48dBm -3dBm


Commission Requirement and Method for Other Boards2. OMU/ODU, optical component

Commission requirement These boards do not have special requirements for the received optical power. But

in case of any problems, other boards such as optical amplifier board, are affected. Check each channel to find the incorrectly connected fiber jumpers, and check

whether the lines on the optical channels and whether the insertion loss and attenuations of the optical components are normal.

Board & Port Insertion Loss Board & Port Insertion LossMR2: IN － DROP <2.5dB MB2 : IN － DROP <3dBMR2: ADD － OUT <2.5dB MB2 : ADD － OUT <3dBMR2: IN － MO <3dB MB2 : IN-MRO ， MRI-

OUT<2dB

MR2: MI － OUT <3dB MB2 : IN-BMO ， BMI-OUT

<1dB

FIU: IN － TM <1.5dB M40 <10dBFIU: IN － TC <1.5dB D40 <10dBFIU: RM － OUT <1.5dB Fiber connector <0.5dB/pieceFIU: RC － OUT <1.5dB ITL <3dB


3. Line board Commission method

The fiber connection from FIU-OUT to ODF, and the one from downstream ODF to FIU-IN are connected by installers who are responsible for the quality of the connection.

The optical power from FIU-RC through FIU-TC should be smaller than the planned attenuation. If the value exceeds the planned attenuation, you need to use the optical power tester to test the following section by section: FIU insertion loss, fiber-routing attenuation, connected ring flange attenuation, and cable attenuation.

For a fiber/cable problem, request the customer to change the fiber core or rectify it.

Commission Requirement and Method for Other Boards


Commission Requirement and Method for Other Boards

Notes: The planned attenuation is a reference value that allows for specific margins, which is provided based on the information provided by customers. Usually, the actual attenuation is smaller than the planned attenuation. Only in this case, can the planned SNR be ensured. Hence, you need to check the actual attenuation and the planned attenuation during the commissioning.

FIU

FIU

A B

Ring flange of line-side ODF, in

between is a optical fiber/cable

OUT INRC TC


Questions

Questions

Question 1: How much optical power should be commissioned for WDM-side 2.5G APD and 10G PIN?

Question 2: If the receive range of a board is 0 ~ -18 dBm, and the at the received end of the interconnected SDH equipment, the optical power is -2 dBm, how much dB should be the fixed attenuator?

Question 3: Which part of the attenuation does the attenuation planned by the market telecom refers to?


Summary

In this chapter ,we have learned:

Commission Requirement and Method for Optical amplifier unit, Optical Transponder Unit, and Other units


Contents

Preparation for Commission


System Commission


Contents

System Commission OTM Commission OLA Commission OADM Commission ROADM Commission


Typical Network and application of WDM product


System Commission

F

I

U

OBU

OAU

SC1/TC1

MCAMON

DCM

TM

RM

RM

TM

OUT

IN

RC

TC

IN

TDC

RDC

OUT

MON

D40

D01

D40

IN

M40

M01

M40

OUT

LWF

MON

M02 LWF

LWF

OUTRx

LWFD02 LWF

LWF

INTx

5dBOut line ODF

ClientODF

OUTIN

VOA

FOA

ODF

Fiber

1.OTM Commission


OTM Commission 1. Optical power commission for OTM

The output optical power commission for OTM

－ 2dBm － 9dBm － 2dBm 6dB -19dBm +4dBm 1dB +3dBm

LWF M40 OBU FIUSDHRX OUT M01 OUT IN OUT RC RM OUT

1 1 2 3 3 4 5 6 6 6

SC1 6

LWF M40 OBU FIUSDHRX OUT M01 OUT IN OUT RC RM OUT

1 1 2 3 3 4 5 6 6 6

SC1 6

－ 2dBm － 9dBm － 2dBm 6dB -19dBm +4dBm 1dB +3dBm

Note: Different from the 1600G, the commission for Metro 6100 is dedicated to each wavelength.


OTM CommissionStep

Actions in commissioning OTM transmit optical power

1 Test the optical power of the interconnected SDH equipment of the ODF. The optical power is -2dBm. Be informed that the client-side of the LWF is the PIN receive optical module, and the optical power should between -6 and -12dBm. Add 7dB fixed attenuation. The tested optical power of the LWF-RX is -9dBm.Operations in this step can be performed during the service cutover.

2 After the SDH signals are access or after the lights are forced to emit, test the optical power of LWF-OUT to see whether the optical power is normal.

3 Test the optical power of M40-M0/M40-OUT. The typical insertion loss of M40 is about 6dB.

4 Test the optical power of OBU-IN. Adjust the VOA to set the average single-wavelength optical power of OBU-IN to -19dBm (OBU-3 single-wavelength standard optical power).

5 Test the optical power of OBU-OUT. The average single-wavelength optical power is about =4dBm.

6 Test the optical power of FIU-RC/FIU-OUT/ SC1-TM/FIU-RM and ODF to set whether the FIU insertion loss and fiber jumper attenuation are normal.

Note: Only the optical power described in step 1 and 4 can actually be adjusted. Other operations are performed to ensure the normal test of the fiber and boards. Attentions are paid to the optical power commissioning of LWF-IN/LWF-OUT/OBU-IN/OBU-OUT.


OTM Commission 1.Optical power commission for OTM

The input optical power commission for OTM

－ 2.5dBm － 2dBm － 9dBm 6dB +4dBm － 20dBm -16dBm 1dB － 15dBm

－ 2.5dBm － 2dBm － 9dBm 6dB +4dBm -24dBm 1dB － 23dBm

LWF D40 OAU FIUSDHTX IN D01 IN OUT IN TC TM IN

6 6 5 4 4 3 2 1 1 1

SC1 1

DCM

LWF D40 OAU FIUSDHTX IN D01 IN OUT IN TC TM IN

6 6 5 4 4 3 2 1 1 1

SC1 1

DCM


OTM CommissionStep

Actions of OTM receive optical power commission

1 Test the optical power of the line ODF/FIU-IN/FIU-TC/FIU-TM/SC1-RM. The attenuation=upstream FIU-RC optical power-local FIU-TC optical power=28dB. The value is smaller than the planned attenuation (30dB), which indicates that the line attenuation, FIU, and the fiber connected are all normal.

2 Test the single-wavelength optical power of FIU-TC. The tested value is -24dBm, smaller than -20dBm (E3OAUC03E standard single-wavelength input optical power). Remove the VOA, use the short fiber jumper to directly connect FIU-TC/OAU-IN.

3 Set the gain. (The gain=4-(-24) ＝ 28dB) Test the average single-wavelength optical power of OAU. The value is +4dBm.

4 Test the optical power of the D40-IN/D40-D0 optical ports.5 Test the optical power of LWF-IN. The value is -2dBm. Add 7dBm fixed attenuation,

so that the optical power is -9dBm, meeting the required value between -6 － -10dBm.

6 Test the optical power of LWF-TX. Test the optical power of the client-side ODF (The received optical attenuation at the client equipment is provided and added by the customer).

Note: Except in step 2, 3 and 5, the operations in other steps are performed to test whether the line, fiber jumper and board are normal. If they are all normal, you can skip the corresponding operations.


OTM Commission

F

I

U

O

B

U

O

A

U

TC2TM

RM

RM2

TM2

IN

RC

TCIN

TDC

RDC

OUT

MON

D01

D40

IND40

M01

M40

OUT

LWF

MON

M02 LWF

LWC

OUTRx

LWFD02 LWF

LWC

INTx

LWF

LWF

LWC

TxIN

LWF

LWF

LWC

RxOUT

D40

O

B

U

OUTINOUT

MON

F

I

U

TM

RM

RC

TC

O

A

U

RDC

MON

TDC

TM1

RM1

IN

15dB

OUTINOUTIN

TC2RM2

TM2

TM1

RM115dB

VOA DCM

DCM

OUT

OUT

D05

D12 M13 D01M02

D05

D06D06

D12M13M02

D01

IN

D01

M01

M40

M40

FOA

ODF

1. 2OTM in 1600G


OTM Commission

D40

F

I

U

O

B

U

O

A

U

SC2TM

RM

RM2

TM2

IN

RC

TCIN

TDC

RDC

OUT

MON

D01

D40

IN

M01

M40

OUT

LWF

MON

M02 LRF

OUTRx

LWFD02

INTx

LWFTxIN

LWF

LRF

RxOUT

D40

O

B

U

OUTINOUT

MON

F

I

U

TM

RM

RC

TC

O

A

U

RDC

MON

TDC

TM1

RM1

IN

15dB

OUTINOUTIN

SC2RM2

TM2

TM1

RM115dB

VOA DCM

DCM

OUT

OUT

D05

D12 M13 D01M02

D05

D06D06

D12M13M02

D01

IN

D01

M01

M40

M40

FOA

ODF

D02

M02

M40

D40

1. 2OTM in 6100


Questions Questions

1. If the fiber/cable is normal and no fault occurs on the board, what operations should be performed to commission the OTM optical power?

2. If the average single-wavelength optical power received at FIU-TC is -16dBm, how to adjust the optical power?

3. Are there any differences between the OTM commissioning for the Metro 6100 and for the Metro 1600G?

4. In the previous example, the optical power commissioning is on a single wavelength basis. If no spectrum analyzer is available, how to perform commissioning based on the total optical power?


Contents System Commission

OTM Commission OLA Commission OADM Commission ROADM Commission


OLA Commission

F

I

U

F

I

U

OBU

OAU

DCM

SC2/TC2

OUT

RM RM2

RMRM1TM

TM1 TM

TM2

RC

MON

OUT

IN

IN

MON

IN

RDC

TDC

DCM

OUT IN OUT

RDC

TDC

TCRC

TC

INOUT

MON

D05 D09

D01 D03

OAUD12


OLA Commission 1. OLA optical power commission

OLA optical power commission Site B (CBA direction) two wavelengths/32dB attenuation

(including FIU insertion loss). The calculated OSNR is as follows: the output OSNR of the OBU at the upstream site C is 33dB. The output OSNR of the local OAU is 24.13dB. The output OSNR of the OUB at site A is 23.6dB.

FIU OAU DCM FIU

IN TM TC IN OUT IN OUT RC RM OUTSC1

OBU

-28 +4 － 19 +4

FIU OAU DCM FIU-24.7 +9.1 -13.9 +9.3

OBU


OLA CommissionStep

Actions of OLA Optical Power Commissioning － (Single Wavelength Optical Power Commissioning)

1 Test the optical power of the line ODF/FIU-IN/FIU-TC/FIU-TM/SC2-RM1. The attenuation=upstream FIR-RC optical power-local FIU-TC optical power=32dB. This value is smaller than 33dB, the planned attenuation. This fact indicates that the line attenuation, FIU, and the connected fiber are all normal.

2 Test the single wavelength optical power of FIU-TC. The value is -28dBm, smaller than -20dBm (E3OAUC03E standard single wavelength input optical power). Remove the VOA and use the short fiber jumper to directly connect the FIU-TC/OAU-IN.

3 Set the gain as follows: 4- (-28) ＝ 32dB. Test the single wavelength optical power at OAU. The tested output single wavelength optical power should be between 3.5 and 4.5dBm.

4 Adjust the VOA in front of the DCM so that the average input single wavelength optical power of the OBU is -19dBm.

5 Test the average single wavelength optical power of OBU-OUT. The value is around =4dBm.

6 Test the optical power of FIU-RC/FIU-OUT/ SC2-TM2/FIU-RM and ODF to see whether the FIU insertion loss and the fiber jumper attenuation are normal.

Note: The OLA optical power commissioning is the same as the commissioning for the OAU, FIU, and line of the OTM. In case the fiber jumper quality is ensured, the commissioning is mainly for the optical power of the OAU.


OLA CommissionStep

Actions of OLA Optical Power Commissioning － (General Wavelength Optical Power Commissioning)


2 Calculate the single wavelength optical power of OAU-IN. The evaluated offset = 0.3dB. The general standard optical power = -20+10lg2+0.3 = -16.7dBm. The tested FIU-TC optical power is -24.7dBm, smaller than -16.7dBm. Remove the VOA in front of the OAU.

3 Calculate the average single wavelength optical power of the OAU-IN. The value = 24.7 － 10lg2 － 0.3 = -28dBm. Set the gain as follows: 4 － (-28) ＝ 32dB. Then the tested output is 9,1dBm, compliant with the calculated offset, which is 2.1dB.

4 Calculate the standard general optical power of OBU-IN as follows: -19+10lg2+2.1 = -13.9dBm. Adjust the VOA in front of the DCM so that the optical power of OBU-IN is -13.9dBm.

5 Test the average single wavelength optical power of OBU-OUT. The value is around =9.3dBm.

6 Test the optical power of FIU-RC/FIU-OUT/SC2-TM2/FIU-RM and ODF to see whether the FIU insertion loss and the fiber jumper attenuation are normal.


OLA CommissionStep

Actions of OLA Optical Power Commissioning － (Improved General Wavelength Optical Power Commissioning)


2 The output optical power of the upstream is 7.3dBm. The local standard general optical power is 7.3 － (4 － (-20)) ＝ -16.7dBm, and the tested FIU-TC optical power is -24.7dBm, smaller than -16.7dBm. Remove the VOA in front of the OAU.

3 Calculate the average single wavelength optical power of OAU-IN as follows: 4 －(7.3 － 24.7) = － 28dBm. Set the gain as follows: 4 － (-28) ＝ 32dB. The tested output is 9.1dBm.

4 Calculate the standard general optical power of OBU-IN as follows: 9.1 － (4 － (-19) ＝ -13.9dBm. Adjust the VOA in front of the DCM to set the optical power of OBU-In to -13.9dBm.

5 Test the average single wavelength optical power of OBU-OUT. The value is around =9.3dBm.

6 Test the optical power of FIU-RC/FIU-OUT/SC2-TM2/FIU-RM and ODF to see whether the FIU insertion loss and the fiber jumper attenuation are normal.


OLA Commission The commissioned single wavelength input optical power of

downstream OAU = upstream output standard single wavelength optical power － (queried general output optical power of upstream OAU － queried general input optical power of downstream OAU).

Downstream OAU gain = standard single wavelength output optical power of downstream OAU － commissioned single wavelength input optical power of downstream OAU = (standard single wavelength output optical power of downstream OAU － standard single wavelength output optical power of upstream OAU) + (queried output general optical power of upstream OAU － queried input general optical power of downstream OAU)


Questions 1. Can the DCM position and the VOA position be exchanged between?

Why? 2. Can the DCM configured for OAU+OBU be placed between the TDC

and RDC of the OAU? 3. How to use the three ways of commissioning to practice the optical

power commissioning from ABC. Suppose four wavelengths are available, and the output OSNRs of the four OAU are respectively 33dB, 30dB, 23.6dB, and 23.13dB.

Questions


OADM Commission

F

I

U

O

B

U

OAU

TC2TM

RM

RM2

TM2

OUT

IN

RC

TC

IN

TDC

RDC

OUT

MON

IN

OUTMON

OBU

OUT

INOUT

MON

F

I

U

TM

RM

RC

TC

OBU

MON

TM1

RM1

OUT

IN

OUTINOUTINM

R

2

M

R

2

M

R

2

M

R

2

LWX

LWX

IN

MI

MO

OUT

IN

MI

MO

MO

MI

IN

OUT

MO

LWX

LWX

LWX

LWX

LWX

LWX

5dB

DCM

DCM

VOA

FOA

ODF

Fiber


OADM Commission 1. OADM optical power commission

On station E (FED direction), four wavelengths are added/dropped, and four are passed through. The output OSNR of the receive OAU is 25.86dB. The optical power commissioning for FIU/ODF and SC2 is the same as that for the OLA. The optical power commissioning for the OUT to ODF direction is the same as the OTM optical power commissioning. Other parts are illustrated in the following figure.

Note: 1.The VOA between the OAU and OADM is available for the Metro 1600G, but not the Metro 6100. 2. You need to add fixed attenuation for the drop wavelength of the PIN of the Metro 6100G, but not the Metro 1600G.

OAU MR2 MR2 OBUOUT IN MO IN MO MI OUT MI OUT IN MR2MR2

LWF

LWF

LWF

LWF

LWF

LWF

LWF

LWF

－ 6 dBm－19dBm


OADM CommissionStep Actions of OADM Optical Power Commissioning － (Single

Wavelength Optical Power Commissioning)1 Adjust the VOA of the receive OAU and OADM so that for the OADM, the optical

power of the drop wavelength that has the smallest insertion loss is -6dBm. (Metro 6100 does not have the attenuator, and needs not to be adjusted.)

2 Test the optical power of the drop wavelength from LWF-IN. The largest optical power is -6dBm and others are about -6.5dBm, -8dBm, and -8,5dBm. If the wavelength dropped from the OUT is received by APD, you need to add 10dBm attenuation. (For the Metro 6100, you need to add the fixed attenuation, and add a 10dBm attenuator for LWF. The input optical power of LWF is about -8dBm.)

3 Use the spectrum analyzer to test the single wavelength optical power of the OBU-IN. Adjust the VOA between the west and east OADMs so that the average single wavelength optical power of the pass-through wavelengths is -19dBm (standard OBU single wavelength optical power) at the transmit OBU-IN.

4 Adjust the VOA between the MR2 and each LWF-OUT with wavelengths added so that the single wavelength optical power of each added wavelength is -19dBm on the OBU-IN.

Merit You can use the MON port of the OAU to perform the commission without interrupting the signals of the wavelengths dropped, added and passing through the local NE. You do not need to calculate the Offset.

Defect A spectrum analyzer is required.


OADM Commission

Note: The single wavelength optical power of the pass-through wavelengths can be a bit higher than the added wavelength. The final average single wavelength optical power is -19dBm. Why?

To equalize the OSNR, you can elevate the OSNR because the optical power of pass-through wavelengths are comparatively low.


OADM Commission


LWF

LWF

LWF

LWF

LWF

LWF

LWF

LWF

－ 6 dBm－19dBm


LWF

LWF

LWF

LWF

LWF

LWF

LWF

LWF

－ 6 dBm－12.3dBm

Adjust this VOA

Adjust this VOA


OADM CommissionStep Actions of OADM Optical Power Commissioning － (General

Optical Power Commissioning)1 Adjust the VOA of the receive OAU and OADM so that for the OADM, the optical

power of the drop wavelength that has the smallest insertion loss is -6dBm. (Metro 6100 does not have the attenuator, and needs not to be adjusted.)

2 Test the optical power of the drop wavelength from LWF-IN. The largest optical power is -6dBm and others are about -6.5dBm, -8dBm, and -8,5dBm. If the wavelength dropped from the OUT is received by APD, you need to add 10dBm attenuation. (For the Metro 6100, you need to add the fixed attenuation. Add a 10dBm attenuator for LWF. The input optical power of LWF is about -8dBm.)

3 Disconnect the add-wavelength fiber or shut down the add-wavelength LWF laser. Adjust the VOA between the east and west OADMs so that the optical power of the pass-through wavelength at the transmit OBU-IN is -12.3dBm, which is calculated as follows: -19+10lg4+0.7= -12.3dBm.

4 Disconnect the fiber between the east and west MR2s. Each time only enable the WDM-side laser of the LWF of one wavelength. Adjust the VOA between the add-wavelength LWF-OUT and the MR2 so that the optical power of OBU-IN is -19dBm.

Merit No spectrum analyzer is required.Defec

tThe Offset may not be precise. To calculate the Offset, you need the OSNR value, and need to shut down the add-wavelength laser and the pass-through wavelength at the local station.


OADM CommissionStep Actions of OADM Optical Power Commissioning － (Improved General Optical

Power Commissioning)1 Adjust the VOA of the receive OAU and OADM so that for the OADM, the optical power of the drop

wavelength that has the smallest insertion loss is -6dBm. (Metro 6100 does not have the attenuator, and needs not to be adjusted.)

2 Test the optical power of the drop wavelength from LWF-IN. The largest optical power is -6dBm and others are about -6.5dBm, -8dBm, and -8,5dBm. If the wavelength dropped from the OUT is received by APD, you need to add 10dBm attenuation. (For the Metro 6100, you need to add the fixed attenuation. Add a 10dBm attenuator for LWF. The input optical power of LWF is about -8dBm.)

3 Shut down the local laser used for wavelength drop from the upstream station, and test the OAU output optical power, which is 10.7dBm. Disconnect the add-wavelength fiber or shut down the add-wavelength LWF laser. Adjust the VOA between the east and west OADMs so that the optical power of the pass-through wavelength at the transmit OBU-IN is -12.3dBm, which is calculated as follows: - 10.7 － (4 － (-19)) ＝ -12.3dBm.

4 Disconnect the fiber between the east and west MR2s. Each time only enable the WDM-side laser of the LWF of one wavelength. Adjust the VOA between the add-wavelength LWF-OUT and the MR2 so that the optical power of OBU-IN is -19dBm

Merit To calculate the Offset, you neither need the OSNR nor the spectrum analyzer.

Defect

You need to shut down laser used to drop the wavelength from the upstream, and shut down the add-wavelength laser and the pass-through wavelength at the local station.


Questions Question

1. If there is temporarily no pass-through wavelength on an OADM, can the pass-through VOA of the east and west MR2s not be adjusted, or can it be directly connected with a fiber?

2. If there are two channels of add/drop wavelengths and two channels of pass-through wavelengths, but four wavelengths are tested at the east MO. Why does this happen considering there should only be two wavelengths passing through?


ROADM Commission

FIU

FIUTo D

IN

OUT

To F

OUT

IN

Site E

SC2RM1

TM1RM

TM RMTM2

TMRM2

OBUOUT OUT

OUT IN OUTOUT

TC

RCININ

INRC

OBU OAU

OBU

TDCRDC

DWC DWCINTC OUT

DCM

D40

LWF

LWF

LWF

LWF

D40

MO

MI

MI

MO

DROP ADD DROP

West East

M40 M40

ADD

ROADM in OptiX BWS 1600G


ROADM Commission

ROADM in OptiX OSN 6800

FIU

FIUTo D

IN

OUT

To F

OUT

IN

Site E

SC2RM1

TM1RM

TM RMTM2

TMRM2

OBU1OUT OUT

OUT IN OUT OUT TC

RCININ

INRC

OBU1 OAU1

OBU1

TDCRDC

ROAM ROAMINTC OUT

DCM

D40

LQM

L4G

LQM

L4G

D40

EXPO

EXPI

EXPI

EXPO

DMM01

DMM01

West East


ROAM Commission

… …

…EXPI

EXPO

OUT

IN

DM

Mn

40

ROAM

Coupler

ROAM board of OSN 6800 DWC board of 1600G Inside a ROAM board is actually a PLC ROADM plus a coupler that is used to implement the

optical power division. One channel is dropped at the local site, and the other channel is transmitted to the opposite ROAM. The PLC ROADM in the ROAM controls the pass-through optical signals.

The PLC ROADM in the ROAM board has the power detection function. So the optical power detection and MON port are not configured. The embedded optical power detection function detects the optical power of each channel at the in port and the out port.

The VOA in the PLC ROADM component equalizes the optical power.


ROADM Commission

1. ROADM optical power commission － DWC+DWC Two added or dropped wavelengths/two pass-through wavelengths. The

optical power commissioning for the FIU/ODF and for SC2 is the same as that for the OLA. The optical power commissioning for the OTU to ODF is the same as that for the OTM. The commissioning for the receive OAU is the same as that for the OLA. The parts using different ways of commissioning are shown in the following figure.

Note: Currently, only the 1600G supports the DWC.

OAU OBUOUT IN MO MI OUT IN DWCDWC

LWF

LWF

<4dB －19dBm

D404dBm <8dB 6.5dB

<12dB

M40

LWF

LWF

6.5dB <4dB


ROADM CommissionStep

Actions of ROADM Optical Power Commission －DWC+DWC

1 Dispatch wavelengths. Set congestion for the wavelength to be dropped, and set pass-through for the pass-through wavelengths. (Note: Set these attributes at the receiving direction of the DWC.)

2 Connect the optical power to the fiber jumper of the IN port of the west LWF and do not add optical attenuation to the PIN. In this case the WDM-side input optical power of the OTU is 4-6-6 = -8dBm. Add 10dBm optical attenuation for the ADP and the WDM-side input optical power of the OTU is 4-6-6-10 = -18dBm, which meets the requirement for the optical power.

3 Test the optical power of the IN port of the OBU and set attenuation for the wavelengths passing through the DWC so that the tested single-wavelength optical power is -19dBm.

4 Test the optical power of the IN port of the OBU and adjust the VOA between the M40 and DWC so that the tested optical power of an added single wavelength is -19dBm.


ROADM Commission 1. ROADM optical power commission － ROAM+ROAM

Two added or dropped wavelengths/two pass-through wavelengths. The optical power commissioning for the FIU/ODF and for SC2 is the same as that for the OLA. The optical power commissioning for the OTU to ODF is the same as that for the OTM. The commissioning for the receive OAU is the same as that for OLA. The parts using different ways of commissioning are shown in the following figure.

Note: Currently only the NG WDM supports ROAM.

OBU1 OBU1OUT IN EXPO EXPI OUT IN ROAMROAM

L4G

LQM

<14dB －19dBm

D40

L4G

LQM

4dBm <7dB <6.5dB

<3dB



Actions of ROADM Optical Power Commission －ROAM+ROAM

1 Create fiber connections on the T2000.2 On the T2000, create optical cross-connections from the west FIU to

the east FIU and optical cross-connections from the east transmit end of OTU to the east FIU.

3 Set the rated optical power at the IN port of the east transmit end of OBU to -19dBm (typical input single-wavelength optical power of OBU1). The system automatically sets the pass-through wavelength and the add wavelength at the ROAM-OTU to -19dBm.

4 Connect the optical power to the fiber jumper of the IN port of the west OTU and do not add optical attenuation to the PIN. In this case the WDM-side input optical power of the OTU is 4-6-6 = -8dBm. Add 10dBm optical attenuation for the ADP and the WDM-side input optical power of the OTU is 4-6-6-10 = -18dBm, which meets the requirement for the optical power.


ROADM Commission

Site E

West East


ROADM Commission 1. ROADM optical power commission － WSM9+WSD9

Two added or dropped wavelengths/two pass-through wavelengths. The optical power commissioning for the FIU/ODF and for SC2 is the same as that for the OLA. The optical power commissioning for the OTU to ODF is the same as that for the OTM. The commissioning for the receive OAU is the same as that for OLA. The parts using different ways of commissioning are shown in the following figure.

OBU1 OBU1OUT IN EXPO EXPI OUT IN WSM9WSD9

L4G

LQM

－19dBmD40 M40

L4G

LQM

L4G

LSR

L4G

LQM

4dBm

<8dB <8dB

<8dB <8dB


ROADM CommissionStep Actions of ROADM Optical Power Commission － WSD9+WSM9

(NG WDM)1 On the T2000, create optical cross-connections from the west FIU to

the west FIU, optical cross-connections from west FIU to east FIU, and optical cross-connections from the east transmit end of OTU to the east FIU.

2 Set the optical power at the OUT port of the west receive end of the OAU1 to 4dBM (standard single-wavelength output optical power). Set the rated optical power at the IN port of the east transmit end of the OBU1 to -19dBm (standard single-wavelength input optical power). Set the receive optical power of the OTU that drops wavelengths to -8dBm (The allowed margin is base on the optical power commissioning requirements).

3 WSD9 and WSM9 automatically adjust the optical power of the wavelengths dropped from the east OTU, added to the east OTU and passing through from the east. In this way the average input optical power at the IN port of the east transmit end of OBU1 and the receive optical power of the drop-wavelength OTU meet the requirement.



Actions of ROADM Optical Power Commission － WSD9+WSM9 (1600G)

1 Test the input optical power of the LWF-IN. Set the drop-wavelength EVOA of the WSD9 so that the tested value is about -8dBm.

2 Test the optical power at the IN port of the east transmit end of the OBU and adjust the attenuation of WSD9/WSM9 so that the tested optical power of the pass-through wavelengths is -19dBm. (Set the EVOA attenuation.)

If no spectrum analyzer is available, congest the added wavelength to test the IN optical power of the OBU. Meanwhile, reduce or increase the attenuation of the pass-through wavelengths of WSD9/WSM9 so that the optical power matches the calculated general optical power (the same as the OADM commission).

3 Test the optical power at the IN port of the east transmit end of the OBU and adjust the attenuation of WSM9 so that the tested optical power of the added wavelengths is -19dBm. (Set the EVOA attenuation.)If no spectrum analyzer is available, congest the pass-through wavelength to test the IN optical power of the OBU. Meanwhile, reduce or increase the attenuation of the added wavelengths of WSM9 so that the optical power is -19dBm.Restore the original configurations.


ROADM Commission

－19dBm

West East


ROADM Commission

Site E

West East


ROADM CommissionEXPI OUT

MI

MO

AddRMU

MON

MON

When the RMU is used for inter-ring interconnection, only the Add to MO section is involved. Hence, if the WSS+RMU is used in inter-ring interconnection, the default pass-through port is no longer the IN port, but one of the Add ports.

RMU also supports cascading multiple levels and adding/dropping more wavelengths. But this way of configuration is not recommended because in this scenario, the optical power budget is very tight.

The optical detection function and MON port are configured at the IN and MO ports of the RMU. They are used to supervise the optical signals and detect the in signals and out signals by using the external meters or the MCA functional unit.

RMU is mainly used together with WSS to realize the wavelength adding at the local site and the inter-ring connections from multiple directions.

Normally, you only need to cascade MI and MO to add or drop the local wavelength through the Add port.

If the optical power budget for some adding signals is tight, you can cascade an amplifier between MI and MO. For example, if the optical power becomes low after a 10G signal experiences the duel fed and selective receiving at the OLP, the optical power may be too low for an add wavelength. In this case, you need to cascade an amplifier to solve the problem.


ROADM Commission

The RMU is used to play the part of the multiplexing function of WSS. Since the Add port is insensitive to the wavelengths, RMU enables any wavelengths to be added from any port. RMU includes a 1*2 combiner and a 1*8 combiner. When it is used as an intra-ring ROADM, the MI and MO can be directly connected, and an amplifier can be cascaded. The 1*8 combiner is used to combine the adding signals, and the 1*2 combiner is used to combine the local signals with the pass-through signals. When it is used as an inter-ring ROADM, the MI and OUT ports are not involved in the channel combination. Only the 1*8 combiner is used to combine the signals from different directions.


ROADM Commission 1. ROADM optical power commission － RMU9+WSD9

Four added or dropped wavelengths/four pass-through wavelengths. The optical power commissioning for the FIU/ODF and for SC2 is the same as that for the OLA. The optical power commissioning for the OTU to ODF is the same as that for the OTM. The commissioning for the receive OAU is the same as that for OLA. The parts using different ways of commissioning are shown in the following figure.

OBU1 OBU1OUT IN EXPO EXPI OUT IN RMU9WSD9

LWF

LWF

－19dBmD40 MR4

LWF

LWF

LWF

LWF

LWF

LWF



Actions of ROADM Optical Power Commission － WSD9+RMU9 (NG WDM)

1 On the T2000, create optical cross-connections from the west FIU to the west receive end of the OTU, optical cross-connections from west FIU to east FIU, and optical cross-connections from the east transmit end of OTU to the east FIU.

2 Set the optical power at the OUT port of the west receive end of the OAU1 to 4dBM (standard single-wavelength output optical power). Set the rated optical power at the IN port of the east transmit end of the OBU1 to -19dBm (standard single-wavelength input optical power). Set the receive optical power of the OTU that drops wavelengths to -8dBm (The allowed margin is base on the optical power commissioning requirements).

3 WSD9 and WSM9 automatically adjust the optical power of the wavelengths dropped from the west OTU, directly added to the east OTU and passing through from the east. In this way the average input optical power at the IN port of the east transmit end of OBU1 and the receive optical power of the drop-wavelength OTU meet the requirement.

4 The east OTU adds wavelengths through OADM or M40. You need to adjust the VOA of the OTU and M40 as follows. Test the output optical power of M40. Set the VOA to the lowest and find out the wavelength that has the lowest optical power. Adjust the VOA for all other wavelengths so that the single-wavelength optical power of each wavelength equals to the lowest optical power.

5 Set the channel insertion loss for the multiplexed wavelength of the OTU that is indirectly connected to the RMU so that the tested single-wavelength optical power of OBU-IN is -19dBm.


Summary

In this course, we have learned:

The commission requirement and method for WDM deployment

The WDM deployment and commission of typical network

The optical power commission for WDM product

Thank Youwww.huawei.com

WDM Commissioning Guide-A

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Transcript of WDM Commissioning Guide-A