WDM System Commissioning

7/27/2019 WDM System Commissioning

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HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

Huawei Confidential

Security Level: internal use only2013/7/29

Jiang Luyong 17748

WDM SystemCommissioning


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HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential Page 2

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.


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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 1600GDebugging and Commissioning Guide.

The emphases and difficulty of this

course is the optical power

Commissioning.


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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


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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


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Contents

Preparation for Commission

Commission Requirement andMethod

System Commission


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Contents


Document Preparation Tools Preparation

Commission Precaution


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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 inthe 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 ofequipment function and feature, especially the requirement of

commission.

Testing record table: according to the engineering, prepare the testing

record table before commission.


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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.


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Preparation for Commission Commissioning Precautions

Before commissioning, the installation engineer must work out the hardware quality checkreport. 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 andflange) 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).


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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 commissioningprocess?

Answer:

1. The instrument is faulty or is not calibrated.

2. Fibers must be cleaned.


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Summar

y

In this chapter, we have

learned:

Document Preparation

Tools Preparation

Commission Precaution


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Contents



System Commission


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Content

Commission Requirement and

Method Optical amplifier unit

Optical Transponder Unit

Other units


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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.


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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+10lgNmaximum input and output optical power

The one-channel standard input and output optical power 10lgSmaximum 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 20-10lg404dBm 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.


Amplifier Unit


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Amplifier Unit

Board

nameModule

Minimu

m input

optical

power

(dBm)

Maximu

m input

optical

power

(dBm)

Input/Outp

utsingle-

wavelengt

h standard

power

(dBm)

10-

wavelength

Input/Outp

ut single-

wavelengt

h nominal

optical

power

(dBm)

32-

wavelengt

h

Input/Output

single-

wavelength

nominal

optical power

(dBm)

40-

wavelength

Input/Output

single-

wavelength

nominal

optical power

(dBm)

80-

wavelength

Gain

(dB)

Maximum

output

optical

power for

full

waveleng

th (dBm)

E3OAUC01

A/B/C/D

(C band)

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

E3OAUC02

A/B/C/D

(C band)

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

E3OAUC03A/B/C/D

(C band)

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

E3OAUC03

E

(C band)

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

1.Commission Requirement and Method for Optical amplifier unit


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Board nameModul

e

Minim

um

input

optical

power

(dBm)

Maxim

um

input

optical

power

(dBm)

Input/Out

putsingle-

wavelengt

h

standard

power

(dBm)

10-

wavelength

Input/Out

put

single-

wavelengt

h nominal

optical

power

(dBm)

32-wavelengt

h

Input/Out

put

single-

wavelengt

h nominal

optical

power

(dBm)

40-wavelengt

h

Input/Out

put

single-

wavelengt

h nominal

optical

power

(dBm)

80-wavelengt

h

Gain (dB)

Maximum

output

optical

power for

full

wavelengt

h (dBm)

E3OAUC05

A

(C band)/ -32 0 / -15/8 -16/7 -19/4 23-36 23

E3OBUC03

A/C(C band)/ -24 -3 / -18/5 -19/4 -22/1 20.5-25.5 20

E3OBUC05

A(C band)/ -24 0 -15/8 -16/7 -19/4 20.5-25.5 23

E3OPUC03

C(C band)/ -32 -8 / -23/0 -24/-1 -27/-4 20.5-25.5 15

Notes: here take the E3OAU/OBU/OPU for example, other boards such as E4/C6 and so on

the principle is the same.


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


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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 endmonitor the receive end and adjust thetransmit 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.


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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 gainone-channelstandard output optical poweradjusted one-channel average inputoptical power

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


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Sample E3OAU commissioning The input optical power of the E3OAUC03E ranges from 32 dBm to4 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 is15 dBm, how do you

commission the system? If the value is25 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.


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Sample E3OAU commissioning

The OptiX 1600G III model system is a 40x10G system. The calculated one-channel

standard input optical power is20 dBm and the output optical power is +4 dBm.

If the one-channel average input optical power before you add a VOA is15 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 power20 dBm, the

gain is4(20)24dB.


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 power25 dBm,

the gain is4(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).


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

The input optical power of the E3OBUC03 ranges from 24 dBm to3 dBm, the gainis 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 is14dBm, how do you commission the system?

The OptiX 1600G III model system is a 40x10G system. The calculated one-channel

standard input optical power19 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 power19dBm, andthe tested one-channel average output optical power is +4 dBm.

INBA OUT21OBU diagram

VOA


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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 powerone-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 opticalpower 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.


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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.


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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-channeloptical 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 offset10lg (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.


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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


Amplifier Unit


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Sample E3OAU commissioning The input optical power of the E3OAUC03E ranges from32 to4 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 is9 dBm, how

do you commission the system? If the value is20 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.


Amplifier Unit


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Sample E3OAU commissioning

The OptiX 1600G III model system is a 40x10G system. The calculated one-

channel standard input optical power is20 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.


you can adjust the VOA to enable the total input optical power to reach the

standard value13 dBm.

the one-channel average optical power is calculated as the one-channel

standard optical power20 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.


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If the total input optical power before you add a VOA is20 dBm,

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

20 dBm.

the one-channel average input optical power =20110lg4=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.


Amplifier Unit


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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 amplifierunit 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 directionone-

channel standard input optical power of the optical amplifier unit in the

downstream direction). Adjust the VOA to enable the total input opticalpower 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.


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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 thedownstream 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 directionadjusted one-channel input optical power of

the optical amplifier unit in the downstream direction = (one-channelstandard output optical power of the optical amplifier unit in the

downstream directionone-channel standard optical power in the

upstream direction) + (queried total output optical power of the

optical amplifier unit in the upstreamqueried total input optical

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


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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


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.


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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.


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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 Short

Cost High Low Low

Correctness High Low Medium

Impact 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


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6. Commissioning Requirement on Optical Power of Raman Amplifier

Requirements

The switch gain of a Raman amplifier10 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 dBm

G.653 23.0 dBm 22.5 dBm


Amplifier Unit


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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.


Amplifier Unit

C i i R i t d M th d f O ti l


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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 toverify 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.


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6. Commissioning Requirement and Method on Optical Power of RamanAmplifier

Method of commissioning optical power of Raman amplifier gain

flatness

1529.58nm

-2.5

-2

-1.5

-1

-0.5

0

0. 5

1

1525 1530 1535 1540 1545 1550 1555 1560 1565

ASE

1

2

210.7dB

Zero at 1529.58nm

Gain spectrum

ASE spectrum


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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.


Amplifier Unit

Commission Requirement and Method for


41/107



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 0.1dB (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.

Commission Requirement and Method for

Optical Amplifier Unit



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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.


Amplifier Unit


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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.


Amplifier Unit


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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 theone-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 unitinput 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?


45/107


Summary In this chapter, we have learned:

The commission requirement of OA

Three commission methods for OA

Example for OA Commission


46/107


Contents


Method

Optical amplifier unit


Other units

C i i R i t d M th d f OTU


47/107


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


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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 withFEC/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.



49/107


1. Commissioning Requirement for OTU

Commissioning requirements on special OTU

There is no difference in the commissioning requirements and methods for10G 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 biterrors. 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.



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OTU

2.5GPIN:7dB

7CLIENT

OTU

10GPIN:7dB

7CLIENT

OTU2.5GAPD:15dB15CLIENT

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.


51/107


Commission Requirement and Method for OTUIN TX

D

4

0

OTU

APD:15dB

15 CLIENT

OTUPIN:7dB

CLIENT

OTUAPD:15dB

15

OTU

PIN:7dB

OTU

OTU

RX OUT

IN OUT

M

4

0

O

A

U

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.


52/107



OTU in BWS 1600G

Receiver

sensitivity

(dBm)

Receiver

overload

(dBm)

Output

optical

power(dB

m)

The scope of

Input optical

power (dBm)

LWC

LWC

1

DWDM SideORP:-18 ORP:0 -10~0 -12~-6

ORA:-28 ORA:-9 -10~0 -22~-16

Client

side

I-16 ORP:-18 ORP:-3 -10~-3 -14~-8

S-16.1 ORP:-18 ORP:0 -5~0 -12~-6

L-16.1 ORA:-27 ORA:-9 -2~3 -22~-16

L-16.2 ORA:-28 ORA:-9 -2~3 -22~-16

LWFLWF

S

DWDM

Side

100GHz ORP:-14 ORP:0 -5~0 -10~-6

50GHz ORP:-14 ORP:-1 -5~0 -10~-6

CRZ ORP:-16 ORP:0 -5~0 -12~-6

Client

side

I-64.1 ORP:-11 ORP:0 -6~-1 -8~-4

I-64.2 ORP:-14 ORP:0 -5~-1 -10~-6

S-64.2b ORP:-14 ORP:0 -1~2 -10~-6

S-64.2a ORA:-18 ORA:-8 -1~2 -15~-11


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Contents


Method

Optical amplifier unit


Other units

Commission Requirement and Method for Other


54/107



Boards

1. 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

-70dBm 1500nm1520nm -48dBm -3dBm



55/107



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 Loss

MR2: INDROP


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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.


Boards

C i i R i t d M th d f Oth


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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.

F

I

U

F

I

U

A B

Ring flange ofline-side ODF, in

between is aoptical fiber/cable

OUT INRC

TC


58/107


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 thereceived 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?


59/107


Summar

y

In this chapter ,we have

learned:

Commission Requirement andMethod for Optical amplifier

unit, Optical Transponder Unit,

and Other units


60/107


Contents



System Commission


61/107


Contents

System Commission

OTM Commission OLA Commission

OADM Commission

ROADM Commission


62/107


Typical Network and application of WDM product


63/107


System Commission

F

I

U

O

B

U

O

A

U

SC1/

TC1

MCAMON

D

C

M

TM

RM

RM

TM

OUT

IN

RC

TC

IN

TDC

RDC

OUT

MON

D

4

0

D01

D40

IN

M

4

0

M01

M40

OUT

LWF

MON

M02LWF

LWF

OUTRx

LWF

D02LWF

LWF

INTx

5dB

Out line

ODF

Client

ODF

OUTIN

VOA

FOA

ODF

Fiber

1.OTM Commission


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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 FIUSDH

RX OUT M01 OUT IN OUT RC RM OUT

1 1 2 3 3 4 5 6 6 6

SC16

LWF M40 OBU FIUSDH

RX OUT M01 OUT IN OUT RC RM OUT

1 1 2 3 3 4 5 6 6 6

SC16

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

1dB +3dBm

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

wavelength.

OTM C i i


65/107


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 theoptical 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.


66/107


OTM Commission

1.Optical power commission for OTM

The input optical power commission for OTM

2.5dBm 2dBm 9dBm 6dB +4dBm 20dBm -16dBm 1dB15dBm

2.5dBm 2dBm 9dBm 6dB +4dBm -24dBm 1dB23dBm

LWF D40 OAU FIUSDH

TX IN D01 IN OUT I

6 6 5 4 4 3

2 1 1 1

SC11

DCM

LWF D40 OAU FIUSDH

TX IN D01 IN OUT I

6 6 5 4 4 3

2 1 1 1

SC1 1

DCM

OTM Commission


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OTM Commission

Step 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 issmaller 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 receivedoptical 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


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OTM Commission

F

I

U

O

B

U

O

A

U

TC2

TM

RM

RM2

TM2

IN

RC

TCIN

TDC

RDC

OUT

MON

D01

D40

IN

D

4

0

M01

M40

OUT

LWF

MON

M02LWF

LWC

OUTRx

LWF

D02LWF

LWC

INTx

LWF

LWF

LWC

TxIN

LWF

LWF

LWC

RxOUT

D

4

0

O

B

U

OUTINOUT

MON

F

I

U

TM

RM

RC

TC

O

A

U

RDC

MON

TDC

TM1

RM1

IN

15dB

OUTINOUTIN

TC2

RM2

TM2

TM1

RM1

15dB

VOAD

C

M

D

C

M

OUT

OUT

D05

D12 M13 D01M02

D05

D06D06

D12M13M02

D01

IN

D01

M01

M

4

0

M

4

0

FOA

ODF

1. 2OTM in 1600G


69/107


OTM Commission

D

4

0

F

I

U

O

B

U

O

A

U

SC2

TM

RM

RM2

TM2

IN

RC

TCIN

TDC

RDC

OUT

MON

D01

D40

IN

M01

M40

OUT

LWF

MON

M02LRF

OUTRx

LWF

D02

INTx

LWF

TxIN

LWF

LRF

RxOUT

D

4

0

O

B

U

OUTINOUT

MON

F

I

U

TM

RM

RC

TC

O

A

U

RDC

MON

TDC

TM1

RM1

IN

15dB

OUTINOUTIN

SC2

RM2

TM2

TM1

RM1

15dB

VOAD

C

M

D

C

M

OUT

OUT

D05

D12 M13 D01M02

D05

D06D06

D12M13M02

D01

IN

D01

M01

M

4

0

M

4

0

FOA

ODF

D02

M02

M40

D40

1. 2OTM in 6100

Questions


70/107


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 asingle wavelength basis. If no spectrum analyzer is available, how to

perform commissioning based on the total optical power?


71/107


Contents

System Commission

OTM Commission

OLA Commission

OADM Commission

ROADM Commission


72/107


OLA Commission

F

I

U

F

I

U

O

B

U

O

A

U

D

C

M

SC2/TC2

OUT

RM RM2

RMRM1TM

TM1 TM

TM2

RC

MON

OUT

IN

IN

MON

IN

RDC

TDC

D

C

M

OUT IN OUT

RDC

TDC

TCRC

TC

INOUT

MON

D05 D09

D01 D03

O

A

U

D12

OLA Commission


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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 OUT

SC1

OBU

-28 +4 19 +4

FIU OAU DCM FIU

-24.7 +9.1 -13.9 +9.3

OBU

OLA Commission


74/107


Step Actions of OLA Optical Power Commissioning(Single Wavelength OpticalPower 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 issmaller 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 theFIU 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 Commission


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Step Actions of OLA Optical Power Commissioning(General Wavelength OpticalPower 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 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 = 24.710lg2

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 FIUinsertion loss and the fiber jumper attenuation are normal.

OLA Commission


76/107


OLA Commission

Step Actions of OLA Optical Power Commissioning(Improved GeneralWavelength Optical Power Commissioning)

1Test the optical power of the line ODF/FIU-IN/FIU-TC/FIU-TM/SC2-RM1. Theattenuation=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 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(7.324.7)

=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.


77/107


OLA Commission

The commissioned single wavelength input optical power of downstreamOAU = 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


78/107


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


79/107


Contents

System Commission

OTM Commission

OLA Commission

OADM Commission

ROADM Commission

OADM C i i


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OADM Commission

F

I

U

O

B

U

O

A

U

TC2TM

RM

RM2

TM2

OUT

IN

RC

TC

IN

TDC

RDC

OUT

MON

IN

OUT

MON

O

B

UOUT

INOUT

MON

F

I

U

TM

RM

RC

TC

O

B

U

MON

TM1

RM1

OUT

IN

OUTINOUTIN

M

R

2

M

R

2

M

R

2

M

R

2

L

W

X

L

W

X

IN

MI

MO

OUT

IN

MI

MO

MO

MI

IN

OUT

MO

L

W

X

L

W

X

L

W

X

L

W

X

L

W

X

L

W

X

5dB

D

C

M

D

C

M

VOA

FOA

ODF

Fiber

OADM Commission


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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 OBU

OUT IN MO IN MO MI OUT

MI OUT INMR2MR2

LW

F

LW

F

LW

F

LW

F

LW

F

LW

F

LW

F

LW

F

6 dBm

19dBm

OADM Commission


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Step Actions of OADM Optical Power Commissioning(Single WavelengthOptical 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 theattenuator, 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 thesingle 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 thesignals 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.

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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 theoptical power of pass-through wavelengths are comparatively low.

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OADM Commission

OAU MR2 MR2 OBU

OUT IN MO IN MO MI OUT

MI OUT INMR2MR2

LW

F

LW

F

LW

F

LW

F

LW

F

LW

F

LW

F

LW

F

6 dBm

19dBm

OAU MR2 MR2 OBU

OUT IN MO IN MO MI OUTMI OUT IN

MR2MR2

LW

F

LW

F

LW

F

LW

F

LW

F

LW

F

LW

F

LW

F

6 dBm

12.3dBm

Adjust this VOA

Adjust this VOA

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Step Actions of OADM Optical Power Commissioning(General Optical PowerCommissioning)

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-sidelaser 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.

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

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Step Actions of OADM Optical Power Commissioning(Improved General Optical PowerCommissioning)

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 opticalpower, 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 ofOBU-IN is -19dBm

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

Defec

t

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.

Q ti


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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?


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Contents

System Commission

OTM Commission

OLA Commission

OADM Commission

ROADM Commission


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ROADM Commission

F

I

U

F

I

UTo D

IN

OUT

To F

OUT

IN

Site E

SC2RM1

TM1RM

TM RMTM2

TMRM2

OBU

OUT OUT

OUT INOUT

OUT

TC

RCININ

IN

RC

OBU OAU

OBU

TDCRDC

DWC DWC

INTC OUT

DCM

D40

L

W

F

L

W

F

L

W

F

L

W

F

D40

MO

MI

MI

MO

DROP ADD DROP

West East

M40 M40

ADD

ROADM in OptiX BWS 1600G

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ROADM Commission

ROADM in OptiX OSN 6800

F

I

U

F

I

UTo D

IN

OUT

To F

OUT

IN

Site E

SC2RM1

TM1RM

TM RMTM2

TMRM2

OBU1

OUT OUT

OUT INOUT OUT TC

RCININ

INRC

OBU1 OAU1

OBU1

TDCRDC

ROAM ROAM

INTC OUT

DCM

D40

L

Q

M

L

4

G

L

Q

M

L

4

G

D40

EXPO

EXPI

EXPI

EXPO

DMM01

DMM01

West East

ROAM Commission40


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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


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Commission 1. ROADM optical power commissionDWC+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 OBU

OUT IN MO

MI OUT INDWCDWC

L

WF

LW

F


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Step Actions of ROADM Optical Power CommissionDWC+DWC1 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.

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1. ROADM optical power commissionROAM+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 OBU1

OUT IN EXPO

EXPI OUT INROAMROAM

L

4G

LQ

M


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Step Actions of ROADM Optical Pow