Calibrating ROADM Networks

ECI Telecom Ltd.

30 Hasivim Street, P.O.Box 500 Petach Tikva 49517, Israel Tel: +972-3-926-6555 Fax: +972-3-928-7100 www.ecitele.com

Technical Procedure

Calibrating ROADM Networks NAME ENG. Q.M.

Slavik B. Oron K.

SIGNATURE

DATE 19/07/09 03/08/09

Report No.

Rev

I

Page

1 of 18

File name

Emphasizing DWDM Installation and Maintenance

Emphasizing DWDM Installation and Maintenance Date: August, 2009

© Copyright by ECI Telecom, 2008-2009. All rights reserved worldwide. The information contained in the documentation and/or disk is proprietary and is subject to all relevant copyright, patent, and other laws protecting intellectual property, as well as any specific agreement protecting ECI Telecom's rights in the aforesaid information. Neither this document nor the information contained in the documentation and/or disk may be published, reproduced, copied, modified or disclosed to third parties, in whole or in part, without the express prior written permission of ECI Telecom. In addition, any use of this document, the documentation and/or the disk, or the information contained therein for any purposes other than those for which it was disclosed, is strictly forbidden. ALL RIGHTS NOT EXPRESSLY GRANTED ARE RESERVED BY ECI TELECOM. Any representation(s) in the documentation and/or disk concerning performance of ECI Telecom product(s) are for informational purposes only and are not warranties of product performance or otherwise, either express or implied. ECI Telecom's standard limited warranty, stated in its sales contract or order confirmation form, is the only warranty offered by ECI Telecom. The documentation and/or disk is provided “AS IS” and may contain flaws, omissions, or typesetting errors. No warranty is granted nor liability assumed in relation thereto, unless specifically undertaken in ECI Telecom's sales contract or order confirmation. Information contained in the documentation and in the disk is periodically updated, and changes will be incorporated in subsequent editions. If you have encountered an error, please notify ECI Telecom. All specifications are subject to change without prior notice.

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Contacts ECI – tier 3 Support line Tel: +972-3-9266565

Document History The following table records information regarding released editions of this document and briefly describes the changes made to them. Rev. No.

Release Date

Responsible

1

19.07.2009

Slavik B.

2

03.08.2009

Oron K.

Approved by

Oron K.

Description of Changes

Writing original document Repairing and editing

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Table of Contents 1.

Introduction ............................................................................................................... 5

2.

Calibrating ROADM Networks .................................................................................. 5 2.1 ROADM8............................................................................................................. 5 2.1.1 2-Degree Setup ...................................................................................... 5 2.1.2 Add unit configuration............................................................................. 6 2.1.3 Drop unit configuration ........................................................................... 8 2.1.4 Power Control ........................................................................................ 8 2.1.5 3-Degree (or more) Setup ...................................................................... 9 2.2 ROADM8D ........................................................................................................ 10 2.2.1 Introduction .......................................................................................... 10 2.2.2 Why to use ROADM8D? ...................................................................... 11 2.2.3 ROADM8D Calibration ......................................................................... 12 2.2.4 Power Control ...................................................................................... 12 2.3 ROADM40 (PLC) .............................................................................................. 13 2.3.1 Block Diagram ...................................................................................... 13 2.3.2 Power Control Configuration ................................................................ 14 2.3.3 Power Control Equalization .................................................................. 15

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List of Figures Figure 1: 2-degree ROADM8 setup .................................................................................................................................... 5 Figure 2: Power control window ........................................................................................................................................ 6 Figure 3: Added channel configuration by power control .................................................................................................. 7 Figure 4: Drop power limitation by WSS ........................................................................................................................... 8 Figure 5: 3-degree ROADM8 setup .................................................................................................................................... 9 Figure 6: ROADM8D block diagram ............................................................................................................................... 10 Figure 7: ROADM8D vs. ROADM8 ................................................................................................................................ 11 Figure 8: ROADM8D 2-degree setup ............................................................................................................................... 12 Figure 9: ROADM40 block diagram ................................................................................................................................ 13 Figure 10: ROADM40-power control configuration ........................................................................................................ 15 Figure 11: ROADM40 power equalization....................................................................................................................... 16

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1.

Introduction

The purpose of this document is to describe ROADMs calibration steps and describe the common sense behind it. IMPORTANT: This document does not replace the Installation and Maintenance Manual released with every new HW version.

2.

Calibrating ROADM Networks

2.1

ROADM8

2.1.1

2-Degree Setup T R P Drop 1-8

Add 1-8

-1 dbm manual -19dbm ppc **

-13.5dbm ppc * B

16

5d

7.

Drop in

dB

WSS

Drop out

Add in

COUPLER

Add out

5.5dB

7.5dB East direction ***

ROADM8

ROADM8 Add out

COUPLER

Add in

Drop out

Add 1-8

WSS

Drop in

Drop 1-8 Figure 1: 2-degree ROADM8 setup

*Set by WSS power limitation (page 8). **Set by power control (pages 6-7). ***This example is for East direction only. West direction remains exactly the same.

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2.1.2

Add unit configuration

2.1.2.1.

Configuration

Follow these steps to configure the add unit 1.

Right-click power control  power control  open Attenuation control window.

Figure 2: Power control window

2.

Set the following fields in the Attenuation Control window:



Base Power control = Manual



Power per Channel = -19 dBm



NoC add = number of channels added in each port

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Figure 3: Added channel configuration by power control

2.1.2.2.

Equalization

Sometimes, due to HW accuracy, fine tuning is required for achieving flat tilt. Follow these steps to equalize the channels connected to ports Add1 to Add2. 3.

Connect OSA to monitor ADD port.

4.

Use the “Offset” column to equalize the add channels to be -19dBm.

2.1.2.3.

Why Manual -19 dBm?

Manual: The APC (Automatic Power Control) calculations refer to the Add in point. Since we do not know if the Add in point is the main chain (other chains might be connected to Add 1 – Add 8 ports), we set the ROADM to work in Manual mode with fixed target power (EPpcO). Therefore -19 dBm: Coupler attenuation = 16 dB (2 dB accuracy), TRP min. output power = -1 dBm. Therefore, -1 dBm -16 dB -2 dB = -19 dBm.

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2.1.3

Drop unit configuration

2.1.3.1.

Configuration

Follow these steps to configure the drop unit. 5.

Go to configuration  channel XC.

6.

Set multichannel power offset to -3.5.

Figure 4: Drop power limitation by WSS

Multichannel target power = -13.5 dBm (power per channel target)

2.1.3.2.

Why -13.5 dBm?

Add in  Add out attenuation: 5.5 dB Target power: -19 dBm X dBm – 5.5 dB = -19 dBm X = -13.5 dBm

2.1.4

Power Control

Power Control parameters are not relevant for ROADM8 applications and should not be configured. Power Control alarms should be masked by alarm severity.

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2.1.5

3-Degree (or more) Setup

-13.5dBm*

Figure 5: 3-degree ROADM8 setup

The OFA2 amplifier between ROADM8 degrees (except Express ports) is mandatory. The above OFA-2 configuration must be MANUAL GAIN = 12.5 dB.

2.1.5.1.

Why manual 12.5dB?

7.

Drop ports Ppch = -13.5 dBm

8.

OFA2 out Ppch = -1 dBm

9.

-1dbm – (-13.5dbm) = 12.5 dBm

There is no need to update the “number of channels in”

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2.2

ROADM8D

Figure 6: ROADM8D block diagram

2.2.1

Introduction

The ROADM8D exhibits the following features: 

Same functionality as ROADM8



New coupler attenuation for Add direction only, as shown in the following table. ROADM8

ROADM8D

Add in – Add out

5.5 dB

14 dB

Add 1-8 – Add out

16 (18) dB

14 dB

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2.2.2

Why to use ROADM8D?

The following figure show multi-degree configuration with ROADM8D. Comparing Figure 7 (ROADM8D) with Figure 5 (ROADM8) explain how ROADM8D eliminate the need for OFA2 between the degrees. OFA2 elimination has 2 benefits: network cost reduction and OSNR improvement. +4dBm

-5dBm*

-19 dBm**

7dB ROADM8D ROADM8D

-5dBm* +4dBm 7dB ROADM8D

*Set by WSS power limitation (power per channel) **Set by Attenuation control window

Figure 7: ROADM8D vs. ROADM8

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2.2.3

ROADM8D Calibration

ROADM8D calibration is very similar to that of ROADM8. The WSS target power for entire drop ports (Drop1 till Drop8 and Drop Out) = -5 dBm All other configuration should be the same as ROADM8. T R P Drop 1-8

Add 1-8

-1 dbm manual -19dbm ppc **

-5dbm ppc * 14

B

5d

Drop in

dB

WSS

Drop out

Add in

5dB

COUPLER

Add out

14dB East direction ***

ROADM8D

ROADM8D Add out

Add in

COUPLER

Drop out

Add 1-8

WSS

Drop in

Drop 1-8 Figure 8: ROADM8D 2-degree setup

*Set by WSS power limitation. **Set by Attenuation control window. ***This example is for East direction only. West direction remains exactly the same.

2.2.3.1.

Add Out Power Control Configuration and Equalization

Add unit configuration and equalization of the ROADM8D is exactly the same as that of the ROADM8, meaning manual -19 dBm (see paragraph 2.1.2).

2.2.3.2.

Drop Out Configuration

Drop unit configuration of the ROADM8D is similar to that of the ROADM8 (see paragraph 2.1.3) just the target power value is -5 dBm (instead of -13.5 dBm at ROADM8).

2.2.4

Power Control

Power Control parameters are not relevant for ROADM8D applications and should not be configured. Power Control alarms should be masked by alarm severity.

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2.3

ROADM40 (PLC)

ROADM40 is a Reconfigurable 40-channel OADM with internal switches (PLC) designed for 2-degree ROADM sites. Power control in the ROADM40 is very similar to I/O OADM power control (see paragraph 2.3.2).

2.3.1

Block Diagram Switch array

PLC Dmux

PLC Mux

EXP IN 40 ch

LINE OUT 40 ch

PLC ch21

ADD ch40

EXP OUT

SPLITTER 60/40

40 ch

LINE IN 40 ch

dmux

ch21

DROP ch40

Figure 9: ROADM40 block diagram

* Note – the above diagram is conceptual; refer to the SRQ for a more detailed diagram.

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ADD Unit The add unit is composed of three primary sections built into one component – the Planar Lightwave Circuit (PLC): 

40 Mux/DeMux channels



40 ‘3-state switches’



40 add ports

DROP Unit The drop unit consists of two components: 

40/60 splitter



40 DeMux channels (with 40 drop ports) All the 40 channels (coming from the Line in direction) are dropped into the DeMux and pass through to Exp out.

2.3.2

Power Control Configuration

Configure the power control by clicking Card view  Power control  right-click Info  Configuration. The power control configuration in ROADM40 is similar to that in OADM except for 4 dB deduction which is required for channel equalization needs, as follows: EPpcO = EIP(per channel)-Insertion loss-ReqCorr-ChannelOffset-4dB* *4 dB kept for tilt correction. Reminders: Power control parameters must be configured according to relevant power budget (as appears in the project book). The power control reference point is the Exp-in port.

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Figure 10: ROADM40-power control configuration

2.3.3

Power Control Equalization

This window can be opened from three different locations: 

Card view configuration  channel XC  power control



Card view  PowerCtrl  right-click  power control



Card view  PowerCtrl  right-click  info  File  power control

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Figure 11: ROADM40 power equalization

The ROADM40 power control mechanism is similar to that of OADM power control functionality. This means that the ADD channels are equalized according to the EXPRESS channels. The fields in the Power Control window are described in the following table. Field

Description

Base power source

Power per channel out In E/W mode must be set as calculated (calculates the PPch out according to the power control configuration as explained at paragraph 2.3.2). In terminal mode must be set as manual and then the PPch out value must be configured.

Expected power per channel out

Calculated by the power control configuration (relevant only if working in calculated).

Tracking

Button to be checked or unchecked according to power budget (enable/disable).

Required Add power

In calculated mode must be the same as the Expected power per channel out field; in manual mode as power per channel – Current.

Measured Add power

Power measured by the Photo Diode in the ADD out.

Current Offset

Current configured offset.

New Offset

Changing this field can increase or decrease the Power Per Channel Out (fine tuning of 0 dB to -10 dB).

Power change (in the left)

Enables the user to change the offset for several channels simultaneously.

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After connecting the OSA, follow these steps for equalization: 1.

Connect an OSA to the ADD OUT monitor point and check the equalization (tilt between the lowest and the highest channels).

2.

Equalize the channels using the NEW OFFSET field according to the lowest channel (and according to power budget document).

*** End of document ***

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