1600g amplifier optical layer applications guide · dwdm transmitters and wavelength translators...

NTY315DX

*A0810309*

Nortel Networks

OPTera Long Haul 1600Optical Line System1600G Amplifier Optical Layer Applications Guide Standard Rel 3 Issue 2 October 2000

What’s inside...

IntroductionOptical layer building blocksOptical link engineering rulesApplication-independent optical link engineering rulesOptical layer components specificationsAppendix A: Description of commercially available optical fiber typesAppendix B: Overview of fiber-optic fundamentalsAppendix C: 1600G Amplifier power specificationsAppendix D: External tap couplers

Copyright 2000 Nortel Networks, All Rights Reserved.

The information contained herein is the property of Nortel Networks and is strictly confidential. Except as expressly authorized in writing by Nortel Networks, the holder shall keep all information contained herein confidential, shall disclose it only to its employees with a need to know, and shall protect it, in whole or in part, from disclosure and dissemination to third parties with the same degree of care it uses to protect its own confidential information, but with no less than reasonable care. Except as expressly authorized in writing by Nortel Networks, the holder is granted no rights to use the information contained herein.

*Nortel Networks, the Nortel Networks logo, the Globemark, How the World Shares Ideas, S/DMS TransportNode, OPTera, Preside, and Unified Networks are trademarks of Nortel Networks.

TrueWave is a registered trademark of Lucent Technologies Inc.LEAF is a registered trademark of Corning Incorporated.SMF-LS and SMF-28 are trademarks of Corning Incorporated.

Printed in Canada and in the United Kingdom

iii

Publication history 0October 2000

Issue 2 of the 1600G Amplifier Optical Layer Applications Guide introduces link engineering rules for TrueWave Plus, LS, and TrueWave RS fiber. It also provides additional information on power specifications and 1600G amplifiers equipped with external tap couplers.

July 2000The first issue of the 1600G Amplifier Optical Layer Applications Guide.

1600G Optical Layer Applications Guide NTY315DX Rel 3

iv Publication history

1600G Optical Layer Applications Guide NTY315DX Rel 3

v

Contents 0About this document ix

Introduction 1-1Chapter overview 1-1Describing and understanding optical networks 1-1OPTera Long Haul 1600 technologies for optical layer solutions 1-3

DWDM transmitters and wavelength translators with tightly controlled wavelengths 1-3

Multiwavelength optical signal amplifiers and integrated components, 1600G Amplifiers 1-3

OPTera Long Haul 1600 DWDM couplers 1-3OPTera Long Haul 1600 OADM couplers 1-3Dispersion compensating modules (DCM) 1-3Dispersion slope compensating modules (DSCM) 1-3

Optical layer building blocks 2-1Optical layer functional building blocks 2-1Link Models 2-1Configuration overview 2-3Standard configurations building blocks 2-3Special configuration building blocks 2-6

1600G amplifier group description 2-61600G Amplifier building block components 2-7Wavelength capacity 2-7Mid-stage access (MSA) rules 2-7Padding rules 2-8Usage with 1480/1510 nm OSCs or 1510/1615 nm OSCs 2-8Unused ports 2-8

Mux/Demux building blocks 2-9Configuration description 2-10Mux/Demux building blocks components 2-11Wavelength capacity 2-11Spare wavelengths 2-11Module deployment 2-11Unused ports 2-12

Optical link engineering rules 3-1Link engineering rules for OPTera Long Haul 1600 C-Band unidirectional

1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

vi Contents

applications 3-3Deployment considerations for OPTera Long Haul 1600 optical layer applications 3-4Optical link engineering procedure 3-5

Optical link budgets and span loss rules 3-5Span loss rules and guidelines 3-7Derating example 3-10Padding rules 3-11

Optical patch panel rule 3-11Optical link transmission performance guarantee 3-12

OPTera Long Haul 1600 C-Band unidirectional applications on NDSF fiber multiplexing 10 Gbit/s channels 3-13

OPTera Long Haul 1600 C-Band unidirectional applications on TrueWave Classic fiber multiplexing 10 Gbit/s channels 3-25

OPTera Long Haul 1600 C-Band unidirectional applications on E-LEAF fiber multiplexing 10-Gbit/s channels 3-30

OPTera Long Haul 1600 C-Band unidirectional applications on TrueWave Plus fiber multiplexing 10-Gbit/s channels 3-35

OPTera Long Haul 1600 C-Band unidirectional applications on SMF-LS fiber multiplexing 10-Gbit/s channels 3-40

OPTera Long Haul 1600 C-Band unidirectional applications on TrueWave RS fiber multiplexing 10-Gbit/s channels 3-45

Application-independent optical link engineering rules 4-1Tx chirp adjustment for dispersion compensation 4-1NLS dithering provisioning 4-1OPTera Long Haul 1600 mid-stage access (MSA) loss restrictions 4-2Polarization mode dispersion (PMD) consideration 4-4

Nortel Networks 100 GHz ITU-T compliant wavelength grid 4-5Wavelength plans 4-6OADM Applications 4-6

Optical layer components specifications 5-1Fiber optic attenuators 5-17

Fixed attenuators 5-17Specifications 5-17

Appendix A: Description of commercially available optical fiber types 6-1

NDSF 6-1DSF 6-1NZ-DSF 6-2LEAF and E-LEAF (LEAF with reduced dispersion slope) 6-2

Appendix B: Overview of fiber-optic fundamentals 7-1Effects in the optical fiber 7-1

Fiber effects affecting the energy of an optical pulse 7-2Fiber effects affecting the shape of an optical pulse 7-4

Chromatic dispersion in DWDM systems 7-4

OPTera Long Haul 1600 NTY315DX Rel 3

Contents vii

Chromatic dispersion compensation strategies 7-6Polarization Mode Dispersion (PMD) 7-7Self-Phase Modulation (SPM) and Cross-Phase Modulation (XPM) 7-7

Appendix C: 1600G Amplifier Power specifications 8-11600G EOL Power Mask Specifications 8-1Optical power requirements 8-2

Appendix D: External tap couplers 9-1First generation of the 1600G C-band amplifier cards 9-1Main function of the external tap couplers 9-1Optical specifications of external tap couplers 9-3Optical layer functional building blocks with external tap couplers 9-4

Building blocks for standard configurations with external tap couplers 9-4Special configuration building blocks with external tap couplers 9-8


viii Contents


ix

About this document 0This guide describes the DWDM system applications designed with 1600G Amplifiers. This guide also provides planning, link engineering processes, and component specifications for the OPTera Long Haul 1600 C-Band Unidirectional Optical Systems. The Nortel Networks OPTera Long Haul 1600 Optical Line System (formerly OPTera LH) Release 3 with the OPTera Long Haul 1600 optical amplifiers scales up to 40λ in the C-Band. Future releases will introduce amplification for the C- and L-Band wavelengths in both unidirectional and bidirectional configurations.

This document contains the following chapters:

• Chapter 1, Introduction

Provides an overview of the optical networks and how the OPTera Long Haul 1600 technologies interoperate with other Nortel Networks components to offer a generic optical layer solution.

• Chapter 2, Optical layer building blocks

Provides a description of the functional building blocks required for deploying all the OPTera Long Haul 1600 applications.

• Chapter 3, Optical link engineering rules

Provides the optical link budgets and engineering rules required to deploy 1600G Amplifier DWDM systems.

• Chapter 4, Application-independent optical link engineering rules

Provides additional rules for Tx Chirp Adjustment, Mid-Stage Access Loss Restrictions, polarization mode dispersion (PMD) consideration and Wavelength Plans.

• Chapter 5, Optical layer components specifications

Describes the optical building block components specifications required to deploy the OPTera Long Haul 1600 applications.

• Appendix A: Description of commercially available optical fiber types

Provides description of the major fiber types that are commercially available today (NDSF, DSF, NZ-DSF, LEAF and E-LEAF)


x About this document

• Appendix B: Overview of fiber-optic fundamentals

Presents the fiber effects affecting the energy or shape of an optical pulse. It also explains chromatic dispersion, polarization mode dispersion (PMD), self-phase modulation (SPM) and cross-phase modulation (XPM or CPM), four-wave mixing (FWM), modulation instability (MI) impact in DWDM systems.

• Appendix C: 1600G Amplifier power specifications

Provides power mask specifications for the 1600G amplifiers. It also includes the power requirement figures used when you equalize the system following a system line-up and test (SLAT) procedure, or after adding or removing optical channels.

• Appendix D: External tap couplers

Provides basic information about external tap couplers in specific OPTera Long Haul 1600 amplifier configurations.

AudienceThis document is for the following members of the operating company:

• strategic and current network planners

• provisioners

• transmission standards engineers

• network administrators

The OPTera Long Haul 1600 Amplifier LibraryThe 1600G Amplifier Optical Layer Application Guide is part of the 1600G Amplifier documentation library. This library consists of NTPs and Planning Guides. The NTPs contain procedural information that explain how to perform specific tasks. The Planning Guides contain contextual information to help you understand why you perform those procedures.

The Planning Guides complement the NTPs by providing the technical background on issues related to planning, installing, provisioning and maintaining your optical network. The figure on the following page represents the relationship between the Planning Guides and the NTPs of the 1600G Amplifier documentation library.


About this document xi

OTP1468p.eps

Engineering Guides323-1808-1xx

Installation,Commissioning,and Testing Guides323-1801-3xx

1600G AmplifierNetworkApplicationGuide

NTPs

Optical Add/DropMultiplexer UserGuide

PlanningGuides

PEC: NTY314AX• New Product features• Positioning the 1600G amplifier• 1600G amplifier application• Transmission and topologies• Amplifier building blocks• DWDM building blocks• Shelf configurations and bay footprint• Ordering information• Engineering documentation• Technical support and information• Power requirements• External tap couplers• Control shelf configurations

PEC: NTY313GC• 1600G OADM general

guidelines• OADM fiber routing• Connecting and site testing

topology 1/2 amplifiers withOADM in Direction 1

• Connecting and site testingtopology 1/2 amplifiers withOADM in Direction 2

• Completing connections atan OADM site

• Coupler specifications andordering information

PEC: NTY315DX• Optical layer building blocks• Link engineering rules• Application-independent link engineering rules• Optical layer components specifications• Optical fiber types• Fiber-optic fundamentals

PEC: NTY317DX• Logical, physical and software views of Amplifier• Provisioning and facility management• Optical layer alarms• Level 2 routing

1600G AmplifierOptical LayerApplication Guide

1600G AmplifierOAM&P Guide

Operations,Administration, andProvisioning Guides323-1801-3xx

MaintenanceGuides323-1801-5xx

OPTera Long Haul 1600 Optical Line SystemNetwork Application Libraries

RepeaterLibrary

1600G AmplifierLibrary

CombinerLibrary


xii About this document

ReferencesThis document refers to the following documents:

• 1600G Amplifier Network Application Guide (NTY314AX)

• OPTera Long Haul 1600 Release 3 NTP Library (NTCA65EC)


1-1

Introduction 1-Chapter overview

The following sections provide an overview of optical networks including:

• “Describing and understanding optical networks” on page 1-1

• “OPTera Long Haul 1600 technologies for optical layer solutions” on page 1-3

Describing and understanding optical networksA transport network can be split into two primary layers (see Figure 1-1):

• a data layer (SONET, SDH, IP, ...) consisting of line, section, or path terminating equipment

• an optical or photonic layer, optical throughways where data payloads are transported

The optical layer can be divided further into four sublayers:

• optical components

• functional building blocks

• optical spans

• optical links

Optical components are the physical boxes that perform core optical functions, both active and passive, and include such devices as:

• optical amplifiers such as erbium-doped fiber amplifiers (EDFA)

• wavelength multiplexing/demultiplexing couplers

• wavelength add/drop couplers

• dispersion and dispersion slope compensating modules (DCM/DSCM)

These optical components, in turn, can be combined in a variety of ways to form functional building blocks. For example, optical amplifiers and add/drop couplers can be combined to form an add/drop multiplexing site.


1-2 Introduction

A functional building block is associated with a specific geographic site. An optical span is created when two functional building block sites are interconnected with an optical fiber plant. Optical spans require amplification of incoming and outgoing wavelength signals to compensate for loss.

Several spans combined together form an optical link, the boundaries of which are defined by the data network element interfaces, specifically the transmitters and receivers. The optical link can contain several DWDM wavelength channels or signals. Two counterpropagating channels are required to form a single bidirectional data transmission channel.

The optical layer of a transport system is the combination of all the optical links.

Figure 1-1 Data and optical layers of transport network

F4716-MOR_R80.eps

Open ArchitectureInterfaces

STE's

Opticallink

Optical link Optical amplifier(uni or bidirectional)

Optical terminating site(optic - electric &electro-optical conversion)

LTE/ADM

SONET/SDHLTE's

SONET/SDH/IP/ATM

OPTICALLAYER


Introduction 1-3

OPTera Long Haul 1600 technologies for optical layer solutionsA generic optical layer solution contains a number of key technology components that set it apart from a traditional SONET/SDH network. For optical layer applications with a spacing of 100 GHz between the optical channels, Nortel Networks provides the following:

DWDM transmitters and wavelength translators with tightly controlled wavelengths

Nortel Networks offers DWDM transmitters at 10-Gbit/s line rates for a maximum of 40 wavelengths (unidirectional), with bidirectional applications planned for the future.

Multiwavelength optical signal amplifiers and integrated components, 1600G Amplifiers

1600G Amplifiers can amplify a maximum of 160 wavelengths. The 1600G Amplifier is the baseline amplifier for 160λ applications and provides a mid-stage access functionality where you can insert components such as DCMs/DSCMs or optical add/drop multiplexer (OADM) couplers, improving deployment flexibility.

OPTera Long Haul 1600 DWDM couplersDWDM couplers multiplex and demultiplex optical channels in and out of a single fiber. These couplers consist of passive filters that are packaged as stand-alone optical components, with one port for each DWDM channel and a common port which connects to the fiber plant. Monitoring taps, variable optical attenuators for received power adjustment, and expansion ports for upgrades are also included.

OPTera Long Haul 1600 OADM couplersOPTera Long Haul 1600 OADM couplers selectively add and drop DWDM channels at a site while passing through other channels in the optical link. Such configurations improve connectivity and flexibility, and offer services such as wavelength leasing. OPTera Long Haul 1600 OADM deployment rules are under development.

Dispersion compensating modules (DCM)DCMs are used to counter chromatic dispersion in long haul transmission systems. DCMs contain dispersion compensating fiber that apply a predefined level of dispersion to reconstruct (compress) the optical pulses. Optical pulses need to be reconstructed after they have spread out over a given length of fiber.

Dispersion slope compensating modules (DSCM)A second type of dispersion compensation modules is used in OPTera Long Haul 1600 applications, namely the Dispersion Slope Compensating Module (DSCM).


1-4 Introduction

Each channel experiences a different amount of dispersion in the transmission fibre. The DCMs provide an appropriate amount of compensation for a single channel. With the MOR Plus, the RED and BLUE Erbium bands were narrow enough that the difference in dispersion experienced by each channel in a given band was small. The Erbium gain windows used by OPTera Long Haul 1600 are about 2.5 times larger than MOR Plus therefore optimizing the dispersion compensation for a subset of wavelength in the band is not appropriate. DSCMs address this issue by providing a wavelength dependent amount of dispersion compensation.


2-1

Optical layer building blocks 2-This chapter describes the Nortel Networks optical layer solution for transport networks. It provides a description of the functional building blocks required for deploying all the applications described in this applications guide.

Optical layer functional building blocksYou can combine the components of the optical layer in several ways to make a variety of optical link applications. To facilitate the planning process, Nortel Networks has defined building blocks which you can combine using engineering rules to create the required applications.

The building blocks in this applications guide consist of OPTera Long Haul 1600 DWDM components. These components are used to create a 100 GHz spaced system with the 1600G Amplifiers. Currently, OPTera Long Haul 1600 C-Band unidirectional applications support a maximum of 40 wavelengths.

Link modelsIn OPTera Long Haul 1600 line applications, Terminal sites are designated as Term1 or Term2, and Line Amplifier Sites are designated as LA1, LA2, LA3, LA4 or LA5. Refer to Figure 2-1 for a better understanding of the OPTera Long Haul 1600 naming conventions used to identify the terminal amplifier sites and the line amplifier sites.

In all the link budgets rules, LA1 is the first line site nearest to the transmitter. With the DCMs/DSCMs deployment rule, note that LA1 in one direction does not correspond LA1 in the opposite direction. The same principle also applies to the other LA sites.


2-2 Optical layer building blocks

Figure 2-14-span unidirectional link

OTP1128.eps

Tx Rx

Mux

Dem

ux

λs

λsTxRx

Mux

Dem

ux

Legend

- 1600G Amplifier - unidirectional

Term1, Rx LA3

Direction 1

Direction 2

Term1, Tx LA1 LA2 LA3

LA2 LA1 Term2, Tx

Term2, Rx


Optical layer building blocks 2-3

Configuration overviewThis section describes, at the functional level, the key attributes and the various configurations for the OPTera Long Haul 1600 based building blocks. These building blocks are divided into three categories:

• Standard configurations building blocks

• Special configuration building blocks

• Mux/Demux building blocks

Standard configurations building blocksThis section provides specific descriptions of all amplifier sites used in OPTera Long Haul 1600 C-Band unidirectional applications.

Figure 2-2 shows the Tx-end amplifier site, commonly called Term1. In addition to Term1, Figure 2-3 also shows one amplifier in the link. This amplifier is designated as a line amplifier site, commonly known as an LA.

Figure 2-4 shows the Rx-end amplifier site, commonly called Term2.

Figure 2-2Term1 site configuration

OTP1633p.eps

Dual Amp

UniOSC

OS

C2

OS

C1

MSA 1AB

MSA 2AB

Legend

- WDM Coupler

- Faceplate connector

- EDFA

- Circulator

- Pad

- Internal Tap Coupler

Booster Amp

Booster Amp Direction 1Direction 2

OSC1ADD

OSC1DROP

2B

1A

2A

1B

Mux

Dem

ux

Note: MSA is mid-stage access for the DCM/DSCM

Common Tx Pad

MSAPad

SpanPad

MSAPad

IN-1

IN-2

OUT-2 UPB

UPA-2

OUT-1



Figure 2-3LA site configuration

OTP1637p.eps

Dual Amp

UniOSC

OS

C2

OS

C1

MSA 1AB

MSA 2AB

Legend

- WDM Coupler


- EDFA

- Circulator

- Pad

Booster Amp

Booster Amp

Direction 1

Direction 2

OSC2ADD

OSC1ADD

OSC1DROP

OSC2DROP

2B

1A 1B

2A

Note: MSA is mid-stage access for the DCM/DSCM and/or the OADM filter

SpanPad

SpanPad

MSAPad

MSAPad


IN-1

IN

IN

OUT

UPB

UPB

UPA-2

UPA-1OUT

IN-2

OUT-2

OUT-1




OTP1635p.eps

Dual Amp

Uni OSCO

SC

2

OS

C1

MSA 1AB

MSA 2AB

Legend

- WDM Coupler


- EDFA

- Circulator

- Pad


Booster Amp

Booster Amp

Direction 1

Direction 2

OSC2ADD

OSC2DROP

2B

1A

2A

1B

Mux

Dem

ux

MSAPad

Common Tx Pad

SpanPad

MSAPad




Special configuration building blocksFigure 2-5 shows the special asymmetric configuration required at the Tx-end terminal amplifier site used in some of the OPTera Long Haul 1600 C-Band unidirectional applications. The special link engineering considerations require signals to bypass the dual amplifier in the Tx direction at the head-end Tx site.

Figure 2-5Term1 site special configuration (dual amplifier bypass)

OTP1639p.eps

1600G amplifier group descriptionThe 1600G amplifier group, which includes the C-Band Dual-Amplifier and Boosters 18 and 21, amplifies a maximum of 40λ C-Band wavelengths in a unidirectional DWDM link. Dispersion compensation is achieved by installing DCMs/DSCMs in the mid-stage access (MSA) of the OPTera Long Haul 1600.

The Dual-Amplifier supports two independent amplifiers that are each provisionable for a total output power of up to +15.5 dBm.

Booster18 can be provisioned to provide +18 dBm of output power. Booster21 can be provisioned to provide +21 dBm of output power.

Legend

- WDM Coupler


- EDFA

- Circulator

- Pad Note: MSA is mid-stage access for the DCM/DSCM

Dual Amp

UniOSC

OS

C2

OS

C1

MSA 2AB

Booster Amp 1B

Booster Amp 2BDirection 1

UPB

UPA-2

Direction 2

OSC1ADD

OSC1DROP

Dem

ux

1A

2A

1B

2B

MSAPad

SpanPad


Mux

Common Tx Pad



Booster18 and Booster21 are amplifiers that consist of an input port, output port, a coupler port, and an interleave port (circulator port) for bidirectional configurations. The circulator port acts as an output isolator and an upgrade port for interleaved filter-based amplifier topology. The interleave port will be available in future releases where bidirectionality is supported.

The Line Amp Site is the only site which applies OADM support.

Tap couplers provide access to optical signals for the purpose of power measurement and monitoring. While the current version of the C-Band Dual Amplifier has a built-in internal tap coupler, earlier versions did not. If you have an earlier version of the C-Band Dual Amplifier, you must use an External Tap Coupler Assembly to gain access to optical signals for monitoring.

1600G Amplifier building block componentsThe following components are used in specific amplifier sites:

• C-Band Dual-Amplifier

• C-Band Booster18/Booster21 amplifiers

• Optical pads where applicable

• Dispersion and dispersion slope compensating modules (DCM/DSCM)

• UniOSC or BiOSC

• C-Band Grid 1 Mux/Demux couplers (Terminal sites only)

• OADM couplers (Line amplifier sites only)

Wavelength capacityIn a unidirectional application, the Dual Amplifier used with Booster18 can support up to 20 C-Band wavelengths on one fiber.

In a unidirectional application, the Dual Amplifier used with Booster21 can support up to 40 C-Band wavelengths on one fiber.

Mid-stage access (MSA) rulesTo enhance optical networking, optical passive devices such as OADM and DCMs/DSCMs are used in the mid-stage access. The optical loss in the mid-stage access of the 1600G amplifiers must be kept close to 10 dB. Therefore, the sum of the insertion loss of all the components inserted in the mid-stage (DCMs/DSCMs and optical pads) must be as close as possible to 10 dB, unless specified otherwise.

ATTENTIONFor 1600G amplifiers without internal tap couplers, please refer to OPTera Long Haul 1600 External Tap Coupler Guide (NTY312GC).



Padding rulesCommon padding is used at Tx, MSA, and span (link) side. The intent of the rules is to deploy common pads for all wavelength counts. This way, there is no need to change pads as channels are added.

The Common Tx Pad must be placed between the output of Mux and the input to the first in-service amplifier (FISA). MSA pads must be placed between Dual-Amp and DCM/DSCM if there is a DCM/DSCM present. Span pads must be placed after the Booster output. Refer to Figure 2-2, Figure 2-3, Figure 2-4, and Figure 2-5.

Usage with 1480/1510 nm OSCs or 1510/1615 nm OSCsNortel Networks offers two types of OSC circuit packs: a unidirectional and bidirectional OSC. Use the UniOSC 1480/1510 nm only in a unidirectional network. If there are plans to migrate from a unidirectional network to a bidirectional network, then use the BiOSC 1480/1510 nm circuit pack.

Note: Nortel Networks has introduced a new OSC which uses wavelengths 1510/1615 nm.

Note: Link budgets for unidirectional and bidirectional implementations of OPTera Long Haul 1600 are different. If you plan to transition a network from a unidirectional to bidirectional implementation, contact Nortel Networks for detailed guidelines.

Unused ports Amplifier unused portsDo not terminate the unused ports of the Dual Amp and Booster. The unused ports of the Dual Amp are labelled UPB-1 and UPB-2. The unused ports of the Booster are labelled UPB and INTLV.



Mux/Demux building blocksThis section provides specific descriptions for Mux/Demux modules used in OPTera Long Haul 1600 C-Band unidirectional applications. Figure 2-6 and Figure 2-7 show Mux/Demux architectures.

Figure 2-6Mux modules architecture

OTP0828.eps

1546.12 through 1554.13

To 1600G Amplifier

Monitor Port (Tx)

Common Port

Note: A and B are external patchcords.

Tx

Module 1

Module 2Module 3

Module 4

TxTx

Tx

1538.19 through 1545.32

1530.33 through 1537.40

1554.94 through 1562.23

SpareWavelength

Port

A B

A B A B



Figure 2-7Demux modules architecture

OTP0829.eps

Configuration descriptionThe Mux modules multiplex a maximum of 40 wavelengths onto a single fiber. The Demux modules demultiplex a maximum of 40 wavelengths from a single fiber.

Rx

Module 1

Module 2Module 3

Module 4

RxRx

Rx

SpareWavelength

Port 1546.12 through 1554.13

1538.19 through 1545.32

1530.33 through 1537.40

1554.94 through 1562.23

Note: A and B are external patchcords.

A BA B

A B

Monitor Port (Rx)

Common Port

To 1600G Amplifier



Mux/Demux building blocks componentsThe following components are currently used in specific Mux/Demux configurations:

Grid 1:

• Module 1 (1546.92 nm to 1554.13 nm, Spare: 1546.12 nm)

• Module 2 (1554.94 nm to 1562.23 nm)

• Module 3 (1538.19 nm to 1545.32 nm)

• Module 4 (1530.33 nm to 1537.40 nm)

Grid 2:

• Module 1 (1547.32 nm to 1554.54 nm, Spare: 1546.52 nm)

• Module 2 (1555.34 nm to 1562.64 nm)

• Module 3 (1538.58 nm to 1545.72 nm)

• Module 4 (1530.72 nm to 1537.79 nm)

Wavelength capacityUp to four modules (mux/demux) are interconnected in cascade to support up to 40 C-Band wavelengths, plus 1 optional spare, in each wavelength grid. Each module carries 10 C-Band wavelengths except for the first module that contains the spare wavelength.

Spare wavelengthsOne spare wavelength, 1546.12 nm Grid 1 or 1546.52 nm Grid 2, can be added or extracted from the fiber using the DWDM baseline coupler.

Module deploymentIn a typical unidirectional application, the Mux and Demux is based on the same grid. This means that when starting to deploy Grid 1, you have to continue deploying Grid 1 until all its capacity is exhausted for all fiber types. If you intend to migrate a unidirectional application to a bidirectional application at a later date, you must use Grid 1 on one direction, and Grid 2 on the counterpropagating direction.

Note: Link budgets for unidirectional and bidirectional implementations of OPTera Long Haul 1600 are different. If you plan to transition a network from a unidirectional to bidirectional implementation, contact Nortel Networks for detailed guidelines.



Unused ports All unused upgrade ports of Mux modules must be terminated with low-reflection terminators. Terminate all ports of the Demux modules with low-reflection terminators.

The upgrade ports of Mux Module 1 are:

• Upgrade A from Module 2

• Upgrade B from Module 2



The upgrade ports of Demux Module 1 are:

• Upgrade A to Module 2

• Upgrade B to Module 2



The upgrade ports of Mux Module 3 are:



The upgrade ports of Demux Module 3 are:




3-1

Optical link engineering rules 3-This chapter provides the optical link budgets and engineering rules required to deploy 1600G amplifiers DWDM systems. Table 3-1 provides the steps to follow when using this guide to design the links. This chapter includes the following sections:

• optical link engineering procedure

• optical link transmission performance guarantee

• link engineering rules

ATTENTIONFor all optical link budgets for the OPTera Long Haul 1600 systems, the specified bit error rate (BER of 10-15) is guaranteed for the projected end-of-life (EOL) target of 10 years with single Forward Error Correction (FEC) turned on.

For all WT applications which presently do not support FEC feature, contact Nortel Networks.

ATTENTIONLink budgets for unidirectional and bidirectional implementations of OPTera Long Haul 1600 are different. If you plan to transition a network from a unidirectional to bidirectional implementation, contact Nortel Networks for detailed guidelines.

ATTENTIONOptical links deployed on a mix of fiber types are not supported in the rules provided in this applications guide. For more information, contact Nortel Networks.


3-2 Optical link engineering rules

ATTENTIONFor the 10 Gbit/s system link budgets, the numbers given in this chapter for maximum allowed span loss take into account the presence of an optical patch panel that connects the OPTera Long Haul 1600 input/output port to the line fiber. Read “Optical patch panel rule” on page 3-11 for more information when designing systems with sites equipped with optical patch panels.

ATTENTIONThe link engineering rules for 2.5 Gbit/s systems are not currently documented. Contact Nortel Networks for more information.

Table 3-1Link design steps

Step no. Action

1 Use Table 3-2 on page 3-3 to locate the engineering rules specific to the deployed application on the selected fiber type, and read the corresponding rules.

If the link engineering rules are not available, contact Nortel Networks.

2 Refer to Chapter 2, “Optical layer building blocks” for more information about the building blocks for the system to be deployed. For detailed information about the building block components, refer to Chapter 5, “Optical layer components specifications”.

3 Use Chapter 3, “Optical link engineering rules” to design the optical link properly. Proceed with the following steps:

• Read “Deployment considerations for OPTera Long Haul 1600 optical layer applications” on page 3-4 for an overview of the link engineering process. Look at the link engineering process flow chart (Figure 3-1 on page 3-6) to verify the required steps required to design of a DWDM link.

• Read the “Application-independent optical link engineering rules” on page 4-1 for application type independent rules (Tx chirp, PMD and MSA loss).

• Check the appropriate wavelength plan required for the system by reading “Nortel Networks 100 GHz ITU-T compliant wavelength grid” on page 4-5.


Optical link engineering rules 3-3

Link engineering rules for OPTera Long Haul 1600 C-Band unidirectional applications

Use Table 3-2 to find the page number of the unidirectional engineering rules for each fiber type.

Table 3-2Page location of the engineering rules

Fiber type Line rate Wavelength capacity

Number of spans

Supported configuration

Page

NDSF 10 Gbit/s 1 to 40 1 to 6 Dual-Amplifier and Booster21, Dual-Amplifier

Bypass

page 3-13

(see Note 1)

TW Classic 10 Gbit/s 1 to 30

(see Note 2)

1 to 6 Dual-Amplifier and Booster18

or Dual-Amplifier and Booster21

page 3-25

(see Note 1)

E-LEAF 10 Gbit/s 1 to 40

(see Note 2)

1 to 6 Dual-Amplifier and Booster21,

Dual-Amplifier Bypass

page 3-30

(see Note 1)

TW Plus 10 Gbit/s 1 to 40

(see Note 2)



(See Note 3)

page 3-35

LS 10 Gbit/s 1 to 20 1 to 6 Dual-Amplifier and Booster18

page 3-40

TW RS 10 Gbit/s 1 to 40

(see Note 2)



page 3-45

Note 1: Read the attention messages on page 3-4

Note 2: Currently, 1 to 20λ can be deployed with OPTera Long Haul 1600 Release 3.

Note 3: 6-span TW+ link requires the use of a Dual Amp and Booster 18 rather than the Dual Amp and Booster 21 suggested.



Deployment considerations for OPTera Long Haul 1600 optical layer applications

The selection of an application and its corresponding link engineering rules depends on the following factors:

• the fiber plant on which the application is to be deployed

• the maximum wavelength capacity the link is designed to support

• the number of optical spans in the link and their loss profile

• the total length of the link

OPTera Long Haul 1600 optical link currently supports up to 40 wavelengths on a single fiber with 100 GHz spacing between the copropagating optical channels. Future releases of OPTera Long Haul 1600 will support up to 160 wavelengths on a single fiber. However, to fully define an application, link budgets and engineering rules are required.

Link budgets are in constant development, supporting new fiber types and increasing the capacity of the systems. In the following sections, the statement that a given combination of wavelength number and fiber type is not supported might not mean that the hardware is not designed to meet the requirement, but rather that the link budget and engineering rules for that specific application have not been developed.

If specific information is required about an application type that does not have link engineering rules for a given fiber and wavelength capacity scenario, contact Nortel Networks.

For more information about how the characteristics of various optical fibers affect the link budget and engineering rules, refer to “Appendix B: Overview of fiber-optic fundamentals”.

ATTENTIONOPTera Long Haul 1600 OADM deployment rules are under development and will be presented at a later date.



Optical link engineering procedureBefore you perform an optical link design, refer to the following requirements:

• the span loss profile

Note: Measured data is recommended.

• the span lengths in kilometers

Note: Measured data is recommended.

• the chromatic and polarization mode dispersion (PMD) profile

Note: If required, Nortel Networks can provide engineering services for performing and interpreting these measurements. Contact your Nortel Networks sales representative for details.

Optical link budgets and span loss rulesTo make network planning easier, special span loss rules and guidelines have been developed to provide added flexibility in matching Nortel Networks link budgets with field systems. The link budget tables detail loss in terms of a maximum allowed loss per span. This loss is the typical acceptable maximum loss per span for the link.

The design can exceed this span loss slightly on some of the spans if the cumulative loss for the link (the sum of all the span losses) remains within a predetermined range. The approach is to acquire unused marginal loss from shorter spans and add it to the higher loss spans. A detailed interpretation of the guidelines and rules follow. Figure 3-1 shows the link design procedure flow chart.



Figure 3-1Link design procedure flow chart

OTP1155.eps

No

No

Re-engineer the link

Yes

Yes

Yes

Contact Nortel Networks

for more information

Is total link loss > (maximum allowed span loss x number of spans)?

Link design is complete

Yes

Yes

No Contact Nortel Networksfor more information

Does any span exceed maximum allowed + 1 dB?

Determine the Excess Loss in

the link

Is the Total Excess Loss

≤ 1 dB?


> 1 dB but ≤ 2 dB?

No

No

No derating required

Derate the maximum span loss by the amount indicated in Table 3-3

Is total link loss > (maximum derated span loss x number of spans)?

No

Yes

Yes

Does any span exceed maximum allowed + 2 dB?

Determine the Excess Loss in

the link


≤ 2 dB?


≤ 3 dB?

No

Derate the maximum span loss by the amount indicated in Table 3-5

Is total link loss > (maximum derated span loss x number

of spans)?

No

Derate the maximum span loss by the amount indicated in Table 3-4Yes

No

Link design is complete

Determine the following:1. Common Tx Pad2. MSA Pad and DCMs/ DSCMs required and their locations3. Span PadDetermine the following:

1. Common Tx Pad2. MSA Pad and DCMs/ DSCMs required and their locations3. Span Pad

No

Yes

Is the link within the supported window of operation (km)?

Yes

Calculate total link loss (sum of span losses) for the link

If required, add fixed pads to get span

loss ≥ minimum required

Is there a configuration that supports this fibertype for a particuliar

number of wavelengths and determined number

of spans ?



Span loss rules and guidelinesSpan loss assumptionThe span losses listed in the link budget tables are specified from the output of the Booster to the input of the Dual-Amplifier. They assume measured or calculated losses between building blocks, including a 0.25 dB connector loss at each amplifier. Additional loss must be added to the span as follows:

• When using OPTera Long Haul 1600 C-Band unidirectional link engineering rules for 10 Gbit/s, you can increase 1600G amplifier peak power clamp (overlaunch) to compensate for fiber patch panel losses at the head end of a span. See the “Optical patch panel rule” on page 3-11 for more details.

• Any losses related to splices or fiber distribution panels along the span must be added to the calculated or measured fiber loss.

Figure 3-2 shows the span loss (Lspan) calculation zone where Lspan is the sum of the fiber patch panel losses (Lopp) and the fiber loss (Lfiber). The value of Lspan must be between 17 dB and the maximum allowed loss per span (Lmax).

Figure 3-2Span loss calculation

OTP1156.eps

from mux/demux or MSA site

to mux/demux or MSA site

Direction 1

optical patch panel

opticalpatch panel

Span loss (Lspan) Calculation Zone

Legend

1600G Amplifier

Lspan = Lopp + Lfiber + Lopp17 dB ≤ Lspan ≤ Lmax

Lopp Lfiber

Lopp



Total allowed link lossThe total allowed link loss is the sum of the maximum allowed span loss for the candidate link.

Total link loss marginThe total link loss (the sum of all span losses for the candidate link) must be between N x Lmin and N x Lmax, where N is number of spans, Lmax is the maximum allowed loss per span provided in the link budget tables, and Lmin is the minimum average loss per span.

Minimum allowable span lossThe minimum allowable loss per span is 17 dB unless otherwise indicated. If a measured span loss is below this threshold, add fixed attenuation to achieve the minimum requirement. Use this higher loss as your measured span loss. Make sure that the fixed pads attenuate all wavelengths linearly and do not introduce ripple.

Excess lossThe excess loss penalty is defined as a function of fiber type and span count. The excess loss of each span is defined as the excess loss above Lmax (the maximum allowed loss per span). For each span, note the amount of loss that exceeds the maximum allowed span loss. Each of the obtained values constitutes the per-span excess loss. See “Link design procedure flow chart” on page 3-6 to follow the procedure for derating the link budgets for excess loss when it applies. This procedure refers to Table 3-3, Table 3-4 andTable 3-5. Please note that excess loss penalty rules are defined only for NDSF, TWTM Classic, and E-LEAF fiber in this issue.

Maximum allowable per-span excess lossThe maximum allowable per-span excess loss is Lmax + εi dB, where εi is the excess loss for span i (1 ≤ i ≤ n; n = total number of spans).

Total excess loss (EL)The total excess loss (EL) is the sum of all per-span excess loss over the link.

EL = , where n is the total number of spans.

Table 3-3, Table 3-4, and Table 3-5 provide the derating factor which needs to be subtracted from the link budget given in this applications guide. These derating factors are based on Lmax and EL.

εi

i 1=

n

∑



PMD marginRefer to “Polarization mode dispersion (PMD) consideration” on page 4-4 to determine if the average loss per span must be derated.

Table 3-3Per span excess loss ≤≤≤≤ 1 dB with total excess loss > 1 dB but ≤ ≤ ≤ ≤ 2 dB

Per fiber type derating values

Span Count NDSF TWTM Classic E-LEAF

3 0 dB 0 dB 0 dB

4 0.5 dB 0 dB 0 dB

5 0 dB 0 dB 0 dB

6 0 dB 0 dB 0.5 dB

Table 3-4Per span excess loss ≤≤≤≤ 2 dB with total excess loss ≤ ≤ ≤ ≤ 2 dB



2 1 dB 0 dB 0.5 dB

3 0 dB 0.5 dB 0.5 dB

4 0.5 dB 0 dB 0.5 dB

5 0.5 dB 0 dB 0.5 dB

6 0.5 dB 0 dB 1 dB

Table 3-5Per span excess loss ≤≤≤≤ 2 dB with total excess loss ≤ ≤ ≤ ≤ 3 dB



3 0.5 dB 0.5 dB 1 dB

4 1.5 dB 0.5 dB 1 dB

5 1 dB 0 dB 1.5 dB

6 1 dB 0 dB 1.5 dB



Derating exampleUse the following example to understand the procedure for derating link budgets when excess loss rules apply.

Link information:

• Fiber type: 300 km of E-LEAF

• Span 1: 98 km with a loss of 28.5 dB

• Span 2: 100 km with a loss of 17 dB

• Span 3: 102 km with a loss of 29 dB

• Link budget for 3-span E-LEAF is 28 dB. The supported window for this budget is between 253 km and 345 km as detailed in Table 3-14.

The allowable difference in span lengths for E-LEAF system is 28 km. The difference in length between the minimum and maximum span length cannot be greater than 28 km, otherwise an alternative DCM/DSCM strategy is required. In this example, the minimum span length is 98 km and the maximum span length is 102 km. 102 km - 98 km = 2 km which is lower than 28 km. Therefore, we can apply the DCM/DSCM strategy provided in Table 3-14.

Follow the flow chart on page 3-6 to find:

1 Is the total link loss greater than the maximum allowed span loss times the number of spans?

No, because (28.5 dB + 17 dB + 29 dB = 74.5 dB) is not greater than(3 × 28 dB = 84 dB).

2 Does any span exceed the maximum allowed by more than 1 dB?Yes.

3 Does any span exceed the maximum allowed by more than 2 dB?No.

4 Determine the total excess loss (EL).

Span 1: 28.5 dB ⇒ Excess Loss of Span 1 = ε1 = 0.5 dB

Span 2: 17 dB ⇒ Excess Loss of Span 2 =ε2 = 0 dB

Span 3: 29 dB ⇒ Excess Loss of Span 3 = ε3 = 1 dB

EL = ε1 + ε2 + ε3 =0.5 dB + 0 dB + 1 dB = 1.5 dB

5 Is EL lower or equal to 2 dB?

Yes. Then derate the maximum span loss by the amount indicated in Table 3-4. For a 3-span system on E-LEAF, Table 3-4 shows that the link budget must be derated by 0.5 dB. This means that our new budget is:

New budget = 28 dB/span − 0.5 dB/span = 27.5 dB/span



6 Is the total link loss greater than the maximum derated span loss times the number of spans?

No, because (28.5 dB + 17 dB + 29 dB = 74.5 dB) is not greater than(3 × 27.5 dB = 82.5 dB).

7 Derating and Excess Loss Procedure completed.

Padding rulesThree types of pads are used in all OPTera Long Haul 1600 applications: Common Tx pads, MSA pads and Span pads.

Common Tx padsCommon Transmitter (Tx) pads are attenuators placed at the head-end of the optical link. The strategy is to use the same attenuators for all channel counts supported by any application. The common Tx pad must be placed between the output of the Mux coupler and the input of the first-in-service amplifier (FISA), that is before the DCM/DSCM if there is a DCM/DSCM present. See Figure 2-2, Figure 2-3, Figure 2-4, and Figure 2-5 for detailed placement of Common Tx pads at Term1 and Term2 Amplifier sites.

MSA padsMSA pads are attenuators placed in the OPTera Long Haul 1600 mid-stage access (MSA). MSA pads must be placed immediately after the Dual-Amplifier output, that is before the DCM/DSCM if there is a DCM/DSCM present. See Figure 2-2, Figure 2-3, Figure 2-4, and Figure 2-5 for detailed placement of MSA pads at Term1, Term2 and Line Amplifier sites.

Span padsSpan pads are attenuators placed in line in order to bring the link attenuation within the prescribed range. Span pads must be placed after the Booster output. See Figure 2-2, Figure 2-5, and Figure 2-4 for detailed placement of MSA pads at Term1, Term2 and Line Amplifier sites.

Optical patch panel ruleFor the OPTera Long Haul 1600 C-Band unidirectional applications with 10 Gbit/s link budgets, provisioning rules are designed to compensate for the patch panel loss at the head-end of the span, after the 1600G amplifier configured as a post or MSA post-amplifier.

Compensating for the patch panel loss requires higher output power from the amplifier. Therefore, if the patch panel is not installed at the head-end site, the output power of the OPTera Long Haul 1600 must be reduced to eliminate additional distortion penalties caused by channel powers being launched too high directly into the line fiber. In addition, to meet the specified performance, the maximum allowed span loss must be reduced by 0.5 dB if there is no optical patch panel at either head end site. Equivalently, a 0.5 dB penalty can be added to the measured span loss and the maximum allowed span loss given in this guide can be used without modification.



Optical link transmission performance guaranteeThe transmission performance of S/DMS TransportNode 10 Gbit/s and equivalent SDH systems for OPTera Long Haul 1600 C-Band unidirectional applications is provided for worst-case end-of-life (EOL) parameters. EOL parameters include system and equipment impairments caused by deployment, aging, and temperature degradation over a 10-year period.

The link budgets provided are guaranteed for an EOL bit error rate (BER) of 10-15 on all DWDM channels, with single Forward Error Correction (FEC) turned on.

To comply with the Nortel Networks performance guarantee, you must meet the following requirements:

• Use Nortel Networks optical modules (transmitters, couplers, DCMs, amplifiers, receiver).

• Design the optical link according to the link engineering and provisioning rules defined in this application guide.

• Set up the optical link according to the system lineup and test (SLAT) procedures provided by Nortel Networks.

Note: Nortel Networks guarantees BER performance for links that have optical return loss (ORL) equal to or in excess of 24 dB. Customers must note that networks containing mechanical splices and biconic connectors may not meet this requirement. It is recommended that you use tuned optical connectors.



OPTera Long Haul 1600 C-Band unidirectional applications on NDSF fiber multiplexing 10 Gbit/s channels

Use this section for DWDM systems carrying 10 Gbit/s channels.

You can deploy the following:

• 1 to 6 span systems with a maximum of 40 wavelengths

For a proper design, you must follow these steps:

• Verify that the loss of each span in the link is equal to or below the values that appear in Table 3-6. If optical patch panels are not installed at all sites, follow the derating procedure explained in “Optical patch panel rule” on page 3-11. You can use the excess loss borrowing method described on page 3-9 in paragraphs 4 to 7, if applicable.

• Select the appropriate DCM/DSCM deployment for the given link length using Table 3-6. DCM/DSCM placement is very specific. DCMs/DSCMs must be placed as indicated in Table 3-6.

• Read the remainder of the section for amplifier provisioning rules and padding rules information.

ATTENTION• All links must meet both the maximum allowed span loss and the related dispersion window of operation.

• Dispersion windows of operation are strictly applicable to the number of spans for which they are designed.

ATTENTIONFEC must always be turned on. For all WT applications which presently do not support FEC feature, contact Nortel Networks.

ATTENTIONAlthough the current OPTera Long Haul 1600 hardware is compatible for a channel count of 40λ per band on NDSF, OPTera Long Haul 1600 Release 3 only supports channel power monitoring capabilities for a wavelength count less than or equal to 20 (Module 1 and Module 2 only). As a result, peak power clamp and Power Optimizer is only available for links with channel counts less than or equal to 20 (Module 1 and Module 2 only).



Maximum allowed span loss, dispersion windows and DCM/DSCM deployment rulesAlways design the link for the final number of wavelengths that is to be multiplexed in it after all the planned upgrades.

NDSF wavelength planThis application supports wavelength plans spanning from 1530.33 nm to 1562.23 nm (Grid 1) or 1530.72 nm to 1562.64 nm (Grid 2). Use Module 1, Module 2, Module 3 and Module 4 with applications on NDSF fiber. NSDF has a special wavelength upgrade plan requiring that the wavelengths fall within successive groups of five Reddest. See “Wavelength plans” on page 4-6 for more information.

Tx chirpThe required transmitter chirp is negative chirp for this particular fiber type application. See “Tx chirp adjustment for dispersion compensation” on page 4-1 for more information.

FEC rulesFor all spans, FEC must be turned on and the EOL BER is 10-15.

Common Tx PadsCommon Transmitter (Tx) Pads are attenuators placed at the head-end of the optical link. The strategy is to use the same attenuators for all channel counts supported by any application. The common Tx pad must be placed between the output of the Mux coupler and the input of the first-in-service amplifier (FISA), that is before the DCM/DSCM if there is a DCM/DSCM present. See Table 3-6 for detailed placement of Common Tx Pads.

ATTENTIONFor NDSF applications, in conjunction with OPTera Long Haul 1600 Release 3 software, an external Optical Spectrum Analyzer (OSA) must be used to scale capacity and balance power levels above 20 wavelengths. Above 20 wavelengths, scaling channel capacity with Power Optimizer (PO) will be addressed in future OPTera Long Haul 1600 software releases.

ATTENTIONThe allowable difference in span lengths for NDSF system is 5 km. The difference in length between the maximum and minimum span length cannot be greater than 5 km, otherwise, an alternative DCM/DSCM strategy is required.



MSA padsIt is possible that MSA padding is required at OPTera Long Haul 1600 line amplifier sites to set the loss in the mid-stage. MSA Pads must be placed immediately after the Dual Amplifier output (before the DCM/DSCM) if there is a DCM/DSCM present. See the OPTera Long Haul 1600 MSA rules on page 4-2 for more information.

Span padsSpan Pads are attenuators placed in line in order to bring the link attenuation within the prescribed range. Span Pads must be placed after the Booster output.

NDSF fiber link with external tap couplerFor applications with an external tap coupler at the amplifier output, an additional power loss of 0.5 dB must be considered for the tap coupler and connector.

In general, all external tap couplers at the output of the dual amplifier are placed before the fixed pad or DSCM at MSA.

The following engineering rules apply:

• At the dual amplifier output, there is no change to the MSA padding rule. However, the Dual Amp peak power must be increased by 0.5 dB (over launching).

• There is no need to over-launch at booster outputs.

For more information, refer to Appendix D: External tap couplers. If you do not have a 1600G C-band amplifier with an external tap coupler, these rules do not apply.



Table 3-6Maximum allowed span loss, dispersion compensation rules and padding rules for 1-40λλλλ applications deployed on NDSF fiber, 10 Gbit/s channels (See Note 1 and Note 2)

10G, NDSF, C-Band, Unidirectional, 1-40λ, Dual-Amp and Booster21 Config., Dual-Amp Bypass

Span Max. Avg. Loss

[dB/span](see Note 3)

DSCM(see Notes 4, 5, 6, and 7)

Total Length Compensation

[km](see Note 10)

Common Tx Pad Required

[dB](see Notes 8

and 9)

1 32 T1C DSCM-70 at Rx 74-142 2

2 30

T1C DSCM-70 at LA1, T1C DSCM-40 at Rx

142-175

2


171-202


200-229

T1C DSCM-100 at LA1,

T1C DSCM-90 at Rx

227-253

3 28

T1C DSCM-100 at LA1, T1C DSCM-40 at LA2, T1C DSCM-50 at Rx

212-244

2


239-273


270-301


300-328

T1C DSCM-100 at LA1, LA2, Rx 327-353

—continued—



4 26

T1C DSCM-90 at LA1,T1C DSCM-60 at LA2,

T1C DSCM-50 at LA3, Rx

267-300

2



296-324

T1C DSCM-90 at LA1,

T1C DSCM-70 at LA2, LA3, Rx

318-345



343-370

T1C DSCM-110 at LA1,LA2,T1C DSCM-70 at LA3, Rx

370-396

T1C DSCM-110 at LA1,T1C DSCM-100 at LA2, T1C DSCM-90 at LA3, T1C DSCM-80 at Rx

392-413

T1C DSCM-110 at LA1, LA2, LA3,

T1C DSCM-70 at Rx

411-435

—continued—

Table 3-6 (continued)Maximum allowed span loss, dispersion compensation rules and padding rules for 1-40λλλλ applications deployed on NDSF fiber, 10 Gbit/s channels (See Note 1 and Note 2)


Span Max. Avg. Loss




[km](see Note 10)


[dB](see Notes 8

and 9)



5 25

T1C DSCM-100 at LA1, LA2,


415-439

2


T1C DSCM-70 at LA3,T1C DSCM-80 at LA4, Rx

436-459


T1C DSCM-90 at LA3, T1C DSCM-80 at LA4, Rx

454-478



477-498

T1C DSCM-100 at LA1, LA2, LA3


492-508



505-520


T1C DSCM-100 at LA3, LA4, T1C DSCM-90 at Rx

518-532



531-544

—continued—



Span Max. Avg. Loss




[km](see Note 10)


[dB](see Notes 8

and 9)



6 24


T1C DSCM-90 at LA2, LA3, LA4,


541-551

2


T1C DSCM-90 at LA2, LA3, LA4, LA5

T1C DSCM-80 at Rx

549-569




568-577




576-586

T1C DSCM-110 at LA1, LA2, LA3

T1C DSCM-80 at LA4, LA5

T1C DSCM-100 at Rx

586-598




590-607

—continued—



Span Max. Avg. Loss




[km](see Note 10)


[dB](see Notes 8

and 9)



Provisioning rules

The provisioning rules over NDSF are described in the following tables:

• Table 3-7 gives the 1-20λ provisioning rules





For the wavelength count 1-20λ, the peak power clamp is enabled on all line amplifiers.

For the wavelength count 21-40λ, the peak power clamp is enabled on all amplifiers at Tx. Also, the peak power clamp is enabled on all amplifiers at Rx in 1-span case.

Note 1: All budgets require single Forward Error Correction (FEC) on.

Note 2: Loss is calculated from the Fiber Side of Post Amp to fibre side of Pre Amp.

Note 3: The supported minimum span loss is 17 dB for 1- to 5-span links. Minimum span loss is 18dB for 6 span.

Note 4: LA1 is the first line site closest to the transmitter, LA2 is the second line site closest to thetransmitter on a direction basis.

Note 5: All the DSCM used here are C-Band Type 1 DSCMs (T1C DSCM).

Note 6: MSA loss rule is 10dB (8 to 11dB)

Note 7: DSCM at the MSA site must be placed after the MSA pad. DSCM at Rx must be placed in the MSA of the Demux site.

Note 8: The same fixed transmitter pad is applied to 1-40λ applications.

Note 9: The Common Tx Pad must be placed between the output of the Module 1 Mux DWDMcoupler and at the input of the head-end amp.

Note 10: The allowable difference between the minimum and maximum span lengths for the NDSF system is 5 km, with the exception of single span.



Span Max. Avg. Loss




[km](see Note 10)


[dB](see Notes 8

and 9)



Table 3-7Provisioning rules for 1-20λλλλ applications deployed on NDSF fiber, 10 Gbit/s channels

10G, NDSF, C-Band, Unidirectional, 1-20λ, Dual Amp. Booster21 Config., Dual-Amp Bypass

Span

Transmitter Site Line Site Receiver Site

Dual Booster21 Dual Booster21 Dual Booster21

Peak Power [dBm]

Total Power[dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

1 N/A N/A 6.5 21 -- -- -- -- 0 15.5 8 21

2 N/A N/A 6.5 21 0 15.5 6.5 21 0 15.5 8 21

3 N/A N/A 6.5 21 0 15.5 6.5 21 0 15.5 8 21

4 N/A N/A 6.5 21 0 15.5 6.5 21 0 15.5 8 21

5 N/A N/A 6.5 21 0 15.5 6.5 21 0 15.5 8 21

6 N/A N/A 6.5 21 0 15.5 6.5 21 0 15.5 8 21

Note: The peak power clamp is enabled on all amplifiers.



Span



Peak Power [dBm]

Total Power[dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

1 N/A N/A 6.5 21 -- -- -- -- 0 15.5 8 21

2 N/A N/A 6.5 21 -- 13.7 -- 20.8 -- 13.7 -- 21

3 N/A N/A 6.5 21 -- 13.6 -- 19.4 -- 13.6 -- 21

4 N/A N/A 6.5 21 -- 13.0 -- 19.4 -- 13.0 -- 21

5 N/A N/A 6.5 21 -- 13.8 -- 19.0 -- 13.8 -- 21

6 N/A N/A 6.5 21 -- 14.4 -- 19.5 -- 14.4 -- 21

Note 1: The peak power clamp is enabled on all amplifiers in a 1-span link

Note 2: The peak power clamp is disabled on all line amplifiers and Term2 amplifiers. The peak power clamp is enabled on all Term1 amplifiers in all applications.

Note 3: Do not round the total power value.





Span



Peak Power [dBm]

Total Power[dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

1 N/A N/A 6.5 21 -- -- -- -- 0 15.5 8 21

2 N/A N/A 6.5 21 -- 13.7 -- 20.8 -- 13.7 -- 21

3 N/A N/A 6.5 21 -- 14.0 -- 19.4 -- 14.0 -- 21

4 N/A N/A 6.5 21 -- 13.8 -- 19.4 -- 13.8 -- 21

5 N/A N/A 6.5 21 -- 14.2 -- 19.4 -- 14.2 -- 21

6 N/A N/A 6.5 21 -- 14.8 -- 19.8 -- 14.8 -- 21








Span



Peak Power [dBm]

Total Power[dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

1 N/A N/A 6.5 21 -- -- -- -- 0 15.5 8 21

2 N/A N/A 6.5 21 -- 13.7 -- 20.8 -- 13.7 -- 21

3 N/A N/A 6.5 21 -- 14.3 -- 19.4 -- 14.3 -- 21

4 N/A N/A 6.5 21 -- 14.0 -- 19.4 -- 14.0 -- 21

5 N/A N/A 6.5 21 -- 14.5 -- 19.4 -- 14.5 -- 21

6 N/A N/A 6.5 21 -- 15.2 -- 20.1 -- 15.2 -- 21








Span



Peak Power [dBm]

Total Power[dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

1 N/A N/A 6.5 21 -- -- -- -- 0 15.5 8 21

2 N/A N/A 6.5 21 -- 13.8 -- 21 -- 13.8 -- 21

3 N/A N/A 6.5 21 -- 14.3 -- 20.0 -- 14.3 -- 21

4 N/A N/A 6.5 21 -- 15.0 -- 20.0 -- 15.0 -- 21

5 N/A N/A 6.5 21 -- 15.0 -- 20.0 -- 15.0 -- 21

6 N/A N/A 6.5 21 -- 15.5 v 20.5 -- 15.5 -- 21






OPTera Long Haul 1600 C-Band unidirectional applications on TrueWave‘ Classic fiber multiplexing 10 Gbit/s channels

Use this section for DWDM systems carrying 10 Gbit/s.

You can deploy 1 to 6 span systems with a maximum of 30 wavelengths.




• Read the remainder of the section for amplifier provisioning rules, padding rules information.

ATTENTIONAll links must meet both the maximum allowed span loss and the related dispersion window of operation.

Dispersion windows of operation are strictly applicable to the number of spans for which they are designed.


ATTENTIONThe link budgets rules are compatible for 30 wavelengths channel count.

ATTENTIONThe power provisioning rules are available for up to 20 wavelengths applications. The power provisioning rules for 30 wavelengths count will be provided with a future OPTera Long Haul 1600 software release.




TrueWave ClassicTM Wavelength planThis application supports wavelength plans spanning from 1538.19 nm to 1562.23 nm (Grid 1) or 1538.58 nm to 1562.64 nm (Grid 2). Use Module 1, Module 2 and Module 3 with applications on TrueWave ClassicTM fiber. This channel wavelength plan is optimized for TrueWave ClassicTM fiber. See the Wavelength plans on page 4-6 for more information.



Common Tx PadsCommon Transmitter (Tx) Pads are attenuators placed at the head-end of the optical link. The strategy is to use the same attenuators for all channel counts supported by any application. The common Tx pad must be placed between the

ATTENTIONAlthough the current OPTera Long Haul 1600 hardware is compatible for a channel count of 30λ per band on TrueWave ClassicTM, OPTera Long Haul 1600 Release 3 only supports channel power monitoring capabilities for a wavelength count less than or equal to 20 (Module 1 and Module 2 only). As a result, peak power control and Power Optimizer is only available for links with channel counts less than or equal to 20 (Module 1 and Module 2 only). Above 20λ, scaling channel capacity with PO will be addressed in future OPTera Long Haul 1600 software releases.

ATTENTIONWith TrueWave ClassicTM, Booster18 is the optimum amplifier and must be used as the standard configuration. Booster21 can also be supported for the same application.

ATTENTIONThe allowable difference in span lengths for TrueWave ClassicTM system is 28 km. The difference in length between the maximum and minimum span length cannot be greater than 28 km, otherwise, an alternative DCM/DSCM strategy is required.



output of the Mux coupler and the input of the first-in-service amplifier (FISA), that is before the DCM/DSCM if there is a DCM/DSCM present. See Table 3-12 for detailed placement of Common Tx Pads.

MSA PadsIt is possible that MSA padding be required at OPTera Long Haul 1600 line amplifier sites to set the loss in the mid-stage. MSA Pads must be placed immediately after the Dual-Amplifier output, that is before the DCM/DSCM if there is a DCM/DSCM present. See the OPTera Long Haul 1600 MSA rules on page 4-2 for more information.

Span PadsSpan Pads are attenuators placed in line in order to bring the link attenuation within the prescribed range. Span Pads must be placed after the Booster output.

TrueWave ClassicTM fiber link with external tap couplerFor applications with an external tap coupler at the amplifier output, an additional power loss of 0.5 dB must be considered for the tap coupler and connector.



• At the dual amplifier output, reduce the fixed MSA pad requirement from 5 dB to 4 dB. There is no need to over-launch at the Dual Amp output.

• Over launch by 0.5 dB (peak power) at booster output.




Table 3-12Maximum allowed span loss, dispersion compensation rules and padding rules for 1-30λλλλ applications deployed on TW Classic fiber, 10 Gbit/s channels (See Notes 1, 2, and 11)

10G, TWC, C-Band, Unidirectional, 1-30λ, Dual Amp. Booster18 Config., No Bypass

Span Max. Avg. Loss


DCM/DSCM(see Notes 4, 5, 6, 7, and 8)


[km](see Note 12)

Common Tx Pad

Required [dB]

(see Notes 9 and 10)

1 31 two 1600 DCM 200P at Tx site 122 - 185 6

2 29 1600 DCM 300P at Tx,

T1C DSCM-5 at Rx

155 - 274 6

3 27 1600 DCM 300P at Tx,

T1C DSCM-20 at Rx

290 - 398 6

4 25 1600 DCM 200P at Tx, T1C DSCM-30 at Rx 442 - 504 6

5 23 two 1600 DCM 200P at Tx, T1C DSCM-10 at LA1, LA2, LA3, LA4, Rx

502 - 556 6

6 22 two 1600 DCM 200P at Tx, T1C DSCM-10 at LA1, LA2, LA3, LA4, LA5, Rx

555 - 588 6



Note 3: The supported minimum span loss is 17 dB for 1- to 6-span links.

Note 4: LA1 is the first line site closest to the transmitter, LA2 is the second closest line site to the transmitter, on a direction basis.


Note 6: Use the same DCM strategy for 1-30λ applications.

Note 7: DSCM at Tx must be placed in the MSA of the Mux site. DSCM at the MSA site must be placed after the MSA pad. DSCM at Rx must be placed in the MSA of the Demux site.



Note 10: The Common Tx Pad should be placed between the output of the Module 1 Mux DWDM coupler and at the input of the head-end amp.

Note 11: The minimum loss between the output of the dual amplifier and the input of the DSCM is 5 dB for line and Rx sites. The purpose of having a 5 dB pad is to ensure that power launch into the DSCM is low enough to prevent nonlinear distortion. Even with this 5 dB pad, the MSA loss rule of 8 to 11 dB must be followed.

Note 12: The allowable difference between the minimum and maximum span lengths for the TWC system is 28 km, with the exception of single span.



Provisioning rulesTable 3-13 shows the 1-20λ provisioning rules over TrueWave ClassicTM.

Table 3-13Provisioning rules for 20-λλλλ applications deployed on TW Classic fiber, 10 Gbit/s channels

10G, TWC, C-Band, Unidirectional, 1-20λ, Dual Amp. Booster18 Config., No Bypass

Span


Dual Booster 18 Dual Booster 18 Dual Booster 18

Peak Power [dBm]

Total Power[dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

1 5 15.5 3.5 18 -- -- -- -- 5 15.5 8 18

2 5 15.5 2.5 18 5 15.5 2.5 18 5 15.5 8 18

3 5 15.5 2.5 18 5 15.5 2.5 18 5 15.5 8 18

4 5 15.5 2.5 18 5 15.5 2.5 18 5 15.5 8 18

5 5 15.5 1.5 18 5 15.5 1.5 18 5 15.5 8 18

6 5 15.5 1.5 18 5 15.5 1.5 18 5 15.5 8 18

Note 1: The peak power clamp is enabled on all amplifiers

Note 2: Provisioning rules assume an overlaunch of 0.5 dB to account for a head-end optical patch panel.



OPTera Long Haul 1600 C-Band unidirectional applications on E-LEAF fiber multiplexing 10-Gbit/s channels















E-LEAF Wavelength planThis application supports wavelength plans spanning from 1530.33 nm to 1562.23 nm (Grid 1) or 1530.72 nm to 1562.64 nm (Grid 2). Use Module 1, Module 2, Module 3 and Module 4 with applications on E-LEAF fiber. See “Wavelength plans” on page 4-6 for more information.




ATTENTIONAlthough the current OPTera Long Haul 1600 hardware is compatible for a channel count of 40λ per band on E-LEAF, OPTera Long Haul 1600 Release 3 only supports channel power monitoring capabilities for a wavelength count less than or equal to 20 (Module 1 and Module 2 only). As a result, peak power control and Power Optimizer is only available for links with channel counts less than or equal to 20 (Module 1 and Module 2 only).

Above 20λ, scaling channel capacity with PO will be addressed in future OPTera Long Haul 1600 software releases.

ATTENTIONThe allowable difference in span lengths for E-LEAF system is 28 km. The difference in length between the maximum and minimum span length cannot be greater than 28 km, otherwise, an alternative DCM/DSCM strategy is required.





E-LEAF fiber link with external tap couplerFor applications with an external tap coupler at the amplifier output, an additional power loss of 0.5 dB must be considered for the tap coupler and connector.




• Over launch by 0.5dB (peak power) at booster output.




Table 3-14Maximum allowed span loss, dispersion compensation rules and padding rules for 1-40λλλλ applications deployed on E-LEAF fiber, 10 Gbit/s channels (See Notes 1, 2, and 11)

10G, E-LEAF, C-Band, Unidirectional, 1-40λ, Dual Amp. Booster21 Config., Dual-amp Bypass

Span Max. Avg. Loss


DCM/DSCM(see Notes 4, 5, 6, 7, and 8)


[km](see Note 12)


[dB](see Notes 9

and 10)

1 33 1600 DCM 200P at Tx site 87-172 0

2 31 1600 DCM 200P at Tx, T1C DSCM-10 at LA1 & Rx

180-279 0

3 28 1600 DCM 100P at Tx, T1C DSCM-10 at LA1 & LA2, T1C DSCM-20 at Rx

253-345 2

4 27 T1C DSCM-10 at LA1 & LA2,

T1C DSCM-20 at LA3 & Rx

415-447 2

5 25 T1C DSCM-10 at LA1, LA3 & LA4,

T1C DSCM-20 at LA2, T1C DSCM-5 &

T1C DSCM-20 at Rx

494-505 2

6 23.4 T1C DSCM-10 at LA1, LA3 & LA4,

T1C DSCM-20 at LA2 & Rx, T1C DSCM-5 & T1C DSCM-10 at LA5

533-545 2










Note 10: The Common Tx Pad should be placed between the output of the Module 1 Mux DWDM coupler and at the input of the head-end amplifier.


Note 12: The allowable difference between the minimum and maximum span lengths for the E-LEAF system is 28 km, with the exception of single span.



Provisioning rulesTable 3-15 shows the 1-20λ provisioning rules over E-LEAF.

Table 3-15Provisioning rules for 20-λλλλ applications deployed on E-LEAF fiber, 10 Gbit/s channels

10G, E-LEAF, C-Band, Unidirectional, 1-20λ, Dual Amp. Booster21 Config., Dual-amp Bypass

Span



Peak Power [dBm]

Total Power[dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

Peak Power [dBm]

Total Power [dBm]

1 N/A N/A 6.5 21 -- -- -- -- 5 15.5 8 21

2 N/A N/A 6.5 21 5 15.5 6.5 21 5 15.5 8 21

3 N/A N/A 5.5 21 5 15.5 5.5 21 5 15.5 8 21

4 N/A N/A 5.5 21 5 15.5 5.5 21 5 15.5 8 21

5 N/A N/A 4.5 21 5 15.5 4.5 21 5 15.5 8 21

6 N/A N/A 3.5 21 5 15.5 3.5 21 5 15.5 8 21


Note 2: Provisioning rules assume an over-launch of 0.5 dB to account for a head-end optical patch panel.

Note 3: N/A is short for not applicable.



OPTera Long Haul 1600 C-Band unidirectional applications on TrueWave Plus fiber multiplexing 10-Gbit/s channels











ATTENTION6-span TW+ link requires the use of a Dual Amp and Booster 18 rather than the Dual Amp and Booster 21 suggested.





TrueWave Plus Wavelength planThis application supports wavelength plans spanning from 1530.33 nm to 1562.23 nm (Grid 1) or 1530.72 nm to 1562.64 nm (Grid 2). Use Module 1, Module 2, Module 3 and Module 4 with applications on TrueWave Plus fiber. See “Wavelength plans” on page 4-6 for more information.




ATTENTIONAlthough the current OPTera Long Haul 1600 hardware is compatible for a channel count of 40λ per band on TrueWave Plus, OPTera Long Haul 1600 Release 3 only supports channel power monitoring capabilities for a wavelength count less than or equal to 20 (Module 1 and Module 2 only). As a result, peak power control and Power Optimizer is only available for links with channel counts less than or equal to 20 (Module 1 and Module 2 only).


ATTENTIONThe allowable difference in span lengths for system TrueWave Plus is 50 km. The difference in length between the maximum and minimum span length cannot be greater than 50 km, otherwise, an alternative DCM/DSCM strategy is required.





TrueWave Plus fiber link with external tap couplerFor applications with an external tap coupler at the amplifier output, an additional power loss of 0.5 dB must be considered for the tap coupler and connector.




• Over-launch by 0.5dB (peak power) at booster output.




Table 3-16Maximum allowed span loss, dispersion compensation rules and padding rules for 1-40λλλλ applications deployed on TrueWave Plus fiber, 10 Gbit/s channels (See Notes 1, 2, 11 and 12)

10G, TW+, C-Band, Unidirectional, 1-40 λ, Topology 2, Dual-amp Bypass

Span Max. Avg. Loss

(dB/span)(see Note 3)

DCM/DSCM(see Notes 4, 5, 6, 7 and 8)


(km)

Fixed Tx Pad

Required (dB)

(See Notes 9 and 10)

1 34 1600 DCM200P at Tx 44-185 0

2 28 1600 DCM200P at Tx, T1C DSCM20 at Rx 171-318 0

3 26 1600 DCM200P at Tx, T1C DSCM20 at LA1, T1C DSCM10 at LA2 and Rx

326-408 0

4 25 1600 DCM100P at Tx, T1C DSCM20 at LA1, and LA2, T1C DSCM10 at LA3 and Rx

490-509 0

5 23 1600 DCM200P at Tx, T1C DSCM20A at LA1, LA2, LA3, and LA4

553-572 0

6 (See Note 13)

22 1600 DCM200P at Tx, T1C DSCM20A at LA1 and LA2, T1C DSCM10 at LA3, LA4 and

Rx

511-526 0












Note 12: The allowable difference between the minimum and maximum span lengths for the TW+ system is 50 km, with the exception of single span.




Provisioning rulesTable 3-17 shows the 1-20λ provisioning rules over TrueWave Plus.

Table 3-17Provisioning rules for 20-λλλλ applications deployed on TrueWave Plus fiber, 10 Gbit/s channels

10G, TW+, C-Band, Unidirectional, 1-20 λ, Topology 2, Dual-amp Bypass

Span



Peak Power (dBm)

Total Power(dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

1 N/A N/A 5.5 21 -- -- -- 21 5 15.5 8 21

2 N/A N/A 5.5 21 5 15.5 5.5 21 5 15.5 8 21

3 N/A N/A 3.5 21 5 15.5 3.5 21 5 15.5 8 21

4 N/A N/A 2.5 21 5 15.5 2.5 21 5 15.5 8 21

5 N/A N/A 2.5 21 5 15.5 2.5 21 5 15.5 8 21

6 N/A N/A 2.5 18 5 15.5 2.5 18 5 15.5 8 18







OPTera Long Haul 1600 C-Band unidirectional applications on SMF-LS fiber multiplexing 10-Gbit/s channels











ATTENTIONThe allowable difference in span lengths for system SMF-LS is 50 km. The difference in length between the maximum and minimum span length cannot be greater than 50 km, otherwise, an alternative DCM/DSCM strategy is required.




SMF-LS Wavelength planThis application supports wavelength plans spanning from 1530.33 nm to 1545.32 nm (Grid 1) or 1530.72 nm to 1545.72 nm (Grid 2). Use Module 3 and Module 4 with applications on LS fiber. See “Wavelength plans” on page 4-6 for more information.

Tx chirpThe required transmitter chirp is positive chirp for this particular fiber type application. See “Tx chirp adjustment for dispersion compensation” on page 4-1 for more information.





ATTENTIONThe 20 wavelength plan for SMF-LS link fall within MUX/DEMUX modules 3 and 4 (short wavelength end). Because the MUX common output is in module 1, module 1, 3, and 4 must be used to implement the C-Band wavelength plan. Any channel in the 20 wavelength plan can be replaced with the spare channel in module 1 without budget penalty.



SMF-LS fiber link with external tap couplerFor applications with an external tap coupler at the amplifier output, an additional power loss of 0.5 dB must be considered for the tap coupler and connector.



• At the dual amplifier output, there is no change to the MSA padding rule. There is no need to over-launch at the Dual Amp output.





Table 3-18Maximum allowed span loss, dispersion compensation rules and padding rules for 1-40λλλλ applications deployed on SMF-LS fiber, 10 Gbit/s channels (See Notes 1, 2, 11 and 12)

10G, SMF-LS, C-Band, Unidirectional, 1-20 λ, Topology 1, No Bypass

Span Max. Avg. Loss




(km)

Fixed Tx Pad

Required (dB)


1 34 T1C DSCM50 at Tx, 1600 DCM300P at Rx 101-200 6

2 30 T1C DSCM40 at Tx, two 1600 DCM200P at Rx

232-318 6


279-351 6


344-416 6

5 24 T1C DSCM20 at Tx, 1600 DCM200P at LA4, 2DCM200P at Rx

426-534 6

6 22 T1C DSCM30 at Tx, two 1600 DCM200P at LA5, two 1600 DCM200P at Rx

533-572 6






Note 6: Use the same DCM/DSCM strategy for 1-20λ applications.






Note 12: The allowable difference between the minimum and maximum span lengths for the SMF-LS system is 50 km, with the exception of single span.



Provisioning rulesTable 3-19 shows the 1-20λ provisioning rules over SMF-LS.

Table 3-19Provisioning rules for 20-λλλλ applications deployed on SMF-LS fiber, 10 Gbit/s channels

10G, SMF-LS, C-Band, Unidirectional, 1-20 λ, Topology 1, No Bypass

Span



Peak Power (dBm)

Total Power(dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

1 5 15.5 4.5 18 -- -- -- - 5 15.5 8 18

2 5 15.5 4.5 18 5 15.5 4.5 18 5 15.5 8 18

3 5 15.5 3.5 18 5 15.5 3.5 18 5 15.5 8 18

4 5 15.5 3.5 18 5 15.5 3.5 18 5 15.5 8 18

5 5 15.5 2.5 18 5 15.5 2.5 18 5 15.5 8 18

6 5 15.5 1.5 18 5 15.5 1.5 18 5 15.5 8 18


Note 2: Provisioning rules assume a booster over-launch of 0.5 dB to account for a head-end optical patch panel.



OPTera Long Haul 1600 C-Band unidirectional applications on TrueWave RS fiber multiplexing 10-Gbit/s channels















TrueWave RS Wavelength planThis application supports wavelength plans spanning from 1530.33 nm to 1562.23 nm (Grid 1) or 1530.72 nm to 1562.64 nm (Grid 2). Use Module 1, Module 2, Module 3 and Module 4 with applications on TrueWave RS fiber. See “Wavelength plans” on page 4-6 for more information.




ATTENTIONAlthough the current OPTera Long Haul 1600 hardware is compatible for a channel count of 40λ per band on TrueWave RS, OPTera Long Haul 1600 Release 3 only supports channel power monitoring capabilities for a wavelength count less than or equal to 20 (Module 1 and Module 2 only). As a result, peak power control and Power Optimizer is only available for links with channel counts less than or equal to 20 (Module 1 and Module 2 only).


ATTENTIONThe allowable difference in span lengths for system TrueWave RS is 14 km. The difference in length between the maximum and minimum span length cannot be greater than 14 km, otherwise, an alternative DCM/DSCM strategy is required.





TrueWave RS fiber link with external tap couplerFor applications with an external tap coupler at the amplifier output, an additional power loss of 0.5 dB must be considered for the tap coupler and connector.








Table 3-20Maximum allowed span loss, dispersion compensation rules and padding rules for 1-40λλλλ applications deployed on TrueWave RS fiber, 10 Gbit/s channels (See Notes 1, 2, 11 and 12)

10G, TWRS, C-Band, Unidirectional, 1-40 λ, Topology 2, Dual-amp Bypass

Span Max. Avg. Loss




(km)

Fixed Tx Pad

Required (dB)


1 34 1600 DCM200P at Tx 42-187 0

2 28 1600 DCM200P at Tx, T1C DSCM10 at L1 & Rx

135-324 0

3 26 1600 DCM200P at Tx, T1C DSCM-10 at LA1, LA2, DSCM30 at Rx

235-430 0

4 25 1600 DCM200P at Tx, T1C DSCM10 at LA1, LA3, DSCM20 at LA2, T1C DSCM30 at Rx

326-465 0

5 24 1600 DCM200P at Tx, T1C DSCM10 at LA2, LA4, T1C DSCM20 at LA1, LA3, T1C

DSCM30 at Rx

444-466 0

6 23 T1C DSCM20 at LA1, LA3, LA5, T1C DSCM10 at LA2 & LA4, T1C DSCM30 at Rx

558-571 2












Note 12: The allowable difference between the minimum and maximum span lengths for the TWRS system is 14 km, with the exception of single span.



Provisioning rulesTable 3-21 shows the 1-20λ provisioning rules over TrueWave RS.

Table 3-21Provisioning rules for 20-λλλλ applications deployed on TrueWave RS fiber, 10 Gbit/s channels

10G, TWRS, C-Band, Unidirectional, 1-20 λ, Topology 2, Dual-amp Bypass

Span



Peak Power (dBm)

Total Power(dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

Peak Power (dBm)

Total Power (dBm)

1 N/A N/A 5.5 21 -- -- -- -- 5 15.5 8 21

2 N/A N/A 4.5 21 5 15.5 4.5 21 5 15.5 8 21

3 N/A N/A 4.5 21 5 15.5 4.5 21 5 15.5 8 21

4 N/A N/A 4.5 21 5 15.5 4.5 21 5 15.5 8 21

5 N/A N/A 4.5 21 5 15.5 4.5 21 5 15.5 8 21

6 N/A N/A 3.5 21 5 15.5 3.5 21 5 15.5 8 21





4-1

Application-independent optical link engineering rules 4-

The following rules apply to all OPTera Long Haul 1600 C-Band Unidirectional applications.

Tx chirp adjustment for dispersion compensationDepending on the fiber type you use in the application, use a DWDM transmitter with positive or negative chirp to pre-compensate for dispersion. The 10 Gbit/s DWDM transmitters are software provisioned for positive or negative chirp.

The selection of a positive or negative chirp transmitter depends on the exact value of λ0. For example, a transmitter which sees negative dispersion (λ < λ0) should have its chirp set to positive. Table 4-1 shows the engineering rules for selecting the appropriate 10 Gbit/s transmitter chirp as a function of wavelength and fiber type.

NLS dithering provisioningStimulated Brillouin scattering (SBS) is a nonlinear scattering effect that transfers energy from one light wave to a counter-propagating light wave of longer wavelength. Therefore, the pulses of the shorter DWDM wavelengths

Table 4-110 Gbit/s Tx chirp polarity selection criteria with OPTera Long Haul 1600

Fiber type Net link dispersion Required transmitter chirp

NDSF positive negative chirp

TrueWave Classic positive negative chirp

E-LEAF positive negative chirp

TrueWave Plus positive negative chirp

SMF-LS negative positive chirp

TrueWave RS positive negative chirp


4-2 Application-independent optical link engineering rules

will see their energy being transferred to longer wavelengths while they propagate through the fiber. SBS effects become more significant with increasing power of DWDM channels and increasing length of the optical link.

Since SBS is a narrowband effect, it is possible to dither the source to decrease the penalty. The frequency excursion of the dither must be sufficient to increase the SBS threshold, but small enough so that the dispersion penalty is not seriously increased. NLS dithering must be turned on for OPTera Long Haul 1600 Releases 1.2 and higher. See the OPTera Long Haul 1600, or OPTera Long Haul 1600 Optical Amplifier Shelf NTP libraries for NLS dither provisioning procedures.

OPTera Long Haul 1600 mid-stage access (MSA) loss restrictionsWhen 1600G amplifiers are used, components can be inserted between them. To optimize the performance of the line amplifier, the loss in the MSA must be adjusted within certain limits. The total loss in the MSA is the sum of the loss of all the components inserted between two 1600G amplifiers. Table 4-2 gives MSA loss targeted values unless otherwise indicated in the tables of Chapter 3, “Optical link engineering rules”.

It is important to keep the loss within the prescribed limits. Additional padding can be required to bring the total loss within the desired operating point.

The 1600G amplifiers are designed for 10 dB of mid-stage access (MSA) loss. However, the recommended MSA padding value can be anywhere between 8 to 11 dB. The MSA loss includes connector, DCM/DSCM, OADM, and pad losses within the MSA site.

To calculate the required pads for Network Planning purposes, the loss of the inserted components must be known. Table 4-3 gives the loss of all components that can be inserted in the MSA.

Table 4-2MSA loss recommendations

MSA loss [dB] Link budget impact

< 8 Not supported. Pad required to reach the 8-11 dB supported range at this moment.

8-11 No link budget penalty.

>11 Not supported at this time.


Application-independent optical link engineering rules 4-3

.

Table 4-3Maximum DCM losses used for total MSA loss calculation

Type DCM Module Maximum Loss [dB]

Positive DCM 1600 DCM 100P 2.3



C-Band Type 1 DSCM T1C DSCM-5 2.2













ATTENTIONMeasured loss due to patch panels and other passive components must be taken into account when determining the required pads to adjust the MSA loss to the prescribed MSA loss recommendations (Table 4-2). This measured loss can be determined from OAM&P Display Total Power Recommendations Screen.



Polarization mode dispersion (PMD) considerationIn rare cases, the signal distortion and performance degradation resulting from PMD must be compensated for by reducing the link budgets provided in this chapter by the appropriate amount. Table 4-4 provides the specifications for the modification to be made to the link budgets.

To obtain the mean link differential group delay (DGD), you can use data provided by the fiber supplier or, preferably, you can measure the mean DGD directly using commercially available test equipment.

Data provided by the fiber supplier is normally specified as a PMD coefficient [ps/√km]. To calculate the mean DGD for a link, use the following formula:

Mean link DGD={∑ [(PMD value/span) ps/√km]2 x [(length of span) km]}1/2

For example, in a 3-span system with span lengths of 80 km, 60 km, and 40 km in which the PMD coefficients are 0.2 ps/√km, 0.16 ps/√km, and 0.13 ps/√km, respectively, the DGD would be calculated as:

Mean link DGD = (0.22 x 80 + 0.162 x 60 + 0.132 x 40)1/2 = 2.33 ps

Table 4-4PMD specifications for 10 Gbit/s DWDM applications

Differential group delay [ps]

10 Gbit/s Engineering rules

0 - 4 No change

4 - 9 De-rate average loss per span by 1 dB

9 - 14 De-rate average loss per span by 2 dB

14 - 22 Contact Nortel Networks.

> 22 Reduce the number of spans (see Note 2)

Note 1: In these ranges the probability of a protection switch when the signal degrade threshold is set to 10-8 is one per year.

Note 2: If PMD compensation is needed, contact Nortel Networks for more information.



Nortel Networks 100 GHz ITU-T compliant wavelength gridThe Nortel Networks DWDM wavelength grid is compliant with the international 100 GHz ITU-T wavelength grid. The 1600G amplifiers provide optical amplification in two separate bands of transmission: the Conventional Band (C-Band) and the Long Band (L-Band). The C-Band ranges from 1530 nm to 1563 nm. The L-Band ranges from 1570 nm to 1603 nm. Currently, a maximum of 40 C-Band wavelengths selected from the 100 GHz ITU-T wavelength grid are provided. The L-Band capability will be introduced in future releases of OPTera Long Haul 1600.

To simplify the network planning of a unidirectional or bidirectional DWDM architecture, the Nortel Networks wavelength plan is divided into two Grids in the C-Band:

• Grid 1 Wavelengths Range: 1530.33 nm to 1562.23 nm, Spare 1546.12 nm. Grid 1 is based on the 100 GHz ITU-T wavelength grid.

• Grid 2 Wavelengths Range: 1530.72 nm to 1562.64 nm, Spare 1546.52 nm. Grid 2 is offset by 50 GHz from the 100 GHz ITU-T wavelength grid.

To ensure optimal use of the OPTera Long Haul 1600 gain spectrum, the OSC signal wavelengths (UniOSC 1480nm/1510 nm, BiOSC 1480 nm/1510 nm, UniOSC 1510/1615 or BiOSC 1510/1615) are allocated outside the channel wavelength plan grid. Figure 4-1 shows Nortel Networks’ 1600G Amplifier Gain Spectrum and channel allocation grid.

Figure 4-1 1600G Amplifier Gain Spectrum

OTP1631.eps

1530 nm1480 nm 1510 nm

Conventional Band(C-Band)

OSCs OSCLong Band

(L-Band)

1563 nm 1570 nm 1603 nm 1615 nm

OPTera Long Haul 1600 gain window



Wavelength plansThe wavelength upgrade plans for OPTera Long Haul 1600 C-Band are shown in Table 4-5 (Grid 1) and Table 4-6 (Grid 2). The tables specify the Channel Wavelength-to-DWDM Mux/Demux Module mapping.

For all fiber types, the engineering rules for DWDM Mux/Demux Module deployment sequence are:

• Deploy Module 1 until all the capacity is exhausted for all fiber types.

• Deploy Module 2 next for all fiber types except certain types of NZ-DSF fiber.

• Deploy Module 3 next for all fiber types.

• Finally, deploy Module 4 for all fiber types except TrueWave ClassicTM.

OADM Applications For OADM applications, choose the wavelengths according to 1-channel, 2-channel, or Band OADM drop recommendations. OADM modules are to be introduced in 1-channel, 2-channel, or multichannel band drop. See Table 4-5 and Table 4-6 for the wavelength plan corresponding to the OADM couplers.

Channels designated to support express or OADM channels need to be assigned correctly to either express or OADM applications. As a result, careful planning of wavelengths before deployment is required. For example, if all wavelengths from Module 1 are to be deployed as express channels, the OADM wavelengths on that module should remain as express wavelengths. In the event that OADM is required at a later date, the OADM wavelengths from modules 2, 3, or 4 should be used providing that the OADM wavelengths on them have not yet been deployed as express.



Table 4-5C-Band Grid 1 wavelength plan for the 1600G Amplifier

C-Band Grid 1 wavelengths, 10-Lambda modular plan (100-GHz ITU-T)Express OADM

Frequency (THz) Wavelength (nm) Mod 1 Mod 2 Mod 3 Mod 4 1-channel 2-channel 195.90 1530.33195.80 1531.12195.70 1531.90195.60 1532.68195.50 1533.47195.40 1534.25195.30 1535.04 o195.20 1535.82 x o195.10 1536.61 o195.00 1537.40 x o194.90 1538.19 x o194.80 1538.98 o194.70 1539.77 x o194.60 1540.56 o194.50 1541.35194.40 1542.14194.30 1542.94194.20 1543.73194.10 1544.53194.00 1545.32193.90 1546.12 Spare x193.80 1546.92193.70 1547.72193.60 1548.51193.50 1549.32193.40 1550.12193.30 1550.92193.20 1551.72 o193.10 1552.52 x o193.00 1553.33 o192.90 1554.13 x o192.80 1554.94 x o192.70 1555.75 o192.60 1556.55 x o192.50 1557.36 o192.40 1558.17192.30 1558.98192.20 1559.79192.10 1560.61192.00 1561.42191.90 1562.23Note: Shaded boxes in the Mod 1, 2, 3, 4 columns represent wavelengths supported on each module.



Table 4-6C-Band Grid 2 wavelength plan for the 1600G Amplifier

C-Band Grid 2 wavelengths, 10-Lambda modular plan (-50 GHz offset from 100-GHz ITU-T)Express OADM

Frequency (THz) Wavelength (nm) Mod 1 Mod 2 Mod 3 Mod 4 1-channel 2-channel 195.85 1530.72195.75 1531.51195.65 1532.29195.55 1533.07195.45 1533.86195.35 1534.64195.25 1535.43 o195.15 1536.22 x o195.05 1537.00 o194.95 1537.79 x o194.85 1538.58 x o194.75 1539.37 o194.65 1540.16 x o194.55 1540.95 o194.45 1541.75194.35 1542.54194.25 1543.33194.15 1544.13194.05 1544.92193.95 1545.72193.85 1546.52 Spare x193.75 1547.32193.65 1548.11193.55 1548.92193.45 1549.72193.35 1550.52193.25 1551.32193.15 1552.12 o193.05 1552.93 x o192.95 1553.73 o192.85 1554.54 x o192.75 1555.34 x o192.65 1556.15 o192.55 1556.96 x o192.45 1557.77 o192.35 1558.58192.25 1559.39192.15 1560.20192.05 1561.01191.95 1561.83191.85 1562.64Note: Shaded boxes in the Mod 1, 2, 3, 4 columns represent wavelengths supported on each module.


5-1

Optical layer components specifications5-This chapter describes the optical building block components specifications required to deploy the applications described in this applications guide. The components specifications are split into the following two groups:

Active components• Optical Service Channel (unidirectional or bidirectional) (Table 5-1 on

page 5-2)

• Dual amplifier circuit pack (Table 5-2 on page 5-4)

• Booster amplifier (Table 5-3 on page 5-6)

Passive components• DWDM couplers, C-Band, Grid 1 or Grid 2, Mux or Demux (Table 5-4 on

page 5-9)

• Dispersion and Dispersion Slope Compensating Modules (DCM/DSCM) (Table 5-5 on page 5-12)

• Fiber optic attenuators (Table 5-6 on page 5-17 and Table 5-7 on page 5-19)

Provided within this chapter are functional descriptions of each optical component, package options, and input/output interface specifications. The specifications described are for reference only and are not to be used for any other purpose.

With the exception of optical fixed pad attenuators, Nortel Networks makes all the passive components described in this chapter and considers these components as an integrable part of its network solution. Two key advantages to purchasing these components from Nortel Networks is a total quality guarantee for the manufacture of all its subcomponents, including those provided by subcontractors, and access to the Nortel Networks end-of-life (EOL) performance guarantee.


5-2 Optical layer components specifications

Table 5-1Optical Service Channel (unidirectional or bidirectional)

OTP0836.eps

—continued—

UniOSC1510/1615 nm

OSC-1

OSC-2

12

OSC-21615 Add 1510 Drop





Optical layer components specifications 5-3

Functional descriptionNortel Networks offers two types of OSC circuits packs: a bidirectional OSC and a unidirectional OSC. This circuit pack is mandatory in all configurations and is supported in slots 1 (G0) and 6 (G5) of the main shelf.

Use the UniOSC 1480/1510 nm or UniOSC 1510/1615 nm only in a unidirectional network. If there are plans to migrate from a unidirectional network to a bidirectional network, then use the BiOSC 1480/1510 nm or BiOSC 1510/1615 nm circuit pack.

Hardware descriptionThe OSC circuit pack is equipped with 2 trays named OSC-1 and OSC-2. OSC-1 contains connectors to support optical service channel in Direction 1. OSC-2 contains connectors to support optical service channel in Direction 2.

The faceplate includes four LEDs. A green LED identifies an active circuit pack. A red LED indicates a failed circuit pack. Two yellow LEDs indicate a loss of signal (LOS) for OSC-1 and OSC-2.

The UniOSC 1480/1510 nm supports four ports, allowing OSC add/drop capabilities at both 1510 nm and 1480 nm. The UniOSC 1510/1615 nm supports four ports, allowing OSC add/drop capabilities at both 1615 nm and 1480 nm.

The faceplate shown in the figure on the previous page represents the UniOSC 1510/1615 nm. The OSC port labeling is 1615 nm ADD, 1510 nm DROP, 1615 nm DROP and 1510 nm ADD.

The BiOSC 1480/1510 nm contains two ports: 1510 nm ADD/1480 nm DROP and 1480 nm ADD/1510 nm DROP. The BiOSC 1510/1615 nm contains two ports: 1615 nm ADD/1510 nm DROP and 1510 nm ADD/1615 nm DROP.The bidirectional OSC circuit pack is the same as that shown in the figure on page 5-2 except that the BiOSC only has two connectors instead of four. You can order FC, ST, or SC type adapters to match the fiber plant connector types.

OAM&P featuresThe OSC circuit pack has the following features: remote provisioning and alarm reporting.

Options

Definition PEC

UniOSC 1480/1510 nm NTCA15AA/ NTCA15AB/ NTCA15AC

BiOSC 1480/1510 nm NTCA15BA/ NTCA15BB/ NTCA15BC

UniOSC 1510/1615 nm NTCA15AE/ NTCA15AF/ NTCA15AG

BiOSC 1510/1615 nm NTCA15BE/ NTCA15BF/ NTCA15BG

Note: For more details, refer to the 1600G Amplifier Network Application Guide (NTY314AX).



Table 5-2Dual amplifier circuit pack

OTP1402.eps

Functional descriptionThe Dual Amplifier is mandatory. Deploy the Dual Amplifier first in any amplifier configuration. The Dual Amplifier provides amplification of up to +15.5 dBm. The first extension shelf houses this circuit pack in slots 1 and 6.

OPTera Long Haul 1600 Release 3 introduces the Dual Amplifier to support amplification in the C-Band only. A separate Dual Amplifier will be introduced to support transmission in the L-Band.

—continued—

AMP

C-band Dual Amplifier

AMP

12

MON-1 UPA-1 OUT-1 IN-1






Hardware descriptionThe Dual Amplifier supports two amplifiers located in two different trays named Amp-1 and Amp-2. The upgrade port UPA provides OSC drop capabilities. The Dual Amplifier has eight ports.

You can order FC, ST, or SC type adapters to match the fiber plant connector types.

The faceplate includes four LEDs. A green LED identifies an active circuit pack. A red LED indicates a failed circuit pack. Two yellow LEDs indicate a loss of signal (LOS) for the following incoming signals: traffic 1, and traffic 2.

OAM&P and control features• remote provisioning

• total and per-channel optical power monitoring (analog maintenance 2)

• optical link equalization software to optimize link performance

• alarm reporting

• optical reflectometer

• channel autodiscovery

• autopropagation of provisioned values

• local locking of provisioned power values

• gain control or total power control (with and without peak power clamping)

Options

Definition PEC

Dual Amplifier C-Band NTCA15CK/ NTCA15CL/ NTCA15CM


Specifications

Wavelengths (nm) 1530 to 1563

Output power (dBm) 15.5

Design flat gain (dB) 19.5 (see Note 1)

Gain control for minimal channel interaction

yes

OADM support yes (see Note 2)

Note 1: An additional 0.5 dB has been added to ensure enough gain to overcome amplifier connector losses (assumed to be 0.25 dB per mated connector).

Note 2: OADM support when combined with a Booster Amplifier. Refer to Table 5-3 for Booster Amplifier specifications.

Table 5-2Dual amplifier circuit pack (continued)



Table 5-3Booster amplifier

OTP1422.eps

—continued—

AMP

AMP

AMP

OS

AMPOUT(Bi:IN) IN

UPG

UPB INTLV MON

C-Band Booster18 (or Booster21)

Note: Install fixed attenuation pad inlocation indicatedif required.

AMPOUT(Bi:IN) IN

UPG UPB INTLV MON



Functional descriptionNortel Networks offers two Booster amplifiers: Booster18 C-Band and Booster21 C-Band. Both Boosters have the same faceplate.

Booster18 C-Band provides amplification of up to 18 dBm. Coupled with the Dual Amplifier, Booster18 can support up to 20 wavelengths (unidirectional) on each fiber on all fiber types. Coupled with the Dual Amplifier, Booster18 can support up to 30 wavelengths (unidirectional) on each fiber on specific fiber types. Extension shelf 1 houses this circuit pack in slots 2, 3, 7 and 8.

Booster21 C-Band provides amplification of up to 21 dBm. Coupled with the Dual Amplifier, Booster21 can support up to 40 wavelengths on each fiber on all fiber types. Extension shelf 1 houses this circuit pack in slots 4, 5, 9 and 10.

Figure 2-2, Figure 2-3, Figure 2-4, and Figure 2-5 show the three configurations where the Dual Amplifier is coupled with the Booster Amplifier. The application space for each configuration is based on the OADM, DCM/DSCM, interleave filter (ILF), and wavelength count requirements.

Hardware descriptionThe Booster Amplifier circuit packs have two different trays: one for traffic handling, the other for the OSC add and the interleave access. Booster18 C-Band and Booster21 C-Band amplifiers have four ports.

You can order FC, ST, or SC type adapters to match the fiber plant connector types.

The Booster faceplate includes four LEDs. A green LED identifies an active circuit pack. A red LED indicates a failed circuit pack. Two yellow LEDs indicate a loss of signal (LOS). The AMP LED indicates a LOS of the incoming signal while the OS LED indicates an LOS of the optical service coming through upgrade port B (UPB).

OAM&P and control features• remote provisioning

• total and per-channel optical power monitoring (analog maintenance 2)

• optical link equalization software to optimize link performance

• alarm reporting

• optical reflectometer

• autopropagation of provisioned values

• local locking of power provisioned values

• tilt control

• gain control (with or without peak power clamping)

—continued—

Table 5-3Booster amplifier (continued)



Options

Description PEC

Booster18 C-Band Amplifier NTCA15CN/ NTCA15CP/ NTCA15CQ

Booster21 C-Band Amplifier NTCA15CR/ NTCA15CS/ NTCA15CT


Specifications

Booster18 amplifier Booster21 amplifier

Output power (dBm) 18 21

Design flat gain (dB) 14.5 (see Note 1) 17.5 (see Note 1)

Amplification capacity (Wavelengths/fiber)

30 40

Gain control for minimal channel interaction

yes yes

OADM support yes yes

Tilt control yes yes

Note: An additional 0.5 dB has been added to ensure enough gain to overcome amplifier connector losses (assumed to be 0.25 dB per mated connector).

Table 5-3Booster amplifier (continued)



Table 5-4DWDM couplers, C-Band, Grid 1 or Grid 2, Mux or Demux

OTP1126.eps

Functional descriptionEach Mux module can support up to 10 wavelengths. Module 1 (first module of the four interconnected modules) includes a monitor port and spare wavelength port. The Mux modules are a mirror image of the Demux modules. Use two patchcords (A and B) to interconnect the modules.

Each Demux module can support up to 10 wavelengths and contains a miniature variable attenuator (mVOA) for each wavelength. Module 1 (first module of the four interconnected modules) includes a monitor port and spare wavelength port. The Mux modules are a mirror image of the Demux modules. Use two patchcords (A and B) to interconnect the modules

Options

Description PEC

C-Band Grid 1 Mux Module 1 NTCA15NA (SC), NTCA15NK (FC), NTCA15NS (ST)

C-Band Grid 1 Mux Module 2 NTCA15NB (SC), NTCA15NL (FC), NTCA15NT (ST)

C-Band Grid 1 Mux Module 3 NTCA15NC (SC), NTCA15NM (FC), NTCA15NU (ST)

C-Band Grid 1 Mux Module 4 NTCA15ND (SC), NTCA15NN (FC), NTCA15NV (ST)

C-Band Grid 1 Demux Module 1 NTCA15MA (SC), NTCA15MK (FC), NTCA15MS (ST)

C-Band Grid 1 Demux Module 2 NTCA15MB (SC), NTCA15ML (FC), NTCA15MT (ST)

C-Band Grid 1 Demux Module 3 NTCA15MC (SC), NTCA15MM (FC), NTCA15MU (ST)

C-Band Grid 1 Demux Module 4 NTCA15MD (SC), NTCA15MN (FC), NTCA15MV (ST)

—continued—

Spare 1546.12

Spare 1546.12

1554.13

1554.13

1553.33

1553.33

1552.52

1552.52

1551.72

1551.72

1550.92

1550.92

1550.12

1550.12

1549.32

1549.32

1548.51

1548.51

1547.72

1547.72

1546.92

1546.92

Monitor

Command In

Monitor

Command In

Upgrade A

Upgrade B

To module 2

Upgrade A

Upgrade B

From module 3

To module 3

From module 2

C-Band 10+1λ Demux Grid 1 Module 1

C-Band 10+1λ Mux Grid 1 Module 1



C-Band Grid 2 Mux Module 1 NTCA15NF (SC), NTCA15NE (FC), NTCA15NW (ST)

C-Band Grid 2 Mux Module 2 NTCA15NG (SC), NTCA15NP (FC), NTCA15NX (ST)

C-Band Grid 2 Mux Module 3 NTCA15NH (SC), NTCA15NQ (FC), NTCA15NY (ST)

C-Band Grid 2 Mux Module 4 NTCA15NJ (SC), NTCA15NR (FC), NTCA15NZ (ST)

C-Band Grid 2 Demux Module 1 NTCA15MF (SC), NTCA15ME (FC), NTCA15MW (ST)

C-Band Grid 2 Demux Module 2 NTCA15MG (SC), NTCA15MP (FC), NTCA15MX (ST)

C-Band Grid 2 Demux Module 3 NTCA15MH (SC), NTCA15MQ (FC), NTCA15MY (ST)

C-Band Grid 2 Demux Module 4 NTCA15MJ (SC), NTCA15MR (FC), NTCA15MZ (ST)


Specifications

Mux Demux

Minimum Maximum Minimum Maximum

All ports

Optical Return Loss (ORL) 40 dB 40 dB

Polarization Dependent Loss (PDL) 0.6 dB 0.6 dB

Polarization Mode Dispersion (PMD) 0.4 ps 0.4 ps

Common - Channel Ports

Insertion Loss (Grid A or B) Module 1 5.6 dB 7.3 dB




Directivity (channel to channel) 55 dB 55 dB

Chromatic Dispersion over passband −35 ps/nm +35 ps/nm −35 ps/nm + 35 ps/nm

—continued—

Table 5-4DWDM couplers, C-Band, Grid 1 or Grid 2, Mux or Demux (continued)



Specifications continuedCommon - Upgrade Ports

Mux Demux

Minimum Maximum Minimum Maximum

Loss 1A Upgrade to 2A 6.3 dB 6.3 dB

Loss 1B Upgrade to 2B 5.9 dB 5.9 dB





Monitor Port

Monitor Port Insertion Loss 24.0 dB 19.0 dB

Monitor Port Ripple 0.5 dB 0.5 dB

Table 5-4DWDM couplers, C-Band, Grid 1 or Grid 2, Mux or Demux (continued)



Table 5-5Dispersion and Dispersion Slope Compensating Modules (DCM/DSCM)

F4726-MOR_R80.eps and OTP1127.eps

Functional descriptionTwo types of dispersion compensation modules are used, namely the Dispersion Compensating Module (DCM) and the Dispersion Slope Compensating Module (DSCM). Dispersion compensating modules provide negative or positive dispersion in order to compensate the dispersion accumulated in a given fiber type.

Each channel experiences a different amount of dispersion in the transmission fibre. The DCMs provide an appropriate amount of compensation for a single channel. With the MOR Plus, the RED and BLUE Erbium bands were narrow enough that the difference in dispersion experienced by each channel in a given band was small. The Erbium gain window used by OPTera Long Haul 1600 are about 2.5 times larger than MOR Plus and optimizing the dispersion compensation for only a single wavelength in the band is not appropriate. DSCMs, specifically designed for the C-Band or L-Band, address this issue by providing a wavelength dependent amount of dispersion compensation after a span of a given length.

—continued—

Dispersion Compensating

Dispersion Slope

Module (DCM)

Fiber out

Fiber in

Dispersion Slope CompensatingModule (DSCM)



Hardware description

The following DCMs are available:

• 1600 DCM 100P • 1600 DCM 200P • 1600 DCM 300P

The following DSCMs are available:

• C-Band Type 1 DSCM-5













Options

Description PEC

1600 DCM 100P (see Note 1) NTCC14FD (SC), NTCC14FF (FC)

1600 DCM 200P (see Note 2) NTCC14GG (SC), NTCC14GJ (FC)

1600 DCM 300P (see Note 3) NTCC14GD (SC), NTCC14GF (FC)

C-Band Type 1 DSCM-5 NTCA14CN (ST), NTCA14DN (FC)

C-Band Type 1 DSCM-10 NTCA14AA (SC), NTCA14CA (ST), NTCA14DA (FC)

C-Band Type 1 DSCM-20 NTCA14AB (SC), NTCA14CB (ST), NTCA14DB (FC)

C-Band Type 1 DSCM-30 NTCA14AC (SC), NTCA14CC (ST), NTCA14DC (FC)

C-Band Type 1 DSCM-40 NTCA14AD (SC), NTCA14CD (ST), NTCA14DD (FC)

C-Band Type 1 DSCM-50 NTCA14AE (SC), NTCA14CE (ST), NTCA14DE (FC)

C-Band Type 1 DSCM-60 NTCA14AF (SC), NTCA14CF (ST), NTCA14DF (FC)

C-Band Type 1 DSCM-70 NTCA14AG (SC), NTCA14CG (ST), NTCA14DG (FC)

C-Band Type 1 DSCM-80 NTCA14AH (SC), NTCA14CH (ST), NTCA14DH (FC)

C-Band Type 1 DSCM-90 NTCA14AJ (SC), NTCA14CJ (ST), NTCA14DJ (FC)

C-Band Type 1 DSCM-100 NTCA14AK (SC), NTCA14CK (ST), NTCA14DK (FC)

C-Band Type 1 DSCM-110 NTCA14AL (SC), NTCA14CL (ST), NTCA14DL (FC)

C-Band Type 1 DSCM-120 NTCA14AM (SC), NTCA14CM (ST), NTCA14DM (FC)

—continued—

Table 5-5Dispersion and Dispersion Slope Compensating Modules (DCM/DSCM) (continued)



Specifications

1600 DCM 100P

Insertion Loss (1527.5 to 1560.5 nm) maximum: 2.3 dB

Average Polarization Mode Dispersion maximum: 0.55 ps

Optical Return Loss minimum: 27 dB

1600 DCM 200P

Insertion Loss (1527.5 nm to 1560.5 nm) maximum: 4.6 dB



1600 DCM 300P

Insertion Loss (1527.5 nm to 1560.5 nm) maximum: 6.9 dB



C-Band Type 1 DSCM-5

Insertion Loss (1530 nm to 1567 nm) maximum: 2.2 dB











—continued—
































—continued—
















Note 1: 1600 DCM 100P compensates for approximately -100 ps/nm of dispersion






Fiber optic attenuatorsFixed attenuators

There are two different types of fixed attenuators used on Nortel Networks DWDM systems. These fixed attenuators are made by third-party manufacturers, such as JDS Fitel and AMP. One attenuator is the plug (bulkhead) type, and the other is an in-line type.

Fixed attenuators are typically installed into optical fiber networks to reduce the received power to the optimum operating level. Their small size allows for easy insertion into Nortel Networks fiber management trays for each network element. The advantage of using fixed attenuators in network applications are their low cost and small size. These high performance fixed attenuators have very low back reflection, very low optical ripple, and provide good optical performance.

The technical specifications for 5 dB and 10 dB fixed attenuators are listed in the tables below.

Note: If you intend to order these fixed attenuators from other vendors rather than the ones recommended by Nortel Networks, ensure that the technical specifications of those fixed attenuators follow Nortel Networks’ strict guidelines listed in the tables below. Additionally, you should contact your next level of support or Nortel Networks technical assistance.

SpecificationsThe following are the specifications for both plug-in and in-line attenuator types.

Table 5-6Specifications for plug-in attenuators

Characteristics Manufacturer

JDS Fitel AMP

Fixed attenuator type 5 dB (plug-in) 5 dB (plug-in)

Connector type FC FC

Attenuation range 5 dB ± 0.5 dB 5 dB ± 0.5 dB

Back reflection < –50 dB < –50 dB

Part number FA100-35-05-HP5 PF98-0014-3

Connector type SC SC


—continued—



Connector type N/A ST

Attenuation range 5 dB ± 0.5 dB

Back reflection < –45 dB

Part number PF98-0014-5

Fixed attenuator type 10 dB (plug-in) 10 dB (plug-in)









Connector type N/A ST

Attenuation range 10 dB ± 0.5 dB

Back reflection < –45 dB

Part number PF98-0014-6

Note: N/A indicates not available.

—end—

Table 5-6Specifications for plug-in attenuators (continued)


JDS Fitel AMP



Table 5-7Specifications for in-line attenuators


JDS Fitel

Fixed attenuator type 5 dB (in-line) 10 dB (in-line)



Pigtail length 1.5 m (4.9 ft) ± 5% 1.5 m (4.9 ft) ± 5%

Cable type 3.0 mm (0.12 in) cable 3.0 mm (0.12 in) cable

Part number FA5B05-NT01 FA5B10-NT01






Connector type ST ST





—end—


6-1

Appendix A: Description of commercially available optical fiber types 6-

Nortel Networks optical layer solutions with 1600G Amplifiers are currently compatible with NDSF and TrueWave Classic fiber plant. Studies are underway to extend Nortel Networks link budgets to include the latest technology optical fiber such as dispersion managed fiber.

The following is a description of the major fiber types that are currently commercially available:

NDSFCommonly referred to as standard single-mode silica fiber, this fiber type is also known as non-dispersion-shifted fiber (NDSF). The SMF-28, made by Corning, is one of the most popular NDSF fibers deployed today. The main disadvantage of NDSF is that it has an operating wavelength for zero chromatic dispersion (called λo) of 1310 nm. Transmission wavelengths used with EDFA amplification systems (1550 nm window) undergo significant chromatic dispersion and hence require dispersion compensation, particularly at 10 Gbit/s rates (see page 7-4 for more information about chromatic dispersion). Typical losses range from 0.21 to 0.25 dB/km.

DSFTo minimize chromatic dispersion at 1550 nm, a new fiber called dispersion-shifted fiber (DSF) was introduced in the early 1980s. By changing the index profile and reducing the core radius, fiber designers were able to move λo from the 1310 nm window to the 1550 nm window. While it is very effective in reducing chromatic dispersion effects, the positioning of λo in close proximity to the operating wavelengths has resulted in susceptibility to a nonlinear distortion effect called four wave mixing (FWM), particularly in DWDM applications with more than eight wavelengths (see page 7-2 for more details on FWM). Typical losses range from 0.25 to 0.30 dB/km.


6-2 Appendix A: Description of commercially available optical fiber types

NZ-DSFTo counteract the FWM limits of DSF, non-zero dispersion-shifted fiber (NZ-DSF) has been developed. This fiber moves λo to either end of the EDFA spectrum thus ensuring that all the wavelength channels have slightly different optical speeds in the fiber. Common brands are TrueWave Classic (λo < 1530 nm), TrueWave Plus (λo = 1497 nm), TrueWave RS (λo < 1452 nm) by Lucent, and SMF-LS (λo > 1560 nm) by Corning. The advantage that these fibers have over DSF is a slightly lower degree of integrated dispersion compensation and a higher tolerance to nonlinear distortion effects.

LEAF and E-LEAF (LEAF with reduced dispersion slope) Although the concentration of optical power in a fiber core is directly related to higher susceptibility to nonlinear distortion effects, large effective area fibers (LEAF) with λo = 1513 nm, and E-LEAF with λo = 1500 nm, are being introduced to the market. They offer both effective integrated dispersion compensation and a higher tolerance to nonlinear distortion as compared to NZ-DSF. The latter benefit permits higher per channel optical launch powers thus improving the span loss margin.

Note: The vintage of the LEAF fiber may impact performance. Consult with Corning about the type of LEAF that is deployed.


7-1

Appendix B: Overview of fiber-optic fundamentals 7-

Optical fiber is currently the best guided wave medium for long haul, high speed, high channel density applications. However, some physical properties of the fiber tend to generate effects that limit the reach of an optical link to less than the loss limited achievable distance (the distance that can be covered when only loss is taken into account in the link design). This section will discuss the various impairments that can limit the distance * bandwidth (L * B) product of a link. By using appropriate methods to counteract these impairments, the reach of an optical link can be significantly increased.

Factors other than the fiber properties themselves affect the L * B product, such as transmitter and receiver performance, coupler and filter characteristics and amplifier performance (noise, gain profile...). This section will only describe the fiber related limitations.

Effects in the optical fiberEach data channel in a DWDM link is a train of pulses. Being finite in time, each of these optical pulse is composed of a range of wavelengths distributed around a central optical wavelength, which corresponds to the central wavelength of a specific DWDM channel. The total signal in the fiber is then the combination of all the DWDM optical channels multiplexed in the fiber.

While propagating in the fiber, each of the pulses will see their shape and amplitude modified by various effects arising from the physical properties of the fiber material. This section discusses these properties and explains their effects on the optical pulse.

These effects are not necessarily occurring simultaneously with equal importance in all optical links. Their strengths depend on many factors such as the specific wavelengths multiplexed in the link, the number of wavelengths, the fiber type (different dispersion, attenuation and nonlinear effect threshold), the power in each optical channel and the length of the link.


7-2 Appendix B: Overview of fiber-optic fundamentals

The various effects can be grouped according to their action on the optical pulses. It is useful to categorize them in two main categories: pulse energy variations and pulse shape variations. Pulse energy variations are related to the intensity change of the various wavelengths that form the pulse as it propagates in the link. Pulse shape variations are related to the pulse distortion, which is a modification of the pulse shape that can potentially affect its duration.

Fiber effects affecting the energy of an optical pulseThe pulse energy is affected by fiber loss and four nonlinear effects: stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS), four wave mixing (FWM) and modulation instability (MI). The importance of the penalty related to these effects depends on the power concentrated in the effective area of the fiber (light intensity).

Fiber lossFiber loss results in a progressive attenuation of the optical pulse while it is traveling in the fiber. For example, typical fiber loss at 1550 nm is between 0.21 and 0.25 dB/km for NDSF fiber. Fiber loss is also wavelength dependent. Different DWDM channels undergo slightly different attenuation. Optical amplifiers are used to extend the reach of an optical link by optically amplifying the attenuated signal.

SBS and SRS SBS and SRS are two nonlinear scattering effects that transfer energy from one light wave to another light wave of longer wavelength. Therefore, the pulses of optical channels with the shorter DWDM wavelength have their energy transferred to longer wavelengths as they propagate through the fiber.

Both SBS and SRS effects become more important with increasing power in the DWDM channels and increasing length of the optical link.

In the case of SBS, the energy transfer occurs in a narrow linewidth (for example, around 20 MHz around 1550 nm). Therefore, with today’s DWDM links having 100 GHz of wavelength spacing, the energy transfer does not create interaction between different DWDM channels. However, it does impact the wavelength intensity within each DWDM channel. SBS will transfer part of the energy contained in a DWDM channel propagating in one direction to other wavelengths generated and propagating in the opposite direction. The transmitted signals are attenuated as they travel through the fiber, adding a power penalty.

The SBS-related penalty can be minimized by keeping the per-channel power below the SBS threshold, which depends on the size of the fiber core and on the transmitter linewidth. Because SBS is a narrowband effect, it is also possible to dither the source to decrease the penalty. The frequency excursion of the dither must be sufficient to increase the SBS threshold, but small enough so that dispersion penalty is not seriously increased.


Appendix B: Overview of fiber-optic fundamentals 7-3

SRS is a broadband effect that transfers power from a shorter wavelength to a longer wavelength. SRS couples energy in both the transmission direction and the reverse direction. Coupling occurs when two optical pulses (two 1s) from two DWDM channels overlap each other. However, the SRS threshold is significantly higher than SBS, therefore this effect has an insignificant impact on most of the applications described in this guide.

FWMFWM mixing is another nonlinear effect where the optical power in some wavelengths is transferred to other wavelengths. Due to the physical properties of the fiber (in this case, nonlinear induced polarization in the fiber material), the DWDM channels centered at optical frequencies ω1, ..., ωn, interact to create new optical waves at frequencies such as 2ωi - ωj and ωi + ωj - ωk. The penalty resulting from this effect is bit rate independent and highly dependent on the spacing between the DWDM channels and the dispersion in the fiber.

Like SRS, the impairment related to FWM increases when dispersion is lower in the link. Very low dispersion leads to wavelengths traveling at identical speeds, creating a “phase matching condition” which increases the interaction between optical pulses. Therefore, FWM can be important in some NZ-DSF and in DSF fiber because their zero dispersion wavelengths may fall very close or right in the DWDM channels optical band. Decreasing the channel spacing also results in more penalty because of FWM.

The generated signals with frequencies ωi + ωj - ωk cause the most problems. They are likely to generate significant cross-talk in the optical link. Therefore, the penalty arises not only from a loss of power in the DWDM optical channels, but also from the cross-talk generated by the waves created when their frequencies fall on or very close to the frequencies of the DWDM channels.

Solutions to reduce FWM includes a careful selection of the DWDM channel center frequencies to avoid equal spacing between them, which reduces the cross-talk and hence the penalty related to FWM. Like other nonlinear effects, limiting the per-channel power also reduces the FWM in the link.

MIMI is a complex effect that occurs when the optical channels in the DWDM system are seeing positive (or anomalous) dispersion. The interaction between the nonlinear and the dispersive effects results in a frequency-dependent gain for the ASE (noise generated by the optical amplifiers in the link). It is a single channel effect in which the high channel power acts as a pump to provide gain for the ASE. The amount by which the ASE noise gets amplified depends on the channel power and the net downstream dispersion which is perceived.



Fiber effects affecting the shape of an optical pulseThese effects change the shape of the pulses, potentially increasing or decreasing their time duration. Increased time duration can result in intersymbol interference (ISI) when the pulse duration becomes longer than the bit period, seriously impairing the performance of the system. Chromatic dispersion and polarization-mode dispersion (PMD) are two fiber properties that change the pulse shape. Two nonlinear effects also change the pulse duration: self-phase modulation (SPM) and cross-phase modulation (XPM or CPM).

The resulting penalty is greater in 10 Gbit/s systems. The 2.5 Gbit/s channels have a longer bit period (around 0.4 ns) compared to 0.1 ns for 10 Gbit/s channels and have more margin before their performance is affected. As a result, 10 Gbit/s links must be carefully designed with correct dispersion compensation to avoid performance degradation.

Chromatic dispersion in DWDM systemsTwo main dispersion phenomena are taken into account when designing DWDM systems in single mode fibers: chromatic dispersion and PMD.

Chromatic dispersion is due to an inherent property of silica fiber. The speed of a lightwave depends on the refractive index, n, of the medium within which it is traversing. In silica fiber, as well as many other materials, n changes as a function of wavelength. Thus, different wavelength channels travel at slightly different speeds along the fiber. A wavelength pulse is composed of several wavelength components or a spectra. Each of its spectral constituents travel at slightly different speeds within the fiber. The result is a spreading of the transmission pulse as it travels through the fiber; the slower energy components tend to fall behind the primary energy group, the faster energy components tend to lead the primary energy group.

Another property of silica fibers is that the difference of the speed at which two wavelength channels travel varies with the wavelength range within which they are situated. To understand this property better, note that all fibers have a wavelength at which chromatic dispersion is practically zero. This wavelength is called the fiber zero dispersion wavelength, or λo (see Figure 7-1). Two co-propagating wavelength channels that are in close proximity to λo have a smaller speed difference than two co-propagating wavelength channels, with the same spacing, but located further from λo. Therefore, a wavelength channel’s position in relation to λo must be considered to accurately assess the degree of dispersion that affects the channel. Also, as shown in Figure 7-1, transmitters with a center wavelength greater than λo realize a positive (or anomalous) dispersion. Transmitters with a center wavelength less than λo realize a negative (or normal) dispersion. A wavelength channel subjected to positive dispersion sees its longer wavelength components travel more slowly



than its shorter counterparts, whereas a wavelength channel subjected to negative dispersion will see its longer wavelength components travel faster than its shorter counterparts.

Figure 7-1Illustration of zero dispersion wavelength

F5930-MOR_R80.eps

This last property is important, as a light pulse that has undergone a certain amount of negative dispersion can essentially correct itself by travelling through a medium that has an equivalent amount of positive dispersion. This is the function that dispersion compensating modules perform in optical links; they introduce, in-line, an opposite dispersion medium to that of the fiber.

Depending on the type of fiber and transmitter wavelengths used, the form of dispersion will vary as follows:

Non Dispersion Shifted Fiber (NDSF)NDSF fiber has a λo around 1310 nm, thus the dispersion in the 1550 nm wavelength window (C-Band) will always be positive.

Standard Dispersion Shifted Fiber (DSF)Standard DSF fiber has a λo anywhere between 1535 nm to 1565 nm, thus an optical channel in the lower wavelength range of the C-Band will always see negative dispersion, whereas an optical channel in the higher wavelength range of the C-Band may see positive or negative dispersion.

SMF-LSSMF-LS (commonly known as LS-DSF) fiber has a λo > 1560 nm, thus optical channels in the C-Band will always see negative dispersion.

Dispersion D(ps/nm.km)

Negative(normal)dispersion

Positive(anomalous)dispersion

Transmitter 2 < 0

2

0 1

Transmitter 1 > 0



TrueWave ClassicTrueWaveTM Classic fiber has a λo< 1530 nm, thus most optical channels in the C-Band will generally see positive dispersion. The 1528 and 1530 nm wavelengths may see negative dispersion.

TrueWave RSTrueWaveTM RS fiber has a λo < 1452 nm, thus optical channels in the C-Band will always see positive dispersion.

LEAFLEAF fiber has a λo < 1513 nm, thus optical channels in the C-Band will always see positive dispersion.

E-LEAFE-LEAF fiber has a λo < 1500 nm, thus optical channels in the C-Band will always see positive dispersion.

Chromatic dispersion compensation strategiesSeveral techniques can be used to counteract chromatic dispersion in an optical link. They include:

Dispersion-shifted fiberFiber made today is available with λo that have been shifted towards the EDFA portion of the optical spectrum. For more information, consult the list of fibers in this chapter.

DWDM transmitters or narrow-band wavelength transmittersAs a laser emits energy over a defined spectral band which is centered about the primary wavelength of the laser, the transmission pulses will be subject to chromatic dispersion. By narrowing the spectral content of the wavelength signal, transmission pulses can be made more robust to dispersion. For this reason, on long optical links, DWDM transmitters with externally modulated narrow linewidth lasers are preferred over broadband transmitters.

ChirpChirp is a software-provisionable transmitter pre-compensation technique. Chirp essentially pre-distorts the output signal pulse, acting on the spectral content of the pulse so that it will experience compression instead of expansion over a given distance of propagation. Chirp is defined as negative or positive, in relation with the nature of dispersion in the fiber. Typically, chirp will be set to the opposite of the dispersion in the fiber.

Dispersion and slope compensation modules (DCMs)DCMs/DSCMs are used to provide dispersion correction in a DWDM link on various types of fibers. Different DCM or DSCM modules can be used to correct for positive or negative dispersion, depending on which fiber type is being used for the link deployment.



Polarization Mode Dispersion (PMD)Another dispersion phenomenon that is taken into account when designing DWDM systems in single mode fibers is PMD. PMD can affect higher data rate systems such as 10 Gbit/s. It is an inherent property of fiber which results from a nonideal fiber manufacturing process and from stresses on the fiber. The dispersion of the optical pulse results from the different propagation velocity of the two orthogonal modes of polarization that the light signal can borrow as it travels along the fiber. The propagation delay between the two modes, accumulated over the length of the fiber, is known as differential group delay (DGD) and is measured in units of picoseconds [ps]. PMD is a statistical phenomena and the DGD produced by PMD change randomly in time. Therefore the mean value of DGD is used to characterize PMD. As a rule of thumb, the mean DGD increases as the square root of the fiber length.

In a few cases, especially for old fiber, the signal distortion and performance degradation must be compensated for by reducing the link budgets, provided in this chapter, by the appropriate amount depending on the mean DGD in the system.

Data provided by the fiber supplier can be used to obtain the mean link DGD. However, it is preferable to measure the mean DGD directly using commercially available test equipment.

Data provided by the fiber vendor is normally specified as a PMD coefficient [ps/√km]. To calculate the mean DGD for a link, use the following formula:

Mean link DGD= {∑ [(PMD value/span) ps/√km]2 x [(length of span) km]}1/2

= {∑ (PMD value/span)2 x length of span}1/2

For example, in a 3-span system with span lengths of 80 km, 60 km, and 40 km in which the PMD coefficients are 0.2 ps/√km, 0.16 ps/√km, and 0.13 ps/√km respectively, the mean link DGD = (0.22 x 80 + 0.162 x 60 + 0.132 x 40)1/2 = 2.33 ps.

Self-Phase Modulation (SPM) and Cross-Phase Modulation (XPM) These two effects, like dispersion, alter the pulse shape and potentially generate ISI. The penalty of these two effects highly depends on the per-channel power, the dispersion in the fiber and the optical link length.

SPM occurs because the refractive index of the fiber depends on the per-channel power. This change in refractive index will result in phase shifts which are proportional to the intensity of the pulse. Because the pulse does not have constant intensity throughout its duration, different parts of the pulse sees a different phase shift, causing induced chirp.



SPM does not modify the pulse shape by itself. The pulse distortion occurs when SPM arises in a dispersive medium. This induced chirp will either increase the pulse broadening caused by dispersion, compress the pulse or even result in amplitude modulation of the pulse, depending on the dispersion characteristic of the fiber and on the level of SPM,.

For example, in NDSF fiber, the combination of SPM-induced chirp and positive dispersion seen by all optical channels in the 1550 nm window results in an initial compression of the pulse, followed by pulse broadening.

XPM causes similar pulse chirping as SPM. However, the chirp level is increased by the interaction of pulses from the different DWDM channels in the system. Two pulses overlapping in the fiber causes a local increase in power, which changes the refractive index. As a result, the two pulses see additional chirp increasing the effect generated by SPM.

In a dispersive medium, pulse distortion also increases. However, high local dispersion can also decrease the effect of XPM because the probability of two pulses overlapping with each other over a long distance is reduced. By reducing the net dispersion experienced by the pulse, dispersion compensation added downstream of the fiber also reduces the broadening effect caused by the interaction between XPM and dispersion. The balance between all these effects must be considered.

When designing DWDM links, you must consider the magnitude of dispersion correction provided by the compensation modules as well as their placement in the link.

ConclusionAlthough dispersion must be reduced in a link to increase the reach of a system, the compensation strategy must be carefully implemented to prevent a significant increase in the penalty arising from nonlinear effects. This penalty could seriously affect the link reach and system performance.

All the link engineering rules provided in this chapter were carefully developed to optimize both reach and performance of a DWDM system by taking into account the long list of impairments present in that kind of system.

Proper link design is even more important for 10 Gbit/s systems. 10 Gbit/s systems must conform to both maximum average span loss and related dispersion windows. When 10 Gbit/s channels are multiplexed in a DWDM system, both span loss and total link length must be taken into account.


8-1

Appendix C: 1600G Amplifier power specifications 8-1600G EOL power mask specifications

The 1600G amplifier output power mask for the dual and booster amplifier modules are shown in Table 8-1 and Table 8-2. These tables compare the input power for the amplifier to the end-of-life (EOL) total output power. For example, when the input power to the dual amplifier is -5 dBm, the output power at end-of-life can be adjusted from 0 to +15.5 dBm.

Table 8-11600G C-Band Dual Amp EOL Power Mask Specifications

Total Input Power [dBm] Total Dual Amp Output Power [dBm]

4 15.5

0 15.5

-5 15.5

-10 14.0

-16 12.8

-22 11.8

-25 8.8


8-2 Appendix C: 1600G Amplifier power specifications

Optical power requirementsThis section briefly describes the optical power requirements of the 1600G Amplifier topologies. These power requirement figures are used when you equalize the system following a system line-up and test (SLAT) procedure, or after adding or removing optical channels.

Table 8-3 lists the total optical power requirements at the first in-service amplifier (FISA) in an amplifier chain. The total input power of the first in-service amplifier should fall within the range shown in Table 8-3. The power provisioning rules provided in Chapter 3, Optical link engineering rules ensure that the total input power falls within the range shown in Table 8-3. These values are provided for reference only. If your input power is not within this range, contact Nortel Networks.

Table 8-4 lists the required optical output at the receiver based on the fiber type, number of spans, and the topology of your configuration. The optical power of your receiver must fall within the range shown in Table 8-4.

For details about adjusting the total input power and optical power at the receiver, refer to the 1600G Amplifier SLAT and Upgrade Procedures, 323-1801-226.

Table 8-21600G C-Band Booster Amp EOL Power Mask Specifications

Total Input Power [dBm] Total Booster18 Output Power [dBm] at VCA = 0

Total Booster21 Output Power [dBm] at VCA = 0

11 18.0 21.0

8 18.0 21.0

4 18.0 21.0

-1 18.0 21.0

-10 16.6 19.4


Appendix C: 1600G Amplifier power specifications 8-3

Table 8-3Total input power required at the FISA

Fiber type Span count

Topology Number of wavelengths

Required total input power [dBm]

PMaxSpec PMinSpec

NDSF

ELEAF

TW+

TWRS

1 to 6 Topology 2, C-band,

unidirectional, Dual Amp bypass

1 to 10 +11.0 -10.0

11 to 20 +11.0 -5.5

21 to 25 +11.0 -4.0

26 to 30 +11.0 -3.0

31 to 35 +11.0 -1.5

36 to 40 +11.0 +1.0

TWc 1 to 6 Topology 1, C-band,

unidirectional, no bypass

1 to 10 +3.0 -12.0

11 to 20 +4.0 -5.5

21 to 30 +3.0 -4.0

LS 1 to 6 Topology 1, C-band,

unidirectional,no bypass

1 to 10 +3.0 -12.0

11 to 20 +3.0 -5.5

Table 8-4Optical power required at the Rx

Fiber type Span count Topology Number of wavelengths

Rx power range [dBm]

NDSF

ELEAF

TW+

TWRS

1 to 6 Topology 2, C-band,

unidirectional, Dual Amp bypass

1 to 40 -6.0 to -11.5

TWc 1 to 6 Topology 1, C-band,


1 to 30 -6.0 to -11.5

LS 1 to 6 Topology 1, C-band,


1 to 20 -6.0 to -11.5


8-4 Appendix C: 1600G Amplifier power specifications


9-1

Appendix D: External tap couplers 9-

Tap couplers provide access to optical signals for the purpose of power measurement and monitoring. Although the current version of the C-band dual amplifier has a built-in internal tap coupler, earlier versions did not. If you have an earlier version of the C-band dual amplifier, you must use an external tap coupler assembly to gain access to optical signals for monitoring.

First generation of the 1600G C-band amplifier cardsThe first generation of C-band amplifier cards did not have a MON port to allow monitoring. Nortel Networks is discontinuing these circuit packs. Table 9-1 lists the PEC codes of these discontinued circuit packs.

Main function of the external tap couplersThe external tap coupler drop-in plate assembly includes four independently terminated 2% couplers installed in the OPTera Long Haul 1600 fiber management trays (FMTs). The assembly permits output power monitoring

Table 9-1Discontinued 1600G C-band amplifiers without MON port

Description PEC CPC

C-Band Dual Amplifier (SC) NTCA15CA A0781500

C-Band Dual Amplifier (ST) NTCA15CB A0806763

C-Band Dual Amplifier (FC) NTCA15CC A0806164

C-Band Booster18 Amplifier (SC) NTCA15CE A0784190

C-Band Booster18 Amplifier (ST) NTCA15CF A0806163

C-Band Booster18 Amplifier (FC) NTCA15CG A0806765

C-Band Booster21 Amplifier (SC) NTCA15CH A0784191

C-Band Booster21 Amplifier (ST) NTCA15CI A0806768

C-Band Booster21 Amplifier (FC) NTCA15CJ A0806161


9-2 Appendix D: External tap couplers

with existing dual amplifier and booster modules. This is achieved by connecting one external tap coupler to the output port of an existing dual amplifier and another coupler to the booster module. The external tap coupler drop-in plate assembly is illustrated in Figure 9-1, External tap coupler drop-in plate assembly.

Future releases of Nortel Networks OPTera Long Haul 1600 product line will feature an in-skin optical spectrum analyzer (OSA) module. The external tap couplers are inserted at the output of all 1600G amplifiers to access the system signals to be monitored by the OSA.

Future releases of the Nortel Networks OPTera Long Haul 1600 product line will use the tap coupler ports to increase the accuracy of amplifier output power measurements. This will allow you to scale the capacity of the 1600G amplifier above 40 wavelengths and into the L-band.

Figure 9-1External tap coupler drop-in plate assembly

OTP1688p.eps

Figure 9-2 illustrates the functional blocks of the 1600G amplifiers with external tap couplers.

External Tap coupler Assembly

Fiber Management Tray


Appendix D: External tap couplers 9-3

Figure 9-2Functional block diagram

OTP1558t.eps

Optical specifications of external tap couplersThe optical specifications of the external tap coupler drop-in plate assembly are shown in Table 9-2.

Table 9-2Optical specifications of external tap couplers

Minimum Maximum

Operating Wavelength Range 1480 nm 1615 nm

Insertion Loss 98% Port Input 0.8 dB (See Note 1)

Insertion Loss 2% Port Output 16 dB 18 dB

Return Loss all ports 45 dB

Directivity all ports 55 dB

PDL 0.1 dB

Dual AmpInput 1

2B

1A

2A

1B

Tap 1 Tap 3

Tap 2Tap 4Dual Amp

Input 22%

To OSA2%

To OSA

2% To OSA

2% To OSA

98% 98%

98%98%



Optical layer functional building blocks with external tap couplersFor more information on the 1600G Amplifier building block components, refer to Chapter 2, Optical layer building blocks. The external tap couplers are used with these components to create the following two categories of configurations:

• Building blocks for standard configurations with external tap couplers

• Building blocks for special configuration with external tap couplers

Building blocks for standard configurations with external tap couplersThis section provides specific descriptions of all amplifier sites with external tap couplers used in unidirectional C-band applications of OPTera Long Haul 1600.

Figure 9-3 shows the Tx-end amplifier site, commonly called Term1.

Figure 9-4 also shows one amplifier group in the link. This amplifier group is designated as the line amplifier site, commonly known as an LA site.

Figure 9-5 shows the Rx-end amplifier site, commonly called Term2.




OTP1632p.eps

Dual Amp

UniOSC

OS

C2

OS

C1

MSA 1AB

MSA 2AB

Legend

- WDM Coupler


- EDFA

- Circulator

- Pad

Booster Amp

Booster Amp

Direction 1

Direction 2

OSC1ADD

OSC1 DROP

2B

1A

2A

1B

Mux

Dem

ux


Common Tx Pad

MSAPad

SpanPad

MSAPad

- External Tap Coupler



Figure 9-4LA site configuration

OTP1636p.eps

Dual Amp

UniOSC

OS

C2

OS

C1

MSA 1AB

MSA 2AB

Legend

- WDM Coupler


- EDFA

- Circulator

- Pad


Booster Amp

Booster Amp

Direction 1

Direction 2

OSC2ADD

OSC1ADD

OSC1DROP

OSC2DROP

2B

1A 1B

2A

Note: MSA is mid-stage access for the DCM/DSCM and/or the OADM filter

SpanPad

SpanPad

MSAPad

MSAPad




OTP1634p.eps

Dual Amp

Uni OSCO

SC

2

OS

C1

MSA 1AB

MSA 2AB

Legend

- WDM Coupler


- EDFA

- Circulator

- Pad


Booster Amp

Booster Amp

Direction 1

Direction 2

OSC2ADD

OSC2DROP

2B

1A

2A

1B

Mux

Dem

ux

MSAPad

Common Tx Pad

SpanPad

MSAPad




Special configuration building blocks with external tap couplersFigure 9-6 shows the special asymmetric configuration required at the Tx-end terminal amplifier site used in some of the OPTera Long Haul 1600 C-Band unidirectional applications with External Tap Couplers. The special link engineering considerations require signals to bypass the dual amplifier in the Tx direction at the head-end Tx site.

Figure 9-6Term1 site special configuration (dual amplifier bypass)

OTP1638p.eps

Legend

- WDM Coupler


- EDFA

- Circulator

- Pad

- External Tap Coupler Note: MSA is mid-stage access for the DCM/DSCM

Dual Amp

UniOSC

OS

C2

OS

C1

MSA 2AB

Booster Amp 1B

Booster Amp 2BDirection 1

Direction 2

OSC1ADD

OSC1DROP

Mux

Dem

ux

1A

2A

1B

2B

MSAPad

SpanPad

Common Tx Pad


Nortel Networks

OPTera Long Haul 1600 Optical Line System1600G Amplifier Optical Layer Applications Guide

Copyright 2000 Nortel Networks, All Rights Reserved.

The information contained herein is the property of Nortel Networks and is strictly confidential. Except as expressly authorized in writing by Nortel Networks, the holder shall keep all information contained herein confidential, shall disclose it only to its employees with a need to know, and shall protect it, in whole or in part, from disclosure and dissemination to third parties with the same degree of care it uses to protect its own confidential information, but with no less than reasonable care. Except as expressly authorized in writing by Nortel Networks, the holder is granted no rights to use the information contained herein.

*Nortel Networks, the Nortel Networks logo, the Globemark, How the World Shares Ideas, S/DMS TransportNode, OPTera, Preside, and Unified Networks are trademarks of Nortel Networks.

TrueWave is a registered trademark of Lucent Technologies Inc.LEAF is a registered trademark of Corning Incorporated.SMF-LS and SMF-28 are trademarks of Corning Incorporated.

NTY315DX Rel 3 October 2000Printed in Canada and in the United Kingdom

1600g amplifier optical layer applications guide · dwdm transmitters and wavelength translators...

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