Nortel Networks OPTera Long Haul 1600 Optical Line System. 1600G Amplifier Optical Layer Applications Guide

Transcription

1 NTY315DX Nortel Networks OPTera Long Haul 1600 Optical Line System 1600G Amplifier Optical Layer Applications Guide Standard Rel 3 Issue 2 October 2000 What s inside... Introduction Optical layer building blocks Optical link engineering rules Application-independent optical link engineering rules Optical layer components specifications Appendix A: Description of commercially available optical fiber types Appendix B: Overview of fiber-optic fundamentals Appendix C: 1600G Amplifier power specifications Appendix D: External tap couplers *A *

2 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

3 iii Publication history 0 October 2000 July 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. The first issue of the 1600G Amplifier Optical Layer Applications Guide. 1600G Optical Layer Applications Guide NTY315DX Rel 3

4 iv Publication history 1600G Optical Layer Applications Guide NTY315DX Rel 3

5 v Contents 0 About this document ix Introduction 1-1 Chapter overview 1-1 Describing and understanding optical networks 1-1 OPTera 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 1-3 OPTera Long Haul 1600 OADM couplers 1-3 Dispersion compensating modules (DCM) 1-3 Dispersion slope compensating modules (DSCM) 1-3 Optical layer building blocks 2-1 Optical layer functional building blocks 2-1 Link Models 2-1 Configuration overview 2-3 Standard configurations building blocks 2-3 Special configuration building blocks G amplifier group description G Amplifier building block components 2-7 Wavelength capacity 2-7 Mid-stage access (MSA) rules 2-7 Padding rules 2-8 Usage with 1480/1510 nm OSCs or 1510/1615 nm OSCs 2-8 Unused ports 2-8 Mux/Demux building blocks 2-9 Configuration description 2-10 Mux/Demux building blocks components 2-11 Wavelength capacity 2-11 Spare wavelengths 2-11 Module deployment 2-11 Unused ports 2-12 Optical link engineering rules 3-1 Link engineering rules for OPTera Long Haul 1600 C-Band unidirectional 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

6 vi Contents applications 3-3 Deployment considerations for OPTera Long Haul 1600 optical layer applications 3-4 Optical link engineering procedure 3-5 Optical link budgets and span loss rules 3-5 Span loss rules and guidelines 3-7 Derating example 3-10 Padding rules 3-11 Optical patch panel rule 3-11 Optical 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 4-1 Tx chirp adjustment for dispersion compensation 4-1 NLS dithering provisioning 4-1 OPTera Long Haul 1600 mid-stage access (MSA) loss restrictions 4-2 Polarization mode dispersion (PMD) consideration 4-4 Nortel Networks 100 GHz ITU-T compliant wavelength grid 4-5 Wavelength plans 4-6 OADM Applications 4-6 Optical layer components specifications 5-1 Fiber optic attenuators 5-17 Fixed attenuators 5-17 Specifications 5-17 Appendix A: Description of commercially available optical fiber types 6-1 NDSF 6-1 DSF 6-1 NZ-DSF 6-2 LEAF and E-LEAF (LEAF with reduced dispersion slope) 6-2 Appendix B: Overview of fiber-optic fundamentals 7-1 Effects in the optical fiber 7-1 Fiber effects affecting the energy of an optical pulse 7-2 Fiber effects affecting the shape of an optical pulse 7-4 Chromatic dispersion in DWDM systems 7-4 OPTera Long Haul 1600 NTY315DX Rel 3

7 Chromatic dispersion compensation strategies 7-6 Polarization Mode Dispersion (PMD) 7-7 Self-Phase Modulation (SPM) and Cross-Phase Modulation (XPM) 7-7 Contents vii Appendix C: 1600G Amplifier specifications G EOL Mask Specifications 8-1 Optical power requirements 8-2 Appendix D: External tap couplers 9-1 First generation of the 1600G C-band amplifier cards 9-1 Main function of the external tap couplers 9-1 Optical specifications of external tap couplers 9-3 Optical layer functional building blocks with external tap couplers 9-4 Building blocks for standard configurations with external tap couplers 9-4 Special configuration building blocks with external tap couplers G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

8 viii Contents OPTera Long Haul 1600 NTY315DX Rel 3

9 ix About this document 0 This 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) 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

10 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. Audience This 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 Library The 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. OPTera Long Haul 1600 NTY315DX Rel 3

11 About this document xi OTP1468p.eps OPTera Long Haul 1600 Optical Line System Network Application Libraries Repeater Library 1600G Amplifier Library Combiner Library Planning Guides NTPs Maintenance Guides xx Installation, Commissioning, and Testing Guides xx Engineering Guides xx 1600G Amplifier Network Application Guide 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 requirements External tap couplers Control shelf configurations Operations, Administration, and Provisioning Guides xx Optical Add/Drop Multiplexer User Guide PEC: NTY313GC 1600G OADM general guidelines OADM fiber routing Connecting and site testing topology 1/2 amplifiers with OADM in Direction 1 Connecting and site testing topology 1/2 amplifiers with OADM in Direction 2 Completing connections at an OADM site Coupler specifications and ordering information 1600G Amplifier Optical Layer Application Guide PEC: NTY315DX Optical layer building blocks Link engineering rules Application-independent link engineering rules Optical layer components specifications Optical fiber types Fiber-optic fundamentals 1600G Amplifier OAM&P Guide PEC: NTY317DX Logical, physical and software views of Amplifier Provisioning and facility management Optical layer alarms Level 2 routing 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

12 xii About this document References This document refers to the following documents: 1600G Amplifier Network Application Guide (NTY314AX) OPTera Long Haul 1600 Release 3 NTP Library (NTCA65EC) OPTera Long Haul 1600 NTY315DX Rel 3

13 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 networks A 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. 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

14 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 Architecture Interfaces STE's SONET/SDH LTE's SONET/ SDH/ IP/ ATM LTE/ADM Optical link OPTICAL LAYER Optical link Optical amplifier (uni or bidirectional) Optical terminating site (optic - electric & electro-optical conversion) OPTera Long Haul 1600 NTY315DX Rel 3

15 Introduction 1-3 OPTera Long Haul 1600 technologies for optical layer solutions A 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 couplers DWDM 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 couplers OPTera 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). 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

16 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. OPTera Long Haul 1600 NTY315DX Rel 3

17 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 blocks You 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 models In 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. 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

18 2-2 Optical layer building blocks Figure span unidirectional link OTP1128.eps Direction 1 Tx λs Mux Demux Rx Term1, Tx LA1 LA2 LA3 Term2, Rx Rx Demux Mux λs Tx Term1, Rx LA3 LA2 LA1 Term2, Tx Legend Direction G Amplifier - unidirectional OPTera Long Haul 1600 NTY315DX Rel 3

19 Optical layer building blocks 2-3 Configuration overview This 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 blocks This 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 2-2 Term1 site configuration OTP1633p.eps Mux Demux Direction 2 MSA 1AB Common Dual Amp Booster Amp Span Tx Pad Pad 1A 1B IN-1 OUT-1 Booster Amp Direction 1 MSA OUT-2 Pad UPB 2B 2A IN-2 UPA-2 MSA Pad MSA 2AB UniOSC OSC1 ADD Legend - WDM Coupler - Faceplate connector - EDFA - Circulator - Pad - Internal Tap Coupler OSC2 OSC1 OSC1 DROP Note: MSA is mid-stage access for the DCM/DSCM 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

20 2-4 Optical layer building blocks Figure 2-3 LA site configuration OTP1637p.eps MSA 1AB Direction 2 OUT Span Pad UPB Booster Amp 2B IN UPA-1 IN-1 OUT-2 MSA Pad Dual Amp 1A 2A OUT-1 MSA Pad IN-2 UPA-2 IN Booster Amp 1B Direction 1 OUT Span Pad UPB MSA 2AB OSC2 DROP UniOSC OSC1 ADD Legend OSC2 ADD OSC2 OSC1 OSC1 DROP - WDM Coupler - Faceplate connector - EDFA - Circulator - Pad - Internal Tap Coupler Note: MSA is mid-stage access for the DCM/DSCM and/or the OADM filter OPTera Long Haul 1600 NTY315DX Rel 3

21 Optical layer building blocks 2-5 Figure 2-4 Term2 site configuration OTP1635p.eps MSA 1AB Dual Amp Booster Amp Direction 1 Direction 2 Span Pad Booster Amp 2B MSA Pad 1A 2A MSA Pad Common Tx Pad 1B Mux Demux MSA 2AB OSC2 DROP Uni OSC Legend OSC2 ADD OSC2 OSC1 - WDM Coupler - Faceplate connector - EDFA - Circulator - Pad - Internal Tap Coupler Note: MSA is mid-stage access for the DCM/DSCM 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

22 2-6 Optical layer building blocks Special configuration building blocks Figure 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 2-5 Term1 site special configuration (dual amplifier bypass) OTP1639p.eps Mux Common Tx Pad Dual Amp 1A Booster Amp 1B 1B Span Pad Demux Direction 2 Booster Amp 2B 2B 2A UPB Direction 1 MSA Pad UPA-2 Legend - WDM Coupler - Faceplate connector - EDFA - Circulator - Pad - Internal Tap Coupler MSA 2AB UniOSC OSC2 OSC1 OSC1 ADD OSC1 DROP Note: MSA is mid-stage access for the DCM/DSCM 1600G amplifier group description The 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 The Dual-Amplifier supports two independent amplifiers that are each provisionable for a total output power of up to dbm. Booster18 can be provisioned to provide +18 dbm of output power. Booster21 can be provisioned to provide +21 dbm of output power. OPTera Long Haul 1600 NTY315DX Rel 3

23 Optical layer building blocks 2-7 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. ATTENTION For 1600G amplifiers without internal tap couplers, please refer to OPTera Long Haul 1600 External Tap Coupler Guide (NTY312GC). 1600G Amplifier building block components The 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 capacity In 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) rules To 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. 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

24 2-8 Optical layer building blocks Padding rules Common 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 OSCs Nortel 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 ports Do 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. OPTera Long Haul 1600 NTY315DX Rel 3

25 Optical layer building blocks 2-9 Mux/Demux building blocks This 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 2-6 Mux modules architecture OTP0828.eps To 1600G Amplifier Common Port Monitor Port (Tx) Module 1 Spare Wavelength Port through Tx Module 3 A B A B Module through Tx through Tx Module 4 A B Note: A and B are external patchcords through Tx 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

26 2-10 Optical layer building blocks Figure 2-7 Demux modules architecture OTP0829.eps To 1600G Amplifier Module 1 Common Port Monitor Port (Rx) Spare Wavelength Port through Rx Module 3 A B Module 2 A B Rx Rx through through A B Module 4 Note: A and B are external patchcords. Rx through Configuration description The 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. OPTera Long Haul 1600 NTY315DX Rel 3

27 Optical layer building blocks 2-11 Mux/Demux building blocks components The following components are currently used in specific Mux/Demux configurations: Grid 1: Module 1 ( nm to nm, Spare: nm) Module 2 ( nm to nm) Module 3 ( nm to nm) Module 4 ( nm to nm) Grid 2: Module 1 ( nm to nm, Spare: nm) Module 2 ( nm to nm) Module 3 ( nm to nm) Module 4 ( nm to nm) Wavelength capacity Up 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 wavelengths One spare wavelength, nm Grid 1 or nm Grid 2, can be added or extracted from the fiber using the DWDM baseline coupler. Module deployment In 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. 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

28 2-12 Optical layer building blocks 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 Upgrade A from Module 3 Upgrade B from Module 3 The upgrade ports of Demux Module 1 are: Upgrade A to Module 2 Upgrade B to Module 2 Upgrade A to Module 3 Upgrade B to Module 3 The upgrade ports of Mux Module 3 are: Upgrade A from Module 4 Upgrade B from Module 4 The upgrade ports of Demux Module 3 are: Upgrade A to Module 4 Upgrade B to Module 4 OPTera Long Haul 1600 NTY315DX Rel 3

29 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 ATTENTION For all optical link budgets for the OPTera Long Haul 1600 systems, the specified bit error rate (BER of ) 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. ATTENTION 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. ATTENTION Optical 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. 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

30 3-2 Optical link engineering rules ATTENTION For 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. ATTENTION The link engineering rules for 2.5 Gbit/s systems are not currently documented. Contact Nortel Networks for more information. Table 3-1 Link 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. OPTera Long Haul 1600 NTY315DX Rel 3

31 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 3-2 Page 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) E-LEAF 10 Gbit/s 1 to 40 (see Note 2) TW Plus 10 Gbit/s 1 to 40 (see Note 2) 1 to 6 Dual-Amplifier and Booster18 or Dual-Amplifier and Booster21 1 to 6 Dual-Amplifier and Booster21, Dual-Amplifier Bypass 1 to 6 Dual-Amplifier and Booster21, Dual-Amplifier Bypass (See Note 3) page 3-25 (see Note 1) page 3-30 (see Note 1) 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) 1 to 6 Dual-Amplifier and Booster21, Dual-Amplifier Bypass 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. 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

32 3-4 Optical link engineering rules 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. ATTENTION OPTera Long Haul 1600 OADM deployment rules are under development and will be presented at a later date. OPTera Long Haul 1600 NTY315DX Rel 3

33 Optical link engineering rules 3-5 Optical link engineering procedure Before 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 rules To 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. 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

34 3-6 Optical link engineering rules Figure 3-1 Link design procedure flow chart OTP1155.eps Is there a configuration that supports this fiber type for a particuliar number of wavelengths and determined number of spans? No Contact Nortel Networks for more information If required, add fixed pads to get span loss minimum required Calculate total link loss (sum of span losses) for the link Is the link within the supported window of operation (km)? No Contact Nortel Networks for more information Does any span exceed maximum allowed + 2 db? No Determine the Excess Loss in the link Yes Yes Is total link loss > (maximum allowed span loss x number of spans)? Yes No Does any span exceed maximum allowed + 1 db? No Determine the Excess Loss in the link Yes Is the Total Excess Loss 2 db? No Is the Total Excess Loss 3 db? Yes Yes Derate the maximum span loss by the amount indicated in Table 3-4 Derate the maximum span loss by the amount indicated in Table 3-5 Is the Total Excess Loss 1 db? Yes No derating required Is total link loss > (maximum derated span loss x number of spans)? No Is the Total Excess Loss > 1 db but 2 db? No Yes Derate the maximum span loss by the amount indicated in Table 3-3 No Yes Re-engineer the link Yes Is total link loss > (maximum derated span loss x number of spans)? No Determine the following: 1. Common Tx Pad 2. MSA Pad and DCMs/ DSCMs required and their locations 3. Span Pad Determine the following: 1. Common Tx Pad 2. MSA Pad and DCMs/ DSCMs required and their locations 3. Span Pad Link design is complete Link design is complete OPTera Long Haul 1600 NTY315DX Rel 3

35 Optical link engineering rules 3-7 Span loss rules and guidelines Span loss assumption The 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 3-2 Span loss calculation OTP1156.eps Span loss (Lspan) Calculation Zone optical patch panel Direction 1 optical patch panel from mux/demux or MSA site to mux/demux or MSA site Lopp Lfiber Lopp Lspan = Lopp + Lfiber + Lopp 17 db Lspan Lmax Legend 1600G Amplifier 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

36 3-8 Optical link engineering rules Total allowed link loss The total allowed link loss is the sum of the maximum allowed span loss for the candidate link. Total link loss margin The 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 loss The 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 loss The 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 and Table 3-5. Please note that excess loss penalty rules are defined only for NDSF, TW TM Classic, and E-LEAF fiber in this issue. Maximum allowable per-span excess loss The maximum allowable per-span excess loss is Lmax + ε i db, where ε i 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 = n i = 1 εi, 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. OPTera Long Haul 1600 NTY315DX Rel 3

37 Optical link engineering rules 3-9 Table 3-3 Per span excess loss 1 db with total excess loss > 1 db but 2 db Per fiber type derating values Span Count NDSF TW TM Classic E-LEAF 3 0 db 0 db 0 db db 0 db 0 db 5 0 db 0 db 0 db 6 0 db 0 db 0.5 db Table 3-4 Per span excess loss 2 db with total excess loss 2 db Per fiber type derating values Span Count NDSF TW TM Classic E-LEAF 2 1 db 0 db 0.5 db 3 0 db 0.5 db 0.5 db db 0 db 0.5 db db 0 db 0.5 db db 0 db 1 db Table 3-5 Per span excess loss 2 db with total excess loss 3 db Per fiber type derating values Span Count NDSF TW TM Classic E-LEAF db 0.5 db 1 db db 0.5 db 1 db 5 1 db 0 db 1.5 db 6 1 db 0 db 1.5 db PMD margin Refer to Polarization mode dispersion (PMD) consideration on page 4-4 to determine if the average loss per span must be derated. 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

38 3-10 Optical link engineering rules Derating example Use 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 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 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 = ε 1 = 0.5 db Span 2: 17 db Excess Loss of Span 2 =ε 2 = 0 db Span 3: 29 db Excess Loss of Span 3 = ε 3 = 1 db EL = ε 1 + ε 2 + ε 3 =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 OPTera Long Haul 1600 NTY315DX Rel 3

39 Optical link engineering rules 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 ( db = 82.5 db). 7 Derating and Excess Loss Procedure completed. Padding rules Three types of pads are used in all OPTera Long Haul 1600 applications: Common Tx pads, MSA pads and Span pads. Common Tx pads Common 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 pads MSA 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 pads Span 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 rule For 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. 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3

40 3-12 Optical link engineering rules Optical link transmission performance guarantee The 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 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 NTY315DX Rel 3

41 Optical link engineering rules 3-13 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 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. ATTENTION FEC must always be turned on. For all WT applications which presently do not support FEC feature, contact Nortel Networks. ATTENTION Although 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 Optimizer is only available for links with channel counts less than or equal to 20 (Module 1 and Module 2 only). 1600G Amplifier Optical Layer Applications Guide NTY315DX Rel 3