Technology Options for 400G Implementation - …

1 1 Technology Options for 400g Implementation July 2015 The Optical Internetworking Forum, 48377 Fremont Blvd., Suite 117, Fremont, CA 94538 510-492-4040 2 Working Group: Joint Carrier and Physical and Link Layer Working Groups TITLE: 400g White Paper SOURCE: TECHNICAL EDITOR WORKING GROUP CHAIR Name: Jacklyn D. Reis, Name: Vishnu Shukla, PhD Company Name: CPqD Company Name: Verizon Address Address Address 2: Address 2: Phone: + Phone: + Email: Email: WORKING GROUP CHAIR WORKING GROUP VICE CHAIR Name: David R. Stauffer, Name: Karl Gass Company Name: Kandou Bus, Company Name: Qorvo Address Address Address 2 Address 2 Phone: + Phone: + Email: Email: ABSTRACT: This contribution presents the 400g White Paper document.

2 The OIF is an international non-profit organization with over 100 member companies, including the world s leading carriers and vendors. Being an industry group uniting representatives of the data and optical worlds, OIF s purpose is to accelerate the deployment of interoperable, cost-effective and robust optical internetworks and their associated technologies. Optical internetworks are data networks composed of routers and data switches interconnected by optical networking elements. With the goal of promoting worldwide compatibility of optical internetworking products, the OIF actively supports and extends the work of national and international standards bodies. Working relationships or formal liaisons have been established with COAST, Ethernet Alliance, Fibre Channel T11, IEEE , IEEE , IETF, ITU-T SG13, ITU-T SG15, MEF, ONF, Rapid I/O, SAS T10, SFF Committee, TMF and TMOC.

3 This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its Implementation may be prepared, copied, published and distributed, in whole or in part, without restriction other than the following, (1) the above copyright notice and this paragraph must be included on all such copies and derivative works, and (2) this document itself may not be modified in any way, such as by removing the copyright notice or references to the OIF, except as needed for the purpose of developing OIF Implementation Agreements. By downloading, copying, or using this document in any manner, the user consents to the terms and conditions of this notice. Unless the terms and conditions of this notice are breached by the user, the limited permissions granted above are perpetual and will not be revoked by the OIF or its successors or assigns.

4 This document and the information contained herein is provided on an AS IS basis and THE OIF DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY, TITLE OR FITNESS FOR A PARTICULAR PURPOSE 3 Table of Contents Table of Contents .. 3 List of Acronyms .. 5 List of Figures .. 7 List of Tables .. 8 1 Project Summary .. 9 Working Group project(s) .. 9 Working Group(s) .. 9 Date Approved .. 9 Original Document .. 9 Problem Statement .. 9 Scope .. 9 Expected Outcome .. 9 Schedule .. 9 Merits to OIF .. 9 Merits to working group .. 9 Relationship to other Working Groups .. 9 Relationship to other Standards Bodies.

5 9 2 Motivation or Executive Summary .. 10 3 Introduction .. 11 4 Carriers view on 400g transmission systems .. 12 Context .. 12 Constraints & Challenges for 400g .. 12 Long-Haul requirements for 400g .. 13 Networking requirements for 400g .. 15 Metro requirements for 400g .. 16 Conclusion .. 16 5 Basics Concepts on 400g WDM Transmission .. 17 Coherent Systems .. 17 Digital Signal Processing .. 19 Optical Channel Multiplexing .. 21 Optical Path .. 23 Optical Network Subsystem Elements .. 25 Software Defined Optics .. 27 6 List of potential 400g transmission solutions and their characteristic parameters .. 29 State of the Art on Optical 400g Transmission .. 29 Short Haul .. 31 Metropolitan .. 32 Long-Haul .. 35 Ultra-Long-Haul.

6 38 7 Comparison of 400g transmission technologies .. 40 System parameters for all modulation formats .. 40 Comparison and preference listing of technologies .. 41 4 8 Summary .. 43 9 References .. 44 5 List of Acronyms ACO Analog Coherent Optics ADC Analog-to-Digital Converter AGC Automatic Gain Control ASE Amplified Spontaneous Emission ASIC Application-Specific Integrated Circuit AWGN Additive White Gaussian BER Bit Error Rate CapEX Capital Expenditures CD Chromatic Dispersion CDC Colorless Directionless Contentionless CFP 100G Form Factor Pluggable CMOS Complementary Metal-Oxide Semiconductor DAC Digital-to-Analog Converter DBP Digital Back-Propagation DCF Dispersion Compensating Fiber DCM Dispersion Compensation Module DD-LMS Decision-Directed Least Mean Squared DFB Distributed-Feedback DGD Differential Group Delay DRA Distributed Raman Amplifier DSF Dispersion Shifted Fiber DSP Digital Signal Processing DWDM Dense Wavelength-Division Multiplexing ECL External Cavity Laser EDFA Erbium-Doped Fiber

7 Amplifier ENOB Effective Number of Bits FCRT Fixed-Code-Rate Transceiver FEC Forward Error Correction FIR Finite Impulse Response FWM Four-Wave Mixing GFF Gain Flattened Filter GN Gaussian-Noise GVD Group Velocity Dispersion HD-FEC Hard-Decision FEC HW Hardware ICR Integrated Coherent Receiver ISI Inter-Symbol Interference ITLA Integrable Tunable Laser Assembly LH Long-Haul LO Local Oscillator MMF Multimode Fiber MIMO Multiple Input Multiple Output MZM Mach-Zehnder Modulator 6 MQAM M-ary Quadrature Amplitude Modulation NCG Net Coding Gain NF Noise Figure NLSE Nonlinear Schr dinger Equation OEO Optical-Electro-Optical OFDM Orthogonal Frequency Division Multiplexing OpEX Operational Expenditures OSNR Optical Signal-to-Noise Ratio OTN Optical Transport Network OTU Optical Transport Unit PBC Polarization Beam Combiner PBS Polarization Beam Splitter PD Photo Detector PDM Polarization-Division Multiplexing PMD Polarization Mode Dispersion PMQ integrated Polarization Multiplexed Quadrature modulated transmitter PSD Power Spectral Density QAM Quadrature Amplitude Modulation QPSK Quadrature Phase Shift Keying RF Radio Frequency ROADM Reconfigurable Optical Add/Drop Multiplexer SBS Stimulated Brillouin Scattering SDN Software Defined Network SDO Software Defined Optics SD-FEC Soft-Decision FEC SE Spectral Efficiency SH Short-Haul SSMF Standard Single-Mode Fiber SNR Signal-to-Noise Ratio SPM Self-Phase Modulation SRS Stimulated Raman Scattering SSFM Split-Step Fourier Method TR Timing Recovery TIA Transimpedance Amplifier ULH Ultra-Long-Haul WDM Wavelength-Division Multiplexing WSS Wavelength Selective Switching XPM Cross-Phase Modulation

8 7 List of Figures FIGURE 1 NEW FLEXGRID DEFINED IN ITU-T RECOMMENDATION.. 15 FIGURE 2 COHERENT TRANSCEIVER CONCEPT DESIGN FOR PDM SYSTEMS WITH AN INTEGRATED TRANSMITTER AND COHERENT RECEIVER. : LASER SOURCE; IQM: IN-PHASE QUADRATURE MODULATOR; PBS: POLARIZATION BEAM SPLITTER; PBC: POLARIZATION BEAM COMBINER; PR: POLARIZATION ROTATOR; LO: LOCAL OSCILLATOR.. 18 FIGURE 3 TRANSMITTER-SIDE DSP FUNCTIONS.. 19 FIGURE 4 DSP FLOW IN A DIGITAL COHERENT OPTICAL RECEIVER.. 20 FIGURE 5 CONSTELLATION EVOLUTIONS FOR QPSK/8 QAM/16 QAM SIGNALS IN A DIGITAL OPTICAL COHERENT RECEIVER.. 21 FIGURE 7: CONCEPTUAL STRUCTURE OF A SUPER-CHANNEL TRANSCEIVER. CO RX: COHERENT RECEIVER; PDM-IQM: POLARIZATION-DIVISION MULTIPLEXING IQ MODULATOR.. 22 FIGURE 6: OPTICAL CHANNEL MULTIPLEXING FOR SPECTRALLY-EFFICIENT WDM NETWORKS. (A) NYQUIST WDM.

9 (B) MULTI-BAND OFDM.. 22 FIGURE 8: GENERIC SCHEME FOR THE GENERATION AND DETECTION OF OFDM SIGNALS. THE DSP FUNCTIONS INCLUDE SERIAL/PARALLEL (S/P) AND PARALLEL/SERIAL (P/S) CONVERSION, SYMBOL MAPPING AND DEMAPPING, CYCLIC PREFIX (CP) INSERTION AND EXTRACTION, TRAINING SEQUENCE (TS) INSERTION, AND EQUALIZATION.. 23 FIGURE 9 STRUCTURE OF A HYBRID OPTICAL AMPLIFIER (THREE PUMPS DRA AND SINGLE STAGE EDFA).. 25 FIGURE 10 (A) BROADCAST-AND-SELECT AND (B) ROUTE-AND-SELECT ROADMS.. 26 FIGURE 11 SOFTWARE DEFINED OPTICS FOR FLEXIBLE 400g OPTICAL TRANSCEIVERS.. 27 FIGURE 12 TRANSCEIVER ARCHITECTURE FOR METROPOLITAN APPLICATION 2X200G PDM-16 QAM.. 33 FIGURE 13 MULTI-BAND OFDM SPECTRAL ALLOCATION HIGHLIGHTING THE GUARD BAND ( F1), BANDWIDTH ( F2) AND FREQUENCY SPACING ( F3) BETWEEN THE OFDM SUB-BANDS.. 34 FIGURE 14 TRANSCEIVER ARCHITECTURE FOR METROPOLITAN APPLICATION 2X200G PDM-QPSK.

10 36 FIGURE 15 TRANSCEIVER ARCHITECTURE FOR 400g LONG-HAUL APPLICATIONS BASED ON 4X100G PDM-QPSK.. 36 FIGURE 16 LONG-HAUL 400 GB/S TRANSCEIVER ARCHITECTURE. (A) ONE SUB-CHANNEL TRANSMITTER BLOCK; (B) TRANSCEIVER COMPLETE MODULE BASED ON 4X100G PDM-16 QAM.. 37 8 List of Tables TABLE 1 CONSTRAINTS AND CHALLENGES FOR 400g WDM.. 13 TABLE 2 400g TRANSMISSION EXPERIMENTS REPORTED RECENTLY.. 29 TABLE 3 OSNR REQUIREMENTS (THEORY) FOR 400g MODULATION FORMAT Options . ACHIEVABLE OSNR WITHOUT DECREASING NET BIT RATE IS HIGHLIGHTED IN BOLD TEXT. TYPICAL Implementation PENALTY IS AROUND 2 DB.. 40 TABLE 4 POTENTIAL 400g ARCHITECTURES IN THE STATE OF THE ART.. 41 9 1 Project Summary Note: This section is removed when the document is forwarded to the TC for vote. It is used to help maintain the progress of the document.