Submarine Networks – Today and Tomorrow Geoff Bennett Director, Solutions and Technology Geoff Bennett Director, Solutions & Technology Nottingham, United Kingdom Today’s Rules Have a Question? Ask all questions in the Questions Tab Experiencing Technical issues? Use the Chat tab for all tech questions. Poll Question Poll Question © 2020 Infinera. All rights reserved. Company Confidential. 5 From Telegraph to Telephone to Data Telegraph → Telephone Before 1956 calls were made over radio telephony Transatlantic Cable Capacity (circuits) 4500 4k 4k 4000 LEO Telstar 1 July 10th 1962 3500 3000 GEO 2500 2000 Intelsat 1 th 1500 April 6 1965 845 1000 500 36 48 138 138 0 TAT-1 TAT-2 TAT-3 TAT-4 TAT-5 TAT-6 TAT-7 1956 1959 1963 1965 1970 1976 1978 © 2020 Infinera. All rights reserved. Company Confidential. 7 Copper vs Fiber Capacity Levels Transatlantic Cable Capacity (circuits) 45000 40000 35000 30000 25000 20000 40k 15000 Copper 10000 Fiber 4k 4k 5000 36 48 138 138 845 0 TAT-1 TAT-2 TAT-3 TAT-4 TAT-5 TAT-6 TAT-7 TAT-8 1956 1959 1963 1965 1970 1976 1978 1988 © 2020 Infinera. All rights reserved. Company Confidential. 8 Transatlantic Fiber Optic Cable Evolution From TAT-10 onwards cable capacity moves to data rate, not telephone channels… …because, by 1992, voice was just another type of data Source: Wikipedia © 2020 Infinera. All rights reserved. Company Confidential. 9 Today there are a lot of submarine cables! telegeography.com Europe They carry >95% of Mediterranean international bandwidth Asia © 2020 Infinera. All rights reserved. Company Confidential. 10 How much traffic is carried by Submarine Cables? About 1.5 x 1015 bits per second Worldwide Growth (1.5 petabits per second) Growth is forecast at 39% ICPs dominate globally CAGR from 2019-2026 Historically transatlantic and trans- Source: Telegeography 2020 pacific, but spreading to all routes © 2020 Infinera. All rights reserved. Company Confidential. 11 Are we in another bubble? Not even close… Dotcom Bubble Coherent ($B) Coherent CapEx Post Bubble SLTE Upgrades ICP Surge © 2020 Infinera. All rights reserved. Company Confidential. 12 The anatomy of a submarine cable Laying the cable Cable laying ship Plough Cable Submarine cable © 2020 Infinera. All rights reserved. Company Confidential. 14 Amplifiers in Submarine Cables 25 year design life +10kV -10kV 50-80km © 2020 Infinera. All rights reserved. Company Confidential. 15 Danger to Submarine Cables • Sharks did used to attack galvanic telegraph cables • 1988 onwards – metal tape screening introduced Sharks! • No more problems with sharks! On average there are over 100 cable outages per year – but you rarely hear about them © 2020 Infinera. All rights reserved. Company Confidential. 16 Open Cables: Key Trend in Submarine Cables Before 2010 Circa 2009 Accelerated Innovation Cable vendor gets 100% Closed Closed cable SLTE Coherent! transponder revenue Cables contracts expire Upgrades 2014→ Spectrum Sharing New cables are • One network operator for the cable designed to be “Open” – Possibly different operators per fiber pair Transponders – Possibly different operators on a single fiber pair Vendor A Vendor A Vendor B • Challenges . – How to “accept” the new cable is RFS? Wet Plant + . Vendor Z – How to manage spectrum for multiple tenants © 2020 Infinera. All rights reserved. Company Confidential. 17 Open Cable Network Architecture Vendor A Vendor B Infinera Cable Landing Station Transponder(s) Transponder(s) Transponder(s) ASE and/or Idlers Some or all transponders will be located in PoP/DC Power Management ROADM Controller Wet plant PoP or monitoring Data Center Backhaul “Glass through” To the Wet Plant © 2020 Infinera. All rights reserved. Company Confidential. 18 Submarine Cable Capacity Evolution Poll Question Submarine Cable Types Ultra Long Haul 1 Dispersion Managed Cable (→2010) 2 Uncompensated (2014→) +ve -ve +ve -ve +ve Positive Dispersion Deployed up to 2010 Deployed 2014-2019 Examples: Hundreds of cable systems worldwide Examples: SeaBRAS-1, MONET, BRUSA, MAREA, AAE-1 etc. 3 Festoon/Unrepeatered 4 Space Division Multiplexing (2020→) No Amp Chain RFS 2020 onwards Examples: Dozens of cable systems worldwide Examples: Dunant – others in planning Relatively Short Distance © 2020 Infinera. All rights reserved. Company Confidential. 22 Dispersion Managed Cables 1 Dispersion Managed Cable (→2010) +ve -ve +ve -ve +ve Deployed up to 2010 Examples: Hundreds of cable systems worldwide These cables were designed Chromatic dispersion has to be and deployed before coherent managed by alternating positive technology was available and negative dispersion fibers along the cable © 2020 Infinera. All rights reserved. Company Confidential. 23 Capacity Evolution over Dispersion Managed Cables • Example: Transatlantic cable – Dispersion Managed – Transponder Evolution – Four fiber pairs – Design capacity: 800 Gb/s per fiber pair (80 waves at 10Gb/s per wave) LC-PCS 60 Coherent 200G 50 Coherent 48Tb/s 100G Coherent 40Tb/s 40 32Tb/s 30 40G Coherent 20 10G IM-DD 12.8Tb/s 10 Total Cable Capacity (Tb/s) Cable Capacity Total 3.2Tb/s 0 2005 2010 2012 2016 2020 © 2020 Infinera. All rights reserved. Company Confidential. 24 MAREA: A Coherent-Optimized Submarine Cable The Cable System The Field Trial Results 6,644 km Production Gear – Hero Capacity 6,644 km One-Way Results (16QAM) Bilbao 6.21 bit/s/Hz Spectral Efficiency 26.2 terabit/s capacity Virginia Beach 13,210 km Loopback Results (8QAM) 4.46 bit/s/Hz Spectral Efficiency ▪ MAREA Cable System 18.6 terabit/s capacity ▪ Virginia Beach, USA to Bilbao, Spain Commercial Margin Capacity ▪ 6,644km 24.2 Tb/s ▪ Large Area, +ve dispersion cable © 2020 Infinera. All rights reserved. Company Confidential. 25 Where Next for Increasing Cable Capacity? Submarine Amplifiers and Capacity Amplifier Location ←C-Band EDFA→ • Submarine cables need amplifiers ←C-Band EDFA→ • Amplifiers must be powered ←C-Band EDFA→ ←C-Band EDFA→ Let’s look at some key facts +10-15 kV -10-15 kV Amplifier power is Amplifiers are only Copper conductor Transponder inserted at cable about 1.2% efficient has resistance of performance end points about 0.75 Ω/km depends on high OSNR – so high amp power levels © 2020 Infinera. All rights reserved. Company Confidential. 27 Technology Option: Light C+L Bands Amplifier Location C+L doubles fiber ←C-Band EDFA→ ←C-Band EDFA→ XTb/s capacity at the pair capacity, but has ←C-Band EDFA→ cost of 4 fiber pairs ←C-Band EDFA→ no effect on total cable capacity C Band only Amplifier Location ←C-Band EDFA→ ←L-Band EDFA→ XTb/s capacity at the Limited by ability to ←C-Band EDFA→ cost of 2 fiber pairs ←L-Band EDFA→ power the amp chain C+L Band © 2020 Infinera. All rights reserved. Company Confidential. 28 What is SDM? → How do we maximize capacity? Amplifier Location ←C-Band EDFA→ All of these work to limit the ←C-Band EDFA→ ←C-Band EDFA→ number of fiber pairs in the cable ←C-Band EDFA→ Maximize capacity Maximize capacity Cable design goals per fiber pair per cable • Shorter amp spacing • Higher order modulation • Longer amp spacing • LC-PCS • Higher amp power • Fewer fiber pairs • Lower amp power • More fiber pairs • Examples: • Pump sharing • Example: Dunant • MAREA, BRUSA, etc. © 2020 Infinera. All rights reserved. Company Confidential. 29 SDM Comparison: MAREA vs Dunant SDM Roadmap Future transatlantic cable 40 fiber pairs @ 25Tb/s Petabit scale cable MAREA Dunant State of the art State of the art SDM cable UNCOMPENSATED cable • 6,600 km cable • 6,600 km cable • 8 fiber pairs • 12 fiber pairs • 24 Tb/s per fiber pair* • 25 Tb/s per fiber pair** • Total capacity 192 Tb/s • Total capacity 300 Tb/s *In service **Planned © 2020 Infinera. All rights reserved. Company Confidential. 30 Challenges for Submarine Transponder Design Poll Question Cable and Transponder Life Cycles Submarine cable design lifetime Coherent optical engine technology cycle 25 Years 4 Years The cable you lay this year may not be the “ideal cable” for future transponders BUT… Regardless of cable type, each generation of transponder delivers more capacity © 2020 Infinera. All rights reserved. Company Confidential. 34 The only real solution… You need a comprehensive toolkit © 2020 Infinera. All rights reserved. Company Confidential. 35 ICE6: 5th Generation Coherent Optical Engine 7nm DSP Analog ASIC PIC 20% 33% Ultra High Baud Rate LC-PCS Subsea Modulations High Gain SD-FEC (32-96 Gbaud) (ME-8QAM, etc) • Compact DCO • 1.6Tb/s Optical Engine • 2λ x up to 800Gb/s CHM6 Nyquist Subcarriers DBA Super-Gaussian Encryption Gain Sharing Groove (GX) C L 1 2 3 4 . 1529 1567 1569 1610 192 192 192 192 Shared Wavelocker SD-FEC Gain Sharing Lightning Tolerance C+L Band DRX XTC © 2020 Infinera. All rights reserved. Company Confidential. 36 TERMINOLOGY: Nyquist Subcarriers: What and Why? Carrier 1 Carrier 2 Carrier 1 Carrier 2 Carrier 1 Carrier 2 Carrier 1 Carrier 2 Subcarriers Subcarriers Subcarriers Subcarriers Laser 1 Laser 2 Laser Laser 1 Laser 2 Laser Laser 1 Laser 2 Laser Laser 1 Laser 2 Laser 1st Gen: No shaping 2nd Gen: Nyquist shaping ICE4: Nyquist subcarriers ICE6: Nyquist subcarriers • Higher spectral efficiency • Higher spectral efficiency • Add subcarriers • Driven by FlexGrid • Enhanced clock recovery • High Baud rate carrier • Linear tolerance • Low Baud rate subcarriers • Non-linear tolerance © 2020 Infinera. All rights reserved. Company Confidential. 37 Two options for increasing capacity* *For both per-wavelength and total fiber capacity QPSK 16QAM Time Time 2 Bits/symbol 4 Bits/symbol Symbols per Second Increase the modulation order Increase the Baud rate (ie. bits per symbol) (ie. symbols per second) © 2020 Infinera. All rights reserved. Company Confidential. 38 Baud Rate Dependencies: Chromatic Dispersion Chromatic Dispersion is a function of Square of the Baud Rate Compensating CD creates noise inside (2xBaud Rate = 4xCD) the transceiver (lower modem SNR) Coherent Transceiver CD Compensation NOISE Chromatic Chromatic Dispersion Baud Rate Uncompensated cables rely on high CD can be a big problem for CD to mitigate nonlinear effects trans-oceanic (14,000km+) © 2020 Infinera.