Huawei-10G to 40G to 100G DWDM Networks

of 30/30 The Road from 10G to 40G to 100G DWDM Networks Christopher Skarica Chief Technology Officer North American MSO and Cable Ottawa, Ontario
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Transcript of Huawei-10G to 40G to 100G DWDM Networks

The Road from 10G to 40G to 100G DWDM

Christopher SkaricaChief Technology Officer North American MSO and Cable Ottawa, Ontario


WDM Introduction Optical Layer Convergence Dense and Coarse WDM DWDM System Building Blocks DWDM Optical Line Design Considerations Current DWDM Networks and Service Drivers 40G Overview 40G Facts 40G System Design Considerations 40G Deployment Challenges 100G Status 100G Standards Bodies Work and Review (IEEE, ITU, OIF) 100G System Design Considerations 100G Deployment Challenges 40G/100G Components Maturity Review Conclusions

Page 2

Definition of WDM



MMultiplexi ng

Wavelengt h Division

A technology that puts data from different optical sources together, on a single optical fiber, with each signal carried on its own separate light wavelength or optical channel

Page 3

Easy Integration of WDM Technology with Existing Optical Transport EquipmentWDM Fiber Mux 1 SONET

Independent Optical Bit Rates and Formats



3 Gigabit Ethernet Fibre Channel 4 Single Optical Fiber

WDM systems integrate easily with existing optical transport equipment and enable access to the untapped capacity of the embedded fiber. They also eliminate the costs associated with mapping common data protocols into traditional networking payloads.Page 4

Convergence at the Optical LayerTraditional Approach Wavelength NetworkingD1 Video Video Video Commercial Commercial Services Services IP IP SONET SONET ESCON SONET OC-1/3/12/48 Fibre Channel Gigabit Ethernet FICON

DWDM Optical Network


Special Assemblies Network Overlays

Ubiquitous Networking Forecast Tolerant

One Network = Rapid Services Turn-up & Reduced Operations CostsPage 5

DWDM and CWDM Technology DefinitionsDWDM Dense WDM Technology for amplified, high bandwidth applications. Ideal for Metro Core,Regional, and Long Haul applications. Squeezes as many channels as possible into optical spectrum supported by todays optical amplifier technology. Characterized by a tight channel spacing over a narrow wavelength spectrum, typically 50 200 GHz (I.e. 0.4nm 1.6nm) spacing in the C and L Bands

O - Band

E - Band 1360 1400 1440

S - Band 1480 1520

C-Band 1560

L - Band 1600 1640 (nm)



1310 nm


CWDM Coarse WDM Technology for un-amplified, lower channel count applications. Less costthan DWDM. Ideal for Metro Access applications. Characterized by a wide channel spacing over a wide optical spectrum 20 nm spacing from 1270 1610 nm1310 1290 1330 1270 1350 1370 1450 1470 1490 1530 1590 1390 1410 1430 1510 1550 1570 1610

O - Band 1280 (nm) 1320 1360

E - Band 1400 1440

S - Band 1480 1520

C-Band 1560

L - Band 1600 1640 (nm)


EDFA Gain SpectrumO - Band E - Band 1360 1400 1440 S - Band 1480 1520 C-Band 1560 L - Band 1600 1640 (nm)



1310 nm


Operates in 3rd low-loss window of optical fiber near 1.5 m Broad operating range of >30nm

Amplification across multiple wavelengths

Available for both C-Band and L-Band High optical gain of 20dB to 30dB All-optical amplification

Bit-rate insensitive (OC-12, OC-48, OC-192 and beyond)

Page 7

Dense WDM Wavelength Plan ITU-T G.694.1

ITU-T G.694.1 Standard DWDM Channel Assignments 200 GHz spacing = 20 Channels in C Band 100 GHz spacing = 40 Channels in C Band 50 GHz spacing = 80 Channels in C Band 25 GHz spacing = 160 Channels in C Band

Standard ITU Grid allows lasers and filters to be built to a common specification Page 8

Optical Network Building BlocksTerminal Translator for Pt. to Pt. connectivity


Terminal Translator for Pt. to Pt. connectivity

L2/L3 Switch or SONET Cross Connect

L2/L3 Switch or SONET Cross Connect

L2/L3 Switch or SONET Cross Connect

Line a DWDM fiber optic system with Optical Amplifiers, dispersion compensation, and optical couplers providing high capacity, pt. to pt., ring, or mesh based connectivity between end points 100s or 1000s of km apart Terminal wavelength translators/combiners for conversion of client optical signals to 1550 nm, DWDM compliant wavelengths AND/OR SONET and L2/L3 switches providing client signal aggregation and presentation of 1550nm, DWDM compliant wavelengths.Page 9

DWDM Building BlocksSoftware Control ROADMChannel FilterTransponders

Group Filter

Lambda Granularity Optical Branching Remote Reconfiguration




AmpProduct x


Channel Filters 200Ghz, 100Ghz, 50Ghz, or 25GHz spacing


Low Noise Variable Gain/Flexible Link Budgets Page 10

Optical Line Design Considerations

Optical Signal to Noise Ratio performance

Dictated by amplifier gain and spacing, no. of channels of system, and OSNR tolerance of DWDM receiver

Chromatic and Polarization Mode Dispersion of fiber

Different for different bit rate signals Causes Pulse spreading over distance More critical for 10Gbps and higher bit rate signals

Non Linear effects that disturb the energy and shape of a signal

Caused by high optical power levels, small fiber core diameter, and dispersion characteristic of fiber

Page 11

DWDM Optical Line Systems Today

The majority of deployed terrestrial DWDM optical line systems have been designed for 40/80 channels (100/50GHz spacing) of 10Gbps signals

Amplifier spacing and OSNR performance, dispersion compensation, and NLE avoidance is optimized for 10 Gbps signals in the majority of todays networks

SO, Why the talk of 40G and 100G and how do we accommodate for these higher rate signals without re-designing the embedded optical line systems ????

Page 12

MSO/Telco Optical Transport TrendsNational NetworkLong Haul Optical Networks being deployed/investigated Metro optical primary to reduce the no. of ring transport capacity Internet peering points upgrades and enable long underway.Metro Network Operation Center distance VOIP transit DWDM Technology is DWDM Technology Call Processing Center winning the day Dominating

300-1200Km per span

Regional Regional Headend Network Primary Network

Methods of Access network Fiber expansion being investigated expanded ~5km Primary Hub business and residential Secondary Hub service offerings

Data Center Internet Peering Point

180 ~ 300km circumference

DSL HFC PON Secondary Network

Page 13

Evolving DWDM Transport NetworkSw itch e dD igitO eo Vid d an m De n


al B roa



Over the Top Video

Digital DWDM Digital DWDM Transport Network Transport NetworkLarger Capacity Larger Capacity Flexible Flexible Hub & Mesh Traffic Flows Hub & Mesh Traffic Flows High Reliability High Reliability Efficient Efficient

DVR Start Over/n

W av elen gth S e


TV HDa di e tim ulWireless


Co m m er

ci al

Da t





Se rv

ic e


Page 14

40G Here Today

Commercially deployed and available 40G technology is now standardized in the SDH (STM-256), SONET (OC-768), and OTN (OTU-3) worlds

40G has become commercially deployed (starting in 2007) to increase fiber capacity many large operators (eg. Verizon, AT&T, Comcast) are running out of wavelengths on existing 10G DWDM line systems

40G DWDM interfaces are about 7-8 X that of a 10G and 10G has been dropping in price more rapidly than 40G BUT, lets not confuse this with 40 Gigabit Ethernet which is being ratified and is not an approved standard today !!! (well talk about that shortly)

Page 15

40G Facts

Thus far, the largest 40G application has been router-router interconnects (using PoS) with the largest commercial deployments having been Comcast and AT&T Global revenue for 40G line cards in 2007 was $178M expected to grow 48 percent annually through 2013 and reach almost $2B annually (Ovum) 40 G services expected to grow at a compound annual rate of 59% from 20072011 (Infonetics) 40 G is here to stay and will grow dramatically over the coming years How do we accommodate for these higher rate 40G signals without re-designing the embedded optical line systems ? By using advanced modulation techniques (amplitude and phase not just 1+0s, on and off anymore) to gain spectral efficiencies, coherent receiving, as well as advanced dispersion compensation techniques to make the 40G signal look like a 10G signal

Page 16

40G Transmission Platform1*40G SDH/SONET 4*10G SDH/SONET 1*40G SDH/SONET43Gb/s

43Gb/s 4x10Gb/s

10G, 40G uniform platform 15*22dB @80*40G design rule

Router STM-256/OC-768

Router STM-256/OC-768

Page 17

40G is More Nonlinear Sensitive than 10Gadditional Chirp introduction Reduce Nonlinearity impairment Differential phase instead of absolute phase Lower input power under given BER

RZ format

40G is 4 times the frequency of 10G, so inter-channel and intra-channel interferences bring a bigger problem. Long distance transmission systems solve this problem by introducing additional laser chirp, RZ format, differential phase and lower input power

Page 18

Technical Challenges from 10G 40Gitem OSNR Required Filtering effect CD tolerance Nonlinear effects Challenges: 10G40G6dB more

SolutionsAdvanced modulation formats

4x more

Spectral-efficient modulation format (ODB, xRZ-DQPSK for [email protected])


TODC (per channel compensation)

More sensitive to iFWM & iXPM

Nonlinear-resilient RZ format ,chirp processing

PMD Tolerance


Multi-level (/multi-carrier) modulation (DQPSK for reduced symbol rate and better optical spectrum utilization)

Advanced Optical Modulation formats and Adaptive per Channel Dispersion Compensation are at the heart of solutions.Page 19

40G Formats Channel Space

40Gbit/s Modulation summaryNonlinear Tolerance Launch Power (15 spans)

Max possible OSNR Sensitivity PMD Tolerance








Very Good













>6x (6x is 10Gs PMD tolerance)







Fragmented components supply chain reducing 40G cost reduction abilityPage 20

Adaptive Dispersion Compensation

Uneven residual dispersion due to unmatched dispersion slopes of DCM and fiber may exceed the dispersion tolerance of a 40G DWDM system ADC (Adaptive Dispersion Compensation) allows DWDM systems to compensate dispersion on per channel basis, and therefore optimize the receiving performance for native 40G over 10G optical line systems3000 2000Accumulated Dispersion (ps/nm)nnel th Cha veleng ger Wa Lon

1000 0Short W avelen gth Ch a

-1000 -2000 -3000 0


Terminal's Dispersion Equalization






Distance (km)

Same receiving performance in 400ps/nm tolerancePage 21

Native 40G over 10G Optimized Optical Line System10 G Optimized Optical Line SystemVOA









40G transceiver unit (OTU)





40G wavelength directly over the existing optimized 10G optical line system

Advanced coding format allows for existing 10G MUX/DMUX Built-in VOA and ADC allows for perfect match with 10G in power level and dispersion High sensitivity receiver (similar power level and OSNR tolerance as for 10G) Same EDFA Transparent transport of client signal

4*10G(OC-192/STM-64) 1*40G(OC-768/STM-256, 10GE WAN/LAN)

Page 22

40G/100G Quick Overview

The push for 40G and 100G involves BOTH Routing and Transport systems Why the quick jump to 100G from 40G ? Network traffic growth, router efficiencies and a standards body (IEEE) that decided to work on both 40GbE and 100 GbE at the same time thereby aligning the timetables for both

Is this about Cable, Telcos or both ? Both mostly driven in North America by Comcast, AT&T, and Verizon

Whats the hype factor Higher for 100G than 40G The 40G and 100G buzz is coming from both service providers and vendorsPage 23

100G Standards Forums

IEEE 802.3(40/100GE Interface)

Has approved 40G/100G Ethernet Draft Standard-- IEEE802.3ba (In Dec. 2007) Final Ratification Expected in mid 2010 100GE expected to be applied in core networking (Router) and 40GE expected to be applied in servers and computing networking (LAN Switches) Two kinds of 100GE PHY optical client interface were selected: i) 4x25G CWDM for SMF; ii) 10x10G Parallel module for MMF Provide appropriate support for OTN framing (100GE to ODU-4) Proposal for ODU4 Framing It has been accepted in G.709 in Dec.2008; the rate of OTU-4 is 111.809973 Gb/s Proposal for 100GE mapping to ODU4 frame: It is under discussion Proposal for OTN evolution: It is under discussion This project will specify a 100G DWDM transmission implementation agreement to include: i) Propagation performance objective ii) Modulation format : Optimized DP-QPSK with a coherent receiver OFDM also being considered iii) Baseline Forward Error Correction (FEC) algorithm iv) Integrated photonics transmitter/receiverPage 24

ITU-T SG15(100G OTN Mapping/Framing)

OIF PLL(100G LH Transmission components/DSP)

100G A Developing StandardWe Are Here2007J F M A M J J A S O N D J F M

2008A M J J A S O N D J F M

2009A M J J A S O N D J F M A M

2010J J A S O N D

IEEE802.3 100GE Standard

IEEE 802.3ba 40GE/100GE PAR Approved

IEEE 802.3ba D1.0 TF Draft

IEEE 802.3ba D2.0 802.3WG Ballot

IEEE 802.3ba D3.0 LMSC Ballot

IEEE 802.3ba 40GE/100GE Standard

ITU-T Q11/SG15 OTN StandardODU4 Proposal G.709 Amd3 Consent OTU4 Definition G.709 New Version Consent ITU-T SG15 OTU-4 standard

OIF PLL 100G LH Transmission

100G Project Kick off

IA Draft

IA to Straw Ballot

Project Complete

IA to Principal Ballot

Page 25

From 40G to 100G: Additional ChallengesChallenges OSNR Required 10G 40G6dB more

40G 100G~4dB more

CD tolerance

1/16 (4km vs 65km SSMF for NRZ)