The Path to 100GNew challenges for 40G and 100G NetworksNew challenges for 40G and 100G Networks

Arthur MollArthur MollBDM T&D EMEABDM T&D EMEA

Braodband Technology EventBraodband Technology EventRotterdam, November 10th, 2009Rotterdam, November 10th, 2009

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Why is 40G - 100G introduction so difficult?

We are reaching the limits of the physics Limits of the optical fiber Limits of the optics

Traditional technologies (NRZ, DWDM, EDFAs, ROADMs, etc) have issues at 100G

Old Rule of Thumb 4xData Rate = 2,5xCosts Still valid forSTM-16 to STM-64 Not valid STM-64 to STM-256 (4xData = 5x Costs)

Mapping of 1GigE and 10GigE is difficult E.g. 10GigE with GFP in OTU2 muxed in OTU3

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From 10 G to 40G or 100G – Fiber Limit

CD Limit: 16 x less (120x) PMD Limit: 4 x less (11x) 2nd order PMD can not be neglected anymore Makes some current network structure un-usable

TT

STM-64 T= 100 psSTM-256 T= 25 psOTU-4 T= 8ps

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From 10 G to 40G or 100G – Optic Limit

10Gbps

40Gbps

100Gbps???

Faster Modulation = Broader Spectrum - FWHM Spec meaningless! Broader Spectrum ->Peak Power is not the answer -> Integrated Power OSNR needs to be defined&measured differently Curve shape needs to be considered. Can we still do WDM? Risk of Cross-Talk.

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“Standard” OSNR measurement methodIEC 61280-2-9

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• For filtered signals (ROADMs), Interpolation method under-estimates the noise level as noise is « carved » with the signal by the filter

• Different paths have different Noise Contribution

•Real noise

•Interpolated noise

•OSNR measurement methodSpecial case of filtered signals

•OSNR measurement methodSpecial case of filtered signals

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EXFO Innovative In-band OSNR methodPolarization diversity method

• Theory: Signal is polarized and noise is depolarized

• EXFO OSA have a polarization controller and polarization beam splitter at the input , allowing automated In-band OSNR measurement

•Noise •In-band

•Noise •In-band

•Signal•Signal •OSNR

•Power vs polarization

•Ppeak

•PNoise

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What are conditions for usable 100G System?

Conditions for usable 100G Line Side Transmision-System: More tolerant against CD&PMD Fit into WDM Grid – 100GHz, but 50GHz is better

Co-operate with existing 10G/40G channels Compatible with EDFAs and ROADMs High OSNR

High Rx Sensitivity Low EDFA Noise

The answer:New Transmission System with new Modulation format

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NRZ/RZ Intensity modulation

NRZ-OOK (On/Off Keying) vs.

RZ-OOK (On/Off Keying)

NRZ-OOK

RZ-OOK

The intensity modulation is easily detected by direct detection with a photo detector

Rx

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Phase Modulation: DPSK

DPSK (Differential Phase Shift Keying):

A logical « 1 » and a « 0 » have light

A « 1 » is represented by a phase shift by .

1 1 10 0 0

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QPSK/DQPSK modulation

4 phases 2 bits/symbol

QPSK DQPSK

Phase Modulation: QPSK-DQPSK

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PolMuxed – Phase Modulation: DP-QPSK

DP-QPSK Modulation

Two independent Data StreamsMultiplexed with Polarization

To achieve 112 Gbit/s typical with 28 Gbaud PM-(D)QPSK

Very complex, cost intensive, but really robust!

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Performance Overview

Ref: Can 100Gb/s wavelengths be deployed using 10Gb/s engineering rules? StrataLight Communications Inc, Cisco Systems Inc

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DP-QPSK Testing – Constellation Analyser

Confidential

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IEEE 802.3ba Pluggable Modules

CFP form factor package (86x127x14 mm / 3.4”x5.0”x0.55”)

100 GbE, 40 km on SMF (4x 25G LAN WDM, centered at 1305nm) 100 GbE, 10 km on SMF (4x 25G LAN WDM, centered at 1305nm) 40 GbE, 10 km on SMF (4x 10G CWDM, centered at 1305nm) 100 GbE, 10 km on SMF (10x 10G CWDM, centered at 1550nm)

From Santur Corporation

100 GbE, 100 m on MMF (850 nm parallel optics, 10x 10G)

CXP form factor (approx 20x54x11 mm / 0.78”x2.13”x0.43”)

100 GbE, 100 m on MMF (850 nm parallel optics, 10x 10G) 100 GbE, 10 m on active cable

QSFP form factor (18.4x72x8.5 mm / 0.72”x2.8”x0.33”)

40 GbE, 100m on MMF (850 nm parallel optics, 4x 10G) 40 GbE, 10 m on active cable

CONFIDENTIAL

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#5

#6

#8

#9

#7

#0

#1

#3

#4

#2

Mux/Demux in PCS Lanes

12 11 10 9 8 7 6 5 4 3 2 1 0 19 18 17 16

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14

13

Mux/Demux

Mux/Demux (2:5 5:10)

1284

0

16

11

73

1915

106

2

1814

95

1

17

13

16048 12

16048 12

16048 12

12

15193 11 7

15193 11 7

15193 11 7

11 7

14182610

14182610

14182610

14182610

14182610

13 17159

17159

100 GbE serial bit stream

Each PCS Lane is 5G bit stream

Mux/Demux (2:5 5:10)

b bits

aka: CFP

MAC & PHY

8 4 0 16 12 3 19 15 11 7 10 6 2 18 14 13 9 5 1 17

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Implications? What needs to be tested?

148 Mio packets/s or 3xDVDs per sec BERT of complete link BERT per PCS Lane

PCS Lane concept is complex and has trouble zone PCS Lane Marker (Order, Mapping) Lane Skew Mapping 10x10G elec. into 4x 25G bring new challenges

Ethernet Parameter (standard) Frame Size distribution, Errors (FCS, Runt) ThruPut, Frame Loss

Skew=Propagation Difference,Bit delay,Offset

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FTB-85100G – First portable 100G Tester

BERT On physical lane, PCS Lane or trunk

PCS Error injection and monitoring Bit error in Physical Lane or in PCS Lane Invalid 64b/66b or unsupported PCS code Invalid or duplicate PCS Lane markers

PCS Lanes Monitors lane marker period and reports

any changes to PCS lane table User defined or random mapping

supported

PCS Lane Skew Dynamically change and measure PCS

lane skew

Ethernet & IP Testing Layer 1 error/alarm injection and

monitoring

Packet Definition User defined rate utilization User defined MAC and IP address User defined packet size up to 16k

Error injection and monitor Layer 2 Payload and FCS

Ethernet statistics Jabber, giant, runt, oversize, FCS, total

frames

IP statistics Multicast, broadcast, unicast, total

Actual bandwidth usage statistics

CONFIDENTIAL

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85100G – Interface Specifications

Client Interfaces Very high CFP connector insertion rating 100G CFP, 100G CXP, 40G CFP,

40G QSFP

Clocking Stratum-3e clock with +/- 115 ppm user

controllable offset Support 100G /112G and 40G/43G rates

OTU3 and OTU4 hardware ready Unframed BERT (PRBS) at OTN rate Framed OTN with parallel optics support

on roadmap

Pluggable interface controls & monitoring

Detailed CFP interface control Control: laser on/off & amplitude (per lane) Monitoring: Input level (per lane),

Rx frequency

CONFIDENTIAL

Questions?