8/22/2019 Jdsu in Service Measurement of the Osnr in Roadm Based Networks

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-60

-50

-40

-30

-20

-10

dB

1550 1551 1552 1553 1554 nm

1 2 3 54

Out-of-bandOSNR

-60

-50

-40

-30

-20

-10

dB

1550 1551 1552 1553 1554 nm

1 2 3 54

Out-of-band

OSNR

In-band

OSNR

To learn more, visit jdsu.com/fibertestNote: Specifications, terms, and conditions are subject to change without notice.

30149237 000 1107 ECOC.PO.FOP.TM.AE

In-Service Measurement of the OSNR in ROADM-based Networks

Measurement Challenge

Glossary

Demux DemultiplexerEDFA Erbium Doped Fiber Amplifier

I&M Installation and MaintenanceMUX Multiplexer

NEMs Network Equipment Manufacturers

OPS Optical Polarization SplittingOSA Optical Spectrum Analyzer

OSNR Optical Signal to Noise RatioPMD Polarization Mode Dispersion

ROADM Reconfigurable Optical Add Drop MultiplexerRx Receiver

Tx Transmitter

OSNR is a performance limiting parameter

NEMs and operators need credible OSNR

measurement during I&M

An instrument to measure OSNR must provide

the true OSNR for every network topology

The standard OSNR method indicates wrong8-10 dB or higher values than the true OSNR

Need for accurate method to measure the OSNR

Conventional OSNR Measurement Noise Filtering Challenge

Measurement methods: In-band OSNR

Measurement technique: OPS Method

Signal deactivation

+ Use standard OSA Forces service interruption

Inaccurate noise power measurement(e.g., due to spectral hole burning in EDFAs)

Signal suppression based on polarization nulling+ Suitable for in-service testing

+ No EDFA fluctuation problems Sensitive to PMD

New OPS-Method(based on the polarization nulling technique)+ Overcomes PMD sensitivity problems

PolarizationSplitter

Dual Port

OSAPolarizationController

SignalProcessing

Lin. Pol P

Lin. Pol S

Drop Add

DEMUX

MUX

MUX

ROADM

Tx1

Tx2

Tx3

Tx4

Txn

DEMUX

Rx1

Rx2

Rx3

Rx4

Rxn

Polarization

Splitter

SOP-1

Noise

SOP-2

Signal + Noise

Arbitrarily polarized signal

+ ASE noise

Polarization

Controller

8/22/2019 Jdsu in Service Measurement of the Osnr in Roadm Based Networks

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To learn more, visit jdsu.com/fibertestNote: Specifications, terms, and conditions are subject to change without notice.

30149237 000 1107 ECOC.PO.FOP.TM.AE

In-Service Measurement of the OSNR in ROADM-based Networks

Test Setup

Conclusion

Regular OSA could overestimate OSNR results byup to 10 dB

JDSUs in-band OSNR testing with OPS-Method overcomes noisefiltering problems in ROADM networks

Experiments with real 10 G and 43 G systems showed:> Measurement accuracy better than 1 dB

> High tolerance to PMD> Data rate and modulation format transparent

> OPS-Method is suitable for in-service measurement of the true OSNRin ROADM-based networks

Tx OSA

OPS OSA

In-band OSNR

Ref. OSNR

Filters

OSNREmulator

SoP PMD

DGDEmulator

10 G NRZ43G NRZ-DPSK43 G RZ-DPSK43 G PSBT Equivalent to

11/22 ROADMs0.5 dB BW: 32/23 GHz

OPS Benefits

High perf polarizationsplitting/filtering

Narrowbandoptical filtering (7.5 GHz)

Adaptive off-centernoise measurements

Simultaneous Dual-SoPmeasurements

PMD

DynamicRange

SoPFluctuation

Depolarization

DOPChange

Adaptive Narrowband

Off Center Measurement

0

-10

-30

-20

-40

-50

-60

1 55 5.2 1 55 5.4 1 55 5. 6

Signal + Noise

1555.8 1556 1556.2

nm

dBm

In-band OSNR Testing

Noise

Test Results

Measurement Dynamic

43G DPSK-NRZ

43G DPSK-RZ

10G ook-NRZ

Ref

34

30

26

22

18

14

10

610 14 18 22 26

OSNRRef[dB]

OSNRIn-band

[dB]

OSNR Accuracy

PMD Sensitivity at 43 Gb/s

27

26

25

24

22

23

21

20

18

19

170 5 10 15 20

DGD [ps]

OSNR[dB]

In-band OSNR: 43 G DPSK-NRZ

PMD Sensitivity at 10 Gb/s

26

25

24

23

21

22

20

19

17

18

160 10 20 30 40 50

DGD [ps]

OSNR[dB]

In-band OSNR: 10 G ook-NRZ

11 ROADMs

22 ROADMs

Glossary

DGD Differentia l Group DelayDPSK Differential Phased Shift Keying

I&M Installatio n and MaintenanceNRZ Non Return-to-Zeroook on off keying

OPS Optical Polarizatio n SplittingOSA Optical Spectrum Analyzer

OSNR Optical Signal-to- Noise RatioPMD Polarization Mode DispersionPSBT Phase Shaped Binary TransmissionROADM Reconfigurab le Optical Add Drop Multiplexe r

SoP State of PolarizationTx Transmitter