40Gb/s alien-wavelength experiment over 1000km TWRS fiber between Amsterdam and Copenhagen

Roeland Nuijts, SURFnet, roeland.nuijts@surfnet.nl

Lars Lange Bjørn, NORDUnet, longbear@nordu.net

Terena Networking Conference 2010, Vilnius, Lithuania

Outline

Alien wavelength concept

Alien wavelength advantages and disadvantages

Amsterdam-Hamburg-Copenhagen DWDM transmission systems

Alien wavelength channel allocation plan

Simple method to measure OSNR in presence of ROADMs

Results of alien wavelength experiments Amsterdam-Copenhagen

Conclusions & acknowledgements

Alien wavelength conceptRx

Tx

Tx

Rx

Rx

Tx

Tx

Rx

Tx

Rx

Rx

Tx

Rx

Tx

Tx

Rx

(a) conventional closed DWDM system

(b) multi-domain DWDM systems

(c) multi-domain DWDM systems with alien wavelength

Alien wavelength advantages

• direct connection of customer equipment cost savings

• avoid OEO regeneration power savings

• faster time to service time savings

• support of different modulation formats extend network lifetime

Alien wavelength challenges

• complex end-to-end optical path engineering in terms of linear (i.e. OSNR, dispersion) and non-linear (FWM, SPM, XPM, Raman) transmission effects for different modulation formats

• complicated system integration/functional testing

• end-to-end monitoring, fault isolation and resolution

• end-to-end service activation

JOINT SURFnet/NORDUnet 40Gb/s PM-QPSK alien

wavelength DEMONSTRATION

W S S

W S S

10G40G

10G

W S S W S S10G

40G alien wave

10G

40G

416km TWRSAlcatel-Lucent

(with dispersion compensation)

640km TWRSNortel

(without dispersion compensation)

5x10Gb/s @ 50GHz

5x10Gb/s350GHz900GHz

End-to-end FoM = 1400 (a couple of dB margin over BOL OSNR limit - set against nonlinearities and

potentially adverse effect from filter concatenation [4])

Am

sterdam

Hamburg

Copenhagen

Ham

burg40G

40G

Transmission system configuration

Wavelength plan

194,00 193,95 193,90 193,85 193,80 193,75 193,70 193,65 193,60 193,55 193,50 193,45 193,40 193,35 193,30 193,25 193,20 193,15 193,10 193,05 193,00 192,95 192,90 192,85 192,80 192,75 192,70 192,65

900GHz

350GHzguard band

40Gb/salien

wavelength

5x10Gb/swavelengths

5x10Gb/swavelengths

40Gb/swavelength

hr(t)

hi(t)

DAC

DAC

M-Z

M-Z 90o

CW sourceData

I

QLPF

LPF

10Gb/s Electronic Dispersion Pre-compensation

Slide courtesy of Kim Roberts, CIENA

4400 4600 4800 5000 5200 5400timeps0.5

1

1.5

2

2.5Optical PowerArb. Units

4400 4600 4800 5000 5200 5400timeps0.5

1

1.5

2

2.5Optical PowerArb. Units

z=0km z=5000km

D=-87500ps/nm

4400 4600 4800 5000 5200 5400timeps0.5

1

1.5

2

2.5Optical PowerArb. Units

4400 4600 4800 5000 5200 5400timeps0.5

1

1.5

2

2.5Optical PowerArb. Units

z=0km z=5000km

D=+87500ps/nmEDC off

EDC on

EDC (Electrical Dispersion Compensation)

Rx

Total 5000km standard transmission fiberH(f)

OA OA OA

hr(t)

hi(t)

DAC

DAC

M-Z

M-Z 90o

CW sourceData

I

QLPF

LPF

High PAPR (Peak-to-Average Power Ratio) ⇒ Low power per channel ⇒ Low OSNR ⇒ Strong FEC

Eye diagram before and after transmission with EDC

Transmitted signal (z=0km) Signal after 1600 km of NDSFwith no optical compensation

Slide courtesy of Kim Roberts, CIENA

OSNR measurement inoptically amplified system

11

Optical spectrum at output of transmit OA in Amsterdam1(RB=0.5nm)

-60

-55

-50

-45

-40

-35

-30

-25

-20

-15

-10

1526 1530 1534 1538 1542 1546 1550 1554 1558 1562 1566

Wavelength (nm)

Pow

er (d

Bm)

OSNR

OSNR measurements insystems with ROADMs

12

WSS

1xN

WSS

1xN

WSS

1xN

Tx

Tx

Rx

Rx

Difficult to determine OSNR level due to data modulation

OSNR measurements in systems with ROADMs – cont’d

13

WSS

1xN

WSS

1xN

WSS

1xN

Tx

Tx

Rx

Rx

1558.5 1558.6 1558.7 1558.8 1558.9 1559 1559.1 1559.2 1559.3 1559.4 1559.5-55

-50

-45

-40

-35

-30

-25

wavelength (nm)

pow

er (d

Bm

)

0.1nm resolutionAdvantest

0.1nm resolution

1558.5 1558.6 1558.7 1558.8 1558.9 1559 1559.1 1559.2 1559.3 1559.4 1559.5-65

-60

-55

-50

-45

-40

-35

-30

-25

wavelength (nm)

pow

er (d

Bm

)

0.02nm resolutionAdvantest

0.02nm resolution

1558.5 1558.6 1558.7 1558.8 1558.9 1559 1559.1 1559.2 1559.3 1559.4 1559.5-60

-55

-50

-45

-40

-35

-30

-25

wavelength (nm)

pow

er (d

Bm

0.05nm resolutionAdvantest

0.05nm resolution

Use tunable laser ⇒ no modulation but amplifier link setting remains same

JOINT SURFnet/NORDUnet 40Gb/s PM-QPSK alien

wavelength DEMONSTRATION

W S S

W S S

10G40G

10G

W S S W S S10G

40G alien wave

10G

40G

416km TWRSAlcatel-Lucent

(with dispersion compensation)

640km TWRSNortel

(without dispersion compensation)

5x10Gb/s @ 50GHz

5x10Gb/s350GHz900GHz

End-to-end FoM = 1400 (a couple of dB margin over BOL OSNR limit - set against nonlinearities and

potentially adverse effect from filter concatenation [4])

Am

sterdam

Hamburg

Copenhagen

Ham

burg40G

40G

Transmission system configuration

Error-free transmission for 30 days BER < 9.6 10-18

15

SURFnet networkGUI - Optical Modeler

16

- We have investigated experimentally the all-optical transmission of a 40Gb/s PM-QPSK alien wavelength via a concatenated native and third party DWDM system that both were carrying live 10Gb/s wavelengths

- The end-to-end transmission system consisted of 1056km of TWRS (TrueWave Reduced Slope) transmission fiber

- We demonstrated error-free transmission for 30 days (i.e. BER below 10-17)

Conclusions

17

Acknowledgements

The research leading to these results has received part of its funding from the European Community¹s Seventh Framework Programme (FP7/2007-2013) under grant agreement nº

238875 (GÉANT)

18

Thanks for your attention!

Questions?

roeland.nuijts@surfnet.nl+31-30-2305 305