Akihiko Matsuura NTT Network Service Systems Laboratories - - PowerPoint PPT Presentation

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Field PMD Measurements of a New 900-km Repeatered Submarine System Designed for Repeatered Submarine System Designed for 43 Gbps WDM Transmission

Akihiko Matsuura

NTT Network Service Systems Laboratories

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Presenter Profile

Akihiko Matsuura was born in Toyama, Japan in 1969. He received his B. E. degree from the Tokyo University of Science in 1995, and the M. E. degree from Tokyo Institute of Technology in 1997. Since 1997 he has been with NTT Optical Since 1997 he has been with NTT Optical Network Systems Laboratories, where he researched 40 G optical transmission. From 2002 to 2010, he designed commercial 40-G WDM systems and submarine transmission systems. Akihiko Matsuura Email: matsuura.akihiko@lab.ntt.co.jp Tel: (+81) 46 859 4664

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Background

40-G based WDM transmission services

• Supports the increase in IP traffic cost effectively
• Commercially available in the last few years

The main factor limiting 40 G transmission

• PMD

PMD impact on 40 G transmission must be assessed

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Outline

Transmission design of newly installed 40-G based submarine system

• 30 ch x 40-G submarine system design
• 900-km Straight line transmission experiments
• 900-km Straight line transmission experiments

Field PMD measurements of repeatered submarine system

• Measurement setup
• Measured results

Conclusions

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Newly Installed Submarine System

Kyushu We are here

Route length :

about 900 km (between Kyushu and Okinawa- Island) Okinawa-Island 900 km Kyushu Island)

Capacity :

80 ch x 10 G (initial capacity) 30 ch x 40 G (finally supported)

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40 G System Design (S/N)

Considering commercial technologies ...

RZ-DPSK modulation format 100-GHz channel spacing

Theoretical OSNR calculations ...

#1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 Kyushu Okinawa- Island inline amplifiers ...

Theoretical OSNR calculations ...

74-km mean repeater spacing

RZ-DPSK, 100-GHz channel spacing 74-km mean repeater spacing ...

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40 G System Design (Nonlinear)

By computer simulations ...

11 spans of NZ-DSF two spans of SMF for dispersion compensation

From our previous RZ-DPSK research ... From our previous RZ-DPSK research ...

(2-dB PMD penalty @ DGD = 9.2-ps) allowable PMD for transmission line = 2.6 ps

Kyushu Okinawa- Island NZ-DSF SMF land fiber ... allowable PMD 2.6 ps

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Transmission Experiments

LD 1 LD 33 MUX RZ-DPSK modulator post amp TX spectrum monitor (next slide) SMF NZ-DSF rep 1 rep 2 rep 6 rep 12 pre amp DEMUX RZ-DPSK demodulator (MZI) balanced receiver variable dispersion compensator RX spectrum monitor (next slide)

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Experimental Results

PMD of entire transmission line = 0.3 ps mean received OSNR = 17.6 dB (@43 GHz optical bandwidth) nonlinear penalty = 1 dB

power density [5 dB / div] 1528 1548 1568 wavelength [nm] TX power density [5 dB / div] 1528 1548 1568 wavelength [nm] RX

nonlinear penalty = 1 dB

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Our PMD Measurement Techniques

In automatic PMD measurement, inline amplifiers generate

• 1. cummulated ASE noise

we reduced it by inserting programmable optical filters

• 2. optical surges
• 2. optical surges

we suppressed it by using continuous dummy lights

measurement equipment (TX) measurement equipment (RX) dummy lights programmable filter

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PMD Measurement Setup

Kyushu Okinawa-Island

We measured 12 fibers We injected 4 continuous dummy lights

Kyushu Okinawa-Island down (6 fibers) up (6 fibers) CTF RX TX 4 CTF RX TX 4

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Dummy Lights’ Positions

dummy lights programmable filter bandwidth measuring signal

• 10

received optical spectrum (measuring center wavelength)

• 70
• 60
• 50
• 40
• 30
• 20
• 10

measuring longer wavelength

• 70
• 60
• 50
• 40
• 30
• 20

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Measured Mean DGD

2.0 2.5 3.0

specified value (2.6 ps)

0.0 0.5 1.0 1.5 2.0 1 3 5 7 9 11 2 4 6 8 10 12 down up fibers mean DGD [ps] shorter center longer

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Evaluated DGD Value

2.0 2.5 3.0

specified value (2.6 ps) margin (2 sigma)

0.0 0.5 1.0 1.5 2.0 1 3 5 7 9 11 2 4 6 8 10 12 down up fibers DGD [ps] mean DGD margin (2 sigma)

mean DGD

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Conclusions

We developed and deployed a new 900-km submarine DWDM system that offers 30 ch x 43-G transmission

• 11 spans of NZ-DSF and two spans of SMF
• 11 spans of NZ-DSF and two spans of SMF
• mean repeater spacing is 74 km
• end to end DGD of submarine facilities is under 2.6 ps
• transmission experiments in our laboratory

We confirmed our 43 G design by measuring PMD of installed submarine facilities

2010

enabling the next generation of networks & services

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Pacifico Convention Plaza Yokohama & InterContinental The Grand Yokohama 11 ~ 14 May 2010 www.suboptic.org The 7th International Conference & Convention

• n Undersea Telecommunications