Tatsuhiro Nakada Yoshiro Sato, Yasushi Hara, Shigehisa Sugiyama, - - PowerPoint PPT Presentation

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FULLY FLEXIBLE AND AUTOMATED SUBMARINE LINE TERMINATING EQUIPMENT FOR ADVANCED DWDM SYSTEMS FOR ADVANCED DWDM SYSTEMS

Tatsuhiro Nakada

Yoshiro Sato, Yasushi Hara, Shigehisa Sugiyama, Takaaki Ogata and Yasuhiro Aoki NEC Corporation

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OUTLINE

Introduction Submarine Line Terminal Equipment for Advanced DWDM Submarine Line Terminal Equipment for Advanced DWDM System

Main features

• Key functions
• Future technologies

Conclusion

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Market background: Evolution of Global IP Network

Internet Traffic Growth

Traffic movement to larger multimedia embedded content and streaming video Shift to larger bandwidth FTTH by content providers and other high- end customers with 10 to 15 % traffic growth per every year Communication industry to support growth by reducing costs

IP over SDH/WDM/Submarine IP over SDH/WDM/Submarine

Rapidly expanding Data Centers worldwide for growing IP Traffic and

Cloud Computing Transition to Ethernet-based access (GE, 10GE, and beyond) Separation of private and public domains for secured network Submarine to accommodate scalable, high-capacity IP network with a secured manner

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Important features of Submarine Cable System to meet the Global IP Network demand

Extremely large capacity over 10 Tb/s per cable Long haul transmission over trans-pacific distance Accommodation of Ethernet traffic Secured traffic signal with high system availability Flexible logical network design capability Small latency for TCP/IP Easy and Efficient operation and maintenance To provide all these features, highly flexible and automated submarine line terminating equipment has been developed.

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Main Features of Submarine Line Terminal Equipment (T740SW)

– Modular architecture for flexible capacity upgrade – High transmission performance for extremely large capacity and ultra long-haul distance – Automatic optimization function for easy and precise adjustment – Various and flexible tributary interfaces including the Ethernet interface – Wavelength Protection for high system availability – OADM system support for flexible logical network – OADM system support for flexible logical network design – Efficient spare for easy O&M – Compact size for small foot print

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Modular Architecture for Flexible Upgrade (1)

Basic Configuration

Initial

Sub Block Multiplexer(25G Spacing)

Gain Bandwidth

Initial

Upgrade

additional

Upgrade to 40G

Additional Sub Block Multiplexer for 40G (50G Spacing) 40G Signal additional 40G Signal additional additional

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Modular Architecture for Flexible Upgrade (2)

STM64 STM64

STM64 STM64 STM64

STM64

33GHz Grid 25GHz Grid 50GHz Grid Rambda

10G LAN-PHY

10G LAN-PHY

STM64

STM64

STM16 x 4

STM16 x 4

STM64

STM64

STM256 STM256

10G LAN-PHY x 4 STM256

STM256

STM64 x 4

STM64 x 4 STM64 STM64

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Hyper FEC for High transmission performance

▐ FEC coding gain at BER=10

• 13 : 10dB

1.0E-04 1.0E-03 1.0E-02 1.0E-01 1.0E+00

w/o FEC w/o FEC w/o FEC w/o FEC

T BER

1.0E-04 1.0E-03 1.0E-02 1.0E-01 1.0E+00

w/o FEC w/o FEC w/o FEC w/o FEC

T BER

1.0E-12 1.0E-11 1.0E-10 1.0E-09 1.0E-08 1.0E-07 1.0E-06 1.0E-05 1.0E-04 1.0E-05 1.0E-04 1.0E-03 1.0E-02 1.0E-01

RS(255,239) RS(255,239) RS(255,239) RS(255,239) A-FEC A-FEC A-FEC A-FEC Ex Ex Ex Ex A-FEC A-FEC A-FEC A-FEC

Hyper FEC

INPUT BER OUTPUT B

1.0E-12 1.0E-11 1.0E-10 1.0E-09 1.0E-08 1.0E-07 1.0E-06 1.0E-05 1.0E-04 1.0E-05 1.0E-04 1.0E-03 1.0E-02 1.0E-01

RS(255,239) RS(255,239) RS(255,239) RS(255,239) A-FEC A-FEC A-FEC A-FEC Ex Ex Ex Ex A-FEC A-FEC A-FEC A-FEC

Hyper FEC

INPUT BER OUTPUT B

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RZ-DPSK for High transmission performance

DFB LD DPSK-mod RZ-mod 10GHz Clock

RZ-DPSK Transmitter RZ-DPSK Receiver

Balanced Receiver Data Clock DPSK Demodulator 10Gb/s-Data Clock/ Data Recovery Pre-coder

OSNR tolerance

OSNR tolerance

OSNR tolerance

Dispersion tolerance

RZ-DPSK RZ

2.5dB improvement

RZ-DPSK RZ

2.5dB improvement

RZ-DPSK RZ

2.5dB improvement

1 2 3 4

• 800
• 600
• 400
• 200

200 400 600 800 Dispersion (ps/nm) Q degradation (dB)

RZ-DPSK RZ

OSNR tolerance Improvement of approx. 2.5dB High quality transmission against dispersion-related non-linear degradation High tolerance for Stimulated Brillouin Scattering

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Future 40G DP-QPSK for High capacity transmission performance +

＝

DP-RZ-QPSK signal Demodulated signal after digital signal process

LD

Client Interface SerDes FEC Client Interface SerDes FEC

Transmitter Receiver

T740SW platform can support the future 40G technologies

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Tunable Dispersion Compensation for Automatic adjustment function

• Excellent transmission performance thanks to the precise and automatic dispersion

tuning capability

• Latency reduction by eliminating individual DCFs and associated amplifiers
• Non-interruptive adjustment of dispersion amount through EMS during the O&M

activity

AMP DCF

Transponder

AMP DCF

Common Part Individual Part

Transponder with TDCM

Common Part Individual Part DEMUX WDM signals Transponder Transponder Transponder Transponder DEMUX WDM signals

with TDCM Transponder with TDCM Transponder with TDCM Transponder with TDCM

Conventional DCF method TDCM method

• 1000
• 800
• 600
• 400
• 200

TDCM dispersion is optimized automatically after scanning the tuning range.

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Pre-emphasis control for Automatic adjustment function — Optical channel power at transmitter is adjusted automatically so that the optimum transmission performance is obtained.

Tx Signal Tx Signal Rx Signal Rx Signal Rx Signal Rx Signal Tx Signal Tx Signal Rx Signal Rx Signal Pre Pre-Emphasis Control Emphasis Control

• 1. Measure Q value of each wavelength at Rx side.
• 2. Feed-back measured Q value to Tx Side
• 3. Control optical launch power of each wavelength

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Wavelength protection for High system availlability

SLTE SLTE W M R S

Transponder Transponder (Work) (Work) Transponder Transponder

C C

SLTE SLTE W R

Transponder Transponder (Work) (Work) Transponder Transponder

C

M E S E

Transponder Transponder (Work) (Work) Transponder Transponder (Protection) (Protection)

C C T B B

M E S E

Transponder Transponder (Work) (Work) Transponder Transponder (Protection) (Protection)

C T B

Submarine Cable

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Meshed Submarine Network with OADM Scheme

Logical Configuration

T-1 T-3 T-5 T-6 B-1 B-2 B-3 B-4 T-1 T-2 T-5 T-6

OADM-BU Mesh

Physical Configuration

T-1 T-2 T-4 T-6 B-2 B-4 T-2 T-3 T-4 T-5

OADM-BU

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Dry plant OADM application

W M E O D F

TPND TPND TPND TPND

W M E

TPND TPND

―Terminal Application : Transponder Back-to-Back Solution All wavelengths are terminated at Transponders.

W M E

O D F

Optical Amplifier

W M E

Optical Amplifier TPND TPND

All wavelengths are terminated at Transponders. ―Fixed OADM Application :Optical Pass-Through WME is connected directly through optical amplifier without Transponder.

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Wet plant OADM application

Sub-band CW tones insertion from the SLTE If a cable failure occurs, all terminals inform of their received signal conditions to a centralized management system which analyses the information and controls the CW tone signals. Then, CW tone signals are inserted at the relevant SLTEs in order to maintain the channel power of the survived signals automatically.

CW tones Signals

SLTE SLTE SLTE SLTE

Information Control Cable Failure +

Centralized Management System

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Conclusion

We developed new SLTE for the next generation DWDM submarine cable systems which support following advanced features. Flexible capacity upgrade Large capacity transmission Automatic adjustment Automatic adjustment Various tributary interfaces Wavelength Protection OADM system support Compact size for small foot print The SLTE can provide the best solution for both newly cable systems and capacity upgrades of existing systems.

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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