Invited Paper Advanced Technologies for Unrepeatered · PDF file ·...

© 2014 Xtera Communications, Inc. Proprietary & Confidential

Maximizing Network Capacity, Reach and Value Over land, under sea, worldwide

1

Invited Paper

Advanced Technologies for Unrepeatered Transmission Systems and Their Applications

Do-il Chang, Wayne Pelouch, Sergey Burtsev, Bertrand Clesca, Philippe Perrier, Herve Fevrier

Xtera Communications, Inc.

13 November 2014

Asia Communications and Photonics (ACP) Conference 2014 (Shanghai, China) – ATh4E.4

© 2014 Xtera Communications, Inc. Proprietary & Confidential 2

• Introduction – Unrepeatered transmission system and applications

– Key technologies

– Summary of recent unrepeatered transmission results

• Experimental demonstrations of unrepeatered transmission – Distributed Raman pump modules / 100G cards

– 557 km unrepeatered 100G transmission

– 15 Tbit/s unrepeatered transmission

• Applications in submarine / terrestrial systems – 8 x 120 Gbit/s transmission over a cascade of two spans

(59.7 dB + 60.8 dB)

– Applications in terrestrial network

• Summary

Content


Unrepeatered System and Applications


• System that operates without active element between the terminals – No in-line amplifiers, no repeaters, no regenerators

• Typical operational conditions – Fiber type: Legacy (SMF, PSCF, NZDSF)

New installation (Ultra low loss, large effective core area fiber)

• Distance (with 100G): 100 km to 560 km, span loss: 40 dB to 90 dB

• Applications – Communication between islands or main lands

Unrepeatered Transmission System

Passive fiber cable







– Communication for oil platforms (oil & gas industry)









– Skipping intermediate sites in hostile areas (tropical forest, desert...)


Communication using high-voltage transmission towers with Optical Ground Wire (OPGW) cable










Communication using high-voltage transmission towers with Optical Ground Wire (OPGW) cable

OPGW Cable and Amazon River Crossing


Key Technologies in Unrepeatered Transmission


Channel Power Management in Unrepeatered

Transmission

Distance

Per

channel pow

er

pro

file

Non-linear limitation

Fiber attenuation

Amplifier power boost

Noise limitation

Non-linear limitations • SPM, XPM • FWM • SBS • Polarization X-talk

Noise limitation • OSNR requirement



Transmission

Distance

Per

channel pow

er

pro

file


Fiber attenuation


Noise limitation



Transmission

Distance

Per

channel pow

er

pro

file


Fiber attenuation


Noise limitation

Increase the threshold of non-linear limitation • Large core effective area fiber • Digital nonlinear mitigation • Polarization interleaving (RZ)



Transmission

Distance

Per

channel pow

er

pro

file


Fiber attenuation


Noise limitation


Reduce the threshold of noise limitation • Stronger FEC



Transmission

Distance

Per

channel pow

er

pro

file


Fiber attenuation


Noise limitation


Reduce the threshold of noise limitation • Stronger FEC

Lower fiber attenuation



Transmission

Distance

Per

channel pow

er

pro

file


Noise limitation



Transmission

Distance

Per

channel pow

er

pro

file


Noise limitation

Optical gain created within the line fiber by distributed Raman amplification

Pump power is limited by MPI penalty or lasing



Transmission

Distance

Per

channel pow

er

pro

file


Noise limitation



Transmission

Distance

Per

channel pow

er

pro

file


Noise limitation

Forward pump power is limited by RIN, MPI penalty



Transmission

Distance

Per

channel pow

er

pro

file


Noise limitation



Transmission

Distance

Per

channel pow

er

pro

file


Noise limitation

ROPA*

* Remote Optically- Pumped Amplifier

Pump power is limited by MPI penalty or lasing

Gain from ROPA

Residual pump power



Transmission

Distance

Per

channel pow

er

pro

file


Noise limitation

ROPA



Transmission

Distance

Per

channel pow

er

pro

file


Noise limitation

ROPA ROPA

Gain from ROPA (Forward)

Forward pump power is limited by RIN, MPI penalty

Residual pump power


• Higher order can provide better performance

• Requires much stronger pump (> 5 W for 3rd order pumping)

Further Improvement: High-Order Raman Pump

Distance

Per

channel pow

er

pro

file

Noise limitation

ROPA

Final pump is developed within the span

Within MPI limitation


Xtera system uses 1st ~ 2nd order pumping

1455 1360 1280 nm


• Higher order can provide better performance

• Requires much stronger pump (> 5 W for 3rd order pumping)

Further Improvement: High-Order Raman Pump

Distance

Per

channel pow

er

pro

file

Noise limitation

ROPA

Final pump is developed within the span

Within MPI limitation


Xtera system uses 1st ~ 2nd order pumping

1455 1360 1280 nm

7W

OFC 2005, OThF4

Pump power : 7W


Fiber Type ROPA Length (Km) Loss (dB)

ALU, ECOC 2009 2.626x112 Gb/s

(50GHz)PDM-QPSK Offline E-PSCF (115mm2) YES 401 67 1.04

Corning, ECOC 2010 4.040x112 Gb/s

(50GHz)PM-QPSK Offline

EX1000, 2000, Dev

(76mm2, 112mm2, 128mm2)No 365 59.6 1.46

ALU, ECOC 2010 0.164x43 Gb/s

(100GHz)PDM-RZ-BPSK Offline EX2000 (115mm2) Yes 525 84 0.08

ALU, OFC 2011 2.5664x43 Gb/s

(50GHz)PDM-RZ-BPSK Offline E-PSCF (115mm2) Yes 440.7 71.5 1.13

Bell Labs, ALU, OFC 2011 0.88x112 Gb/s

(50GHz)PDM-iRZ-BPSK Offline NZDSF (LEAF) No 300 66 0.24

Xtera, ECOC 2011 0.88x120 Gb/s

(100GHz)PM-NRZ-QPSK Offline Z (Legacy, 76mm2) Yes 444.2 76.6 0.36

ALU, ECOC 2011 0.44x100 Gb/s

(50GHz)PDM-QPSK Real Time

ULA-PSCF, E-PSCF

(135mm2, 115mm2)Yes 462 76.9 0.18

Fujitsu, ECOC 2011 1680x224 Gb/s

(50GHz)DP-16QAM (50GHz) Offline Large Aeff PSCF (133mm2) No 240 39.1 3.84

Xtera, ECOC 2012 3.434x120 Gb/s

(50, 100GHz)PM-NRZ-QPSK Real Time Z (Legacy, 76mm

2) Yes 432.8 74.4 1.47

ALU, ECOC 2012 6.060x100 Gb/s

(40GHz)PDM-RZ-QPSK Offline

ULA-PSCF, E-PSCF

(135mm2, 115mm

2)

Yes 437 71.0 2.62

Z (Legacy, 76mm2) 383.5 66.7 0.46

SMF (Legacy, 80mm2) 342.7 66.8 0.41

Xtera, OFC 2013 0.88x120 Gb/s

(100GHz)PM-QPSK Real Time

Z, EX2000

(76mm2, 112mm2)Yes 480.4 80.8 0.38

OFS, OFC 2013 3.2 32x120 Gb/s PDM-NRZ-QPSK OfflineULAF1, ULAF2, AW

(150mm2, 125mm

2, 80mm

2)

Yes 445 79.0 1.42

ALU, ECOC 2013 1.61x400 Gb/s +

12x100 Gb/s

PDM-NRZ-16QAM,

PDM-RZ-QPSKOffline

ULA-PSCF, E-PSCF

(135mm2, 115mm2)Yes 401 65.5 0.64

OFS, OFC 2014 6.3 63x128 Gb/s PDM-NRZ-QPSK OfflineULAF1, ULAF2, AW

(150mm2, 125mm2, 80mm2)Yes 402 ? 2.53

0.1 1 x120 Gb/s 556.7 90.2 0.06

0.44 x120 Gb/s

(100GHz)523.2 84.8 0.21

Offline EX3000 (152mm2) 286 44.5 2.29

OfflineEX3000, EX2000

(152mm2, 110mm2)292 45.5 2.34

OfflineEX3000, EX2000

(152mm2, 110mm

2)

304 47.4 2.43

ALU, ECOC 2014 8.0 40x200 Gb/s PDM-16QAM Real TimeULA-PSCF, E-PSCF

(135mm2, 115mm2)Yes 363 59.1 2.90

No 333.6 55.4 5.00

Yes 389.6 64.3 5.84

No

Xtera, Corning

ECOC 201415

150x120 Gb/s

(50GHz)PM-RZ-QPSK Real Time SMF-ULL (80mm2)

Corning, OpticsExpress 2014 8.040x256 Gb/s

(50GHz)PDM-16QAM

Xtera, Verizon, Corning

OFC 2014 (PD)PM-iRZ-QPSK Real Time

EX2000 (112mm2) fiber cable in

OSP Environment

Forward and

Backward

Capacity x

Reach

(Pb/s Km)

No

Reference

Total

Capacity

(Tb)

No CHs x Bit

rate (ch

spacing)

Signal FormatCoherent

Processing

Span Info

Xtera, IPC 2012 1.212x120 Gb/s

(100GHz)PM-NRZ-QPSK Real Time

Recent Unrepeatered Transmission Results

300

350

400

450

500

550

600

2008 2009 2010 2011 2012 2013 2014 2015

Dis

tan

ce (

Km

)

Year

OFS

AlcaLu

Corning

Xtera

0

1

2

3

4

5

6

2008 2009 2010 2011 2012 2013 2014 2015

Cap

acit

y x

Rea

ch (

Pb

/s -

Km

)

Year

OFS

AlcaLu

Corning

Fujitsu

Xtera

* with coherent signal processing


Experimental Demonstrations of Unrepeatered Transmission


• Basic features – Commercially available

– Consists of five pump wavelengths distributed in the spectral range between

1420 and 1500 nm

– Uses polarization balanced and wavelength multiplexed laser diodes

(RIN < -105 dB/HZ)

– Total pump power < 1.8 W

– Uses commercial high power connector (Diamond, E2000PS) to connect

span

Distributed Raman Pumps: Nu-Wave OptimaTM SE24

from span

ES2000PS


• Flexible operation – Can be used in forward or backward pumping scheme

– Can provide flexible gain profiles based on the application (C, L, Wide-band,

w/wo ROPA etc..)

– Can increase pump power (up to ~ 2.6W) by using power expansion module

(e.g. Large Aeff fiber)

Distributed Raman Pumps: Nu-Wave OptimaTM SE24

C-band L-band Wide-band (61 nm)

Wide-band (61 nm) with ROPA

ROPA


• 100G line card – Modulated at 120 Gbit/s

PM-QPSK

– 15% overhead SD-FEC

(FEC threshold: 6.4dB)

– Real-time ASCI processing

• 100G comb modulator – Modified 100G line card

– Receives CW comb signals and

outputs 120 Gbit/s PM-QPSK

(15% overhead)

100G Line Card / 100G Comb Modulator


557 km Unrepeatered 100G Transmission with Commercial Raman DWDM System, Enhanced ROPA, and Cabled Large Aeff

Ultra-Low Loss Fiber in OSP Environment

OFC 2014, Post-Deadline Paper Th5A.7 IEEE Journal of Lightwave Technology (to be published 2015)

• Enhanced ROPA configuration • Cabled fiber in uncontrolled OutSide Plant (OSP) Environment • Longest 100G unrepeatered transmission up to date


Enhanced ROPA configuration

ROPA

ROPA

Backward ROPA configuration

Signal

Signal


Forward + Backward ROPA configuration


ROPA

ROPA F-ROPA

F-ROPA

Signal

Signal


• Remote optically pumped amplifiers in two directions in same enclosure

• Residual pump powers from other direction help signal going further.


ROPA

ROPA F-ROPA

F-ROPA

Signal

Signal


• 100G channels: 120 Gbit/s PM-QPSK (15% overhead, 6.4 dB Q SD-FEC threshold)

• BER is measured by 100G line card with real-time ASIC processing.

• Forward and Backward distributed Raman: commercial Nu-Wave OptimaTM SE24 + HP extension

• Residual pump sharing in unidirectional transmission

• Spans consist of Corning® Vascade® EX2000 (G.654B) fiber with Aeff=112 µm2.

• Distance between ROPAs: – Case 1: 289.3 km (total 556.7 km) for 1 x 100G channel transmission

– Case 2: 255.8 km (total 523.2 km) for 4 x 100G channels transmission

System Configuration

100G MXP l1

100G MXP l2

100G MXP l3

100G MXP l4

WSS

DCU

EOA Distance between ROPAs*

ROPA (F)

133.7 km

EOA

ROPA (B)

Residual pump

sharing

WSS

Forward Raman

Backward Raman

100G MXP l1

100G MXP l2

100G MXP l3

100G MXP l4

133.7 km

ROPA (B)

ROPA (F)

P’

p


• Cable: 8.3 km Altos gel filled loose tube cable on a 0.9 m diameter spool

• Corning® Vascade® EX2000 (G.654B), Aeff=112 µm2

• Span: 556.7 km, total loss 90.2 dB

• Spliced fiber attenuation: 0.162 dB/km

Corning® Vascade® EX2000 Cabled Optical Fiber Deployed Outside the Lab

0%

20%

40%

60%

80%

100%

0.15 0.155 0.16 0.165 0.17 0.175 0.18

Cu

mm

ula

tive

Pro

bab

lity

(%)

Attenuation at 1550 nm (dB/km)

CableFiber

• Nominal outer diameter: 16.0 mm • Min. bend radius installation: 240 mm • Min. bend radius operation: 160 mm • Fiber length in the cable: 8.1 to 8.5 km (average 8.3 km)

Vascade® EX2000 drum


• Pump powers – Forward: 2,510 mW

– Backward: 2,520 mW

• OSNR – Measured: 13.7 dB/0.1nm

– Simulated: 13.6 dB/0.1nm

• Measured Q: 6.54 dB (BER = 1.65 x 10-2)

1 x 100G Transmission over 556.7 km

-50

-45

-40

-35

-30

-25

-20

1558 1560 1562 1564 1566 1568

Pow

er

(dB

m)

Wavelength (nm)

Input-0.2nm RBW

Output-0.2nm RBW

Measured OSNR :

13.7dB (0.1 nm)

Forward ROPA gain : 4.6 dB Backward ROPA gain : 19.4 dB Simulated OSNR : 13.6 dB

Signal Z Profile

Pump Z Profiles

Remaining power from Raman for EDF: 6.6 mWResidual power for use in other direction: 0.6 mW

Remaining power from Raman for EDF: 8.6 mWResidual power for use in other direction: 2.7 mW

Forward pumps Backward pumps


• Pump powers – Forward: 2,690 mW

– Backward: 2,520 mW

• OSNR – Measured: 14.2 dB/0.1nm

• Measured Q: 6.9 dB (BER = 1.4 x 10-2)


Forward ROPA gain : 2.6 dB

Backward ROPA gain : 20.4 dB

Signal Z Profile

Pump Z Profiles

Residual forward pump : 5.1mW

Residual backward pump : 8.6mW

10

11

12

13

14

15

-50

-40

-30

-20

-10

0

1558 1560 1562 1564 1566

OS

NR

(d

B)

Po

we

r (d

Bm

)

Wavelength (nm)

Input-0.2nm RBW

Output-0.2nm RBW

OSNR (Sim.)


Long Term Stability Test

1.2E-02

1.3E-02

1.4E-02

1.5E-02

1.6E-02

1.7E-02

1.8E-02

1.9E-02

2.0E-02

0.0 2.0 4.0 6.0 8.0 10.0

BE

R

Hours

1563.86 nm 1563.05 nm

1562.23 nm 1561.42 nm

SD-FEC Threshold

1.60E-02

1.65E-02

1.70E-02

1.75E-02

1.80E-02

1.85E-02

1.90E-02

1.95E-02

0 10 20 30 40 50 60

BE

R

Hours

BER before SD-FEC

SD-FEC Threshold




150 x 120 Gbit/s Unrepeatered Transmission over 333.6 km and 389.6 km (with ROPA) G.652 Fiber

ECOC 2014, Paper Tu.1.5.4

• G.652 fiber with standard core area fiber • Highest Capacity x Reach (5.84 Pbit/s km) unrepeatered

transmission up to date


• LRA: (Wide-band) Lumped (discrete) Raman Amplifier – LRA-2 provides average -670 ps/nm pre-dispersion compensation.

• 100G channels: 120 Gbit/s PM-QPSK (15% overhead, 6.4 dB Q SD-FEC threshold)

• BER is measured by 100G line card with real-time ASIC processing.

• Forward and backward distributed Raman: commercial Nu-Wave OptimaTM SE24

• Spans consist of Corning® SMF-28® ULL fiber (G.652B). – Without ROPA: 333.6 km (55.4dB), Accumulated dispersion: +4,300 ps/nm (average)

– With ROPA: 389.6 km (64.3dB)

• ROPA (Isolator + 12m erbium) is located 116.7 km form RX.

• Accumulated dispersion : + 5,150 ps/nm (average)

System Configuration

45 C-Band

(odd) DFBs

30 L-Band

(odd) DFBs

45 C-Band

(even) DFBs

30 L-Band

(even) DFBs

100G

Comb

100G

Comb

100 GHz PM-AWG

: PM 3dB (50/50) coupler : 3 dB (50/50) coupler

WSS

C-100G MXP

C-100G MXP

L-100G MXP

WSS

C-100G MXP

C-100G MXP

L-100G MXP

Backward Raman

Forward Raman

Span without ROPA 333.6 km (55.4 dB)

Span with ROPA 389.6 km (64.3 dB)

ROPA

116.7 km 272.9 km

LRA-1 LRA-2 LRA-3


-25

-20

-15

-10

-5

0

5

1525 1535 1545 1555 1565 1575 1585 1595

Pow

er

(dB

m)

Wavelength (nm)

-25

-20

-15

-10

-5

0

5

1525 1535 1545 1555 1565 1575 1585 1595

Po

we

r (d

Bm

)

Wavelength (nm)

5

7

9

11

13

15

17

1525 1535 1545 1555 1565 1575 1585 1595

OS

NR

an

d Q

(d

B)

Wavelength (nm)

Measured OSNR

Simulated OSNR

Q before FEC(dB)

SD-FEC Threshold

• Input signals – Channels are pre-emphasized to provide flat Q over spectrum at receive side.

– Average power into span: -9.8 dBm/channel

• At receiver – Ripple is flattened by WSS.

– Average OSNR: 14.5 dB, average Q: 7.1 dB

– All channels are error free after SD-FEC.

Transmission Over 333.6 km SMF-28® ULL Fiber Without ROPA

Input to the Span (LRA-2 Out)

At the RX (LRA-3 Out)


Transmission Over 333.6 km SMF-28® ULL Fiber Without ROPA

Signal Z Profile

Pump Z Profiles

Forward Pump Power : 1590 mW Backward Pump Power : 1670 mW

Max Signal power : +8.9 dBm at 21.7 Km

Forward Raman gain Includes ~ 28 dB span loss

Back Raman gain Includes ~ 28 dB span loss

• Raman gain (On/Off) • Forward: 19.3 dB • Backward: 30.5 dB

• Noise Figure includes 55.8 dB span loss • 34.6 dB (Effective NF < -21 dB)


5

7

9

11

13

15

17

1525 1535 1545 1555 1565 1575 1585 1595

OS

NR

an

d Q

(d

B)

Wavelength (nm)

Measured OSNR

Simulated OSNR

Q before FEC(dB)

SD-FEC Threshold

-25

-20

-15

-10

-5

0

5

1525 1535 1545 1555 1565 1575 1585 1595

Pow

er

(dB

m)

Wavelength (nm)

-25

-20

-15

-10

-5

0

5

1525 1535 1545 1555 1565 1575 1585 1595

Pow

er

(dB

m)

Wavelength (nm)

• Input signals – Channels are pre-emphasized to provide flat Q over spectrum at receive side.

– Average power into span: -10.8 dBm/channel

• At receiver – Ripple (~10dB) is flattened by WSS.

– Average OSNR: 14.1 dB, average Q: 6.7 dB

– All channels are error free after SD-FEC.

Transmission Over 389.6 km SMF-28® ULL Fiber With ROPA

Input to the Span (LRA-2 Out)

At the RX (LRA-3 Out)


Signal Z Profile

Pump Z Profiles

Forward Pump Power : 1590 mW Backward Pump Power : 1790 mW

Max Signal power : +8.1 dBm at 21.3 Km

Forward Raman gain Includes ~ 50 dB span loss

Back Raman gain Includes ~ 28 dB span loss

Transmission Over 389.6 km SMF-28® ULL Fiber With ROPA

ROPA Gain

Residual Pump at ROPA : 11.5 mW

Noise Figure includes 64.3 dB span loss 34.6 dB (Effective NF < -30 dB)


Unrepeatered Transmission Applications in Submarine / Terrestrial Systems


8 x 120 Gbit/s Transmission Over a Cascade of Two Spans With a Total Loss in Excess of 120 dB

OFC/NFOEC 2013, Paper NM2E.6

• Advanced configuration for the cascade of long spans • 8 x 120 Gbit/s transmission over SMF 305.5 km with 59.7 dB and

PSCF 342.9 km with 60.8dB • Achieved with standard core effective area fiber


Objectives & Background

Intermediate site PoP

Length of cables > 200 km

PoP

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

XPDR

PoP

PoP

PoP : Point-of-Presence

Submarine Cable

Suggested configuration can provide huge cost savings especially for high-capacity transmission systems

E.g. up to 45% cost reduction for 6Tbit/s (60 x 100G) transmission system

Example : Submarine transport system with

regeneration at intermediate land site.


• Signals: 8 x 120 Gbit/s (1558.2 nm to 1563.9 nm)

• Span configuration: – Total 646.4 km, 120.5 dB, +11,374 ps/nm

– SMF 303.5 km, 59.7 dB (+5,024 ps/nm )

– PSCF 342.9 km, 60.8 dB (+6,340 ps/nm)

• Bi-directional transmission – Direction A: SMF Span PSCF Span, Pre-DCU: -540 ps/nm

– Direction B: PSCF Span SMF Span, Pre-DCU: -650 ps/nm

• ASE suppression filter is used to remove ASE accumulation from the first span.

Experimental Setup for 8 x 100G Transmission Over Two Spans With Total Loss of 120.5 dB

FWD Pumps

BKWD Pumps

DFB

DFB

DFB

100G MXP

100G Comb

DCM PM

MU

X

EOA EOA

Filter for ASE suppression

EOA

BKWD Pumps

FWD Pumps

8 x 120 Gbit/s PM-QPSK

8 c

hannels

100 G

Hz

spaci

ng

Direction A) SMF 303.5 km. 59.7 dB Direction B) PSCF 342.9 km. 60.8 dB

Direction A) PSCF 342.9 km. 60.8 dB Direction B) SMF 303.5 km. 59.7 dB

0

5

10

15

20

25

30

35

40

1530 1540 1550 1560 1570 1580

Lo

ss (

dB

)

Wavelength (nm)

ASE Suppression Filter


Numerical Analysis and Measured Spectra – Direction A

Span-1 SMF 303.5 km

Span-2 PSCF 342.9 km

Direction A

The maximum signal power +9.5 dBm at 29.9 km from

the transmit side

The maximum signal power +7.6 dBm at 37.4 km from the start of the 2nd

span

Forward pump 1,170 mW


Backward pump 1,040 mW

12

14

16

18

20

1556 1557 1558 1559 1560 1561 1562 1563 1564 1565

Wavelength (nm)

Direction A: Span-1 Output

10

12

14

16

18

1556 1557 1558 1559 1560 1561 1562 1563 1564 1565

OS

NR

(dB

)

Wavelength (nm)

Direction A: Span-2 Output

1556 1557 1558 1559 1560 1561 1562 1563 1564 1565

Pow

er

(5dB

/div

)

Wavelength (nm)

Direction A: Input



12

14

16

18

20

1556 1557 1558 1559 1560 1561 1562 1563 1564 1565

Wavelength (nm)

Direction B: Span-2 Output

10

12

14

16

18

1556 1557 1558 1559 1560 1561 1562 1563 1564 1565

OS

NR

(d

B)

Wavelength (nm)

Direction B: Span-1 Output

1556 1557 1558 1559 1560 1561 1562 1563 1564 1565

Po

we

r (5

dB

/div

)

Wavelength (nm)

Direction B: Input

Span-2 SMF 303.5 km

Span-1 PSCF 342.9 km

Direction B

The maximum signal power +9.8 dBm at 34.1 km from

the transmit side

The maximum signal power +6.4 dBm at 35.1 km from the start of the 2nd

span





Measured Spectra and Numerical Analysis – Direction B


• Direction A – OSNR: Avg. 18.3 dB (Span-1 Out), 14.7 dB (Span-2 Out)

– Q: Avg. 7.0 dB

– Error free after SD-FEC

• Direction B – OSNR: Avg. 18.2 dB (Span-1 Out), 14.7 dB (Span-2 Out)

– Q: Avg. 6.7 dB

– Error free after SD-FEC

Measured OSNR and Q

6.0

6.4

6.8

7.2

7.6

8.0

8.4

8.8

9.2

9.6

10

11

12

13

14

15

16

17

18

19

1558 1559 1560 1561 1562 1563 1564

Q (

dB

)

OS

NR

(d

B)

Wavelength (nm)

6.0

6.4

6.8

7.2

7.6

8.0

8.4

8.8

9.2

9.6

10

11

12

13

14

15

16

17

18

19

1558 1559 1560 1561 1562 1563 1564

Q (

dB

)

OS

NR

(d

B)

Wavelength (nm)

Span-1 Out:Measured OSNR

Span-1 Out:Simulated OSNR

Span-2 Out:Measured OSNR

Span-2 Out:Simulated OSNR

Span-2 Out:Measured Q

Q threshold ofSD-FEC

Direction A Direction B


Implementation in 100 Gbit/s System

XLA (XLS + ILA)

5 intermediate sites are supported by XLA configuration, which can save more than 300 x 100G transponders over entire network.


150 x 120 Gbit/s Field Trial Over 1,504 km Using All-Distributed Raman Amplification

OFC 2014, Paper Tu2B.2

• All-distributed Raman amplification for coherent signal transmission is introduced.

• 15 Tbit/s (150 x 120 Gbit/s) field trial over 1,504 km with all-distributed Raman amplification


150 x 120 Gbit/s Field Trial Over 1,504 km Using All-Distributed Raman Amplification

Aged network fiber

79.2 km

IL: 20 - 23 dB

45 C-Band

(odd) DFBs

30 L-Band

(odd) DFBs

45 C-Band

(even) DFBs

30 L-Band

(even) DFBs

100G

Comb

100G

Comb

L-100G MXP

C-100G MXP

WSS

x19

C-100G MXP

C-100G MXP

90/10

100 GHz PM-AWG

Wide-band Booster

Backward Raman

Forward Raman

GFF

Optional modules

: PM 3 dB (50/50) coupler : 3 dB (50/50) coupler : 90/10 coupler

L-band De-Mux

C-100G MXP

L-100G MXP

Span # 01 20.3 dB

Span # 02 22.5 dB

Span # 03 22.8 dB

Span # 04 22.2 dB

Span # 05 21.5 dB

Span # 06 20.4 dB

Span # 07 22.6 dB

Span # 08 20.1 dB

Span # 09 21.4 dB

Span # 11 22.9 dB

Span # 12 20.5 dB

Span # 13 21.3 dB

Span # 14 22.1 dB

Span # 15 21.8 dB

Span # 16 23.1 dB

Span # 10 21.6 dB

Span # 17 22.2 dB

Span # 18 22.4 dB

Span # 19 22.1 dB

19 x 7 x

Backward Raman pump module

GFF Type I 5 x GFF Type II 5 x

Forward Raman pump module

Total distance: 1,504 km (19 spans)


• All-distributed Raman amplification makes the span output signal power higher than the input signal power.

– Signal power rises sharply at the end of the span caused by strong backward

Raman pumping.

– Average signal input power: -6.0 dBm/channel

– Average signal output power: -4.3 dBm/channel

Simulated Per Channel Power Profiles Over Distance

• Steep rise at Rx side • Lower input power to the next

span due to the insertion loss of Raman pump modules and GFFs

Power profile with forward Raman pump


• OSNR: Average = 19.6 dB

• Q (dB): Average = 11.4 dB, Min = 11.2 dB (Threshold = 6.4 dB)

Transmission Results: Measured OSNR and Q Factor (150 x 100G Over 19 Spans – 1,504 km)

Wavelength (nm)

1530 1540 1550 1560 1570 1580 1590 10

12

14

16

18

20

22

11.0

11.5

12.0

12.5

13.0

13.5

14.0

Q facto

r befo

re S

D-F

EC

(dB

)

OS

NR

(dB

/ 0

.1nm

)


• Unrepeatered transmission systems provide cost effective solution for – Communication between islands or main-lands

– Communication for oil platforms (for oil and gas company)


• Key technologies for unrepeatered transmission – Distributed Raman amplification

– ROPAs, high-order pumping

• Current 100G unrepeatered transmission system can support – Up to 557 km (90.2 dB) distance

– 15 Tbit/s transmission over 389 km G.652 fiber (5.84 Pbit/s km)

• Application in “repeatered” system – Transmission over cascaded “very long” spans

– Improving performance over difficult spans in terrestrial network

Summary

100G + Raman Powering Submarine and

Terrestrial Networks

“15 Tb/s Unrepeatered Transmission Over 409.6 km Using Distributed Raman Amplification and ROPA“ ACP 2014 Post-Deadline Paper AF4B.4

Thanks

Any Questions ?

Invited Paper Advanced Technologies for Unrepeatered · PDF file ·...

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Transcript of Invited Paper Advanced Technologies for Unrepeatered · PDF file ·...