2015 09 09-unrepeatered-systems-presentation-snw-singapore-2015
TRANSCRIPT
© 2015 Xtera Communications, Inc. Proprietary & Confidential 1
Unrepeatered Systems:Farther, Faster Over a Single Span
9 September 2015
Philippe A. Perrier
© 2015 Xtera Communications, Inc. Proprietary & Confidential 2
Innovative Unrepeatered Offering Confidential – Xtera Communications, Inc. Proprietary
Example of Driver for Longer Single-Span Systems
PoPCable Landing StationSubmarine cableTerrestrial extension
City A
City B
© 2015 Xtera Communications, Inc. Proprietary & Confidential 3
Innovative Unrepeatered Offering Confidential – Xtera Communications, Inc. Proprietary
Example of Driver for Longer Single-Span Systems (Cont’d)
City A
City B
BMH
BMH
PoP
Submarine cableTerrestrial extension
• Because unrepeatered systems are loss-limited, there is a direct link between capacity and reach performance
© 2015 Xtera Communications, Inc. Proprietary & Confidential 4
1. Fiber:– Lower attenuation fiber is always better Ultra low-loss (G.652B, G.654B)
– Type Fibers with large effective area tolerant to higher launched power
2. Line rateModulation formatPulse shapingChannel densityWavelength of transmission (fiber attenuation lower in L-band)Detection (direct / coherent) Forward Error Correction (Hard-Decision FEC / Soft-Decision FEC)
3. Power management– Launched power; power in the line fiber
– Non-linearities mitigation
Maximizing Reach in Single-Span SystemsTool Kit
© 2015 Xtera Communications, Inc. Proprietary & Confidential 5
4. Raman amplification– Results from the interaction of an optical radiation (“pump”) with molecular
vibrations of the glass
• Maximum gain at a shift of ~ 100 nm in the 1550 nm window
– In any fiber types
– The more pump power the more gain
– Raman gain improves with lower
fiber attenuation (larger Leff)
Thus the NF and OSNR improvements
due to Raman will be larger in lower
attenuation fiber at the same
Raman pump power.
Maximizing Reach in Single Span SystemsTool Kit (Cont’d)
0
1
3
4
5
6
6 12 18 24 30 36 42
2
048
Frequency shift (THz)
Ram
an g
ain
(a.u
.)
PumpResulting gain
~ 100 nm
© 2015 Xtera Communications, Inc. Proprietary & Confidential 6
Raman AmplificationPower Profile along the Span (Backward Raman)
266 km (61.2 dB); G.652D
Gain from backwardRaman pumping
Fiber attenuation
15x100G
© 2015 Xtera Communications, Inc. Proprietary & Confidential 7
Raman Amplification Power Profile along the Span (BWD & FWD Raman)
288 km (65.5 dB); G.652D
Gain from backwardRaman pumping
Fiber attenuation
15x100G
Gain fromforwardRamanpumping
© 2015 Xtera Communications, Inc. Proprietary & Confidential 8
5. Remote Optically Pumped Amplifier (ROPA)– Passive sub-system, made up of a few optical components (housed in an
enclosure jointed to the cable) and pumped from one end of the span
(typically, receive end)
– Basically, performs the function of a mid-span EDFA
– More pump power allows ROPA to be located further away from the terminals
Maximizing Reach in Single Span SystemsTool Kit (Cont’d)
ROPA
Erbiumdoped
fibreSignalin
Signalout
Optical pump (from the receive terminal)
~ 100 km
© 2015 Xtera Communications, Inc. Proprietary & Confidential 9
ROPAPower Profile along the Span
373 km (76.1 dB); G.652B
Gain from backwardRaman pumping
Fiber attenuation
15x100G
Gain fromforwardRamanpumping
GainfromROPA
ROPA
107 km
© 2015 Xtera Communications, Inc. Proprietary & Confidential 10
• Corning® Vascade® EX2000 (G.654B), Aeff=112 mm2
• Span loss = 90.2 dB (cable attenuation = 0.162 dB/km)
Unrepeatered 1x100G Transmission over 557kmField Trial with Verizon Business
ROPA
ForwardRamanpumping
BackwardRaman
pumping
Gain fromforwardRamanpumping
Gain from backwardRaman pumping
Fiber attenuation
Gainfrom
ROPA
Direction oftransmission
291 km 133 km
1 wavelength
ROPA
133 km
GainfromROPA
Pe
r ch
an
ne
l po
we
r (d
Bm
)
Transmission distance (km)
EDFA
© 2015 Xtera Communications, Inc. Proprietary & Confidential 11
• EDFA only at transmit and receive sidesSD-FEC (15%; 6.4 dBQ threshold); target OSNR = 13.5 dB
Contribution of Key Techniques to Transmission Performance – Baseline
340 km (55.5 dB)
Launched power = 14.8dBm
OSNR
Signal
ASE
© 2015 Xtera Communications, Inc. Proprietary & Confidential 12
+56 km / +9 dB with respect to the baseline
Contribution of Backward Raman Amplification
396 km (64.5 dB)
Launched power = 14.8dBm
© 2015 Xtera Communications, Inc. Proprietary & Confidential 13
Extra +63 km / +10.3 dB
Contribution of Forward Raman Amplification
459 km (74.8 dB)
DCM
Launched power = -4.4dBm
© 2015 Xtera Communications, Inc. Proprietary & Confidential 14
Extra +67 km / +10.8 dB
Contribution of Backward ROPA
526 km (85.6 dB)
Launched power = -4.4dBm
DCM
ROPA
© 2015 Xtera Communications, Inc. Proprietary & Confidential 15
Extra +31 km / +4.6 dB
Contribution of Forward ROPA
Launched power = -4.9dBm
DCM
ROPAROPA
557 km (90.2 dB)
© 2015 Xtera Communications, Inc. Proprietary & Confidential 16
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Po
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Wavelength (nm)
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Wavelength (nm)
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Po
wer (d
Bm
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Wavelength (nm)
410 km (68.2 dB), 150 x 100G Unrepeatered Transmission over G.654B Fiber
289 km
ROPA
121 km
Gain fromforwardRamanpumping
Gain from backward
Raman pumping
Fiber attenuation
150 wavelengths
Gainfrom
ROPA
Pe
r ch
an
ne
l po
we
r (d
Bm
)
Transmission distance (km)
LRA (Discrete Raman amplifier) LRA
<Pout> = -2.8 dBm/ch <OSNR> = 14.2 dB
© 2015 Xtera Communications, Inc. Proprietary & Confidential 17
Innovative Unrepeatered Offering Confidential – Xtera Communications, Inc. Proprietary
Conclusion
PoPCable Landing StationSubmarine cableTerrestrial cableROPAILA
• Not limited to single-span systems
© 2015 Xtera Communications, Inc. Proprietary & Confidential 18
• Span 1: G.654C fiber; 330 km (59 dB)
• Span 2: G.652D fiber; 300 km (59 dB)
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Pow
er
(dB
m)
Wavelength (nm)
150 x 100G Transmission over Cascade of 2 Unrepeatered Spans (630 km, 118 dB)
ROPA
LRA LRALRA
Span 1
ROPA
Span 2
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Po
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Wavelength (nm)
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Po
we
r (d
Bm
)Wavelength (nm)
100 km 110 km
<Q> = 7.0dB
© 2015 Xtera Communications, Inc. Proprietary & Confidential 19
Innovative Unrepeatered Offering Confidential – Xtera Communications, Inc. Proprietary
Conclusion
PoPCable Landing StationSubmarine cableTerrestrial cableROPA
• Not limited to single-span systems
• Not limited to submarine space (e.g., terrestrial, DCI)
Maximizing Network Capacity, Reach and ValueOver land, under sea, worldwide
© 2015 Xtera Communications, Inc. Proprietary & Confidential 20