This presentation reviews the current status and the forecast for international connectivity to Africa and traffic demands inside the continent. In a second step, the technical solutions, including wider spectrum as enabled by Xtera’s Wise Raman technology, to respond to the traffic growth are described. This presentation was delivered at WDM & Next Generation Optical Networking Africa 2015 conference (4-5 February 2015 – Cape Town, South Africa).

1. © 2015 Xtera Communications, Inc. Proprietary & Confidential 1
Forecasting International Optical
Transport Developments and
Understanding How
Africa’s Optical System Differs
From the Rest of the World
Herve Fevrier– Chief Strategy Officer – Xtera Communications
4-5 February 2015
WDM Africa 2015 (Cape Town, South Africa)

2. © 2015 Xtera Communications, Inc. Proprietary & Confidential 2
The Bandwidth Demand is Insatiable
0.001
0.01
0.1
1
10
100
1,000
10,000
100,000
1,000,000
1985 1990 1995 2000 2005 2010 2015 2020
Year
Datatraffic(petabyte/month)
Minnesota Internet Traffic Studies
(MINTS) for US IP traffic
High
Low
Swanson-Gilder for US IP traffic
Cisco Visual Networking Index
Forecast and Methodology
2007-2012 and 2012–2017
For global IP traffic
 Doubling about every 18 months (≈2 dB per year)

3. © 2015 Xtera Communications, Inc. Proprietary & Confidential 3
With 100G Being The Dominant Line Rate
Global 10G, 40G, 100G & 100+G DWDM line card revenue
(After Ovum)
0,00
1,75
3,50
5,25
7,00
8,75
Year
2019
10G revenues
40G revenues
100G revenues
100G+ revenues
2011 2012 2013 2014 2015 2016 2017 2018
DWDMlinecardrevenues($B)

4. © 2015 Xtera Communications, Inc. Proprietary & Confidential 4
• 40G is dying much faster than it was anticipated a year ago.
– 100G did win in terms of cost and performance due to some industry
“agreements” which created good price points at the start and then volume
etc… the virtuous circle!!
• 100G+
– People talk about 400G, 1T… when it is really a matter of
• Going from 100G to 150G and 200G per optical carrier
• And introducing super channels … kind of super dense wavelength division
multiplexing
• But spectral efficiency has a limit… and we are getting close to it
(Google at ECOC’2014 - Nice).
• Need for more spectrum
Channel Rates

5. © 2015 Xtera Communications, Inc. Proprietary & Confidential 5
The Internet Growth
2B 11/10/2010
1B 10/05/2005
After Internet Society Annual Report
2012 Internet Penetration
Global IP traffic will grow from 43 PB/month
in 2012 to 120PB/month in 2017
(23% CAGR)
After Cisco VNI (2013)

6. © 2015 Xtera Communications, Inc. Proprietary & Confidential 6
• Undersea is approx. 35% of
total used international
bandwidth.
• It is dominated by Internet
bandwidth.
• The traffic matrix is
becoming more balanced.
Undersea Communications Forecast
0,0%
20,0%
40,0%
60,0%
80,0%
100,0%
0
100 000
200 000
300 000
400 000
2011 2013 2015 2017 2019
Totalusedsubmarinecapacity(Gbps)
Used for Internet (%)
Used for private networks (%)
Used for switched voice (%)
Total Used Submarine Capacity (Gbps)
31,3%
32,5%
33,8%
35,0%
36,3%
37,5%
0
250 000
500 000
750 000
1 000 000
2011201220132014201520162017201820192020
Submarinebandwidth
percentage
Totalusedinternational
bandwidth(Gbps)
0%
10%
20%
30%
40%
2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Trans-Atlantic
Trans-Pacific
US-Latin America
Intra-Asia
Europe-ME & Egypt
250T

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• The submarine high-capacity belt is now deployed.
• Prime time is for Internet growth from the shores through the continent.
Africa Connectivity: Land of Contrast
After TeleGeography After Ovum
Mobile Broadband Subscription ForecastInternational Used Bandwidth

8. © 2015 Xtera Communications, Inc. Proprietary & Confidential 8
Africa Connectivity: Land of Contrast
Least Connected Countries (as of 2013) Mobile Subscriptions
After ITU
IDI: ICT Development index taking into account
ICT access, ICT use and ICT skills

9. © 2015 Xtera Communications, Inc. Proprietary & Confidential 9
Five multiplexing dimensions available:
• Time
– Faster opto-electronics (enabling 10G, 40G, 100G…)
– Current practical limit: about 30 Gbaud devices
• Frequency
– Multiplexing more optical carriers at different frequencies
– Conventional EDFA-based WDM technology limited to C
band (≈ 38 nm)
• Polarization
– Propagation of several states of optical polarization, each
supporting a data stream
– Practical today’s implementation: two polarizations
• Quadrature
– Multi-level modulation format
– BPSK, QPSK, 8QAM, 16QAM, 64QAM… leading to reach
reduction
• Space
– More transmission media are made available in parallel
– Different flavors of Spatial Division Multiplexing (SDM):
ribbon fiber, multi-core fiber, multi-mode fiber
How to Keep up With Bandwidth Demand?
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✔
✔ 1100
Q
1101
I
16-QAM
1110
1111
0101
0111
1000
I
Q
1101
QPSK
0
I
Q
1
BPSK

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Evolution With Optical Spectrum Expansion As Enabled
With Raman Optical Amplification
All-Raman provides x 3 in terms of spectrum
All-Raman provides x 2 in terms of reach
All-Raman provides x 6 in terms of Capacity x Reach
Maximizing spectral efficiency
AND spectrum
without compromising reach -30
-25
-20
-15
-10
-5
0
5
1515 1535 1555 1575 1595 1605
Power(dBm)
1625
Wavelength (nm)
100 nm of continuous
optical bandwidth
in the field since 2004

11. © 2015 Xtera Communications, Inc. Proprietary & Confidential 11
• Sir Venkata Raman earned the Nobel prize in Physics in 1930.
– Prize motivation: “for his work on the scattering of light and for the
discovery of the effect named after him”.
• Raman effect
– Inelastic scattering
• Applications
– Raman Spectroscopy
– Raman Amplification
• Laser sources and amplifiers
• Optical Communications
– 1962: SRS observation
– 1973: Raman in optical fibers
• Xtera Communications Inc. (1998)
– Mohammed Islam (founder – worked on soliton transmission with
L. Mollenauer)
– “Ideas in a different light”: Raman for different windows, a broader spectrum
and obviously reach
Raman History

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• Founded in 1998
• Opening new windows:
The S-band (2000-2001)
• Broadening the spectrum:
100nm window (2002-2005)
– 1st commercial deployment
2004: 2.4 Tbit/s
Xtera Communications: The first steps

13. © 2015 Xtera Communications, Inc. Proprietary & Confidential 13
Verizon Field Trials
• Deployed more than ten years ago
• Multiple ODFs in the path
• G.652 fiber with multiple splice points as a
result of construction activities in the
metropolitan area
• Length: 79.2 km per span
• 19 fibers/spans equipped (1,504 km total)
• Average span loss: 21.8 dB
• Existing standard connectors (SC/PC)
• Average fiber attenuation: 0.275 dB/km
• Shows three lumped loss of 1.2 ~ 1.9 dB
Bi-directional OTDR example of Verizon span
Challenging environment
G.652 field fiber
79.2 km per span
IL: 20 - 23 dB

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Verizon infrastructure representative of end-of-life numbers
Results for 1,504 km, 61 nm spectrum transmission
with high margins
• First trial: 100G
– 150 x 100G PM-QPSK (50 GHz) on 1,500 km: 15T / 4,500+ km
• Second trial: 400G (4 x 100G)
– MC 4 x 100G PM-QPSK (33 GHz) on 1,500 km: 20T / 3,000+ km
• Third trial: 400G (2 x 200G)
– DC PM-16QAM (2 x 200G)
• 50 GHz spacing:
30T / 2,000+ km
• 37.5 GHz spacing:
40T /1,500+ km
Validation Field Trial – Summary

15. © 2015 Xtera Communications, Inc. Proprietary & Confidential 15
XWDM [Capacity – Reach] Metric
240 x 100G
• 100 nm spectrum
• PM-QPSK channels
• 50 GHz channel spacing
• 2 bit/s/Hz spectral efficiency
120 x 400G
• 100 nm spectrum
• PM-16QAM 200G carriers
spaced 50 GHz apart
• 4 bit/s/Hz spectral efficiency
160 x 400G
• 100 nm spectrum
• PM-16QAM 200G carriers
spaced 37.5 GHz apart
• 5.3 bit/s/Hz spectral efficiency
 16QAM on more than 2,000 km of aged fiber (0.28 dB/km)

16. © 2015 Xtera Communications, Inc. Proprietary & Confidential 16
• Maximizing the reach at 100G
– 1 x 100G on 520 km of ULL fiber, with ROPA
– 4 x 100G on 523 km of Vascade EX2000 fiber, with ROPA
– 1 x 100G on 557 km of Vascade EX2000 fiber, with ROPA
• Maximizing the capacity over long unrepeatered distances
– 150 x 100G on 334 km of ULL fiber, without ROPA
– 150 x 100G on 390 km of ULL fiber, with ROPA
– 150 x 100G on 410 km Vascade EX2000 fiber, with ROPA
Recent Unrepeatered
100G Transmission Results

17. © 2015 Xtera Communications, Inc. Proprietary & Confidential 17
Optical Repeater for
Subsea Cable Systems Launched at
Innovation:
Electrical Improved powering enabling Raman amplification.
Optical Modular optical design. Spectrum increased by 50%.
Mechanical Marine grade titanium. Compact, light and strong.
Manufacturability Flexible and simplified manufacturing process.
-1
0
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2
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5
1540 1550 1560 1570 1580 1590 1600 1610
Wavelength (nm)
Effectivenoisefigure(dB)
-4
-3
-2
-1
0
1
2
3
1540 1550 1560 1570 1580 1590 1600 1610
Wavelength (nm)
Relativegain(dB)

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• 4 projects:
– 1 short
– 2 regional
– 1 long haul
• Deployments:
– 2 in 2015
– 1 in 2016
Status of Xtera Repeatered Projects

19. © 2015 Xtera Communications, Inc. Proprietary & Confidential 19
• People have worked hard on spectral efficiency since 1989.
– 4 x 2.5G in the C-band
– 40 x 10G in the C-band
– 80 x 10G in the C-band
– 93 x 100G in the C-band
– …BUT…
– The industry still uses
only the C band
• Raman technology offers the possibility to multiply by a factor of x6.5
the available bandwidth in deployed optical fibers which ultimately could
mean 200 Tbits/s per fiber pair.
Wireline So Far…
Fiber attenuation (dB/km)
1.0
0.8
0.4
0.2
1.2 1.71.61.51.41.3
Optical wavelength (µm)
C band
Old
fibers
Modern
fibers

20. © 2015 Xtera Communications, Inc. Proprietary & Confidential 20
Raman amplification brings several benefits to the design of
high-capacity optical networks:
• Increase the reach
• Ability to deal with very long spans
• Increase capacity / spectrum
Conclusion
Sir Chandrasekhara Venkata Raman
(1888 – 1970)
First Asian scientist to receive the
Nobel prize in physics (in 1930)

21. © 2015 Xtera Communications, Inc. Proprietary & Confidential 21
• Africa has now a submarine high-capacity communications belt.
• The next few years is about the penetration of this bandwidth from the
shores to the heart of the continent.
• It is of paramount importance that the deployed infrastructure is future-
proof both from a longevity point of view (e.g. OPGW cables on high-
voltage lines, …) and from the telecommunications point of view (high
EOL capacity as compared to BOL capacity, support of future transport
rates).
Conclusion: Africa

22. Maximizing Network Capacity, Reach and Value
Over land, under sea, worldwide
© 2015 Xtera Communications, Inc. Proprietary & Confidential 22