The document discusses the need for more efficient optical transport networks in Africa to support increasing network traffic and provide terrestrial backup for submarine cables. It presents Xtera's coherent optical technology using Raman amplification as an efficient solution, highlighting a 2,266 km Amazon network case study. This technology maximizes capacity and reach while minimizing components, enabling long spans suitable for Africa's sparse networks along power grids and between population centers.

1. © 2016 Xtera Communications, Inc. Proprietary & Confidential 1
Efficient Optical Transport Layer for
High-Capacity Optical Networking
Bertrand Clesca – Head of Global Marketing – Xtera Communications
2-3 February 2016
NGON Africa 2016 (Cape Town, South Africa)

2. © 2016 Xtera Communications, Inc. Proprietary & Confidential 2
• Capacity trends: Why and how much?
• New players: New types of service providers and
network operators with new requirements
• Case study: Efficient DCI Terrestrial restoration
alternatives for subsea cable systems as enabled by
coherent technologies and Raman optical amplification
Content

3. © 2016 Xtera Communications, Inc. Proprietary & Confidential 3
Capacity Trends: Why and How Much?

4. © 2016 Xtera Communications, Inc. Proprietary & Confidential 4
Every Minute…
Facebook users share nearly 2.5 million pieces of content.
Twitter users tweet nearly 300,000 times.
Instagram users post nearly 220,000 new photos.
YouTube users upload 72 hours of new video content.
Apple users download nearly 50,000 apps.
Email users send over 200 million messages.
Amazon generates over $80,000 in online sales.
Google receives over 4,000,000 search queries.
Pandora users listen to 62,000 hours of music.
Yelp users post 26,000 reviews.
Skype users connect for 23,300 hours
Tinder users swipe 416,667 times.
WhatsApp users share 347,222 photos.
Source: Simon Cooper
COO, NEXTDC Limited
SNW Singapore 2015 Presentation

5. © 2016 Xtera Communications, Inc. Proprietary & Confidential 5
… Leading to Huge Growth in
Core Network Traffic
Analysis of the growth in core network traffic (purple curve) since the dawn of the Internet era in terms of the
constituent five-year trend segments (data shown with expanded scales). Source: Bell Labs Consulting.
1st era of the internet 2nd era

6. © 2016 Xtera Communications, Inc. Proprietary & Confidential 6
Capacity and Reach Limitations
With EDFA-Based Networks

7. © 2016 Xtera Communications, Inc. Proprietary & Confidential 8
New Networks Requirements

8. © 2016 Xtera Communications, Inc. Proprietary & Confidential 9
• Dense, mesh network with many traffic locations
• Fibers owned, plenty of dark fibers available
Traditional Telecom Networks

9. © 2016 Xtera Communications, Inc. Proprietary & Confidential 10
• By design, fiber drops at very few locations  Long
spans
OPGW Network
OPGW Network Over Power Grids

10. © 2016 Xtera Communications, Inc. Proprietary & Confidential 11
• Network on leased fibers with few traffic locations
• Sparse population distribution and power availability
issues  Long spans
Backbone/Backhaul Networks

11. © 2016 Xtera Communications, Inc. Proprietary & Confidential 12
• Technical + commercial innovations
• Long span capability vs back-to-back terminal
equipment (red sites)  Long reach and high capacity
Backhaul Networks for Subsea
Cable Systems
London
Dublin

12. © 2016 Xtera Communications, Inc. Proprietary & Confidential 13
• Sparse network  Long reach
• Large pipes over leased fibers  High capacity
• Benefits from skipping sites  Long spans
Data Center Operator Networks

13. © 2016 Xtera Communications, Inc. Proprietary & Confidential 14
No Major Content Provider Data
Centers in Africa in 2015

14. © 2016 Xtera Communications, Inc. Proprietary & Confidential 15
No Major Content Provider Data
Centers in Africa Planned in 2017

15. © 2016 Xtera Communications, Inc. Proprietary & Confidential 16
Terrestrial Connectivity Needs in Africa

16. © 2016 Xtera Communications, Inc. Proprietary & Confidential 17
Light to Africa In The Old Days
Optical international connectivity
Main subsea routes to Africa before 2009

17. © 2016 Xtera Communications, Inc. Proprietary & Confidential 18
Light to Africa In The Old Days
Optical international connectivity
Building new subsea routes to Africa

18. © 2016 Xtera Communications, Inc. Proprietary & Confidential 19
Light to Africa Today
Optical international connectivity
Main subsea routes to Africa today

19. © 2016 Xtera Communications, Inc. Proprietary & Confidential 20
Need For More Diversity
January 2016:
• Three subsea cable cuts off Alexandria
• Cuts on two
independent
terrestrial
segments
across
Egypt
74% of
internet
connectivity
lost in Gulf
countries,
and 100% in South Africa for few hours

20. © 2016 Xtera Communications, Inc. Proprietary & Confidential 21
Need For More Light Into Africa
To backhaul traffic to land-locked countries
and inland PoPs / DCs
To offer restoration
alternatives for
subsea cable
systems

21. © 2016 Xtera Communications, Inc. Proprietary & Confidential 22
• Efficient optical layer
– Long end-to-end reach
– Long spans between sites
– Plus:
Reliability
Flexibility
Capacity
Low latency
Etc.
• More backhaul networks are
needed for route diversity and global resiliency.
Need For Optical Backhaul
Networks

22. © 2016 Xtera Communications, Inc. Proprietary & Confidential 23
Power Grids: Infrastructure
Suitable for Optical Network
Aluminum alloy
Aluminum-clad steel
Stainless steel tube
Optical fiber
OPGW cable between
transmission towers

23. © 2016 Xtera Communications, Inc. Proprietary & Confidential 24
Power Grids: Infrastructure
Suitable for Optical Networks
• OPGW cable between
transmission towers
• Not a telco network:
– Long distances between
intermediate ODF sites

24. © 2016 Xtera Communications, Inc. Proprietary & Confidential 25
Power Grids: Infrastructure
Suitable for Optical Networks
• OPGW cable between
transmission towers
• Not a telco network:
– Long distances between
intermediate ODF sites
– Telecom sites maybe off the
power grid

25. © 2016 Xtera Communications, Inc. Proprietary & Confidential 26
Power Grids: Infrastructure
Suitable for Optical Networks
• OPGW cable between
transmission towers
• Not a telco network:
– Long distances between
intermediate ODF sites
– Telecom sites maybe off the
power grid
Very long spans

26. © 2016 Xtera Communications, Inc. Proprietary & Confidential 27
Xtera’s [Capacity – Reach] Metric
In Terrestrial Networks

27. © 2016 Xtera Communications, Inc. Proprietary & Confidential 28
Xtera’s [Capacity – Reach] Metric
Unrepeatered Links

28. © 2016 Xtera Communications, Inc. Proprietary & Confidential 29
• Interface cards  On a per wavelength basis
• Line amplifiers  A few to several
• Line fiber  On a per kilometer basis
Components of
Optical Transport Layer
In-Line
Amplifier (ILA)
Reconfigurable Optical
Add Drop Multiplexer
(ROADM)
Booster
Amplifier
Pre-
Amplifier
Interface cards Interface cards

29. © 2016 Xtera Communications, Inc. Proprietary & Confidential 30
Raman-Assisted Transmission
For Multi-Span Transport
Much less
breathing
Higher noise performance
Raman chain
Lower non-linearity
A
Backward Raman pumping Forward Raman pumping
Fiber attenuation
Distributed Raman
gain
B C D E F
Distance
Perchannelpowerprofile
Lower limit: Optical noise accumulation
Upper limit: Nonlinear distortions
High
peak-to-
peak
power
excursion
EDFA chain
A B C D E F
Fiber
attenuation
Power
boost

30. © 2016 Xtera Communications, Inc. Proprietary & Confidential 31
2,266 km Amazon Network
ROADM
43 km
13.9 dB
237 km
53.8 dB
278 km
63.1 dB
ILAILA ROADM
142 km
34.6 dB
ILA 138 km
33.1 dB
235 km
53.5 dB
ILA
Villa
Camburão
ROADM
183 km
46.1 dB
141 km
33.9 dB
157 km
37.2 dB
ILAILA ILA
91 km
23.8 dB
ILA
229 km
52.8 dB
ROADM
239 km
54.2 dB
110 km
27.2 dB
ROADM
ILA ILA
43 km
13.9 dB
Manaus
TIM
Terra SantaManaus
Rod Lexuga
Silves Oriximiná
Macapá
TIM
Jurupari
Macapá Sub Laranjal do Jari
Gopa XinguTucuruí Pacaja Vitória do Xingu
Core
amplifier
Backward Raman span
extension module
Forward Raman span
extension module
G.652
fiber span
Longest span:
• 278 km
• 63 dB

31. © 2016 Xtera Communications, Inc. Proprietary & Confidential 32
• Multi Terabit route with only two regeneration sites
• To be compared with subsea route via South Africa:
– Twice lower latency
– Saving 4 interface cards  Lower cost per transported bit
Applicability to Africa
Kinshasa
Muanda
Inga
Cable
landing
station
Cable
landing
station

32. © 2016 Xtera Communications, Inc. Proprietary & Confidential 33
• Stronger terrestrial backhaul networks required for:
– Backhauling subsea capacity inland
– Offering restoration alternatives to subsea cable systems
– Higher global land/subsea resiliency
• Raman amplification enables:
– Long spans between sites (as found in OPGW networks or
sparsely populated areas)
– Long end-to-end reach (as required by African geography)
– Efficient transport of 100G/200G/400G channels with the
minimal number of inline amplification and regeneration sites
– Turning OPGW plant into future proof optical networks
Summary

33. © 2016 Xtera Communications, Inc. Proprietary & Confidential 34
Maximizing Network Capacity, Reach and Value
Over land, under sea, worldwide