Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
An Introduction to Optical
Backbone Ne...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Content
2
WDM
OTN
Optical
Communicatio...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
3
WDM
OTN
Optical
Communication
Basics...
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Waves
4
Longitudinal wave
• Oscillates...
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Terminology
5
: length of a wave in a...
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6
cannot see!
1. wavelength of these w...
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dB vs. dBm
dB (Decibels)
• unit of lev...
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Optical Fiber
Source : 1. http://www.o...
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Fiber
• Capacity
• Distance
The optica...
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CladdingCore
Coating
Fiber Geometry
• ...
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q1
n2
n1
Cladding
q0 Core
Intensity Pr...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Single vs. multi mode
Source: http://o...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
n2
n1
Cladding
Core
n2
n1
Cladding
Cor...
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Simple optical link
14
Source : http:/...
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Are our senses analog or digital?
15
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Attenuation
Dispersion
Nonlinearity
Wa...
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Analog transmission effects
• Attenuat...
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Attenuation
• The extent to which ligh...
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Attenuation, cont.,
Source: http://osd...
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OA
(works fully in the optical domain)...
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• Polarization Mode Dispersion (PMD)
S...
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Chromatic dispersion
22
Source: http:/...
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60 Km SMF-28
4 Km SMF-28
10 Gbps
40 Gb...
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Combating CD
• Use DSF and NZDSF fiber...
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DSF and NZDSF
Wavelength/nm
Dispersion...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Dispersion Compensation
Transmitter
Di...
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DCF
Source: http://www.thorlabs.com/ne...
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Polarization Mode Dispersion
(PMD)
• R...
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Combating PMD
• Improved fibers
• Rege...
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ITU Wavelength Grid
• Standard set of ...
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31
WDM
OTN
Optical
Communication
Basic...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
How to increase network
capacity?
Spac...
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What’s WDM?
• A technology that utiliz...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
What’s WDM? , Contd.,
Gas Station
Free...
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TDM Vs. WDM
SONET
35
• Takes sync and ...
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Example
36
Source : http://www.transmo...
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WDM History
• Early WDM (late 80s)
– T...
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Why WDM?
• Capacity upgrade of existin...
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WDM principle elements
• Allow traffic...
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Optical Multiplexer
Optical De-multipl...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Optical Amplifier
(EDFA)
Optical Atten...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
System structure
OTU1
OTUn
OTU2
OTU1
O...
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Loss
• Passive => Loss (power reductio...
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Definition of the line side
44
Source ...
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OTU- Optical Transponder Unit
O
OE
ENo...
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Uni Versus Bi-directional WDM
WDM syst...
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WDM network topologies
• Point to Poin...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
CWDM vs. DWDM
Source: http://www.cable...
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CWDM vs. DWDM, cont.,
Types CWDM DWDM
...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Applicability of CWDM & DWDM
50
Source...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
SDH/SONET vs. WDM
51
All traffic signa...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Modulation
• DAC?
– medium/channel is ...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Modulation, cont.,
53
on/off keying
Bi...
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Modulation, cont.,
54
21
22
23
24
Phas...
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QAM
55
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Comparison of optical modulators
Types...
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57
Direct
Detection
(optical
power
mea...
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Tx and Rx
Optical transmitter
• Semico...
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The Big Leap: 10G to 100G Coherent
59S...
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Beyond 100G - Enhanced Encoding
60Sour...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Amplification and
regeneration
61
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
• Compensates the loss
• Any analog si...
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Amplifier types
• EDFA - Erbium Doped ...
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Principles of 3R regeneration
64Source...
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Optical Multiplexer and de-
multiplexe...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
TFF
Source: http://www.fiberoptics4sal...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
AWG
Source: http://docstore.mik.ua/uni...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Transponder & muxponder
68
Source : ht...
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Supervisory technologies
• OSC - Optic...
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70
ADM OADM ROADM
function in the
trad...
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OADM
OADMs allow flexible add/drop of ...
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Key attributes of ROADM Module
• Fully...
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Static Networks Based on Fixed-
Wavele...
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ROADMs Enable Any-Node-to-
Any-Node To...
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ROADM Generations
• 1st generation: Wa...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
2 degree ROADM
76
No. of
inputs
Source...
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Good features to have on a WSS
system
...
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Colorless 2 degree ROADM
78
Source : h...
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Directionless 2 degree ROADM
79
can be...
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Directionless and contentionless
2 deg...
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4 degree ROADM
81Source : http://www.t...
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8 degree ROADM
82Source : http://www.t...
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Control plane
83
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Automatically Switched Optical
Network...
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85
Source: http://en.wikipedia.org/wik...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
WSON
86
WDM
fiber link
OXC
(GMPLS)
Sou...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Generalized Multi-Protocol Label
Switc...
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88
WDM
OTN
Optical
Communication
Basic...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
What is “OTN”?
• As per ITU-T, it’s G....
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
OTN aim
• Combine the
– Benefits of SO...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Main functionality provided by
an OTN
...
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STM-1 frame is the basic transmission ...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
SONET & SDH multiplexing
hierarchies
9...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
OTN signal structure and terminology (...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
ITU-T G.709 ODUs
95
Source : http://ww...
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OTN vs. SDH/SONET line rates
96
Source...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Pre-OTN WDM Vs. OTN
Pre-OTN WDM
• simp...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
OTN switching
98
• Prime advantage: su...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
OTN networking efficiency:
virtual wav...
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All-Optical (without digital switching...
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WDM + Stand-alone OXC’s: 2
Platform So...
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Converged DWDM & OTN Switching
:Collap...
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Available options
103
1. FOADM
2. ROAD...
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3 CAPEX components
104
Cost of adding ...
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Optical Backbone Networks
- evolution ...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Architecture Comparisons
106
Source: 2...
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107
WDM
OTN
Optical
Communication
Basi...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Packet and optical
108
Source: 2nd Ann...
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109Source: 2nd Annual WDM & Next Gener...
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Alternative implementations of IP over...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Future of transport & switching
111
So...
Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU
Conclusion
112
WDM
OTN
Optical
Communi...
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Introduction to Optical Backbone Networks

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The slides cover: optical communication basics, WDM, OTN and Packet Optical Integration

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Introduction to Optical Backbone Networks

  1. 1. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU An Introduction to Optical Backbone Networks April 2014 1
  2. 2. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Content 2 WDM OTN Optical Communication Basics Future (Packet Optical Integration)
  3. 3. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 3 WDM OTN Optical Communication Basics Future (Packet Optical Integration) Content
  4. 4. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Waves 4 Longitudinal wave • Oscillates in the same direction as propagation • Ex:- Sound waves Transverse waves • Ex:- Light Both longitudinal or transverse waves follow basic wave principles
  5. 5. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Terminology 5 : length of a wave in a particular medium. Common unit: nanometers (nm), 10-9 m f: the number of times that a wave is produced within a particular time period. Common unit: TeraHertz (Thz), 1012 cycles per second c = f  c = velocity of light in a vacuum = 3 x 108 m/s (constant) f = frequency (Hz)  = wavelength (m) f  1 / 
  6. 6. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 6 cannot see! 1. wavelength of these waves is too long for the human eye to detect 2. radio waves are not scattered as much as light waves by gas and dust, and can penetrate clouds 850, 1310, 1550 nm
  7. 7. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU dB vs. dBm dB (Decibels) • unit of level (relative measure) • Standard logarithmic unit for the ratio of two quantities • X dB is 10-X/10 in linear dimension • Ex:- 3 dB Attenuation = 10-0.3 = 0.501 • In optical fibres, the ratio is power and represents loss or gain dBm (Decibels-milliwatt) • absolute value • used for output power and receive sensitivity • dBm : Decibel referenced to a milliwatt • X mW = 10log10(X) dBm • Y dBm = 10Y/10 mW • Ex:- 0 dBm = 1 mW, 17dBm = 50 mW 7
  8. 8. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Optical Fiber Source : 1. http://www.okokchina.com/product/Electrical/Generators-Cables-Related-Products/Insulated-Wires-Cables-Including-Optical-Fibers/index_13.htm 2. http://en.wikipedia.org/wiki/Multi-mode_optical_fiber 1. 2. Metal (copper) loop Fiber cable 8
  9. 9. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Fiber • Capacity • Distance The optical fiber cable in the foreground has the equivalent capacity of the copper cable in the background Source : http://www.igpolicysummit.org/uncategorized/copper-v-fiber-verizon-makes-a-change-following-sandys-devastation/ 9
  10. 10. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU CladdingCore Coating Fiber Geometry • Core: carries the light signals • Cladding: keeps the light in the core • Coating: protects the glass
  11. 11. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU q1 n2 n1 Cladding q0 Core Intensity Profile Propagation in Fiber • Light propagates by total internal reflections at the core-cladding interface • Total internal reflections are lossless • Each allowed ray is a mode
  12. 12. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Single vs. multi mode Source: http://osd.com.au/multimode-versus-singlemode/ Mode=Path of light High Attenuation (3 dB/km) High dispersion Expensive today (because of less demand) Attenuation = 0.22 dB/km (G.652 @ 1550nm) No mode dispersion 12
  13. 13. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU n2 n1 Cladding Core n2 n1 Cladding Core Multi mode vs. Single mode propagation • Multimode –Core diameter varies • step index: 50 mm • graded index: 62.5 mm • Single-mode –Core diameter is about 9 mm Refractive index n = c / v
  14. 14. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Simple optical link 14 Source : http://www.transmode.com/en/technologies/wdm
  15. 15. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Are our senses analog or digital? 15
  16. 16. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Attenuation Dispersion Nonlinearity Waveform After 1000 KmTransmitted Data Waveform Distortion It may be a Digital signal, but It’s an Analog optical transmission Propagation issues 16 1 0 Fiber is not a perfect waveguide for light Processed in the electrical domain Processed in the optical domain
  17. 17. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Analog transmission effects • Attenuation: – Reduces power level with distance • Dispersion and nonlinear effects: – Erodes clarity with distance and speed • Noise and Jitter: Leading to a blurred image 17 Ex:-FWM
  18. 18. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Attenuation • The extent to which lighting intensity from the source is diminished as it passes through a given length of FO cable, tubing or light pipe • Loss due to absorption by impurities – 1400 nm peak due to OH ions • Specified in loss per kilometer (dB/km) – 0.40 dB/km at 1310 nm – 0.25 dB/km at 1550 nm 1310 Window 1550 Window
  19. 19. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Attenuation, cont., Source: http://osd.com.au/multimode-versus-singlemode/ Water peak created by fiber imperfections Lowest loss band 19
  20. 20. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU OA (works fully in the optical domain) Solution for Attenuation Loss Optical Amplification 20
  21. 21. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU • Polarization Mode Dispersion (PMD) Single-mode fiber supports two polarization states Fast and slow axes have different group velocities Causes spreading of the light pulse • Chromatic Dispersion (CD) Different wavelengths travel at different speeds Causes spreading of the light pulse (ps/nm-km) Types of Dispersion 21 Physical phenomenon of signal distortion caused when various modes carrying signal energy or different frequencies of the signal have different group velocity and disperse from each other during propagation
  22. 22. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Chromatic dispersion 22 Source: http://www.bubblews.com/news/2058509-somewhere-over-the-rainbow degrades the signal shape color Inter-symbol Interference (ISI) leads to performance impairments Source : http://www.transmode.com/en/technologies/wdm
  23. 23. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 60 Km SMF-28 4 Km SMF-28 10 Gbps 40 Gbps Limitations From CD t t • Dispersion causes pulse distortion • Higher bit-rates and shorter pulses are less robust to Chromatic Dispersion • Limits "how fast“ and “how far” 23
  24. 24. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Combating CD • Use DSF and NZDSF fibers – G.653 & G.655 • Dispersion Compensating Fiber (DCF/DCM) • Transmitters with narrow spectral width 24
  25. 25. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU DSF and NZDSF Wavelength/nm Dispersion coefficient 1310 1550 17 ps/nm/km 4.5 ps/nm/km G.652: widely used, need DCF for high rate transmission, cheapest G.655: little dispersion to avoid FWM, expensive G.653: Main application: submarine 25
  26. 26. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Dispersion Compensation Transmitter Dispersion Compensators Dispersion Shifted Fiber Cable +100 0 -100 -200 -300 -400 -500 CumulativeDispersion(ps/nm) Total Dispersion Controlled Distance from Transmitter (km) No Compensation With Compensation 26
  27. 27. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU DCF Source: http://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=5719 Dispersion-> DCF ->Dispersion longer fiber distance -> attenuation  -> Optical Amplifiers -> noise  -> S/N DCM (Dispersion Compensation Module) . Usually placed at bottom of rack 27
  28. 28. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Polarization Mode Dispersion (PMD) • Resulting from different propagation velocities of 2 states of cross polarization of optical signal in fiber • Can’t avoid • Due to – Manufacturing process – Installation/usage (temperature, vibration, bending (DCM) • Both PMD and CD are sensitive at higher bit rates Source: http://www.fiberoptics4sale.com/wordpress/optical-fiber-dispersion/ 28
  29. 29. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Combating PMD • Improved fibers • Regeneration – Light signal is detected & converted to an electrical signal that is amplified, reshaped & converted back to an optical signal • Follow manufacturer’s recommended installation techniques for the fiber cable 29
  30. 30. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU ITU Wavelength Grid • Standard set of wavelengths to be used in FO communications • ITU-T  grid is based on 191.7 THz + 100 GHz • It is a standard for laser in DWDM systems • Wavelength spacing could be 50GHz, 100GHz, 200GHz, …. 1530.33 nm 1553.86 nm 0.80 nm 195.9 THz 193.0 THz 100 GHz
  31. 31. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 31 WDM OTN Optical Communication Basics Future (Packet Optical Integration) Content
  32. 32. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU How to increase network capacity? Space Division Multiplexing (SDM) • Add more fiber & equipment • Slow Time to Market • Expensive Engineering • Limited Rights of Way • Duct Exhaust Time Division Multiplexing (TDM) • PDH/SDH (STM- 16->STM-64(10G)- >STM-256(40G) • Complexity • Electronics more expensive Wavelength Division Multiplexing (WDM) • Economical, mature & quick • Fast Time to Market 32
  33. 33. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU What’s WDM? • A technology that utilizes the properties of refracted light to both combine and separate optical signals based on their wavelengths within the optical spectrum • Different signals with specific wavelength are multiplexed into a fiber for transmission 33
  34. 34. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU What’s WDM? , Contd., Gas Station Free Way Petrol Car Freeway : Fiber Petrol Car : Supervisory Signal Gas Station : Optical relay Gray Car : Client Service Colored Car : Service in different channels (wavelength) Driveway : Optical wavelength 34
  35. 35. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU TDM Vs. WDM SONET 35 • Takes sync and async signals & multiplexes them to a single higher optical bit rate • 4 STM-1 channels in STM-4 • 4 STM-4 channels in STM-16 • 16 STM-4 channels in STM-64 • E/O or O/E/O conversion • Single wavelength per fiber • Takes multiple optical signals and multiplexes onto a single fiber • No signal format conversion • Multiple wavelengths per fiber
  36. 36. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Example 36 Source : http://www.transmode.com/en/technologies/wdm
  37. 37. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU WDM History • Early WDM (late 80s) – Two widely separated wavelengths (1310, 1550nm) • “Second generation” WDM (early 90s) – Two to eight channels in 1550 nm window – 400+ GHz spacing • DWDM systems (mid 90s) – 16 to 40 channels in 1550 nm window – 100 to 200 GHz spacing • Next generation DWDM systems – 64 to 160 channels in 1550 nm window – 50 and 25 GHz spacing 37
  38. 38. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Why WDM? • Capacity upgrade of existing fiber networks (without adding fibers) • Transparency: Each optical channel can carry any transmission format (different asynchronous bit rates, analog or digital) • Scalability: Buy and install equipment for additional demand as needed • Wavelength routing and switching: Wavelength is used as another dimension to time and space 38
  39. 39. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU WDM principle elements • Allow traffic to enter and leave the optical network – Transponder • Signal/wavelength converter – Muxponder • Combines several client signals into one line signal • Multiplex wavelengths – Optical multiplexer (MUX) and de-multiplexer • Send wavelengths in different directions – ROADM • Optical Amplifier (Amp) • Supervisory channel • Optical Source 39
  40. 40. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Optical Multiplexer Optical De-multiplexer Optical Add/Drop Multiplexer (OADM) Transponder WDM Components 1 2 3 1 2 3 850/1310 15xx 1 2 3 1...n 1...n 40
  41. 41. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Optical Amplifier (EDFA) Optical Attenuator Variable Optical Attenuator Dispersion Compensator (DCM / DCU) More WDM Components 41
  42. 42. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU System structure OTU1 OTUn OTU2 OTU1 OTUn OTU2 OSCOSCOSC OLA Optical Transponder Unit: Access the client services & convert the wavelength compiled with ITU standard Optical Multiplexer Unit: Multiplex several services with different wavelength into one main path signal OA Optical Amplifier: Amplifies the optical signal Optical Supervisory Channel: Terminate & Re-generation. Not amplification. Optical De-multiplexer Unit: De-multiplex one main path signal into several individual signals Optical Line Amplifier 1 2 n nm nm 1,2..n 1 2 n P A A P A A P A P Active Passive OA A 1,2..n P O M U P O D U 42 P
  43. 43. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Loss • Passive => Loss (power reduction) – Ex:- Input power to the MUX 0 dB. Output power from the MUX -6 dB. Therefore the loss is 6 dB • Loss can be due to splicing, distance, bending, aging, connectors 43 Source: http://www.thefoa.org/tech/lossbudg.htm
  44. 44. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Definition of the line side 44 Source : http://www.transmode.com/en/technologies/wdm
  45. 45. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU OTU- Optical Transponder Unit O OE ENon-color (Not defined by ITU-T) Ex:- 1310 nm short reach SMF 1550 nm long reach SMF 850 nm MMF Can’t use these in WDM without OTU Color (Defined by ITU-T) Ex:- 1: 1550.51 nm 2 :1551.23 nm 45 SMF-Single Mode Fiber MMF-Multi Mode Fiber Optical to Electrical conversion Electrical to Optical conversion Wavelength conversion
  46. 46. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Uni Versus Bi-directional WDM WDM systems can be implemented in two different ways Bi -directional  5  6  7  8 Fiber  1  2  3  4 Uni -directional  1  3  5  7 Fiber Fiber  1  3  5  7  2  4  6  8  2  4  6  8 • Uni-directional: wavelengths for one direction travel within one fiber two fibers needed for full-duplex system • Bi-directional: a group of wavelengths for each direction single fiber operation for full-duplex system 46
  47. 47. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU WDM network topologies • Point to Point • Ring • Mesh Cost  Complexity  Reliability  47
  48. 48. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU CWDM vs. DWDM Source: http://www.cable360.net/tech/strategy/businesscases/30007.html CWDM- Coarse WDM, DWDM-Dense WDM DWDM: smaller transmission window CWDM: larger transmission window 48 Closer wavelength spacing: need to maintain stable wavelengths / frequencies
  49. 49. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU CWDM vs. DWDM, cont., Types CWDM DWDM Channel spacing (Grid) 20 nm (fixed) 100 GHz/ 50 GHz/ 25 GHz Band 1311~1611 nm (All bands) C-band: 1529nm~1561nm L-band: 1570nm~1603nm Capacity (max) 18 x 10 Gbps 192 x 10 Gbps Laser Un-cooled Laser Cooled Laser Cost 70% 100% Application 100 km (max) 5000 km 49 Since f  1 / , channel spacing can be denotes as both distance and frequency As CWDM works in all 5 bands, amplification is NOT possible
  50. 50. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Applicability of CWDM & DWDM 50 Source : http://www.transmode.com/en/technologies/wdm
  51. 51. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU SDH/SONET vs. WDM 51 All traffic signals are regenerated and switched, making them available for add and drop Only selected signals (wavelengths) are available for add and drop, the rest are “glassed through”. Source : http://www.transmode.com/en/technologies/wdm • Signals are regenerated at each node- the equivalent uninterrupted “wire” stretches only between 2 nodes • A new power budget is calculated for each hop between 2 adjacent node • Light paths in a WDM network are e2e connections, & should be considered as the equivalents of uninterrupted “wires”, stretching from one point in the network to another while passing one or several nodes • Optical transmission characteristics for a wavelength has to be calculated for the complete distance the light path traverse
  52. 52. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Modulation • DAC? – medium/channel is band pass (Ex:- light), and/or – multiple users need to share the medium • Analog signal – Typically sinusoidal • Amplitude->ASK • Frequency->FSK • Phase->PSK • Digital signal – 1 – 0 52 QAM Susceptible to noise
  53. 53. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Modulation, cont., 53 on/off keying Binary phase- shift keying
  54. 54. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Modulation, cont., 54 21 22 23 24 Phase only Phase & Amplitude (2-PSK) (4-PSK) OOK (ASK) Amplitude only
  55. 55. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU QAM 55
  56. 56. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Comparison of optical modulators Types Direct Electro- Absorption External Mach- Zehnder External Coherent Max. dispersion tolerance (ps/nm) 1200-4000 7200-12800 >12800 40000 Cost moderate expensive Very expensive Very expensive Wavelength stability good better best best 56
  57. 57. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 57 Direct Detection (optical power measuring process) Coherent detection (process is sensitive to the amplitude, frequency and phase (Ex:- 16QAM, 64QAM for 100G and above)
  58. 58. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Tx and Rx Optical transmitter • Semiconductor – LED – Laser Optical receiver • Photodetector 58 Source : http://www.transmode.com/en/technologies/wdm Produces a coherent (light of one wavelength with all the light waves being in same phase) light Coherent light is a prerequisite for long reach over fiber
  59. 59. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU The Big Leap: 10G to 100G Coherent 59Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014 Hard Decision FEC: for every input and output signal a hard decision is made whether it corresponds to a one or a zero bit Soft Decision FEC: process analog signals, allowing much higher error- correction performance Dual Polarization
  60. 60. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Beyond 100G - Enhanced Encoding 60Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  61. 61. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Amplification and regeneration 61
  62. 62. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU • Compensates the loss • Any analog signal system has noise. Optical signal is also analog • More Amps-> more accumulated noise (N)->S/N->BIR – Amp keeps Signal (S) constant. • Solution: re-generation (electrical domain: OEO regeneration) • Amplification and regeneration gives unlimited distance, theoretically – Ex:- 1500 km if the link has FEC • Optical Signal to Noise Ration (OSNR) = Ratio of optical signal power to noise power for the receiver 62 Pout = GPinPin G
  63. 63. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Amplifier types • EDFA - Erbium Doped Fiber Amplifier – Widely used – Only applicable for wavelengths in the C-band used by DWDM • RFA - Raman Fiber Amplifier – Uses non-linearity effect – Uses high power class 4 laser • Use APC (Angular Physical Contact) connectors instead of PC – Ex:-LC/APC (Lucent Connector), SC/APC, FC/APC – 20 km distance • Need to maintain splice loss <0.1dB within 1st 10 km and <0.2dB within next 10 km – Low noise – Low gain efficiency (10~12 dB) 63
  64. 64. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Principles of 3R regeneration 64Source : http://www.transmode.com/en/technologies/wdm
  65. 65. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Optical Multiplexer and de- multiplexer • TFF - Thin Film Filter – when no. of channels<16 • AWG - Arrayed Waveguide Grating – when no. of channels>=16 – expensive 65
  66. 66. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU TFF Source: http://www.fiberoptics4sale.com/wordpress/what-is-multilayer-dielectric-thin-film-filter/ 0.1 dB loss. Therefore max. of 16 channels Has the lowest power 66
  67. 67. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU AWG Source: http://docstore.mik.ua/univercd/cc/td/doc/product/mels/cm1500/dwdm/dwdm_ovr.htm All have the same power 67
  68. 68. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Transponder & muxponder 68 Source : http://www.transmode.com/en/technologies/wdm
  69. 69. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Supervisory technologies • OSC - Optical Supervisory Channel – Often used in backbone systems – Uses OTN (G.709) framing (similar to SDH) – Costly • ESC - Electrical Supervisory Channel – Often used in metropolitan systems – OTU is mandatory at every site • OLA sites don’t have OTU. Therefore can’t mange OLAs with ESC 69
  70. 70. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 70 ADM OADM ROADM function in the traditional SONET/ SDH networks • is a device used in photonic domain under WDM systems for multiplexing and routing different channels of light into or out of a single mode fiber • best solution for a small & static optical network • OADM with remotely reconfigurable optical switches in the middle stage • Enables more automation, reducing the risk for manual errors • best solution for a larger optical network
  71. 71. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU OADM OADMs allow flexible add/drop of channels Drop Channel Add Channel Drop & Insert 71
  72. 72. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Key attributes of ROADM Module • Fully Flexible, Remotely Reconfigurable Optical Add Drop • Automatic power equalization on inputs, outputs, adds, drops • Optical Power Monitoring (OPM) of all channels Key benefits of ROADM Module • Elimination of the OEO “Pass-through” tax • Scalable Bandwidth (Start with 1, grow by 1 ) • Single Wavelength Granularity – No stranded bandwidth • Fully Automated Optical Layer 72Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  73. 73. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Static Networks Based on Fixed- Wavelength Filters • Topology and capacity/node determined at time of network design – Traffic projections based upon best estimates at the time – Not always cost effective to “overbuild” the system • Can lead to premature system exhaust – Expected system lifetime: 5-10 yrs – Traffic projections not accurate leading to premature system exhaust • Insufficient ’s available to hot spots • Unlit ’s to cold spots cannot be utilized – Topology is inconsistent for emerging applications • Telephony, SAN, Enterprise, VoD 73 Physical WDM Ring Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  74. 74. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU ROADMs Enable Any-Node-to- Any-Node Topologies • Provision wavelengths independently between nodes • No blocking extends system life to capacity limitation – Relieves need for accurate traffic growth forecasting 74 Physical WDM Ring Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  75. 75. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU ROADM Generations • 1st generation: Wavelengths Blocker based ROADMs – 2 degree nodes only – 100 GHz channel spacing – Add/Drop only – Neither colorless nor directionless • 2nd generation – 2 degree nodes and very limited multi degree functionality – 100 GHz channel spacing – Add/Drop only – Neither colorless nor directionless node support • 3rd generation: WSS 1:N based ROADMs – Multi degree node support – 50 GHz and 100 GHz channel spacing – Colorless and directionless node support • 3rd + generation – Multi degree node support – Flexible channel spacing – Future proof on • Colorless and directionless node support • Contentionless node support 75Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  76. 76. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 2 degree ROADM 76 No. of inputs Source : http://www.transmode.com/en/technologies/wdm 1 MUX per direction 1 MUX per direction Specific  MUX port
  77. 77. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Good features to have on a WSS system 77 • Colorless • Directionless • Contentionless
  78. 78. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Colorless 2 degree ROADM 78 Source : http://www.transmode.com/en/technologies/wdm Any  connected to any MUX port 1 MUX per direction 1 MUX per direction
  79. 79. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Directionless 2 degree ROADM 79 can be made colorless by combining with traffic units having tunable transceivers Source : http://www.transmode.com/en/technologies/wdm Share MUX between directions
  80. 80. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Directionless and contentionless 2 degree ROADM 80 can be made colorless by combining with traffic units having tunable transceivers Source : http://www.transmode.com/en/technologies/wdm 1 MUX per direction Multiples of same  can be add/drop to same MUX
  81. 81. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 4 degree ROADM 81Source : http://www.transmode.com/en/technologies/wdm
  82. 82. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 8 degree ROADM 82Source : http://www.transmode.com/en/technologies/wdm
  83. 83. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Control plane 83
  84. 84. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Automatically Switched Optical Network (ASON) • Non-IP network layer control • Alternative/supplement for/to NMS based connection management • Does not change transport plane functionality • Signaling between transport equipment for network discovery • Each network element knows the network topology • Requirements and architecture => ITU-T (G.8080/Y.1304) • Protocols => IETF (GMPLS) • ASON types – Electrical (ODU/OTN switching, a.k.a Layer-1 ASON) • Granular • Fast – Optical (Wavelength SON (WSON), a.k.a Layer-0 ASON) •  switching 84
  85. 85. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 85 Source: http://en.wikipedia.org/wiki/Automatically_switched_optical_network Common control plane simplify network OAM & automatic e2e provisioning
  86. 86. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU WSON 86 WDM fiber link OXC (GMPLS) Source: Wikipedia
  87. 87. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Generalized Multi-Protocol Label Switching (GMPLS) • The optical layer is connection oriented (circuit switched), Light paths are easy to be established • Light paths can be seen as LSPs between ingress and egress OXCs. • Multiprotocol Lambda Switching (MPλS) was defined as a control plane for optical networks • MPLS and MPλS were then unified and called GMPLS (RFC 3945) • Extends MPLS to provide the control plane (signaling and routing) for devises that switch in any of these domains: packet, time, wavelength and fiber • GMPLS starting point is based on the IP view of the transport plane: one physical layer – Fibers are the reference points – Equipment are black boxes identified by switching capabilities – Topology and link state information distributed to all equipment independent of network layer the equipment operates on (“peering”) • GMPLS is a tool box which can be used to support ASON’s view of the transport plane 87
  88. 88. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 88 WDM OTN Optical Communication Basics Future (Packet Optical Integration) Content
  89. 89. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU What is “OTN”? • As per ITU-T, it’s G.709 standard – a.k.a Digital Wrapper (DW) – a.k.a Optical Transport Hierarchy (OTH) standard • OTN could mean; – OTN wrapper capability – OTN switching capability • In the industry/telco field? – OTN – POT (Packet Optical Transport) • packet (MPLS-TP?)+ TDM (SDH/PDH) + WDM + ROADM – Optical Packet Transport layer 89
  90. 90. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU OTN aim • Combine the – Benefits of SONET/SDH (OAM&P) • Monitoring a connection e2e over multiple transport segments – Bandwidth expandability of DWDM • Designed to transport both – Packet mode traffic : IP and Ethernet – Legacy SDH/SONET traffic • Includes FEC 90
  91. 91. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Main functionality provided by an OTN • Transparent transport of different optical clients • Interconnection of different administrative domains • Optical channel networking and protection • Performance monitoring and alarm supervision • Network management 91
  92. 92. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU STM-1 frame is the basic transmission format for SDH 92Source : http://www.transmode.com/en/technologies/wdm
  93. 93. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU SONET & SDH multiplexing hierarchies 93 Source : http://www.transmode.com/en/technologies/wdm All the clocks in the SDH/SONET network are perfectly synchronized to a single master clock. This allows lower speed signals to be added/dropped from the SDH/SONET stream without de-multiplexing the entire stream into its individual components
  94. 94. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU OTN signal structure and terminology (Ex:-) 94 Carrier Ethernet frame is carried as the payload of an Optical Channel Payload Unit (OPU) Source : http://www.transmode.com/en/technologies/wdm
  95. 95. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU ITU-T G.709 ODUs 95 Source : http://www.transmode.com/en/technologies/wdm
  96. 96. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU OTN vs. SDH/SONET line rates 96 Source : http://www.transmode.com/en/technologies/wdm
  97. 97. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Pre-OTN WDM Vs. OTN Pre-OTN WDM • simple transport • Bandwidth multiplication by means of WDM transport • Point-to-point application that can transport STM-N/OC- N as a service OTN • networking – solution • Management enabler of WDM network • First transmission technology in which each stakeholder gets its own (ODUk) connection monitoring 97
  98. 98. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU OTN switching 98 • Prime advantage: sub-lambda grooming at intermediate sites. • Industry trend(both suppliers and operators): Start WITHOUT OTN switching and go for OTN switching in the future if all the lambdas run out/close to run out (aka Wave-length blocking). • This requires that you select a vendor who's capable of OTN switching but you need NOT purchase OTN switching components (cards) on day one. • You do NOT need OTN switching to achieve mesh protection. What is then required is ASON/GMPLS.
  99. 99. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU OTN networking efficiency: virtual wavelengths • Flexible granularity options to maximize services and revenue per wavelength 99 Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  100. 100. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU All-Optical (without digital switching) • “Services over wavelengths” - static • Inefficient • Optical-only switching • No digital switching & reconfiguration • Patch panel & truck-roll re-grooming 100 Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  101. 101. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU WDM + Stand-alone OXC’s: 2 Platform Solution • OXC provides network efficiency • 2 platform solution: space & power • Back-back client connections • Segmented provisioning/protection • No end-end management/automation 101 Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  102. 102. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Converged DWDM & OTN Switching :Collapsing Layers, Simplifying Networks • Converged OTN/WDM switching • Eliminate I/C cost, extra space/power • Eliminates many points of failure • Automated, end-end provisioning • End-to-end service protection 102 Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  103. 103. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Available options 103 1. FOADM 2. ROADM 3. Tunable ROADM (TROADM) 4. FOADM with ASON/GMPLS control plane 5. ROADM with ASON/GMPLS control plane 6. TROADM with ASON/GMPLS control plane 7. FOADM with ASON/GMPLS control plane and OTN switching 8. ROADM with ASON/GMPLS control plane and OTN switching 9. TROADM with ASON/GMPLS control plane and OTN switching Note: All options need to support OTN wrapper Costincreases
  104. 104. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 3 CAPEX components 104 Cost of adding OTN switching capability vs. loosing sub-lambda grooming at intermediate sites need to be properly analyzed based on your current and future traffic matrix. CAPEX I When you want to do sub-lambda grooming at intermediate sites, you'll have to have OTN switching CAPEX II When you have OTN switching, the earlier Point-to- Point lambda passed through several intermediate nodes at the optical domain (OOO) now need to go to electrical domain to do grooming (OEO) making it multi-segment. This requires several OTN ports . However, you use only one lambda. Some call the latter as Layer 1-ASON and former as Layer 0-ASON. CAPEX III If you do not do sub- lambda grooming at the intermediate site, you will have to have a separate lambda at the intermediate site, though the traffic goes to the same destination.
  105. 105. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Optical Backbone Networks - evolution scenarios short term medium term long term Introduction of reconfigurable WDM networks (ROADM) GFP, enhanced SDH/SONET technologies and OTN addition of a control plane, either ASON or GMPLS based. 105
  106. 106. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Architecture Comparisons 106 Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  107. 107. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 107 WDM OTN Optical Communication Basics Future (Packet Optical Integration) Content
  108. 108. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Packet and optical 108 Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  109. 109. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU 109Source: 2nd Annual WDM & Next Generation Optical Networking APAC 2014
  110. 110. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Alternative implementations of IP over WDM 110 Packet over SONET with HDLC framing Packet over SONET with GFP framing Ethernet framing Source : http://www.transmode.com/en/technologies/wdm
  111. 111. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Future of transport & switching 111 Source: http://www.transmode.com/en/technologies/wdm and Infonetics Research
  112. 112. Anuradha Udunuwara | udunuwara@ieee.org | www.linkedin.com/in/anuradhau | @AnuradhU Conclusion 112 WDM OTN Optical Communication Basics Future (Packet Optical Integration)

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