Reconfigurable Optical Networksusing WSS based ROADMs
Steven D. RobinsonVP, Product Management
Five Essential Elements of the NG Optical Network
. . . moving from static networks to dynamic networks What does a ROADM do? Which type is better? Key Technologies for 3rd Generation ROADM systems OEO vs. All Optical ROADMs Digital ROADM Hybrid Solution Intelligent Electrical & Optical Switching
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Reconfigurability Simple, Flexible, Self Maintaining Systems
Pay as You Grow Scalability Start with 1 , grow by 1
Seamless upgrade to 100G (efficiently)
Aggregation & Sub- Switching Integrated “ADM-on-a-blade”, High BW
efficiency
Multi-Degree Operation Both Optical & Electrical Multi-degree Options
Automated Network Planning One time Node Engineering, GMPLS Control
and Management Systems Plane & True “Point-and-Click” Provisioning
Five Essential Elements of Next Generation Optical Networks
ROADM
OPM
OPM
Mux Mux
ADM ADM
West East
Design Networksin Minutes
Up to 16 degrees
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What is a ROADM?What is a ROADM?
DROPsADDs
ROADMModule
OPM
ROADMModule
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
Reconfigurable Optical Add/Drop Multiplexer (ROADM)
Key benefits of ROADM Module
Elimination of the OEO “Pass-through” tax Scaleable Bandwidth (Start with 1 , grow by 1 )
Single Wavelength Granularity – No stranded bandwidth
Fully Automated Optical Layer
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WDM Optical Transport Technology Options
Fixed Port ROADM
FOADM
Multi-Degree WSS ROADMwith colorless ports
Fully Flexible Multi-degree
ROADM
Per Optical Switch
Multi-port Mux/Demux
OPM
Drops
OPM
Multi-Degree WSS with fixed filters
Fixeddrops
OPM
Per Optica
l Switch
Multi-port Mux/Demux
OPM
FixedAdds
2 Degree ROADMBlocker/IPLC
with fixed filtersOPM
Splitter /Drop filters
Add Filters/Combiner
OPM
WB Module
OEO Regen(Point-to-point DWDM)
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Which ROADM Technology is best?Full Flexible, WSS based ROADMs
Wavelength Selective Switch (WSS) ROADM: Utilizes a single element to multiplex AND demux all express and all add/drop wavelengths
Contains a built-in Optical Switch which can direct/select one or more wavelengths to/from any port
Provides Automated, per channel equalization on all wavelengths
Typically includes full Optical Power Monitoring on all wavelengths
Can be configured for truly colorless ports for widely tunable lasers & dynamic wavelength management
Can be modular (low first in costs) or fully installed on day one
Key * Manages all wavelengths
Features: * Lower system cost
* No OEO Pass-thru tax
* Fully Flexible Ports enable:
Any wavelength to any port
Supports Tunable lasers
Dynamic Management
Jumper-less provisioning
* Multiple wavelengths/ drop port
Mesh node capability
Ring interconnection
Key * Manages all wavelengths
Features: * Lower system cost
* No OEO Pass-thru tax
* Fully Flexible Ports enable:
Any wavelength to any port
Supports Tunable lasers
Dynamic Management
Jumper-less provisioning
* Multiple wavelengths/ drop port
Mesh node capability
Ring interconnection
MP-WSS
Flexible Drops
Flexible Adds
WSS
OPM
ROADM MODULE
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Key Technologies used in Core Reconfigurable Networks
Fully Flexible WSS ROADMs
ROADM Systems provide much more than just Wavelength Reconfigurability They provide a total “Agile Optical Network” Solution
Integrated Platforms
RapidAutomated Network
Planning
Cross Optical Switchw/ Integrated. Transport
GMPLSControl Plane
and End-to-End Management
Widely TunableLasersFully Automated
Optical Layer
Hot- Pluggable SFPs & XFPs
Multi-Service ADM-on-a-
blade
Ethernet Networking
True Point-and-click Planning & Provisioning
AGC / Transient Controlled Optical Amplifiers (OAs)
Integrated Optical Cabling
Flexible, Transparent Optical Interfaces
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Why do customers like “All optical”
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Relative Cost, $
All Optical All OEO
OEO becomes more expensive as the node count goes up (# Regens x # nodes)
OEO becomes more expensive as the number of wavelengths increases (# WL x # Regens x #nodes)
Use of Analog Optical Amplifiers lowers cost – unless you need to drop traffic
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All OEO or “Digital Transport”: At least 380 Transponders
ILA
All Optical ROADM : 42 Transponders
21 121 1 1 1 1 1 1 1 1
ILA
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OEO or ROADMWhich is the better choice?
Decision depends on: Bit Rate; Number of Wavelengths Topology & Traffic Patterns Switching Need (which determines # of pass-thrus vs # of drops)
Size (# nodes and span length) Amplify? Regen? Total Cost of Ownership (OPEX vs. CAPEX)
ROADMROADM
2 4 6 8 10 12 14 16 182 4 6 8 10 12 14 16 18
40 Gb/s40 Gb/s
Number of Pass-Thru ChannelsNumber of Pass-Thru Channels
Bit
Rat
eB
it R
ate
10 Gb/s10 Gb/s
2.5 Gb/s2.5 Gb/s
OEO
OEO ROADMROADM
ROADMROADM
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Integrated OEO (Digital Transport)Multi-Service & Investment Protection Issues
Net
wo
rk B
and
wid
th E
ffic
ien
cy
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
ATM ESCON FC1 GbE FC2 OC-48 10G 40G 100G
4 x 10G
10 x 10G
10 x 10G
Integrated Tx
OEO Regen OEO Regen OEO Regen OEO Regen
Integrated Rx
Integrated 10G OEO: Optimized for 10G client transmission Other services require muxing or inverse muxing (no transparent transmission) Support for native 40G or 100G will require ripping out OEO fabric
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2.5G
2.5G Per WL OEO Switch
10G
10G
40G
100G
Multi-Degree OEO Switching
Multi-degree ROADM or OEO?Why be forced to choose?
All Optical ROADM Advantages: Fully Bit Rate Transparent
1G 10G 100G Per wavelength Scaleable
1 2 . . . 40 Lower Power Fully Automated Optical Layer Low Pass-thru costs
OEO Advantages: Sub-Wavelength Switching Potentially Lower Terminal Costs
(at full capacity) Simpler Optical Engineering Simpler Multi-Degree Operation
Multi-DegreeROADM Switch
Digital ROADMNode
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Digital ROADM Hybrid NodeLowest Overall Cost & Flexibility
DigitalROADM
Node
0
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2
3
4
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Relative Cost, $
All Optical DigitalROADMHybrid
All OEO
Topology Agnostic Traffic Pattern Agnostic Bit Rate Agnostic Simpler Optical Engineering Simpler Multi-Degree Operation Lower overall cost solution
Per WL OEO
Switch
Multi-DegreeAll Optical ROADM
Multi-Degree Digital
Switching
2.5G2.5G10G10G
40G100G
All Optical Spur
All OpticalROADM
Maintain manageable regions of transparency
TRTR
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Intelligent Optical & Electrical Switching
WSS ROADM(Optical Switch)
Add6 GbE
Drop/Add1 GbE
ElectricalADM
ElectricalADM
Switching Options:
• Pass Thru Entire Wavelength
• Electrically Add/Drop on a per Service Basis
Optical Drop Wavelength
• Optically Add/Drop Entire Wavelength
Transponderwith ElectricalADM Switch
Mux Mux
ADM ADM
• Optically Add/Drop Multiple Wavelengths (Multi-degree)
• Add/Drop Multiple Services/Wavelengths for Cross Wavelength Grooming & Multi-degree Switching
Cross-WLOptical Switchwith integrated
WDM
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ROADM Networks Summary
Customers have recognized that low OPEX is now just as important as the lowest CAPEX
ROADM Modules are just one part of realizing the Next Generation Agile Optical Network
Other technologies such as automated planning tools, widely tunable lasers, optical backplanes, Pluggables, and GMPLScan dramatically simplify planning, operation & management
Selection of the right kind of ROADM is crucial to realizing these savings (Colorless Port, modular, WSS based ROADMs are the best choice)
These systems must be designed from the ground up to realize their full potential (Bolt-on ROADMs don’t work)
Digital ROADM Hybrid Solution may offer the best flexibility and lowest overall cost
MP-WSS OPM
Flexible Drops Flexible
Adds
WSS
2.5G2.5G10G10G
40G100G