Reconfigurable Optical Networks using WSS based ROADMs

1. Reconfigurable Optical Networksusing WSS based ROADMs Steven D. RobinsonVP, Product Management srobinson@meriton.com • 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

2. Five Essential Elements of Next Generation Optical Networks OPM ADM ADM Mux Mux ROADM O P M Design Networksin Minutes West East Up to 16 degrees • 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

3. What is a ROADM? Reconfigurable Optical Add/Drop Multiplexer (ROADM) ROADMModule ROADMModule OPM DROPs ADDs 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  • Scaleable Bandwidth (Start with 1 , grow by 1 ) • Single Wavelength Granularity – No stranded bandwidth • Fully Automated Optical Layer

4. WDM Optical Transport Technology Options 2 Degree ROADMBlocker/IPLC with fixed filters WB Module Add Filters/Combiner Splitter /Drop filters O P M OEO Regen(Point-to-point DWDM) Fixed Port ROADM OPM Per  Optical Switch Multi-port Mux/Demux Multi-Degree WSSwith fixed filters OPM Fixeddrops OPM OPM FixedAdds Per Optical Switch Fully Flexible Multi-degreeROADM Multi-port Mux/Demux O P M FOADM Drops Multi-Degree WSS ROADMwith colorless ports

5. Which ROADM Technology is best?Full Flexible, WSS based ROADMs O P M MP-WSS WSS Flexible Drops Flexible Adds 1 3 4 5 + 7 Wavelength Selective Switch (WSS) ROADM: • Utilizes a single element to multiplex AND demux all express andall 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 portsfor widely tunable lasers & dynamic wavelength management • Can be modular (low first in costs) or fully installed on day one Key * Manages all wavelengthsFeatures: * 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 ROADM MODULE

6. Key Technologies used in Core Reconfigurable Networks True Point-and-click Planning & Provisioning RapidAutomated NetworkPlanning and End-to-End Management GMPLSControl Plane Widely TunableLasers Fully AutomatedOptical Layer Integrated Optical Cabling Integrated Platforms AGC / Transient Controlled Optical Amplifiers (OAs) Multi-Service ADM-on-a-blade Cross  Optical Switchw/ Integrated. Transport Hot- Pluggable SFPs & XFPs Flexible, Transparent Optical Interfaces Ethernet Networking Fully Flexible WSS ROADMs ROADM Systems provide much more than just Wavelength Reconfigurability They provide a total “Agile Optical Network” Solution

7. Why do customers like “All optical” All Optical ROADM : 42 Transponders 12 21 1 1 1 1 1 1 1 1 1 ILA 14 13 15 20 19 16 18 17 19 18 17 16 15 14 13 12 All OEO or “Digital Transport”: At least 380 Transponders 21 21 20 12 ILA Source 1 2 3 13 14 15 16 17 18 19 20 21 1-12 21 • 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

8. OEO or ROADMWhich is the better choice? ROADM 40 Gb/s ROADM OEO 10 Gb/s Bit Rate ROADM OEO 2.5 Gb/s 2 4 6 8 10 12 14 16 18 Number of Pass-Thru Channels 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)

9. Integrated OEO (Digital Transport)Multi-Service & Investment Protection Issues Network Bandwidth Efficiency 4 x 10G 10 x 10G 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 Integrated Tx Integrated Rx OEO Regen OEO Regen OEO Regen OEO Regen 10 x 10G 

10. Multi-degree ROADM or OEO?Why be forced to choose? Multi-DegreeROADM Switch 2.5G 2.5G 10G 10G 40G 100G Per WL OEO Switch Multi-Degree OEO Switching Digital ROADMNode 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

11. Digital ROADM Hybrid NodeLowest Overall Cost & Flexibility All OpticalROADM 2.5G 2.5G 10G 10G 40G 100G TR TR All Optical Spur • Maintain manageable regions of transparency Multi-DegreeAll Optical ROADM Per WL OEO Switch Multi-Degree Digital Switching DigitalROADMNode • Topology Agnostic • Traffic Pattern Agnostic • Bit Rate Agnostic • Simpler Optical Engineering • Simpler Multi-Degree Operation • Lower overall cost solution

12. Intelligent Optical & Electrical Switching Optical Drop Wavelength Cross-WLOptical Switchwith integratedWDM ElectricalADM ElectricalADM Transponderwith ElectricalADM Switch • Optically Add/Drop Entire Wavelength ADM ADM • Optically Add/Drop Multiple Wavelengths (Multi-degree) Add6 GbE Drop/Add1 GbE Mux Mux • Electrically Add/Drop on a per Service Basis • Add/Drop Multiple Services/Wavelengths for Cross Wavelength Grooming & Multi-degree Switching WSS ROADM(Optical Switch) • Switching Options: • Pass Thru Entire Wavelength

13. ROADM Networks Summary 2.5G 2.5G 10G 10G 40G 100G O P M MP-WSS WSS Flexible Drops Flexible Adds • 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