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

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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”

13 14 15 16 17 18 19 20 21 1-12

Source321

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0

1

2

3

4

5

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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

1

2

3

4

5

6

7

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