Bandwidth-Flexible CDC ROADMs Massimo Di Blasio, Director, Carrier Business DevelopmentBandwidth-Flexible CDC ROADMs Massimo Di Blasio, Director, Carrier Business Development

Market FocusECOC 2011

Topics Being Presented

Where are ROADMs today and how did we get here?

Flexgrid™ WSS: What are they and how do they work?

Next generation ROADMs: More than just a WSS

2© 2011 Finisar Corporation

Optical Transport Network Evolution - Connectivity

3© 2011 Finisar Corporation

1. Transition from SONET/SDH to IP Networks

2. Continual increase in transmission speeds

3. Fiber moving closer to customer (e.g. FTTH, Mobile Backhaul)

4. Connectivity evolving from Point-to-Point to Mesh

Interconnected Rings

Point-to-Point MeshInterconnected Rings

Network Evolution - Spectral Efficiency

System capacity now constrained by spectral efficiency (non-linear Shannon limit)

4© 2011 Finisar Corporation

Source: Essiambre et al, JLT, 2010

Future Network Requirements

Heterogeneous network traffic

Alphabet soup of modulation formatsOOK/DPSK/DQPSK/DP-QPSK/DP-OOFDM/DP-mPSK

Network potentially needs to support up to two orders of

magnitude variation in bit-rate 10/40/100/400/1000 Gb/sec

Non-intrusive parallel multiport optical channel monitoringMore than 4 ports

Match transport channel capacity to router port capacity (40/100GbE)Future ROADMs need to maximize network flexibility while being virtually invisible

5© 2011 Finisar Corporation

But what really matters is…

5 Year Growth (Sources: Cisco, Verizon)

Carrier Revenue Growth (6.6% per annum) Data Usage Growth (38% per annum)

Drives operational efficiencies (OPEX reduction) in carriers and rapid adoption of more cost-effective technologies, such as:

IP Everywhere – match pipe sizes4G/LTE for mobileROADMs & coherent transmission for optical transport

6© 2011 Finisar Corporation

Input

Current Degree 8 ROADM Colored Add/Drop

1

2

8

All Drop Wavelengths

available, separation by

AWGs

Add Wavelengths

aggregated by passive

combiners

… … …

9x1 WSS

9x1 WSS

9x1 WSS

Monitor Ingress and

Egress signals with Optical

Channel Monitors (OCM)

…AWG

…AWG

…AWG

Output

7© 2011 Finisar Corporation

Broadcast & Select

Evolution of the Optical Add/Drop Node

Fixed Optical Add/Drop (Thin Film/Grating/AWG)

Wavelength Blocker

WSS (up to 8-D)

Flexgrid

Tech

nolo

gica

l Com

plex

ity

CDCF*

* CDCF = Colourless, Directionless, Contentionless, Flexgrid

PLC-based 2D ROADM

8© 2011 Finisar Corporation, Confidential

WSS (up to 20D)

WSS Switching: Matrix versus Channelised

First Generation WSS allocated a single channel to a single pixel (e.g. MEMS, LC, etc)

Second Generation WSS use matrix-based switching

Phase (LCoS) – 8 bitAngle (DLP) – 2 bit

9© 2011 Finisar Corporation

LC/MEMSLC/MEMS

LCoSLCoS

Flexgrid™ and LCoS: Ultimate Flexibility

Ability to set ROADM channel bandwidth and centre frequency to optimize system performance

Match channel bandwidth to signal bandwidthPack them as closely together as possible

LCoS provides the ultimate flexibility and allows left and right edges of channels, as well as centre frequency, to be trimmed independently

Arbitrary Bandwidth, Centre Frequency12.5 GHz as trade-off between OS complexity, flexibility, performanceSupport dual channel plan or full flexgrid

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

-25 -20 -15 -10 -5 0 5 10 15 20 25

Rel Freq (GHz)

Rel

IL (d

B)

-3.0

-2.5

-2.0

-22 -21 -20 -19 -18 -17

Rel Freq (GHz)

Rel

IL (d

B)

10© 2011 Finisar Corporation

Flexgrid™ Implementation for ITU G.694.1

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12.5 GHz as trade-off between Network OSS complexity, flexibility, performanceAllows for full compliance with ITU G.694.1 down to 25 GHz channel spacing

DWP9f WSS 12.5 GHz Flexgrid Performance

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50 62.5 75 87.5 100 50

Announced Flexible Bandwidth WSS

Company Technology Slice WidthCoAdna Liquid Crystal 25 GHz

Finisar LCoS 12.5 GHz

Nistica DLP MEMS Array 25 GHz

Oclaro Liquid Crystal 25 GHz

Santec* LCoS

JDSU LCoS

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* Santec product is a 4x4 OXC, rather than a true 1xN WSS

Flexgrid™ 8D ROADM; Passive Drop, Active Add

1

2

8

… … …

16x1Flex WSS

16x1Flex WSS

16x1Flex WSS

1x23 Flex Demux…

1x23 Flex Demux…

1x23 Flex Demux…

OCM must be Flexgrid compatible14© 2011 Finisar Corporation

What is CDCF?

CDCF = Colorless, Directionless, Contentionless, FlexgridCurrent ROADMs provide ability to provision core network paths remotely, but still require manual patching of transceivers to set Add/Drop directionalityNext generation of ROADMs will be designed to (finally) to do away with the need for thisMay require changes to how WSS are used to achieve performance required

15© 2011 Finisar Corporation

Programmable Demux/SwitchProgrammable Demux/SwitchProgrammable Demux/SwitchProgrammable Demux/SwitchProgrammable Demux/SwitchProgrammable Demux/SwitchProgrammable Demux/Switch

Programmable Mux/Demux

Drop

CDCF ROADM: Back-to-Back WSS

1

2

8

16x1 WSS

1 - 8

9 - 16

1 - 8

9 - 16

1 - 8

9 - 16

16x1 FlexWSS

1 - 8

9 - 16

16x1 FlexWSS

1 - 8

9 - 16

16x1 FlexWSS

1 - 8

9 - 16

16x1 FlexWSS

16x1 FlexWSS

16x1 FlexWSS

Input Output

Programmable Demux/SwitchProgrammable

Demux/SwitchProgrammable Demux/SwitchProgrammable

Demux/SwitchProgrammable Demux/SwitchProgrammable

Demux/SwitchProgrammable Demux/SwitchProgrammable

Mux/Demux

Add

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Back-to-Back High Port Count WSS

High port count Flexgrid™ WSS on both add and drop sides of core

Shared with Mux and Demux

AdvantagesEfficient flexible architecture that minimizes contentionReduces WSS crosstalk requirements Compatible with multiple approaches for Add/Drop routing and switchingPower budget efficient for reduced amplification requirements

DisadvantageDoubles the number of filter passes in the core network –however this is minimized with bandwidth enhancement

17© 2011 Finisar Corporation

8x16/20/24/32 Programmable Mux/Demux

Single Flexgrid™ Channel Add/DropAsymmetric: transponder side port {1,..,20, 24, 32} can be assigned to at most one (reconfigurable) direction {1,..,8}

From WSS

To Transponders18© 2011 Finisar Corporation

1 2 8

OKOK

NOT SUPPORTED

1 32

Programmable Mux/Demux

8xN MCS Options

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MCS with Single EDFA per direction

MCS with EDFAs & Tunable Filter Array

MCS with EDFA Array

Possible Architectures using multi-cast switch (MCS)Key Issue is the IL of the MCS and the TFA

Programmable Mux/Demux vs. MCS

Key drivers to technology selectionCost

• When comparing the MCS to the programmable Mux Demux, you need to evaluate the complete financial solution

MCS + EDFA Array versus Programmable Mux/DemuxMCS + EDFA + TFs versus Programmable Mux/Demux

TF = Tunable Filter

Port Count• > 16 ports, IL becomes an issue for MCS

CDC Add-Drop Port Expansion • More than 16 ports → 24, 32, 40, 48 ports…

Modulation Format • Coherent Vs. Non Coherent

Channel Flexibility

20© 2011 Finisar Corporation

Summary

Flexgrid™-capable ROADMs will be key subsystems for the next generation of optical networks

Matrix-based switching elements (LCoS, DLP) provide most flexible platform for Flexgrid WSS

To achieve benefits of Flexgrid requires a whole eco-system of Flexgrid-compatible components, as well as developments in Network OSS, not just WSS

21© 2011 Finisar Corporation

Bandwidth-Flexible CDC ROADMs Massimo Di Blasio, Director, Carrier Business DevelopmentBandwidth-Flexible CDC ROADMs Massimo Di Blasio, Director, Carrier Business Development

Market FocusECOC 2011