Optical Switches Alfred Poon Amy Ng Derric Lam Ritter Chak Members : CSIT 560 Project Presentation

Optical SwitchesOptical Switches

Alfred PoonAmy NgDerric LamRitter Chak

Members :

CSIT 560 Project Presentation

AgendaAgenda

Optical Switch BackgroundOptical Switch BackgroundOptical Switching Fabric & Optical Switching Fabric &

RequirementRequirementProduct ExampleProduct ExampleMarket TrendMarket TrendConclusionConclusion

Optical Switch Optical Switch BackgroundBackground

Optical Switch Background | Optical Switching Fabric & Requirement | Product Example | Market Trend | Conclusion

From Digital to AnalogFrom Digital to Analog

TDM system multiplexes the input streams, and generates fast speed TDM system multiplexes the input streams, and generates fast speed streamsstreams ~ around 10Gbs (still the fastest?) ~ around 10Gbs (still the fastest?)

WDM system converts each high speed TDM stream into the laser WDM system converts each high speed TDM stream into the laser beam beam with different wavelengths with different wavelengths

WDM system multiplexes the laser beams to utilize the capacity of WDM system multiplexes the laser beams to utilize the capacity of a single fiber ~ around 1.6 Tbps at 160 wavelength a single fiber ~ around 1.6 Tbps at 160 wavelength

Generic Optical NetworkGeneric Optical Network

Optical network usually consists of various kinds of optical Optical network usually consists of various kinds of optical switch:switch:

Optical Protection SwitchOptical Protection Switch OADM (Optical Add-Drop Multiplexer)OADM (Optical Add-Drop Multiplexer) OXC (Optical Cross Connect)OXC (Optical Cross Connect)

• Wavelength SwitchWavelength Switch• Optical Burst SwitchOptical Burst Switch• Optical Packet SwitchOptical Packet Switch

Basic of Optical SwitchBasic of Optical Switch

Switching Switching wavelength (laser wavelength (laser beam) from input beam) from input port to output portport to output port

Using the value of Using the value of wavelength to wavelength to make the switching make the switching decisiondecision

Detector 1

Detector 2

Detector 3

Detector 4

Demux

Classification of Optical Classification of Optical SwitchSwitch

Network Traffic TypeNetwork Traffic Type Optical Circuit SwitchOptical Circuit Switch

• by wavelength, by waveband and by fiberby wavelength, by waveband and by fiber Optical Packet SwitchOptical Packet Switch

• by optical data packetby optical data packet

Nature of Switching Fabric TechniqueNature of Switching Fabric Technique Optical-Electrical-Optical (OEO) SwitchOptical-Electrical-Optical (OEO) Switch All-optical (OOO) SwitchAll-optical (OOO) Switch OEOEO Switch (very Complex)OEOEO Switch (very Complex)

FunctionalitiesFunctionalities Brand-width Management SwitchBrand-width Management Switch

• capable of bandwidth grooming and local add-drop muxcapable of bandwidth grooming and local add-drop mux Optical Transport SwitchOptical Transport Switch

• rerouting optical circuits or wavelength from one path to rerouting optical circuits or wavelength from one path to anotheranotheron the transport network on the transport network

Optical ChallengeOptical Challenge

Difficult to read and processing bits at extremely Difficult to read and processing bits at extremely high speedshigh speeds especially on Optical Packet Switch and OEO circuit especially on Optical Packet Switch and OEO circuit

switchswitch

Difficult to buffer optical packetsDifficult to buffer optical packets Delay Line TechniqueDelay Line Technique

• Length Crucial TechniqueLength Crucial Technique• if line is too long, switching fabric needs to wait for the if line is too long, switching fabric needs to wait for the

packets to come out (Sequential Access)packets to come out (Sequential Access) Hierarchical Trees DesignHierarchical Trees Design

• to direct packet through a given incremental set of delaysto direct packet through a given incremental set of delays(reduce the Sequential Access Effect)(reduce the Sequential Access Effect)

• complex and expensivecomplex and expensive

Optical Circuit SwitchingOptical Circuit Switching

To set up a Wavelength path, a signal enters and To set up a Wavelength path, a signal enters and exits the optical layers at the same wavelengthexits the optical layers at the same wavelength limitation on available wavelengthlimitation on available wavelength

Virtual Wavelength path overcomes the limitation Virtual Wavelength path overcomes the limitation by allowing a signal to travel on different by allowing a signal to travel on different wavelength throughout the wavelength pathwavelength throughout the wavelength path

Optical Packet SwitchingOptical Packet Switching

RoutingTags

Header180ns

14 bytes

Guard time> 26 ns

Payload1.35 s

105 1680 bytes

Synchronizationpattern

Payloadsynchronizationpatterns

Time slot T : 1.646 s = 128 bytes (@ 622 Mb/s)

KEOPS Packet Format

Optical Switching Optical Switching Fabric & RequirementFabric & Requirement


OEO vs OOOOEO vs OOO

ProsPros ConsCons

OEOOEO

- Known and mature technology- 3R regeneration for free- capable of bandwidth grooming bit error rate monitoring and statistical multiplexing

- Optical Scalability limit- Not bit-rate transparency- Not protocol transparency- Expensive

OOOOOO

- Optical Scalability- Bit-rate transparency- service/protocol transparency

- Emerging Technology- not capable of bandwidth grooming, bit error rate monitoring and statistical multiplexing

Optical Switch Optical Switch RequirementsRequirements

MEMS Frustrated Refractions

Gratings and Circulators

Holographic Switches

Waveguide Switches

Space Switches

Port Count HighHigh LowLow LowLow LowLow LowLow LowLowSwitching Speed SlowSlow FastFast FastFast FastFast SlowSlow FastFastSignal Loss (dB) LowLow ?? ?? HighHigh ?? ??Cross Talk NoNo NoNo NoNo YesYes YesYes ??ReconfigurationSpeed

SlowSlow FastFast SlowSlow FastFast FastFast FastFast

Wavelength Independence YesYes YesYes NoNo YesYes NoNo YesYesBit-rateIndependence

YesYes YesYes YesYes YesYes YesYes YesYes

Additional Requirements: Power Consumption and Cost per Port

OXC

PacketSwitch

BurstSwitch

OADM

ProtectionSwitch

Requirements of Optical Requirements of Optical SwitchSwitch

10,000

1,000

100

10

1

PortCount

10ns 1s 1ms 1s

Reconfiguration Speed

FastElectro-optic

Tuneable

Laser

Liquid CrystalGrating

3D FastMEMS

3D SlowMEMS

2D SlowMEMS

BulkMechanical

RealityRealityProtection (1x2)Protection (1x2) OADMOADM OXCOXC OPSOPS

Bulk mechanicalBulk mechanical

2D slow MEMS2D slow MEMS

3D slow MEMS3D slow MEMS

Beam steering – moving fiberBeam steering – moving fiber

Beam steering – moving imageBeam steering – moving image

2.5D slow MEMS2.5D slow MEMS

1D fast MEMS1D fast MEMS

3D fast MEMS3D fast MEMS

Electro-optic (bulk)Electro-optic (bulk)

Electro-optic (waveguide)Electro-optic (waveguide)

Thermo-optic (waveguide)Thermo-optic (waveguide)

GratingsGratings

BubbleBubble

FTIRFTIR

Broadcast & selectBroadcast & select

Wavelength routingWavelength routing

Shutter gatingShutter gating

Amplifier gatingAmplifier gating

Acousto-opticAcousto-optic

Polarization switchingPolarization switching

Application vs Technologies

Product ExampleProduct Example


33D MEMS-Based Optical Switch HandlesD MEMS-Based Optical Switch Handles80-by-80 Fibers (Glimmerglass)80-by-80 Fibers (Glimmerglass)

80 X 80 port with 3D MEMS mirror arrays80 X 80 port with 3D MEMS mirror arrays

switch signals within 10 ms with an insertion loss of switch signals within 10 ms with an insertion loss of 2 dB2 dB

the cost per port is five to 10 times less than other the cost per port is five to 10 times less than other all-optical switching techniquesall-optical switching techniques

compatible with any network topology, every compatible with any network topology, every protocol and any data rateprotocol and any data rate

contains optical-channel power monitors, a fiber contains optical-channel power monitors, a fiber patch panel and an Ethernet control interface and patch panel and an Ethernet control interface and packed into a 4.5 by 9.5 by 7.0-inches rack-packed into a 4.5 by 9.5 by 7.0-inches rack-mountable case that consumesmountable case that consumes just 20Wjust 20W

$200 to $700 us per port$200 to $700 us per port

33D MEMS-Based Optical Switch Handles 80-D MEMS-Based Optical Switch Handles 80-by-80 Fibers (Glimmerglass)by-80 Fibers (Glimmerglass)

Market TrendMarket Trend


Optical Network GrowingOptical Network Growing

1999 2000 2001 2002 2003 20040

2000

4000

6000

8000

10000

12000

Market Projections of DWDM

Source: MSDW and RHK

Optical NetworkingOptical NetworkingMarket ForecastMarket Forecast

02468

1012141618202224

1999 2000 2001 2002 2003 2004

Ship

ments (U

SD

– B

illions)

Source: MSDW and RHK

Growth Rate

Worldwide market for Worldwide market for optional switching systemsoptional switching systems

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

2001 2004

OOO oxc

OEO oxc

USD

(B

illion

)

Source: ARC Group

Optical Switches Cost Optical Switches Cost OOO vs OEOOOO vs OEO

2002 2004 2006 2008 2010

OOO

OEO

Cost p

er

Port

Source: ARC Group

ConclusionConclusion


ConclusionsConclusions

In the near future :In the near future : All optical networks may not be possible All optical networks may not be possible

due to constraint of OOO technologiesdue to constraint of OOO technologies OOO still cannot replace OEOOOO still cannot replace OEO

Established Photonic Companies.

. Some Recent Acquisitions

CompaniesCompanies

Some New Players.

ReferencesReferences

http://www.lightreading.com/document.asp?http://www.lightreading.com/document.asp?doc_id=9016&site=lightreadingdoc_id=9016&site=lightreading



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Optical Switches Alfred Poon Amy Ng Derric Lam Ritter Chak Members : CSIT 560 Project Presentation