optical switches alfred poon amy ng derric lam ritter chak members : csit 560 project presentation
TRANSCRIPT
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
Optical Switch Background | Optical Switching Fabric & Requirement | Product Example | Market Trend | Conclusion
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
Optical Switch Background | Optical Switching Fabric & Requirement | Product Example | Market Trend | Conclusion
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 Switch Background | Optical Switching Fabric & Requirement | Product Example | Market Trend | Conclusion
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
Optical Switch Background | Optical Switching Fabric & Requirement | Product Example | Market Trend | Conclusion
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
ReferencesReferences
http://www.lightreading.com/document.asp?http://www.lightreading.com/document.asp?doc_id=9016&site=lightreadingdoc_id=9016&site=lightreading
http://www.lightreading.com/document.asp?http://www.lightreading.com/document.asp?doc_id=9017&site=lightreadingdoc_id=9017&site=lightreading
http://www.lightreading.com/document.asp?http://www.lightreading.com/document.asp?doc_id=11753&site=lightreadingdoc_id=11753&site=lightreading