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NetLight Introduction to FSO Tecnology © Copyright Netronics Inc. 2008
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Why Free Space Optics (FSO)? 2
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FSO Communication is using the LASER light as the carrier. Full Duplex, Full Speed AND No Delay. Up to 1 Gbps Ethernet Distances – up to 5km. No License is required. Easy to install and almost no maintenance is required. I - What is FSO 3 Why Free Space Optics (FSO)?
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4 Only about 10% of commercial buildings are lit with fiber Wide Area Networks between major cities are extremely fast Fiber based >2.5 Gbps Local Area Networks in buildings are also fast >100Mbps The connections in between are typically a lot slower 0.3-1.5 Mbps The “Last Mile” Bottleneck Problem
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5 Why Free Space Optics? Why Not Just Bury More Fiber? Cost Rights of Way Permits Trenching Time With FSO, especially through the window, no permits, no digging, nofees no digging, no fees
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6 Examples of FSO Systems Ground Lasercom Terminal Satellite Lasercom Terminal 1 Gbps 2000 km range Commercial Lasercom
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7 Netronics Communications: More than 7000 links installed Worldwide Installations USA Canada Mexico Brazil Argentina Uruguay China Singapore Japan India Philippines Taiwan S. Korea Australia Thailand Vietnam Malaysia Indonesia South Africa Nigeria Slovenia Croatia Latvia Czechoslovakia Gibraltar Luxemburg Netherlands France Norway Greece Germany England Switzerland Sweden Portugal Spain Italy Turkey Israel Saudi Arabia
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8 III – The Technology Spread spectrum Microwave 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 910 10 11 10 12 10 13 10 14 10 15 10 16 HertzkHzMHzGHzTHz 10 7 10 6 10 5 10 4 10 3 10 2 1010.110 -2 10 -3 10 -4 10 -5 10 -6 10 -7 10 -8 Frequency Wavelength Radio WavesMicrowavesInfraredUVPower & Telephone Copper wire transmission kmmetercmmm 10 -9 nm 10 17 Coaxial cable Fiber optic AM radio FM radio Laser communication Electromagnetic Spectrum Unlicensed Smaller carrier wavelength / Higher Bandwidth
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9 Near Infrared Visible Spectrum 400 nm500 nm600 nm700 nm800 nm900 nm HeNe 780 nm 810 nm 850 nm 1550 nm Near Infrared 1300 nm
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10 How does it work? Network Fiber Optic Cable Laser Transmitter Receiver Lens Free space Network
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11 How FSO works? 2 Transmitter projects the carefully aimed light pulses into the air 5 Reverse direction data transported the same way. Full duplex 1 Network traffic converted into pulses of invisible light representing 1’s and 0’s 3 A receiver at the other end of the link collects the light using lenses and/or mirrors 4 Received signal converted back into fiber or copper and connected to the network Anything that can be done in fiber can be done with FSO
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12 IV - Free Space Optics Positioning High Bandwidth Wireless Secure Wireless Short distances Within Urban areas Eye safe
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13 Bandwidth - Wireless? What is the fiber technology bandwidth limitation? Unlimited What is the radio technology bandwidth limitation? Limited (only GHz frequencies) What is the FSO technology bandwidth limitation? Unlimited FSO ≡ Ultra Bandwidth Wireless Solutions Netronics Leading the Gigabit Wireless Revolution
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14 Bandwidth - Wireless? c 10 Gbps 1 Gbps 100 Mbps 10 Mbps 1 Mbps 200 m50 m500 m1 km5 km15 km+ Fiber LMDS WiFi Optical Wireless T-1DSL Future Performances
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15 Security Wireless ? Is Radio signal secure ? What is the RF signal spectrum ? Very wide How many times did you see other Radio network in your area? FSO ≡ Most Secure Wireless Solutions Very narrow and directional mrad divergence Range = R = 1000 m = 1 km ~2 m Is NetLight FSO signal secure ?
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16 Narrow Beam Advantages Beams only a few meters in diameter at a kilometer Allows VERY close spacing of links without interference No side lobes Highly secure Efficient use of energy Ranges of 20m to more than 8km possible
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17 Applications Point-to-Point Secure Ultra Bandwidth Wireless Mesh Ring
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18 V - General Terms Beam Divergence - measure of angle or how much the beam spreads circle: 360° (degrees) = 2π radians 1 radian = 57° (degrees) 1 milliradian = 0.001 rad = 0.057° (degree) 80 µ radians = 0.00008 rad = 0.0046° (degree) (satellite) 1 radian Laser Communication System 2.5 mrad divergence 1 mrad divergence Range = R = 1000 m = 1 km 2.5 m 1 m 80 µrad divergence 8 cm STRV-2 Satellite Laser Communication System
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19 Link stability – Depending on Beam divergence Tx High geometric loss......good link stability. Narrow angle Tx...poor link stability. Wide angle
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20 Geometric loss Beam Area Receiver Lens Area dBdB = divergence angle, d B = R GM (Geometric Loss) = 10 log (Rx lens Area/Beam Area) = 10 log [d R /( R )] 2 dRdR R (air transmission distance) Tx
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21 The Decibel - dB A logarithmic ratio between two values In the optical world of Power in mW, dB=10*Log(power2/power1) 3 dB = ratio of 2/1 6 dB = ratio of 4/1 10 dB = ratio of 10/1 20 dB = ratio of 100/1 50 dB= ratio of 100,000/1 Gain/Loss Multiplier +30 db +20 db +10 db 0 db -10 db -20 db -30 db 1000 100 10 1.1.01.001
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22 Link Budget System Gain Transmitter(s) power Receiver sensitivity Attenuation Geometrical attenuation Atmospheric attenuation Scattering Scintillation Turbulence System factors Components and assemblies tolerances System misalignment Total available margins = System Gain - Attenuation
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23 Environmental factors Building Motion Alignment Window Attenuation Fog Each of these factors can “attenuate” (reduce) the signal. However, there are ways to mitigate each environmental factor. Scintillation Range Obstructions Low Clouds Sunlight
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24 Environmental effects – Rain, Scintillation & Haze Type of events
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25 Fade Margin calculation
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26 VI – Effects of the weather on FSO com. Effects of the atmosphere on laser beam propagation Atmospheric attenuation absorption scattering Atmospheric turbulence laser beam wander scintillation
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27 Environmental effects–Scattering, Scintillation & Turbulence Scattering Major Factor – Haze, Fog, Smog Scintillation Moderate Factor - Air shimmering off hot surfaces Turbulence / Beam Wander Minor Factor – Different density air layers formed locally by temperature differences
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28 Scattering Typical Scattering Attenuation Factors for Various Weather Conditions
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29 Effective Link Range vs. Winter Visibility For laser transmission, attenuation by fog is much greater than attenuation by rain (opposite for microwaves) Fog droplet size (5 to 15 µm) laser wavelength Rain droplet size (200 to 2000 µm) microwave wavelength Effect of snow is between rain and fog FOG RAINSNOW
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30 Scintillation & Turbulence Atmospheric turbulence (ie. wind) produce temporary pockets of air with different temperature thus different density thus different index of refraction. These air pockets and are continuously being created and then destroyed as they are mixed. The effect of these cells which lie along the laser beam path depends on the size of the cells. Laser Beam Wander if the cells are larger than the beam diameter Scintillation if the cells are smaller than the beam diameter. The wavefront becomes distorted due to constructive and destructive interference creating fluctuations in receive power, similar to the twinkling of a distant star.
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31 Scintillation & Turbulence Power Time Power Time Laser Beam Wander Transmit power Receive power Power Time Power Time Scintillation Total Effect is the sum of both Power Time
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32 Scintillation caused burst errors Serial bit stream Fluctuating received laser power Minimum receive power threshold Burst error
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33 Link Bandwidth vs. Link Range @ various Atmospheric attenuation values * * NetLight G-3500 NetLight 155-5400 Ethernet/4E1 E1 Bandwidth 1 km 1.25Gbps 100Mbps 10Mbps 2Mbps 2 km3 km 4 km 5 km * 30 dB/km 17 dB/km 10 dB/km 3 dB/km @ @ @ * @ For operation under light to medium rain, light snow, light haze. * For operation under medium to heavy rain – snow, thin fog. For operation under cloudburst, medium snow, light fog. For operation under blizzard, moderate fog. @ 6 km
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34 VII - Competitive Technology Spread Spectrum Disadvantages Susceptible to RF interference in congested areas Can be monitored easily Limited actual bandwidth (throughput of 2-54 Mbps half duplex) Microwave Disadvantages Cost (the higher the bandwidth, the greater the cost) Complex installations Licensing required for higher frequencies
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35 VIII - Netronics NetLight™ Series - Matrix The Most Comprehensive Free Space Optics Solutions In The Industry DistancesShortMeduimLong 100Mbps (Fast-Ethernet) Fast Ethrnet NetLight 100-800 1-155Mbps 155 NetLight 155-1900 NetLight 155-5400 1.25Gbps (Giga-Ethernet) Gigabit NetLight G-1000NetLight G2300 NetLight G-3500
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36 IX – TS Installation Examples NetLight G-3500 Datec
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37 NetLight with Fusion M6- France DisneyLand - France
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38 Sofdit, 7m pole - France Yanisahra - Turkey
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40 Vitrolles – France 10 links
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42 1-155Mbps Interface unit Air Link Transmitter Air Link Receiver AC / DC Power Supply Clock / Data Recovery Data Out Data In Interface A - BLOCK DIAGRAM RSM-DC (Option) Control Panel Management Unit(optional) X - NetLight Structure
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43 4 E1/T1 Multiplexer / Demultiplexer Device Clock/Data Recovery Air Link Transmitter Air Link Receiver E1/T1 Line Interface unit E1/T1 Line Interface unit E1/T1 Line Interface unit E1/T1 Line Interface unit Control Panel Management Unit (optional) AC/DC Power Supply B - BLOCK DIAGRAM
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44 Very high bandwidth (1.5GBps) License free Most secure wireless medium RFI/EMI immunity No cross-talk or cross interference Safe, no health hazards Easy to relocate links Low maintenance Fast deployment Advantages of Infrared Wireless links XI - Summary
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Thank You © Copyright Netronics Inc.
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