Introduction To Fso Technology

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Descripcion de la tecnologia y sistemas de luz para transmitir señales
Sistemas de transmision por fibra optica, equipos de fibra optica para transmision inalambrica

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  • Introduction To Fso Technology

    1. 1. Wireless Product Division Introduction to FSO Technology By Itshak Kidouchim – Jan 2007
    2. 2. Introduction to FSO – Free Space Optics <ul><li>FSO Communication is using the LASER light as the carrier. </li></ul><ul><li>Full Duplex, Full Speed AND No Delay. </li></ul><ul><li>Up to 1 Gbps Ethernet </li></ul><ul><li>Distances – up to 5km. </li></ul><ul><li>No License is required. </li></ul><ul><li>Easy to install and almost no maintenance is required. </li></ul>I - What is FSO
    3. 3. II - Why Free Space Optics (FSO)? The “Last Mile” Bottleneck Problem Only about 10% of commercial buildings are lit with fiber <ul><li>Wide Area Networks between major cities are extremely fast </li></ul><ul><ul><li>Fiber based </li></ul></ul><ul><ul><li>>2.5 Gbps </li></ul></ul><ul><li>Local Area Networks in buildings are also fast </li></ul><ul><ul><li>>100Mbps </li></ul></ul><ul><li>The connections in between are typically a lot slower </li></ul><ul><ul><li>0.3-1.5 Mbps </li></ul></ul>
    4. 4. Why Free Space Optics? Why Not Just Bury More Fiber? <ul><li>Cost </li></ul><ul><li>Rights of Way </li></ul><ul><li>Permits </li></ul><ul><li>Trenching </li></ul><ul><li>Time </li></ul>With FSO, especially through the window, no permits, no digging, no fees
    5. 5. Ground Lasercom Terminal Satellite Lasercom Terminal 1 Gbps 2000 km range Commercial Lasercom Examples of FSO Systems
    6. 6. 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 MRV Communications: More than 7000 links installed
    7. 7. Electromagnetic Spectrum Spread spectrum Microwave 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13 10 14 10 15 10 16 Hertz kHz MHz GHz THz 10 7 10 6 10 5 10 4 10 3 10 2 10 1 0.1 10 -2 10 -3 10 -4 10 -5 10 -6 10 -7 10 -8 Frequency Wavelength Radio Waves Microwaves Infrared UV Power & Telephone Copper wire transmission km meter cm mm mm 10 -9 nm 10 17 Coaxial cable Fiber optic AM radio FM radio Laser communication Unlicensed III – The Technology Smaller carrier wavelength / Higher Bandwidth
    8. 8. Near Infrared Visible Spectrum 400 nm 500 nm 600 nm 700 nm 800 nm 900 nm HeNe 780 nm 810 nm 850 nm 1550 nm Near Infrared 1300 nm
    9. 9. How does it work? Fiber Optic Cable Laser Transmitter Receiver Network Network Lens Free space
    10. 10. How FSO works? Anything that can be done in fiber can be done with FSO 1 Network traffic converted into pulses of invisible light representing 1’s and 0’s 2 Transmitter projects the carefully aimed light pulses into the air 5 <ul><li>Reverse direction data transported the same way. </li></ul><ul><ul><li>Full duplex </li></ul></ul>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
    11. 11. IV - Free Space Optics Positioning <ul><li>High Bandwidth Wireless </li></ul><ul><li>Secure Wireless </li></ul><ul><li>Short distances </li></ul><ul><li>Within Urban areas </li></ul><ul><li>Eye safe </li></ul>
    12. 12. Bandwidth - Wireless ? <ul><li>What is the fiber technology bandwidth limitation ? </li></ul><ul><ul><li>Unlimited </li></ul></ul><ul><li>What is the radio technology bandwidth limitation ? </li></ul><ul><ul><li>Limited (only GHz frequencies) </li></ul></ul><ul><li>What is the FSO technology bandwidth limitation ? </li></ul><ul><ul><li>Unlimited </li></ul></ul>FSO ≡ Ultra Bandwidth Wireless Solutions MRV Leading the Gigabit Wireless Revolution
    13. 13. Access Technologies Positioning c 10 Gbps 1 Gbps 100 Mbps 10 Mbps 1 Mbps 200 m 50 m 500 m 1 km 5 km 15 km+ Fiber LMDS WiFi Optical Wireless T-1 DSL Future Performances
    14. 14. Security Wireless ? <ul><li>Is Radio signal secure ? What is the RF signal spectrum ? </li></ul>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 <ul><li>Is TereScope FSO signal secure ? </li></ul>
    15. 15. <ul><li>Beams only a few meters in diameter at a kilometer </li></ul><ul><li>Allows VERY close spacing of links without interference </li></ul><ul><li>No side lobes </li></ul><ul><li>Highly secure </li></ul><ul><li>Efficient use of energy </li></ul><ul><li>Ranges of 20m to more than 8km possible </li></ul>Narrow Beam Advantages
    16. 16. Applications Point-to-Point Ring Secure Ultra Bandwidth Wireless Mesh
    17. 17. 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) 2.5 mrad divergence 1 mrad divergence Range = R = 1000 m = 1 km 80 µrad divergence 1 radian Laser Communication System 2.5 m 1 m 8 cm STRV-2 Satellite Laser Communication System
    18. 18. Tx Tx High geometric loss. . . . . .good link stability. Narrow angle Tx . . .poor link stability. Wide angle Link stability – Depending on Beam divergence Tx
    19. 19. Geometric loss Beam Area Receiver Lens Area  d B <ul><li>= divergence angle, d B =  R </li></ul><ul><li>GM (Geometric Loss) = 10 log (Rx lens Area/Beam Area) </li></ul><ul><li> = 10 log [d R /(  R )] 2 </li></ul>d R R (air transmission distance) Tx
    20. 20. The Decibel - dB <ul><li>A logarithmic ratio between two values </li></ul><ul><li>In the optical world of Power in mW, </li></ul><ul><li>dB=10*Log(power2/power1) </li></ul><ul><li>3 dB = ratio of 2/1 </li></ul><ul><li>6 dB = ratio of 4/1 </li></ul><ul><li>10 dB = ratio of 10/1 </li></ul><ul><li>20 dB = ratio of 100/1 </li></ul><ul><li>50 dB= ratio of 100,000/1 </li></ul>Gain/Loss Multiplier +30 db +20 db +10 db 0 db -10 db -20 db -30 db 1000 100 10 1 .1 .01 .001
    21. 21. <ul><li>System Gain </li></ul><ul><ul><li>Transmitter(s) power </li></ul></ul><ul><ul><li>Receiver sensitivity </li></ul></ul><ul><li>Attenuation </li></ul><ul><ul><li>Geometrical attenuation </li></ul></ul><ul><ul><li>Atmospheric attenuation </li></ul></ul><ul><ul><ul><li>Scattering </li></ul></ul></ul><ul><ul><ul><li>Scintillation </li></ul></ul></ul><ul><ul><ul><li>Turbulence </li></ul></ul></ul><ul><ul><li>System factors </li></ul></ul><ul><ul><ul><li>Components and assemblies tolerances </li></ul></ul></ul><ul><ul><ul><li>System misalignment </li></ul></ul></ul>Total available margins = System Gain - Attenuation Link Budget
    22. 22. Environmental factors Sunlight 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
    23. 23. Environmental effects – Rain, Scintillation & Haze Type of events
    24. 24. Fade Margin calculation
    25. 25. <ul><li>Effects of the atmosphere on laser beam propagation </li></ul><ul><ul><ul><li>Atmospheric attenuation </li></ul></ul></ul><ul><ul><ul><ul><ul><li>absorption </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>scattering </li></ul></ul></ul></ul></ul><ul><ul><ul><li>Atmospheric turbulence </li></ul></ul></ul><ul><ul><ul><ul><ul><li>laser beam wander </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>scintillation </li></ul></ul></ul></ul></ul>VI – Effects of the weather on FSO com.
    26. 26. <ul><li>Scattering Major Factor – Haze, Fog, Smog </li></ul><ul><li>Scintillation Moderate Factor - Air shimmering off hot surfaces </li></ul><ul><li>Turbulence / Beam Wander Minor Factor – Different density air layers formed locally by temperature differences </li></ul>Environmental effects – Scattering, Scintillation & Turbulence
    27. 27. Typical Scattering Attenuation Factors for Various Weather Conditions Scattering
    28. 28. Effective Link Range vs. Winter Visibility <ul><li>For laser transmission, attenuation by fog is much greater than attenuation by rain (opposite for microwaves) </li></ul><ul><ul><li>Fog droplet size (5 to 15 µm)  laser wavelength </li></ul></ul><ul><ul><li>Rain droplet size (200 to 2000 µm)  microwave wavelength </li></ul></ul><ul><ul><li>Effect of snow is between rain and fog </li></ul></ul>FOG RAIN SNOW
    29. 29. 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.
    30. 30. 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
    31. 31. Scintillation caused burst errors Serial bit stream Fluctuating received laser power Minimum receive power threshold Burst error Burst error
    32. 32. Link Bandwidth vs. Link Range @ various Atmospheric attenuation values * * TS5000/G TS5000/155 Ethernet/4E1 E1 Bandwidth 1 km 1.25Gbps 100Mbps 10Mbps 2Mbps 2 km 3 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
    33. 33. VII - Competitive Technology <ul><li>Spread Spectrum Disadvantages </li></ul><ul><ul><ul><li>Susceptible to RF interference in congested areas </li></ul></ul></ul><ul><ul><ul><li>Can be monitored easily </li></ul></ul></ul><ul><ul><ul><li>Limited actual bandwidth (throughput of 2-54 Mbps half duplex) </li></ul></ul></ul><ul><li>Microwave Disadvantages </li></ul><ul><ul><ul><li>Cost (the higher the bandwidth, the greater the cost) </li></ul></ul></ul><ul><ul><ul><li>Complex installations </li></ul></ul></ul><ul><ul><ul><li>Licensing required for higher frequencies </li></ul></ul></ul>
    34. 34. VIII - MRV TereScope™ Series - Matrix <ul><li>The Most Comprehensive Free Space Optics Solutions </li></ul><ul><li>In The Industry </li></ul>
    35. 35. IX – TS Installation Examples TS5000 Datec
    36. 36. DisneyLand - France TS3303 with Fusion M6- France
    37. 37. Sofdit, 7m pole - France TS707/4E1, Yanisahra - Turkey
    38. 39. Vitrolles – France 10 links
    39. 41. X - TereScope Structure בס &quot; ד A - TS155 BLOCK DIAGRAM 1-155Mbps Interface unit Control Panel Management Unit(optional) Air Link Transmitter Air Link Receiver AC / DC Power Supply Clock / Data Recovery RSM-DC (Option) Data Out Data In Interface
    40. 42. B - 4E1 BLOCK DIAGRAM E1/T1 Line Interface unit E1/T1 Line Interface unit E1/T1 Line Interface unit E1/T1 Line Interface unit 4 E1/T1 Multiplexer / Demultiplexer Device Clock/Data Recovery Control Panel Management Unit(optional) Air Link Transmitter Air Link Receiver AC / DC Power Supply
    41. 43. Advantages of Infrared Wireless links <ul><li>Very high bandwidth (1.5GBps) </li></ul><ul><li>License free </li></ul><ul><li>Most secure wireless medium </li></ul><ul><li>RFI/EMI immunity </li></ul><ul><li>No cross-talk or cross interference </li></ul><ul><li>Safe, no health hazards </li></ul><ul><li>Easy to relocate links </li></ul><ul><li>Low maintenance </li></ul><ul><li>Fast deployment </li></ul>XI - Summary
    42. 44. THANK YOU ww.mrv.com [email_address]

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