ContentsIntroductionHistoryWhat is FSO?What to do with it?Is it safe?Why FSO?LimitationsConclusion
IntroductionEthernet and implementationsWhere does RF and Optical fibers
falls short?Gigabit Ethernet?FSO for Gigabit Ethernet.
HistoryAlexander Graham Bell’s
Photo-phone in 1880
1960s for military purposes
For communication between
satellites
After 2000, commercially
popular
What is FSO?Wireless ‘line of sight’
Optical network.Low power infrared lasers:
wavelength range between 850nm and 1600nm.
Commercially available systems: 100Mbps to 2.5Gbps
What is FSO?Still relatively newProvides Full duplex
communication Telescopes or TransceiversPowerful LASERs or LEDs
can be used.
What to do with it?Wireless Gigabit EthernetsWhen wiring is not feasibleAs a redundant networkIn classified sitesStrict RF restrictionsFor temporary networksIncase of EmergenciesFor Satellite constellations
Gigabit Ethernet many ways…
•Mesh•Point-to-point•Chain•Ring
Is it Safe?Is perfectly SafeClass I lasers are
usedNo problem to
eye or skin etcRays get
absorbed before reaching retina
Is it Safe?
FSO TransceiverThe basic
componentProvides
bidirectional communication
Why FSO?Easy ImplementationBi-directional
communicationHigh bitrates and
low error ratesHigh securityNo license needed
Why FSO?Protocol Transparency
Why FSO?Fiber laying is
difficult
Or it is Costly
LimitationsOnly for line-of-
sight communication
Fog, snow, rain and Sand storms.
Low CloudsScintillation
LimitationsBuilding Motions
Type Cause(s) Magnitude Frequency
Tip/tilt Thermal expansion
High Once per day
Sway Wind Medium Once every several seconds
Vibration Equipment (e.g., HVAC),
door slamming, etc.
Low Many times per second
ComparisonFSO is best for small and high speed networks
Network Speed
Distance
Latency
Security
Cost
FSO 10 4 10 10 8
Telco 10 10 10 10 1
5.8GHzRF 2 9 5 1 10
24GHz RF 5 6 6 2 5
60GHz RF 9 3 9 3 6
Available productsMany commercial
products since 2001FSONAAIR FIBERLIGHT POINTEAIR LINXCABLE-FREETERABEAMLASESUN FLOWER
ConclusionProper FSO implementation gives 99.9%
efficiencyIs highly secure and cost efficientWill eliminate the ‘last mile bottleneck’.Eliminate RF traffic problems
Major References usedhttp://en.wikipedia.org/wiki/Free_Space_Opticshttp://en.wikipedia.org/wiki/RONJAFree space optics Propagation and Communication By
Oliver Bouchet, Herve Sizun, Christian Boisrobert, Frederique de Fornel, Pierre-Noel Favennec
http://www.freespaceoptics.org/freespaceoptics/default.cfmhttp://www.eurekalert.org/pub_releases/2009-03/siot-
sfr031709.phphttp://www.freespaceoptic.com/bestfit.htmhttp://www.free-space-optics.org/Ultra-high Frequency Linear Fiber Optic System
By Kam Y Lauhttp://www.opticsinfobase.org/oe/browse.cfm