FSO- Seminar 2009

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