FREE SPACE OPTICSFREE SPACE OPTICSA NEXT GENRATION WIRELESS

COMMUNICATION

Presented By

B. Chandu AVINASHG.V.P college of engg.M . Naga

SRINIVASJ.N.T.U KAKINADA

OVERVIEWOVERVIEW Deals with FSO – a latest communication

technique

Used in MAN’s

Transmission through air

Doesn’t involve optical fibers

Uses INFRARED RAYS

Doesn’t involve jamming

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CHALLENGE CHALLENGE AND AND IT’S IT’S

SOLUTIONSOLUTION

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BASICSBASICSOptical wireless

Different topologies

Involves transmission of data, voice and video

Many advantages when compared to fibers

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TOPOLOGIESTOPOLOGIES

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MESH POINT TO MULTI POINT

POINT TO POINT RING TOPOLOGY

IS FSO OPTICAL OR IS FSO OPTICAL OR WIRELESS?WIRELESS?

Shares some concepts of fiber optics

wavelength’s 850nm to 1550 nm

laser and amplifiers

Sending and receiving is done by

OPTICAL-ELECTRICAL-OPTICAL [O-E-O]

presently

FSO can scale easily ultra bandwidth’s6

EDFAEDFA

EDFA-Erbium Doped Fiber Amplifier

A path way for high wavelengths and

longer distances

Less expenses for [O-E-O] conversion and

electrical amplification for each wavelength

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BANDWIDTH BANDWIDTH DRIVERS/TRENDSDRIVERS/TRENDS

Helps to attain high bandwidths

Telecommunication carriers implement FSO

as best access technology

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USAGE AND SPEED OF THE FSO AT VARIOUS APPLICATIONS

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FEATURESFEATURESFULLDUPLEX (bidirectional)

Uses lenses, optical wireless

unit, telescope for transmission

Very sensitive transmission

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DESIGN ISSUESDESIGN ISSUES

Apertures are used

Follows reflection,

refraction, diffraction,

combination of all

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TRANSMITTER APERTURETRANSMITTER APERTURE

Important aspects

Size

Quality

Size determines maximum eye safe laser

Quality with f-number tells us minimum divergence

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RECIEVER APERTURERECIEVER APERTURE

Follows aperture size and f-number

Aperture size gives amount of collected

data

f-number gives the detector field of view

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FSO SYSTEMSFSO SYSTEMS

Doesn’t require any license

Wavelength is about 1micrometer

1 micrometer beam can translate into frequencies

of several hundred terahertz

Better than the micro wave transmission (40gHz)

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FSO SYSTEMS(Contd…)FSO SYSTEMS(Contd…)

Divergence of 0.3 for distance of 1 KM

4mts diameter of beam

Those values are much more better than the radial beams, micro beams

Since it works in free space it needs little maintenance

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SECURITYSECURITY

Transmission is not

visible to human eye

Difficult for intruder to

get IR beam by direct

method since beam is

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SECURITY(Contd…)SECURITY(Contd…)

Transmission beam passes

well above the ground level

It is impossible for an

intruder by indirect method

by using light photons since

IR has low power levels

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DRIVING FORCEDRIVING FORCEIncludes

Market driver

Economic driver

Service driver

Business driver

Environment driver

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APPLICATIONSAPPLICATIONS

Metro network extensions

to connect to new networksEnterprise

LAN-LAN connectivityEnterprise applicationsPoint to multipoint

Fiber complementAs redundant link

DWDM Services

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CHALLENGESCHALLENGESPhysical obstructionsBuilding seismic

activityScintillationAbsorptionBeam wanderBeam spreadingSafety

Human exposure to laserHigh voltages

Weather Severity

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EFFECT OF ATMOSPHEREEFFECT OF ATMOSPHERE

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CONCLUSIONCONCLUSION

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FSO allows us to provide optical

connectivity cost effectively, quickly,

reliably and is a most secured data

transmission technology.

REFERENCESREFERENCES

Mendelson , James S. and Dorrier , Charles R. “Free Space

Optics: Fixed Wireless Broadband”

White, Chad “How to Squeeze More Data Over What’s

Already There ”

www.laseroptronics.com

www.ieee.org

www.science tech.com

www.efymag.com

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ANY QUERIES?ANY QUERIES?

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THANK YOUTHANK YOU

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