Optical Wireless Netwoking

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MADE BY :MRAMIK PALIWAL

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OPTICAL FIBERAn optical fiber is a thin, flexible, transparent fiber

that acts as a waveguide, or "light pipe", to transmitlight between the two ends of the fiber.

Optical fiber is used, glass or plastic, to contain andguide light waves

Capacity

Microwave at 10 GHz with 10% utilization ratio:1 GHz BW

Light at 100 Tera Hz (1014 ) with 10% utilization ratio:

100 THz (10,000GHz)

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EVOLUTION OF FIBER 1880 Alexander Graham Bell

1930 Patents on tubing

1950 Patent for two-layer glass wave-guide 1960 Laser first used as light source

1965 High loss of light discovered

1970s Refining of manufacturing process

1980s OF technology becomes backbone of longdistance telephone networks in NA.

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INTRODUCTION

Fibers of glass .

Usually 120 micrometers in diameter Used to carry signals in the form of light over

distances up to 50 km.

No repeaters needed.

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INTRODUCTION (CONT)

Core thin glass center of the fiber

where light travels. Cladding outer optical material

surrounding the core

Buffer Coating plastic coating

that protects the fiber.

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How Does Optical Fiber

Transmit Light??

Total Internal Reflection.

Fiber Optics Relay Systems has Transmitter

Optical Fiber

Optical Regenerator

Optical Receiver

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TOTAL INTERNAL REFLECTION

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TYPES OF FIBERS

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TYPES OF FIBERS(CONT.)Optical fibers come in two types:

Single-modefibers used to transmit one signalper fiber(used in telephone and cable TV).They have small cores(9 microns in diameter) andtransmit infra-red light from laser.

Multi-mode fibers used to transmit manysignals per fiber(used in computer networks).They have larger cores(62.5 microns in diameter) andtransmit infra-red light from LED.

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ACCEPTANCE CORE &

NUMERICAL APERATURE

Acceptance

Cone

Acceptance angle, c, is the maximum angle in whichexternal light rays may strike the air/Fiber interface and

still propagate down the Fiberwith < 10 dB loss.c = Sin-1n1

2 n22 Numerical aperture:

NA = sin c= n12 n2

2

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ADVANTAGES Capacity: much wider bandwidth (10 GHz)

Crosstalk immunity Safety: Fiber is non-metalic

Less Signal Degradation& Digital Signals

Security: tapping is difficult

Economics: Fewer repeaters

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DISADVANTAGES

Higher initial cost in installation

Interfacing cost Strength: Lower tensile strength

Remote electric power

More expensive to repair/maintain.

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AREAS OF APPLICATION

Telecommunications

Local Area Networks Cable TV

CCTV

Optical Fiber Sensors

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OPTICAL FIBERCOMMUNICATION

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What is Optical Fiber

Communication???Method of transmitting information from one place to

another by sending pulses of light through an opticalfiber.

Basic steps :

Creating the optical signal using transmitter,

Relaying the signal along the fiber, ensuring that the

signal does not become too distorted or weak,Receiving the optical signal,

Converting it into an electrical signal.

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OPTICAL FIBER LINKTransmitter

Input

Signal

Fiber-Optic Cable

Output

Receiver

Coder orConverter Light Source Source-to-Fiber

Fiber-to-lightInterface

Light DetectorAmplifier/Shaper

Decoder

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WAVELENGTH DIVISON MULTIPLEXING It is a technology which multiplexes a number of

optical carrier signals onto a single optical fiber byusing different wavelengths (colours) of laser light.

Enables bidirectional communications over onestrand of fiber, as well as multiplication of capacity.

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WIRELESSTRANSMISSION

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BANDWIDTHEvery day the demand for more capacity grows.

AVAILABILITY High speed throughput is limited by the last mile .

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THE DIFFERENCE

FIBER OPTIC BACKBONE

Fiber has demonstratedspeeds up to 100 Gbps

LOCAL LOOP

Average download speed forthe nation: 5.1 mbps

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WIRES To avoid Wi-Fi bottlenecks, this is the alternative:

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A NEW SOLUTION

Researchers discovered a way to encode infraredlight with data in a way that dramaticallyimproves transmission speed The methoddelivers speeds more than 1 Gbps

BREAKTHROUGH

Replace radio waves with beams of light

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RADIO VS. INFRAREDUnlike radio waves used

by Wi-Fi, light photons

can deliver broaderbandwidth that can beused simultaneously bymultiple devices.

Also, photons do notinterfere with each otheror pass through walls likeradio transmissions

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HOW IT WORKS The encoded infrared light is sent through a special

holographic grid resulting in multiple beams allcarrying the same data

THE LIGHT GRID The pencil-thin beams of infrared light fill the volume

of a room, and devices fitted with infrared receiverspick up data from the beams anywhere within thearray

Beams reflect off of walls, desktops, even faces

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THE NEXT STEP Capable of even higher

bandwidth, white LED lampscould replace infrared infuture optical wirelesssystems.

White LEDs could light uprooms efficiently whilesimultaneously providingbroadband wireless access.

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WHITE LED LIGHT Experts believe the cost of white LEDs will drop and

they will become the standard light source for homesbecause of their energy efficiency.

Wireless systems based

on them would be easy to

integrate into existingfixtures

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MORE ADVANCEMENTS Chosen for systems requiring higher bandwidth or

spanning longer distances than electrical cablingcan accommodate.

Can be installed in areas with high electromagneticinterference (EMI), such as alongside utility lines,

power lines, and railroad tracks and areas of highlightning.

With these benifits,optical fiber technology isstretching its hands in communication field,wherethousands of electrical links would be required to

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/ / M ik

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Optical Wireless Netwoking