LIFI(LIGHT FIDELITY)

LIFI(LIGHT FIDELITY) PRESENTED BYT.SUNIL REDDY,141FA05116,ECE.

TABLE OF CONTENT:-INTRODUCTIONLIFE OF LIFIELECTROMAGNETIC SPECTRUMWHY ONLY VLC?PRESENT SCENARIOISSUES OF RADIO SPECTRUMWORKING PROCESS OF LIFIWHY FLUCTUATIONS ARE NEEDED?IMPLEMENTATION OF LIFI SYSTEM AND ITS WORKINGLIFI VS WIFIADVANTAGESLIMITATIONS AND CHALLENGESAPPLICATIONS CONCLUSION

Introduction:-Light based WI-FI Light is used instead of radio-waves to transmit information. Transceiver fitted LED lamps acts like Wi-Fi modems. LED lamps can light a room as well as transmit-receive information. Provides illumination as well as data communication.

LIFE OF LIFI:- Introduced by Professor Herald Hass, at the university of Edinburgh.

Established in 2011 TED global talk.The promotion of idea through TED helped to start a company, Pure LiFi.

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Visible spectrum has times more broad spectrum than comparison to the radio spectrum.

ELECTROMAGNETIC SPECTRUM:-

WHY ONLY VLC?Gama rays cant be used as they could be dangerous.

X-rays have similar health issues.

Ultraviolet rays is good for place without people, but otherwise dangerous for the human body.

Infrared rays due to eye safety regulation, can only be used with low power.

Continuation..Radio waves is used as transceiver for communication, television, cell phones and radios .But these waves are restricted in many areas of industries, airlines etc.

Microwaves are used in radar communications, and for heating in microwave ovens and in various industrial processes.

Hence we are left with only visible spectrum. visible spectrum.Hence we are left with only

PRESENT SCENARIO:-Radio Spectrum is congested but the demand for wireless data doubles each year. Everything, it seems want to use wireless data but the capacity is drying up.

1.4 MILLION BASE STATIONS5 BILLION MOBILE PHONES

ISSUES OF RADIO SPECTRUM:-

WHAT CAN BE REPLACED IN PLACE OF RADIO WAVES FOR WIRELESS COMMUNICATION?LIFI-LIGHT FIDELITY

WORKING PROCESS OF LIFI:-Operational procedure is very simple, if the led is on, you transmit a digital 1, if its off you transmit a 0. The LEDs can be switched on and off very quickly, which gives nice opportunities for transmitting data. Hence all that required is some LEDs and a controller that code data into those LEDs. We have to just vary the rate at which the LEDs on and off.Flicker depending upon the data we want to encode.Thus every light source will works as a hub for data transmission.

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WHY FLUCTUATIONS ARE NEEDED?101010101010101010101010101010101010010101010101001010101010101010101001010101010100101010101010101010101010101010010101010110101010101010101010101010101001011010101110101010101101010101010010101010101010101100101010100101001010101010101010101010101010101010101010100101010101010101010010111010101010101011001010101010010111001010110010100001010101001010101010101010101010101101010101010101010101010101010101010101010100101010101010101010110111010111010111011010101010101110101010101010101010011010101101001010101010101010101010101010101010101010101010101010101010101010101101110110110101011010100110101010101011

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Implementation of lifi system:-

LED DRIVER CIRCUIT:-This led driver is base for generating required fluctuations in the leds.This is the major part of the lifi technology which varies the normal leds with that of a lifi leds.

HOW LIFI WORKS?On one end all the data on the internet will be streamed to a lamp driver when the led is turned on the microchip converts the digital data in form of light.

A light sensitive device (photo detector) receives the signal and converts it back into original data. This method of using rapid pulses of light to transmit information wirelessly is technically referred as Visible Light Communication.

HUB:-A hub is a common connection point fordevicein anetwork. Hubs are commonly used to connectsegmentsof aLAN. A hub contains multipleports. When apacketarrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.Lamp driver is connected to a hub and given to different leds in our surroundings.

LIFI VS WIFI:-S.No.PARAMETERSLIGHT FIDELITYWIRELESS FIDELITY1.Speed for data transferFaster transfer speed(>1Gbps)Data transfer speed(150Mbps)2.Medium through which data transfer occursUses light as carrierUses radio spectrum3.Spectrum RangeVisible light spectrum has 10,000 times more broad spectrum in comparison to radio spectrumRadio frequency spectrum range is far less than the visible light spectrum4.CostCheaper than Wifi because it is a free band and dont need any license as it uses lightExpensive in comparison to Lifi because it uses radio spectrum5.SecurityHigh secureLess secure6.Operating frequencyHundreds of Tera Hz2.4 GHz

ADVANTAGES:- It can be used anywhere in the RF restricted areas. Since light waves it does not interfere with any radio waves. Mostly LED bulbs are used,which consumes less energy.Hence cost efficient. As light cant penetrate through walls it is more secured communication. More efficient than radio waves wireless communication. Date rate is greater than 1 gbps.Hence we can download any files in fews seconds.

LIMITATIONS & CHALLENGES:- Light cannot penetrate through solid objects . Interferences from external light sources like sun light, normal bulbs, and opaque materials in the path of transmission will cause interruption in the communication. A major challenge facing LiFi is how the receiving device will transmit back to transmitter. Light communication is not possible in darkness.

Applications:-Traffic lights:- Traffic lights can communicate to the car and with each other. Cars have LED-based headlights, LED-based back lights, and cars can communicate with each other and prevent accidents in by exchanging information.

Continuation..Airlines:- Whenever we travel through airways we face the problem in communication media ,because the whole airways communication are performed on the basis of radio waves. To overcome this drawback on radiowaves, li-fi is introduced.

Continuation.. Ocean Beds :- LiFi can even work underwater were Wi-Fi fails completely, thereby throwing open endless opportunities for military/navigation operations.

Continuation.. Street Lamps:- There are millions of street lamps deployed around the world. Each of these street lamps could be a free access point.

Continuation.. Industries:-Used in RF restricted environments like chemical industries,nuclear power plants, petrol pumps.

LATEST SOLUTIONS:-Receiver dongle is created for receiving the data from leds and decoding it.

Continuation..The first VLC Smartphone was presented by Consumer Electronics in January, 2014. The phone uses Wysips connect a clear thin layer of crystal glass is added to the small screens. Smartphone could get 15% more battery life in a day.

Conclusion:-Thus,the possibilities are numerous and can be explored further. It provides simple, faster and efficient wireless data communication. Li-Fi will make us to proceed towards the cleaner, greener, safer and brighter future.

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