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How does li-fi technology work

Li-Fi is a technology that uses the LIGHT EMITTING DIODES (LED) to transmit the wireless data and how to use li fi technology and future scope of lifi technology free ppt download
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Published Date:09-03-2017
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Li- Fi (Light – Fidelity)Contents - INTRODUCTION - HOW LI-FI IS DIFFERENT ? - HISTORY OF LI-FI - LI-FI CONSTRUCTION - WHY LI-FI COMES ? - HOW LI-FI WORKS ? - LI-FI VS WI-FI - FEATURES - ADVANTAGES - DIADVANTAGES - APPLICATIONS - FUTURE SCOPE - CONCLUSIONIntroduction ▸ Li-Fi means “LIGHT FIDELITY” ▸ Li-Fi is fast and cheap optical version of wi-Fi. ▸ Li-Fi is a technology that uses the LIGHT EMITTING DIODES (LED) to transmit the data wirelessly . ▸ Li-Fi based on VISIBLE LIGHT COMMUNICATION (VLC). ▸ VLC is a data communication medium, which uses the visible light between 400 THz (780 nm) and 800 THz (375 nm) as optical carrier for data transmission.How Li-Fi Is Different ? - Li-Fi technology is based on LEDs for the transfer of data. - The transfer of the data can be with the help of all kind of light i.e., Light may be Invisible, Ultraviolet or Visible part of spectrum. - The speed of the internet is incredibly high and the user everything in just a few minutes.History of Li-Fi This technology was invented by German Physicist “HARALD HASS”, from the university of Edinburgh, U.K. - He demonstrated it in the year 2012. - But, the technology was truly began during the 1990‟s in countries like Germany, Korea & Japan. - where they discovered LED‟s could be retrofitted to send information UNIVERSITY OF EDINBURGH :-Li-Fi Construction ▸ The Li-Fi product consists of three primary sub- assemblies:- ▸ Emitter (including bulb) ▸ RF Driver. ▸ Power supplyFunction of Bulb Assembly ▸ At the heart of LIFI is the bulb sub-assembly where a sealed bulb is embedded in a dielectric material. ▸ The dielectric material serves two purposes: ▸ 1) waveguide ▸ 2) Electric fieldRF Drive ▸ Power amplifier (PA) assembly that uses an LDMOS device. ▸ Converts electrical energy into RF power. ▸ The PA is designed for ruggedness and efficiency. ▸ The RF driver also contains controls circuit for digital and analog lighting controls.A Typical Li-Fi ScenarioWhy Li-Fi comes ? - Due to Issues regarding with Radio frequency Spectrum - Electromagnetic spectrum - These are - Capacity Availability Efficiency SecurityRadio Spectrum Issues Security Capacity • Less secure(passes  Radio waves. through the walls)  Cost and Expensive.  Less Bandwidth compared to other spectrums.  Insufficient spectrum for increasing Efficiency data.  Millions of base stations consume huge amount of energy for Availability 1.) Transmitting the radio waves  Available within the range of 2.) To cool the base station cabins Base stations.  Limited availability. 5% Efficiency  Unavailable in aircrafts.Electromagnetic SpectrumRadio Infrared Visible Ultraviolet Gama Rays X- Rays Waves Rays Rays Rays • Gama rays cant be used as they could be dangerous. • X-rays have similar health issues. • Ultraviolet light is good for place without people, but other wise dangerous for the human body. • Infrared, due to eye safety regulation, can only be used with low power. • HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT SPECTRUM.WHAT USES CAN REPLACE RADIO WAVES FOR WIRELESS COMMUNICATION ?THROUGH LI-FI - By the use of li-fi we can replace radio waves for wireless communicationHow Li-Fi Works ? • Procedure is very simple, if the LED is on , then your device transmit a digit „1‟ & if it is off, then your device transmit a digit „0‟. • The LED can be switched on & off very quickly, which gives nice opportunities for transmitting data. • Hence, all that required is some LEDS & a controller that code data into those LEDS.Comparison Between Li-Fi vs. Wi-FiFeatures of Li-Fi • CAPACITY - 10,000 Times more spectrum then RW. - Light boxes are already present, so infrastructure is available already and installed . • EFFICIENCY - Highly efficient because LED consume less energy. • AVAILABLITY - Light is present every where. - Data is present where light is present. • SECURITY - Light waves does not penetrate through walls. - Hence they can not be INTERCEPTED.Advantages of Li-Fi • It is impossible to achieve more than 10Gbps, theoretically allowing a high-definition film to be downloaded in 30 sec. • Mostly powered by LEDs so it is cost efficient MAPS Transmission of data is fast and easy.Disadvantages of Li-Fi Presence of light is essential There should be line of sight Works better with fluorescent light and LEDs but very low efficiency with bulbs.