Li-Fi

PowerPoint Presentation

Li-FiByMithun Madhusoodanan

Introduction

Li-Fi is transmission of data through illumination.LED Bulb varies in intensity faster than the human eye can follow.LED lights can be switched on and off at high speeds.This property is the basics for Li-FiLED when on gives binary 1 and off gives binary 0

2Present Scenario

We have 1.4 million cellular base stations deployedWe also have 5 billion of mobile phonesMobile phones transmit 600tb of data every monthWireless communication has become an utility like electricity and waterWe use it in our everyday life, private life, business lifeCurrently Wi-Fi uses radio waves .3Issues with radio wavesCapacityAvailability EfficiencySecurity4CapacityWe transmit wireless data through radio waves.Radio waves are limited.Radio waves are scarce and expensive.We only have certain range of it.With advent of new technologies like 2G,3G,4G we are running out of spectrum.

5EfficiencyThere are 1.4 million cellular radio base stations.They consume massive amount of energy.Most of this energy is not used for transmission but for cooling down the base stations.Efficiency of such a base station is only 5% and that rise a big problem.

6AvailabilityAvailability of radio waves or RF signals causes another concern.We have to switch off mobile phones in airplanes.Radio waves cannot be used under waterIt is not advisable to use mobiles at places like petrochemical plants and petrol pumps.

7SecurityRadio waves penetrates through walls.They can be intercepted.If someone has a knowledge and bad intentions then he may misuse it.

8Alternative to Radio Waves in Electromagnetic spectrumLooking at EM spectrum.

Gamma rays are simply dangerous and thus cant be used for our purpose of communication.X-rays are good in hospitals and cant be used either.Ultra violet rays are sometimes good for our skin but for long duration it is dangerous.Infrared rays are bad for our eyes and are therefore used at low power levels.We have already seen the short comings of radio waves.So we are now left with Visible Rays.

Radio-WavesInfra-WavesVisibleRaysUltra-VioletX-raysGammaRays9Light for Wireless communicationLight has been around for millions of yearsIt has created us, has created life and has created all stuffs of life.Light is part of electromagnetic spectrumThere are 40 billion light box already installed Flickering lights are annoying but thy may have an upside. Li-Fi uses rapid pulses of light to transmit information wirelessly.It is inherently safe to use and would be great if we can use it for our wireless communication.

10What we have to do?We have to replace the inefficient fluorescent lights with new dignitaries of LED lights.It is a semi conductive e-device.Light intensity can be modulated at very high speeds to send data by tiny changes in amplitude.

11How we do this?Remote controls have an IR led.It creates a single data stream.Replace remote control with light box.With this technology we transmits 1000s of data stream in parallel at high speeds.

12How it Works?

13Is it a proven technology?Yes, this is already proven.Harald Hass demonstrated his invention using an ordinary table lamp that successfully transmitted data at speeds exceeding 10Mbps .To prove that the light bulb was the source of data stream, he periodically blocked the beam of light, causing the connection to drop.

14Overcoming the four issues in Li-FiCapacity 10000times more spectrum than Radio waves.Light box are already present.We have the infrastructure available and already installed.

EfficiencyData through illumination and thus data transmission comes for free.Led light consumes less energy.High efficient.

15Availability Light is present everywhere.Can be used in airplanesIt can be underwater where radio waves cannot.

SecurityLight waves doesnt penetrate through walls.Cant be intercepted and misused.Data is present where there is light.

16ApplicationsCan be used in the places where it is difficult to lay the optical fiber like hospitals. In operation theatre Li-Fi can be used for modern medical instruments.In traffic signals Li-Fi can be used which will communicate with the LED lights of the cars and accident numbers can be decreased.Thousands and millions of street lamps can be transferred to Li-Fi lamps to transfer data.In aircraft Li-Fi can be used to transmit data.It can used in petroleum or chemical plants where other transmission or frequencies could be hazardous.

17LimitationsThere should be line of sight between sender and receiverVisible light cannot penetrate through solid objectsInterference with other electromagnetic waves makes the transmitting data to distortLight cannot approach the range and penetration of radio waves

18ConclusionThe possibilities are numerous and can be explored further. If this technology can be put into practical use, every bulb can be used something like Wi-Fi hotspot to transmit wireless data and we will proceed onwards the

Cleaner, Greener, Safer and Brighter future.

19Thank You For Your Attention!

Li-FiA Seminar Presentation by Mithun Madhusoodanan20

Questions21Video Demonstration

Li-Fi Demonstration by Harald Hass at TED talk.22