LI-FI TECHNOLOGY

INTRODUCTION• Light Fidelity (Li-Fi) is a bidirectional, high-speedand fully networked wireless communicationtechnology similar to Wi-Fi.

• LI-FI is a technology that uses the light emittingdiodes to transmit the data wirelessly.

• LI-FI is fast and cheap practical version of WI-FI,based on visible light communication (VLC).

• VLC is a data communication medium, which usesthe visible light between 400 Thz (780 nm) and 800Thz (375 nm) as optical carrier for data transmission

HistoryThe technology truly began during the 1990's in countries like Germany, Korea, and Japan where they discovered LED's could be retrofitted to send information. Harald Haas continues to wow the world with the potential to use light for communication.

HE DEMONSTRATED IT IN THE YEAR2012.

PROFESSOR,UNIVERSITY OF

EDINBURGH, UK

Li-fi environment

“Mobile phones transmit 600 TB data every month.

Wireless communication has become an utility like electricity and water.

PRESENT SCENARIO

RADIO SPECTRUM ISSUES

◎ CAPACITY

Radiowaves

Cost and Expensive

Less Bandwidth compared to other spectrums

Insufficient spectrum for increasing data

◎ EFFICIENCY

Millions of base stations consume huge amount of

energy for

1.Transmitting the radio waves

2.To cool the base station cabins

5% Efficiency

RADIO SPECTRUM ISSUES

◎ AVAILABILITY

Available within the range of Base stations

Limited availability

Unavailable in aircrafts

◎ SECURITY

Less secure(passes through the walls)

Anyone with knowledge and bad intention can

misuse it

Alternative of radio waves

WHY ONLY VLC ??

Radio Waves

Infrared Rays

Visible Rays

Ultraviolet Rays

X- Rays Gama 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.

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 us required

is some LEDs and a controller that code data into those

LEDs. We have to just vary the rate at which the LED’s .

Flicker depending upon the data we want to encode .

Thus every light source will works as a hub for data

transmission .

Working Process

LI-FI CONSTRUCTIONThe LI FI product consists of 4 primary sub-assemblies:

• Bulb

• RF power amplifier circuit (PA)

• Printed circuit board (PCB)

• Enclosure

1. The high concentration of energy in the electric field vaporizes the contents of the

bulb to a plasma state at the bulb’s center; this controlled plasma generates an

intense source of light.

2. The PCB controls the electrical inputs and outputs of the lamp and houses the

microcontroller used to manage different lamp functions.

3. An RF (radio-frequency) signal is generated by the solid-state PA and is guided

into an electric field about the bulb.

4. All of these subassemblies are contained in an aluminum enclosure

How It 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.

On the other hand, this light is detected by photo sensitive

devices.

Next this device is amplified and processed and then fed to

the device.

APPLICATION AREAS

◎TRAFFIC LIGHTS

Traffic lights can communicate to the

car and with each other. Cars have

LED-based headlights, LED-based

cack lights, and cars can

communicate with each other and

prevent accidents in by exchanging

information.

APPLICATION AREAS

◎HOSPITALS

In operation theatre, Li-Fi can be used for modern medical instruments

APPLICATION AREAS

◎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.

APPLICATION AREAS

◎INTRINSICALLY SAFE ENVIRONMENT

It can be used in petroleum or chemical plants where other transmission or frequencies could be hazardous.

APPLICATION AREAS

◎ON OCEAN BED

Li-Fi can even work underwater

were Wi-Fi fails completely, thereby

throwing open endless opportunities

for military/navigation operations.

APPLICATION AREAS

◎STREET LAMPS

There are millions of street lamps

deployed around the world.

Each of these street lamps could be a

free access point.

LIMITATIONS

There should be line of sight between senderand receiver

Visible light cannot penetrate through solidobjects

High installation cost of the VLC systems

Interferences from external light sources likesun light, normal bulbs, and opaque materials inthe path of transmission will cause interruption inthe communication

A major challenge facing Li-Fi is how thereceiving device will transmit back to transmitter.

IS IT A PROVEN TECHNOLOGY

• Yes, this is already proven.

• Dr. Harald has demonstrated his invention using an ordinary table lamp that successfully transmitted data at speed exceeding 10 mbps.

• To prove that light bulb was the source of data stream, he periodically blocked the beam of light, causing the connection to drop.

FUTURE OF LI-FI

“In November 2014, Li-Fi pioneers pureLiFi joined

forces with French lighting company Lucibel aiming to

bring out Li-Fi enables products, by the end of 2015.

pureLiFi already have two products on the market: Li-

Flame Ceiling Unit to connect to an LED light

fixture and Li-Flame Desktop Unit which connects to a

device via USB, both aiming to provide light and

connectivity in one device.

Plus, with faster connectivity and data transmission it’s an

interesting space for businesses.

“Continued..

Li-Fi is reportedly being tested in Dubai, by UAE-based

telecommunications provider, du and Zero1. Du claims to

have successfully provided internet, audio and video

streaming over a Li-Fi connection.

What's more, reports suggest that Apple may build future

iPhones with Li-Fi capabilities. A Twitter user found that

within its iOS 9.1 code there were references to Li-Fi

written as 'LiFi Capability' hinting that Apple may

integrate Li-fi with iPhones in the future.

Li-Fi has proven itself as a viable, efficient and secure solution.

CONCLUSION

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

Cleaner, Greener, safer and Brighter Future

Thanks..!!