Page 1 of 18

INTORODUCTION & IMPLEMENTATION OF

Li - Fi

By Anjeet Kumar 1301326440

CSE 6th Semester

A Seminar Report Submitted In Partial Fulfillment of the

Requirement For the 6th

Semester CSE.

UNDER THE GUIDANCE OF

DR. SAMBIT KUMAR MISHRA

( HOD OF CSE )

GANDHI INSTITUTE FOR EDUCATION & TECHNOLOGY

BPUT

YEAR- 2015-2016

Page 2 of 18

Acknowledgement

I thank my seminar guide Dr. Sambit Kumar Mishra

H.O.D of Computer Science Department, GIET, for his proper

guidance, and valuable suggestions. I am indebted to other

faculty members of Computer Science Department for giving

me an opportunity to learn and present the seminar. If not for

the above mentioned people my seminar would never have

been completed successfully.

I once again extend my sincere thanks to all of them.

Anjeet Kumar

1301326440

CSE 6th

Sem

Page 3 of 18

Contents

Sl. No. Content Page No.

1. Acknowledgement 1

2. Abstract 3

3. Introduction 4 - 5

4. Review Of Literature 6

5. Principles Of Li-Fi 7-9

6. Comparison with Other Technologies 10

7. Applications 11

8. Future Prospectus 12-14

9. Advantages 15

10. Limitations 15

11. Conclusions 16

12 Reference 17

Page 4 of 18

Abstract

Whether we are using wireless internet in a shopping mall, in college

campus or borrowing it from the friend, or competing for bandwidth at a

conference, we usually get frustrated at the slow speeds we face when more

than one device is tapped into the network. As more and more people and their

many devices access wireless internet, clogged airwaves are going to make it

increasingly difficult to latch onto a reliable signal. But radio waves are just one

part of the spectrum that can carry our data. What if we could use other waves

to surf the internet?

One German physicist, DR. Harald Haas, has come up with a solution

he calls “Data Through Illumination”—taking the fiber out of fiber optics by

sending data through an LED light bulb that varies in intensity faster than the

human eye can follow. It’s the same idea behind infrared remote controls, but

far more powerful. Haas says his invention, which he calls D-Light, can

produce data rates faster than 10 megabits per second, which is speedier than

your average broadband connection. He envisions a future where data for

laptops, smartphones, and tablets is transmitted through the light in a room. And

security would be a snap—if you can’t see the light, you can’t access the data.

Li-Fi is a VLC, visible light communication, technology developed by a

team of scientists including Dr Gordon Povey, Prof. Harald Haas and Dr

Mostafa Afgani at the University of Edinburgh. The term Li-Fi was coined by

Prof. Haas when he amazed people by streaming high-definition video from a

standard LED lamp, at TED Global in July 2011.

Li-Fi is now part of the Visible Light Communications (VLC) PAN

IEEE 802.15.7 standard. “Li-Fi is typically implemented using white LED light

bulbs. These devices are normally used for illumination by applying a constant

current through the LED. However, by fast and subtle variations of the current,

the optical output can be made to vary at extremely high speeds. Unseen by the

human eye, this variation is used to carry high-speed data,” says Dr Povey, ,

Product Manager of the University of Edinburgh's Li-Fi Program ‘D-Light

Project’.

Page 5 of 18

Introduction

Li-fi basically known as “LIGHT FEDILITY” is an

outcome of twenty first century. The basic ideology behind this

technology is that the data can be transmitted through LED

light whose intensity varies even faster than the human eye.

In simple terms, Li-Fi can be thought of as a light-based Wi-Fi.

That is, it uses light instead of radio waves to transmit information.

And instead of Wi-Fi modems, Li-Fi would use transceiver-fitted

LED lamps that can light a room as well as transmit and receive

information. Since simple light bulbs are used, there can technically

be any number of access points.

This technology uses a part of the electromagnetic spectrum that

is still not greatly utilized- The Visible Spectrum. Light is in fact very

much part of our lives for millions and millions of years and does not

have any major ill effect. Moreover there is 10,000 times more space

available in this spectrum and just counting on the bulbs in use, it also

multiplies to 10,000 times more availability as an infrastructure,

globally.

It is possible to encode data in the light by varying the rate at

which the LEDs flicker on and off to give different strings of 1s and

0s. The LED intensity is modulated so rapidly that human eyes cannot

notice, so the output appears constant.

As the transmission of the data takes place through the light

emitting diodes (LED’s) the amount is comparatively small .In

modern times, it is called as the optimized version of WI-FI .The

advantageous thing is the wireless communication which decreases

the cost enormously. HARALD HASS, says that the heart of this

technology lies in the intensity and the potential of the light emitting

diodes. The major reason which lead the modern man through this

invention is that the confinement of Wi-Fi to comparatively small

distance. As there are more and more devices coming up day-by-

day the signals are being clogged up due to heavy traffic, there

arised a need for an error free transmission technology. And the

Page 6 of 18

solution to this problem was the Li-fi technology.. It has been

designed in such a way that it overcomes the disadvantages that

occurs during the usage of wi-fi. In general terms, Li- fi works even

under water thereby causing a great benefit to the military operations.

The phycists envisions that this technology would make a great

difference between the assumption and the proof in this case .The

demonstration took place using two Casio smart phones. The data was

made to exchange between the phones using light. Even though the

distance was nominal, it is sure that there would be a rapid increase in

the distance of transmission.AS there is a limited amount of Radio

based wireless spectrum available, a number of companies formed a

consortium called Li-fi consortium in order to promote high speed

optical wireless systems .The members of this consortium believes

that a speed of 10 Gbps can be achieved in no time. If this would be

possible then a high clarity image would take about 30 seconds to

download.

Page 7 of 18

Review Of Literature

In July 2011, Dr. Herald Hass, Professor, mobile communication, University of

Edinburgh, demonstrated Light fidelity for the first time, a method of Visible

light communication (VLC) technology. Li-Fi technology change the scenario

of accessing the internet, stream video, receive emails and much more. This is

come in familiar forms such as infrared, ultraviolet and visible light.

Research into this VLC has been conducted in 2003,mainly in UK, US,

Germany, Korea and Japan. Experiments have shown that VLC is faster, safer

and cheaper than other forms of wireless internet and also eliminates the need

of costly mobile phone radio masts.

In 2007, Hass’s assistant, Mostafa Afgani, first sent data using light signals in

his small lab with equipment including table lamp and its box of electronics.

Hass’s invention centres on modulation of the information embedded from the

LED’s is transmitted by means of many subtle changes made to the intensity of

the light at the ultra high rate of 100 millions cycles per second(100MHZ).The

photo detector in the Hass box converts this tiny variations into a digital signal

from which the transmitted information is extracted.

Using a standard white-light LED, researchers at the Heinrich Hertz Institute

in Berlin, Germany, have reached data rates of over 500 megabytes per second.

Li-Fi Consortium was formed in October 2011 by a group of companies and

industry groups to promote high-speed optical wireless systems and overcome

the limited amount of radio based wireless spectrum. According to the Li-Fi

Consortium, it is possible to achieve more than 10 Gbps of speed, theoretically

which would allow a high-definition film to be downloaded in just 30 seconds.

Page 8 of 18

Principle Of Li-Fi Technology

The basic idea behind this communication scheme is transmission of ‘Data

through illumination’ . Heart of Li-Fi technology is high brightness LED’s.

The on-off activity of LEDs enables a kind of data transmission using binary

codes mode however the human eye cannot perceive this change and the LEDs

appear to have a constant intensity. Switching on an LED is a logical ‘1’

switching it off is a logical ‘0’. A light sensitive device (LDR) receives the

signal and converts it back into original data. This method of using rapid pulses

of light to transmit data is called Visible Light Communication the basic

principle of VLC.

How Li-Fi Works?

There are many situations in which people get frustrated with the dull

performance signals of Wi-Fi at a place with many network connections in

seminars conferences etc. Li-Fi fulfils these needs .This fantabulous idea first

stroked the mind of Harald Haas from University of Edinburgh, UK, in his TED

Global talk on VLC. His idea was very simple that if the LED is “on” then the

digital 1 can be transmitted and if the led is “off” then the digital 0 can be

transmitted. Led’s can be switched on and off very quick. For transmitting

data this way all that we require is LED’s and controller that code data into

Led’s. Parallel data transmission can be done by using array of LED’s or by

using red, green, blue LED’s to alter light frequency with the frequency of

different data channel. Advancements and enhancements in this field generate

a speed of 10 gbps! But amazingly fast data rates and lowering band widths are

not the only reasons that enhance this technology. Lifi usually is based on light

and so it can be probably implemented in articrafts and hospitals that are prone

to inference from radio waves. Unlike Wi-Fi Li-Fi can work even under- water

which makes it more advantageous for military operations. Radio waves are

replaced by light waves in data transmission called Li- Fi.

Light emitting diodes can be switched on and off very much faster than the

human eye allowing the light source to appear continuously. The data

transmission is done through binary codes which involve switching on LED can

be done by logic 1 and switch off using logic 0.The encoding of information in

light can therefore be identified by varying the rate at which the LED’s flicker

Page 9 of 18

on and off to give strings of 0’s and 1’s.visible light communication is this

method of using rapid pulses of light to transmit information wirelessly.

To further get a grasp of Li-Fi consider an IR remote. It sends a single

data stream of bits at the rate of 10,000-20,000 bps. Now replace the IR LED

with a Light Box containing a large LED array. This system, is capable of

sending thousands of such streams at very fast rate.

Light is inherently safe and can be used in places where radio frequency

communication is often deemed problematic, such as in aircraft cabins or

hospitals. So visible light communication not only has the potential to solve the

problem of lack of spectrum space, but can also enable novel application. The

visible light spectrum is unused, it's not regulated, and can be used for

communication at very high speeds.

Page 10 of 18

LI-FI CONSTRUCTION:-

The Li-Fi product consists of 4 primary sub-assemblies:

• LED Bulb

• RF power amplifier circuit (PA)

• Printed circuit board (PCB)

• Enclosure

The PCB controls the electrical inputs and outputs of the

lamp and houses the microcontroller used to manage different lamp

functions.

An RF (radio-frequency) signal is generated by the solid-

state PA and is guided into an electric field about the bulb.

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.

All of these subassemblies are contained in an aluminum

enclosure

Page 11 of 18

Comaparison With Other Technology

Li-Fi is the name which is used for wireless communication, similar to Wi-Fi.

Wi-Fi works well for general wireless coverage within buildings, and

Li-Fi is ideal for high density wireless data coverage inside a confined

area or room and for relieving radio interference issues. The Table

given below shows a comparison between wireless technologies.

Wi-Fi currently offers high data rates. The IEEE 802.11.n in most

provides up to 150Mbit/s although practically, very less speed is

received.

Page 12 of 18

APPLICATIONS:

There is a wide necessity for data transfer and by the end of the day

every field involves the use of technologies. One such technology is

Li-Fi which can have its applications extended in areas where the Wi-

Fi technology lack its presence like medical technology, powerplants

and various other areas where Li-Fi proved it excellence of the

undersea awesomeness.

At present its applications are beyond imagination but still if to think

about few then they are :

Can be used in the places where it is difficult to lay the optical

fiber like hospitals. In operation theatre LiFi can be used for

modern medical instruments.

In traffic signals LiFi can be used which will communicate with

the LED lights of the cats and accident numbers can be

decreased.

Thousand and millions of street lamps can be transferred to LiFi

lamps to transfer data.

In aircraft LiFi can be used for data transmission.

It can be used in petroleum or chemical plants where other

transmission or frequencies could be hazardous.

Replacement for other technologies as compare with other

wireless technology Li-Fi have great features, for money

applications we can use Li-Fi as wireless technology.

Page 13 of 18

FUTURE PROSPECTS

First applications of Li-Fi have been put to use already, for

example,in hospitals where RF signal are a threat due to interference

problems with medical equipment such as blood pumps and other

life supporting instruments. Axiomtek Europe presented such a

product at the Embedded World exhibition in Nurnberg, Germany.

The prototype of a mobile phone with an incorporated VLC

system was presented by Casio at the Consumer Electronics Show in

Las Vegas last year. In the coming years, we will see more Li-Fi

products entering the market, both in the industrial as well as

consumer markets.

Enhanced & Exclusive Shopping Experience

Imagine yourself walking into a mall where GPS signals are

unavailable but the mall is equipped with ceiling bulbs that

create their own ‗constellation‘ of navigation beacons. As the

camera of your cellphone automatically receives these signals,

it switches your navigation software to use this information to

guide you to the ATM machine you‘re looking for.

You conclude your ATM transaction and notice the GigaSpot

sign for instant digital movie downloads. You pick out that new

Tom Cruise movie using your phone‘s payment facility, and

then download within a few seconds the high-definition movie

into the GigaLink flash drive plugged into the USB port of your

smartphone. As you walk away, your phone notifies you that the

leather jacket Tom featured in the movie is on sale nearby. You

walk over towards the show window and your image comes up

on the screen, wearing that coveted jacket. You turn and pose

while the image matches your orientation and body gestures for

a ‗digital fitting.‘ When you walk into the store, the clerk hands

you the actual jacket in exactly your size.

Page 14 of 18

You Might Just Live Longer

For a long time, medical technology has lagged behind the rest

of the wireless world. Operating rooms do not allow Wi-Fi over

radiation concerns, and there is also that whole lack of dedicated

spectrum. While Wi-Fi is in place in many hospitals,

interference from cell phones and computers can block signals

from monitoring equipment. Li-Fi solves both problems: lights

are not only allowed in operating rooms, but tend to be the most

glaring (pun intended) fixtures in the room. And, as Haas

mentions in his TED Talk, Li-Fi has 10,000 times the spectrum

of Wi-Fi, so maybe we can delegate red light to priority medical

data. Code Red!

Airlines ( Data on the go!)

Nothing says captive audience like having to pay for the

"service" of dial-up speed Wi-Fi on the plane. And don‘t get me

started on the pricing. The best I‘ve heard so far is that

passengers will "soon" be offered a "high-speed like"

connection on some airlines. United is planning on speeds as

high as 9.8 Mbps per plane. Uh, I have twice that capacity in my

living room. And at the same price as checking a bag, I expect

it. Li-Fi could easily introduce that sort of speed to each seat's

reading light.

Smarter Power Plants

Wi-Fi and many other radiation types are bad for sensitive areas.

Like those surrounding power plants. But power plants need

fast, inter-connected data systems to monitor things like

demand, grid integrity and (in nuclear plants) core temperature.

The savings from proper monitoring at a single power plant can

add up to hundreds of thousands of dollars. Li-Fi could offer

Page 15 of 18

safe, abundant connectivity for all areas of these sensitive

locations. Not only would this save money related to currently

implemented solutions, but the draw on a power plant’s own

reserves could be lessened if they haven’t yet converted to LED

lighting.

Lightings Points Used as Hotspot:-

Any lightings device is performed as a hotspot it means that the

light device like car lights, ceiling lights , street lamps etc area

able to spread internet connectivity using visual light

communication. Which helps us to low cost architecture for

hotspot.

Green information technology:-

Green information technology means that unlike radiowaves and

other communication waves affects on the birds , human bodys

etc. Li-Fi never gives such side effects on any living thing.

Undersea Awesomeness:

Underwater ROVs, those favourite toys of treasure seekers and

James Cameron, operate from large cables that supply their

power and allow them to receive signals from their pilots above.

ROVs work great, except when the tether isn‘t long enough to

explore an area, or when it gets stuck on something. If their

wires were cut and replaced with light — say from a submerged,

high-powered lamp — then they would be much freer to

explore. They could also use their headlamps to communicate

with each other, processing data autonomously and referring

findings periodically back to the surface, all the while obtaining

their next batch of orders.

Page 16 of 18

Reduction in accident numbers:

At traffic signals, we can use LIFI in order to communicate

with LED lights of the cars by the number of accidents can be

reduced. Data can be easily transferred by making use of LIFI

lamps with the street lamps

ADVANTAGES

Li-Fi has low implementation and maintenance costs.High data

transmission rates of up to 10 Gbps can be achieved.

It is safe for humans since light, unlike radio frequencies,

cannot penetrate human body.

Efficiency: Data transmission using Li-Fi is very cheap

A free band that does not need license.

Availability: Availability is not an issue as light sources are

present everywhere.

LIMITATIONS

Only works if there is direct line of sight (LOS) between the

transmitter and receiver.

Data transmission can be easily obstructed by opaque obstacles.

The use of very high frequencies (400-800THz) limits it to very

short distances and

Point to Point communications only.

Page 17 of 18

CONCLUSION:

Li-Fi is the upcoming and on growing technology acting as competent

for various other developing and already invented technologies. Since

light is the major source for transmission in this technology it is very

advantageous and implementable in various fields that can’t be done

with the Wi-Fi and other technologies. Hence the future applications

of the Li-Fi can be predicted and extended to different plat- forms like

education fields, medical field, industrial areas and many other fields.

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 hotspot to transmit wireless data and we will

proceed towards the cleaner, Greener, Safer and Brighter future.

Li-Fi has great technology in the field of wireless data transmission. It

is advanced Conventional methods of wireless communications that

use light as data carrier. Many Enhancements can be made to the

existing technology, by using fast-switching LEDs, data transmission

rates can be further enhanced. The driving speed of the circuit can be

improved by using fastswitching transistors. Li-Fi is feature key of

high speed data transmission. If LI-FI technology can be put into

practical use, every bulb used to transmit a data and will lead toward

the brighter future.

Page 18 of 18

REFERENCES

[1] Akshata M Sonnad, Anjanagopan, Sailakshmi N R, Divya S,

Ambika R, “Recent Advancements in li-fi Technology” International

Journal of Electrical, Electronics and Data Communication, volume-

1, issue-10, dec-2013 issn: 2320-2084.

[2] Balaramghosal , Asim Kumar Panda “li-fi a green energy

initiative” International Journal of Computer Applications (0975 –

8887) volume 95– no. 11 june 2014.

[3] Jay h. Bhut, Dharmrajsinh N. Parmar, Khushbu V. Mehta,

Electronics & Communication Engineering, Marwadi Education

Foundation, Rajkot, India. Communication system engineering,

[4] Rahul R. sharma1, Raunak2, Akshay Sanganal Department of

Computer Engineering fr.crit, Vashimumbai, India“li-fi technology

transmission of data through light”int. J. computer Technology &

applications, vol 5 (1),150-154 issn:2229-6093.

[5] Kanchan Gupta, Kajal, Ashish saini, “lifi- light fidelity

technology- a review” international journal of emerging research in

management & technology issn: 2278-9359 (volume-3, issue-10).

[6] Vitthal S Saptasagare ,student m.tech, dept of cse, canara

engineering college, mangalore, karnataka “india next of wi-fi an

future technology in wireless networking li-fi using led over internet

of things” international journal of emerging research

in management &technology issn: 2278-9359 (volume-3, issue-3).