DATA TRANSMISSION USING Li-Fi

A MINI PROJECT REPORT

Submitted by

NIMALAN. S
PARATHASARATHY. B
PONSELVAM .M
RAGHUL B. M

In partial fulfilment for the award of the degree

of

BACHELOR OF ENGINEERING

in

ELECTRONICS AND COMMUNICATION ENGINEERING

SRM VALLIAMMAI ENGINEERING COLLEGE

(An Autonomous Institution)
ANNA UNIVERSITY: CHENΝΝΑΙ 600 025
 ANNA UNIVERSITY: CHENNAI 600 025

BONAFIDE CERTIFICATE

Certified that this project report “DATA TRANSMISSION USING LI-FI” is bonafide work
of

NIMALAN.S -142221106095

PARTHASARATHY.B -142221106100

PONSELVAM .M -142221106103

RAGHUL B.M -1422211063150

Who carried out the project work under our supervision

SIGNATURE SIGNATURE

Dr. KOMALA JAMES, M.E., (Ph.D). Mr.S.SENTHILMURUGAN, M.E.,(Ph.D).

HEAD OF THE DEPARTMENT SUPERVISOR

Professor Asst. Professor

Department of Electronic and Department of Electronic and
Communication Engineering. Communication Engineering.
SRM Valliammai Engineering College, SRM Valliammai Engineering College,
Kattankulathur – 603 203. Kattankulathur – 603 203.

Submitted for viva voce held on ________________ at SRM Valliammai Engineering

college, Kattankulathur-603 203

INTERNAL EXAMINER EXTERNAL EXAMINER

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 ACKNOWLEDGEMENT

A project work of this magnitude would have not been possible without the of
guidance and coordination of many people. Our sincere thanks and profound
sense of gratitude goes to our respected Founder Chairman &Chancellor
Dr.T.R. PAARIVENDHAR and Chairman Thiru. RAVI
PACHAMOOTHOO, Vice-charman Mrs. PADMAPRIYA RAVI and
Correspondent Ms. R. HARINI for providing us with adequate infrastructure
and Congenial academic environment.

We consider it a great privilege to recur our deep sense of gratitude to our

Director Dr.B.CHIDAMBARARAJAN and our Principal
Dr.M.MURUGAN. We also express our sincere gratitude and profound thanks to
the head of the department Dr.KOMALA JAMES who patronized us throughout
our project work.

Our heartfelt thanks to our project coordinator Mr.S.SENTHILMURUGAN

Assistant Professor, for his constant support, guidance and motivation in the
course of our project and help in making this project a successful one. We
express our sincere salutation to all other teaching and non-teaching staffs for
their valuable suggestions in this endeavour of us. Last but not the least, we
dedicate this work to our parents and the Almighty who have been with us to
overcome the hard times

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 INDEX

CHAPTER No TITLE PAGE NO

ABSTRACT 6

1 INTRODUCTION 7

1.1 OBJECTIVE 9

1.2 METHODOLOGY 9

2 LITERATURE SURVEY 10

2.1 LITERATURE SURVEY 1 10

2.2 LITERATURE SURVEY 2 11

2.3 LITERATURE SURVEY 3 12

3 SOFTWARE USED 14

4 HARDWARE REQUIREMENTS 15

5 BLOCK DIAGRAM 20

6 CIRCUIT DIAGRAM 21

7 WORKING OF LI-FI 22

8 COMMUNICATION WITH VISIBLE LIGHT 24

9 FEATURES AND BENIFITS 28

10 RESULT AND ANALYSIS 31

11 COMPARISON OF LI-FI WITH WI-FI 33

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 11.1 ADVANTAGES OF LI-FI 35

11.2 DISADVANTAGES OF LI-FI 36

12 APPLICATIONS 38

13 FUTURE POSSIBILITIES 42

14 CONCLUSION 43

15 REFERENCES 46

ABBREVIATIONS

Li-Fi Light-Fidelity
Wi-Fi Wireless-Fidelity
VLS Visible Light Spectrum
VLC Visible Light Communication
IRDA Infrared Data Association
NFC Near Field Communication
LDR Light Dependent Resistor
LCD Liquid-Crystal Display
EM Electro Magnetic Waves
AVR Advanced Virtual RISC
LED light emitting diode
GHz Gigahertz
RF Radio Frequency
IoT Internet of Things

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 LIST OF FIGURES

FIG NO FIGURE NAME PAGE NO

1 Introduction about Li-Fi 8
2 Introduction about Li-Fi 9
3 Li-Fi app 15
4 Arduino 16
5 LDR sensor 17
6 LCD display 18
7 Jumper wire 19
8 Resistor 19
9 Block Diagram 20
10 Circuit Diagram 21
11 Result and analysis 32
12 Mobile Connectivity 40
13 Underwater Communication 41

LIST OF TABLES

TABLE NO TABLE NAME PAGE NO

1 Comparison of different 10
wireless technologies
2 Comparison between Li-Fi 35
and Wi-Fi

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 ABSTRACT

Everyday numbers of people use the internet. Demand for net access increased
as a result. Wi-Fi (wireless fidelity) is more expensive and exhibits sluggish data
speeds. The focal objective of this paper is to develop improvements in the
modern communication due to the emergence of wireless technology; there is a
vast growth in the devices with the need to access the internet. Congestion is the
major evident complication created due to it. It is the need of the hour to find
another means of communication. The transmitter and Receiver system to verify
the performance and compile the text transmission using Li-Fi under Varying
limitations such as light intensity, output quality and Distance. By conducting
experiments, the System described in this paper can deliver data over a variety
of distances. We are also putting into practice the application of how this
previously mentioned concept might be indicated for indoor location-based
services. It has high durability, high data transmission rate with its additional
quality of long- life expectancy. In this proposed paper, an innovative concept
Light Fidelity (Li-FI) is used to transmit the data in order to demonstrate the use
the case study of Light Fidelity technology. Here, types of data transmission is
text and is carried out using Li – Fi. We are also implementing an application of
how this above concept can be implied for indoor Location Based Services for
the visually challenged.

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 CHAPTER 1
Introduction about Li-Fi

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 Light 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 Is and Os. The LED intensity is
modulated so rapidly that human eyes cannot notice, so the output appears
constant.

In the most recent years, the studies on Visible Light Communication (VLC) are conducted
to overcome the radio spectrum congestion. The process behind Li-Fi is to transfer data
at high-speed using light waves from any light source even the ordinary light table.

1
Li-Fi can be considered as an optical version of Wi-Fi, so that instead of using radio waves
to transfer the data it uses visible light. Professor Harald Hass, the chair of Mobile
Communications at the University of Edinburgh, institute Li-Fi; demonstrated a Li-Fi
prototype at the TED Global conference in Edinburgh on 12th July 2011. He illustrated the
ability of using Light Emitting Diodes

In order to prove the truth of Li-Fi, a comparison must be made to know the fundamental
difference between Wi-Fi and Li-Fi technologies. Therefore, according to the studies that
made Li-Fi has many great features such as it can achieve high data rates as compared to
Wi-Fi technology.

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In addition, the Li-Fi consume less power, more efficient, and word world availability of
light source, while Radio waves cannot be used in all environments, particularly in
airplanes, chemical and power plants, and in hospitals since it causes malfunction or

substantial problems to the human and this equipment.

Technology Speed
Li-Fi ~1 Gbps
Wi-Fi ~150 Mbps
(LED’s) for IrDA ~4 Mbps data transmission [2]. In his
experiment, Bluetooth ~3 Mbps a LED bulb of table lamp was
NFC ~424 Kbps
usedto send a blooming flower video which
was displayed on a screen. In the meanwhile, thelight of LED bulb was blocked
from time to time with his hand to prove that the blub was

By using the Internet of Things (IoT) technology, there will be an enormous

number of devices that will be connected to internet. This causes another issue

3
for the current Wi-Fi networks and might be completely saturated and incapable
to accommodate that number of users

1.1 OBJECTIVE

The main objective of this project is to provide an efficient and low cost, secure
data transmission using Light-Fidelity and to construct a very simple and easily
understandable model. To discover more innovative applications and to make
use of it

1.2 METHODOLOGY
In this project, we propose a novel method of data communication using Li-Fi
technology. The light data is transmitted from app which is then received by
Arduino uno board using LDR module. The received data is displayed on a
LCD screen

CHAPTER 2
LITERATURE SURVEY

2.1 LITERATURE SURVEY 1

TITLE: Li-Fi based data transmission using under water communication

AUTHORS: Vismaya V Nair, Sridhar N, Venkateswaran K

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ABSTRACT: Communication imparts a major role in the survival of mankind.
Communication rather than being a survival, it is being identified as basic purpose of
understanding between every organism for their safe and healthy well-being. Earlier

Electromagnetic (EM) waves were used for communication . But later, it was realized that
these waves were less efficient. Here, this research work mainly focuses on the concept of
data transmission.

Li-Fi (Light Fidelity) was new to everyone a decade before, but now it’s one of the
emerging methodologies. The medium selected for data transmission is water. Unlike Wi-
Fi, here the data will be transmitted without the need of internet and it also opts for wireless
connectivity. The present system utilizes Li-Fi with the high complexity circuit, which is
very inappropriate in their implementation for underwater communication. Hence, it
necessitates the need to develop a system, which can be cost effective as well as reduced
area complexity in the arrangement of such a setup

KEYWORDS- Li-Fi, EM Wave, Underwater Communication, Visible Light, Wi-Fi, Data

transmission, LDR, Arduino.

CONCLUSION: Remote communication or submerged water underwater communication

by using visible white light transmits the information or text data instantly. The time needed
to achieve the result is just a jiffy. Here, in this paper, we have given our prime focus on the
text data transmission wherein the visible light is responsible for carrying out this data to
the output LDR. The intensity of text data transmission over distance is measured and
estimated the approximate distance of possible data transfer with the status of visibility.

2.2 LITERATURE SURVEY 2

TITLE: Implementation of a Data Transmission System using Li-Fi Technology

AUTHORS: Ifada E, Surajudeen-Bakinde N.T, Faruk N, Abubakar A, Mohammed O.O

and Otuoze A.O

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ABSTRACT: Over the years, the overdependence on Wireless Fidelity (Wi-Fi) for data
transmission necessitated the need for an alternate and more reliable means of
communication, hence, Light Fidelity (Li-Fi). It involves the use of Light Emitting Diode to
transmit data by blinking (i.e. switching them On and Off) at a speed not noticeable to the
eye.

. The proposed system utilizes an embedded system with dual-core Advanced Virtual RISC
(AVR) microcontroller (ATmega16L) interfaced to input/output circuits comprising of the
Light Emitting Diode (LED), LM358N Operational Amplifier and a photodiode. Also, by
developing a user (Receiver PC) interface using JAVA programming, the sample data (text)
transferred was monitored and the speed, efficiency, security and capacity of the system
was examined and discovered to be top notch

Key Words: Light Fidelity (Li-Fi), Wireless Fidelity (Wi-Fi) Optical communication,
Telecommunication

CONCLUSION: The aim of this work was to design a Li-Fi Data Transmission system to
send data (limited to text – strings) from a PC to another PC. The Data Transmission system
constructed when tested showed satisfactory performances. The Li-Fi data transmission
system constructed was very cheap making it satisfy the major aim of the project –
incorporation of a Li-Fi medium using off the shelf electronic devices.

Therefore, a Li-Fi prototype has been developed which demonstrates the basic principle and
also supports the advantages of Li-Fi over Wi-Fi. The system constructed has some
limitations also. The Li-Fi prototype designed does not support multi-user access. The
speed achieved with this prototype is 11,520 bps only which is not of a high order of Gbps.
Also, this prototype is not bidirectional.

2.3 LITERATURE SURVEY 3

TITLE: Complete Data Transmission using Li-Fi Technology with Visible Light
Communication

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AUTHORS: Asmita Pandit Sonawane, Janhavi Sanjay Pradhan, Vaibhavi Prakash
Waghmare, Saurabh Kesari, Shashank Kumar Singh

ABSTRACT: Everyday numbers of people use the internet. Demand for net access

increased as a result. Wi-Fi (wireless fidelity) is more expensive and exhibits sluggish data
speeds when more than two routers are connected. Li-Fi (light fidelity) is a good solution to
solve these problems. It is a wireless technology that uses LED or infrared light to transfer
data. This method uses a light source to transmit data while using VLC. This paper
proposed a device that transfers all data using VLC (visible light communication). While a
photodiode is placed in the receiver component to receive light arrays, the transmitter
device uses high-power LED arrays to transmit audio, video, text, and images.

Li-Fi uses LED for up to 500 Mbit/s of communication over short distances or regular
lamps for transmissions at 10 Kbit/s. By conducting experiments, the system described in
this paper can deliver data over a variety of distances.

CONCLUSION: This work describes visible light communication for the transfer of
audio, text, images, and video. The experimental results are detailed and discussed in depth,
and the gadget design is thorough. With the addition of a focusing sensor between the
transmitter and the receiver, it has been shown that high-quality video/audio and image
transmission is possible across 12 feet. Even yet, there are still limitations when comparing
photos taken before and after transmission. It is shown that LEDs may be used to transmit
high-quality wireless optical data. Additionally, the measurement setup and findings have
been described.

CHAPTER 3

SOFTWARE USED

LI-FI APP

We make use of a Li-Fi transmitter open-source android app to demonstrate this

concept. The app converts written text message into light flash data for
7
transmission. The user needs to start the app and type the message to be
transmitted and press enter key to transmit the text in form of light. It flashes the
light for few seconds according to coding of the text through the help of
flashlight in the mobile phone. From this app we can send messages like Hi,
good morning…etc. We can only transmit a limited data, which is specified in
this app. To transmit a lot of new data to the receiver we have to alter the source
code of the app with that new data

CHAPTER 4

HARDWARE REQUIREMENTS

ARDUNIO UNO:

For the conduction of the experiment, we have used Arduino Uno, which is a
simple microcontroller-based sensor board on the Microchip ATmega328P and a
developing environment that implements the Processing language.

8
The board is equipped with sets of digital and analog input/output pins that may be
interfaced to various expansion boards and other circuits. Some of the applications
of Arduino include Vehicle Tracking,

IoT based Automation, Accident Detection, Pick and Place Robotic Arm as well as
in the Smart Blind Stick. Also, the medical field have found the maximum usage of
these Arduinos, in heartbeat as well as temperature sensing systems

LDR SENSOR:

LDR sensors are used on the receiver side to trace the light signals. The light
signal is converted into serial data by the control unit. This data sends to suitable
output sources.

A photoresistor can be used in light-sensitive detector circuits and light-

activated. In the dark, a photoresistor can have a resistance as high as
several megaohms (MΩ), while in the light, it can have a resistance as low as a
few hundred ohms.

Photoresistors also exhibit a certain degree of latency between exposure to light

and the subsequent decrease in resistance, usually around 10 milliseconds .

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LCD DISPLAY:

As discussed in the Light Receiver part, the medium or the method by which we
can analyse and say that the data that we have transmitted have been reached the
receiver end is only by observing the display on the Liquid Crystal Display.

The LCD that we have used for this experimentation is a16X2 display.

LCD consists of a layer of liquid crystals sandwiched between two transparent

electrodes. When an electric current is applied, the crystals align to control the

amount of light passing through them, creating the image you see on the screen.

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 JUMPER WIRES:

Jumper wires are simply wires that have connector pins at each end, allowing
them to be used to connect two points to each other without soldering. A jump
wire (also called as jumper, jumper wire, DuPont wire) is an electrical wire,
or group of them in a cable, with a connector or pin at each end (or sometimes
without them – simply "tinned"), which is normally used to interconnect the
components of a breadboard or other prototype or test circuit, internally or with
other equipment or components, without soldering.

1K OHM RESISTOR:

A resistor is a passive two-terminal electrical component that implements electrical

resistance as a circuit element. In electronic circuits, resistors are used to reduce current
flow, adjust signal levels, to divide voltages, bias active elements, and terminate
transmission lines, among other uses. Here the main purpose of this resistor is to limit the

11
voltage from the Arduino in between 1 to 3.3volts so that the data can be displayed in the
LCD board very efficiently

CHAPTER 5
BLOCK DIAGRAM

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Here we give power supply to Arduino using the laptop and on the other end the light data
from the app is flashed on the LDR sensor which is processed by the Arduino and the
output is displayed in the LCD display

CHAPTER 6
CIRCUIT DIAGRAM

13
The analog ground pin of Arduino is connected to the ground of breadboard and the +5v
input is connected to the vcc of the breadboard. The LDR’s vcc pin is connected the vcc of
the breadboard, the digital output pin of the LDR is connected to digital pin 7 of Arduino. A
resistor is connected to the LCD display in order to restrict the voltage from the Arduino in
between 1 to 3.3 volts so that the LCD display can work efficiently. D4-7 pins of LCD
display is connected to Arduino’s digital pins to get the digital output. The anode and
cathode pins of LCD display are connected to vcc and ground respectively. As there is no
read/write operation the pins 5 is connected to ground. The LDR can be connected to either

5V or 3.3V.

CHAPTER 7
WORKING OF LI-FI

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Li-Fi makes use of visible light through overhead lighting for the transmission of data. This
is possible through the use of a Visible Light Communications (VLC) system for data
transmission. A VLC system has two qualifying components:
1. At least one device containing a photodiode in order to receive light signals; and
2. A light source equipped with a signal processing unit for the transmission of signals.
The VLC light source can be in the form of a fluorescent bulb or a light emitting diode
(LED). LED light bulbs are the most optimum VLC light source, however, since a robust
Li-Fi system requires extremely high rates of light output. Fluorescent bulbs emit light in a
much wider band of wavelengths, which makes it a relatively less efficient light source than
LED. LED, on the other hand, is a light source that emits light in a very narrow band of
wavelengths, making it a more efficient light source.

Li-Fi is a fast and cheap optical version of Wi-Fi, the technology of which is
based on Visible Light Communication (VLC). VLC is a data communication
medium, which uses visible light between 400 THz (780 nm) and 800 THz (375
nm) as optical carrier for data transmission and illumination. It uses fast pulses of
light to transmit information wirelessly. The main components of this
communication system are:

3. A high brightness white LED, which acts as a communication source and

4. A silicon photodiode which shows good response to visible wavelength
region serving as the receiving element.

To be clearer, by modulating the LED light with the data signal, the LED illumination can
be used as a communication source. As the flickering rate is so fast, the LED output
appears constant to the human eye. A data rate of greater than 100 Mbps is possible by
using high speed LEDs with appropriate multiplexing techniques. VLC data rate can be
increased by parallel data transmission using LED arrays where each LED transmits a
different data stream. There are reasons to prefer LED as the light source in VLC while a
lot of other illumination devices like fluorescent lamp, incandescent bulb etc. Are available,
15
and the prime reason among then is its high flickering rates. conventional single-carrier
modulation schemes in the same bandwidth.

LED is also a semiconductor, which implies that it can amplify light intensity and switch
rapidly. This is an important quality to look for in a VLC light source because Li-Fi relies
on the constant stream of photons emitted as visible light for the transfer of data. When the
current applied to the light source is varied slowly, the light source dims up and down,
which makes it unsuitable as a source of light, not for the Li-Fi system,

CHAPTER 8
COMMUNICATION WITH VISIBLE LIGHT
The frequency spectrum that is available to us in the atmosphere consists of
many wave regions like X-rays, gamma rays, ultraviolet region, infrared region,
visible light rays, radio waves, etc. Anyone of the above waves can be used in
the upcoming communication technologies but why the Visible Light part is
chosen? The reason behind this is the easy availability and lesser harmful effects
that occur due to these rays of light. VLC uses the visible light between 400
THz (780 nm) and 800 THz (375 nm) as medium which are less dangerous for

high-power applications and also humans can easily perceive it and protect
themselves from the harmful effects whereas the other wave regions have
following disadvantages:

•Radio waves are expensive (due to spectrum charges) and less secure (due to
interference and possible interception etc.)

Gamma rays are harmful because it could be dangerous dealing with it, by the
human beings due to their proven adverse effects on human health. X-rays have
health issues, similar to the Gamma Rays. Ultraviolet light can be considered for
communication technology purposes at place without people, otherwise they can
also be dangerous for the human body when exposed continuously.
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Infrared, due to high safety regulation, can only be used with low power.

Hence the Visible light portion (from red to blue) of the electromagnetic
spectrum does not cause any harm to the people as visible rays are safe to use,
provide larger bandwidth and also have a promising future in the
communication field.

In the early 1990’s, mobile phones were mainly used for voice conversation or
text messaging. However, the introduction of the iPhone in 2007 has started a
new era in wireless communication. Nowadays smartphones are equipped with
all kinds of sensors and applications to provide health monitoring, video
chatting, online streaming along with bank transactions and using cloud
services.

A larger bandwidth should be allocated for wireless communication in order to

provide seamless connectivity and higher data rates. However, frequency
spectrum below 5 GHz is well utilised, which leave no room to relocate
spectrum for mobile communication.

This led scientists to seek new wireless technologies that can fulfil the needs of
the higher data rate at a low cost. One such candidate is the use of the visible
light spectrum.

It has the advantage of its availability (LED lights), link level security, higher
bandwidth, and frequency reuse.

CHAPTER 9

FEATURES AND BENIFITS

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Li-Fi features include benefits to the capacity, energy efficiency, safety and
security of a wireless system with a number of key benefits over Wi-Fi but is
inherently a complementary technology.

9.1. BANDWIDTH

As we know, Li-Fi uses the visible light spectrum (400 THz to 800 THz), and
this spectrum is plentiful (10,000 times more than RF spectrum), unlicensed and
free to use, providing us a much greater bandwidth than Wi-Fi or any other
wireless communication technology.

9.2 DATA DENSITY

Li-Fi has a considerably high data density. The traditional radio frequencies,
used in the wireless communication tend to spread out and cause interference.
But this is not the case with visible light. Visible light is having the capability to
be contained in a tight illumination area, which ultimately increases data
density. A higher data density means a greater number of data packets

transmitted per unit time.

9.3. HIGH SPEED

As discussed earlier, the Li-Fi is having a considerably high bandwidth, and a

high data density. Moreover, the intensity of LED is also much higher. All these

factors lead to the transmission of considerably higher amount of data per unit
time, which ultimately increases the data transmission speed to a great extent.

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9.4. PLANNING

As the Li-Fi technology is based on the illumination infrastructure, a good

signal strength can literally be seen. Also, the intensity variation and switching
of LED is fast enough that it can’t be seen by human eyes. This makes the
capacity planning much easier.

9.5. LOW COST

Li-Fi mainly uses LEDs and Photo Detectors for the transmission and reception
of data, which makes it much cheaper than the current RF based wireless
technologies, which are composed with numerous components. Also, the data
transmission speed is 10- 100 times higher in Li-Fi, which makes it much more

cost efficient.

9.6. EFFICIENCY

LED is itself power efficient. And all the other components used in Li-Fi are
minor power consumers. This makes Li-Fi a greatly power efficient technology.
Moreover, we don’t need additional power for the Li-Fi, as it will be using the
same power used for the illumination of a room.

9.7. ENVIRONMENT

Transmission and propagation of RF in water is extremely difficult, which

makes underwater communication impossible. But that’s not the case with Li-Fi,
as it uses the visible spectrum of light; and the transmission and propagation of
visible light in water is very easy.

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9.8. SAFETY

Until now, there’s no known safety issues with Li-Fi, as it uses visible light. And
visible light can never be harmful for anyone, considering the fact that the
current RF technologies emit harmful radiation. The transmission of light avoids
the use of radio frequencies which can dangerously interfere with electronic

circuitry in certain environments.

9.9. SECURITY

For getting access to the Li-Fi signal, it is the prime need to keep the signal
receiver directly in the illuminated area. In other words, no signal without direct
light. This property prevents the Li-Fi network from the outside intruders,
hackers and unwanted users.

9.10. CONTROL

Data may be directed from one device to another and the user can see where the
data is going, there is no need for additional security such as pairing for RF
interconnections such as Bluetooth. This gives the user a great control over what
to send and where to send, and also prevents data leakage.

9.11 Augmented reality

Exhibits in museums and galleries are illuminated with specific lighting. Li-Fi enabled
lighting can provide localised information within that light. This means that a visitor’s
camera or mobile phone can be used to download further information regarding the object
being viewed from the light that illuminates the exhibit.

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 CHAPTER 10

RESULT AND ANALYSIS

21
The text will be displayed in the output LED board which we gave as input through the
mobile phone’s flashlight and with the help of LDR module

22
 CHAPTER 11
COMPARISION OF LI-FI WITH WI-FI

There are several advantages of Li-Fi over Wi-Fi:

Li-Fi uses light rather than radio frequency signals so are intolerant to
disturbances.

• VLC could be used safely in aircraft without affecting airlines signals.

Integrated into medical devices and in hospitals as this technology doesn’t deal
with radio waves, so it can easily be used in all such places where Bluetooth,
infrared, Wi-Fi and internet are broadly in use. Under water in sea Wi-Fi does
not work at all but light can be used and hence undersea explorations are good
to go now with much ease.

There are billions of bulbs worldwide which just need to be replaced with LEDs
to transmit data. Security is a side benefit of using light for data transfer as it
does not penetrate through walls. On highways for traffic control applications
like where Cars can have LED based headlights, LED based backlights, and
they can communicate with each other and prevent accidents.

Using this Technology worldwide every street lamp would be a free data access
point. The issues of the shortage of radio frequency bandwidth may be sorted
out by Li-Fi.

 Wi-Fi is susceptible to electromagnetic interference from various

electronic devices and can operate effectively in dense environments.

 Conversely, Li-Fi is less prone to such interference but is more suitable for
high-density settings due to its use of light for data transmission.

23
  Wi-Fi networks are generally more vulnerable to security breaches as radio
waves can penetrate through walls.

 Li-Fi offers enhanced security as its light-based signals cannot pass

through opaque structures,

11.1 ADVANTAGES OF LI-FI

The current operational concepts and experimental applications of Li-Fi

technology centre on the use of light-emitting diode or LED lamps. This means
that a Li-Fi network can be integrated readily with existing lighting systems.
Hence, wherever there is a light source, there can be access to the local area
network or the internet. LED lamps are also easier and have become inexpensive
to produce while their market price has become more affordable.

24
Improving wireless communication is another advantage of Li-Fi. It can support
high-speed internet services and data-demanding applications such as cloud
computing. The fact that it offers faster data transfer rates means that it can
advance the deployment of the Internet of Things or IoT and the use of smart or
interconnected devices.

The shortage issue of radio frequency bandwidth may be solved by using Li-Fi.
Using Li-Fi each street lamp can be used as a free data access point. Underwater
Wi-Fi does not work at all, here Li-Fi can be used for data transmission

The radio frequency spectrum used by Wi-Fi is becoming increasingly congested,

leading to interference, slower speeds, and reduced performance. Li-Fi, however,
utilizes the vast and underutilized visible light spectrum, offering a much wider
bandwidth for interference-free data transmission.

Li-Fi offers a stable connection, creating a smoother and more reliable digital
experience for users. Compared to traditional internet, it gives an exponentially
improved connectivity experience by minimizing dropouts and disruptions that
are a common problem when using radio frequency-based signals.

Since Li-Fi relies on light waves to transmit data, it completely eliminates

dependence on radio frequency signals. Research shows that prolonged exposure
to electromagnetic waves is harmful to living populations and the environment at
large.

11.2 DISADVANTAGES OF LI-FI

Every good thing comes with a bad side. For example, in case of Li-Fi, internet
cannot be used without a light source. This could limit the locations and
situations in which Li-Fi could be used. Similarly, there are few more
disadvantages, which should be taken care of.

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 • Because it uses visible light, and light cannot penetrate walls, the signal’s
range is limited by physical barriers.

Other sources of light may interfere with the signal. One of the biggest potential
drawbacks is the interception of signals outdoors. Sunlight will interfere the
signals, resulting in interrupted Internet.

A whole new infrastructure for Li-Fi would need to be constructed.

Cost is also another factor. As each LED bulb requires a module attached to it to
convert incoming data into flickers, it could be expensive to retrofit whole
buildings with such equipment.

Computers or mobile devices will also need to be fitted with sensors that can read
the light signals and convert them into data. The sensors are currently about the
size of a smartphone and thus not very convenient for mobile users.

A device has to be within the line of sight of the light source, unlike Wi- Fi which
can penetrate most walls.

The problem of how the receiver will transmit back to the transmitter still
persists.

We become dependent on the light source for internet access. If the light source
malfunctions, we lose access to the internet. But considering the fact that
research works are still going on, there are bright chances that most of these
problems will soon be eradicated in the near future. Wi-fi and radiofrequency
will be required in the remote areas where trees and walls will facilitate as an
obstacle.

CHAPTER 12

APPLICATIONS

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 The dramatic growth in the use of LEDs (Light Emitting Diodes) for
lighting provides the opportunity to incorporate Li-Fi into a plethora of LED
environments.

Li-Fi is particularly suitable for many popular internet “content

consumption” applications such as video and audio downloads, live streaming,
etc. These applications place heavy demands on the downlink bandwidth, but
require minimal uplink capacity. In this way, the majority of the internet traffic
is off- loaded from existing RF channels, thus also extending cellular and Wi-Fi
capacities.

There are many applications for Li-Fi. These include:

12.1. RF SPECTRUM RELIEF

Excess capacity demands of cellular networks can be off- loaded to Li-Fi

networks where available. This is especially effective on the downlink where
bottlenecks tend to occur.

12.2. SMART LIGHTING

Any private or public lighting including street lamps can be used to provide Li-
Fi hotspots and the same communications and sensor infrastructure can be used
to monitor and control lighting and data.

12.3. MOBILE CONNECTIVITY

Laptops, smart phones, tablets and other mobile devices can interconnect
directly using Li-Fi. Short range links give very high data rates and also

provides security.

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12.4. HAZARDOUS ENVIRONMENTS

Li-Fi provides a safe alternative to electromagnetic interference from radio

frequency communications in environments such as mines and petrochemical
plants.

12.5 UNDERWATER COMMUNICATION

Due to strong signal absorption in water, RF use is impractical. Acoustic waves

have extremely low bandwidth and disturb marine life. Li-Fi provides a solution
for short-range communications.

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12.6. VEHICLE AND TRANSPORTATION

LED headlights and tail-lights are being introduced. Street lamps, signage and
traffic signals are also moving to LED. This can be used for vehicle-to-vehicle
and vehicle-to-roadside communications. This can be applied for road safety
and traffic management.

12.7. RF AVOIDANCE

Some people claim they are hypersensitive to radio frequencies and are looking
for an alternative. Li-Fi is a good solution to this problem.

12.8. LOCATION BASED SERVICES

Highly accurate location-specific information services such as advertising and

navigation that enables the recipient to receive appropriate, pertinent
information in a timely manner and location.

12.9. HOPITALS AND HEALTH CARE

Li-Fi emits no electromagnetic interference and so does not interfere with

medical instruments, nor is it interfered with by MRI scanners.

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 CHAPTER 13

FUTURE POSSIBILITIES

Li-Fi is purely a technology of future. It is having a potential to take over all the
internet market on its own. The main points to be noted here are as follows:

• With the advancement of Li-Fi technology, it will become more portable,

taking its rightful places in our phones and laptops.

It will give the field of IoT a considerable boost as more and more number of
devices will be able to connect and interact with each other through Li-Fi.

We will also be able to access the internet in places like Hospitals and Airplanes
where traditional network systems can never be used. Underwater
communication will become much easier with the use of Li-Fi. In future, it may
be possible that we will be having an internet with a speed of multi gigabits per
second.

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 With Li-Fi, we will also be moving towards a much more secured network,
which will be safeguarding us from unwanted hackers. Depletion of
Environment due to increased use of radio frequencies will also decrease, as the
Li-Fi technology uses the visible spectrum of light to transmit data.

Installation will also not be an issue with Li-Fi. Multi user support of Li-Fi will
ensure that every individual is getting a high speed of internet.

CHAPTER 14

CONCLUSION

Although there’s still a long way to go to make this technology a commercial

success, it promises a great potential in the field of wireless internet.

A significant number of researchers and companies are currently working on this

concept, which promises to solve the problem of lack of radio spectrum, space
and low internet connection speed. By deployment of this technology, we can
migrate to greener, cleaner, safer communication networks.

The very concept of Li-Fi promises to solve issues such as, shortage of radio-
frequency bandwidth and eliminates the disadvantages of Radio communication
technologies.

Li-Fi is the upcoming and growing technology acting as catalyst for various other
developing and new inventions/technologies. Therefore, there is certainty of
development of future applications of the Li-Fi which can be extended to
different platforms and various walks of human. The Li-Fi technology is now
developed into an omnipresent system technology with ground-breaking
networking capabilities for universal application to deliver a variety of device
platforms for high-speed internet communications.

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VLC will be able to solve many of the problems people have been facing for
many years. In spite of the research problems, it is our belief that the VLC system
will become one of the most promising technologies for the future generation in
optical wireless communication

This technology has a bright scope in future. This technology established a solution to the
problem of integrating Visible Light Communication technology with present
infrastructure, without having to make major changes to that set-up. Visible Light
Communication is a rapidly growing segment of the field of communication. There are
many advantages to using VLC. There are also many challenges. VLC will cleverly solve
many of the problems people have been facing for many years,

CHAPTER 15

REFERENCES

1. Yoti Rani, Prerna Chauhan, Ritika Tripathi, "Li-Fi (Light Fidelity)-The future
technology in Wireless communication ", International Journal of Applied
Engineering Research, ISSN 0973-4562 Vol.7 No.11 (2012).

2. S. Vinay Kumar, Sudhakar, L. Sudha Rani, "Emerging Technology Li-Fi over

Wi-Fi ", International Journal of Inventive Engineering and Sciences (IJIES)
ISSN: 2319 – 9598, Volume -2, Issue-3, February 2014

. 3. Durgesh Choudhary, " Next Generation Communication Li-Fi Technology “,

International Journal of Engineering Research & Technology Website:
www.ijert.orgVolume/Issue: Vol.2 - Issue 11 (November - 2013) e-ISSN: 2278-
0181.

4. Rahul R. Sharma, Raunak, Akshay Sanganal," Li-Fi Technology

Transmission of data through light ", Int.J.Computer Technology &
Applications, Vol 5 (1),150-154.

32
 5. Kshata M Sonnad et al, " Recent advancements in Li-Fi technology ",
International Journal of Electrical, Electronics and Data Communication, ISSN:
2320-2084Volume-1, Issue-10, Dec-2013.

6. M.Mutthamma, " A survey on Transmission of data through illumination-Li-

Fi ", International Journal of Research in Computer and Communication
Technology, Vol 2, Issue 12,December-2013.

7 . Sridharan, " Intelligence with Li-Fi Technology ", International Journal of

Computer Engineering & Science, Jan. 2014.

8. Nivrutti, D.V., Nimbalkar, R.R. (2013). Light-Fidelity: A Reconnaissance of

Future Technology, International Journal of Advanced Research in Computer

9. Science and Software Engineering (IJARCSSE), Vol. 3 Issue 11, October

2013

10. Khandal, D., Jain, S. (2014). Li-Fi (Light Fidelity): The Future
Technology in Wireless Communication, International Journal of Information
& Computing Technology, Vol. 4 No. 16, 2014

11. Singh, A.J., Veeraiahgari (2014). Light Fidelity Technology IOSR Journal
of Electronics and Communication Engineering (IOSR-JECE), Vol. 9 Issue 2,
Mar – Apr 2014

12. Sharma, R.R., Raunak, Sanganal, A. Li-Fi Technology: Transmission of

Data Through Light, International Journal of Computer Technology &
Applications, Vol. 5 (1)

13. Little, T. (2012). Exploding Interest in Visible Light Communications: An

Applications Viewpoint, Smart Lighting Annual Industry-Academia Days,
February 13-15 2012

33
14. Singh, J., Vikash (2014). A New Era in Wireless Technology using Light-
Fidelity, International Journal of Recent Development in Engineering and
Technology (IJRDET), Vol. 2 Issue 6, June 2014

15. Sonnad, A.M., Gopan, A., Sai Lakshmi N.R., Divya S., Ambika R., (2013).
Recent Advancements in Li-Fi Technology, International Journal of Electrical,
Electronics and Data Communication, Vol. 1 Issue 10, December 2013

16. Tanwar, K., Gupta, S., (2014). Smart Class Using Li-Fi Technology,
International Journal of Engineering and Science (IJES), Vol. 3 Issue 7, 2014

17. R. Karthika, Balakrishnan, (2015). Wireless Communication using Li-Fi

Technology SSRG International Journal of Electronics and Communication
Engineering (SSRG-IJECE), Vol. 2 Issue 3, Mar 2015

18. Abu-alhiga, R.; Haas, H., "Subcarrier-index modulation OFDM," Personal,

Indoor and Mobile Radio Communications, 2009 IEEE 20th International
Symposium on, vol., no., pp.177,181, 13-16 Sept. 2009

19. “Harald Haas: Wireless data from every light bulb”,

https://www.youtube.com/watch?v=NaoSp4NpkG

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