Lifi New Project
Lifi New Project
Lifi New Project
JnanaSangama, Belagavi-590018
BACHELOR OF ENGINEERING
IN
ELECTRONICS AND COMMUNICATION ENGINEERING
Submitted by
Chaithanya.R (1RR17EC021)
Megha.B (1RR17EC070)
Lekhana.H.M (1RR18EC045)
Monica.N (1RR18EC055)
Dr. P Bhuvaneswari
Associate Professor
[Accredited by NBA & NAAC, Affiliated to VTU, Belagvi, Approved by AICTE, NewDelhi]
CERTIFICATE
This is to clarify that the mini project work entitled “AUDIO TRANSMISSION USING
LIFI TECHNOLOGY” is a bonafide work carried out by CHAITHANYA R
(1RR17EC021), MEGHA B (1RR17EC070), LEKHANA H M (1RR18EC045),
MONICA N(1RR18EC055) in partial fulfilment for the award of Bachelor of Engineering
in Electronics and Communication Engineering of the Visvesvaraya Technological
University, Belgavi during the year 2020-2021. It is certified that all corrections &
suggestions indicated for internal assessment have been incorporated in the report &
deposited in the departmental library. The project report has been approved as it satisfies the
academic requirements.
1.
2.
DECLARATION
We, CHAITHANYA R ( 1RR17EC021), MEGHA B (1RR17EC070), LEKHANA H M
(1RR18EC045), MONICA N (1RR18EC055) students of 6th semester BE in Electronics
and Communication Engineering , RajaRajeswari College of Engineering, Bangaluru
hereby declare that the Mini project work entitled “AUDIO TRANSMISSION USING
LIFI TECHNOLOGY” submitted to Visvesvaraya Technological University during the
academic year 2020-2021,is record of an original work done by us, under the guidance of Dr.
P. Bhuvaneswari, associate professor, Electronics & Communication Engineering,
RajaRajeshwari college of Engineering, Bengaluru. This project work is submitted in partial
fulfilment of the requirements for the award of the degree of Bachelor of Engineering in
Electronics & Communication Engineering. The results embodied in this have not been
submitted to any other University or Institute for the award of any degree.
Chaithanya. R (1RR17EC021)
Megha . B ( 1RR17EC070)
Lekhana. H M (1RR18EC045)
Monica. N (1RR18EC055)
DATE:
PLACE: BENGALURU
ACKNOWLEDGEMENT
We hereby take this opportunity to express our sincere gratitude to the following eminent
personalities whose aid and advice helped us to complete this project Report work
successfully without any difficulty.
We would like to acknowledge our regards to Prof. Dr. L. Rangaiah HOD, Electronics
and communication department, Rajarajeswari college of engineering.
We would like to acknowledge our regards to our guide, Associate Professor. Dr. P.
Bhuvaneswari, Electronics and Communication Engineering, RajaRajeswari College of
Engineering, Bengaluru, whose valuable inputs have made us richer in terms of knowledge
and also for guiding us at a place where everything was not familiar and also her consistent
motivation and encouragement.
We would like to acknowledge our regards to our mini project co-ordinators Dr. R.
Gangadhar Reddy & Prof. Sunitha R , Associate Professors, Electronics and
Communication Engineering department, for their encouragement and valuable guidance.
We take this opportunity to express our gratitude to all and non-teaching staff of
Department of Electronics and Communication Engineering and also those individuals who
helped and motivated us at different times in our career. Last and not the least, our heart full
thanks to our dearest family for their reliable support and prayers forever.
ABSTRACT
In the world of wireless technology, Wi-Fi is most versatile and effective technology
which compact with radio frequencies for data transmission .The number of devices use
wireless communication to access internet of sharing data. This has unfortunately led to
increase in network complexity, shortage of wireless radio bandwidth and increase risk of
interference of radio frequency. This project focuses on Li-fi technology which is used to
transmit the data using visible light communication by using light emitting diodes. Li-fi is the
novel technology for high density wireless data transfer relieving no radio interference in
confined areas. The signals are transmitted for one system to another by using LED as Li-fi
transmitter and photo detector as Li-fi receiver. This is much more secure method of
transmission compared to existing technology. Noticeable light communication has increased
extraordinary enthusiasm for most recent decade because of quick improvement of LED
manufacture, adequacy, durable, long life, expectancy of LEDs and also as quick information
exchange gear. Data transmission rate is very high around few Gbps . This technology
envisions future where data for laptops, smart phones, tablets will be transmitted in an
economic and eco friendly medium of light.
TABLE OF CONTENTS
CERTIFICATE 2
DECLARATION 3
ACKNOWLEDGEMENT 4
ABSTRACT 5
TABLE OF CONTENT 6
LIST OF FIGURES 8
LIST OF TABLES 9
Chapter 1 – INTRODUCTION 10
6.1 Advantages 33
6.2 Limitations 34
6.3 Applications 35
7.1 Conclusion 37
REFERENCE 38
TABLE OF FIGURE
WIFI
AUDIO TRANSMISSION USING LIFI TECHNOLOGY
CHAPTER 1
INTRODUCTION
Over the past few years there has been a rapid growth in the utilization of the RF region of
the electromagnetic spectrum. This is because of the huge growth in the number of mobile
phones subscription in recent times. This has been causing a raid reduction in free spectrum
for future devices. Light fidelity (Li-Fi) operates in the visible light spectrum of the
electromagnetic spectrum i.e. it uses visible light as a medium of transmission rather than the
traditional radio waves.
Li-Fi stands for Light-Fidelity. Li-Fi is transmission of data using visible light by sending
data through an LED light bulb that varies in intensity faster than the human eye can
follow .If the LED is on, the photo detector registers a binary one; otherwise it’s a binary
zero. The idea of Li-Fi was introduced by a German physicist, Harald Hass, the light, which
he referred to as ‘DLight’ , can be used to produce data rates higher than 1 Giga bits per
second which is much faster than our average broadband connection.
The high speed achievement of Li-Fi can be explained using frequency spectrum of
Electromagnetic Radiations. From the electromagnetic spectrum we can see that the
frequency band of the visible light is in between 330THz to 770HZ and that of Radio
Frequency Band is in between 1Hz to 3THz, hence the Frequency Bandwidth of the visible
light is about 400 times greater than the radio frequency Bandwidth .Hence Data rate will be
higher in the Li-Fi and higher seed can be achieved. Using Li-Fi we can transmit any data
that can be transferred using conventional Wi-Fi network. That can be Images, Audio,
Vedio , Internet connectivity, etc.. but the advantages over the Wi-Fi network are High
speed, increased security, More number of connected devices, and Less cost. In coming years
number of devices that support Li-Fi will hit the market.
Fig 1.1 shows electromagnetic spectrum .This Mini project discuss the implementation of the
most basic Li-Fi base system to transmit Sound signal from one device to another through
visible light. The purpose is to demonstrate only the working of the simplest model of Li-Fi
with no major consideration about the data transfer speed. This model will demonstrate how
the notion of one-way communication via visible light works, in which Light emitting diodes
(LEDs) are employed as the light sources or Transmitter antennas. The model will transmit
digital signal via direct modulation of the light. The emitted light will be detected by an
optical receiver. In addition to the demonstration purpose, the model enables investigation
into the features of the visible light and LEDs incorporated in the communication model.
CHAPTER 2
2. LITERATURE SURVEY
Now-a-days, majority of us are familiar with Wi-Fi (Wireless Fidelity), which generally uses
2.4, 5 GHz radio frequencies to transmit data wirelessly. But, these radio waves are harmful
for living beings. So, the best alternative for this problem is Visible Light Communication
(VLC), where LED lights are used to transfer the data wirelessly. VLC is recently referred as
Li-Fi. It is a term often used to describe high speed VLC in application scenarios where Wi-
Fi might also be used. The term Li-Fi is similar to Wi-Fi with the exception that light rather
than radio is used for transmission. Professor Harald Haas, from the University of Edinburgh
in the UK, is widely recognized as the original founder of Li-Fi. By the end of AUGUST
2013, data rates of over 1.6 Gbps were achieved using Li-Fi (Light Fidelity). In APRIL 2014,
the Russian company Stins Coman has announced the development of a Li-Fi wireless local
network called Beam Caster. They achieved data rates of 1.25 Gbps. With Li-Fi, we can able
to communicate under water, gives more security compares to Wi-Fi as light cannot pass
through wall of the room.
Transmitting data through photo diodes has been happening for long time through our
IR remotes.
Every time we pressed a button on our television remote IR LED in the remote pulses
vary fast this will be received by television and then decoded to each other using
wireless network
Other inconveniences of this method are special equipment requirement, high power
consumption and high cost. Secure data transmission is not available here. WPS key
encryption can be provided and hacking can also easily done, since it uses radio wave
transmission is harmful to health
Visible light is a new technique of data transmission method. Li-fi data is transmitted
by modulating the intensity of light which is then received by photosensitive detector.
This modulation is performed in such a way that they not perceptible to human eye.
VLC consists of a light source a transmitter and detector as a receiver.
This electrical signal is amplified by the amplifier circuit and fed into the power LED.
The light signal from the LED varies according to the intensity of voice signal louder
the voice the glow of the LED will be more.
The receiver section interprets the incoming light which is detected using a solar
panel and converts to the audio sound signal with the help of the speaker
Hence with Li-fi this method is made sophisticated by using more than one LED and
passing more than one data stream at a given time.
This way more information can be passed and hence a faster data communication is
possible.
CHAPTER 3
INTRODUCTION
Our system represents audio transmission using Li-fi technology which it includes input,
comparator, lampdriver, LED, photodetector, amplifier, speaker and output.
BLOCK DIAGRAM
Fig
3.1
Block Diagram
Lamp driver
LEDs
Photo detector
Amplifier and Speaker
Output at the destination
INPUT
Input consists of analog signal, which is usually taken from the audio output of the Mobile
phone. The signal will be at low voltage level which is not enough to drive an LED, So in
order to drive the LEDs we have to amplify the signal using amplifier
COMPARATOR
The input signal from an audio device will be at low voltage level, so in order to modulate the
signal using visible light, we have to convert the signal into a Pulse Wave format (signal
representing 0 & 1). To accomplish this task we use an Op-Amp IC. The comparator
compares the input signal with a reference voltage and produces an output which will be in
pulse wave form. The pulse wave so found is amplified and modulated at the lamp driver.
LAMP DRIVER
The pulse wave from the comparator has to be amplified to drive the LEDs. And Modulation
of the input signal and Carrier light signal is also taking place at the Lamp driver using a
transistor called BC548 , which is general purpose silicon transistor uses as application
transistor as well as modulation transistor.
The amplified and modulated pulse is used to drive the LEDs. These LEDs transmit the
modulated signals to the receiver.
LEDs
In Li-Fi Transmission, the most important requirement of light sources is its ability to turn
ON and OFF repeatedly in very short intervals (in ns range).So we use LEDs which have
very low switching time. These LEDs turn ON and OFF in Nano second based on the pulse
signal. Since the switching taking at a faster rate, it cannot be detected by human eye. So it
will appear as illuminating even though they are blinking. Thus modulated signl is
transmitted to receiver via visible light.
PHOTO DETECTOR
The transmitted signal from the LEDs has to be detected, demodulated n acknowledged. So in
order detect the message signal from the blinking LED light, we use a photo cell or a Solar
cell ( which comprises large no of photo cells connected in series).The solar cell detects only
the variation of the light, since the blinking can be easily detected and output of the solar cell
will be the message signal in the analog form. So using solar we could detect and demodulate
the message signal transmitted.
The demodulated signal will be at low voltage range. So it is Amplified to the arbitrary
voltage level using an amplifier. This amplifier will be same type of amplifier which we used
in transmitter side. This is due to the fact that if any phase errors occurred, it will be cleared
at this stage. The speaker will convert the electrical signal to audible from using electro
magnets present in the speaker.
OUTPUT
The demodulated audible signal is transmitted from speaker to its final destination. So that
the audience can listen to the message that has been transmitted from the source.
CHAPTER 4
The above figure 4.1.1 depicts the transmitter circuit of the Li-Fi circuit. We know that
carrier waves can take signals along destinations, so this is simple concept when we put
photons with speed of light by source to destination it can also carry signals of low frequency
to destination so we build a circuit which can modulate light with low frequency signals.
Take input from an audio device, the input will be very low audio signals of 20Hz to
20KHz. These signals paces through C1 (100nf) where DC (Direct Current) components are
filtered removed. Through R3 100kΩ which is a current limit for comparator µA741 (Op-
Amp) to protect it from the high current which cause destruction of the Op-Amp. Through R1
100kΩ and R4 100kΩ, voltage at the inverting terminal of the Op-Amp limit to 5v/2=2.5v.
Input signal at pin 3 of op-amp and compare with pin 2 of Op-Amp and output will be present
at the Pin No 6 of the Op-Amp IC.470kΩ pot or feedback gain controller to control volume at
output of the Op-Amp if there is no input is fed to the comparator, a positive DC wave will
present at pin 6 of Op-Amp, which make transistor Q1 keep alive and LED starts to glow
continuously. The C3, C4 (Both are 470µF) are filters to reduce AC components spike in
circuit.
Whenever signals interrupt through pin 3 of op-amp (input from Audio device). The
comparator compares the input signal with the reference voltage and produces an pulse wave
output at the pin 6.The width of the pulse wave is controlled by the input signal frequency.
The pulse signal is equivalent to the ON/OFF signal which control the intensity of the light
source LED (D1). The pulse is further amplified and modulated using transistor BC548 (T1),
which is an amplifier modulator having high current gain. The transistor will act as a lamp
driver and drives the LED. LED emits light according to the pulse waveform and make VLC
(Visible light communication) alive. Since the blinking of the LED is controlled by the input
signal, it will take place in Nano Seconds (ns) it cannot detected human eyes.
The power supply is the most indispensable part of any project. IC Regulators are
versatile and relatively inexpensive and are available with features such as current/voltage
boosting, internal short circuit current limiting, thermal shutdown and floating operation for
high voltage applications. The regulated circuit is used to maintain constant output level. The
regulator IC here used is LM 7805. It provides regulated 5V to the circuit. Its maximum input
voltage is 35V and minimum voltage is 8V. Output is constant 5V.The pin out diagram of
LM 7805 IC is given below LM7805 have several features, they are listed below.
We can also use 5V DC cell for the power supply of the circuit
4.3.2 CAPACITORS
is a big capacitor. Usually we’ll see capacitors rated in the Pico-(10 -12) to microfarad (10-6)
range.
4.3.3 RESISTORS
Resistors are the most commonly used components in electronics and their purpose is to
create specified values of current and voltage in a circuit. The unit for measuring resistance is
the OHM. (The Greek letter Ω - called Omega). Higher resistance values are represented by
“k” (kilo-ohms) and M (Mega ohms). For example, 120 000 Ω is represented as 120k, while
1200000 Ω is represented as 1MΩ. The dot is generally omitted as it can easily be lost in the
printing process. In some circuit diagrams, a value such as 8 or 120 represents a resistance in
ohms. Another common practice is to use the letter E for resistance in ohms.
Resistance value is marked on the resistor body. Most resistors have 4 bands. The first two
bands provide the numbers for the resistance and the third band provides the number of zeros.
The fourth band indicates the tolerance. Tolerance values of 5%, 2%, and 1% are used.
The following table shows the Color Code used to identify resistor values.
Yellow 4 x 10 kW ±25*10-6/K
Green 5 x 100 kW ±0.5%
Blue 6 x 1 MW ±0.25% ±10*10-6/K
Violet 7 x 10 MW ±0.1% ±5*10-6/K
Grey 8 x 100 MW
Operational amplifiers had their origin in analog computers, where they were used to do
mathematical operations in many linear, non-linear and frequency-dependent circuits.
The popularity of the op-amp as a building block in analog circuits is due to its versatility.
Due to negative feedback, the characteristics of an op-amp circuit, its gain, input and output
impedance, bandwidth etc., are determined by external components and have little
dependence on temperature coefficients or manufacturing variation in the op-amp itself
Op-amps are among the most widely used electronic devices today, being usual in a
vast array of consumer, industrial and scientific devices. Many standard IC op-amps cost only
a few cents in moderate production volume; however, some integrated or hybrid operational
amplifiers with special performance specifications may cost over $100 US in small
quantities.
Features of op-amp IC
Short-circuit protection
Offset-voltage null capability.
Large common-mode and differential voltage ranges.
No frequency compensation required and latch up.
A-741 is general exhibits high stability.
It can be configured in inverting and non-inverting mode.
It can be used to implement comparators, A stable, Monostable, Multivibrators,
Amplifiers, etc.,
4.3.5 POTENTIOMETER
The measuring instrument called a potentiometer is essentially voltage divider used for
measuring electric potential(voltage), the component is an implementation of the same
principle, hence its name.
Potentiometer are commonly used to control electrical devices such as volume controls on
audio equipment. Potentiometer operated by a mechanism can be used as position
transducers, for example in joystick. Potentiometer are rarely used to directly control
significant power(more than a watt), since the power dissipated in the potentiometer would be
comparable to the power in the controlled load.
The most important requirement that a light source has to meet in order to serve.
Communication purpose is the ability to be switched on and off repeatedly in very short
intervals. By utilizing the advantage of fast switching characteristics of LED’s compared with
the conventional lightening, the LED illumination is used as a communication source. Since
the illumination exists everywhere, it is expected that the LED illumination device will act as
alighting device and a communication transmitter simultaneouslyeverywhere in a near future.
Typically, red, green, and blue LEDs emit band of spectrum, depending on the materials
system. The white LED draws much attention for the illumination devices. Comparing the
LED illumination with the conventional illumination such as fluorescent lamps.
Incandescent bulbs, the LED illumination has many advantages as high efficiency
environmental-friendly manufacturing design flexibility, long life time, and better spectrum
performance.
LEDs emit light when energy levels change in the semiconductor diode. This shift in
energy generates protons, some of which are emitted as light the specific wave length of the
light depends on the difference in energy levels as well as the type of semiconductor material
used to for the LED clip. Solid-state designed allow LEDs to withstand shock vibration
frequent switching (electrical on and off shocks) and environmental (mechanical shocks)
extremes without compromising their famous long life typically 1,00,000 hours or more.
The basic LED consists of a semiconductor diode chip mounted in the reflector cup of
a lead frame that is connected to electrical (wire bond) wires, and then encased in a solid
epoxy lens. The architecture of LEDs is shown in figure
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AUDIO TRANSMISSION USING LIFI TECHNOLOGY
The solar cell is used to detect the light from the transmitting LEDs. And it produces an
analog output corresponding to the input signal. The frequency of the analog will be same as
that of input signal, since the flickering of LED is controlled by the input signal and solar cell
detects only the fluctuation in the LED signal and produces the output. The output is then
amplified using BC 548. It also helps in removing any pulse changes occurs in the
transmitting signal. The amplified signal is fed to the speaker. The speaker converts the
analog signal to the audible sound signal using the electromagnet present in the speaker.
A solar cell is an electrical device that converts the energy of light directly to
electric signal or analog signal by the photovoltaic effect, which is a chemical physical
phenomenon. When photons are strikes on its wall electron flow occurs which will store as
electrical energy it have slower time response as their area increases. Solar cell is formed
connecting large number of photo detectors connecting in series. It works in the reverse
Biased mode. Usually the efficiency of solar cell is low. Even through it regulated as green
technology.
4.6.2 SPEAKER
In this project we use speakers which has in-built Amplifier, which amplifies the
analog signal received from the output of the solar cell. It also helps to remove any phase
errors that may occur during the transmitting or producing of the input signal the main
functions of the speaker is to convert electrical or analog signal into the audible form to reach
the receptor. I converts the sound signal with the help of electromagnets present in the
speaker. Receptors receive the input that has been transmitted from the transmitter.
Design of printed circuit circuit board (PCB) can be considered as well as the last step
in electronic circuit design as well as the first step in production. It plays important role in the
performance and reliability of electronic circuits, the production of the PCB’s its assembling,
and its service ability depends on design. All these factors get reflected in a piece of
electronic equipment. It is clear that task of PCB design is not very simple or always straight
forward. The schematic is follower by layout generation. Layout design is the stage where
engineering capacity combined with creativity is the governing inputs.
Most product testing is being done is done with the help of computer program. The
term Electronic Design Automation (EDA) is begin used to describe the use of these tools.
With the help of advantages powerful computing
Systems and interactive software tools and development of electronic circuits has undergone
automation . Thus the software and hardware tools, which enables this automation includes
PCB designing ,IC design , circuit simulation etc. These tools helps us in such a way that we
can draw the circuit; test the functioning of the circuit in response to test inputs in simulation
software.
After successfully simulation we can get the PCB art work done by replacing the
routing software. The design automation tool used here is ORCAD.
The next step is to assign part reference. Each component has to be assigned footprint
or PCB pattern name. The footprint gives the actual size physical representation of
components on the PCB artwork. The component symbol and foot symbol should correspond
in all respects.
After the circuit schematic is completed with all required information such as part
reference and footprints, the design rule check can be used for checking errors in the design.
It will check for duplicate symbols, overlapped lines and dangling line.
After the schematic design file passes the DRC check, it is processed by a program
called an electric rule checks for writing errors. The final operation to be done before starting
PCB artwork is the net list creation.
A net list creation of the components and interconnection along with other
information such as foot prints , track width etc. A net list software or tool can take the circuit
schematic as input and generate net list. The net list can be used as an information source for
the remaining stages.
In automatic design, the net list obtained from the previous stage is used for getting
the required foot print and interconnection . The software used for the PCB artwork design in
the ORCAD LAYOUT.
PCB FABRICATION
You need to generate a positive (copper black) UV translucent art work film. you will never
get a good board without good art work .so it is important to get the best possible quality at
this stage. The most important thing is to get a clear sharp image with a very solid opaque
black. Art work is done using ORCAD software. It is absolutely essential that your PCB
software points holes in the middle of pads. Which will act as centre marks when drilling.It is
virtualy imposibel to accurately hand- drill boards without these holes.If you are looking to
buy PCB software at any cost level and want to do hand- prototyping of boards before
production,check that this facility is available when defining pad and line shapes, the
minimum size recommended (through-linking hole) for reliable result is 50mil,
assuming0.8mm drill size:1 mil=(1/1000)th of an inch . You can go smaller drill size , but
through linking will be harder , 65mil round or square pads for normal components.
ICs, with 0.8 mm hole. Will allow a 12.5mil, down to 10mil if you really need to.
Centre-to-centre spacing of 12.5mil tracks should be 25 mil-slightly less may be possible if
your printer can manage it. Take care to preserve the correct diagonal track-track spacing on
metered corners: grid is 25 mil track width 12.5 mil. The art work must be printed such that
the printed side is in contact with PCB surface when exposing, to avoid blurred edges. In
practice, this means that if you design the board as seen from the component side, the bottom
(solder side ) layer should be printed the ‘correct ‘way round, and top side of the double-
sided board must be printed mirrored.
PCB LAYOUT
CHAPTER 5
Li-Fi is a term of one used to describe visible light communication technology applied to
high speed wireless communication. It acquired this name due to the similarity to Wi-Fi, only
using light instead of radio. Wi-Fi is great for general wireless coverage within buildings, and
Li-Fi is ideal for high density wireless data coverage in confined area and for relieving radio
interference issues, so the two technologies can be considered complimentary.
LIFI WIFI
1.Medium Light as a carrier Radio Spectrum
2.Speed .>1 GB/s 150 Mb/s
3.Security Cannot penetrate walls and Wifi is less secure
ceiling thus highly secure
from external sniff
4.Operating frequency Hundred of Tera Hz 2.4 Giga Hz
5.Sprectrum Range About 10 mts About 32 mts
6.Cost Cheaper than wifi Expensive in comparison
with Lifi
CHAPTER 6
In our project we designed and implemented a wireless communication device which transmit
audio message wirelessly known as LIGHT FIDELITY (Li-Fi). The project contains two
sections 1 – Transmitter Section and 2 – Receiver Section. The transmitter section modulate
the incoming message audio signal and transmit towards the receiver in the form Visible
Light using LED. The receiver section interprets the incoming light which is detected using a
solar panel and converts to the audible sound signal with the help of Speaker.
This picture shows the transmitting and receiving section of Lifi model.
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AUDIO TRANSMISSION USING LIFI TECHNOLOGY
6.1 ADVANTAGES
Li-fi technology is based on Leds or other light source for the transfer if data. The transfer of
the data can be with the help of all kinds of light, no matter the part of the spectrum that they
belong. That is, the light can belong to the invisible, ultraviolet or the visible part of the
spectrum. Also, the speed of the communication is more than sufficient for downloading
movies, games, music and all in very less time. Also, Li-fi removes the limitation that have
been put on the user by the Wi-fi.
CAPACITY
Light has 400 times wider bandwidth than radio waves. Also, light sources are already
installed. So, Li-fi has got better capacity and also the infrastructure are already available.
EFFICIENCY
Data transmission using Li-fi is very cheap. Led lights consume less energy and are highly
effective and long lasting
AVAILABILITY
Availability is not an issue as light sources are presents everywhere. There are billions of
lightsworldwide. They just need to be replaced with Leds for proper transmission of data.
SECURITY
Light waves do not penetrate through walls. So, they can’t be interrupted and misused.
6.2 LIMITATIONS
The major Limitations of this technology are
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The artificial light cannot penetrate into walls and other opaque materials which radio
waves can do. So, a Li-fi enables and device (through its inbuilt phot receiver) will never be
as fast and handy as a Wi-fi enabled device if any doubts if any obstacle is present between
transmitter and receiver.
To function Li-fi with full efficiency. It requires line of sight. That is the transmitter
antenna and receiver antenna should be in a time (face to face). Still, Li-fi could emerge as a
born to the rapidly depleting bandwidth of radio waves. And it will certainly be the first
choice for accessing internet in a confirmed room at cheaper cost.
6.3 APPLICATIONS
There are numerous applications of this technology, from public internet access
through street lamps to auto-piloted cars that communicate through their headlights.
Applications of Li-fi can extend in areas where the Wi-fi technology lacks its presence like
medical technology, power plants and various other areas. Since Li-fi uses just the light, it
can be used safely in aircrafts and hospital where Wi-fi is banned because they are prone to
interfere with the radio waves. All the street lamps can be transferred to Li-fi lamps to
transfer data. As a result of it, it will be possible to access internet at any public place and
street. Some of the future applications of Li-fi are as follows.
EDUCATION SYSYTEMS
Li-fi is the latest technology that can provide fastest speed internet access. So, it can replace
Wi-fi at educational institutions and at companies so that all the people can make use of Li-fi
with the same speed intended in a particular area.
MEDICAL APPLICATIONS
Operation theatres(OTs) do not allow Wi-fi due to radiation concerns. Usage of Wi-fi
at hospital interferes with the Mobile and PC which blocks the signals for monitoring
equipment’s. It may be hazardous to the patient’s health. To overcome this and to make OT
tech savvy Li-fi can be used to accessing internet and to control medical equipment’s
procedures.
The passengers travelling in aircrafts get access at low speed intend at a very high rate. Also,
Wi-fi is not used because it may interfere with the navigational systems is the plots. In
aircrafts Li-fi can be used for data transmission. Li-fi can easily provide high speed internet
via every light source such as overhead reading bulb, etc, present inside the airplane.
DISASTER MANAGEMENT
UNDERWATER APPLICATIONS
Under water ROVs (Remotely operated vehicles) operate from large cables that supply their
power and allow them to receive signals from their pilots above. But the lether used in ROVs
is not long enough to allow them to explore largest areas. If their wires were replaced with
light say from submerged, high powerful lamp then they would be much freer to explore.
They could also use their headlamps to communicate with each other, processing data
autonomously and sending their findings periodically back to the surface. Li-fi can even work
underwater where Wi-fi fails completely, thereby throwing open endless opportunities for
military operations.
Power plants need fast, inter-connected data system so that demand, grid integrity and
core temperature (in case of nuclear power plants) can be monitored. Wi-fi and many other
radiation types are bad for sensitive areas surrounding the power plants, Li-fi cold offer safe,
abundant connectivity for all areas of these sensitive locations. This can save money as
compared to the currently implemented solutions. Also, the pressure on a powerplant’s own
reserves could be lessened. Li-fi can also be used in petroleum or chemical plants where other
transmission or frequencies could be hazardous
.
Department of ECE, RRCE, Bangalore 28 2020-
2021
AUDIO TRANSMISSION USING LIFI TECHNOLOGY
TRAFFIC MANAGEMENT
In traffic signals Li-fi can be used which will communicate with Led lights of the cars which
can help in managing the traffic in a better manner as the accident numbers can be decreased.
Also, led car lights can alert drivers when other vehicles are too close.
Li-fi doesn’t work using radio waves. So, it can be used in the places where Bluetooth,
infrared, Wi-fi, etc., are banned.
CHAPTER 7
7.1 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 hotspot to transmit wireless
data and we will proceed towards the cleaner, greener, safer and brighter future. The concept
of Li-fi is currently attracting a great deal of interest, not least because it may offer a genuine
and very efficient alternative to radio-based wireless. As a growing number of people and
their many devices access wireless internet, the airwaves are becoming increasingly clogged,
making it more and more difficult to get a reliable, high speed signal. This may solve issues
such as shortage of radio frequency bandwidth and also allow internet where traditional
radio-based wireless isn’t allowed such as aircraft or hospital. The main shortcoming
however is that it only works in direct line of sight.
By using Li-fi we can have energy saving parallelism. With growing number of people
and their many devices access wireless internet, on one-way data transfer at high speed and at
cheap cost. In future we can have Led array beside m motorway helping to light the road,
displaying the latest
REFERENCES
Zashi P. Choudhari, Satish R. Devane,” High sensitivity universal Li-Fi receiver for
IEEE.
Luis Bica Oliveira, Nuno Paulino, Joao P. Oliveira, Rui Santos, Nuno Pereira, Joao
Mohit Sanjeev Kumar, Gujar Shrikant, Velankar Arun Chavan “Realtime audio