Seminar Report Submitted for the fulfillment of requirement for 6th sem . CSE

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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

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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

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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

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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’.

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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

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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.

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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.

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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

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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.

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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

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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.

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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.

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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.

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 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

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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.

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 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.

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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.

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