This document summarizes a presentation on Li-Fi technology. It begins with an introduction and overview of Li-Fi, noting that it uses visible light communication and LED bulbs to transmit data. It then discusses the history of Li-Fi, including the first public demonstration in 2011. The document outlines the basic working process and construction of Li-Fi systems. It compares Li-Fi to Wi-Fi and discusses some applications. The document also briefly mentions security benefits and challenges facing Li-Fi development, such as the need for line of sight transmission. It concludes by stating that Li-Fi could provide a high-speed wireless alternative to congested radio frequencies.

2. A
Presentation on
LI-FI TECHNOLOGY
for the partial fulfillment of the requirement
for the degree of
Bachelor of Technology
in
Computer Science And Engineering

3.  Introduction
 History
 Present Scenario
 Working Process
 Construction
 Li-Fi vs Wi-Fi
 Applications
 Security
 Challenges for Li-Fi
 Conclusion

4.  Li-Fi is the transmission of data through
illumination by taking the fiber out of
fiber optics by sending data through a
LED light bulb.
 This varies in intensity faster than human
eye can follow.
 It is the fast and cheap wireless
communication system which is optical
which is optical version of the Wi-Fi.

5. Harald Hass, a professor at the
University of Edinburgh who
began his research in the field in
2004, gave a debut demonstration
of what he called a Li-Fi prototype
at the TEDGlobal conference in
Edinburgh on 12th July 2011.

6. on 12th July 2011. He used a table lamp with an LED
bulb to transmit a video of blooming flowers that was
then projected onto a screen behind him. During the
event he periodically blocked the light from lamp to
prove that the lamp was indeed the source of incoming
data.
At TEDGlobal, Haas demonstrated a data rate of
transmission of around 10Mbps -- comparable to a fairly
good UK broadband connection. Two months later he
achieved 123Mbps.
Back in 2011 German scientists succeeded in creating
an800Mbps (Megabits per second) capable wireless
network by using nothing more than normal red, blue,
green and yellow.

7.  Radio Spectrum is congested but the demand for wireless data
double each year .Every thing, it seems want to use wireless
data but the capacity is drying up.
1.4 Million Base Stations 5 Billion

8.  Issues regarding Radio Spectrum

9.  Capacity
 Radiowaves
 Cost and Expensive
 Less Bandwidth compared to other spectrums
 Insufficient spectrum for increasing data
 Millions of base stations consume huge amount
of energy for
1.Transmitting the radio waves
2.To cool the base station cabins
 5% Efficiency
Efficiency

10.  Availability
 Available within the range of Base stations
 Limited availabity
 Unavailable in aircrafts
 Less secure(passes through the walls)
 Security

12. Radio
Waves
Infrared
Rays
Visible
Rays
Ultraviole
t Rays
X- Rays
Gama
Rays
 Gama rays cant be used as they could be dangerous.
 X-rays have similar health issues.
 Ultraviolet light is good for place without people, but other
wise dangerous for the human body.
 Infrared, due to eye safety regulation, can only bse used with
low power.
HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT
SPECTRUM.

13.  Operational procedure is very simple, if the led is on, you transmit a
digital 1, if its off you transmit a 0. The LEDs can be switched on and
off very quickly, which gives nice opportunities for transmitting data.
Hence all that us required is some LEDs and a controller that code data
into those LEDs. We have to just vary the rate at which the LED’s .
 Flicker depending upon the data we want to encode .
 Thus every light source will works as a hub for data transmission
.

15. Li-Fi product consists of 4 primary sub-
assemblies:
 Bulb
 RF power amplifier circuit (PA)
 Printed Circuit Board (PCB)
 enclosure

16.  The PCB controls the electric 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 electronic field about the
bulb.

17.  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 sub-assemblies are contained
in an aluminum enclosure.

18.  Li- Fi is a term of one used to describe
visible light communication technology
applied to high speed wireless
communication.
 It acquires this name due to the similarity
to Wi-Fi, only using light instead of radio.

19.  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.

20. Technology Speed Data
density
Wireless (future)
 Wi-Gig 2Gbps **
 Giga-IR 1Gbps ***
 Li-Fi 1Gbps ****

22.  Li-Fi technology is based on LEDs for the
transfer of data.
 The transfer of the data can be with the
help of all kind of light i.e., Light may be
Invisible, Ultraviolet or Visible part of
spectrum.
 The speed of the internet is incredibly
high and the user everything in just a few
minutes.

23. Some of the applications of Li-Fi are given
below:
 Airways
 Green information technology
 Free from frequency bandwidth problem
 Increase communication safety
 Multi user communication
 Lightings points used as hotspot
 Smarter power plants
 Under sea Awesomeness

24.  Li Fi technology is still in its infancy .However some areas
where it seems perfectly applicable are:-
1 . Traffic Lights :
Traffic lights can communicate
to the car and with each other.
Cars have LED-based
headlights, LED-based cack
lights, and cars can
communicate with each other
and prevent accidents in by
exchanging information.

25. 2. Intrinsically Safe Environment :
Visible Light is more safe than RF, hence it can be used in
places where RF can't be used such as petrochemical plants .

26.  Hospitals(In Few Medical Equipements) :

27. 3. Airlines :
Whenever we travel through airways we face the problem in
communication media ,because the whole airways communication are
performed on the basis of radio waves. To overcome this drawback on
radioways , li-fi is introduced.

28. 4. On Ocean Beds :
Li-Fi can even work underwater were Wi-Fi fails
completely, thereby throwing open endless opportunities for
military/navigation operations.

29. • There are millions of street lamps deployed around the world.
 Street Lamps (As free Access Points) :
• Each of these street lamps could be a free access point.

30. In a meeting room environment, the access area of each channel is the width of
the light pool, and can be accessed by multiple users. Each user can receive
higher data rates than would be the case for an equivalent Wi-Fi channel. In the
Wi-Fi case, each user or group of users directly competes for access to
bandwidth. The net result is that the more connections there are, the slower the
download speeds are for all. By contrast, in the case of Li-Fi, with its greater
number of available access points, each pool of light provides full channel data
rates with fewer simultaneous users. The overall net bene??t to each user is up
to 1000 times greater speeds. In addition, and in contrast to radio waves, the
light does not pass through the walls. Therefore, with minimal precautions to
avoid leakage from windows, etc., security is fundamentally enhanced as
compared with Wi-Fi.
SECURITY

31.  Light can't pass through objects .
 Interferences from external light sources like sun light, normal
bulbs, and opaque materials in the path of transmission will cause
interruption in the communication.
 High installation cost of the VLC systems .
 A major challenge facing Li-Fi is how the receiving device
will transmit back to transmitter.
 Li-Fi requires line of sight.

32.  Li-Fi technic can not work on dark and outdoor
 Unlike Wi-Fi we can not move to other room
because there are wired bulb too

33.  As a growing number of people and their
devices access wireless internet, the air waves are
becoming increasingly clogged, making it more and
more difficult to get a reliable, high-speed signal.

34.  attracting a great deal of interest, not least because
it may offer a genuine and efficient alternative to
radio-based wireless.
It’s estimated that the Li-Fi market will be worth more than $6 billion by
2018 , according to analysis by MarketandMarkets

35.  The possibilities are numerous and can be explored
further. If this technology can be put into practical use ,
every bulb can be used something like a Wi-Fi hotspots to
transmit wireless data
 Li-Fi is an emerging technology which is quick
and reliable
 Hence let’s proceed to Li-Fi for a brighter ,cheaper
and greener future

36. 1. Our respected teacher- Mrs. Meena Verma
2..http://www.electronicsforu.com/electronicsforu/circuitar
chives/view_article.asp?sno=778&title%20=%20Li-
Fi%3A+A+New+Paradigm+in+Wireless+Communication
&b_type=new&id=12042
3. http://en.wikipedia.org/wiki/Li-Fi
4. International Journal of advances in computing &
communications, vol 1, 2013,page no-12
www.ijacc.org

37. A PRESENTATION BY
ANY QUERIES…..THANK YOU…