Li-Fi technology Presented by Manglesh & Chandrashekhar

1. PRESENTATION ON
PRESENTED BY:
 Manglesh Karn
 Chandra Shekhar Bist
 Abhinav Karn
CSE 4th
sem

2. Content
 Introduction
 History
 Present Scenario
 Working Process
 Li-Fi vs Wi-Fi
 Applications
 Challenges for Li-Fi
 Conclusion

3. INTRODUCTION
 Li-Fi stands for light fidelity.
 It is bidirectional high speed and fully networked
wireless communication technology similar to Wi-
Fi.
 Li-Fi is a technology that uses the Light Emitting
Diodes (LED) to transmit data wirelessly.
 Li-Fi is based on Visible Light Communication
(VLC).
 This varies in intensity faster than human eye can
follow.
 Li-Fi is fast and cheap optical version of Wi-Fi.

4. HISTORY OF WIRELESS
 Discovered by Alexander
Graham Bell in 1980
 Photophone (first wireless
phone,used modulated light
to send audio signal)
 Microwave Transmission(1
mobile tower to another
mobile tower)
 Radio Frequency
 Application
:Mobile,WiFi.BT,others

5. HISTORY
 This technology was invented by German
Physicist “HARALD HAAS”, from the university of
Edinburgh, U.K.
 He demonstrated it in the year 2012.
 In April 2014, the Russian company Stins Coman
announced the development of a Li-Fi wireless
local network called Beam Caster.
 In 2014 a new record was established by Sisoft (a
Mexican company) that was able to transfer
data at speeds of up to 10Gbit/s across a light
spectrum emitted by LED lamps

6. Present Scnerio
 Radio spectrum is congested but the demand for wireless
data double each year.
 Bandwidth limitation.
 Data Security.
1.4 million 5.0 billion

7. PROCESS
 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 .
 Thus every light source will works as a hub for data transmission .

10. Li-Fi Vs Wi-Fi
S.N Parameters Wireless Technologies
Light Fidelity Wireless Fidelity
1. Speed for data
transfer
Faster transfer
speed(>150Gbps)
Less transfer speed(1Gbps)
2. Medium
through which
data transfer
occurs
Used light as a carrier Used radio spectrum
3. Spectrum range 10000 times more then
Radio frequency
Less then visible light
spectrum
4 Cost Cheaper than Wi-Fi
because free band
doesn’t need license & it
uses light
Expensive than Li-Fi
because it uses radio
spectrum
5 Operating
frequency
Hundreds of Tera Hz 2.4GHz
6 Coverage
distance
About 10m About 32m vary according
to bandwidth.

11. Li-Fi Vs Wi-Fi

12. APPLICATIONS
 Li Fi technology is still in its infancy .However some areas
where it seems perfectly applicable are:-
1. Traffic lights
2. Intrinsically Safe Environment
3. Hospitals( In few medical equipments )
4. Airlines
5. On ocean Beds
6. Street Lamps(As Free Access Point)

13. 1. Traffic lights:
 Traffic light can communicate to the car and
with each others. Cars have LED based
headlights, LED based back light , and cars can
communicate with each other and prevent
accident by exchanging information.

14. Instrinsically safe environment:
 In explosion hazard environments, the use of
electrical equipment, including mobile phones,
is generally greatly restricted. The use of Li-Fi to
pass data will simplify the configuration of data
networks in such environments, and can enable
new systems to enhance security in these
environments.

15. Hospital (In Few Medical Equipments):
 There are advantages for using VLC in hospitals
and in healthcare. Mobile phones and Wi Fi are
undesirable in certain parts of hospitals,
especially around MRI scanners and in operating
theatres.

16. 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

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

18. Street Lamps(As Free Access )
 There are millions of street lamps developed around the
world.
 Each of these street lamps could be a free access point.

19. LIMITATION OR CHALLENGES
 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
 A major challenge facing Li-Fi is how the receiving device
will transmit back to transmitter.

20. Why VLC
 Gama rays cant be used as they could be dangerous.
X-rays have similar health issues.
Infrared, due to eye safety regulation, can only be used with low power.
Ultraviolet light is good for place without people.
HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT SPECTRUM.

23. 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.
 we will proceed toward the cleaner, greener,
safer and brighter future.
 Allows internet where traditional radio based
wireless isn’t allowed such as aircraft or hospitals.