This document provides an introduction and overview of Li-Fi technology. It discusses the history of Li-Fi, how it works by transmitting data through LED light, its advantages over Wi-Fi including increased bandwidth and security, and potential applications. Some key points covered include: - Li-Fi was originally proposed by Professor Harald Haas and uses visible light communication through LED bulbs to transmit data. - It has advantages over radio spectrum technologies as the light spectrum is much larger and data can be transmitted at high speeds through subtle variations in light intensity. - Potential applications include use in traffic lights to prevent accidents, underwater communications, and in places like hospitals, factories that restrict radio signals. -

1. SUBMITTED BY SUPERVISED BY
Name Name of the Supervisor
Endollment number Name
Course
SUBMITTED TO
Department of Computer Science & Engineering
School of Engineering Sciences & Technology
JAMIA HAMDARD
Seminar Report
PRESENTATION
LI-FI

2. CONTENTS
➢INTRODUCTION
➢HISTORY
➢REAL TIME USAGE OF LIFI
➢HOW TO WORK?
➢WORKING PROCESS
➢WHY WE USE VISIBLE LIGHT
➢RADIO SPECTRUM
➢PRESENT SCENARIO
➢APPLICATIONS
➢ADVANTAGES and DISADVANTAGES
➢CONCLUSION

3. LI- FI

4. INTRODUCTION
1. LIGHT FIDELITY
2. Light based WI-FI
3. Li-Fi is a technology for wireless communication
between devices using light to transmit data
4. Li-Fi is a visible light communications system
5. Visible light capable of transmitting data at high speeds
6 . LiFi data is transmitted by the LED bulbs and received by
photoreceptors.
4

5. HISTORY
5
➢ Professor Harald Haas, from the University of
Edinburgh in the UK, is widely recognised as the
original founder of Li-Fi.

6. ➢Haas promoted this technology in his 2011 TED
Global talk
➢In October 2011, companies and industry groups
formed the Li-Fi Consortium, to promote high-
speed optical wireless systems.
➢The first Li-Fi smartphone prototype was
presented at the Consumer Electronics Show in
Las Vegas from January 7–10 in 2014.
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7. Li-1st, the first Li-Fi product

8. REAL TIME USAGE OF LIFI

9. How to work ?
¬ 1. If LED is ON, digital data ‘1’ is transmitted & if LEDis
OFF, digital data ‘0’istransmitted.
¬2 . LEDs varies in intensity so fast that a human eye cannot
detect it
¬3. Thus every light source will works as a hub for data
transmission
¬4 . Also called as 5G optical communication.

10. IMPLEMENTATION
1. All the data from Internet is streamed into
lamp driver.
2.Data from internet is used to modulate the
intensity of LED light source.
3. Thus by fast and subtle variations of current,
optical output can be made to vary at
extremely high speed
4. The photodetector picks up the signal
5. The receiver dongle then converts the tiny
changes in amplitude into a data stream.

11. WHY WE USE VISIBLE LIGHT

12. RADIO
WAVES
INFRARED
RAYS
VISIBLE
RAYS
Ultraviolet
Rays
X-Rays
Gama
Rays
➢Gama rays can’t be used as they could be
dangerous.
➢X-rays have similar health issues.
➢Ultraviolet light is good for place without
people, but otherwise dangerous for the human
body.
➢Infrared, due to eye safety regulation, can only
be used with
• low power.

13. PRESENT SCENARIO
➢ 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 MILLION5 MILLION

14. APPLICATIONS
!Traffic scenarios, thereby reducing accidents
!Underwater applications where radio waves cannot
propagate.
!Industries like petrochemical plants, nuclear power plants ,
petrol pumps etc
=>. Hospital

15. TRAFFIC LIGHT
Traffic lights can communicate to the car and with each other. Cars
have LED-based headlights, and cars can communicate with each
other and prevent accidents

16. 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

17. LIMITATION
➢ 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.
➢ Li-Fi requires line of sight.
➢ High installation cost of the VLC systems.
➢ A major challenge facing Li-Fi is how
the receiving device will transmit back
to transmitter.

18. THAN YOU