3. Introduction To
Li-Fi
3
▸ Li-Fi Stands for Light Fidelity
▸ Li-Fi transmits data through illumination
▸ Li-Fi is a light based Wi-Fi , it Uses light in place of radio waves
to transmit information.
▸ Li-Fi sends data through a LED light bulb that varies in intensity
faster than human eye can follow.
4. History of Li-Fi
4
▸ Beginning of Li-Fi technology in the year 1990 in countries
like Korea, Germany and Japan
▸ Professor Harald Haas coined the term “Li-Fi” at his 2011
TED Global Talk
▸ He introduced the idea of wireless data from every light.
6. Working of Li-Fi
▸ On one end all the data on the internet will be streamed
to a lamp driver when the led is turned on the microchip
converts the digital data in form of light
▸ A light sensitive device (photo detector) receives the
signal and converts it back into original data. This
method of using rapid pulses of light to transmit
information wirelessly is technically referred as visible
light communication
6
7. 7
▸ LEDs can be switched on and off faster than the human eyes can detect
since the operating speed of LEDs is less than microsecond.
▸ This invisible switching activity enables data transmission using binary
codes.
▸ If the LED is on, a digital signal ‘1’ is transmitted and if the LED is off, a
digital signal ‘0’ is transmitted. Also these LEDs can be turned on and off
very quickly which gives us a very nice opportunity for transmitting data
through LED lights,
9. Wi-Fi Li-Fi
Data Transfer
Medium
Radio waves
1
2
3
4
5
Speed
Low (150MBps-1GBps)
Cost
Expensive
Power
Consumption
High
Range
100m-500m
1
2
3
4
5
Data Transfer
Medium
Visible light
Speed
>10GBps
Cost
Cheaper than Wi-Fi
Power
Consumption
Low
Range
Based on the LED
Wi-Fi Vs Li-
Fi
10. Advantages of Li-Fi
10
▸ Larger Bandwidth
▸ More Availability
▸ High Speed
▸ High Efficiency
▸ Low Power
▸ Highly Secure
11. Disadvantages of Li-Fi
11
▸ Li-Fi doesn’t work in Dark
▸ Light cannot Penetrate through solid objects
▸ Speed and range can be affected by intensity of
light
▸ Interference from external Light sources like
sunlight and other LEDs
12. 2
Applications of Li-Fi
1. Airlines :
Whenever we travel
airways we face the
in communication media
because the whole airways
communication are
on the basis of radio
To overcome this
on radio waves, li-fi is
introduced.
13. 13
Applications of Li-Fi
2. On Ocean Beds :
Li-Fi can even work underwater were
Fi fails completely, thereby throwing
open endless opportunities for
military/navigation operations.
14. Applications of Li-Fi
14
3. Hospitals :
The proposed model
helps in the Patient
monitoring in the
hospitals and can be
by using the concept
Li-Fi instead of the Wi-
technology to avoid
frequency interference
with the human body.
Sensors such as
temperature,
glucose and
used in this model
perform its respective
functions.
15. Applications of Li-Fi
15
4. Traffic Lights :
Traffic lights can communicate to
the car and with each other.
Cars have LED-based headlights,
LED-based car lights, and cars can
communicate with each other and
prevent accidents in by exchanging
information.
16. Applications of Li-Fi
16
5. Home And Small Offices :
In home and small offices, Li-Fi can
used to communicate with devices
Laptops, Printers…etc.
17. Conclusion
17
Thus, if Li-Fi technology can be put into practical use,
every bulb can be used as an alternative to Wi-Fi hotspots.
It provides simple, faster and efficient wireless data
communication. Li-Fi will make us to proceed towards the
cleaner, greener, safer and brighter future.
