Li-Fi is a wireless communication technology that uses light to transmit data between devices. It was introduced in 2011 as an alternative to Wi-Fi that uses light frequencies instead of radio waves. Li-Fi works by transmitting data through light frequencies of LED bulbs that are switched on and off rapidly, which can achieve speeds over 10 Gbps. It has advantages over Wi-Fi like higher speed, bandwidth and security, but does not work in darkness and can be interrupted by obstacles. Future developments of Li-Fi seek to overcome its limitations and provide a more efficient, cheaper and greener alternative to radio-based wireless networks.

1. FUAD SINEEN
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2. Introduction
 Li-Fi -"LIGHT FIDELITY" is a wireless
communication technology that utilizes
light to transmit data and position between
devices.
 LI-FI
 Li-Fi is a light-based Wi-Fi it uses light
instead of radio waves to
transmit information.

3. HISTORY
 The term LI-FI was first introduced
by Harald Haas during a TED
Global talk in Edinburgh.
 He introduced this in the year 2011

4. IMPLEMENTATION OF LI-FI
 The LI-FI products consist of three primary sub-assemblies
A. Emitter
B. RF Driver
C. Power Supply

5. HOW LI-FI WORKS
 Data is captured in modulated light frequencies of a
solid-state LED light source and is then transmitted
and received by Li-Fi-enabled devices. A
photosensitive detector demodulates the light
frequency signal and converts it back into an
electronic data stream and in so doing allows for
faster than ever, more secure, bi-directional wireless
communication.

6. HOW LI-FI WORKS
 Operational procedure is very simple if
the LED is on, you transmit a digit 1, if
it’s off you transmit a digit 0.
 The LEDs can be switched on and off
quickly. which gives nice opportunities for
transmitting data. hence all that is required
is some LEDs and a controller that codes
data into those LEDs.
 We have to just vary the rate at which the
LEDs flicker depending on the data we
want to encode.
 Thus every light source will work as a hub
for data transmission.

7. LIFI/WIFI COMPARISON
PARAMETER LI-FI WIFI
1. Speed High High
2. Range Low Medium
3. Data density High Low
4. Security High Medium
5. Transmit/receive
power
High Medium
6. Device-to-Device
connectivity
High High
7. Reliability Medium Medium
8. Obstacle Interference High Low

8. APPLICATIONS
 Used for modern medical instruments.
 In aircraft, it can be used for data
transmission.
 Used in petroleum or chemical plants
where other transmission or frequencies
can be hazardous.
 In traffic signals, LI-FI can be used
which will communicate with the LED
lights of the car and the number of
accidents can be decreased.
 Location-based services:-GPS
 Underwater communication.
 RF Spectrum relief
 Li-Fi can be used effectively in places where
it is difficult to lay the optical fiber cable

9. ADVANTAGES
 Larger bandwidth.
 High efficiency.
 More availability.
 High security.
 Thousands and millions of street lamps can be
converted into Li-Fi spots.
 No license needed
 green information technology.
 Lighting points are used as Hotspots.
 The issues of the shortage of radio frequency
bandwidth may be sorted out by Li-Fi.
 This technology worldwide can be used for
every street lamp and would be a free
data access point.

10. LIMITATIONS
 Li-Fi doesn’t work in dark.
 Li-Fi has a big drawback compared to
Wi-Fi, unlike Wi-Fi we cannot move
to other rooms unless there are wired
bulbs too.
 Light can't pass through the objects.
 Interference from external sources like sunlight,
normal bulbs, and opaque materials in the path of
transmission will course an interruption in
communication.
 High installation cost of the VLC systems
 A major challenge facing Li-Fi is how the receiving
device will transmit back to the transmitter

11. FUTURE DEVELOPMENTS
 Efficient alternative to radio-based wireless
 Li-Fi is an emerging technology that is quick and reliable
 Airwaves are clogged so let's use light waves.
 Hence, let's proceed to Li-Fi for a brighter cheaper, and greener future.

12. CONCLUTION
 Overcomes the limitations of the radio spectrum
 High speed of 10 Gbps can be achieved
 The possibilities are numerous and can be explored further.
 If this technology can be put into practical use, every bulb can be used as something like a
Wi-Fi hotspot
 we will proceed toward a cleaner, greener, safer and brighter future
 This may solve issues such as the shortage of radio-frequency bandwidth
 LI-FI is enabled by advanced digital transmission technologies
 Allows internet where traditional radio-based wireless isn't allowed such as aircraft or
hospitals

13. QUESTIONS ?

14. THANK YOU