LI-FI TECHNOLOGY and its advantages and disadvantages
Light Fidelity (Li-Fi) is a bidirectional, high-speed and fully networked wireless communication technology similar to Wi-Fi. li-fi technology ppt free download
• Light Fidelity (Li-Fi) is a bidirectional, high-speed
and fully networked wireless communication
technology similar to Wi-Fi.
• LI-FI is a technology that uses the light emitting
diodes to transmit the data wirelessly.
• LI-FI is fast and cheap practical version of WI-FI,
based on visible light communication (VLC).
• VLC is a data communication medium, which uses
the visible light between 400 Thz (780 nm) and 800
Thz (375 nm) as optical carrier for data transmissionHistory
The technology truly began during the 1990's in
countries like Germany, Korea, and Japan
where they discovered LED's could be
retrofitted to send information. Harald Haas
continues to wow the world with the potential
to use light for communication.
HE DEMONSTRATED IT IN THE YEAR
EDINBURGH, UKLi-fi environmentPRESENT SCENARIO
transmit 600 TB data
become an utility like
electricity and water.RADIO SPECTRUM ISSUES
Cost and Expensive
Less Bandwidth compared to other spectrums
Insufficient spectrum for increasing data
Millions of base stations consume huge amount of
1.Transmitting the radio waves
2.To cool the base station cabins
5% EfficiencyRADIO SPECTRUM ISSUES
Available within the range of Base stations
Unavailable in aircrafts
Less secure(passes through the walls)
Anyone with knowledge and bad intention can
misuse itAlternative of radio wavesWHY ONLY VLC ??
Radio Infrared Visible Ultraviolet
X- Rays Rays
Waves Rays Rays 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 be used with low
HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT
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 .LI-FI CONSTRUCTION
The LI FI product consists of 4 primary sub-assemblies:
• RF power amplifier circuit (PA)
• Printed circuit board (PCB)
1. 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.
2. The PCB controls the electrical inputs and outputs of the lamp and houses the
microcontroller used to manage different lamp functions.
3. An RF (radio-frequency) signal is generated by the solid-state PA and is guided
into an electric field about the bulb.
4. All of these subassemblies are contained in an aluminum enclosureHow It Works ??
On one end all the data on the internet will be streamed to a
When the led is turned on, the microchip converts the digital
data in form of light.
On the other hand, this light is detected by photo sensitive
Next this device is amplified and processed and then fed to
the device.APPLICATION AREAS
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
In operation theatre, Li-Fi can be
used for modern medical
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 radiowaves , li-fi is introduced.APPLICATION AREAS
◎INTRINSICALLY SAFE ENVIRONMENT
It can be used in petroleum or chemical
plants where other transmission or
frequencies could be hazardous.APPLICATION AREAS
◎ON OCEAN BED
Li-Fi can even work underwater
were Wi-Fi fails completely, thereby
throwing open endless opportunities
for military/navigation operations.APPLICATION AREAS
There are millions of street lamps
deployed around the world.
Each of these street lamps could be a
free access point.