Li-Fi Technology

2. • Introduction
• What is Li-Fi??
• What is VLC??
• Why only VLC??
• Architecture of Li-Fi.
• How does Li-Fi works??
• Advantages, Disadvantage, Limitation.
• Comparison with other
• Applications.

3. In the olden days.
Wired networking
Satellites Communications.
Wireless Networking

4. • LI-FI (Light Fidelity) is transmission of data through
illumination-taking the fiber optics by sending data
through an LED light bulb.
• At the heart of this technology is a new generation
of high brightness LEDs.
• If the LED is on a digital 1 is transmitted, if the LED
is off then a digital 0 is transmitted. They can be
switched on and off in order to transmit data
continuously.

5. It is transmission of data through
illumination, i.e. sending data through a
LED light bulb that varies in intensity faster
than human eye can follow.

6.  Li-Fi is a fast and cheap optical version of Wi-Fi,
The technology of which is based on Visible
light Communication(VLC).
 VLC is a data communication medium, which
uses visible light between 400 THz(780 nm) and
800 THz (375 nm) as optical carrier for data
Transmission and illumination.
 It uses fast pulses of light to transmit information
wirelessly.

7. Radio
Waves
Infrared
Rays
Visible
Rays
Ultraviolet
Rays
X-Rays
Gama
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 power.
Hence we left with the only the VISIBLE- LIGHT SPECTRUM.

9. Conversion of data to light
Morse code is used
Fast speed
Microchip
Photo sensitive device

10. 1. Cost is low as compare to other light device.
2. Visible light spectrum is 10000 times more
compared to radio wave spectrum.
3. Speed can reach up to thousands of GBps.
4. Parallel data transmission that helps to
increase speed.
5. Tariff rates cheap.

11. Presence of Light is essential.

12.  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.
 High installation cost of the VLC system
 A major challenge facing Li-Fi is how the receiving
will transmit back to transmitter.

13. Technology Speed Data density
Wireless(Current)
Wi-Fi
IEEE802.11n
150Mbps *
Bluetooth 3Mbps *
IrDA 4Mbps ***
Wireless(Future)
WiGig 2Gbps **
Giga-IR 1Gbps ***
Li-Fi >1Gbps ****

14.  Traffic lights
Safe Environments

15. On Ocean Beds
Public internet hotspots
Aircrafts