Li-Fi uses white LED light bulbs to transmit data through variations in light intensity. A receiver converts the light signals to an electrical signal and data stream. Li-Fi has advantages over Wi-Fi like better security, higher speeds, and lack of interference. However, it requires line of sight and may be affected by other light sources. The technology has been successfully demonstrated with a table lamp transmitting over 10Mbps.

16. CONSTRUCTION & WORKING OF LI-FI

17. ж Li-Fi is implemented using white LED light bulbs at downlink transmitter.
ж By fast variations of the current, optical output can be made to vary at extremely
high speeds.
ж An overhead lamp fitted with an LED with signal processing technology streams
data embedded in its beam at ultra high speeds to the photodiodes.
ж A receiver dongle then converts the tiny changes in amplitude into an electrical
signal, which is then converted back into a data stream & transmitted to a
computer or mobile device.

19.  In vehicles and traffic lights,reducing traffic accidents
and traffic congestion

24. Availability Efficiency Harmless
High
Security
Ease of
use
Fast Data
Transfer
Low Cost

25. What will be the effect of interferences from external light sources like sun light &
normal bulbs?
What about the limited bandwidth of the existing copper cables used for electrical
connections?
Where do the connections uplink, how serious are the modifications needed to the
power grid?
How will other devices react if you inject a high frequency into mains?
Initial setup cost.
Presence of light is essential.
There should be line of sight.

27.  YES THIS ALREADY PROVEN.
 HARALD HAAS DEMONSTRATED HIS INVENTION
USING AN ORDINARY TABLE LAMP THAT
SUCCESSFULLY TRANSMITTED DATA AT SPEEDS
EXCEEDING 10Mbps USING LIGHT WAVES FORM
LED LIGHT BULBS TO A COMPUTER LOCATED
BELOW THE LAMP.TO PROVE THAT THE LIGHT WAS
THE SOURCE OF THE DATA STREAM HE
PERIODICALLY BLOCKED THE BEAM OF LIGHT ,
CAUSING THE CONNECTION TO DROP.