3. LiFi is a wireless optical networking technology that uses light-emitting diodes (LEDs) for
data transmission.
LiFi is designed to use LED light bulbs similar to those currently in use in many energy-
conscious homes and offices.
However, LiFi bulbs are outfitted with a chip that modulates the light imperceptibly for
optical data transmission.
LiFi data is transmitted by the LED bulbs and received by photoreceptors.
Introduction
4. History
• Professor Harald Haas, from the University of Edinburgh in
the UK, is widely recognised as the original founder of Li-Fi.
• He coined the term Li-Fi and is Chair of Mobile
Communications at the University of Edinburgh and co-
founder of pure LiFi.
• Haas promoted this technology in his 2011 TED Global talk
and helped start a company to market it.
• In October 2011, companies and industry groups formed the
Li-Fi Consortium, to promote high-speed optical wireless
systems.
• The first Li-Fi smartphone prototype was presented at the
Consumer Electronics Show in Las Vegas from January 7–10
in 2014.
Prof. Harald Haas
9. The LEDs can be switched on and off very quickly which gives nice
opportunity for data transfer in the form of Binary code.
Switching ON an LED is logical ‘1’,switching of an LED is logical ‘0’.
Hence it is possible to encode the data into the LED’s by using a controller ,we
just have to vary at which LED’s flicker depending on the data we want to
encode to give different strings of 0’s and 1’s.
UK researches say that using a micro-LED light bulb they have achieved a data
transmission speed of 10Gbps using LI-FI.
Working of LI-FI
12. A high brightness white LED, Which act as a communication source.
A silicon photodiode which shows good response to visible wavelength region
serving as the receiving element.
Main Components Of Communication
System
Receiving elements
Transmitting elements
17. Higher speeds than Wi-Fi.
10000 times the frequency spectrum of radio.
More secure because data cannot be intercepted without a clear line of
sight.
Prevents piggybacking.
Eliminates neighboring network interference.
Unimpeded by radio interference.
Does not create interference in sensitive electronics, making it better for
use in environments like hospitals and aircraft.
Advantages
18. Light can't pass through objects.
A major challenge facing Li-Fi is how the receiving device will
transmit back to transmitter.
High installation cost of the VLC systems
Interferences from external light sources like sun, light, normal bulbs,
opaque materials .
Disadvantages
19. By using Li-Fi in all the lights in and around a building, the
technology could enable greater area of coverage than a single Wi-
Fi router. Drawbacks to the technology include the need for a clear
line of sight, difficulties with mobility and the requirement that lights
stay on for operation.
Conclusion
