Li-Fi is a wireless optical networking technology that uses light-emitting diodes (LEDs) for data transmission.Li-Fi is designed to use LED light bulbs similar to those currently in use in many energy-conscious homes and offices.
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.
• Professor Harald Haas, from the University of Edinburgh
in the UK, is widely recognised as the original founder of
• He coined the term Li-Fi and is Chair of Mobile
Communications at the University of Edinburgh and co-
founder of pureLiFi.
• 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
• 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
Issues Regarding Radio Spectrum
It is not
Disadvantages Of Other Spectrums
Working of LI-FI
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.
Main Components Of
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.
Advantageous Due To
Parallel Data Transmission.
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.
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.
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 .
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