Light Fidelity (Li-Fi) uses visible light to transmit data, providing solutions to issues like radio spectrum congestion and security. It operates by modulating LED light intensity to represent binary data, enabling high-speed communication in sensitive and RF-restricted areas. Despite challenges such as light interference and limited range, Li-Fi offers a faster, more efficient alternative to traditional Wi-Fi, paving the way for innovative wireless data communication solutions.

1. Content:-
• LIGHT FIDELITY
• NEED FOR LI-FI
• OVERCOMING WIFI ISSUES
• VISIBLE LIGHT COMMUNICATION
• LIFE OF LIFI
• HOW IT WORKS?
• IMPLEMENTATION
• LI-FI NETWORKS
• APPLICATIONS
• ADVANTAGES
• LIMITATIONS
• CONCLUSION

2. • LIGHT FIDELITY
 Light is used instead of radio-waves to transmit information.
 Transceiver fitted LED lamps acts like Wi-Fi modems.
 LED lamps can light a room as well as transmit-receive information.
 Provides illumination as well as data communication.
 Light based WI-FI.
• NEED FOR LI-FI
 Radio spectrum is congested, but the demand for wireless data doubles each
year.
 Issues regarding radio spectrum, such as capacity, availability, efficiency,
security are solved using LIFI.
 Speed of data transmission can be increased.
• OVERCOMING WIFI ISSUES
 CAPACITY:
Spectrum is 10,000 times greater than that of radio frequency.
 EFFICIENCY:
Highly efficient since LED consumes less energy.
 AVAILABILITY:
Light waves are available everywhere.
 SECURITY:
Light can’t penetrate through walls. Hence data cannot be intercepted.
• VISIBLE LIGHT COMMUNICATION
 In electromagnetic spectrum, gamma, UV rays are dangerous for human body.
 IR rays, due to eye safety regulations, are not used.

3. • LIFE OF LIFI
 Introduced by Professor Herald hass, at the University of Edinburgh.
 Established in 2011 TED global talk.
 The promotion of idea through TED helped to start a company, Pure LiFi
 Pure LiFi, formerly pure VLC, is an original equipment manufacturer firm
setup to commercialize Li-Fi products for integration with existing LED
lighting systems.
 In October 2011, few companies and industries group formed Li-Fi consortium
to promote the high speed optical wireless systems.
• HOW IT WORKS?
 Operational procedure is very simple.
 If LED is ON, digital data ‘1’ is transmitted & if LED is OFF, digital data ‘0’ is
transmitted.
 LEDs varies in intensity so fast that a human eye cannot detect it
 A controller connected at the back side of these LEDs is used to code data.
 Also called as 5G optical communication.
• IMPLEMENTATION

4.  All the data from Internet is streamed into lamp driver.
 Data from internet is used to modulate the intensity of LED light source.
 Thus by fast and subtle variations of current, optical output can be made to vary
at extremely high speed.
 The photo detector picks up the signal.
 The receiver dongle then converts the tiny changes in amplitude into a data
stream.
• LI-FI NETWORKS
 Li-Fi connector and router are the main components for a network
 Room connector:
 Optical signals cannot penetrate through walls, in order to provide an
optical WLAN, rooms need to be connected with each other.
 Li-Fi room connector is a replicator, which sends the data stream from
one side of the wall to the other side via an optical fiber.
 For smaller rooms, connector act as the only Li-Fi hotspot in the room.

5. • APPLICATIONS
 LIFI can be used in sensitive areas such as aircrafts for data transmission
without causing interference
 Places where it is difficult to lay optical fibers like Operation theaters, Traffic
scenarios.
 Underwater applications where radio waves cannot propagate.
Industries like petrochemical plants, nuclear power plant, petrol pumps etc.
• ADVANTAGES
 Data rate greater than 10 Gbps; Theoretically allowing HD film to be
downloaded in 30 seconds
 Can be used anywhere, even in RF restricted areas; since light waves will not
interfere with radio waves.
 Mostly LED light bulbs are used, which consumes less energy.
 As light waves cannot penetrate through walls, the data cannot be intercepted;
thus provides secured communication.
 Efficient alternative to radio based wireless; since it is quick and reliable.
• LIMITATIONS
 Visible light cannot penetrate through solid objects.

6.  A major challenge of LiFi is how the receiving device will transmit back to
transmitter.
 Interferences from external light sources like sunlight, in the path of
transmission will cause interruption in the communication.
 Data transmission can be easily blocked by any object placed in front of LED
source.
• CONCLUSION
Thus, if Li-Fi technology can be put into practical use, every bulb can be used
as an alternative to Wi-Fi hotspots. It provides simple, faster and efficient
wireless data communication. Li-Fi will make us to proceed towards the
cleaner, greener, safer and brighter future.
• REFERENCE
www.wikipedia.com www.purelifi.com
www.lifi-centre.com www.slideshare.net

7.  A major challenge of LiFi is how the receiving device will transmit back to
transmitter.
 Interferences from external light sources like sunlight, in the path of
transmission will cause interruption in the communication.
 Data transmission can be easily blocked by any object placed in front of LED
source.
• CONCLUSION
Thus, if Li-Fi technology can be put into practical use, every bulb can be used
as an alternative to Wi-Fi hotspots. It provides simple, faster and efficient
wireless data communication. Li-Fi will make us to proceed towards the
cleaner, greener, safer and brighter future.
• REFERENCE
www.wikipedia.com www.purelifi.com
www.lifi-centre.com www.slideshare.net