Li-Fi is a wireless communication technology that uses visible light communication to transmit data using light-emitting diodes (LEDs). It provides high-speed communication in a similar manner to Wi-Fi but avoids issues with radio frequency bands having limited availability, security, and capacity. Li-Fi was originally proposed by Professor Harald Haas from the University of Edinburgh in 2011 and research has expanded globally since the 1990s, though it has limitations around line of sight transmission and interference from other light sources.

1. LIGHT
FIDELITY
(LI-FI)
BY SAI CHARAN TEJA

2. • Present Usage of Communication
• Electromagnetic spectrum
• What is Li-Fi?
• History
• Working principle
• Applications
• Limitations
• Conclusion
Contents:

3. • The Need of wireless data has been
increasing day by day in this modern world.
• The major source used for wireless
transmission is Radio frequency.
Present usage of communication:
1.4 Million Base
Stations
5 Billion

4. ELECTRO MAGNETIC SPECTRUM

5. Radio Frequency-Issues
Availability
Security
Capacity
Efficiency

6. What is Li-Fi?
• Li-Fi, or light fidelity, is 5G visible light communication systems
using light from light-emitting diodes(LEDs) as a medium to
deliver networked, mobile, high-speed communication in a
similar manner as Wi-Fi and Optical fiber.
• Visible light communications (VLC) signals work by switching
bulbs on and off within nanoseconds , which is too quick to be
noticed by the human eye.

7. History:
• Professor Harald Haas, from
the University of Edinburgh in
the UK, is widely recognized as
the original founder of Li-Fi
• Research has been going on in
all the developed countries from
1990, but Dr. Harald has stunned
the world when he presented on
Li-Fi during Global Ted talk
2011.

10. TYPICAL LI-FI ENVIRONMENT

13. STREET LIGHT
SCENARIOS

14. UNDER
WATER
SCENARIOS

15. AEROPLANE
SCENARIOS

16. In RF
restricted
environments

17. LIMITATIONS & CHALLENGES
• Interferences from external light sources like sun light, normal
bulbs, and opaque materials in the path of transmission will cause
interruption in the communication.
• Li-Fi requires line of sight.
• High installation cost of the VLC systems.
• A major challenge facing Li-Fi is how the receiving device will
transmit back to transmitter.

18. CONCLUSION
BROWSE DATA WITH SPEED OF LIGHT