1. Li-Fi Technology

2. Introduction
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.

3. 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 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 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

4. Li-1st, the first Li-Fi product

5. Present Scenario
6.8 billion +
1.4 millions +

6. Issues Regarding Radio Spectrum
Capacity
Availability
Efficiency
Security

7. Disadvantages Of Other Spectrums
Insufficient spectrum for increasing data
Dangerous for human body
Low power application
It is not used generally
Which is not used so far.
Used for hospitals

8. 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.

11. Main Components Of Communication System
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.
Transmitting elements
Receiving elements

12. Advantageous Due To Parallel Data Transmission.

14. Differences Between Technologies

15. Applications RF Spectrum Relief Smart Lighting Mobile Connectivity
Hazardous Environments
Hospital & Healthcare
Aviation
Underwater Communications
Vehicles & Transportation
RF Avoidance
Location Based Services (LBS)
Toys

16. Advantages 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.

17. Disadvantages 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 .

18. Conclusion
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.

19. References http://whatis.techtarget.com/definition/LiFi