Light Fidelity Li-Fi - Advanced Seminar Topics

Abstract

         Whether you’re using wireless internet in a coffee shop, stealing it from the guy next door, or competing for bandwidth at a conference, you’ve probably gotten frustrated at the slow speeds you face when more than one device is tapped into the network. As more and more people and their many devices access wireless internet, clogged airwaves are going to make it increasingly difficult to latch onto a reliable signal. 

What Is Li-Fi?      

        Li-Fi is a VLC, visible light communication, technology developed by a team of scientists including Dr Gordon Povey, Prof. Harald Haas and Dr Mostafa Afgani at the University of Edinburgh. The term Li-Fi was coined by Prof. Haas when he amazed people by streaming high-definition video from a standard LED lamp, at TED Global in July 2011. Li-Fi is now part of the Visible Light Communications (VLC) PAN IEEE 802.15.7 standard.

Why Li-Fi?

•  There are 1.4 million cellular radio masts deployed worldwide.
•  There are more than five billion wi-fi devices present.
•  With all these devices, we transmit more than 600 terabytes of data every month.

How Li-Fi Works?

           Li-Fi is typically implemented using white LED light bulbs at the downlink transmitter.  These devices are normally used for illumination only by applying a constant current.  However, by fast and subtle variations of the current, the optical output can be made to vary at extremely high speeds.

Light For Wireless Communication

            Light is inherently safe and can be used in places where radio frequency communication is often deemed problematic, such as in aircraft cabins or hospitals. So visible light communication not only has the potential to solve the problem of lack of spectrum space, but can also enable novel application. The visible light spectrum is unused, it's not regulated, and can be used for communication at very high speeds.

Conclusion

         The fact that Li-Fi is being considered as one of the IEEE 802.xx standards bodes well for its potential success. Like other 802.xx standards, it is defined only at layers 1 and 2 (physical and media access control (MAC) layers) of the Open Systems Interconnection (OSI) model. Layer 3 and higher layers need to be designed using the Internet Engineering Task Force (IETF) packet transport standards.