International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 07 Issue: 05 | May 2020 www.irjet.net p-ISSN: 2395-0072 © 2020, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 6358 A Brief Introduction of the Li-Fi Technology, its Implementations and Applications Saurav Acharya Postgraduate student, Department of Physics, Dibrugarh University, Assam, India -----------------------------------------------------------------------***-------------------------------------------------------------------------- Abstract- The use of LEDs is not limited only to illumination, but can be used to transmit data at a much higher rate in comparison to Wi-Fi. The mechanism is called Li-Fi and uses VLC (Visible Light Communication) for the transfer of data. Light Fidelity is abbreviated as Li-Fi. This paper draws attention on the construction, working and application of the Li-Fi system. KEYWORDS- Li-Fi, Wi-Fi, VLC, photodiode, wireless communication 1. INTRODUCTION Presently, the wireless communication that we are using is through radio waves which have got a number of disadvantages being primarily the radiations that harm the human body. The other disadvantages include the slow speed. The remedy to this slow speed and harmful radiations is Li-Fi (Light Fidelity). Li-Fi was first introduced by Harald Hass in a TED talk in Edinburgh, UK. Li-Fi uses VLC (visible light communication) for the transmission of data, thus its speed being 1000 times faster than Wi-Fi [1]. Li-Fi is the transmission of data through illumination by taking the fiber out of fiber optics by sending data through an LED light bulb that varies in intensity much faster than the human eye can follow [2]. Since the reach of Li-Fi is within the reach of the illumination, hence it is safe from being hacked and thus is more secure. The difference between VLC and Li-Fi is that VLC has a unidirectional, point-to-point light communication at low data rates while Li-Fi introduces advanced networking capabilities, higher speed, and multiple access. Li-Fi is fully networked, bidirectional, and high-speed wireless communication using light [3]. Li-Fi can be also called optical Wi-Fi since it uses visible light for the transmission of data unlike Wi-Fi that uses radio waves. Due to low cost and availability of LEDs, we can use the Li-Fi technology for attaining a greater speed in all the places, e.g. It can be used in the headlight of cars to receive data so that accidents do not occur, it can be used in our houses to access data at a very high speed, it can be used in underwater transmission, etc. This paper explains the new Li-Fi technology, its basic architecture, working, applications, and how this new technology can surpass all the other technologies we have now. It includes future research based on mobile and other applications. 2. WORKING OF LI-FI Li-Fi works on the Visible Light Communication principle. The data is sent in the form of binary bits. The working is very simple: When the transmitter transmits the signal, the transmitted data is sent in like 1 or 0 which are binary bits. The transmission of digital 1 means that the signal should switch ‘ON’ the output while the transmission of digital 0 means the output should be switched ‘OFF’. This transmission of binary bits 1 or 0 happens so fast that it is out of reach of human eye, it appears as a continuous glow to our eye [4]. Figure1. Working of Li-Fi technology