Summer Research Fellowship Programme of India's Science Academies

LED based optical communication

Siva Sravani Kandula

Sri Sadhana Degree College, Markapur 523316

Dr. Appala Venkata Ramana Murthy

Defence Institute of Advanced Technology, DIAT, Pune 411025


The prominent technologies at present for communication are mainly RF based. Even though these technologies are popular they have a lot of limitations like limited bandwidth of RF spectrum, EMI, lack of security since these waves can penetrate through walls etc. So, research started moving to a new portion of the EM spectrum i.e., the visible spectrum. The advantages are many when using visible light for communication, like a larger bandwidth, no EMI, more secure as they don’t penetrate through walls etc. LEDs and lasers are commonly used optical sources that could be used for data transmission as well. The basis of light communication can be traced back to ancient historical roots but, in terms of the modern age can perhaps be said to have started with Alexander Graham Bell's Photo Phone. In recent times, VLC was pioneered by Nakagawa and others. In this project, we are using LED-based data communication called Li-Fi, the term Li-Fi which stands for Light Fidelity, was coined by professor Harald Hass of the University of Edinburgh during his 2011 TED talk. Li-Fi is the new generation of data communication that replaces Wi-Fi. Li-Fi works based on Visible Light Communication (VLC), and the transmission of data is achieved by modulating the intensity of light which cannot be observed by the naked human eye. Li-Fi will enable many more things to be connected to the internet, diversifying and increasing the number of available applications. Li-Fi is where light becomes data so that’s why Li-Fi is an Optical networking technology that uses light emitting diodes for transmission of data. Li-Fi uses VLC technology that uses light as the medium to deliver high-speed communication in a manner similar to Wi-Fi, but in Li-Fi the frequency of visible spectrum is ten thousand times more than the RF spectrum.

Keywords: Li-Fi, Wi-Fi, VLC, RF spectrum, visible light spectrum

Siva Sravani Kandula

Written, reviewed, revised, proofed and published with