This thesis is focused on the use of light and LEDs for communication between the light and the user. In the introduction, the principles of VLC, which Li-Fi is part of, are described. The work also contains issues on the topics of Li-Fi, such as methods of modulation of carrier signals for data transmission, comparisons between other wireless communications, individual elements of optical frontends, current versions of Li-Fi and other possible uses of this technology. The work also contains the designing of a system working on the principle of Li-Fi.

To light up the world of technology, where wireless communication has bloomed to a great extend which requires a lot of data to be transmitted and received every fraction of the second a new era is coming. Electro-magnetic waves i.e., radio waves are the main way to transmit wireless data but certain limitations are there because radio waves can only support less bandwidth because of compact spectrum availability and intrusions. Visible Light Communication (VLC) has come to take way those issues. The new technology Li-Fi which stands for Light-Fidelity is a new kind of wireless communication system which uses light waves as a medium instead of radio frequency electromagnetic waves. This pro-ject presents an eco-friendly data communication system through visible light which consists of LEDs that transmit audio signals and sensor data to the receiver. A connection protection mechanism that co-operates with wireless network and visible light communication to achieve relia-bility and performance overcoming the drawbacks from the pre-existing system is proposed here.