Due to the increasing demand for wireless data communication, the available radio spectrum below 10 GHz (cm wave communication) has become insufficient. The wireless communication industry has responded to this challenge by considering the radio spectrum above 10 GHz (mm-wave communication). However, the higher frequencies, f, mean that the path loss, L, increases according to the Friis free space equation (L α f2). Light-Fidelity (LiFi) is a continuation of the trend to move to higher frequencies in the electromagnetic spectrum. Specifically, LiFi could be classified as nano-meter wave communication. LiFi uses light emitting diodes (LEDs) for high-speed wireless communication.

VLC(visible light communication) uses LEDs to transmit data wirelessly by using intensity modulation. At the receiver, the signal is detected by an LDR/photodiode and by using the principle of direct detection. VLC has been conceived as a point-to-point data communication technique – essentially as a cable replacement. This has led to early VLC standardization activities as part of IEEE 802.15.7. This standard, however, is currently being revised to include LiFi. LiFi, in contrast, describes a complete wireless networking system. This includes bidirectional multiuser communication, i.e. point-to-multipoint and multipoint-to-point communication.

As compared to the general broadband connection, this technology provides higher data speed than 10 Mbps which is much faster. Li-Fi is an OWC (Optical Wireless Communication) system which uses light from the LED (Light Emitting Diode), acts as a medium to deliver networked, and mobile, high-speed communication similar to Wi-Fi. Both Wi-Fi and Li-Fi transmit the data over the electromagnetic spectrum only difference is that Wi-Fi utilizes radio waves whereas Li-Fi utilizes visible light. As the velocity of light is much large, hence due to this the rate of data transmission is more as compared to Wi-Fi which uses radio waves for data transmission.

Li-Fi has more advantages over Wi-Fi and limited disadvantages, also the area of application of Li-Fi is wider than Wi-Fi.

Advantages :

oHigh Speed (10Gbps>)

oHigh capacity (bandwidth >10000 times of Wi-Fi)

oHighly Secure

oConsume less energy Highly Efficiently

oEasily available

oEase in implementation

Disadvantages :

oRequire Line of Sight for efficient working.

Applications :

oThis technology is useful in airlines, power plants, petrochemicals, Underwater, etc.

oLi-Fi never gives any harm to living thing like radio waves affect the human body as well as birds, plants.

oThis technology provides a better way to manage traffic. It can avoid accidents.

oIt is applicable in GPS usage.