Li-Fi or Light Fidelity
LiFi or Light Fidelity is a wireless communication or a Visible Light Communication (VLC) that uses the infrared or visible spectrum for high-speed data communication (Mercer, 2018). It aims at achieving high-speed, secure and fully-networked wireless communications (Haas, 2018).
Data is transmitted over Li-Fi by modulating the intensity of light. The light is then received by the photosensitive detector and demodulated in the electronic form. It uses common household LED light bulbs to enable data transfer, boosting speeds of up to 224 gigabits per second (Mundy & Kavanaugh, 2018). LiFi supports multiuser access and user mobility and it uses visible light instead of the Gigahertz radio waves for data transfer (Sharma R.R. et al., 2014).
Li-Fi is considered a fast and cheap version of Wi-Fi. Li-Fi is used in more dense environments as it has less interference of light as compared to radio frequency waves. In fact, the environments that Li-Fi networks use are safe for its use (Cisco & Cisco Router, Network Switch, 2017).
It will also provide more secure data transfer as light is blocked by the walls in this type of data transfer. As the light emitting diodes (LEDs) have been successfully adopted, the opportunity to use the visible light spectrum for wireless networking has been arising. The traditional use of VLC transmitting was the only point-to-point wireless communication link between an LED light source and a receiver (Haas, 2018).
Li-Fi wireless networking has a number of advantages over the other forms of the networking technologies. The Li-Fi networking has three orders of magnitude enhanced data densities and unique properties to enhance physical layer security. As the use of Power-over-Ethernet (PoE) and its uses in lighting are increasing, there exist an opportunity to rely on the existing data network infrastructures (Haas, 2018).
The concept of Li-Fi Networking
In order to create a Li-Fi network, a room is lit with light fixtures which provide illumination. Each light is then driven by a Li-Fi modem and they serve as an optical base station, which is then connected by high-speed backhaul connections. The light fixtures have an infrared detector to receive signals from the terminals. Data can be encrypted in the light by changing the flickering rate of the LED.
The frequency of the illuminating light is so high that it is not visible to the occupants of the room. The light fixture is being provided with power by various different sources. The optical link is implemented by using a transmitter. These networking systems cover a large area and they are also able to connect multiple user equipment simultaneously (Haas, 2018).
There are various disadvantages of using point-point networks. Firstly, there can be multiple users and hence a multiple access scheme needs to be implemented. Also, the uplink light is visible to the users which distract them from their tasks. Hence, the use of an infrared light source is appropriate for the uplink. The modulation techniques also need to be high-speed and spectrum efficient as well as power efficient (Haas, 2018).
The use of Li-Fi networking has various advantages over other forms of networking. The LED light source radiates the optical power and signals directionally. Hence, its radiation is confined to a limited region. Moreover, the implementation of Li-Fi networks is also easy as they can be implemented by just modifying the existing lighting systems.
They have the capacity to augment 5G cellular systems as they can provide the extra wireless capacity without any interference of RF networks. These systems are also very cost efficient. In addition to this, it combines the illumination and data communication by using the same device to transmit data and to provide lighting (Mundy, J., & Kavanagh, S., 2018).
There are many misconceptions about Li-Fi. The first misconception is that Li-Fi is a LoS (line of sight) technology. However, there is no direct link between Li-Fi and LoS. Some people also believe that Li-Fi doesn’t work in the sunlight. Hence, it can work in sunlight.
Li-Fi uses advanced modulation techniques and hence, the lights can be dimmed. The flicker rate of the light is almost 10,000 higher than that of the computer screen. Therefore, the flicker is not perceived or seen by the peoples (Haas, 2018).
The trends of communication are changing. Now people aim at using communication techniques that have higher frequencies. Therefore, there is a standard shift in the field of networking. We are moving towards the implementation of Li-Fi as a networking tool. Li-Fi products have entered the market which has enabled the wireless networking through light. Therefore, Li-Fi (Light Fidelity) has become a reality and this technology will be very helpful in the future advancements.
