• Bhavya Putta

Li-Fi Technology - The future of the internet


Li-Fi technology
Li-Fi technology

Wireless data transfer has become an active part of every aspect of the modern world. It was first pioneered by the Indian scientist Jagadish Chandra Bose in the late 1890's. Now, #WiFi drives our daily activities. It is something without which many of the services would stop. Its usage has become so intense that people are facing internet connectivity issues lately. Thus, #LiFi technology comes into the picture.


Imagine if you could transfer data wirelessly just by switching on your light at home. Yes, this is possible by employing the brand new Li-Fi technology. It is a wireless optical network technology that transmits data through visible light from the LEDs. Li-Fi technology takes the #wireless transmission to the next level by using the much greater visible light spectrum. It is about 100 times more agile than Wi-Fi. Many companies are now deploying Li-Fi technology due to its added advantages over Wi-Fi. In this article, let's discuss how Li-Fi technology works, its advantages, disadvantages, and whether Li-Fi can actually replace Wi-Fi.


History of Li-Fi


The term Li-Fi(which stands for light fidelity) was first coined by Professor Harald Haas at a TEDx global talk in 2011. He is the Chair of Mobile Communications at the University of Edinburgh. Wi-Fi generally uses radio frequencies for wireless data transmission. Professor Harald states that Li-Fi technology can be employed in environments where radio frequencies are dangerous. Li-Fi brings internet access to the places radio frequencies cannot reach.

Harald Haas explaining Li-Fi
Harald Haas explaining Li-Fi

pureLiFi, a company co-founded by Haas, released the world's first commercially available Li-Fi technology in 2013. In February 2015, Li-Flame, the first LiFi product that allowed for mobile wireless communications was released. The LiFi-XC system was released in October 2017. This is a certified device that works with USB and is small enough to be integrated with your mobile, laptop, etc.


How does Li-Fi work?


Li-Fi uses visible light for the transmission of data through visible light communications(VLC) system. It has two essential components:

  • A device equipped with a photodiode to receive the light signals.

  • A light source equipped with a signal processing unit for the transmission of data through light.

LEDs and fluorescent bulbs are the two light sources that can be considered in this context. The fluorescent bulbs emit light in a wide band of wavelengths whereas the LEDs emit light in a very narrow band of wavelengths. Li-Fi requires a high rate of light output for efficient operation. Thus, the LEDs are effective sources of light than fluorescent bulbs.

A white LED
A white LED

Data is captured by a #LED light source in the modulated light frequencies and is then transmitted to the Li-Fi enabled devices. The transmitted signals are identified by a photosensitive detector deployed in the Li-Fi enabled devices. This device converts the light frequency signals back into an electronic stream, thus allowing the fastest bidirectional communication. However, there is a major constrain in using the LED light source.


LEDs are basically semiconductor devices that amplify the light signal and also switch rapidly. But, #Li-Fi depends on the constant flow of photons emitted as visible light from the source. When the input current to the LED is varied slowly, the intensity of light emitted also changes, making them unfit for household illumination. To overcome this shortcoming, the current and the optical output are modulated at extremely high speeds that are detectable by the photodiode but unperceived by the human eye. This maintains a balance between the VLC light source and household illumination.


An illustration of the working of Li-Fi
An illustration of the working of Li-Fi

Advantages


Li-Fi has many advantages over Wi-Fi which make it more suitable as a means of wireless data transfer. A few are mentioned below.

  • It is 100 times faster than Wi-Fi.

  • Its transmission speed can go up to 100 Gbps which is 14 times faster than WiGig, the world's fastest Wi-Fi.

  • It encounters less interference from other sources.

  • It can pass through salty seawater as well.

  • It can work effectively in denser regions.

  • It transfers data more securely.

Disadvantages

  • It has a lesser coverage distance(about 10 meters).

  • Not many devices are Li-Fi compatible.

  • Employing Li-Fi will be absurd if the internet speed from service providers is slow.

Can Li-Fi replace Wi-Fi?


Firstly, does Wi-Fi really needs a replacement? Many government organizations, Multinational companies, educational and research organizations carry out many of their activities through Wi-Fi. Thus there is a necessity to enhance the existing Wi-Fi technology, given its various limitations such as radio interference, less effective for dense usage, and security concerns.


Li-Fi seems to eliminate all the shortcomings of Wi-Fi. A few experts have also declared Li-Fi as the future of wireless transmission. To apprehend if Li-Fi can completely replace Wi-Fi, let's now compare them using a few properties.


Transmission speed:

Studies have revealed that Li-Fi transmission speed can reach up to 224 Gbps, whereas the maximum transmission speed of Wi-Fi is 100 Mbps. This is due to the fact that the visible light spectrum is almost 1000 times greater than the Radiofrequency spectrum.


Coverage:

The Wi-Fi has a coverage distance of about 32 meters as the radio waves can pass even through the walls. On the contrary, Li-Fi has a coverage distance of 10 meters as light cannot pass through the walls. Thus the transmission range of Li-Fi is limited within the walls of a room, which is its significant downside.


Data density:

The Wi-fi becomes less effective in an area of a high volume of users. Whereas, Li-Fi doesn't have any such property. In fact, it works more efficiently when there are more users. Li-Fi can also be used in areas viz hospitals and chemical industries where the vicinity is sensitive to Radiofrequencies.


Energy efficiency:

Wi-Fi consists of two radios continuously communicating with each other through the RF transmitters and a baseband chip. They take up a lot of energy just to recognize the signal from the noise of various other devices. Li-Fi requires a light source and a photodiode to transmit and decode the light signals, and hence consumes lesser energy.


Security:

Data transfer through Li-F is more secure as its coverage distance is less, making it useful for various strategic and sensitive applications such as defence, research, etc.


Thus the benefits of Li-Fi are extensive. But, Li-Fi cannot replace Wi-Fi completely as it is still under development. It is being developed by numerous organizations across the world. It is possible that it can be a potential source of connectivity soon.


A Li-Fi enabled room
A Li-Fi enabled room

Companies developing Li-Fi technology


Using Li-Fi for larger applications is not yet feasible as there is no simple infrastructure that can provide Li-Fi technology on an extensive scale. But many companies have deployed Li-Fi systems and are utilizing their resources for the growth of Visible Light Communications. A few such organizations are as follows.

  • pureLiFi

  • ZERO1

  • Signify

  • Oledcomm

  • Lucibel

  • LumEfficient

  • Firefly LiFi

  • Velmenni

  • VLNcomm

  • LIFX(Li-Fi labs)

  • Lightbee

  • Global LiFi Tech

Conclusion


Wi-Fi has definitely improved various work conditions, but its performance is being affected by various factors. Thus organizations are now embracing new #technologies for much better performance. Li-Fi seems to be a potential alternate for Wi-Fi, although there are quite a few limitations in its basic infrastructure.


Thus, it cannot be affirmed that it can completely replace Wi-Fi. It may take a few years for full-scale development. There are varying answers to when it would be available in the market. Some say after ten years, others say twenty, and a few also say that in the next five years. But, regardless of the exact time of availability, many believe that Li-Fi technology will be the future of the #internet.


See Also

WiMAX | An Overview

5G Communications

Smart Lighting system for home