224 Gigabits Per Second?

Imagine every light bulb in use today as a wireless hotspot delivering connectivity at speeds that can only be dreamed of with Wi-Fi. This is no longer a science fiction with the invention of LiFi technology by the Professor Harald Haas which has proved to transmit data at a speed, 100 times faster than current Wi-Fi.

What is Li-Fi?

Light Fidelity or Li-Fi is a light based communications technology that uses light-emitting diodes (LEDs) for data transmission in a similar manner as Wi-Fi in other words use of LED bulbs as wireless routers.

LiFi is designed to use LED light bulbs similar to the ones that we use at our homes and offices. However, these LiFi bulbs are outfitted with a chip that regulates the light imperceptibly for optical data transmission.

Early developmental models were capable of transmitting data a rate of 150 megabits-per-second (Mbps). Some commercial kits enabling that speed have been released. At the same time they have been able to transmit data at 10 gigabits-per-second (Gbps) in their research labs, with stronger LEDs and different technology. And they assume that this technology has potential to grow up to 224 gigabits per second (Theoretical speed).

Who Invented Li-Fi?

German physicist Harald Haas, brought this technology in to the light at the TED Global Talk (July, 2011) where he introduced the idea of “Wireless data from every light”. Haas, is a professor of mobile communications at the University of Edinburgh, created pureLiFi with a group of people who had been researching the technology since 2008. They recognize themselves as the leaders in Li-Fi technology.

How Does Li-Fi Work?

This is how pureLiFi describes the operation of its technology:

“When a constant current is applied to an LED light bulb a constant stream of photons is emitted from the bulb which is observed as visible light. If the current is varied slowly the output intensity of the light dims up and down. Because LED bulbs are semi-conductor devices, the current, and hence the optical output, can be modulated at extremely high speeds which can be detected by a photo-detector device and converted back to electrical current. The intensity modulation is imperceptible to the human eye, and thus communication is just as seamless as RF. Using this technique, high speed information can be transmitted from an LED light bulb.


Radio frequency communication requires radio circuits, antennas and complex receivers, whereas Li-Fi is much simpler and uses direct modulation methods similar to those used in low-cost infra-red communications devices such as remote control units. Infra-red communication is limited in power due to eye safety requirements, whereas LED light bulbs have high intensities and can achieve very large data rates.”

(Source; http://purelifi.com/what_is_li-fi/how-does-vlc-work/)

What are the Benefits of LiFi?

  • Much more faster than Wi-Fi
  • More secure because data cannot be intercepted without a clear line of sight.
  • Prevents unauthorized use of personal networks and neighboring network interference.
  • Has an operating frequency of Hundreds of Tera Hz
  • Will be cheaper than Wi-Fi
  • By using LiFi in all the lights in and around a building, the technology could enable greater coverage than a single Wi-Fi

What are the CONs?

  • Need of a clear line of sight as light waves cannot penetrate walls
  • Difficulties with mobility and the requirement that lights stay on for operation.
  • It is still unclear how interference and sun issues will be dealt with
  • LiFi has no standard yet, so equipment from one vendor won’t work with another.

When Will Li-Fi be Available?

Speaking to International Business Times UK, Deepak Solanki, CEO of Velmenni, has said that, with the success of the pilot projects could see Li-Fi technology rolled out for consumers within the next three to four years. While, Li-Fi may not completely replace Wi-Fi, the technologies could be used in parallel to create more efficient networks.

By ; Harindu Abeysinghe.



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