June 27, 2016


Li-Fi: Data through illumination

What is Li-Fi?

Li-Fi or Light Fidelity, term coined by Professor Harald Haas at TeD talks, is next generation technology of wireless communications or to put it simply Li-Fi is data through illumination. Li-Fi is similar to Wi-Fi but differs in terms of speed, security, and most importantly the electromagnetic spectrum.

Li-Fi is based on visible light spectrum instead of radio waves, which are used in Wi-Fi and other communication networks like mobile devices. With the lack of radio frequency spectrum available for mobile devices these days, Li-Fi provides a new platform for devices to communicate. Visible light spectrum is 10,000 times the size of radio wave.

How Li-Fi works?

Li-Fi takes advantage of the new LED (light emitting diodes). LEDs are semiconductor devices whose optical output can be manipulated at very high speeds; this change is unapparent to human eye but can be discerned by a photo-detector device. This means that every LED bulb in your house, not only house, the LED light in your mobile phone too, is a potential source of data transmission. Well, the next question that pops-up is “Does the light have to remain switched on all the time?” Well, the answer is yes. However, there is a catch; the intensity of light can be dimmed down to a level that it appears off to human eye but is still capable of transmitting data. A special mention must be made to the energy efficiency of LEDs; if all the devices now used for communication are replaced with LED, it would save the world a lot of power plants.

Li-Fi vs Wi-Fi

Li-Fi boasts of 224 gigabits per second in lab, which makes Wi-Fi looks ancient. With that speed, you can download 18 movies of 1.5GB each in a single second. Li-Fi, coupled with fiber-optic cables, can easily surpass Wi-Fi. Scientists took Li-Fi out of lab and tested it in the real world in Tallinn, Estonia. They were able to achieve a transmission speed of 1 GB per second.

In the future, you can expect Li-Fi hotspots around, but this technology has yet to be commercialized for common use. The hype is definitely there, but will this tech hit everything and blow it away, or will it bite the dust, is yet to be decided.