The Latest in Li-Fi

Newly developed technologies are allowing wireless networks to operate several hundred times faster than Wi-Fi—one of them is Li-Fi or Light Fidelity. Simply by switching on a light bulb, it is possible to encode data within the visible light spectrum rather than allow them to ride on radio waves as traditional wireless technologies such as Wi-Fi do.

So far, research labs had confined Li-Fi within their closed doors. Of late, however, several new products using the Li-Fi technology has started to appear on the market. While the majority of the wireless industry focused their attention on developing 5G or the fifth generation wireless technology, PureLiFi presents a new dongle for laptops and computers that uses the latest light fidelity technology. Another startup company, Oledcomm from France, offers their Internet lighting system for hospitals and offices.

Light bulbs use LEDs, which are semiconductor devices able to switch at very high speeds, unlike the incandescent or fluorescent bulbs, which are rather slow in turning on and off. Li-Fi technology interrupts the electric current through the LEDs at high speeds, making them flicker and at the same time, encoding the light they produce with parallel streams of data. The analogy here is the process is very much like producing the Morse code in a digital manner, the difference being the flickering is much faster than the human eye can follow.

Dongles, smartphones, and other devices with built-in photo detectors can receive this light encoded with data. This manner of communication is not new, as remote controls have been using this technology using infrared lights. The remote sends tiny data stream commands to toys and televisions, and they interpret the information, process it, and change their functioning accordingly. Li-Fi uses visible light spectrum, as it can reach intensities capable of transmitting much larger amounts of data than infrared light can. For instance, it is common to find Li-Fi networks operating at speeds around 200 gigabytes per second.

The only downside to Li-Fi is it works on line-of-sight. As light does not bend around corners, the transmitter and receiver must physically see each other to communicate effectively. According to Harald Haas, the professor of mobile communications who introduced the world to Li-Fi, this handicap is easy to overcome by fitting a small microchip in every potential illumination device. The microchip would serve to combine two basic functionalities in an LED light bulb—illumination and wireless data transmission—one need only place the microchip embedded LED light bulbs in sight of one another to act as repeaters in between the transmitter and the receiver.

Haas spun out PureLiFi, whose initial products had a throughput of 10 Mbits per second, making them comparable to Wi-Fi versions available at the time. Since then, PureLiFi has advanced the technology to produce LiFi-X, an access point connecting LED bulbs and dongles and providing 40 Mbits per second for both downloads and uploads speeds.

Another company from Estonia, Velmenni, has already demonstrated Li-Fi technology in their products that offer speeds around one Gbits per second. Oledcomm has developed kits for retrofitting Li-Fi into existing LED light bulbs, useful for communication within supermarkets and retail stores.