Most wireless communications use RF or radio frequency communications to send data back and forth. But all that information can slow things down especially with clogged networks. As our nonstop exchange of information fills the electromagnetic spectrum available for Wi-Fi, light fidelity (Li-Fi) is emerging as one solution to pick up the slack. The technology is what is known as Visible Light Communication (VLC). Unlike infrared-based systems, VLC involves transmitting data using light visible to the human eye. In this case it is transmitted as intermittent, imperceptible flickers of light emitted by LEDs. Li-Fi turns LED lamps into internet and broadcast data transmitters, creating a new form of high-speed, optical wireless communication.
To send data, Li-Fi relies on the modulation of light at frequencies that are imperceptible to the human eye in most lighting applications. As semiconductors, LEDs can turn on and off up to a million times per second, enabling the diodes to send data quickly, says Tom Van den bussche, founder of Toric, a lighting-technology company based near Paris
In a Li-Fi installation, a digital signal processor integrated or attached to an LED driver takes data from a network, server, or the internet and converts it into a digital signal-basically a sequence of discrete voltage levels. The LED driver in each fixture converts the digital signal into a photonic signal, transmitting it at a very high frequency as an Orthogonal Frequency Division Multiplex (OFDM) signal, says PureLiFi chief operating officer Harald Burchardt. OFDM signals are also employed in 4G LTE and Wi-Fi technologies because they use many small-bandwidth channels collectively rather than a single large-bandwidth channel. The decoder on the receiving device-say, a computer or smartphone-then translates the OFDM signals into data for the user. PureLifi is a private company that was Co-Founded by Li-Fi's developer, CSO Professor Harald Haas.
All these then begs the question, what makes Li-Fi better than Wi-Fi? When it comes to data transmission, two characteristics that are of note are speed and security. In terms of speed, Li-Fi transmits date at rates of up to 10 gigabits per second. This is according to Scisoft, another leading private company that is into the development of Li-Fi technology. This is an improvement over similar Li-Fi systems developed at Siemens and Pennsylvania State University that achieved transfer rates of 500 Mbps and 1.6 Gbps, respectively. Still, all these recorded speeds are better than the fastest recorded Wi-Fi speed which is at 150 Mbps. In addition to its impressive transfer rate, Sisoft also highlighted its security advantage. Given that the data is transferred via light, there is no way to hack it, making it safer.
Given all these information, we then leave you with PureLifi's catch phrase that says, "Imagine a world where every light connects us with unprecedented data and bandwidth. Imagine LiFi.. Join the light revolution."
