Li-Fi (Light Fidelity) is a bidirectional, high speed and fully networked wireless communication technology similar to Wi-Fi. The term was coined by Harald Haas and is a form of visible light communication and a subset of optical wireless communications (OWC) and could be a complement to RF communication (Wi-Fi or Cellular network), or even a replacement in contexts of data broadcasting. It is so far measured to be about 100 times faster than some Wi-Fi implementations, reaching speeds of 224 gigabits per second.
LiFi is a disruptive technology which will shift business models and create opportunities ripe for exploitation. The dominance and lifetime of LED lighting has created a need for new business models in the lighting industry. The need to offer services, including new payment and financing models, creates an unprecedented opportunity for LiFi.
It is wireless and uses visible light communication or infra-red and near ultraviolet (instead of radio frequency waves) spectrum, part of optical wireless communications technology, which carries much more information, and has been proposed as a solution to the RF-bandwidth limitations.
Li-Fi, or Light Fidelity, is suddenly in the news these days because an Estonian company called Velmenni conducted a real-world test where it was able to transfer data between devices at 1 Gbps, which is roughly 100 times faster than Wi-Fi in the real world. In lab tests, the fastest recorded speed was 224 Gbps!
Li-Fi’s biggest proponent is Harold Haas, a professor at The University of Edinburgh, and founder of the company pureLiFi, which is trying to bring the technology into real world markets.
Li-Fi is dependent entirely on light, specifically LED bulbs. In a way, it’s the next step in connected lighting. In the simplest terms, Li-Fi transfers data over light waves. By comparison, Wi-Fi uses radio waves.
Li-Fi works much like the infrared technology in your television, and infrared works on a simple principle: an input command is given (e.g., “change channel” when you press a button) and that input is turned into binary code.
That code is then transmitted over infrared light waves by your remote’s sensor, and the light waves are received by your TV’s infrared sensor, which decodes the light and performs the intended input action.
PureLiFi’s infographic above shows how this works. The Internet and router/server is hooked to a cable, and the cable is attached to any number of LED bulbs in your house. The LED bulbs then transmit the data as modulating light waves while a photodetector on your phone or laptop picks up those light waves and decodes them.
So anywhere that your LED bulb is casting light that your photodetector can “see”, you’re ready to get Internet access — and at speeds faster than Wi-Fi.
Credit : http://www.ed.ac.uk/home
http://purelifi.com/