Li-Fi
Wi-fi: it’s in coffee shops, airports, malls, workplaces, and probably even your own home. Wireless networking (Wi-Fi) is one of the fastest growing technologies across the world. According to Strategic Analytics, 1 in 4 internet-connected households uses Wi-Fi, and this number is only expected to increase. However, in the coming years Wi-Fi may have competition in the form of Visible Light Communications (VLC), also known as Li-Fi.
Li-Fi uses LEDs to communicate information by switching them on and off in nanoseconds. The light signals are communicated so quickly that the human eye is unable to distinguish any change in light levels. Li-Fi can be used for all the same functions as Wi-Fi, but while Wi-Fi uses radio signals to transfer information, Li-Fi uses light in the visible or infrared and ultraviolet spectra. Li-Fi may prove to be more popular in coming years due to the limited operating space in the existing radio frequency ranges. Wi-Fi is prone to interference and spatial issues, and it also cannot be used in areas containing radio-sensitive equipment such as hospitals, aircraft, and nuclear power plants. With Li-Fi there is no risk of electromagnetic interference with equipment, and since the visible light spectrum is 10,000 times larger than the radio frequency spectrum, there should be virtually no problems with interference.
Li-Fi does have some drawbacks compared to Wi-Fi. Since light cannot travel through solid objects, such as walls, the operating distance for Li-Fi is limited. However, devices using Li-Fi do not have to be in a direct line of sight from the light source as the light can reflect off surfaces in the room at the expense of bandwidth. The short operating range may discourage some people, but it can also be seen as a positive since it makes Li-Fi a more secure form of communication.
One of the latest developments for Li-Fi comes from Disney’s research team: In September they announced the development of their LED-to-LED Linux light bulb system. The Linux light bulbs work the same as a standard Li-Fi network, but Disney offers a much cheaper price point at the expense of bandwidth capacity. Disney hopes to use this technology for toys, wearables, and smartphone interaction. Items developed with Linux light bulbs can be given simple commands over the network as well as communicate with other Li-Fi capable objects in a room. Disney’s Linux bulbs have a maximum bandwidth of 1kb/s, meaning that it is currently only able to communicate simple commands such as a toy’s movement or two toys communicating to one another.
Other companies and researchers have been able to develop VLCs with much higher bandwidth. Stins Coman, a Russian communications company, announced the development of a local Li-Fi network called BeamCaster in 2014. At the time, they announced a 1.25 Gb/s transfer rate, which they hope to increase to 5 Gb/s in the future. In 2014 PureLiFi also demonstrated the first commercially available Li-Fi system, Li-1st, which is available in limited release as of January 2014.
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[iv] Visible Light Communication. (2015, September 7). Retrieved October 7, 2015, from http://www.disneyresearch.com/project/visible-light-communication/
[v] The Home of LiFi – pureLiFi™. (n.d.). Retrieved October 7, 2015, from http://purelifi.com/
[vi] [Li Fi ]. (n.d.). Retrieved from https://i.ytimg.com/vi/tDQTWux9rGQ/maxresdefault.jpg
