Light networking

The search for transmission capacity to satisfy the seemly unending thirst for wireless data drives interest in higher frequency bands (tens of Gigaherz), so perhaps the arrival of LiFi (based on modulation of visible light) should not come as too much of a surprise. The principle is that ordinary lighting found in homes and offices is now gradually turning over to LED (Light Emitting Diode) technology. A major advantage that these offer over conventhtional tungsten and flourescent lamps, is that their light output can be modulated at a much greater rate - beyond the perception of the human eye. High modulation rates translate into high data rate and hence network transmission capacity.

This technology is particularly interesting for content distribution, being essential unidirectional. Return paths could be added, possibly using invisible wireless links. Unidirectional content distribution is quite familiar from broadcast networks, where storage can be provided in end-user devices, to enable some degree of choice and interaction. This means that the technology is more likely to complement rather than substitute for bi-directional network technologies such as Wi-Fi.

MarketsandMarkets, a research company, estimates that the market for visible light communications equipment could be worth over $6 billion, by 2018.

A company called Pure VLC, co-founded by Professor Harald Haas from University of Edinburgh, has recently shipped its first £5000 order for a medical application.

Reported in the FT, 11th October 2013