In 2011 Prof. Harald Haas (pictured) of the University of Edinburgh demonstrated streaming a hi-def video signal using a light beam as a transmission medium. He went on to explain how this technology might be used to address the growing paucity of free RF bandwidth and suggested that domestic LED lamps may in future provide an internet access point, once the necessary control electronics to modulate the light are integrated into the lamp.
The key to this technique (dubbed LiFi) is a modified type of Orthogonal Frequency Division Multiplexing called SIM OFDM. This splits the serial data stream into thousands of parallel streams, using multiple carrier frequencies to modulate the light source and achieve a high throughput.
Prof Haas has set up a company PureVLC to develop the technology but it seems as though a Chinese team have stolen a march on the technology. Chi Nan, information technology professor at Shanghai's Fudan University, working with a research team of scientists from Shanghai Institute of Technical Physics at the Chinese Academy of Sciences announced they would be demonstrating and making available a LiFi kit at the China International Industry Fair in November. She said that the kit uses a one-watt light emitting diode (LED) to provide 150 Mbps access to the Internet for up to four computers.