A plan to turn every lightbulb into an ultra-fast alternative to Wi-Fi

Current wireless networks have a problem: The more popular they become, the slower they are. Researchers at Fudan University in Shanghai have just become the latest to demonstrate a technology that transmits data as light instead of radio waves, which gets around the congestion issue and could be ten times faster than traditional Wi-Fi.

In dense urban areas, the range within which Wi-Fi signals are transmitted is increasingly crowded with noise -- mostly, other Wi-Fi signals. But what if you could transmit data using waves of much higher frequencies, and without needing a spectrum license from your country’s telecoms regulator? Light, like radio, is an electromagnetic wave, but it has about 100,000 times the frequency of a Wi-Fi signal, and nobody needs a license to make a light bulb. All you need is a way to make its brightness flicker very rapidly and accurately so it can carry a signal. Because of its limitations -- so-called “Li-Fi” cannot penetrate walls -- it won’t do away with other wireless networks. But it could supplement them in congested areas, and replace them in places where radio signals need to be kept to a minimum, like hospitals, or where they don’t work, such as underwater.