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General Lighting

Li-Fi – Using Light to Transmit Data

Light is virtually a magical power, right? It enables us to see the world, use a computer, along with countless other things. In the last couple years, researchers have been trying to use light as a new way to transmit data. In other words, as an alternative to Wi-Fi!

But what’s wrong with Wi-Fi? Well, nothing, if only a limited amount of people use it. In a story posted on Quartz, it explains Wi-Fi’s problem: the more popular the wireless networks, the slower they are. You can only transmit so much data at a given frequency. Light, on the other hand, is about 100,000 times the frequency of a Wi-Fi signal.

A light bulb can carry a signal if it flickers rapidly and accurately. The flicker is so fast that the human eye cannot perceive it. For instance, did you know the average CFLs already flicker between 10,000 and 40,000 times per second? Then, a receiver on a computer or mobile device decodes the flickering into data.

Li-Fi was proposed two years ago and is advancing rapidly. Researchers at Fudan University in Shanghai have become the latest to demonstrate the technology that transmits data as light instead of radio waves. Li-Fi has the potential to solve the congestion issue while working 10 times faster than traditional Wi-Fi. Quite literally—functioning at the speed of light!

Other researchers are working on transmitting data via different colors of LED lights. Different signals would be transmitted through red, green, and blue LEDs inside a multi-colored LED bulb.

According to Quartz, it doesn’t need to be a special bulb. I wonder if the LED troffers in my office could be wired to transmit data?

It’s almost too good to be true. I, Dr. Bulb, am disappointed at one big dilemma. The device needs to be within sight of the bulb in order to function. Sadly, you cannot pick up your laptop and move to the next room unless both rooms have wired bulbs. This is the same problem that the new generation of ultrafast Wi-Fi devices have. They use a higher range of radio frequencies, but cannot transmit through walls.

Li-Fi cannot replace other wireless networks, but it could supplement them in congested areas or places where radio signals need to be kept at a minimum or where they don’t work. Could this be the solution for hospitals? Underwater? Overcrowded coffee shops?

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