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“That’s a video, a high-definition video that is transmitted through that light beam.”
It’s been dubbed “Li-Fi,” and last month, Harald Haas, Chair of Mobile Communications in the Institute for Digital Communications at the University of Edinburgh, gave an eye-popping demonstration of what he’s been developing during a TED talk on “Wireless data from every light bulb”.
Haas is, as his bio puts it, “the pioneer behind a new type of light bulb that can communicate as well as illuminate.”
At about 6 minutes into the 13 minute presentation, Haas gives his first public demonstration of how it works. If you don’t have time to watch the whole talk, watch at least the 90 seconds from 5:50 to 7:20. Haas shows how a beam from a light bulb can be rigged up to transmit a high definition video stream:
Here’s how Haas describes the technology: “replace these inefficient incandescent light bulbs, florescent lights, with this new technology of LED, LED light bulbs. An LED is a semiconductor. It’s an electronic device. And it has a very nice acute property. Its intensity can be modulated at very high speeds, and it can be switched off at very high speeds. And this is a fundamental basic property that we explored with our technology. . . . We transmit with our technology, not only a single data stream, we transmit thousands of data streams in parallel, at even higher speeds. And the technology we have developed — it’s called SIM OFDM. And it’s spacial modulation — these are the only technical terms, I’m not going into details — but this is how we enabled that light source to transmit data.”
The big vision: One day we might be able to use light to access the Internet in addition to — or even instead of — radio waves. Microchips in street lights and car headlights and lights in our home would give us wireless data transmission right along with illumination.
“It’s this symbiosis that I personally believe could solve the four essential problems that face us in wireless communication these days,” says Haas. Those problems: finite capacity, security, the need to turn off phones in places like hospitals, and energy efficiency (1.4 million cellular radio base stations, he says, “consume a lot of energy. And mind you, most of the energy is not used to transmit the radio waves, it is used to cool the base stations”). Li-Fi, he says, fixes all four things.
“You would not only have 14 billion light bulbs, you may have 14 billion Li-Fis deployed worldwide — for a cleaner, a greener, and even a brighter future,” he says.