The BBC reports about a new method of delivering data that's being successfully tested, using the visible spectrum rather than invisible radio waves. So-called "li-fi" can deliver internet access 100 times faster than current wi-fi, with up to 1 Gbps. A standard LED bulb, an internet connection, and a photo detector are used by the Estonian start-up company Velmenni. The company's laboratory tests have proven theoretical speeds of 224Gbps. The company's chief executive Deepak Solanki predicts consumers will be using li-fi "within three to four years." Professor Harald Haas from Edinburgh University first demonstrated the technology at a TED conference in 2011, showing how it does not interfere with other radio signals, and uses a part of the radio spectrum, the visible waves, that's 10,000 times larger then where radio waves currently travel. Sunlight is li-fi's kryptonite, and it does not travel through walls, so this is an end-of-the-line technology for large office buildings.