WiFi uses limited bandwidth in the 2.4 GHz and 5 GHz bands. If it could use light instead of radio frequency signaling, the sky’s the limit in terms of performance.
Using light, researchers at Oxford are looking at possible speeds of 3 terabits per second. Currently, WiFi can hit 7 gigabits per second on a good day. Beyond speed, the other advantage of using light is that it is unlicensed – you can use as much as you need without interfering with other services (or requiring a permit from the FCC...)
So far, they’ve been able to transmit at over 200 gigabits per second using an access point in the ceiling directing a beam toward the computer. Currently, the computer needs to be in a fixed position relative to the access point, but they’re working on a tracking system that would allow for more portable operation.
It will be a while before something like this makes it into commercial products. When it comes it will really up the ante in wireless communications - great for HD video transmission, for instance.
For more details see: http://spectrum.ieee.org/tech-talk/semiconductors/optoelectronics/fiber-to-the-living-room