multiple uni-directional radio emitters
using trial-and-error, multiple aerials, uni-directional in nature, as opposed to emitting in an omni-directional manner, could be more efficient with bandwidth if each of the multiple aerials in a telecommunications device were pointing at the most efficient route to it's target receiving telecommunications device.
basically it's a bunch of aerials that point directly at the most efficient way to it's target, which would be less polluting and possibly even more secure.
i'd imagine a small device such as a wire-less router with many aerials on top of it, and whenever someone or something moves in the room, the aerials would move about trying to determine a new best route for the radio-waves to reach their target.
this could be applied to cellular/mobile phones, or basically any telecommunications device, and could result in multiple times more bandwidth whilst still using the same frequencies.