How is this even physically possible? Is this for a small mobile device? It would imply a spectral efficiency of 10000 bits/s/hz. To put in perspective [1], 4G

How is this even physically possible? Is this for a small mobile device? It would imply a spectral efficiency of 10000 bits/s/hz. To put in perspective [1], 4G claims a best case spectral efficiency of 30 (!) bits/s/hz using 4x4 MIMO. I'm not sure there are even enough physical degrees of freedom to allow that with a small device, given the wavelength of light at the Ghz range is ~10cm (i.e. sure, if you use 10000 antennas over a large area, you can have 10000 b/s/hz!; in this case, I would estimate it to need ~2000 antennas). To be clear, for a single "degree of freedom" you are limited by the Shannon capacity [2], which we are pretty close to already in most technologies. So I'm skeptical. It's either a nice optical link, a massive device, or some high freq. radiation I'm not familiar with. [1] http://en.wikipedia.org/wiki/Spectral_efficiency http://en.wikipedia.org/wiki/Spectral_efficiency [2] http://en.wikipedia.org/wiki/Channel_capacity#AWGN_channel http://en.wikipedia.org/wiki/Channel_capacity#AWGN_channel