On Tue, 9 Dec 2014, Ian Tomkins wrote:
> In essence their technology seems to revolve around using software
> defined radios to dynamically create radio interference patterns

To echo Ian's summary, it's real-time dynamic beam-forming the
discrete "APs" are treated as a giant 3D phased array:

  "pCell demonstration at Columbia by Steve Perlman, CEO, Artemis Networks"
  http://youtu.be/5bO0tjAdOIw?t=26m  (onwards)
  T+30m onwards is N times 4K content streaming
  T+39m has some heckling
  T+40m onwards has Matlab heatmap visualisation
  T+45m covers being backwards compatible with existing standards
  T+46m covers using licenced + unlicenced spectrem.
  T+51m the phased antennas are running at 1milliwatt

What matters is having having immense backhaul from each phased
antenna to the local datacentre, because what you're transferring is a
I/Q (SDR) sampling of the radio spectrum.

In summary this is the ultimate solution, and it's the practical one
because the hardwork is all on the infrastructure side and requires
zero-change on the device and protocol side.  The hard parts are:

  1. Using the return signals for position tracking
  2. Recomputing the beam-forming matrix in near-realtime
  3. Calculating and distributing those huge SDR I/Q streams

It is possible to already encounter these types of techniques in a
more familiar way: beam-forming can be used with a (phased) array of
speakers to allow each person to hear their own music/telephone call
without needing a phone to do it.  This is used on a very small scale
of advertising, but without the dynamic tracking.

It's also used for RADAR, and spot-beam generation on communications
spacecraft.

        -Paul




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