2013/9/26 Eugen Leitl <[1]eugen@leitl.org>

   It's really hard to jam the sky, especially in VIS range.

   "Huh. Guys, what's that on our radio scanner? Someone calls us?"
   Hard to jam, easy to trace. Even regular Dutch police forces have
   triangulation tactics to find pirate radio stations.
   This is where I'm more enthusiastic about near-optical connections. A
   laser, invisible spectrum ofc, and a small black surface (iow:detector)
   are all it takes. It will still be visible (at night) with special
   hardware. Street lanterns (depending on the type) might make them
   invisible at night too. Bandwidth is wonderful, and there's plenty of
   spectrum to duplicate bandwidth too. Quite like fiber, except for the
   ideal transmission.
   And that highlights the problems. You have to keep the laser pointed,
   that means not diffracted by thermic differences or blocked by dust and
   other particles (like, you know, leaves). This might be less trouble
   than it'd seem at first, and even better it can be automated by a lens
   system.
   A just graduated ship's lieutenant laughed at me for suggesting laser
   communication as the future. "No spying, very high speed, very wide
   bandwidth!" and he effectively answered "Line of sight, irreliable, no
   need for speed and just use satellite".
   A yagi pointed skywards should be hidable inside the house, so I guess
   he's somewhat right.

References

   1. mailto:eugen@leitl.org