Problems
  communication protocol
    message authentication
      sign hash w/ shared secret
      keypairs probably unnecessary
    naming
      number nodes
    detecting nearby devices
      beacon frames?
      who's-here? I'm here?
    robustness 
      hash
      error-correcting codes
    unreliable sensors
      repeating measurements
      repeat twice, then repeat again to arbitrate as necessary.
    rover failures
    amendments
   
Scheduling