2 ms·

> What other air-based telecommunications infrastructure is there? Radio.

• tzs 13y ago
  In particular, look at what the hams have done with cheap, low power radios. Many take it as a challenge to see how far they can reach on low power. This is called QRP. The QRP hobbyists regularly communicate over hundreds or even a thousand miles on a few milliwatts of power. The record is 1650 miles with a 1 microwatt (micro, not milli!) transmitter.