We often debate signal bleed in wireless audits. This NY Times report has a fun and detailed look at a wireless signal that works across the 50km between Windblown California Islands and San Francisco.

Both atmospheric attenuation and refraction cause signals to fade. The engineers tackled these problems with several steps, including using powerful antennas and narrow channels. An IEEE 802.11n radio can use channels as wide as 40Mhz, but Pozar limited the channel width to 10MHz, creating a more focused signal. This sacrificed speed for distance.

“Because we’re going over 50 kilometers of water, I’m being extremely conservative. So I’ve actually cranked this back to only around 12 megabits,” Pozar said.