I think the solution you're looking for, is actually to establish internet, but maybe a network that's dedicated to Bitcoin transactions? Anyway, look here: https://www.althea.net/
You're going to want to look at UHF for long haul communications, and long distance WiFi extenders if the haul is only a few miles.
For shorter distances, you'll want this: https://www.instructables.com/LoRa-Mesh-Radio/
If you happen to be working with a community that doesn't have internet access like the Central African Republic for example, these projects are the way to go. Its just, internet citizens such as ourselves have a hard time getting this information to people who aren't on the internet.