Ham Radio Networking
Using AREDN firmware on off the shelf wifi hardware, you can join an off-the-grid IP network using Amateur Radio frequencies. This is generally on the 2.4, 3.8 and 5.2GHz bands.
Any types of applications and services can run on this network, subject to FCC Part 97 Rules.
tl;dr - Find a node near your location that you have line of sight to, get some equipment and a pole to mount it on, flash it and configure.