Could you send ePub files over ham radio? Let’s forget about TCP-IP mesh networking like AREDN for now. That’s too easy. Let’s look at radio protocols. D-Star can run at 128 Kbps on the 23 cm band. That’s not too common. Drop down to HF and you’re looking at 9 Kbps via PACTOR-IV.
In comparison, landline dial-up modems topped out at around 56 Kbps.
Now, I’ve seen ePub files around 1-2 MB, but that’s with cover art, images, embedded fonts, and all that fun stuff. With enough patience, that can work. But, strip out all that, leaving behind plain text and XML, and you’ve got something much more manageable that can be sent relatively quickly.
I can’t speak for Spain, but in the U.S., the FCC recently removed most symbol rate restrictions, so we might be able to squeeze out a little more speed.
Does CB radio allow data emissions? I thought it was only AM and SSB voice.