Nostr web services (NWS) could also be useful as an overlay network. I've heard lots of good things about the mesh ISPs in Barcelona. 

Currently contributing to TollGate, which aims to put networking infrastructure onto Bitcoin rails. Bitcoin support for your wifi captive portal, Bitcoin support for your internet gateway and Bitcoin support for your gateway's Internet Gateway 😀

Please ping us if you know about the GSM stack and its open source components

https://github.com/chGoodchild/GLTollGate