I was just reading about LORAWAN and it sounds interesting. If you never heard of it, it's a digital radio system that has long range (~15km LOS, ~2km urban jungle) and low bitrates ( < 4kbps ). The city of Amsterdam deployed a network and they have 100% coverage of the city with only 15 "gateways". It uses the unlicensed radio spectrum (433, 868).
Transceiver modules (with tuned external antennas) cost around $75USD.
One use I can see for this network is telemetry for mobile devices (such as cars) with city-wide coverage without incurring the monthly expense of commercial radio WAN services (such as cellular).
My thought is that we could start an open, community based network in the city by setting up gateways in our homes.
A gateway would consist of a transceiver module, a computer of some sort ( BeagleBone, R-Pi ) and an internet connection.
There would need to be a central server that could take on one of two roles: Gateway into the network (users would connect to the server in order to receive and transmit packets to the radio nodes) or Directory (would provide the gateways with an internet destination for the packets from a radio node, the gateway would contact the destination, and deliver a packet) or a combination of both ... who knows, I'm just brainstorming at the moment.
The advantages of this system over the amateur radio repeaters are: 1) users would not need an amateur radio license, 2) the data could be encrypted (theoretically all amateur radio transmissions are supposed to be "in the clear" and anybody should be able to receive and interpret it with the right equipment)
Anybody interested in talking about this idea?