Open source project idea: Combine solar-assisted drones like this with a mesh network, where the drone carries network node hardware and can be deployed to a rooftop or other high point. Multiple drones could be programmed to fly out and land in strategic locations to quickly set up a mesh network that can stay up for some time with solar power. Haven't seen anything like this outside closed military industrial projects. https://www.youtube.com/watch?v=rAw7hD2ApWA