Comment by ianburrell

There are a few problems with this. Mesh is cool for other uses but can't replace the infrastructure of mobile operator.

One, what frequency are you going to use? If you use 2.4GHz or 5GHz, your Wifi-using neighbors will hate you. There is the 6GHz spectrum but has problems with long ranges. The 3.5GHz CBRS is probably the best bet but that requires spectrum allocation and organization to run it. The mobile operators have all the good low frequency, long range spectrum.

Two, the range with home routers is going to be pretty short, maybe 1mi. That means lots of node to cover a city. Also, 5G routers are not that cheap. It also means that there will be no reception away from the city. Most routers are meant to be used inside, and good coverage, requires mounting them outside on a pole.

Three, I'm not sure there is 5G device-to-device. There was LTE-Direct but it never got implemented. There D2D in 5G spec but I can't find any implementations.