Comment by athrowaway3z

> What would be the best band for this kind of infrastructure? ( Disregarding any existing FCC licenses )

The frequency bands that have been licensed for cellular infrastructure.

Its all a trade-off. Higher frequencies get you better data bandwidth, but require more power and get attenuated more by stuff (buildings, trees). Lower frequencies get you much better range for a given power level and better building penetration, but lower data bandwidth.

Exceptions to this are the "crap" bands, like 2.4GHz and 60GHz. Microwave ovens (which are great interferers, BTW) use 2.4GHz because it is absorbed by water. Great for heating your food. No so great trying to transmit data in an outdoor environment with rain and fog.

60GHz gets absorbed by the oxygen in the atmosphere, so that's another band that's only good for very short ranges.

The bands the cellular carriers have now are a good trade-off between power requirements, data bandwidth, and other issues (like absorption). The ISM bands exist basically because nobody would pay to use them.

The biggest advantage to the cellular bands is that they are exclusively licensed, so noise is a non-issue, or at least an issue that you are in control of, since you are the only one allowed to build infrastructure in a given area.

Cell carriers have a wide variety of bands they can deploy, from frequencies above 1GHz, which doesn't propagate well through free space or obstructions, but allows for high-density, high-bandwidth use, to frequencies below 1GHz (600, 700 and 800MHz bands in the US), which propagate well in free space and reasonably well around and through obstructions (but cant be deployed with as high a density, since signals propagate well).

That being said, the infrastructure is the biggest advantage.

My gut says that absent FCC regulations and allocations, for wide area coverage something like 500-900 MHz is an ideal spot between propagation and required antenna size. Guess where TV stations are (historically at least)?