We all love faster speeds for our cellular connections, and technology is on a path for that to happen again with 5G. See this article that has a segment in it on 5G. Just page down a ways.
The piece that grabbed my attention is the fact that the big cellphone towers we've become accustomed to are not what is needed to make 5G a reality.
How all of the above meshes with FirstNet cellular service is not explained, so we'll have to see what AT&T says about it in the future.