That may be cellular.
I've got a corridor I drive through to/from work that's a few miles long with hills close in on either side. Cellular coverage was non-existent.
Verizon started installing those on top of existing utility poles.
The middle box is the cellular RRU, remote radio unit.
The lower box is often an Alpha Technolgoies Cellect (or similar) power unit. It takes utility power, converts it to 48 volts DC powers the RRU and float charges the batteries.
Feedline (usually heliax) runs up to the can antenna on the top of the pole.
Might be 700 MHz public safety, but they usually like larger coverage areas, systems like this mounted on a 30 foot pole wouldn't be as useful. They'd also have more equipment if it was a P25 system.
I'd be surprised if it was a FirstNet style LTE system.
