I admit that I don't have much expertise on the matter, having only ever operated a GSM cell site simulator (never LTE), but the max range I remember (in ideal conditions) is something like 35 miles.
(Note there's and "extended range" feature, where you can halve the cell site's capacity by waiting two timeslots in the TDMA schedule instead of one - which lets you go as far as 120km...)
https://en.wikipedia.org/wiki/Timing_advance
(Note there's and "extended range" feature, where you can halve the cell site's capacity by waiting two timeslots in the TDMA schedule instead of one - which lets you go as far as 120km...)