Present 5G is total and utter mess.

Almost each country reserve different bands, and even plans to change allocation with time, removing one bands and adding another.

They include parts in 26, 28, 38, and 60 GHz regions.

“Low-band 5G” and “Mid-band 5G” use frequencies from 600 MHz to 6 GHz, especially 3.5-4.2 GHz.

Most current smartphones do not support most of the bands and have issues with standards implementation being more like alpha version.

Energy efficiency will drop significantly as antennas will be much less efficient.

Tarriffs for same amount of traffic and time are expected to rise 3-5x times, as now they need to build much more base stations. Stations >26Ghz region must be present literally at each 50-150 meters.

https://www.cablefree.net/wirelesstechnology/4glte/5g-frequency-bands-lte/