30+ GHz require line of sight. It's not feasible to deploy stations, except maybe indoors like shopping mauls. More realistic is the 700 MHz range. 2100 TDD is

30+ GHz require line of sight. It's not feasible to deploy stations, except maybe indoors like shopping mauls. More realistic is the 700 MHz range. 2100 TDD is also pretty much unused, as well as 2600 TDD. Then again you can reuse existing frequencies that were previously used for GSM/UMTS/LTE.