https://www.mwrf.com/technologies/components/active-components/article/21846766/researchers-claim-record-for-terrestrial-radio-transmission
Researchers Claim Record for Terrestrial Radio Transmission | Microwaves & RF
Engineers from two German research institutes developed a radio that could transmit data around six gigabits per second over roughly 40 kilometers.
terrestrial radioresearchersclaimrecordtransmission