EM radiation in between 300Mhz and 300GHz, this broad range of frequencies offers usable spectrum for broadband point-to-point communications(requires line-of-sight). Since microwaves can be focused into narrow beams its widely employed by satellite communications to form uplinks/downlinks with high bandwidth. This frequency band includes the milimeter waves that are being tested for 5G usage. see also: line-of-sight, EM Spectrum