The High Frequency Global Communications System (HFGCS) is a network of single sideband shortwave transmitters of the United States Air Force which is...

The Defence High Frequency Communications Service or the DHFCS is a British military beyond line-of-sight communication system operated by the Ministry...

USNS Potomac (T-AO-181). The United States Air Force operates a High Frequency Global Communications System transceiver site located on the south end of the atoll...

The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the...

Advanced Extremely High Frequency (AEHF) is a constellation of communications satellites operated by the United States Space Force. They are used to relay...

main uses of the high frequency spectrum are: Military and governmental communication systems Aviation air-to-ground communications Amateur radio Shortwave...

GSM-R, Global System for Mobile Communications – Railway or GSM-Railway is an international wireless communications standard for railway communication...

The High-frequency Active Auroral Research Program (HAARP) is a University of Alaska Fairbanks program which researches the ionosphere – the highest, ionized...

Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) from 30 to 300 megahertz (MHz), with...

A communications system or communication system is a collection of individual telecommunications networks systems, relay stations, tributary stations...