List of abbreviations: U

UAPT Union of African Post- and Telecommunication
UHF Ultra High Frequency (300 to 3000 MHz)
UIC International Union of Railways
ULP-AID Ultra Low Power Animal Implant Devices
UMTS Universal Mobile Telecommunication System (= FPLMTS)
UNESCO United Nations Education, Scientific and Cultural Organization
UNO United Nations Organization
URSI Union Radio Scientifique International
USAT Ultra-Small Aperture Terminals
UT Universal Time
UTC Coordinated Universal Time
UTRA UMTS Terrestrial Radio Access
UWB Ultra Wide Band