ITU-T - International Telecommunication Union/ITU Telcommunication Sector,关于ETC的标准
ITU-T H.53 SPANISH-1984 Transmission of wide-spectrum signals (data@ etc.) over wideband supergroup links
ITU-T H.52 SPANISH-1984 Transmission of wide-spectrum signals (data@ facsimile@ etc.) on wideband group links
ITU-T H.52 FRENCH-1984 Transmission of wide-spectrum signals (data@ facsimile@ etc.) on wideband group links
ITU-T H.53 FRENCH-1984 Transmission des signaux à large spectre (données@ etc.) sur des liaisons à large bande en groupe secondaire
ITU-T M.900 SPANISH-1988 UTILIZACl?N DE ENLACES ARRENDADOS EN GRUPO PRIMARIO Y SECUNDARIO PARA LA TRANSMISI?N DE SE?ALES DE ESPECTRO ANCHO (DATOS@ FACS?MIL@ ETC.)