Art. 2 Radioreglement 1979, Nomenclature
Section I – Frequency and wavelength bands
2.1 The radio spectrum shall be subdivided into nine frequency bands, which shall be designated by progressive whole numbers in accordance with the following table. As the unit of frequency is the hertz (Hz), frequencies shall be expressed:
– in kilohertz (kHz), up to and including 3 000 kHz;
– in megahertz (MHz), above 3 MHz, up to and including 3 000 MHz;
– in gigahertz (GHz), above 3 GHz, up to and including 3 000 GHz.
However, where adherence to these provisions would introduce serious difficulties, for example in connection with the notification and registration of frequencies, the lists of frequencies and related matters, reasonable departures may be made. (WRC-15)
Band number Symbols Frequency range (lower limit exclusive, upper limit inclusive) Corresponding metric subdivision
4 VLF 3 to 30 kHz Myriametric waves
5 LF 30 to 300 kHz Kilometric waves
6 MF 300 to 3 000 kHz Hectometric waves
7 HF 3 to 30 MHz Decametric waves
8 VHF 30 to 300 MHz Metric waves
9 UHF 300 to 3 000 MHz Decimetric waves
10 SHF 3 to 30 GHz Centimetric waves
11 EHF 30 to 300 GHz Millimetric waves
12 300 to 3 000 GHz Decimillimetric waves
NOTE 1: “Band N” (N = band number) extends from 0.3 × 10N Hz to 3 × 10N Hz.
NOTE 2: Prefix: k = kilo (103), M = mega (106), G = giga (109).
2.2 In communications between administrations and the ITU, no names, symbols or abbreviations should be used for the various frequency bands other than those specified in No. 2.1.
Section II – Dates and times
2.3 Any date used in relation to radiocommunication shall be according to the Gregorian Calendar.
2.4 If in a date the month is not indicated either in full or in an abbreviated form, it shall be expressed in an all-numeric form with the fixed sequence of figures, two of each representing the day, month and year.
2.5 Whenever a date is used in connection with Coordinated Universal Time (UTC), this date shall be that at the prime meridian, the prime meridian corresponding to zero degrees geographical longitude. (WRC-15)
2.6 Whenever a specified time is used in international radiocommunication activities, UTC shall be applied, unless otherwise indicated, and it shall be presented as a four-digit group (0000-2359). The abbreviation UTC shall be used in all languages.
Section III – Designation of emissions
2.7 Emissions shall be designated according to their necessary bandwidth and their classification in accordance with the method described in Appendix 1.