Sec.  2.101   Frequency and wavelength bands.

   (a) 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:

   (1) In kilohertz (kHz), up to and including 3 000 kHz;

   (2) In megahertz (MHz), above 3 MHz, up to and including 3 000 MHz;

   (3) In gigahertz (GHz), above 3 GHz, up to and including 3 000 GHz.

   (b) 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.
   Band
   number Symbols Frequency range (lower limit
   exclusive, upper limit inclusive) Corresponding metric subdivision Metric
   abbreviations
   for the bands
   4 VLF 3 to 30 kHz Myriametric waves B.Mam
   5 LF 30 to 300 kHz Kilometric waves B.km
   6 MF 300 to 3 000 kHz Hectometric waves B.hm
   7 HF 3 to 30 MHz Decametric waves B.dam
   8 VHF 30 to 300 MHz Metric waves B.m
   9 UHF 300 to 3 000 MHz Decimetric waves B.dm
   10 SHF 3 to 30 GHz Centimetric waves B.cm
   11 EHF 30 to 300 GHz Millimetric waves B.mm
   12 300 to 3 000 GHz Decimillimetric waves

   Note 1:“Band N” (N = band number) extends from 0.3 × 10^NHz to 3 × 10^NHz.

   Note 2:Prefix: k = kilo (10^3), M = mega (10^6), G = giga (10^9).

   (c) 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 this section.

   [ 70 FR 46583 , Aug. 10, 2005;  70 FR 53074 , Sept. 7, 2005]