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.


-------------------------------------------------------------------------------
---------------------------------
                                                        Frequency range
                                                         (lower limit        Co
rresponding          Metric
          Band  number                  Symbols        exclusive, upper   metri
c subdivision  abbreviations  for
                                                       limit inclusive)
                    the bands
-------------------------------------------------------------------------------
---------------------------------
4...............................  VLF...............  3 to 30 kHz.......  Myria
metric waves.  B.Mam
5...............................  LF................  30 to 300 kHz.....  Kilom
etric waves..  B.km
6...............................  MF................  300 to 3 000 kHz..  Hecto
metric waves.  B.hm
7...............................  HF................  3 to 30 MHz.......  Decam
etric waves..  B.dam
8...............................  VHF...............  30 to 300 MHz.....  Metri
c waves......  B.m
9...............................  UHF...............  300 to 3 000 MHz..  Decim
etric waves..  B.dm
10..............................  SHF...............  3 to 30 GHz.......  Centi
metric waves.  B.cm
11..............................  EHF...............  30 to 300 GHz.....  Milli
metric waves.  B.mm
12..............................  ..................  300 to 3 000 GHz..  Decim
illimetric     ..................
                                                                           wave
s.
-------------------------------------------------------------------------------
---------------------------------
Note 1: ``Band N'' (N = band number) extends from 0.3 x 10\N\ Hz to 3 x 10\N\ H
z.
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]