§  2.102   Assignment of frequencies.

   (a) Except as otherwise provided in this section, the assignment of
   frequencies and frequency bands to all stations and classes of stations
   and the licensing and authorizing of the use of all such frequencies
   between 8.3 kHz and 275 GHz, and the actual use of such frequencies for
   radiocommunication or for any other purpose, including the transfer of
   energy by radio, shall be in accordance with the Table of Frequency
   Allocations in § 2.106.

   (b) On the condition that harmful interference will not be caused to
   services operating in accordance with the Table of Frequency
   Allocations the following exceptions to paragraph (a) of this section
   may be authorized:

   (1) In individual cases the Commission may, without rule making
   proceedings, authorize on a temporary basis only, the use of
   frequencies not in accordance with the Table of Frequency Allocations
   for projects of short duration or emergencies where the Commission
   finds that important or exceptional circumstances require such
   utilization. Such authorizations are not intended to develop a service
   to be operated on frequencies other than those allocated such service.

   (2) [Reserved]

   (3) Experimental stations, pursuant to part 5 of this chapter, may be
   authorized the use of any frequency or frequency band not exclusively
   allocated to the passive services (including the radio astronomy
   service).

   (4) In the event a band is reallocated so as to delete its availability
   for use by a particular service, the Commission may provide for the
   further interim use of the band by stations in that service for a
   temporary, specific period of time.

   (c) Non-Federal stations may be authorized to use Federal frequencies
   in the bands above 25 MHz:

   (1) If the Commission finds, after consultations with the appropriate
   Federal agency or agencies, that such use is necessary for coordination
   of Federal and non-Federal activities. Such operations must meet the
   following requirements:

   (i) Non-Federal operation on Federal frequencies shall conform with the
   conditions agreed upon by the Commission and NTIA;

   (ii) Such operations shall be in accordance with NTIA rules governing
   the service to which the frequencies involved are allocated;

   (iii) Such operations shall not cause harmful interference to Federal
   stations and, should harmful interference result, that the interfering
   non-Federal operation shall immediately terminate; and

   (iv) Non-Federal operation has been certified as necessary by the
   Federal agency involved and this certification has been furnished, in
   writing, to the non-Federal licensee with which communication is
   required; or

   (2) Pursuant to the provisions of § 90.25 of this chapter, provided that
   such operations shall not cause harmful interference to Federal
   stations and, should harmful interference result, that the interfering
   non-Federal operation shall immediately terminate.

   (d) Aircraft stations may communicate with stations of the maritime
   mobile service. They shall then conform to those provisions of the
   international Radio Regulations which relate to the maritime mobile
   service. For this purpose aircraft stations should use the frequencies
   allocated to the maritime mobile service. However, having regard to
   interference which may be caused by aircraft stations at high
   altitudes, maritime mobile frequencies in the bands above 30 MHz shall
   not be used by aircraft stations in any specific area without the prior
   agreement of all administrations of the area in which interference is
   likely to be caused. In particular, aircraft stations operating in
   Region 1 should not use frequencies in the bands above 30 MHz allocated
   to the maritime mobile service by virtue of any agreement between
   administrations in that Region.

   (e) Non-Federal services operating on frequencies in the band 25-50 MHz
   must recognize that it is shared with various services of other
   countries; that harmful interference may be caused by skywave signals
   received from distant stations of all services of the United States and
   other countries radiating power on frequencies in this band; and that
   no protection from such harmful interference generally can be expected.
   Persons desiring to avoid such harmful interference should consider
   operation on available frequencies higher in the radio spectrum not
   generally subject to this type of difficulty.

   (f) The stations of a service shall use frequencies so separated from
   the limits of a band allocated to that service as not to cause harmful
   interference to allocated services in immediately adjoining frequency
   bands.

   (g) In the bands above 25 MHz which are allocated to the non-Federal
   land mobile service, fixed stations may be authorized on the following
   conditions:

   (1) That such stations are authorized in the service shown in Column 5
   of the Table of Frequency Allocations in the band in question;

   (2) That harmful interference will not be caused to services operating
   in accordance with the Table of Frequency Allocations.

   (h) Special provisions regarding the use of spectrum allocated to the
   fixed and land mobile services below 25 MHz by non-Federal stations.

   (1) Only in the following circumstances will authority be extended to
   stations in the fixed service to operate on frequencies below 25 MHz.

   (i) With respect to aeronautical fixed stations, only when a showing
   can be made that more suitable facilities are not available.

   (ii) With respect to fixed stations, except aeronautical fixed
   stations, only to:

   (A) Provide communication circuits in emergency and/or disaster
   situations, where safety of life and property are concerned;

   (B) Provide standby and/or backup facilities to satellite and cable
   circuits used for international public correspondence;

   (C) Provide standby and/or backup communications circuits to regular
   domestic communication circuits which have been disrupted by disasters
   and/or emergencies;

   (D) Provide communication circuits wholly within the State of Alaska
   and the United States insular areas in the Pacific; and

   (E) Provide communication circuits to support operations which are
   highly important to the national interest and where other means of
   telecommunication are unavailable.

   (2) Only in the following circumstances will authority be extended to
   stations in the land mobile service to operate below 25 MHz.

   (i) Provide communication circuits in emergency and/or disaster
   situations, where safety of life and property are concerned;

   (ii) Provide standby and/or backup communications circuits to regular
   domestic communication circuits which have been disrupted by disasters
   and/or emergencies;

   (iii) Provide communication circuits wholly within the State of Alaska
   and the United States insular areas in the Pacific; and

   (iv) Provide communication circuits to support operations which are
   highly important to the national interest and where other means of
   telecommunication are unavailable.

   (3) Except in the State of Alaska and the United States Pacific insular
   areas, the Commission does not intend to seek international protection
   for assignments made pursuant to paragraphs (h) (1)(ii) and (2) of this
   section; this results in the following constraints upon the
   circuits/assignments.

   (i) The Commission will not accept responsibility for protection of the
   circuits from harmful interference caused by foreign operations.

   (ii) In the event that a complaint of harmful interference resulting
   from operation of these circuits is received from a foreign source, the
   offending circuit(s) must cease operation on the particular frequency
   concerned.

   (iii) In order to accommodate the situations described in paragraphs
   (h)(3) (i) and (ii) of this section, equipments shall be capable of
   transmitting and receiving on any frequency in the bands assigned to
   the particular operation and capable of immediate change among the
   frequencies.

   [ 49 FR 2373 , Jan. 19, 1984,  70 FR 46585 , Aug. 10, 2005, as amended at
    78 FR 25161 , Apr. 29, 2013;  82 FR 27185 , June 14, 2017;  83 FR 19977 ,
   May 7, 2018;  85 FR 38633 , June 26, 2020]