Sec.  23.20   Assignment of frequencies.

   

   (a) Only those frequencies which are in accordance with Sec. 2.106 of this
   chapter may be authorized for use by stations in the Fixed Public and
   Fixed Public Press Services. Selection of specific frequencies within
   such bands shall be made by the applicants therefor. After an
   application has been filed with the Commission for a particular
   frequency, its availability for assignment as requested will be
   determined by a study of the probabilities of interference to and from
   existing services assigned on the same or adjacent frequencies and, if
   necessary, by coordination with other agencies utilizing frequencies
   in these ranges. The applicant will be notified of the results of such
   study and coordination. All new assignments of frequencies may be made
   subject to certain conditions as may be required to minimize the
   possibility of harmful interference to existing services.

   (b) In order to minimize possible harmful interference at the National
   Radio Astronomy Observatory site located at Green Bank, Pocahontas
   County, West Virginia, and at the Naval Radio Research Observatory
   site at Sugar Grove, Pendleton County, West Virginia, any applicant
   for a station authorization other than mobile, temporary base,
   temporary fixed, Personal Radio, Civil Air Patrol, or Amateur seeking
   a station license for a new station, a construction permit to
   construct a new station or to modify an existing station license in a
   manner which would change either the frequency, power, antenna height
   or directivity, or location of such a station within the area bounded
   by 39°15' N. on the north, 78°30' W. on the east, 37°30' N. on the
   south and 80°30' W. on the west shall, at the time of filing such
   application with the Commission, simultaneously notify the Director,
   National Radio Astronomy Observatory, P. O. Box No. 2, Green Bank,
   West Virginia, 24944, in writing, of the technical particulars of the
   proposed station. Such notification shall include the geographical
   coordinates of the antenna, antenna height, antenna directivity if
   any, proposed frequency, type of emission, and power. In addition, the
   applicant shall indicate in his application to the Commission the date
   notification was made to the Observatory. After receipt of such
   applications, the Commission will allow a period of twenty (20) days
   for comments or objections in response to the notifications indicated.
   If an objection to the proposed operation is received during the
   twenty day period from the National Radio Astronomy Observatory for
   itself or on behalf of the Naval Radio Research Observatory, the
   Commission will consider all aspects of the problem and take whatever
   action is deemed appropriate.

   (c) [Reserved]

   (d) Protection for Table Mountain Radio Receiving Zone, Boulder
   County, Colorado: Applicants for a station authorization to operate in
   the vicinity of Boulder County, Colorado under this part are advised
   to give due consideration, prior to filing applications, to the need
   to protect the Table Mountain Radio Receiving Zone from harmful
   interference. These are the research laboratories of the Department of
   Commerce, Boulder County, Colorado. To prevent degradation of the
   present ambient radio signal level at the site, the Department of
   Commerce seeks to ensure that the field strengths of any radiated
   signals (excluding reflected signals) received on this 728 hectare
   site (in the vicinity of coordinates 40°07'50" N Latitude, 105°14'40"
   W Longitude) resulting from new assignments (other than mobile
   stations) or from the modification or relocation of existing
   facilities do not exceed the following values:


------------------------------------------------------------------------
                                                              Power flux
                                                   Field     density \1\
                                                  strength   (dBW/m \2\)
                Frequency range                  (mV/m) in        in
                                                 authorized   authorized
                                                 bandwidth    bandwidth
                                                 of service   of service
------------------------------------------------------------------------
Below 540 kHz.................................           10         65.8
540 to 1600 Khz...............................           20         59.8
1.6 to 470 MHz................................           10     \2\ 65.8
470 to 890 MHz................................           30     \2\ 56.2
Above 890 MHz.................................            1     \2\ 85.8
------------------------------------------------------------------------
\1\ Equivalent values of power flux density are calculated assuming free
  space characteristic impedance of 376.7=120p ohms.
\2\ Space stations shall conform to the power flux density limits at the
  earth's surface specified in appropriate parts of the FCC rules, but
  in no case should exceed the above levels in any 4 kHz band for all
  angles of arrival.

   (1) Advance consultation is recommended particularly for those
   applicants who have no reliable data which indicates whether the field
   strength or power flux density figures in the above table would be
   exceeded by their proposed radio facilities (except mobile stations).
   In such instances, the following is a suggested guide for determining
   whether coordination is recommended:

   (i) All stations within 2.4 kilometers;

   (ii) Stations within 4.8 kilometers with 50 watts or more effective
   radiated power (ERP) in the primary plane of polarization in the
   azimuthal direction of the Table Mountain Radio Receiving Zone;

   (iii) Stations within 16.1 kilometers with 1 kW or more ERP in the
   primary plane of polarization in the azimuthal direction of Table
   Mountain Receiving Zone;

   (iv) Stations within 80.5 kilometers with 25 kW or more ERP in the
   primary plane or polarization in the azimuthal direction of Table
   Mountain Receiving Zone.

   (2) Applicants concerned are urged to communicate with the Radio
   Frequency Management Coordinator, Department of Commerce, Research
   Support Services, NOAA R/E5X2, Boulder Laboratories, Boulder, CO
   80303; telephone (303) 497-6548, in advance of filing their
   applications with the Commission.

   (3) The Commission will not screen applications to determine whether
   advance consultation has taken place. However, applicants are advised
   that such consultation can avoid objections from the Department of
   Commerce or proceedings to modify any authorization which may be
   granted which, in fact, delivers a signal at the site in excess of the
   field strength specified herein.

   (e) Protection for Federal Communications Commission monitoring
   stations:

   (1) Applicants in the vicinity of an FCC monitoring station for a
   radio station authorization to operate new transmitting facilities or
   changed transmitting facilities which would increase the field
   strength produced over the monitoring station over that previously
   authorized are advised to give consideration, prior to filing
   applications, to the possible need to protect the FCC stations from
   harmful interference. Geographical coordinates of the facilities which
   require protection are listed in Sec. 0.121(c) of the Commission's Rules.
   Applications for stations (except mobile stations) which will produce
   on any frequency a direct wave fundamental field strength of greater
   than 10 mV/m in the authorized bandwidth of service ( -65.8 dBW/m 2
   power flux density assuming a free space characteristic impedance of
   120 ohms) at the referenced coordinates, may be examined to determine
   extent of possible interference. Depending on the theoretical field
   strength value and existing root-sum-square or other ambient radio
   field signal levels at the indicated coordinates, a clause protecting
   the monitoring station may be added to the station authorization.

   (2) In the event that calculated value of expected field exceeds 10
   mV/m ( -65.8 dBW/m 2 ) at the reference coordinates, or if there is
   any question whether field strength levels might exceed the threshold
   value, advance consultation with the FCC to discuss any protection
   necessary should be considered. Prospective applicants may communicate
   with: Chief, Compliance and Information Bureau, Federal Communications
   Commission, Washington, DC 20554, Telephone (202) 632-6980.

   (3) Advance consultation is suggested particularly for those
   applicants who have no reliable data which indicates whether the field
   strength or power flux density figure indicated would be exceeded by
   their proposed radio facilities (except mobile stations). In such
   instances, the following is a suggested guide for determining whether
   an applicant should coordinate:

   (i) All stations within 2.4 kilometers (1.5 statute miles);

   (ii) Stations within 4.8 kilometers (3 statute miles) with 50 watts or
   more average effective radiated power (ERP) in the primary plane of
   polarization in the azimuthal direction of the Monitoring Stations.

   (iii) Stations within 16 kilometers (10 statute miles) with 1 kW or
   more average ERP in the primary plane of polarization in the azimuthal
   direction of the Monitoring Station;

   (iv) Stations within 80 kilometers (50 statute miles) with 25 kW or
   more average ERP in the primary plane of polarization in the azimuthal
   direction of the Monitoring Station;

   (4) Advance coordination for stations operating above 1000 MHz is
   recommended only where the proposed station is in the vicinity of a
   monitoring station designated as a satellite monitoring facility in
   Sec. 0.121(c) of the Commission's Rules and also meets the criteria
   outlined in paragraphs (e)(2) and (3) of this section.

   (5) The Commission will not screen applications to determine whether
   advance consultation has taken place. However, applicants are advised
   that such consultation can avoid objections from the Federal
   Communications Commission or modification of any authorization which
   will cause harmful interference.

   (f) Any applicant for a new permanent base or fixed station to be
   located on the islands of Puerto Rico, Desecheo, Mona, Vieques, and
   Culebra, or for a modification of an existing authorization which
   would change the frequency, power, antenna height, directivity, or
   location of a station on these islands and would increase the
   likelihood of the authorized facility causing interference, shall
   notify the Interference Office, Arecibo Observatory, Post Office Box
   995, Arecibo, Puerto Rico 00613, in writing or electronically, of the
   technical parameters of the proposal. Applicants may wish to consult
   interference guidelines, which will be provided by Cornell University.
   Applicants who choose to transmit information electronically should
   e-mail to: prcz@naic.edu

   (1) The notification to the Interference Office, Arecibo Observatory
   shall be made prior to, or simultaneously with, the filing of the
   application with the Commission. The notification shall state the
   geographical coordinates of the antenna (NAD-83 datum), antenna height
   above ground, ground elevation at the antenna, antenna directivity and
   gain, proposed frequency and FCC Rule Part, type of emission,
   effective radiated power, and whether the proposed use is itinerant.
   Generally, submission of the information in the technical portion of
   the FCC license application is adequate notification. In addition, the
   applicant shall indicate in its application to the Commission the date
   notification was made to the Arecibo Observatory.

   (2) After receipt of such applications, the Commission will allow the
   Arecibo Observatory a period of 20 days for comments or objections in
   response to the notification indicated. The applicant will be required
   to make reasonable efforts in order to resolve or mitigate any
   potential interference problem with the Arecibo Observatory and to
   file either an amendment to the application or a modification
   application, as appropriate. If the Commission determines that an
   applicant has satisfied its responsibility to make reasonable efforts
   to protect the Observatory from interference, its application may be
   granted.

   (3) The provisions of this paragraph do not apply to operations that
   transmit on frequencies above 15 GHz.

   [ 28 FR 13032 , Dec. 5, 1963, as amended at  42 FR 8329 , Feb. 9, 1977;  42 FR 27894 , June 1, 1977;  44 FR 77167 , Dec. 31, 1979;  50 FR 39002 , Sept.
   26, 1985;  58 FR 44904 , Aug. 25, 1993;  61 FR 8477 , Mar. 5, 1996;  62 FR 55530 , Oct. 27, 1997]