Sec.  97.303   Frequency sharing requirements.

   The following is a summary of the frequency sharing requirements that apply
   to amateur station transmissions on the frequency bands specified in  Sec. 97.301
   of this part. (For each ITU Region, each frequency band allocated to the
   amateur service is designated as either a secondary service or a primary
   service. A station in a secondary service must not cause harmful
   interference to, and must accept interference from, stations in a primary
   service. See  Sec.  Sec. 2.105 and 2.106 of the FCC Rules, United States Table of
   Frequency Allocations for complete requirements.)

   (a) Where, in adjacent ITU Regions or sub-Regions, a band of frequencies is
   allocated to different services of the same category (i.e., primary or
   secondary allocations), the basic principle is the equality of right to
   operate. Accordingly, stations of each service in one Region or sub-Region
   must operate so as not to cause harmful interference to any service of the
   same or higher category in the other Regions or sub-Regions. (See ITU Radio
   Regulations, edition of 2004, No. 4.8.)

   (b) No amateur station transmitting in the 1900–2000 kHz segment, the 70 cm
   band, the 33 cm band, the 23 cm band, the 13 cm band, the 9 cm band, the 5
   cm band, the 3 cm band, the 24.05–24.25 GHz segment, the 76–77.5 GHz
   segment, the 78–81 GHz segment, the 136–141 GHz segment, and the 241–248 GHz
   segment shall not cause harmful interference to, nor is protected from
   interference due to the operation of, the Federal radiolocation service.

   (c) No amateur station transmitting in the 1900–2000 kHz segment, the 3 cm
   band, the 76–77.5 GHz segment, the 78–81 GHz segment, the 136–141 GHz
   segment, and the 241–248 GHz segment shall cause harmful interference to,
   nor is protected from interference due to the operation of, stations in the
   non-Federal radiolocation service.

   (d) No amateur station transmitting in the 30 meter band shall cause harmful
   interference to stations authorized by other nations in the fixed service.
   The licensee of the amateur station must make all necessary adjustments,
   including termination of transmissions, if harmful interference is caused.

   (e) In the 1.25 m band:

   (1) Use of the 219–220 MHz segment is limited to amateur stations
   participating, as forwarding stations, in point-to-point fixed digital
   message forwarding systems, including intercity packet backbone networks. It
   is not available for other purposes.

   (2) No amateur station transmitting in the 219–220 MHz segment shall cause
   harmful interference to, nor is protected from interference due to operation
   of Automated Maritime Telecommunications Systems (AMTS), television
   broadcasting on channels 11 and 13, 218–219 MHz Service systems, Land Mobile
   Services systems, or any other service having a primary allocation in or
   adjacent to the band.

   (3) No amateur station may transmit in the 219–220 MHz segment unless the
   licensee has given written notification of the station's specific geographic
   location for such transmissions in order to be incorporated into a data base
   that has been made available to the public. The notification must be given
   at least 30 days prior to making such transmissions. The notification must
   be given to: The American Radio Relay, Inc., 225 Main Street, Newington, CT
   06111–1494.

   (4) No amateur station may transmit in the 219–220 MHz segment from a
   location that is within 640 km of an AMTS Coast Station that uses
   frequencies in the 217–218/219–220 MHz AMTS bands unless the amateur station
   licensee has given written notification of the station's specific geographic
   location for such transmissions to the AMTS licensee. The notification must
   be given at least 30 days prior to making such transmissions. The location
   of AMTS Coast Stations using the 217–218/219–220 MHz channels may be
   obtained from either:

   The American Radio Relay League, Inc., 225 Main Street, Newington, CT
   06111–1494;

   or

   Interactive Systems, Inc., Suite 1103, 1601 North Kent Street, Arlington, VA
   22209; Fax: (703) 812–8275; Phone: (703) 812–8270.

   (5) No amateur station may transmit in the 219–220 MHz segment from a
   location that is within 80 km of an AMTS Coast Station that uses frequencies
   in the 217–218/219–220 MHz AMTS bands unless that amateur station licensee
   holds written approval from that AMTS licensee. The location of AMTS Coast
   Stations using the 217–218/219–220 MHz channels may be obtained as noted in
   paragraph (e)(4) of this section.

   (f) In the 70 cm band:

   (1) No amateur station shall transmit from north of Line A in the 420–430
   MHz segment.

   (2) The 420–430 MHz segment is allocated to the amateur service in the
   United States on a secondary basis, and is allocated in the fixed and mobile
   (except aeronautical mobile) services in the International Table of
   allocations on a primary basis. No amateur station transmitting in this band
   shall cause harmful interference to, nor is protected from interference due
   to the operation of, stations authorized by other nations in the fixed and
   mobile (except aeronautical mobile) services.

   (3) The 430–440 MHz segment is allocated to the amateur service on a
   secondary basis in ITU Regions 2 and 3. No amateur station transmitting in
   this band in ITU Regions 2 and 3 shall cause harmful interference to, nor is
   protected from interference due to the operation of, stations authorized by
   other nations in the radiolocation service. In ITU Region 1, the 430–440 MHz
   segment is allocated to the amateur service on a co-primary basis with the
   radiolocation service. As between these two services in this band in ITU
   Region 1, the basic principle that applies is the equality of right to
   operate. Amateur stations authorized by the United States and radiolocation
   stations authorized by other nations in ITU Region 1 shall operate so as not
   to cause harmful interference to each other.

   (4) No amateur station transmitting in the 449.75–450.00 MHz segment shall
   cause interference to, nor is protected from interference due to the
   operation of stations in, the space operation and space research services.

   (g) In the 33 cm band:

   (1) No amateur station shall transmit from within the States of Colorado and
   Wyoming, bounded on the south by latitude 39 ° N., on the north by latitude
   42 ° N., on the east by longitude 105 ° W., and on the west by longitude 108 °
   W. This band is allocated on a secondary basis to the amateur service
   subject to not causing harmful interference to, and not receiving protection
   from any interference due to the operation of, industrial, scientific and
   medical devices, automatic vehicle monitoring systems or Government stations
   authorized in this band.

   (2) No amateur station shall transmit from those portions of the States of
   Texas and New Mexico bounded on the south by latitude 31 °41' N., on the
   north by latitude 34 °30' N., on the east by longitude 104 °11' W., and on the
   west by longitude 107 °30' W.

   (h) No amateur station transmitting in the 23 cm band, the 3.3–3.4 GHz
   segment, the 3 cm band, the 24.05–24.25 GHz segment, the 76–77.5 GHz
   segment, the 78–81 GHz segment, the 136–141 GHz segment, and the 241–248 GHz
   segment shall cause harmful interference to, nor is protected from
   interference due to the operation of, stations authorized by other nations
   in the radiolocation service.

   (i) In the 23 cm band, no amateur station shall cause harmful interference
   to, nor is protected from interference due to the operation of, stations in
   the radionavigation-satellite service, the aeronautical radionavigation
   service, the Earth exploration-satellite service (active), or the space
   research service (active).

   (j) In the 13 cm band:

   (1) The amateur service is allocated on a secondary basis in all ITU
   Regions. In ITU Region 1, no amateur station shall cause harmful
   interference to, and shall be not protected from interference due to the
   operation of, stations authorized by other nations in the fixed and mobile
   services. In ITU Regions 2 and 3, no amateur station shall cause harmful
   interference to, and shall not be protected from interference due to the
   operation of, stations authorized by other nations in the fixed, mobile and
   radiolocation services.

   (2) In the United States:

   (i) The 2300–2305 MHz segment is allocated to the amateur service on a
   secondary basis. (Currently the 2300–2305 MHz segment is not allocated to
   any service on a primary basis.);

   (ii) The 2305–2310 MHz segment is allocated to the amateur service on a
   secondary basis to the fixed, mobile, and radiolocation services;

   (iii) The 2390–2417 MHz segment is allocated to the amateur service on a
   primary basis.

   (A) The 2390–2395 MHz segment is shared with Federal and non-Federal
   Government mobile services on a co-equal basis. See 47 CFR 2.106, footnote
   US276.

   (B) Amateur stations operating in the 2400–2417 MHz segment must accept
   harmful interference that may be caused by the proper operation of
   industrial, scientific and medical equipment.

   (iv) The 2417–2450 MHz segment is allocated to the amateur service on a
   co-secondary basis with the Federal Government radiolocation service.
   Amateur stations operating within the 2417–2450 MHz segment must accept
   harmful interference that may be caused by the proper operation of
   industrial, scientific, and medical devices operating within the band.

   (k) No amateur station transmitting in the following segments shall cause
   harmful interference to stations in the radio astronomy service: 3.332–3.339
   GHz, 3.3458–3.3525 GHz, 76–77.5 GHz, 78–81 GHz, 136–141 GHz, 241–248 GHz,
   275–323 GHz, 327–371 GHz, 388–424 GHz, 426–442 GHz, 453–510 GHz, 623–711
   GHz, 795–909 GHz, and 926–945 GHz. No amateur station transmitting in
   following segments shall cause harmful interference to stations in the Earth
   exploration-satellite service (passive) and space research service
   (passive): 275–277 GHz, 294–306 GHz, 316–334 GHz, 342–349 GHz, 363–365 GHz,
   371–389 GHz, 416–434 GHz, 442–444 GHz, 496–506 GHz, 546–568 GHz, 624–629
   GHz, 634–654 GHz, 659–661 GHz, 684–692 GHz, 730–732 GHz, 851–853 GHz, and
   951–956 GHz.

   (l) In the 9 cm band:

   (1) In ITU Regions 2 and 3, the 9 cm band is allocated to the amateur
   service on a secondary basis. In ITU Region 1, the segment 3.4–3.475 GHz is
   allocated to the amateur service on a secondary basis for use only in
   Germany, Israel, and the United Kingdom.

   (2) In the United States, the 9 cm band is allocated to the amateur and
   non-Federal radiolocation services on a secondary basis.

   (3) In the 3.4–3.5 GHz segment, no amateur station shall cause harmful
   interference to, nor is protected from interference due to the operation of,
   stations in the fixed and fixed-satellite services.

   (4) In the 3.4–3.5 GHz segment, no amateur station shall cause harmful
   interference to, nor is protected from interference due to the operation of,
   stations authorized by other nations in the fixed and fixed-satellite
   service.

   (m) In the 5 cm band:

   (1) In the 5.650–5.725 GHz segment, the amateur service is allocated in all
   ITU Regions on a co-secondary basis with the space research (deep space)
   service.

   (2) In the 5.725–5.850 GHz segment, the amateur service is allocated in all
   ITU Regions on a secondary basis. No amateur station shall cause harmful
   interference to, nor is protected from interference due to the operation of,
   stations authorized by other nations in the fixed-satellite service in ITU
   Region 1.

   (3) No amateur station transmitting in the 5.725–5.875 GHz segment is
   protected from interference due to the operation of industrial, scientific
   and medical devices operating on 5.8 GHz.

   (4) In the 5.650–5.850 GHz segment, no amateur station shall cause harmful
   interference to, nor is protected from interference due to the operation of,
   stations authorized by other nations in the radiolocation service.

   (5) In the 5.850–5.925 GHz segment, the amateur service is allocated in ITU
   Region 2 on a co-secondary basis with the radiolocation service. In the
   United States, the segment is allocated to the amateur service on a
   secondary basis to the non-Government fixed-satellite service. No amateur
   station shall cause harmful interference to, nor is protected from
   interference due to the operation of, stations authorized by other nations
   in the fixed, fixed-satellite and mobile services. No amateur station shall
   cause harmful interference to, nor is protected from interference due to the
   operation of, stations in the non-Government fixed-satellite service.

   (n) In the 3 cm band:

   (1) In the United States, the 3 cm band is allocated to the amateur service
   on a co-secondary basis with the non-government radiolocation service.

   (2) In the 10.00–10.45 GHz segment in ITU Regions 1 and 3, no amateur
   station shall cause interference to, nor is protected from interference due
   to the operation of, stations authorized by other nations in the fixed and
   mobile services.

   (o) No amateur station transmitting in the 1.2 cm band is protected from
   interference due to the operation of industrial, scientific and medical
   devices on 24.125 GHz. In the United States, the 24.05–24.25 GHz segment is
   allocated to the amateur service on a co-secondary basis with the
   non-government radiolocation and Government and non-government Earth
   exploration-satellite (active) services.

   (p) The 2.5 mm band is allocated to the amateur service on a secondary
   basis. No amateur station transmitting in this band shall cause harmful
   interference to, nor is protected from interference due to the operation of,
   stations in the fixed, inter-satellite and mobile services.

   (q) No amateur station transmitting in the 244–246 GHz segment of the 1 mm
   band is protected from interference due to the operation of industrial,
   scientific and medical devices on 245 GHz.

   (r) In the 4 mm band:

   (1) Authorization of the 76–77 GHz segment of the 4 mm band for amateur
   station transmissions is suspended until such time that the Commission may
   determine that amateur station transmissions in this segment will not pose a
   safety threat to vehicle radar systems operating in this segment.

   (2) No amateur or amateur-satellite station transmitting in the 75.5–76 GHz
   segment shall cause interference to, nor is protected from, interference due
   to the operation of stations in the fixed service. After January 1, 2006,
   the 75.5–76 GHz segment is no longer allocated to the amateur service or to
   the amateur-satellite service.

   (3) No amateur or amateur-satellite station transmitting in the 75.5–76 GHz
   segment shall cause interference to, nor is protected from, interference due
   to the operation of stations in the fixed service. After January 1, 2006,
   the 75.5–76 GHz segment is no longer allocated to the amateur service or to
   the amateur-satellite service.

   (s) An amateur station having an operator holding a General, Advanced or
   Amateur Extra Class license may only transmit single sideband, suppressed
   carrier, (emission type 2K8J3E) upper sideband on the channels 5332 kHz,
   5348 kHz, 5368 kHz, 5373 kHz, and 5405 kHz. Amateur operators shall ensure
   that their transmission occupies only the 2.8 kHz centered around each of
   these frequencies. Transmissions shall not exceed an effective radiated
   power (e.r.p) of 50 W PEP. For the purpose of computing e.r.p. the
   transmitter PEP will be multiplied with the antenna gain relative to a
   dipole or the equivalent calculation in decibels. A half wave dipole antenna
   will be presumed to have a gain of 0 dBd. Licensees using other antennas
   must maintain in their station records either manufacturer data on the
   antenna gain or calculations of the antenna gain. No amateur station shall
   cause harmful interference to stations authorized in the mobile and fixed
   services; nor is any amateur station protected from interference due to the
   operation of any such station.

   (t)(1) The 7–7.1 MHz segment is allocated to the amateur and
   amateur-satellite services on a primary and exclusive basis throughout the
   world, except that the 7–7.05 MHz segment is:

   (i) Additionally allocated to the fixed service on a primary basis in the
   countries listed in 47 CFR 2.106, footnote 5.140; and

   (ii) Alternatively allocated to the fixed service on a primary and exclusive
   basis (i.e., the segment 7–7.05 MHz is not allocated to the amateur service)
   in the countries listed in 47 CFR 2.106, footnote 5.141.

   (2) The 7.1–7.2 MHz segment is allocated to the amateur service on an
   exclusive basis in Region 2. Until March 29, 2009, the 7.1–7.2 MHz segment
   is allocated to the amateur and broadcasting services on a co-primary basis
   in Region 1 and Region 3 and the use of the 7.1–7.2 MHz segment by the
   amateur service shall not impose constraints on the broadcasting service
   intended for use within Region 1 and Region 3. After March 29, 2009, the
   7.1–7.2 MHz segment is allocated to the amateur service on a primary and
   exclusive basis throughout the world, except that the 7.1–7.2 MHz segment is
   additionally allocated to the fixed and mobile except aeronautical mobile
   (R) services on a primary basis in the countries listed in 47 CFR 2.106,
   footnote 5.141B.

   (3) The 7.2–7.3 MHz segment is allocated to the amateur service on an
   exclusive basis in Region 2 and to the broadcasting service on an exclusive
   basis in Region 1 and Region 3. The use of the 7.2–7.3 MHz segment in Region
   2 by the amateur service shall not impose constraints on the broadcasting
   service intended for use within Region 1 and Region 3.

   [ 54 FR 25857 , June 20, 1989;  54 FR 39536 , Sept. 27, 1989, as amended at  56 FR 19611 , Apr. 29, 1991;  56 FR 23025 , May 20, 1991;  56 FR 32518 , July 17,
   1991;  56 FR 40801 , Aug. 16, 1991;  57 FR 40344 , Sept. 3, 1992;  60 FR 15687 ,
   Mar. 27, 1995;  61 FR 15386 , Apr. 8, 1996;  62 FR 9673 , Mar. 3, 1997;  63 FR 42280 , Aug. 7, 1998;  68 FR 33026 , June 3, 2003;  69 FR 3265 , Jan. 23, 2004;
    69 FR 77950 , Dec. 29, 2004;  70 FR 46681 , Aug. 10, 2005]