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 Secs. 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 Subregions, a band of 
frequencies is allocated to different services of the same category, the 
basic principle is the equality of right to operate. The stations of 
each service in one region must operate so as not to cause harmful 
interference to services in the other Regions or Subregions. (See ITU 
Radio Regulations, No. 346 (Geneva, 1979).)
    (b) An auxiliary station may transmit only on shorter wavelength 
bands, except the 431-433 MHz and 435-438 MHz segments.
    (c) No amateur station transmitting in the 1900-2000 kHz segment, 
the 3 cm band, the 76-81 GHz segment, the 144-149 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-Government 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, Interactive Video and 
Data 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

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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 449.75-450.25 MHz segment 
shall cause interference to, nor is protected from itnerference due to 
the operation of stations in, the space operation service and the space 
research service or Government or non-Government stations for space 
telecommand.
    (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 deg. N., on 
the north by latitude 42 deg. N., on the east by longitude 105 deg. W., 
and on the west by longitude 108 deg. 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 deg.41' N., on the north by latitude 34 deg.30' N., on the east by 
longitude 104 deg.11' W., and on the west by longitude 107 deg.30' W.
    (h) No amateur station transmitting in the 23 cm band, the 3 cm 
band, the 24.05-24.25 GHz segment, the 76-81 GHz segment, the 144-149 
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 1240-1260 MHz segment, 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, or the radiolocation service.
    (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,

[[Page 697]]

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 2390-2400 MHz segment is allocated to the amateur service 
on a primary basis; and
    (iv) The 2400-2402 MHz segment is allocated to the amateur service 
on a secondary basis. (Currently the 2400-2402 MHz segment is not 
allocated to any service on a primary basis.) The 2402-2417 MHz segment 
is allocated to the amateur service on a primary basis. The 2417-2450 
MHz segment is allocated to the amateur service on a co-secondary basis 
with the Government radiolocation service. Amateur stations operating 
within the 2400-2450 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 3.332-3.339 GHz and 
3.3458-3525 GHz segments, the 2.5 mm band, the 144.68-144.98 GHz, 
145.45-145.75 GHz and 146.82-147.12 GHz segments and the 343-348 GHz 
segment shall cause harmful interference to stations in the radio 
astronomy service. No amateur station transmitting in the 300-302 GHz, 
324-326 GHz, 345-347 GHz, 363-365 GHz and 379-381 GHz segments shall 
cause harmful interference to stations in the space research service 
(passive) or Earth exploration-satellite service (passive).
    (l) In the 9 cm band:
    (1) In ITU Regions 2 and 3, the band is allocated to the amateur 
service on a secondary basis.
    (2) In the United States, the band is allocated to the amateur 
service on a co-secondary basis with the non-Government radiolocation 
service.
    (3) In the 3.3-3.4 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.
    (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.

[[Page 698]]

    (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.
[ 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]