§  90.307   Protection criteria.

   The tables and figures listed in § 90.309 shall be used to determine
   the effective radiated power (ERP) and antenna height of the proposed
   land mobile base station and the ERP for the associated control station
   (control station antenna height shall not exceed 31 meters (100 feet)
   above average terrain (AAT)).

   (a) Base stations operating on the frequencies available for land
   mobile use in any urbanized area and having an antenna height (AAT)
   less than 152 meters (500 feet) shall afford protection to co-channel
   and adjacent channel television stations in accordance with the values
   set out in tables A and E of § 90.309, except for channel 15 in New
   York, NY, and Cleveland, OH, and channel 16 in Detroit, MI, where
   protection will be in accordance with the values set forth in tables B
   and E in 47 CFR 90.309.

   (b) For base stations having antenna heights between 152 and 914 meters
   (500-3000 feet) above average terrain, the effective radiated power
   must be reduced below 1 kilowatt in accordance with the values shown in
   the power reduction graph in Figure A in § 90.309, except for channel
   15 in New York, NY, and Cleveland, OH, and channel 16 in Detroit, MI,
   where the effective radiated power must be reduced in accordance with
   Figure B in § 90.309. For heights of more than 152 meters (500 feet)
   above average terrain, the distance to the radio path horizon will be
   calculated assuming smooth earth. If the distance so determined equals
   or exceeds the distance to the Grade B contour of a co-channel TV
   station (Grade B contour defined in § 73.683(a) of this chapter), an
   authorization will not be granted unless it can be shown that actual
   terrain considerations are such as to provide the desired protection at
   the Grade B contour, or that the effective radiated power will be
   further reduced so that, assuming free space attenuation, the desired
   protection at the Grade B contour will be achieved.

   (c) Mobile units and control stations operating on the frequencies
   available for land mobile use in any given urbanized area shall afford
   protection to co-channel and adjacent channel television stations in
   accordance with the values set forth in table C in § 90.309 and
   paragraph (d) of this section except for channel 15 in New York, NY,
   and Cleveland, OH, and channel 16 in Detroit, MI, where protection will
   be in accordance with the values set forth in table D in § 90.309 and
   paragraph (d) of this section.

   (d) The minimum distance between a land mobile base station which has
   associated mobile units and a protected adjacent channel television
   station is 145 km (90 miles).

   (e) The television stations to be protected (co-channel, adjacent
   channel, IM, and IF) in any given urbanized area, in accordance with
   the provisions of paragraphs (a), (b), (c), and (d) of this section,
   are identified in the Commission's publication "TV stations to be
   considered in the preparation of Applications for Land Mobile
   Facilities in the Band 470-512 MHz." The publication is available at
   the offices of the Federal Communications Commission in Washington, DC
   or upon the request of interested persons.

   [ 72 FR 35197 , June 27, 2007]