§ 22.911   Cellular geographic service area.

   The Cellular Geographic Service Area (CGSA) of a cellular system is the
   geographic area considered by the FCC to be served by the cellular
   system. The CGSA is the area within which cellular systems are entitled
   to protection and within which adverse effects for the purpose of
   determining whether a petitioner has standing are recognized.

   (a) CGSA determination. The CGSA is the composite of the service areas
   of all of the cells in the system, excluding any Unserved Area (even if
   it is served on a secondary basis) or area within the CGSA of another
   Cellular system. The service area of a cell is the area within its
   service area boundary (SAB). The distance to the SAB is calculated as a
   function of effective radiated power (ERP) and antenna center of
   radiation height above average terrain (HAAT), height above sea level
   (HASL), or height above mean sea level (HAMSL).

   (1) Except as provided in paragraphs (a)(2) and (b) of this section,
   the distance from a cell transmitting antenna to its SAB along each
   cardinal radial is calculated as follows:

   d = 2.531 × h0.34 × p0.17

   where:

   d is the radial distance in kilometers

   h is the radial antenna HAAT in meters

   p is the radial ERP in Watts

   (2) The distance from a cell transmitting antenna located in the Gulf
   of Mexico Service Area (GMSA) to its SAB along each cardinal radial is
   calculated as follows:

   d = 6.895 × h0.30 × p0.15

   Where:

   d is the radial distance in kilometers

   h is the radial antenna HAAT in meters

   p is the radial ERP in Watts

   (3) The value used for h in the formula in paragraph (a)(2) of this
   section must not be less than 8 meters (26 feet) HASL (or HAMSL, as
   appropriate for the support structure). The value used for h in the
   formula in paragraph (a)(1) of this section must not be less than 30
   meters (98 feet) HAAT, except that for unserved area applications
   proposing a cell with an ERP not exceeding 10 Watts, the value for h
   used in the formula in paragraph (a)(1) of this section to determine
   the service area boundary for that cell may be less than 30 meters (98
   feet) HAAT, but not less than 3 meters (10 feet) HAAT.

   (4) The value used for p in the formulas in paragraphs (a)(1) and
   (a)(2) of this section must not be less than 0.1 Watt or 27 dB less
   than (1/500 of) the maximum ERP in any direction, whichever is more.

   (5) Whenever use of the formula in paragraph (a)(1) of this section
   pursuant to the exception contained in paragraph (a)(3) of this section
   results in a calculated distance that is less than 5.4 kilometers (3.4
   miles), the radial distance to the service area boundary is deemed to
   be 5.4 kilometers (3.4 miles).

   (6) The distance from a cell transmitting antenna to the SAB along any
   radial other than the eight cardinal radials is calculated by linear
   interpolation of distance as a function of angle.

   (b) Alternative CGSA determination. If a carrier believes that the
   method described in paragraph (a) of this section produces a CGSA that
   departs significantly (±20% in the service area of any cell) from the
   geographic area where reliable cellular service is actually provided,
   the carrier may submit, as an exhibit to an application for
   modification of the CGSA using FCC Form 601, a depiction of what the
   carrier believes the CGSA should be. Such submissions must be
   accompanied by one or more supporting propagation studies using methods
   appropriate for the 800-900 MHz frequency range, including all
   supporting data and calculations, and/or by extensive field strength
   measurement data. For the purpose of such submissions, cellular service
   is considered to be provided in all areas, including “dead spots”,
   between the transmitter location and the locus of points where the
   predicted or measured median field strength finally drops to 32 dBµV/m
   (i.e. does not exceed 32 dBµV/m further out). If, after consideration
   of such submissions, the FCC finds that adjustment to a CGSA is
   warranted, the FCC may grant the application.

   (1) The alternative CGSA determination must define the CGSA in terms of
   distances from the cell sites to the 32 dBuV/m contour along the eight
   cardinal radials, with points in other azimuthal directions determined
   by the method given in paragraph (a)(6) of this section. The distances
   used for the cardinal radials must be representative of the coverage
   within the 45�° sectors, as depicted by the alternative CGSA
   determination.

   (2) If an uncalibrated predictive model is used to depict the CGSA, the
   alternative CGSA determination must identify factors (e.g. terrain
   roughness or features) that could plausibly account for the difference
   between actual coverage and that defined by the formula in paragraph
   (a)(1) of this section. If actual measurements or a
   measurement-calibrated predictive model are used to depict the CGSA,
   and this fact is disclosed in the alternative CGSA determination, it is
   not necessary to offer an explanation of the difference between actual
   coverage and that defined by the formula in paragraph (a)(1) of this
   section. If the formula in paragraph (a)(1) of this section is clearly
   inapplicable for the cell(s) in question (e.g. for microcells), this
   should be disclosed in the alternative CGSA determination.

   (3) The provision for alternative CGSA determinations was made in
   recognition that the formula in paragraph (a)(1) of this section is a
   general model that provides a reasonable approximation of coverage in
   most land areas, but may under-predict or over-predict coverage in
   specific areas with unusual terrain roughness or features, and may be
   inapplicable for certain purposes, e.g., cells with a coverage radius
   of less than 8 kilometers (5 miles). In such cases, alternative methods
   that utilize more specific models are appropriate. Accordingly, the FCC
   does not consider use of the formula in paragraph (a)(1) of this
   section with parameters outside of the limits in paragraphs (a)(3),
   (a)(4) and (a)(5) of this section or with data for radials other than
   the cardinal radials to be a valid alternative method for determining
   the CGSA of a cellular system.

   (c) [Reserved]

   (d) Protection afforded. Cellular systems are entitled to protection
   only within the CGSA (as determined in accordance with this section)
   from co-channel and first-adjacent channel interference and from
   capture of subscriber traffic by adjacent systems on the same channel
   block. Licensees must cooperate in resolving co-channel and
   first-adjacent channel interference by changing channels used at
   specific cells or by other technical means.

   (e) Unserved Area. Unserved Area is area outside of all existing CGSAs
   on either of the channel blocks, to which the Communications Act of
   1934, as amended, is applicable.

   [ 59 FR 59507 , Nov. 17, 1994, as amended at  59 FR 59954 , Nov. 21, 1994;
    63 FR 68951 , Dec. 14, 1998;  67 FR 9609 , Mar. 4, 2002;  67 FR 77191 , Dec.
   17, 2002;  68 FR 42295 , July 17, 2003;  79 FR 72151 , Dec. 5, 2014]

   return arrow Back to Top