Goto Section: 21.909 | 21.912

FCC 21.911
Revised as of May 5, 2005
Goto Year:2004 | 2006
Sec.  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 area outside the
   cellular market boundary, except as provided in paragraph (c) of this
   section, and excluding any 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 xp0.17

   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) CGSA extension areas. SAB extensions (areas outside of the
   cellular market boundary, but within the service area as calculated
   using the methods of paragraph (a) of this section) are part of the
   CGSA only under the following circumstances:

   (1) During the five year build-out period of the system in the
   cellular market containing the extension, the licensees of systems on
   the same channel block in adjacent cellular markets may agree that the
   portion of the service area of one system that extends into unserved
   areas in the other system's cellular market is part of the CGSA of the
   former system.

   (2) At the end of the five year build-out period of the system in the
   cellular market containing the extension, the portion of the service
   area that extends into unserved areas in another cellular market
   becomes part of the CGSA, provided that the licensee of the system so
   extended files a system information update in accordance with
   Sec. 22.947(c).

   (3) For original systems in MSAs, extensions of the CGSA authorized by
   the FCC are part of the CGSA to the extent authorized.

   (d) Protection afforded. Within the CGSA determined in accordance with
   this section, cellular systems are entitled to protection from
   co-channel and first-adjacent channel interference and from capture of
   subscriber traffic by adjacent systems on the same channel block.

   (1) Licensees must cooperate in resolving co-channel and
   first-adjacent channel interference by changing channels used at
   specific cells or by other technical means.

   (2) Protection from capture of subscriber traffic is applied and
   limited in accordance with the following:

   (i) Subscriber traffic is captured if an SAB of one cellular system
   overlaps the CGSA of another operating cellular system. Therefore,
   cellular licensees must not begin to operate any facility that would
   cause an SAB to overlap the existing CGSA of another cellular system
   on the same channel block, without first obtaining the written consent
   of the licensee of that system. However, cellular licensees may
   continue to operate existing facilities that produce an SAB
   overlapping a subsequently-authorized portion of the CGSA of another
   cellular system on the same channel block until the licensee of that
   system requests that the SAB be removed from its CGSA. Such request
   may be made directly to the licensee of the overlapping system or to
   the FCC. In the event such request is made, the licensee of the
   overlapping system must reduce the transmitting power or antenna
   height (or both) at the pertinent cell site as necessary to remove the
   SAB from the CGSA of the other system, unless a written consent from
   the licensee of the other system allowing the SAB to remain is
   obtained. Cellular licensees may enter into contracts with the
   licensees of other cellular systems on the same channel block to allow
   SABs to overlap CGSAs.

   (ii) Cellular licensees are at most entitled to have a CGSA free of
   SABs from other cellular systems on the same channel block.

   (e) Unserved areas. Unserved areas are areas 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]


Goto Section: 21.909 | 21.912

Goto Year: 2004 | 2006
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