Sec.  90.545   TV/DTV interference protection criteria.

   Public safety base, control, and mobile transmitters in the 764–776 MHz and
   794–806 MHz frequency bands must be operated only in accordance with the
   rules in this section, to reduce the potential for interference to public
   reception of the signals of existing TV and DTV broadcast stations
   transmitting on TV Channels 62, 63, 64, 65, 67, 68 or 69.

   (a) D/U ratios. Licensees of public safety stations must choose site
   locations that are a sufficient distance from co-channel and adjacent
   channel TV and DTV stations, and/or must use reduced transmitting power or
   transmitting antenna height such that the following minimum desired signal
   to undesired signal ratios (D/U ratios) are met:

   (1) The minimum D/U ratio for co-channel stations is 40 dB at the
   hypothetical Grade B contour (64 dB µV/m) (88.5 kilometers or 55.0 miles) of
   the TV station or 17 dB at the equivalent Grade B contour (41 dB µV/m) (88.5
   kilometers or 55.0 miles) of the DTV station.

   (2) The minimum D/U ratio for adjacent channel stations is 0 dB at the
   hypothetical Grade B contour (64 dB µV/m) (88.5 kilometers or 55.0 miles) of
   the TV station or −23 dB at the equivalent Grade B contour (41 dB µV/m) (88.5
   kilometers or 55.0 miles) of the DTV station.

   (b) Maximum ERP and HAAT. The maximum effective radiated power (ERP) and the
   antenna height above average terrain (HAAT) of the proposed land mobile base
   station, the associated control station, and the mobile transmitters shall
   be determined using the methods described in this section.

   (1) Each base station is limited to a maximum ERP of 1000 watts.

   (2) Each control station is limited to a maximum ERP of 200 watts and a
   maximum HAAT of 61 m. (200 ft).

   (3) Each mobile station is limited to a maximum ERP of 30 watts and a
   maximum antenna height of 6.1 m. (20 ft.).

   (4) Each portable (handheld) transmitter is limited to a maximum ERP of 3
   watts.

   (5) All transmitters are subject to the power reductions given in Figure B
   of  Sec. 90.309 of this chapter, for antenna heights higher than 152 meters (500
   ft).

   (c) Methods. The methods used to calculate TV contours and antenna heights
   above average terrain are given in  Sec.  Sec. 73.683 and 73.684 of this chapter.
   Tables to determine the necessary minimum distance from the public safety
   station to the TV/DTV station, assuming that the TV/DTV station has a
   hypothetical or equivalent Grade B contour of 88.5 kilometers (55.0 miles),
   are located in  Sec. 90.309 and labeled as Tables B, D, and E. Values between
   those given in the tables may be determined by linear interpolation. The
   locations of existing and proposed TV/DTV stations during the transition
   period are given in Part 73 of this chapter and in the final proceedings of
   MM Docket No. 87–268. The DTV allotments are:


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                State                          City           NTSC TV Ch.    DT
V Ch.      ERP (kW)     HAAT (m)
-------------------------------------------------------------------------------
---------------------------------
California..........................  Stockton..............           64
     62         63.5          874
California..........................  Los Angeles...........           11
     65        688.7          896
California..........................  Riverside.............           62
     68        180.1          723
California..........................  Concord...............           42
     63         61.0          856
Pennsylvania........................  Allentown.............           39
     62         50.0          302
Pennsylvania........................  Philadelphia..........            6
     64       1000.0          332
Pennsylvania........................  Philadelphia..........           10
     67        791.8          354
Puerto Rico.........................  Aguada................           50
     62         50.0          343
Puerto Rico.........................  Mayaguez..............           16
     63         50.0          347
Puerto Rico.........................  Naranjito.............           64
     65         50.0          142
Puerto Rico.........................  Aguadilla.............           12
     69        691.8          665
-------------------------------------------------------------------------------
---------------------------------

   The transition period is scheduled to end on December 31, 2006. After that
   time, unless otherwise directed by the Commission, public safety stations
   will no longer be required to protect reception of co-channel or adjacent
   channel TV/DTV stations.

   (1) Licensees of stations operating within the ERP and HAAT limits of
   paragraph (b) must select one of three methods to meet the TV/DTV protection
   requirements, subject to Commission approval:

   (i) utilize the geographic separation specified in the tables referenced
   below;

   (ii) Submit an engineering study justifying the proposed separations based
   on the parameters of the land mobile station and the parameters, including
   authorized and/or applied for facilities, of the TV/DTV station(s) it is
   trying to protect; or,

   (iii) obtain written concurrence from the applicable TV/DTV station(s). If
   this method is chosen, a copy of the agreement must be submitted with the
   application.

   (2) The following is the method for geographic separations.

   (i) Base stations having an antenna height (HAAT) less than 152 m. (500 ft.)
   shall afford protection to co-channel and adjacent channel TV/DTV stations
   in accordance with the values specified in Table B (co-channel frequencies
   based on 40 dB protection) and Table E (adjacent channel frequencies based
   on 0 dB protection) in  Sec. 90.309 of this part. For base stations having an
   antenna height (HAAT) between 152–914 meters (500–3,000 ft.) the effective
   radiated power must be reduced below 1 kilowatt in accordance with the
   values shown in the power reduction graph in Figure B in  Sec. 90.309 of this
   part. For heights of more than 152 m. (500 ft.) 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
   hypothetical or equivalent Grade B contour of a co-channel TV/DTV station
   (i.e., it exceeds the distance from the appropriate Table in  Sec. 90.309 to the
   relevant TV/DTV station) an authorization will not be granted unless it can
   be shown in an engineering study (method 2) that actual terrain
   considerations are such as to provide the desired protection at the actual
   Grade B contour (64 dB µV/m for TV and 41 dB µV/m for DTV stations), or that
   the effective radiated power will be further reduced so that, assuming free
   space attenuation, the desired protection at the actual Grade B contour (64
   dB µV/m for TV and 41 dB µV/m coverage contour for DTV stations) will be
   achieved. Directions for calculating powers, heights, and reduction curves
   are listed in  Sec. 90.309 for land mobile stations. Directions for calculating
   coverage contours are listed in  Sec.  Sec. 73.683–685 for TV stations and in  Sec. 73.625
   for DTV stations.

   (ii) Control and mobile stations (including portables) are limited in height
   and power and therefore shall afford protection to co-channel and adjacent
   channel TV/DTV stations in accordance with the values specified in Table D
   (co-channel frequencies based on 40 dB protection) in  Sec. 90.309 of this part
   and a minimum distance of 8 kilometers (5 miles) from all adjacent channel
   TV/DTV station hypothetical or equivalent Grade B contours (adjacent channel
   frequencies based on 0 dB protection for TV stations and—23 dB for DTV
   stations). Since control and mobile stations may affect different TV/DTV
   stations than the associated base station, particular care must be taken by
   applicants to ensure that all the appropriate TV/DTV stations are considered
   (e.g., a base station may be operating on TV Channel 64 and the mobiles on
   TV Channel 69, in which case TV Channels 63, 64, 65, 68, and 69 must be
   protected). Since mobiles and portables are able to move and communicate
   with each other, licensees or coordinators must determine the areas where
   the mobiles can and cannot roam in order to protect the TV/DTV stations, and
   advise the mobile operators of these areas and their restrictions.

   (iii) In order to protect certain TV/DTV stations and to ensure protection
   from these stations which may have extremely large contours due to unusual
   height situations, an additional distance factor must be used by all public
   safety base, control and mobile stations. For all co-channel and adjacent
   channel TV/DTV stations which have an HAAT between 350 and 600 meters,
   public safety stations must add the following DISTANCE FACTOR to the value
   obtained from the referenced Tables in  Sec. 90.309 and to the distance for
   control and mobile stations on adjacent TV/DTV channels (96.5 km).

   DISTANCE FACTOR = (TV/DTV HAAT−350) ÷ 14 in kilometers, where HAAT is the TV
   or DTV station antenna height above average terrain obtained from its
   authorized or proposed facilities, whichever is greater.

   (iv) For all co-channel and adjacent channel TV/DTV stations which have an
   antenna height above average terrain greater than 600 meters, public safety
   stations must add 18 kilometers as the DISTANCE FACTOR to the value obtained
   from the referenced Tables in  Sec. 90.309 and to the distance for control and
   mobile stations on adjacent TV/DTV channels (96.5 km).

   Note to  Sec. 90.545: The 88.5 km (55.0 mi) Grade B service contour (64 dB µV/m)
   is based on a hypothetical TV station operating at an effective radiated
   power of one megawatt, a transmitting antenna height above average terrain
   of 610 meters (2000 feet) and the Commission's R–6602 F(50,50) curves. See
    Sec. 73.699 of this chapter. Maximum facilities for TV stations operating in the
   UHF band are 5 megawatts effective radiated power at an antenna HAAT of 610
   meters (2,000 feet). See  Sec. 73.614 of this chapter. The equivalent contour for
   DTV stations is based on a 41 dB µV/m signal strength and the distance to the
   F(50,90) curve. See  Sec. 73.625 of this chapter.

   [ 63 FR 58651 , Nov. 2, 1998, as amended at  65 FR 53646 , Sept. 5, 2000;  69 FR 63933 , Nov. 3, 2004]