Sec.  27.55   Signal strength limits.

   (a) Field strength limits. For the following bands, the predicted or
   measured median field strength at any location on the geographical border of
   a licensee's service area shall not exceed the value specified unless the
   adjacent affected service area licensee(s) agree(s) to a different field
   strength. This value applies to both the initially offered service areas and
   to partitioned service areas.

   (1) 2110–2155, 2305–2320 and 2345–2360 MHz bands: 47 dB µV/m.

   (2) 698–764 and 776–794 MHz bands: 40 dB µV/m.

   (3) The paired 1392–1395 MHz and 1432–1435 MHz bands and the unpaired
   1390–1392 MHz band (1.4 GHz band): 47 dB µV/m.

   (4) BRS and EBS: The predicted or measured median field strength at any
   location on the geographical border of a licensee's service area shall not
   exceed the value specified unless the adjacent affected service area
   licensee(s) agree(s) to a different field strength. This value applies to
   both the initially offered services areas and to partitioned services areas.
   Licensees may exceed this signal level where there is no affected licensee
   that is constructed and providing service. Once the affected licensee is
   providing service, the original licensee will be required to take whatever
   steps necessary to comply with the applicable power level at its GSA
   boundary, absent consent from the affected licensee.

   (i) Prior to transition, the signal strength at any point along the
   licensee's GSA boundary does not exceed the greater of that permitted under
   the licensee's Commission authorizations as of January 10, 2005 or 47 dB
   [m µ]V/m.

   (ii) Following transition, for stations in the LBS and UBS, the signal
   strength at any point along the licensee's GSA boundary must not exceed 47
   dB[m µ]V/m. This field strength is to be measured at 1.5 meters above the
   ground over the channel bandwidth (i.e., each 5.5 MHz channel for licensees
   that hold a full channel block, and for the 5.5 MHz channel for licensees
   that hold individual channels).

   (iii) Following transition, for stations in the MBS, the signal strength at
   any point along the licensee's GSA boundary must not exceed −73.0 +
   10log(X/6) dBW/m ^2 , where X is the bandwidth in MHz of the channel.

   (b) Power flux density limit. For base and fixed stations operating in the
   698–746 MHz band, with an effective radiated power (ERP) greater than 1 kW,
   the power flux density that would be produced by such stations through a
   combination of antenna height and vertical gain pattern must not exceed 3000
   microwatts per square meter on the ground over the area extending to 1 km
   from the base of the antenna mounting structure.

   [ 69 FR 5715 , Feb. 6, 2004, as amended at  69 FR 72034 , Dec. 10, 2004]