§ 15.249   Operation within the bands 902-928 MHz, 2400-2483.5 MHz, 5725-5875
MHZ, and 24.0-24.25 GHz.

   (a) Except as provided in paragraph (b) of this section, the field strength
   of emissions from intentional radiators operated within these frequency
   bands shall comply with the following:
   Fundamental frequency Field strength of fundamental (millivolts/meter) Field
   strength of harmonics (microvolts/meter)
   902-928 MHz 50 500
   2400-2483.5 MHz 50 500
   5725-5875 MHz 50 500
   24.0-24.25 GHz 250 2500

   (b) Fixed, point-to-point operation as referred to in this paragraph shall
   be limited to systems employing a fixed transmitter transmitting to a fixed
   remote location. Point-to-multipoint systems, omnidirectional applications,
   and  multiple  co-located  intentional radiators transmitting the same
   information are not allowed. Fixed, point-to-point operation is permitted in
   the 24.05-24.25 GHz band subject to the following conditions:

   (1) The field strength of emissions in this band shall not exceed 2500
   millivolts/meter.

   (2) The frequency tolerance of the carrier signal shall be maintained within
   ±0.001% of the operating frequency over a temperature variation of -20
   degrees to + 50 degrees C at normal supply voltage, and for a variation in
   the primary supply voltage from 85% to 115% of the rated supply voltage at a
   temperature of 20 degrees C. For battery operated equipment, the equipment
   tests shall be performed using a new battery.

   (3) Antenna gain must be at least 33 dBi. Alternatively, the main lobe
   beamwidth must not exceed 3.5 degrees. The beamwidth limit shall apply to
   both the azimuth and elevation planes. At antenna gains over 33 dBi or
   beamwidths narrower than 3.5 degrees, power must be reduced to ensure that
   the field strength does not exceed 2500 millivolts/meter.

   (c) Field strength limits are specified at a distance of 3 meters.

   (d) Emissions radiated outside of the specified frequency bands, except for
   harmonics, shall be attenuated by at least 50 dB below the level of the
   fundamental or to the general radiated emission limits in § 15.209, whichever
   is the lesser attenuation.

   (e)  As  shown in § 15.35(b), for frequencies above 1000 MHz, the field
   strength limits in paragraphs (a) and (b) of this section are based on
   average limits. However, the peak field strength of any emission shall not
   exceed the maximum permitted average limits specified above by more than 20
   dB under any condition of modulation. For point-to-point operation under
   paragraph (b) of this section, the peak field strength shall not exceed 2500
   millivolts/meter at 3 meters along the antenna azimuth.

   [ 54 FR 17714 , Apr. 25, 1989, as amended at  55 FR 25095 , June 20, 1990;  67 FR 1625 , Jan. 14, 2002;  77 FR 4914 , Feb. 1, 2012]

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