§  15.255   Operation within the band 57-64 GHz.

   (a) Operation under the provisions of this section is not permitted for
   the following products:

   (1) Equipment used on aircraft or satellites.

   (2) Field disturbance sensors, including vehicle radar systems, unless
   the field disturbance sensors are employed for fixed operation. For the
   purposes of this section, the reference to fixed operation includes
   field disturbance sensors installed in fixed equipment, even if the
   sensor itself moves within the equipment.

   (b) Within the 57-64 GHz band, emission levels shall not exceed the
   following:

   (1) For products other than fixed field disturbance sensors, the
   average power density of any emission, measured during the transmit
   interval, shall not exceed 9 mW/cm^2 , as measured 3 meters from the
   radiating structure, and the peak power density of any emission shall
   not exceed 18 mW/cm^2 , as measured 3 meters from the radiating
   structure.

   (2) For fixed field disturbance sensors that occupy 500 MHz or less of
   bandwidth and that are contained wholly within the frequency band
   61.0-61.5 GHz, the average power density of any emission, measured
   during the transmit interval, shall not exceed 9 mW/cm^2 , as measured
   3 meters from the radiating structure, and the peak power density of
   any emission shall not exceed 18 mW/cm^2 , as measured 3 meters from
   the radiating structure. In addition, the average power density of any
   emission outside of the 61-61.5 GHz band, measured during the transmit
   interval, but still within the 57-64 GHz band, shall not exceed 9
   nW/cm^2 , as measured 3 meters from the radiating structure, and the
   peak power density of any emission shall not exceed 18 nW/cm^2 , as
   measured three meters from the radiating structure.

   (3) For fixed field disturbance sensors other than those operating
   under the provisions of paragraph (b)(2) of this section, the peak
   transmitter output power shall not exceed 0.1 mW and the peak power
   density shall not exceed 9 nW/cm^2 at a distance of 3 meters.

   (4) Peak power density shall be measured with an RF detector that has a
   detection bandwidth that encompasses the 57-64 GHz band and has a video
   bandwidth of at least 10 MHz, or using an equivalent measurement
   method.

   (5) The average emission levels shall be calculated, based on the
   measured peak levels, over the actual time period during which
   transmission occurs.

   (c) Limits on spurious emissions:

   (1) The power density of any emissions outside the 57-64 GHz band shall
   consist solely of spurious emissions.

   (2) Radiated emissions below 40 GHz shall not exceed the general limits
   in § 15.209.

   (3) Between 40 GHz and 200 GHz, the level of these emissions shall not
   exceed 90 pW/cm^2 at a distance of 3 meters.

   (4) The levels of the spurious emissions shall not exceed the level of
   the fundamental emission.

   (d) Only spurious emissions and transmissions related to a
   publicly-accessible coordination channel, whose purpose is to
   coordinate operation between diverse transmitters with a view towards
   reducing the probability of interference throughout the 57-64 GHz band,
   are permitted in the 57-57.05 GHz band.

   Note to paragraph (d): The 57-57.05 GHz is reserved exclusively for a
   publicly-accessible coordination channel. The development of standards
   for this channel shall be performed pursuant to authorizations issued
   under part 5 of this chapter.

   (e) Except as specified elsewhere in this paragraph (e), the total peak
   transmitter output power shall not exceed 500 mW.

   (1) Transmitters with an emission bandwidth of less than 100 MHz must
   limit their peak transmitter output power to the product of 500 mW
   times their emission bandwidth divided by 100 MHz. For the purposes of
   this paragraph (e)(1), emission bandwidth is defined as the
   instantaneous frequency range occupied by a steady state radiated
   signal with modulation, outside which the radiated power spectral
   density never exceeds 6 dB below the maximum radiated power spectral
   density in the band, as measured with a 100 kHz resolution bandwidth
   spectrum analyzer. The center frequency must be stationary during the
   measurement interval, even if not stationary during normal operation
   (e.g. for frequency hopping devices).

   (2) Peak transmitter output power shall be measured with an RF detector
   that has a detection bandwidth that encompasses the 57-64 GHz band and
   that has a video bandwidth of at least 10 MHz, or using an equivalent
   measurement method.

   (3) For purposes of demonstrating compliance with this paragraph (e),
   corrections to the transmitter output power may be made due to the
   antenna and circuit loss.

   (f) Fundamental emissions must be contained within the frequency bands
   specified in this section during all conditions of operation. Equipment
   is presumed to operate over the temperature range -20 to +50 degrees
   celsius with an input voltage variation of 85% to 115% of rated input
   voltage, unless justification is presented to demonstrate otherwise.

   (g) Regardless of the power density levels permitted under this
   section, devices operating under the provisions of this section are
   subject to the radiofrequency radiation exposure requirements specified
   in § § 1.1307(b), 2.1091 and 2.1093 of this chapter, as appropriate.
   Applications for equipment authorization of devices operating under
   this section must contain a statement confirming compliance with these
   requirements for both fundamental emissions and unwanted emissions.
   Technical information showing the basis for this statement must be
   submitted to the Commission upon request.

   (h) Any transmitter that has received the necessary FCC equipment
   authorization under the rules of this chapter may be mounted in a group
   installation for simultaneous operation with one or more other
   transmitter(s) that have received the necessary FCC equipment
   authorization, without any additional equipment authorization. However,
   no transmitter operating under the provisions of this section may be
   equipped with external phase-locking inputs that permit beam-forming
   arrays to be realized.

   (i) For all transmissions that emanate from inside of a building,
   within any one second interval of signal transmission, each transmitter
   with a peak output power equal to or greater than 0.1 mW or a peak
   power density equal to or greater than 3 nW/cm^2 , as measured 3 meters
   from the radiating structure, must transmit a transmitter
   identification at least once. Each application for equipment
   authorization for equipment that will be used inside of a building must
   declare that the equipment contains the required transmitter
   identification feature and must specify a method whereby interested
   parties can obtain sufficient information, at no cost, to enable them
   to fully detect and decode this transmitter identification information.
   Upon the completion of decoding, the transmitter identification data
   block must provide the following fields:

   (1) FCC Identifier, which shall be programmed at the factory.

   (2) Manufacturer's serial number, which shall be programmed at the
   factory.

   (3) Provision for at least 24 bytes of data relevant to the specific
   device, which shall be field programmable. The grantee must implement a
   method that makes it possible for users to specify and update this
   data. The recommended content of this field is information to assist in
   contacting the operator.

   [ 63 FR 42279 , Aug. 7, 1998, as amended at  66 FR 7409 , Jan. 23, 2001;  68 FR 68547 , Dec. 9, 2003]