Sec.  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 μW/cm ^2 , as measured 3 meters from the radiating structure,
   and the peak power density of any emission shall not exceed 18 μW/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 μW/cm ^2 , as measured 3 meters from the
   radiating structure, and the peak power density of any emission shall not
   exceed 18 μW/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
    Sec. 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  Sec.  Sec. 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]