§ 15.407   General technical requirements.

   (a) Power limits:

   (1) For the band 5.15-5.25 GHz.

   (i) For an outdoor access point operating in the band 5.15-5.25 GHz,
   the maximum conducted output power over the frequency band of operation
   shall not exceed 1 W provided the maximum antenna gain does not exceed
   6 dBi. In addition, the maximum power spectral density shall not exceed
   17 dBm in any 1 megahertz band. If transmitting antennas of directional
   gain greater than 6 dBi are used, both the maximum conducted output
   power and the maximum power spectral density shall be reduced by the
   amount in dB that the directional gain of the antenna exceeds 6 dBi.
   The maximum e.i.r.p. at any elevation angle above 30 degrees as
   measured from the horizon must not exceed 125 mW (21 dBm).

   (ii) For an indoor access point operating in the band 5.15-5.25 GHz,
   the maximum conducted output power over the frequency band of operation
   shall not exceed 1 W provided the maximum antenna gain does not exceed
   6 dBi. In addition, the maximum power spectral density shall not exceed
   17 dBm in any 1 megahertz band. If transmitting antennas of directional
   gain greater than 6 dBi are used, both the maximum conducted output
   power and the maximum power spectral density shall be reduced by the
   amount in dB that the directional gain of the antenna exceeds 6 dBi.

   (iii) For fixed point-to-point access points operating in the band
   5.15-5.25 GHz, the maximum conducted output power over the frequency
   band of operation shall not exceed 1 W. Fixed point-to-point U-NII
   devices may employ antennas with directional gain up to 23 dBi without
   any corresponding reduction in the maximum conducted output power or
   maximum power spectral density. For fixed point-to-point transmitters
   that employ a directional antenna gain greater than 23 dBi, a 1 dB
   reduction in maximum conducted output power and maximum power spectral
   density is required for each 1 dB of antenna gain in excess of 23 dBi.
   Fixed, point-to-point operations exclude the use of point-to-multipoint
   systems, omnidirectional applications, and multiple collocated
   transmitters transmitting the same information. The operator of the
   U-NII device, or if the equipment is professionally installed, the
   installer, is responsible for ensuring that systems employing high gain
   directional antennas are used exclusively for fixed, point-to-point
   operations.

   (iv) For mobile and portable client devices in the 5.15-5.25 GHz band,
   the maximum conducted output power over the frequency band of operation
   shall not exceed 250 mW provided the maximum antenna gain does not
   exceed 6 dBi. In addition, the maximum power spectral density shall not
   exceed 11 dBm in any 1 megahertz band. If transmitting antennas of
   directional gain greater than 6 dBi are used, both the maximum
   conducted output power and the maximum power spectral density shall be
   reduced by the amount in dB that the directional gain of the antenna
   exceeds 6 dBi.

   (2) For the 5.25-5.35 GHz and 5.47-5.725 GHz bands, the maximum
   conducted output power over the frequency bands of operation shall not
   exceed the lesser of 250 mW or 11 dBm + 10 log B, where B is the 26 dB
   emission bandwidth in megahertz. In addition, the maximum power
   spectral density shall not exceed 11 dBm in any 1 megahertz band. If
   transmitting antennas of directional gain greater than 6 dBi are used,
   both the maximum conducted output power and the maximum power spectral
   density shall be reduced by the amount in dB that the directional gain
   of the antenna exceeds 6 dBi.

   (3) For the band 5.725-5.85 GHz, the maximum conducted output power
   over the frequency band of operation shall not exceed 1 W. In addition,
   the maximum power spectral density shall not exceed 30 dBm in any
   500-kHz band. If transmitting antennas of directional gain greater than
   6 dBi are used, both the maximum conducted output power and the maximum
   power spectral density shall be reduced by the amount in dB that the
   directional gain of the antenna exceeds 6 dBi. However, fixed
   point-to-point U-NII devices operating in this band may employ
   transmitting antennas with directional gain greater than 6 dBi without
   any corresponding reduction in transmitter conducted power. Fixed,
   point-to-point operations exclude the use of point-to-multipoint
   systems, omnidirectional applications, and multiple collocated
   transmitters transmitting the same information. The operator of the
   U-NII device, or if the equipment is professionally installed, the
   installer, is responsible for ensuring that systems employing high gain
   directional antennas are used exclusively for fixed, point-to-point
   operations.

   Note to paragraph (a)(3): The Commission strongly recommends that
   parties employing U-NII devices to provide critical communications
   services should determine if there are any nearby Government radar
   systems that could affect their operation.

   (4) The maximum conducted output power must be measured over any
   interval of continuous transmission using instrumentation calibrated in
   terms of an rms-equivalent voltage.

   (5) The maximum power spectral density is measured as a conducted
   emission by direct connection of a calibrated test instrument to the
   equipment under test. If the device cannot be connected directly,
   alternative techniques acceptable to the Commission may be used.
   Measurements in the 5.725-5.85 GHz band are made over a reference
   bandwidth of 500 kHz or the 26 dB emission bandwidth of the device,
   whichever is less. Measurements in the 5.15-5.25 GHz, 5.25-5.35 GHz,
   and the 5.47-5.725 GHz bands are made over a bandwidth of 1 MHz or the
   26 dB emission bandwidth of the device, whichever is less. A narrower
   resolution bandwidth can be used, provided that the measured power is
   integrated over the full reference bandwidth.

   (b) Undesirable emission limits. Except as shown in paragraph (b)(7) of
   this section, the maximum emissions outside of the frequency bands of
   operation shall be attenuated in accordance with the following limits:

   (1) For transmitters operating in the 5.15-5.25 GHz band: All emissions
   outside of the 5.15-5.35 GHz band shall not exceed an e.i.r.p. of -27
   dBm/MHz.

   (2) For transmitters operating in the 5.25-5.35 GHz band: All emissions
   outside of the 5.15-5.35 GHz band shall not exceed an e.i.r.p. of -27
   dBm/MHz.

   (3) For transmitters operating in the 5.47-5.725 GHz band: All
   emissions outside of the 5.47-5.725 GHz band shall not exceed an
   e.i.r.p. of -27 dBm/MHz.

   (4) For transmitters operating in the 5.725-5.85 GHz band: All
   emissions within the frequency range from the band edge to 10 MHz above
   or below the band edge shall not exceed an e.i.r.p. of -17 dBm/MHz; for
   frequencies 10 MHz or greater above or below the band edge, emissions
   shall not exceed an e.i.r.p. of -27 dBm/MHz.

   (5) The emission measurements shall be performed using a minimum
   resolution bandwidth of 1 MHz. A lower resolution bandwidth may be
   employed near the band edge, when necessary, provided the measured
   energy is integrated to show the total power over 1 MHz.

   (6) Unwanted emissions below 1 GHz must comply with the general field
   strength limits set forth in § 15.209. Further, any U-NII devices using
   an AC power line are required to comply also with the conducted limits
   set forth in § 15.207.

   (7) The provisions of § 15.205 apply to intentional radiators operating
   under this section.

   (8) When measuring the emission limits, the nominal carrier frequency
   shall be adjusted as close to the upper and lower frequency band edges
   as the design of the equipment permits.

   (c) The device shall automatically discontinue transmission in case of
   either absence of information to transmit or operational failure. These
   provisions are not intended to preclude the transmission of control or
   signalling information or the use of repetitive codes used by certain
   digital technologies to complete frame or burst intervals. Applicants
   shall include in their application for equipment authorization a
   description of how this requirement is met.

   (d) [Reserved]

   (e) Within the 5.725-5.85 GHz band, the minimum 6 dB bandwidth of U-NII
   devices shall be at least 500 kHz.

   (f) U-NII devices are subject to the radio frequency radiation exposure
   requirements specified in § 1.1307(b), § 2.1091 and § 2.1093 of this
   chapter, as appropriate. All equipment shall be considered to operate
   in a "general population/uncontrolled" environment. 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.

   (g) Manufacturers of U-NII devices are responsible for ensuring
   frequency stability such that an emission is maintained within the band
   of operation under all conditions of normal operation as specified in
   the users manual.

   (h) Transmit Power Control (TPC) and Dynamic Frequency Selection (DFS).

   (1) Transmit power control (TPC). U-NII devices operating in the
   5.25-5.35 GHz band and the 5.47-5.725 GHz band shall employ a TPC
   mechanism. The U-NII device is required to have the capability to
   operate at least 6 dB below the mean EIRP value of 30 dBm. A TPC
   mechanism is not required for systems with an e.i.r.p. of less than 500
   mW.

   (2) Radar Detection Function of Dynamic Frequency Selection (DFS).
   U-NII devices operating with any part of its 26 dB emission bandwidth
   in the 5.25-5.35 GHz and 5.47-5.725 GHz bands shall employ a DFS radar
   detection mechanism to detect the presence of radar systems and to
   avoid co-channel operation with radar systems. Operators shall only use
   equipment with a DFS mechanism that is turned on when operating in
   these bands. The device must sense for radar signals at 100 percent of
   its emission bandwidth. The minimum DFS detection threshold for devices
   with a maximum e.i.r.p. of 200 mW to 1 W is -64 dBm. For devices that
   operate with less than 200 mW e.i.r.p. and a power spectral density of
   less than 10 dBm in a 1 MHz band, the minimum detection threshold is
   -62 dBm. The detection threshold is the received power averaged over 1
   microsecond referenced to a 0 dBi antenna. For the initial channel
   setting, the manufacturers shall be permitted to provide for either
   random channel selection or manual channel selection.

   (i) Operational Modes. The DFS requirement applies to the following
   operational modes:

   (A) The requirement for channel availability check time applies in the
   master operational mode.

   (B) The requirement for channel move time applies in both the master
   and slave operational modes.

   (ii) Channel Availability Check Time. A U-NII device shall check if
   there is a radar system already operating on the channel before it can
   initiate a transmission on a channel and when it has to move to a new
   channel. The U-NII device may start using the channel if no radar
   signal with a power level greater than the interference threshold
   values listed in paragraph (h)(2) of this section, is detected within
   60 seconds.

   (iii) Channel Move Time. After a radar's presence is detected, all
   transmissions shall cease on the operating channel within 10 seconds.
   Transmissions during this period shall consist of normal traffic for a
   maximum of 200 ms after detection of the radar signal. In addition,
   intermittent management and control signals can be sent during the
   remaining time to facilitate vacating the operating channel.

   (iv) Non-occupancy Period. A channel that has been flagged as
   containing a radar system, either by a channel availability check or
   in-service monitoring, is subject to a non-occupancy period of at least
   30 minutes. The non-occupancy period starts at the time when the radar
   system is detected.

   (i) Device Security. All U-NII devices must contain security features
   to protect against modification of software by unauthorized parties.

   (1) Manufacturers must implement security features in any digitally
   modulated devices capable of operating in any of the U-NII bands, so
   that third parties are not able to reprogram the device to operate
   outside the parameters for which the device was certified. The software
   must prevent the user from operating the transmitter with operating
   frequencies, output power, modulation types or other radio frequency
   parameters outside those that were approved for the device.
   Manufacturers may use means including, but not limited to the use of a
   private network that allows only authenticated users to download
   software, electronic signatures in software or coding in hardware that
   is decoded by software to verify that new software can be legally
   loaded into a device to meet these requirements and must describe the
   methods in their application for equipment authorization.

   (2) Manufacturers must take steps to ensure that DFS functionality
   cannot be disabled by the operator of the U-NII device.

   (j) Operator Filing Requirement: Before deploying an aggregate total of
   more than one thousand outdoor access points within the 5.15-5.25 GHz
   band, parties must submit a letter to the Commission acknowledging
   that, should harmful interference to licensed services in this band
   occur, they will be required to take corrective action. Corrective
   actions may include reducing power, turning off devices, changing
   frequency bands, and/or further reducing power radiated in the vertical
   direction. This material shall be submitted to Laboratory Division,
   Office of Engineering and Technology, Federal Communications
   Commission, 7435 Oakland Mills Road, Columbia, MD 21046. Attn: U-NII
   Coordination, or via Web site at https://www.fcc.gov/labhelp with the
   SUBJECT LINE: "U-NII-1 Filing".

   [ 63 FR 40836 , July 31, 1998, as amended at  69 FR 2687 , Jan. 20, 2004;
    69 FR 54036 , Sept. 7, 2004;  79 FR 24579 , May 1, 2014;  79 FR 56988 ,
   Sept. 24, 2014]

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Subpart F--Ultra-Wideband Operation

   Source:  67 FR 34856 , May 16, 2002, unless otherwise noted.

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