§  15.709   General technical requirements.

   (a) Power limits for TVBDs. (1) For fixed TVBDs, the maximum power
   delivered to the transmitting antenna shall not exceed one watt per 6
   megahertz of bandwidth on which the device operates. The power
   delivered to the transmitting antenna is the maximum conducted output
   power reduced by the signal loss experienced in the cable used to
   connect the transmitter to the transmit antenna. If transmitting
   antennas of directional gain greater than 6 dBi are used, the maximum
   conducted output power shall be reduced by the amount in dB that the
   directional gain of the antenna exceeds 6 dBi.

   (2) For personal/portable TVBDs, the maximum EIRP shall not exceed 100
   milliwatts (20 dBm) per 6 megahertz of bandwidth on which the device
   operates with the following exceptions; Mode II personal/portable TVBDs
   that do not meet the adjacent channel separation requirements in
   § 15.712(a) and Mode I personal/portable TVBDs that operate on
   available channels (provided by a Mode II TVBD) that do not meet the
   adjacent channel separation requirements of § 15.712(a) are limited to
   a maximum EIRP of 40 milliwatts (16 dBm) per 6 megahertz of bandwidth
   on which the device operates.

   (3) TVBDs shall incorporate transmit power control to limit their
   operating power to the minimum necessary for successful communication.
   Applicants for equipment certification shall include a description of a
   device's transmit power control feature mechanism.

   (4) Maximum conducted output power is the total transmit power over the
   occupied bandwidth delivered to all antennas and antenna elements
   averaged across all symbols in the signaling alphabet when the
   transmitter is operating at its maximum power control level. Power must
   be summed across all antennas and antenna elements. The average must
   not include any time intervals during which the transmitter is off or
   is transmitting at a reduced power level. If multiple modes of
   operation are possible (e.g., alternative modulation methods), the
   maximum conducted output power is the highest total transmit power
   occurring in any mode.

   (5) The power spectral density conducted from the TVBD to the antenna
   shall not be greater than the following values when measured in any 100
   kHz band during any time interval of continuous transmission:

   (i) Fixed devices: 12.2 dBm.

   (ii) Personal/portable devices operating adjacent to occupied TV
   channels: -1.8 dBm.

   (iii) Sensing-only devices: -0.8 dBm.

   (iii) All other personal/portable devices: 2.2 dBm.

   (6) TVBDs shall incorporate adequate security measures to prevent the
   TVBD from accessing databases not approved by the FCC and to ensure
   that unauthorized parties can not modify the TVBD or configure its
   control features to operate inconsistent with the rules and protection
   criteria set forth in this subpart.

   (b) Antenna requirements. (1) All transmit and receive antenna(s) of
   personal/portable devices shall be permanently attached.

   (2) The transmit antenna used with fixed devices may not be more than
   30 meters above the ground. In addition, fixed devices may not be
   located at sites where the height above average terrain (HAAT) at
   ground level is more than 76 meters. The ground level HAAT is to be
   calculated by the TV bands database that the device contacts for
   available channels using computational software employing the
   methodology in § 73.684(d) of this chapter.

   (3) For personal/portable TVBDs operating under § 15.717, the
   provisions of § 15.204(c)(4) do not apply to an antenna used for
   transmission and reception/spectrum sensing.

   (4) For personal/portable TVBDs operating under § 15.717 that
   incorporate a separate sensing antenna, compliance testing shall be
   performed using the lowest gain antenna for each type of antenna to be
   certified.

   (c) Emission limits for TVBDs. (1) In the television channels
   immediately adjacent to the channel in which a TVBD is operating,
   emissions from the TVBD shall be at least 72.8 dB below the highest
   average power in the TV channel in which the device is operating.

   (2) Emission measurements in the channel of operation shall be
   performed over a reference bandwidth of 6 megahertz with an average
   detector. Emission measurements in the adjacent channels shall be
   performed using a minimum resolution bandwidth of 100 kHz with an
   average detector. A narrower resolution bandwidth may be employed near
   the band edge, when necessary, provided the measured energy is
   integrated to show the total power over 100 kHz.

   (3) At frequencies beyond the television channels immediately adjacent
   to the channel in which the TVBD is operating, the radiated emissions
   from TVBDs shall meet the requirements of § 15.209.

   (4) Emissions in the band 602-620 MHz must also comply with the
   following field strength limits at a distance of one meter.
   Frequency
   (MHz) Field strength
   dBuV/meter/120 kHz
         602-607       120-5[F(MHz)-602]
         607-608       95
         608-614       30
         614-615       95
         615-620       120-5[620-F(MHz)]

   (5) TVBDs connected to the AC power line are required to comply with
   the conducted limits set forth in § 15.207.

   (d) Compliance with radio frequency exposure requirements. To ensure
   compliance with the Commission's radio frequency exposure requirements
   in § § 1.1307(b), 2.1091 and 2.1093 of this chapter, fixed TVBDs shall
   be accompanied by instructions on measures to take to ensure that
   persons maintain a distance of at least 40 cm from the device, as well
   as any necessary hardware that may be needed to implement that
   protection. These instructions shall be submitted with the application
   for certification. Personal/portable TVBDs that meet the definition of
   portable devices under § 2.1093 of this chapter and that operate with a
   source-based time-averaged output of less than 20 mW will not be
   subject to routine evaluation for compliance with the radio frequency
   exposure guidelines, while devices that operate with a source-based
   time-average output power greater than 20 mW will be subject to the
   routine evaluation requirements.

   [ 74 FR 7326 , Feb. 17, 2009, as amended at  75 FR 75836 , Dec. 6, 2010]