§  15.709   General technical requirements.

   Link to an amendment published at  86 FR 2291 , Jan. 12, 2021.

   (a) Radiated power limits. The maximum white space device EIRP per 6
   MHz shall not exceed the limits of paragraphs (a)(2) through (4) of
   this section.

   (1) General requirements. (i) White space devices may be required to
   operate with less power than the maximum permitted to meet the
   co-channel and adjacent channel separation requirements of § 15.712 of
   this part.

   (ii) Mode I personal/portable devices are limited to 40 mW, if the
   white space device that controls it is limited to 40 mW.

   (2) TV bands and 600 MHz service band. (i)(A) Fixed devices in the TV
   bands below 602 MHz: Up to 4 W (36 dBm) EIRP, and up to 16 W (42 dBm)
   EIRP in less congested areas. Fixed devices in the 602-608 MHz band may
   operate with up to 4 W (36 dBm) EIRP.

   (B) Fixed devices in the 600 MHz service bands above 620 MHz: Up to 4 W
   (36 dBm) EIRP, and up to 10 W (40 dBm) EIRP in less congested areas.
   Fixed devices that operate in any portion of the 614-620 MHz band may
   operate with up to 4 W (36 dBm) EIRP.

   (ii) Personal/Portable devices: Up to 100 mW (20 dBm) EIRP.

   (3) 608-614 MHz band (channel 37). Up to 40 mW (16 dBm) EIRP.

   (ii) Personal/Portable devices: Up to 100 mW (20 dBm) EIRP.

   (4) 600 MHz duplex gap and guard bands. Up to 40 mW (16 dBm) EIRP.

   (5) Mobile devices in the TV bands below 602 MHz. Up to 16 W (42 dBm)
   EIRP in less congested areas. Mobile device operation is not permitted
   above 602 MHz. Mobile devices may operate only in less congested areas.

   (b) Technical limits—(1) Fixed and mobile white space devices. (i)
   Technical limits for fixed and mobile white space devices are shown in
   the table in paragraph (b)(1)(iii) of this section and subject to the
   requirements of this section.

   (ii) For operation at EIRP levels of 36 dBm (4,000 mW) or less, fixed
   and mobile white space devices may operate at EIRP levels between the
   values shown in the table in paragraph (b)(1)(iii) of this section
   provided that the conducted power and the conducted power spectral
   density (PSD) limits are linearly interpolated between the values shown
   and the adjacent channel emission limit of the higher value shown in
   the table is met. Operation at EIRP levels above 36 dBm (4,000 mW) but
   not greater than 40 dBm (10,000 mW) shall follow the requirements for
   40 dBm (10,000 mW). Operation at EIRP levels above 40 dBm (10,000 mW)
   shall follow the requirements for 42 dBm (16,000 mW).

   (iii) The conducted power spectral density from a fixed or mobile white
   space device shall not be greater than the values shown in the table in
   this paragraph (b)(1)(iii) when measured in any 100 kilohertz band
   during any time interval of continuous transmission.

   Table 1 to Paragraph (b)(1)(iii)
   EIRP
   (6 MHz) Conducted power limit
   (6 MHz) Conducted PSD limit^1
   (100 kHz)
   (dBm) Conducted adjacent channel emission limit
   (100 kHz)
   (dBm)
           16 dBm (40 mW)                           10 dBm (10 mW)    −7.4 −62.8
           20 dBm (100 mW)                          14 dBm (25 mW)    −3.4 −58.8
           24 dBm (250 mW)                          18 dBm (63 mW)     0.6 −54.8
           28 dBm (625 mW)                          22 dBm (158 mW)    4.6 −50.8
           32 dBm (1,600 mW)                        26 dBm (400 mW)    8.6 −46.8
           36 dBm (4,000 mW)                        30 dBm (1,000 mW) 12.6 −42.8
           40 dBm (1,0000 mW)                       30 dBm (1,000 mW) 12.6 −42.8
           42 dBm (16,000 mW)                       30 dBm (1,000 mW) 12.6 −42.8

   (2) Personal/portable white space devices. (i) Technical limits for
   personal/portable white space devices are shown in the table in
   paragraph (b)(2)(ii) of this section and subject to the requirements of
   this section.

   (ii) The radiated power spectral density from a personal/portable white
   space device shall not be greater than the values shown in the table in
   this paragraph (b)(2)(ii) when measured in any 100 kHz band during any
   time interval of continuous transmission.

   Table 2 to Paragraph (b)(2)(ii)
   EIRP
   (6 MHz) Radiated PSD
   limit EIRP
   (100 kHz)
   (dBm) Radiated adjacent
   channel emission
   limit EIRP
   (100 kHz)
   (dBm)
           16 dBm (40 mW)   −1.4 −56.8
           20 dBm (100 mW)   2.6 −52.8

   (3) Sensing-only devices. Sensing-only white space devices are limited
   to 17 dBm (50 mW) EIRP and are subject to the requirements of this
   paragraph and of § 15.717 of this part.

   (i) Radiated PSD limit: −0.4 dBm EIRP.

   (ii) Adjacent channel emission limit: −55.8 dBm EIRP.

   (4) Narrowband white space devices. (i) A narrowband white space device
   that operates as a client must communicate with a master device (fixed,
   Mode II, mobile or narrowband) that contacts the white space database
   to obtain a list of available channels and operating powers at its
   location. A narrowband white space device that acts as a master must
   incorporate a geo-location mechanism and be capable of obtaining lists
   of available channels and operating powers from the white space
   database.

   (ii) Narrowband white space devices shall operate on channel sizes that
   are no more than 100 kilohertz. The edge of a narrowband channel shall
   be offset from the upper and lower edge of the 6 megahertz channel in
   which it operates by at least 250 kilohertz, except in the case where
   bonded 6 megahertz channels share a common band edge. Narrowband
   operating channels shall be at integral multiples of 100 kilohertz
   beginning at a 250 kilohertz offset from a 6 megahertz channel's edge,
   or with no offset at the common band edge of two bonded 6 megahertz
   channels.

   (iii) The conducted power limit is 12.6 dBm in a 100 kilohertz segment.
   The EIRP limit is 18.6 dBm in a 100 kilohertz segment. The conducted
   power spectral density limit is 12.6 dBm in any 100 kilohertz band
   during any time interval of continuous transmission.

   (iv) Conducted adjacent channel emissions shall be limited to −42.8 dBm
   in 100 kilohertz in a first adjacent 6 megahertz channel, starting at
   the edge of the 6 megahertz channel within which the narrowband device
   is operating. This limit shall not apply between the edge of the
   narrowband channel and the edge of the 6 megahertz channel that
   contains it.

   (v) If transmitting antennas of directional gain greater than 6 dBi are
   used, the maximum conducted power output shall be reduced by the amount
   in dB that the directional gain of the antenna exceeds 6 dBi.

   (vi) Total occupancy for each narrowband channel shall be limited to 36
   seconds per hour.

   (c) Conducted power limits. (1) The conducted power, PSD and adjacent
   channel limits for fixed white space devices operating at up to 36 dBm
   (4000 milliwatts) EIRP shown in the table in paragraph (b)(1) of this
   section are based on a maximum transmitting antenna gain of 6 dBi. 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) The conducted power, PSD, and adjacent channel limits for fixed and
   mobile white space devices operating at greater than 36 dBm (4,000
   milliwatts) EIRP shown in the table in paragraph (b)(1)(iii) of this
   section are based on a maximum transmitting antenna gain of 12 dBi. If
   transmitting antennas of directional gain greater than 12 dBi are used,
   the maximum conducted output power shall be reduced by the amount in dB
   that the directional gain of the antenna exceeds 12 dBi.

   (3) 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 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.

   (4) White space devices connected to the AC power line are required to
   comply with the conducted limits set forth in § 15.207.

   (d) Emission limits. (1) The adjacent channel emission limits shown in
   the tables in paragraphs (b)(1) and (2) of this section apply in the
   six megahertz channel immediately adjacent to each white space channel
   or group of contiguous white space channels in which the white space
   device is operating.

   (2) At frequencies beyond the six megahertz channel immediately
   adjacent to each white space channel or group of contiguous white space
   channels in which the white space device is operating the white space
   device shall meet the requirements of § 15.209.

   (3) Emission measurements in the adjacent bands 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.

   (e) Transmit power control. White space devices 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 the device's transmit
   power control feature mechanism.

   (f) Security. White space devices shall incorporate adequate security
   measures to prevent the devices from accessing databases not approved
   by the FCC and to ensure that unauthorized parties cannot modify the
   device or configure its control features to operate in a manner
   inconsistent with the rules and protection criteria set forth in this
   subpart.

   (g) Antenna requirements—(1) Fixed white space devices— (i) Above
   ground level. The transmit antenna height shall not exceed 10 meters
   above ground level in any area for fixed white space devices operating
   in the TV bands at 40 mW EIRP or less or operating across multiple
   contiguous TV channels at 100 mW EIRP or less.

   (ii) Height above average terrain (HAAT). The transmit antenna shall
   not be located where the height above average terrain is more than 250
   meters. The HAAT is to be calculated by the white space database using
   the methodology in § 73.684(d) of this chapter.

   (2) Personal/portable white space devices. Personal/portable devices
   shall have permanently attached transmit and receive antenna(s).

   (3) Sensing-only white space devices operating under the provisions of
   § 15.717 of this subpart. (i) The provisions of § 15.204(c)(4) do not
   apply to an antenna used for transmission and reception/spectrum
   sensing.

   (ii) Compliance testing for white space devices that incorporate a
   separate sensing antenna shall be performed using the lowest gain
   antenna for each type of antenna to be certified.

   (h) Compliance with radio frequency exposure requirements. White space
   devices shall ensure compliance with the Commission's radio frequency
   exposure requirements in § § 1.1307(b), 2.1091 and 2.1093 of this
   chapter, as appropriate. Applications for equipment authorization of RF
   sources under this section must contain a statement confirming
   compliance with these requirements. Technical information showing the
   basis for this statement must be submitted to the Commission upon
   request.

   [ 80 FR 73070 , Nov. 23, 2015, as amended at  84 FR 34797 , July 19, 2019;
    85 FR 18149 , Apr. 1, 2020;  86 FR 2291 , Jan. 12, 2021]

   Editorial Note: At  86 FR 2291 , Jan. 12, 2021, paragraph (g)(1)(ii) was
   revised. The revision was delayed indefinitely.