Goto Section: 15.707 | 15.711 | Table of Contents
Revised as of October 1, 2014
Goto Year:2013 |
§ 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 from the TVBD 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: 12.6 dBm conducted power. If transmitting antennas
of directional gain greater than 6 dBi are used, this conducted power
level shall be reduced by the amount in dB that the directional gain of
the antenna exceeds 6 dBi.
(ii) Personal/portable device operating adjacent to occupied TV
channels: -1.4 dBm EIRP.
(iii) Sensing-only devices: -0.4 dBm EIRP.
(iv) All other personal/portable devices: 2.6 dBm EIRP.
(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 antenna height above average terrain is more
than 250 meters. The 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
(c) Emission limits for TVBDs.--(1) In the television channels
immediately adjacent to the channel in which the TVBD is operating,
emissions from the TVBD shall not exceed the following levels.
(i) Fixed devices: -42.8 dBm conducted power.
(ii) Personal/portable device operating adjacent to occupied TV
channels: -56.8 dBm EIRP.
(iii) Sensing-only devices: -55.8 dBm EIRP.
(iv) All other personal/portable devices: -52.8 dBm EIRP.
(2) 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.
(MHz) Field strength
(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; 77 FR 29245 , May 17, 2012]
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Goto Section: 15.707 | 15.711
Goto Year: 2013 |
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