§  15.717   TVBDs that rely on spectrum sensing.

   (a) Applications for certification. Parties may submit applications for
   certification of TVBDs that rely solely on spectrum sensing to identify
   available channels. Devices authorized under this section must
   demonstrate with an extremely high degree of confidence that they will
   not cause harmful interference to incumbent radio services.

   (1) In addition to the procedures in subpart J of part 2 of this
   chapter, applicants shall comply with the following.

   (i) The application must include a full explanation of how the device
   will protect incumbent authorized services against interference.

   (ii) Applicants must submit a pre-production device, identical to the
   device expected to be marketed.

   (2) The Commission will follow the procedures below for processing
   applications pursuant to this section.

   (i) Applications will be placed on public notice for a minimum of 30
   days for comments and 15 days for reply comments. Applicants may
   request that portions of their application remain confidential in
   accordance with §  0.459 of this chapter. This public notice will
   include proposed test procedures and methodologies.

   (ii) The Commission will conduct laboratory and field tests of the
   pre-production device. This testing will be conducted to evaluate proof
   of performance of the device, including characterization of its sensing
   capability and its interference potential. The testing will be open to
   the public.

   (iii) Subsequent to the completion of testing, the Commission will
   issue by public notice, a test report including recommendations. The
   public notice will specify a minimum of 30 days for comments and, if
   any objections are received, an additional 15 days for reply comments.

   (b) Power limit for devices that rely on sensing. The TVBD shall meet
   the requirements for personal/portable devices in this subpart except
   that it will be limited to a maximum EIRP of 50 mW per 6 megahertz of
   bandwidth on which the device operates and it does not have to comply
   with the requirements for geo-location and database access in
   §  15.711(b). Compliance with the detection threshold for spectrum
   sensing in §  15.717(c), although required, is not necessarily
   sufficient for demonstrating reliable interference avoidance. Once a
   device is certified, additional devices that are identical in
   electrical characteristics and antenna systems may be certified under
   the procedures of Part 2, Subpart J of this chapter.

   (c) Sensing requirements.

   (1) Detection threshold.

   (i) The required detection thresholds are:

   (A) ATSC digital TV signals: -114 dBm, averaged over a 6 MHz bandwidth;

   (B) NTSC analog TV signals: -114 dBm, averaged over a 100 kHz
   bandwidth;

   (C) Low power auxiliary, including wireless microphone, signals: -107
   dBm, averaged over a 200 kHz bandwidth.

   (ii) The detection thresholds are referenced to an omnidirectional
   receive antenna with a gain of 0 dBi. If a receive antenna with a
   minimum directional gain of less than 0 dBi is used, the detection
   threshold shall be reduced by the amount in dB that the minimum
   directional gain of the antenna is less than 0 dBi. Minimum directional
   gain shall be defined as the antenna gain in the direction and at the
   frequency that exhibits the least gain. Alternative approaches for the
   sensing antenna are permitted, e.g., electronically rotatable antennas,
   provided the applicant for equipment authorization can demonstrate that
   its sensing antenna provides at least the same performance as an
   omnidirectional antenna with 0 dBi gain.

   (2) Channel availability check time. A TVBD may start operating on a TV
   channel if no TV, wireless microphone or other low power auxiliary
   device signals above the detection threshold are detected within a
   minimum time interval of 30 seconds.

   (3) In-service monitoring. A TVBD must perform in-service monitoring of
   an operating channel at least once every 60 seconds. There is no
   minimum channel availability check time for in-service monitoring.

   (4) Channel move time. After a TV, wireless microphone or other low
   power auxiliary device signal is detected on a TVBD operating channel,
   all transmissions by the TVBD must cease within two seconds.

   [ 75 FR 75842 , Dec. 6, 2010]

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