§ 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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