Goto Section: 15.715 | 15.717 | Table of Contents

FCC 15.717
Revised as of September 1, 2021
Goto Year:2020 | 2022
  §  15.717   White space devices that rely on spectrum sensing.

   (a) Applications for certification. Parties may submit applications for
   certification of white space devices 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

   (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 white space
   device 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), (d), and (e). 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

   (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 white space device 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 white space device 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

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


   Need assistance?

Goto Section: 15.715 | 15.717

Goto Year: 2020 | 2022
CiteFind - See documents on FCC website that cite this rule

Want to support this service?

Report errors in this rule. Since these rules are converted to HTML by machine, it's possible errors have been made. Please help us improve these rules by clicking the Report FCC Rule Errors link to report an error.
Helping make public information public