§ 15.711   Interference avoidance methods.

   Except as provided in § 15.717, television channel availability for a
   TVBD is determined based on the geo-location and database access method
   described in paragraphs (a) and (b) of this section.

   (a) Geo-location and database access. A TVBD shall rely on the
   geo-location and database access mechanism to identify available
   television channels consistent with the interference protection
   requirements of § 15.712. Such protection will be provided for the
   following authorized and unlicensed services: digital television
   stations, digital and analog Class A, low power, translator and booster
   stations; translator receive operations; fixed broadcast auxiliary
   service links; private land mobile service/commercial radio service
   (PLMRS/CMRS) operations; offshore radiotelephone service; low power
   auxiliary services authorized pursuant to § § 74.801 through 74.882 of
   this chapter, including wireless microphones and MVPD receive sites;
   and unlicensed wireless microphones used by venues of large events and
   productions/shows as provided under § 15.713(h)(8). In addition,
   protection shall be provided in border areas near Canada and Mexico in
   accordance with § 15.712(g).

   (b) Geo-location and database access requirements. (1) The geographic
   coordinates of a fixed TVBD shall be determined to an accuracy of +-50
   meters by either an incorporated geo-location capability or a
   professional installer. In the case of professional installation, the
   party who registers the fixed TVBD in the database will be responsible
   for assuring the accuracy of the entered coordinates. The geographic
   coordinates of a fixed TVBD shall be determined at the time of
   installation and first activation from a power-off condition, and this
   information may be stored internally in the TVBD. If the fixed TVBD is
   moved to another location or if its stored coordinates become altered,
   the operator shall re-establish the device's:

   (i) Geographic location and store this information in the TVBD either
   by means of the device's incorporated geo-location capability or
   through the services of a professional installer; and

   (ii) Registration with the database based on the device's new
   coordinates.

   (2) A Mode II personal/portable device shall incorporate a geo-location
   capability to determine its geographic coordinates to an accuracy of
   +-50 meters. A Mode II device must also re-establish its position each
   time it is activated from a power-off condition and use its
   geo-location capability to check its location at least once every 60
   seconds while in operation, except while in sleep mode, i.e., in a mode
   in which the device is inactive but is not powered-down.

   (3)(i) Fixed devices must access a TV bands database over the Internet
   to determine the TV channels that are available at their geographic
   coordinates, taking into consideration the fixed device's antenna
   height, prior to their initial service transmission at a given
   location. Operation is permitted only on channels that are indicated in
   the database as being available for such TVBDs. Fixed TVBDs shall
   access the database at least once a day to verify that the operating
   channels continue to remain available. Operation on a channel must
   cease immediately if the database indicates that the channel is no
   longer available. Fixed TVBD must adjust their use of channels in
   accordance with channel availability schedule information provided by
   their database for the 48-hour period beginning at the time of the
   device last accessed the database for a list of available channels.

   (ii) Mode II personal/portable devices must access a TV bands database
   over the Internet to determine the TV channels that are available at
   their geographic coordinates prior to their initial service
   transmission at a given location. Operation is permitted only on
   channels that are indicated in the database as being available for
   personal/portable TVBDs. A Mode II personal/portable device must access
   the database for a list of available channels each time it is activated
   from a power-off condition and re-check its location and the database
   for available channels if it changes location during operation by more
   than 100 meters from the location at which it last accessed the
   database. A Mode II personal/portable device that has been in a powered
   state shall re-check its location and access the database daily to
   verify that the operating channel(s) continue to be available. Mode II
   personal/portable devices must adjust their use of channels in
   accordance with channel availability schedule information provided by
   their database for the 48-hour period beginning at the time of the
   device last accessed the database for a list of available channels. A
   Mode II personal/portable device may load channel availability
   information for multiple locations around, i.e., in the vicinity of,
   its current location and use that information in its operation. A Mode
   II TVBD may use such available channel information to define a
   geographic area within which it can operate on the same available
   channels at all locations, for example a Mode II TVBD could calculate a
   bounded area in which a channel or channels are available at all
   locations within the area and operate on a mobile basis within that
   area. A Mode II TVBD using such channel availability information for
   multiple locations must contact the database again if/when it moves
   beyond the boundary of the area where the channel availability data is
   valid, and must access the database daily even if it has not moved
   beyond that range to verify that the operating channel(s) continue to
   be available. Operation must cease immediately if the database
   indicates that the channel is no longer available.

   (iii) If a fixed or Mode II personal/portable TVBD fails to
   successfully contact the TV bands database during any given day, it may
   continue to operate until 11:59 p.m. of the following day at which time
   it must cease operations until it re-establishes contact with the TV
   bands database and re-verifies its list of available channels.

   (iv)(A) A Mode I personal/portable TVBD may only transmit upon
   receiving a list of available channels from a fixed or Mode II TVBD. A
   fixed or Mode II device may provide a Mode I device with a list of
   available channels only after it contacts its database, provides the
   database the FCC Identifier (FCC ID) of the Mode I device requesting
   available channels, and receives verification that the FCC ID is valid
   for operation.

   (B) A Mode II device must provide a list of channels to the Mode I
   device that is the same as the list of channels available to the Mode
   II device.

   (C) A fixed device may provide a list of available channels to a Mode I
   device only if the fixed device HAAT as verified by the TV bands
   database does not exceed 106 meters. The fixed device must provide a
   list of available channels to the Mode I device that is the same as the
   list of channels available to the fixed device, except that a Mode I
   device may operate only on those channels that are permissible for its
   use under § 15.707. A fixed device may also obtain from a database a
   separate list of available channels that includes adjacent channels
   that would be available to a Mode I personal/portable device and
   provide that list to the Mode I device.

   (D) To initiate contact with a fixed or Mode II device, a Mode I device
   may transmit on an available channel used by the fixed or Mode II TVBD
   or on a channel the fixed or Mode II TVBD indicates is available for
   use by a Mode I device on a signal seeking such contacts. At least once
   every 60 seconds, except when in sleep mode, i.e., a mode in which the
   device is inactive but is not powered-down, a Mode I device must either
   receive a contact verification signal from the Mode II or fixed device
   that provided its current list of available channels or contact a Mode
   II or fixed device to re-verify/re-establish channel availability. A
   Mode I device must cease operation immediately if it does not receive a
   contact verification signal or is not able to re-establish a list of
   available channels through contact with a fixed or Mode II device on
   this schedule. In addition, a Mode II device must re-check/re-establish
   contact with a fixed or Mode II device to obtain a list of available
   channels if it loses power. Collaterally, if a Mode II device loses
   power and obtains a new channel list, it must signal all Mode I devices
   it is serving to acquire and use a new channel list.

   (v) Device manufacturers and database administrators may implement a
   system that pushes updated channel availability information from the
   database to TVBDs. However, the use of such systems is not mandatory,
   and the requirements for TVBDs to validate the operating channel at
   least daily and to cease operation in accordance with paragraph
   (b)(3)(iii) of this section continue to apply if such a system is used.

   (vi) TV bands devices shall incorporate adequate security measures to
   ensure that they are capable of communicating for purposes of obtaining
   lists of available channels only with databases operated by
   administrators authorized by the Commission, and to ensure that
   communications between TV bands devices and databases between TV bands
   devices are secure to prevent corruption or unauthorized interception
   of data. This requirement includes implementing security for
   communications between Mode I personal portable devices and fixed or
   Mode II devices for purposes of providing lists of available channels.

   (4) All geographic coordinates shall be referenced to the North
   American Datum of 1983 (NAD 83).

   (c) Display of available channels. A TVBD must incorporate the
   capability to display a list of identified available channels and its
   operating channels.

   (d) Identifying information. Fixed TVBDs shall transmit identifying
   information. The identification signal must conform to a standard
   established by a recognized industry standards setting organization.
   The identification signal shall carry sufficient information to
   identify the device and its geographic coordinates.

   (e) Fixed devices without a direct connection to the Internet. If a
   fixed TVBD does not have a direct connection to the Internet and has
   not yet been initialized and registered with the TV bands database
   consistent with § 15.713, but can receive the transmissions of another
   fixed TVBD, the fixed TVBD needing initialization may transmit to that
   other fixed TVBD on either a channel that the other TVBD has
   transmitted on or on a channel which the other TVBD indicates is
   available for use to access the database to register its location and
   receive a list of channels that are available for it to use.
   Subsequently, the newly registered TVBD must only use the television
   channels that the database indicates are available for it to use. A
   fixed device may not obtain lists of available channels from another
   fixed device as provided by a TV bands database for such other device,
   i.e., a fixed device may not simply operate on the list of available
   channels provided by a TV bands database for another fixed device with
   which it communicates but must contact a database to obtain a list of
   available channels on which it may operate.

   (f) Security. (1) For purposes of obtaining a list of available
   channels and related matters, fixed and Mode II TVBDs shall only be
   capable of contacting databases operated by FCC designated
   administrators.

   (2) Communications between TV bands devices and TV bands databases are
   to be transmitted using secure methods that ensure against corruption
   or unauthorized modification of the data; this requirement applies to
   communications of channel availability and other spectrum access
   information between fixed and Mode II devices (it is not necessary for
   TVBDs to apply security coding to channel availability and channel
   access information where they are not the originating or terminating
   device and that they simply pass through).

   (3) Communications between a Mode I device and a fixed or Mode II
   device for purposes of obtaining a list of available channels shall
   employ secure methods that ensure against corruption or unauthorized
   modification of the data. When a Mode I device makes a request to a
   fixed or Mode II device for a list of available channels the receiving
   device shall check with the TV bands database that the Mode I device
   has a valid FCC Identifier before providing a list of available
   channels. Contact verification signals transmitted for Mode I devices
   are to be encoded with encryption to secure the identity of the
   transmitting device. Mode I devices using contact verification signals
   shall accept as valid for authorization only the signals of the device
   from which they obtained their list of available channels.

   (4) A TV bands database shall be protected from unauthorized data input
   or alteration of stored data. To provide this protection, the
   administrator of the TV bands database administrator shall establish
   communications authentication procedures that allow the fixed or Mode
   II devices to be assured that the data they receive is from an
   authorized source.

   (5) Applications for certification of TV bands devices are to include a
   high level operational description of the technologies and measures
   that are incorporated in the device to comply with the security
   requirements of this section. In addition, applications for
   certification of fixed and Mode II devices are to identify at least one
   of the TV bands databases operated by a designated TV bands database
   administrator that the device will access for channel availability and
   affirm that the device will conform to the communications security
   methods used by that database.

   (g) A personal/portable TVBD operating in Mode I may only transmit upon
   receiving the transmissions of fixed or Mode II TVBD. A
   personal/portable device operating in Mode I may transmit on either an
   operating channel of the fixed or Mode II TVBD or on a channel the
   fixed or Mode II TVBD indicates is available for use.

   [ 74 FR 7326 , Feb. 17, 2009, as amended at  75 FR 75837 , Dec. 6, 2010;  77 FR 29245 , May 17, 2012]

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