§ 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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