Sec.  74.936   Emissions and bandwidth.

   

   (a) An ITFS station may employ amplitude modulation (C3F) for the
   transmission of the visual signal and frequency modulation (F3E) or
   (G3E) for the transmission of the aural signal when transmitting a
   standard analog television signal. Quadrature amplitude modulation
   (QAM), digital vestigial sideband modulation (VSB), quadrature phase
   shift key modulation (QPSK), code division multiple access (CDMA) and
   orthogonal frequency division multiplex (OFDM) emissions may be
   employed, subject to compliance with the policies set forth in the
   Declaratory Ruling and Order, 11 FCC Rcd 18839 (1996). Use of OFDM
   also is subject to the subsequently Digital Declaratory Ruling and
   Order, DA 99-554 (Mass Med. Bur. rel. Mar. 19, 1999). Other digital
   emissions may be added to those authorized above, including emissions
   with non-uniform power spectral density, if the applicant provides
   information in accordance with the guidelines and procedures set forth
   in the Declaratory Ruling and Order which clearly demonstrates the
   spectral occupancy and interference characteristics of the emission.
   The licensee may subchannelize its authorized bandwidth, provided that
   digital modulation is employed and the aggregate power does not exceed
   the authorized power for the channel, and may utilize all or a portion
   of its authorized bandwidth for ITFS response stations authorized
   pursuant to Sec. 74.939. The licensee may also, jointly with affected
   adjacent channel licensees, transmit utilizing bandwidth in excess of
   its authorized frequencies, provided that digital modulation is
   employed, all power spectral density requirements set forth in this
   part are met and the out-of-band emissions restrictions set forth in
   Sec. 74.936 are met at the edges of the channels employed. The wider
   channels thus created may be redivided to create narrower channels.

   (b) Notwithstanding the above, any digital emission which complies
   with the out-of-band emission restrictions of Sec. 21.908 of this chapter
   may be used in the following circumstances:

   (1) At any ITFS main or booster station transmitter which is located
   more than 160.94 km (100 miles) from the nearest boundary of all
   cochannel and adjacent channel ITFS and MDS protected service areas,
   including Basic Trading Areas and Partitioned Service Areas; and

   (2) At all ITFS response station transmitters within a response
   service area if all points along the response service area boundary
   line are more than 160.94 km (100 miles) from the nearest boundary of
   all cochannel and adjacent channel ITFS and MDS protected service
   areas, including Basic Trading Areas and Partitioned Service Areas;
   and

   (3) At any ITFS transmitter where all parties entitled by this part to
   interference protection from that transmitter have mutually consented
   to the use at that transmitter of such emissions.

   (c) The maximum out-of-band power of an ITFS station transmitter or
   booster transmitting on a single 6 MHz channel with an EIRP in excess
   of -9 dBW employing analog modulation shall be attenuated at the
   channel edges by at least 38 dB relative to the peak visual carrier,
   then linearly sloping from that level to at least 60 dB of attenuation
   at 1 MHz below the lower band edge and 0.5 MHz above the upper band
   edge, and attenuated at least 60 dB at all other frequencies. The
   maximum out-of-band power of an ITFS station transmitter or booster
   transmitting on a single 6 MHz channel or a portion thereof with an
   EIRP in excess of -9 dBW (or, when subchannels are used, the
   appropriately adjusted value based upon the ratio of the
   channel-to-subchannel bandwidths) employing digital modulation shall
   be attenuated at the 6 MHz channel edges at least 25 dB relative to
   the licensed average 6 MHz channel power level, then attenuated along
   a linear slope to at least 40 dB at 250 kHz beyond the nearest channel
   edge, then attenuated along a linear slope from that level to at least
   60 dB at 3 MHz above the upper and below the lower licensed channel
   edges, and attenuated at least 60 dB at all other frequencies.
   Notwithstanding the foregoing, in situations where an ITFS station or
   booster station transmits, or where adjacent channel licensees jointly
   transmit, a single signal over more than one contiguous 6 MHz channel
   utilizing digital modulation with an EIRP in excess of -9 dBW (or,
   when subchannels or superchannels are used, the appropriately adjusted
   value based upon the ratio of 6 MHz to the subchannel or superchannel
   bandwidth), the maximum out-of-band power shall be attenuated at the
   channel edges of those combined channels at least 25 dB relative to
   the power level of each channel, then attenuated along a linear slope
   from that level to at least 40 dB at 250 kHz above or below the
   channel edges of those combined channels, then attenuated along a
   linear slope from that level to at least 60 dB at 3 MHz above the
   upper and below the lower edges of those combined channels, and
   attenuated at least 60 dB at all other frequencies. However, should
   harmful interference occur as a result of emissions outside the
   assigned channel, additional attenuation may be required. A
   transmitter licensed prior to November 1, 1991, that remains at the
   station site initially licensed, and does not comply with this
   paragraph, may continue to be used for its life if it does not cause
   harmful interference to the operation of any other licensee. Any
   non-conforming transmitter replaced after November 1, 1991, must be
   replaced by a transmitter meeting the requirements of this paragraph.

   (d) A booster transmitting on multiple contiguous or non-contiguous
   channels carrying separate signals (a "broadband" booster) with an
   EIRP in excess of -9 dBW per 6 MHz channel and employing analog,
   digital or a combination of these modulations shall have the following
   characteristics:

   (1) For broadband boosters operating in the frequency range of
   2.150-2.160/2 GHz, the maximum out-of-band power shall be attenuated
   at the upper and lower channel edges forming the band edges by at
   least 25 dB relative to the licensed analog peak visual carrier or
   digital average power level (or, when subchannels are used, the
   appropriately adjusted value based on upon the ratio of the
   channel-to-subchannel bandwidths), then linearly sloping from that
   level to at least 40 dB of attenuation at 0.25 MHz above and below the
   band edges, then linearly sloping from that level to at least 60 dB of
   attenuation at 3.0 MHz above and below the band edges, and attenuated
   at least 60 dB at all other frequencies.

   (2) For broadband boosters operating in the frequency range of
   2.500-2.690 GHz, the maximum out-of-band power shall be attenuated at
   the upper and lower channel edges forming the band edges by at least
   25 dB relative to the licensed analog peak visual carrier or digital
   average power level (or, when subchannels are used, the appropriately
   adjusted value based on upon the ratio of the channel-to-subchannel
   bandwidths), then linearly sloping from that level to at least 40 dB
   of attenuation at 0.25 MHz above and below the band edges, then
   linearly sloping from that level to at least 50 dB of attenuation at
   3.0 MHz above and below the band edges, then linearly sloping from
   that level to at least 60 dB of attenuation at 20 MHz above and below
   the band edges, and attenuated at least 60 dB at all other
   frequencies.

   (3) Within unoccupied channels in the frequency range of 2.500-2.690
   GHz, the maximum out-of-band power shall be attenuated at the upper
   and lower channel edges of an unoccupied channel by at least 25 dB
   relative to the licensed analog peak visual carrier power level or
   digital average power level of the occupied channels (or, when
   subchannels or 125 kHz channels are used, the appropriately adjusted
   value based upon the ratio of the channel-to-subchannel bandwidths),
   then linearly sloping from that level to at least 40 dB of attenuation
   at 0.25 MHz above and below the occupied channel edges, then linearly
   sloping from that level to at least 50 dB of attenuation at 3.0 MHz
   above and below the occupied channel edges, and attenuated at least 50
   dB at all other unoccupied frequencies.

   (e) Boosters operating with an EIRP less than -9 dBW per 6 MHz channel
   shall have no particular out-of-band power attenuation requirement,
   except that if they cause harmful interference, their operation shall
   be terminated within 2 hours of notification by the Commission until
   the interference can be cured.

   (f) The maximum out-of-band power of an ITFS response station using
   all or part of a 6 MHz channel, employing digital modulation and
   transmitting with an EIRP greater than -6 dBW per 6 MHz channel shall
   be attenuated (as measured in accordance with Sec. 21.908(e)) at the 6 MHz
   channel edges at least 25 dB relative to the average 6 MHz channel
   power level, then attenuated along a linear slope to at least 40 dB at
   250 kHz beyond the nearest channel edge, then attenuated along a
   linear slope from that level to at least 60 dB at 3 MHz above the
   upper and below the lower licensed channel edges, and attenuated at
   least 60 dB at all other frequencies. The maximum out-of-band power of
   an ITFS response station using all or part of a 6 MHz channel,
   employing digital modulation and transmitting with an EIRP no greater
   than -6 dBW per 6 MHz channel shall be attenuated (as measured in
   accordance with Sec. 21.908(e)) at the channel edges at least 25 dB
   relative to the average 6 MHz channel transmitter output power level
   (P), then attenuated along a linear slope to at least 40 dB or
   33+10log(P) dB, whichever is the lesser attenuation, at 250 kHz beyond
   the nearest channel edge, then attenuated along a linear slope from
   that level to at least 60 dB or 43+10log(P) dB, whichever is the
   lesser attenuation, at 3 MHz above the upper and below the lower
   licensed channel edges, and attenuated at least 60 dB or 43+10log(P)
   dB, whichever is the lesser attenuation, at all other frequencies.
   Where ITFS response stations with digital modulation utilize all or
   part of more than one contiguous 6 MHz channel to form a larger
   channel (e.g., a channel of width 12 MHz), the above-specified
   attenuations shall be applied only at the upper and lower edges of the
   overall combined channel. Notwithstanding these provisions, should
   harmful interference occur as a result of emissions outside the
   assigned channel(s), additional attenuation may be required by the
   Commission.

   (g) The requirements of Sec. 73.687(c)(2) will be considered to be
   satisfied insofar as measurements of operating power are concerned if
   the transmitter is equipped with instruments for determining the
   combined visual and aural operating power. However, licensees are
   expected to maintain the operating powers within the limits specified
   in Sec. 74.935. Measurements of the separate visual and aural operating
   powers must be made at sufficiently frequent intervals to insure
   compliance with the rules, and in no event less than once a month.
   However, the provisions of Sec. 73.687(c)(2) and of this paragraph shall
   not be applicable to ITFS response stations or to low power ITFS
   booster stations authorized pursuant to Sec. 74.985(e).

   (h) Compliance with the out-of-band emissions limitations shall be
   established in accordance with Sec. 21.908(e) of this chapter.

   [ 63 FR 65117 , Nov. 25, 1998, as amended at  64 FR 63740 , Nov. 22, 1999;
    65 FR 46622 , July 31, 2000]