Goto Section: 25.52 | 25.54

FCC 25.53
Revised as of May 5, 2005
Goto Year:2004 | 2006
Sec.  27.53   Emission limits.

   

   Link to an amendment published at  70 FR 21664 , Apr. 27, 2005.

   (a) For operations in the bands 2305-2320 MHz and 2345-2360 MHz, the
   power of any emission outside the licensee's frequency band(s) of
   operation shall be attenuated below the transmitter power (P) within
   the licensed band(s) of operation, measured in watts, by the following
   amounts:

   (1) For fixed, land, and radiolocation land stations: By a factor not
   less than 80 + 10 log (p) dB on all frequencies between 2320 and 2345
   MHz;

   (2) For mobile and radiolocation mobile stations: By a factor not less
   than 110 + 10 log (p) dB on all frequencies between 2320 and 2345 MHz;

   (3) For fixed, land, mobile, radiolocation land and radiolocation
   mobile stations: By a factor not less than 70 + 10 log (p) dB on all
   frequencies below 2300 MHz and on all frequencies above 2370 MHz; and
   not less than 43 + 10 log (p) dB on all frequencies between 2300 and
   2320 MHz and on all frequencies between 2345 and 2370 MHz that are
   outside the licensed bands of operation;

   (4) Compliance with these provisions is based on the use of
   measurement instrumentation employing a resolution bandwidth of 1 MHz
   or less, but at least one percent of the emission bandwidth of the
   fundamental emission of the transmitter, provided the measured energy
   is integrated over a 1 MHz bandwidth;

   (5) In complying with the requirements in Sec. 27.53(a)(1) and
   Sec. 27.53(a)(2), WCS equipment that uses opposite sense circular
   polarization from that used by Satellite DARS systems in the 2320-2345
   MHz band shall be permitted an allowance of 10 dB;

   (6) When measuring the emission limits, the nominal carrier frequency
   shall be adjusted as close to the edges, both upper and lower, of the
   licensee's bands of operation as the design permits;

   (7) The measurements of emission power can be expressed in peak or
   average values, provided they are expressed in the same parameters as
   the transmitter power;

   (8) Waiver requests of any of the out-of-band emission limits in
   paragraphs (a)(1) through (a)(7) of this section shall be entertained
   only if interference protection equivalent to that afforded by the
   limits is shown;

   (9) In the 2305-2315 MHz band, if portable devices comply with all of
   the following requirements, then paragraph (a)(2) of this section
   shall not apply to portable devices, which instead shall attenuate all
   emissions into the 2320-2345 MHz band by a factor of not less than 93
   + 10 log (p) dB:

   (i) The portable device has a duty cycle of 12.5% or less, with at
   most a 312.5 microsecond pulse every 2.5 milliseconds;

   (ii) The portable device must employ time division multiple access
   (TDMA) technology;

   (iii) The nominal peak transmit output power of the portable device is
   no more than 200 milliwatts (25 milliwatts average power);

   (iv) The portable device operates with the minimum power necessary for
   successful communications;

   (v) The nominal average base station transmit output power is no more
   than 800 milliwatts when the base station antennas is located at a
   height of at least 8 meters (26.25 feet) above the ground;

   (vi) Only fixed and portable devices and services may be provided:
   vehicle-mounted units are not permitted; and

   (vii) Transmitting antennas shall employ linear polarization or
   another polarization that provides equivalent of better discrimination
   with respect to a DARS antenna;

   (10) The out-of-band emissions limits in paragraphs (a)(1) through
   (a)(9) of this section may be modified by the private contractual
   agreement of all affected licensees, who shall maintain a copy of the
   agreement in their station files and disclose it to prospective
   assignees or transferees and, upon request, to the Commission.

   (b) For WCS Satellite DARS operations: The limits set forth in
   Sec. 25.202(f) of this chapter shall apply, except that Satellite DARS
   operations shall be limited to a maximum power flux density of -197
   dBW/m2/4 kHz in the 2370-2390 MHz band at Arecibo, Puerto Rico.

   (c) For operations in the 747 to 762 MHz band and the 777 to 792 MHz
   band, the power of any emission outside the licensee's frequency
   band(s) of operation shall be attenuated below the transmitter power
   (P) within the licensed band(s) of operation, measured in watts, in
   accordance with the following:

   (1) On any frequency outside the 747 to 762 MHz band, the power of any
   emission shall be attenuated outside the band below the transmitter
   power (P) by at least 43 + 10 log (P) dB;

   (2) On any frequency outside the 777 to 792 MHz band, the power of any
   emission shall be attenuated outside the band below the transmitter
   power (P) by at least 43 + 10 log (P) dB;

   (3) On all frequencies between 764 to 776 MHz and 794 to 806 MHz, by a
   factor not less than 76 + 10 log (P) dB in a 6.25 kHz band segment,
   for base and fixed stations;

   (4) On all frequencies between 764 to 776 MHz and 794 to 806 MHz, by a
   factor not less than 65 + 10 log (P) dB in a 6.25 kHz band segment,
   for mobile and portable stations;

   (5) Compliance with the provisions of paragraphs (c)(1) and (c)(2) of
   this section is based on the use of measurement instrumentation
   employing a resolution bandwidth of 100 kHz or greater. However, in
   the 100 kHz bands immediately outside and adjacent to the frequency
   block, a resolution bandwidth of at least 30 kHz may be employed;

   (6) Compliance with the provisions of paragraphs (c)(3) and (c)(4) of
   this section is based on the use of measurement instrumentation such
   that the reading taken with any resolution bandwidth setting should be
   adjusted to indicate spectral energy in a 6.25 kHz segment.

   (d) For operations in the 746-747 MHz, 762-764 MHz, 776-777 MHz, and
   792-794 MHz bands, transmitters must meet the following emission
   limitations:

   (1) The adjacent channel coupled power (ACCP) requirements for
   transmitters designed for various channel sizes are shown in the
   following tables. Mobile station requirements apply to handheld, car
   mounted and control station units. The tables specify a maximum value
   for the ACCP relative to maximum output power as a function of the
   displacement from the channel center frequency. In addition, the ACCP
   for a mobile station transmitter at the specified frequency
   displacement must not exceed the value shown in the tables. For
   transmitters that have power control, the latter ACCP requirement can
   be met at maximum power reduction. In the following charts, "(s)"
   means that a swept measurement is to be used.

                                  6.25 kHz Mobile Transmitter ACCP Requirements
-------------------------------------------------------------------------------
---------------------------------
                                                  Measurement
      Offset from center frequency (kHz)           bandwidth     Maximum ACCP
    Maximum ACCP absolute (dBm)
                                                     (kHz)      relative (dBc)
-------------------------------------------------------------------------------
---------------------------------
6.25..........................................            6.25             -40
 not specified
12.50.........................................            6.25             -60
 -45
18.75.........................................            6.25             -60
 -45
25.00.........................................            6.25             -65
 -50
37.50.........................................           25.00             -65
 -50
62.50.........................................           25.00             -65
 -50
87.50.........................................           25.00             -65
 -50
150.00........................................          100.00             -65
 -50
250.00........................................          100.00             -65
 -50
>400 to receive band.......................           30(s)             -75  -5
5
In the receive band...........................           30(s)            -100
 -70
-------------------------------------------------------------------------------
---------------------------------

                                  12.5 kHz Mobile Transmitter ACCP Requirements
-------------------------------------------------------------------------------
---------------------------------
                                                  Measurement
      Offset from center frequency (kHz)           bandwidth     Maximum ACCP
    Maximum ACCP absolute (dBm)
                                                     (kHz)      relative (dBc)
-------------------------------------------------------------------------------
---------------------------------
9.375.........................................            6.25             -40
 not specified
15.625........................................            6.25             -60
 -45
21.875........................................            6.25             -60
 -45
37.500........................................           25.00             -65
 -50
62.500........................................           25.00             -65
 -50
87.500........................................           25.00             -65
 -50
150.000.......................................          100.00             -65
 -50
250.000.......................................          100.00             -65
 -50
>400 to receive band.......................           30(s)             -75  -5
5
In the receive band...........................           30(s)            -100
 -70
-------------------------------------------------------------------------------
---------------------------------

                                   25 kHz Mobile Transmitter ACCP Requirements
-------------------------------------------------------------------------------
---------------------------------
                                                  Measurement
      Offset from center frequency (kHz)           bandwidth     Maximum ACCP
    Maximum ACCP absolute (dBm)
                                                     (kHz)      relative (dBc)
-------------------------------------------------------------------------------
---------------------------------
15.625........................................            6.25             -40
 not specified
21.875........................................            6.25             -60
 -45
37.500........................................           25.00             -65
 -50
62.500........................................           25.00             -65
 -50
87.500........................................           25.00             -65
 -50
150.000.......................................          100.00             -65
 -50
250.000.......................................          100.00             -65
 -50
>400 to receive band.......................           30(s)             -75  -5
5
In the receive band...........................           30(s)            -100
 -70
-------------------------------------------------------------------------------
---------------------------------

           150 kHz Mobile Transmitter ACCP Requirements 12.5 kHz Mobile Transmi
tter ACCP Requirements
-------------------------------------------------------------------------------
---------------------------------
                                                  Measurement
      Offset from center frequency (kHz)           bandwidth     Maximum ACCP
    Maximum ACCP absolute (dBm)
                                                     (kHz)      relative (dBc)
-------------------------------------------------------------------------------
---------------------------------
100...........................................              50             -40
 not specified
200...........................................              50             -50
 -35
300...........................................              50             -50
 -35
400...........................................              50             -50
 -35
600 to 1000...................................           30(s)             -60
 -45
1000 to receive band..........................           30(s)             -70
 -55
In the receive band...........................           30(s)            -100
 -75
-------------------------------------------------------------------------------
---------------------------------

                                   6.25 kHz Base Transmitter ACCP Requirements
-------------------------------------------------------------------------------
---------------------------------
                                                               Measurement
             Offset from center frequency (kHz)                 bandwidth
       Maximum ACCP (dBc)
                                                                  (kHz)
-------------------------------------------------------------------------------
---------------------------------
6.25.......................................................            6.25  -4
0
12.50......................................................            6.25  -6
0
18.75......................................................            6.25  -6
0
25.00......................................................            6.25  -6
5
37.50......................................................           25.00  -6
5
62.50......................................................           25.00  -6
5
87.50......................................................           25.00  -6
5
150.00.....................................................          100.00  -6
5
250.00.....................................................          100.00  -6
5
>400 to receive band....................................           30(s)  -80 (
continues @-6dB/oct)
In the receive band........................................           30(s)  -1
00
-------------------------------------------------------------------------------
---------------------------------

                                   12.5 kHz Base Transmitter ACCP Requirements
-------------------------------------------------------------------------------
---------------------------------
                                                               Measurement
             Offset from center frequency (kHz)                 bandwidth
       Maximum ACCP (dBc)
                                                                  (kHz)
-------------------------------------------------------------------------------
---------------------------------
9.375......................................................            6.25  -4
0
15.625.....................................................            6.25  -6
0
21.875.....................................................            6.25  -6
0
37.500.....................................................           25.00  -6
0
62.500.....................................................           25.00  -6
5
87.500.....................................................           25.00  -6
5
150.000....................................................          100.00  -6
5
250.000....................................................          100.00  -6
5
>400 to receive band....................................           30(s)  -80 (
continues @-6dB/oct)
In the receive band........................................           30(s)  -1
00
-------------------------------------------------------------------------------
---------------------------------

                                    25 kHz Base Transmitter ACCP Requirements
-------------------------------------------------------------------------------
---------------------------------
                                                               Measurement
             Offset from center frequency (kHz)                 bandwidth
       Maximum ACCP (dBc)
                                                                  (kHz)
-------------------------------------------------------------------------------
---------------------------------
15.625.....................................................            6.25  -4
0
21.875.....................................................            6.25  -6
0
37.500.....................................................           25.00  -6
0
62.500.....................................................           25.00  -6
5
87.500.....................................................           25.00  -6
5
150.000....................................................          100.00  -6
5
250.000....................................................          100.00  -6
5
>400 to receive band....................................           30(s)  -80 (
continues @-6dB/oct)
In the receive band........................................           30(s)  -1
00
-------------------------------------------------------------------------------
---------------------------------

                                   150 kHz Base Transmitter ACCP Requirements
-------------------------------------------------------------------------------
---------------------------------
                                                               Measurement
             Offset from center frequency (kHz)                 bandwidth
       Maximum ACCP (dBc)
                                                                  (kHz)
-------------------------------------------------------------------------------
---------------------------------
100........................................................              50  -4
0
200........................................................              50  -5
0
300........................................................              50  -5
5
400........................................................              50  -6
0
600 to 1000................................................           30(s)  -6
5
1000 to receive band.......................................           30(s)  -7
5 (continues @-6dB/oct)
In the receive band........................................           30(s)  -1
00
-------------------------------------------------------------------------------
---------------------------------

   (2) ACCP measurement procedure. The following procedures are to be
   followed for making ACCP transmitter measurements. For time division
   multiple access (TDMA) systems, the measurements are to be made under
   TDMA operation only during time slots when the transmitter is on. All
   measurements must be made at the input to the transmitter's antenna.
   Measurement bandwidth used below implies an instrument that measures
   the power in many narrow bandwidths (e.g. 300 Hz) and integrates these
   powers across a larger band to determine power in the measurement
   bandwidth.

   (i) Setting reference level: Using a spectrum analyzer capable of ACCP
   measurements, set the measurement bandwidth to the channel size. For
   example, for a 6.25 kHz transmitter, set the measurement bandwidth to
   6.25 kHz; for a 150 kHz transmitter, set the measurement bandwidth to
   150 kHz. Set the frequency offset of the measurement bandwidth to zero
   and adjust the center frequency of the spectrum analyzer to give the
   power level in the measurement bandwidth. Record this power level in
   dBm as the "reference power level".

   (ii) Measuring the power level at frequency offsets <600kHz: Using a
   spectrum analyzer capable of ACCP measurements, set the measurement
   bandwidth as shown in the tables above. Measure the ACCP in dBm. These
   measurements should be made at maximum power. Calculate the coupled
   power by subtracting the measurements made in this step from the
   reference power measured in the previous step. The absolute ACCP
   values must be less than the values given in the table for each
   condition above.

   (iii) Measuring the power level at frequency offsets >600kHz: Set a
   spectrum analyzer to 30 kHz resolution bandwidth, 1 MHz video
   bandwidth and sample mode detection. Sweep ±6 MHz from the carrier
   frequency. Set the reference level to the RMS value of the transmitter
   power and note the absolute power. The response at frequencies greater
   than 600 kHz must be less than the values in the tables above.

   (iv) Upper Power Limit Measurement: The absolute coupled power in dBm
   measured above must be compared to the table entry for each given
   frequency offset. For those mobile stations with power control, these
   measurements should be repeated with power control at maximum power
   reduction. The absolute ACCP at maximum power reduction must be less
   than the values in the tables above.

   (3) Out-of-band emission limit. On any frequency outside of the
   frequency ranges covered by the ACCP tables in this section, the power
   of any emission must be reduced below the unmodulated carrier power
   (P) by at least 43 + 10 log (P) dB.

   (4) Authorized bandwidth. Provided that the ACCP requirements of this
   section are met, applicants may request any authorized bandwidth that
   does not exceed the channel size.

   (e) For operations in the 746-764 MHz and 776-794 MHz bands, emissions
   in the band 1559-1610 MHz shall be limited to -70 dBW/MHz equivalent
   isotropically radiated power (EIRP) for wideband signals, and -80 dBW
   EIRP for discrete emissions of less than 700 Hz bandwidth. For the
   purpose of equipment authorization, a transmitter shall be tested with
   an antenna that is representative of the type that will be used with
   the equipment in normal operation.

   (f) For operations in the 698-746 MHz band, the power of any emission
   outside a licensee's frequency band(s) of operation shall be
   attenuated below the transmitter power (P) within the licensed band(s)
   of operation, measured in watts, by at least 43 + 10 log (P) dB.
   Compliance with this provision is based on the use of measurement
   instrumentation employing a resolution bandwidth of 100 kilohertz or
   greater. However, in the 100 kilohertz bands immediately outside and
   adjacent to a licensee's frequency block, a resolution bandwidth of at
   least 30 kHz may be employed.

   (g) For operations in the 1710-1755 MHz and 2110-2155 MHz bands, the
   power of any emission outside a licensee's frequency block shall be
   attenuated below the transmitter power (P) by at least 43 + 10 log[10]
   (P) dB.

   (1) Compliance with this provision is based on the use of measurement
   instrumentation employing a resolution bandwidth of 1 megahertz or
   greater. However, in the 1 megahertz bands immediately outside and
   adjacent to the licensee's frequency block, a resolution bandwidth of
   at least one percent of the emission bandwidth of the fundamental
   emission of the transmitter may be employed. The emission bandwidth is
   defined as the width of the signal between two points, one below the
   carrier center frequency and one above the carrier center frequency,
   outside of which all emissions are attenuated at least 26 dB below the
   transmitter power.

   (2) When measuring the emission limits, the nominal carrier frequency
   shall be adjusted as close to the licensee's frequency block edges,
   both upper and lower, as the design permits.

   (3) The measurements of emission power can be expressed in peak or
   average values, provided they are expressed in the same parameters as
   the transmitter power.

   (h) When an emission outside of the authorized bandwidth causes
   harmful interference, the Commission may, at its discretion, require
   greater attenuation than specified in this section.

   (i) For operations in the unpaired 1390-1392 MHz band and the paired
   1392-1395 MHz and 1432-1435 MHz bands, the power of any emission
   outside the licensee's frequency band(s) of operation shall be
   attenuated below the transmitter power (P) by at least 43 + 10 log (P)
   dB. Compliance with these provisions is based on the procedures
   described in paragraph (a)(4) of this section.

   (j) For operations in the 1670-1675 MHz band, the power of any
   emission outside the licensee's frequency band(s) of operation shall
   be attenuated below the transmitter power (P) by at least 43 + 10 log
   (P) dB. Compliance with these provisions is based on the procedures
   described in paragraph (a)(4) of this section.

   (k) [Reserved]

   (l) For BRS and EBS stations, the power of any emissions outside the
   licensee's frequency bands of operation shall be attenuated below the
   transmitter power (P) measured in watts.

   (1) Prior to the transition, and thereafter, solely within the MBS,
   for analog operations with an EIRP in excess of -9 dBW, the signal
   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.

   (2) For fixed and temporary fixed digital stations, the attenuation
   shall be not less than 43 + 10 log (P) dB, unless a documented
   interference complaint is received from an adjacent channel licensee.
   Provided that the complaint cannot be mutually resolved between the
   parties, both licensees of existing and new systems shall reduce their
   out-of-band emissions by at least 67 + 10 log (P) dB measured at 3 MHz
   from their channel's edges for distances between stations exceeding
   1.5 km. For stations separated by less than 1.5 km, the new licensee
   shall reduce attenuation at least 67 + 10 log (P) - 20 log(D[km]/1.5),
   or when colocated, limit the undesired signal level at the affected
   licensee's base station receiver(s) at the colocation site to no more
   than -107 dBm. Mobile Service Satellite licensees operating on
   frequencies below 2495 MHz may also submit a documented interference
   complaint against BRS licensees operating on channel BRS1 on the same
   terms and conditions as adjacent channel BRS or EBS licensees.

   (3) Prior to transition and thereafter solely within the MBS, and
   notwithstanding paragraph (l)(2) of this section, the maximum
   out-of-band power of a digital transmitter operating on a single 6 MHz
   channel with an EIRP in excess of -9 dBW employing digital modulation
   for the primary purpose of transmitting video programming 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.

   (4) For mobile digital stations, the attenuation factor shall be not
   less than 43 + 10 log (P) dB at the channel edge and 55 + 10 log (P)
   dB at 5.5 MHz from the channel edges. Mobile Service Satellite
   licensees operating on frequencies below 2495 MHz may also submit a
   documented interference complaint against BRS licensees operating on
   channel BRS1 on the same terms and conditions as adjacent channel BRS
   or EBS licensees.

   (5) Notwithstanding the provisions of paragraphs (l)(2) and (l)(4) of
   this section, prior to transition, a licensee may continue to operate
   facilities deployed as of January 10, 2005 provided that such
   facilities operate in compliance with the emission mask applicable to
   those services prior to January 10, 2005.

   (6) Measurement procedure. Compliance with these rules is based on the
   use of measurement instrumentation employing a resolution bandwidth of
   1 MHz or greater. However, in the 1 MHz bands immediately outside and
   adjacent to the frequency block a resolution bandwidth of at least one
   percent of the emission bandwidth of the fundamental emission of the
   transmitter may be employed. A narrower resolution bandwidth is
   permitted in all cases to improve measurement accuracy provided the
   measured power is integrated over the full required measurement
   bandwidth (i.e. 1 MHz or 1 percent of emission bandwidth, as
   specified). The emission bandwidth is defined as the width of the
   signal between two points, one below the carrier center frequency and
   one above the carrier center frequency, outside of which all emissions
   are attenuated at least 26 dB below the transmitter power. With
   respect to television operations, measurements must be made of the
   separate visual and aural operating powers at sufficiently frequent
   intervals to ensure compliance with the rules.

   (7) Alternative out of band emission limit. Licensees in this service
   may establish an alternative out of band emission limit to be used at
   specified band edge(s) in specified geographical areas, in lieu of
   that set forth in this section, pursuant to a private contractual
   arrangement of all affected licensees and applicants. In this event,
   each party to such contract shall maintain a copy of the contract in
   their station files and disclose it to prospective assignees or
   transferees and, upon request, to the FCC.

   (m) When an emission outside of the authorized bandwidth causes
   harmful interference, the Commission may, at its discretion, require
   greater attenuation than specified in this section.

   [ 62 FR 16497 , Apr. 7, 1997, as amended at  65 FR 3147 , Jan. 20, 2000;
    65 FR 17602 , Apr. 4, 2000;  65 FR 42883 , July 12, 2000;  67 FR 5511 ,
   Feb. 6, 2002;  67 FR 41855 , June 20, 2002;  69 FR 5715 , Feb. 6, 2004;  69 FR 72034 , Dec. 10, 2004;  69 FR 77950 , Dec. 29, 2004;  70 FR 1190 , Jan.
   6, 2005]


Goto Section: 25.52 | 25.54

Goto Year: 2004 | 2006
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