Title 47: Telecommunication
PART 27—MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES
Subpart C—Technical Standards
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§ 27.53 Emission limits.
(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 §27.53(a)(1) and §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 §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 power (ACP) 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 value for the ACP as a function of the displacement from the channel center frequency and measurement bandwidth. In the following tables, “(s)” indicates a swept measurement may be used.
6.25 kHz Mobile Transmitter ACP Requirements------------------------------------------------------------------------ Measurement Offset from center frequency (kHz) bandwidth Maximum ACP (kHz) (dBc)------------------------------------------------------------------------6.25 6.25 -4012.5 6.25 -6018.75 6.25 -6025.00 6.25 -6537.50 25.00 -6562.50 25.00 -6587.50 25.00 -65150.00 100.00 -65250.00 100.00 -65350.00 100.00 -65>400 kHz to 12 MHz 30(s) -7512 MHz to paired receive band 30(s) -75In the paired receive band 30(s) -100------------------------------------------------------------------------
12.5 kHz Mobile Transmitter ACP Requirements------------------------------------------------------------------------ Measurement Offset from center frequency (kHz) bandwidth Maximum ACP (kHz) (dBc)------------------------------------------------------------------------9.375 6.25 -4015.625 6.25 -6021.875 6.25 -6037.50 25.00 -6062.50 25.00 -6587.50 25.00 -65150.00 100 -65250.00 100 -65350.00 100 -65>400 to 12 MHz 30(s) -7512 MHz to paired receive band 30(s) -75In the paired receive band 30(s) -100------------------------------------------------------------------------
25 kHz Mobile Transmitter ACP Requirements------------------------------------------------------------------------ Measurement Offset from center frequency (kHz) bandwidth Maximum ACP (kHz) (dBc)------------------------------------------------------------------------15.625 6.25 -4021.875 6.25 -6037.50 25 -6062.50 25 -6587.50 25 -65150.00 100 -65250.00 100 -65350.00 100 -65>400 kHz to 12 MHz 30(s) -7512 MHz to paired receive band 30(s) -75In the paired receive band 30(s) -100------------------------------------------------------------------------
150 kHz Mobile Transmitter ACP Requirements------------------------------------------------------------------------ Measurement Offset from center frequency (kHz) bandwidth Maximum ACP (kHz) relative (dBc)------------------------------------------------------------------------100 50 -40200 50 -50300 50 -50400 50 -50600-1000 30(s) -601000 to receive band 30(s) -70In the receive band 30(s) -100------------------------------------------------------------------------
6.25 kHz Base Transmitter ACP Requirements------------------------------------------------------------------------ Measurement Offset from center frequency (kHz) bandwidth Maximum ACP (kHz) (dBc)------------------------------------------------------------------------6.25 6.25 -4012.50 6.25 -6018.75 6.25 -6025.00 6.25 -6537.50 25 -6562.50 25 -6587.50 25 -65150.00 100 -65250.00 100 -65350.00 100 -65>400 kHz to 12 MHz 30(s) -8012 MHz to paired receive band 30(s) -80In the paired receive band 30(s) -100------------------------------------------------------------------------
12.5 kHz Base Transmitter ACP Requirements------------------------------------------------------------------------ Measurement Offset from center frequency (kHz) bandwidth Maximum ACP (kHz) (dBc)------------------------------------------------------------------------9.375 6.25 -4015.625 6.25 -6021.875 6.25 -6037.5 25 -6062.5 25 -6587.5 25 -65150 100 -65250 100 -65350.00 100 -65>400 kHz to 12 MHz 30(s) -8012 MHz to paired receive band 30(s) -80In the paired receive band 30(s) -100------------------------------------------------------------------------
25 kHz Base Transmitter ACP Requirements------------------------------------------------------------------------ Measurement Offset from center frequency (kHz) bandwidth Maximum ACP (kHz) (dBc)------------------------------------------------------------------------15.625 6.25 -4021.875 6.25 -6037.5 25 -6062.5 25 -6587.5 25 -65150 100 -65250 100 -65350 100.00 -65>400 kHz to 12 MHz 30(s) -8012 MHz to paired receive band 30(s) -80In the paired receive band 30(s) -100------------------------------------------------------------------------
150 kHz Base Transmitter ACP Requirements------------------------------------------------------------------------ Measurement Offset from center bandwidth Maximum ACP (dBc) frequency (kHz) (kHz)------------------------------------------------------------------------100 50 -40200 50 -50300 50 -55400 50 -60600-1000 30(s) -651000 to receive band 30(s) -75 (continues at -6dB/octIn the receive band 30(s) -100------------------------------------------------------------------------
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(2) ACP measurement procedure. The following procedures are to be followed for making ACP 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 ACP 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) Non-swept power measurement. Using a spectrum analyzer capable of ACP measurements, set the measurement bandwidth as shown in the tables above. Measure the ACP 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 ACP values must be less than the values given in the table for each condition above.
(iii) Swept power measurement. Set a spectrum analyzer to 30 kHz resolution bandwidth, 1 MHz video bandwidth and sample mode detection. Sweep ±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.
(3) Out-of-band emission limit. On any frequency outside of the frequency ranges covered by the ACP 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 ACP 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 log10 (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. BRS and EBS stations that are not in compliance with the standards below, after receiving a documented interference complaint from an adjacent channel licensee, have 60 days to coordinate with the affected licensee and meet a mutual resolution before both parties employ a more rigorous emission mask.
(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(Dkm/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 72033, Dec. 10, 2004; 69 FR 77950, Dec. 29, 2004; 70 FR 1190, Jan. 6, 2005; 70 FR 21664, Apr. 27, 2005; 71 FR 35190, June 19, 2006]
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