§  27.50   Power limits and duty cycle.

   (a) The following power limits and related requirements apply to
   stations transmitting in the 2305-2320 MHz band or the 2345-2360 MHz
   band.

   (1) Base and fixed stations. (i) For base and fixed stations
   transmitting in the 2305-2315 MHz band or the 2350-2360 MHz band:

   (A) The average equivalent isotropically radiated power (EIRP) must not
   exceed 2,000 watts within any 5 megahertz of authorized bandwidth and
   must not exceed 400 watts within any 1 megahertz of authorized
   bandwidth.

   (B) The peak-to-average power ratio (PAPR) of the transmitter output
   power must not exceed 13 dB. The PAPR measurements should be made using
   either an instrument with complementary cumulative distribution
   function (CCDF) capabilities to determine that PAPR will not exceed 13
   dB for more than 0.1 percent of the time or other Commission approved
   procedure. The measurement must be performed using a signal
   corresponding to the highest PAPR expected during periods of continuous
   transmission.

   (ii) For base and fixed stations transmitting in the 2315-2320 MHz band
   or the 2345-2350 MHz band, the peak EIRP must not exceed 2,000 watts.

   (iii) Base stations supporting frequency division duplex (FDD) mobile
   and portable operations are restricted to transmitting in the 2345-2360
   MHz bands.

   (2) Fixed customer premises equipment stations. For fixed customer
   premises equipment (CPE) stations transmitting in the 2305-2320 MHz
   band or in the 2345-2360 MHz band, the peak EIRP must not exceed 20
   watts within any 5 megahertz of authorized bandwidth. Fixed CPE
   stations transmitting in the 2305-2320 MHz band or in the 2345-2360 MHz
   band must employ automatic transmit power control when operating so the
   stations operate with the minimum power necessary for successful
   communications. The use of outdoor antennas for CPE stations or outdoor
   CPE station installations operating with 2 watts per 5 megahertz or
   less average EIRP is prohibited. For WCS CPE using TDD technology, the
   duty cycle must not exceed 38 percent; for WCS CPE using FDD
   technology, the duty cycle must not exceed 12.5 percent in the
   2315-2320 MHz band, and must not exceed 25 percent in the 2305-2315 MHz
   band.

   (3) Mobile and portable stations. (i) For mobile and portable stations
   transmitting in the 2305-2317.5 MHz band or the 2347.5-2360 MHz band,
   the average EIRP must not exceed 250 milliwatts within any 5 megahertz
   of authorized bandwidth and must not exceed 50 milliwatts within any 1
   megahertz of authorized bandwidth. For mobile and portable stations
   using time division duplex (TDD) technology, the duty cycle must not
   exceed 38 percent in the 2305-2317.5 MHz and 2347.5-2360 MHz bands. For
   mobile and portable stations using frequency division duplex (FDD)
   technology, the duty cycle must not exceed 12.5 percent in the
   2315-2317.5 MHz band and must not exceed 25 percent in the 2305-2315
   MHz band. Mobile and portable stations using FDD technology are
   restricted to transmitting in the 2305-2317.5 MHz band. Power averaging
   shall not include intervals in which the transmitter is off.

   (ii) Mobile and portable stations are not permitted to operate in the
   2317.5-2320 MHz and 2345-2347.5 MHz bands.

   (iii) Automatic transmit power control. Mobile and portable stations
   transmitting in the 2305-2317.5 MHz band or in the 2347.5-2360 MHz band
   must employ automatic transmit power control when operating so the
   stations operate with the minimum power necessary for successful
   communications.

   (iv) Prohibition on external vehicle-mounted antennas. The use of
   external vehicle-mounted antennas for mobile and portable stations
   transmitting in the 2305-2317.5 MHz band or the 2347.5-2360 MHz band is
   prohibited.

   (b) The following power and antenna height limits apply to transmitters
   operating in the 746-763 MHz, 775-793 MHz and 805-806 MHz bands:

   (1) Fixed and base stations transmitting a signal in the 757-758 and
   775-776 MHz bands must not exceed an effective radiated power (ERP) of
   1000 watts and an antenna height of 305 m height above average terrain
   (HAAT), except that antenna heights greater than 305 m HAAT are
   permitted if power levels are reduced below 1000 watts ERP in
   accordance with Table 1 of this section.

   (2) Fixed and base stations transmitting a signal in the 746-757 MHz,
   758-763 MHz, 776-787 MHz, and 788-793 MHz bands with an emission
   bandwidth of 1 MHz or less must not exceed an ERP of 1000 watts and an
   antenna height of 305 m HAAT, except that antenna heights greater than
   305 m HAAT are permitted if power levels are reduced below 1000 watts
   ERP in accordance with Table 1 of this section.

   (3) Fixed and base stations located in a county with population density
   of 100 or fewer persons per square mile, based upon the most recently
   available population statistics from the Bureau of the Census, and
   transmitting a signal in the 746-757 MHz, 758-763 MHz, 776-787 MHz, and
   788-793 MHz bands with an emission bandwidth of 1 MHz or less must not
   exceed an ERP of 2000 watts and an antenna height of 305 m HAAT, except
   that antenna heights greater than 305 m HAAT are permitted if power
   levels are reduced below 2000 watts ERP in accordance with Table 2 of
   this section.

   (4) Fixed and base stations transmitting a signal in the 746-757 MHz,
   758-763 MHz, 776-787 MHz, and 788-793 MHz bands with an emission
   bandwidth greater than 1 MHz must not exceed an ERP of 1000 watts/MHz
   and an antenna height of 305 m HAAT, except that antenna heights
   greater than 305 m HAAT are permitted if power levels are reduced below
   1000 watts/MHz ERP accordance with Table 3 of this section.

   (5) Fixed and base stations located in a county with population density
   of 100 or fewer persons per square mile, based upon the most recently
   available population statistics from the Bureau of the Census, and
   transmitting a signal in the 746-757 MHz, 758-763 MHz, 776-787 MHz, and
   788-793 MHz bands with an emission bandwidth greater than 1 MHz must
   not exceed an ERP of 2000 watts/MHz and an antenna height of 305 m
   HAAT, except that antenna heights greater than 305 m HAAT are permitted
   if power levels are reduced below 2000 watts/MHz ERP in accordance with
   Table 4 of this section.

   (6) Licensees of fixed or base stations transmitting a signal in the
   746-757 MHz, 758-763 MHz, 776-787 MHz, and 788-793 MHz bands at an ERP
   greater than 1000 watts must comply with the provisions set forth in
   paragraph (b)(8) of this section and §  27.55(c).

   (7) Licensees seeking to operate a fixed or base station located in a
   county with population density of 100 or fewer persons per square mile,
   based upon the most recently available population statistics from the
   Bureau of the Census, and transmitting a signal in the 746-757 MHz,
   758-763 MHz, 776-787 MHz, and 788-793 MHz bands at an ERP greater than
   1000 watts must:

   (i) coordinate in advance with all licensees authorized to operate in
   the 698-763 MHz, 775-793, and 805-806 MHz bands within 120 kilometers
   (75 miles) of the base or fixed station;

   (ii) coordinate in advance with all regional planning committees, as
   identified in §  90.527 of this chapter, with jurisdiction within 120
   kilometers (75 miles) of the base or fixed station.

   (8) Licensees authorized to transmit in the 746-757 MHz, 758-763 MHz,
   776-787 MHz, and 788-793 MHz bands and intending to operate a base or
   fixed station at a power level permitted under the provisions of
   paragraph (b)(6) of this section must provide advanced notice of such
   operation to the Commission and to licensees authorized in their area
   of operation. Licensees who must be notified are all licensees
   authorized to operate in the 763-775 MHz and 793-805 MHz bands under
   part 90 of this chapter within 75 km of the base or fixed station and
   all regional planning committees, as identified in §  90.527 of this
   chapter, with jurisdiction within 75 km of the base or fixed station.
   Notifications must provide the location and operating parameters of the
   base or fixed station, including the station's ERP, antenna
   coordinates, antenna height above ground, and vertical antenna pattern,
   and such notifications must be provided at least 90 days prior to the
   commencement of station operation.

   (9) Control stations and mobile stations transmitting in the 746-757
   MHz, 758-763 MHz, 776-793 MHz, and 805-806 MHz bands and fixed stations
   transmitting in the 787-788 MHz and 805-806 MHz bands are limited to 30
   watts ERP.

   (10) Portable stations (hand-held devices) transmitting in the 746-757
   MHz, 758-763 MHz, 776-793 MHz, and 805-806 MHz bands are limited to 3
   watts ERP.

   (11) For transmissions in the 757-758, 775-776, 787-788, and 805-806
   MHz bands, maximum composite transmit power shall be measured over any
   interval of continuous transmission using instrumentation calibrated in
   terms of RMS-equivalent voltage. The measurement results shall be
   properly adjusted for any instrument limitations, such as detector
   response times, limited resolution bandwidth capability when compared
   to the emission bandwidth, etc., so as to obtain a true maximum
   composite measurement for the emission in question over the full
   bandwidth of the channel.

   (12) For transmissions in the 746-757, 758-763, 776-787, and 788-793
   MHz bands, licensees may employ equipment operating in compliance with
   either the measurement techniques described in paragraph (b)(11) of
   this section or a Commission-approved average power technique. In both
   instances, equipment employed must be authorized in accordance with the
   provisions of §  27.51.

   (c) The following power and antenna height requirements apply to
   stations transmitting in the 698-746 MHz band:

   (1) Fixed and base stations transmitting a signal with an emission
   bandwidth of 1 MHz or less must not exceed an effective radiated power
   (ERP) of 1000 watts and an antenna height of 305 m height above average
   terrain (HAAT), except that antenna heights greater than 305 m HAAT are
   permitted if power levels are reduced below 1000 watts ERP in
   accordance with Table 1 of this section;

   (2) Fixed and base stations located in a county with population density
   of 100 or fewer persons per square mile, based upon the most recently
   available population statistics from the Bureau of the Census, and
   transmitting a signal with an emission bandwidth of 1 MHz or less must
   not exceed an ERP of 2000 watts and an antenna height of 305 m HAAT,
   except that antenna heights greater than 305 m HAAT are permitted if
   power levels are reduced below 2000 watts ERP in accordance with Table
   2 of this section;

   (3) Fixed and base stations transmitting a signal with an emission
   bandwidth greater than 1 MHz must not exceed an ERP of 1000 watts/MHz
   and an antenna height of 305 m HAAT, except that antenna heights
   greater than 305 m HAAT are permitted if power levels are reduced below
   1000 watts/MHz ERP in accordance with Table 3 of this section;

   (4) Fixed and base stations located in a county with population density
   of 100 or fewer persons per square mile, based upon the most recently
   available population statistics from the Bureau of the Census, and
   transmitting a signal with an emission bandwidth greater than 1 MHz
   must not exceed an ERP of 2000 watts/MHz and an antenna height of 305 m
   HAAT, except that antenna heights greater than 305 m HAAT are permitted
   if power levels are reduced below 2000 watts/MHz ERP in accordance with
   Table 4 of this section;

   (5) Licensees seeking to operate a fixed or base station located in a
   county with population density of 100 or fewer persons per square mile,
   based upon the most recently available population statistics from the
   Bureau of the Census, and transmitting a signal at an ERP greater than
   1000 watts must:

   (i) coordinate in advance with all licensees authorized to operate in
   the 698-763 MHz, 775-793, and 805-806 MHz bands within 120 kilometers
   (75 miles) of the base or fixed station;

   (ii) coordinate in advance with all regional planning committees, as
   identified in § §  90.527 of this chapter, with jurisdiction within 120
   kilometers (75 miles) of the base or fixed station.

   (6) Licensees of fixed or base stations transmitting a signal at an ERP
   greater than 1000 watts and greater than 1000 watts/MHz must comply
   with the provisions of paragraph (c)(8) of this section and §  27.55(b),
   except that licensees of fixed or base stations located in a county
   with population density of 100 or fewer persons per square mile, based
   upon the most recently available population statistics from the Bureau
   of the Census, must comply with the provisions of paragraph (c)(8) of
   this section and §  27.55(b) only if transmitting a signal at an ERP
   greater than 2000 watts and greater than 2000 watts/MHz;

   (7) A licensee authorized to operate in the 710-716, 716-722, or
   740-746 MHz bands, or in any unpaired spectrum blocks within the
   698-746 MHz band, may operate a fixed or base station at an ERP up to a
   total of 50 kW within its authorized, 6 MHz spectrum block if the
   licensee complies with the provisions of §  27.55(b). The antenna height
   for such stations is limited only to the extent required to satisfy the
   requirements of §  27.55(b).

   (8) Licensees intending to operate a base or fixed station at a power
   level permitted under the provisions of paragraph (c)(6) of this
   section must provide advanced notice of such operation to the
   Commission and to licensees authorized in their area of operation.
   Licensees who must be notified are all licensees authorized under this
   part to operate on an adjacent spectrum block within 75 km of the base
   or fixed station. Notifications must provide the location and operating
   parameters of the base or fixed station, including the station's ERP,
   antenna coordinates, antenna height above ground, and vertical antenna
   pattern, and such notifications must be provided at least 90 days prior
   to the commencement of station operation.

   (9) Control and mobile stations are limited to 30 watts ERP;

   (10) Portable stations (hand-held devices) are limited to 3 watts ERP;
   and

   (11) Licensees may employ equipment operating in compliance with either
   the measurement techniques described in paragraph (b)(11) of this
   section or a Commission-approved average power technique. In both
   instances, equipment employed must be authorized in accordance with the
   provisions of §  27.51.

   (d) The following power and antenna height requirements apply to
   stations transmitting in the 1710-1755 MHz and 2110-2155 MHz bands:

   (1) The power of each fixed or base station transmitting in the
   2110-2155 MHz band and located in any county with population density of
   100 or fewer persons per square mile, based upon the most recently
   available population statistics from the Bureau of the Census, is
   limited to:

   (A) an equivalent isotropically radiated power (EIRP) of 3280 watts
   when transmitting with an emission bandwidth of 1 MHz or less;

   (B) an EIRP of 3280 watts/MHz when transmitting with an emission
   bandwidth greater than 1 MHz.

   (2) The power of each fixed or base station transmitting in the
   2110-2155 MHz band and situated in any geographic location other than
   that described in paragraph (d)(1) is limited to:

   (A) an equivalent isotropically radiated power (EIRP) of 1640 watts
   when transmitting with an emission bandwidth of 1 MHz or less;

   (B) an EIRP of 1640 watts/MHz when transmitting with an emission
   bandwidth greater than 1 MHz.

   (3) A licensee operating a base or fixed station in the 2110-2155 MHz
   band utilizing a power greater than 1640 watts EIRP and greater than
   1640 watts/MHz EIRP must coordinate such operations in advance with all
   Government and non-Government satellite entities in the 2025-2110 MHz
   band. Operations with power greater than 1640 watts EIRP and greater
   than 1640 watts/MHz EIRP must be coordinated in advance with the
   following licensees authorized to operate within 120 kilometers (75
   miles) of the base or fixed station operating in this band: all
   Broadband Radio Service (BRS) licensees authorized under part 27 in the
   2155-2160 MHz band and all advanced wireless services (AWS) licensees
   authorized to operate on adjacent frequency blocks in the 2110-2155 MHz
   band.

   (4) Fixed, mobile, and portable (hand-held) stations operating in the
   1710-1755 MHz band are limited to 1 watt EIRP. Fixed stations operating
   in this band are limited to a maximum antenna height of 10 meters above
   ground. Mobile and portable stations operating in this band must employ
   a means for limiting power to the minimum necessary for successful
   communications.

   (5) Equipment employed must be authorized in accordance with the
   provisions of §  24.51. Power measurements for transmissions by stations
   authorized under this section may be made either in accordance with a
   Commission-approved average power technique or in compliance with
   paragraph (d)(6) of this section. In measuring transmissions in this
   band using an average power technique, the peak-to-average ratio (PAR)
   of the transmission may not exceed 13 dB.

   (6) Peak transmit power must be measured over any interval of
   continuous transmission using instrumentation calibrated in terms of an
   rms-equivalent voltage. The measurement results shall be properly
   adjusted for any instrument limitations, such as detector response
   times, limited resolution bandwidth capability when compared to the
   emission bandwidth, sensitivity, etc., so as to obtain a true peak
   measurement for the emission in question over the full bandwidth of the
   channel.

   (e) The following power limits apply to the paired 1392-1395 MHz and
   1432-1435 MHz bands as well as the unpaired 1390-1392 MHz band (1.4 GHz
   band):

   (1) Fixed stations transmitting in the 1390-1392 MHz and 1432-1435 MHz
   bands are limited to 2000 watts EIRP peak power. Fixed stations
   transmitting in the 1392-1395 MHz band are limited to 100 watts EIRP
   peak power.

   (2) Mobile stations transmitting in the 1390-1392 MHz and 1432-1435 MHz
   bands are limited to 4 watts EIRP peak power. Mobile stations
   transmitting in the1392-1395 MHz band are limited to 1 watt EIRP peak
   power.

   (f) The following power limits apply to the 1670-1675 MHz band:

   (1) Fixed and base stations are limited to 2000 watts EIRP peak power.

   (2) Mobile stations are limited to 4 watts EIRP peak power.

   (g) [Reserved]

   (h) The following power limits shall apply in the BRS and EB§ 

   (1) Main, booster and base stations. (i) The maximum EIRP of a main,
   booster or base station shall not exceed 33 dBW + 10log(X/Y) dBW, where
   X is the actual channel width in MHz and Y is either 6 MHz if prior to
   transition or the station is in the MBS following transition or 5.5 MHz
   if the station is in the LBS and UBS following transition, except as
   provided in paragraph (h)(1)(ii) of this section.

   (ii) If a main or booster station sectorizes or otherwise uses one or
   more transmitting antennas with a non-omnidirectional horizontal plane
   radiation pattern, the maximum EIRP in dBW in a given direction shall
   be determined by the following formula: EIRP = 33 dBW + 10 log(X/Y) dBW
   + 10 log(360/beamwidth) dBW, where X is the actual channel width in
   MHz, Y is either (i) 6 MHz if prior to transition or the station is in
   the MBS following transition or (ii) 5.5 MHz if the station is in the
   LBS and UBS following transition, and beamwidth is the total horizontal
   plane beamwidth of the individual transmitting antenna for the station
   or any sector measured at the half-power points.

   (2) Mobile and other user stations. Mobile stations are limited to 2.0
   watts EIRP. All user stations are limited to 2.0 watts transmitter
   output power.

   (3) For television transmission, the peak power of the accompanying
   aural signal must not exceed 10 percent of the peak visual power of the
   transmitter. The Commission may order a reduction in aural signal power
   to diminish the potential for harmful interference.

   (4) For main, booster and response stations utilizing digital emissions
   with non-uniform power spectral density ( e.g. unfiltered QPSK), the
   power measured within any 100 kHz resolution bandwidth within the 6 MHz
   channel occupied by the non-uniform emission cannot exceed the power
   permitted within any 100 kHz resolution bandwidth within the 6 MHz
   channel if it were occupied by an emission with uniform power spectral
   density, i.e. , if the maximum permissible power of a station utilizing
   a perfectly uniform power spectral density across a 6 MHz channel were
   2000 watts EIRP, this would result in a maximum permissible power flux
   density for the station of 2000/60 = 33.3 watts EIRP per 100 kHz
   bandwidth. If a non-uniform emission were substituted at the station,
   station power would still be limited to a maximum of 33.3 watts EIRP
   within any 100 kHz segment of the 6 MHz channel, irrespective of the
   fact that this would result in a total 6 MHz channel power of less than
   2000 watts EIRP.

   (i) Peak transmit power shall be measured over any interval of
   continuous transmission using instrumentation calibrated in terms of
   rms-equivalent voltage. The measurement results shall be properly
   adjusted for any instrument limitations, such as detector response
   times, limited resolution bandwidth capability when compared to the
   emission bandwidth, etc., so as to obtain a true peak measurement for
   the emission in question over the full bandwidth of the channel.

   Table 1 to §  27.50—Permissible Power and Antenna Heights for Base and
   Fixed Stations in the 757-758 and 775-776 MHz Bands and for Base and
   Fixed Stations in the 698-757 MHz, 758-763 MHz, 776-787 MHz and 788-793
   MHz Bands Transmitting a Signal With an Emission Bandwidth of 1 MHz or
   Less
   Antenna height (AAT) in
   meters
   (feet) Effective radiated power (ERP)
   (watts)
          Above 1372 (4500)                  65
          Above 1220 (4000) To 1372 (4500)   70
          Above 1067 (3500) To 1220 (4000)   75
          Above 915 (3000) To 1067 (3500)   100
          Above 763 (2500) To 915 (3000)    140
          Above 610 (2000) To 763 (2500)    200
          Above 458 (1500) To 610 (2000)    350
          Above 305 (1000) To 458 (1500)    600
          Up to 305 (1000)                 1000

   Table 2 to §  27.50—Permissible Power and Antenna Heights for Base and
   Fixed Stations in the 698-757 MHz, 758-763 MHz, 776-787 MHz and 788-793
   MHz Bands Transmitting a Signal With an Emission Bandwidth of 1 MHz or
   Less
   Antenna height (AAT) in
   meters
   (feet) Effective radiated power (ERP)
   (watts)
          Above 1372 (4500)                 130
          Above 1220 (4000) To 1372 (4500)  140
          Above 1067 (3500) To 1220 (4000)  150
          Above 915 (3000) To 1067 (3500)   200
          Above 763 (2500) To 915 (3000)    280
          Above 610 (2000) To 763 (2500)    400
          Above 458 (1500) To 610 (2000)    700
          Above 305 (1000) To 458 (1500)   1200
          Up to 305 (1000)                 2000

   Table 3 to §  27.50—Permissible Power and Antenna Heights for Base and
   Fixed Stations in the 698-757 MHz, 758-763 MHz, 776-787 MHz and 788-793
   MHz Bands Transmitting a Signal With an Emission Bandwidth Greater than
   1 MHz
   Antenna height (AAT) in
   meters
   (feet) Effective radiated power (ERP) per MHz
   (watts/MHz)
          Above 1372 (4500)                       65
          Above 1220 (4000) To 1372 (4500)        70
          Above 1067 (3500) To 1220 (4000)        75
          Above 915 (3000) To 1067 (3500)        100
          Above 763 (2500) To 915 (3000)         140
          Above 610 (2000) To 763 (2500)         200
          Above 458 (1500) To 610 (2000)         350
          Above 305 (1000) To 458 (1500)         600
          Up to 305 (1000)                      1000

   Table 4 to §  27.50—Permissible Power and Antenna Heights for Base and
   Fixed Stations in the 698-757 MHz, 758-763 MHz, 776-787 MHz and 788-793
   MHz Bands Transmitting a Signal With an Emission Bandwidth Greater than
   1 MHz
   Antenna height (AAT) in
   meters
   (feet) Effective radiated power (ERP) per MHz
   (watts/MHz)
          Above 1372 (4500)                      130
          Above 1220 (4000) To 1372 (4500)       140
          Above 1067 (3500) To 1220 (4000)       150
          Above 915 (3000) To 1067 (3500)        200
          Above 763 (2500) To 915 (3000)         280
          Above 610 (2000) To 763 (2500)         400
          Above 458 (1500) To 610 (2000)         700
          Above 305 (1000) To 458 (1500)        1200
          Up to 305 (1000)                      2000

   [ 62 FR 16497 , Apr. 7, 1997]

   Editorial Note: For   Federal Register   citations affecting §  27.50,
   see the List of CFR Sections Affected, which appears in the Finding
   Aids section of the printed volume and at www.fdsys.gov .

   Effective Date Note: At  72 FR 27709 , May 16, 2007, §  27.50 was amended,
   in part, by revising paragraph (c). Paragraphs (c) (5) and (8) contain
   information collection and recordkeeping requirements and will not
   become effective until approval has been given by the Office of
   Management and Budget.

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