Section 27.1507 - Effective radiated power limits for 900 MHz broadband systems(a)Maximum ERP. The power limits specified in this section are applicable to operations in areas more than 110 km (68.4 miles) from the U.S./Mexico border and 140 km (87 miles) from the U.S./Canada border.(1)General limit.(i) The ERP for base and repeater stations must not exceed 400 watts/megahertz power spectral density (PSD) per sector and an antenna height of 304 m height above average terrain (HAAT), except that antenna heights greater than 304 m HAAT are permitted if power levels are reduced below 400 watts/megahertz ERP in accordance with Table 1 of this section.(ii) Provided that they also comply with paragraphs (b) and (c) of this section, licensees are permitted to operate base and repeater stations with up to a maximum ERP of 1000 watts/megahertz power spectral density (PSD) per sector and an antenna height of 304 m height above average terrain (HAAT), except that antenna heights greater than 304 m HAAT are permitted if power levels are reduced below 1000 watts/megahertz ERP in accordance with Table 2 of this section.(2)Rural areas. For systems that are located in counties with population densities of 100 persons or fewer per square mile, based upon the most recently available population statistics from the Bureau of the Census: (i) The ERP for base and repeater stations must not exceed 800 watts/megahertz power spectral density (PSD) per sector and an antenna height of 304 m height above average terrain (HAAT), except that antenna heights greater than 304 m HAAT are permitted if power levels are reduced below 800 watts/megahertz ERP in accordance with Table 3 of this section.(ii) Provided that they also comply with paragraphs (b) and (c) of this section, base and repeater stations may operate with up to a maximum ERP of 2000 watts/megahertz power spectral density (PSD) per sector and an antenna height of 304 m height above average terrain (HAAT), except that antenna heights greater than 304 m HAAT are permitted if power levels are reduced below 2000 watts/megahertz ERP in accordance with Table 4 of this section.(3)Mobile, control and auxiliary test stations. Mobile, control and auxiliary test stations must not exceed 10 watts ERP.(4)Portable stations. Portable stations must not exceed 3 watts ERP.(b)Power flux density (PFD). Each 900 MHz broadband base or repeater station that exceeds the ERP limit of paragraph (a)(1)(i) or (a)(2)(i) of this section must be designed and deployed so as not to exceed a modeled PFD of 3000 microwatts/m2/MHz over at least 98% of the area within 1 km of the base or repeater station antenna, at 1.6 meters above ground level. To ensure compliance with this requirement, the licensee must perform predictive modeling of the PFD values within at least 1 km of each base or repeater station antenna prior to commencing such operations and, thereafter, prior to making any site modifications that may increase the PFD levels around the base or repeater station. The modeling must take into consideration terrain and other local conditions and must use good engineering practices for the 900 MHz band.(c)Power measurement. Measurement of 900 MHz broadband base transmitter and repeater ERP must be made using an average power measurement technique. Power measurements for base transmitters and repeaters must be made in accordance with either of the following:(1) A Commission-approved average power technique (see FCC Laboratory's Knowledge Database); or(2) For purposes of this section, peak transmit power must be measured over an 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.(d)PAR limit. The peak-to-average ratio (PAR) of the transmission must not exceed 13 dB.(e)Height-power limit. As specified in paragraph (a) of this section, the following tables specify the maximum base station power for antenna heights above average terrain (HAAT) that exceed 304 meters. Table 1 to § 27.1507 -Permissible Power and Antenna Heights for Base Stations and Repeaters Permitted To Transmit With Up to 400 Watts/Megahertz
Antenna height (AAT)
in meters
(feet) | Effective radiated
power (ERP)
(watts/megahertz) |
| Above 1372 (4500) | 26 |
| Above 1220 (4000) To 1372 (4500) | 28 |
| Above 1067 (3500) To 1220 (4000) | 30 |
| Above 915 (3000) To 1067 (3500) | 40 |
| Above 763 (2500) To 915 (3000) | 56 |
| Above 610 (2000) To 763 (2500) | 80 |
| Above 458 (1500) To 610 (2000) | 140 |
| Above 305 (1000) To 458 (1500) | 240 |
| Up to 305 (1000) | 400 |
Table 2 to § 27.1507 -Permissible Power and Antenna Heights for Base Stations and Repeaters Permitted To Transmit With Up to 1000 Watts/Megahertz
Antenna height (AAT)
in meters
(feet) | Effective radiated
power (ERP)
(watts/megahertz) |
| 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 3 to § 27.1507 -Permissible Power and Antenna Heights for Base Stations and Repeaters Permitted To Transmit With Up to 800 Watts/Megahertz
Antenna height (AAT)
in meters
(feet) | Effective radiated
power (ERP)
(watts/megahertz) |
| Above 1372 (4500) | 52 |
| Above 1220 (4000) To 1372 (4500) | 56 |
| Above 1067 (3500) To 1220 (4000) | 60 |
| Above 915 (3000) To 1067 (3500) | 80 |
| Above 763 (2500) To 915 (3000) | 112 |
| Above 610 (2000) To 763 (2500) | 160 |
| Above 458 (1500) To 610 (2000) | 280 |
| Above 305 (1000) To 458 (1500) | 480 |
| Up to 305 (1000) | 800 |
Table 4 to § 27.1507 -Permissible Power and Antenna Heights for Base Stations and Repeaters Permitted To Transmit With Up to 2000 Watts/Megahertz
Antenna height (AAT)
in meters
(feet) | Effective radiated
power (ERP)
(watts/megahertz) |
| 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 |