25.252—Special requirements for ancillary terrestrial components operating in the 2000-2020 MHz/2180-2200 MHz bands.
(a)
Applicants for an ancillary terrestrial component in these bands must demonstrate that ATC base stations shall not:
(1)
Exceed an EIRP of −100.6 dBW/4 kHz for out-of-channel emissions at the edge of the MSS licensee's selected assignment.
(3)
Exceed an EIRP toward the physical horizon (not to include man-made structures) of 25.5 dBW in 1.23 MHz.
(4)
Be located less than 190 meters from all airport runways and aircraft stand areas, including takeoff and landing paths.
(5)
Exceed an aggregate power flux density of −51.8 dBW/m 2 in a 1.23 MHz bandwidth at all airport runways and aircraft stand areas, including takeoff and landing paths and all ATC base station antennas shall have an overhead gain suppression according to the following.
(6)
Be located less than 820 meters from a U.S. Earth Station facility operating in the 2200-2290 MHz band. In its MSS ATC application, the MSS licensee should request a list of operational stations in the 2200-2290 MHz band.
(7)
Generate EIRP density, averaged over any two millisecond active transmission interval, greater than -70 dBW/MHz in the 1559-1610 MHz band. The EIRP, measured over any two millisecond active transmission interval, of discrete out-of-band emissions of less than 700 Hz bandwidth from such base stations, shall not exceed -80 dBW in the 1559-1610 MHz band. A root-mean-square detector function with a resolution bandwidth of one megahertz or equivalent and no less video bandwidth shall be used to measure wideband EIRP density for purposes of this rule, and narrowband EIRP shall be measured with a root-mean-square detector function with a resolution bandwidth of one kilohertz or equivalent.
(8)
Use ATC base station antennas that have a gain greater than 17 dBi and must have an overhead gain suppression according to the following:
| Angle from direction of maximum gain, in vertical plane, above antenna (degrees) | Antenna discrimination pattern (dB) |
|---|---|
| 0 | Gmax |
| 2 | Not to Exceed Gmax −14 |
| 8 to 180 | Not to Exceed Gmax −25 |
| Where: Gmax is the maximum gain of the base station antenna in dBi. | |
(b)
Applicants for an ancillary terrestrial component in these bands must demonstrate that ATC mobile terminals shall:
(2)
Limit out-of-channel emissions at the edge of a MSS licensee's selected assignment to an EIRP density of −67 dBW/4 kHz.
(3)
Not generate EIRP density, averaged over any two-millisecond active transmission interval, greater than -70 dBW/MHz in the 1559-1610 MHz band. The EIRP, measured over any two-millisecond active transmission interval, of discrete out-of-band emissions of less than 700 Hz bandwidth from such mobile terminals shall not exceed -80 dBW in the 1559-1610 MHz band. The EIRP density of carrier-off-state emissions from such mobile terminals shall not exceed -80 dBW/MHz in the 1559-1610 MHz band, averaged over a two-millisecond interval. A root-mean-square detector function with a resolution bandwidth of one megahertz or equivalent and no less video bandwidth shall be used to measure wideband EIRP density for purposes of this rule, and narrowband EIRP shall be measured with a root-mean-square detector function with a resolution bandwidth of one kilohertz or equivalent.
(c)
For ATC operations in the 2000-2020 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 within the 2000 to 2020 MHz band outside the licensee's frequency band(s) of operations, emissions shall be attenuated by at least 43 10 log (P) dB.
(2)
Emissions on frequencies lower than 1995 MHz and higher than 2025 MHz shall be attenuated by at least 70 10 log P. Emissions in the bands 1995-2000 MHz and 2020-2025 MHz shall be attenuated by at least a value as determined by linear interpolation from 70 10 log P at 1995 MHz or 2025 MHz, to 43 10 log P dB at the nearest MSS band edge at 2000 MHz or 2020 MHz respectively.
(3)
When an emission outside of the authorized bandwidth causes harmful interference, the Commission may, in its discretion, require greater attenuation than specified in paragraphs (c)(1) and (2) of this section.
(4)
Compliance with these provisions is based on the use of measurement instrumentation employing a resolution bandwidth of 1 megahertz or greater.
Code of Federal Regulations
Code of Federal Regulations
277
[68 FR 33651, June 5, 2003, as amended at 70 FR 19318, Apr. 13, 2005]