47 C.F.R. § 101.113

Current through September 30, 2024

Section 101.113 - Transmitter power limitations

(a) On any authorized frequency, the average power delivered to an antenna in this service must be the minimum amount of power necessary to carry out the communications desired. Application of this principle includes, but is not to be limited to, requiring a licensee who replaces one or more of its antennas with larger antennas to reduce its antenna input power by an amount appropriate to compensate for the increased primary lobe gain of the replacement antenna(s). In no event shall the average equivalent isotropically radiated power (EIRP), as referenced to an isotropic radiator, exceed the values specified below. In cases of harmful interference, the Commission may, after notice and opportunity for hearing, order a change in the effective radiated power of this station. Further, the output power of a transmitter on any authorized frequency in this service may not exceed the following:

Frequency band (MHz)	Maximum allowable EIRP^{1 2}
Frequency band (MHz)	Fixed^{1 2} (dBW)	Mobile (dBW)
928.0-929.0(2)	+ 17
932.0-932.5(2)	+ 17
932.5-935.0	+ 40
941.0-941.5(2)	+ 30	+ 14
941.5-944.0	+ 40
952.0-960.0(2)	+ 40	+ 14
1,850-1,990	+ 45
2,110-2,150	+ 45
2,150-2,180³	+ 45
2,180-2,200	+ 45
2,450-2,500	+ 45
2,500-2,686
2,686-2,690	+ 45
3,700-4,200	+ 55
5,925-6,425	+ 55
6,425-6,525		+ 35
6,525-6,875	+ 55
6,875-7,125	+ 55
10,550 to 10,600⁵	+ 55
10,600 to 10,680⁵	+ 40
10,700-11,700	+ 55
12,200-12,700¹¹	+ 50
12,700-13,200⁴	+ 50
13,200-13,250⁴	+ 55
14,200-14,400¹²	+ 45
17,700-18,600	+ 55
18,600-18,800⁶	+ 35
18,800-19,700	⁵ + 55
21,200-23,600¹⁰	+ 55
24,250-25,250	⁵+ 55
29,100-29,250	(⁷)
31,000 to 31,075^{8 9}	30 dBW/MHz	30 dBW/MHz
31,075 to 31,225^{8 9}	30 dBW/MHz	30 dBW/MHz
31,225 to 31,300^{8 9}	30 dBW/MHz	30 dBW/MHz
71,000-76,000 ¹³¹⁴	+55	+55
81,000-86,000 ¹³¹⁴	+55	+55
92,000-95,000	+ 55	+ 55

¹ Per polarization.

² For multiple address operations, see § 101.147 . Remote alarm units that are part of a multiple address central station projection system are authorized a maximum of 2 watts.

³ When an omnidirectional antenna is authorized in the 2150-2160 MHz band, the maximum power shall be 60 dBm.

⁴ Also see § 101.145 .

⁵ The output power of a DEMS System nodal transmitter shall not exceed 0.5 watt per 250 kHz. The output power of a DEMS System user transmitter shall not exceed 0.04 watt per 250 kHz. The transmitter power in terms of the watts specified is the peak envelope power of the emission measured at the associated antenna input port. The operating power shall not exceed the authorized power by more than 10 percent of the authorized power in watts at any time. Frequencies from 10,600-10,680 MHz are subject to footnote US265 in the Table of Frequency Allocations in § 2.106 of the Commission's Rules. Stations authorized prior to April 1, 2003 to exceed the 40 dBW limit may continue to operate at their authorized output power level indefinitely, provided that neither end point of the relevant link is relocated.

⁶ Maximum power delivered to the antenna shall not exceed -3 dBw.

⁷ See § 101.113(c) .

⁸ For stations authorized prior to March 11, 1997, and for non-Local Multipoint Distribution Service stations authorized pursuant to applications refiled no later than June 26, 1998, the transmitter output power shall not exceed 0.050 watt.

⁹ For subscriber transceivers authorized in these bands, the EIRP shall not exceed 55 dBw or 42 dBw/MHz.

¹⁰ See § 101.147(s) .

¹¹ The EIRP for MVDDS stations is limited to 14.0 dBm per 24 MHz (-16.0 dBW per 24 MHz). Incumbent point-to-point stations may use up to + 50 dBW except for low power systems which were licensed under § 101.147(q) .

¹² Beginning March 1, 2005, no new LTTS operators will be licensed and no existing LTTS licensees will be renewed in the 14.2-14.4 GHz band.

¹³ The maximum transmitter power is limited to 3 watts (5 dBW) unless a proportional reduction in maximum authorized EIRP is required under § 101.115 . The maximum transmitter power spectral density is limited to 150 mW per 100 MHz.

¹⁴ The EIRP limit for fixed and mobile stations used for aeronautical and maritime endpoints in motion is 57 dBW.

(b) The power of transmitters that use Automatic Transmitter Power Control shall not exceed the power input or output specified in the instrument of station authorization. The power of non-ATPC transmitters shall be maintained as near as practicable to the power input or output specified in the instrument of station authorization.

(c)

(1)Transmitter power limitations. Point-to-point stations in the 29.1-29.25 GHz band for the LMDS backbone between LMDS hubs shall be limited to a maximum allowable e.i.r.p. density per carrier of 23 dBW/MHz in any one megahertz in clear air, and may exceed this limit by employment of adaptive power control in cases where link propagation attenuation exceeds the clear air value due to precipitation and only to the extent that the link is impaired.

(2)Hub transmitter EIRP spectral area, density limit. LMDS applicants shall demonstrate that, under clear air operating conditions, the maximum aggregate of LMDS transmitting hub stations in a Basic Trading Area in the 29.1-29.25 GHz band will not transmit a co-frequency hub-to-subscriber e.i.r.p. spectral area density in any azimuthal direction in excess of X dBW/(MHz-km²) when averaged over any 4.375 MHz band, where X is defined in Table 1. Individual hub stations may exceed their clear air e.i.r.p.s by employment of adaptive power control in cases where link propagation attenuation exceeds the clear air value and only to the extent that the link is impaired.

(i) The e.i.r.p. aggregate spectral area density is calculated as follows:

View Image

where:

N = number of co-frequency hubs in BTA.

A = Area of BTA in km².

pi = spectral power density into antenna of i-th hub (in W/MHz).

gi = gain of i-th hub antenna at zero degree elevation angle.

Each pi and gi are in the same 1 MHz within the designated frequency band.

(ii) The climate zones in Table 1 are defined for different geographic locations within the US as shown in Appendix 28 of the ITU Radio Regulations.

Table 1¹

Climate zone	e.i.r.p. Spectral Density (Clear Air) (dBW/MHz-km²)²
1	-23
2	-25
3,4,5	-26

¹ LMDS system licensees in two or more BTAs may individually or collectively deviate from the spectral area density computed above by averaging the power over any 200 km by 400 km area, provided that the aggregate interference to the satellite receiver is no greater than if the spectral area density were as specified in Table 1. A showing to the Commission comparing both methods of computation is required and copies shall be served on any affected non-GSO 20/30 GHz MSS providers.

² See § 21.1007(c)(i) for the population density of the BTA.

(3)Hub transmitter e.i.r.p. spectral area density limit at elevation angles above the horizon. LMDS applicants shall demonstrate that, under clear air operating conditions, the maximum aggregate of LMDS transmitting hub stations in a Basic Trading Area in the 29.1-29.25 GHz band will not transmit a co-frequency hub-to-subscriber e.i.r.p. spectral area density in any azimuthal direction in excess of X dBW/(MHz-km²) when averaged over any 4.375 MHz band where X is defined in Table 2. Individual hub stations may exceed their clear air e.i.r.p.s by employment of adaptive power control in cases where link propagation attenuation exceeds the clear air value and only to the extent that the link is impaired.

(i) The e.i.r.p. aggregate spectral area density is calculated as follows:

View Image

where:

N = number of co-frequency hubs in BTA.

A = Area of BTA in km².

e.i.r.p. (ai) = equivalent isotropic radiated spectral power density of the i-th hub (in W/MHz) at elevation angle a where a is the angle in degrees of elevation above horizon. e.i.r.p.(0°) is the hub e.i.r.p. area density at the horizon used in Section 101.113c(2). The nominal antenna pattern will be used for elevation angles between 0° and 8°, and average levels will be used for angles beyond 8°, where average levels will be calculated by sampling the antenna patterns in each 1° interval between 8° and 9015, dividing by 83.

Table 2

Elevation angle (a)	Relative e.i.r.p. density (dBW/MHz-km²)
0° [LESS THAN EQUAL TO]a [LESS THAN EQUAL TO]4.0°	e.i.r.p.(a) = e.i.r.p.(0°) + 20 log (sin x)(1/ x) where x = (a + 1)/7.5°.
4.0° [LESS THAN]a [LESS THAN EQUAL TO]7.7°	e.i.r.p.(a) = e.i.r.p.(0°) - 3.85a + 7.7.
a [GREATER THAN]7.7°	e.i.r.p.(a) = e.i.r.p.(0°) - 22.

(ii) LMDS system licensees in two or more BTAs may individually or collectively deviate from the spectral area density computed above by averaging the power over any 200 km by 400 km area, provided that the aggregate interference to the satellite receiver is no greater than if the spectral area density were as specified in Table 1. A showing to the Commission comparing both methods of computation is required and copies shall be served on any affected non-GSO MSS providers.

(4)Power reduction techniques. LMDS hub transmitters shall employ methods to reduce average power levels received by non-geostationary mobile satellite receivers, to the extent necessary to comply with paragraphs (c)(1) and (c)(2) of this section, by employing the methods set forth below:

(i)Alternate polarizations. LMDS hub transmitters in the LMDS service area may employ both vertical and horizontal linear polarizations such that 50 percent (plus or minus 10 percent) of the hub transmitters shall employ vertical polarization and 50 percent (plus or minus 10 percent) shall employ horizontal polarization.

(ii)Frequency interleaving. LMDS hub transmitters in the LMDS service area may employ frequency interleaving such that 50 percent (plus or minus 10 percent) of the hub transmitters shall employ channel center frequencies which are different by one-half the channel bandwidth of the other 50 percent (plus or minus 10 percent) of the hub transmitters.

(iii)Alternative methods. As alternatives to paragraphs (c)(4)(i) and (c)(4)(ii) of this section, LMDS operators may employ such other methods as may be shown to achieve equivalent reductions in average power density received by non-GSO MSS satellite receivers.

47 C.F.R. §101.113

61 FR 26677, May 28, 1996

81 FR 79945, 12/14/2016; 89 FR 33259, 5/29/2024

For Federal Register citations affecting § 101.113, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.fdsys.gov.