#### § 25.218 Off-axis EIRP density envelopes for FSS earth stations transmitting in certain frequency bands.

(a) *Applicability.* This section applies to applications for fixed and temporary-fixed FSS earth stations transmitting to geostationary space stations in the conventional C-band, extended C-band, conventional Ku-band, extended Ku-band, conventional Ka-band, extended Ka-band, or 24.75-25.25 GHz, and applications for ESIMs transmitting in the conventional C-band, conventional Ku-band, conventional Ka-band, except for applications proposing transmission of analog command signals at a band edge with bandwidths greater than 1 MHz or transmission of any other type of analog signal with bandwidths greater than 200 kHz.

(b) *Routine processing.* Earth station applications subject to this section may be routinely processed if they meet the applicable off-axis EIRP density envelopes set forth in this section.

(c) *Analog earth station operation in the conventional or extended C-bands.*

(1) For co-polarized transmissions in the plane tangent to the GSO arc, as defined in § 25.103:

| 29.5-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |
| 8.5 | dBW/4 kHz | for 7° < θ ≤ 9.2°. |
| 32.5-25log10θ | dBW/4 kHz | for 9.2° < θ ≤ 48°. |
| −9.5 | dBW/4 kHz | for 48° < θ ≤ 180°. |

Where θ is the angle in degrees from a line from the earth station antenna to the assigned orbital location of the target satellite. The EIRP density levels specified for θ > 7° may be exceeded by up to 3 dB in up to 10% of the range of theta (θ) angles from ±7-180°, and by up to 6 dB in the region of main reflector spillover energy.

(2) For co-polarized transmissions in the plane perpendicular to the GSO arc, as defined in § 25.103:

| 32.5-25log10θ | dBW/4 kHz | for 3° ≤ θ ≤ 48°. |
| --- | --- | --- |
| −9.5 | dBW/4 kHz | for 48° < θ ≤ 180°. |

Where θ is as defined in paragraph (c)(1) of this section. These EIRP density levels may be exceeded by up to 6 dB in the region of main reflector spillover energy and in up to 10% of the range of θ angles not included in that region, on each side of the line from the earth station to the target satellite.

(3) For cross-polarized transmissions in the plane tangent to the GSO arc and in the plane perpendicular to the GSO arc:

| 19.5-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |

Where θ is as defined in paragraph (c)(1) of this section.

(d) *Digital earth station operation in the conventional or extended C-bands.*

(1) For co-polarized transmissions in the plane tangent to the GSO arc:

| 26.3-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |
| 5.3 | dBW/4 kHz | for 7° < θ ≤ 9.2°. |
| 29.3-25log10θ | dBW/4 kHz | for 9.2° < θ ≤ 48°. |
| −12.7 | dBW/4 kHz | for 48° < θ ≤ 180°. |

Where θ is as defined in paragraph (c)(1) of this section. The EIRP density levels specified for θ > 7° may be exceeded by up to 3 dB in up to 10% of the range of theta (θ) angles from ±7-180°, and by up to 6 dB in the region of main reflector spillover energy.

(2) For co-polarized transmissions in the plane perpendicular to the GSO arc:

| 29.3-25log10θ | dBW/4 kHz | for 3° ≤ θ ≤ 48°. |
| --- | --- | --- |
| −12.7 | dBW/4 kHz | for 48° < θ ≤ 180°. |

Where θ is as defined in paragraph (c)(1) of this section. These EIRP density levels may be exceeded by up to 6 dB in the region of main reflector spillover energy and in up to 10% of the range of θ angles not included in that region, on each side of the line from the earth station to the target satellite.

(3) For cross-polarized transmissions in the plane tangent to the GSO arc and in the plane perpendicular to the GSO arc:

| 16.3-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |

Where θ is as defined in paragraph (c)(1) of this section.

(4) A license application for earth station operation in a network using variable power density control of earth stations transmitting simultaneously in shared frequencies to the same target satellite receiving beam may be routinely processed if the applicant certifies that the aggregate off-axis EIRP density from all co-frequency earth stations transmitting simultaneously to the same target satellite receiving beam, not resulting from colliding data bursts transmitted pursuant to a contention protocol, will not exceed the off-axis EIRP density limits permissible for a single earth station, as specified in paragraphs (d)(1) through (d)(3) of this section.

(e) *Analog earth station operation in the conventional Ku-band.*

(1) For co-polarized transmissions in the plane tangent to the GSO arc:

| 21-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |
| 0 | dBW/4 kHz | for 7° < θ ≤ 9.2°. |
| 24-25log10θ | dBW/4 kHz | for 9.2° < θ ≤ 19.1°. |
| −8 | dBW/4 kHz | for 19.1° < θ ≤ 180°. |

Where θ is as defined in paragraph (c)(1) of this section. The EIRP density levels specified for θ > 7° may be exceeded by up to 3 dB in up to 10% of the range of theta (θ) angles from ±7-180°, and by up to 6 dB in the region of main reflector spillover energy.

(2) For co-polarized transmissions in the plane perpendicular to the GSO arc:

| 24-25log10θ | dBW/4 kHz | for 3° ≤ θ ≤ 19.1°. |
| --- | --- | --- |
| −8 | dBW/4 kHz | for 19.1° < θ ≤ 180°. |

Where θ is as defined in paragraph (c)(1) of this section. These EIRP density levels may be exceeded by up to 6 dB in the region of main reflector spillover energy and in up to 10% of the range of θ angles not included in that region, on each side of the line from the earth station to the target satellite.

(3) For cross-polarized transmissions in the plane tangent to the GSO arc and in the plane perpendicular to the GSO arc:

| 11-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |

Where θ is as defined in paragraph (c)(1) of this section.

(f) *Digital earth station operation in the conventional Ku-band.*

(1) For co-polarized transmissions in the plane tangent to the GSO arc:

| 15-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |
| −6 | dBW/4 kHz | for 7° < θ ≤ 9.2°. |
| 18-25log10θ | dBW/4 kHz | for 9.2° < θ ≤ 19.1°. |
| −14 | dBW/4 kHz | for 19.1° < θ ≤ 180°. |

Where θ is as defined in paragraph (c)(1) of this section. The EIRP density levels specified for θ > 7° may be exceeded by up to 3 dB in up to 10% of the range of theta (θ) angles from ±7-180°, and by up to 6 dB in the region of main reflector spillover energy.

(2) For co-polarized transmissions in the plane perpendicular to the GSO arc:

| 18-25log10θ | dBW/4 kHz | for 3° ≤ θ ≤ 19.1°. |
| --- | --- | --- |
| −14 | dBW/4 kHz | for 19.1° < θ ≤ 180°. |

Where θ is as defined in paragraph (c)(1) of this section. These EIRP density levels may be exceeded by up to 6 dB in the region of main reflector spillover energy and in up to 10% of the range of θ angles not included in that region, on each side of the line from the earth station to the target satellite.

(3) For cross-polarized transmissions in the plane tangent to the GSO arc and in the plane perpendicular to the GSO arc:

| 5-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |

Where θ is as defined in paragraph (c)(1) of this section.

(4) A license application for earth station operation in a network using variable power density control of earth stations transmitting simultaneously in shared frequencies to the same target satellite receiving beam may be routinely processed if the applicant certifies that the aggregate off-axis EIRP density from all co-frequency earth stations transmitting simultaneously to the same target satellite receiving beam, not resulting from colliding data bursts transmitted pursuant to a contention protocol, will not exceed the off-axis EIRP density limits permissible for a single earth station, as specified in paragraphs (f)(1) through -(f)(3) of this section.

(g) *Analog earth station operation in the extended Ku-band.*

(1) For co-polarized transmissions in the plane tangent to the GSO arc:

| 21-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |
| 0 | dBW/4 kHz | for 7° < θ ≤ 9.2°. |
| 24-25log10θ | dBW/4 kHz | for 9.2° < θ ≤ 48°. |
| −18 | dBW/4 kHz | for 48° < θ ≤ 180°. |

Where θ is as defined in paragraph (c)(1) of this section, and N is as defined in paragraph (d)(1) of this section. The EIRP density levels specified for θ > 7° may be exceeded by up to 3 dB in up to 10% of the range of theta (θ) angles from ±7-180°, and by up to 6 dB in the region of main reflector spillover energy.

(2) For co-polarized transmissions in the plane perpendicular to the GSO arc:

| 24-25log10θ | dBW/4 kHz | for 3° ≤ θ ≤ 48°. |
| --- | --- | --- |
| −18 | dBW/4 kHz | for 48° < θ ≤ 180°. |

Where θ is as defined in paragraph (c)(1) of this section. These EIRP density levels may be exceeded by up to 6 dB in the region of main reflector spillover energy and in up to 10% of the range of θ angles not included in that region, on each side of the line from the earth station to the target satellite.

(3) For cross-polarized transmissions in the plane tangent to the GSO arc and in the plane perpendicular to the GSO arc:

| 11-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |

Where θ is as defined in paragraph (c)(1) of this section.

(h) *Digital earth station operation in the extended Ku-band.*

(1) For co-polarized transmissions in the plane tangent to the GSO arc:

| 15-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |
| −6 | dBW/4 kHz | for 7° < θ ≤ 9.2°. |
| 18-25log10θ | dBW/4 kHz | for 9.2° < θ ≤ 48°. |
| −24 | dBW/4 kHz | for 48° < θ ≤ 180°. |

Where θ is as defined in paragraph (c)(1) of this section. The EIRP density levels specified for θ > 7° may be exceeded by up to 3 dB in up to 10% of the range of theta (θ) angles from ±7-180°, and by up to 6 dB in the region of main reflector spillover energy.

(2) For co-polarized transmissions in the plane perpendicular to the GSO arc:

| 18-25log10θ | dBW/4 kHz | for 3° ≤ θ ≤ 48°. |
| --- | --- | --- |
| −24 | dBW/4 kHz | for 48° < θ ≤ 85°. |

Where θ is as defined in paragraph (c)(1) of this section. These EIRP density levels may be exceeded by up to 6 dB in the region of main reflector spillover energy and in up to 10% of the range of θ angles not included in that region, on each side of the line from the earth station to the target satellite.

(3) For cross-polarized transmissions in the plane tangent to the GSO arc and in the plane perpendicular to the GSO arc:

| 5-25log10θ | dBW/4 kHz | for 1.5° ≤ θ ≤ 7°. |
| --- | --- | --- |

Where θ is as defined in paragraph (c)(1) of this section.

(4) A license application for earth station operation in a network using variable power density control of earth stations transmitting simultaneously in shared frequencies to the same target satellite receiving beam may be routinely processed if the applicant certifies that the aggregate off-axis EIRP density from all co-frequency earth stations transmitting simultaneously to the same target satellite receiving beam, not resulting from colliding data bursts transmitted pursuant to a contention protocol, will not exceed the off-axis EIRP density limits permissible for a single earth station, as specified in paragraphs (h)(1) through (h)(3) of this section.

(i) *Digital earth station operation in the conventional or extended Ka-band.*

(1) For co-polarized transmissions in the plane tangent to the GSO arc:

| | | | |
| --- | --- | --- | --- |
| 32.5-25log(θ) | dBW/MHz | for | 2.0° ≤ θ ≤ 7°. |
| 11.5 | dBW/MHz | for | 7° ≤ θ ≤ 9.2°. |
| 35.5-25log(θ) | dBW/MHz | for | 9.2° ≤ θ ≤ 19.1°. |
| 3.5 | dBW/MHz | for | 19.1° < θ ≤ 180°. |

where θ is as defined in paragraph (c)(1) of this section.

(2) For co-polarized transmissions in the plane perpendicular to the GSO arc:

| 35.5-25log(θ) | dBW/MHz | for | 3.5° ≤ θ ≤ 7°. |
| --- | --- | --- | --- |
| 14.4 | dBW/MHz | for | 7° < θ ≤ 9.2°. |
| 38.5-25log(θ) | dBW/MHz | for | 9.2° < θ ≤ 19.1°. |
| 6.5 | dBW/MHz | for | 19.1° < θ ≤ 180°. |

where θ is as defined in paragraph (c)(1) of this section.

(3) The EIRP density levels specified in paragraphs (i)(1) and (2) of this section may be exceeded by up to 3 dB, for values of θ > 7°, over 10% of the range of theta (θ) angles from 7-180° on each side of the line from the earth station to the target satellite.

(4) For cross-polarized transmissions in the plane tangent to the GSO arc and in the plane perpendicular to the GSO arc:

| 22.5-25log(θ) | dBW/MHz | for | 2.0° < θ ≤ 7.0°. |
| --- | --- | --- | --- |

where θ is as defined in paragraph (c)(1) of this section.

(5) A license application for earth station operation in a network using variable power density control of earth stations transmitting simultaneously in shared frequencies to the same target satellite receiving beam may be routinely processed if the applicant certifies that the aggregate off-axis EIRP density from all co-frequency earth stations transmitting simultaneously to the same target satellite receiving beam, not resulting from colliding data bursts transmitted pursuant to a contention protocol, will not exceed the off-axis EIRP density limits permissible for a single earth station, as specified in paragraphs (i)(1) through (4) of this section.

(j) *Non-qualifying applications.* Applications for authority for fixed earth station operation in the conventional C-band, extended C-band, conventional Ku-band, extended Ku-band, conventional Ka-band, extended Ka-band, or 24.75-25.25 GHz, that do not qualify for routine processing under relevant criteria in this section, § 25.211, or § 25.212 are subject to the requirements in § 25.220.

[81 FR 55339, Aug. 18, 2016, as amended at 84 FR 53656, Oct. 8, 2019; 85 FR 44787, July 24, 2020; 87 FR 72407, Nov. 25, 2022]