#### § 22.537 Technical channel assignment criteria.

The rules in this section establish technical assignment criteria for the channels listed in [§ 22.531](/on/2024-09-20/title-47/section-22.531). These criteria permit channel assignments to be made in a manner such that reception by public paging receivers of signals from base transmitters, within the service area of such base transmitters, is protected from interference caused by the operation of independent co-channel base transmitters.

(a) *Contour overlap.* The FCC may grant an application requesting assignment of a channel to a proposed base transmitter only if:

(1) The interfering contour of the proposed transmitter does not overlap the service contour of any protected co-channel transmitter controlled by a carrier other than the applicant, unless that carrier has agreed in writing to accept any interference that may result from operation of the proposed transmitter; and,

(2) The service contour of the proposed transmitter does not overlap the interfering contour of any protected co-channel transmitter controlled by a carrier other than the applicant, unless the applicant agrees to accept any interference that may result from operation of the protected co-channel transmitter; and,

(3) The area and/or population to which service would be provided by the proposed transmitter is substantial, and service gained would exceed that lost as a result of agreements to accept interference.

(b) *Protected transmitter.* For the purposes of this section, protected transmitters are authorized transmitters for which there is a current FCC public record and transmitters proposed in prior-filed pending applications.

(c) *VHF service contour.* For paging stations transmitting on the VHF channels, the distance from the transmitting antenna to the service contour along each cardinal radial is calculated as follows:

d = 1.243 × h0.40 × p0.20

where d is the radial distance in kilometers

h is the radial antenna HAAT in meters

p is the radial ERP in Watts

(1) Whenever the actual HAAT is less than 30 meters (98 feet), 30 must be used as the value for h in the above formula.

(2) The value used for p in the above formula must not be less than 27 dB less than the maximum ERP in any direction or 0.1 Watt, whichever is more.

(3) The distance from the transmitting antenna to the service contour along any radial other than the eight cardinal radials is routinely calculated by linear interpolation of distance as a function of angle. However, in resolving petitions to deny, the FCC may calculate the distance to the service contour using the formula in [paragraph (c)](/on/2024-09-20/title-47/section-22.537#p-22.537(c)) of this section with actual HAAT and ERP data for the inter-station radial and additional radials above and below the inter-station radial at 2.5° intervals.

(d) *VHF interfering contour.* For paging stations transmitting on the VHF channels, the distance from the transmitting antenna to the interfering contour along each cardinal radial is calculated as follows:

d = 6.509 × h0.28 × p0.17

where d is the radial distance in kilometers

h is the radial antenna HAAT in meters

p is the radial ERP in Watts

(1) Whenever the actual HAAT is less than 30 meters (98 feet), 30 must be used as the value for h in the above formula.

(2) The value used for p in the above formula must not be less than 27 dB less than the maximum ERP in any direction or 0.1 Watt, whichever is more.

(3) The distance from the transmitting antenna to the interfering contour along any radial other than the eight cardinal radials is routinely calculated by linear interpolation of distance as a function of angle. In resolving petitions to deny, however, the FCC may calculate the distance to the interfering contour using the formula in [paragraph (d)](/on/2024-09-20/title-47/section-22.537#p-22.537(d)) of this section with actual HAAT and ERP data for the inter-station radial and additional radials above and below the inter-station radial at 2.5° intervals.

(e) *931 MHz service contour.* For paging stations transmitting on the 931 MHz channels, the service contour is a circle, centered on the transmitting antenna, with a radius determined from Table E-1 of this section.

Table E—1-931 MHz Paging Service Radii

| Service radius km (miles) | Effective radiated power (Watts) | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| Antenna HAAT meters (feet) | 0-125 | 126-250 | 251-500 | 501-1000 | 1001-1860 | 1861-3500 |
| 0-177 | 32.2 (20) | 32.2 (20) | 32.2 (20) | 32.2 (20) | 32.2 (20) | 32.2 (20) |
| (0-581) | | | | | | |
| 178-305 | 32.2 (20) | 32.2 (20) | 32.2 (20) | 32.2 (20) | 37.0 (23) | 41.8 (26) |
| (582-1001) | | | | | | |
| 306-427 | 32.2 (20) | 32.2 (20) | 37.0 (23) | 41.8 (26) | 56.3 (35) | 56.3 (35) |
| (1002-1401) | | | | | | |
| 428-610 | 32.2 (20) | 37.0 (23) | 41.8 (26) | 56.3 (35) | 56.3 (35) | 56.3 (35) |
| (1402-2001) | | | | | | |
| 611-861 | 37.0 (23) | 41.8 (26) | 41.8 (26) | 56.3 (35) | 83.7 (52) | 83.7 (52) |
| (2002-2825) | | | | | | |
| 862-1219 | 41.8 (26) | 56.3 (35) | 56.3 (35) | 83.7 (52) | 83.7 (52) | 83.7 (52) |
| (2826-3999) | | | | | | |
| 1220 + | 56.3 (35) | 56.3 (35) | 83.7 (52) | 83.7 (52) | 83.7 (52) | 83.7 (52) |
| (4000 + ) | | | | | | |

(f) *931 MHz interfering contour.* For paging stations transmitting on the 931 MHz channels, the interfering contour is a circle, centered on the transmitting antenna, with a radius determined from Table E-2 of this section.

Table E—2-931 MHz Paging Interfering Radii

| Interfering radius km (miles) | Effective radiated power (Watts) | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| Antenna HAAT meters (feet) | 0-125 | 126-250 | 251-500 | 501-1000 | 1001-1860 | 1861-3500 |
| 0-177 | 80.5 (50) | 80.5 (50) | 80.5 (50) | 80.5 (50) | 80.5 (50) | 80.5 (50) |
| (0-581) | | | | | | |
| 178-305 | 80.5 (50) | 80.5 (50) | 80.5 (50) | 80.5 (50) | 88.5 (55) | 96.6 (60) |
| (582-1001) | | | | | | |
| 306-427 | 80.5 (50) | 80.5 (50) | 88.5 (55) | 96.6 (60) | 130.4 (81) | 130.4 (81) |
| (1002-1401) | | | | | | |
| 428-610 | 80.5 (50) | 88.5 (55) | 96.6 (60) | 130.4 (81) | 130.4 (81) | 130.4 (81) |
| (1402-2001) | | | | | | |
| 611-861 | 88.5 (55) | 96.6 (60) | 96.6 (60) | 130.4 (81) | 191.5 (119) | 191.5 (119) |
| (2002-2825) | | | | | | |
| 862-1219 | 96.6 (60) | 130.4 (81) | 130.4 (81) | 191.5 (119) | 191.5 (119) | 191.5 (119) |
| (2826-3999) | | | | | | |
| 1220 + | | | | | | |
| (4000 + ) | 130.4 (81) | 130.4 (81) | 191.5 (119) | 191.5 (119) | 191.5 (119) | 191.5 (119) |

(g) *In-building radiation systems.* The locations of in-building radiation systems must be within the service contour(s) of the licensee's authorized transmitter(s) on the same channel. In-building radiation systems are not protected facilities, and therefore do not have service or interfering contours.

(h) *Signal boosters on 931 MHz channels.* For the purpose of compliance with [§ 22.165](/on/2024-09-20/title-47/section-22.165) and notwithstanding [paragraphs (e)](/on/2024-09-20/title-47/section-22.537#p-22.537(e)) and [(f)](/on/2024-09-20/title-47/section-22.537#p-22.537(f)) of this section, signal boosters operating on the 931 MHz channels with an antenna HAAT not exceeding 30 meters (98 feet) are deemed to have as a service contour a circle with a radius of 1.0 kilometer (0.6 mile) and as an interfering contour a circle with a radius of 10 kilometers (6.2 miles).

[[59 FR 59507](https://www.federalregister.gov/citation/59-FR-59507), Nov. 17, 1994, as amended at [61 FR 31051](https://www.federalregister.gov/citation/61-FR-31051), June 19, 1996]