#### § 90.723 Selection and assignment of frequencies.

(a) Phase II applications for frequencies in the 220-222 MHz band shall specify whether their intended use is for 10-channel nationwide systems, 10-channel EA systems, 15-channel Regional systems, public safety/mutual aid use, or emergency medical use. Phase II applicants for frequencies for public safety/mutual aid use or emergency medical use shall specify the number of frequencies requested. All frequencies in this band will be assigned by the Commission.

(b) Phase II channels will be assigned pursuant to [§§ 90.717](/on/2024-09-20/title-47/section-90.717), [90.719](/on/2024-09-20/title-47/section-90.719), [90.720](/on/2024-09-20/title-47/section-90.720), [90.721](/on/2024-09-20/title-47/section-90.721), [90.761](/on/2024-09-20/title-47/section-90.761) and [90.763](/on/2024-09-20/title-47/section-90.763).

(c) Phase II applicants for public safety/mutual aid and emergency medical channels will be assigned only the number of channels justified to meet their requirements.

(d) Phase I base or fixed station receivers utilizing 221-222 MHz frequencies assigned from Sub-band A as designated in [§ 90.715(b)](/on/2024-09-20/title-47/section-90.715#p-90.715(b)) will be geographically separated from those Phase I base or fixed station transmitters utilizing 220-221 MHz frequencies removed 200 kHz or less and assigned from Sub-band B as follows:

Geographic Separation of Sub-Band A; Base or Fixed Station Receivers and Sub-Band B; Base or Fixed Station Transmitters Effective

| Separation distance (kilometers) | Radiated power (watts)1 |
| --- | --- |
| 0.0-0.3 | (2) |
| 0.3-0.5 | 5 |
| 0.5-0.6 | 10 |
| 0.6-0.8 | 20 |
| 0.8-2.0 | 25 |
| 2.0-4.0 | 50 |
| 4.0-5.0 | 100 |
| 5.0-6.0 | 200 |
| Over 6.0 | 500 |
| | |
| --- | --- |
| 1 Transmitter peak envelope power shall be used to determine effective radiated power. | |
| 2 Stations separated by 0.3 km or less shall not be authorized. This table does not apply to the low-power channels 196-200. See [§ 90.729(c)](/on/2024-09-20/title-47/section-90.729#p-90.729(c)). | |

(e) Phase II licensees authorized on 220-221 MHz frequencies assigned from Sub-band B will be required to geographically separate their base station or fixed station transmitters from the base station or fixed station receivers of Phase I licensees authorized on 221-222 MHz frequencies 200 kHz removed or less in Sub-band A in accordance with the Table in [paragraph (d)](/on/2024-09-20/title-47/section-90.723#p-90.723(d)) of this section. Such Phase II licensees will not be required to geographically separate their base station or fixed station transmitters from receivers associated with additional transmitter sites that are added by such Phase I licensees in accordance with the provisions of [§ 90.745(a)](/on/2024-09-20/title-47/section-90.745#p-90.745(a)).

(f) Phase II licensees with base or fixed stations transmitting on 220-221 MHz frequencies assigned from Sub-band B and Phase II licensees with base or fixed stations receiving on Sub-band A 221-222 MHz frequencies, if such transmitting and receiving frequencies are 200 kHz or less removed from one another, will be required to coordinate the location of their base stations or fixed stations to avoid interference and to cooperate to resolve any instances of interference in accordance with the provisions of [§ 90.173(b)](/on/2024-09-20/title-47/section-90.173#p-90.173(b)).

(g) Phase I licensees with base or fixed stations transmitting on 220-221 MHz frequencies assigned from Sub-band B and Phase I licensees with base or fixed stations receiving on Sub-band A 221-222 MHz frequencies (if such transmitting and receiving frequencies are 200 kHz or less removed from one another) that add, remove, or modify station sites in accordance with the provisions of [§ 90.745(a)](/on/2024-09-20/title-47/section-90.745#p-90.745(a)) will be required to coordinate such actions with one another to avoid interference and to cooperate to resolve any instances of interference in accordance with the provisions of [§ 90.173(b)](/on/2024-09-20/title-47/section-90.173#p-90.173(b)).

(h) Phase I licensees with base or fixed stations transmitting on 220-221 MHz frequencies assigned from Sub-band B that add, remove, or modify station sites in accordance with the provisions of [§ 90.745(a)](/on/2024-09-20/title-47/section-90.745#p-90.745(a)) will be required to coordinate such actions with Phase II licensees with base or fixed stations receiving on Sub-band A 221-222 MHz frequencies 200 kHz or less removed.

(i) A mobile station is authorized to transmit on any frequency assigned to its associated base station. Mobile units not associated with base stations (*see* [§ 90.720(a)](/on/2024-09-20/title-47/section-90.720#p-90.720(a))) must operate on “mobile” channels.

(j) A licensee's fixed station is authorized to transmit on any of the licensee's assigned base station frequencies or mobile station frequencies.

(k) Except for nationwide assignments, the separation of co-channel Phase I base stations, or fixed stations transmitting on base station frequencies, shall be 120 kilometers. Except for Phase I licensees seeking license modification in accordance with the provisions of [§§ 90.751](/on/2024-09-20/title-47/section-90.751) and [90.753](/on/2024-09-20/title-47/section-90.753), shorter separations between such stations will be considered by the Commission on a case-by-case basis upon submission of a technical analysis indicating that at least 10 dB protection will be provided to an existing Phase I station's predicted 38 dBu signal level contour. The existing Phase I station's predicted 38 dBu signal level contour shall be calculated using the F(50,50) field strength chart for Channels 7-13 in [§ 73.699](/on/2024-09-20/title-47/section-73.699) (Fig. 10) of this chapter, with a 9 dB correction factor for antenna height differential. The 10 dB protection to the existing Phase I station's predicted 38 dBu signal level contour shall be calculated using the F(50,10) field strength chart for Channels 7-13 in [§ 73.699](/on/2024-09-20/title-47/section-73.699) (Fig. 10a) of this chapter, with a 9 dB correction factor for antenna height differential.

[[62 FR 15995](https://www.federalregister.gov/citation/62-FR-15995), Apr. 3, 1997, as amended at [62 FR 18936](https://www.federalregister.gov/citation/62-FR-18936), Apr. 17, 1997; [63 FR 32590](https://www.federalregister.gov/citation/63-FR-32590), June 12, 1998]