---
kind: "section"
citation: "47 C.F.R. § 90.361"
title: "47"
number: "90.361"
heading: "Interference from part 15 and Amateur operations."
url: "https://uscodex.org/cfr/47/90.361"
---

# §90.361. Interference from part 15 and Amateur operations.


Operations authorized under parts [15](/cfr/47/part15.md) and [97](/cfr/47/part97.md) of this chapter may not cause harmful interference to LMS systems in the 902-928 MHz band. These operations will not be considered to be causing harmful interference to a multilateration LMS system operating in one of the three EA sub-bands (see [§ 90.357(a)](/cfr/47/90.357.md?p=a)) if they are non-video links operating in accordance with the provisions of parts [15](/cfr/47/part15.md) or [97](/cfr/47/part97.md) of this chapter and at least one of the following conditions are met:

- (a) It is a field disturbance sensor operating under [§ 15.245](/cfr/47/15.245.md) of this chapter and it is not operating in the 904-909.750 or 919.750-928.000 MHz sub-bands; or
- (b) It does not employ an outdoor antenna; or
- (c) If it does employ an outdoor antenna, then if:
  - (1) The directional gain of the antenna does not exceed 6 dBi, or if the directional gain of the antenna exceeds 6 dBi, it reduces its transmitter output power below 1 watt by the proportional amount that the directional gain of the antenna exceeds 6 dBi; and
  - (2) **Either—**
    - (i) The antenna is 5 meters or less in height above ground; or
    - (ii) The antenna is more than 5 meters in height above ground but less than or equal to 15 meters in height above ground and either:
      - (A) Adjusts its transmitter output power below 1 watt by 20 log (h/5) dB, where h is the height above ground of the antenna in meters; or
      - (B) Is providing the final link for communications of entities eligible under subpart B or C of this part, or is providing the final link for communications of health care providers that serve rural areas, elementary schools, secondary schools or libraries.

## Notes

### Amendments

[60 FR 15253, Mar. 23, 1995, as amended at 62 FR 52044, Oct. 6, 1997]

### Source

Source: 89 FR 100852, Dec. 13, 2024, unless otherwise noted.

### Source

Source: 60 FR 15253, Mar. 23, 1995, unless otherwise noted.

### Authority

Authority: 47 U.S.C. 154(i), 161, 303(g), 303(r), 332(c)(7), 1401-1473

### Source

Source: 43 FR 54791, Nov. 22, 1978, unless otherwise noted.

### Amendments

[60 FR 15253, Mar. 23, 1995, as amended at 62 FR 52044, Oct. 6, 1997]