---
kind: "section"
citation: "47 C.F.R. § 90.557"
title: "47"
number: "90.557"
heading: "Secondary fixed signaling operations."
url: "https://uscodex.org/cfr/47/90.557"
---

# §90.557. Secondary fixed signaling operations.


Trunked and conventional 700 MHz narrowband systems may conduct fixed ancillary signaling and data transmissions subject to the following requirements:

- (a) **Operations are permitted only on—**
  - (1) Narrowband State License channels specified in [§ 90.531(b)(5)](/cfr/47/90.531.md?p=b-5), subject to the discretion of the relevant State licensee; and
  - (2) Narrowband General Use channels specified in [§ 90.531(b)(6)](/cfr/47/90.531.md?p=b-6), subject to the discretion of the regional planning committee.
- (b) All operations must be on a secondary, non-interference basis to the primary mobile operation of any other licensee.
- (c) The output power at the remote site must not exceed 30 watts.
- (d) Automatic means must be provided to deactivate the remote transmitter in the event the carrier remains on for a period in excess of three minutes.
- (e) Operational fixed stations authorized pursuant to this section are exempt from the requirements of §§ [90.425](/cfr/47/90.425.md), [90.429](/cfr/47/90.429.md), and [90.559](/cfr/47/90.559.md).
- (f) Any operations undertaken in a shared use environment must be conducted pursuant to an agreement between the licensee and each participant, as set forth in [§ 90.179](/cfr/47/90.179.md).

## Notes

### Amendments

[79 FR 39341, July 10, 2014]

### Source

Source: 63 FR 58651, Nov. 2, 1998, 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

[79 FR 39341, July 10, 2014]