USA - Rules for FM Terrestrial Digital Audio Broadcasting Systems

​The following communication, dated October 22, 2024, is being circulated at the request of the delegation of the United States of America.

In this document, the Federal Communications Commission (Commission) adopts rules to allow digital FM broadcast radio stations to operate with different power levels on the upper and lower digital sidebands, by notification to the Commission.

The rule changes will facilitate greater digital FM radio coverage without interfering with adjacent-channel FM broadcast stations.

The intended effect is to advance the broader adoption of digital FM broadcasting by authorizing digital FM broadcasters to implement such asymmetric sideband operation by simple notification to the Commission, rather than by requesting experimental authorization as is the current practice.

This final rule is effective November 20, 2024, except for the amendments in instruction 4 (47 CFR 74.404) and instruction 5 (47 CFR 74.406), which are delayed indefinitely.