The FCC Media Bureau has adopted new rules to allow FM stations to up their digital signal power up to 10% of their analog power (a hike of 6 dB). The rule change lets FMs do this on a voluntary basis. Grandfathered “super-powered” stations (i.e. WRVQ-FM Richmond, VA @ 200kW) will have their HD increases limited to protect against first-adjacent channel interference to other stations.
The new rules also create remediation procedures to settle interference disputes with other stations within 90 days, and leaves the issue open for revisitation if the upped digital signals continue to interfere with other stations.
The full notice:
The Federal Communication Commission’s Media Bureau adopted an Order that permits FM radio stations to voluntarily increase digital power levels up to ten percent of analog power levels and establishes interference mitigation and remediation procedures to promptly resolve complaints of interference to analog stations. These rule changes will substantially boost digital signal coverage while safeguarding analog reception against interference from higher power digital transmissions.
In 2002, the Commission adopted the in-band on-channel digital audio broadcasting system developed by iBiquity Digital Corporation (“iBiquity”) as the de facto standard for FM station digital operations. Stations are currently permitted to transmit digitally at one percent of analog power. In June 2008, iBiquity, 18 group owners of 1200 radio stations and four major radio equipment manufacturers requested that the Commission increase digital power levels by 10 dB, i.e., to ten percent of analog power levels. Both iBiquity and National Public Radio have submitted detailed studies assessing the potential for improved digital service and increased interference to analog reception.
The Bureau Order will:
• Permit most FM stations to immediately increase digital power by 6 dB, a four-fold power increase;
• Limit power increases for stations currently licensed in excess of class maximums, i.e., “super-powered” stations, to protect analog radio service from interference;
• Establish application procedures for power increases up to 10 dB;
• Establish interference remediation procedures that require the Media Bureau to resolve each bona fide dispute or impose tiered power reductions within 90 days; and
• Reserve the right to revisit the issue of digital power levels if significant interference results to analog reception.
Action by the Media Bureau, January 27, 2010 by Order (DA 10-208). Docket 99-325.
RBR-TVBR observation: We’re not sure how many stations will jump at the chance to up their power, as it is a significant added expense to implement. But we’re sure a few will, and the improved reception results in their markets may drive many more to do the same. The hope with these increases is to reduce digital dropouts in areas that are still in the station’s protected contour, but experience reception challenges because of hills, excessive ground clutter, etc. — especially on HD multicast channels with no analog backup. Another goal is to help the HD signals penetrate buildings better for improved in-home and office reception. The best-case scenario would be closely matching the analog coverage with stable digital reception — both traveling in the car and inside structures.