Glenn Fleishman sez,
The FCC approved the rules for in-band, on-channel (IBOC) digital AM and FM yesterday, and didn't include a broadcast flag requirement. Digital radio has been broadcasting in the US under interim rules, mostly on the FM band and initially largely on public radio, for over three years. One company, iBiquity, controls this particular form of digital audio broadcasting (DAB). About 1,200 stations broadcast digital signals, 300 of them multicasting, or providing one or more additional digital-only broadcasts.
Part of what has held back DAB in the US has been uncertainty about the FCC's ultimate statement on IBOC would be, especially in regards to AM, and about a broadcast flag. Because IBOC's FM flavor has the dynamic range of a CD (albeit with somewhat less fidelity than a good MP3 or AAC), the RIAA and others have raised the same bugbears for terrestrial DAB as they have for Sirius and XM.
IBOC's particular difference from European DAB, by the way, is that it allows existing broadcasters to use their current frequencies and nestle digital signals alongside the stronger analog signals. (IBOC requires 1 percent of the power to reach a similar geographic area: 100,000 watt stations broadcast 1,000 watts of IBOC.)
There is a fair amount of opposition to IBOC particularly in the AM band, because of the concern of how AM signals propagate between dusk and dawn, with buzz from digital signals allegedly affecting reception far distance. Hobbyists DXers also hate IBOC because it interferes with their hobby (pun intended). The FCC dismissed all the petitions against IBOC as part of yesterday's order, and allowed 24-hour-a-day AM broadcasting, which was previously restricted.
With the FCC approving IBOC without a broadcast flag requirement, Congress would have to impose a regulatory requirement. Which seems unlikely with the current composition.
(Thanks, Glenn!)
