HD Radio Cracked on Receiver-Side

One of the largest controversies involving the U.S. digital radio standard, HD Radio, has been its proprietary nature. The technology’s owner, iBiquity DTS Tessera Xperi Corporation, has refused to make public all the necessary technical information within the standard, dubbed by the National Radio Systems Committee as NRSC-5; this ostensibly prevents anyone from developing or manufacturing any HD-related transmission or reception technologies without express licensure from Xperi.

The specific “black box” that has kept the technology proprietary has been the algorithm Xperi uses to encode and decode HD audio signals. If you look at the publicly-available NRSC-5 documentation, you find no meaningful detail about this aspect of HD technology beyond a description of how it works.

This was a site of controversy during HD’s tortured development: initially, the standard was to utilize an algorithm derived from publicly-accessible code – but once the FCC gave the standard its blessing, then-developer iBiquity swapped out the codec under which the technology had been tested with a new one that it had ginned up wholly in-house. But it performed so poorly that HD’s proprietors replaced it again with the variant onboard transmitters and receivers today. Read More

LPFM + HD Radio = 💰🔥

Another LPFM station has taken the plunge into the HD Radio space: introducing KVCB-LP, run by the Vacaville (CA) Christian Schools. KVCB is the second LPFM station to be authorized by the FCC to broadcast in HD – the first was WGVV-LP in Rock Island, Illinois, which received FCC authorization for digital broadcasting last decade, though it’s unclear if the station ever deployed it.

KVCB-LP was the brainchild of music teacher and genuine prodigy Ralph Martin, who’s long had the radio-bug: in 1997 he built a network of Part 15 AM transmitters for the students to use, and when the LPFM service was initially authorized in 2000, Martin made all the necessary plans to apply for a license.

Congressional meddling into LPFM – namely, tightening the interference-protection standards on these small stations – meant that Vacaville went from having potential channels available to having none. But Martin bided his time, and when Congress undid many of the restrictions on LPFM earlier this decade and the FCC opened another application-filing window, he was ready. Construction permit in hand, the station went on the air, initially analog-only, in 2014. Read More

Digital Radio: Norway and U.S. Pursue Different Paths, Yet Share Uncertainties

There’ve been some interesting developments in the digital radio realm over the last couple of months. The one that’s gotten the most press is Norway’s decision to begin shutting down its FM radio stations in favor of its DAB/DAB+ digital radio network. This has been a long time in coming, first proposed in 2015 by the Norwegian government and with buy-in from the country’s national broadcasters. That’s an important point, because the FM-shutdown, as reported in various press outlets, insinuates that all FM broadcasting in Norway is being silenced immediately.

Not true: the shutdown of stations that began this month, and continues incrementally throughout this year, only affects the country’s national broadcasters; local FM stations have at least another five years on the air before they, too, may be asked to cede the analog airwaves. A lot can happen in those years…at present, the popular sentiment in Norway about the FM shutdown is running 2-to-1 against it, especially as the analog stations disappear, their coverage areas are not served by DAB/DAB+ to the same extent as they were with plain ol’ FM, and Norwegians find themselves forced to buy digital receivers to stay engaged with radio.

It comes as no surprise that American journalists, seeing themselves at the center of the universe, would pose the question: could such an analog/digital shutdown happen here? If they were more knowledgeable about the digital radio technologies that exist they’d know the answer is no, as the U.S. has elected to use its own homegrown and proprietary digital radio technology, whose adoption is entirely voluntary. There’s also the fact that Norway only has a population of five million people — equivalent to the state of Wisconsin – and navigating a shutdown in a nation with 64 times the residents means an entirely different transition-mechanmism, which hasn’t even been seriously consered by any constituency here. Read More