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

Nodes of Resistance: Sampling the Haitian Diaspora via FM+Internet

17 years ago(!), I left a budding career in radio journalism out of disgust with the trajectory the industry was taking. The break-point came when the National Association of Broadcasters and National Public Radio teamed up in Congress to conduct a disinformation campaign designed to eviscerate the FCC’s then-newly proposed LPFM radio service.

However, A few months before I actually quit my job, I acquired all the components necessary to start an unlicensed microbroadcast station. “System P” was a 40-watt frequency-agile FM rig that used a portable military surplus antenna mast to conduct tactical broadcasts from a wide variety of locations. You could often hear the station in Madison, Wisconsin, primarily on evenings and weekends; but since the station was mobile much fun was had taking it to peoples’ homes and public events around the country to give the public a more substantive appreciation of the ease by which it could make “the public airwaves” very real.

Another key element of System P was to provide a last-mile node for what was then quite an experiemental webcast-activism scene (today commonly known as “livestreaming”). These often manifested in Independent Media Centers during times of protest, most notably against corporate global trade deals. Activists would converge on a city to fill the streets in order to disrupt the negotiation of these agreements, and the media coverage would invariably skew toward painting the activists as violent thugs and police/other security forces as the guardians of order. But when activists gained the ability to counteract this narrative – oftentimes by live reports from the streets directly – the discursive dynamic around these events changed. Read More