CPB/NPR to Fit Square HD Peg Into Round Technical Hole

If you haven’t noticed already, it’s that time of the semester when teaching takes precedence over everything else; extended office-hours are in full effect and this spring’s crop of students are both insightful and delightful. In about a month from now I’ll begin an eight-month break from that “grind,” during which I plan to dissertate full-time. Since I’ll be spending most of my waking hours in front of my computer, that means you can most likely expect more stuff here.
But, in the interim, from the better-late-than-never notable news department comes word of a new project from the Corporation for Public Broadcasting to better-study the implications of interference between FM radio stations that might operate under a proposed increase in the strength of their HD (digital) sidebands. Although the announcement simply formalizes and expands upon a policy the FCC’s had in place for several months now, it’s an interesting development for two particular reasons.
First, National Public Radio (through the CPB) has already extensively studied this issue, more than anyone else in the industry, and the results are pretty unequivocal that increasing the power of a station’s FM digital signal will adversely affect not only its own analog host-signal, but also those of neighboring stations. So much so, in fact, that the (first) study’s coordinating engineer has admitted in other fora that an increase in HD sideband power levels is much more likely to do harm than good.
Secondly, it’s important to note the understated yet formative role that public broadcasting has played in the development of HD Radio. The protocol’s first (and, arguably, still only) “killer application” is multicasting, or the ability to split a single FM radio signal into multiple program streams. iBiquity’s initial HD technology did not include that feature – it was wholly developed in a crash-program undertaken by NPR in 2003, and was not even deployment-ready until 2006. Therefore, it’s safe to say that not only does NPR have an historically-vested interest in the success of a flawed digital broadcast protocol, but it’s also been the most innovative developer of the technology to-date. Although the private sector foisted this dog of a digital radio protocol upon us all, it’s been the public sector that’s invested the most in trying to teach it new tricks (your tax dollars at work!).
CPB’s newly-launched study is literally an effort to squeeze blood out of a stone. According to Radio World, the study is “being conducted to eke out more data to answer the question of what would constitute a manageable HD Radio power increase.” It goes on to detail some of the research questions – none of which address the inherently-interferent nature of the protocol itself, and how it might possibly be corrected. If you read between the lines of the CPB proposal, it would seem to suggest that the $350,000 effort to more “closely manage” a potential HD Radio upgrade is geared more toward figuring out how to allow individual stations to maximize their digital power, as opposed to devising a universal solution to the interference problem.
Truly resolving that problem is the one question nobody will touch, because it’s a design flaw in the technology. Rethinking that would involve perhaps rethinking the entire U.S. DAB protocol.
Unfortunately or not (depending on your point of view), if there were a time to rethink radio’s digital future, it would be now. The regulatory environment is in flux; thanks to the economy, stations are incredibly hesitant to commit to an unproven and highly expensive “signal upgrade” with no discernible return-on-investment; and the HD Radio protocol itself is, at this point, 15 years old – geriatric in technological terms. Regardless, all signs point toward continuing to waste time, money, and spectrum in what is already an also-ran digital broadcast technology. Study results are expected in the fall.