The lesser of two evils

If I had to pick between allowing HD RadioTM a 6 dB increase or removing the third adjacent protection for LPFM stations, I’d choose LPFM.

In tests performed by NPR, Ibiquity’s In Band On Channel (IBOC) digital radio scheme created significant interference to the first adjacent channel when running with 6% of the analog carrier power (-14 dB referenced to carrier) vs. the 1% (-20 dB referenced to carrier) currently allowed.  The NAB has would like to see -10 dB referenced to carrier or 10% of the analog carrier power.

Remember Bill Clinton’s sign during his first election, something about the economy, stupid.  In this case, it’s the Bandwidth, Stupid.  In the US and Canada, FM stations are allowed 200 kHz of spectrum to transmit their analog signals.   Analog signals include main channel mono (left plus right), and sub channels for stereo pilot (19 kHz) stereo matrix (left minus right), RDS (57 kHz) and any subcarriers in the 67-92 kHz range.

HD RadioTM radio requires 400 kHz of spectrum to transmit it’s digital carriers.  Here come those laws of nature again, you can’t fit 400 kHz bandwidth into 200 kHz of spectrum.

Ibiquity decided to try it anyway, contravening the FCC’s rules about FM broadcasting bandwidth channels which had been in place since the advent of FM broadcasting in the early 1940’s.  What they attempted to do was make the power level on the adjacent channel so low that most analog radios would not have a problem with it while there was a strong signal from another station present.  (hey buddy, how about a little of this new thing called crack?) This is known as the capture effect.

Now, Ibiquity created this whole thing to make some money.  Nothing wrong with that, this is a market economy after all.  They marketed the hell out of HD RadioTM radio, I saw them at various trade shows, they had full page advertisements in all the trade magazines, they hit the phones, it was a full court press (it’ll make you really cool, you’ll be able to do things you can do now and you’ll feel really good).  They would even reduce or waive the license fee (here, just take a little rock, try it, on me, you’ll see).

So they were able to sell a very expensive system that has significant coverage issues because of the low power levels needed to satisfy the FCC’s concerns about adjacent channel interference.  The NAB and many of the big radio groups bought in to it (gotcha, crackhead, you’re mine now).

Now, of course, those that bought into HD RadioTM radio want their investment to work, (which it doesn’t right now) so all the talk of power increases and hey, lets just disregard that pesky interference issue.  If you ignore it, eventually it will go away (along with the entire FM band).

The problems with HD RadioTM radio are:

  1. Inadequate building penetration at the current power level (1% of carrier power)
  2. Bandwidth that exceeds current channel assignments on both AM and FM frequencies.
  3. Proprietary nature of HD RadioTM‘s CODECs and licensing for second channels give Ibiquity too large a role saying how radio is broadcast in the US.  Remember, radio station licenses are granted in the public interest, the owners are trustees of the public
  4. Complete lack of public awareness.
  5. It doesn’t really improve anything anyway.

By the way, shame on NPR (again) for their corporate stance contrary to maintaining good quality radio and serving public interest.

Compared to that, LPFM is a very minor thing.  As I said before, removing the third adjacent protection will raise the noise floor in the FM band and by default cause more interference.  However, I’ll take a little more interference created by community radio stations over the complete rack and  ruin of the FM band.

IBOC=POS

The further we get into HD radio, Ibiquity‘s IBOC system, the weaker it looks.  Ibiquity has admitted that the digital signal lacks building penetration, calling indoor reception “impossible” and “non-existent” 10 miles from the transmitter site.   They have also stated the system has serious coverage problems during driving tests. Even with the proposed power increase from -20 dB to -14 dB, a 6 dB increase (squaring the power) showed some improvement, but still had significant signal problems.

Good thing all of those early adopters plunked down $25,000.00 in licensing fees to use it.  At least it provided “High Definition” radio, right?  Well, not exactly.  The HD in HD radio really doesn’t stand for anything, so says Ibiquity, it is just two letters they picked to name the system.  As far as the improved audio quality between the analog FM signal and the HD Radio signal goes, will the average listener care?  I doubt it very much.

Well then, what, exactly do stations get for implementing HD radio?  For a cut of the action, Ibiquity will allow stations to broadcast a second channel, which, isn’t that nice, especially since Ibiquity is paying all of those FCC spectrum use fees, right?  Wrong again, the station pays those fees every year and they can get quite hefty for class B radio stations in major markets.

Then there is the complete lack of public awareness, which, in light of the above problems, might be a good thing.  To date, only one car manufacturer, BMW, has installed stock HD radios in any car models.  If one where to go to a best buy and ask for a “digital radio,” they would likely show a radio with a digital readout on the tuner.  If one were to ask for a “HD Radio” they may or may not know what you are asking for.

Ibiquity’s answer to this is “Well, you guys are radio stations, right?  You should be able to market this system yourself.”  Okay, true enough.  If station WXYZ ran a HD radio awareness campaign, where would they send the bill?  That would be fair, after all, for using the station’s inventory to promote somebody else’s product.  Would Ibiquity take some money off the substantial licensing fee for this?  Somehow, I doubt it.

AM HD radio is is even more of a mess.  On AM HD Radio stations, analog signals are limited to 5 kHz, slightly better than telephone audio.  The digital signal washes out the first two adjacent channels on either side of the assigned carrier and can only be used during the day.  To me, last time I listened to it, it sounded strident and harsh, sort of like Sirius Satellite Radio, altogether another topic.

Then, there is the FCC mandating a proprietary codec for digital broadcasting.  I am not the only one who is being rubbed the wrong way by this, others have commented on it too.

If we are serrious about adopting a digital radio format in this country, all of the above issues need to be worked out.  It is time to sit down and take a long, hard, critical look at the IBOC system and evaluate it on its merits, not its marketing.  If indeed, an IBOC system is the best way to impliment digital radio, then the kinks need to be worked out now, else it will spell the end of part 73 broadcasting.