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A Bumpy Ride for Ibiquity at NAB2002

By Guy Wire

It wasn't quite what the Ibiquity Digital brass had been hoping for.
The long-awaited official rollout year for IBOC at the NAB spring show hit at least two major snags: No NRSC endorsement for nighttime AM operation, and consternation over those nasty software licensing fees.

Not that broadcasters didn't have advance knowledge of the disappointing fee news, thanks to coverage in Radio World. But the fees took the glow off what has been heralded as technology to lead radio into its digital future - an uncertain and increasingly competitive future.

Just a few more tests

All of the Ibiquity boys at the show put a positive spin on the lack of an NRSC green light for AM IBOC at night.

"It's just a matter of doing some more tests and gathering some more data," they said. Yes, there will be increased skywave interference from and towards adjacent-channel stations, but they tell us it should not be a significant detriment to nighttime listening for most stations, considering the overall quality improvement achieved.

Ibiquity CEO Bob Struble thinks this bit of unfinished business will be resolved by late summer. Let's hope so.

Assuming Struble is right and AM IBOC is approved by the NRSC and the commission, we will hear a lot more hash on the AM band at night as stations start transmitting the hybrid mode.

But the band is mostly a lost cause after sundown anyway, so a little higher noise floor will not likely drive too many listeners away, except perhaps in those situations where a strong adjacent-channel skywave signal lands on top of a local station's coverage outside their primary contour. That's at least 5 mV/m and maybe10 mV/m or higher with the addition of IBOC.

Just how well either analog or IBOC digital reception holds up in the presence of such interference has not been evaluated fully.

Remember that the primary digital carriers for AM IBOC sit right in the middle of the first adjacent passband. Because of that, some are now calling it IBAC, for in-band, adjacent-channel.

How many stations will be affected by this new form of interference, and by how much? Ibiquity predicts it won't be that bad. The digital carriers are 23 dB lower than the analog carriers, plus the analog sidebands will stop at +/- 5 kHz with Ibiquity's requirement that analog response using IBOC be cut off at 5 kHz instead of the present NRSC limit of 10 kHz. That alone will reduce splatter from first adjacents but will only be a benefit from those stations transmitting IBOC.

It is likely many stations will not add IBOC until it's clear the technology will be a winner. I wonder if the FCC would consider requiring that all stations limit their transmitted response to 5 kHz just to help out the IBOC hybrid transition?

Not an easy task

The NRSC is looking for scientifically supportable evidence in its effort to reach conclusions and make recommendations. Anecdotal assumptions or estimates will not be compelling.

The 10-percent skywave curves long used by the FCC to predict how AM signals propagate at night only projects what happens 10 percent of the time. The ionosphere makes lots of shifty and unpredictable moves. Just ask the inventors of the various attempts at "anti-skywave" antennas.

Trying to quantify and then interpret the amount of interference and potential in lost listening due to the addition of IBOC AM will not be an easy task for Ibiquity nor for the NRSC.

The only preliminary conclusion we can draw on this issue is that the effective NIF (nighttime interference free) contour for many stations likely will go up. You will have to be sitting in a stronger signal contour area than you do now after IBOC digital is added for either clean analog or high-fidelity digital reception at night without interference.

How the IBOC digital decoders will behave in the presence of adjacent channel digital skywave interference is unknown.

Most high-power AMs are looking forward dearly to the dramatic increase in quality with IBOC digital that will allow them to better compete with FMs. Music formats on AM stand to get a huge shot in the arm. Fifty-gallon clear-channel powerhouses are drooling over the prospects of expanded skywave listening audiences with the improved fidelity IBOC delivers.

Will they be disappointed?

Skipping the AM hybrid

The period of transition, in which some stations are transmitting IBOC and many others are not transmitting analog/digital signals, will be messy.

Some well-known industry observers think we should skip the hybrid mode for AM IBOC digital altogether. The FCC could mandate that all stations switch to pure digital together when receiver penetration at some point in the future is justified - something akin to Digital Radio Mondiale, the all-digital mode developed for international broadcasting. Its future looks promising although commercially available receivers are not yet on the market.

That would be theoretically possible, assuming IBOC works well for the FM band, given that Ibiquity will only license receiver chips equipped for both AM and FM digital reception.

Such a scheme would require AM to wait maybe another 5 to 10 years before the fruits of digital could be enjoyed; but the prospect of having the band dramatically cleaned up for long-term benefit is enticing. Unfortunately the politics of placing AM at an even greater competitive disadvantage short-term would likely make this undoable.

The Continental booth at NAB had an impressive demo of Digital Radio Mondiale skywave reception. Let me tell you, that system works just fine day or night, and is damn impressive.

You can bet that the FCC will not authorize AM IBOC digital until the issue of increased nighttime interference is investigated thoroughly and nighttime operation ultimately is endorsed by the NRSC. After the boondoggle of AM stereo, it is unthinkable that the FCC would "decide not to decide" and leave the choice of whether to deploy AM IBOC digital transmission up to broadcasters.

Tweaking the codec

Several IBOC demos were available for evaluation at NAB2002. Many attendees who sampled the Ibiquity, Harris and Nautel IBOC exhibits and listened to local stations KSFN(AM) and KLUC(FM) reported hearing significant digital compression artifacts, especially on voice-only program.

Apparently Ibiquity had just released the Lucent Digital Radio PAC compression algorithm to exciter and codec manufacturers and the software had not yet been optimized, especially while running MPEG programming. Previous IBOC demonstrations used the MPEG AAC codec, which frankly sounded better than anything I heard this year.

NAB floor demos often are somewhat suspect for various reasons and do not always exhibit what is likely to occur in the real world. I think it's fair to conclude that the PAC codec will continue to undergo many iterations of change and optimization before chip sets are shipped in retail versions of IBOC transmission and receiver hardware.

XM already is improving its codec implementation amid fanfare and press releases. Compression at 64 kilobits per second now is heralded as "virtual CD-quality." Ibiquity will surely make its 96 kbps codec on FM work as well if not better.

At only 36 kbps, the AM codec is much more challenging. But that part of this technology will continue to get better for all digital audio conveyed in limited bandwidth media.

Who will pay?

The thorny issue of broadcasters having to pay for both IBOC hardware and software licensing has many station owners and managers reeling, especially in the smaller markets.

As I reported in a recent online tête-à-tête on IBOC with Skip Pizzi, Ibiquity is following the Microsoft model and wants to charge stations 15 times the annual FCC license fee just for the privilege of using their software to transmit IBOC signals.

That's on top of the markup we'll pay to exciter manufacturers to cover their Ibiquity license fees, something like $3,000 per box. We get to pay twice.

And then of course we also have to buy and install a digital transmitter, plus add widebanding to many of our antenna systems. Paying for IBOC will be painful for many stations, especially with no assurance the investment will ever pay off.

We learned before the show that some members of the Ibiquity advisory board had warned the partnership management that charging the proposed software license fees would cause problems and could delay IBOC conversion for many stations and potentially jeopardize the entire venture.

A few unnamed Ibiquity managers privately think those fees should be waived for the first year, to encourage early adoption. They know that unless the majority of stations in larger markets add IBOC digital out of the gate, their technology may not succeed. But the marketing folks apparently won out and are holding fast to their rate card for the fees. No "deals" will be cut, they said.

It's a delicate balancing act for Bob Struble of Ibiquity, who knows he has to start making money for the partnership investors at some point. Apparently Bob is willing to risk the ultimate success of Ibiquity on the backs of broadcasters by making them pay for most of the $50 million to $100 million spent so far, even before receiver chip licensing fees start rolling in.

Somebody's gotta pay. Receiver manufacturers want broadcasters or Ibiquity to pay. Broadcasters want receiver manufacturers to pay. In the end, of course, consumers will pay, but only if they are convinced IBOC digital is worth buying. Before that happens, there will need to be lots of stations transmitting IBOC and affordable receivers that work very well, available almost everywhere.

In spite of the recent complications, I'm still supporting the Ibiquity Digital solution for radio's future. It's our best shot to get radio updated and competitive with all other electronic media.

Analog is a dying horse, folks. It's time to mount the digital pony. But to give this technology the best chance for success, stations need more financial incentive to make the conversion.

In the long run, waiving the licensing fee for early adopters during the first year will do much more to ensure Ibiquity's success than merely disappointing investors in the short run.

Strap yourselves in and stay tuned. This is going to be interesting.

Guy Wire is the pseudonym for a veteran radio broadcast engineer. RW welcomes other points of view.