Paris — With competing digital satellite systems — XM Radio and Sirius — beginning to penetrate the U.S. market along with one terrestrial system, HD Radio, consumers would seem to have an adequate choice of digital radio formats. But Peter Senger, chairman of the Digital Radio Mondiale (DRM) consortium, thinks otherwise.

DRM, a digital AM radio system that operates on broadcast bands below 30 MHz, is broadcast by more than 65 stations worldwide, though not in the United States, where Senger believes the battle over digital radio is far from over. The emergence of software-defined, multiformat digital radio receivers and the opportunity to access a nonproprietary, international digital radio format could make DRM a good bet for U.S. stations, he said.

Digital Radio Mondiale could land in the U.S. market "as early as 2006" if integrated into U.S. digital receivers, Senger said last week. Aside from being DRM chairman since the consortium's inception in 1998, Senger is also the COO at Deutsche Welle, a German broadcaster.

Senger's bold prediction, if it comes true, could put DRM into direct competition with HD Radio, the only U.S.-based terrestrial digital radio system with a Federal Communications Commission license. HD Radio operates on FM and AM bands.

Little-known in the United States, DRM has gained recognition elsewhere as a nonproprietary digital AM system for short-wave, medium-wave and long-wave radio with near-FM-quality sound. In contrast, HD Radio is a proprietary technology owned by iBiquity Digital Corp.

Although HD Radio already occupies the medium wave of FM and AM bands in the United States, "Digital Radio Mondiale can send its digital signals on the short wave, and that's wide open," Senger said.

Still, throwing one more system into a crowded digital radio field looks like an uphill battle. Citing what he termed "a cozy relationship between the FCC and HD Radio," Senger acknowledged that no radio station in the United States today has a license to broadcast DRM signals.

A number of overseas operations are broadcasting programming in DRM, and their signals reach the United States. Among them are BBC World Service, Deutsche Welle, National Association of Shortwave Broadcasters, RCI, Radio Netherlands, Swedish Radio International and Radio Vaticana. With a DRM receiver, North American listeners can tune in to any of these sources.

That's where software-defined digital radio might be able to waltz in through the back door, making the battle over digital radio formats almost moot.

RadioScape Ltd. (London), a software-defined radio developer, said last week that it was working with Texas Instruments Inc. to develop multiformat radio receivers that can pick up Digital Audio Broadcast (DAB), DRM, FM and AM broadcasts. RadioScape said it will deliver the receivers by Christmas.

Since the products are designed for Europe, HD Radio isn't in the mix.

But in theory, the combination of DRM with any other digital radio, including HD Radio, is feasible. "That's the beauty of being digital," Senger said.

However, an early courtship between HD Radio and DRM has cooled, and "the cooperation between us is slipping," Senger said. It is still possible that DRM will be incorporated into such satellite-based radio systems as XM Radio or Sirius, he said.

"HD Radio is a closed system, and we've chosen not to pursue HD Radio for now," said Andrew Moloney, marketing manager at RadioScape. RadioScape has focused on the development of software-defined DAB, a terrestrial digital radio system developed in Europe.

AM lifeline
DRM offers a possible lifeline for AM radio, which has suffered from interference, signal fade and a steady erosion in listenership, Senger said. It offers two distinct advantages over HD Radio and DAB, he said: wide coverage area and low-cost infrastructure.

Because DRM can attain the same AM coverage using 40 percent less power, broadcasters can use it to reach a larger audience over a long distance or they can offer special-interest programming. Existing AM transmitters can be reused for DRM transmission: all it takes is a DRM exciter, which can be plugged in, holding broadcasters' investment to a minimum.

Lend a hand
DRM may also lend a hand to DAB. Despite their large theoretical coverage area, DAB receivers haven't seen strong demand outside of the United Kingdom, frustrating DAB receiver manufacturers. But DAB radio vendors are plotting to use DRM to accelerate demand for both DAB and DRM. With support from pan-European media companies like RTL Group (Luxembourg), Europe's largest TV, radio and production company, "we are hoping that the DRM can light a fire under DAB," RadioScape's Moloney said.

RTL Group is using DRM to wrap speech in multiple languages around a single music stream, doubling or tripling the reach of existing audio content.

In the U.S. market, Senger believes that short-wave radio will provide an initial opening for DRM. He estimated that several million U.S. listeners are already tuning in to short-wave international broadcasts, albeit in analog format.

Moreover, a huge number of religious programs go out on short wave in the United States. DRM allows such short-wave broadcasters to offer their programs digitally, without paying a licensing fee to iBiquity, which owns all intellectual-property rights to the HD Radio system, Senger said.

Separately, DRM is exploring the possibility of broadcasting in higher-frequency bands than its current, below-30-MHz, range. The steering board of the DRM Consortium recently floated a proposal to extend the system to frequency bands up to 120 MHz.

The proposal would lead to better-quality radio, advocates say, including surround sound and the ability to mix audio and data. The board plans to submit the proposal to the full DRM general assembly when the group meets next month.