Defense officials seek better management of radio spectrum

Military users have been forced to make tough choices about when to use conflicting radio systems.

Competing battlefield demands for radio frequencies have potentially lethal consequences and require new approaches to spectrum management, Defense Department officials said Wednesday.

Wireless voice and data communications are an increasingly integral part of military tactics. But as more radio-based capabilities are introduced, so too is the possibility of clashing signals.

Signal conflicts might force a commander in the field to decide among calling for air support by radio, operating radar or using a jamming device to prevent the activation of an improvised explosive device, said Paige Atkins, director of the Defense Spectrum Organization within the Defense Information Systems Agency. She spoke to reporters in Annapolis, Md., during the annual Defense Spectrum Summit, sponsored by the Armed Forces Communications and Electronics Association.

"We have had some folks who have had to make that decision," said Atkins, recently tapped to head DISA's reorganized spectrum office. The office has merged with the DISA Joint Spectrum Center.

Part of the problem is that the military does not have a single authoritative source to track use of radio frequencies, which can be assigned dynamically as new capabilities come online in different geographical areas. DISA draws on a number of military databases to form a picture of frequencies in use, but not all of those databases are updated in real time, Atkins said.

The agency needs to become more agile in its processes, she said. A possible solution is to develop a standard for reporting spectrum use across the military. That could be accomplished with standardized Extensible Markup Language metadata.

The military also is actively interested in WiMax, a nascent wireless broadband standard, as a way of getting data to warfighters, Atkins said. WiMax would complement, not replace, similar efforts such as the Joint Tactical Radio System, she added.

But WiMax also illustrates deeper challenges to radio system compatibility. Different countries often assign different portions of the radio spectrum to different uses, potentially causing further disruption for U.S. forces. WiMax interferes with military radar when it is deployed in the 3.4 to 3.6 gigahertz range, Atkins noted.

"It used to be that the U.S. could take the radios, turn them on and jump into any theater," said John Grimes, assistant secretary of defense for networks and information integration, at the conference. "I'm here to tell you that doesn't happen anymore."

The Defense Department is working on a policy to make more efficient use of the spectrum, both for communication systems and radar, said Ron Jost, director of wireless in the office of the assistant secretary of Defense for networks and information integration. "Everyone would like to see a more spectrally efficient waveform for radar systems, if there is one," he said.

But the proliferation of wireless capabilities, along with an insatiable commercial appetite for more licensed frequencies, threatens to overwhelm radio technology's ability to harness the spectrum, according to some panelists at the conference.

"At some point very soon, we're going to have a tremendous spectrum crunch," unless management and technology improves, said Richard Russell, associate director of the White House Office of Science and Technology Policy. He is likely to become the next U.S. ambassador to the World Radiocommunication Conference, an international radio frequency oversight body, according to Grimes.

Russell defended a recent Federal Communications Commission auction of 90 megahertz worth of previously government-held frequency licenses that ended in September. The sale raised $13.9 billion. Agencies sometimes hold onto frequency licenses without knowing their true value, he said. Seeing private sector firms spend money on the licenses reminds government officials of their importance, he added.

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