DARPA-Funded Tests Show Radios Can Share Sensitive Military Bands

The following is an article published in Communications Daily, Vol. 26, No. 181, on Tuesday, September 19, 2006.

Posted by permission of Warren Communications News, Inc. (www.warren-news.com). Reproduction without permission is prohibited.

Shared Spectrum Co. said Mon. tests conducted at Fort A.P. Hill in Va. demonstrated that other radios can share military frequencies without causing harmful interference to the military systems, using a complex version of dynamic frequency sharing. The tests were conducted under the neXtGeneration Communications (XG) program financed by the Defense Advanced Research Projects Agency (DARPA). More tests are planned over the next year.

"The field exercises demonstrated the operational utility of XG: that XG causes no harm to existing military radios in compliance with emission/regulatory rules; XG will allow additional radio networks or communication capacity than currently possible using existing procedures; and that XG can operate in the presence of electromagnetic interference (i.e., jamming)," Shared Spectrum said. "Overall program capabilities and potential immediate benefit for DOD operations were shown."

"This is basically the first show that this is a real technology -- that it's demonstrated to actually work," Peter Tenhula, a former top FCC staffer who works for Shared Spectrum, told us. "The auctions for big blocks of spectrum are going to be over in the next couple of years... We're going to have to figure how are folks going to access the spectrum that is already out there and owned by a variety of different users."

Tenhula said the first applications will be military, which is why DARPA is underwriting tests. "The next logical set of applications is for public safety, disaster relief, maybe for using unmanned aerial vehicles that don't have allocated spectrum," he said. "The next could be commercial applications, to the extent that there's not dedicated spectrum like in rural areas, and it can be shared on a secondary basis."

Mike Gallagher, former NTIA dir. who witnessed the tests, said he has watched the technology develop since it was little more than a PowerPoint presentation 5 years ago. A year ago, the technology required rooms full of equipment. "What used to be a room is now a rack of computers and they have a demo unit that is about the size of a cable modem," Gallagher told us. "It just shows the tremendous acceleration we're seeing in the development of new technologies." He added: "They had the toughest engineers from the govt. side and several representatives from the private side, and everybody came away impressed."

Gallagher said the technology will be important to DoD, which has long acknowledged that its spectrum needs will soon increase several times over. "It's going to allow them to use more spectrum more efficiently," he said. It will also have many commercial implications, he said, opening up the secondary market for spectrum.

"What Shared Spectrum is embarked on is the Google of spectrum access," he said. "When you think about how efficient [Google] makes the Internet... this has the same capability for spectrum use. We have siloed the uses and applications for so many years and now there's a need to unlock the unused portion of those frequency bands."

The company said the program’s goal is to "demonstrate the ability to access 10 times more spectrum with near-zero setup time; simplify RF spectrum planning, management and coordination; and automatically de-conflict operational spectrum usage." The first test used 6 radios, but tests are planned for up to 25. "We're going to make the device ssmaller now," Tenhula said. "The more and more we can scale it the closer it becomes to deployable." -- Howard Buskirk

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