Shared Spectrum will demonstrate its cognitive-radio system developed for the military’s neXt Generation (XG) program this week at an IEEE symposium on shared-spectrum technologies that begins tomorrow in Dublin, Ireland.

Shared Spectrum’s demonstration will be a scaled-down version of tests conducted last August for the Defense Advanced Research Projects Agency (DARPA) of the U.S. Department of Defense, said Peter Tenhula, the company’s vice president of regulatory affairs and business development. In those tests, Shared Spectrum demonstrated the ability to automatically and dynamically accesses multiple frequencies without interfering with legacy radios using the same frequencies.

“The fantasy for the ultimate cognitive radio is that it has both waveform agility and frequency agility,” Tenhula said. “We’re focusing on the frequency agility right now using a WiMAX platform, because accessing spectrum is really the big problem right now.”

While spectrum often is licensed or allocated, studies have shown that a given frequency is not actively used to transmit signals the vast majority of the time, but traditional radios could not take advantage of these “holes” in spectrum usage. Shared Spectrum’s solution enables a radio to use such frequencies until the incumbent licensee begins to transmit a signal, at which time the XG radio automatically abandons that frequency and begins utilizing other available spectrum.

For the military, automatically accessing temporarily unused swaths of spectrum will simplify operations as personnel cross the borders of foreign countries and provide greater spectral efficiency, allowing more communications to reach troops, said Mark McHenry, president and co-founder of Shared Spectrum.
“We’re talking about a 100-to-1 improvement of capacity,” McHenry said.

For the test last summer, Shared Spectrum used two PCs and other equipment to create each of the six radio nodes in the fixed WiMAX demonstration network, Tenhula said. When manufacturing begins, the functionality of these radio nodes will be housed in a package that will be the size of a cable modem, he said.

McHenry said the first Shared Spectrum radios being built for the military will be available this summer.
“Our radios are going to cost $3,000-5,000 in about three months. … We think there is going to be a niche market for a radio at that cost-performance point,” he said.

Although the XG program is designed to serve the military, the technology might have significant implications domestically in the public-safety and commercial arenas. Public-safety agencies could use such technology to address issues of interoperability and long-term migration to next-generation technologies, but they typically lack the budget resources to buy military-grade equipment.

However, the price of the XG radios will drop significantly “within a year or two,” according to McHenry, when a partnership between Shared Spectrum and M/A-COM is scheduled to produce a four-channel XG radio with MIMO technology that will cost less than $500.

“When it’s all said and done, it’s going to take one [XG-enabled] DSP chip that’s not in a current multiband radio,” McHenry said. “So, if you have a Palm Pilot, imagine adding a centimeter-by-centimeter chip in there that might cost $20.”