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Proposals outlining various trial test-beds to explore spectrum sharing technologies submitted to the federal government could foster further development of software defined radios (SDRs) and cognitive radios, eventually leading to commercialization of ubiquitous radio access networks, leading experts said.

Under a joint initiative by the Federal Communications Commission and the U.S. Commerce Department, companies and the general public had until July 10 to submit comments and proposals on creating a Spectrum Sharing Innovation Test-Bed to explore how to make use of the precious electromagnetic spectrum.

In response, proposals were submitted earlier this week by ten organizations ranging from companies like Motorola (News - Alert) and Cingular (News - Alert) Wireless to trade groups like CTIA and the SDR Forum. These organizations have until July 24 to file formal replies.

“I think that the FCC (News - Alert) has done a good job up ‘til now balancing unlicensed spectrum with licensed spectrum,” said Mike Jacobs, vice president and chief technology officer at Star-H Corporation, a privately held Army contractor. “Where this is eventually going to go is future SDR will have more frequencies.”

Commerce and FCC are undertaking the endeavor in response to the Bush Administration’s “Spectrum Policy Initiative” dating back to 2003. In March 2004, the President announced that all Americans should have universal, affordable access to broadband technology by 2007. Three months later, a special task force working with DoC’s National Telecommunications and Information Administration (NTIA) issued its “Spectrum Policy for the 21^st Century” report, which called for the creation of a spectrum-sharing plan and test-bed by 2006. Two years after the pilot program, NTIA and the FCC are supposed to report on their findings and suggest appropriate procedures to expand the program. But at least one official has expressed his concerns about meeting those deadlines.

“I do have some concern, however, about the fact that we are initiating this process two years after the Commerce Department’s recommendation.  I hope that our late start will not prevent us from meeting the June 2008 recommended deadline for delivering a report outlining the results of this program and suggesting appropriate expansions,” FCC Commissioner Michael J. Copps said in his prepared statement.

So how limited of a resource is the electromagnetic spectrum exactly? Based on joint research, the NTIA and the FCC (the two agencies responsible for managing spectrum) have divided the usable radio spectrum – 3 kHz-300 GHz – into about 800 frequency bands and have allocated these bands to 34 radio services (e.g., fixed, radio-navigation, mobile, broadcasting, and various satellite services ). Certain bands are allocated as exclusive to certain federal government users while others are exclusive to non-federal government users but an overwhelming majority of the airwaves are designed as shared bands.

Among those shared bands, approximately 2/3 of those frequencies reside above 24.1 GHz. But since technology limits most mobile voice communications to lower frequencies, almost 92 percent of the assignments authorizing government radio stations are below 3.1 GHz. In the range of valuable spectrum below 3.1 GHz, 14.1 percent is allocated to the government on an exclusive basis and 31.7 percent is allocated for exclusive non-federal use, leaving roughly 54 percent to spectrum sharing, the Administration’s Spectrum Task Force reported.

Big deal!?  Does that have a big impact to me?  Academics overwhelming believe “Yes!”

“Because of an alleged spectrum shortage, many wireless products and services are far more expensive than they should be, and others are never brought to market.  Spectrum sharing could change all that,” said Professor Jon M. Peha, the Associate Director of the Center for Wireless and Broadband Networking at Carnegie Mellon University.

But even though licensed spectrum holders currently have very little incentive to share their precious radio resources, SDR technology (particularly cognitive radios which have the intelligence to recognize prevailing frequencies and modulation schemas) could provide the business models needed to justify sharing.

“I would think it's going to have to be,” Jacobs said.  “If you monitor the RF spectrum right now, all of those frequencies sit vacant for a significant portion of the time. That's where the real policy-level decision has to be made. There's a cost per unit but there's also a cost to the economy of not having it.”

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Robert Liu is Executive Editor at TMCnet. Previously, he was Executive Editor at Jupitermedia and has also written for CNN, A&E, Dow Jones and Bloomberg. For more articles, please visit Robert Liu's columnist page.