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PCAST report concludes spectrum scarcity 'an illusion'

Contrary to commonly accepted wisdom, there is no scarcity of spectrum, and any shortage is "an illusion" created by how the federal government manages its own use of the resource, says a comprehensive report released last week by the President's Council of Advisors on Science and Technology (PCAST).

The 192-page report,"Realizing the Full Potential of Government-Held Spectrum to Spur Economic Growth," faults current spectrum allocation practice that assigns specific swaths of the resource to different users for the shortage. Rather, the report envisions "a new spectrum architecture and a corresponding shift in the architecture of future radio systems that use it."

It recommends President Barack Obama make it the policy of the government "to share underutilized federal spectrum to the maximum extent possible" that remains consistent with the government goals. It asks the president to issue a policy memorandum requiring the Secretary of Commerce "to immediately identify 1000MHz of federal spectrum in which to implement" the new spectrum architecture proposed in the report.

At the heart of the new federal spectrum architecture is the concept of sharing, not exclusivity, something the report says "can multiply the effective capacity of spectrum by a factor of 1000."

The report, penned by an advisory group of leading U.S. scientists and engineers, identifies two technology trends that make the change in approach "eminently achievable." First, small cell-based operations reduce the possibility of harmful interference while allowing other wireless services to be in closer proximity. It points to Wi-Fi deployment as an example. Second, greater performance allows devices to provide services, even when signals from other systems are present, "so that they do not need exclusive frequency assignments, only an assurance that potentially interfering signals will not rise above a certain level," says the report.

These developments and others make it possible to manage spectrum "not by fragmenting it into ever more finely divided exclusive frequency assignments, but by specifying large frequency bands that can accommodate a wide variety of compatible uses and new technologies that are more efficient with larger blocks of spectrum," it says.

The report draws an analogy between how it envisions future spectrum use and the nation's highways. "Spectrum superhighways would be large stretches of spectrum that can be shared by many different types of wireless services, just as vehicles share a superhighway by moving from one lane to another," it says. Just as ordinary drivers yield the right of way to government vehicles in times of emergency, the wireless approach envisioned by the report would allow the government to preempt commercial users for various safety, emergency and security reasons.

In 2010, Obama issued a Presidential Memorandum entitled "Unleashing the Wireless Broadband Revolution" that requires the federal government to make available 500MHz of federal or nonfederal spectrum by 2020 for mobile and fixed wireless broadband use by commercial users. Earlier this year, Congress granted the FCC authority to conduct voluntary incentive auctions of television spectrum in an effort to clear 120MHz for future wireless use. The PCAST report concludes that "clearing and reallocation of federal spectrum is not a sustainable basis for spectrum policy."

"If the Nation instead expands its options for managing federal spectrum, we can transform the availability of a precious national resource — spectrum — from scarcity to abundance," the report says.

Commenting on the PCAST report, FCC commissioner Ajit Pai expressed worry over some of the report's conclusions. "I have serious concerns about the report's apparent dismissal of clearing and reallocating federal spectrum for commercial use. To be sure, geographic spectrum sharing has its place — all reasonable means of making more spectrum available for commercial use do. But I continue to believe that clearing federal spectrum bands and reallocating them for exclusive commercial use is a critical component of any sensible spectrum strategy," he says.