Government and industry urged to share airwaves

A White House science advisory panel has recommended federal and commercial users share 1,000 MHz of government spectrum to meet seemingly insatiable demand for wireless broadband communications in the United States, rather than auctioning off the frequencies at a high cost to carriers and federal users.

In a report titled “Realizing the Full Potential of Government-Held Spectrum to Spur Economic Growth,” the President’s Council of Advisors on Science and Technology said sharing spectrum would be the best way to meet the growing commercial demand in a timely and cost-effective manner.

President Obama directed the National Telecommunications and Information Administration to identify 500 MHz of federal spectrum that could be sold or shared with commercial carriers within 10 years. But sales can be expensive; in March, NTIA designated 95 MHz of federal spectrum for auction, a process that will cost $18 billion (paid for by auction fees) and take a decade to complete.

NTIA Director Lawrence Strickling endorsed the advisory panel’s spectrum sharing plan. Speaking at the White House Friday, Strickling said, “the old method of clearing spectrum of federal users and then making it available for the exclusive use of commercial providers is not sustainable . . . To continue the old method of spectrum reallocation costs too much money and takes too long.” He added, “The industry and their customers, as well as our economy, cannot afford the cost and delay.”

Mark Gorenberg, chairman of the PCAST working group responsible for the report, said spectrum sharing “could transform the availability of this national resource from scarcity to abundance.”

The White House report recommends modeling spectrum sharing on wireless technology, with multiple low powered transmitters -- or small cell sites -- supporting numerous users in the same slice of spectrum.

Teresa Takai, the Defense Department’s chief information officer, said: “The move from an exclusive-right spectrum management regime to one focused on large-scale spectrum sharing between federal and commercial systems represents a major shift in the way spectrum is managed.” She said Defense will work with industry and federal agencies “to develop equitable spectrum sharing solutions."

The PCAST report identified four bands that total 950 contiguous MHz between 2700 MHz and 3650 MHz as the “most promising” for sharing. Combined with another 50 MHz slice in the 3650–3700 MHz radar band already allocated for low power sharing, this would result in 1,000 MHz for shared federal and commercial use. The report recommended a quick test of sharing in the 3650–3700 MHz radar band.

Development of small, low-powered cell architecture by commercial carriers -- as opposed to today’s high-powered cell transmitters -- would allow for frequency reuse and sharing, the PCAST report said, based on the experience with Wi-Fi. Developing receivers that can withstand interference -- another Wi-Fi model -- also will enable spectrum sharing, according to the report.

“The rise of Wi-Fi exemplifies many of the advantages the new architecture can offer,” the report noted. “Its tolerance of interference makes it common to see 25 or more independent Wi-Fi networks in a single location, sharing the same spectrum. Although interference has some effect on each network, the effect is minor compared to the massive increase in aggregate throughput.”

Spectrum sharing also will require developing smart cognitive radios to manage the arrangement and to control interference.

The PCAST report recommended President Obama sign an executive order setting aside 1,000 MHz of spectrum for sharing and that NTIA and federal agencies establish a Federal Spectrum Access System to serve as a clearinghouse for access to shared spectrum. It also called for developing a public-private partnership to ensure optimal use of federal spectrum with widespread sharing envisioned within a decade.

CTIA --The Wireless Association, which represents cellular carriers, indicated in a statement that it had no desire to share spectrum. CTIA said, “cleared spectrum and an exclusive-use approach has enabled the U.S. wireless industry to invest hundreds of billions of dollars, deploying world-leading mobile broadband networks and resulting in tremendous economic benefits for U.S. consumers and businesses.”

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