PCAST Report Built on a Shaky Foundation, Redl Says

House Republicans have been relatively quiet on the PCAST report, but Redl indicated some members have concerns. “We basically have taken a look at it and while we think it’s a great long-term solution, something that we can look at for the long term for government users, we don’t want the promise of technologies like dynamic spectrum access to hold up opportunities to do actual clearing,” Redl said. From a technical perspective, the report “lacks a proper foundation,” he said. “There seem to be number of things in the report that assume that there is commercial viability ... technology that we have not seen come to fruition in the commercial space.”

The report also “assumes that there is a market for a piece of spectrum where you are sharing with unlicensed on the bottom end and you may or may not access from government on the top end,” Redl said. When the FCC tried to auction the 700 MHz D block, it imposed a requirement on the block that the buyer share use with public safety, he said. “It didn’t work. Nobody would pay for it,” he said. “I'm not sure that there’s evidence in this PCAST paper that shows that there’s an economic viability to that model.” There remains as well no good information on the real spectrum needs of federal agencies, he said. “There’s no one really checking to see whether the agencies are using spectrum on the smallest footprint they need,” Redl said. “Until we go back and take a hard look at the analysis that underlies the foundation of why we're saying we should stop looking at 500 MHz for reallocation and start looking at 1,000 MHz for sharing, I think we should look at whether or not we can make our first plan work instead of rolling the dice on an untested technology.”

Wireless carriers are open minded on sharing, but the government must still sell spectrum for exclusive use whenever possible, Guttman-McCabe said. “My biggest concern is on page one [of the PCAST report] in bold that the new norm is sharing,” Guttman-McCabe said. If PCAST members intended that some federal spectrum should still be subject to clearing and auctions, “it’s not in this paper and this is 200 pages and it doesn’t talk about that.” Workable dynamic spectrum access is still years in the future, he said. “I was concerned when I saw in black and white ... that there was a disproportionate emphasis on intelligent or cognitive sharing."

Preston Marshall, a professor at the University of Southern California who worked on the PCAST report, defended it at the session. The PCAST report doesn’t “walk away” from auctions “to go to a totally new regime,” Marshall said. “If you make spectrum free and clear” such as through an incentive auction of broadcast spectrum, “there’s nothing in the PCAST report that says ‘don’t go do that,'” Marshall said. “It is clear we should have talked more” about clearing and other approaches than just sharing in the report, he conceded.

The report’s ultimate argument is that “trying to clear a whole band of all possible federal users is extremely difficult, expensive and time consuming,” Marshall said. In areas like the West, where a Defense Department band may be needed for training, DOD should be able to keep that spectrum, he said. “But in New York City that spectrum is available right now, let’s get that into the hands of innovators, cellular companies, backhaul.” The FCC’s work on the TV white spaces “offered a right-now technology of the white space databases” that can be applied elsewhere, he said. “It’s something you can do right now.”

The FCC is “embracing this all-of-the-above approach that people have been talking about” for making more spectrum available for broadband, said John Leibovitz, deputy chief of the Wireless Bureau. Spectrum below 3 GHz can’t be viewed as a “tabula rasa,” [blank slate] he said. “We're working with bands that have really complicated, complex back stories, sometimes tortured back stories. ... There are different approaches that work in different contexts and different bands have different sets of facts on the ground."

The FCC is following three “parallel paths” to making more spectrum available for broadband, Leibovitz said. The first is “removing obstacles to spectrum use” in the 800 MHz and AWS-4 and other bands, he said. Second, “we're working on employing new tools that are now available to us to find new ways to bring spectrum to market” such as an incentive auction of broadcast spectrum and the use of the TV white spaces, Leibovitz said. “And we're looking at new frontiers” such as spectrum for small cells in the 3.5 GHz band and some form of licensed sharing in the 1.7 GHz band. “So our approach at the FCC is pragmatic, fundamentally,” he said.

Most of the discussion focused on the PCAST report, which was released July 20 (CD July 23 p1), but the stated purpose of the meeting was discussion of a report by ITIF Senior Fellow Richard Bennett, calling for fundamental changes in how the government makes spectrum assignments, based on a set of core principles (http://xrl.us/bniwai).

"Lawmakers and regulators concerned with spectrum allocation have no choice but to meet the current spectrum crisis by making better use of current technology,” the report said. “This requires repurposing and reallocating the pool of spectrum best able to meet the needs of the mobile revolution, a job that is best undertaken by adopting principles that reflect the best understanding of spectrum usage technology as it is today and as it will be in the next five to ten years.”

"The most desirable allocations are those that can be shared by large numbers of people,” the report said. “Commercial Mobile Networks are one very good example of efficient spectrum sharing: The larger networks, operated by Verizon and AT&T in the United States, support approximately 100 million users with 100 MHz of spectrum, for a sharing factor of one hertz per user. Wi-Fi has similar efficiency, with some 300 million U.S. users on 300 MHz of spectrum. In contrast, broadcast television consumes 10 hertz per actual user.” The report also suggested putting emphasis on dynamic capacity assignments. “The most desirable allocations are those that can be shared by large numbers of applications,” such as cellular and Wi-Fi, the report said. “In contrast, most historical spectrum allocations have been made to single-purpose systems such as AM/FM radio, TV, satellite TV and radio, and taxi networks.”