Spectrum Sharing Will Spur Competition, PCAST Official Says

"We're hoping to really turn spectrum from scarcity to abundance so that we can create that innovative, virtuous cycle and really have the opportunity to create a lot of companies as we saw in the Internet in the 1990s,” Gorenberg said. For venture capitalists, the creation of a new “innovation cycle” is “the most important thing,” he said. “To the folks in this room who are looking at creating new companies, [it’s] the most important thing to them as well.”

One key finding of the report (CD July 23 p1), Gorenberg said, is that the U.S. needs to move away from long-term spectrum licenses. “We all know there is an expectation, important to the people who bid on these auctions early, that there’s sort of a lifetime renewal as long as they want to use it because of the capital expenditures they put in place. … What about the notion of short-term and medium-term licenses that match the capital investment that people will want to put forward, particularly around small cell?” Gorenberg said he believes a dynamic spectrum sharing mechanism could be in place in about three years. “We think we can get people faster, actually … which is really important,” he said. “In terms of clearing versus sharing, I think everybody, actually, has agreed that sharing is important. What they don’t agree on is when, how and how fast and that is really what the debate is."

Preston Marshall, a professor at the University of Southern California who worked on the PCAST report, said the report seeks to push the focus from spectrum efficiency to spectrum effectiveness. “Effectiveness is really what we're after in delivering broadband,” Marshall said. “We created a matrix on that. … One of the keys to that is it really focuses not on how transmitters use spectrum but on how systems and architectures allow spectrum to be reused. What is measured is how one use of spectrum precludes another use of spectrum."

"Interference radius” is critical, Marshall said. “How do we get more and more systems into the spectrum?” he asked. “CMRS or capacity of any of these broadband systems is not a function of their spectrum. It’s a function of how many times you can repopulate the infrastructure within an area.” NTIA’s report on the 1755-1850 MHz band looked at a lot of bands and said high-power LTE couldn’t be deployed because of interference. “True, but the PCAST argument was that’s really not where you have to go,” he said. “You have to go to lots and lots of spectrum reuse. So even if you can’t run a 50 watt, six sector LTE tower, you could run hundreds of femtocells or Wi-Fi like devices that are unlicensed equipment in that band. We should look at federal sharing not against towers but against a large, innovative infrastructure.” That supports investment, Marshall said. “Small cheap things are much easier to innovate than big tall towers that take 10 years of building and populating and all.”

Carrier infrastructure shouldn’t be the primary focus of sharing between federal and commercial users, Marshall said. “It should be more … a hospital wanting to put in a body-area network or someone like LightSquared, but wanting to [offer service] through thousands and thousands of cable boxes,” he said. Tunable filters will also be critical in the new sharing regime, he said. “If you look at the blogosphere, on the attacks on the report, in large part they are we don’t have tunable filters,” he said. “If there’s an engine for innovation it’s the guy who figures out how to make a tunable filter at the cost of five or 10 soft filters. That’s the enabler."

Power, who was in the audience, was asked by Marshall about the politics of getting the PCAST report converted to federal policy. “I didn’t realize you were allowed to call on me,” Power joked. “You know the way things work in Washington, it does tend to be incremental,” he said. “There are obviously a lot of stakeholders, folks coming at this from completely different directions and it’s not binary, it’s not just black and white. There are … shades of gray.”

Carriers remain “a little apprehensive” and “bullish on clearing,” Power said. “My sense is there are folks on the Hill who reacted very positively to the report as ‘Let’s get more spectrum from the federal agencies.’ In standing up and supporting your efforts … probably thought they were on the side of the carriers, but they weren’t, exactly because the carriers were actually somewhat apprehensive about it. So you have these pressures coming from a million different directions. It’s really important to have all the carriers at the table and getting buy in.”

As the “telecom guy” in the White House, Power said he could be spending his time on other issues, from universal service, to the end of the plain-old telephone system to media ownership. “I'm spending the majority of my time on spectrum because it’s a priority of this president,” he said. “We do have emphasis that doesn’t have to be there.”

The PCAST report was built on work that has come before, some going back a decade or more, Gorenberg said. “The work that we did I think really was much more of adding on top of a lot of great work that’s been done through the industry,” he said. “We saw as our sort of work point, the idea of going from scarcity to abundance, the idea of supporting economic growth, the idea of ensuring U.S. competitiveness and leadership."

Carriers aren’t unique in facing a spectrum crisis unless the federal approach to spectrum changes markedly, Gorenberg said. “It’s not just the commercial side that needs more spectrum,” he said. “The federal government continues to use and will continue to use more and more spectrum for its work.” He noted that the government launched 167 unmanned aerial flights eight years ago and 7,500 last year.

A second panel Thursday looked at enforcement and other regulatory issues tied to sharing.

"We can try and define sharing to the ‘nth’ degree of detail, but actually that may be wasted effort because there many unanticipated things that come up,” said William Webb of Neul Ltd., a former Ofcom official. “We need to learn from the past that defining interference caused to other spectrum users is a really difficult problem.” Ofcom looked at the issue over several years and developed a regime of spectrum usage rights. “If you want to go down the route of defining interference caused to others that’s one particular way you can go,” he said. “But what we've learned from [TV] white spaces access is that may not tell the whole story.” In the U.K., regulators found that “bursty” transmissions from a white spaces device caused much more interference than a continuous wave form. “The reason that was happening was because the automatic gain control in the TV receiver front end was not set up to handle bursty interference. It was set up to handle continuous transmissions."

U.S. regulators have a choice, Webb said. Regulators could require “exhaustive” testing, examining interference based on various models “and then you derive what should be allowed and that’s basically the approach that was adopted in TV white space,” he said. “The other approach is to be much lighter on those sort of tests, to do some, but not to spend too much time and effort on that and then to get stuff out and to monitor what happens and adjust quickly … to change the rules.” Webb recommended the second approach and said it would make more spectrum available much more quickly.

"I've been surprised … that the word ‘enforcement’ has not come up as often and as strongly as perhaps it might,” said Dale Hatfield of the University of Colorado, a former FCC and NTIA official. The spectrum landscape today is more complicated than ever before, he said. “We need to do something on the enforcement side that really recognizes and takes into account that new environment.”

Hatfield said self-enforcement through multi-stakeholder groups could play a big role. Such groups “can and indeed already are playing an important role in designing sharing arrangements. We've heard that repeatedly,” he said. “Certainly, multi-stakeholder organizations like those represented here today can play a key role in designing tools, for example, that prohibit devices from even transmitting in some unauthorized manner or locating misbehaving devices and actually shutting them off automatically.” Government can still step in when if a particular industry player won’t cooperate, he said. Hatfield said he still has concerns about receivers, and the combination of “a very dynamic spectrum sharing environment coupled with receiver inadequacies. … You've got to take that receiver stuff into account here or we're not going to make progress."

"The underlying message … is that in a world of dynamic sharing and in a world of complex systems, we are going to have to rebalance the scale a bit with much more ex-post component to balance the complete reliance on ex ante validation and regulation today,” said John Chapin, program manager at the Defense Advanced Research Projects Agency.

Tom Kidd, U.S. Navy director of strategic spectrum policy, acknowledged that spectrum policy has been slow to change. Kidd serves on the Interdepartment Radio Advisory Committee (IRAC), which represents the spectrum interests of government agencies. “When I first came to D.C. and I had to deal with the IRAC I used to say, ‘It’s a hundred-year-old organization and most of the members are founding members.’ Now that I'm on the IRAC I don’t say that anymore. My point is this industry has been very entrenched in tradition.”