New Airwave-Sharing Scheme Will Launch a Wireless Revolution
A policy change means that sections of spectrum can be “checked out” for different purposes at specific locations.
The future growth and economic viability of wireless communications depends on the smart management of limited wireless spectrum.
Aiming to boost wireless bandwidth and innovation, the U.S. Federal Communications Commission is poised to recommend the biggest regulatory change in decades: one that allows a newly available chunk of wireless spectrum to be leased by different companies at different times and places, rather than being auctioned off to one high bidder.
The step “is a critical milestone,” said David Tennenhouse, Microsoft’s vice president of technology policy, adding that it will not only release more spectrum but also enable “dynamic spectrum sharing that is particularly well suited for absorbing growing wireless data traffic.”
Cisco Systems estimates that mobile data traffic will grow by a factor of 18 by 2016, and Bell Labs predicts it will increase by a factor of 25. Many more airwaves could eventually be shared with the help of cognitive radios, which sense available frequencies and shift between them.
The move will open up a piece of spectrum in the 3.550 to 3.650 gigahertz band now used by radar systems. The move in effect allocates spectrum for another Wi-Fi—a technology that has had tremendous impact. But it is the sharing approach that represents a dramatic change in unleashing bandwidth.
The new rule—technically a “notice of proposed rulemaking,” followed by a regulation-writing process—is scheduled to be voted upon on Wednesday by the FCC. A commission spokesman did not discuss its details, saying they would be released after the vote, but experts familiar with them described them to MIT Technology Review.
Under the proposed rule, wireless carriers, corporate offices, or researchers could reserve pieces of that spectrum in different regions and at different times—a system managed by a central database. The approach guarantees that the spectrum will be available and not subject to interference in certain areas by a crush of new users, as might happen if the new chunk of spectrum were made available with no regulation at all.
Although the checked-out spectrum might be free of charge at first, eventually, depending on the level of demand, a pricing system could be implemented. In theory, this could allow a wireless carrier to pay for priority access in rare cases of extremely high demand. This would give it the right to temporarily evict another party—such as an academic lab, which might be willing to tolerate short-term interruptions in exchange for low- or no-cost access to the spectrum.
Whatever the details, the move spells the beginning of the end of a system in which spectrum is either exclusively owned by a private company, walled off for government and military use, or unlicensed and crowded.
“It’s very different—this is going to allow for people to get low-cost access to the spectrum, to support new types of wireless devices,” said one wireless researcher familiar with the approach. “Initially, you might not pay anybody. But as spectrum becomes more cluttered, you may have to pay something to get access to it.”
Under the new approach, a startup that wants cheap spectrum to test a breakthrough idea would no longer have to rely on cluttered unlicensed bands—such as the “garbage bands” that handle baby monitors and garage-door openers—to experiment with its idea in the real world. Rather, it could use a slice of choice spectrum at zero or low cost—and for a short time period if desired. With the changes expected tomorrow, FCC chairman Julius Genachowski will be following through on earlier pledges to implement recommendations of an advisory report whose authors include Eric Schmidt, Google’s executive chairman. The report said spectrum sharing could provide thousands of times the current capacity by reducing inefficiencies (see “The Spectrum Crunch That Never Really Was” and “Spectrum of Issues”) and explained how that could be done by spectrum sharing in a system managed by a database.
Genachowski said in September that the commission would open up some spectrum and promised a “a major innovation in spectrum policy that will in turn enable innovations in wireless applications throughout the economy, including energy, health care, education, and other uses yet to be discovered.”
“This is awesome,” said Vanu Bose, CEO of Vanu, a wireless company in Cambridge, Massachusetts. Bose served as a technical advisor on the report. He added that the move “will set the groundwork for spectrum sharing in general” but held off on discussing the notice further until after its release.
Already, in some settings, most mobile operators employ Wi-Fi—using 2.4 gigahertz and 5 gigahertz unlicensed bands—to supplement 3G and 4G coverage in “hot spots” like train stations and stadiums.
Dipankar “Ray” Raychaudhuri, head of the wireless research lab at Rutgers University, said the rule might allow the broader use of spectrum-sharing technologies that have long been reserved for research labs. He added that it isn’t clear how the major carriers will use the new system. “There is still some debate about whether operators will embrace the idea of sharing small cell bands, even though it is a supplementary service and doesn’t have to be as reliable” as a major base station, he said.
In some ways, the move resembles what the FCC did when it opened up so-called “white spaces”—unused bands between TV channels (see “Wi-Fi via White Spaces” and “White Spaces Finally Open for Business”). In both cases, the availability of spectrum is to be managed via a centralized database.