For years now, U.S. utilities have been hunting for an expensive and critical commodity -- electromagnetic spectrum. The energy sector has long jockeyed for its own slices of the public airwaves, preferring them for the networks that support their most critical assets like key safety gear, backup generators, black-start support systems, and the like. The rise of distributed grid assets and energy resources has only upped the value of reliable communications.
But utilities can’t compete with telecoms and other deep-pocketed bidders for the increasingly rare bits of the airwaves the Federal Communications Commission puts up for auction. That’s pushed them into auxiliary efforts, like seeking out partnerships with government agencies on some 10-megahertz channels in the 700-megahertz band given to the public safety sector by Congress in 2012 -- an effort that has yet to yield fruit, according to people involved.
Another enticing bit of spectrum lies in the Upper 700 megahertz “A Block,” in the form of two narrow, 1-megahertz channels. They’re more or less the leftover slices between blocks owned by AT&T, Verizon and the like, too narrow to support broadband communications demanded by today’s wireless customers.
But this set of spectrum slices has, in fact, been in use by U.S. utilities for the past half-decade. Unfortunately for those that invested in radios and other technology to work in the A Block, the entities created by Wall Street firms to license and rent the airspace across most of the country fell on hard times, with one in particular, Goldman Sachs-funded Arcadian Networks, closing its doors in 2011.
It’s taken a few years to pick up the pieces, but we’re now seeing a new push to put the A Block to use. The Utilities Telecom Council trade group, which advocates for utility access to spectrum, got the ball rolling in late 2013 with a white paper (PDF), noting its suitability for long-range, high-penetration propagation – i.e., it can cover rural areas as well as built-up areas -- and its adjacency to the FirstNet public responder emergency broadband spectrum, creating potential for utility-public agency partnerships.
The UTC also noted that it’s “available for acquisition from the three licensees that hold the A Block nationwide for a reasonable price, without the need for any FCC rulemaking or allocation proceeding.” That’s the end result of Arcadian’s collapse, which led to three companies, Access Spectrum, Select Spectrum and Columbia Capital, splitting up the rights across different portions of the country.
They’re now looking for buyers, and according to Tim Godfrey, technical executive at the Electric Power Research Institute (EPRI), some of it is owned by utilities, or in the case of California, the high-speed rail authority and other public entities.
“It’s all happened within the last year and a half," Godfrey said in an interview last week. What’s attractive about this spectrum, besides what UTC described as its ‘reasonable price,” is that it fits a utility need that lies between what’s out there today.
“On the high end, we have commercial LTE that can provide megabits per second of download speed, optimized for streaming video, all the other things we do with our mobile devices.” For critical utility operations, these are overkill – and they’re also not available at a cost they can support. On the other end of the spectrum, there are standard and non-standard proprietary technologies, working on the internet of things.” These are built to support massive scale, but “they’re very low throughput -- they can send messages maybe once an hour or a day.”
“In between is where the utilities are really interested -- that’s for the critical operating network for SCADA, the communications to substations,” as well as “new applications likesolar smart inverters, smart charging of electric vehicles, microgrids -- all these things need communications over a wide area.” These applications can make do with relatively low bandwidth, about 500 kilobits per second, he said.
But they have to have low latencies, in the tens to hundreds of milliseconds, to support critical operations and automated responses. “Maybe 200 is mostly OK, but a second is not so good.” That outstrips many of the IOT-centric networks out there today. It also rules out most wireless mesh smart meter networks, which aren’t optimized to support split-second, point-to-multipoint communications.
EPRI notes that there are a handful of companies, including Full Spectrum, 4RF, GE, and MimoMAX, making narrowband wireless routers capable of working in the A Block’s narrowband channels. What utilities don’t have, at least yet, is a technology standard. Godfrey has been leading EPRI’s work on an amendment to the IEEE 802.16 standard (PDF) for narrowband wireless, to extend its narrowest channel of 1.5 megahertz, “a bit further down to 1 megahertz,” by modifying existing profiles to meet the A Block’s constraints. Until then, any technology used in the field is technically proprietary, he said.
Stewart Kantor, CEO of Full Spectrum, wants that to change as quickly as possible The Sunnyvale, Calif.-based company has sold wireless networking gear to utilities including Great River Energy, Pepco, We Energies and Northwestern. Several of these clients have also bought A Block spectrum, including Pepco, he said in an interview last month.
Utilities involved in the first wave of deployments, such as Minnesota generation and transmission cooperative Great River Energy, have shown that the equipment works for its suited purpose, although Arcadian’s loss of the spectrum rights put an end to its ongoing use. “We’re talking like 30 devices per square mile, on a critical network -- very low latency, very high reliability, and good bandwidth,” running up to 1 megabit per second across hundreds of square miles, Kantor said.
But without a standard in place, utilities are likely to balk at scaling up for fear of vendor lock-in, he said. That may be why utilities including Pepco, Puget Sound Energy, National Grid and about a dozen others are supporting the standards process, with Great River Energy taking the lead role.