Utility Tests White Spaces for Smart Grid
That would be Northern California utility Plumas-Sierra Rural Electric Cooperative & Telecommunications (PSREC), which, with help from spectrum reseller Spectrum Bridge Inc. and Google (Nasdaq: GOOG), is testing what it's billing as the nation's first smart grid wireless network trial using the abandoned spectrum.
Unlike most utilities that have several infrastructure options for smartening up the grid, rural companies like PSREC are financially and geographically limited. They often can't afford to build their own networks, can't access a carrier's 3G or 4G network, and can't effectively rely on WiFi alone.
The transition to digital TV, however, has left white spaces in most US markets, especially rural ones where there aren't many competing stations or broadband connectivity.
Spectrum Bridge vice president of business development Neeraj Srivastava says the biggest advantage to using low-frequency white spaces is their ability to penetrate foliage and non-line-of-sight connectivity without requiring operational costs.
This is the third trial Spectrum Bridge has done using white spaces. The first was in Claudville, Va., bringing broadband access to the rural town, and the second was in Wilmington, N.C., where the city was building a smart city network for a number of connected apps.
The PSREC trial has now been going on for a few months now, with 12 households from the co-op's 6,600 customer members. The utility serves three counties in the heart of the Sierra Nevada Mountains, where wireless coverage is constrained by vast forests and mountainous terrain, but Srivastava says that so far there has been no interference whatsoever.
The utility uses microwave links for some of its substations, but most remain unconnected or unable to address the demands of the terrain. With white spaces, PSREC can monitor everything remotely, Srivastava says, as well as ping substations for data, manage the power flow, and protect the system.
"We gave [PSREC] longer-range connectivity and broadband speeds," he says. "They could do things like monitor power and put up a camera for remote monitoring. They can now also provide broadband access to end-user customers, which is another business opportunity."
Google's contribution to the trial is its PowerMeter energy monitoring tool, which lets consumers track energy usage and the electricity bill. Google offers a similar service with 10 other utilities.
Waiting on the FCC
White spaces were first made available nearly two years ago through the FCC's National Broadband Plan, which ruled that they were well suited for delivering mobile broadband to underserved areas, but regulations surrounding the reallocation of white spaces spectrum have been slow moving. Critics claim that use of the white spaces could interfere with digital TV service, a claim that Srivastava says is a moot point with Spectrum Bridge's advanced database. (See Policy Watch: FCC Broadband Update.)
Spectrum Bridge's technology, which is embedded in the network equipment, addresses interference by using an intelligent database of TV white spaces, accessible online in an interactive map. The database dynamically matches non-interfering frequencies with white spaces devices, and adapts immediately to new TV broadcasts or other protected TV band users operating in the area.
PSREC would like to roll out the smart grid to the rest of its regions, but right now it only has a temporary experimental license from the FCC. If the FCC completes its final rulemaking on white spaces by the end of the third quarter, as promised, Spectrum Bridges would be able to get its radios certified and could sell commercial devices soon after.
In the meantime, Spectrum Bridges, along with companies like Google, Microsoft Corp. (Nasdaq: MSFT), Motorola Inc. (NYSE: MOT), and Nokia Corp. (NYSE: NOK), is working to prove that white spaces are an effective and viable alternative for bringing broadband and apps like the smart grid to rural America. With three successful trials under his belt, Srivastava believes that won't be a problem.
"The beautiful thing is there have been no interference complaints of any kind," Srivastava says. "We were prepared just in case, because we're using an experimental license, so we could quickly tweak anything on the ground if we needed to, but we haven't had any problems in any of the trials. We're feeling good that it's proven the spectrum works and the radios work well."
— Sarah Reedy, Senior Reporter, Light Reading Mobile