Hytera-Cobb TETRA collaboration might be the start of something big
Last September, the FCC sanctioned the use of Terrestrial Trunked Radio (TETRA) technology in the U.S. The action was the culmination of a long lobbying battle to bring the popular technology that is being used worldwide—predominantly in Europe—to the U.S. to provide a digital radio option that was less expensive than Project 25, but more feature-rich and hardened than Digital Mobile Radio (DMR) technology. But, in the ensuing months, TETRA’s arrival has been more about promise than actual deployments, though some experts believe that significant activity has been bubbling beneath the surface.
A couple of weeks ago, Cobb EMC—an electrical cooperative that serves metropolitan Atlanta and southeast Georgia—announced what is believed to be the first TETRA deployment in the United States by a utility. Previously, PowerTrunk conducted TETRA trials with New Jersey Transit and MTA New York City Transit, and is in the process of building a 36-site system that will support approximately 4,000 buses and light-rail vehicles.
Cobb’s four-site system will be installed by Norcross, Ga.-based two-way radio dealer Radio One and will leverage infrastructure and subscriber gear manufactured by Hytera. Testing is expected to begin by Thanksgiving, and the system is scheduled to be operational by the first of 2014.
At the beginning, all Cobb officials knew was that their existing digital radio system had reached the end of its life—they had no preconceived notions as to what would replace it. Their vendor had suggested an upgrade to the latest version of the existing technology, but the utility’s officials suspected that there were a lot more options to consider. To ensure a thorough vetting of the myriad options, Cobb hired a consultant.
“We were going to be spending a lot of money, so it was important that we got the most bang for the buck,” said Jay Kenyon, a Cobb vice president. “Our consultant didn’t tell us what to buy but instead gave us all of the options.”
That was accomplished by conducting an open-house event, where representatives of 12 companies made their pitches, not just to Cobb executives, but also to stakeholders—a wrinkle that impressed Gary Lorenz, Hytera’s vice president of sales and marketing.
“They brought in the people in the bucket trucks, the ones who are out in horrible storms trying to restore power,” Lorenz said. “I was struck by that. The whole process was very thorough—they wanted to get this exactly right.”
The choice came down to Hytera’s TETRA system and another vendor’s DMR system. Though the TETRA system was more expensive, it had a few significant advantages. One is that it will cover Cobb’s 400 square-mile footprint with just four sites, compared with the seven sites that the DMR system would have required, resulting in significantly reduced infrastructure costs. Another is that TETRA gear is public-safety rugged, an important consideration given the harsh conditions in which utility workers often find themselves.
But the tipping point was that TETRA is based on four-slot TDMA, while DMR is based on two-slot TDMA.
“With TETRA, we could have one control channel and three talk paths,” Kenyon said. “So we had full-duplex capability. In contrast, DMR [requires] two control channels, so if we had a full-duplex conversation on a four-channel site, there wouldn’t be any channels left for any standard radio communications.”
Kenyon said that the DMR vendor promised a four-slot TDMA option by the first quarter of 2014, but Cobb decided to go with the sure bet.
“I’ve been in the communications business for a long time, and one thing I’ve learned is that futures are nice, but you can’t take them to the bank.”
However, Kenyon admitted that Cobb had a few initial qualms about TETRA, because it has very little track record in North America—currently, the only utility system in use in the continent is the one deployed by BC Hydro—but the fact that it is a mature technology used around the world allayed those concerns.
Lorenz fully understood Cobb’s reticence.
“We’ve been working for the past couple of years to debunk some of the myths that surround TETRA—it’s an educational process,” Lorenz said. “The psychological barrier is noteworthy—a lot of people don’t want to be the early adopter. But that’s really not the case with TETRA. It’s the global standard that is being used in more than 140 countries.”
The education process extends not just to the end-user community, but also to the dealer level. Steve Keller, co-founder of Radio One and a member of Urgent Communication’s editorial advisory council, admitted that TETRA is new to them.
“Very few people in the U.S. have any experience with TETRA,” Keller said. “We are looking forward to learning more about this technology.”
Keller said he has been impressed by what he’s discovered so far. He described TETRA as a cost-effective, spectrum-efficient technology that will gain traction in the U.S. going forward. This belief is driven by the fact that there are many utilities across the country whose communications technology is getting older and will need to be upgraded or replaced soon.
“As they begin looking for new systems, TETRA will be a very viable option for them–if 25 kHz channels are available in their areas,” Keller said.
It may already be starting to happen. According to Lorenz, Diverse Power—a larger Georgia energy cooperative that provides service over multiple counties—took a look at what Cobb is doing and is now considering its own TETRA deployment. Lorenz said that Diverse hopes to become a carrier of sorts, providing communications services not only for its own purposes, but also to smaller utilities and other public and private enterprises throughout the region.
There is one significant obstacle standing in the way of TETRA’s widespread deployment: in the U.S., such systems operate in the 450-470 MHz and 809-824/854-869 MHz spectrum bands, and UHF channels are difficult to find, particularly in large urban areas.
“That’s the biggest obstacle,” Lorenz said. “Finding channels will depend on where you’re located. But, where there’s a will, there’s a way—work with your frequency coordinators. People are looking for options, and TETRA provides them.”
Updated on 7/26/13.