With TETRA, appearances can be deceiving

Several years ago, Rick Nielsen heard the rumblings and decided to take action. Judging from what he was hearing at various industry events — in particular, the International Wireless Communications Expo (IWCE) — there seemed to be significant pent-up demand for Terrestrial Trunked Radio (TETRA) technology, which was being used just about everywhere but the United States,
particularly in Europe, where it is ubiquitous. More telling was that the FCC was being pressured to allow TETRA to be used in the U.S., and indications were that the commission was leaning in that direction.

So, Nielsen — co-owner of Nielsen Communications, a two-way radio dealer in Green Bay, Wis. — conducted a three-site pilot of the technology in 2010. He was pleased with the results.

"The coverage we’re getting is similar to what you would get from an analog system, and the voice quality is far superior," Nielsen said. "We did some testing where we had an air-compressor and a chop saw going in the background. Talking on the analog, you can’t understand a thing, but with TETRA, your voice comes through — it totally eliminates the background noise."

Coverage has been a major knock against TETRA, which largely is perceived as an urban play that doesn’t fare well in rural environments. But, Phil Kidner, CEO of the TETRA + Critical Communications Association, said that’s a misconception.

"The standardized radius of TETRA can be 35 miles plus, and the reality is that they can go to 50 miles plus," Kidner said. "In some of the most rural parts of the U.S., you still have a long way further to go, I understand that. But [TETRA] is not just small cells for urban environments — they can deliver in the countryside as well."

Given Kidner’s position, one would expect him to defend TETRA. But Klaus Bender, director of standards and engineering for the Utilities Telecom Council (UTC), who has no such obligations, agreed with him on this point.

"There are certain density assumptions related to TETRA, and TETRA is a bit more of an urban technology than a rural technology," Bender said. "But I don’t see any reason why TETRA can’t be used in a more-sparse environment."

Meanwhile, the voice quality in noisy environments has been an issue for digital radios that are built on the Project 25 digital standard used in the U.S. and Canada. While improvements have been made to the vocoders used in these radios, Bruce Varner — retired chief of the Santa Rosa (Calif.) Fire Department and chairman of the National Fire Protection Association’s electronic safety equipment committee — said recently that audio quality hasn’t been fixed to the satisfaction of the fire service. For that and other reasons, the NFPA has decided to develop its first standard governing firefighter handheld radios.