NPSTC to pursue comparison of TETRA and P25

Board members for the National Public-Safety Telecommunications Council (NPSTC) this week voted to proceed with an effort to provide a written comparison of radio systems using Project 25 (P25) and Terrestrial Trunked Radio (TETRA) technologies.

To date, P25 has served as the radio interoperability standard in North America, while TETRA has filled a similar role in Europe. However, representatives of the TETRA manufacturers have been making efforts during the past year to get TETRA accepted in the U.S. market, particularly in the utility industry and within the federal government, said Tom Sorley, NPSTC’s technology committee chairman.

A NPSTC comparison of TETRA and P25 would not involve any real-world technical tests but would provide a document in which experts familiar with each technology would be able to answer common questions, Sorley said. Such a comparison would serve two primary purposes, he said.

“One is just to educate people who are going to be approached about this and to give them an idea of what the differences and similarities are between the two technologies … and, secondly, [let potential users understand] its impact on interoperability,” Sorley said during an interview with Urgent Communication. “If this does get introduced, what does it do to interoperability? Are there ways to address that? Can you put TETRA and P25 in the same radio and have them interoperate, for instance? And, if you do, what does that do to the cost of the radio?”

Interoperability was at the forefront of the NPSTC board’s discussion of the potential TETRA-P25 comparison during its meeting last week. Some attendees noted that NPSTC has played a key role in the development of the P25 standard and effectively making its adoption a condition for public-safety agencies to access many federal grants.

“From a public-safety standpoint, part of our issue is that we’ve been working for 20 years to get P25 developed and get people standardized—we finally got it in grant guidance and all this stuff,” Sorley said. “We’re really concerned that if they’re successful in introducing this other technology [TETRA], is that going to blow our whole interoperability efforts out of the water?”

Most public-safety officials believe TETRA works well in dense urban environments that are commonplace in Europe, but it would be too expensive to deploy in vast rural areas that a prevalent in the United States, particularly in the western half of the country.

In addition, the spectral environments in which TETRA and P25 are designed to operate differ greatly, said Larry Nyberg of Motorola—the vendor that owns much of the intellectual property included in the TETRA standard.

“In Europe, they were going into brand-new, green virgin spectrum—they had spent 10 years cleaning that spectrum out, so there was absolutely no co-channel users, no adjacent-channel users, no nothing,” Nyberg said during the NPSTC meeting. “Project 25, on the other hand, had [to deal with] VHF, UHF, 800 MHz, co-channel users, adjacent-channel users, conventional systems, simulcast systems, voting-receiver systems, [and] multiple applications of all of those combinations. The technologies that Project 25 chose were able to meet all of those system requirements.”

Sorley said he would be contacting the TETRA Association and representatives of the P25 community to determine their willingness to participate in the comparison.