With these updates, SRTS bus drivers like the push-to-talk-over-cellular (PoC) system, Miller said.

“At the moment, they’re pretty happy, because the coverage has been better, and the reliability actually has been pretty good,” he said.

Meanwhile, the economic advantages of the PoC system are considerable. Miller, who used to work for Sioux City, said replacement radios for the 800 MHz trunked system typically cost between $800 to $1,200—several times more than the $199 vintage Samsung tablets that SRTS uses today. And the $4,300 annual cost for the Zello PTT application is a fraction of the $30,000 cost to rent tower space from RACOM, he said.

While there are cases of governments and enterprises migrating non-mission-critical push-to-talk service to a PoC solution, most of them have been in urban or suburban locations that boast strong cellular coverage from a wireless carrier. However, the SRTS service area is “80% to 90% rural,” Miller said.

Verizon’s coverage in the SRTS service area is better than the coverage provided by the LMR system, but Miller acknowledged that there is a downside to scrapping the LMR solution.

“I have everything running through Verizon right now,” Miller said. “So, the only risk I have is that—if the Verizon system went down—I don’t have a backup or alternative. With the radios, I had the radio and cell-phone systems; so, if one went down, I’d still have some backup.

“I’ve kind of got a little more risk, because I’ve got everything on one system now. But, for us, I don’t see that as a critical issue. Out in the counties where we’re driving around, I’ve got a driver who’s carrying passengers and knows where he’s got to take the next one. If something happens, he could stop and get a landline [phone connection] or find another way to communicate back, if he needed to … We’re not a critical service; we don’t do critical medical transportation or something like that.”

For non-mission-critical enterprises, making the transition to a PoC solution is becoming increasingly commonplace, according to Dave George, president of Pryme Radio Products.

“It’s pretty typical of what’s going on right now,” George said during an interview with IWCE’s Urgent Communications. “We just seem to sell more and more accessories that are going on devices that are taking the place of radios—it just continues on.”

Two years ago, Pryme Radio Products’ sales of microphones, headsets and other accessories to be used in association with PoC systems represented less than 1% of the company’s business. Today, PoC-related sales accounted for about 15% of the company’s revenues.

“It [PoC] continues to grow; it’s definitely the growth side of our business,” George said. “I would say that the radio side is slowing down, for sure.”

George said a pattern is developing in PoC enterprise adoption, which he believes is being driven typically after the adoption of an application that leverages data connectivity.

“It seems to us that it always starts nowadays with an application, whether it’s special software for a transit company, like in this [SRTS] case,” George said. “If you talk to the customer, they had the dispatch software first. The software runs on tablets, so they needed tablets. The tablets need connectivity, so they talk to Verizon.

“Eventually, somebody says, ‘Hey, since we got these [tablets], I wonder if we can use them to talk, so we don’t need these old radios anymore?’ And then they need me, because I can make them a microphone, headset, a speaker or whatever it is they need. We just see that all the time now.”