PTT-over-cellular improvements could impact new private LMR network builds within five years, speakers say

Graves echoed this sentiment, noting that the maintenance issues associated with private LMR systems are problematic, particularly as key support staff members retire and replacements become difficult to find and/or train.

“I’m totally with you,” Graves said. “From an IT perspective, I look at where we’re going with what they call the cloud, what I call outsourcing. [Transitioning to PoC] is the same principle, when you start thinking about it.”

Cellular carriers have much greater resources to address network problems than a government entity like the city of Richardson, Graves said.

 “I have a 4.9 GHz wireless system right now; it’s WiMAX,” he said. “I can tell you that it’s a maintenance nightmare for us. If something happens, I have to have someone come out, climb poles, pull base stations down, pull down different devices.

“From our perspective, when we put it up, there wasn’t anything out there to work in its place. What ended up happening is that LTE now has end points, so I can replace my WiMAX system with these end points, and I don’t have to mess with the actual network itself—AT&T, or whomever, takes care of that for me. It makes it a whole lot easier on us for maintenance on all of those things.”

Graves noted that there are some key considerations that governments should evaluate before making a complete transition to PoC, such as the coverage and reliability of the service provided by the carrier.

“You definitely want to have good cellular coverage,” Graves said. “If you’re enhancing an LMR system—in other words, they’re going to have both [LMR and PoC]—then I wouldn’t worry about it. But, if you’re trying to remove radios from the field and just want to use the app, you want to make sure you have good coverage.”

Graves also said that he wants the PoC system to provide the kind of encryption that will allow PoC users to participate in LMR conversation on encrypted P25 communications—something that AT&T partner Kodiak has indicated will be available during the first quarter of next year.

Meanwhile, when carriers deliver the mission-critical push-to-talk (MCPTT) services that meet the 3GPP specifications with appropriate priority for public-safety users, the offering could result in fewer entities subscribing to FirstNet, Graves said.

“I’m going to make a lot of FirstNet people mad,” Graves said. “These kinds of technologies are FirstNet killers, in my opinion.

“Let me tell you why: Because, once they figure out the priority of the calls, and once they—and I know it’s a touchy subject, and a lot of people are going to cringe when I say it—but once they figure out how to drop calls on a network in an emergency and they have priority set for officers, firemen, … Once they do that, I don’t know why we have to spend billions of dollars on a private network across the country when we already have state-of-the-art networks out there with AT&T, Verizon—we could go on and on. But, in my opinion—for what it’s worth—I think that, once they clear up a few things, this is a FirstNet killer.”

PoC also could have a negative impact on the usage of private LMR networks, Graves said.

“That’s going to go away, too, sooner or later,” he said. “It will, as soon as people realize that you can run across these networks and be safe.”

In contrast, Hamlet Sarokhanian of AT&T said that the carrier giant has based its business plans on the idea that LMR networks will remain viable for the foreseeable future.

“We convinced ourselves a few years ago that our strategy should be based on the fact that LMR is not going to go away for a long time,” Sarokhanian said during the webinar. “Our basic approach is that LMR is not going to go away.”

“In profiling the customers, it shows that they’re inclined more and more to being open to augmenting their system with push to talk over cellular. The trend is going to increase more and more, but it’s not going to be overnight.”