三星电子美国公司（Samsung Electronics America）移动B2B产品负责人鲍勃埃斯卡尔（Bob Escalle）表示，LTE推送通话服务通常可以为第一响应者提供更好的音频质量，它利用比窄带LMR更大的频谱
Public-safety users are benefiting from the data-oriented capabilities enabled by LTE on trusted networks today and also will transition voice communications to the broadband platform, although the timetable for this change remains unclear, according to experts discussing the topic this week.
“We always end up in this conversation about when—or will, even—will LTE replace LMR, and can it, but we may want to reverse that conversation,” Johnson said during IWCE’s In-Building Forum virtual conference, which was conducted in partnership with the Safer Buildings Coalition. “It’s already replaced some components. I don’t know of anybody buying LMR-based data systems anymore, because the thirst for our applications, our data needs, are so much that you can’t possibly make that work in a rational fashion.
But that could change in the future, depending on the development of push-to-talk voice offerings in the LTE realm, particularly those operated on public-safety-centric networks like the FirstNet system being built by AT&T, Johnson said.
“That’s true on both LMR and LTE. So, what’s irreplaceable? When you look at it that way, it’s feature sets and how it performs. So, will it [LTE replace LMR]? Well, it will replace it, if you solve the operational requirements, and it performs at least as good or better than LMR on push to talk, and it’s already outperforming it in the other areas.”
“We’re striving to get there,” Brown said during the panel discussion. “We’re building mission-critical [services], based on 3GPP-standard devices, with the help of our partners at Samsung, to deliver those solutions that the chief so eloquently put together.
Bob Escalle, head of products for the Mobile B2B of Samsung Electronics America, said one advantage that LTE push-to-talk services typically can provide to first responders is better audio quality that leverages much larger swaths of spectrum than is available in narrowband LMR.
“But you do lose some of the voice qualities—the inflection you hear around somebody’s voice—and you don’t have that on a broadband codec. You really get that rich voice coming out. So, it really is a voice-centric device, and it takes advantage—of course—of the broadband network.”
Some LTE proponents contend that “bring the network with you” solutions—particularly those that can be carried in backpacks and Pelican cases—could minimize the amount of time that first responders would need direct-mode functionality.
“Right now, we know it’s in a mobile-class router device—more of an in-vehicle-type device—but we know that there are a lot of UE companies that are working on it,” Escalle said. “Eventually, I think you’ll see a high-power UE version in a handheld device at some point in time. I think there are benefits around that.
Johnson said that LTE push-to-talk services will have to demonstrate a very high performance level before public-safety officials will consider switching off LMR systems that offer some trusted characteristics.
“I also think they’ve done a great job with security—encryption has been a great feature. And for the fact that they are excellent for in-building penetration and for long-range operation, both from the mobile and the handset. So these high-power units have served us well for a long time, even though it is push to talk and let up to listen, and public safety has evolved beyond that.
AT&T’s Brown said he certainly understands this sentiment.
“I would never try to take that LMR radio out of public safety’s hands. But one day, who knows?”
“When you start [using broadband applications], you make having a smartphone for a first responder indispensable,” Johnson said. “Once it’s indispensable, if you have push-to-talk capability and the coverage and in-building penetration is reliable, then you’re going to have a lieutenant say someday to a battalion chief, ‘How come I have this thing [LMR portable radio] when all I have used is my smartphone with push to talk?’