Panelists note public-safety benefits in LTE standard, cite work that needs to be done

Public-safety LTE can provide much greater data speeds than LMR systems and potentially better audio quality in the future, but key first-responder capabilities—notably, group communications and off-network functionality—are not yet in the LTE standard, economic pressures could hinder their development, panelists said during a public-safety session at the recent LTE North America conference in Dallas.

Currently, 3GPP—the global standards body that oversees the development of LTE—has plans to include public-safety functionality in Release 12 (expected to be “frozen” in March 2015) and Release 13 (with a scheduled “freeze” date of March 2016). But these standardized features will only be included in actual LTE products if manufacturers see a clear market for them, according to Emil Olbrich, vice president of network technology at Signals Research Group.

“When you look at features that are being developed in the standard right now—for instance, direct mode or pro se proximity services, which is the ability for one device to communicate directly to another device—that’s in Release 12 of the [LTE] standard right now. That work is being done,” Olbrich said. “The ability for group communications—that work is ongoing right now. High-powered UE for high-powered devices—that’s in the standard right now.

“Here’s the problem. All of those public-safety features are in [the LTE standard] right now, but none of those will get developed, unless there’s money behind it—that’s just the reality. We can beat our chest as an industry all we want, but this industry is driven by money, by economics.”

Phil Kidner, CEO of the TETRA + Critical Communications Association (TCCA), echoed this sentiment.

“Let’s say there are 7 million [users of TETRA and P25 LMR equipment],” Kidner said. “Well, there are about 7 billion consumer phones. So, guess where are all of the innovation and investment are going?”

Given this market-share challenge that public safety faces, Kidner said that it is important that first responders worldwide use the same technology, so they can at least leverage their economies of scale.

“There are only 7 million of us, so let’s not have an American system and European system,” Kidner said. “Let’s have a global critical-communications system. The only way we’re going to get our voice heard in this state of things is if we say, ‘The whole critical-communications world wants this requirement,’ because we do the same jobs, and we do have the same requirements.”

Olbrich noted that tests of voice over LTE (VoLTE) on existing commercial networks have been promising, with the high-definition voice service consistently yielding a mean opinion score (MOS) of 3.9 or 4.0 under even the most trying of conditions, when the network is heavily loaded and the signal strength is weak.

“That’s LTE,” Olbrich said. “Whereas, under ideal conditions, a completely unloaded P25 network may yield a 2.3 MOS score—at best. What that means is that, on a scale of 1 to 5, your intelligibility is significantly increased.”