LA County portion of LA-RICS public-safety LTE network halted for two weeks, as deadline looms

At the same time as LA-RICS is building the public-safety 700 MHz LTE system on FirstNet’s Band 14 broadband spectrum, it also has contracted with Motorola Solutions to build a P25 land-mobile-radio (LMR) system on 700 MHz public-safety narrowband spectrum.

Although P25 systems operate at much greater power levels than an LTE system, firefighters and residents have not expressed the same RF-emissions concerns that they have with the public-safety LTE sites, Edson said.

“No one’s complaining about that [LMR network],” Edson said. “But that build is coming behind [the proposed deployment sites for] LTE. And that build is going to make use of a lot of existing hilltops and not so much the parking lot of a fire station, a sheriff’s station or a police department. We might have receiver sites at those kind of locations, but as far as the transmitter sites, they are not going to be nearly as prevalent. They will be more where we currently have existing sites.”

At the moment, the focus for county officials and other members of the LA-RICS JPA is to allay fears among firefighters and residents that LTE cell sites are unsafe, as well as address concerns about the way the sites appear, Edson said.

“I’m comfortable—and I believe the sheriff is comfortable—that the technology is safe,” Edson said. “The bottom line is that we’re going to have to prove to the firefighters and prove to the public that they’re safe. So, the next issue that we’ll need to address is aesthetics.

“I believe, and the sheriff believes, that we’ll be able to convince the public and the firefighters that these are safe. We’ll resume and continue to build out—with public support, because of the value that the network brings—and then we’ll just have to ensure a better communication and discussion to the area that we’re going to be building this about the aesthetics. It might cost us a little more, but ultimately we feel pretty confident that we’re going to get there.”

Getting beyond this controversy is critical, because the public-safety LTE network is needed in the LA region for several reasons, Edson said. Commercial wireless carriers have blanketed the area with cell coverage and bandwidth capacity, but getting permission to deploy additional sites is almost impossible. As a result, when a public-safety incident occurs, first responders that try to utilize a commercial system are stuck trying to compete with the hoards of general-public users that also seek access to the network.

In addition to operating on a network dedicated to public safety, the LA-RICS sites are designed to be hardened to withstand weather-related and other physical circumstances that many commercial sites are not built to handle, Edson said.

“So, when there’s a train crash in Chatsworth, which we had years ago and those kinds of situations that happen, you get all of law enforcement and fire showing up, you get the media showing up, and you get the public showing up,” Edson said. “As you know, that fills up the cell site, and we [public-safety officials] can’t get access.

“Having these LTE cell sites on our Band 14 [spectrum] makes it private for us, and they are public-safety grade. So, when that large earthquake occurs or that train crash happens, we will be able to communicate, while everybody else is disconnected.”

Although most public-safety LTE systems in the country are focused almost exclusively on broadband data, a key component of the LA-RICS LTE system is to provide voice over LTE from the outset. Mallon has said that this is needed, because Los Angeles is one of several metropolitan areas that are scheduled to lose their rights to operate on T-Band spectrum in the 470-512 MHz range in 2021.

LA-RICS is building the 700 MHz P25 network and hopes to migrate many current T-Band LMR operations to the new LMR system, but there are not available channels in that spectrum swath to replace the voice capacity lost via the T-Band mandate, Mallon has said. To help address the problem, LA-RICS plans to offload voice traffic that is not mission critical to its LTE network and reserve the P25 network for mission-critical-voice operations initially, he has said.

Meanwhile, the standards body overseeing LTE technology has taken steps to address public safety’s communications needs. Current plans call for an LTE standard that supports mission-critical voice to be released next spring.

“More than half of the law-enforcement agencies in LA County, including the sheriff’s department, is [on] T-Band,” Edson said. “LA-RICS is the savior for that. We’ll be starting out with a lot of UHF and as much 700 [MHz spectrum] as we can get our hands on. Between now and [the T-Band deadline in] 2021, we’ll be looking for more 700 [MHz spectrum] and reducing the UHF footprint.

“Everyone thinks that we can get to mission-critical voice over LTE sometime down the road and get rid of some of these other radio system. So, ultimately, those LTE towers are going to be even more important to be public-safety grade, because—at some point—we’ll be doing some voice operations on them.”