Private LTE fills coverage gaps for communication emergencies

The Colorado Department of Transportation (CDOT) and students at the University of Denver are preparing to pilot new technology that aims to fill gaps in cellular coverage along highways.

“There’s pockets of high terrain, low valleys, [so] cellular service cannot get everywhere,” said Bob Fifer, CDOT’s deputy director of operations. 

This point was driven home last year when heavy rains left debris in Glenwood Canyon, about two and a half hours west of Denver, blocking Interstate 70.

“In that canyon, the only thing we had in there were radios,” Fifer said. “The radios worked fine, but … our fiber optics were destroyed in the canyon, so we were having intermittent communication issues,” he said. What’s more, responders couldn’t share photos and videos to provide full situational awareness, putting them and other officials at a disadvantage as they tried to reopen the affected stretch of road.

We thought that “if you could create some kind of private-type communication network that allows our first responders and our CDOT employees at least to have communications with one another … then we’d have some backup,” Fifer said.

The pilot will look at how a “network in a box” – or in a backpack or in a vehicle – could help during future incidents. The technology is from Eucast Global, a company that is setting up shop in Denver after spinning off from its South Korean founder, Eucast Co.

Housed in a metal box, the base station requires a power source and broadband connection via fiber optics, satellite or cell tower. Once on, the base station or backpack unit creates a private LTE, 4G or 5G network that everyone who logs into that base station can use to communicate. Several base stations can be connected to extend coverage.

In CDOT’s case, workers in an area without a signal would connect the base station into the state’s fiber as a backhaul and broadcast signal to allow people to access the internet, said Chris Medina, who sits on Eucast Global’s board of directors.

The base stations “connect to the very last mile of fiber that was set out there and literally daisy chain all the way to wherever coverage needs to be, spanning a mile, 2 miles, depending on the terrain,” said Medina, who’s also co-founder and chief strategy officer at Clovity, a software and IT services company that develops proprietary internet-of-things software. “Obviously, flat terrain is going to give you a little more distance and span. One that has a little more treacherous terrain, you would strategically place them where they can overlap.”

If none of those backhauls is present, CDOT could use the backpack version that’s available out of the box or a car unit that gets power from a vehicle. Someone turns it on and everyone subscribed to it can communicate, Medina said.

Each network can handle about 200 concurrent users, but if all 200 are not actively using the network, the technology can dynamically load balance to ensure users can get on. If more people need to connect, more base stations can be added.

“It has seamless mobility. That means, as long as it’s overlapped, one base station is telling the other that ‘I’m on my way, going to that direction. Don’t drop the call, don’t have any lag.’ It’s connecting itself as you go, so you’re always staying connected,” Medina said.

Fifer said CDOT will deploy two or three base stations near Bayfield in an area just east of the Eisenhower-Johnson Memorial Tunnels where there are 3 to 5 miles of dead zone. If the technology is not set up by November, he said testing will likely start next spring, after the tourist-heavy winter season. 

He wants the tests to run for a year. “You have all sorts of different environmental impacts that happen in a year: weather, high temperatures, cold temperatures, sun flares,” he said. “You’ve got all sorts of different things to see how stable that system is.”

To take the Eucast technology further, Fifer said he will need to see two things. First, smartphones with a dual SIM card should be able to switch to the private network – which he dubs CDOT LTE – and then back off of it, and users on the network must be able to call people not on it.

“If that doesn’t work at all, then obviously this is not interesting to us because I’m just trying to create coverage that is carrier-agnostic for basically the state employees that have to work in that area,” Fifer said.

If it does work, he views Eucast as a temporary fix until one of the three main carriers – AT&T, T-Mobile or Verizon – can set up shop in the unserved areas.

“To me, FirstNet is the one who’s solving for those first responder networks, so I’m not trying to compete nor even suggest competing with FirstNet,” he added. “It’s more [like access for the] little spots that could temporarily – that could be one, two, 10 years – cover the cellular for first responders that have the program to access LTE.”

Meanwhile, the company is plowing ahead with testing of its own, including a network in a box attached to a drone, which, without terrestrial obstructions, could reach farther than the 2 miles the other systems do. That solution should be available in the third quarter of 2023, said Gary Sumihiro, CEO of Sumihiro Investments, which helped bring Eucast to the States.

Stephanie Kanowitz is a freelance writer based in northern Virginia.