CDOT finds a low-cost answer to its cellular dead zones, making canyon calling possible

Flooding and massive rockslides in Glenwood Canyon in 2021 cut fiber optic lines and created a communications nightmare for the Colorado Department of Transportation, making it hard to stay in touch and share data with crews as they worked on the emergency response and later on repairs.

And every day, along long stretches of Colorado highways, cellular service can be spotty or nonexistent, causing employees and vehicles to disappear off the radar screen. For a snowplow driver navigating an isolated road in a blizzard, it can be the equivalent of a pilot losing all contact with the control tower in a thunderstorm. No one would hear a distress call.

Since last fall, the department has been testing a South Korean communications technology, supplied through a Denver startup called Eucast Global, along a problematic four-mile stretch of highway from the Bakerville to Silver Plume exits, east of the Eisenhower Tunnel, where the terrain makes it difficult for cellular signals.

“The test results were amazing and very impressive,” said Bob Fifer, deputy director of operations at CDOT. “We went from zero cellular services to a full signal with video streaming, calling, talking.”

Eucast boxes are relatively small and the tests proved they were weather resistant. They attached to existing light poles, drawing on the nearby power supply. Once powered, they connect to nearby cellular or satellite networks or tap into fiber optic lines and can handle about 200 devices. But their real power comes in using a spectrum the FCC recently opened up for public use called Citizens Band Radio Service or CBRS.

“We have identified a technology that is faster, more efficient and less expensive,” said Gary Sumihiro, an international trade consultant who came across the technology while in Asia. Eucast Global has the rights to deploy the technology to the Americas and Europe, and is starting with Colorado. The goal is to eventually manufacture the devices domestically.

By dropping a second SIM card into its devices, whether in the hands of an employee or mounted on equipment, CDOT can communicate on a secure and private network without any additional monthly service charges. And because the boxes can communicate with each other, CDOT doesn’t have to run fiber to each location.

“We are doing one last test. I am having my technology team install a camera on a wireless cellular modem,” Fifer said. The goal is to see how well the Eucast boxes can live stream video, something CDOT has struggled with because wireless providers don’t want their bandwidth hogged up by live feeds, especially in areas with limited cellular tower coverage.

Many cameras on COTrip.org show a static picture rather than a constant feed because of that limitation. Also, having cameras and message boards on a private network allows for greater autonomy when it comes to adding or removing devices, avoiding a call to the cellular provider to switch out gear. And private networks are more secure against hacking, making it harder for people to take over highway signs and change the message.

Four boxes were installed along I-70, more than would normally be required, because of the tricky terrain. Students from the University of Denver helped configure the system and conduct the tests.