Chongqing — Researchers at Chongqing University of Posts and Telecommunications have developed a long-range communication system recently, designed to maintain connections in remote polar regions and open seas where satellite signals are unreliable or unavailable.

The project, led by Li Guojun, director of the university's Lab of Beyond Line-of-Sight Reliable Information Transmission, won first prize in technological invention at the 2025 Chongqing Science and Technology Awards, announced October 16.

Li Guojun (second from right) guides students during an experiment at the Lab of Beyond Line-of-Sight Reliable Information Transmission at Chongqing University of Posts and Telecommunications on September 30, 2026. (Photo/Chongqing Daily)

Polar regions present major communication challenges. Vast distances, limited ground infrastructure, and extreme space weather can disrupt satellite services, affecting shipping operations and scientific expeditions.

To address these challenges, the team developed technology that uses the Earth's ionosphere and troposphere to reflect or scatter radio waves, allowing signals to travel beyond the horizon without relying on satellites.

Over more than a decade, the researchers established more than 20 observation stations in China and abroad, building China's first atmospheric beyond-line-of-sight communication testing platform covering major polar regions.

The work was far from routine laboratory research. With little existing data or established models to draw on, team members conducted field measurements in harsh environments, from the Gobi Desert to Antarctica. They often built observation stations themselves, enduring extreme temperatures and difficult terrain.

In the Gobi, a shortage of construction workers turned researchers into masons, steelworkers and welders. They dug pits, poured concrete foundations and welded equipment mounts. Moving instruments weighing more than 200 kilograms required help from local herders, with researchers walking several kilometers to arrange transport. 

Sunburn left their skin peeling and painful even at the touch of water. In Antarctica, extreme cold, salt spray and freezing rain tested both crews and equipment.

“You have to know how to do everything, and do it all,” said Li. Despite the difficulties, he said, the team needed to collect firsthand data in deserts and polar regions to meet major national needs.

Their research produced a polar communication database, specialized transmission equipment and a communication guide for the Arctic Northeast Passage, supporting communication needs for polar shipping and scientific research.

The technology could also help closer to home. During earthquakes or floods, damaged ground networks and disrupted satellite signals can leave communities isolated. Li said the system could provide an independent communication link for emergency responders, complementing existing satellite networks such as China's BeiDou system.

The team, which has grown from four researchers to more than 40, now plans to expand applications to disaster response in remote communities and communication with low-altitude aircraft.