Drones can bring benefits to disaster-relief scenarios in a few ways. One is by providing search and rescue workers with an eye in the sky, another is by delivering aid, and a third is serving as temporary communications networks in place of those destroyed by the event. Researchers at the University of Texas (UNT) have taken a promising step forward in this last area by demonstrating a drone-based cell network system that offers coverage kilometers away.

When violent storms, tornadoes and hurricanes strike, they can not only bring buildings to the ground but communication infrastructure too. This makes things even harder for workers relying on these networks to coordinate their relief efforts, and the idea behind research projects such as these is to provide a temporary solution.

And these research projects have been in the works for a while. Wi-Fi-beaming micro-drones developed by German researchers back in 2009 are an early example of this, while these days even big private players like Verizon are getting in on the action, as evidenced by its much larger, fixed-wing approach that was revealed last October.

The scientists in the University of North Texas' electrical engineering department have also been active players in this field. In 2014 they exhibited a new kind of directional antenna they said could be attached to drones to provide Wi-Fi signals up to 5 km (3.1 mi) away.

Now, in what the team is calling the "first-ever drone-provided cell service," the researchers have taken their airborne communications tech into the field. It says its Aerial Deployable Communication System is the first of its kind, and they were able to successfully test it in Waxahachie, Texas. This involved fixing the system to a drone and sending it up to an altitude of 400 ft (121 m). The cellular technology was programmed to tune into the bandwidth assigned to first responders, offering them a high-flying replacement for damaged cell towers.

"We demonstrated a portable communication system that can be attached to a drone," said Kamesh Namuduri, an associate professor in the Department of Electrical Engineering at UNT. "The system, with just 250 milliwatt transmit power, is capable of providing instant cellular coverage up to two kilometers during disaster-relief operations. If the system is scaled with a 10 watt transmit power, the system can provide cellular coverage to the entire city of Denton (Texas)."

In August, the team will present the results of the experiment at the 2017 Global City Teams Challenge Expo in Washington, D.C., where they will also be showing off the communications system.