German researchers in Berlin have successfully trialed using cellular voice networks to remotely control drones.
Networks enable signals to be sent to and from UAVs and their controllers and communicates the drone’s location in space. At present, the communication between drones and their pilots is generally governed via mobile data networks. The Drive reports that Researchers from the Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institute (HHI) in Berlin discovered that by using existing mobile voice channels, the connection between drones and controllers were far more reliable than the equivalent mobile data channels.
The problem with mobile data networks is they are often unreliable and prone to interruptions which can be highly hazardous when a drone is flying in densely packed urban environments. It is vitally important that drones have stability of service, particularly in the industrial sphere where they may be carrying out important duties like delivering medical supplies.
HHI research associate Tom Piechotta told The Drive: “A major advantage is that – unlike the data connections – the voice channels are available almost everywhere and they’re highly reliable, too.” “Even in areas where there is only a limited data connection, or even none at all, there is usually still network coverage for voice channels,” he said.
How is data transmitted through voice?
HHI researchers found that because the data required for communicating between a drone and operator were relatively small, converting the digital signal into an audio signal was a straight-forward process.
“We convert the commands into audio signals, in much the same way as modems used to. A small module on the drone then translates the audio signal back into a command. Transmitting the information in this way is extremely favorable given that it works in real-time and is highly resilient to failures and connection disruptions,” Piechotta said.
But what about in areas where there is no voice signal?
The beauty of this system is that when this happens, the drone switches from one type of mobile network (LTE or GSM) to another (UMTS). The other security backup is for when signal is completely lost and in that case, the drone simply returns back to base.
The Berlin researchers that basing the communication between drone and operator through voice networks is smart because voice channels are a permanent feature of any mobile network and are unlikely to be affected by some as yet unforseen new type of mobile data solution (e.g a new 6G network). We’ll continue to monitor this story and give you the latest.