Drone detection using existing mobile networks is being tested in Sweden, with radio signals from cellular towers used to locate small drones in the air. Tests have detected even very small aircraft with an accuracy of a few metres, according to Sveriges Radio, potentially allowing tens of thousands of mobile towers to contribute to future airspace surveillance. Sveriges Radio reports on the Swedish tests
The technology remains experimental. Sweden has not created an operational nationwide system, and the trials concern the detection and positioning of drones, rather than measures to disable or destroy them.
How mobile towers could support drone detection
The system being tested uses radio signals already transmitted by mobile towers. When those signals encounter a drone in the air, part of the signal is reflected and can be analysed to determine the aircraft’s position.
According to Sveriges Radio, the trials have been able to locate very small drones with a precision of only a few metres. If the technology can be developed further and deployed at scale, Sweden’s extensive mobile network could provide a widely distributed source of signals for monitoring parts of the airspace.
The approach is related to passive radar, which uses existing radio transmissions rather than relying exclusively on a dedicated radar transmitter. Mobile towers themselves would therefore not simply become conventional radars: receivers, signal processing and other equipment are still required to identify and track objects from the reflected signals.
Sweden has already researched passive radar for drones
The current tests are part of a broader Swedish interest in using passive radar against unmanned aircraft.
Sweden’s innovation agency Vinnova previously supported the PARAD project, which examined how bistatic passive radar could be incorporated into multisensor systems for drone surveillance. Field tests identified two possible system architectures that met the project’s main requirements. Vinnova’s PARAD project
The Swedish Defence Research Agency (Totalförsvarets forskningsinstitut, FOI) has also explored the use of telecommunications infrastructure for passive radar. Its 2026 research programme included experimental work using LTE and 4G signals to detect targets, with possible applications for monitoring vehicles and drones in urban areas and around critical infrastructure.
Small drones are becoming harder to ignore
The tests come as European defence authorities devote increasing attention to small unmanned aircraft. Sveriges Radio points to recent security incidents in Europe, including attempted sabotage in Germany and military drone activity around the Baltic region and Finland, as part of the wider context driving interest in better detection systems.
Small drones can be difficult to monitor using a single type of sensor. Swedish research on counter-drone systems has therefore increasingly focused on combining different technologies. A 2026 FOI report on counter-unmanned aerial systems concluded that effective protection requires a combination of technical systems, training, tactics and information sharing, rather than a single detection method.
Using mobile-network signals could eventually add another layer to that system by taking advantage of infrastructure already spread across Sweden. For now, however, the technology remains under testing, and there is no indication that the country’s tens of thousands of mobile towers are being used as an operational national drone-detection network.
