T-Mobile tests drones as flying 5G base stations for uninterrupted coverage
T-Mobile has deployed two fixed-wing drones from Primoco UAV during a running event in the Czech Republic to provide temporary mobile coverage in an area where existing infrastructure only offers partial coverage. The drones effectively acted as airborne mobile base stations. At the same time, the trial tested whether two aircraft could alternate during the operation, including landing, refueling and taking off again, without interrupting the mobile service.
5G coverage from the air
The trial took place in a sparsely populated former military area. A small mobile base station was installed at the start and finish of the race and connected to the mobile network via satellite. Two Primoco One 150 drones operated above the race route, extending mobile coverage from the air.
The equipment carried by the drones functions as a mobile base station. The connection to the core network is provided via satellite, eliminating the need for a fixed or microwave backhaul connection on the ground. For users, nothing changes: smartphones automatically connect to the available mobile cell.
At an altitude of approximately 2.3 kilometers, each drone could provide coverage over an area of up to around 20 square kilometers. During the test, data speeds of up to 100 Mbit/s were achieved using a 10 MHz channel. Almost 1,900 participants took part in the race.
Two drones for continuous operation
An important part of the trial was not only providing mobile coverage, but also testing the handover from one aircraft to the other. While one drone remained operational, the other could land and be refueled. It could then take over the task again.
According to T-Mobile and Primoco, this approach could allow such an airborne mobile coverage system to remain operational for much longer periods. This could be relevant when mobile communications need to be temporarily restored following an incident or natural disaster. The current trial, however, focused on testing the technology during an event.
Primoco uses its One 150 for the operation. The aircraft can remain airborne for up to 15 hours, has a maximum operating altitude of 3,300 meters and can carry up to 30 kilograms of equipment. Previous tests involved a mobile installation weighing approximately 8 kilograms.
Earlier airborne 5G deployments
Using drones to provide temporary mobile coverage is not a new concept. In 2017, US telecom operator AT&T deployed a tethered drone in Puerto Rico to help restore parts of the mobile network following Hurricane Maria. The so-called Flying COW (Cell on Wings) was connected to the ground by a cable and provided 4G coverage over an area of more than 100 square kilometers from an altitude of approximately 60 meters. According to AT&T, the system could serve up to 8,000 users.
The main difference with the current trial is that the Primoco drones are not tethered to the ground and operate at a much higher altitude. This makes it possible to provide temporary mobile coverage over relatively large or difficult-to-reach areas with a small number of aircraft.
The technology is particularly relevant as a temporary supplement to existing mobile infrastructure. A drone can potentially be deployed relatively quickly in locations where conventional cell towers are unavailable, damaged or unable to provide sufficient coverage. The combination with satellite connectivity also allows the temporary base station to operate independently of local ground infrastructure.
