DTM 2026: What's behind the mysterious U-shaped piece on the roof?

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A white U-shaped attachment mounted on the roof of most DTM cars first drew attention during the official pre-season test at Spielberg in mid-April. Interestingly, by last month's season opener at the Red Bull Ring, every car was fitted with the device, with a cable leading into the cockpit.

As it turns out, for the first time this season, DTM cars are equipped with onboard antennas capable of transmitting data at 5G speed. 5G – the fifth generation of mobile communications technology – currently represents the most advanced wireless standard available, enabling large volumes of data to be transmitted in real time with virtually no delay.

The onboard antenna is mounted on the roof of the car in a position designed to avoid interference from other radio signals. It even features an integrated router and connects to access points positioned around the circuit, allowing onboard camera footage from inside the car to be transmitted through a dedicated wireless network.

The system, supplied by Riedel, is not only being used in DTM from 2026 onward, but also in the ADAC GT Masters and GT4 Germany championships. However, because not every car currently carries onboard cameras for the TV broadcast – the remaining cars run dummy units for weight-balancing purposes.

Teams must also ensure that the antenna’s cooling duct is not obstructed. The long-term goal of the 5G rollout is for every car in the field, rather than only around one-third of the grid, to feature onboard cameras for live TV coverage.

Until now, onboard footage was transmitted using conventional signal technology alongside a fibre-optic network installed around the circuit to relay the video feed back to the broadcast trucks.

Onboard Antenna

Onboard Antenna

Antennas made less conspicuous after testing

Interestingly, the position of the U-shaped antennas changed on several cars between the pre-season test and the opening race weekend, and some units were even painted in team colours. This followed efforts by DTM organisers to make the devices visually less intrusive after the initial test outing.

On the Mercedes-AMG GT3, for example, the component was initially mounted toward the front of the roof during testing before being relocated further rearward by the start of the season.

The innovation could also pave the way for further developments. At present, the cars can carry up to three separate camera systems: one for the TV broadcast, one for the team, and the incident camera system used by the stewards to review contentious situations.

Currently, incident cameras store footage on sealed memory cards that are retrieved and downloaded by technicians after each session. With the new 5G system, it may eventually become possible to use a single camera system capable of transmitting all video data live in real time.

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