Overview

• The BBK will trigger a Probewarnung via MoWaS, distributing test alerts through Cell Broadcast, warning apps, radio and TV, sirens, and digital displays.
• An all-clear is planned around 11:45, though Cell Broadcast cannot deliver Entwarnungen and will not issue one.
• Participation differs by location, with some areas testing sirens and loudspeaker vehicles while others like Munich rely on digital channels; MoWaS stays available for real incidents during the exercise.
• Only devices with recent software (iOS 16.1 or later, Android 11 or later) reliably receive Cell Broadcast, so users should verify settings and connectivity.
• The BBK will collect public feedback in an online survey from September 11 to 18 to guide improvements.