Overview

• At 11:00 the BBK will issue a test alert via MoWaS, with local sirens using a one‑minute rising‑and‑falling tone and a one‑minute steady tone planned for the all‑clear around 11:45.
• Cell Broadcast will deliver the warning to compatible smartphones but will not send an Entwarnung, as the service currently supports alerts only.
• Multiple channels will be exercised, including radio and television, warning apps such as NINA, KATWARN and BIWAPP, digital city displays, Deutsche Bahn systems and local sirens or loudspeaker vehicles.
• Participation is voluntary and coverage varies by municipality, with some areas lacking sirens or relying on apps and Cell Broadcast only, including Munich where fixed sirens were removed.
• The BBK will collect user feedback through an online survey from 11 to 18 September to inform technical analyses and targeted upgrades.