Description

If a warning message via a specific warning medium (such as television, radio or smartphone) is not perceived by a person in the danger zone or if a warning medium fails, a warning is issued simultaneously via a variety of other warning media (such as city information boards, warning apps, loudspeaker vans and websites). The more warning media are included in the warning media mix, the greater the probability that a warning message will reach people in Bavaria.

In addition, the warning media mix makes it possible to transmit warning messages in different ways. When used together, the individual warning devices complement each other. For example, a siren can broadcast a warning loudly, but only individual signal sequences are possible. The information content of a message in a warning app or on the radio, on the other hand, is significantly higher. The important initial recommendations on how those affected can protect themselves from danger in the first instance can only be presented in this way. And finally, warnings can be disseminated by acoustic, visual and haptic means (e.g. the vibration alarm of a smartphone).

The security and civil protection authorities use the following means in particular to issue general warnings to the population:

• Official hazard announcements and hazard notifications via radio,
• Sirens, which can also be used to broadcast the signal "Switch on radio and listen for announcement",
• Cell broadcast,
• warning apps.

Radio announcements

In the event of disasters, other incidents below the disaster threshold and large-scale hazardous situations, as well as false sirens, it may be necessary to warn and inform the population at a local level. For this reason, the security and disaster control authorities and the Bavarian police can arrange for announcements to be made over the radio using a defined procedure; subtitling on television is also possible.

In the case of radio announcements, a distinction is made between official hazard announcements, which are broadcast immediately and in full by the radio stations, and hazard announcements, which provide information at the earliest possible time (e.g. in the news) about expected hazards, damage situations and any expected effects.

Official hazard announcements or hazard notifications can be forwarded by the security and disaster control authorities - if necessary with the involvement of the integrated control centers - via the Modular Warning System of the Federal Government (MoWaS) and via the operations centers of the Bavarian police to the radio stations connected to the traffic warning service. In the case of warnings due to the risk of forest fires or severe weather, these are sent directly from the German Weather Service to the radio stations.

Siren signals

Sirens are also used to warn the population, primarily in areas or in the vicinity of facilities with a particular risk potential.

Bavaria has defined the meaning of the siren signals used in Bavaria in its ordinance on public sound signals. The most important siren signals are

• the alarm in the event of fire and other emergencies, which is used to alert the fire department.
  Signal: Three constant tones (continuous tone), each lasting twelve seconds, with a twelve-second pause between each tone.
  _ _ _

• The alarm, which is intended to prompt the population to pay attention to radio announcements in the event of serious threats to public safety.
  Signal: a rising and falling wailing tone lasting one minute.
  
  ~ ~ ~

• to give the all-clear that the danger no longer exists.
  Signal: continuous continuous tone lasting one minute.
  
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In areas where sirens are available to warn the population, the population is usually informed about the siren signals and their meaning from time to time in brochures or on the websites of the responsible authorities. In addition, every year in the first half of the year (second Thursday in March) there is a standardized nationwide test alarm and in the second half of the year (second Thursday in September) there is a nationwide warning day in which every municipality that has the appropriate sirens can participate. These test alarms are used not only to

In addition to testing the function of the sirens, these test alarms also serve to inform the population about the importance of warning messages in general, but in particular the siren signal in preparation for radio announcements.

Cell broadcast

Cell broadcast uses the signaling channels of the mobile radio network to transmit messages. Individual addressing is not necessary. Alerts are sent from the antenna like a radio signal to all devices logged into the radio cell and received by them. With cell broadcast, the wake-up effect is significantly increased. A warning message of warning level 1 (highest danger) triggers a perceptible signal tone even on smartphones set to silent in order to react to a warning message.

The advantage of this is that all persons in an area who are carrying a mobile device set up for this purpose and ready to receive can be reached anonymously as recipients of a warning message. In the event of a hazardous incident, all persons within the affected radio cell who are carrying a mobile radio terminal that is set up for this purpose and ready to receive alerts will receive a warning message in the form of a cell broadcast message on their mobile radio terminal (see: further links).

In addition to radio announcements and sirens, loudspeaker vehicles, digital city information boards, passenger information systems and smartphone apps are also used to warn the population.