Warning and alarming take place with the aim to communicate as fast as possible and in an organized unitary fashion all information concerning a potential disaster or another unwanted event, which might affect the population.
Notifying, warning, pre-alarming and alarming take place also with the aim to avoid catching off guard and to take all measures on population sheltering, material goods protection, as well as for limiting the effects of disasters, air attacks and those of military actions.
Usually, the public alarming systems are made up of speakers or sirens having various powers and command centrals. They may be pre-programmed or remote command activated.
Most public alarming subsystems have one or several electrical engine sirens located near the administrative institutions or certain economic entities. The sirens may be actuated from the operating panel located found in locations or by some classical phone circuits.