The Fire/EMS Pager + Fire Siren is a resource that allows players to have a pager on their person at all times. The pager is off by default, and must be tuned to tones in order to be paged. Once a tone or tones are paged, pagers tuned to these tones will receive the tone/s; if a tone is paged that a player is tuned to, they will hear a vibration sound and a notification will pop-up on their screen informing them of the call type, if a player is not tuned to a paged tone they will hear the tone sound, but not hear a vibration or receive a notification.
The fire siren allows a siren to be sounded at any of the fire stations around the map (custom stations for the fire siren, as well as custom tones for the pager can also be added to the resource). Once sounded, a siren can be heard within a predefined radius per station, and the further from the origin of the siren a player is, the quieter it will sound for them.
In the case of the pager, multiple tones can be tuned to, and paged at once; for the fire siren, multiple stations can be sounded at once as well. Once tones are being paged, or a siren sounded, they must finish completely before more tones are paged or sirens sounded, as tones cannot be paged over other tones, and sirens cannot be sounded over other sirens (note however, sirens can be sounded at the same time as tones paged, and vice versa).
The Fire/EMS Pager + Fire Siren resource is not only designed to be as efficient and lightweight as possible, but also to be customizable, and allow server owners to have as much control as possible over the resource, without the need to edit any code (with the exception of the configuration).