Normal 120 Volt smoke detectors with battery backup do not send signals to a central station that dispatches the authorities.
System smoke detectors will notify the central station rather than just making noise. Normally the smoke detectors are set up just to wake you up. Sometimes people do not wake up but are overcome by smoke and they die.
I like designing a security system in a home with at least one smoke detector up and one down that is tied to the system and will send signals. If you are on vacation these detectors will also notify dispatch who in turn can call the fire department.
Call Larry Love Larry.love@jci.com (801) 898 6003 for more information