Reverse 911 Systems are used by counties to provide residents with phone, text or email notification of emergency situations, or other situations that warrant community notification, such as major weather events. These systems are set up and run at the county--not the network--level, and automatically include traditional landlines.
How do I know if my county has a Reverse 911 System?
You can either search online for "reverse 911 system + your county" or check your county's website. Not all areas have a Reverse 911 System so confirm with your county to be sure.