APRS

Automatic Packet Reporting System (APRS) is an amateur radio system used to digitally communicate data such as GPS coordinates, weather, text messages, etc.

APRS typically uses a single shared frequency (144.39MHz in North America) depending on geographic area and repeated via digipeater and relayed to the Internet via IGates.

https://en.wikipedia.org/wiki/Automatic_Packet_Reporting_System

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