The HC12 is a wireless transceiver with ~1 km range. It is exceedingly easy to integrate into wireless applications as a wireless serial port extender.
Complete Project Instructions shown at https://www.allaboutcircuits.com/projects/understanding-and-implementing-the-hc-12-wireless-transceiver-module/ and https://www.allaboutcircuits.com/projects/gps-transmission-with-the-hc-12-transmitter/
Example01 is a simple proof-of-concept sketch that allows a user to determine if everything is wired correctly and working. Example02 is a versatile sketch that handles local and remote control of HC12 transmitters using AT commands. Example03 integrates a GPS receiver into the mix Example04 provides NMEA sentence decoding and transmission.