It is the case that two device want to communicate but there is a pretty big distance between the two. The only solution to do that is to employ a protocol, specifically the Lora and not for example a satellite link. In fact Lora is a terrestrial link which require very low power and NOT visual communication because the frequency at which it works 915 MHz and the modulation called Chirp Spread Spectrum consent the receiver to ALWAYS get a clean signal.
The SX1278 module contains a modem which allows the sensitivity to reach over -148Dbm, and it also programmable to 300kbps datarate and providing excellent blocking immunity.
This device also offers GFSK modes.
Links
https://www.semtech.com/products/wireless-rf/lora-core/sx1278
https://www.raveon.com/wp-content/uploads/2019/02/AN205LoRa.pdf
