And how will your device know it is close to a gateway?
Hmmmm, no fix is like saying “on planet earth, last seen in the vicinity of” and is made somewhat redundant by the quality figure.
Maybe roll that in to one bit rather than a whole byte. What do you report after they have fallen. How can you tell they have fallen. And the fact you have “fallen” in your payload turns this from a bit of ‘too and fro’ and some discussion repeated else where on the forum in to a “you are kidding”.
Hmmmmm, you get two free bytes at SF7, one at SF8, four at SF9 and one at SF10. But you have the port numbers to use as well. However unless something really radical happens to battery life, it’s not really needed on every uplink - there are techniques to transmit it as it changes regardless of the payload format in use at the time of the uplink that I have but commercial in confidence.
Apart from the general consensus that tracking using LoRaWAN has some very specific useful use cases but not as a general tracker and certainly not to track little old ladies and if they have taken a tumble, you are going to have to get very scientific if you don’t want your plans shredded on here.
If you do go ahead, can you tell us which papers to look out for in your area so we can read about the court case!