We are 3 university students, our idea is to make (at least) a couple of devices that can measure the relative distance between them using rssi measurement. They would be wearable devices like "smartwatch" (just to give an idea), in order to monitor social distancing in workspaces, therefore to be used in indoor environment. We would like to use 868 MHz frequency to avoid attenuation of 2.4 Ghz due to human body and here comes your help... Our problem is that we are looking for a 868Mhz transreceiver compatible with arduino and easy to use (it's our first arduino project ever) but we have been finding nothing cheap. Moreover we would like to know if an addressing protocol is mandatory in order to know which device we are computing the distance of... e.g. i know there is the mac address for bluetooth devices to distinguish them, is there something similar for 868 MHz? If someone of you had some experience with this stuff it would be extremely useful if you could suggest us some module or give us some tips.
thank you so much