unless confirmed, clutter free, direct line of sight with RSSI >>say -110dbm at low to mid SF 
But yeh 10-15m with minor absorber best! 
In practice RSSI’s in Range -65 to -90dBm general good to go…
and then the in the detail 
unless confirmed, clutter free, direct line of sight with RSSI >>say -110dbm at low to mid SF But yeh 10-15m with minor absorber best! In practice RSSI’s in Range -65 to -90dBm general good to go…
and then the in the detail