There is a feature enabled on Samsung phones that allow nearby phones to scan the area. My guess is … it’s using some sort of Bluetooth wireless technology.
Taken from Engadget … Samsung’s Find My Mobile feature can now work even if your device is offline. If, say, someone has stolen your phone and turned off the data and WiFi antennae, you might still be able to track it down.
Offline tracking works with the help of nearby phones and tablets, as Samsung Galaxy devices that have the feature enabled can scan the area for others. As such, they can report the location of a lost phone or tablet, and even watches or earbuds that they’re able to ping. This might not be truly effective in rural areas where there’s a lower density of devices, but it’s a welcome update that could help owners of lost phones and tablets recover them more frequently.
Looks like Samsung just added offline finding to Samsung’s Find My Mobile.
Let’s you track your phone even if it doesn’t have WiFi or cellular by using other Galaxy users. pic.twitter.com/psLl1rcb4X
— Max Weinbach (@MaxWinebach) August 22, 2020
Source: Engadget