What proximity does my iPhone need to be for this to work
What proximity does my iPhone need to be for fall detection to work with Apple Watch.
Apple Watch Series 4
Question marked as
I'm assuming you have a GPS only Apple Watch.
Bluetooth range is typically 30 to 50 feet (10 to 15 meters). This depends on the number of walls and floors are between the iPhone and the Apple Watch, and what the walls and floors are made of (reinforced concrete is worse than wood and drywall).
If the iPhone and the Apple Watch are on the same WiFi network, AND your Cellular provider supports WiFi Calling, AND you have enabled WiFi calling on your iPhone and your Apple Watch. Then if you are at home, it should work as long as both the iPhone and the Apple Watch are in range of your WiFi.
If you have a Cellular Apple Watch, and are in range of your Cellular carrier's signal, then it does not matter where the iPhone is, as the Cellular Apple Watch will just make the emergency services call directly.