Your phone is NEVER off. That's why you can no longer take your battery out of your phone. Part of that battery is reserved for "Off". It takes days to drain the "off' usage of your phone as it requires very little power from the reserve part of the battery to run and if you have a 5g phone, even less as the signal itself can partially power your phone.
Faraday cage it, or wrap it in crinkled tin foil, this will give you the best chance to isolate your phone from sending and responding to the signals.
Ever look inside an old phone? It has a tiny battery in addition to the removable main battery.
It causes the phone to irreversibly corrode if dropped into water.
It maintains the clock when you switch batteries.
Probably some other nefarious purpose. The most benign might be storing encryption keys to prevent phone cloning. Storing keys in battery backed ram is one of the most secure ways to do it. See Capcom Kabuki and DigiCipher II.
Aside from #1 these are the same reasons we have kept a cmos battery on PC motherboards for decades. The ability for 3rd parties to still access your device without your knowledge from the "off" state is a newer event.
What if the phone is off during this scam fema test?
Your phone is NEVER off. That's why you can no longer take your battery out of your phone. Part of that battery is reserved for "Off". It takes days to drain the "off' usage of your phone as it requires very little power from the reserve part of the battery to run and if you have a 5g phone, even less as the signal itself can partially power your phone.
Faraday cage it, or wrap it in crinkled tin foil, this will give you the best chance to isolate your phone from sending and responding to the signals.
Ever look inside an old phone? It has a tiny battery in addition to the removable main battery.
It causes the phone to irreversibly corrode if dropped into water.
It maintains the clock when you switch batteries.
Probably some other nefarious purpose. The most benign might be storing encryption keys to prevent phone cloning. Storing keys in battery backed ram is one of the most secure ways to do it. See Capcom Kabuki and DigiCipher II.
Aside from #1 these are the same reasons we have kept a cmos battery on PC motherboards for decades. The ability for 3rd parties to still access your device without your knowledge from the "off" state is a newer event.