Thank you and about airplane mode cell tracking

MonkeyOverSheep

Hi!
Few days ago I meet Russian journalist-in-field. They do research and writing about corruption within chechens republic. Crazy brave person... People who investigate such questions disappears sometimes.
They told to me about tec stuff they use like wireless modems mtk SOC based (to change IMEI), not personalized SIM cards, vpn, signal etc etc. And show me Pixel with unusual Android OS I never saw before. GrapheneOS. Not an Iphone I did suspect but this project. They voted to safety and security, to keep low profile.

Thus I wish to say THANK YOU for this fascinating and important project! Peoples need to sleep safely at night...

After this conversation I feel little involved.
May I ask of proof of concept? How it was confirmed that modems are turned off completely when "Airplane mode" turned on?

Airplane mode is the only way to avoid the cellular network tracking your device and works correctly on the devices we support.

unwat

MonkeyOverSheep

Looks like the Android TelephonyManager service is just told to stop listening, as in if the mobile carrier pings the phone, the phone won't respond, and the OS stops using mobile data.

For proof, you'd just have to read the source code.

MonkeyOverSheep

unwat
Thank you for answer! I will try to understand source code you link me.
But my question about hardware in general not software. Or modem.bin are not an abstraction but the OS itself? Does it possible to ask modem to stop listening and do not replay for pings?

unwat

MonkeyOverSheep
I think modem.bin is firmware for the modem.

I read through related code and I can't figure out whether it's a physical power thing or just a software thing. Either way, GrapheneOS's website says airplane mode completely disables the cellular radio. That means the phone can't/won't respond to any pings from a cellular network.