Does GoS airplane mode disable baseband processor?

K8y

If not, what will?

userofgos

K8y yet again another reminder to please read the GrapheneOS documentation which already answers your question: https://grapheneos.org/faq#cellular-tracking

Connecting to your carrier's network inherently depends on you identifying yourself to it and anyone able to obtain administrative access. Activating airplane mode will fully disable the cellular radio transmit and receive capabilities, which will prevent your phone from being reached from the cellular network and stop your carrier (and anyone impersonating them to you) from tracking the device via the cellular radio. The baseband implements other functionality such as Wi-Fi and GPS functionality, but each of these components is separately sandboxed on the baseband and independent of each other. Enabling airplane mode disables the cellular radio, but Wi-Fi can be re-enabled and used without activating the cellular radio again. This allows using the device as a Wi-Fi only device.

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

schklom

I think Android (GOS included) airplane mode disables all radios, the baseband processor is likely not turned off but instead does not connect to radio towers.

Short of modifying your phone hardware, I doubt anything can disable it at the hardware level.

Johnnyloans

shutting down and initializing hardware isn't as trivial as a flip of a switch. It'd take a lot of work and GOS said they are happy with airplane mode.

I'm sure shutting that down would require lots of code changes for that new situation.

other8026

Johnnyloans incorrect. The website says

Activating airplane mode will fully disable the cellular radio transmit and receive capabilities, which will prevent your phone from being reached from the cellular network and stop your carrier (and anyone impersonating them to you) from tracking the device via the cellular radio. The baseband implements other functionality such as Wi-Fi and GPS functionality, but each of these components is separately sandboxed on the baseband and independent of each other. Enabling airplane mode disables the cellular radio, but Wi-Fi can be re-enabled and used without activating the cellular radio again. This allows using the device as a Wi-Fi only device.

Also, this post may be of interest to anyone reading this thread https://discuss.grapheneos.org/d/26586-brief-note-on-mobile-phone-measurements-with-airplane-mode-onoff

Johnnyloans

other8026

Thank you for the article, I will read through it.

In the case of Pixels with a separate Exynos modem engaging airplane mode, the phone instructs the Exynos modem to shut off the relevant RF transmission. At a later time the phone will instruct the modem to reverse this action. The modem's microprocessor is still running in order receive this message, albeit likely in an ultra low power state.

The original question was "Does GoS airplane mode disable [the] baseband processor".
I think shutting down the modem's microprocessor would introduce new challenges for:

communication with the modem
hardware initializion -- which typically only occurs at early boot

Yes, it is impossible to receive certain/all RF communication depending on the user's preference. What the OP desires isn't an easy, drop-in replacement.

Johnnyloans shutting down and initializing hardware isn't as trivial as a flip of a switch. It'd take a lot of work and GOS said they are happy with airplane mode.

I'm sure shutting that down would require lots of code changes for that new situation.

MrLinux

I drop my phone into a mission darkness faraday bag I don't get calls, or texts and no tracking. Ps before I drop my phone in the bag I turned on airplane mode.

Quantum

userofgos I was like a post away from snapping, so thanks for saying it in a nicer way...

de0u

Johnnyloans In the case of Pixels with a separate Exynos modem engaging airplane mode, the phone instructs the Exynos modem to shut off the relevant RF transmission. At a later time the phone will instruct the modem to reverse this action. The modem's microprocessor is still running in order receive this message, albeit likely in an ultra low power state.

This sort of claim could be improved by citing sources.

Also, if the RF chip(s) are powered off then it may not matter whether the baseband is running. Here is a document indicating that the modem and RF transceiver are independent on at least one Pixel device: https://www.techinsights.com/blog/teardown/google-pixel-6-pro-teardown