[Algent]

> When you put your phone in airplane mode, you are simply telling your phone's OS to stop using the mobile network. The baseband system is still on and can be pinged by the mobile network.

I just started reading and there is already a sentence I don't believe very much, even less as a generalization. Does anyone here have a basis that could explain this bold statement ?

[CharlesW]

> Does anyone here have a basis that could explain this bold statement ?

It's just wrong. On iPhones, Airplane Mode turns off all radios except Bluetooth.

[grenoire]

WiFi still remains on, no?

[FreezerburnV]

By default the WiFi system is turned off, but you can turn it back on individually. If you want to connect to an in-flight system for watching shows, as an example.

[arubania2]

I think they probably mean that this switch is software-based, so turning it on does not physically disconnect the underlying hardware.

I doubt there is any proof that some kind of system activity is still taking place while in airplane mode, but that might be irrelevant.

For some people, depending on their threat model and personal preference, what's important is that it's impossible to prove beyond any doubt that this is _not_ the case.

[Algent]

Ok I see, I understood the first sentence like you then but wasn't sure what was the point of a blanket statement there. I do feel like this this is something measurable with tool it could be easy to prove but I guess this isn't the point of this paper.

[fsflover]

Technically, you are only asking your software to turn the modem off. It can disobey if it wants, you can't be sure.

[jeffbee]

The reason airplane mode exists is a radio 30000 feet above the ground violates assumptions baked into the terrestrial cellular architecture. If iPhones were regularly flying around with their radios enabled we would have heard about it by now.

[fsflover]

It doesn't have to do this "regularly", only when someone (not you) wants it.

[jeffbee]

How would the baseband get the signal to reenable itself?

[fsflover]

Hypothetically, it could switch on every hour waiting for a command.