A previous post raised an important privacy question about disabling the cellular modem.
However, the post was auto-closed due to no response or activity.
I would like to ask the same question again and hopefully someone from dev team can respond in time.
In most “normal” cellular modules and phones, one can disable the radio modem in several different ways, usually in different sleep (including complete radio power-down) states.
Will the Brax3 phone support changing these states?
You can disable the cellular modem by going to test mode. Type the symbols and numbers as per the picture below. Then go to Phone Information and disable Mobile Radio Power.
Note that Mobile Radio Power gets automatically enabled on every reboot, and also every time you dial emergency (the last is a requirement to get the phone certified).
This is not very useful.
First, it seems that the “Mobile Radio Power” option is automatically disabled by simply switching on airplane mode. Turning on airplane mode is simpler (no need to dial secret incantations). I already turn airplane mode on anyway. Also, airplane mode state does persist on reboot. So, your method seems worse, correct me if I am wrong.
Second, I am paranoid and don’t trust these methods. I don’t know much about the inner workings of Android and the phone hardware, but disabling radio power does not imply powering off the modem CPU / shutting down the modem firmware. It would be helpful to know hardware fixes for this. Perhaps an antenna trace can be cut or something like that. Cutting power to the modem would be better.
Regarding phone certification, I don’t require it. Also, a hardware modem power switch shouldn’t cause an issue with certification, does it? Alternatively, maybe you can reclassify these phones as tablets or something.
It’s up to you if you want to modify your hardware and risk voiding your warranty.
It’s not really about if you require it or not. The phone needs to be certified in order to get imported and/or connected to networks.
Sounds like you need a tablet with no cellular modem. We designed a smartphone that’s affordable and free from big tech. Features like the cellular modem killswitch isn’t available in this model. We’re looking into implementing features like that in future models.
Voiding warranty is a lesser concern than loss of privacy.
It would be great to have that technical documentation to help with the modification:
Allow me to counter your other points. I’m not an expert in this area, but I think there are plenty of devices that get imported without being required to have emergency calling feature. There are also plenty of devices that connect to cellular networks that don’t have the emergency calling feature, such as tablets. It seems to me that this stuff is not required to be imported or allowed on networks. I actually don’t need a tablet, I need something exactly like a phone (small size, usable for making calls), minus the cellular modem. At least, not one that cannot be turned off temporarily.
I appreciate your consideration of my input. Thank you for your responses.
I’m sure that the modem is inside the Mediatek SoC, the only phones with distinct USB modems that can be switched off are Pinephones and Librem as far as I know. You could probably put an insulator at the pins of the modem’s inverted-F antennae though I haven’t opened the phone and I don’t know whether the WiFi antenna is shared with the modem.
That sucks. I’m waiting on the promised technical documentation before messing with it.
you are going too far with this, if you check Mediatek’s binaries (brax · GitLab) they are so many and massive that the SoC could do whatever spying conceivable, of course you could say that you don’t care whether China and Mediatek is spying on you but since those platforms are sold in the USA and the EU they have at least a minimum compromise with your local authorities
No, I don’t want anybody spying on me, not China, not Mediatek, not local authorities, not any commercial interests. I would think those that put together a phone focused on privacy would do their homework when selecting a non-spying platform. Maybe I’ve made a mistake with my choice of a phone.
Modern computers are very complicated to be completely open source except for OpenPower . Pinephones and Librem are the most open source ones but they are low-end compared to Brax3, again their modems have a binary blob for the radio functions since there is no Osmocom 4G modem yet. Maybe a Pinephone Pro would do the job for you but no mainstream platform like Mediatek, Qualcomm, Google, Samsung etc
I wasn’t specifically looking for open source, although having open source stuff is better. I was looking for something that can be trusted not to have any backdoors. Still, with open source stuff the fab can add a backdoor anyway, so there is that.
It’s worth noting a couple of things.
While we can’t publicly share the full source code on the device, we have access to it in full. It’s a licensing restriction from MediaTek and we’re not sure whether that will ever change (same with Qualcomm, Tensor, Exynos). We’ve done our part in looking through the code to ensure there is no spyware built in.
The chip PinePhone is using is Rockchip. Their license of Rockchip allows you to open up the source code. We’re looking into designing a device using Rockchip, but we’re still evaluating the performance we can get out of it too. We don’t want to just make another “toy”.
@plamen so now you can tell me how to hook to the dual camera function, I don’t want the source code, just how to call it or you to enable the combined camera streaming in an upcoming update