4 ms·

Can that closed source blob be bypassed and still allow compatible communication with carrier networks? Or is there some ip or contract nonsense that allows Qua

Can that closed source blob be bypassed and still allow compatible communication with carrier networks? Or is there some ip or contract nonsense that allows Qualcomm this stranglehold? This seems like exactly what we dealt with in requiring phone companies to allow dialup modems to connect to whoever the customer wants, and so on. Seems shady as hell.

judge2020 5y ago
Most likely the blobs are signed/encrypted and the modem ensures that before running them, so without them it wouldn't work.
- robbedpeter 5y ago
  I guess I was thinking more in line with SDR or foss hardware and not using Qualcomm at all. I need to do a deep dive, but it looks like there's a couple FOSS 4g LTE and 5g modems around - maybe running a soft phone and personal voip setup would bypass a lot of the security concerns. It sucks that any time you start to inspect almost any tech, there are assholes trying to exploit every last bit of data and microamp of processing power to screw you in some way.
  - marcan_42 5y ago
    SDRs are for research and base stations. Trying to do a mobile phone based on an SDR stack would eat through your battery in minutes. You need dedicated silicon.
    - userbinator 5y ago
      I believe mobile radios are effectively narrowband SDRs, optimised for the application. Hence the concerns around firmware and FCC certification.
      - marcan_42 5y ago
        Kind of, but they are built around DSP architectures with dedicated hardware accelerator blocks. It's not the same thing as GNURadio. Base stations are often built out of more generic SDR tech, and those do chew power like crazy.
nucleardog 5y ago
Besides the technical difficulties (trying to reverse engineer the modem internals and reimplement the firmware with no clear reference; likely encrypted and signed firmwares; etc) there's a good chance there's also legal issues. If the hardware itself is capable of operating outside of its license (frequencies, modulations, etc), then various certifications from the FCC would likely be invalidated by replacing the firmware and it would become illegal to operate.
marcan_42 5y ago
There are significant regulatory issues involved. In principle it's possible (see osmocombb), but the legal hurdles around actually having user-controlled basebands in a shipping product are significant. Of course, nothing says the baseband couldn't be open source, and even if codesigning is involved, the manufacturer could sign verifiable builds that can be reproducibly built. That should solve all regulatory concerns while still allowing users to inspect the baseband firmware for flaws or backdoors. But, of course, no actual baseband manufacturer cares about that.

judge2020 5y ago

Most likely the blobs are signed/encrypted and the modem ensures that before running them, so without them it wouldn't work.

robbedpeter 5y ago
I guess I was thinking more in line with SDR or foss hardware and not using Qualcomm at all. I need to do a deep dive, but it looks like there's a couple FOSS 4g LTE and 5g modems around - maybe running a soft phone and personal voip setup would bypass a lot of the security concerns. It sucks that any time you start to inspect almost any tech, there are assholes trying to exploit every last bit of data and microamp of processing power to screw you in some way.
- marcan_42 5y ago
  SDRs are for research and base stations. Trying to do a mobile phone based on an SDR stack would eat through your battery in minutes. You need dedicated silicon.
  - userbinator 5y ago
    I believe mobile radios are effectively narrowband SDRs, optimised for the application. Hence the concerns around firmware and FCC certification.
    - marcan_42 5y ago
      Kind of, but they are built around DSP architectures with dedicated hardware accelerator blocks. It's not the same thing as GNURadio. Base stations are often built out of more generic SDR tech, and those do chew power like crazy.

nucleardog 5y ago

Besides the technical difficulties (trying to reverse engineer the modem internals and reimplement the firmware with no clear reference; likely encrypted and signed firmwares; etc) there's a good chance there's also legal issues. If the hardware itself is capable of operating outside of its license (frequencies, modulations, etc), then various certifications from the FCC would likely be invalidated by replacing the firmware and it would become illegal to operate.

marcan_42 5y ago

There are significant regulatory issues involved. In principle it's possible (see osmocombb), but the legal hurdles around actually having user-controlled basebands in a shipping product are significant. Of course, nothing says the baseband couldn't be open source, and even if codesigning is involved, the manufacturer could sign verifiable builds that can be reproducibly built. That should solve all regulatory concerns while still allowing users to inspect the baseband firmware for flaws or backdoors. But, of course, no actual baseband manufacturer cares about that.