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Every radio regulation agency on the planet? Most radio hardware is capable of operating outside of regulated limits. The device firmware is usually what keeps

Every radio regulation agency on the planet? Most radio hardware is capable of operating outside of regulated limits. The device firmware is usually what keeps the devices running within their regulated limits and gets those components licenses to be sold. Anyone selling regulated devices running outside of their regulated envelope faces fines and even criminal charges. Cell phones only work because the millions of devices run within strict limits and behave reasonably. There's not a lot of difference between a properly operating radio and a radio jammer. Purism isn't going to find a baseband vendor that's going to risk their licenses by allowing for open source firmware.

baybal2 6y ago
No, pretty of radio transmitting equipment are fully open soft modems. As far as I know, there is no licensing whatsoever for baseband makers? Where did you get that it is?
- giantrobot 6y ago
  In the US a baseband processor's entire software stack that controls the radio front end must be certified. They'll also have the modems to talk to the cellular networks. BPs use their own CPU(s) and an RTOS firmware that's FCC certified. This is why a baseband processor is a fully separate component from a device's application processor(s). Since the AP doesn't talk directly to the radio it doesn't need to be certified and can be updated without recertification. The BP can also get certification and any manufacturer using that BP doesn't need to re-certify it. The interfaces are also such that the AP can't (or shouldn't be able to) tell the BP firmware to boost the output power above legal limits or something. Radios that have "open" soft modems don't typically have fully software controlled radio front ends. The radio front end will have its statutory limits baked in electrically or have very limited software control. The modulation on the back end isn't as important as the front end. Broken modulation just means you can't talk to anyone, an overdriven transmitter is effectively a radio jammer or can give someone an RF burn.
  - baybal2 6y ago
    > In the US a baseband processor's entire software stack that controls the radio front end must be certified. Can you point where it is stated?
    - giantrobot 6y ago
      47 CFR.
      - baybal2 6y ago
        What rule in particular?
        giantrobot 6y ago
        Part 2 covers recertification of changes to radio equipment (everything touching the front end of the radio). Part 24 cover broadband PCS while Part 15 covers WiFi and Bluetooth since they're ISM band components. If you're actually interested read the regulations and look up some FCC IDs for devices.

baybal2 6y ago

No, pretty of radio transmitting equipment are fully open soft modems. As far as I know, there is no licensing whatsoever for baseband makers? Where did you get that it is?

giantrobot 6y ago
In the US a baseband processor's entire software stack that controls the radio front end must be certified. They'll also have the modems to talk to the cellular networks. BPs use their own CPU(s) and an RTOS firmware that's FCC certified. This is why a baseband processor is a fully separate component from a device's application processor(s). Since the AP doesn't talk directly to the radio it doesn't need to be certified and can be updated without recertification. The BP can also get certification and any manufacturer using that BP doesn't need to re-certify it. The interfaces are also such that the AP can't (or shouldn't be able to) tell the BP firmware to boost the output power above legal limits or something. Radios that have "open" soft modems don't typically have fully software controlled radio front ends. The radio front end will have its statutory limits baked in electrically or have very limited software control. The modulation on the back end isn't as important as the front end. Broken modulation just means you can't talk to anyone, an overdriven transmitter is effectively a radio jammer or can give someone an RF burn.
- baybal2 6y ago
  > In the US a baseband processor's entire software stack that controls the radio front end must be certified. Can you point where it is stated?
  - giantrobot 6y ago
    47 CFR.
    - baybal2 6y ago
      What rule in particular?
      - giantrobot 6y ago
        Part 2 covers recertification of changes to radio equipment (everything touching the front end of the radio). Part 24 cover broadband PCS while Part 15 covers WiFi and Bluetooth since they're ISM band components. If you're actually interested read the regulations and look up some FCC IDs for devices.