[Cerowrt-devel] [Make-wifi-fast] [bufferbloat-fcc-discuss] arstechnica confirmstp-link router lockdown

Jonathan Morton chromatix99 at gmail.com
Mon Mar 14 10:14:58 EDT 2016

> On 14 Mar, 2016, at 16:02, dpreed at reed.com wrote:
> The WiFi protocols themselves are not a worry of the FCC at all. Modifying them in software is ok. Just the physical emissions spectrum must be certified not to be exceeded.
> So as a practical matter, one could even satisfy this rule with an external filter and power limiter alone, except in part of the 5 GHz band where radios must turn off if a radar is detected by a specified algorithm.
> That means that the radio software itself could be tasked with a software filter in the D/A converter that is burned into the chip, and not bypassable. If the update path requires a key that is secret, that should be enough, as key based updating is fine for all radios sold for other uses that use digital modulation using DSP.
> So the problem is that 802.11 chips don't split out the two functions, making one hard to update.

To put this another way, what we need is a cleaner separation of ISO Layers 1 (physical) and 2 (MAC).

The FCC is concerned about locking down Layer 1 for RF compliance.  We’re concerned with keeping Layer 2 (and upwards) open for experimentation and improvement.

These are compatible goals, at the fundamental level, but there is a practical problem with existing implementations which mix the layers inappropriately.

 - Jonathan Morton

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