Re: A question about learning 802.11

Hello, Sergey Ryazanov,

Thank you for the detailed description, It's very helpful !

Sergey Ryazanov <ryazanov.s.a@gmail.com> 於 2022年8月27日 週六 晚上11:11寫道：

> Hello,
>
> On Tue, Aug 23, 2022 at 2:59 PM 吳恩緯 <rickywu0421@gmail.com> wrote:
> > My question is, if I want to learn the work net80211 has to do to
> support modes like 802.11n/ac, do I need to know what exactly the physical
> layer has done? (I'm majoring in computer science, and I just want to write
> some codes to help net80211)
>
> Generally speaking, you should not know too much about PHY for the
> regular driver hacking. All PHY things are done by a chip and usually
> you can not interfere with its work. All you need is chip
> documentation, IEEE 802.11 standard knowledge and net80211 subsystem
> concepts. All other PHY stuff you can assume as some kind of "magic".
>
> But if you want to know exactly what you are doing, what is the
> difference between MU-MIMO and OFDM-A or if you want to implement
> something non-standard, then yes, it is better to have some signal
> processing knowledge. Some knowledge of electronics is useful too,
> especially when you have to deal with transmit power control or
> receiver sensitivity.
>
> Usually all this is a matter of time and wish. Just select a task,
> start doing it, google unknown terms, and after a while you will
> surprisingly realize that you know perfectly well what to do with all
> these registers and knobs of a wireless chip. The road will be handled
> by the walker. While the study + practice mix is a good way to walk.
>
> Or as I said before, just consider it "magic" and you will be a happy
> developer too if it is okay for you to work with "magic" :) Anyway you
> can not "inspire" a 802.11n chip to support the 802.11ax frame format
> :)
>
> --
> Sergey
>