Date: Mon, 29 Aug 2022 14:08:13 +0800 From: =?UTF-8?B?5ZCz5oGp57ev?= <rickywu0421@gmail.com> To: Sergey Ryazanov <ryazanov.s.a@gmail.com> Cc: freebsd-wireless@freebsd.org Subject: Re: A question about learning 802.11 Message-ID: <CAM71Uge7kuHBfXTgO30rbRsSxtgCAvjMBH2YJejj9848w5YFzQ@mail.gmail.com> In-Reply-To: <CAHNKnsRYOJ6jgcVsRK=EnrGfYdMp3aJ3NVXtWEH-timTtdGijA@mail.gmail.com> References: <CAM71Ugdv5s5P3-2mvhp__FBHceVqD7WUzVKRNyykA2tCzo7QCQ@mail.gmail.com> <CAHNKnsRYOJ6jgcVsRK=EnrGfYdMp3aJ3NVXtWEH-timTtdGijA@mail.gmail.com>
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[-- Attachment #1 --] 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 > [-- Attachment #2 --] <div dir="ltr">Hello, Sergey Ryazanov,<div><br></div><div>Thank you for the detailed description, It's very helpful !</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Sergey Ryazanov <<a href="mailto:ryazanov.s.a@gmail.com">ryazanov.s.a@gmail.com</a>> 於 2022年8月27日 週六 晚上11:11寫道：<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">Hello,<br> <br> On Tue, Aug 23, 2022 at 2:59 PM 吳恩緯 <<a href="mailto:rickywu0421@gmail.com" target="_blank">rickywu0421@gmail.com</a>> wrote:<br> > 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)<br> <br> Generally speaking, you should not know too much about PHY for the<br> regular driver hacking. All PHY things are done by a chip and usually<br> you can not interfere with its work. All you need is chip<br> documentation, IEEE 802.11 standard knowledge and net80211 subsystem<br> concepts. All other PHY stuff you can assume as some kind of "magic".<br> <br> But if you want to know exactly what you are doing, what is the<br> difference between MU-MIMO and OFDM-A or if you want to implement<br> something non-standard, then yes, it is better to have some signal<br> processing knowledge. Some knowledge of electronics is useful too,<br> especially when you have to deal with transmit power control or<br> receiver sensitivity.<br> <br> Usually all this is a matter of time and wish. Just select a task,<br> start doing it, google unknown terms, and after a while you will<br> surprisingly realize that you know perfectly well what to do with all<br> these registers and knobs of a wireless chip. The road will be handled<br> by the walker. While the study + practice mix is a good way to walk.<br> <br> Or as I said before, just consider it "magic" and you will be a happy<br> developer too if it is okay for you to work with "magic" :) Anyway you<br> can not "inspire" a 802.11n chip to support the 802.11ax frame format<br> :)<br> <br> -- <br> Sergey<br> </blockquote></div>home | help
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