Support 80+80 MHz channels for 802.11ac and 802.11ax

Feature Requests
1

Some 802.11ac chipsets support 80+80 MHz channel operation in addition to 160 MHz channel operation, e.g. QCA9886, QCA9888.

OpenWrt currently only let users choose a contiguous 160 MHz channel.
By setting hostapd parameters like vht_oper_chwidth, he_oper_chwidth, vht_oper_centr_freq_seg1_idx, he_oper_centr_freq_seg1_idx, it should be possible to achieve 80+80 MHz channel operation.

https://www.qnap.com/en/how-to/faq/article/how-are-the-160-mhz-and-80-mhz80mhz-channels-different-from-ieee802-11ac-or-wi-fi-5 has more information on 80+80 MHz, including why one may want to use 80+80 MHz.

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2

Search the forum for “VHT80P80” for relevant patches you can apply yourself.
I’ve not submitted these to the project (maybe I will…) but they work fine.

2 Likes
3

Please create a PR with the necessary changes :slight_smile:

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4

Is it AC-specific or does it work for AX and above as well?

5

You can plant 80+80 parameter with ACS, but not uci or luci precise channel setup.

6

It has 2 extra lines needed for AX which I didn’t realise until I looked again last night.
It needs to set he_oper_chwidth and he_center_seg1

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he_center_seg1

From hostapd.conf, apparently it should be he_oper_centr_freq_seg1_idx?

Thank you - it would be great if you can submit the patch to OpenWrt, since it will gain higher visibility (other users may not know that there is a patch in a forum topic), and if it gets accepted (merged), users will be able to enjoy the feature without having to manually patch their scripts / repos.

8

From https://documentation.meraki.com/MR/Wi-Fi_Basics_and_Best_Practices/Wi-Fi_6_(802.11ax)_Technical_Guide, 80+80 channel width also applies to 802.11ax.

I have therefore edited my original post to reflect this.

9

That’s right, the patch translates it out (in the VHT case). I would do the same for HE.

I will submit it when I find time. We have carried this patch over in Gargoyle for quite some time.
I don’t know if “channel2” is an appropriate config name for this, but I can’t think of anything better.

5 Likes
10

Is mac80211.sh the only thing that needs patching?

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Besides luci, yes

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imho note that these scripts are in the process to be migrated to ucode ... so one will need to update these as well besides mac80211.sh

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*instead of?
Yes I was aware thank you

Edit: just went and looked. Which uc script do you think needs modding? It still looks like sh to me in 24.10

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@lantis1008 Any progress with making 80+80 MHz upstream?

15

I’ve been tied up rewriting iptables kmods.
I should be finished the current one this week, I’ll take a break and look at this issue instead.

Can’t jump halfway though, my brain doesn’t jump tasks like it used to :slight_smile:

3 Likes
16

Great. When the changes are complete I plan to test the non-contiguous channels in the channel analyzer :smiley: