Primary Channel is not changing as expected

Installing and Using OpenWrt
1

Hi there,

I am tryting change the primary channel and bandwidth using UCI.
uci set wireless.radio1.channel='44';uci set wireless.radio1.txpower='20';uci set wireless.radio1.htmode='VHT80';uci commit wireless; wifi reload;
But it ended up in channel 48. And whenever i try to change to channel40 with bandwidth 80, it goes to 36. Can someone help me on this? Thanks in advance.

2

The signalling sub-band of 20MHz is chosen automatically, you cannot control that.

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3

Ok. Is there anyway i can change primary channel to 40 and bandwidth to 80?

4

Yes, move to other place.

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5

The center frequencies for the 5 GHz range are strictly enforced by the standard. For instance, any channel selected between 36-48 (VHT80/HE80) will have a center frequency at channel 42.

You can view the table here: https://en.wikipedia.org/wiki/List_of_WLAN_channels#5_GHz_(802.11a/h/n/ac/ax/be)

In the 2.4 GHz bands bonded 40 MHz channels are uniquely named by the primary and secondary 20 MHz channels, e.g. 9+13. In the 5 GHz bands they are denoted by the center of the wider band and the primary 20 MHz channel e.g. 42[40]

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6

move to other country?

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7

but can i choose the primary channel? like 36 as primary channel and bandwidth 80 or 40 as primary channel and bandwidth 80 like that?

8

Yes, but like I said, it doesn't matter which channel you select between 36-48, they will use the exact same frequency range for VHT80/HE80, so this isn't a problem at all.

But it ended up in channel 48.

Where did you see 48? What are the output of the following commands?

grep channel /var/run/hostapd-phy*.conf
iwinfo | grep Channel
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9

Your observation might depend on your hardware or wireless driver.

I tested on my WRT1900ACS running 23.05.5.

With 80 MHz channel width, I can set the primary channel to 36, 40, 44 or 48. iwinfo reports the primary (master) channel, and always channel 42 as Center Channel.

Luci's Status-Channel Analysis reports the primary channel, and also displays it as shading in the graphical overview.

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10

Out of the city, middle of the desert, and disable all your other wifi and bluetooth for access point startup.

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