[SOLVED] 80 MHZ channel not visible

anjris

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Aug 5, 2019
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Hi,

MY ISP has installed the wireless access point at my home which is Nokia G-140W-F.

And this AP is not showing the 80MHZ channel at all. It is showing only 20MHZ channel in drop down list.

Even 40MHZ channel it is not showing

Below Channels it is showing
36 40 44 48 52 56 60 64 149 153 157 161

Why it is not showing me the 80 MHZ channels in the access point.
 
Solution
Thanks for posting the images, that is very helpful. You expected to see the channels (42, 58, 106, 122, 138, 155), right?

What I expect will happen is if you select any of 36-48 you will get channel 42, any of 52-64 you will get channel 58, etc.

In Wi-Fi, the wide channels (40 MHz and 80 MHz) aren't 'wide' all the time, the control and management traffic is sent over a 20 MHz control channel, and the radio switches into the wider channel modes for data traffic.

I expect that if you select, for example, channel 40, you will use that channel for control traffic, channel 40- (channels 40 &36) for 40 MHz (802.11n) traffic, and 36-48 for 80 MHz 802.11ac traffic.

I don't know this AP, so I might be wrong, but that is my best...
Because the channels are actually only 20mhz wide. The so called channels on the 2.4g band are worse they are 5mhz wide even though the minimum wifi signal need 20mhz.

To some extent it depends on the router. Some if you pick a channel it will allocate 2 on either side or if you pick the bottom one it will use that and three above it. Other routers you can pick the center channel like 42.

Most times it works just as well to force the router to use 80mhz only and leave the channel selection on auto. I am somewhat surprised your router has channels 52-64 these are in a restricted range you generally can not use if you manually set them. It depends on the country what is restricted.
 

anjris

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Aug 5, 2019
501
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4,915
Because the channels are actually only 20mhz wide. The so called channels on the 2.4g band are worse they are 5mhz wide even though the minimum wifi signal need 20mhz.

To some extent it depends on the router. Some if you pick a channel it will allocate 2 on either side or if you pick the bottom one it will use that and three above it. Other routers you can pick the center channel like 42.

Most times it works just as well to force the router to use 80mhz only and leave the channel selection on auto. I am somewhat surprised your router has channels 52-64 these are in a restricted range you generally can not use if you manually set them. It depends on the country what is restricted.
Sorry not to mention. I am talking about here 5ghz band

under 5ghz band. Only 20 mhz channels are showing.
Why not 80 mhz channels are listed in my router.

i am based in India.
 
How to put screenshot as Toms forum is not allowing me to attach file.

There is no option
 

anjris

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Aug 5, 2019
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Sometimes the order you configure options can effect what is shown in the user interface.
Can you post some screen shots of the configuration page?
Please find the 2 images.

  1. Image for frequency showing upto 80 MHZ.
  2. Channel list showing which is only 20 MHZ channel list. No channel which support 80MHZ.

So my question is in Frequency table i have selected 80MHZ. And channel i can select any all are 20 MHZ.

So in my desktop if i will see through wifi analyzer. it is shwoing it is connected to 20MHZ.

View: https://imgur.com/6ZHWa17

View: https://imgur.com/nyCA4Nr
 
Thanks for posting the images, that is very helpful. You expected to see the channels (42, 58, 106, 122, 138, 155), right?

What I expect will happen is if you select any of 36-48 you will get channel 42, any of 52-64 you will get channel 58, etc.

In Wi-Fi, the wide channels (40 MHz and 80 MHz) aren't 'wide' all the time, the control and management traffic is sent over a 20 MHz control channel, and the radio switches into the wider channel modes for data traffic.

I expect that if you select, for example, channel 40, you will use that channel for control traffic, channel 40- (channels 40 &36) for 40 MHz (802.11n) traffic, and 36-48 for 80 MHz 802.11ac traffic.

I don't know this AP, so I might be wrong, but that is my best guess.

I hope this helps.

-DD
 
Solution

anjris

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Aug 5, 2019
501
9
4,915
Thanks for posting the images, that is very helpful. You expected to see the channels (42, 58, 106, 122, 138, 155), right?
yes exactly, i want to see those channels. You got my point. :)
In Wi-Fi, the wide channels (40 MHz and 80 MHz) aren't 'wide' all the time, the control and management traffic is sent over a 20 MHz control channel, and the radio switches into the wider channel modes for data traffic.
This is the first time i am hearing from you. Strange.

I expect that if you select, for example, channel 40, you will use that channel for control traffic, channel 40- (channels 40 &36) for 40 MHz (802.11n) traffic, and 36-48 for 80 MHz traffic.
Are you sure? How to differentiate if the 80 MHZ is selected for data traffic?
 
yes exactly, i want to see those channels. You got my point. :)

This is the first time i am hearing from you. Strange.


Are you sure? How to differentiate if the 80 MHZ is selected for data traffic?
I'm not sure that this particular AP works exactly that way, but as a general principal - yes I'm sure.

As far as how you differentiate between channel widths - the AP broadcasts its capabilities, including channels and channel widths, in beacon and probe response frames, and the clients do the same in probe request frames.