What are the 5Ghz non-DFS, non-overlapping channels?

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What are the 5Ghz non-DFS,  non-overlapping channels?
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Laura

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Posted 3 years ago

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John

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Laura:

Not all of the channels in the 5 Ghz band are useable all of the time.  If you are near an airport then some of the 5 Ghz channels are not available to you.  DFS stands for Dynamic Frequency Selection so basically you have that feature turned on and your APs will listen for Radar or first responders using those 'shared' frequencies and not use those channels if they are being used.

Check this out.

John

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Ronald Dvorak, Embassador

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I'm not an expert on the US regulatory domain so here a link to wikipedia...
http://en.wikipedia.org/wiki/List_of_WLAN_channels

The 5GHz channels don't overlap, BUT if you use channel bonding for 802.11n or 802.11ac to bond more channels to a 40 or 80 MHz channel you'd need to make sure you don't overlap.

In the latest controller version the GUI also show which of your 5GHz channels are non-DFS - just choose custom channel plan and you get the list.
The below screenshot is for AP country set to Austria ...

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Laura

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Thanks,
We use the non DFS channels: 36, 40, 44, 48, 149, 153, 157, 161
At some schools we use 40Mhz and other school use 20Mhz. I don't know why.
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Walfs Adam

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Which country do you live?
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Here another slide that illustrate how channel width affects the available non-overlapping channels...

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Laura

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So if I were to use 5Ghz, non overlapping.  non DFS channels at 40MHz, I could use 36 , 44, 149, and 157? Would that work?
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Laura

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Thanks for all the info. Since we have the enterasys 3605 APs, there are 2 radios. one is set to g/n 20MHz and one is set to a/n 40MHz. When i get an AP up and running and attach to it, my transmit rate on my MacAir says its 300Mbps. Does that mean I am sharing that 300Mbps with everyone else that is on the same radio as me? I dont actually get 300 Mbps to my self, do I?

Each radio should be transmitting 300Mbps, which is just the connection from the wireless device to the Access Point.
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Yes, that is correct, the medium air is shared with all devices on the same channel.
This is why you shouldn't have more then 1 AP in the same area with the same channel configured as they would share the medium.

Also please keep in mind that it's a half duplex medium so only one client could tx or you have a collision .... like a hub in the good old days.

As a result you'll never see a thruput of 300Mbps on your client... I assume about 150Mbs if you test with iperf (https://iperf.fr/) and more then one stream.
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Hartmut Sachse

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Like Ronald told you at 300 mbps PHY rate you could assume about 145-150mbps throughput with iperf (udp) for a device like a laptop with a wifi adapter 2x2:2 MIMIO or better. Most tablets only have 1x1:1 MIMO wifi adapter limiting there speed to around 65 mbps throughput.

For more deeper understanding of wifi throughput i would recommend you watching this video and the reading to background pdf:

 http://www.wlanpros.com/wi-fi-stress-test-a-vendor-independent-access-point-analysis/

Still waiting for the second round of the wifi stress including the extreme wireless access points.
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wyfy

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Hi 
is there way to know adapter support 2x2 MIMO ,or 1x1 . Normally vendors does not include it in their datasheet . 
And if you see other vendors test result (iperf ) they are using tcp and published result is  same like 150 when the phy rate is 300 Mbps
Thanks
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If the client is connected to the AP/controller you'd look into the GUI > Report > Clients.
The column Avg. Rate Sent/Rec gives a small clue what the client is capable off.

-Ron
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Looks fine to me...
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Daniel Flouret, Employee

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Laura,

Hope this helps

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Ryan Mathews, Alum

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Good reference
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Ryan Mathews, Alum

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Great....welcome to the Hub.  We're very glad you joined us!
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wyfy

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Hi,

In middleeast and asia

how is the non-dfs channel allocated ? 

Can we use dfs and non dfschannel together ?

Thank you