ArubaOS 6.3 and Above [802.11ac] - Enable VHT even if you are running 20mhz channels

By Srynearson posted Mar 04, 2014 04:00 PM

  

Tutorial By: 

It is well known that 802.11ac produces high data rates, and most people assume that you can only take advantage of higher rates when you are running 40 or 80mhz channels.  Some people cannot run 40 or 80 mhz channels due to their high density requirements.   Enabling Very High Throughput (VHT) on your 802.11a radio profile even when running 20mhz channels will also increase performance for 802.11ac clients that are connecting to those same 20mhz channels:

vht.png

Here is the output of two devices connecting to an access point running 20mhz channels with VHT turned off (802.11n or HT is turned on):  One is 3 spatial stream 802.11ac MacBook Pro and the other is a single spatial stream 802.11ac smartphone:

vht-before-2.png

 

Note the  TX and RX rates of those two devices when VHT is turned off:

 

vht-before-1.png

 

When VHT is enabled, there is no change in channel width, but we recognize clients that can take advantage of 802.11ac when VHT is enabled and we put VHT in the phy type column:

vht-after-1.png

 

Both of those clients also receive a bump in their TX and RX rate when VHT is enabled:

vht-after-2.png

 

The access point is only running 20 mhz channels, but just enabling VHT in the 802.11a radio profile will give a boost to 802.11ac capable clients connecting to an 802.11ac access point with VHT enabled.

 

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Jan 15, 2015 04:05 PM

Thanks Victor!

Jan 15, 2015 04:03 PM

You should disable it there also and in the radio profile

Jan 15, 2015 04:00 PM

...and I should disable "40 MHz channel usage" in the HT ssid profile if I'm using 20MHz channel width in the radio profiles section or does one setting overrule the other?

Jan 15, 2015 03:51 PM

Yes

Jan 15, 2015 03:42 PM

 

Do you have to enable VHT in the high-throughput ssid profile as well?