Newer Wifi 6 .ax APs with BSS Coloring, OFDMA

  • 30 April 2021
  • 3 replies

Userlevel 2

Hi guys, 

I couldnt find info in the help pages about the settings with .ax radio profiles. By the default BSS Coloring and OFDMA are turned off. Where can i find information from Extreme about these Wifi 6 features and why they are disabled by default?


Would be nice if in future release of the cloud the integrated help function would see more love again.



3 replies

Userlevel 6

BSS Coloring: How Does BSS Coloring Work in 802.11ax? (

OFDMA: Why is OFDMA One of the Most Important Features in 802.11ax? (

Some disadvantages of OFDMA are listed in the wikipedia article: Orthogonal frequency-division multiple access - Wikipedia

Userlevel 2

@Stefan K. Do you know why Extreme choose not to enable it by default? Do you use in your installations? What would be possible scenarios to turn on OFDMA but not tick Up- and/or Downlink?

Userlevel 6

Hi Andi,


To add some food for thoughts, I don’t see any reason to pick just one direction for OFDMA. But I’d consider whether to have OFDMA or not have it at all. Last year it was still a subject to in-field proof if the algorithms to allow STAs use particular RUs on a given TxOP are well implemented, efficient and so on. I’d try to play with that feature if I had (vast) majority of 11ax clients among all wireless devices. Besides, As I’ve limited experience with live 11ax environments, I’ll try to reach out to someone to grab more details on the OFDMA caveats as I couldn’t find much about this on the Internet (everyone’s just amazed like we were about MU-MIMO in the dark ages ;) ).

BSS Coloring and TWT sound cool, BSS Coloring is my favourite as it adds some sort of real-life mechanics into the quite sensitive process of the Clear Channel Assessment. Imagine groups of people speaking within different corners of the room. Even though people from one group can hear people from another one, they are able to talk without issues (and all talk on the same channel). On the other hand, it introduces the need to not only plan the channels, but also BSS Color identifiers. But when we look at a single channel after the channel reuse plan is done, it shouldn’t be much of hassle to configure it properly… Of course again, 11ax clients will benefit, older ones not. Some more theory on BSS Coloring from a while ago:


Hope that helps,