Wifi 6: Will OFDMA & MU-MIMO operate simultaneously?

[paul_ainslie_8q]

Once OFDMA is enabled on the new WiFi 6 AP's, will OFDMA and MU-MIMO operate simultaneously? 

For example, let's say you have a factory with 100 clients connected to an R730 AP.  (For simplicity, I'll just look at the 5 GHz running 40MHz wide channels.)  The majority of the clients are lightweight and using under 500Kbps of bandwidth and, say, 10 AP's are using ~4Mbps. 

1. Is it an either/or situation in that the AP will decide to use either use OFDMA or MU-MIMO?
   
2. Or will it transmit a few frames with OFDMA and then a few frames with MU-MIMO?
3. Or will it transmit 8 MIMO spacial streams while simultaneously splitting each stream into 18 RU's and allocating them to the clients as needed?
   

I've scoured the internet and can't find any answers on this.  So any insight would be appreciated.

[paul_ainslie_8q]

My guess, it will be months!  Do any of the big companies have fully functioning Wifi 6 AP's yet?
"...the folks writing the code for the AP airtime scheduler have a hellaciously difficult job. In the old days, all the scheduler had to do was send out packets using simple methods like round-robin. Now with AX, the scheduler has all the previous methods at hand, plus OFDMA. To complicate the scheduler's task even further, OFDMA also works in the uplink direction. So the scheduler must also decide if it wants to receive data simultaneously from multiple STAs. UL OFDMA requires precise synchronization between AP and STA, which, of course, isn't easy. Of course, all these decisions must be made for each transmit opportunity (TXOP). As I said, this is complex stuff."
Tim Higgins, Friday, 03 January 2020
https://www.smallnetbuilder.com/wireless/wireless-features/33221-what-s-missing-from-your-wi-fi-6-ro...
You could also try posting the question on a separate appropriately named thread - it should get more visibility.

[john_d]

Well the R750 already supports OFDMA in both directions with SmartZone 5.2. It is worrisome because it almost feels like the R750 might have newer components and the R730 might not be capable.

[hayward_kong]

Yeah, I know what you mean... which also might be a reason why the R730 was orphaned from unleashed... these days I just avoid buying draft based APs.

[john_d]

Yeah that's unfortunate. In this case I would argue though that because OFDMA, TWT, and other specific 802.11ax features were advertised and still advertised on R730's datasheet, there's a reasonable expectation that they aren't going to just abandon those features for this AP. It would be great to have Ruckus employees chime in on the status of the R730.

Heck even TxBf and MU-MIMO are 802.11ac features and those still aren't activated on R730.

I'm okay with Unleashed not being supported mainly because it was never advertised on the datasheet. I can't say I bought the R730 having any expectation of using it with Unleashed.

I am hoping the resolution is not a quiet removal of those features from the list.

[hayward_kong]

I'm sure they will eventually support it on the other platforms for the features.. but I believe it's on the back burner for now since their priority seems to be on the current development.