I'm testing L22 hardware right now. I can't see any indication of OFDMA or a way to turn it on. In my tests, it's clearly not enabled in 2.4 or 5Ghz. I can get about 375Mbps in 40Mhz but when I step on the channel edges a little bit with another radio performance tanks. Clear sign that OFDMA is not in use. I see no configuration option for this. I also see no mention of this in the routeros changelogs.

Is this something we are expecting to show up soon? It's sort of a requirement for us to move forward with the platform. Without OFDMA, wifi6 is really not any better than wifi5. We're not able to utilize the higher modulations without OFDMA because the noise floor and random spikes hits the entire OFDM carrier.

@Normis any comments you're willing to make?

Thanks.

Better contact Mikrotik support directly to get a response.

https://mikrotik.com/support

If your modulations are ax, aka up to 573mbps on 40mhz wide channel, then OFDMA is used. I dont know what do you mean by "step on the channel edges", OFDMA generally means that airtime is divided into RUs if ax stations are connected for more efficient airtime utilization.

If your modulations are ax, aka up to 573mbps on 40mhz wide channel, then OFDMA is used. I dont know what do you mean by "step on the channel edges", OFDMA generally means that airtime is divided into RUs if ax stations are connected for more efficient airtime utilization.

I'm not sure where you're getting this, but it's not true. ax can do full modulations in CSMA or OFDMA.

Step on channel edges can't be a whole lot more detailed. overlap the edges enough to interfere with the channel. In it's current state, if you overlap a 40Mhz 'ax channel by 10Mhz, you half the channel bandwidth. This is a clear indicator of CSMA mode, or more precisely the 2 carrier 20+20 scheme of <=ac wifi and you added substantial noise to 20Mhz of it. OFDMA would shed only about 25% of throughput instead of 50%, just the actual overlap and the OOBE curtain in the 'unoverlapped' RUs.

Interesting read: https://www.smallnetbuilder.com/wireles ... rk-part-1/

@syadnom, just curious but is there a particular use case you have in mind for this?

also note that if you run in compatability mode (essentially all consumer routers will do this) you have additional overheads for handling OFDMA plus CSMA clients. Convincing client devices to speak OFDMA, or them even supporting it, is exceptionally questionable, and devices that are in CSMA have no schedule so if they don't recognize the OFDMA packets they'll transmit over the top.

Backwards compatability is a noble goal, but when changing the underlying airtime scheduler it's probably best to split the channels and do a greenfield deployment. wifi6 (or 7) and link puncturing is probably the best solution, reduce your WiFi5 channels to 20Mhz, and puncture around them, and force OFDMA for a separate SSID etc.

When you do find a device pair (ie, AP and STA) that support OFDMA it's fantastic. Eero7 and iPhone 16 pro for instance support it and you can handle crazy noise on them, I've attacked them with cambium 4625 in PTP and traffic generating and they still hold up. Tarana BN6 to RN6 with iperf running over the top does hurt (a LOT... powerful gear there) but it says linked and still gives me very usable service. The same exact setup on an iPhone 14 and it's completely crushed. I have a WiFi5 Motorola/Android and a Samsung that are completely unusable.

@syadnom, just curious but is there a particular use case you have in mind for this?

yes, wide channel micro/pico pops (outdoor/WISP). There's enough noise around from random netgears that it's important to have OFDMA to work around it. Link puncturing (especially automatic) would be fantastic but I don't really expect that on qualcomm wifi6 so I'm not asking for it. OFDMA-only mode would do what I want in these price points.

Unless they want to drop a whole new wifi7+6GhzAFC product...

Regarding the original question, it could be OFDMA is probably not enabled by Mikrotik. I just checked on the Pixel 7 (connected to wap ax) by using the analiti app and it reports using OFDM.

yeah, I'm seeing the same and getting matching results. I want to know if we're going to see it enabled.

Whit questions like this we need sniffing:
As we can see, RUs are at least assigned to user upload, so I assume OFDMA is there and working.


Resources about this:

https://gjermundraaen.com/2019/10/10/ul ... wireshark/

I need to re-check. I do not have access to the Pixel 7 (which supports AX) and can only see on my phone (which does only have 802.11ac). But I see a difference in analiti: yesterday the BSSID was recognized as AC1766 while today it is shown as AX2402. Must be either some hickup in analiti or some capsman radio provisioning issue.

I checked today on the Pixel 7 and analiti app. Most of the time it reports OFDM for Rx and Tx. But sometimes Rx switches to OFDMA - for some seconds - as well. Tx on the other hand always stays at OFDM.

May i ask how you check this?

On the Analiti free version i cant find it (maybe need to buy the expert version?)

Go to "Networks", select the network you are currently connectes to, select "OPER" tab. Section is called "PHY SPEEDS.

FYI, I asked mikrotik support and they said that the proprietary OFDMA code in the qualcomm driver is on so given the right conditions it should do it. I ordered some of the new SXTsq5ax units to play with to confirm as well as test noise avoidance etc. This is great news.

Go to "Networks", select the network you are currently connectes to, select "OPER" tab. Section is called "PHY SPEEDS.

I tested this with an ax3 and a wap ax.

The wap ax supports 160mhz which allowed me to overlap with the ax3 as well as one of my neighbors easily.

I had my phone connected to the wap ax and my laptop to the ax3 while the ax3 was downloading a game from steam (analiti shows around 70% airtime usage for the channel)
But the phone never showed OFDMA.

Even when running iperf between the 2 clients, it never changed to OFDMA.

You seem to be conflating OFDMA with preamble puncturing.
Preamble puncturing lets device avoid a narrow section of a channel which is experiencing inerference, without avoiding the whole corresponding half of the channel.
OFDMA lets a device simultaneously transmit to multiple receivers by dividing the available sub-carrier frequencies between them.
OFDMA transmission capability is a non-optional part of the 802.11ax specification. Support for preamble puncturing is optional and, as of writing, is unimplemented for our 802.11ax products.

You seem to be conflating OFDMA with preamble puncturing.
Preamble puncturing lets device avoid a narrow section of a channel which is experiencing inerference, without avoiding the whole corresponding half of the channel.
OFDMA lets a device simultaneously transmit to multiple receivers by dividing the available sub-carrier frequencies between them.
OFDMA transmission capability is a non-optional part of the 802.11ax specification. Support for preamble puncturing is optional and, as of writing, is unimplemented for our 802.11ax products.

The problem is that it's optional on STAs (OFDMA), so in the context of this request it's really an ask if STAs support it.

I don't think we're actually discussing puncturing here, more RU allocation for noise avoidance (or rather, low modulation avoidance). This is what sorta sucks about wifi6, it's implementation of OFDMA distributes RUs to STAs based on demand, but it doesn't consider the modulation of those RUs. STAs get what they get so an RU that has some noise gets a lower modulation and the STA just lives with it and hopes the AP will assign it more RUs.

I've been hoping mikrotik would do a WiFi7 setup since WiFi7 has a more sophisticated OFDMA schedule and considers RU modulation in the assignment of RUs. ...and that those features are enabled...

All that said, the AP and STA both have to trigger OFDMA for either version to work and that seems to be a challenge. Not sure why though, maybe black-box qualcomm code is too conservative or something.