MU-MIMO timeframe


Santa is coming soon. Will he be bringin the sync package to us? He’d better hurry up… 10 days to go…


“The last reply to this topic was 224 days ago.”

Any updates?


TDMA GPS-Sync (SRS) was delivered and is available now. As soon SRS was released, we were flooded with requests for other features ahead of MU-MIMO. We tend to prioritize development based on user demand, and we’ve been told by many WISPs that there are more immediate needs - like automated client provisioning.

@Andrewski, Can you tell us why MU-MIMO is your biggest need? We’d like to understand the priority from your perspective.


Higher client counts on an AP? And more throughput simultaneously to several stations in parallel?

Apart from SRS another way of saving spectrum is more stations per AP. In stead of 50 stations per ap 100 per AP could save spectrum. Compared to MIMO the AP in MU-MIMO can serve twice as much stations with the same throughput while not needing more spectrum…


Hey Chris,

@Chris MU-MIMO isn’t my biggest need per se. My biggest concern is the fact that SRS was promised to be rock solid when it was released. Then within minutes of releasing it, traffic shaping for download speed was completely broken. There have been a handful of firmware releases (I chat with support frequently) and none of them have ever indicated that they know what is being tested and when various bugs are going to be fixed. I built a new company using pure Mimosa based on the fact that Mimosa claimed it could offer 200-300Mbps to the end user(see YouTubeVideo). I bought a GB fiber pipe, hooked up an A5 and gave it a go. The reality is that I have a hard time delivering 50Mbps to my subscribers. I was told that SRS was going to be immune to other 5G Wifi devices and yet my network is still struggling. I was forced to stop offering my 100Mbps plan because I simply cannot do it consistently. PER was supposed to be lower on SRS but in the GUI I’ve got clients in the red constantly during peak usage. It is frustrating being blind to what are known issues/bugs and what is being fixed in the next firmware and how the beta testings are going.


Hi @Andrewski,

The differences in throughput between WiFi Interop and SRS are because of the 50/50 traffic split and protocol overhead. We’re working on some additional controls for those, but there is no real difference in the traffic shaping between protocols except for the built-in airtime fairness in SRS.

It looks like the PER on your A5-network is between 1-2% which is far less than WiFi Interop at 10-12%. The PHY rates of your clients range from 100-400 Mbps on a 40 MHz channel. Client signal strengths range from -70 to -44 dBm. The clients with lower signal strength are operating on a single chain, so would have lower throughput, and would cause AGC to use a much lower threshold value. Other than improving the signal strength of the weaker clients and moving to an 80 MHz channel, you may want to go back to WiFi Interop for throughput reasons if there are no other Mimosa Access Points nearby with which to sync.

Our Product Management group manages the beta program, so the Support team doesn’t always have the latest updates to share. If you are interested in joining the beta program, I can put you touch with the right folks. We have dramatically improved the traffic shaping algorithm in the latest 2.3.3 beta. It works really well now. The beta also contains AGC improvements, channel selection in 5 MHz increments in WiFi Interop, DFS support for C5c and more.


Hi Chris, can you add me as well to use that beta firmware? Many thanks.


Hi @J.Enrique

Yes, will do.


@Chris Is there a way to follow the Product Management Group in a forum or something that I am missing? Thank you.


Hi @Andrewski,

There is not one specific Product Marketing area within the Mimosa Community, but we do occasionally discuss upcoming firmware features within public threads. Some of the discussion is limited to closed beta groups in early beta phases, and we share it more broadly as the new firmware features stabilize.

Feature requests are usually directed to related threads under each sections for each product family. For example, A5 feature requests are concentrated in this thread, but there are certainly others about specific topics: Feature Requests - A5 Products

If you want to provide specific feedback or ask related questions here, then please go ahead. You could also start a new thread about a different topic if desired.


I have been told by support the 5Mhz increments are not working for interop mode? And indeed it didn’t on my end.
They told me it only would work in ‘interop’ mode if all clients are Mimosa! Well, in that case it is not really ‘interop’ mode. It is just csma mode for Mimosa only…

In ‘interip’ mode we’d expect, ‘3rd party’ devices mode. So basic csma mode.

Please check that info.


Support for channel selection in 5 MHz increments will be available in the upcoming 2.3.3 firmware. There is a toggle switch on the Channel & Power screen called, “5 MHz Enable” that activates the feature.

Some third-party clients can use non-standard channels, and some can only use Wi-Fi defined channels.


I am running 2.3.3 beta 5 and have been running every 2.3.3 version before and it has is already.
I can switch it on or off and can pick channels this way that under normal mode are not possible.

But my clients are all Mikrotik, that can be configured into 1Mhz steps if needed.
The default setting is a 5Ghz granularity and channels can be set to 5, 10, 20, 40 and 80Mhz wide too.
These radios have the most versatile config you’ll find in a Wifi radio!

Still when I set an A5 on a channel that my Mikrotik NetMetal presently works on, not a single clients connects to the A5.
Set the A5 in ‘normal’ mode with a DFS channel and all clients connect.
I can connect these Mikrotik units in csma mode to any other vendor in every frequency but not the A5

To me it looks the 5Ghz granularity doesn’t work well on Mimosa, something actually one on the help desk told me it didn’t.


This feature definitely works well with Mimosa clients. I don’t want others to be confused by your last comment above.

We have not tested with every third-party client model and version, but we do know that some work well, and others may not. Some of this has to do with configuration settings on third-party clients that we cannot support because they are not our product.

You may want to experiment with the Primary Channel selection during your testing, as some vendors expect it to be in the upper or lower part of 40 MHz channel.

That is as much help as we’re able to provide with third-party devices at this time (during the beta).


I never contested the 5Ghz granularity doesn’t work with Mimosa clients.
The remark I made was that if your full Mimosa based P2MP Network (AP + Clients) is in ‘interop’ mode, what would be the use of that? I’d presume that in that case you go to SRS mode?

Imho ‘interop’ mode is a modus that can be used in the migration from a 3rd party network towards a full Mimosa network since SRS is like every vendor’s tdma a proprietary protocol.

This is now exactly what many existing WISP will have to do. First change the ‘old’ 3rd party AP for a Mimosa AP and then start exchanging the clients. Since this is almost impossible to do in a very short time during this migration you need the basic 802.11 csma mode as an ‘inter operational’ solution not to deprive your existing clients from a service for too long.

If anybody is creating confusion it is Mimosa. The 5Ghz granularity was introduced in the first 2.3.3 beta.

The text in the info section actually reads: "5 MHz Enable - In WiFi Interop mode, click the slider to turn on channel selection in 5 MHz increments."
This gives me the conclusion is works in interop mode.

The next reads; "When off, channel selection is limited to defined Wi-Fi channels for maximum compatibility with third-party devices."
I can understand that.

When I found our Mikrotik’s cannot work and spoke about that issue with the helpdesk it has been said the 5Ghz granularity is only for SRS mode.
And you actually state it only works on Mimosa C5’s and ‘maybe’ others.

Now pardon me, if it works in a full C5 P2MP network then there is no more need for ‘interop’ mode?

In my opinion this is all very confusing.

And I can’t understand that a Mikrotik radio that is worldwide know for its versatility in adapting to almost any wireless constellation cannot work with the 5Ghz granularity of a Mimosa.
And this is a very important item. Many WISPs work in an existing environment where virtually any channel is already in use by itself or other operators. To find now a free 40, or 80Mhz band you sometimes need to move that bandwith 5Ghz up or down in the band to make sure you stay out of other band users.

If this is limited it automatically means the usage of the Mimosa is limited in ‘real world’ scenarios. Imho there are not a lot ‘virgin’ radio spectrum regions to be found to roll out Mimosa without any issue around on the world anymore. Mayby North Korea! LOL

But OK I am going to see if I can follow your suggestion and see if I can get it to work by swapping the ‘pilot’ channel.


Are you willing to perform a wireless packet capture to understand why the third-party clients are not associating? That would help us get to an answer faster.


Tonight I tried to use 5Ghz granulation.
My A5 is working on 5670 in normal mode and has some 40 (Mikrotik clients) and 2 C5’s connected.

I have one Mikrotik Omnitik antenna that has 20 more CPE’s connected that can also connect to this A5.

When I swap the A5 to 5Ghz granularity mode only the AP works normal. All clients stay connected and have traffic.

When I go now to 5665 then all Mikrotik clients stay connected but have no more traffic. The 2 C5’s disconnect and will not connect anymore. (7 mins wait)
If I try to connect more CPE’s (from the other Mikrotik AP) to connect to this A5 it won’t happen. (In ‘normal’ mode at 5670 they connect without issue)

I tried both options for the ‘primary’ channel (the high or the low one) but that makes no difference.


  1. Mikrotik clients stay connected to AP in 5Ghz granularity mode if outside standard channel. But no more traffic is seen.
  2. New Mikrotik clients will not be allowed to associate to A5 in 5Ghz granularity mode outside standard channel.
  3. Mimosa C5 client disassociate from A5 upon change of channel in 5Ghz granulatiry mode outside standard channel. (I tried this 4, 5 times. Even with a reboot of A5. I also waited 7 minutes to see if the C5 would associate again. But no. No association in non standard channel!

5Ghz granularity mode in ‘interop’ mode is completely unusable. Even for C5!


Tell me how to do the wireless packet capture so mayby I can give you guys an understanding what is happening?


Hi Rudy,

I hear that our Support staff is helping you with a potential radar detection problem that may be the cause of the issues you are seeing above on the DFS channels. It is more appropriate to continue that discussion with them directly.

We recommend the use of a free software package called Wireshark for capturing packets when troubleshooting association issues. This would probably best be done in a lab environment to limit the number of external variables.


Indeed. It might be an issue. The DFS I mean.

For the association issue I need to setup an AP in our under-build with one or two C5’s to connect to it under 5Ghz granularity modes?
How do we ‘see’ the data transfers between radio’s if there is no higher level traffic yet?
That will be a nice job for my technician I’ll guess… Are there any specific code we are looking for?