Are all 4x4 AP antenna configurations useless and 2x2 performs actually exactly the same?

Are all 4x4 AP antenna configurations useless and 2x2 performs actually exactly the same?

Are all 4x4 AP antenna configurations useless and 2x2 performs actually exactly the same?
Are all 4x4 AP antenna configurations useless and 2x2 performs actually exactly the same?
2 weeks ago - last edited a week ago

After years of experimenting and trying to find ANY information (as a matter of fact there is no information on this topic in the entire internet), its pretty clear to me, that spatial streams of WiFi 5 and 6 are simply not working for multi user configurations. 

 

Even if the clients are perfectly compatible with DL-MU-MIMO and there is no interference and other signals nearby, its impossible to get more spatial streams then the smallest client has. So normally you never exceed 2 streams. 


Which means, in all tests, 4x4 APs achieved the _exact_ same performance as the smaller 2x2 counterpart. As soon as more then 1 client was active in the cell, the performance degraded.


The only case where 4x4 really works is with a 4x4 client, and because there is not a single client device with 4x4 antennas, only a wireless link would actually benefit from 4x4. As soon as a 2x2 client joins the same network, the 4x4 link is also degraded.

 

It seems spatial streams are nothing more than just another layer of QAM and therefore have the same limitations. 

 

 

Or did anyone in this forum ever achieve a higher total bandwidth with a 4x4 AP compared to an 2x2 AP? Would be interesting, it seems that this is literally impossible but I stand corrected. Even talking to an Cisco engineer lately he couldnt deny my observerations (but didnt want to go into the detail as well...)

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Re:Are all 4x4 AP antenna configurations useless and 2x2 performs actually exactly the same?
2 weeks ago - last edited a week ago

Hi  @RobertMEF 

 

Thank you for sharing your extensive experimentation and observations.

Firstly, it's important to note that while it may seem that spatial streams are not working as expected in multi-user configurations, there could be several factors at play. For one, even if clients are compatible with DL-MU-MIMO, there could be other environmental factors or settings that are impacting the performance. Just because there is no visible interference nearby doesn't necessarily mean there aren't other issues affecting the signal.

 

Regarding the performance degradation when multiple clients are active, this is not uncommon as the network resources are shared among the connected devices. However, it doesn't necessarily mean that the spatial streams are not working as intended. As for the comparison between 4x4 and 2x2 APs, in an ideal scenario, a 4x4 AP should offer better performance and higher total bandwidth. But in real-world scenarios, as you've experienced, it may not always be the case due to various factors such as client capabilities, network congestion, and interference. It's also possible that there could be some configuration or optimization that you haven't tried yet that might improve the performance.

Have you checked for firmware updates for your devices? Sometimes, new firmware can address performance issues and improve the functionality of the network.

 

In conclusion, while it's understandable that you're frustrated with the results of your experiments, it's important to consider all possible factors and continue to explore different solutions to optimize your network performance. If you haven't already, you might also want to reach out to our technical support team directly for more in-depth troubleshooting and advice. 😊

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Re:Are all 4x4 AP antenna configurations useless and 2x2 performs actually exactly the same?
a week ago
Im working in the field of wireless networks over different kind of radios for more than 20 years, so of course I know all that simple stuff what to look for. Ive tested at least 30 different APs and devices with a wide range of vendors for the modems. Even under LAB-conditions (no reflections, no interference, "free field") it was not possible to achieve any performance gain. To go more into detail: the 4x4 AP should share one RU (resource unit) with two 2x2 devices in MU-MIMO mode. That is the definition in IEEE 802.11ax. But actually no matter what conditions, there are always 2 RU allocated and therefore the AP degrades to 2x2 mode. Which means that there is an error in the implementation on AP side.
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