Is Anyone Using MU-MIMO?

[sfx2000]

Broadcom deal was blocked for national security reasons.

Interesting read now that we've gone off topic...

1) They propose to buy, if rejected
2) They propose to do a Joint Venture, if rejected
3) They do a price fixing investigation... and get a settlement

Made in China 2025 initiative...

Good read here -- https://www.theregister.co.uk/2018/06/26/dram_technology_thievery_by_taiwanese_tech_co/

 

[System Error Message]

Interesting read now that we've gone off topic...

1) They propose to buy, if rejected
2) They propose to do a Joint Venture, if rejected
3) They do a price fixing investigation... and get a settlement

Made in China 2025 initiative...

Good read here -- https://www.theregister.co.uk/2018/06/26/dram_technology_thievery_by_taiwanese_tech_co/

Cool, i cant wait for DRAM prices to drop, ram pricing has been terrible. Once the market gets flooded with chinese ram thats as good as the high performing ones, we'll finally be able to afford the ram we need.

 

[thiggins]

Back on topic please, gentlemen.

 

[sfx2000]

Jump to hyperspace for those who might be interested in Orbi and MU...

https://www.snbforums.com/threads/orbi-using-mu-mimo-in-backhaul.48346/

Can continue the Orbi specifics there...

 

[doczenith1]

I've stepped up my testing game and installed iPerf 3. Therefore it was prudent to run some additional tests. It's been a while since I ran the tests...been busy with other things.

Test performed using iPerf 3.1.3 x64 on Win10 and Magic iPerf 1.0 on Android 9
Testing on RT-86U with 384.8 firmware
I am using the command line iperf3 -c x.x.x.x -O5 -i 5 -w 4M -t 60
After turning MU-MIMO on the router was rebooted and the clients "forgot" the SSID (same for going back to SU-MIMO)
Phones are in server mode to test the transmit speed of the router
Two wired computers used as clients
Devices are one room away with full link speed (866). With respect to the router the devices are at 11 o'clock and 1 o'clock for the two phone tests and 10, 12 and 2 for the three phone tests.
10 tests run for each scenario. The average total throughput is shown.

Pixel XL and Pixel 2 XL
SU-MIMO Test #1 - 516 Mbps
MU-MIMO Test #1 - 663 Mbps

Pixel 2 XL and Pixel 3 XL
SU-MIMO Test #2 - 655 Mbps
MU-MIMO Test #2 - 701 Mbps

Pixel XL, Pixel 2 XL and Pixel 3 XL
SU-MIMO Test #3 - 623 Mbps
MU-MIMO Test #2 - 723 Mbps

So, with capable clients MU-MIMO does increase throughput a little. Depending on your environment the perfect storm to benefit from the increased throughput might not happen very often though.

 

[avtella]

Also dependent on WiFi chipset, if I recall the R7800’s QCA9984 showed decent gains while the Broadcom chipset in the R8500/AC88U etc was kinda bad if not performance degrading with MU.

Of course distance between clients and client chipsets also make a difference, but hey you are getting an improvement even if minor. So Broadcom must have somewhat improved MU in the newer chipset on the 86U which is good to know.

 

[sfx2000]

So, with capable clients MU-MIMO does increase throughput a little. Depending on your environment the perfect storm to benefit from the increased throughput might not happen very often though.

Not really - these tests, depending on how many, are within expectations - if one were to run the same tests just for SU-MIMO, you'd likely see the same variance test over test...

Good news perhaps, seems that Broadcom/Avago has sorted out of some the Downlink MU-MIMO stuff they have previously... MU should have little effect for the most part - and MU is fairly complicated overall - which is why Broadcom missed on the first round of firmware/silicon - not blaming them, but MU also depends on the traffic type from the network, gathering groups of candidates for Tx beamforming and MCS, and pairing things up in appropriate groups.

Should serve perhaps as a word of heads-up - 11ax isn't going to be that much better for a single client station...

 

[rmiller1959]

So I'm a bit of a novice when it comes to the topic of MU-MIMO, so please bear with me. I am assuming that the iPhone X, Pixel 3a and Pixel 4XL are MU-MIMO capable (I haven't been able to find a list). I have a Google WiFi mesh network with a router and three nodes in a 3,742 square foot three-level home.

Obviously, I don't use MU-MIMO right now because Google WiFi doesn't support it. I recently pre-ordered the new Google Nest WiFi router as a replacement, however, because it has, at least on paper, better specifications - AC2200 MU-MIMO Wi-Fi, with 4x4 (5GHz) and 2x2 (2.4GHz) antenna configurations. I didn't buy the Nest WiFi Points because I have plenty of Google Nest (Home) Minis and a Google Nest (Home) Hub, and the Nest WiFi router is supposed to be backward-compatible with my existing Google WiFi setup.

Here are my questions:

1) Since my Google WiFi access points are not MU-MIMO capable (the Nest WiFi Points are), is it correct to assume MU-MIMO functionality within the router's range only? My assumption is that the mesh network can't extend to the Google WiFi access points a capability they don't support.

2) Will the higher speed and antenna count (AC2200 4x4 vs AC1200 2x2) of the Nest WiFi router make a noticeable difference in my network performance?

I'd appreciate your feedback. I'm looking to learn more about what actually makes a difference with Wi-Fi performance so I can sort the wheat from the chaff in the marketing language. Thanks!

 

[avtella]

You need 2 or more clients for MU to work. It also requires clients to be apart by a few feet for it to be effective otherwise those clients are treated like any regular non-MU device. It basically groups 2 or more MU capable clients to receive transmissions (downlink only in WiFi-5/AC) in parallel, whereas regular clients receive and send transmissions one after the other in a round robin fashion. It can give a decent boost in throughput but don’t expect a night and day difference.

Don’t let MU keep you away from purchasing a decent AC router. Some routers and MU clients mostly first gen Wave 2 Broadcom chipset based ones from all brands, have bad implementations infact, where MU causes worse performance. Some of the MU capable Galaxy phones like the S7 would drop to a single antenna performance level in MU mode (They use Broadcom WiFi chipsets). The Qualcomm chipset based Netgear R7800, R9000 and possibly the Synology RTAC2600 are the only AC routers that probably implemented MU in a proper manner.

I don’t think the iPhone X supports MU. Another thing is that MU needs a 4 antenna (4x4) router to be useful as most MU capable clients have 2 antennas and so an MU two client pair would be using four streams. They advertise MU even on two or three stream routers which is kinda pointless ie Orbi which is two stream client side and Linksys WRT1900ACS which has 4 antennas but is actually a 3 stream router.

 

[thiggins]

2) Will the higher speed and antenna count (AC2200 4x4 vs AC1200 2x2) of the Nest WiFi router make a noticeable difference in my network performance?

This more likely to make a difference than MU-MIMO. The four stream radio on the AP has higher effective receive gain, which can help improve range for even 1 and 2 stream clients.

 

[rmiller1959]

Thanks for the excellent feedback! It sounds like MU-MIMO is a specification I can safely ignore.

I look forward to the router upgrade. I've been pleased with the reliability of my Google WiFi system, so I'm glad the Nest WiFi router integrates with existing Google WiFi systems, or so they claim. I guess I'll know first-hand once the router is released in early November.

 

[Maghook]

Well, a little bit outdated but still interesting read concerning outcome of MIMO together with A-MPDU: https://www.hindawi.com/journals/jcnc/2018/3518352/

 

[frankhere]

Hello,
Since I have the new Asus zenwifi 6 router it is MU-MIMO compliant ( as the AP comes std. with the purchase). I have been working with the features of the unit for a day or two.
Now that said I also have the Pixel 3a cell phone , an 802.11 a/b/g/n/ac with 2×2 MIMO.

The phone has been quirky these last two days. In one instance I can send/receive text messages yet I get no audible notification that use to be standard and without issue. I did all the 'gymnastics' to insure I have every option correct on the Pixel 3A phone, yet it will not ~ notify ~ me audibly . Visually all's well and I can see messages but cannot hear when a text message has arrived from another phone ( either externally to the home or inside the home).

I was going to turn off MU MIMO on the Asus router side as a test, but did not want to do that as yet without asking the experts here. Is that an option, AND should anything else be disabled on the router side to disable MU MIMO for the test? And, am I barking up the wrong tree on this.

Note that this feature of an audible notification works outside the home :
a. On LTE network ( driving)
b. On another network ( example: Starbucks , at the gym, etc)
c. Works with Gmail ; audible notifications work fine in the home or elsewhere
d. Audible Notifications work fine with the 2.4ghz security system ( Blink) in the home or elsewhere


Curious eh?

Any pointers are welcomed.

thank you,

 

[L&LD]

Can the phone sense you are near? It may be silencing itself if it can.

Test by putting it in a drawer or laptop bag.

 

[frankhere]

Can the phone sense you are near? It may be silencing itself if it can.

Test by putting it in a drawer or laptop bag.

Good Idea, yet this is not the case. Two tests:
a. Leave the phone in another room - no sound notification
b. Leave the home and go to another location ( a store, park, etc) and the phone notification rings while on the person.
I have not found any option that would offer the ability to silence the phone due to its proximity of the user.
This may be a feature on other phones.

When using my old router ( Netgear) no issues; sound notifications where not an issue. Yet to go back to Netgear ( as it is 5 years old) does not seem like a viable option for this one inconvenience .



thanks for the idea.

 

[L&LD]

@frankhere, I can't see how this is a router issue though? Will probably be proved wrong.

 

[frankhere]

@frankhere, I can't see how this is a router issue though? Will probably be proved wrong.

Not proved wrong...
Took some digging and patience, but got it done. NOT a router issue, but was ~ suspect~ as that was the last significant change to the 'mix' of technology in my home.
I will not explain as it then would be a cell phone conversation and take us off topic of MU MIMO


thanks!!!!

 

[coxhaus]

So I have a MIMO AP, iPhone11, and a new laptop with Intel AX200 card which has MIMO on. Is there any way to tell if there is a benefit? The Cisco WAP581 list as 3x3 MIMO with 2 spatial streams at 5 GHz and 3x3 MIMO with 2 spatial streams at 2.4 GHz.

 

[thiggins]

MIMO is not the same as MU-MIMO. Any router using more than one spatial stream is using MIMO. See this article https://www.smallnetbuilder.com/wireless/wireless-features/33100-why-you-don-t-need-mu-mimo

 

[avtella]

So I have a MIMO AP, iPhone11, and a new laptop with Intel AX200 card which has MIMO on. Is there any way to tell if there is a benefit? The Cisco WAP581 list as 3x3 MIMO with 2 spatial streams at 5 GHz and 3x3 MIMO with 2 spatial streams at 2.4 GHz.

Your AP is MU capable but you only have 1 MU capable device, the AX200 laptop. You won’t gain any benefit unless you have two or more. MU only is 5Ghz AC thing. Also MU needs a 4 stream AP or router (which yours is) to be effective as most MU capable clients are 2 stream. I mean I have seen a few cheap Acers here and there with single stream QCA MU chipsets but otherwise single stream MU clients are quite rare.