Beamforming / Mu-MIMO / Airtime Fairness

[DocUmibozu]

now i am expanding , purchased a RT-AC88U for main roater and 2 x RT-AC86U to setup aimesh to make wifi better

Do i still need to disable those options? i bought mainly the other asus products fir aimesh, especiallo for roaming
i have now setup on manual channels (far away), but seems my androids phones dont roam to the strongest wifi, i always need to disable/enable wifi

Those advices are a bit old... born at a time when Broadcom SOC were clearly defecting regarding MU-MIMO and Beamforming.
You have a recent router model, so I'd try to enable both AC / Explicit Beamforming and MU-MIMO.
Airtime fairness has to be disabled 'cause it generates a lot of troubles with home assistant (echo, google nest) and with google cast.
Universal Beamforming is useless.

 

[dlandiss]

Multiple APs that are using Ethernet for backhaul should be set to use different channels, using 1,6,11 in 2.4 GHz with 20 MHz channel bandwidth.

Thank you for that. I was wondering if client roaming from the gateway router to the access point would be smoother (no dropouts) if they were on the same channel, but maybe interference is the deciding factor?

 

[dscline]

I have explicit beamforming and MU-MIMO enabled on the 5ghz band. The devices I have on 5ghz are all reasonably new. I haven't had any issues, though I've not done any testing to see if they help or hinder performance. I have them disabled on 2.4ghz, as well as airtime fairness & implicit beamforming on both bands.

 

[thiggins]

Thank you for that. I was wondering if client roaming from the gateway router to the access point would be smoother (no dropouts) if they were on the same channel, but maybe interference is the deciding factor?

No, channel doesn't matter. Clients make roaming decisions based on signal strength and sometimes quality / potential bandwidth.

 

[dlandiss]

No, channel doesn't matter. Clients make roaming decisions based on signal strength and sometimes quality / potential bandwidth.

Thanks again!

 

[ugandy]

i have some 2.4 devices quite far from the router (other side of the house). they can only connect if beamforming is enabled. not sure if beamforming is supposed to help devices far from the router, but in my case i need it enabled so they can connect. if I disable it they disconnect.

 

[Morris]

My take on this is to disable non standard based (proprietary protocols) They are not tested by the WiFi consortium for interrogability and I've seen them cause problems. There fore I do the following:

On my 2.4 GHz band I've disabled:
Universal Beamforming
Airtime Fairness
Multi-User MIMO
Explicit Beamforming

Explanation: 2.4 GHz tends to have legacy clients and they don't support any of these except Airtime Fairness and in my experience Airtime Fairness is a performance killer with little benefit.

On my 5 GHz band I've disabled:
Airtime Fairness
Universal Beamforming

Explanation: 5 GHz contains more modern clients and well defined protocols. Universal Beamforming is for clients that don't support beamforming and can cause return signal issues confusing clients. 802.11AC Beam Forming works well and will only happen on clients that negotiate it. This will give AC clients better range and signal preventing drops. Multi-User MIMO is starting to show up on clients and works well when negotiated.

I recommend one other change for both bands. Limit the modulation Scheme to standards based ones so don't go higher than 802.11AC on 5 GHz and 802.11n on 2.4 GHz. This avoids clients not being able to hear other clients and transmit collisions, a real performance killer.

Morris

 

[MvW]

i have some 2.4 devices quite far from the router (other side of the house). they can only connect if beamforming is enabled. not sure if beamforming is supposed to help devices far from the router, but in my case i need it enabled so they can connect. if I disable it they disconnect.

Out of curiosity: which kind of beamforming did you enable to make sure these devices are within reach?

 

[Pergola Fabio]

i am setting up my rt-ac88u as main router (8 ports) and 2 nodes rt-ac86u
i had a long time the rt-ac86u as main router and some other brands access points (old firmware)
the main router is on main floor, i enabled 2.4 and 5.gh like before, both on fixed 2.4 - 40mhz and 5.0 - 80mhz, so i have the 300mbit for 2.4 and 877 for 5.0.. , also same as before on rt-ac86u , never had issues

2 issues happened so far (airtime/beamform/mmu disabled) , all updated to 386.2
- if i read threads here, everyone tells to setup 2.4 on 20mhz, but if i do that, i have terrible low speeds, browsing , downloading, is just not possible, its connected to 144, but i get copy speeds like 1MB/ sec, while it should be like 10mb, if i fix it to 40mhz, then all works fine, 20 mhz is just not possible...
- second isssue, i had some wireless devices connected to the main router, mainly smart devices, all working fine, all conncted to 2.4 , next day, i noticed all my smart stuff was not working anymore, like a google harmoy hub, esphome, smart lights... they were still connected, i was able to ping the stuff, they were all still connected to the router with verry good connection status, but i was just not able to control them? for example , 1 smart device has a webserver running, i was not able to access it from the notebook (local) , allthough it was still reachable, so i rebooted the router, and all devices were working again... verry strange, all pingable, but seems i was not able to access the services on in? seems it was blocked like a firewall does ,... any idea what could cause this? i hope it doesnt happen again

 

[Morris]

i am setting up my rt-ac88u as main router (8 ports) and 2 nodes rt-ac86u
i had a long time the rt-ac86u as main router and some other brands access points (old firmware)
the main router is on main floor, i enabled 2.4 and 5.gh like before, both on fixed 2.4 - 40mhz and 5.0 - 80mhz, so i have the 300mbit for 2.4 and 877 for 5.0.. , also same as before on rt-ac86u , never had issues

2 issues happened so far (airtime/beamform/mmu disabled) , all updated to 386.2
- if i read threads here, everyone tells to setup 2.4 on 20mhz, but if i do that, i have terrible low speeds, browsing , downloading, is just not possible, its connected to 144, but i get copy speeds like 1MB/ sec, while it should be like 10mb, if i fix it to 40mhz, then all works fine, 20 mhz is just not possible...
- second isssue, i had some wireless devices connected to the main router, mainly smart devices, all working fine, all conncted to 2.4 , next day, i noticed all my smart stuff was not working anymore, like a google harmoy hub, esphome, smart lights... they were still connected, i was able to ping the stuff, they were all still connected to the router with verry good connection status, but i was just not able to control them? for example , 1 smart device has a webserver running, i was not able to access it from the notebook (local) , allthough it was still reachable, so i rebooted the router, and all devices were working again... verry strange, all pingable, but seems i was not able to access the services on in? seems it was blocked like a firewall does ,... any idea what could cause this? i hope it doesnt happen againC

Channel 144 is on 5-GHz. 2.4-GHz settings will have no effect on that channel. I suggest you force the distant devices to the 2.4-GHz channels by either using 2 SSIDs and configuring devices to connect the best channel for them or by setting up mac address deny filters on 5-GHz for the distant devices.

I suggest you address the first issue and see if you still get the second one. The problem with using parapatry beamforming is that only the router dose it. There for the signal from the router to the host is strong and the host hears and connects to the router yet the signal from the host to the router is not beamformed and week so the router can't hear the host. Take a look at my post above for my recommended settings.

Good luck,

Morris

 

[Pergola Fabio]

Channel 144 is on 5-GHz. 2.4-GHz settings will have no effect on that channel. I suggest you force the distant devices to the 2.4-GHz channels by either using 2 SSIDs and configuring devices to connect the best channel for them or by setting up mac address deny filters on 5-GHz for the distant devices.

I suggest you address the first issue and see if you still get the second one. The problem with using parapatry beamforming is that only the router dose it. There for the signal from the router to the host is strong and the host hears and connects to the router yet the signal from the host to the router is not beamformed and week so the router can't hear the host. Take a look at my post above for my recommended settings.

Good luck,

Morris

yeah, i already have seperate ssid for 2.4 and 5.0 , configured now with fixed channels
2.4 , 40 mhz, channel 11
5.0 , 80 mhz , channel 36



lets see what happens after a few days

with aimesh, i have also bind some devices to the nearest node

 

[leerees]

I run what most would consider a sizable wireless mesh network. It consists of a mish mash of G, N, AC and AX devices across all bands, all competing for bandwidth, all of the time.

Universal beamforming: This needs to be on, if this is off legacy devices will get a worse wifi signal.

DL OFDMA: This is crucial to the performance of a network with many AX devices. Disabling it will cause lag and buffer bloat on busy networks. Without OFDMA, Gaming pings and web browsing responsiveness will be noticeably slower on a network under load.

MU MIMO: Again, crucial to allow your router to communicate with multiple streams simultaneously. Disabling it will impact the performance of your WiFi. If you manage to find an IOT device that isn't compatible with this (i haven't) then you need to put that IOT device on eBay and be done with it.

I'm well aware that tests have been run that find no difference in performance with these settings on. But when you have a busy network, I can assure you they have a massive impact on improving network performance. These settings are enabled by default because Asus is aware within a few years most smart IOT devices will be AX and thus will take advantage of these features.

 

[Tech9]

If you manage to find an IOT device that isn't compatible with this (i haven't) then you need to put that IOT device on eBay and be done with it.

You may have to put all your IoT devices on eBay. What IoT device supports MU-MIMO? Do you know the relation between radio number of streams and possible MU-MIMO devices support? How many MU-MIMO devices your 2x2 AC radio on AX92U supports? What about 2x2 N radio, serving most of IoT devices?

 

[leerees]

You may have to put all your IoT devices on eBay. What IoT device supports MU-MIMO? Do you know the relation between radio number of streams and possible MU-MIMO devices support? How many MU-MIMO devices your 2x2 AC radio on AX92U supports?

None of my IoT devices support MU-MIMO. It was in reference to people who claim MU-MIMO is the cause of their IOT's disconnecting.

The WiFi6 devices connect to our AX92u's on a number of different streams up to 4x4 160Mhz

 

[Tech9]

The WiFi6 devices connect to our AX92u's on a number of different streams up to 4x4 160Mhz

Now many MU-MIMO devices 4x4 AX radio can serve in the same time?

Sorry, I want to find out if you understand how the tech works before you make suggestions. My next question would be about spatial diversity requirement with MU-MIMO. Honestly, the whole story with 8x flawlessly working AX92Us with 160MHz wireless backhaul shared with clients, extremely busy Wi-Fi network with hundreds of clients in Airbnb place... sounds hard to believe. The guys you rent the apartments to must be throwing LAN parties all day long. You're one of the few AX92U owners around happy with this half baked Asus solution, originally designed to use the single AX radio as dedicated wireless backhaul only.

 

[leerees]

Now many MU-MIMO devices 4x4 AX radio can serve in the same time?

Sorry, I want to find out if you understand how the tech works before you make suggestions. My next question would be about spatial diversity requirement with MU-MIMO. Honestly, the whole story with 8x flawlessly working AX92Us with 160MHz wireless backhaul shared with clients, extremely busy Wi-Fi network with hundreds of clients in Airbnb place... sounds hard to believe. The guys you rent the apartments to must be throwing LAN parties all day long. You're one of the few AX92U owners around happy with this half baked Asus solution, originally designed to use the single AX radio as dedicated wireless backhaul only.

I like to ensure my network performs the best it can, if people want to throw LAN parties, they can.

I'm using the AX92u's exactly for what they was intended, to build a large mesh of AP's. I'm not sure why you think they shouldn't work or are somehow a bad product. What is the issue you actually have with them?

Do not dedicate the AX radio to the wireless backhaul. It has more than enough bandwidth to share with the clients if your WAN is 1Gbps.

I am not endorsing the AX92u. If people want a mesh today, they should buy the XT8. However, at the time when I brought them, they was the best solution for me. They work perfectly, so I won't be upgrading for a very long time.

 

[Tech9]

What I'm trying to say is MU-MIMO in particular doesn't have the massive impact you imagine on your wireless network performance. It may eventually serve 2-3 clients per radio at a time with reduced link speeds, if all the conditions are met. In some cases it may actually hurt the performance to single STA. I don't know how well your system works, but you steal the entire Wi-Fi spectrum bandwidth around. If people want real mesh today, they should stay clear of all single channel consumer products and 160MHz wide channels.

 

[Wycleff]

I like to ensure my network performs the best it can, if people want to throw LAN parties, they can.

View attachment 36726

I'm using the AX92u's exactly for what they was intended, to build a large mesh of AP's. I'm not sure why you think they shouldn't work or are somehow a bad product. What is the issue you actually have with them?

Do not dedicate the AX radio to the wireless backhaul. It has more than enough bandwidth to share with the clients if your WAN is 1Gbps.

I am not endorsing the AX92u. If people want a mesh today, they should buy the XT8. However, at the time when I brought them, they was the best solution for me. They work perfectly, so I won't be upgrading for a very long time.

@leerees

I would really like to see your entire wifi settings for 5 Ghz and 2.4 Ghz as a screenshot.

Maybe I can use it as inspiration for a mesh network in my new apartment.
Thanks.

 

[leerees]

What I'm trying to say is MU-MIMO in particular doesn't have the massive impact you imagine on your wireless network performance. It may eventually serve 2-3 clients per radio at a time with reduced link speeds, if all the conditions are met. In some cases it may actually hurt the performance to single STA. I don't know how well your system works, but you steal the entire Wi-Fi spectrum bandwidth around. If people want real mesh today, they should stay clear of all single channel consumer products and 160MHz wide channels.

What do you mean by "real mesh"? We do have a 160mhz wide channel, but it's in the unused DFS band. The other 5ghz channel is 80mhz.

 

[Tech9]

What do you mean by "real mesh"?

You don't have a mesh. What you have is centrally managed wireless repeaters, all working on the same wireless channels, called by Asus with marketing name AiMesh. The more you add the worse the interference and they all cut the throughput in half, when the same radio is used for backhaul and clients in the same time. Half of your available Wi-Fi environment throughput is wasted by design. In one of my business places I run a system with 8x wired AC access points, all using 40MHz wide channels and spread out in non-DFS spectrum. The total throughput is perhaps higher than what you have with AX wireless repeaters. I can serve 120-160 active clients at the same time with no significant system load and no unnecessary Wi-Fi pollution.