WiFi congestion - maybe nothing to be done?

[crary]

Hi there, long time amateur network guy with just enough knowledge to be dangerous here. In other words, there's plenty I don't know. After marriage, I moved in with my wife, going from a very large 3-story house to a 1,000 square foot condo, and I thought networking and especially WiFi would be an absolute breeze. I was wrong. Given that we live in a crowded condo complex in a fairly well-connected part of the world (Calgary, AB), the amount of WiFi traffic is just insane. At any given time, literally dozens of network SSIDs are visible from our condo. So, I naturally did what any network guy worth his salt would do: I ran wire (some of it professionally, for a stretch I couldn't figure out). I also upgraded to an Asus GT-AX110000 when it was time for WiFi 6, hoping that a beefy router would help the signal within the condo. Well, for the most part that has worked, but I still have some IoT things that seem to be affected. Namely a smart lock and a light at opposite corners of our condo that seem to frequently disconnect (I am assuming from the 2.4 band). I have tried looking for clearer channels to no avail. To be sure, it's a minor problem, but one that gnaws at me for no good reason. So I guess I would ask anyone smarter than me (which is most people): (1) am I right in thinking the IoT disconnections are likely due to large amounts of WiFi traffic? And (2) if so, can I do anything? I've considered putting in a mesh system, but that seems a little ridiculous in our little homestead. Would love to hear others' thoughts. Thanks!

 

[Tech Junky]

First thing you need to do is grab a wifi analyzer app and figure out what channels have the best shot at being clear enough to not conflict with your neighbors.

Second thing after you find the channels is to take your router out of AUTO mode and pick the channels that look less congested or overlapping with your neighbors.

Once you're out of AUTO mode the IOT devices should stabilize as the channels aren't changing all of the time.

Dense communities = more WIFI interference. Everyone runs in AUTO mode and it just makes a mess of the air space. If installers would take the extra 2 minutes to scan the air and set a static channel on devices it would be much better for everyone and reduce calls for support from users which means less money spent on support.

For me picking CH 8 on 2.4 works best as you can see it's a stand out option since all of the AUTO settings only choose 1/6/11.
5GHZ gets a little trickier since you have to choose the channel width and that will span several channels as you go up 20/40/80/160mhz. Once again by default devices are dumb and all try to use the same base channel. It might take a couple of attempts to find which one provides the best signal / speed but, once you lock it down it should be stable.

 

[crary]

Thank you for the input! I have used a WiFi analyzer, and didn't see a notable outlier like in your example, but I'll give it another shot. It makes a lot of sense that channel switching due to the "auto" setting could be producing the issue. If nothing else, I have a new approach to try when I get home. Cheers!

 

[Tech9]

(1) am I right in thinking the IoT disconnections are likely due to large amounts of WiFi traffic?

No, IoT devices need very little bandwidth. Check the signal level from your IoT devices in Wireless Log. It's probably too low for stable connection.

Would love to hear others' thoughts.

Don't use WiFi Analyzer apps - they only show what channels other APs are tuned to, but not what channels have the best bandwidth available. Run the router on Auto for some time and observe in System Log what channels it picks based on what the router (not your phone) sees around. After some time lock the channels and hold your ground. Routers around on Auto will move away. Use 20MHz wide channel only on 2.4GHz band. I own a condo in downtown Toronto and have no issues pushing >500Mbps on channels 36-48. There are multiple other networks around, but not all active and taking the entire available bandwidth. By the way, you don't need this 3-band router in your condo. It only takes more space. AX86U is more compact, cheaper and with the same CPU/RAM. Dual-band router is all you need in a condo with expected relatively low number of wireless clients.

 

[Tech9]

I also upgraded to an Asus GT-AX11000

This router has a lot of beefy plastic to look more "gaming". The antennas are omnidirectional 2dBm and stick outside mostly for marketing purposes. The actual antenna inside the plastic shell is a standard dipole 5cm long. This is the reality with home AIO routers - you pay for the looks as well.

Here, I'm in the apartment right now:

About 400Mbps to 2-stream AC client on channel 36 @80MHz wide. Sometimes it goes up to 520Mbps. Synology RT2600ac router, dual-band.

 

[tgl]

For me picking CH 8 on 2.4 works best as you can see it's a stand out option since all of the AUTO settings only choose 1/6/11.

I'm having a hard time believing that that's good advice. AIUI, the rationale for the "use channel 1, 6, or 11" rule is that that's the only way to fit 3 non-overlapping 20MHz channels into the frequency range allotted for 2.4GHz wifi. (Remember that the channel numbering is based on the assumption of 5MHz-wide channels: so a 20MHz signal requires four numbered channels, plus a little bit of extra bandwidth because transmitters aren't perfect.) If you've got neighbors running on channels 6 and 11, that does not mean channel 8 is free air. What it means is that if you broadcast on 8, you are overlapping/interfering with two sets of neighbors not just one. Your results will be twice as bad as your neighbors', because you'll see twice as much congestion. Don't do it unless you live somewhere with no nearby wifi-using neighbors.

(This is also the reason for not using a 40MHz channel in 2.4GHz: you'll be overlapping with two sets of neighbors not just one.)

(Things are different in the 5GHz range, btw. But I'm not getting into that here.)

 

[Tech Junky]

use channel 1, 6, or 11" rule

In an office space that's how it's done for roaming between aps to get that honeycomb effect. The client picks the strongest signal and associates with that AP.

 

[sfx2000]

Here, I'm in the apartment right now:

About 400Mbps to 2-stream AC client on channel 36 @80MHz wide. Sometimes it goes up to 520Mbps. Synology RT2600ac router, dual-band.

Stop and consider - how often does one copy files from one PC to another - answer, not very often...

You'll fnd a lot of mis-guided inputs here - esp in 2.4GHz feedback... and most of this is based on info from 10 years ago.

 

[sfx2000]

This is also the reason for not using a 40MHz channel in 2.4GHz: you'll be overlapping with two sets of neighbors not just one.

Keeping the control channel on 1/6/11 - that's ok...

That being said - going wide there - the secondary channel has to do clear channel procedures before enabling it - this is all spec and part of 802.11...

 

[tgl]

That being said - going wide there - the secondary channel has to do clear channel procedures before enabling it - this is all spec and part of 802.11...

Sure. Nonetheless, when you do get the channel and transmit at 40MHz, you are eating two-thirds of the available resources. That isn't a terribly friendly thing to do in an already overcrowded bit of spectrum.

(Of course, sending an 80MHz signal in the 5GHz band is not great from that standpoint either. However, 5GHz attenuates a lot faster so the number of neighbors you're truly contending with is far less.)

 

[Tech9]

Stop and consider - how often does one copy files from one PC to another

This is over Wi-Fi file transfer. I'm showing the Wi-Fi speed. It's the same to Internet if you have 500Mbps Internet access.

the rationale for the "use channel 1, 6, or 11" rule is that that's the only way to fit 3 non-overlapping 20MHz channels

This rule applies only if you control all the APs around. When you don't you use the channel with maximum available bandwidth.

 

[tgl]

This rule applies only if you control all the APs around. When you don't you use the channel with maximum available bandwidth.

When 90% of your near neighbors are following the 1/6/11 rule, you do too, unless you want to make things worse for both yourself and your neighbors. Who "controls" any particular AP is quite irrelevant to what is happening on the air.

 

[Tech9]

you do too

No. As @sfx2000 said above things have changed. Modern routers work better on any channel with better bandwidth available and filter much more efficiently the interference and noise from adjacent channels and other RF communications. If you always follow 1-6-11 "rule" on 2.4GHz band there is a chance you only hurt yourself. In my condo place there are multiple networks on any channel available 1-11. It works best for me on Ch4 and Ch8. I prefer Ch4 because Ch8 is very close to microwave ovens frequency and they leak in operation enough to disrupt Wi-Fi. It's more about understanding how it works and less following "rules" written by someone who retired during 802.11g era.

 

[tgl]

When 90% of your near neighbors are following the 1/6/11 rule, you do too ...

Just to clarify the kind of situation I'm dealing with, which I suspect @crary has in spades, here's WiFi Scanner's view of the 2.4GHz situation in my living room:

No points for guessing which AP is mine ... but I want to point out that its signal is barely stronger than half a dozen of my neighbors'. I'd be an idiot to want to be contending for airtime with two-thirds of them rather than one-third. The two nearby APs that are not following 1/6/11-20MHz are not doing anybody any favors. I'm sure they're both auto-configured on behalf of people who know nothing about wifi, so I'm not casting blame, but they're not helping.

 

[Tech9]

You won't hurt anyone if you move to Ch8 or Ch9. This "situation" doesn't show you available bandwidth per channel, but only how many APs are tuned to specific channel. If they are all idle you can even hit 40MHz wide channel right in the middle with full speed. The opposite is valid as well - you tune to Ch11 just because there is only one other network the app is showing you on Ch11. This channel may be actually the worst with very active other AP and very low bandwidth available. Forget about the graph and set your router to Auto for a day. The channel it picks more often using built-in SoC algorithm is the best channel for you. Are you smarter than Broadcom or Qualcomm? Your "rules" can make things only worse.

Also note - this Wi-Fi scanner works on one of your clients. This is what its Wi-Fi adapter sees. Does the router sees the same?

 

[tgl]

Forget about the graph and set your router to Auto for a day.

[shrug...] That AP is using auto channel selection.

Also, while I didn't show it here, WiFi Scanner does show the channel utilization figures reported by a lot of these APs. Right now they're all running between 20-45%. I'm still not liking the odds of contending on two of these channels instead of one.

(This is all sort of academic for my day-to-day use, because I use the 5GHz band for anything where I actually care about performance. But I can't see how varying from the 1/6/11 convention is going to make anything better in 2.4GHz.)

 

[Tech9]

1/6/11 convention

There is no such convention. There was a recommendation in the past. Test different "non-standard" channels and don't be surprised if your router achieves 2x throughput. On 1-6-11 I can't get even 20Mbps in the condo. On Ch4 and Ch8 I can reach 50Mbps with 40Mbps almost guaranteed.

Synology router there is Qualcomm IPQ8065 with dual 4x4 QCA9984 radios. The same hardware as the king of AC routers Netgear R7800. Why I need to apply Linksys WRT54G rules to it? It doesn't make much sense to me when the hardware is capable of doing its thing well in dense Wi-Fi environment.

 

[tgl]

There is no such convention. There was a recommendation in the past. Test different "non-standard" channels and don't be surprised if your router achieves 2x throughput. On 1-6-11 I can't get even 20Mbps in the condo. On Ch4 and Ch8 I can reach 50Mbps with 40Mbps almost guaranteed.

As I said, I don't really care about performance on that band, so I don't plan to accept this homework assignment. What I do care about is reliability (for the few devices I have using that band) and being a good wifi neighbor, so minimizing the number of neighbors that that AP contends with seems like a good plan. It evidently seems like a good plan to the AP's ACS algorithm as well.

Anyway, we've gotten pretty far afield from @crary 's original question, which was what to do for some IoT devices in an oversaturated wifi environment. Max performance wasn't part of the concern there either. My inclination (assuming that neither device can be wired) would be to try to move the main AP closer to one of them, and put a secondary AP close to the other, probably dialing the secondary AP's transmit power down some.

 

[Tech9]

and being a good wifi neighbor

No one around is still using Linksys WRT54G either.

 

[L&LD]

That is simply not true.