Comment by neilalexander 2 days ago
This may not help if you can’t control your environment. You will often benefit from nearby routers hearing you and each other if you are forced to share a channel with them, as that is what enables the carrier sensing to work correctly. Otherwise neighbouring APs that can’t hear your quieter use of the channel may shout over your devices rather than backing off, creating collisions and resulting in retransmits.
You can get this kind of interfere even if the signal from the router to your device is sitting just above the noise floor and the property next to you is doing the same thing. Both signals are so weak they get drowned out by an even weaker signal. The router on the other hand can’t tell the message is corrupted until your device responds.
You control your environment by not adding yourself to the dicks creating the bad environment. Everything else is just rationalizing for your own maximum convenience.
There is no such problem as "you have to shout enough so the others hear that you're there". There's no such thing, by at least 2 different vectors. 1, They hear everyone just fine, weak and strong, all at the same time. 2, It doesn't matter even if they didn't, because you obviously hear them if you're getting clobbered by them, and so your router can channel hop around them even if they don't channel hop around you.
While indeed you shouldn't fix noise by shouting louder, your justification isn't quite right.
1. It's the AP that has to decide to change channel, and if you live somewhere with channel contention, from its perspective all channels will be busy. At that point, if your channel appears the quietest (either by being the least noisy or by your clients not being active), then the AP will decide to clobber your channel. Their WiFi devices may also not hear you and won't back off to give your airtime, even though you hear theirs and give them airtime.
2. Having your AP change channel (note: channel hopping is something else entirely, which isn't used for WiFi) wouldn't help when all channels are busy. As long as your usage appears quiet, other APs will keep moving on top of you during their channel optimization.
For residential, the only solution is to use technology that cannot propagate to neighbors. 5/6GHz and many APs, and good thick walls (mmm, reinforced concrete). WiFi channels is a solution to make a few bits of equipment coexist in the same space, but is of limited use when it comes to segregating your space from that of your neighbors. Especially if you want good performance, as there's very few wide channels available.
If you’re using the same channel as a neighbouring router that’s close enough to overpower yours then you’ve already lost, pick a different channel. If you stick to 20 mhz there are plenty options, even more if you are able to use DFS channels.
Yes, exactly, this means you shouldn’t use 320Mhz.
Find quietest 20mhz available on 5 or 6 GHz. It’ll be far more reliable than trying to battle someone over the 320.
How likely am I to even detect my neighbors 6GHz network?
I live in a very dense part of Chicago. 2.4 and 5 are a minefield, just a thick soup of interference on everything but the DFS channels (which I get kicked off of too often being close to two airports). While it could be that zero neighbors have 6E or 7 equipment, I find that hard to believe, but nothing comes up on the scan.
6 GHz capable access points / routers are in the Extremely Expensive realm, as a 6 GHz radio on its own is almost useless these days unless all your devices are high end and brand new. Got a security camera? No 6 GHz. Got an old laptop? Nope. What about that iPad from 2019 that still works great? Nope. Smart TV? Nope.
Very few people are using 6 GHz at this time.
You're describing the situation where the prisoner's dilemma has already gone wrong, with someone else not-nice shouting over you trying to be nice.
In other words: you don't need carrier sensing to work if you're not getting drowned in noise to begin with.