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Bye Bye 40 MHz Mode in 2.4 GHz

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That's incorrect. Any network that meets the coexistence interference criteria should prevent 40 MHz mode operation.

Is there any scenario where 2 x 802.11n WiFi networks could be operating in the same vicinity at 40 MHz then? I suppose if they have the same primary or secondary channel?
 
Is there any scenario where 2 x 802.11n WiFi networks could be operating in the same vicinity at 40 MHz then? I suppose if they have the same primary or secondary channel?
Yes. That is correct. But if only one neighboring network is detected on a different and interfering channel, 40 MHz operation should not be allowed.

For all practical purposes, in crowded 2.4 GHz airspace and if products are operating in compliance with 802.11n, you should not be able to operate in 40 MHz bandwidth mode.
 
For all practical purposes, in crowded 2.4 GHz airspace and if products are operating in compliance with 802.11n, you should not be able to operate in 40 MHz bandwidth mode.
But don't many products give an option, or default to, a configuration to ignore neighbor-networks and blast away in 40MHz mode? (It's not an FCC issue; and WiFi doesn't care about RF politeness).
 
Yes, some products, like the current ASUS routers have a 40 MHz only mode. But they are not WiFi certified and not 802.11n compliant.
 
another question regarding co-existence...

should this be implemented 'dynamically' on the router? For example, if the router detects non-interference on startup and resolves to 40mhz bandwidth, but subsequently an interfering network comes online later - should the router then automatically switch down to 20mhz mode?

I've seen behaviour whereby a router switches down to 20mhz mode only after a power-cycle in the above scenario... I couldn't see mention in your article whether this should be a dynamic behaviour according to IEEE or whether thats down to the vendor (as long as on startup it follows correct procedure).
 
another question regarding co-existence...

should this be implemented 'dynamically' on the router?
Yes. But the spec does not state how long an AP can take to make the mode switch. In some cases, this can be more than 5 minutes.

You could be seeing the behavior you describe due to auto channel setting that some routers use.
 
Yes. But the spec does not state how long an AP can take to make the mode switch. In some cases, this can be more than 5 minutes.

You could be seeing the behavior you describe due to auto channel setting that some routers use.

yes, although i'm purposely moving another router into the channel range of the one at 40mhz - it's switching back to 20mhz after power-cycle... saying that I didn't monitor for 5 minutes (maybe 2 minutes max) so will take another look. the device i'm looking at is already WiFi Alliance Certified, so must conform to the co-existence mechanism
 
Asus allows it

All asus routers allow u to FORCE 40mhz in 2.4ghz, and they will do it no matter what problems it causes. I've seen netgear do the same. No matter how bad is, if I set my asus to 40, it will stay there. It only plays nice in 20/40 mode. These are the new asus AC routers that came out 2 months ago or so (their top end)

So clearly this good behavior isn't being adopted like it should

I have a neighbor on ch 7/11 and he causing everyone around him to pile up one one.but I've been helping ppl to use 1,7,11 around him. 1,7,11 won't overlap.

But of people use anything other than ch 1 or 11 for 40mhz, it's bad.

5ghz is a non issue as it's at -90 by 25 to 50 feet out of your house More like 25.

What worse is this guy put in a second router and uses both 1 at 40 and 11 and 40. So he slightly overlaps on 6 and screws the rest of us. Bastard even put a repeater outside!

He says he has all devices that won't use 5ghz and he needs to 40mhz wifis to split his bandwidth.

I bought a 2000ft range GRID antenna and fired it up for a day to teach him a lesion. Put it on ch11. Effectively jammed one of his routers wifi due to too much snr.
 
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Yes, some products, like the current ASUS routers have a 40 MHz only mode. But they are not WiFi certified and not 802.11n compliant.

It's not just asus. Using inssider, I see netgear and Cisco routers violating this 40,the policy in my neighborhood

I'm guessing companies do t care if they are certified or not for residential use
 
I think there is a loophole in the Wifi certification and 802.11 spec that allows 40MHz coexistence and Fat channel intolerance to be disabled. But it must be enabled for out of box operation. I need to check on this.

40 MHz operation in crowded areas is just highly inconsiderate at best.
 
I think there is a loophole in the Wifi certification and 802.11 spec that allows 40MHz coexistence and Fat channel intolerance to be disabled. But it must be enabled for out of box operation. I need to check on this.

40 MHz operation in crowded areas is just highly inconsiderate at best.

I'm
Guessing rural people and some suburb people complained. Im in a suburb were each plot is .5-1.5 acres and out HOA is about to form
A wifi comitte and FORCE anyone of 40mhz in the 2.4 band and on 1,6,11. Mainly because we have ppl on 40mhz all over, desperate people using boosters, grid antennas (all that's gonna be banned). I live in a harsh state , NC. An HOA can for lose your house if u don't comply

But it's Sort of hard to get ppl on 5ghz, when Sony does lame a$& sh&t with the ps4 .... ONLY does 2.4ghz. I bought a gaming box for it tri antenna 5gz AC 80mhz to Ethernet.
 
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I'm
Guessing rural people and some suburb people complained. Im in a suburb were each plot is .5-1.5 acres and out HOA is about to form
A wifi comitte and FORCE anyone of 40mhz in the 2.4 band and on 1,6,11. Mainly because we have ppl on 40mhz all over, desperate people using boosters, grid antennas (all that's gonna be banned). I live in a harsh state , NC. An HOA can for lose your house if u don't comply

But it's Sort of hard to get ppl on 5ghz, when Sony does lame a$& sh&t with the ps4 .... ONLY does 2.4ghz. I bought a gaming box for it tri antenna 5gz AC 80mhz to Ethernet.

In the US, the 2.4GHz band's max radiated power is regulated by the Federal Communications Commission; the State has no authority. A homeowner's association has no authority either, unless the CC&Rs try to address WiFi - which wouldn't hold up in court. And would not apply retroactively.
 
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But it's Sort of hard to get ppl on 5ghz, when Sony does lame a$& sh&t with the ps4 .... ONLY does 2.4ghz. I bought a gaming box for it tri antenna 5gz AC 80mhz to Ethernet.

Just... wow. And this is a device they intend to be selling for the next 5-7 years?
 
In the US, the 2.4GHz band's max radiated power is regulated by the Federal Communications Commission; the State has no authority. A homeowner's association has no authority either, unless the CC&Rs try to address WiFi - which wouldn't hold up in court. And would not apply retroactively.

Actually, there's an excellent chance that an HOA will win in this case. Given that prior to purchasing within an HOA the buyer is required to read the HOA's by-laws and CC&Rs. There has always been a perpetual argument that purchasing within an HOA means you're forfeiting some of your rights (even constitutional) that you have elsewhere. The premise of an HOA is have to a regulated environment of likeminded members—in respect to community living. Hence, even in arbitration (the way the majority of HOAs now handle matters) this issue will sway in favor of the HOA as the majority of its members' will likely be in favor of it.
 
Yes, but modified cc&r's cannot be imposed to current residents... Only new titles. I was on our HOA board for years. A wifi restriction would be unenforcable.
 
Yes, but modified cc&r's cannot be imposed to current residents... Only new titles. I was on our HOA board for years. A wifi restriction would be unenforcable.

Doesn't make sense as amendments/revisions are done all the time in regard to evolving situations. I've seen grandfathering concerning rent restrictions as the result of State statue and retirement communities have some special rights.
 
Depends on by laws. Ours are tightly written to limit the board's power to disadvantage homeowners.
 
All asus routers allow u to FORCE 40mhz in 2.4ghz, and they will do it no matter what problems it causes. I've seen netgear do the same. No matter how bad is, if I set my asus to 40, it will stay there. It only plays nice in 20/40 mode. These are the new asus AC routers that came out 2 months ago or so (their top end)

So clearly this good behavior isn't being adopted like it should

I have a neighbor on ch 7/11 and he causing everyone around him to pile up one one.but I've been helping ppl to use 1,7,11 around him. 1,7,11 won't overlap.

But of people use anything other than ch 1 or 11 for 40mhz, it's bad.

5ghz is a non issue as it's at -90 by 25 to 50 feet out of your house More like 25.

What worse is this guy put in a second router and uses both 1 at 40 and 11 and 40. So he slightly overlaps on 6 and screws the rest of us. Bastard even put a repeater outside!

He says he has all devices that won't use 5ghz and he needs to 40mhz wifis to split his bandwidth.

I bought a 2000ft range GRID antenna and fired it up for a day to teach him a lesion. Put it on ch11. Effectively jammed one of his routers wifi due to too much snr.

Hilarious.

Grid would go too far and affect others. You need to be more selective.

I would have bought 4 cheap routers & cheap directional antennas for them. Place the routers close to his place. Adjust antennas properly. Then initiate a continuous transfer loop designed to make the routers blast continuously on 1 & 11 with "40 MHz only" set.

"Have fun with your wireless setup neighbor. I know I am."
 
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