AP setting: 40Mhz or 20Mhz Channel with?

[sfx2000]

I've seen a few 802.11ac deployments where they run 40MHz channels - 11ac supports this just fine...

 

[thiggins]

Can somebody tell me more about the pros/cons of using 40Mhz or 20Mhz Channel on the 2.4Ghz radio?

Did you get an answer to your question?

 

[nikleb]

Did you get an answer to your question?

Yes, I got plenty of input. I will stick with 20Mhz for now.

 

[maxbraketorque]

...

Apple's 802.11n Airports, FWIW, set 40MHz intolerant in their beacon frames (AC models don't), so if you're tinkering about trying 40MHz, and an Airport or Apple device is near by...

Interesting. I run a 40 MHz wide "only" 2.4 GHz network (done it with my 68U and my AC3100), and I have several connected Apple devices. Your comment suggests that my 2.4 GHz network should be stepping down to 20 MHz width, but all the wifi snoopers show the network as still being 40 MHz wide. Does this mean that the router is broadcasting that its a 40 MHz wide network but in fact its only 20 MHz wide?

 

[bodean]

All the cool kids do the 20MHz thing in the 2.4GHz playground...

So your saying for netgear routers, under 2.4, to uncheck "Enable 20/40 MHz Coexistence" and leave mode "Up to 800Mbps"?

 

[avtella]

No either reduce it to 347 Mbps or keep coexistence on. If you disable coexistence it will try to stay at 40Mhz even with interference. I would just set it to 347 Mbps.

 

[sfx2000]

FWIW - for 2.4GHz - I would keep things clean and simple...

20MHz channels
Disable Beamforming
Disable Turbo/Nitro QAM (sometimes mentioned as speed up to "up to 800Mbps"

Mostly because inconsistent implementations of features outside of 802.11n across different vendors, and this applies to one's own WLAN along with neighbors that might overlap.

One does get a bit of range extension with 20MHz in 2.4GHz with most radios - it's modest, but 2-3 dB can help between being attached or not.

There are some advantages to 40MHz channels in 2.4GHz with AP's that are standards compliant - e.g. "20/40 auto", as they really are "20+20" and the secondary channel is used only when that channel passes the clear to send processes defined in the IEEE spec - the problem is the older AP's that were "Draft 802.11n", but most of those have aged out and have been replaced.

See my post regarding Google Fiber insights there...

With Marvell based chipsets - I've found that in 2.4GHz, they work best in 20MHz, b/g/n-mixed mode, and pick the channel - and then they work extremely well - even across client chipsets that may support extra features outside of the standards (thank you broadcom..)

 

[sfx2000]

And for 5GHz - I'm on the road at the moment - and the hotel does have 5GHz coverage - 802.11ac using 20MHz channels across UNII-1 and UNII-3 bands - Ruckus Wireless AP's, and they're "hot", e.g. Ch48 is 23 dBm...

No DFS channels deployed, but they don't need to since they're keeping narrow channels...

And FWIW - I see over 10AP's across both bands - and they're all single SSID - nicely planned network - and a really nice hotel to stay at, btw, right in the middle of Silicon Valley...

 

[sfx2000]

I'll probably edit the above post - but I'll add that the BW avail on the Avatar network for the hotel guests is 5Mb up/down, and while BW might be low, the bufferbloat is also low - and very consistent and predictable. I tend to do my VOIP telecons with our international teams at the hotel rather than the office due to the quality of the network - and this is a hotel network with over 200 rooms.

If you're doing business in the Valley - Avatar is in Santa Clara - it's clean, reasonably priced, and nearby everything that is worth being next to - Sunnyvale, Mountain View, Cupertino - and it's a half-mile away from Intel over in Santa Clara...