Enable 40 Mhz channels for 2.4 Ghz band

[qin]

Im looking into having 40 Mhz channels over 2.4Ghz band, is there a way to have this enabled? Any suggestions?

[BHC_RESORTS · Accepted solution]

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@qin wrote:

Im looking into having 40 Mhz channels over 2.4Ghz band, is there a way to have this enabled? Any suggestions?

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40mhz on 2.4ghz is really not recommended. By taking up two channels (bonding them) you are taking up 66% of the available airspace - leaving only one channel still usable. Technically, 2.4ghz has more channels available, but due to co-channel interference, in reality only channels 1, 6, and 11 are available in the US.

Meraki sets the channel width on 2.4 ghz at 20mhz - from a default dashboard, I'm not aware it can be changed. You may be able to contact Meraki support to enable it, but I wouldn't recommend it.

For higher bitrates/throughput, 5ghz is really the way to go. However it comes with its own caveats as well - remember, the more channels being bonded, the less that are available.

Here is an excellent article about some of the different frequencies: http://www.networkcomputing.com/wireless/channel-bonding-wifi-rules-and-regulations/199326059

[AlexP]

The above is a great post, but I wanted to throw in one more little detail that makes 40Mhz-bonded 2.4Ghz pretty infeasible as well: https://superuser.com/questions/143578/how-do-i-get-a-300mbps-connection-over-802-11n

Whether anyone honors the 40MHz-intolerant bit or not is hard to really say with any certainty, but it's in the 802.11n standard, and you're better erring towards people adhering to it rather than them not, which means you wouldn't be likely to see a lot of reliable performance increase even if you did enable it.

[nikiwaibel]

well, in europe you may use channel 12 and 13 also. so there is 2 non overlapping 2.4ghz/40mhz channels: 3 and 11

further, i wonder why meraki uses 1 6 11 for autochannel only. having 12 and 13 available in addition, 1 5 9 13 is valid option as well.

hiding the option to choose 40mhz channel at 2.4ghz - at least manually - is not okay, @Meraki-PM-Team! same applies to 1 5 9 13 autochannel, in case 12/13 is available, IMHO.

[ChrisR]

As BHC already pointed out... that is really not a recommended way to deploy wireless on the 2.4 frequency. Typically most systems (especially enterprise level wireless systems) will not allow you to make that change. I know I have seen it in my neighborhood with people and their Comcast wireless out there chewing up 40Mhz wide, and it baffles me that they will allow that to happen.

  Is there some specific reason that you are looking to do this?

Best of Luck,

Chris

[tmburke]

Hey @qin I'd highly suggest against for 2 reasons-

1. Device support for 40mhz 2.4 channels is sparse and often unsupported. If at all possible 5ghz is a much better bet.
2. 40mhz channels on 2.4 chew up so much available airtime/spectrum/bandwidth that it's not a very "good neighbor" thing to do. At one of our locations a company on the floor above us in the same building is using 40mhz 2.4 channels at very high power which makes the entire 2.4 band almost impossible for us to use. Not a good way to make friends with the neighbors.

If you could clarify your use case (and client devices) here I'm sure the community can point you in the right direction.