40MHz 2.4GHz overlap?

I have Main router on 1st floor and AP in 2nd floor.
Is it ok to put them both on 40mhz 2.4ghz?
20 mhz is too slow...
Is there overlap if im doing so?

  1. Please tell us the name of your main router and the name of your AP
  2. If you live in apartment complex with many flatmates and neighbours, wifi bands and channels might be contested. In this case, it is advised to remain at 20 MHz. This decreases overall interference, which in turn increases overall performance of all devices involved. Try to use a wifi analyzer or OpenWRT's channel analysis graphs, to check if your channels are contested. If so, try to communicate with your neighbours and negotiate certain fixed channels for them and for you, so that everybody is best of. If you are living out in the woods, or with high distance to any neighbours, 40 MHz is perfectly fine. The magic word here is "Signal Noise Ratio". If there is a big gap between your signal level and noise level, all is fine. You will want to avoid overlapping signals with same "dbm".

Yes there will be overlap. Look at a 2.4GHz channel map and this is easy to see.


Besides putting both on 20Mhz, put the router and AP on channels 1 and 11. That will help with devices roaming and minimize interference between the two.

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even if you were to establish a 40 MHz connection you probably will find your data throughput no better or worse than connecting at 20 MHz in the crowded 2.4 GHz band. If you want faster connection switch to 5 GHz band.

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