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I have an AP that serves both 2.4 and 5 GHz networks (on separate SSIDs, without fallback). The neighborhood is quite busy (residential neighborhood)

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A ping from a wired device to a device on the 2.4 GHz network looks like this (the x axis is time, y is RTT in ms):

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The equivalent ping on the 5 GHz network is much more stable ("flat").

While I understand that heavily loaded channels lead to worse performance, I am very curious about the regular nature of the graph.

I gathered a larger sample and can run it through a Fourier transform to get the frequencies (but I doubt that this would be of help?)

WoJ
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1 Answers1

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2.4 GHz is messy.

Use 5 GHz where possible. Fewer users, shorter range, less interference. Wired Ethernet is even better, full duplex over a dedicated medium.

If you must improve 2.4 GHz, do an RF site survey with spectrum analysis gear. Map out where interference comes from. Regular Wi-Fi NICs are not great at this, being designed to tune out everything else as noise. A pattern of poor IP performance over Wi-Fi doesn't tell you much, as the RF environment is complicated. Could be many 802.11 radios interfering, cordless phones, smart home gadgets, unshielded USB 3 peripherals, microwave ovens...

John Mahowald
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  • Thanks for the answer. I completely understand that 2.4 GHz is a complicated place and that there are plenty of interferences. I have access to a spectrum analyzer (when COVID is over) so I will have a look. What really was surprising is the periodicity of the changes. If it was a chaotic graph I would understand, but its nature raided that question.One of the problem with 5 GHz is that it is often not available to IoTs (of which I make a lot of use) – WoJ Dec 18 '20 at 09:25