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I got lot of complains from colleagues on one of the sites where Cisco APs are installed, usually about poor quality and corrupted audio conferencing. But when I'm on site, everything is usually just fine. So recently I converted one extra AP into spectrum analyzer and ... gotcha (yeah, I understand that devices pane shows there is no active Wifi transmitters, but I can imagine what happens when there are some; furthermore, this spectrum probe is installed near the conference room, looks like it was just empty this time). Site is a two-stories building where work spaces are joined by a kitchen. So obvious question is - do all the microwave ovens do that, or my employer just got the lucky one ? And how do I deal with this, - I mean - as you can see, that oven shines like through most of the channels.

spectrogram devices pane

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    The thing about unlicensed channels is that you are not allowed to interfere with other devices in the same channel space, but you must also suck it up and deal with any interference you receive. Microwaves use 2.4 GHz, too. A microwave is required to minimize leakage, but it could be a cheap one (lied to the regulators) or damaged. Spend the money to get a good name brand microwave (Amana actually has an RF choke and was exempt from government regulations because it is so good).
    – Ron Maupin
    Feb 22 at 13:28
  • Perhaps you did this, but does the spectral interference disappear when the microwave is off? If it's the microwave, it will do nothing when off, and appear and disappear when it is on as the magnetron cycles (magnetron is not used all the time - normally makes a different noise).
    – abligh
    Feb 23 at 6:45

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Yes, microwave ovens commonly run at ~2.45 GHz. The ISM band is not exclusively used by any technology, so the various uses may collide.

There are several ways to cope:

  • get another microwave that uses a different band
  • explore options to screen the microwave radiation
  • move your wireless network to primarily 5 GHz

The general problem with wireless networking is one of the reasons why many network planers deploy cabled networks for primary use, with wireless being just an option.

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    Yep. I almost always advise against WiFi entirely unless necessary. It is a pain in the ass and always has been. At a past company we had to shape the WiFi layout around lead-lines rooms with directional antennas, position the APs to avoid bleeding into parking lots, deal with interference from fluorescent lights and microwaves, etc. While not uncommon, it is always such a pain.
    – Jesse P.
    Feb 22 at 13:13
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    @JesseP. I was only asked once to build a wireless network as primary for a newly built office. When they saw the cost calculation for decent coverage and the overall performance prognosis that I sent along with it, we quickly settled on doing an "old-fashioned" wired network for roughly the same cost, but nearly 10x the performance. Saved everyone much pain, too.
    – Zac67
    Feb 22 at 13:19
  • A coworker of mine was once asked to build a WiFi infrastructure as the ONLY connectivity in an environment. The client was advised against it but continued. They put wireless adapters in all of their servers, workstations, etc. Then they wondered why their mail, file services, authentication, etc. was horribly slow. So, of course, it was an “I told you so” scenario and they backtracked to convert things back to wired. Sometimes they just have to touch the fire to see for themselves.
    – Jesse P.
    Feb 22 at 13:23
  • Wifi for servers is undoubtedly a bad idea. But for users it can make sense, especially if you have to wire a building.
    – Ron Trunk
    Apr 15 at 15:39

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