@Garrett wrote: My understanding has always been 20MHz channels for a high density environment in a must. This gives a more stable wireless network and less chance of channel overlapping. Typically it is recommended that in high-density environments you utilize 20 MHz because you will have multiple APs and you don't want any co-channel interference. Reducing to 20 MHz will allow you to utilize a larger number of channels and you won't have APs utilizing the same channel. You can utilize 40 MHz Channels with 9 APs utilizing every single 40 MHz channel, in an auditorium for example. The problem here is if some sort of interference or a rogue AP is introduced to your environment. If said device utilizes the channel very heavily then your APs ability to service your wireless clients will be degraded and all clients on that AP will experience poor or slow connections. The above example was for an auditorium, where high density is expected and APs would be within audible distance of each other. Now if you have a more spread out building system, 1 classroom per building/bungalow, you can get away with the APs utilizing 40 MHz. The reason being is that the APs will be at a fairly good distance from each other. So if some sort of interference or rogue AP is introduced that utilizes the entire channel then the AP will be able to move to another Channel with Meraki's AutoChannel. With this, of course, you would have other factors to determine. Like how many audible APs are at a particular location, how strong is it broadcasting, how is the channel overlap, etc. And you would have to run a predictive or have someone run a passive survey. It would depend on your environment whether you can get away with running 40 MHz. How close are your classrooms, how thick are your walls, any RF interference, how many floors, etc. Which would involve some sort of wireless survey. @Garrett wrote: The argument that is being had is performance. Does 40MHz give better performance? Or does it not matter since we are limiting devices speeds anyway? This will depend on what you are limiting the clients too and how many clients you are anticipating per classroom. Utilizing that you can determine if the 20 MHz channel will provide enough throughput. You also have to consider if every single device will be downloading/uploading at that speed simultaneously. But yes, utilizing 40 MHz will essentially double your speed if your environment permits.
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