Is there a cap on simultaneously active Wi-Fi Access points in a single area?
I'm writing an API for controlling an external device. Part of this API is having the device scan for Wi-Fi access points. The API will be implemented across many types of devices, with varying memory capacity. I want to know whether I can just allocate a buffer for found access points once and then forget about it, or whether I need to handle this via dynamic memory allocation.
To make that decision, I need to know how many different Wi-Fi networks/access points can be available in a given area.
At work, when I do a Wi-Fi scan, I pick up 16 different Wi-Fi networks. Even if most of these Wi-Fi networks are poorly reachable, I still wish to pick them up with my Wi-Fi scan.
Is there a cap on simultaneously active Wi-Fi Access points in a single area? More specifically, is there a cap on simultaneously active Wi-Fi networks in a single area? If so, what happens if you go over it?
What I tried (Research)
I tried googling, but the only thing that seems to come up is a limit on the amount of devices per access point. Various searches ("access point limit", "wifi max access point") didn't give me the result I was looking for.
I then tried with different search terms, trying to find out how Wi-Fi scans work. I found out that they work via sending a packet that basically says hello, and then listening for how many hellos they get back.
This seems to indicate to me that there is no cap; I could, in theory, buy many power strips, plug a lot of Wi-Fi access points in (perhaps all connected to one big router so they're connected to the internet, perhaps not), do a Wi-Fi scan and find many access points, provided they have different SSID's. (I don't plan on doing this; even if I did, there'd be no way to know if I'm being limited by the protocol or by the scanner.)
Is this correct? Is there no cap on Wi-Fi access points? Would said theoretical scenario even work in practice?
The wifi standard 802.11 (and its variants) do not provide a technical limitation to the number of active SSIDs in any given area. In fact, many newer routers and APs can, and do, broadcast multiple SSIDs and manage multiple virtual networks. Thus you can have dozens, even hundreds, of SSIDs operating and "visible" in a given area. Further, as newer technologies and bands become available, the bandwidth is better utilized, thus allowing the spectrum in a given area to be more crowded without significant interference.
If you really must be able to hold information about all of them, rather than the X best signals available, then you will need to use dynamic allocation.
There is no cap on active Wi-Fi devices. However, too many Wi-Fi Access Points (WAPs) might result in some not being shown on your device due to a device limitation. If two WAPs use the same channel there will be interference, resulting in drop outs of signal.
The actual Wi-Fi access points will work, and if there is no limitation on the device then you could scan and get back as many WAPs as there are available.