That is not possible, it's not part of the spec. Maybe what you're thinking of is the wifi hotspot selecting the channel automatically when setting up a network based on the neighbours it can see. Nothing to do with frequency hopping. AFH happens between packets and maps out bad channels. Wifi does not do that, never has and never will because it's governed by different rules.
Just because a spec doesn't have it doesn't mean it can't be done. At the same time, implementing something that makes you out-of-spec (like Zero Handoff with a virtual floating BSSID between multiple orchestrated AP's -- totally unsupported and not in the spec) and designing it the right way can sometimes mean that a function you thought could not be there is there anyway.
What he is probably referring to isn't frequency hopping, because what it sounds like and that it actually refers to means different things to different people. For someone who is not a RF engineer, hopping might simply mean "an AP that has multiple radios that uses one to scan the 802.11 2.4Ghz space to see what channels have the least utilization, and then restarts the other radios on a that channel, possibly forcing all clients to lose their connection as if out-of-range and reconnecting again on the new channel as they find it".
This, of course, has nothing to do with RF frequency hopping, but if you don't actually know anything about RF, you won't know what hopping means either, and just imagine that what your router with built in AP is doing must therefore be that 'hopping'.
> For someone who is not a RF engineer, hopping might simply mean "an AP that has multiple radios that uses one to scan the 802.11 2.4Ghz space to see what channels have the least utilization, and then restarts the other radios on a that channel, possibly forcing all clients to lose their connection as if out-of-range and reconnecting again on the new channel as they find it".
Nope, I’m thinking of when I transparently switch channels when my neighbor comes home and starts blowing up his own network. I’m aware it’s not part of the specification, which I’m sure you’re aware doesn’t mean anything except that it’s not part of the specification.
I don't know what you're thinking of but no, you can't have that because if you had this magical hotspot your network card in your iThing would not know what to do because wifi does not do frequency hopping. Every time your hotspot changes channels it disconnects all your devices.
I can't speak for jsmthrowaway but I think that he's referring to Band Steering (please correct me if I'm wrong). It's not in the spec but my Unifi gear definitely has a checkbox to enable it if I opt-in to see "advanced settings".
As far as I know it's not dynamic, though. It just happens when a device connects to a base station and only "steers" the client to connect using one of the 2.4 or 5 GHz bands, and that doesn't interfere with channel selection.
The AP also has a function to scan bands to find the "best" channel to use but that disconnects all devices while the scan is in progress. I think some APs might be doing this automatically (?). My other AP (a Mikrotik) has an "auto" channel selector but I don't know what it does or when.
Correct. I’m on Unifi gear with two bands. When it has opportunities to do so, it moves around the SSIDs themselves, too, which seems to happen after every client gets steered to one of them (it’ll reconfigure the other). I might have enabled this feature at some point without realizing it.
My neighbor moves around his channels, too. That’s what’s making me comment that it’s likely more common than we think. I’m not at home to prove this and I’m getting downvoted for sharing, but I’ve watched him move between 36, 40, and 44 at a frequency that suggests it is happening automatically, probably when all of his sessions go idle or something. I have observed this with multiple tools.
My 5 GHz was on 44 this morning, because I happened to look for unrelated reasons. I just SSH’d home and it’s now on 36 without interaction from me. Specifications are not implementations. I’m almost positive this is a common feature which I’ve seen in many APs over the years, even though it’s not per-packet like Bluetooth (which I was also aware of, given that I'm experimenting with a Bluetooth 5 mesh system for IIoT).
You're forgetting devices with two bands, and assuming a lot about my devices (and competence). I know my network and its behavior, and I'm not just spewing hot air here.
(it does mention a frequency hopping physical layer but that was part of the obsolete predecessor from 1997, the modern spec uses OFDM so unless all your equipment is from the last century you're not using frequency hopping)
I think there is a misunderstanding related to the terms here:
1. IIRC my router is supposed to switch channel (i.e. frequency) automatically unless I explicitly set it to a fixed channel.
I don't know how but my devices figures out and continues working.
2. I think the misunderstanding is related to the word frequency hopping or whatever was used further up in the discussion.
I normally take "frequency hopping" to mean changing frequncy multiple times a minute or even faster while I doubt my wireless access point will switch channels more than a few times in 24 hours.
Disclaimer: I never really sat down and verified if it ever changed.
Also agree with logicalle that I wish for a bit more civility.
Based on my frequent lurking, I would guess it was due to the personal (and off topic) nature of the comment. Addressing users specifically in this way seems to be looked down upon here.
