When booting my Airport Extreme AC, the 5ghz defaults to channel 132 all the time. Wireless Diag. reports good signal strength and no other AP’s on any other DFS channels. Yet, some of the Apple devices like 2.4 ghz better...but when manually selecting a non DFS 5ghz channel, with with poorer signal strength, it will choose it over the non DFS channel. Wonder what gives?
Yet, some of the Apple devices like 2.4 ghz better
Once a wireless device moves a room or so away from the AirPort router, the 2.4 GHz signal is going to be stronger than the 5 GHz signal......and wireless devices are programmed to favor a stronger signal over a weaker signal.....even if the weaker signal is faster.
If you want your devices to specifically connect to 5 GHz, you will likely need to set up a separate name for the 5 GHz network, and then "point" WiFi devices at that network.
As far as Channel 132.....no one really knows what criteria goes into Apple's "Automatic' setting for Channels, and Apple is not telling. As you are probably aware, there is no way for you to manually select Channel 132 for the AirPort to use......even if you wanted to.
but when manually selecting a non DFS 5ghz channel, with with poorer signal strength, it will choose it over the non DFS channel.
If you select a non DFS 5 GHz channel manually for the AirPort to use, there is really nothing for a WiFi device to "choose" as far as 5 GHz, since it will connect to whatever 5 GHz channel you have chosen, unless you are using the same wireless network name for both the 2.4 GHz and 5 GHz bands.
Keep in mind that wireless in general has always been a mix of half-science and half-voodoo, so you should expect some weirdness at times.
Where in the world are you??
Some modifications can fix the problem.. but try the mod to the config file first.
There is some discussion
Guess iPhones actually don’t support DFS
Some third-party devices may not see 5GHz AirPort base station Wi-Fi networks - Apple Support
but when manually selecting a non DFS 5ghz channel, with with poorer signal strength, it will choose it over the non DFS channel.
Sorry but I am having trouble interpreting this..
You manually select a NON-DFS 5ghz channel.. lets say 161.
The client you are connecting still joins to the 2.4ghz. Is that what you mean?
The answer is fairly simple.. 2.4ghz is still higher signal than 5ghz.. only needs 1db higher and it will always pick 2.4ghz.
What is the client btw??
Do a wireless diagnostic scan to check the actual signals if you want to do this with a bit more science. Not that wireless is always amenable to scientific solutions.. being half voodoo.
Very interesting.. I understand now.
I am not so conversant with the deep internals of iOS.. and it is generally much better hidden anyway.. but if you check your Mac.. system information. you can see possible channels for the wireless.
1 a/b/g/n/ac
Now Apple do some interesting stuff in how they detect the channels from the airport.. instead of just based on Country.. I need to go back and study it a bit more but your client devices may not have 132 as allowed channel so they simply do not see it. I have seen this sort of issues with people from US in Australia not able to connect to channel 12 and 13 which are allowed here.. their wireless systems are set to 11 and simply cannot see our wireless.
Did you happen to buy any of the equipment overseas.. ?? It all originates from your local market?
I have SSID’s set the same in both scenarios. What I find is that, when manually selecting a 5ghz channel, the devices connect via 5g. When I let the router choose the best channel, it chooses 132 and the devices prefer 2.4 ghz instead. Even though the RSSI on 132 seems to be equal or better than manually selecting. Like they shy away from the 5g connection on 132. Maybe something having to do with DFS characteristics...
If your goal is to have all of your devices connect to 5 GHz....and....you do not want to set up a separate 5 GHz name for the 5 GHz band.....you do have the option of turning off the 2.4 GHz band on the AirPort.
Correct. The iPhones and Apple TV (3G) will always connect via 5g if I manually set a 5g channel (161 or any other one). If I let the router choose an auto channel, it chooses 132 (DFS) and from the wireless diagnostic scan, shows a better RSSI than the manual choice, but the clients choose 2.4 ghz. I realize I can set different ssid’s And force them to 5g (that works) but I’m thinking these devices, when given the choice, just don’t prefer the 5ghz signal if the channel is a DFS channel.
As we said, there is a good deal of voodoo involved with wireless.
My two AirPort Extremes never automatically select Channel 132, so I'm not able to test things to see if clients prefer 2.4 GHz under that condition.
Maybe something having to do with DFS characteristics...
Might be. But, if Channel 132 is somehow more "desirable" than other channels, you would think that Apple would provide a way for users to choose 132 if they wanted to......if it did not interfere with radar in the area.
You can with a bit of complex manipulation .. contact me directly to help with.. change your settings to remove the DFS channels.. but it might only be a selection of them.. if you can fix it via config file that would be great.. post back your results.. and if you want to go deeper we can try.
Thanks for pointing it out.. It is yet another bit of that wireless voodoo.
Right. No biggie. Just perplexing. The router likes 132....some devices don’t. Unless that’s all there is to choose from.
Colorado, USA. Router set to US. Configure file is with a try. I’ll give it a shot when I have some time.
But, if Channel 132 is somehow more "desirable" than other channels, you would think that Apple would provide a way for users to choose 132 if they wanted to......if it did not interfere with radar in the area.
It is part of the regulations.. FCC in US that end user cannot select the DFS channels.. and since they cannot select them, only the router itself can check for clear band and swap to that channel.
But I also find it rather voodooish that it always chooses 132.. it seems difficult to pick the same one every time.
It might be possible to remove some channels from the DFS.. if you save a config file from your Airport and then edit it.. remove any occurance of 132 and a few channels around it.. save the file and then restore to the airport Extreme.. but that might not fix the problem.. ie it could pick a different DFS channel and still have problems with client not connecting.. although I am not aware of what the problem really is.. just that you need to use manually set channels is not really a biggie..
BTW you might have an explanation for some other threads where people have complained their iOS devices always connect to 2.4ghz instead of 5ghz.. if the router is choosing DFS freq that iOS is not able to connect to .. it is worth some more investigation.
Like Bob though.. the problem is left to its own devices.. my airports can jump all over the place.. it is running 52 at the moment.. which is a DFS channel.
AirPort Extreme Channel 132 Default?
