I have the hardware listed above and want to know why my AC enabled gear is not using anything but 20Mhz wide channels?
Airport Time Capsule 2TB ME177LL/A-OTHER, OS X El Capitan (10.11.2)
Is it only your iPhone 6S+ that is unable to connect to the AirPort Extreme in the 802.11ac radio mode? That is, did you verify that other 802.11ac-capable devices do connect in this mode?
If they can, then the issue most likely will be with the iPhone and not the base station.
<duplicate reply, deleted by Tesserax>
Well, I don't know of any settings in Airport Utility app to confirm ac operation or wide channels being used. Likewise with the Iphone. I did a Wi-Fi scan with the AU app and only see 20MHz channels in operation. My understanding is that the enable wide channels setting was removed from the app 3-4 years ago and now the Airport Extreme uses wide channels automatically.
My Macbook Air might also be AC, but I keep it wired. My main want is for 40 or 80Mhz wide channels for the (2) Iphones in the house.
To answer your question, I have not tried any other AC device at this time.
Well, I don't know of any settings in Airport Utility app to confirm ac operation or wide channels being used.
For an iOS device, the AirPort Utility does provide you with the Data Rate, RSSI, & Mode that the device is connected at. For example, my iPhone 5 SE shows the following values when near my 802.11ac AirPort Extreme: Data Rate = 433 Mbps, RSSI = -57 dBm, & Mode = 802.11a/n/ac. This is telling me that it is connecting with the 802.11ac radio mode with a 80 MHz wide channel. This would also indicate that the connection is using just a single spatial stream. Pretty much what I would expect for my iPhone.
I did a Wi-Fi scan with the AU app and only see 20MHz channels in operation.
I believe that's because the Wi-Fi scan feature of the iOS AirPort Utility only shows 20 MHz channels for either the 2.4 or 5 GHz bands. The Mac version of the utility does not show anything but 20 MHz-wide channel settings as well.
In my case, the AirPort Utility on my iPhone told me that I was connected on channel 149. This channel is one of the 20 MHz wide ones, but it is also the lower boundary for both the 40 & 80 MHz wide channels. The following image may better explain this.
You would need a different app to be able to determine the channel width of the connection. I'm not aware of any for iOS devices. On the Mac, a utility like Wi-Fi Explorer provides this
My understanding is that the enable wide channels setting was removed from the app 3-4 years ago and now the Airport Extreme uses wide channels automatically.
That is partially correct. The option was removed with version 6.x of the AirPort Utility. However, in version 5.x it just allowed you to enable 40 MHz wide channels on the 5 GHz band for 802.11n.
My main want is for 40 or 80Mhz wide channels for the (2) Iphones in the house.
From the iOS AirPort Utility:
Airport Extreme & Iphone 6S+
