Are Intel 8260 and other wifi chips limited to 5.2 GHz?

[JImps]

There are settings in the Windows driver for my 8260 Wifi adapter that suggest that the hardware operates 5.2GHz range within the 5 GHz band allocated for IEEE 802.11n. Is that true? Why can't it access all the 5 GHz band channels available? In the US, the range is valid from 5180 kHz up through 5825 kHz.

Or is 5.2 GHz being use as a misleading synonym for 5 GHz for some reason?

I know the device can also operate in the 2.4 GHz band. I'm not talking about that.

[David_V_Intel]

Hello JImps, Thank you for posting on the Intel ® communities. Seeing the band at 5.2 GHz is normal, 5 GHz is just the name of the technology, in other words it is perfectly normal to see the 5.2 GHz, it is working with the 5 GHz technology. Regarding the channels available, what are you referring to exactly? Which bands do you have available? Let me know please . Regards, David V Intel Customer Support Technician Under Contract to Intel Corporation

[JImps]

Hello David, thanks for your reply. I agree it's normal to use 5.2 GHz frequencies, but the 5 GHz band for IEEE 802.11n extends beyond the 5.2 GHz frequencies. As documneted here: https://www.electronics-notes.com/articles/connectivity/wifi-ieee-802-11/channels-frequencies-bands-bandwidth.php, under the section titled 5 GHz WiFi channels & frequencies, there are around 24 different channels within the 5 GHz band that have been defined for 802.11n (the total number available depend on your local communication laws). Each channel is a specific frequency,

For example, channel 36 is defined as frequency 5180 MHz. Channel 56 is 5280 MHz. Channel 128 is 5640 MHz. And so on. Of the 24 potential channels defined, only five of them fall within the 5.2 GHz frequency range. They are channels 40,44,48,52, and 56. So there are many more that are not within the 5.2 GHz range.

Again, as I look at the Intel 8260 WiFi chip's Windows device driver, I see acouple of settings that talk about 5.2 GHz. My question is, does this fact imply that the 8260 WiFi chip, when operating according to IEEE 802.11n and using 5 GHz band, is limited to only 5 possible channels, rather than the 24 or so (depending on locality and applicable communication laws) that are defined by the IEEE 802.11n standard?

Specifically, when in Windows 10 Professional I right-click on the WiFi task bar icon, choose Open Network and Sharing Center, then on the resulting window I click on Change adapter settings, then on the resulting window I right-click on the WiFi Network Connection and click Properties, then in the the resulting window I click Configure, I am presented with the Intel(R) Dual Band Wireless-AC 8260 Properties pane. WHen I click on Advanced tab, I can see a Property called 802.11n Channel Width for 5.2 GHz. There is another Property called Preferred Band and when I click on it, I can see three different values. One possible value is Prefer 5.2 GHz band.

Does this mean that this hardware only operates using one of the five 802.11n channels that fall within the 5.2 GHz range? Or is this unit able to use other channels within the 5 GHz band besides those that fall in the 5.2 GHz range?

Thanks!

Jeremy

[David_V_Intel]

Hello JImps, Thank you for your response. First, I would like to request an System Support Utility report, this report can be generated from our tool, you can refer to the link below so you can download it:  https://downloadcenter.intel.com/download/25293/Intel-System-Support-Utility-for-Windows- Make sure to attach the created report to this thread. Now, the channels (36 - 40 - 44 -48 as example)can be configured only at router or access point hardware not in the wireless card the channels availability are mostly regulated by the FCC and dynamic frequency selection in the United States. On the other hand the options available on the advanced properties of the Wireless card are related to the preferred band 2.4GHz or 5GHz. The channel width options usually show 20MHz which is recommended to avoid overlapping. Regards, David V Intel Customer Support Technician Under Contract to Intel Corporation

[David_V_Intel]

Hello JImps, I am following up with your case and see that we have not heard back from you. If you need more assistance do not hesitate to reply. Regards, David V Intel Customer Support Technician Under Contract to Intel Corporation

[oka]

The simple question from JImps is not answered yet. Wich frequencies/channels within the 5GHz band are supported by the Intel 8260?

My router supports a lot of channels from channel 36 up to channel 128. My Intel 8260 does see my WLAN in all these frequencies but could only succefully connect to it if I set my router to the lower channels in the range of 5.2 GHz. Is that a hardware limitation of the 8260 chip?

[Taka_K]

I was trying to troubleshoot connectivity problems with this card myself, and I found a couple settings that were interfering. 

First, I had disabled 11n capabilities in the card (via Linux kernel module option 11n_disable=1) because I'm not using 11n but 11ac, and access point radio is broadcasting AC-only signal.  However, this was interfering still and so I had to remove that option.

Second, I had to set the radio in my access point (running dd-wrt) to only 20 MHz.  I had tried other settings like dynamic 20/40, Wide HT40, and very wide VHT80 but the card could only associate with 20 MHz.

Now, the card can associate and all frequencies outside 5.2 GHz that I tested were supported and was able to establish connection.  For example I configured the radio for channel 136 (5.68 GHz) and that was working fine.  Currently, I've got it on the top channel 165 - 5.825 GHz and running great.  Here's output from Intel's iwctl app showing high frequency:

# iwctl
Version: 2.19

[iwd]# station wlan1 show
Station: wlan1
--------------------------------------------------------------------------------
Settable Property Value
--------------------------------------------------------------------------------
Scanning no
State connected
Connected network home
IPv4 address 10.10.10.10
ConnectedBss 01:23:45:67:89:01
Frequency 5825
Channel 165
Security WPA2-Personal
RSSI -42 dBm
AverageRSSI -41 dBm
RxMode 802.11ac
RxMCS 6
TxMode 802.11ac
TxMCS 8
TxBitrate 173300 Kbit/s
RxBitrate 117000 Kbit/s

Hope that helps.

Best Regards,