The story that 5GHz band access point could not be created on Ubuntu

wrap up

When I heard that Ubuntu could replace the wireless LAN router, I couldn't use the 5GHz band. The cause is the specification of the Linux driver iwlwifi for Intel chipsets. It seems that some of the atheros drivers can be used, but I haven't tried it.

environment

OS: Ubuntu 20.04 LTS
Hardware: Small PC. The WiFi chip is Intel AC7265. The interface is m.2 2230.

phenomenon

In Ubuntu, access point can be created from GUI, so the procedure I created an access point along with.
2.4GHz band works fine, but 5GHz band doesn't work.
Of course, the hardware supports both 2.4GHz and 5GHz, and if you set it, you can connect to a 5GHz access point without any problems.

Survey results

Intel driver does not have 5GHz access point mode there were. Certainly, the introduced link says "AP mode on 2.4GHz (on devices driven by iwlmvm)" and says 5GHz. Unwritten. This means that the client mode supports 5GHz, but the access point mode does not support 5GHz.

Intel AC7265 page Compatible frequencies Since it is only written, is it a specification on the driver side rather than hardware?

What I tried before reaching the above

AP mode support check

Link on the above page When I checked with iw list whether it was compatible with AP, it was compatible. I wondered if there was a difference in AP mode support between the 2.4GHz band and the 5GHz band, but it was an item common to both frequencies.

Introduction of create_ap

The point that it works with the 2.4GHz band channel specification and the 5GHz band is not possible remains the same.
[The story that the country code is related](https://wiki.archlinux.jp/index.php/%E3%82%BD%E3%83%95%E3%83%88%E3%82% A6% E3% 82% A7% E3% 82% A2% E3% 82% A2% E3% 82% AF% E3% 82% BB% E3% 82% B9% E3% 83% 9D% E3% 82% A4% E3% 83% B3% E3% 83% 88 # 5Ghz_.E5.B8.AF.E3.81.A7_AP_.E3.83.A2.E3.83.BC.E3.83.89.E3.82.92.E8.B5. From B7.E5.8B.95.E3.81.A7.E3.81.8D.E3.81.AA.E3.81.84), I thought that it might change if JP was specified, but that was not the case.
I thought I could specify multiple channels, but I can't. I was wondering if I could set up separate access points at + 2.4GHz and 5GHz. The number of access points that can be set up at the same time by the chipset is fixed. Since it is the result of ʻiw list`, it is not limited to create_ap.

I didn't try

Kernel rebuild

Answer about no IR flag Write something like Patch the kernel However, since it is a Debian story, at least it cannot be applied as it is. Even if it was possible, I didn't think I would analyze it and apply it.

Replacing the wireless LAN chip

It's better to buy a small WiFi router than to buy an external antenna (wireless adapter), so it's just a route to replace the built-in wireless LAN chip.

Some Qualcomm chip drivers are supported, but unfortunately the card with that chip is Mini PCI Express. Only, m.2 2230 compatible cards are not available at a reasonable price on Amazon.

When I was researching without giving up, I found a chip called Bointec DGF109A QCA6174A-5. A chip of .org / en / users / drivers / ath10k) is used, and if you look for it further, [MOUSER](https://www.mouser.jp/ProductDetail/AAEON-UP/RE-UPWFKITEX2TR?qs= It was sold at PqoDHHvF648qKGsGMqAlMQ% 3D% 3D).

MOUSER itself is not for consumers, but it looks like a company (I'm not sure). However, when I try to purchase, errors occur frequently on the purchase site, 4,118 yen + express fee of 2,000 yen, which is reasonably expensive, and since a 2.4 GHz band access point is required, it can only be operated exclusively with a 5 GHz band access point. If it was a specification, I gave up the order because it would be a wasteful investment even if it could be used at 5GHz.

Consideration

The 5GHz band may be difficult for drivers to handle due to problems such as DFS.

Revision history

2020/5/30: Draft 2020/6/20: First edition