I used intel 5300 on ubuntu 16.04 to setup WIFI AP.
In 2.4GHz, intel 5300 can switch to AP mode,but in 5Ghz, it can't.
I checked it with command "iw list", and found intel 5300's 5G channel is disable or show "NO-IR".
How do I do to enable these 5G channel?
Are you referring to the product Intel WiFi Link 5300, please?
This forum is for the Intel RealSense camera products. Your question is more suited to Intel's 'Wireless Networking' forum.
You may be interested though in this answer about NO-IR.
linux - Wifi 5GHz AP Mode: What does `no IR` means and can I bypass it? - Super User
Retrieving data ...