I have a Meraki MX60W running 17.01.4 MX60 TAR (MX60W TAR is broken) with kmod-ath9k and wpad-mini packages installed.
When I configure the wireless, I can only use either 2.4 or 5.4 GHz. Configuring, or restating the vice vera band results in the other band shutting down, when I look at the other band in LuCI, it has been switched to the last band I applied the config.
The log shows nothing.
Looks like only one radio according to the specs. It supports either band, but not both at the same time.
The documentation says this (https://wikidevi.com/files/Atheros/specsheets/AR9380.pdf):
With its Fast Channel Switch (FCS) feature, the channel switching time
between 2.4 GHz and 5 GHz is reduced from 10 ms to as little as 1 ms.
Please provide information on the specs you note. Because, I don't understand why a human needs to switch the radio at 1 ms speed.
I have no idea why the datasheet says that, but every other simultaneous dual band device has two separate radios, one operating on each band.
draws is completely spot on. Channel switch times mostly matter when it comes to scanning, especially in the relatively large 5 GHz band. Also consider that the kernel schedules regular background scans - and you don't want to lose your primary connection (or affect its throughput too much), just because a background scan is going on (be it for DFS or other purposes).
OK...it appears @drawz is correct indeed. It doesn't do dual band simultaneously. I found more documentation. I guess I'll have to change the card if I want concurrent dual band (miniPCIe).
I don't think there are any simultaneous dual band cards. You have to use two cards.