According to the live demo, they are not, but that appears to be using older firmware. However, it is not mentioned in more recent firmware release notes.

According to this Draytek document, Band C was made available to general use:

https://www.draytek.co.uk/support/guides/the-5ghz-wireless-band

Specifically it says "Band C is permitted for point-to-point applications (fixed wireless access), not general AP-Client usage. Until 2017, Band C required a licence from Ofcom in the UK and was used for fixed wireless links. It has now been made available for general use. In 2020 the requirement for DFS in band C was also removed."

May I suggest that the precise channels available on your products are listed in the specs:

https://www.draytek.com/products/vigorap-903/#specs

oviano wrote:
May I suggest that the precise channels available on your products are listed in the specs

This is a user forum.. no one from DrayTek here

I'm not familiar with "band c", but if you know what channel numbers that equates to, I'll have a look and see if they're an option on my AP903

The highest frequency channel on the AP903 is 140 - i.e. the top of band B. No band C channels available, although one wonders why you would want to use them?

Well they are the only other channels besides 36-48 that don’t have all the DFS stuff potentially overriding my channel selection.

At the moment I basically use a different one of the four main 5ghz channels (36-48) on each floor of a property. If I want to go with 40mhz then I’m restricted to two possible selections (36 + 40 and 44 + 48), 80Mhz width means they’d all be used.

So having an extra bank of four channels gives more possibilities and less risk of clashes. Plus less chance of interference with channels from the neighbours. Even more so if they’ve only recently been made available as less people will be using them!

Anyway thanks for checking, it’s useful to know that the 903 doesn’t support band C so I won’t upgrade from my 902s as there isn’t much to gain apart from the mesh functionality which doesn’t seem to offer anything better than a bunch of 902s each in AP mode and plugged into Ethernet back to the main router.

What are these Bands A,B & C of which you speak :?: :?
All the documentation I see, refers to "UNII-I" or "UNII-II" etc etc. Is one American and the other 'European' ? https://metis.fi/en/2018/02/5ghz-channels/

I'm new to 5GHz Wireless and assumed that the same sort of rules applied, as for 2.4GHz. Imagine my surprise, when Draytek's Mesh configuration set everything to use the same channel(s). How can that be right?

Why does a SKY Q box think that creating an 80MHz wide channel (36-48) is a good idea? (Apparently it's for its own Mesh network, to talk to other Sky boxes - but it's there by default and needs access to a hidden menu to disable )

Documentation on 5GHz wireless often states that there are more channels than 2.4GHz, but since they are seemingly always accessed in blocks of 4 - not to mention the ever present threat of "Radar", there aren't really).

The more I find out, the less I know

I just looked at the table in the Draytek link posted by the OP above https://www.draytek.co.uk/support/guides/the-5ghz-wireless-band

and this which that page links to https://7signal.com/blog/802-11ac-migration-part-2-whats-nobodys-telling-you-about-80mhz-and-160mhz-channel-bonding/