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[burakkucat]

I vaguely recall we have at least one radio Ham among our members?    Don’t recall who that is but if he sees this thread, his contribution might be interesting...

I believe you are possibly thinking of JGO or tbailey2 . . . 

[4candles]

I vaguely recall we have at least one radio Ham among our members?    Don’t recall who that is but if he sees this thread, his contribution might be interesting...

[Tentatively raises hand] Licensed, albeit lapsed, but presently confuddled by this thread, unless someone can elucidate what the basic question is.   

[Weaver]

@Alex the ten mins thing, where does that come from? Does anyone know if it’s prescribed by some standard, or whether it varies according to software implementations?

I seem to remember some ridiculous delay with my ZyXEL WAPs.

[tubaman]

The 10 minute delay appears to be mandated, but I can't find the actual standard that says as much.
 

[sevenlayermuddle]

[Tentatively raises hand] Licensed, albeit lapsed, but presently confuddled by this thread, unless someone can elucidate what the basic question is.   

The question earlier in thread was whether the DFS avoidance was to allow the router to work properly, or to allow the radar to work properly?

If you are picking up radar, would receiving it make the channel unusable for you, so it needs to be avoided?

Methinks you don’t need to avoid it because you would disturb the radar, as it’s too far away considering your own low tx power. It would be a sane algorithm to take you own calculated tx power at that range into account with 1/r² or 1/r³.

See posts #3 to #9 for full discussion.

Not suggesting that radio amateurs are necessarily experts on Radar, but may have better than average knowledge of the characteristics of signal propagation and range.

I personally speculated that the signal transmitted by a WiFi AP, whilst low powered compared to the radar station, would still be much stronger than a radar reflection and therefor the AP may well ‘dazzle‘ the Radar station.

[Alex Atkin UK]

There is one good thing, Ofcom seem to have joined the rest of the world in:

Remove the Dynamic Frequency Selection (DFS) requirements from channels used by Wi-Fi in the 5.8 GHz band (5725-5850 MHz).

Although unless things have changed, that's licensed spectrum so only useful for wireless ISPs.

I'm also yet to understand why my Galaxy S10 can do speeds on 80Mhz what my laptop needs 160Mhz to do.

I really hope 6Ghz will solve this inconsistency in performance due to being exclusively WiFi 6. (not counting the fact I believe there is still potential crosstalk from other uses of 6Ghz, but not older versions of WiFi at least)

There seems to be discussion of why Ubiquiti have such a long wait time here https://community.ui.com/questions/DFS-Wait-Times-by-Frequency-UK/38f730db-8d5a-4b25-bd24-9a89578fdad7#answer/5165bafb-f3ec-4045-966c-7f423a097066 but no real conclusion as to why its 10 minutes.

[meritez]

10 minutes, sounds like someone has added/fudged an extra 0 to the 60 seconds availability check 

[4candles]

Not suggesting that radio amateurs are necessarily experts on Radar, but may have better than average knowledge of the characteristics of signal propagation and range.

I personally speculated that the signal transmitted by a WiFi AP, whilst low powered compared to the radar station, would still be much stronger than a radar reflection and therefor the AP may well ‘dazzle‘ the Radar station.

Unless the WiFi was particularly weak, or the radar station particularly close, I'm inclined to agree with your speculation.   

[tickmike]

I live 7 miles from EMA and one flight path is over the field next to us, so we have the stronger landing radar beam that radiates from the airport.
I do notice if I try to select certain 5GHz frequencies they are not available.
I would think in the Isle of Skye it should not be much of a problem, but you will have shipping radar near you.

[Weaver]

There are several airports within 70 miles, Inverness, Tiree, Benbecula and Barra. I looked into a signal of much lower frequency (x 100 kHz) which I thought might be from one of these but shipping was indeed a possibility. For example, the large Norwegian ships that come to empty the fish farms called ‘well-boats’ could possibly be involved for all I know. (I was on board one once.)