A common setting on Draytek Wireless Routers and Access Points is some variation on:

Code:

Tx Power [x]100% [ ]80% [ ]60% [ ]30% [ ]20% [ ]10%

I was experimenting with the Roaming Parameters on my AP903/AP802 combo and found that the highest (or is it lowest?) you can set the trigger point is -62dBm. I wanted it to consider Roaming earlier, but since this value is fixed in the GUI (and the two nodes are wired i.e. immovable), I seemed to be out of options.

Then I remembered that "TX Power" setting.

I thought if I lowered the AP903's power output a little, I might get a more timely transfer to the AP802. (The AP903 covers most of the house adequately, but the AP802 is plugged in next to me in the lounge - and I'd like it to do something useful :wink:.)

I wondered how much of a reduction would have an effect (See: https://www.metageek.com/training/resources/wifi-signal-strength-basics.html ) and guessed that 50% (3dBm) ought to do it.

It's quite hard to measure a Wifi AP signal strength, as it tends to wander up and down somewhat, but I reckoned 3dBm should be noticeable.

It wasn't

Setting the TX Power to 10%, results in a barely perceptible change.

I can find no Draytek words-of-wisdom on the subject, other than "The default setting is the maximum (100%). Lowering down the value may degrade range and throughput of wireless"

Have I totally misunderstood this subject :?: :lol:

I noticed that this definitely works with my Vigor 2860n. Lowering the Transmit Power on that, makes all the connected clients drop off . (The clients are IOT things, such as Wifi switches embedded in outside light fittings which struggle to connect at the best of times. It probably doesn't take much to upset them!)

It seemed that the AP903's power levels were lower after a reboot - despite it saying it had made the change dynamically. I've not proved this though.

I just noticed something in the Quick Start Guide for the AP802, in the description of "Transmit Power". In the 5GHz section (in a 2pt typeface!), it says:

5G WLAN 5160 - 5340 MHz, max. TX power : 22dBm
5480 - 5720 MHz , max TX power : 29dBm

So on channel 100 - 140 (approx), the output is supposedly a whopping 7dBm greater than on 36 - 64. (In fact it is as high as the AP903). This could be enough to warrant putting up with the inconvenience of all the Radar/DFS malarky.

I tried it ...
...and could see no discernible difference, using any measuring method I could think of

This is all, ever so slightly, odd!

I don't know how you are attempting to measure the signal strength but I suspect that you may have to do it en plein air in order to try and eliminate any problems with reflections at these frequencies. I guess there is also the question of how "smart" these systems are when it comes to adjusting things themselves.

Interesting reading - as is the rest of the linked web site...

"8 reasons to turn down the transmit power of your Wi-Fi": https://metis.fi/en/2017/10/txpower/

I had been thinking along the lines of "what about the signal from the clients" on reading your previous posts. I think I would generally agree with what they say there apart from No 6 (who is No 1? :wink: )

I don't know how the transmitters in these devices are configured but in the days when I built transmitters the output stages ran in Class C - i.e. they were designed such that there was a lot of distortion in terms of harmonics of the radio frequency - the tuned circuits at the output selected the one desired. This was done to achieve greater electrical efficiency. I'm not sure how any radio frequency harmonics (if indeed there are any of significance produced by these devices) could affect the "decoding" of the wifi signal as appears to be suggested here.

But then what do I know?

I also notice when playing around with mine that the settings on the AP903s seem to have a mind of their own - e.g. I set WMM Capable as ON (as per Apple instructions) but when I check again some time later I find that it is OFF again

Oh - and I'm hoping I've solved the "black hole" IP address issue - I realised that I had "Private Address" turned on on the iOS devices - that randomises the MAC address and I'm using IP-MAC binding