Hello,
Recently I’ve noticed some weird behavior with my hAP ax3 (Router OS 7.11).
Topologically, I have two units, one configured as router, the other works essentially as AP with CAPSMAN (the one which casues this problems).
After a while (hours) something trims down TX Power on device which is managed by CAPSMAN to 8 dBm for 5GHz interface. Other TX powers according to status info seem to be fine. Changing TX power value does not help. Helps only restart, or changing country to US. Once I changed country to US, it stopped to degrade tx power. (not that wifi got much more stable but oh well…)
On daily basis I select country which is inside EU regulatory domain. Here’s actual-config extract for this interface:
Hello, I have a similar error. As a solution, I choose the wrong radio in the radios tab and fix it by pressing the provision button. Sometimes it is powered by Cap poe, and the system may stop working due to low voltage. If there is autosupout.rtf in the files, the poe voltage is insufficient.
How / where are you monitoring the TX power?
Are you using the wireless link when the power is decreased? There should be something downloading when you check
Hello. I don’t open new threads. I am writing about my experiences with similar problems. To support myself or to support someone else. There was a return from the support ticket I opened today. My problem was due to choosing different countries for 5 and 2.4 ghz. It used the lowest values on both radios. I confirmed this. I am trying to solve other problems, I will share as I find a solution. Thanks for the response.
I monitor TX power by observing TX Power value in status tab in WinBox
I have not observed value increasing while using the interface though I have to say that the interface is not used by many endpoints
Let me share a bit of background story why I even asked this question. I struggle with general wifi instability. There are hours, sometimes days when everything is stable, then magic happens and WiFi stability goes to shit - video calls got delays, ping fluctuates between 10ms and 2000ms (most cases 10ms, but once per few pings it gets 2000ms), RDP connection are broken and so on. There are two repeatable patterns I found:
frequency being changed
TX power being trimmed
Fixing channels did not help much, so I started to investigate TX power issue. So far my theory seems consistent - I have not observed problems with WiFi having bigger TX power.
You’re probably getting your frequency changed due to radar detect, and it’s selecting a TPC DFS channel which is designed for short range devices. Don’t pick DFS channels or use “auto” frequency to avoid this.
I also have tx-power=8 once I set country=Poland. If I unset country or select UK, it increases to 24 or 28 dbi. No radar logged. That is too low signal. I have tried all DFS values, the result is the same. I also reset configuration, simply setting country limits tx-power. What the reason may be?
v.7.11.2
I bought an ax3 recently and wifi was great 800mbps next to the Router and ~400mbps two rooms away. I upgraded to 7.13.3 about a week ago and it went down to 300mbps and -70 Next to the Router and -85 and 10mbps at best two rooms away and lagging and loosing connection. Long story short after reading this thread i changed the country on the interfaces, if i set US tx power on 5ghz goes to 28 and on 2.4ghz goes to 27 if i set another country or none It goes down to 8 on the 5ghz and 16 on the 5ghz and even if modified does not set the new value. I tried downgrading to 7.13.2 and even lower with no luck.
Maybe connected but I suspect the version before 7.13.3 wasn’t setting the regulatory Tx power levels correctly. I certainly spotted a reduction in Tx power in the UK with this version because I happened to be doing some lab work on Tx power when I upgraded. The version notes state that it assumes country = Latvia which possibly has lower Tx power limits than before.
I am playing with a new hAP ax2, which I bought to specifically be able to run 5ghz on channel 149. The reason for 149 is I am annoyed by my Apple devices constantly splitting wifi airtime between my WLAN and AWDL.
If I set the 5ghz channel to 149 my TX Power drops to 9 and signal on a brand new MacBook Pro is -70 dBm about 4 meters away with line of sight.
I’ve got a hAP ax2 as well and yes, almost same in UK - Tx power on channel 149 is 9. Sad as I am, I documented the powers on various devices in the lab. The cAP ac and hAP ac lite have much higher power on that channel. Must be a mistake in the internal configuration table for country vs frequency vs regulatory power. BTW the reason there is a yellow line there is that some cheaper interfaces can’t connect at channel 149 or above.
I was on channel 36 before trying 149 and TX Power was 18. This makes sense from what I understand: 18 + 4.5 = 22.5.
Before switching to 149 I did some very quick tests comparing ax2 wifi to my bridged Eero 6+. Worth noting the Eero likes running 40MHz on 2.4 band and 160 on 5. This is with iperf3 server on NAS, iPerf app on iPhone 12, 2 streams, 30s duration:
Signal on my devices was from memory 5 to 10 dBm better on the Eero, but as you can see speeds are roughly comparable. Note that the double bathroom speeds are probably due to Eero’s 40Mhz width on 2.4. Very impressive for such a tiny device, I would think the overall volume is smaller even than the Eero!
For now however I am disabling wifi and running the Eero again. This bug for TX Power on channels >= 149 kind of defeats the purpose for me, will wait for it to be fixed.
I was on channel 36 before trying 149 and TX Power was 18. This makes sense from what I understand: 18 + 4.5 = 22.5.
Yes, that’s my understanding too. tx power + antenna gain <= regulatory limit. With some rounding down going on I assume. So you can drop tx power but you can’t increase it so total would be over regulatory limit.
Actually for UK, the power might be correct if this table is correct. If antenna gain is 4.5, looks like it’s rounded up to 5.
In band B, maximum should be 1W which ChatGPT tells me is 30dBm so 5490-5730 is correct. Channel C is 4W which is 36dBm so why RouterOS has a limit of 14 is perplexing. I’m clearly missing something.
Sorry for quoting UK but looks like same problem although in our case, the table in RouterOS looks wrong. Should be same as Australia (4W/36dBm). This is the formula BTW for Watts to dBm:
Aside but interesting comments about attenuation through walls, I can certainly attest to the ability of Kingspan to kill Wi-Fi signals.
Scatter
One of the classic problems with any WiFi radio is ‘it don’t go through walls!’. It will, to some extent, penetrate thin wood or plasterboard (assuming the plasterboard is not foil backed) but not bricks-n-mortar Ofcom have done some rough tests which show that half of the wifi signal for 2.4GHz is lost with a single brick wall. So a double brick wall would half it again so that’s something like three quarters of the signal lost going through a normal house outside wall. For 5GHz it’s actually worse by about 40%! So in order to get the wifi signal around a property, to reach the various rooms, WiFi largely needs to reflect off the walls and ceilings and get into the rooms via the door ways (and the windows). Therefore, the better the WiFi reflects or scatters then the better the propagation around a house.
