cAP ax 5GHz low signal strength

RouterOS Wireless Networking
1

Hello guys,

I got the cAP ax thinking it was a good upgrade from a simple TP-Link consumer router/ap. After some reading and some try and error I could not get good signal strength from the cAP ax. Reception is noticeable worse than the TP-Link and even the APs from my neighbors appear stronger in my WiFi list.
I think that looking at the cAP ax status shows the problem:

interface/wifi/monitor 1
               state: running
             channel: 5745/ax/Ceee
    registered-peers: 0
    authorized-peers: 0
            tx-power: 8
  channel-priorities: 0:5180/ax/Ceee,0:5200/ax/eCee,0:5220/ax/eeCe,0:5240/ax/eeeC,0:5745/ax/Ceee,0:5765/ax/eCee,0:5785/ax/eeCe,0:5805/ax/eeeC

Trying to improve the situation I identified two points that I can not make sense of:

  1. The channel list in the WinBox UI only shows “unkown”. I would like to select the 80MHz wide band 42 below the DFS range that should be supported by all clients, but I can’t to select an appropriate option. (Theoretically, an automatic selection could be find if the tx-power would be alright. Maybe some problem is indicated by the unknown channel list?)
  2. The highest output power that I have seen during the testing with interface/wifi/monitor 1 was 8 or sometimes 16. I guess that could be improved, but I don’t know how.

I would be happy to hear some advice from you. :slight_smile: The exported config is shown below.

(I limited the 2.4GHz tx-power so that the clients are more likely to connect to the 5GHz band. DTIM Period is set to 3 because I read that it could save some battery on some mobile devices.)

# 2024-11-26 18:58:46 by RouterOS 7.16.1
# software id = 2N39-0H6G
#
# model = cAPGi-5HaxD2HaxD
# serial number = X
/interface bridge
add admin-mac=X auto-mac=no comment=defconf name=bridgeLocal
/interface wifi datapath
add bridge=bridgeLocal comment=defconf disabled=no name=capdp
/interface wifi security
add authentication-types=wpa2-psk,wpa3-psk disabled=no name="X PSK" \
    wps=disable
/interface wifi configuration
add chains="" country=Germany disabled=no dtim-period=3 mode=ap \
    multicast-enhance=enabled name="X Cfg" security="X PSK" \
    ssid=X tx-power=23
/interface wifi
set [ find default-name=wifi2 ] channel.band=2ghz-ax .frequency=2300-7300 \
    .width=20mhz configuration="X Cfg" configuration.antenna-gain=6 \
    .chains=0,1 .manager=local .mode=ap .multicast-enhance=enabled .ssid=\
    X .tx-chains=0,1 .tx-power=5 datapath=capdp disabled=no name=\
    "X 2.4GHz"
set [ find default-name=wifi1 ] channel.band=5ghz-ax .frequency=2300-7300 \
    .skip-dfs-channels=all .width=20/40/80mhz configuration="X Cfg" \
    configuration.antenna-gain=6 .chains=0,1 .dtim-period=3 .mode=ap \
    .multicast-enhance=enabled .tx-chains=0,1 .tx-power=23 disabled=no name=\
    "X 5GHz"
/interface bridge port
add bridge=bridgeLocal comment=defconf interface=ether1
add bridge=bridgeLocal comment=defconf interface=ether2
/interface detect-internet
set detect-interface-list=all
/interface wifi cap
set discovery-interfaces=bridgeLocal enabled=yes slaves-datapath=capdp
/ip dhcp-client
add comment=defconf interface=bridgeLocal
/system clock
set time-zone-name=Europe/Berlin
/system note
set show-at-login=no
2

I want to add, that I saw for example here http://forum.mikrotik.com/t/cap-ax-strength-range-questions/178266/1 that it can be tricky to make the cAP ax perform nicely. My question remains whether the “unknown” channel list could be a part of the problem and how I could adjust the current config to have the highest chance of getting a solid performance. :slight_smile:

3

:arrow_right:

4

You are surprised no valid frequency is selected with a config line like this ?

set [ find default-name=wifi1 ] channel.band=5ghz-ax .frequency=2300-7300

Steps to be taken
1- start from default config
2- use proper country setting
3- scan your environment, see which channels are free or least used
4- set your channel MANUALLY and EXACT to the earlier selected channel. Don’t be afraid to use a narrower width if you want stability over maximum performance (which still may go down the drain because of earlier detected interference).
5- if you have multiple APs, make sure their frequencies do not overlap (oh yes, keep scanning that environment on each location)
6- typically IoT-style devices hate WPA3. Use a slave SSID only using WPA2 on 2GHz (or if you really must … WPA)
7- don’t mess with signal strength unless you really know what you’re doing

5

What he said set up your config properly/
A clue…


 state: running          running         running          running  
             channel: 5500/ax/Ceee/D   2412/ax         5180/ax/Ceee/I   2462/ax  
    registered-peers: 1                1               2                1        
    authorized-peers: 1                1               2                1        
            tx-power: 22               14              18               15       
  channel-priorities: 0:5500/ax/Ceee/D 0:2412/ax       0:5180/ax/Ceee/I 0:2462/ax

cAP ax left row, hap ax right row!

6

See also http://forum.mikrotik.com/t/hap-ax3-limits-5ghz-tx-power-to-8/169147/1

Check the actual EIRP limit ! (frequency/country/version) dependent

7

Hey, thanks for all the input! I’m new to MikroTik and started trying different things as it didn’t behave initially as I wanted.

TLDR: Signal strength is better with dfs scanning on, but the channel selection does not work yet.

1. I performed a reset and started from the default config.

/interface wifi
set [ find default-name=wifi1 ] channel.band=5ghz-ax .skip-dfs-channels=\
    10min-cac .width=20/40/80mhz configuration.country=Germany .mode=ap \
    .ssid=X disabled=no security.authentication-types=\
    wpa2-psk,wpa3-psk .ft=yes .ft-over-ds=yes
set [ find default-name=wifi2 ] channel.band=2ghz-ax .skip-dfs-channels=\
    10min-cac .width=20/40mhz configuration.country=Germany .mode=ap .ssid=\
    X security.authentication-types=wpa2-psk,wpa3-psk .ft=yes \
    .ft-over-ds=yes

Cool, now with the dfs option “10min CAC” the transmit power seems to be inline with the provided clue and the reg-info.

interface/wifi/radio reg-info country=Germany number: 0
  ranges: 2402-2482/20
          5170-5250/23/indoor
          5250-5330/23/indoor/dfs
          5490-5730/30/dfs
          5735-5875/14
          
interface/wifi/monitor 0
               state: running
             channel: 5720/ax/eeeC
    registered-peers: 2
    authorized-peers: 2
            tx-power: 23
  channel-priorities: 0:5180/ax/Ceee,0:5200/ax/eCee,0:5220/ax/eeCe,
                      0:5240/ax/eeeC,0:5260/ax/Ceee,0:5280/ax/eCee,
                      0:5300/ax/eeCe,0:5320/ax/eeeC,0:5500/ax/Ceee,
                      0:5520/ax/eCee,0:5540/ax/eeCe,0:5560/ax/eeeC,
                      0:5660/ax/Ceee,0:5680/ax/eCee,0:5700/ax/eeCe,
                      0:5720/ax/eeeC,0:5745/ax/Ceee,0:5765/ax/eCee,
                      0:5785/ax/eeCe,0:5805/ax/eeeC

But I can still not change the channel manually. For 2.4 GHz and also using Winbox v3.41 it’s the same. Strangely enough, I can only see the SSID from my laptop and not from my Samsung phone on this channel…
mikrotik_5ghz_channel_selection.png
2. What is wrong with my country code? It’s the correct country and I hope the spelling is also correct because it was just selected from the Winbox 4 option list.

3.,4. The 5 GHz spectrum seems to be not too busy here, so I would ideally choose a channel below the dfs range, which should be uninterrupted and supported by most devices - at least that is what I have read so far. If the tx-power is as expected and I still have stability issues then I will consider making the band narrower. Good tip to know.

5. Yes, I will try to avoid frequency overlaps if I get more APs. :slight_smile:

6. I thought that the WPA2/WPA3 transition mode should also work for WPA2 only devices. Okay, but if could be problematic for simpler IoT devices than I will just use WPA2 for the IoT SSID.


So the question that remains is the channel option.
If a look at

/interface/wifi/edit wifi1 channel

the default value is *0 and entering something like 5220/ax/eeCe does not seem to do anything. What am I missing? :slight_smile:

8

I’m not positive, but I suspect the “unknown” channel in the Winbox v4 screenshot is due to not having anything set on the /interface/wifi/channel tab. That drop-down showing “unknown” is where I would expect to find the defined channel configurations from the channel tab, which are not set by default. If you want to choose something there you would need to set it in the Channel tab of /interface/wifi.

The reason for your low signal may be the AP selecting a higher frequency where it is limited to 25mw output. This is at least true in the most recent /interface/wifi/monitor 0 output. I believe 5720MHz is in this srd range. The AP would see those as clear channels since properly behaving APs in the area would also be putting out very low power on those frequencies. If you want higher output power, consider limiting the use of those higher, more stringently limited frequencies.

For automatic channel selection you could set something like:

/interface/wifi/channel add band=5ghz-ax disabled=no frequency=5160-5650 name=5GHz width=20/40/80mhz

And this for 2.4GHz:

/interface/wifi/channel add band=2ghz-ax disabled=no frequency=2412,2437,2462 name=2GHz width=20mhz

Once you add those (or something like it), those names will be visible in the channel drop-down field for each radio.

Note that you could also set single frequencies there. You mentioned wanting 80MHz ch42, so you could add it as 5180 in that same place for 5GHz band, or set it to 5150-5250 and 20/40/80MHz.

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