Is my AP or my Desktop PC?

Installing and Using OpenWrt
1

Hi,

Checking my Deskotp PC running Ubuntu 20.04 LTS I could see:

wlp0s20f3: Limiting TX power to 17 (20 - 3) dBm as advertised by f4:8c:eb:xx:xx:xx

And my AP:

wlan1     ESSID: "XXXXXX"
          Access Point: F4:8C:EB:xx:xx:xx
          Mode: Master  Channel: 52 (5.260 GHz)
          Center Channel 1: 58 2: unknown
          Tx-Power: 20 dBm  Link Quality: 47/70
          Signal: -63 dBm  Noise: -106 dBm
          Bit Rate: 650.0 MBit/s
          Encryption: WPA2 PSK (CCMP)
          Type: nl80211  HW Mode(s): 802.11nac
          Hardware: 168C:003C 168C:4019 [Qualcomm Atheros IPQ4019]
          TX power offset: none
          Frequency offset: none
          Supports VAPs: yes  PHY name: phy1

Who is pulling my leg, OpenWRT or Ubuntu? Why is OpenWRT limiting dBm if Tx-Power is set to 20 dBm (as default config)?

Thanks for help,

2

are you sure it's not the TX power of your computers wifi adapter ?

3

According to Ubuntu log:

Limiting TX power to 17 (20 - 3) dBm as advertised by f4:8c:eb:xx:xx:xx`

It seems related to AP (OpenWRT), not to wifi adapter.

4

OpenWrt advertises 20 dBm (max.), your client takes that regulatory limit and has to reduce its own tx power by 3 dBm due to a missing TPC implementation in its driver - everything as it has to, according to regulatory requirements.

2 Likes
5

Then the problem is not OpenWRT/Ubuntu, the "guilty" is the driver?