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Opened 4 years ago

Closed 3 years ago

#16744 closed defect (wontfix)

ath9k/mac80211: ignored txpower offset on Ubiquiti devices

Reported by: linus.luessing@… Owned by: developers
Priority: normal Milestone: Barrier Breaker 14.07
Component: packages Version: Trunk
Keywords: ath9k mac80211 ubiquiti nanostation txpower offset Cc:

Description

It seems that the 12 dBi antenna of the Ubiquiti NanoStation M2 is properly set in the firmware, at least a 12dB txpower offset is noted in iwinfo. However, the txpower is not reduced accordingly:

$ iwinfo
wlan0     ESSID: "luebeck.freifunk.net"
          Access Point: 24:A4:3C:AC:F4:AC
          Mode: Master  Channel: 1 (2.412 GHz)
          Tx-Power: 30 dBm  Link Quality: 40/70
          Signal: -70 dBm  Noise: -89 dBm
          Bit Rate: 43.6 MBit/s
          Encryption: none
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: 168C:002A 0777:E012 [Ubiquiti NanoStation M2]
          TX power offset: 12 dB
          Frequency offset: none
          Supports VAPs: yes

wlan0-1   ESSID: "02:d1:11:37:fc:38"
          Access Point: 02:D1:11:37:FC:38
          Mode: Ad-Hoc  Channel: 1 (2.412 GHz)
          Tx-Power: 30 dBm  Link Quality: 69/70
          Signal: -41 dBm  Noise: -89 dBm
          Bit Rate: 102.3 MBit/s
          Encryption: unknown
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: 168C:002A 0777:E012 [Ubiquiti NanoStation M2]
          TX power offset: 12 dB
          Frequency offset: none
          Supports VAPs: yes

The reg domain is set correctly, too:

$ iw reg get
country DE:
        (2400 - 2483 @ 40), (N/A, 20)
        (5150 - 5250 @ 80), (N/A, 20), NO-OUTDOOR
        (5250 - 5350 @ 80), (N/A, 20), NO-OUTDOOR, DFS
        (5470 - 5725 @ 80), (N/A, 27), DFS
        (57240 - 65880 @ 2160), (N/A, 40), NO-OUTDOOR
$ iwinfo wlan0-1 txpowerlist
  12 dBm (  15 mW)
  13 dBm (  19 mW)
  14 dBm (  25 mW)
  15 dBm (  31 mW)
  16 dBm (  39 mW)
  17 dBm (  50 mW)
  18 dBm (  63 mW)
  19 dBm (  79 mW)
  20 dBm ( 100 mW)
  21 dBm ( 125 mW)
  22 dBm ( 158 mW)
  23 dBm ( 199 mW)
  24 dBm ( 251 mW)
  25 dBm ( 316 mW)
  26 dBm ( 398 mW)
  27 dBm ( 501 mW)
  28 dBm ( 630 mW)
  29 dBm ( 794 mW)
* 30 dBm (1000 mW)

For Ubiquiti NanoStation M2 loco and Ubiquiti Unifi-AP things seem to be a bit more tricky, the txpower offset seems to be unavailable here:

Ubiquiti NanoStation M2 loco:

$ iwinfo
wlan0     ESSID: "luebeck.freifunk.net"
          Access Point: 24:A4:3C:74:49:3A
          Mode: Master  Channel: 1 (2.412 GHz)
          Tx-Power: 20 dBm  Link Quality: 32/70
          Signal: -78 dBm  Noise: -95 dBm
          Bit Rate: 34.2 MBit/s
          Encryption: none
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: 168C:002E 0777:E0A2 [Generic MAC80211]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: yes

wlan0-1   ESSID: "02:d1:11:37:fc:38"
          Access Point: 02:D1:11:37:FC:38
          Mode: Ad-Hoc  Channel: 1 (2.412 GHz)
          Tx-Power: 20 dBm  Link Quality: 51/70
          Signal: -59 dBm  Noise: -95 dBm
          Bit Rate: 43.8 MBit/s
          Encryption: unknown
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: 168C:002E 0777:E0A2 [Generic MAC80211]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: yes

Ubiquiti Unifi-AP:

$ iwinfo
wlan0     ESSID: "luebeck.freifunk.net"
          Access Point: 24:A4:3C:7D:D0:1B
          Mode: Master  Channel: 1 (2.412 GHz)
          Tx-Power: 20 dBm  Link Quality: 23/70
          Signal: -87 dBm  Noise: -94 dBm
          Bit Rate: 9.0 MBit/s
          Encryption: none
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: 168C:002E 0777:E512 [Generic MAC80211]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: yes

wlan0-1   ESSID: "02:d1:11:37:fc:38"
          Access Point: 02:D1:11:37:FC:38
          Mode: Ad-Hoc  Channel: 1 (2.412 GHz)
          Tx-Power: 20 dBm  Link Quality: 56/70
          Signal: -54 dBm  Noise: -94 dBm
          Bit Rate: 31.1 MBit/s
          Encryption: unknown
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: 168C:002E 0777:E512 [Generic MAC80211]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: yes

The version of mac80211 used is this. Which should match trunk, r39758.

Attachments (0)

Change History (6)

comment:1 Changed 4 years ago by jow

  • Milestone changed from Attitude Adjustment 12.09 to Barrier Breaker 14.07

Milestone Attitude Adjustment 12.09 deleted

comment:2 Changed 3 years ago by DooMMasteR

my Bullet M2 also reports

TX power offset: 12 dB

but it only has an external 8dBi antenna

in my case

country DE: DFS-ETSI
	(2400 - 2483 @ 40), (N/A, 20)
	(5150 - 5350 @ 80), (N/A, 20), NO-OUTDOOR
	(5470 - 5725 @ 80), (N/A, 27), DFS
	(57240 - 65880 @ 2160), (N/A, 40), NO-OUTDOOR
iwinfo wlan0 txpowerlist
  12 dBm (  15 mW)
  13 dBm (  19 mW)
  14 dBm (  25 mW)
  15 dBm (  31 mW)
  16 dBm (  39 mW)
  17 dBm (  50 mW)
  18 dBm (  63 mW)
* 19 dBm (  79 mW)
  20 dBm ( 100 mW)
  21 dBm ( 125 mW)
  22 dBm ( 158 mW)
  23 dBm ( 199 mW)
  24 dBm ( 251 mW)
  25 dBm ( 316 mW)
  26 dBm ( 398 mW)
  27 dBm ( 501 mW)
  28 dBm ( 630 mW)
wlan0     ESSID: "braunschweig.freifunk.net"
          Access Point: 24:A4:3C:9E:2E:99
          Mode: Master  Channel: 1 (2.412 GHz)
          Tx-Power: 19 dBm  Link Quality: 23/70
          Signal: -87 dBm  Noise: -95 dBm
          Bit Rate: 5.5 MBit/s
          Encryption: none
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: 168C:002A 0777:E202 [Ubiquiti Bullet M2]
          TX power offset: 12 dB
          Frequency offset: none
          Supports VAPs: yes

wlan0-1   ESSID: "02:d1:11:37:fc:38"
          Access Point: 02:D1:11:37:FC:38
          Mode: Ad-Hoc  Channel: 1 (2.412 GHz)
          Tx-Power: 19 dBm  Link Quality: 49/70
          Signal: -61 dBm  Noise: -95 dBm
          Bit Rate: 150.0 MBit/s
          Encryption: unknown
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: 168C:002A 0777:E202 [Ubiquiti Bullet M2]
          TX power offset: 12 dB
          Frequency offset: none
          Supports VAPs: yes

comment:3 Changed 3 years ago by DooMMasteR

I added the antenna, the Bullet has none...

comment:4 Changed 3 years ago by LeSpocky

FWIW the datasheet says to Antenna Information for NSM2: Gain 10.4–11.2 dBi. See: http://dl.ubnt.com/datasheets/nanostationm/nsm_ds_web.pdf

comment:5 Changed 3 years ago by skaapgif@…

Might be related to /ticket/18055.html

Perhaps r43032 solves this issue?

comment:6 Changed 3 years ago by jow

  • Resolution set to wontfix
  • Status changed from new to closed

ath9k, mac80211 or any other part of the linux wireless stack does not care about txpower offsets at all. This is solely a libiwinfo feature used by the LuCI ui to show more sane txpower values.

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