Problems setting tx power in WDR3600

Post new topic   Reply to topic    DD-WRT Forum Forum Index -> Atheros WiSOC based Hardware
Goto page 1, 2, 3  Next
Author Message
michelasso
DD-WRT Novice


Joined: 26 Mar 2015
Posts: 16

PostPosted: Thu Mar 26, 2015 12:10    Post subject: Problems setting tx power in WDR3600 Reply with quote
Hello everybody,
I have just installed DD-WRT (build 25760) on a TPLINK WDR3600. I have a little problem with wireless settings of the 2.4 GHz device (ath0).
I live in Italy, and maximum transmit power for almost all channels is 20 dBm, as it could be verified by iw:

Code:


root@DD-WRT:~# iw reg get
country IT: DFS-ETSI
   (2402 - 2482 @ 40), (N/A, 20), (N/A)
   (5170 - 5250 @ 80), (N/A, 20), (N/A)
   (5250 - 5330 @ 80), (N/A, 20), (N/A)
   (5490 - 5710 @ 80), (N/A, 27), (N/A)
   (57240 - 65880 @ 2160), (N/A, 40), (N/A), NO-OUTDOOR


root@DD-WRT:~# iw phy phy0 info
Wiphy phy0
   max # scan SSIDs: 4
   max scan IEs length: 2257 bytes
   Retry short limit: 7
   Retry long limit: 4
   Coverage class: 5 (up to 2250m)
   Device supports AP-side u-APSD.
   Device supports T-DLS.
   Available Antennas: TX 0x3 RX 0x3
   Configured Antennas: TX 0x3 RX 0x3
   Supported interface modes:
       * IBSS
       * managed
       * AP
       * AP/VLAN
       * WDS
       * monitor
       * P2P-client
       * P2P-GO
   Band 1:
      Capabilities: 0x11ef
         RX LDPC
         HT20/HT40
         SM Power Save disabled
         RX HT20 SGI
         RX HT40 SGI
         TX STBC
         RX STBC 1-stream
         Max AMSDU length: 3839 bytes
         DSSS/CCK HT40
      Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
      Minimum RX AMPDU time spacing: 8 usec (0x06)
      HT TX/RX MCS rate indexes supported: 0-15
      Frequencies:
         * 2412 MHz [1] (19.0 dBm)
         * 2417 MHz [2] (20.0 dBm)
         * 2422 MHz [3] (20.0 dBm)
         * 2427 MHz [4] (20.0 dBm)
         * 2432 MHz [5] (20.0 dBm)
         * 2437 MHz [6] (20.0 dBm)
         * 2442 MHz [7] (20.0 dBm)
         * 2447 MHz [8] (20.0 dBm)
         * 2452 MHz [9] (20.0 dBm)
         * 2457 MHz [10] (20.0 dBm)
         * 2462 MHz [11] (18.0 dBm)
         * 2467 MHz [12] (20.0 dBm)
         * 2472 MHz [13] (20.0 dBm)
   valid interface combinations:
       * #{ managed } <= 2048, #{ AP } <= 8, #{ P2P-client, P2P-GO } <= 1, #{ IBSS } <= 1,
         total <= 2048, #channels <= 1, STA/AP BI must match
       * #{ WDS } <= 2048,
         total <= 2048, #channels <= 1, STA/AP BI must match
   HT Capability overrides:
       * MCS: ff ff ff ff ff ff ff ff ff ff
       * maximum A-MSDU length
       * supported channel width
       * short GI for 40 MHz
       * max A-MPDU length exponent
       * min MPDU start spacing

However, even if I set 20 dBm in the TX Power section of Advanced Settings in the web interface, what I always get from wireless status panel is that TX Power is 17 dBM. This is also confirmed by iwconfig:

Code:
root@DD-WRT:~# iwconfig ath0
ath0      IEEE 802.11bgn  Mode:Master  Tx-Power=17 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:off


Can anybody help me to understand if this is a bug or if I am doing something wrong?
Sponsor
KrypteX
DD-WRT Guru


Joined: 18 Jan 2014
Posts: 737

PostPosted: Thu Mar 26, 2015 12:55    Post subject: Reply with quote
Set channel number manually, e.g. 6, not Auto.
_________________
[Atheros] Netgear WNDR3800 ---> DD-WRT 26446 [k3.10.71-rc1]
[ Ralink ] D-Link DIR-615 D2 ----> DD-WRT 26622 [k3.2.68]
DD-WRT FIRMWARES: ftp://ftp.dd-wrt.com/betas/
DD-WRT CHANGELOG: http://www.dd-wrt.com/phpBB2/viewtopic.php?t=279466
michelasso
DD-WRT Novice


Joined: 26 Mar 2015
Posts: 16

PostPosted: Thu Mar 26, 2015 13:30    Post subject: Reply with quote
KrypteX wrote:
Set channel number manually, e.g. 6, not Auto.


Just tried, but it doesn't help. Still at 17 dBm.
mittelhessen
DD-WRT User


Joined: 26 Jan 2012
Posts: 450

PostPosted: Thu Mar 26, 2015 13:34    Post subject: Reply with quote
Have you applied an antenna gain of 3 dB?
KrypteX
DD-WRT Guru


Joined: 18 Jan 2014
Posts: 737

PostPosted: Thu Mar 26, 2015 13:44    Post subject: Reply with quote
Try Canada or United States instead of Italy and keep the channel manually set. I also get 17 dBm if I set Auto channel and Germany. So now I use Canada, channel 11 (it's not so crowded around it). My WNDR3800 works at 20 dBm without issues. No antenna gain.
_________________
[Atheros] Netgear WNDR3800 ---> DD-WRT 26446 [k3.10.71-rc1]
[ Ralink ] D-Link DIR-615 D2 ----> DD-WRT 26622 [k3.2.68]
DD-WRT FIRMWARES: ftp://ftp.dd-wrt.com/betas/
DD-WRT CHANGELOG: http://www.dd-wrt.com/phpBB2/viewtopic.php?t=279466
mittelhessen
DD-WRT User


Joined: 26 Jan 2012
Posts: 450

PostPosted: Thu Mar 26, 2015 13:47    Post subject: Reply with quote
KrypteX wrote:

Try Canada or United States instead of Italy ...


As you see in his "iw reg get"- and "iw phy phy0 info"-outputs, italy also allows 20 dBm!

KrypteX wrote:

... and keep the channel manually set.


You already mentioned this! Wink

KrypteX wrote:

My WNDR3800 works ...


He has a WDR3600 (which is TP-Link) and no(!) WNDRxxxx (which is Netgear).
michelasso
DD-WRT Novice


Joined: 26 Mar 2015
Posts: 16

PostPosted: Thu Mar 26, 2015 13:50    Post subject: Reply with quote
KrypteX wrote:
Try Canada or United States instead of Italy and keep the channel manually set. I also get 17 dBm if I set Auto channel and Germany. So now I use Canada, channel 11 (it's not so crowded around it). My WNDR3800 works at 20 dBm without issues. No antenna gain.


Ok, now with Canada it is finally working at 20dBm. I assume then this is a bug of wireless implementation, should I report it somewhere?

@mittelhessen No, I didn't set any antenna gain.
michelasso
DD-WRT Novice


Joined: 26 Mar 2015
Posts: 16

PostPosted: Thu Mar 26, 2015 13:52    Post subject: Reply with quote
mittelhessen wrote:
KrypteX wrote:

Try Canada or United States instead of Italy ...


As you see in his "iw reg get"- and "iw phy phy0 info"-outputs, italy also allows 20 dBm!



You're right, this is the reason why I believe this behaviour is a bug of wireless implementation in DD-WRT.
mittelhessen
DD-WRT User


Joined: 26 Jan 2012
Posts: 450

PostPosted: Thu Mar 26, 2015 13:54    Post subject: Reply with quote
If the channel is chosen automatically the tx-power might fall down to the lowest allowed (in this case: chipset-available) power, which is 18 dBm. It shouldln't fall down to 17 dBm, especially when using a manual channel where 20 dBm are allowed. So i think, this might be really a bug!
iliteo
DD-WRT User


Joined: 09 Apr 2014
Posts: 88
Location: Hellas

PostPosted: Thu Mar 26, 2015 14:08    Post subject: Reply with quote
michelasso set:
a fixed allowable channel, like 6
Reg in IT.
Channel Width in HT40
antenna gain to 0.
You must have the max 20dB TX Power w/ this settings.

_________________
dd-wrt is addict...
michelasso
DD-WRT Novice


Joined: 26 Mar 2015
Posts: 16

PostPosted: Thu Mar 26, 2015 14:22    Post subject: Reply with quote
iliteo wrote:
michelasso set:
a fixed allowable channel, like 6
Reg in IT.
Channel Width in HT40
antenna gain to 0.
You must have the max 20dB TX Power w/ this settings.


I am sorry but this does not happen...here's my settings:



and here's the status

mittelhessen
DD-WRT User


Joined: 26 Jan 2012
Posts: 450

PostPosted: Thu Mar 26, 2015 14:41    Post subject: Reply with quote
Have you tried to use normal channel width (20 MHz) instead of wide channel width?
KrypteX
DD-WRT Guru


Joined: 18 Jan 2014
Posts: 737

PostPosted: Thu Mar 26, 2015 14:43    Post subject: Reply with quote
mittelhessen wrote:
KrypteX wrote:

Try Canada or United States instead of Italy ...

As you see in his "iw reg get"- and "iw phy phy0 info"-outputs, italy also allows 20 dBm!
KrypteX wrote:

... and keep the channel manually set.

You already mentioned this! Wink
KrypteX wrote:

My WNDR3800 works ...

He has a WDR3600 (which is TP-Link) and no(!) WNDRxxxx (which is Netgear).

mittelhessen, I know the difference between TP-Link and Netgear models, I'm not blind !
And I know exactly why I said what I said, because this is an old bug in DD-WRT, I even opened a related bug ticket http://svn.dd-wrt.com/ticket/3740 in which I mentioned the 17 dBm only issue and BrainSlayer replied, etc. But still no fix.

That's why I say AGAIN: use Canada or US with channel explicitly set and it will work properly. If you set European countries (Germany, France, Italy etc.) you'll see the bug, especially on the 5G band.

You are all free to reopen/add new info to the ticket. It might get fixed.

_________________
[Atheros] Netgear WNDR3800 ---> DD-WRT 26446 [k3.10.71-rc1]
[ Ralink ] D-Link DIR-615 D2 ----> DD-WRT 26622 [k3.2.68]
DD-WRT FIRMWARES: ftp://ftp.dd-wrt.com/betas/
DD-WRT CHANGELOG: http://www.dd-wrt.com/phpBB2/viewtopic.php?t=279466
iliteo
DD-WRT User


Joined: 09 Apr 2014
Posts: 88
Location: Hellas

PostPosted: Thu Mar 26, 2015 15:49    Post subject: Reply with quote
something going wrong w/ your screenshoots you posted.
In Settings the ACK Timing is 0 meters.
In Status shown as in 2250m.
Maybe you see a status of another router or is the cashe of previous status. Clear your browser cashe.

Also in Mode set the Mixed mode - not NG Mixed.
The build 25760 is old now. Latest is r26490

_________________
dd-wrt is addict...
michelasso
DD-WRT Novice


Joined: 26 Mar 2015
Posts: 16

PostPosted: Thu Mar 26, 2015 16:28    Post subject: Reply with quote
iliteo wrote:
something going wrong w/ your screenshoots you posted.
In Settings the ACK Timing is 0 meters.
In Status shown as in 2250m.
Maybe you see a status of another router or is the cashe of previous status. Clear your browser cashe.

Also in Mode set the Mixed mode - not NG Mixed.
The build 25760 is old now. Latest is r26490


No, no other router, however I cleared the cache and set the mode to mixed, as you suggested, and nothing has changed.
Moreover, web stats could be influenced by old cache, but the output of iwconfig in terminal doesn't, and it always says Tx-Power=17dBm.
Maybe the ack timing not reported correctly is another bug...
Goto page 1, 2, 3  Next Display posts from previous:    Page 1 of 3
Post new topic   Reply to topic    DD-WRT Forum Forum Index -> Atheros WiSOC based Hardware All times are GMT

Navigation

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum