[ath9k-devel] N mode

[Luis R. Rodriguez <lrodriguez@atheros.com>]

On Wed, Aug 05, 2009 at 09:34:34AM -0700, Dmitri Seletski wrote:
> Right after i send message strange things started to happen.
> 
> I didn't use wireless for a while, however, i started to use it now, my
> land lady insist on it, since she really doesnt like cables in her house.
> 
> for last couple of days it seemed to work without problems(in g mode),
> this afternoon i have noticed that connection is shaky. I powerd off/on
> my access point to improve situation - nothing changed.
> 
> I decided to take a look at it.
> 
> I decided to ping another machine connected over access point.
> i noticed it freezes after some time for short period of time.
> I decided to look at it over "iw event -t" as well
> way i pinged other machine: "ping -A"
> at some stage other machine stopped replying.
> I looked into "iw event"
> 
> and got this:
> 1249487677.365807: wlan0 (phy #0): deauth 00:22:b0:bc:1e:1e ->
> 00:1e:58:b4:f6:83 reason 4: Disassociated due to inactivity

That should be your AP telling you that. Can you modify the
time out of inactivity on your AP?
 
> 1249487677.365880: wlan0 (phy #0): disconnected (local request)
> 
> I believe it happened couple of second later after pings stopped
> replying, but i may be wrong, as it happened too quickly.
> 
> 
> 
> 
> iw dev wlan0 scan
> BSS 00:1e:58:b4:f6:83 (on wlan0)
>     TSF: 13042924 usec (0d, 00:00:13)
>     freq: 2442
>     beacon interval: 25
>     capability: ESS ShortPreamble ShortSlotTime (0x0421)
>     signal: -57.00 dBm
>     SSID: dlink
>     Supported rates: 1.0* 2.0* 5.5* 11.0* 6.0 9.0 12.0 18.0
>     DS Paramater set: channel 7
>     ERP: <no flags>
>     Extended supported rates: 24.0 36.0 48.0 54.0
> 
> I manually set wlan0 to use 11M(or less) connection, as my Broadband
> conenction is 12mbit(and it is very quick), which is rather annoying.

Your broadband connection throughput has nothing to do with your
wireless rate selection. Your rate selection is a physical
characteristic chosen on the device for communication. The bitrate
is defined by the modulation scheme used (BPSK, QPSK, 16QAM, 64QAM,
etc) amongst other things.

If you select 54Mbit/s bit rate you won't get exactly 54 MBit/s, the
bit PHY 54 MBit/s bit rate will be selected and what you actually
get will vary due to many factors.

> I hope it could be of help.
> 
> From iwconfig:
> wlan0     IEEE 802.11bgn  ESSID:"dlink"
>           Mode:Managed  Frequency:2.442 GHz  Access Point:
> 00:1E:58:B4:F6:83
>           Bit Rate=1 Mb/s   Tx-Power=20 dBm
>           Retry  long limit:7   RTS thr:off   Fragment thr:off
>           Encryption key:off
>           Power Management:on
>           Link Quality=61/70  Signal level=-49 dBm
>           Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
>           Tx excessive retries:0  Invalid misc:0   Missed beacon:0
> (usually link quality warries between 60-70)

Try to ditch iwconfig, and use iw: iw dev wlan0 link

For more info see:

http://wireless.kernel.org/en/users/Documentation/iw
http://wireless.kernel.org/en/users/Documentation/iw/replace-iwconfig

> Machine started to suffer with disconnects.
> 
> Below is fuller log.
> 1249488753.366831: wlan0 (phy #0): deauth 00:22:b0:bc:1e:1e ->
> 00:1e:58:b4:f6:83 reason 4: Disassociated due to inactivity
> 1249488753.366985: wlan0 (phy #0): disconnected (local request)
> 1249488848.660029: wlan0 (phy #0): auth 00:1e:58:b4:f6:83 ->
> 00:22:b0:bc:1e:1e status: 0: Successful
> 1249488848.668387: wlan0 (phy #0): assoc 00:1e:58:b4:f6:83 ->
> 00:22:b0:bc:1e:1e status: 0: Successful
> 1249488848.668489: wlan0 (phy #0): connected to 00:1e:58:b4:f6:83
> 1249488918.365949: wlan0 (phy #0): deauth 00:22:b0:bc:1e:1e ->
> 00:1e:58:b4:f6:83 reason 4: Disassociated due to inactivity

Can you tune your AP?

  Luis