View Full Version : [ubuntu] Wifi power saving question...

January 17th, 2009, 09:34 PM
I dual boot XP and Ubuntu on my Acer Aspire One.

I used to get numerous network hangups while playing online poker which drove me crazy. I figured the root cause was the wifi power saving feature as I didn't get any hangups if I kept pinging my router in the background while playing.

On XP, I easily disabled the power saving mode for the wireless interface and never got that problem again.

On Ubuntu, I cannot figure how to do this. I checked https://help.ubuntu.com/community/AspireOne and it claims wifi power saving is now fully functional with the Ibex version but I can't find how to disable it or at least configure it anywhere. I'm using the MadWifi driver.

I'd appreciate it very much if someone could help me with this problem.

April 29th, 2009, 07:52 PM
I too would like know how fit out the wifi power saving switch. I've got a Aspire One and Ubuntu 8.10

April 29th, 2009, 08:11 PM
Now that I think about it, I've run into this a few times as well. Might have something to do with:

The ath_hal module contains the Atheros Hardware Access Layer (HAL).
This code manages much of the chip-specific operation of the driver.
The HAL is provided in a binary-only form in order to comply with FCC
regulations. In particular, a radio transmitter can only be operated at
power levels and on frequency channels for which it is approved. The
FCC requires that a software-defined radio cannot be configured by the
user to operate outside the approved power levels and frequency
channels. This makes it difficult to open-source code that enforces
limits on the power levels, frequency channels and other parameters of
the radio transmitter. See
for the specific FCC regulation.

April 29th, 2009, 09:43 PM
On Ubuntu, I cannot figure how to do this.I think it is disabled by default. Please see iwconfig:
iwconfig wlan0
wlan0 IEEE 802.11abg ESSID:"mylilrouter"
Mode:Managed Frequency:2.462 GHz Access Point: 99:24:56:2A:XX:YY
Bit Rate=54 Mb/s Tx-Power=14 dBm
Retry min limit:7 RTS thr:off Fragment thr=2352 B
Power Management:off
Link Quality=57/70 Signal level=-53 dBm Noise level=-127 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0This is from man iwconfig:
power Used to manipulate power management scheme parameters and mode. To set the period between wake ups, enter period ‘value’. To set the timeout before going back to sleep, enter timeout ‘value’. To set the generic level of power saving, enter saving ‘value’. You can also add the min and max modifiers. By default, those values are in seconds, append the suffix m or u to specify values in milliseconds or microseconds. Sometimes, those values are without units (number of beacon periods, dwell, percentage or similar). off and on disable and reenable power management. Finally, you may set the power management mode to all (receive all packets), unicast (receive unicast packets only, discard multicast and broadcast) and multicast receive multicast and broadcast only, discard unicast packets).
Examples :
iwconfig eth0 power period 2
iwconfig eth0 power 500m unicast
iwconfig eth0 power timeout 300u all
iwconfig eth0 power saving 3
iwconfig eth0 power off
iwconfig eth0 power min period 2 power max period 4I have never fooled with all this, so I can't vouch for its effectiveness. I do assume, however, that not every card will do every function, including power management.