Wi-Fi disconnecting randomly

[samsonite2010]

This is not always a huge problem, but sometimes my Wi-Fi (in Ubuntu Lucid) stays connected all day and sometimes it disconnects a few times per day - my Windows laptop stays connected all day, so I don't think there is anything wrong the modem.

To reconnect in Ubuntu, I just have to disable networking and enable again and the connection is back within 10 seconds. Not sure why it would drop off though? It can be a bit of a pain if I am remotely connected to a server and it throws me off.

Maybe there is some strange setting that I can change, but I certainly don't want to make things worse when it works most of the time!

[Roxoff]

Could it be a power management issue? You don't have a wifi card that goes into low-power mode on certain events, do you? If it's a built-in wireless card (in your laptop, etc.) it might even be configurable through the BIOS.

I have seen behaviour like this before, but not for many years. For me (on an early Fedora Core with a Broadcom wireless chipset) the solution was to update the firmware I was using for the wifi chipset.

[samsonite2010]

Power management sounds quite likely - it only happens on my laptop internal card. I will investigate. Thanks!

[waterhead]

You can try manually disabling the power management, if your wireless supports it.

sudo iwconfig wlan0 power off

If your card is named different than wlan0, then substitute the actual name. For more info, read the iwconfig man pages.

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 peri‐
              ods, 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 multi‐
              cast (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 4