wireless got disconnect/idle after a while

iwconfig wlan0

Bit Rate=54 Mb/s Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:on
Link Quality=56/70 Signal level=-54 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:8 Missed beacon:0

ubuntu@omap:~$ uname -a
Linux omap 3.2.0-psp7 #1 Fri Apr 13 04:55:05 UTC 2012 armv7l armv7l armv7l GNU/Linux

I checked this topic and used “sudo iwconfig wlan0 power off” but it didn’t work - After a while I can’t connect beaglebone through ssh. Pull USB wireless card out and plug in again, it can work.

I also found this file but didn’t know it usage.

ubuntu@omap:/usr/lib/pm-utils/sleep.d$ ls

60_wpa_supplicant

My wireless usb card is Belkin Components F5D7050 Wireless G Adapter v3000 [Ralink RT2571W].

I think you could use

ifconfig wlan0 down to turn off radio.

regarding disconnection after few minutes, I don’t have a good idea. however, if the wireless
is not associated with any AP, it will turn off after few scanning APs were failed.

I changed to another one:

Bus 001 Device 006: ID 07d1:3303 D-Link System DWA-131 802.11n Wireless N Nano Adapter(rev.A1) [Realtek RTL8192SU]

everything works fine now.