I have an Acer laptop with Atheros AR928X wireless card installed, supported by ath9k driver in the linux kernel. There are other 5 computers sharing wireless connection via a TPLink 150Mbit/s wireless router. At first I found the network is a little bit slower than it's in Windows7, which I accepted as it should be. However a very strange thing is, each time I connected to the router and downloaded stuff for a while, one of the computers running Windows7 in my local network dropped off from the router. And if I run my laptop under Windows7, everything is fine. What's even stranger is although the network becomes slower, only the certain computer drops and totally freezes in connection with the router. I'm not willing to conclude it's due to the unhealthy connection from my laptop to the router, however we have confirmed this for more than one times and there is no problem with the network when I'm running WIndows7. I'm extremely confused about what's going on. As a Linux user running Ubuntu over 5 years, I am awared that wireless driver in Linux is badly notorious of lack of stability and slow speed. But is it so bad that the unhealthy wireless connection can do damage to another computer in the same local network? I do see a lot of "Tx excessive retries" in iwconfig output. But how exactly does this happen ? Thanks for your help. I guess I have to use this answer box to show the outputs $ sudo iwconfig wlan0 IEEE 802.11bgn ESSID:"TP-LINK111" Mode:Managed Frequency:2.427 GHz Access Point: E0:05:C5:E8:A9:92 Bit Rate=121.5 Mb/s Tx-Power=16 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:off Link Quality=47/70 Signal level=-63 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:2 Invalid misc:23 Missed beacon:0 To show what's wrong with the wireless connection, I ran iwconfig again within 3 minutes, during which time I hardly did anything and the network was not much busy than being nearly idle $ sudo iwconfig wlan0 IEEE 802.11bgn ESSID:"TP-LINK111" Mode:Managed Frequency:2.427 GHz Access Point: E0:05:C5:E8:A9:92 Bit Rate=121.5 Mb/s Tx-Power=16 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:off Link Quality=48/70 Signal level=-62 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:9 Invalid misc:28 Missed beacon:0 You can see Tx excessive retires and Invalid misc increase very quickly. $ sudo iwlist wlan0 modu wlan0 unknown modulation information. $ sudo iwlist wlan0 channel wlan0 13 channels in total; available frequencies : Channel 01 : 2.412 GHz Channel 02 : 2.417 GHz Channel 03 : 2.422 GHz Channel 04 : 2.427 GHz Channel 05 : 2.432 GHz Channel 06 : 2.437 GHz Channel 07 : 2.442 GHz Channel 08 : 2.447 GHz Channel 09 : 2.452 GHz Channel 10 : 2.457 GHz Channel 11 : 2.462 GHz Channel 12 : 2.467 GHz Channel 13 : 2.472 GHz Current Frequency:2.427 GHz (Channel 4)