root@carl-desktop:~/tmp/madwifi-0.9.3.3# iwconfig 
lo        no wireless extensions.

eth0      no wireless extensions.

wifi0     no wireless extensions.

ath0      IEEE 802.11g  ESSID:""  Nickname:""
          Mode:Managed  Frequency:2.437 GHz  Access Point: Not-Associated   
          Bit Rate:0 kb/s   Tx-Power:18 dBm   Sensitivity=1/1  
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=0/70  Signal level=-83 dBm  Noise level=-83 dBm
          Rx invalid nwid:175  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

root@carl-desktop:~/tmp/madwifi-0.9.3.3# iwconfig ath0 essid linksys3
root@carl-desktop:~/tmp/madwifi-0.9.3.3# iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

wifi0     no wireless extensions.

ath0      IEEE 802.11g  ESSID:"linksys3"  Nickname:""
          Mode:Managed  Frequency:2.447 GHz  Access Point: Not-Associated   
          Bit Rate:1 Mb/s   Tx-Power:18 dBm   Sensitivity=1/1  
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=26/70  Signal level=-69 dBm  Noise level=-95 dBm
          Rx invalid nwid:337  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0