I had laying arround a Xtreamer WLAN Stick USB with Realtek RTL8191SU Chip
Standards
IEEE 802.11n (draft 2.0), IEEE 802.11g, IEEE 802.11b, Cisco CCX support, CSMA/CA with ACK
I plugged it, and it worked out of the box with WPA/WPA2!!!
lsusb shows --> Bus 001 Device 002: ID 0bda:8172 Realtek Semiconductor Corp. RTL8191SU 802.11n WLAN Adapter
iwconfig --> shows
lo no wireless extensions.
eth0 no wireless extensions.
wlan0 IEEE 802.11bgn ESSID:"LinkXXXX" Nickname:"XXXXX"
Mode:Managed Frequency:2.412 GHz Access Point: XX:1F:XX:D5:XX:49
Bit Rate:300 Mb/s Sensitivity:0/0
Retry:off RTS thr:off Fragment thr:off
Encryption key:****-****-****-****-****-****-****-**** Security mode:open
Power Management:off
Link Quality=100/100 Signal level=62 dBm Noise level=0 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
I put the DC01 downstairs in the basement even there the datarate was excellent!
(216 MBit/s Fritzbox)
Maybe this helps someone.
Cheers Billy