This is a good wireless 802.11b card that have 2 antennas and it's plugged by USB.
Identification for this card using the lsusb command is:
ID 09aa:3642 Intersil Corp. Prism2.x 802.11b Adapter.
Official specifications are here on the senao.com website:
http://www.senao.com/service%20&%20support/Spec/NL-2511UB_Spec.pdf
This card has an ouput power of: 15 dBm

This was tested on a Notebook Acer Aspire 1300X with Red Hat Linux release 9.0.93 (Severn) it's a BETA version, with Kernel: 2.4.21.20.1.2024.2.1.nptl on an i686 and also on Red Hat 9.0 on Kernel 2.4.20-18.9 athlon on a desktop computer.


This document is based on ftp://ftp.linux-wlan.org/pub/linux-wlan-ng/README
First at all go the this ftp site and download this file:
ftp://ftp.linux-wlan.org/pub/linux-wlan-ng/
linux-wlan-ng-0.2.0.tar.gz
Note: It also tried the linux-wlan-ng-0.2.1-pre11.tar.gz and it works well.

then login as root and type:
tar -zxvf linux-wlan-ng-0.2.0.tar.gz
cd linux-wlan-ng-0.2.0
ln -s /usr/src/linux-2.4 /usr/src/linux
be sure to have a .config file in /usr/src/linux/ check it by typing:
ls -la /usr/src/linux/.config
If you don't have this file that means that you never compiled the Linux Kernel on this system by your own, then you must copy the default Kernel configuration parameters to this location.
Check the Kernel that you have by typing uname -a
now do this:
cp /usr/src/linux/configs/kernel-2.4.21-i686.config /usr/src/linux/.config
where kernel-...... is your system.

make config

you will see this questions, note that the answers between brakets [] will be the default used if you press ENTER and may be different, the point is that you get the idea: 

- "Build Prism2.x PCMCIA Card Services ((_cs) driver? (y/n) [y]: "
yes
- Build Prism2 PLX9052 based PCI (_plx)  adapter driver? (y/n) [y]: 
no
- Build Prism2.5 native PCI (_pci) driveer? (y/n) [y]: 
no
- Build Prism2.5 USB (_usb) driver? (y/nn) [y]: 
yes
- Linux source directory [/usr/src/linuxx]: 
press ENTER
- Alternate target install root directorry on host []: 
press ENTER
- PCMCIA script directory [/etc/pcmcia]:: 
press ENTER
- Module install directory [/lib/moduless/2.4.21-20.1.2024.2.1.nptl]: 
press ENTER
- Prefix for build host compiler? (rarelly needed) []: 
press ENTER
- Build for debugging (see doc/config.deebug) (y/n) [n]: 
no

Configuration succesful.
Now let's compile the whole thing:

make all
make install

now if no errors appear, th installation is done.

Note that this new two files contains the configuration

/etc/wlan/wlan.conf:

This file maps between wlan devices and network IDs, and contains
the names of all devices that should be initialized by the hotplug
and rc scripts.

/etc/wlan/wlancfg-*

These files are per-network configurations. This makes it easy to 
switch between different SSIDs and the various settings they may
require, like WEP keys and whatnot.

You don't need to edit them, you may simply use this script to activate your wireless USB card (change the for your settings:

emacs senao-on.sh

modprobe prism2_usb prism2_doreset=1
wlanctl-ng wlan0 lnxreq_ifstate ifstate=enable
wlanctl-ng wlan0 lnxreq_autojoin ssid= authtype=opensystem
ifconfig wlan0 netmask 
route add default gw 

ctrl-x ctrl-s (to save and exit)
chmod 755 senao-on.sh

Also, don't forget to set up your resolv.conf to point at your DNS server.

Now you card will be working, look at the LED on the USB card to see if it's turned on.
If you power off the computer and then turn it on again, the above commands may give you an error, then, just unplug the USB card and plug it again. Try the script again and it should work.

The iwconfig command will help you to see the connection status.
Also wavemon is a very good text mode graphic to see it.
http://www.jm-music.de/projects.html