Using Google, I think that you need to use an intel driver. You can verify whether you have this controller with the command "sudo /sbin/lspci -v".
Here is a link to the sourceforge homepage for this driver. It includes some instructions on what you may need to do.
In order to use the Intel PRO/Wireless 3945ABG Network Connection driver for Linux you will need the following:
1. The binary microcode image, available here.
2. The binary user space regulatory daemon, available here.
3. The ieee80211 subsystem version 1.1.11 or newer.
4. Linux kernel 2.6.13 or newer. See README.ipw3945 for information on specific options required to be enabled in the kernel.
5. Wireless Extensions (v17) and Tools (v28)
6. For WPA you need a WPA supplicant compatible with the latest versions of the wireless extensions (v18 and newer).
For instructions on how to build and use the driver, please see the INSTALL document.
Fedora Core 7 might supply the driver, but you may still need to download the firmware yourself. Unfortunately this is pretty typical. The firmware isn't open source and so it can't be included in the installation. If you have find-utils installed ( i.e. the locate command ) and have run as root "updatedb", you could look for files containing the pattern "ipw3945". There might be a script that will download and install the firmware for you.
You will want to check if you have the wireless-tools and the wpa_supplicant packages installed.
Using one of the wireless tools packages, you can verify that the wireless device is functioning with the command:
sudo /usr/sbin/iwlist scan
This will scan for Access Points and display the results. If your kernel driver isn't functioning properly, you won't get any result. If you see a list of APs, you can probably proceed with configuring wpa_psk authentication. Your computer will need to be authenticated with the wireless router before it can get an IP address via dhcp.
To monitor the wireless wpa authentication process, you can use the "wpa_cli" program. It is supplied by the wpa_supplicant package.
You need to run it as root.
sudo /usr/sbin/wpa_cli -p /var/run/wpa_supplicant -i <wireless device>
You can enter the "status" command to see whether there is a problem with the wireless authentication process.
There may be other problems that could crop up. For example, I had a problem on my desktop. For the life of me, I couldn't get wpa_supplicant working on it. It would work on my laptop however. I noticed after using "iwlist scan" that someone else had used the same essid as I had. This seemed to confuse wpa_supplicant. Maybe my laptop worked because it was closer to my router, but I'm not certain. Anyway I changed my essid and then the desktop worked.
Also, if your router also has wired ports, connect to it; bring up it's configuration page and copy the preshared key, so that you can past it when trying to connect. ( I use a random 64 digit random key, and there is little chance I would be able to copy it manually. )
If you have an /etc/sysconfig/network/ifcfg-<netdevice> file ( maybe /etc/sysconfig/networking/ifcfg-<netdevice>
) you could manually edit some items there such as the channel number. Also, consider entering your Access Points MAC address. This can prevent false connections.
ps - I spent too much time researching my replay, and you had posted your wireless device in the meantime.