This article explains how to connect to a wireless network with Linux. It has been tested with SUSE Linux 12.2. For the commands below you need to be logged in as root user.
Find out your devices
Find out what wlan devices you have
# hwinfo --wlan --short network: wlan0 Ralink 802.11 bg WLAN
In this example, you have one wireless network device. It is named wlan0.
Activate the card
Yast will offer to install the packages iw and kernel-firmware as well. This is important because the firmware must fit to the drivers' version. So accept installing iw and both iw and kernel-firmware will be installed. Then yast will create a script /etc/sysconfig/ifcfg-wlan0 containing your device's parameters. If you select it, yast will also do everything around wpa-supplicant so you can use WPA secured WLAN.
This will allow you the next command you need to call:
And your device will be activated.
Find out your networks
To find out the networks you can access, use iwlist:
# iwlist wlan0 scanning wlan0 Scan completed : Cell 01 - Address: 00:1D:7E:B4:E9:31 ESSID:"MYLAN" Mode:Master Channel:1 Frequency:2.412 GHz (Channel 1) Quality=48/100 Signal level:-70 dBm Encryption key:on IE: WPA Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: Unknown: 2D1A4C1003FFFF000000000000000000000000000000000000000000 Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s 48 Mb/s; 54 Mb/s Extra:tsf=000001a52e792180 Extra: Last beacon: 764ms ago Cell 02 - Address: 00:0D:88:A0:BD:32 ESSID:"MYLAN" Mode:Master Channel:11 Frequency:2.462 GHz (Channel 11) Quality=52/100 Signal level:-46 dBm Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s 48 Mb/s; 54 Mb/s Extra:tsf=00000000058c6430 Extra: Last beacon: 116ms ago
In this example you have two cells of a wireless network with the ESSID MYLAN. The quality of the connection is 52%.