Fonte: http://raspberrypi.stackexchange.com/questions/7987/wifi-configuration-on-arch-linux-arm
The deprecated netcfg used /etc/network.d/ to store profiles. The successor of netcfg is netctl.
In order to setup a wireless network, install netctl using sudo pacman -S netctl. Next, you have to create a network profile. /etc/netctl/examples/ contains some examples. Let's assume you want to setup a WPA2-PSK network. Simply copy over the example file and start editing:
/etc/netctl# install -m640 examples/wireless-wpa wireless-home
/etc/netctl# cat wireless-home
Description='A simple WPA encrypted wireless connection'