Wireless Networks Made Easy

Check your dmesg

ath0 at pci1 dev 4 function 0 "Atheros AR5212" rev 0x01: irq 11
ath0: AR5212 5.6 phy 4.1 rf5111 1.7 rf2111 2.3, ETSI1W, address 
00:0d:88:c8:a7:c4

Access point, OpenBSD /etc/hostname.ath0:

up media autoselect mediaopt hostap mode 11b chan 6 nwid unwiredbsd \
 nwkey 0x1deadbeef9
inet 10.168.103.1

From OpenBSD 4.4 onwards, we have WPA

Also see FreeBSD setup