/etc/conf.d/wireless:

modules_ra0=("iwconfig")
ifconfig_ra0=("10.10.10.10 netmask 255.255.255.0")
mode_ra0="Ad-hoc"
essid_ra0="SpaceVibes"
channel_ra0="10"

output from /etc/init.d/net.ra0 start
 * Caching service dependencies ...                                       [ ok ] * Starting ra0
 *   Configuring wireless network for ra0
Error for wireless request "Set Mode" (8B06) :
    SET failed on device ra0 ; Network is down.
 *   ra0 does not support setting the mode to "ad-hoc"
Error for wireless request "Set Encode" (8B2A) :
    SET failed on device ra0 ; Network is down.
Error for wireless request "Set ESSID" (8B1A) :
    SET failed on device ra0 ; Network is down.
 *   ra0 does not support setting ESSID to "SpaceVibes"
 *   Failed to configure wireless for ra0                                 [ !! ]