ERROR: A compatible subsystem was not found in the following path[s]:

        /lib/modules/2.6.18-1.2798.fc6 /lib/modules/2.6.18-1.2798.fc6/build

You need to install the ieee80211 subsystem from http://ieee80211.sf.net
and point this build to the location where you installed those sources, eg.:

        % make IEEE80211_INC=/usr/src/ieee80211/

or use the 'make patch_kernel' within the ieee80211 subsystem to patch your
kernel sources.

make: *** [check_inc] Error 1