IEEE80211_DUR_DS_SLOW_CTS 3488 dev/ic/atw.c   	    pre + (IEEE80211_DUR_DS_SLOW_CTS * 2) / ctsrate +
IEEE80211_DUR_DS_SLOW_CTS 3005 dev/ic/rtw.c   	    pre + (IEEE80211_DUR_DS_SLOW_CTS * 2) / ctsrate +