IEEE80211_FH_CHANMOD
#define IEEE80211_FH_CHAN(set,pat) (((set)-1)*IEEE80211_FH_CHANMOD+(pat))
#define IEEE80211_FH_CHANSET(chan) ((chan)/IEEE80211_FH_CHANMOD+1)
#define IEEE80211_FH_CHANPAT(chan) ((chan)%IEEE80211_FH_CHANMOD)