the control circuit selects a second combination of {TAIL ~ transmission elements} from among the plurality of transmission elements so that the second combination of transmission elements is different from the first combination of {HEAD ~ transmission elements} in one of arrangement and the number of transmission elements 
the control circuit selects a second combination of { TAIL ~ transmission elements } from among the plurality of transmission elements so that the second combination of transmission elements is different from the first combination of { HEAD ~ transmission elements } in one of arrangement and the number of transmission elements
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH