It will be apparent that {HEAD ~ multiplexed output signals} will only be produced by the multiplexer or {TAIL ~ multiplexers} to which more than one channel is currently routed, and that the SOAs may be operated to route a given channel to more than one multiplexer if and when desired 
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It will be apparent that { HEAD ~ multiplexed output signals } will only be produced by the multiplexer or { TAIL ~ multiplexers } to which more than one channel is currently routed , and that the SOAs may be operated to route a given channel to more than one multiplexer if and when desired
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL OTH OTH OTH 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH