We demonstrate an all-optical circuit which senses and controls cell compet
ition in an optical asynchronous transfer mode-based switching system. The
operation of the circuit has been confirmed by experiment. When cells injec
ted into a switch from multiple channels overlap in time, the circuit gener
ates buffer-control and switch-control signals to prevent collision between
the cells. The respective signals introduce the cell with a lower order of
priority to a buffer and pass the cell of higher priority to the next swit
ch.