US Patent 7437072 Optical cross-connect with path selecting function

An optical cross-connect for selecting a path between an access-line connected to a router and a trunk-line connected to another optical cross-connect the optical cross-connect has a hash-table H for randomly specifying a trunk-line number k as elements h(i,j)=k in the order of selection j for every access-line number i; and a path selection means for selecting a path of trunk-line number k with a busy flag that has been reset, in the order of selection j by using the hash-table H when a path addition to an access-line number i is requested, the path selection means setting the busy flags of all elements h that specify the selected trunk-line number k in the hash-table H.