OPTICAL CROSS-CONNECTOR CONTAINING A MULTI-STAGE CLOS NETWORK IN WHICH A SINGLE-STAGE MATRIX COMPRISES ONE STAGE OF THE CLOS NETWORK

摘要

A wavelength division multiplex (WDM) optical cross-connect (OXC) has a plurality (N x M) of input and output channels (iI to iM; 01 to oM) for through traffic. A first group of optical switching matrices (SI-I to SI-N) is provided for connecting the through traffic input channels (iI to iM) to the output channels (01 to oM), wherein each through traffic input channel (iI to iM) is connected to an input of a switching matrix (SI-I to SI-N) of the first group and each through traffic (01 to oM) is connected to an output of the switching matrix (S1-1 to S1-N). Additionally a plurality (P) of input channels (a1 to aP) and/or output channels (01 to oP) is provided for adding/dropping traffic. Each add/drop input/output channel (a1 to aP, o1 to oP) is connected to an input/output of a second group of switching matrices (S2’ -1 to S2’ -AD). The outputs/inputs of the second group of switching matrices are connected to inputs of a third group of switching matrices (S3-1 to S3-2M-1) or outputs of a fourth group of switching matrices (S4-1 to S4-(2M-1)) and the outputs/inputs of the third/fourth group of switching matrices are connected to inputs/outputs of the first group of switching matrices such that the switching matrices or the second, third and first groups of the first, fourth and second groups each form a Clos network.