Patent ID: 6563979
Filing Date: 2003-05-13
Classification: H04J,H04Q

Abstract:
A fiber optic system, comprising:a primary transmission path provided from a source; a secondary transmission path provided from the source; a network protection unit coupled to the primary and secondary transmission paths provided from the source, the network protection unit comprising: a first 1Ã—2 switch having a first input optically coupled to said primary transmission path, a second input optically coupled to said secondary transmission path, and an output; a second 1Ã—2 switch having a second input optically coupled to said primary transmission path, a first input optically coupled to said secondary transmission path, and an output; and a third 1Ã—2 switch having a first input optically coupled to said output of said first switch, a second input optically coupled to said output of said second switch, and an output optically coupled to an output transmission path; wherein, in a first mode of operation, the first and third switches are set to provide the primary signal to the output transmission path, wherein, in a second mode of operation, the first and third switches are set to provide the secondary signal to the output transmission path, wherein, in a third mode of operation, the second and third switches are set to provide the primary signal to the output transmission path, and wherein, in a fourth mode of operation, the second and third switches are set to provide the secondary signal to the output transmission path.