Patent ID: 6999677

Claim:
A protection switching arrangement for optical switching systems, comprising: a plurality of optical switching matrices, each one the optical switching matrices having a plurality of inputs and a plurality of outputs and being operative to switch optical channel signals from any one of the inputs to any one of the outputs; a plurality of wavelength division demultiplexers, each one of the wavelength division demultiplexers having a plurality of outputs each coupled to one of the inputs of a respective one of the optical switching matrices, each one of the wavelength division demultiplexers having an input and being operative for dividing a composite optical signal at its input into optical channel signals and providing each optical channel signal to a respective one of the optical switching matrices; a spare wavelength division demultiplexer having a plurality of outputs each coupled to one of the inputs of a respective one of the optical switching matrices, the spare wavelength division demultiplexer having an input and being operative for dividing a composite optical signal at its input into optical channel signals and providing each optical channel signal to a respective one of the optical switching matrices; and a first optical protection switch having a plurality of inputs, a plurality of straight-through outputs, and a protection output, the first optical protection switch being coupled at each of its straight-through outputs to the input of a respective one of the wavelength division demultiplexers and coupled at its protection output to the input of the spare wavelength division demultiplexer; a plurality of second optical protection switches, each one of the second optical protection switches having a plurality of outputs each coupled to one of the inputs of a respective one of the optical switching matrices and a plurality of inputs coupled to the outputs of a respective one of the wavelength division demultiplexers; a spare optical switching matrix having a plurality of inputs and a plurality of outputs and being operative to switch optical channel signals from any one of its inputs to any one of its outputs, each one of the second optical protection switches having a spare output coupled to one of the inputs of the spare optical switching matrix, wherein each one of the second optical protection switches is operative to couple one of its inputs associated with a faulty one of the optical switching matrices to its spare output to enable the spare optical switching matrix to serve as a backup for the faulty one of the optical switching matrices.