Patent ID: 6493119
Filing Date: 2002-12-10
Classification: H04B,H04J,H04Q

Abstract:
For an-optical network having a plurality of optical fibers, each optical fiber carrying M wavelength channels, a DWDM network switch for controllably switching signals on N input optical fibers to N output optical fibers of said optical network, said DWDM network switch comprisinga control unit; a plurality of demultiplexers, each demultiplexer connected to one of said N input optical fibers, said demultiplexer separating signals by said wavelength channels into a plurality of demultiplexer output terminals; a plurality of tunable channel units, each tunable channel unit connected to one of said demultiplexer output terminals associated with one of said wavelength channels, said tunable channel unit capable of switching signals in a first wavelength channel into a second wavelength channel, the second wavelength channel being selectable from a plurality of available wavelength channels, responsive to signals from said control unit; a switch fabric having a plurality of input terminals and output terminals, each input terminal connected to an output terminal of one of tunable channel units, said switch fabric having MÃ—N2 switch points and arranged so that a signal on any one of said input terminals in any wavelength can be sent to any one of said output terminals in any wavelength responsive to signals from said control unit; and a plurality of combiners, each combiner having a plurality of input terminals connected to said output terminals of said switch fabric and an output terminal connected to one of said N output optical fibers, wherein said switch fabric further comprises a plurality of switch modules, each switch module having a plurality of input terminals and output terminals, each input terminal connected to one of a plurality of tunable channel units associated with the same wavelength channel, said output terminals connected to said input terminals of each one of said combiners, and wherein each of said switch modules comprises N 1-to-N switch elements, each switch element having one input terminal connected to a tunable channel unit and N output terminals; N N-to-1 combiners, each combiner having N input terminals and one output terminal, each input terminal connected to an output terminal of one of said switch elements, said output terminal connected to an input terminal of said combiner connected to one of said output optical fibers, and wherein â€œcombinerâ€  means a device for directing light from at least two inputs to at least one output wherein the inputs are capable of accepting light of any wavelength within a band of interest, and wherein light from multiple inputs having substantially the same wavelength is capable of being directed to the output substantially simultaneously.