Reconfigurable optical switching system
View Patent ↗The switching system comprises a routing device having selection modules each having one input and a plurality of outputs adapted to switch spectral channels received selectively to respective outputs as a function of a command. The routing device comprises a first stage comprising a plurality of modules whose inputs constitute the input ports of the device, a second stage comprising at least one first selection module whose outputs constitute the output ports of the device, and an intermediate stage for coupling the input of the first selection module of the second stage both to a first output of a first selection module of the first stage and to a first output of a second selection module of the first stage. The switching system applies to interconnection panels in switching nodes for optical networks.
1. An optical switching system comprising:
input ports adapted to receive respective optical multiplex input signals each consisting of spectral channels carried by respective wavelengths,
output ports, and
a routing device adapted to switch the spectral channels received by a plurality of input ports selectively to respective output ports selected as a function of a command, wherein a selection module is a device having one input and a plurality of outputs, and is adapted to switch spectral channels received at its input selectively to respective outputs of said module as a function of their respective wavelengths and as a function of a command signal, and said routing device comprises:
a first stage comprising a plurality of selection modules whose inputs constitute respective input ports of said switching system,
a second stage comprising at least one first selection module whose outputs constitute respective output ports of said switching system, and
an intermediate stage for coupling the input of said first selection module of said second stage both to a first output of a first selection module of said first stage and to a first output of a second selection module of said first stage.
2. The switching system according to claim 1 , wherein said second stage comprises a second selection module and said intermediate stage couples the input of said second selection module of said second stage both to a second output of said first selection module of said first stage and to a second output of said second selection module of said first stage.
3. The switching system according to claim 2 , wherein said intermediate stage comprises first and second star couplers each having a plurality of inputs and a plurality of outputs and wherein:
said first outputs of said first and second selection modules of said first stage are coupled to two respective inputs of said first coupler,
said second outputs of said first and second selection modules of said first stage are coupled to two respective inputs of said second coupler, and
each output of each coupler is connected to an input of an associated selection module of said second stage.
4. The switching system according to claim 3 , wherein at least two of said selection modules of said second stage associated with the same coupler are adapted to process separate bands of wavelengths.
5. The switching system according to claim 1 , wherein said first stage comprises at least n selection modules, said second stage comprises at least s selection modules, said intermediate stage comprises at least s star couplers each having at least n inputs and at least one output associated with one of said s selection modules of said second stage, and:
each output of each coupler is coupled to an input of an associated selection module of said second stage, and
n inputs of each coupler are coupled to n respective outputs of n separate selection modules of said first stage, each of said outputs being coupled to an input of a single coupler.
6. A switching node for an optical transmission network in which an input patch panel, an optical-to-electrical conversion interface, an electronic switch, an electrical-to-optical conversion interface and an output patch panel are coupled in cascade, wherein said input patch panel comprises the optical switching system of claim 1 .
7. An optical transmission network comprising at least one switching node of claim 6 .
8. An optical switching system comprising:
input ports adapted to receive respective optical input signals carried by respective wavelengths,
output ports,
a routing device adapted to switch the signals received by a plurality of input ports selectively to output ports selected as a function of a command, wherein a selection module is a device having a plurality of inputs and one output, and is adapted to switch signals received at respective inputs to said output of said module selectively as a function of the wavelengths of the signals received at the respective inputs and as a function of a command signal, and said routing device comprises:
a first stage comprising at least one first selection module whose inputs constitute respective input ports of said switching system,
a second stage comprising a plurality of selection modules whose outputs constitute respective output ports of said switching system, and
an intermediate stage for coupling the output of said first selection module of said first stage both to a first input of a first selection module of said second stage and to a first input of a second selection module of said second stage, wherein:
said first stage comprises a second selection module or multiplexer and said intermediate stage couples the output of said second selection module or multiplexer of said first stage both to a second input of said first selection module of said second stage and to a second input of said second selection module of said second stage,
said intermediate stage comprises first and second star couplers each having a plurality of inputs and a plurality of outputs,
said first inputs of said first and second selection modules of said second stage are coupled to two respective outputs of said first coupler,
said second inputs of said first and second selection modules of said second stage are coupled to two respective outputs of said second coupler, and
each input of each coupler is coupled to an output of an associated selection module or multiplexer of said first stage.
9. The switching system according to claim 8 , wherein at least two of said selection modules or multiplexers of said first stage associated with the same coupler are designed to process non-adjacent bands of wavelengths.
10. The switching system according to claim 8 , wherein said second stage comprises at least n selection modules, said first stage comprises at least s selection modules or multiplexers, and said intermediate stage comprises at least s star couplers each having at least n outputs and at least one input associated with one of said s selection modules or multiplexers of said first stage,
each input of each coupler is coupled to an output of a selection module or multiplexer associated with said first stage, and
n outputs of each coupler are coupled to n respective inputs of n separate selection modules of said second stage, each of said inputs being coupled to an output of a single coupler.
11. A switching node for an optical transmission network in which an input patch panel, an optical-to-electrical conversion interface, an electronic switch, an electrical-to-optical conversion interface and an output patch panel are coupled in cascade, wherein said output patch panel comprises the optical switching system of claim 8 .