Photonic cross-connect with reconfigurable add-drop-functionality

1. A photonic cross-connector comprising a cross-connect section with a receiving part including first distributer components receiving incoming super-channels, each represented by a group of sub-channels, and at least two drop outputs, each for dropping at least one drop super-channel, and comprising a transmitting part including further combiner components receiving express signals from the receiving part and emitting outgoing WDM signals and having at least two add-inputs for adding at least an add super-channels, the cross-connect further

comprising

a division-multiplex section, having inputs that are connected to the at least two drop outputs of the receiving part, with a cyclic filter, each filter input receiving a drop super-channel and outputting sub-channels from said super-channels cyclically shifted at filter outputs such that sub-channels from super-channels having a same frequency band and outputted at a same output have different wavelengths;

a transponder arrangement with receivers, each receiving at least a sub-channel from one of said filter outputs of the cyclic filter, whereat each receiver is tunable for extracting one sub-channel, and with transmitters, each outputting a sub-channel fed to an optical combiner outputting said add super-channels fed to at least two add inputs of said transmitting part of the cross-connect section, whereat each transmitter is tuneable for generating a sub-channel of an add super-channel.

2. A photonic cross-connector according to claim 1 , wherein the receiving part of the cross-connect section comprises as distributer component wavelength selecting switches and the transmitting part of the cross-connect section comprises as combiner components further wavelength selecting switches.

3. A photonic cross-connector according to claim 2 , comprising

at least two wavelength selecting switches of the receiving part with drop outputs, each arranged for outputting at least one drop super-channel and

at least two of the further wavelength selecting switches of the transmitting part with add inputs, each arranged for receiving at least one add super-channel.

4. A photonic cross-connector according to claim 1 , wherein outputs of the receivers and inputs of transmitters are connected via a digital signal converter with client ports.

5. A photonic cross-connector according to claim 1 , wherein one add super-channel emitted from the transmitters is fed via a star coupler as optical combiner to add-inputs of the further wavelength selecting switches.

6. A photonic cross-connector according to claim 1 , wherein the at least one add super-channel emitted from the transmitters is fed via a further cyclic filter with inverse function as optical combiner to at least two add-inputs of the further wavelength selecting switches.

7. A photonic cross-connector according to claim 6 , wherein

the outputs of the cyclic filter are connected via splitters to receiver inputs of an extended transponder arrangements for selecting simultaneously sub-channels of at least two drop super-channels; and

the transmitter outputs of the extended transponder arrangements are connected via combiners to input ports a further cyclic filter with inverse function as combination element for outputting at least two add super-channels.

8. A photonic cross-connector according to claim 7 , wherein

the cyclic filter in the drop path comprises M inputs and N outputs;

the further cyclic filter in the add path comprises N input ports and M output ports;

an enlarged splitter-combiner arrangement comprises N splitters, which inputs are connected to the cyclic filter outputs and which outputs are connected to receiver inputs, and further comprises N combiners, which inputs are connected to transmitter outputs and which output ports are connected to add inputs;

an enlarged transponder arrangement comprises a number of transponders corresponding to the maximum number of simultaneously able to be dropped sub-channels;

whereat M is the number of simultaneously able to be dropped/able to be added super-channels, and N is the number of sub-channels of a super-channel.

9. A photonic cross-connector according to claim 1 , wherein

an enlarged splitter-combiner arrangement comprises a plurality of at least M splitters, which inputs are connected to drop outputs and which outputs are connected to inputs of M cyclic filters, and wherein N outputs of the cyclic filters are connected to inputs of the tunable receivers of transponders;

wherein outputs of the tunable transmitters of the transponders are connected to ‘input’ ports of M further inverse working cyclic filters, which output ports are connected to inputs of at least M combiners, and wherein outputs of the combiners are connected to add-inputs of the transmitting WSSs;

whereat M is the number of add/drop-ably super channels; N is the number of sub-channels/super-channel.

10. A photonic cross-connector according to claim 1 , wherein each cyclic filters has M=4 inputs and N=4 outputs and/or each splitter has 4 outputs and each combiner has 4 inputs.

11. An optical transmission system comprising at least one photonic cross-connector according to claim 1 .