Directionless reconfigurable optical add-drop multiplexer systems and methods

• US 8,625,994 B2
• Filed: 04/15/2008
• Issued: 01/07/2014
• Est. Priority Date: 03/11/2008
• Status: Active Grant

• Current Assignee: Ciena Corporation
• Original Assignee: Ciena Corporation
• Inventors: Archambault, Jean-Luc, Frankel, Michael Y., Blair, Loudon, Thiagarajan, Sashisekaran
• Primary Examiner(s): Vanderpuye, Ken
• Assistant Examiner(s): Wolf, Darren E
• Application Number:
  US12/103,204
• Publication Number:
  US 20090232497A1
• Time in Patent Office: 2,093 Days
• Field of Search: None
• US Class Current: 398/83
• CPC Class Codes: H04J 14/0206 Express channels arrangements
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0213 Groups of channels or wave bands arrangements
• CPC Class Codes: H04J 14/0217 Multi-degree architectures, e.g. having a connection degree greater than two
• CPC Class Codes: H04J 14/0284 WDM mesh architectures
• CPC Class Codes: H04J 14/0297 Optical equipment protection
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0009 using wavelength filters
• CPC Class Codes: H04Q 2011/0015 using splitting combining
• CPC Class Codes: H04Q 2011/0016 using wavelength multiplexing or demultiplexing
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0052 Interconnection of switches

Abstract

The present invention provides a directionless reconfigurable optical add/drop multiplexer (ROADM) system. The present invention provides a scalable all-optical switching element that includes a combination of 1×N wavelength selective switches (WSS), 1×N splitters/combiners, optical amplifiers, and tunable filters to provide a fully non-blocking solution which can be deployed in a scalable manner. The 1×N splitters are configured to split multiples copies of a plurality of drop wavelengths which can be amplified and sent to a tunable filter which selects out a particular wavelength for drop. The 1×N combiners are configured to combine multiple add wavelengths for egress transmission.

Claims

1. A directionless reconfigurable optical add-drop multiplexer, comprising:

an ingress device receiving a plurality of wavelengths from an input connection, wherein the ingress device is configured to provide one or more of the plurality of wavelengths on a first output and a second output;

a splitter connected to the first output of the ingress device, wherein the splitter comprises a plurality of stages, wherein the splitter is configured to split the one or more of the plurality of wavelengths from the first output into multiple copies of the one or more of the plurality of wavelengths, and wherein the multiple copies are provided on a plurality of outputs;

a switch connected to the plurality of outputs from the splitter and a plurality of tunable filters, wherein the switch is configured to switch each of the multiple copies to one or more of the plurality of tunable filters, wherein each of the plurality of tunable filters is configured to tune to a wavelength passband to provide a single output of the plurality of wavelengths;

an egress device receiving the second output, wherein the egress device and the ingress device form a plurality of degrees comprising more than two degrees;

at least one transceiver for local add/drop communicatively coupled to the switch, wherein the at least one transceiver comprises a transmitter directly communicatively coupled to the switch and a receiver communicatively coupled to the switch through a tunable filter of the plurality of tunable filters, wherein the transmitter is configured to selectively transmit to any of the plurality of degrees at the egress device based on the switch and the receiver is configured to receive any of the plurality of wavelengths from any of the plurality of degrees at the ingress device based on the switch and the tunable filter.

2. The directionless reconfigurable optical add-drop multiplexer of claim 1, further comprising:

a combiner connected to the egress device and to the switch, wherein the switch is configured to switch a plurality of inputs to the combiner for transmission from the egress device.

3. The directionless reconfigurable optical add-drop multiplexer of claim 2, wherein the switch comprises a first switch fabric and a second switch fabric;

wherein the first switch fabric provides connections between the plurality of outputs from the splitter and a plurality of tunable filters; and

wherein the second switch fabric provides connections between the combiner and the plurality of inputs.

4. The directionless reconfigurable optical add-drop multiplexer of claim 1, further comprising:

an amplifier connected between the first output of the ingress device and the splitter, wherein the amplifier is configured to amplify the one or more of the plurality of wavelengths on the first output prior to the splitter.

5. The directionless reconfigurable optical add-drop multiplexer of claim 1, wherein the ingress device comprises a wavelength selective switch, wherein the switch comprises a photonic cross-connect, and wherein the egress device comprises a coupler.

6. The directionless reconfigurable optical add-drop multiplexer of claim 1, wherein the ingress device comprises a coupler, wherein the switch comprises a photonic cross-connect, and wherein the egress device comprises a wavelength selective switch.

7. The directionless reconfigurable optical add-drop multiplexer of claim 1, wherein the ingress device comprises a wavelength selective switch, wherein the switch comprises a photonic cross-connect, and wherein the egress device comprises a wavelength selective switch.

21. The directionless reconfigurable optical add-drop multiplexer of claim 1, wherein the plurality of stages of the splitter comprise a first splitter stage, a second splitter stage, and an intervening switch.

8. An N degree directionless optical node, comprising:

an N, N>

2, degree reconfigurable optical-add drop multiplexer configured to receive inputs from each of N ingress degrees and to transmit outputs to each of N egress degrees;

N 1×

B splitters each connected to one of the N ingress degrees through the N degree reconfigurable optical-add drop multiplexer, wherein B is an integer;

a switch comprising S×

T ports connected to the N 1×

B splitters and to one or more tunable filters and connected to N 1×

B combiners and to one or more input signals, wherein each of the one or more tunable filters is configured to tune to a wavelength passband to provide a single wavelength output, and wherein S and T comprise integers greater than one; and

at least one transceiver for local add/drop communicatively coupled to the switch, wherein the at least one transceiver comprises a transmitter directly communicatively coupled to the switch and a receiver communicatively coupled to the switch through a tunable filter of the one or more tunable filters, wherein the transmitter is configured to selectively transmit to any of the N egress degrees based on the switch and the receiver is configured to receive any of the plurality of wavelengths from any of the N ingress degrees based on the switch and the tunable filter;

wherein the N 1×

B combiners each connect to one of the N egress degrees through the N degree reconfigurable optical-add drop multiplexer.

9. The N degree directionless optical node of claim 8, wherein the each of the N 1×

B splitters are configured to broadcast received inputs to B output ports;

wherein each of the B output ports connect to the switch and the switch is configured to route each of the B output ports to one of the one or more tunable filters; and

wherein the one of the one or more tunable filters tunes to the single wavelength output of the broadcast received inputs.

10. The N degree directionless optical node of claim 8, further comprising:

N 1×

A splitters;

a first plurality of optical amplifiers;

N 1×

A combiners;

a second plurality of optical amplifiers;

wherein each of the N 1×

A splitters is located between the N degree reconfigurable optical-add drop multiplexer and the N 1×

B splitters;

wherein each of the first plurality of optical amplifiers is located between the N 1×

A splitters and the N 1×

B splitters;

wherein each of the N 1×

A combiners is located between N degree reconfigurable optical-add drop multiplexer and the N 1×

B combiners;

wherein each of the second plurality of optical amplifiers is located between the N 1×

A combiners and the N 1×

B combiners; and

wherein A is based on the number of channels capable of being dropped and added per degree.

11. The N degree directionless optical node of claim 10, wherein the N 1×

A splitters and the N 1×

B splitters are configured to broadcast received inputs to A*B output ports;

wherein each of the A*B output ports connect to the switch and the switch is configured to route each of the A*B output ports to one of the one or more tunable filters; and

wherein the one of the one or more tunable filters tunes to the single wavelength output of the broadcast received inputs.

12. The N degree directionless optical node of claim 10, wherein the switch comprises a first switch;

and

wherein the N degree directionless optical node further comprises a second switch with U×

V ports located between the N 1×

A splitters and the first plurality of optical amplifiers and between the N 1×

A combiners and the second plurality of optical amplifiers.

13. The N degree directionless optical node of claim 8, wherein the switch comprises a first switch fabric and a second switch fabric;

wherein the first switch fabric provides connections between the N 1×

B splitters and to one or more tunable filters; and

wherein the second switch fabric provides connections between the N 1×

B combiners and the one or more input signals.

14. The N degree directionless optical node of claim 8, further comprising:

one or more of a plurality of amplifiers, a plurality of transceivers, a plurality of combiners, a plurality of regenerators, and a plurality of wavelength converters connected to the switch.

15. The N degree directionless optical node of claim 8, wherein the one or more tunable filters comprise any of thin-film filters, a planar lightwave circuit, a micro electro-mechanical system, and a coherent optical receiver electric domain filter.

16. The N degree directionless optical node of claim 10, wherein the N degree directionless optical node is fully non-blocking responsive to a selection of the values of N, A, B, S, and T responsive to a number of drop channels per degree.

17. A directionless method for adding and dropping wavelengths with a reconfigurable optical-add drop multiplexer, comprising:

receiving a plurality of wavelengths at an ingress degree of the reconfigurable optical-add drop multiplexer, the reconfigurable optical-add drop multiplexer comprises three or more ingress degrees comprising the ingress degree;

routing one or more of the plurality of wavelengths to one or more egress degrees of the reconfigurable optical-add drop multiplexer, wherein the reconfigurable optical-add drop multiplexer comprise three or more egress degrees;

broadcasting dropped wavelengths to a switch via a plurality of distribution stages, wherein the dropped wavelengths comprise one or more of the plurality of wavelengths;

switching the broadcasted dropped wavelengths to one or more tunable filters;

filtering at each of the one or more tunable filters to provide one output of the broadcasted dropped wavelengths; and

receiving the one output at a receiver of a transceiver, the receiver communicatively coupled to the one or more tunable filters, wherein the receiver is configured to receive any of the plurality of wavelengths from any of the three or more ingress degrees based on a configuration of the switch thereby enabling the receiver to communicate with any of the egress degrees without a manual disconnect from one of the three or more ingress degrees.

18. The directionless method of claim 17, further comprising:

receiving an input wavelength at the switch from a transmitter of the transceiver;

switching the input wavelength to one or more combiners based on an egress degree for the input wavelength;

combining the input wavelength with additional input wavelengths; and

routing the combined input wavelength and the additional input wavelengths to one of the one or more egress degrees of the reconfigurable optical-add drop multiplexer, wherein the transmitter is configured to selectively transmit to any of the three or more ingress degrees based on a configuration of the switch.

19. The directionless method of claim 17, further comprising:

amplifying the dropped wavelengths either prior to broadcasting or while broadcasting.

20. The directionless method of claim 17, wherein the one or more tunable filters comprise any of thin-film filters, a planar lightwave circuit, a micro electro-mechanical system, and a coherent optical receiver electric domain filter.

22. The directionless method of claim 17, wherein the plurality of distribution stages comprise a first splitter stage, a second splitter stage, and an intervening switch.