DIRECTIONLESS OPTICAL ARCHITECTURE AND HIGHLY AVAILABLE NETWORK AND PHOTONIC RESILIENCE METHODS

• US 20090232492A1
• Filed: 03/11/2008
• Published: 09/17/2009
• Est. Priority Date: 03/11/2008
• Status: Active Grant

• Current Assignee: Ciena Corporation
• Original Assignee: Ciena Corporation
• Inventors: BLAIR, LOUDON, Frankel, Michael Y.
• Granted Patent: US 8,849,115 B2
• Time in Patent Office: Days
• US Class Current: 398/5
• CPC Class Codes: H04J 14/0206 Express channels arrangements
• CPC Class Codes: H04J 14/0209 Multi-stage arrangements, e.g. by cascading multiplexers or demultiplexers
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/02122 Colourless, directionless or contentionless [CDC] arrangements
• 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 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0246 using one wavelength per ONU
• CPC Class Codes: H04J 14/025 using one wavelength per ONU, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0284 WDM mesh architectures
• CPC Class Codes: H04J 14/029 Dedicated protection at the optical multiplex section (1+1)
• CPC Class Codes: H04J 14/0291 Shared protection at the optical multiplex section (1:1, n:m)
• CPC Class Codes: H04J 14/0294 Dedicated protection at the optical channel (1+1)
• CPC Class Codes: H04J 14/0295 Shared protection at the optical channel (1:1, n:m)
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0047 Broadcast; Multicast
• CPC Class Codes: H04Q 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability

Abstract

The present invention provides a directionless optical architecture for reconfigurable optical add/drop multiplexers (ROADMs) and wavelength selective switches (WSSs). The directionless architecture utilizes a directionless wavelength switch coupled between client devices and ROADMs/WSSs to eliminate the need to hard-wire client devices to a wavelength division multiplexed (WDM) network. Accordingly, client device connections can be automatically routed without manual intervention to provide a highly resilient network design which can recover route diversity during failure scenarios. Additionally, the present invention minimizes deployments of costly optical transceivers while providing superior resiliency. Further, the present invention couples the directionless optical architecture and associated optical protection mechanisms with existing mesh restoration schemes to provide additional resiliency.

Claims

1. A directionless optical system, comprising:

a client device;

a reconfigurable optical node comprising one or more degrees; and

a switch connected to each of the one or more degrees;

wherein the client device connects to the switch, and wherein the switch is configured to route signals between the client device and the one or more degrees.

2. The directionless optical system of claim 1, further comprising:

a splitter comprising an input port connected to a transmitter on the client device and dual output ports connected to the switch, wherein the splitter is configured to receive an input from the transmitter on the input port and provide duplicate signals of the input from the transmitter on the dual output ports; and

a tail-end switch comprising dual input ports connected to the switch and an output port connected to a receiver on the client device, wherein the tail-end switch is configured to receive duplicate input signals from the switch on the dual input ports and provide one of the duplicate input signals to the receiver.

3. The directionless optical system of claim 2, wherein the switch comprises a first switch module and a second switch module for redundancy, and wherein each of the dual output ports and dual input ports connect separately to the first switch module and the second switch module.

4. The directionless optical system of claim 3, wherein the one or more degrees comprises two or more degrees;

wherein the first switch module and the second switch module are configured to connect the duplicate signals on the dual output ports to separate degrees of the two or more degrees; and

wherein the first switch module and the second switch module are configured to connect the duplicate input signals on the dual input ports to separate degrees of the two or more degrees.

5. The directionless optical system of claim 4, wherein the two or more degrees comprises an additional degree not utilized by the dual output ports and the dual input ports;

and

wherein, responsive to a failure on one of the separate degrees, the first switch module and the second switch module are configured to redirect one of the dual output ports and one of the dual input from the one of the separate degrees to the additional degree to provide route diversity.

6. The directionless optical system of claim 1, further comprising:

a first transceiver and a second transceiver on the client device, wherein the first transceiver and the second transceiver are connected to the switch;

wherein the one or more degrees comprises two or more degrees; and

wherein the switch is configured to connect the first transceiver and the second transceiver to separate degrees of the two or more degrees.

7. The directionless optical system of claim 6, wherein the switch comprises a first switch module and a second switch module for redundancy, and wherein the first transceiver is connect to the first switch module and the second switch module is connected to the second switch module.

8. The directionless optical system of claim 7, wherein the two or more degrees comprises an additional degree not utilized by the first transceiver and the second transceiver;

and

wherein, responsive to a failure on one of the separate degrees, the first switch module and the second switch module are configured to redirect one of the first transceiver and the second transceiver from the one of the separate degrees to the additional degree to provide route diversity.

9. The directionless optical system of claim 8, wherein the client device comprises a router, and wherein the first transceiver and the second transceiver utilize layer three protection mechanisms.

10. The directionless optical system of claim 1, further comprising:

a regenerator/wavelength converter connected to the switch;

wherein the switch is configured to connect a signal from the one or more degrees to the regenerator/wavelength converter.

11. The directionless optical system of claim 1, wherein the one or more degrees comprises two or more degrees, and wherein the reconfigurable optical node comprises:

a first wavelength selective switch connected to a first set of one or more demultiplexers and to a first set of one or more multiplexers; and

a second wavelength selective switch connected to a second set of one or more demultiplexers and to a second set of one or more multiplexers;

wherein each of the first set of one or more demultiplexers, the first set of one or more multiplexers, the second set of one or more demultiplexers, and the second set of one or more multiplexers comprises a connection to the switch.

12. The directionless optical system of claim 11, wherein the switch comprises two or more optical switches, and wherein the first set of one or more demultiplexers, the first set of one or more multiplexers, the second set of one or more demultiplexers, and the second set of one or more multiplexers are each wavelength independent.

13. The directionless optical system of claim 2, further comprising:

a wavelength division multiplex platform comprising a transponder, the splitter, and the tail-end switch, wherein the transponder connects to the client device;

wherein the client device comprises mesh restoration with a hold-off timer configured to allow the splitter and the tail-end switch to restore service prior to initiated mesh restoration.

14. The directionless optical system of claim 1, wherein the reconfigurable optical node comprises:

a wavelength selective switch for each of the one or more degrees; and

a multi-channel fixed filter comprising one of a band-wide and cyclic Arrayed Waveguide connected to the wavelength selective switch and the switch.

15. A highly available directionless optical method, comprising:

providing a first path and a second path through a network between a first device and a second device, wherein the first device and the second device are each dynamically connected to the first path and the second path;

upon a failure on the first path, restoring service between the first device and the second device on the second path; and

reconfiguring the first path to a third path by dynamically changing a connection from the first path on each of the first device and the second device to the third path.

16. The highly available directionless optical method of claim 15, wherein each of the first path and the second path comprises an optical network;

wherein dynamically connected comprises a directionless optical switch between each of the first path and the second path and each of the first device and the second device.

17. The highly available directionless optical method of claim 16, further comprising performing mesh restoration at each of the first device and the second device following a hold-off time period, wherein the hold-off time period is configured to enable service restoration optically between the first device and the second device.

18. A highly available directionless optical network, comprising:

a first device comprising an optical connection to a first optical switch;

a first optical platform connected to the first optical switch, wherein the first optical platform comprises multiple degrees;

a second device comprising an optical connection to a second optical switch;

a second optical platform connected to the second optical switch, wherein the second optical platform comprises multiple degrees; and

a plurality of interconnected reconfigurable optical nodes between the first optical platform and the second optical platform;

wherein the first optical switch and the second optical switch connect the first optical platform to the second optical platform through a first path and a second path;

wherein the first path utilizes a first degree of the multiple degrees on the first optical platform and a first degree of the multiple degrees on the second optical platform;

wherein the second path utilizes a second degree of the multiple degrees on the first optical platform and a second degree of the multiple degrees on the second optical platform; and

wherein the first optical switch is configured to switch connections from one of the first path and the second path to a third degree of the multiple degrees on the first optical platform and a third degree of the multiple degrees on the second optical platform.

19. The highly available directionless optical network of claim 18, wherein the plurality of interconnected reconfigurable optical nodes are configured in a cascaded protection ring configuration between the first optical platform and the second optical platform;

and

wherein the first optical platform and the second optical platform are configured to provide optical 1+1 protection.

20. The highly available directionless optical network of claim 19, wherein the first device and the second device comprise mesh restoration with a hold-off timer operable to delay mesh restoration for a time period allowing the optical 1+1 protection to reestablish service.

21. The highly available directionless optical network of claim 18, further comprising one or more regenerators at one or more of the plurality of interconnected reconfigurable optical nodes;

wherein each of the one or more of the plurality of interconnected reconfigurable optical nodes comprise an optical switch connected between the one or more regenerators and the one or more of the plurality of interconnected reconfigurable optical nodes.

22. A directionless reconfigurable optical add/drop node, comprising:

a wavelength selective switch connected to a multi-channel fixed filter, wherein the multi-channel fixed filter comprises one of a band-wide and cyclic Arrayed Waveguide;

an optical switch connected to the multi-channel fixed filter; and

a client device connected to the optical switch;

wherein the wavelength selective is configured to provide single channel selectivity across a plurality of wavelengths;

wherein the multi-channel fixed filter receive one of the plurality of wavelengths within a multi-channel range of the multi-channel fixed filter; and

wherein the optical switch routes the one of the plurality of wavelengths to the client device.