Directionless optical architecture and highly available network and photonic resilience methods

Abstract

A directionless optical architecture is described 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.

What is claimed is: 
     
       1. A directionless reconfigurable optical add/drop multiplexer (ROADM) node for high availability between switch or router ports, the node communicatively coupled to an optical network via at least two links, the node comprising:
 a directionless switch, including one or more switches, connected to each of the at least two links and configured to selectively route a lightpath from a client device to any of the at least two links for protection thereof; 
 wherein the directionless switch is located between the at least two links and the client device, and wherein the client device is not hard-wired to any of the at least two links; and 
 wherein the directionless switch is configured with a single input/output for the client device and the protection is 1:1 optical protection. 
 
     
     
       2. The node of  claim 1 , wherein the client device has one protection transceiver for up to N working transceivers, and wherein each of the N working transceivers and the one protection transceiver are connected to the directionless switch. 
     
     
       3. The node of  claim 1 , wherein the directionless switch includes a receive side and a transmit side, and wherein the at least two links each comprise a wavelength selective switch connected to the receive side and a multiplexer connected to the transmit side. 
     
     
       4. The node of  claim 1 , wherein the directionless switch is a combination of switches added based on bandwidth at the node. 
     
     
       5. A directionless switch method for high availability between switch or router ports, the method comprising:
 receiving at least two lightpaths from a client device; and 
 selectively routing the at least two lightpaths to separate degrees of a reconfigurable optical add/drop multiplexer (ROADM) node, wherein each of the separate degrees provides a link to an optical network; 
 wherein the client device is not hard-wired to any of the separate degrees; and 
 wherein the receiving is from one of (i) a single input/output for the client device and the protection is 1:1 optical protection and (ii) dual inputs/outputs for the client device and the protection is 1+1 or 1:1. 
 
     
     
       6. The method of  claim 5 , wherein the receiving is from the dual inputs/outputs for the client device with each of the dual inputs/outputs configured for a maximum fill rate of around 50%, and
 wherein responsive to a failure affecting one of the dual inputs/outputs, the other of the dual inputs/outputs is set to 100% using a reroute, and the method further comprises 
 switching the one of the dual inputs/outputs for restoration, and responsive to the restoration, the dual inputs/outputs are configured for the maximum fill rate of around 50%. 
 
     
     
       7. The method of  claim 5 , wherein the client device has one protection transceiver for up to N working transceivers, and wherein each of the N working transceivers and the one protection transceiver are connected to a directionless switch, including one or more switches. 
     
     
       8. A directionless reconfigurable optical add/drop multiplexer (ROADM) node for high availability between switch or router ports, the node communicatively coupled to an optical network via at least two links, the node comprising:
 a directionless switch, including one or more switches, connected to each of the at least two links and configured to selectively route a lightpath from a client device to any of the at least two links for protection thereof; 
 wherein the directionless switch is located between the at least two links and the client device, and wherein the client device is not hard-wired to any of the at least two links; and 
 wherein the directionless switch is configured with dual inputs/outputs for the client device and the protection is 1+1 or 1:1. 
 
     
     
       9. The node of  claim 8 , wherein each of the dual inputs/outputs is configured for a maximum fill rate of around 50% of traffic, and
 wherein, responsive to a failure affecting one of the dual inputs/outputs, the other of the dual inputs/outputs is set to 100% of the traffic using a reroute, and the directionless switch is configured to switch the one of the dual inputs/outputs for restoration, and responsive to the restoration, the dual inputs/outputs are configured for the maximum fill rate of around 50% of the traffic. 
 
     
     
       10. The node of  claim 8 , wherein the client device has one protection transceiver for up to N working transceivers, and wherein each of the N working transceivers and the one protection transceiver are connected to the directionless switch. 
     
     
       11. The node of  claim 8 , wherein the directionless switch includes a receive side and a transmit side, and wherein the at least two links each comprise a wavelength selective switch connected to the receive side and a multiplexer connected to the transmit side. 
     
     
       12. The node of  claim 8 , further comprising:
 a second directionless switch connected to each of the at least two links, wherein the second directionless switch provides redundancy to the directionless switch, 
 wherein the client device has dual inputs/outputs each provided to one of the directionless switch and the second directionless switch, and 
 wherein the directionless switch and the second directionless switch are configured to selectively route lightpaths from the dual inputs/outputs to any of the at least two links for protection thereof. 
 
     
     
       13. The node of  claim 8 , wherein the directionless switch is a combination of switches added based on bandwidth at the node.