High-density submarine ROADM unit with remote WSS redundancy

A submarine/undersea communications system configuration for communicating in a submarine/undersea transmission network comprising:

• a submarine/undersea branching unit (BU);
• a submarine/undersea reconfigurable optical add/drop multiplexer (ROADM), said ROADM including a plurality of ROADM sub-units (RSUs), each individual one of said plurality of RSU having a plurality of wavelength selective switches (WSS) in optical communication with said BU;
• the submarine/undersea communication system configuration CHARACTERIZED BY:
• remote redundancy of the plurality of RSU WSS;
• wherein the remote redundancy of the plurality of RSU WSS is achieved by providing and configuring a redundant WSS for each individual one of the plurality of WSS included in the submarine/undersea RSU, each redundant WSS being located in a non-submarine/undersea location;
• wherein each redundant WSS is configured to provide dummy signaling during normal operation to the individual one WSS in the submarine/undersea RSU for which it is redundant;
• wherein each redundant WSS is configured to disable providing dummy signaling to the individual one WSS in the submarine/undersea RSU for which it is redundant, during a failure of the individual one WSS;
• wherein each redundant WSS is configured to add/drop channels instead of the individual one WSS in the submarine/undersea RSU for which it is redundant during a failure of the individual one WSS.