An example system includes a first network device having first circuitry. The first network device is configured to perform operations including receiving data to be transmitted to a second network device over an optical communications network, and transmitting first information and second information to the second device. The first information is indicative of the data, and is transmitted using a first communications link of the optical communications network and using a first subset of optical subcarriers. The second information is indicative of the data, and is transmitted using a second communications link of the optical communications network and using a second subset of optical subcarriers. The first subset of optical subcarriers is different from the second subset of optical subcarriers.

An intelligence-defined optical tunnel network system includes multiple Optical Switch Interconnect Sub-systems (OSIS), in which a first OSIS is configured to transmit a first lateral transmission optical signal via a first line to a second OSIS, and transmit a second lateral transmission optical signal via a second line to the second OSIS. The second OSIS includes a failover sub-module and a micro-control unit. The failover sub-module is configured to output one of the first and the second lateral transmission optical signal based on a selective signal. The micro-control unit is configured to output the selective signal to the failover sub-module to control the failover sub-module output the second lateral transmission optical signal if a signal intensity of the first lateral transmission optical signal is lower than a threshold value.

Systems and methods are provided for enabling degree-to-degree protection within an optical node, such as an Optical Add/Drop Multiplexer (OADM) node or Reconfigurable Optical Add/Drop Multiplexer (ROADM) node. According to an exemplary protection method, a step is executed for configuring two degree-to-degree fiber links between a first degree of the OADM node and a second degree of the OADM node. The method also includes designating a first degree-to-degree fiber link of the two degree-to-degree fiber links as a primary fiber link. Also, the method includes designating a second degree-to-degree fiber link of the two degree-to-degree fiber links as a protection fiber link configured for providing protection if a fiber break is detected on the primary fiber link.

An apparatus includes a tail-end optical switch configured to be coupled to a broadcast star network that couples the tail-end optical switch to a head-end optical switch by a primary bidirectional optical path and a second bidirectional optical path. The tail-end optical switch having a first optical switch and a second optical switch configured to provide active switching.

An Optical Protection Switch (OPS) includes a splitter connected to a transmitted input and a path continuity monitor transmitter and configured to output the transmitted input with a path continuity monitor signal to two paths; a switch connected to a receiver output and configured to provide one of two receiver inputs each from one of the two paths based on a setting of the switch; and one or more path continuity monitor receivers connected to the two receiver inputs and configured to detect a corresponding path continuity monitor signal from a complementary OPS, wherein the setting of the switch is set based upon the received path continuity monitor signals. The one or more path continuity monitor receivers each have a narrow optical bandwidth relative to an overall optical bandwidth of the transmitted input.

A system for protecting optical paths may exchange first optical signal traffic between source and destination locations over a first fiber cable comprising optical signals having wavelengths within a first predefined optical wavelength band, exchange second optical signal traffic between the source and destination locations over a second fiber cable comprising optical signals having wavelengths within the first optical wavelength band, convert the first optical signal traffic to third optical signal traffic comprising optical signals having wavelengths within a second predefined optical wavelength band, detect an interruption in the exchange of the first optical signal traffic and, in response to detecting the interruption, cause the third optical signal traffic to be carried from the first location to the second location over the second fiber cable in the second optical wavelength band while the second optical signal traffic is exchanged over the second fiber cable in the first optical wavelength band.

An Optical Protection Switch (OPS) includes a splitter connected to a transmitted input and a path continuity monitor transmitter and configured to output the transmitted input with a path continuity monitor signal to two paths; a switch connected to a receiver output and configured to provide one of two receiver inputs each from one of the two paths based on a setting of the switch; and one or more path continuity monitor receivers connected to the two receiver inputs and configured to detect a corresponding path continuity monitor signal from a complementary OPS, wherein the setting of the switch is set based upon the received path continuity monitor signals. The one or more path continuity monitor receivers each have a narrow optical bandwidth relative to an overall optical bandwidth of the transmitted input.

An optical transmission line switching apparatus relays main signal light input via a main transmission line including at least two transmission lines. When no failure occurs in the main transmission line, a control unit controls an optical switch and an optical switch so that the optical switch and the optical switch are connected to different transmission lines. When a failure occurs in one of the at least two transmission lines, the control unit controls the optical switch and the optical switch so that the optical switch and the optical switch are connected to a transmission line that does not have the failure. When recovery from the failure is completed, the control unit controls the optical switch and the optical switch so that the optical switch and the optical switch are connected to different transmission lines.

An optical transmission line switching apparatus relays main signal light input via a main transmission line including at least two transmission lines. When no failure occurs in the main transmission line, a control unit controls an optical switch and an optical switch so that the optical switch and the optical switch are connected to different transmission lines. When a failure occurs in one of the at least two transmission lines, the control unit controls the optical switch and the optical switch so that the optical switch and the optical switch are connected to a transmission line that does not have the failure. When recovery from the failure is completed, the control unit controls the optical switch and the optical switch so that the optical switch and the optical switch are connected to different transmission lines.

Systems and methods are disclosed, including an optical switching system comprising an upstream optical signal detector between a first node and a second node configured to detect optical signals from the second node and to switch data traffic from a working path to a protecting path when optical signals from the second node are indicative of a failure in the working path; wherein the first node is configured to transmit data traffic in first optical signals with wavelengths in channels in a first band and receive the data traffic in second optical signals with wavelengths in channels in a second band from the second node; and one or more optical filter, between the second node and the upstream optical signal detector, configured to block signals with wavelengths in the first band that are reflected because of a break in the path between the optical filter and the second node.