An optical source switching apparatus including first optical sources, an optical cross-connect device, second optical sources, and a first coupler. The optical cross-connect device is connected to the first optical sources and the first coupler, and the first coupler is connected to the second optical source; both the first optical source and the second optical source are configured to output continuous optical energy, and the optical cross-connect device is configured to enable optical energy output by at least one of the first optical sources to enter the first coupler when at least one of the second optical sources fails; and the first coupler is configured to implement beam splitting of the optical energy output by the first optical source or the second optical source.

Embodiments of this application provide a service protection method, including: A first node determines that a fault occurs on a first working path; the first node generates a bandwidth activation message based on the fault, where the bandwidth activation message indicates a third node to adjust a bandwidth of a service from a protection bandwidth to a target bandwidth, the protection bandwidth represents a pre-occupied bandwidth of a first protection path before transmission of the service, and the target bandwidth represents an actual occupied bandwidth for transmission of the service; and the first node sends the bandwidth activation message on the first protection path.

The technology of this application relates to a fault detection method for an optical switching apparatus, a network device, and a system, to improve accuracy and efficiency of detecting whether the optical switching apparatus is faulty. The method includes sending a probe optical signal to a target path, where the probe optical signal is to be transmitted along the target path, and the target path includes at least one optical switching apparatus, receiving a plurality of reflected optical signals from the target path, where the plurality of reflected optical signals are formed after the probe optical signal is reflected by the target path, determining a target reflected optical signal in the plurality of reflected optical signals, where the target reflected optical signal is a reflected optical signal reflected by the optical switching apparatus, and determining, based on the target reflected optical signal, whether the optical switching apparatus is faulty.

[Problem] whether optical input interruption detected by an OXC device is due to an external failure from an upstream side or an internal failure of the OXC device in a transponder device connected to the OXC device using an optical transmission line, and this determination is implemented at low cost. [Solution] An optical transmission system (10A) is configured by connecting a plurality of OXC devices (14A) using optical fibers (16) between transponder devices (15A1) that relay optical signals transmitted to/from terminals (19a, 19b). The OXC device (14A) includes an OSC part (4d1) and a monitoring control part (4e1). The OSC part (4d1) outputs wavelength information on an optical signal in which optical input interruption has occurred and path information on a path of an optical fiber (16) in which the optical input interruption has occurred, at the time of detecting the optical input interruption from the optical fiber (16). In accordance with the wavelength information and the path information that have been output as above, the OXC device (14A) includes an AIS generation part (4j) that generates an AIS signal including both pieces of information on the wavelength and the path of the optical signal relating to the optical input interruption and alarm information relating to both the pieces of information.

Systems and methods for utilizing backup paths to restore service in a network are provided. A method, according to one implementation, includes obtaining a route list as defined by a user, the route list including a plurality of explicitly-configured backup routes for restoring service between a source node and a destination node in a network when a working route is unavailable. The method also includes receiving input designating one or more of the explicitly-configured backup routes as one or more last-resort routes. In response to determining that the working route is unavailable and that the plurality of explicitly-configured backup routes, excluding the one or more last-resort routes, are unavailable, the method includes automatically computing one or more implicitly-computed backup routes. For restoring service between the source node and destination node, the method also includes utilizing one of the one or more implicitly-computed backup routes before utilizing one of the one or more last-resort routes.

Described herein are techniques for yield enhancement in photonic communications platforms. A photonic communication platform may include a photonic substrate patterned with a plurality of photonic modules including at least first and second photonic modules, wherein the first and second photonic modules are copies of a common template photonic module. Yield enhancement may be accomplished using photonic redundancy and/or electronic redundancy. Photonic redundancy may involve redundant optical lanes provided in parallel to primary optical lanes. Electronic redundancy may involve use of additional electronic circuits or wires running in parallel to electronic circuits or wires. Defective circuits may be disabled to prevent negative impacts on other parts of the electronic system. This can be done by providing power-isolating switches that completely disable and isolate the defective circuits.

A communication network includes a first serving area, a second serving area, a network hub, one or more trunk optical cables, and a first bridging connection. The first serving area includes a first optical switch, a first optical node, and one or more first intra-serving-area (ISA) optical cables communicatively coupling the first optical node to the first optical switch. The second serving area includes a second optical switch, a second optical node, and one or more second ISA optical cables communicatively coupling the second optical node to the second optical switch. The one or more trunk optical cables communicatively couple the first and second optical nodes to the network hub, and the first bridging connection communicatively couples the one or more first ISA optical cables and the one or more second ISA optical cables.

A method to avoid sympathetic switches in path switching protection due to client protection switching includes monitoring a drop side Tandem Connection Monitoring (TCM) entity and a line side TCM entity for a connection, wherein the drop side TCM is provisioned between a drop port of the node and a second drop port of a corresponding node, and wherein the line side TCM entity is provisioned between a plurality of line ports of the node and a second plurality of line ports of the corresponding node; responsive to detecting defects in both the drop side TCM entity and the line side TCM entity on a working line, implementing path protection switching of the working line; and, responsive to detecting defects only in the drop side TCM entity, implementing path protection switching of the working line responsive to persistence of the defects.

An optical component includes a light emitter; an optical receiver; first and second electro-optical crystal layers configured to intersect with each other; and a control line configured to supply a signal for changing refractive indexes of the first and second electro-optical crystal layers, wherein the first and second electro-optical crystal layers are switched according to the signal between a first state where light from the light emitter is transmitted through the first electro-optical crystal layer and a second state where the light is reflected by the first and second electro-optical crystal layers and the reflected light is incident on the optical receiver.

A transmission system includes: a first transmission device that receives a first signal from the work path; a second transmission device, coupled to a protection path in a redundant configuration with respect to the work path, that receives a second signal from the protection path; and a first communication device coupled to the first and second transmission devices, wherein the first communication device, when detecting switching information from the first transmission device, notifies the first transmission device of first switching notification information and notifies the second transmission device of second switching notification information, the first transmission device stops relaying the first signal to the first communication device in response to the first switching notification information from the first communication device, and the second transmission device starts to relay the second signal to the first communication device in response to the second switching notification information from the first communication device.