A method of interrogating a WDM optical communication system is provided to obtain one or more performance parameters. In accordance with the method, an optical probe wavelength is generated and possibly modulated in a prescribed manner. The probe signal is transmitted along a selected optical path through the WDM optical communication system for a duration of time that is less than a response time of network elements that impact signal quality along the selected optical path.

An undersea fiber optic cable routing architecture including a branching unit coupled to three trunk cables capable of switching individual fibers in each fiber pair within a cable to either of the other two cables. The branching unit comprises a plurality of optical switches and a controller for receiving remote command signals and configuring the optical switches in accordance with the remote command signals.

Access nodes of a large-scale network are arranged into a number of groups. The groups are arranged into a number of bands. Each distributor of a pool of distributors interconnects each access node of a selected group to at least one channel from each group of a selected band. A discipline of allocating the selected group and the selected band to a distributor ensures that each access node has: a number, approximately equal to half the number of groups, of parallel single-hop paths to each other access node of a same group; a number, approximately equal to half the number of bands, of parallel single-hop paths to each access node of a different group within a same band; and one single-hop path to each other access node of a different access band. To eliminate the need for cross connectors, geographically-spread distributors are arranged into geographically-spread constellations of collocated distributors.

This application provides example methods for establishing a service path in a transport network and example systems. One example method includes, obtaining, by an automatically switched optical network (ASON) first node, a service path computation result path. The service path includes the ASON first node, an ASON last node, and at least one first edge network node. The method also includes sending, by the ASON first node, a path establishment request message to a downstream node. The path establishment request message carries cross-connection configuration information of the ASON last node and the at least one first edge network node. The method further includes receiving, by the ASON first node, a path establishment response message of the downstream node. The path establishment response message indicates that cross-connection configuration for the ASON last node and the at least one first edge network node is complete.

An undersea fiber optic cable routing architecture including a branching unit coupled to three trunk cables capable of switching individual fibers in each fiber pair within a cable to either of the other two cables. The branching unit comprises a plurality of optical switches and a controller for receiving remote command signals and configuring the optical switches in accordance with the remote command signals.

Embodiments of the present application disclose an optical fiber connection detection method and a related device. A first network device obtains first label information, which indicates a target optical output interface, and the target optical output interface is one of at least one optical output interface of the first network device; the first network device generates an optical signal, where a wavelength of the optical signal is within a wavelength range corresponding to the target optical output interface; the first network device modulates the first label information onto the optical signal, to generate a modulated optical signal; and the first network device sends the modulated optical signal from the target optical output interface to a target optical input interface of a second network device, to detect an optical fiber connection relationship between the target optical output interface and the target optical input interface.

A system and method for performing an in-service optical time domain reflectometry test, an in-service insertion loss test, and an in-service optical frequency domain reflectometry test using a same wavelength as the network communications for point-to-point or point-to-multipoint optical fiber networks while maintaining continuity of network communications are disclosed.

An optical transmission apparatus (1_1) according to the present invention includes a first transmission unit (11_1) that transmits a first optical transmission signal (21_1), a second transmission unit (11_2) that transmits a second optical transmission signal (21_2), and an output unit that outputs, when the first optical transmission signal (21_1) and the second optical transmission signal (21_2) share a set of information, both the first optical transmission signal (21_1) and the second optical transmission signal (21_2) to a first path (26_1) and outputs, when the first optical transmission signal (21_1) and the second optical transmission signal (21_2) do not share the set of information, one of the first optical transmission signal (21_1) and the second optical transmission signal (21_2) to a second path (26_2).

Rectangular equidistant projection is applied to coordinates for path fragments of a plurality of fiber optic routes. A bounding box is generated for each path fragment. For each cell of a grid of cells where its bounding box overlaps with a bounding box created by the cell, each path fragment is placed into the cell of the global grid. For any cell with more than one path fragment, each path fragment inside the cell is compared to every other path fragment in that cell. For any path fragment with overlapping bounding boxes, the length of the overlap is saved. A table of cumulative overlap distances between path fragments is generated to identify overlapping segments and cumulative lengths of the overlap distances.

A system for interconnecting a plurality of computing nodes includes a plurality of optical circuit switches and a plurality of electrical circuit switches. A first network stage comprises a first plurality of circuit switches selected from among the plurality of optical circuit switches and the plurality of electrical circuit switches. Each computing node among the plurality of computing nodes is optically coupled to at least one of the first plurality of circuit switches. A second network stage comprises a second plurality of circuit switches selected from among the plurality of optical circuit switches and the plurality of electrical circuit switches. Each circuit switch among the first plurality of circuit switches is optically coupled to each circuit switch among the second plurality of optical circuit switches.