A method and a device for realizing an optical channel data unit (ODU) shared protection ring (SPRing) are disclosed. The method includes: first, receive an ODUj, wherein the ODUj carries an ODUi; then, perform de-multiplexing processing to obtain the ODUi from the ODUj; next, multiplex the ODUi to an optical channel data unit k (ODUk); meanwhile, keep monitoring the ODUk; and when the monitoring result that is obtained through monitoring the ODUk indicates that a failure has occurred, perform a switching on the ODUi; wherein i, j, k are integers equal to or larger than 0, k is larger than j, j is larger than i, and i, j, k are used to indicate different rates of respective optical channel data unit (ODU) signals.

An optical link redundancy architecture includes an optical switch, an optical coupler, and an optical tap detector. The optical switch including a hub-side switch-port, a normal-mode switch-port, and a failover-mode switch-port. The optical coupler includes (i) a normal-mode coupler-port optically coupled to the normal-mode switch-port via a primary-path optical fiber, and (ii) a failover-mode coupler-port optically coupled to the failover-mode switch-port via a backup-path optical fiber. The optical tap detector (i) is optically coupled to the primary-path optical fiber, (ii) includes a monitor port communicatively coupled to the optical switch, and (iii) outputs a tap signal at the monitor port in response to an optical signal propagating in the primary-path optical fiber. The optical switch optically couples the hub-side switch-port to the failover-mode switch-port when the tap signal is less than a threshold value.

An optical fiber detection method includes: selecting an optical fiber path required to be detected and setting relevant parameters of an optical fiber detection device related to the optical fiber path (S10); sending a detection starting instruction to the optical fiber detection device for the optical fiber detection device to detect the optical fiber path according to the detection starting instruction (S20); receiving a result of the detection performed by the optical fiber detection device on the optical fiber path, and analyzing the result of the detection to acquire the working status of the optical fiber path (S30). A network element management system and an optical fiber detection device and platform are also described.

A transmission device for which a work path is established in a first degree and a protection path is established in a second degree includes: a switch equipped with a plurality of optical ports; an optical signal generator, optically connected to a first optical port, and configured to generate an optical signal that is transmitted through the work path; and a monitor light generator, optically connected to a second optical port, and configured to generate monitor light by using a wavelength tunable light source. The monitor light generator controls a wavelength of the monitor light to be substantially the same as a wavelength of the optical signal. The switch guides the optical signal that arrives at the first optical port toward the first degree and guides the monitor light that arrives at the second optical port toward the second degree.

A bidirectional optical fiber path includes a primary optical fiber path; a secondary optical fiber path coupled to the primary optical fiber path; an optical coupler coupled to both the primary optical fiber path and the secondary optical fiber path; an optical switch coupled to both the primary optical fiber path and the secondary optical fiber path, the optical switch selecting a path of lower optical loses; an optical cross-bar switch coupled to both the primary optical fiber path and the secondary optical fiber path and located between the optical coupler and the optical switch; a primary upstream light detector coupled to the primary optical path between the optical cross bar switch and the optical switch; a secondary upstream light detector coupled to the secondary optical path between the optical cross bar switch and the optical switch; a primary downstream light detector coupled to the primary optical path between the optical cross bar switch and the optical switch; a secondary downstream light detector coupled to the secondary optical path between the optical cross bar switch and the optical switch; and a stabilizing downstream light detector coupled to the primary optical fiber path between the optical coupler and the optical cross bar switch.

A system for performing failover switches in an optical network, such as a time and wavelength division passive optical networks (TWDM PON) like NG-PON2, includes a backup optical line terminal (OLT) for backing up communications of a primary OLT. The backup OLT is configured to allocate small upstream time slots, referred to herein as “de minimis” time slots, to at least one optical network terminal (ONT) communicating with the primary OLT during normal operation. When a failure occurs that prevents communication between the ONT and the primary OLT, the ONT autonomously tunes to the upstream and downstream wavelength pairs of the backup OLT and begins to transmit data to the backup OLT in the de minimis time slot allocated to it. The presence of data in the de minimis time slot indicates the occurrence of a failover switch to the backup OLT, and the backup OLT then begins to allocate time slots to this ONT, which is normally serviced by the primary OLT according to its normal TDM algorithm.

A protection method wherein an ONU switches a reception wavelength to a backup wavelength so as to be logically connected to a backup OSU designated in advance for each ONU when the ONU detects a failure in an OSU to which the ONU is originally assigned, while the ONU keeps on holding its own connection information with the OLT. In the OLT, a backup OSU for the ONU which is originally assigned to the failed OSU is notified of the information on the ONU when the OLT detects a failure in an OSU. In this way, the ONUs which are originally assigned to the failed OSU resumes communication in a short period.

An ONU communicates with an OLT that can transmit optical signals having different wavelengths simultaneously and receive optical signals having different wavelengths simultaneously. The ONU includes: an optical transceiver that receives any one of the optical signals that the OLT can transmit and transmits any one of the optical signals that the OLT can receive; a communication failure detection unit that detects a communication failure between the OLT and the ONU; and a wavelength selection unit that, when the communication failure detection unit detects a communication failure, changes a setting of a downstream wavelength to be received by the optical transceiver and an upstream wavelength to be transmitted by the optical transceiver.

[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.

Aspects of the present disclosure describe systems, methods. and structures directed to an integrated 3-way branching unit switch module suitable for undersea application.