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.

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.

Various embodiments for configurable memory storage systems are disclosed. The configurable memory storages selectively choose an operational voltage signal from among multiple voltage signals to dynamically control various operational parameters. For example, the configurable memory storages selectively choose a maximum voltage signal from among the multiple voltage signals to maximize read/write speed. As another example, the configurable memory storages selectively choose a minimum voltage signal from among the multiple voltage signals to minimize power consumption.

Various embodiments for configurable memory storage systems are disclosed. The configurable memory storages selectively choose an operational voltage signal from among multiple voltage signals to dynamically control various operational parameters. For example, the configurable memory storages selectively choose a maximum voltage signal from among the multiple voltage signals to maximize read/write speed. As another example, the configurable memory storages selectively choose a minimum voltage signal from among the multiple voltage signals to minimize power consumption.

A preFEC BER of a selected optical link is determined. A FEC Detected Degrade (FDD) threshold, FEC Excessive Degrade (FED) threshold, and FEC limit threshold are obtained for the selected optical link. The FDD threshold is less than the FED threshold and the FED threshold is less than the FEC limit. Based on the FDD threshold, FED threshold, the FEC limit, and a determination that a postFEC BER==0, it is determined whether a link down condition of the selected optical link can be asserted or de-asserted.

A preFEC BER of a selected optical link is determined. A FEC Detected Degrade (FDD) threshold, FEC Excessive Degrade (FED) threshold, and FEC limit threshold are obtained for the selected optical link. The FDD threshold is less than the FED threshold and the FED threshold is less than the FEC limit. Based on the FDD threshold, FED threshold, the FEC limit, and a determination that a postFEC BER==0, it is determined whether a link down condition of the selected optical link can be asserted or de-asserted.

A method, implemented in a node in a network, for a preemptible established backup path for a mesh restorable service includes, responsive to a new service request for the mesh restorable service with the preemptible established backup path, establishing a primary path designated as a current path for the mesh restorable service at a designated priority; establishing a backup path for the mesh restorable service at a lower priority than the designated priority, subject to bandwidth availability in the network; and responsive to a fault affecting the primary path, switching to the backup path and raising a priority of the backup path to the designated priority.

It is difficult in an optical network to achieve fault recovery in case of multiple failures without decreasing the usage efficiency of the optical network; therefore, an optical communication system according to an exemplary aspect of the present invention includes an optical network management device including an optical path setting means for setting, to a physical route differing from each other, a backup path corresponding to each of a plurality of active paths on an identical physical route, and a failure-case optical path setting means for setting a failure-case backup path with a compressed band of the backup path, to a physical route without a failure in a case where failures arising on more than one physical route among the physical routes; and an optical node device including an optical transceiver means for transmitting and receiving optical signals using failure-case backup path information resulting from setting by the failure-case optical path setting means.

It is difficult in an optical network to achieve fault recovery in case of multiple failures without decreasing the usage efficiency of the optical network; therefore, an optical communication system according to an exemplary aspect of the present invention includes an optical network management device including an optical path setting means for setting, to a physical route differing from each other, a backup path corresponding to each of a plurality of active paths on an identical physical route, and a failure-case optical path setting means for setting a failure-case backup path with a compressed band of the backup path, to a physical route without a failure in a case where failures arising on more than one physical route among the physical routes; and an optical node device including an optical transceiver means for transmitting and receiving optical signals using failure-case backup path information resulting from setting by the failure-case optical path setting means.

An apparatus is described. The apparatus comprises a downstream wavelength selective switch having an input port, an optical path operable to carry an optical signal, an optical source providing amplified spontaneous emission (ASE) light, an optical switch having a first input coupled to the optical path, a second input coupled to the optical source and receiving the ASE light, and an output coupled to the input port of the downstream wavelength selective switch. The optical switch couples either the first input or the second input to the output. Further included is a photodiode operable to monitor the optical signal, detect an optical loss of signal of the optical signal, and output a switch signal to the optical switch such that the optical switch couples the second input receiving the ASE light to the output whereby the ASE light is directed to the input port of the downstream wavelength selective switch.