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 method for reconfiguring a message encoding parameter used by a first channel node to transmit information to a second channel node via a first optical channel in an optical network comprises the steps of sending, via a second optical channel of the optical network, a reconfiguration request with a message encoding parameter from the first channel node to the second channel node of the first optical channel; receiving, via the second optical channel, a reply to the reconfiguration request from the second channel node; and modifying the first channel node in accordance with the message encoding parameter used to transmit information from the first channel node to the second channel node based on the reply.

An optical transmission apparatus includes the optical transceiver configured to generate a test light for each wavelength assignable to the wavelength multiplex light to transmit the test light to the optical transmission line via the wavelength multiplexer and demultiplexer, detect a reflected light for the test light from the optical transmission line, calculate an arrival distance of the test light for the each wavelength from the reflected light for the each wavelength, and set a wavelength having a longest arrival distance among the arrival distances for the respective wavelengths, as a wavelength to be assigned to the signal light in the optical transceiver.

A transport network is configured to connect one or more optical rings of optical add and drop devices with one or more digital units in a radio access network. The transport network comprises a first electronic cross-connect and a second electronic cross-connect. A switch is provided for connecting the first electronic cross-connect and/or the second electronic cross-connect to the one or more digital units. The first and second electronic cross-connects are each coupled to at least one of the one or more optical rings of optical add and drop devices.

An intelligence-defined optical tunnel network system includes a first pod and a controller. The first pod includes multiple Optical Add-Drop Sub-systems (OADS) configured to transmit data between corresponding servers through ToR switches. First transmission modules of the OADSs are connected to each other in ring to form the first transmission ring. Second transmission modules of the OADSs are connected to each other in ring to form the second transmission ring. The controller is configured to set the ToR switches in order to build the optical tunnel from a first OADS to a second OADS on the second transmission ring by the second transmission modules if a disconnection occurs to the optical tunnel from the first OADS to the second OADS on the first transmission ring.

An optical network communication system includes an optical hub, an optical distribution center, at least one fiber segment, and at least two end users. The optical hub includes an intelligent configuration unit configured to monitor and multiplex at least two different optical signals into a single multiplexed heterogeneous signal. The optical distribution center is configured to individually separate the at least two different optical signals from the multiplexed heterogeneous signal. The at least one fiber segment connects the optical hub and the optical distribution center, and is configured to receive the multiplexed heterogeneous signal from the optical hub and distribute the multiplexed heterogeneous signal to the optical distribution center. The at least two end users each include a downstream receiver configured to receive one of the respective separated optical signals from the optical distribution center.

To enable the transmission and reception of a super-channel optical signal to continue maintaining the possible transmission capacity without providing a redundant configuration in advance even though a failure occurs in a subcarrier, an optical transmitter 10 of the present invention includes a splitting means 20 for splitting an inputted client signal so as to make frequency efficiency in optical modulation means optimized; optical modulation means 31 to 3N for modulating one of subcarriers having mutually different wavelengths with the client signal output; a multiplexing means 40 for multiplexing the modulated signals and outputting a super-channel optical signal; and a control means 50, in a state where a failure occurs in one of the subcarriers, for making a split client signal output to modulation means corresponding to a subcarrier having no failure and applying a modulation method with a higher frequency efficiency to at least one of the modulation means.

Aspects of the present disclosure provide a technical solution that enables various passive optical network (PON) type infrastructures to coexist with dense wavelength division multiplexing (DWDM) network infrastructures. According to an embodiment, an optical communication network framework uses an optical coexistence topology to enable coexistence of PON type components and DWDM components. An optical coexistence system uses an optical coexistor to convey an upstream optical signal to one of an arrayed wave grating (AWG) of a DWDM system and an optical line terminal (OLT) of a PON by conveying unfiltered portions of the upstream optical signal to the OLT and filtered portions of the upstream optical signal to the AWG.

A method of configuring a distributed antenna system (DAS) having digital remote units configured to provide a DAS interface to wireless communication devices connecting to the DAS, and at least one digital master unit configured to provide a DAS interface to base stations connecting to the DAS. The method includes connecting digital remote units such that each digital remote unit is connected either to at least another digital remote unit and the digital master unit or to at least two other digital remote units. The method further includes connecting at least one of the digital remote units either to other the digital remote units and the digital master unit, or to at least three other digital remote units, and connecting the digital master unit to at least two of the digital remote units, thereby providing at least one path for redundant data transport.

A network node (400) for use as a hub node of a network that further comprises one or more remote nodes, wherein the network node (400) is coupled to at least first and second connections (410, 412) for communication with one or more remote nodes, comprises a first band filter (403) adapted to separate a first aggregated signal (404) comprising a plurality of channel signals into a plurality of band signals (408.sub.1 to 408.sub.M). The network node (400) comprises a second band filter (405) and a third band filter (407) adapted to aggregate a plurality of band signals (408.sub.1 to 408.sub.M) into a second aggregated signal (406) comprising a plurality of channel signals and a third aggregated signal (413) comprising a plurality of channel signals, respectively. A switching module (409) is adapted to switch on a per-band granularity the plurality of band signals (408.sub.1 to 408.sub.M) between the first band filter (403) and either the second band filter (405) or the third band filter (407). The first band filter (403) may be adapted to aggregate the plurality of band signals (4081 to 408M) into the first aggregated signal (404); the second band filter (405) and a third band filter (407) may be adapted to separate the second aggregated signal (410) and third aggregated signal (412), respectively, into the plurality of band signals (408.sub.1 to 408.sub.M); and the switching module (409) may be adapted to switch on a per-band granularity the plurality of band signals (408.sub.1 to 408.sub.M) between either the second band filter (405) or the third band filter (407) and the first band filter (403).