Abstract: Techniques for providing high-resolution, standard-format output for line monitoring equipment (LME) of a wavelength division multiplexed (WDM) communication system is disclosed. LME may transmit a plurality of LME test signals via an optical path of the WDM system and perform gain measurements on reflections associated with the same at predetermined intervals. Gain measurements for each of the plurality of LME test signals may be normalized and filtered to derive LME peak data. The WDM communication system may perform full scans with data points totaling millions/billions (e.g., depending on system length, fiber type, and number of transmitted LME test signals or test pulses) and normalize the same into a relatively small number of resulting data points within the LME peak data. The WDM system may then output an LME results file in a standard format which is compatible with commercial viewers and optical time domain reflectometer (OTDR) equipment.

Abstract: Optical amplifier assembly for spatial division multiplexing (SDM) optical communication systems. Each optical amplifier assembly includes a single pump assembly configured for causing amplification of signals traveling on separate fiber paths in different directions. Each fiber path includes a plurality of spatial dimensions. The single pump assembly includes a plurality of pump sources to provide redundancy and the optical amplifier assembly further includes splitters for splitting outputs of the pump sources to amplifiers coupled to the different spatial dimensions. Different modulation formats may be used on the different spatial dimensions with different pump power being provided to each of the modulation formats. Amplifiers with complementary outputs may be coupled to average out gain deviations.

Abstract: A wet plant manager (WPM) platform is disclosed in accordance with an embodiment of the present disclosure, and supports management of Smart Undersea Network Elements (SUNEs) by providing an abstracted view of the same to higher level network management functions within an optical communication system. The optical communication system can include an optical cable system extending between two or more cable landing stations (CLSs). Each CLS may execute a respective instance of a WPM platform service, with the collective WPM platform performing self-coordination such that only one instance of a WPM service is “active” at any given time. The active WPM service supports a plurality of network topologies architected around SUNEs and “bridges” them such that requests to communicate with a particular SUNE get handled in a transparent manner without the requesters specific knowledge of which command/response (CR) telemetry path was utilized to satisfy the request.

Abstract: In general, a branching configuration used in a wavelength division multiplexed (WDM) optical communication system, consistent with the present disclosure, includes a power feed branching unit (PFBU) having a multi-port DC/DC converter (DDCM) arrangement capable of a plurality of operating modes to distribute power in a bi-directional manner. The DDCM arrangement may include a plurality of ports for electrically coupling to one or more trunk path cable segments and for electrically coupling to a branch cable segment. A plurality of PFBUs may be disposed along a trunk path, with each PFBU powering an associated branch path, without each branch path necessarily having local power feed equipment (PFE). In instances where a branch path includes a local PFE, an associated PFBU may draw power from the branch path in order to make power available to the trunk path as needed.

Abstract: Techniques for managing a data communication network (DCN) are disclosed, in accordance with an embodiment, and provide planning, maintenance, and validation (e.g., auditing) functionality for the purpose of managing network elements across a plurality of stations/locations associated with an optical communication network. In accordance with an embodiment, a computing device includes a DCN configuration interface and engine. The DCN configuration interface enables modeling of a DCN based on a plurality of user-provided parameters and constraints. The DCN configuration interface may then generate settings files in accordance with the DCN model. The DCN configuration interface further allows previously-generated configuration files to be read in for the purpose of performing updates, adding new stations, new network elements, new equipment types, new equipment models, and so on.

Abstract: In general, a branching configuration used in a wavelength division multiplexed (WDM) optical communication system includes a branching unit (BU) and a separate predetermined wavelength filter (PWF) unit. The PWF unit may include wavelength selective elements (e.g., filters) for providing a desired wavelength allocation and may also include optical connections (e.g. optical couplers) for coupling the allocated wavelengths between trunk and branch paths in the WDM system. The PWF unit is physically separate from an associated BU but coupled adjacent the BU.

Abstract: An optical communication amplification system may include a number of amplification stages for an optical signal that includes a first optical wavelength band signal portion and a second optical wavelength band signal portion. Each amplification stage may separate the first optical wavelength band signal portion from the second optical wavelength band signal portion. The separated first optical wavelength band signal portion is amplified using one or more first optical wavelength band amplifiers and the separated second optical wavelength band signal portion are amplified using one or more second optical wavelength band amplifiers. The amplified first optical wavelength band signal portion is filtered and a reflected portion of the first optical wavelength band signal portion may be used to provide energy to the one or more second optical wavelength band amplifiers to increase the power or gain of the separated second optical wavelength band signal portion.

Abstract: A system and method involving using a nonlinear reversible code for probabilistic constellation shaping. A nonlinear reversible code encoder receives information bits and applies a nonlinear reversible code to the information bits to provide encoded bits. A mapper maps the encoded bits to successive amplitude and phase-shift keying (APSK) symbols. Each of the APSK symbols has an APSK modulation format with an associated constellation and the mapper maps each of the symbols to an associated constellation location of the constellation in response to one or more associated ones of the encoded bits.

Abstract: A system and method involving a coded modulation scheme using an M-APSK format with a circular constellation. A maximum achievable spectral efficiency for the transmitters may be selected and a spectral efficiency step-size of the maximum achievable spectral efficiency may be specified. The spectral efficiency for any transmitter in the system may be individually selected by reducing its spectral efficiency from the maximum achievable spectral efficiencies by a selected number of steps corresponding to the step size.

Abstract: An optical communication amplification system may include a number of amplification stages for an optical signal that includes a first optical wavelength band signal portion and a second optical wavelength band signal portion. Each amplification stage may separate the first optical wavelength band signal portion from the second optical wavelength band signal portion. The separated first optical wavelength band signal portion is amplified using one or more first optical wavelength band amplifiers and the separated second optical wavelength band signal portion are amplified using one or more second optical wavelength band amplifiers. The amplified first optical wavelength band signal portion is filtered and a reflected portion of the first optical wavelength band signal portion may be used to provide energy to the one or more second optical wavelength band amplifiers to increase the power or gain of the separated second optical wavelength band signal portion.

Abstract: A system and method for transmitting a wavelength division multiplexed (WDM) signal on an optical transmission path. The system includes at least one first modulation format transmitter configured to generate an associated first modulation format signal on an associated signal wavelength using a first modulation format having a first spectral efficiency, and at least one second modulation format transmitter configured to generate an associated second modulation format signal on an associated signal wavelength using a second modulation format having a second spectral efficiency higher than the first spectral efficiency. The second modulation format signals having an optical power set nominally higher than the optical power of the first modulation format signals. The first and second modulation format signals are combined into an aggregate output signal on the optical transmission path.

Abstract: A system and method including multi-dimensional coded modulation wherein symbols within successive blocks of symbols are mapped using at least two different constellations to differentiate the symbols from each other. At least one data bit is encoded by an order of the symbols within each block of symbols. The receiver decodes the data by decoding at least one bit from the order of the symbols mapped with the first and second constellations.

Abstract: A system and method including multi-dimensional coded modulation wherein symbols within successive blocks of symbols are mapped using at least two different constellations to differentiate the symbols from each other. At least one data bit is encoded by an order of the symbols within each block of symbols. The receiver decodes the data by decoding at least one bit from the order of the symbols mapped with the first and second constellations.

Abstract: An optical communication system with a hierarchical branch configuration. The system includes first and second cable landing stations coupled to a trunk path in an optical cable. At least one hub-node is coupled to the trunk path through an associated hub-node branching unit. Sub-nodes are coupled the hub-nodes through associated sub-node branching units and sub-node paths in the optical cable. Sub-node signals may be communicated between the sub-nodes and the hub-nodes without being provided on the trunk path.

Abstract: A system and method for establishing new line monitoring system (LMS) baseline data compared to which faults are identified in a line monitoring system of an optical communication system. The new LMS baseline is established by injecting fault signature data associated with previous unrepaired faults into LMS current measurement loop gain data.

Abstract: An adaptive equalizer with coefficients determined by averaging an estimated filter coefficient over a number, N, of past and future symbols. Estimated filter coefficients may be optimized by optimization of the number N, an averaging window function and a scaling factor using a metric. The metric also allows estimation of the amount of noise that may be compensated by an adaptive equalizer consistent with the present disclosure.

Abstract: An optical communication system with a hierarchical branch configuration. The system includes first and second cable landing stations coupled to a trunk path in an optical cable. At least one hub-node is coupled to the trunk path through an associated hub-node branching unit. In an embodiment, mid-nodes are coupled the hub-nodes through associated mid-node branching units and mid-node paths in the optical cable. Mid-node signals may be communicated between the mid-nodes and the hub-nodes without being provided on the trunk path. Sub-nodes are coupled to at least one of the mid-nodes through associated sub-node branching units and sub-node paths in the optical cable. Sub-node signals may also be communicated between the sub-nodes and the mid-nodes without being provided on the trunk path or the mid-node path.

Abstract: A conductive water blocking material and an optical fiber cable and method of constructing an optical fiber cable including the same. The cable includes at least one optical fiber and strength members disposed around the fiber. A conductor is disposed around the strength members. The conductive water blocking material includes a carrier material and conductive metallic particles and is provided in strength member interstices defined by the strength members.

Abstract: Techniques for communications using optical fiber are disclosed. An optical add/drop multiplexer (OADM) node includes an interface to a first fiber pair connecting a first trunk station and a second trunk station. The OADM node further includes an interface to a second fiber pair connecting the first trunk station and the second trunk station with a branch station. The OADM node includes a plurality of filters configured to provide connectivity between the first trunk station, the second trunk station and the branch station. Other embodiments are described and claimed.

Abstract: An optical subcarrier multiplex system. An input data signal is jointly coded with at least one forward error correction (FEC) code before symbol mapping and before subcarrier modulation. Joint FEC coding mitigates non-uniform subcarrier performance.