Systems and methods for coordinating an optical layer and a packet layer in a network, include a Software Defined Networking (SDN) Internet Protocol (IP) application configured to implement a closed loop for analytics, recommendations, provisioning, and monitoring, of a plurality of routers in the packet layer; and a variable capacity application configured to determine optical path viability, compute excess optical margin, and recommend and cause capacity upgrades and downgrades, by communicating with a plurality of network elements in the optical layer, wherein the SDN IP application and the variable capacity application coordinate activity therebetween based on conditions in the network. The activity is coordinated based on underlying capacity changes in the optical layer and workload changes in the packet layer.

A single-wavelength light path is selected between a source access node and a destination access node of a wavelength-division multiplexed optical network, including selecting an illuminated wavelength of the light path and selecting a start time and duration for a data transfer that would not interfere with other data transfers. If no start time/wavelength combination is available with duration sufficient to transport the data, an additional wavelength is automatically selected, based on modeling, that would not impair traffic being carried by other wavelengths in the network, and without a time-consuming manual process of the prior art. The scheduling process may include selecting a set of optical fibers, a wavelength, a start time and an end time to transport proposed traffic. A novel scheduler avoids checking every possible start time, thereby saving significant processing time. The scheduler schedules single-wavelength light paths, rather than relying on complex wavelength shifting schemes.

A method and apparatus for optimizing optical transport using a software defined network (SDN) controller are disclosed herein. The SDN controller may define a margin optimization function based on at least one optical system performance metric. The function may include at least one related initiation criterion. Further, the SDN controller may collect at least one measurement for the performance metric. The measurement may include an assessment of deployed carriers not carrying client data. The SDN controller may determine whether the initiation criterion is met based on at least one collected measurement. The SDN controller may select a system margin optimization mechanism and define a system margin optimization threshold criterion on a condition that the initiation criterion is met. The SDN controller may determine whether the optimization threshold criterion is met. The SDN controller may implement one or more optimization events on a condition that the optimization threshold criterion is met.

Methods and systems for determining optical network utilization efficiency include generating a random demand set and calculating a demand fill ratio (DFR) based on the random demand set. The random demand set includes network demands for a given optical network topology that provide 100% of the wavelength slots in the optical network topology. The DFR may be calculated using different wavelength assignment algorithms, such as a first fit wavelength assignment algorithm, from the randomly generated demands in the random demand set. The DFR may be calculated without and with wavelength conversion nodes.

An optical access network includes an optical hub having at least one processor. The network further includes a plurality of optical distribution centers connected to the optical hub by a plurality of optical fiber segments, respectively, and a plurality of geographic fiber node serving areas. Each fiber node serving area of the plurality of fiber node serving areas includes at least one optical distribution center of the plurality of optical distribution centers. The network further includes a plurality of end points. Each end point of the plurality of end points is in operable communication with at least one optical distribution center. The network further includes a point-to-point network provisioning system configured to (i) evaluate each potential communication path over the plurality of optical fiber segments between a first end point and a second end point, and (ii) select an optimum fiber path based on predetermined path selection criteria.

In an automatically switched optical network operating according to a wavelength plan, the wavelengths are assigned to an optical path based on availability, performance and SRS wavelength coupling reduction. First, the wavelengths are grouped in static bins based on their reach versus cost performance, and each bin assumes a ?Q of a middle wavelength. Then, the bins are moved into subsets of dynamic bins, constructed using bin constraints that account for the particulars of the respective optical path. The path is characterized taking into account the wavelength currently accessing at the end nodes, and the wavelength tandeming through the end nodes. Wavelength selection starts with the bins that satisfy the maximum number of constraints, and the wavelengths are checked sequentially against wavelength constraints; relaxed constraints are also applied when it is not possible to exactly satisfy one or more constraints.

A method for virtualizing an optical network, comprising: abstracting optical resource information corresponding to resources within the optical network, constructing a plurality of candidate paths for one or more optical reachability graph (ORG) node pairs, determining whether the candidate paths are optical reachable paths, and creating an ORG link between each ORG node pair when at least one optical reachable path exists for the ORG node pair, wherein linking the ORG node pairs creates an ORG. In another embodiment, a computer program product comprising executable instructions when executed by a processor causes a node to perform the following: determine an optical network's optical-electrical-optical (OEO) conversion capability, partition a plurality of service sites into one or more electrical reachability graph (ERG) nodes, determine a grooming capability for each ERG node, and construct a plurality of electrical-layer reach paths between the ERG nodes to form an ERG.

A network control method which is executed by a processor included in a network control device, the network control method includes measuring an amount of time of generation of an optical path that extends via a plurality of nodes in a network; and setting the optical path at a timing that is controlled based on the amount of measured time.

Systems and methods for computing disjoint paths in a network considering continuity constraints include, responsive to a request for disjoint paths in the network which are subject to the continuity constraints, initializing a plurality of variables associated with a graph defining the network where edges constitute nodes and vertices constitute links; determining a first path through the graph; determining an auxiliary directed graph based on the first path; and determining a second path through the auxiliary directed graph, wherein the second path is determined by considering entry into cut edges, exit from cut edges, and a destination in the auxiliary directed graph and the plurality of variables are adjusted based on the entry, the exit, and the destination to address the continuity constraints. This approach concept applies to not just continuity constraints but to any constraints, which are non-additive in nature; the objective function is still additive for Shortest Path First (SPF).

Embodiments of the present disclosure provide a calculating apparatus and method for nonlinear weighting coefficient. The calculating apparatus for nonlinear weighting coefficient includes: an approximation processing unit configured to use a rational function to perform approximation processing on a link loss/gain function in intra-channel nonlinear distortion estimation; and a coefficient calculating unit configured to calculate a nonlinear weighting coefficient in the nonlinear distortion estimation by using the approximated link loss/gain function and a large dispersion approximation, to obtain an analytical closed solution of the nonlinear weighting coefficient. With the embodiments of the present disclosure, a weighting coefficient of high precision may be obtained, thereby performing high-precision estimation on nonlinear distortion in case of loss.