A method may include obtaining a topology of an optical network. The topology may indicate multiple optical links within the optical network. The method may also include obtaining a routing metric for each of the optical links. The routing metric may be used in selecting routes through the optical network along the multiple optical links. The method may further include obtaining a signal noise tolerance of an optical signal to be routed through the optical network and adjusting routing metrics of one or more of the multiple optical links based on the signal noise tolerance of the optical signal. The method may also include after the routing metrics of the one or more of the multiple optical links are adjusted, determining a route for the optical signal through the optical network along two or more of the multiple optical links based on the routing metrics of the multiple optical links.

A host device configured to receive a pluggable optical module, the host device includes circuitry configured to, subsequent to insertion of the pluggable optical module, access an early management interface on the pluggable optical module, prior to the pluggable optical module being fully booted, and, subsequent to the pluggable optical module being fully booted, access a complete management interface on the pluggable optical module. The early management interface provides responses to simple queries, allowing access to one or more registers on the pluggable optical module.

The present application provides a method for transmitting performance parameters of a far-end optical module of a far-end node, a detection method for detecting performance of a far-end optical module, a method for transmitting control parameters for controlling a far-end optical module of a far-end node, a method for controlling a far-end optical module of a far-end node, a far-end optical module, a near-end optical module, and a fronthaul system. The method for transmitting performance parameters includes: generating, in response to at least one of a plurality of registers of the far-end optical module becoming a first source register, an uplink optical signal according to ID information and a register value of the first source register, where the first source register is a register having a changed register value of the plurality of registers, and register values of the registers have a mapping relationship with performance parameters of the far-end optical module; and transmitting the uplink optical signal to a near-end optical module of a near-end node.

Systems and methods include receiving (S11) data for a plurality of elements associated with an optical network; determining (S12) an incremental noise penalty for each element of the plurality of elements based on the received data; and storing (S13) the incremental noise penalty for each element of the plurality of elements. The steps can further include determining (S14) Signal-to-Noise Ratio (SNR) across an optical path in the optical network by concatenating associated incremental noise penalties for each element in the optical path along with corrections. The present disclosure includes a fast, nonlinear estimation process with improved accuracy for low loss spans compared to traditional closed-form GN models, as well as a method to determine the coherent nonlinear penalty in an arbitrary concatenation of mixed heterogeneous fibers which is not considered by existing fast nonlinear interference calculation methods.

A decoder for determining an estimate of a vector of information symbols carried by optical signals propagating along a multi-core fiber in an optical fiber transmission channel according to two or more cores is provided. The decoder is implemented in an optical receiver. The optical signals are encoded using a space-time coding scheme and/or scrambled by at least one scrambling device arranged in the optical fiber transmission channel according to a predefined scrambling function. The decoder comprises a processing unit configured to adaptively: determine, in response to a temporal condition, one or more channel quality indicators from the optical signals; determine a decoding algorithm according to a target quality of service metric and on the one or more channel quality indicators; update the predefined scrambling function and/or the space-time coding scheme depending on the target quality of service metric and on the one or more channel quality indicators. The decoder further comprises a symbol estimation unit configured to determine an estimate of a vector of information symbols by applying the decoding algorithm to the optical signals.

There is provided a method, apparatus and system for determining multipath interference (MPI) in optical communications. It is object of embodiments of the present disclosure to provide an effective, low-cost way of detecting or measuring MPI. To effectively detect and measure the MPI, multiple zero-power gaps are inserted into the transmission signal (optical signal) in time domain. In some embodiments, at least some of the zero-power gaps inserted in the main signal do not overlap the zero-power gaps of the reflection of the main signal. Using the zero-power gaps contained the main signal and the reflection (where applicable), power inside and outside the zero-power gaps are determined. Then, the strength of the MPI is determined based on the determined power inside and outside the zero-power gaps.

Systems and methods for avoiding fiber damage of an optical fiber link are provided. A method, according to one implementation, includes monitoring optical signals transmitted along an optical fiber link from an output port of a first card to an input port of a second card. In response to detecting a fiber disconnection state when an amplifier of the first card is operating in a normal condition, the amplifier of the first card enters a forced Automatic Power Reduction (APR) condition. In addition to potentially reducing the risk of eye damage from laser light emitted from the optical fiber link, the forced APR condition is configured to allow for an uninterrupted debugging procedure. Also, the method includes returning the amplifier of the first card from the forced APR condition back to the normal operating condition after receiving an indication that the fiber disconnection state has cleared.

A method may include obtaining a topology of an optical network. The topology may indicate multiple optical links within the optical network. The method may also include determining a signal noise tolerance for each of multiple optical signal types supported by the optical network and obtaining an optical noise for each of the multiple optical links. The method may also include determining a number of the multiple optical signal types that each of the multiple optical links is able to support based on the optical noise for each of the optical links and the signal noise tolerance for each of the multiple optical signal types and ranking the multiple optical links based on the number of the multiple optical signal types that each of the optical links is able to support.

A network node in an optical network dynamically generates a routing table based on attributes of the optical network. The network node obtains attributes characterizing the optical network, which includes multiple network nodes connected by optical links. The network node calculates cost values for sending data from the network node to one or more next hop nodes that are connected to the network node. Each particular cost value is associated with a probability of success of sending the data to a particular next hop node based on a particular permutation of the attributes characterizing the optical network. The network node generates a routing table correlating the permutations of the attributes with each next hop node based on the cost values.

A method of assigning performance indicators to objects of a network employing a computation to assign performance indicators to said objects of said network such that a sum of said performance indicators of objects along a given path in said network in relation to a first threshold value indicates whether said path fulfils a predetermined criterion, and/or indicates whether said path does not fulfil said predetermined criterion.

A method of evaluating a performance of a path in a network based on the performance indicators involves the steps of calculating a sum of performance indicators for said objects along said path and evaluating a performance of said path by comparing said sum against a first threshold value.