According to an aspect of an embodiment, operations may include receiving a first Ethernet signal having a first data rate less than a second data rate, the second data rate being a ZR data rate. The operations may also include dividing the first Ethernet signal into a plurality of first-signal sub-signals that each have a third data rate that is less than the first data rate. Moreover, the operations may include generating a second Ethernet signal having the second data rate, the generating of the second Ethernet signal being based on the plurality of first-signal sub-signals such that the second Ethernet signal includes the plurality of first-signal sub-signals. Further, the operations may include providing the second Ethernet signal to a ZR network such that the second Ethernet signal is a ZR signal.

This disclosure describes C and L band optical communications module link extender, and related systems and methods. An example method may include receiving, by a dense wave division multiplexer (DWDM) at a headend, one or more optical data signals over a C band and an L band. The example method may also include combining the one or more optical data signals. The example method may also include outputting a second signal to a first WDM at the headend. The example method may also include separating, by the first WDM, the second signal into a C band signal and an L band signal. The example method may also include outputting the C band signal to a first amplifier at the headend and the L band signal to a second amplifier at the headend. The example method may also include amplifying, by the first amplifier, the C band signal. The example method may also include outputting an amplified C band signal to a coexistence filter. The example method may also include amplifying, by the second amplifier, the L band signal. The example method may also include outputting an amplified L band signal to the coexistence filter. The example method may also include outputting, by the coexistence filter, a third signal.

This disclosure describes C and L band optical communications module link extender, and related systems and methods. An example method may include receiving, by a dense wave division multiplexer (DWDM) at a headend, one or more optical data signals over a C band and an L band. The example method may also include combining the one or more optical data signals. The example method may also include outputting a second signal to a first WDM at the headend. The example method may also include separating, by the first WDM, the second signal into a C band signal and an L band signal. The example method may also include outputting the C band signal to a first amplifier at the headend and the L band signal to a second amplifier at the headend. The example method may also include amplifying, by the first amplifier, the C band signal. The example method may also include outputting an amplified C band signal to a coexistence filter. The example method may also include amplifying, by the second amplifier, the L band signal. The example method may also include outputting an amplified L band signal to the coexistence filter. The example method may also include outputting, by the coexistence filter, a third signal.

A first node of a network includes a quantum transmitter, a classical transceiver, and an initial-key generator that cooperate with a second node to transmit an initial key via the quantum transmitter. The first node includes a key-series generator that (i) encrypts a first unencrypted key of a series of unencrypted keys to generate a first encrypted key of a series of encrypted keys and (ii) encrypts each subsequent unencrypted key of the series of unencrypted keys with a preceding unencrypted key of the series of unencrypted keys to generate a subsequent encrypted key of the series of encrypted keys. The encrypted keys are transmitted to the second node. The first node includes one or both of a decryptor and an encryptor. The decryptor decrypts encrypted data using a last unencrypted key of the series of unencrypted keys. The encryptor encrypts unencrypted data using the last unencrypted key.

A first node of a network includes a quantum transmitter, a classical transceiver, and an initial-key generator that cooperate with a second node to transmit an initial key via the quantum transmitter. The first node includes a key-series generator that (i) encrypts a first unencrypted key of a series of unencrypted keys to generate a first encrypted key of a series of encrypted keys and (ii) encrypts each subsequent unencrypted key of the series of unencrypted keys with a preceding unencrypted key of the series of unencrypted keys to generate a subsequent encrypted key of the series of encrypted keys. The encrypted keys are transmitted to the second node. The first node includes one or both of a decryptor and an encryptor. The decryptor decrypts encrypted data using a last unencrypted key of the series of unencrypted keys. The encryptor encrypts unencrypted data using the last unencrypted key.

A method may include determining a number of categories associated with optical network units (ONUs) in a system and assigning an allocation identifier to each of the respective categories. The method may also include transmitting the assigned allocation identifiers to the ONUs and transmitting a contention-based allocation to the ONUs, wherein the contention-based allocation includes a first one of the allocation identifiers.

A method may include determining a number of categories associated with optical network units (ONUs) in a system and assigning an allocation identifier to each of the respective categories. The method may also include transmitting the assigned allocation identifiers to the ONUs and transmitting a contention-based allocation to the ONUs, wherein the contention-based allocation includes a first one of the allocation identifiers.

An amplified optical link having a fault-protection capability that is based, at least in part, on the ability to selectively and independently power up and down different groups of optical amplifiers within the link. In an example embodiment, the optical link is implemented using an optical fiber cable having an electrical power line and arrays of optical amplifiers connected between successive optical fiber segments to form a plurality of disjoint groups of parallel optical paths between the ends of the optical fiber cable. The electrical power line is operable to selectively power, as a group, the optical amplifiers of at least some of the disjoint groups. In various embodiments, different optical paths can be implemented using different respective strands of a single-core optical fiber, different respective cores of a multi-core optical fiber, and/or different respective sets of spatial modes of a multimode optical fiber.

Systems and methods for stabilizing power levels from excessive oscillations in an optical line system of a communications network are provided. A method, according to one implementation, includes the step of detecting a perturbation of an optical power level in an optical line system having a plurality of cascaded optical power controllers. The method also includes the step of determining an estimated location to which a power controller of the plurality of cascaded optical power controllers is positioned downstream of the perturbation with respect to other power controllers of the plurality of cascaded optical power controllers. Based on the estimated location to which the power controller is positioned downstream of the perturbation, the method also includes the step of providing feedback in a control loop to reduce the effects of the perturbation.

Systems and methods for stabilizing power levels from excessive oscillations in an optical line system of a communications network are provided. A method, according to one implementation, includes the step of detecting a perturbation of an optical power level in an optical line system having a plurality of cascaded optical power controllers. The method also includes the step of determining an estimated location to which a power controller of the plurality of cascaded optical power controllers is positioned downstream of the perturbation with respect to other power controllers of the plurality of cascaded optical power controllers. Based on the estimated location to which the power controller is positioned downstream of the perturbation, the method also includes the step of providing feedback in a control loop to reduce the effects of the perturbation.