An optical Internet Protocol (IP) router serves a cell-site over an optical communication network. The optical IP router transmits a network attach request having an optical node name over a control optical wavelength. The optical communication node receives an assignment of a data optical wavelength, a cell-site mode, and an Internet Protocol (IP) address over the control optical wavelength based on the optical node name. The optical communication node operates in the cell-site mode and responsively exchanges cell-site data having the IP address over the data optical wavelength.

Various examples relate to a central unit and a corresponding method and computer program, to a distributed unit and a corresponding method and computer program, to an optical line terminal comprising a central unit, to an optical networking unit comprising a distributed unit, and to a system comprising a central unit and one or more distributed units. The central unit for a time-division multiplexed (TDM) point-to-multipoint (P2MP) network comprises circuitry configured to grant, during a first time window, a first distributed unit not yet registered to the TDM P2MP network to transmit first activation data to the central unit. The circuitry is configured to grant, during the first time window, at least one second distributed unit already registered to the TDM P2MP to transmit upstream data to the central unit. The central unit is configured to receive the first activation data during the first time window. The central unit is configured to determine an estimate for a round-trip time of the first distributed unit based on the first activation data and a length of a second time window based on the estimate for the round-trip time. The circuitry is configured to grant exclusively the first distributed unit to transmit second activation data to the central unit during the second time window. The circuitry is configured to register the first distributed unit to the TDM P2MP network based on the second activation data.

A method of generating multiple channels of optical pulses comprises: providing a continuous wave optical input having an optical power; dividing the optical power of the optical input into equal consecutive slices in the time domain; and allocating the consecutive slices sequentially to two or more optical outputs such that each output forms a channel of optical pulses of equal pulse repetition rate shifted in time relative to the or each other channel.

A transmitter can include a laser operable to output an optical signal; a digital signal processor operable to receive user data and provide electrical signals based on the data; and a modulator operable to modulate the optical signal to provide optical subcarriers based on the electrical signals. A first one of the subcarriers carriers carries first TDMA encoded information and second TDMA encoded information, such that the first TDMA encoded information is indicative of a first portion of the data and is carried by the first one of the subcarriers during a first time slot, and the second TDMA encoded information is indicative of a second portion of the data and is carried by the first one of the subcarriers during a second time slot. The first TDMA encoded information is associated with a first node remote from the transmitter and the second TDMA encoded information is associated with a second node remote from the transmitter. A second one of the subcarriers carries third information that is not TDMA encoded, the third information being associated with a third node remote from the transmitter. A receiver and system also are described.

Provided are techniques, devices and systems that enable updating of a reportable parameter table database when a reconfigured optical communication path is formed by switching performed by a branching unit in an undersea optical communication transmission system. A processor may obtain system attributes of each respective segment of a number of segments of the reconfigured optical communication path from a first end point to a second endpoint. The system attributes of each respective segment of the number of segments may be evaluated from the first end point to the second endpoint of the reconfigured optical communication path. A reportable parameter table may be generated based on the evaluated system attributes that includes a listing of operational and structural parameters of system from the first endpoint to the second endpoint of the reconfigured optical communication path.

An optical module is disclosed. The optical module includes a first downlink port, a second downlink port, a directional coupler, a optical attenuator, a first photodiode (PD), and a second PD. The directional coupler, connected to the first downlink port, is configured to receive a downlink optical signal. The second PD connected to the directional coupler, is configured to obtain a power value. If the power value is greater than a first threshold, the optical attenuator is configured to receive a attenuation control signal, and attenuate, based on the attenuation control signal, a power of an optical signal passing through the second downlink port. The first PD is configured to: convert the downlink optical signal into a downlink electrical signal, and convert the optical signal passing through the second downlink port into an electrical signal. Both the first downlink port and the second downlink port are connected to the first PD.

The present disclosure discloses example method and apparatus for switching a line bandwidth of an optical transport network. One example method includes a network device switching an optical transport network (OTN) frame from a first bandwidth to a second bandwidth at a granularity of a substructure to generate a first OTN frame with the second bandwidth, where a bandwidth of the substructure is a specified value, and a difference between the first bandwidth and the second bandwidth is a multiple of the specified value. The first OTN frame with the second bandwidth is encapsulated as an encapsulated frame with the second bandwidth according to a first encapsulation protocol. The encapsulated frame with the second bandwidth is transmitted at an optical layer.

A highly scalable and modular automated optical cross connect switch devices which exhibit low loss and scalability to high port counts. A device for the programmable interconnection of large numbers of optical fibers (100s-1000s) is provided, whereby a two-dimensional array of fiber optic connections is mapped in an ordered and rule-based fashion into a one-dimensional array with tensioned fiber optic circuit elements tracing substantially straight lines there between. Fiber optic elements are terminated in a stacked arrangement of flexible fiber optic circuit elements with a capacity to retain excess fiber lengths while maintaining an adequate bend radius. The combination of these elements partitions the switch volume into multiple independent, non-interfering zones, which retain their independence for arbitrary and unlimited numbers of reconfigurations. The separation into spaced-apart zones provides clearance for one or more robotic actuators to enter the free volume substantially adjacent to the two-dimensional array of connectors and mechanically reconfigure connectors without interrupting other circuits.

A reduced-complexity optical packet switch which can provide a deterministic guaranteed rate of service to individual traffic flows is described. The switch contains N input ports, M output ports and N*M Virtual Output Queues (VOQs). Packets are associated with a flow f, which arrive an input port and depart on an output port, according to a predetermined routing for the flow. These packets are buffered in a VOQ. The switch can be configured to store several deterministic periodic schedules, which can be managed by an SDN control-plane. A scheduling frame is defined as a set of F consecutive time-slots, where data can be transmitted over connections between input ports and output ports in each time-slot. Each input port can be assigned a first deterministic periodic transmission schedule, which determines which VOQ is selected to transmit, for every time-slot in the scheduling frame. Each input port can be assigned a second deterministic periodic schedule, which determines which traffic flow within a VOQ is selected to transmit. Each input port can be assigned a third deterministic periodic schedule, which specifies to which VOQ an arriving packet (if any) is destined, for each time-slot in a scheduling frame. Each input port can be assigned a fourth deterministic periodic schedule, which specifies to which Flow-VOQ within a VOQ an arriving packet (if any) is destined. In this manner, each traffic flow can receive a deterministic guaranteed-rate of transmission through the switch.

A network switch and a transceiver restart method thereof are provided. The network switch is configured to connect to a transceiver to transmit and receive data packets through the transceiver. The network switch includes a power control circuit and a processor. The power control circuit is controlled to provide electrical power to the transceiver. The processor determines whether the transceiver is in an abnormal state. In response to determining that the transceiver is in the abnormal state, the processor first controls the power control circuit to stop providing the electrical power to the transceiver, and then controls the power control circuit to re-provide the electrical power to the transceiver.