This disclosure describes devices and methods related to multiplexing optical datasignals. A method may be disclosed. The method may comprise receiving, by a dense wave division multiplexer (DWDM), one or more optical data signals. The method may comprise combining, by the DWDM, the one or more optical data signals. The method may comprise outputting, by the DWDM, the combined one or more optical data signals to a first circulator. The method may also comprise combining, by the WDM, the second optical data signal and one or more third signals, and outputting an egress optical data signal to an optical switch. The method may also comprise outputting, by the optical switch, the egress optical data signal on a primary fiber.

Provided is an optical communication system configured as an optical ring network including: a first optical communication device configured to transmit a first optical signal having a first wavelength in a first direction, and to transmit a second optical signal having a second wavelength in a second direction opposite to the first direction; and a second optical communication device configured to generate a first reflected signal by reflecting the first optical signal when the first optical signal is received, to generate a second reflected signal by reflecting the second optical signal when the second optical signal is received, and to transmit the first and second reflected signals to the first optical communication device, wherein the first optical communication device analyzes a connection state of the second optical communication device based on the first and second reflected signals.

An optical network management device (100) which assigns a path from a transmitting node to a receiving node in an optical network system including a multi-core optical fiber, includes at least one processor, the processor being configured to carry out: a core extraction process of extracting a core constituting the path; and a path assignment process of selecting, in accordance with an attribute of the path, a wavelength to which the path is to be assigned, the multi-core optical fiber having an optical amplifier attached thereto, the optical amplifier having an amplification gain that is larger in a first wavelength region than in a second wavelength region, the path assignment process including preferentially assigning, to the first wavelength region, the path having a specific attribute.

A network capable of being used in a datacenter is described. In some embodiments, the network can comprise a set of optical fiber rings, wherein each optical fiber ring carries data traffic on one or more wavelengths, and wherein each optical fiber ring is partitioned into multiple sectors. A reconfigurable optical add-drop multiplexer (ROADM) can be coupled to at least one optical fiber in each of at least two sectors. An electro-optical-switch can be coupled to each ROADM in each of the at least two sectors. A set of switches can be coupled to each electro-optical-switch in each of the at least two sectors. The set of switches can comprise a first layer of aggregation switches that is coupled to a second layer of edge switches, wherein the edge switches can be coupled to servers in a datacenter.

Optical protection switching apparatus (10), for a single fibre bidirectional WDM optical ring, comprising: first (12) and second (14) ports for coupling to first and second adjacent portions of a single fibre bidirectional WDM optical ring; an optical splitter (16) comprising an input to receive a WDM aggregate optical signal, and first and second outputs coupled to the first and second ports; an optical switch (108) between the second output and the second port; and processing circuitry (24) to receive at least one of an indication of transmission continuity in the optical ring and an indication of transmission discontinuity in the optical ring, and to generate a switch control signal (20) comprising instructions to cause the optical switch to be open when there is transmission continuity in the optical ring and to cause the optical switch to be closed when there is transmission discontinuity in the optical ring.

A system for compensating for a latency difference in a fronthaul in ring topology is provided, including a centralization node linked to a BBU group, a plurality of distribution nodes linked to a plurality of RRH groups, an optical bi-directional ring network connecting the central node and the distribution nodes and allows a WDM optical signal to be transmitted and received between the central node and the distribution nodes, and a FIFO buffer that stores an electrical signal. Each of the distribution nodes demultiplexes the WDM optical signal, converts each demultiplexed optical signal into an electrical signal, stores the electrical signal in the FIFO buffer, converts the electrical signal stored in the FIFO buffer into an optical signal, and adjusts a size of the FIFO buffer, thus compensating for a difference between latencies before and after an occurrence of a switchover in the optical bi-directional ring network.

A transmission device for which a work path is established in a first degree and a protection path is established in a second degree includes: a switch equipped with a plurality of optical ports; an optical signal generator, optically connected to a first optical port, and configured to generate an optical signal that is transmitted through the work path; and a monitor light generator, optically connected to a second optical port, and configured to generate monitor light by using a wavelength tunable light source. The monitor light generator controls a wavelength of the monitor light to be substantially the same as a wavelength of the optical signal. The switch guides the optical signal that arrives at the first optical port toward the first degree and guides the monitor light that arrives at the second optical port toward the second degree.

Optical protection switching apparatus (10), for a single fibre bidirectional WDM optical ring, comprising: first (12) and second (14) ports for coupling to first and second adjacent portions of a single fibre bidirectional WDM optical ring; an optical splitter (16) comprising an input to receive a WDM aggregate optical signal, and first and second outputs coupled to the first and second ports; an optical switch (108) between the second output and the second port; and processing circuitry (24) to receive at least one of an indication of transmission continuity in the optical ring and an indication of transmission discontinuity in the optical ring, and to generate a switch control signal (20) comprising instructions to cause the optical switch to be open when there is transmission continuity in the optical ring and to cause the optical switch to be closed when there is transmission discontinuity in the optical ring.

This disclosure describes devices and methods related to multiplexing optical datasignals. A method may be disclosed. The method may comprise receiving, by a dense wave division multiplexer (DWDM), one or more optical data signals. The method may comprise combining, by the DWDM, the one or more optical data signals. The method may comprise outputting, by the DWDM, the combined one or more optical data signals to a first circulator. The method may also comprise combining, by the WDM, the second optical data signal and one or more third signals, and outputting an egress optical data signal to an optical switch. The method may also comprise outputting, by the optical switch, the egress optical data signal on a primary fiber.

Provided is an optical communication system configured as an optical ring network including: a first optical communication device configured to transmit a first optical signal having a first wavelength in a first direction, and to transmit a second optical signal having a second wavelength in a second direction opposite to the first direction; and a second optical communication device configured to generate a first reflected signal by reflecting the first optical signal when the first optical signal is received, to generate a second reflected signal by reflecting the second optical signal when the second optical signal is received, and to transmit the first and second reflected signals to the first optical communication device, wherein the first optical communication device analyzes a connection state of the second optical communication device based on the first and second reflected signals.