According to various aspects of the present disclosure, an apparatus is provided. In an aspect, the apparatus includes an optical transceiver having a first port, a second port and an optical switch coupled to the first port and the second port. The optical switch is switchable between a unidirectional port operation mode and a bidirectional port operation mode. When the optical switch is in the unidirectional port operation mode, the first port is configured to send a first optical signal, and the second port configured to receive a second optical signal. When the optical switch is in the bidirectional port operation mode, the first port configured to send the first optical signal and receive the second optical signal, and the second port configured to receive a third optical signal and not send the first signal. Furthermore, a second bidirectional port operation mode is supported with the second port configured to send the first optical signal and receive the second optical signal, and the first port configured to receive a third optical signal and not send the first signal.

A communication system of a passive optical communication network includes an optical line terminal (OLT) system including a first OLT, a second OLT, and an OLT control device that controls the first OLT and the second OLT, a plurality of splitters that connect the first OLT and the second OLT with an optical communication path, and an ONU that is connected to each of the splitters with an optical communication path. The splitter distributes and outputs an optical signal transmitted from the OLT system to the ONU connected to the splitter and a succeeding device that is another splitter or the OLT system, and the OLT control device determines a distribution ratio at the splitter, the distribution ratio indicating a ratio between the intensity of the optical signal distributed to the succeeding device and the intensity of the optical signal distributed to the ONU.

A communication system of a passive optical communication network includes an optical line terminal (OLT) system including a first OLT, a second OLT, and an OLT control device that controls the first OLT and the second OLT, a plurality of splitters that connect the first OLT and the second OLT with an optical communication path, and an ONU that is connected to each of the splitters with an optical communication path. The splitter distributes and outputs an optical signal transmitted from the OLT system to the ONU connected to the splitter and a succeeding device that is another splitter or the OLT system, and the OLT control device determines a distribution ratio at the splitter, the distribution ratio indicating a ratio between the intensity of the optical signal distributed to the succeeding device and the intensity of the optical signal distributed to the ONU.

A framer in a transmission device that allocates time slots of an optical channel to a logical path, divides client signals received via the logical path to the time slots allocated to the logical path, and transmits the client signals by a plurality of optical suhcarriers using optical wavelengths correlated with the time slots includes: a time slot allocating unit configured to perform a process of reducing a transmission band of the logical path when some of the optical wavelengths are unavailable and changing the time slots allocated to the logical path depending on the reduced transmission band to avoid using the time slots corresponding to the unavailable optical wavelengths.

An example system includes a transceiver and a microcontroller. The microcontroller is configured to receive, from first and second network interfaces of the transceiver, a plurality of messages from a hub node and the leaf nodes. Each of the messages corresponds to a respective one of the ingress or egress data flows. The microcontroller is also configured generate a resource assignment map based on the messages. The resource assignment map includes pairings between a respective one of the ingress data flows and a respective one of the egress data flows, and, for each of the pairings, an indication of a respective network resource assigned to exchange the egress data flow of that pairing with a respective one of the leaf nodes. The microcontroller is also configured to generate a command to cause the transceiver to transmit the egress data flows in accordance with the resource assignment map.

An example system includes a transceiver and a microcontroller. The microcontroller is configured to receive, from first and second network interfaces of the transceiver, a plurality of messages from a hub node and the leaf nodes. Each of the messages corresponds to a respective one of the ingress or egress data flows. The microcontroller is also configured generate a resource assignment map based on the messages. The resource assignment map includes pairings between a respective one of the ingress data flows and a respective one of the egress data flows, and, for each of the pairings, an indication of a respective network resource assigned to exchange the egress data flow of that pairing with a respective one of the leaf nodes. The microcontroller is also configured to generate a command to cause the transceiver to transmit the egress data flows in accordance with the resource assignment map.

A low-level reset message having a reset level provides a mechanism for an optical line terminal (OLT) to remotely reset a dysfunctional optical network unit (ONU). The reset message includes a reset level field which allows the OLT to instruct the ONU to perform a reset of some or all of its hardware and software components.

A low-level reset message having a reset level provides a mechanism for an optical line terminal (OLT) to remotely reset a dysfunctional optical network unit (ONU). The reset message includes a reset level field which allows the OLT to instruct the ONU to perform a reset of some or all of its hardware and software components.

In a multi-layer network, a control load in the upper layer network increases, and the usage efficiency and the reliability of the entire network decrease; therefore, a multi-layer network system according to an exemplary aspect of the present invention includes a first network manager configured to set a logical path in a first network layer; and a second network manager configured to set a physical path corresponding to the logical path, in a second network layer, wherein the second network manager includes a network information storage configured to store physical network information including physical route information and transmission characteristic information on the second network layer, and the first network manager sets the logical path based on the physical network information.

In a multi-layer network, a control load in the upper layer network increases, and the usage efficiency and the reliability of the entire network decrease; therefore, a multi-layer network system according to an exemplary aspect of the present invention includes a first network manager configured to set a logical path in a first network layer; and a second network manager configured to set a physical path corresponding to the logical path, in a second network layer, wherein the second network manager includes a network information storage configured to store physical network information including physical route information and transmission characteristic information on the second network layer, and the first network manager sets the logical path based on the physical network information.