The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. First and second slave station devices are slave station devices that cannot perform communication via the normal path. The magnitude relationship between backup path RTTs is opposite to the magnitude relationship between normal path RTTs. If the second normal path RTT for the second slave station device is longer than the first normal path RTT for the first slave station device, the first backup path RTT is longer than the second backup path RTT, and the second backup path RTT is shorter than the first backup path RTT. Based on this fact, the master station device limits the QuietWindow, which is used in ranging processing for measuring the backup path RTT, to a size smaller than a predetermined maximum size.

An optical access network includes an optical hub having at least one processor, and a plurality of optical fiber strands. Each optical fiber strand has a first strand end connected to the optical hub. The network further includes a plurality of nodes connected to at least one segment of a first fiber strand of the plurality of optical fiber strands. Each node is sequentially disposed at respective locations along the first fiber strand at different differences from the optical hub, respectively. The network further includes a plurality of end-points. Each end-point includes a receiver. Each respective receiver (i) has a different optical signal-to-noise ratio (OSNR) from the other receivers, (ii) is operably coupled with at least one node of the plurality of nodes, and (iii) is configured to receive the same optical wavelength signal from the first fiber strand as received by the other receivers.

A mini-optical line termination (OLT) includes at least one management card for providing control and management functions. A plurality of network cards having a predetermined number of ports are configured to support a predetermined number of subscribers by providing a gigabit passive optical network to the subscribers. At least one network device is coupled to an upstream device and the plurality of network cards. The at least one network device is configured to control the forwarding of data between the upstream device and the subscribers.

Aspects of the present disclosure relates to an indexing terminal including a multi-fiber ruggedized de-mateable connection location, a first single-fiber ruggedized de-mateable connection location and a second single-fiber ruggedized de-mateable connection location. The multi-fiber ruggedized de-mateable connection location includes a plurality of fiber positions with one of the fiber positions optically coupled to the first single fiber ruggedized de-mateable connection location.

An optical access network includes an optical hub having at least one processor, and a plurality of optical fiber strands. Each optical fiber strand has a first strand end connected to the optical hub. The network further includes a plurality of nodes connected to at least one segment of a first fiber strand of the plurality of optical fiber strands. Each node is sequentially disposed at respective locations along the first fiber strand at different differences from the optical hub, respectively. The network further includes a plurality of end-points. Each end-point includes a receiver. Each respective receiver (i) has a different optical signal-to-noise ratio (OSNR) from the other receivers, (ii) is operably coupled with at least one node of the plurality of nodes, and (iii) is configured to receive the same optical wavelength signal from the first fiber strand as received by the other receivers.

An optical access network includes an optical hub having at least one processor, and a plurality of optical fiber strands. Each optical fiber strand has a first strand end connected to the optical hub. The network further includes a plurality of nodes connected to at least one segment of a first fiber strand of the plurality of optical fiber strands. Each node is sequentially disposed at respective locations along the first fiber strand at different differences from the optical hub, respectively. The network further includes a plurality of end-points. Each end-point includes a receiver. Each respective receiver (i) has a different optical signal-to-noise ratio (OSNR) from the other receivers, (ii) is operably coupled with at least one node of the plurality of nodes, and (iii) is configured to receive the same optical wavelength signal from the first fiber strand as received by the other receivers.

[Problem] To provide a novel optical network which can be used as an in-vehicle optical backbone network and exhibits high capacity, low delay, low power consumption, low noise and low cost. [Solution] An optical network system, wherein: a signal processing unit 13 controls a light source 11, and generates an optical signal which includes an information portion to be read by one of the gateway units 5a, and a continuous light portion to be written thereby; a network control unit 15 generates an electrical signal which designates a gate y unit 5a and pertains to whether the information incorporated into the optical signal is to be read or written; and when designated by the electrical signal, each of the gateway units 5a transfers information to and from an electronic control unit 7, and reads information included in the corresponding optical signal or writes information in the continuous light portion, on the basis of the information included in the electrical signal about whether to read or write information.

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 only an L band. The example method may also include combining the one or more optical data signals. The example method may also include outputting the combined one or more optical data signals to a first WDM at the headend. The example method may also include outputting, by a first WDM, the one or more optical data signals to an amplifier at the headend. The example method may also include amplifying, by the amplifier, the one or more optical data signals. The example method may also include outputting the amplified one or more optical data signals to a coexistence filter. The example method may also include outputting, by the coexistence filter, the amplified one or more optical data signals to an optical switch. The example method may also include outputting, by the optical switch, an egress optical data signal to a first fiber.

A counter-directional optical network having multiple channels includes a source module connected with at least two network nodes by a fiber ribbon including an array of optical fibers. Each channel includes at least one optical fiber. The source module includes multiple signal sources, each signal source connected with one of the channels and operable to transmit a source signal in a direction in the channel. Each network node includes a modulator for processing the source signal with a data input signal forming a message signal, a switch for selecting one of the channels to transmit the message signal and a receiver connected with one of the channels for receiving a message signal from another node. The message signal is transmitted to the receiver of a receiving node in a direction opposite to the transmission direction of the source signal via the channel connected to the receiver of the receiving node.

[Problem] To provide a novel optical network which can be used as an in-vehicle optical backbone network and exhibits high capacity, low delay, low power consumption, low noise and low cost. [Solution] An optical network system, wherein: a signal processing unit 13 controls a light source 11, and generates an optical signal which includes an information portion to be read by one of the gateway units 5a, and a continuous light portion to be written thereby; a network control unit 15 generates an electrical signal which designates a gate y unit 5a and pertains to whether the information incorporated into the optical signal is to be read or written; and when designated by the electrical signal, each of the gateway units 5a transfers information to and from an electronic control unit 7, and reads information included in the corresponding optical signal or writes information in the continuous light portion, on the basis of the information included in the electrical signal about whether to read or write information.