An optical system is provided comprising a first node and a channel drop add device. The first node is configured to transmit data onto an optical fiber in a first line direction. The channel drop add device (501) is adapted to receive and add channels onto the optical fiber thereby transmitting the data into the first and a second line direction. The network further comprises a second node configured to form a transmitter/receiver function. The second node is configured to receive data on said optical fiber from said first and second line directions. Further, the second node is adapted to synchronize received data from said first and second line directions by delaying the data signals seeing the shortest delay, by a delay device.

An optical system is provided comprising a first node and a channel drop add device. The first node is configured to transmit data onto an optical fiber in a first line direction. The channel drop add device (501) is adapted to receive and add channels onto the optical fiber thereby transmitting the data into the first and a second line direction. The network further comprises a second node configured to form a transmitter/receiver function. The second node is configured to receive data on said optical fiber from said first and second line directions. Further, the second node is adapted to synchronize received data from said first and second line directions by delaying the data signals seeing the shortest delay, by a delay device.

An autonomous mining system includes a real-time digital video transmission sub-system configured to obtain video streams from underground, and transfer the video streams to a control center located above ground; and an exploration and maintenance sub-system located underground, and configured to extract a resource and bring the resource to the surface, based exclusively on commands received from the control center through the real-time digital video transmission sub-system.

There is provided a communication method used in a communication system in which a plurality of communication apparatuses is connected by an optical ring network, the communication method including: setting one of the plurality of communication apparatuses as a master communication apparatus and the other communication apparatuses as slave communication apparatuses, causing the master communication apparatus to transmit an optical signal at transmission timing determined in the master communication apparatus; causing the master communication apparatus to transmit an assignment signal for assigning, to the slave communication apparatuses, transmission timing at which an optical signal on at least one wavelength is time-division multiplexed and transmitted; and causing the slave communication apparatuses to transmit an optical signal to the optical ring network based on transmission timing assigned by the assignment signal received from the master communication apparatus. As a result, the number of wavelengths needed for communication is reduced, and even when communication paths increases due to an increase in the number of optical transmission apparatuses, there is no need to increase the number of wavelengths, thereby solving the problem in economic efficiency.

There is provided a communication method used in a communication system in which a plurality of communication apparatuses is connected by an optical ring network, the communication method including: setting one of the plurality of communication apparatuses as a master communication apparatus and the other communication apparatuses as slave communication apparatuses, causing the master communication apparatus to transmit an optical signal at transmission timing determined in the master communication apparatus; causing the master communication apparatus to transmit an assignment signal for assigning, to the slave communication apparatuses, transmission timing at which an optical signal on at least one wavelength is time-division multiplexed and transmitted; and causing the slave communication apparatuses to transmit an optical signal to the optical ring network based on transmission timing assigned by the assignment signal received from the master communication apparatus. As a result, the number of wavelengths needed for communication is reduced, and even when communication paths increases due to an increase in the number of optical transmission apparatuses, there is no need to increase the number of wavelengths, thereby solving the problem in economic efficiency.

A single-fiber bidirectional optical ring system includes: a central station; slave stations; and a network which connects the central station and the slave stations in a ring shape by optical fibers. The central station includes: a first single-fiber bidirectional optical transceiver connected in a clockwise direction of the network, which outputs a downstream optical signal of a second wavelength and receives an upstream optical signal of a first wavelength; a second single-fiber bidirectional optical transceiver connected in a counterclockwise direction of the network, which outputs a downstream optical signal of the second wavelength and receives an upstream optical signal of the first wavelength; and a first time synchronization control circuit that adjusts timings at which the downstream optical signals of the second wavelength are outputted, and causes the first and second single-fiber bidirectional optical transceivers to output the downstream optical signals of the second wavelength in different time slots.

A single-fiber bidirectional optical ring system includes: a central station; slave stations; and a network which connects the central station and the slave stations in a ring shape by optical fibers. The central station includes: a first single-fiber bidirectional optical transceiver connected in a clockwise direction of the network, which outputs a downstream optical signal of a second wavelength and receives an upstream optical signal of a first wavelength; a second single-fiber bidirectional optical transceiver connected in a counterclockwise direction of the network, which outputs a downstream optical signal of the second wavelength and receives an upstream optical signal of the first wavelength; and a first time synchronization control circuit that adjusts timings at which the downstream optical signals of the second wavelength are outputted, and causes the first and second single-fiber bidirectional optical transceivers to output the downstream optical signals of the second wavelength in different time slots.

Provided are a method and a device for implementing timeslot synchronization. The method includes: a master node performing timeslot synchronization training of an OBTN according to a timeslot length of the OBTN. By adopting the solution provided by the embodiments of the present disclosure, an FDL does not need to be considered in node design, the node design is simplified, the time precision of synchronization is improved and no loss is caused to optical efficiency.

Provided are a method and a device for implementing timeslot synchronization. The method includes: a master node performing timeslot synchronization training of an OBTN according to a timeslot length of the OBTN. By adopting the solution provided by the embodiments of the present disclosure, an FDL does not need to be considered in node design, the node design is simplified, the time precision of synchronization is improved and no loss is caused to optical efficiency.

According to some embodiments, a network architecture is disclosed. The network architecture includes a plurality of processing network nodes. The network architecture further includes at least one broadcasting medium to interconnect the plurality of processing network nodes where the broadcasting medium includes an integrated waveguide. The network architecture also includes a broadcast and weight protocol configured to perform wavelength division multiplexing such that multiple wavelengths coexist in the integrated waveguide available to all nodes of the plurality of processing network nodes.