A line replacement unit includes a terminal controller, and a plastic optical fiber serial interface module (POFSIM) coupled between the terminal controller and the data bus. The POFSIM is configured to transmit digital optical signals to the data bus based on electrical signals received from the terminal controller, and transmit electrical signals to the terminal controller based on digital optical signals received from the data bus.

An optical communication system configured with a station-side apparatus and a plurality of subscriber-side apparatuses in a bus network topology includes an optical amplification unit installed on a station side, and a drop unit configured to branch an optical signal and excitation light, wherein the optical amplification unit includes an amplifier configured to amplify a downlink signal, and an excitation light output unit configured to output the excitation light for amplifying an uplink signal to a communication path, and the drop unit changes a branching ratio in accordance with a wavelength of the optical signal so that a transmission loss of the excitation light with respect to a trunk fiber is reduced.

An optical communication system configured with a station-side apparatus and a plurality of subscriber-side apparatuses in a bus network topology includes an optical amplification unit installed on a station side, and a drop unit configured to branch an optical signal and excitation light, wherein the optical amplification unit includes an amplifier configured to amplify a downlink signal, and an excitation light output unit configured to output the excitation light for amplifying an uplink signal to a communication path, and the drop unit changes a branching ratio in accordance with a wavelength of the optical signal so that a transmission loss of the excitation light with respect to a trunk fiber is reduced.

At least one source of light mounted in a terrestrial vehicle optically couples to one or more light-bearing conduits. Various sizes of conduit can be utilized and the conduits can be grouped or physically separated. One, some, or all of these light-bearing conduits may carry any or all of visible light, data-bearing light, and power conveying light for use by any of a variety of illumination components, data-capable components, and light-to-electricity conversion components, respectively. A given component may itself constitute both an illumination component and a data-capable component, or both an illumination component and a light-to-electricity conversion component, or both a data-capable component and a light-to-electricity conversion component, or a component that constitutes each of an illumination component, a data-capable component, and a light-to-electricity conversion component as desired.

At least one source of light mounted in a terrestrial vehicle optically couples to one or more light-bearing conduits. Various sizes of conduit can be utilized and the conduits can be grouped or physically separated. One, some, or all of these light-bearing conduits may carry any or all of visible light, data-bearing light, and power conveying light for use by any of a variety of illumination components, data-capable components, and light-to-electricity conversion components, respectively. A given component may itself constitute both an illumination component and a data-capable component, or both an illumination component and a light-to-electricity conversion component, or both a data-capable component and a light-to-electricity conversion component, or a component that constitutes each of an illumination component, a data-capable component, and a light-to-electricity conversion component as desired.

Embodiments of this application disclose a communication method and an apparatus, and relate to the communications field, to resolve a problem of how to simultaneously perform transmission by using a plurality of light sources and increase transmission efficiency in a multi-light source scenario in an optical camera communications system. A specific solution is: generating N physical frames, where each of the physical frames includes a preamble, a mode indication, and valid data, the mode indication is used to indicate a sending mode of N light sources, the sending mode is a diversity mode or a multiplexing mode, and N is a positive integer greater than or equal to 2; and sending the N physical frames by using the N light sources, where one light source sends one physical frame. The embodiments of this application are used in an optical camera communication process.

Embodiments of this application disclose a communication method and an apparatus, and relate to the communications field, to resolve a problem of how to simultaneously perform transmission by using a plurality of light sources and increase transmission efficiency in a multi-light source scenario in an optical camera communications system. A specific solution is: generating N physical frames, where each of the physical frames includes a preamble, a mode indication, and valid data, the mode indication is used to indicate a sending mode of N light sources, the sending mode is a diversity mode or a multiplexing mode, and N is a positive integer greater than or equal to 2; and sending the N physical frames by using the N light sources, where one light source sends one physical frame. The embodiments of this application are used in an optical camera communication process.

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.

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.

Messages on controller area network (CAN) buses are communicated over subsea links. Messages are sent as electrical or optical signals. The present invention provides a subsea CAN BUS electronic distribution unit (EDU) for transmitting, receiving, converting, and routing electrical or optical signals sent over a subsea CAN BUS network. The CAN BUS EDU of the present invention is contained within a single housing and combines the functions of transmitting, receiving, converting, and routing electrical or optical signals sent over a subsea CAN BUS network that would typically be handled by multiple devices.