There is provided a signal transmission device including reception processing units for respective channels, so as to enable multichannel transmission by dividing frequency bands. The total number of channels is equal to or greater than three. When full-duplex two-way communication is applied in any combination of two channels, one of reception processing unit include a signal suppressing unit configured to suppress a signal component of a channel other than a self channel.

The invention relates to an optoelectronic transceiver device comprising a first optical connector (OC1) capable of connection to a first bidirectional optical fibre (OF1), and a second optical connector (OC2) capable of connection to a second bidirectional optical fibre (OF2), the device further comprising: an insertion-extraction module (ADM) capable of: extracting a wave-length (λ.sub.Rx) from a plurality of wavelengths constituting a first optical signal received by the first optical connector (OC1) and transmitting the first optical signal without the extracted wavelength to the second optical connector (OC2); inserting a wavelength (λ.sub.Tx) into a second optical signal received by the second optical connector (OC2) and transmitting the second optical signal with the inserted wavelength to the first optical connector (OC1); an electric-optical conversion module (EC1) capable of providing the insertion-extraction module with the wavelength (λ.sub.Tx) inserted into the second optical signal from an incoming electric signal (Data Tx); and an optical-electric conversion module (EC2) capable of converting the wavelength (λ.sub.Rx) extracted from the first optical signal by the insertion-extraction module into an outgoing electric signal (Data Rx).

A system for testing reflections within a data transmission signal includes a data transmission line configured to transmit the signal in a downstream direction, and a test probe configured to electrically contact a contact point on the transmission line and measure a magnitude of a frequency response of the signal therein. The system further includes a spectrum capturing device in operable contact with the test probe, and configured to collect and arrange data of frequency response magnitudes measured by the test probe. The data transmission line includes at least a first impedance mismatch corresponding to a first reflection point along the transmission line, and the spectrum capturing device is configured to determine a severity of the first reflection based on a comparison of a first voltage V.sub.1 with a second voltage V.sub.2, where V.sub.1 represents a DC term, and where V.sub.2 represents a reflected energy of a subsequent impulse.

A method for aligning a first optical transceiver includes steps of splitting, directing, recording, and actuating. The splitting step includes splitting a light beam into a) a reference beam that propagates along a common optical path within the first optical transceiver and b) a transmit beam that that propagates away from the first optical transceiver and toward a second optical transceiver. The directing step includes directing, with a beam director, a receive beam from the second optical transceiver onto the common optical path. The recording step includes recording, with a tracking focal-plane array (FPA) that intersects the common optical path, a reference-position of the reference beam and an initial-received-position of the receive beam on the tracking FPA. The actuating step includes actuating the beam director based upon the initial-received-position to achieve a subsequent position of the receive beam on the tracking FPA.

Systems and methods for optical communication are provided. For instance, a method for optical communication can include receiving, by a first coupling module, a power-on signal from a first electronic device coupled to the first coupling module. The method can also include relaying, by the first coupling module, a first optical signal to a second coupling module coupled to a second electronic device. The method can also include relaying, by the second coupling module, in response to receipt of the first optical signal, a second optical signal to the first coupling module. The method can also include activating, by the first coupling module, in response to receipt of the second optical signal, a data transfer circuit for relaying data via an optical communication interface between the first coupling module and the second coupling module.

A communication network includes an optical hub having a first coherent optics transceiver, a fiber node having a second coherent optics transceiver, an optical transport medium operably coupling the first coherent optics transceiver to the second coherent optics transceiver, a first optical circulator disposed at the optical hub, and a second optical circulator disposed at the fiber node. The first coherent optics transceiver is configured to (i) transmit a downstream optical signal at a first wavelength, and (ii) receive an upstream optical signal at the first wavelength. The second coherent optics transceiver is configured to (i) receive the downstream optical signal from the first coherent optics transceiver at the first wavelength, and (ii) transmit the upstream optical signal at the first wavelength. The first and second optical circulators are configured to separate the downstream optical signal from the upstream optical signal.

Method comprises: receiving, at a receiving side of the optical transceiver, a received optical signal, wherein the received optical signal corresponds to a first transmit optical signal carrying the data transmitted by an optical source on a first transmission link that includes an optical fiber, determining an interference component of an interference signal in the received optical signal, wherein the interference component is induced by a transmission by a transmitting side of the optical transceiver of a second transmit optical signal on a second transmission link that includes the optical fiber, and processing the received optical signal, based on the determined interference component, to obtain an estimate of the first transmit optical signal.

A terminal device registration method and a device, where the method includes sending upstream registration window information to a terminal device, where the upstream registration window information indicates a starting position of an upstream registration window to the terminal device, receiving an upstream access signal sent by the terminal device from the starting position of the upstream registration window, where the upstream access signal includes a correlation sequence symbol and at least one orthogonal frequency division multiplexing (OFDM) symbol following the correlation sequence symbol, the correlation sequence symbol is constituted by a first sequence that meets a preset condition, and the at least one OFDM symbol modulates access information by means of differential phase modulation in a frequency domain, and performing upstream ranging according to the starting position of the upstream registration window and the correlation sequence symbol.

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.

Systems and methods to implement a USB and Thunderbolt optical signal transceiver are described. One method includes detecting presence of a USB sideband signal received over an optical communication channel and associated with a USB communication request. Responsive to the detecting, the method may determine that the USB communication request corresponds to a USB communication mode and perform a sideband negotiation. The USB communication mode may be enabled. A specified number of channels associated with the USB communication request may be determined. USB communication may be performed using the specified number of channels over the optical communication channel in the USB communication mode.