Provided is a wavelength path communication node device with no collision of wave lengths and routes, capable of outputting arbitrary wavelengths, and capable of outputting them to arbitrary routes. An add/drop multiplexer (11) includes a communication unit (101) that communicates an optical signal with at least one client device and at least one network and a control unit (102) that indicates a transfer destination of the optical signal according to an attribute of the received optical signal to the communication unit (101). The control unit (102) indicates an attenuation amount of the optical signal to the communication unit (101) for each connected device. When a connected device is changed, the control unit (102) instructs the communication unit (101) to change the attenuation amount. The communication unit (101) attenuates the optical signal with the attenuation amount indicated by the control unit (102) and transfers the attenuated optical signal to a transfer destination.

Provided is a wavelength path communication node device with no collision of wave lengths and routes, capable of outputting arbitrary wavelengths, and capable of outputting them to arbitrary routes. An add/drop multiplexer (11) includes a communication unit (101) that communicates an optical signal with at least one client device and at least one network and a control unit (102) that indicates a transfer destination of the optical signal according to an attribute of the received optical signal to the communication unit (101). The control unit (102) indicates an attenuation amount of the optical signal to the communication unit (101) for each connected device. When a connected device is changed, the control unit (102) instructs the communication unit (101) to change the attenuation amount. The communication unit (101) attenuates the optical signal with the attenuation amount indicated by the control unit (102) and transfers the attenuated optical signal to a transfer destination.

A semiconductor circuit is provided having a crossbar switch arrangement, which includes at least one multiplexer, an output of which corresponds to an output of the crossbar switch arrangement. The arrangement also includes: a set of input lines connected to data inputs of the multiplexer, the input lines extending along a first direction of the semiconductor circuit; and a set of select lines connected to select inputs of the multiplexer, the select lines extending along a second direction of the semiconductor circuit, where the second direction differs from the first direction. The multiplexer includes at least one multiplexing circuit for generating a multiplexed signal from signals present at the input lines and at least one primary output driver for generating an output signal from the multiplexed signal.

A non-blocking crossbar switch architecture is disclosed that circumvents the problem present in prior art crossbar switches where input signals may oversubscribe the available inter-die bandwidth. The new non-blocking crossbar switch architecture is split across a plurality of semiconductor dice, including a plurality of interleaved crossbar switch segments. Only one crossbar switch segment is implemented on each semiconductor die. A plurality of input ports and output ports are coupled to the crossbar switch. The crossbar switch is non-blocking, i.e. any one output port not currently receiving data may receive data from any one input port.

It is an object to monitor signal flow (optically switched state) in an optical node without using a monitor light. In each of output ports of the optical node, a part of output signals is turned back, and the output signal light is subjected to intensity modulation or phase modulation, assigned port identification information, and allowed to reverse in the optical node. From an input port corresponding to the reversed output signal, a plurality of signals turned back are output. The plurality of signals are appropriately converted into intensity modulation from phase modulation and separated by a device having a spectroscopic function, and identification information is read out based on an intensity of a signal light for each signal, thereby determining an optically switched state to an output port corresponding to the input port.

It is an object to monitor signal flow (optically switched state) in an optical node without using a monitor light. In each of output ports of the optical node, a part of output signals is turned back, and the output signal light is subjected to intensity modulation or phase modulation, assigned port identification information, and allowed to reverse in the optical node. From an input port corresponding to the reversed output signal, a plurality of signals turned back are output. The plurality of signals are appropriately converted into intensity modulation from phase modulation and separated by a device having a spectroscopic function, and identification information is read out based on an intensity of a signal light for each signal, thereby determining an optically switched state to an output port corresponding to the input port.

An optical reception apparatus includes an equalization processor, an extraction unit, a first ratio calculator, and an instruction transmitter. The equalization processor suppresses fluctuations in amplitude of an electrical signal obtained by converting an optical signal including a plurality of pilot symbols subjected to BPSK modulation by an optical transmission apparatus. The extraction unit extracts the pilot symbols from the electrical signal with suppressed fluctuations in amplitude. The first ratio calculator calculates a ratio of an amplitude component to a phase component of each of the pilot symbols extracted by the extraction unit. The instruction transmitter transmits information relating to skew adjustment based on the ratio of the amplitude component to the phase component calculated by the first ratio calculator for each of different control values to the optical transmission apparatus.

Methods and apparatuses for enhancing flatness of frequency response of couplings of radio frequency (RF) ports in an RF switch matrix. Techniques include determining a second RF port has been selected to be coupled to a first RF port via a coupling, obtaining an indication of a frequency or frequencies to be carried via the coupling, determining an amount of attenuation or amplification for the coupling for the frequency or frequencies, and adjusting attenuation or amplification applied to the coupling according to the determined amount attenuation or amplification.

Techniques including controlling coupling and uncoupling of RF ports included in an RF switch matrix including first-side RF ports and second-side RF ports, where each of the first-side RF ports is configured to be selectively coupled to at least one of two or more of the second-side RF ports, identifying one or more of the second-side RF ports as active ports including an active port, causing the RF switch matrix to couple the active port to a signal port included in the first-side RF ports, obtaining at least one of a bit error rate and a signal to noise ratio for a demodulation of an RF stream received via the active port, and causing, in response to at least one of the bit error rate or the signal to noise ratio, the RF switch matrix to couple the signal port to a spare port included in the second-side RF ports.

Provided is an optical transmission module which can generate PAM4 optical modulation signals without converting a plurality of binary electric signals to a multi-level electric signal. An optical transmission module (200) comprising: a light source (60) for emitting continuous waveform (CW) light; optical modulators (51,52,53) arranged in series with a path of the CW light configured to modulate the CW light by switching relatively large absorption and relatively small absorption of the optical modulators in response to a modulation signal applied to the respective optical modulators; and an arithmetic logic circuit (100) configured to receive a plurality of binary electrical signals, and then to perform logic operation on the plurality of binary electrical signals for generating a new plurality of binary electrical signals, wherein each of the new plurality of binary electrical signals is applied to the respective optical modulators as the modulation signal.