Abstract: In one embodiment, a semiconductor storage device includes a lower electrode layer, a lower insulator, an upper electrode layer and an upper insulator along a first direction. The device further includes a first insulator provided on a side of a second direction of the upper electrode layer, and a second insulator provided between the upper electrode layer and the lower/upper/first insulator. The device further includes a charge storage layer, a third insulator and a semiconductor layer sequentially provided on a side of the second direction of the first insulator. A side face of the first insulator on a side of the upper electrode layer has a convex shape, the charge storage layer includes a first portion having a first thickness, and a second portion having a second thickness less than the first thickness, and the first portion is in contact with the first insulator.

Abstract: An optical frequency control device includes: a detection circuit to receive first light including a first frequency, receive second light including a second frequency, modulate the first light with a local oscillation signal, and detect a differential beat signal between the frequency of sideband light included in the modulated first light and the second frequency; a light source control circuit to change the second frequency by frequency-dividing the differential beat signal with a first frequency division number, by frequency-dividing a reference signal with a second frequency division number, and by outputting a phase error signal indicating a phase difference between the frequency-divided differential beat signal and the frequency-divided reference signal; and a signal processing unit to set each of the first frequency division number and the second frequency division number according to the set value of a frequency difference between the first frequency and the second frequency.

Abstract: An orientation direction control device includes: an orientation direction control information acquisition unit to acquire orientation direction control information for controlling an orientation direction in which a first optical communication terminal as a first transmission/reception device transmits and receives light; and a capture and tracking control unit as an orientation direction control unit to control an orientation direction in which a second optical communication terminal as a second transmission/reception device transmits and receives the light or a radio wave on the basis of the orientation direction control information acquired by the orientation direction control information acquisition unit.

Abstract: Provided is a digital switch including: a plurality of input-side memories, which are arranged in a one-to-one correspondence with a plurality of input ports, and are configured to accumulate time-division multiplexed data; a plurality of output-side memories, which are arranged in a one-to-one correspondence with a plurality of output ports, and are configured to accumulate time-division multiplexed data; and a switch matrix configured to receive, as input, the time-division multiplexed data read out in every cycle from each of the plurality of input-side memories, and execute routing for selecting, in accordance with a connection control signal received from outside, any one of the plurality of output-side memories such that the time-division multiplexed data read out in every cycle is output from each of the plurality of output ports without causing a difference in delay, to output the time-division multiplexed data.

Abstract: A multi-stage demultiplexing circuit in which a plurality of circuits each combining a selector and a frequency decimation circuit are connected is included. The selector selects one of input signals based on a control signal, and generates a plurality of output signals. The plurality of output signals output from the selector are input to the frequency decimation circuit, and the frequency decimation circuit performs frequency conversion processing, low pass filter processing, and down-sampling processing based on a control signal to generate an output signal. Two or more reception signals are input to the multi-stage demultiplexing circuit, and the multi-stage demultiplexing circuit executes demultiplexing processing based on a control signal so that an output signal that includes an unused band portion is prevented from being output downstream.

Abstract: An orientation direction control device includes: an orientation direction control information acquisition unit to acquire orientation direction control information for controlling an orientation direction in which a first optical communication terminal as a first transmission/reception device transmits and receives light; and a capture and tracking control unit as an orientation direction control unit to control an orientation direction in which a second optical communication terminal as a second transmission/reception device transmits and receives the light or a radio wave on the basis of the orientation direction control information acquired by the orientation direction control information acquisition unit.

Abstract: An optical frequency control device includes: a detection circuit to receive first light including a first frequency, receive second light including a second frequency, modulate the first light with a local oscillation signal, and detect a differential beat signal between the frequency of sideband light included in the modulated first light and the second frequency; a light source control circuit to change the second frequency by frequency-dividing the differential beat signal with a first frequency division number, by frequency-dividing a reference signal with a second frequency division number, and by outputting a phase error signal indicating a phase difference between the frequency-divided differential beat signal and the frequency-divided reference signal; and a signal processing unit to set each of the first frequency division number and the second frequency division number according to the set value of a frequency difference between the first frequency and the second frequency.

Abstract: A multi-stage demultiplexing circuit in which a plurality of circuits each combining a selector and a frequency decimation circuit are connected is included. The selector selects one of input signals based on a control signal, and generates a plurality of output signals. The plurality of output signals output from the selector are input to the frequency decimation circuit, and the frequency decimation circuit performs frequency conversion processing, low pass filter processing, and down-sampling processing based on a control signal to generate an output signal. Two or more reception signals are input to the multi-stage demultiplexing circuit, and the multi-stage demultiplexing circuit executes demultiplexing processing based on a control signal so that an output signal that includes an unused band portion is prevented from being output downstream.

Abstract: Provided is a digital switch including: a plurality of input-side memories, which are arranged in a one-to-one correspondence with a plurality of input ports, and are configured to accumulate time-division multiplexed data; a plurality of output-side memories, which are arranged in a one-to-one correspondence with a plurality of output ports, and are configured to accumulate time-division multiplexed data; and a switch matrix configured to receive, as input, the time-division multiplexed data read out in every cycle from each of the plurality of input-side memories, and execute routing for selecting, in accordance with a connection control signal received from outside, any one of the plurality of output-side memories such that the time-division multiplexed data read out in every cycle is output from each of the plurality of output ports without causing a difference in delay, to output the time-division multiplexed data.

Abstract: A delay measuring device of a communication system that includes the delay measuring device sequentially transmitting and receiving frames having a known frame length, and a measurement object device serving as an object for measuring a round trip time by the delay measuring device, includes: an RTT measuring unit to measure a round trip time with respect to the measurement object device a number of times using information for delay measurement in the frame; an RTT change detection unit to detect a change of a value of the round trip time based on the values of the round trip time thus measured; and an RTT determination unit to determine a value of the round trip time to be adopted, from among the values of the round trip time, based on the change of a value of the round trip time.

Abstract: A delay measuring device of a communication system that includes the delay measuring device sequentially transmitting and receiving frames having a known frame length, and a measurement object device serving as an object for measuring a round trip time by the delay measuring device, includes: an RTT measuring unit to measure a round trip time with respect to the measurement object device a number of times using information for delay measurement in the frame; an RTT change detection unit to detect a change of a value of the round trip time based on the values of the round trip time thus measured; and an RTT determination unit to determine a value of the round trip time to be adopted, from among the values of the round trip time, based on the change of a value of the round trip time.

Abstract: An optical transmission system includes: a first optical transmission device that transmits a first frame including a control signal; and a second optical transmission device that receives the first frame, inserts, into a control signal, phase information indicating a transmission position within a frame transmitted at a time at which the control signal of the first frame is received, and transmits a second frame including the control signal into which the phase information is inserted. The first optical transmission device receives the second frame and measures a transmission delay time between the first optical transmission device and the second optical transmission device on the basis of information indicating a time at which the control signal of the first frame is transmitted, information indicating a time at which the control signal of the second frame is received, and the phase information.

Abstract: A reception device has a receiving unit, an extracting unit and an outputting part. The receiving unit receives a lane signal transmitted through each of a plurality of lanes from a transmission device that partitions an OTU frame into a plurality of the lane signal. For each of the plurality of lanes, the extracting unit extracts, from the lane signal received by the receiving unit, data included in an overhead of an OTU frame. The outputting part outputs, as information indicating communication conditions of the lanes transmitting the lane signal from which the data is extracted by the extracting unit, information relating to the data extracted by the extracting unit.

Abstract: Included are a report-frame analysis unit that extracts a requested bandwidth from a report frame; an upload-bandwidth calculation unit that calculates the upload bandwidth; a residual-time calculation unit that acquires the residual time of each LLID before an allowable delay time; a priority calculation unit that acquires a priority of a data request corresponding to the report frame on the basis of the residual time; a report-request registration unit that generates a report request requesting allocation of an upload bandwidth for a report frame and that decides the priority of the report request; an allocation-order reading unit that decides the allocation order for the data request and the report request on the basis of the priority; and a gate-frame creation unit that decides a transmission-permitted time slot for each LLID on the basis of the allocation order and the upload bandwidth and that creates a gate frame.