Abstract: A communication system includes a master communication device and a plurality of slave communication devices. The master communication device obtains, for each of the plurality of slave communication devices, multiple communication characteristics during wireless communication. The communication system further includes a storage unit storing multiple reference communication characteristics. The system determines an abnormality in wireless communication between the at least one master communication device and each of the plurality of slave communication devices based on strength of correlation between (a) an overall trend of the obtained multiple communication characteristics and (b) an overall trend of the multiple reference communication characteristics stored in the storage unit.

Abstract: A communication system includes a master communication device and slave communication devices. The master communication device obtains information indicative of communication characteristics. The communication system records a combination of the master communication device and at least one of the slave communication devices having a communication abnormality. The system finalizes an abnormal position where the abnormality is occurring when an abnormality-determined position is consistent with a recorded combination of the master communication device and the at least one of the slave communication devices having a communication abnormality.

Abstract: A wireless communication system is mounted on a mobile body, and includes: a master device; and a slave device that performs a wireless communication with the master device while switching a frequency channel. The master device determines whether the frequency channel is available. The master device reflects a result of frequency channel availability determination in a use of the frequency channel.

Abstract: A network system includes at least one transmission path and a plurality of terminal devices each connected to the transmission path. Each of the terminal devices includes a transceiver, a startup processing unit, and a switching unit. The transceiver is configured to operate either one of a first standby unit and a second standby unit according to a switching instruction. The switching unit is configured to output the switching instruction to the transceiver to operate the second standby unit when a transmission path empty period lasts for a predetermined preparation time or more after a non-designation period has lasted for a predetermined operation determination time or more.

Abstract: A relay device relays a management frame between nodes connected to mutually different communication buses. The relay device includes (i) communicator units provided respectively to correspond to the communication buses, and (ii) communication controller units provided respectively to correspond to the communicator units. The communication controller unit respectively includes a corresponding transmission buffer configured to store the management frame, which is to be transmitted from the communicator unit corresponding to the communication controller unit. In response to determining that the management frame is retained in the transmission buffer corresponding to the communication controller unit, the communication controller unit transmits the management frame, which is received at a present time and stored in the transmission buffer, from the communicator unit corresponding to the communication controller unit.

Abstract: A relay device in a communication system receives a plurality of wakeup frames from one or more than one communication device connected to each bus of a plurality of buses via a corresponding port. The relay device obtains an aggregated wakeup pattern by aggregating information on an operating mode of each communication device included in the plurality of wakeup frames so as to include predetermined information to be transmitted and received and reduce the number of wakeup patterns. By using the aggregated wakeup pattern obtained by aggregating the information on the operating mode, a wakeup frame for transmission to each bus via the corresponding port is prepared.

Abstract: A communication system, in which a plurality of nodes communicate with each other according to a communication protocol, which wakes up some of the plurality of nodes when a communication frame containing specific start information occurs on or is transmitted to the communication bus, includes a master node determines, for each of slave nodes, a start condition, which is a condition for transition of a subject node from a sleep state to a normal state. The master node transmits, to the communication bus, the determined start condition tailored for each of the slave nodes for a reception thereof by each of the slave nodes.

Abstract: A network system includes at least one transmission path and a plurality of terminal devices each connected to the transmission path. Each of the terminal devices includes a transceiver, a startup processing unit, and a switching unit. The transceiver is configured to operate either one of a first standby unit and a second standby unit according to a switching instruction. The switching unit is configured to output the switching instruction to the transceiver to operate the second standby unit when a transmission path empty period lasts for a predetermined preparation time or more after a non-designation period has lasted for a predetermined operation determination time or more.

Abstract: A relay device relays a management frame between nodes connected to mutually different communication buses. The relay device includes (i) communicator units provided respectively to correspond to the communication buses, and (ii) communication controller units provided respectively to correspond to the communicator units. The communication controller unit respectively includes a corresponding transmission buffer configured to store the management frame, which is to be transmitted from the communicator unit corresponding to the communication controller unit. In response to determining that the management frame is retained in the transmission buffer corresponding to the communication controller unit, the communication controller unit transmits the management frame, which is received at a present time and stored in the transmission buffer, from the communicator unit corresponding to the communication controller unit.

Abstract: A relay device in a communication system receives a plurality of wakeup frames from one or more than one communication device connected to each bus of a plurality of buses via a corresponding port. The relay device obtains an aggregated wakeup pattern by aggregating information on an operating mode of each communication device included in the plurality of wakeup frames so as to include predetermined information to be transmitted and received and reduce the number of wakeup patterns. By using the aggregated wakeup pattern obtained by aggregating the information on the operating mode, a wakeup frame for transmission to each bus via the corresponding port is prepared.

Abstract: A communication system, in which a plurality of nodes communicate with each other according to a communication protocol, which wakes up some of the plurality of nodes when a communication frame containing specific start information occurs on or is transmitted to the communication bus, includes a master node determines, for each of slave nodes, a start condition, which is a condition for transition of a subject node from a sleep state to a normal state. The master node transmits, to the communication bus, the determined start condition tailored for each of the slave nodes for a reception thereof by each of the slave nodes.

Abstract: A PoE power supply system includes a cable, a power supply device, a power reception device, and a request switch. The power supply device includes a power supply block and a power supply control block. The power supply block is configured to enable a connection state between the power supply device and the cable to be switched. The connection state includes a power supply state in which the power supply device is supplied with power required for operating the power supply device via the cable, and a standby state in which the power supply request signal is receivable by the power supply device via the cable. The power supply control block is configured to switch the connection state to the power supply state in response to receiving a power supply request signal output from the request switch and requesting the power supply device to resume supplying the power.

Abstract: A control unit of a suppression circuit turns on an inter-line switching element and maintains an ON state upon detection of a change in the level of a differential signal from high level to low level, and cancels the ON state after a predetermined period of time is measured. A continuous activation prevention unit sets a predetermined mask time period from the time of turning on the inter-line switching element, and masking is performed to prevent the control unit from detecting a change in the level of the differential signal from the high level to the low during the mask time period.

Abstract: A ringing suppressor circuit is connected to a differential signal transmission line that includes a high potential signal line and low potential signal line pair for transmitting high and low level differential signals, and includes a ringing suppressor and a stopper. When the differential signal changes to a high level, the ringing suppressor suppresses ringing by lowering the impedance between the signal lines by turning ON of a switching element. When a differential signal voltage drops below a voltage lowering determination voltage, the stopper stops the impedance lowering function of the ringing suppressor by turning OFF another switching element.

Abstract: A ringing suppression circuit is provided at one or more nodes each having a communication circuit executing communication with another node by transmitting a differential signal through a pair of communication lines connected to the nodes. The circuit includes a suppression circuit and an operation mode controller: The suppression circuit is configured to execute a suppression operation for suppressing ringing in the differential signal. The operation mode controller is configured to set an operation mode of the suppression circuit to one of: a normal operation mode, which enables the suppression circuit to execute the suppression operation in response to detecting a change in a level of the differential signal, and a permanent off mode, which disables the suppression circuit to execute the suppression operation on a steady basis.

Abstract: An electronic control unit coupled to a transmission line of a differential signal includes: a first suppression circuit suppressing a ringing effect and decreasing an impedance of the line for a first time interval when a level of the differential signal changes; a second suppression circuits suppressing a ringing effect and decreasing the impedance of the line for a second time interval when the level of the differential signal changes; and a switching unit isolating the second suppression circuit from the line when the operation power source energizes the electronic control unit, and connecting the second suppression circuit to the line when the operation power source does not energize the electronic control unit.

Abstract: An electronic control unit coupled to a transmission line of a differential signal includes: a first suppression circuit suppressing a ringing effect and decreasing an impedance of the line for a first time interval when a level of the differential signal changes; a second suppression circuits suppressing a ringing effect and decreasing the impedance of the line for a second time interval when the level of the differential signal changes; and a switching unit isolating the second suppression circuit from the line when the operation power source energizes the electronic control unit, and connecting the second suppression circuit to the line when the operation power source does not energize the electronic control unit.

Abstract: An information processing system made up of a plurality of controllers in a vehicle has a tamperproof configuration by including, in a specific controller among the plurality of controllers: a starter putting the specific controller among the plurality of controllers in a executable state which enables the specific controller among the plurality of controllers to execute a preset program; a determiner determining, before the specific controller among the plurality of controllers is put in the executable state, whether software that is memorized in a preset memory area and at least includes the preset program is tampered; and an outputter outputting, to one of processing devices outside the vehicle. In such manner, the tampering of the software is quickly detectable while preventing an increase of communication load of a communication network and/or the information processing system.

Abstract: A ringing suppression circuit connected to a transmission line to suppress ringing caused by the transmission line transmitting a differential signal using a pair of signal lines, the differential signal varying between a high level and a low level, the pair of signal lines including a high potential signal line and a low potential signal line, the ringing suppression circuit including: an inter-line switching element that is connected between the pair of signal lines; a control portion that performs a ringing suppression operation in response to detecting a level change in the differential signal, wherein the ringing suppression operation turns on the inter-line switching element to decrease an impedance between the pair of signal lines; and a suppression operation prohibiting portion that prohibits the control portion from performing the ringing suppression operation in response to detecting a signal caused by a signal on the transmission line.

Abstract: A ringing suppressor circuit is connected to a differential signal transmission line that includes a high potential signal line and low potential signal line pair for transmitting high and low level differential signals, and includes a ringing suppressor and a stopper. When the differential signal changes to a high level, the ringing suppressor suppresses ringing by lowering the impedance between the signal lines by turning ON of a switching element. When a differential signal voltage drops below a voltage lowering determination voltage, the stopper stops the impedance lowering function of the ringing suppressor by turning OFF another switching element.