Abstract: Provided is an on-board apparatus that is connected to an on-board device and communicates with the on-board device, and includes a control unit configured to control communication with the on-board device, and a communication line for communicating with the on-board device, and the control unit communicates with the on-board device via the communication line, detects a communication load on the communication line, and controls a communication speed of communication that is performed via the communication line, based on the detected communication load.

Abstract: A differential signal represented by a voltage difference between two signals that propagate through two signal lines is input to a signal processing circuit from a connector. A first suppressing circuit and a second suppressing circuit suppress peak values of the two signals. A DC removing circuit removes DC components of the two signals. A common mode choke coil (noise removing circuit) removes common mode noise included in the two signals. The DC removing circuit and the noise removing circuit are disposed between the first suppressing circuit and the second suppressing circuits. If the voltage of the signal line is a first threshold voltage, a current flows through a first suppressing device (first connection device). If the voltage of the signal line is a second threshold voltage, a current flows through a second suppressing device (second connection device). The second threshold voltage is less than the first threshold voltage.

Abstract: An in-vehicle communication system, comprises: a first in-vehicle communication device and a second in-vehicle communication device transmitting and receiving a signal to and from each other by a predetermined communication protocol related to Ethernet® (registered trademark), wherein the first in-vehicle communication device includes a PHY unit having a communication circuit, and a determination processing unit for determining whether or not the second in-vehicle communication device is in a link-down sleep state, when determined that the second in-vehicle communication device is in the sleep state, the PHY unit outputs a predetermined signal to the second in-vehicle communication device, and the second in-vehicle communication device includes a PHY unit having a communication circuit, a detection circuit for detecting the predetermined signal input to the PHY unit, and a power supply circuit for waking up the PHY unit when the detection circuit detects the predetermined signal.

Abstract: An in-vehicle communication device for transmitting and receiving a signal by a predetermined communication protocol related to Ethernet® (registered trademark), the in-vehicle communication device comprising: a control circuit configured to generate transmission data including interrupt data inserted into an inter-frame gap between Ethernet frames; and a PHY unit having a communication circuit configured to convert the transmission data generated by the control circuit into a signal and transmit the signal.

Abstract: In a relay device, a control unit stores, in a temporary storage unit data which is received by an Ethernet communication unit through a communication line. When the data stored in the temporary storage unit is transmitted, the control unit deletes the transmitted data from the temporary storage unit. When the control unit determines that, for the data received by the Ethernet communication unit, the amount of data stored in the temporary storage unit is equal to or greater than a threshold value, the Ethernet communication unit transmits instruction data giving an instruction to stop transmission through a communication line and to perform transmission through a communication bus.

Abstract: In a relay device, a communication unit receives a data frame transmitted cyclically through a communication line. A control unit stores, in a temporary storage unit, the data frame received by the communication unit. When the data frame stored in the temporary storage unit is transmitted, the control unit deletes the transmitted data frame from the temporary storage unit. When the control unit determines that, for the data frame received through the communication line, the amount of data relevant to the data frames stored in the temporary storage unit is equal to or greater than a threshold value, the communication unit transmits, through the communication line, a cycle change frame which gives an instruction to change a transmission cycle for transmitting the data frame to a longer cycle.

Abstract: In a relay device, a control unit stores, in a temporary storage unit data which is received by an Ethernet communication unit through a communication line. When the data stored in the temporary storage unit is transmitted, the control unit deletes the transmitted data from the temporary storage unit. When the control unit determines that, for the data received by the Ethernet communication unit, the amount of data stored in the temporary storage unit is equal to or greater than a threshold value, the Ethernet communication unit transmits instruction data giving an instruction to stop transmission through a communication line and to perform transmission through a communication bus.

Abstract: In a relay device, a communication unit receives a data frame transmitted cyclically through a communication line. A control unit stores, in a temporary storage unit, the data frame received by the communication unit. When the data frame stored in the temporary storage unit is transmitted, the control unit deletes the transmitted data frame from the temporary storage unit. When the control unit determines that, for the data frame received through the communication line, the amount of data relevant to the data frames stored in the temporary storage unit is equal to or greater than a threshold value, the communication unit transmits, through the communication line, a cycle change frame which gives an instruction to change a transmission cycle for transmitting the data frame to a longer cycle.

Abstract: In a relay device, a control unit detects simultaneous transmission of a plurality of data through a first communication bus. When the number of times of detection of the simultaneous transmission within a predetermined time by the control unit is less than the predetermined number of times, a CAN communication unit starts transmission of data through the first communication bus. When the number of times of detection of the simultaneous transmission within the predetermined time by the control unit is equal to or greater than the predetermined number of times, an Ethernet communication unit transmits data through a first communication line.

Abstract: In a communication apparatus, an analog circuit executes an analog process to a differential signal in a condition that a potential of a first conductor is a reference. A communication circuit receives, via a connection circuit, a differential signal obtained by the execution of the analog process of the analog process is executed and generates, based on the received differential signal, a signal with a reference corresponding to a potential of a second conductor. An inductor (a connection element) is connected between the first conductor and the second conductor. The connection circuit includes a circuit element other than a capacitor.

Abstract: This on-vehicle communication system is an on-vehicle communication system including one or a plurality of switch devices each configured to relay data between a plurality of function units mounted to a vehicle. The on-vehicle communication system includes: a detection unit configured to detect an abnormality regarding a function unit; and a change unit configured to, when an abnormality has been detected by the detection unit, perform a protocol change process of causing the function unit for which the abnormality has been detected, to change a protocol that is used.

Abstract: In a communication apparatus, an analog circuit executes an analog process to a differential signal in a condition that a potential of a first conductor is a reference. A communication circuit receives, via a connection circuit, a differential signal obtained by the execution of the analog process of the analog process is executed and generates, based on the received differential signal, a signal with a reference corresponding to a potential of a second conductor. An inductor (a connection element) is connected between the first conductor and the second conductor. The connection circuit includes a circuit element other than a capacitor.