Abstract: A communication apparatus includes a communication unit, a power supply unit, a temperature monitoring unit, and a control unit. The communication unit communicates with an additional apparatus. The power supply unit supplies power to components mounted in the communication apparatus. The temperature monitoring unit monitors a temperature in the communication apparatus to detect presence or absence of a temperature abnormality. In a case where the temperature monitoring unit detects the temperature abnormality, the control unit performs power supply stop processing of stopping the power supply from the power supply unit to at least some of the components. Furthermore, the control unit stops or decreases communication of the communication unit in a case where the temperature monitoring unit detects the temperature abnormality.

Abstract: A first communication device, transmits a startup instruction signal and a second communication device restarts supply of power that has been stopped in a sleep state when receiving the startup instruction signal from the first communication device and includes transmission data in a startup completion signal when generating the start completion signal that is a response signal to the startup instruction signal.

Abstract: An aspect of the present invention is an optical communication system in which an optical line terminal and an optical network unit are connected by an optical communication line, in which when receiving a first activation signal from the optical line terminal in a sleep state, the optical network unit executes activation processing for transition from the sleep state to an activation state and notifies the optical line terminal of an activation time that is a time required for executing the activation processing, and the optical line terminal transmits the activation signal at a time of transmission of second and subsequent activation signals, and then the optical line terminal starts data transmission to the optical line terminal after elapse of the activation time a notification of which has been given from the optical network unit.

Abstract: A communication apparatus includes a plurality of devices, each of the plurality of devices includes a monitoring unit configured to monitor at least one other device to detect an error that has occurred in the other device, and each of the plurality of devices is monitored by at least one other device.

Abstract: A communication apparatus includes a communication unit, a power supply unit, a temperature monitoring unit, and a control unit. The communication unit communicates with an additional apparatus. The power supply unit supplies power to components mounted in the communication apparatus. The temperature monitoring unit monitors a temperature in the communication apparatus to detect presence or absence of a temperature abnormality. In a case where the temperature monitoring unit detects the temperature abnormality, the control unit performs power supply stop processing of stopping the power supply from the power supply unit to at least some of the components. Furthermore, the control unit stops or decreases communication of the communication unit in a case where the temperature monitoring unit detects the temperature abnormality.

Abstract: A communication apparatus includes a plurality of devices, each of the devices includes a monitoring unit that monitors at least one other device and detects an error that has occurred in the other device, and if an error is detected by the monitoring unit, the device performs a device reset indicating a reset of the operating state of the other device by the monitoring unit or a power source reset indicating a reset of the supply of electric power to the communication apparatus by a chain-of-command unit included in the device.

Abstract: A communication apparatus includes a plurality of devices, each of the plurality of devices includes a monitoring unit configured to monitor at least one other device to detect an error that has occurred in the other device, and each of the plurality of devices is monitored by at least one other device.