Abstract: A security system includes an information transmission device, and a security device to which a target device is connectable. The information transmission device and the security device are connected to each other via a network. The information transmission device transmits, to the security device, generation information to be used for generating reference identification information. The security device generates the reference identification information by using the generation information received from the information transmission device via the network. The security device acquires identification information of the target device connected to the security device. The security device compares the acquired identification information with the generated reference identification information, and determines validity of the target device connected thereto, based on a result of comparison.

Abstract: A detection system includes: a signal output unit configured to output, to a measurement target, a measurement signal that exhibits a predetermined temporal change; a signal measurement unit configured to measure a response signal, to the measurement signal, from the measurement target; a calculation unit configured to calculate an impulse response of the measurement target, based on a measurement result of the response signal measured by the signal measurement unit; and a detection unit configured to detect abnormality regarding the measurement target, based on the impulse response calculated by the calculation unit.

Abstract: A detection device includes: a switch provided to a transmission path that connects a plurality of function units to each other; a measurement unit configured to measure a signal that passes the transmission path, at a first node on a first end side of the switch and at a second node on a second end side of the switch; and a detection unit configured to compare a measurement result at the first node and a measurement result at the second node, which are obtained by the measurement unit, with a reference measurement result which is a measurement result for reference, and detect abnormality regarding the transmission path, based on a result of the comparison.

Abstract: A vehicle-use communication system includes an in-vehicle device and a portable device. The in-vehicle device transmits a signal from a plurality of transmitting antennas provided in a vehicle. The portable device measures the received signal strength of the signal transmitted from each of the plurality of transmitting antennas and transmits a response signal containing the received signal strength of each signal. The in-vehicle device receives the response signal and stores: small space information concerning a small space of a vehicle cabin; and large space information concerning being the entirety of the vehicle cabin. The in-vehicle device selects the small space information or the large space information in accordance with the situation, and determines whether the portable device is within the vehicle cabin on the basis of the selection of small space information or the large space information and the received signal strengths contained in the response signals.

Abstract: A vehicle-use communication system includes an in-vehicle device and a portable device. The in-vehicle device transmits a signal from a plurality of transmitting antennas provided in a vehicle. The portable device measures the received signal strength of the signal transmitted from each of the plurality of transmitting antennas and transmits a response signal containing the received signal strength of each signal. The in-vehicle device receives the response signal and stores: small space information concerning a small space of a vehicle cabin; and large space information concerning being the entirety of the vehicle cabin. The in-vehicle device selects the small space information or the large space information in accordance with the situation, and determines whether the portable device is within the vehicle cabin on the basis of the selection of small space information or the large space information and the received signal strengths contained in the response signals.