Abstract: Provided are an on-board update system, an on-board update apparatus, an on-board device, and an update method, updates the on-board device without limiting the use of the vehicle for the convenience of the user. An on-board update system for updating a program or data stored in a storage unit of an on-board device transmits an update program or data stored in an update storage unit to the on-board device, and interrupts the transmission of the update program or data to the on-board device depending on the circumstances around a vehicle. The on-board device includes, in its storage unit, a first storage region in which a pre-update program or data is stored and a second storage region configured to store an update program or data. The on-board device restores the execution of the pre-update program or data if the transmission of the update program or data is interrupted.

Abstract: A vehicle communication system comprising a vehicle-mounted device that transmits signals from a plurality of transmitting antennas on a vehicle; and a mobile device that receives signals transmitted from the vehicle-mounted device and transmits a response signal including received signal strengths of received signals. The transmitting antennas include: a first transmitting antenna in the vehicle cabin which is deviated in one direction in the width direction of the vehicle from the central portion in the width direction; and a second transmitting antenna nearer to the other side surface in the width direction of the vehicle. The device determines whether or not the mobile device is present inside an area containing the vehicle interior space and having a boundary surface following at least one side surface in the width direction of the vehicle, based on received signal strengths of signals transmitted from the first transmitting antenna and the second transmitting antenna.

Abstract: A tire air pressure monitoring system that includes a plurality of sensors; a memory that stores a plurality of tire positions at which the plurality of tires are respectively provided and identifiers of the sensors provided in the tires at the plurality of tire positions in correspondence with each other; and a controller that is configured to: perform wireless communication with the plurality of sensors with use of the identifiers of the sensors and monitors the air pressures of the tires, and transmit to at least one of the tire positions, at different timings, a first request signal that requests a piece of information and includes an identifier of the identifiers that is stored by the memory in correspondence with the at least one tire position, and a second request signal that requests a piece of information regardless of identifier content.

Abstract: A tire pressure monitoring system includes a plurality of detection devices that are provided in respective ones of a plurality of tires of a vehicle and each wirelessly transmit an air pressure signal including air pressure information of tire in response to a request signal and a monitoring device that transmits the request signal to each of the detection devices and receives the air pressure signal transmitted from each of the detection devices in response to the request signal, to monitor air pressure of each of the tires. Each of the detection devices, when receiving a request signal, measures the received signal strength of the received request signal and transmits to the monitoring device an air pressure signal at a different diming in accordance with the measured received signal strength. The monitoring device receives the air pressure signals transmitted from the plurality of detection devices at different timings.

Abstract: A tire pressure monitoring system includes a plurality of detection devices that are provided in respective ones of a plurality of tires of a vehicle and each wirelessly transmit an air pressure signal including air pressure information of tire in response to a request signal and a monitoring device that transmits the request signal to each of the detection devices and receives the air pressure signal transmitted from each of the detection devices in response to the request signal, to monitor air pressure of each of the tires. Each of the detection devices, when receiving a request signal, measures the received signal strength of the received request signal and transmits to the monitoring device an air pressure signal at a different diming in accordance with the measured received signal strength. The monitoring device receives the air pressure signals transmitted from the plurality of detection devices at different timings.

Abstract: A vehicle communication system comprising a vehicle-mounted device that transmits signals from a plurality of transmitting antennas on a vehicle; and a mobile device that receives signals transmitted from the vehicle-mounted device and transmits a response signal including received signal strengths of received signals. The transmitting antennas include: a first transmitting antenna in the vehicle cabin which is deviated in one direction in the width direction of the vehicle from the central portion in the width direction; and a second transmitting antenna nearer to the other side surface in the width direction of the vehicle. The device determines whether or not the mobile device is present inside an area containing the vehicle interior space and having a boundary surface following at least one side surface in the width direction of the vehicle, based on received signal strengths of signals transmitted from the first transmitting antenna and the second transmitting antenna.

Abstract: A tire pressure monitoring system includes a plurality of detection devices that are provided a plurality of tires of a vehicle and each wirelessly transmit an air pressure signal including air pressure information in response to a request signal and a monitoring device that transmits the request signal to each of the detection devices and receives the air pressure signal transmitted from each of the detection devices in response to the request signal, to monitor air pressure of each of the tires. The monitoring device includes a request signal transmitting unit that transmits the request signal to a region including one tire position and an air pressure signal receiving unit that receives an air pressure signal. The monitoring device determines whether or not the air pressure signals transmitted from the plurality of detection devices are received and changes the transmission strength of the request signal depending on the determination result.

Abstract: A monitoring device receives air pressure signals transmitted from a plurality of detection devices that are respectively provided in tires of a vehicle and wirelessly transmit air pressure signals each including a respective identifier and air pressure information for a respective tire. A storage unit of the monitoring device stores tire positions at which the tires are provided and identifiers of detection devices in correspondence with each other. The monitoring device includes a request signal transmission unit that transmits, a plurality of times, a request signal requesting an identifier to at least one tire position, and an identifier reception unit that receives identifiers that are transmitted from a detection device. The monitoring device specifies the identifier of the detection device provided at the one tire position based on the identifiers that were transmitted in accordance with the request signal, and updates the identifier stored by the storage unit.