Abstract: A communication apparatus for a vehicle achieves reduction in size and cost of a portable unit by making unnecessary an oscillation circuit and a battery in the portable unit. The apparatus is provided with an on-board unit installed on the vehicle and a portable unit carried by a user of the vehicle. A response signal is sent from the portable unit to the on-board unit in response to a signal transmitted from the on-board unit. The portable unit includes a power generation circuit for supplying electric power to circuits in the portable unit by a power generation radio wave sent from the on-board unit, and the on-board unit sends a communication signal after sending the power generation radio wave.

Abstract: A communication apparatus for a vehicle can achieve an inexpensive technique for determining whether a portable unit exists inside or outside the vehicle without depending upon LF band radio waves through contactless communication using high frequency band radio waves by separating a reader function of a reader/writer into the portable unit and an on-board unit. The apparatus includes at least one ID transmitter installed on a vehicle and sends a transmitter ID possessed by itself in response to reception of a radio wave, an on-board unit installed on the vehicle for radiating a radio wave to the ID transmitter, a portable unit that receives the transmitter ID sent by the ID transmitter, and an ID communication section for sending the transmitter ID from the portable unit 3 to the on-board unit. The on-board unit determines the position of the portable unit based on the transmitter ID received from the portable unit.

Abstract: A communication apparatus for a vehicle achieves reduction in size and cost of a portable unit by making unnecessary an oscillation circuit and a battery in the portable unit. The apparatus is provided with an on-board unit installed on the vehicle and a portable unit carried by a user of the vehicle. A response signal is sent from the portable unit to the on-board unit in response to a signal transmitted from the on-board unit. The portable unit includes a power generation circuit for supplying electric power to circuits in the portable unit by a power generation radio wave sent from the on-board unit, and the on-board unit sends a communication signal after sending the power generation radio wave.

Abstract: A communication apparatus for a vehicle can achieve an inexpensive technique for determining whether a portable unit exists inside or outside the vehicle without depending upon LF band radio waves through contactless communication using high frequency band radio waves by separating a reader function of a reader/writer into the portable unit and an on-board unit. The apparatus includes at least one ID transmitter installed on a vehicle and sends a transmitter ID possessed by itself in response to reception of a radio wave, an on-board unit installed on the vehicle for radiating a radio wave to the ID transmitter, a portable unit that receives the transmitter ID sent by the ID transmitter, and an ID communication section for sending the transmitter ID from the portable unit 3 to the on-board unit. The on-board unit determines the position of the portable unit based on the transmitter ID received from the portable unit.

Abstract: A vehicle-roadside service providing system enables a user to use even a service which is not accommodated by on-board service client equipment installed on a vehicle. A service host equipment (1) stores a service sequence that describes the content of a service. Service client equipment (6) acquires the service sequence from the service host equipment (1) through DSRC equipment (5a, 5b) at the times of execution of the service. The service sequence is sequentially executed by sequence step executing parts (4, 10) while performing data transmission and reception through communications between the service host equipment (1) and the service client equipment (6) based on the service sequence. Information insufficient in the course of the service is received from the user by a human interface part (7).

Abstract: A vehicle-roadside service providing system enables a user to use even a service which is not accommodated by on-board service client equipment installed on a vehicle. A service host equipment (1) stores a service sequence that describes the content of a service. Service client equipment (6) acquires the service sequence from the service host equipment (1) through DSRC equipment (5a, 5b) at the times of execution of the service. The service sequence is sequentially executed by sequence step executing parts (4, 10) while performing data transmission and reception through communications between the service host equipment (1) and the service client equipment (6) based on the service sequence. Information insufficient in the course of the service is received from the user by a human interface part (7).