Abstract: Individual radio sets 12a-12e constituting an onboard radio communication system operate together with an adjacent vehicle detection unit (ultrasonic sensors 13a-13e) for detecting a second vehicle adjacent to a first vehicle 11. When it detects the adjacent vehicle, a radio interference decision unit constituting the radio sets 12a-12e decides radio interference due to an onboard radio communication system with the same radio scheme. When it detects the radio interference, a frequency channel switching unit constituting the radio sets 12a-12e switches the frequency channel to be used to avoid the interference of the radio waves.

Abstract: A radio communication device is provided, including a radio control unit for achieving timing synchronization using frames having a fixed period, assigning a transmission and reception interval during which a report signal for informing state management information about each communication device and a control signal for controlling each radio communication device are transmitted and received to a fixed time interval at the head of each frame, for transmitting and receiving application data to and from a partner radio communication device during another time interval, and for reserving and securing some of communication band units, each of which has a fixed width and into which each frame is divided according to a difference between the transmission rate of the application data and that of a signal in a wireless section, on a unit-by-unit basis by using the report signal and the control signal.

Abstract: A radio communication device is provided, including a radio control unit 20 for achieving timing synchronization using frames having a fixed period, assigning a transmission and reception interval during which a report signal for informing state management information about each communication device 1A to 1D and a control signal for controlling each radio communication device 1A to 1D are transmitted and received to a fixed time interval at the head of each frame, for transmitting and receiving application data to and from a partner radio communication device during another time interval, and for reserving and securing some of communication band units, each of which has a fixed width and into which each frame is divided according to a difference between the transmission rate of the application data and that of a signal in a wireless section, on a unit-by-unit basis by using the report signal and the control signal.

Abstract: Individual radio sets 12a-12e constituting an onboard radio communication system operate together with an adjacent vehicle detection unit (ultrasonic sensors 13a-13e) for detecting a second vehicle adjacent to a first vehicle 11. When it detects the adjacent vehicle, a radio interference decision unit constituting the radio sets 12a-12e decides radio interference due to an onboard radio communication system with the same radio scheme. When it detects the radio interference, a frequency channel switching unit constituting the radio sets 12a-12e switches the frequency channel to be used to avoid the interference of the radio waves.