| 摘要 |
PROBLEM TO BE SOLVED: To provide a radio apparatus allocating a frequency channel, in such a way as to reduce interference caused by a direct wave between a plurality of radio apparatuses mounted on traveling objects which is traveling in the vicinity of a crossing. SOLUTION: When the radio apparatus (j) mounted on a vehicle Cj enters a frequency control area, the radio apparatus (j) detects a forward-moving direction of the vehicle Cj and determines whether the detected forward-moving direction is a direction within the range of south-north±45°or not. If the forward-moving direction of the vehicle Cj is a direction within the range of south-north±45°, the radio apparatus (j) allocates frequencies f1, f2 for transmission of a packet PKT-PS, including positional information and if the forward-moving direction of the vehicle Cj is a direction which is other than the direction within the range of south-north±45°, the radio apparatus (j) allocates frequencies f3, f4 which transmit the packet PKT-PS that contains the positional information. COPYRIGHT: (C)2010,JPO&INPIT |
