On-vehicle wireless communication apparatus and communication system thereof

An on-vehicle wireless communication apparatus mounted on a vehicle for transmitting transmission data wirelessly at a predetermined frequency, the transmission data including at least positional information of the vehicle, the apparatus comprising:

• a receiver that sequentially receives the transmission data transmitted from another on-vehicle wireless communication apparatus mounted on another vehicle;
• a positional information acquiring unit that sequentially acquires the positional information of the vehicle;
• a location specifying unit that specifies a location relationship between the vehicle and the another vehicle based on the positional information of the vehicle acquired by the positional information acquiring unit and the positional information of the another vehicle received by the receiver;
• an another-apparatus transmission timing specifying unit that specifies a transmission timing of the transmission data in the another on-vehicle wireless communication apparatus when the another vehicle is located immediately in front of the vehicle;
• and
• a transmission timing adjusting unit that adjusts a transmission timing of the transmission data to be transmitted from the on-vehicle wireless communication apparatus so that the transmission data is transmitted at the predetermined frequency with an adjusted transmission timing of the on-vehicle wireless communication apparatus, which is later by a predetermined time than the transmission timing of the another on-vehicle wireless communication apparatus;
• wherein
• the transmission data further includes at least travel direction information of the vehicle in addition to the positional information of the vehicle,
• the on-vehicle wireless communication apparatus further comprising:
• a travel direction information acquiring unit that sequentially acquires the travel direction information of the vehicle,
• wherein the location specifying unit specifies the location relationship between the vehicle and the another vehicle disposed in a travel direction of the vehicle based on the positional information of the vehicle, the travel direction information of the vehicle acquired by the travel direction information acquiring unit, and the positional information and the travel direction information of the another vehicle received by the receiver, and
• wherein the other-apparatus transmission timing specifying unit specifies the transmission timing of the another on-vehicle wireless communication apparatus when the another vehicle having a travel direction equal to the travel direction of the vehicle is located immediately in front of the vehicle.