A roadside radio device comprising: a first radio unit (320; 320a; 320b) configured to receive a radio data packet from an in-vehicle radio device; and a first application unit configured to process application data included in the radio data packet, wherein the radio data packet includes vehicle identification information given by a second radio unit (220; 220b) of the in-vehicle radio device, and communication type information given by a second application unit of the in-vehicle radio device, wherein the vehicle identification information comprises information indicating a vehicle in which the in-vehicle radio device is mounted, wherein the communication type information comprises information indicating a vehicle to which the application data relates, wherein the vehicle identification information and the communication type information are indicated using vehicle class information identifying a type of vehicles, wherein the first radio unit (320; 320a; 320b) comprises a radio data processing unit (350; 350a; 350b) including a correlation processing unit (351; 351b) configured to compare a data string of the vehicle identification information with a data string of the communication type information to determine whether there is a correlation in the radio data packet, wherein, when the correlation processing unit (351; 351b) determines that there is the correlation in the radio data packet, the first radio unit (320; 320a; 320b) is configured to output the application data included in the radio data packet to the first application unit, and wherein, when the correlation processing unit (351; 351b) determines that there is no correlation in the radio data packet, the first radio unit (320; 320a; 320b) is configured to treat the radio data packet as invalid data, characterized in that the first radio unit (320; 320a; 320b) further comprises a first frequency channel allocation control unit configured, when the first radio unit (320; 320a; 320b) receives a frequency channel request signal for requesting allocation of a frequency channel for radio communication from the in-vehicle radio device, to determine whether to allocate the frequency channel to the in-vehicle radio device based on whether information identifying the in-vehicle radio device is registered in the first radio unit (320; 320a; 320b) as information of a spoofing radio device. a first radio unit (320; 320a; 320b) configured to receive a radio data packet from an in-vehicle radio device; and a first application unit configured to process application data included in the radio data packet, wherein the radio data packet includes vehicle identification information given by a second radio unit (220; 220b) of the in-vehicle radio device, and communication type information given by a second application unit of the in-vehicle radio device, wherein the vehicle identification information comprises information indicating a vehicle in which the in-vehicle radio device is mounted, wherein the communication type information comprises information indicating a vehicle to which the application data relates, wherein the vehicle identification information and the communication type information are indicated using vehicle class information identifying a type of vehicles, wherein the first radio unit (320; 320a; 320b) comprises a radio data processing unit (350; 350a; 350b) including a correlation processing unit (351; 351b) configured to compare a data string of the vehicle identification information with a data string of the communication type information to determine whether there is a correlation in the radio data packet, wherein, when the correlation processing unit (351; 351b) determines that there is the correlation in the radio data packet, the first radio unit (320; 320a; 320b) is configured to output the application data included in the radio data packet to the first application unit, and wherein, when the correlation processing unit (351; 351b) determines that there is no correlation in the radio data packet, the first radio unit (320; 320a; 320b) is configured to treat the radio data packet as invalid data, characterized in that the first radio unit (320; 320a; 320b) further comprises a first frequency channel allocation control unit configured, when the first radio unit (320; 320a; 320b) receives a frequency channel request signal for requesting allocation of a frequency channel for radio communication from the in-vehicle radio device, to determine whether to allocate the frequency channel to the in-vehicle radio device based on whether information identifying the in-vehicle radio device is registered in the first radio unit (320; 320a; 320b) as information of a spoofing radio device.