To provide a broadband communication system between a road and a vehicle capable of carrying out stable broadband communication for a mobile body during movement at high speed.

The communication system includes: a mobile body side selection apparatus that transmits an uplink signal to a base station with a frequency assigned to each mobile body so as not to be in duplication with a frequency assigned to another mobile body close to the mobile body and selects a received signal addressed to its own apparatus among signals received from the base station; and a base station side selection apparatus that transmits downlink signals to the mobile body by using a common frequency and aborts a duplicate component from the signal received from the mobile body and transfers information to a backbone network.