ROAD SIDE RADIO APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a road side radio apparatus capable of improving stability of communication in a transportation radio system for performing radio transmission of transportation information.SOLUTION: A road side radio apparatus is included in a transportation radio system in which transportation radio apparatuses including a plurality of road side radio apparatuses and one or a plurality of on-vehicle radio apparatuses can perform communication by transmitting/receiving radio signals in the same frequency band. The road side radio apparatus comprises: an antenna selection unit for selecting a use antenna to be used for communication with another transportation radio apparatus, from an antenna group; and a radio communication unit for transmitting/receiving radio signals to/from the other transportation radio apparatus, through the use antenna. The antenna selection unit selects the use antenna on the basis of a radio signal received by the radio communication unit in a predetermined period in which the one or the plurality of road side radio apparatuses other than the road side radio apparatus transmit radio signals.