| 摘要 |
PROBLEM TO BE SOLVED: To permit communication only with an ETC vehicle (vehicle loaded with on-vehicle equipment having an automatic toll exchanging function with on-road equipment installed at a tollgate) entering a communication area by specifying the communication area while using plural beam-shaped reception antennas. SOLUTION: Six reception areas are set by beam formation of plural reception antennas at an antenna 7 of on-road equipment 5 as communication enable areas 9a-9d and communication disable areas 9e and 9f. An ETC vehicle 4 loaded with on-vehicle equipment 11 enters a transmission area 22, and at the time point of entering the reception area 9f, the on-vehicle equipment 11 receiving information on the side of on-road equipment from the antenna 7 transmits information concerning the on-vehicle equipment 11 to the on-road equipment 5. When the ETC vehicle moved forward on a path 2 and the on-vehicle equipment 11 enters the reception area 9d, power from the area 9d is highest in reception power at the on-road equipment 5 and it is discriminated that the on-vehicle equipment 11 exists in the area 9d. The communication is performed between this on-vehicle equipment 11 and the on-road equipment 5.
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