| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical beacon that can appropriately receive a high-rate frame to be transmitted next to a low-rate frame, and is compatible with a multi rate in an uplink direction.SOLUTION: The present invention relates to an optical beacon 4 performing a radio communication with an on-vehicle device 2 of a vehicle 20 in motion by an optical signal. The optical beacon 4 comprises: a light reception part 11 that can perform a photoelectric conversion by a transmission rate of two types of a high rate and a low rate; a light transmission part 10 that can perform a photoelectric conversion by a predetermined transmission rate; and a communication control part (a beacon control apparatus) 7 that can reproduce a low-rate frame UL1 or a high-rate frame UL2 from an electric signal output by the light reception part 11. Further, a position setting is performed in such a way that a second upstream end is positioned on an upper stream side than a first upstream end or is substantially at the same position as the first upstream end, where a first upstream end denotes physical or logical most upstream ends P1 and P1' of an area RA1 capable of reception of the low-rate frame UL1, and a second upstream end denotes physical or logical most upstream ends P2 and P2' of an area RA2 capable of reception of the high-rate frame UL2. |
