The camera which photographs the area along the railroad line

摘要

PROBLEM TO BE SOLVED: To provide a wireless along railway monitor system capable of easily judging whether or not the distance between base stations can be extended.;SOLUTION: A camera 12 photographs the periphery of a along-railway line. A transmitting side radio base station 16 transmits a monitor image to a receiving side radio base station installed together with a monitor. The radio base station 16 comprises an attenuation section 46 between a radio section 42 and an antenna 48. A switching section 42 performs switching operation to attenuate a transmitted signal on the attenuation section 44 and sets an extension judging mode for judging whether or not the distance between the base stations can be extended. The amount of attenuation due to the attenuation section 46 is set in accordance with an extension width of the distance between candidate base stations.;COPYRIGHT: (C)2006,JPO&NCIPI