| 摘要 |
<P>PROBLEM TO BE SOLVED: To execute stable communication by executing control for suppressing mutual interference between transmission signals by communication of a plurality of RFID tag communication devices, in a system operated by using a plurality of RFID tag communication devices, which are wireless facilities for identifying mobile bodies. <P>SOLUTION: When a reception signal is monitored even while an RFID tag communication device is transmitting a transmission signal, and it is observed that the level variation of the reception signal is large in a transmission period in which the level variation of its own transmission signal is small, it is determined that another RFID tag communication device is executing transmission. When a level variation larger than a predetermined level is detected in the reception signal, the transmission signal is stopped before the RFID tag communication device moves to a period for returning a response of a back scatter signal. <P>COPYRIGHT: (C)2010,JPO&INPIT |
