| 摘要 |
<P>PROBLEM TO BE SOLVED: To raise throughput of communication under an LBI system. <P>SOLUTION: Reader/writers RW1, RW2 detect carriers for all channels before transmitting the carrier, calculates a vacant channel area in which channels whose carriers are not detected continuously exist, to start transmission of the carriers when the vacant channel area has width larger than that required for communication with an RF tag. The reader/writer RW1 detects the carriers to update a sense table even during transmission of the carriers, performs data communication using required channel width in the vacant channel area and within a range of the maximum continuous channels from which the carriers are not detected. <P>COPYRIGHT: (C)2008,JPO&INPIT |
