| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a communication system capable of accurately measuring a communication distance between two communication terminals. <P>SOLUTION: The communication system comprises a transmitter and a receiver located in a wireless communication space. The transmitter completes the transmission of data DATT to the receiver synchronously with a start edge (timing t1) of a free period in the wireless communication space. When the receiver completes the reception of data DARR from the transmitter, the receiver measures its own response time Tresp and starts the transmission of data DART including the response time Tresp to an oscillator when the receiver completes the measurement of the response time Tresp. The oscillator starts receiving the data DART from the receiver in a timing t4, measures the total time from timing t1 to timing t4, and determines the communication distance with the receiver on the basis of the measured total time and the response time Tresp received from the receiver. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
