| 摘要 |
<P>PROBLEM TO BE SOLVED: To extract only direct waves for performing positional relationship estimation by sonic waves between terminals having restrictions in their functions and the like. <P>SOLUTION: After positional estimation start confirmations (1) and (2), a search terminal 10 previously sets frequency and an interval of sonic pulses to be sent (3), sends a notification to a searched terminal 20 (4), and the searched terminal 20 starts recording (5). The search terminal 10 sends the sonic pulses according to the setting (7), acquires transmission time of each pulse (8), and notifies the searched terminal 20 of transmission completion (10). The searched terminal 20 terminates the recording (11), determines the sonic pulses in accordance with the preset frequency and interval notified previously from among the sonic pulses included in the recording as pulses receiving direct waves (12), and notifies the search terminal 10 of the receipt time (13). The search terminal 10 estimates positional relationship on the basis of the receipt time and the transmission time (14). <P>COPYRIGHT: (C)2012,JPO&INPIT |
