| 摘要 |
PROBLEM TO BE SOLVED: To detect in an early stage that a holder of a slave terminal is lost in large facilities such as a large-scale commercial facility and amusement park and grasp the position of the slave terminal, so as to find or protect the holder of the slave terminal.SOLUTION: A master terminal transmits a slave terminal search request message to a network control device. The network control device obtains pre-registered information of the slave terminal to be searched for, from a search information database. The network control device determines terminals to which the search is to be requested, from a search request destination database. The network control device simultaneously transmits a search request message and information of a person holding the slave terminal who is to be searched for, to the terminal to which the search is to be requested.SELECTED DRAWING: Figure 3 |
