| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem wherein there is no system utilizing position information by assuming the time and the distance to a specific base position, in a position tracing system which utilizes portable telephones, a monitoring system merely grasps position information of the portable terminal device, even though there are a unit for alarming approaching between two articles and a utilization of position information and schedule information by linking, but there is no unit which examines whether arrival at a specific base position from the present position can be performed within a predetermined time. SOLUTION: If a user carrying a portable terminal device exceeds a movable distance, this situation can be warned to him; and a monitoring device can specify the corresponding portable terminal device at a time point exceeding the movable distance, even if the position information of the portable terminal device is not grasped sequentially, and the portable terminal device can be monitored, without increasing the load of the system. COPYRIGHT: (C)2005,JPO&NCIPI |
