| 摘要 |
PROBLEM TO BE SOLVED: To provide a radio terminal device for detecting whether or not the radio terminal device itself given to a management object such as an article and person has been removed from the management object.SOLUTION: A management system 1 comprises: radio tags T1a to T1m, ..., Tna to Tnm attached to management objects B1a to B1m, ..., Bna to Bnm; and optical sensors arranged on attachment surfaces of the radio tags T1a to T1m, ..., Tna to Tnm to the management objects B1a to B1m, ..., Bna to Bnm. When the optical sensors receive light whose amount is equal to or more than a predetermined amount by the radio tags T1a to T1m, ..., Tna to Tnm being torn off and so on; the radio tags T1a to T1m, ..., Tna to Tnm make these short-range radio communication units perform short-range radio communication with management proximity radio communication units of the management objects B1a to B1m, ..., Bna to Bnm, and make ringing/emission units be driven to output abnormality notification when the short-range radio communication is disabled. |
