| 摘要 |
A wireless tag device (2) receives a response request signal from a wireless reader device (3) and measures the receiving strength thereof. In response to the response request signal, the wireless tag device (2) determines whether a communication with the wireless reader device (3) was successful. The wireless tag device (2) carries out a movement determination on the basis of the increase or decrease of the receiving strength, compares the receiving strength with a threshold and carries out a distance determination, and carries out an area determination on the basis of the results of the movement determination and the distance determination. When the communication with the wireless reader device (3) fails, the wireless tag device (2) controls, on the basis of the result of the area determination, resend timing according to priorities which are determined for each area (long-distance separation: maximum; near-distance separation: high; near-distance approach: medium; long-distance approach: low). It is thus possible, when communication with the wireless reader device has failed, to set appropriate priorities according to the number of future resend opportunities, and to appropriately control resending on the basis of the priorities. |
