| 摘要 |
There is described a method of checking whether a transponder device (220) is in proximity of a reader device (210), the method comprising (a) transmitting a first command (331) from the reader device to the transponder device, (b) in response to receiving the first command at the transponder device, transmitting a first response (332) to the reader device, the first response including an expected transponder device response time (pubRespTime) which is stored in a memory (224) of the transponder device, (c) transmitting a second command (333) from the reader device to the transponder device, (d) in response to receiving the second command at the transponder device, transmitting a second response (334) to the reader device, (e) at the reader device, determining the transponder device response time as the difference in time between transmitting the second command and receiving the second response from the transponder device, and (f) determining whether the determined transponder device response time matches the expected transponder device response time included in the first response. There is also described a reader device (210), a transponder device (220), and a contactless communication system (200). |
