Patent ID: 9002269
Filing Date: 2015-04-07
Classification: G06K

Abstract:
1. A method for a radio-frequency Subscriber Identity Module (SIM) card with low-frequency magnetic communication to trigger a transaction according to determined distance thresholds, wherein the radio-frequency SIM card carries out a distance control of a short-distance communication with a corresponding card reader through a low-frequency channel and conducts the transaction with the card reader through the radio-frequency channel, the method comprising: Step a: setting a Threshold Step b: examining continuously, by the radio-frequency SIM card, an intensity of the low-frequency magnetic field transmitted by the card reader; determining whether the intensity is greater than or equal to the Threshold Step c: further determining, by the radio-frequency SIM card, whether an intensity of the low-frequency magnetic field transmitted by the card reader is greater than or equal to the Threshold Step d: during the transaction process, examining, by the radio-frequency SIM card, an intensity of the low-frequency magnetic field transmitted by the card reader; determining whether the intensity is less than the Threshold wherein in the Step a, the steps for determining the Threshold A. through experiments, measuring, using a radio-frequency SIM card, intensities of a low-frequency magnetic field transmitted by a card reader that matches with the radio-frequency SIM card; determining a correspondence relationship between the intensities and distances; and establishing a correspondence table between the intensities and the distances; and B. based on the correspondence table and requirements for a transaction-triggering distance, setting a low-frequency magnetic field intensity value corresponding to the transaction-triggering distance as the Threshold