The SIM card is used to replace the conventional IC card through the mobile phone card in the mobile phone. First, the user reads the card in the card reader through the SIM card in the mobile phone. The card reader passes the information to the POS terminal through recognition, and the POS terminal sends the data to The management server performs verification and comparison and data exchange processing, and then transmits the data back to the POS terminal to realize the consumption function.
The transaction data is transmitted to the POS terminal. After receiving the data, the POS terminal packages and transmits the transaction data to the NAC card in the NAC. The down card defined by the specific bits of the TPDU forwards the received data to the up card. The destination address in the TPDU header determines the corresponding relationship with the application. The application forwards the data to the specific front-end machine. After the front-end machine receives the data packet, it decompresses the data packet and passes it to the encryption machine to determine the account information. The validity and accuracy of the account balance. If the account data is correct, the encryption machine transmits the verification information to the front-end machine. At this time, the front-end machine transmits the verified information to the core account system, calculates the amount to be deducted from the pos transaction, and then the data Return to the POS machine according to the original way to update the account amount.