Card detection and selection
View Patent ↗Techniques for CSC detection and selection include generating a radio frequency (RF) field that defines a range of communication for the CSC reader, transmitting a signal in the RF field, and detecting a modulation in the RF field indicating that a first CSC is within the RF field and has responded to the signal. The modulation is inspected for collision, wherein collision occurs if more than one CSC within the RF field responds to the poll signal. After determining that the modulation does not contain a collision, a halt command is transmitted to the first CSC instructing the CSC to only respond to one or more specific commands.
1. A method executed by a contactless smart card (CSC) reader for CSC detection and selection, the method comprising:
generating a radio frequency (RF) field that defines a range of communication for the CSC reader;
transmitting a first poll signal for a particular type of CSC in the RF field, the particular type of CSC comprising one of type-A CSC, type-B CSC, proposed type-C CSC, or proposed type-D CSC as defined by ISO 14443;
detecting a modulation in the RF field indicating that a first CSC is within the RF field and has responded to the first poll signal;
inspecting the modulation for a collision, wherein the collision occurs if more than one CSC within the RF field responds to the first poll signal;
determining that the modulation does not contain the collision;
transmitting a halt command to the first CSC in response to determining that the modulation does not contain the collision, wherein the halt command instructs the first CSC to only respond to a wakeup command; and
transmitting a second poll signal for the particular type of CSC in the RF field after transmitting the halt command to the first CSC and before conducting a transaction, wherein the first CSC does not respond to the second poll signal.
2. The method of claim 1 , further comprising:
increasing a power level of the RF field after transmitting the halt command and before transmitting the second poll signal.
3. The method of claim 1 , further comprising the steps of:
attenuating a power level of the RF field after transmitting the halt command and before transmitting the second poll signal.
4. The method of claim 1 ,
wherein the second poll signal is transmitted in the RF field after a preset period of time has passed since transmitting the halt command to the first CSC.
5. The method of claim 1 , further comprising:
transmitting the second poll signal in the RF field for a preset period of time;
transmitting the wakeup command to the first CSC after the preset period of time has passed; and
selecting the first CSC for conducting a transaction.
6. The method of claim 1 , further comprising:
detecting that a second CSC is within the RF field; and
generating at least one of a visual notification and an audio notification for a user, the notification informing the user that more than one CSC has been presented.
7. The method of claim 1 , further comprising:
detecting that a second CSC is within the RF field; and
selecting one of the first CSC and the second CSC for conducting a transaction based on a predefined criteria.
8. A contactless smart card (CSC) reader for CSC detection and selection, the CSC reader comprising:
a radio frequency (RF) transceiver configured to generate an RF field, and transmit and receive signals within the RF field; and
a computer processor coupled to the RF transceiver and configured to utilize the RF transceiver to transmit a first poll signal for a particular type of CSC in the RF field, detect a modulation in the RF field indicating that a first CSC is within the RF field and has responded to the first poll signal, inspect the modulation for a collision, determine that the modulation does not contain the collision, utilize the RF transceiver to transmit a halt command to the first CSC in response to determining that the modulation does not contain the collision, and utilize the RF transceiver to transmit a second poll signal for the particular type of CSC in the RF field after transmitting the halt command to the first CSC and before conducting a transaction, wherein the first CSC does not respond to the second poll signal,
wherein the collision occurs if more than one CSC within the RF field responds to the first poll signal, the particular type of CSC comprises one of type-A CSC, type-B CSC, proposed type-C CSC, or proposed type-D CSC as defined by ISO 14443, and the halt command instructs the first CSC to only respond to a wakeup command.
9. The CSC reader of claim 8 , wherein the computer processor is further configured to increase a power level of the RF transceiver after transmitting the halt command and before transmitting the second poll signal.
10. The CSC reader of claim 8 , wherein the computer processor is further configured to attenuate a power level of the RF transceiver after transmitting the halt command and before transmitting the second poll signal.
11. The CSC reader of claim 8 , wherein the computer processor is further configured to utilize the RF transceiver to transmit the second poll signal in the RF field after a preset period of time has passed since transmitting the halt command to the first CSC.
12. The CSC reader of claim 8 , wherein the computer processor is further configured to utilize the RF transceiver to transmit the second poll signal in the RF field for a preset period of time, utilize the RF transceiver to transmit the wakeup command to the first CSC after the preset period of time has passed, and select the first CSC for conducting a transaction.
13. The CSC reader of claim 8 , wherein the computer processor is further configured to detect that a second CSC is within the RF field, and generate at least one of a visual notification and an audio notification for a user, the notification informing the user that more than one CSC has been presented.
14. The CSC reader of claim 8 , wherein the computer processor is further configured to detect that a second CSC is within the RF field, and select one of the first CSC and the second CSC for conducting a transaction based on a predefined criteria.
15. A non-transitory computer-readable medium, having instructions stored therein, which when executed cause a computer to perform a set of operations comprising:
generating a radio frequency (RF) signal to form an RF field that defines a range of communication;
transmitting a first poll signal for a particular type of CSC in the RF field, the particular type of CSC comprises one of type-A CSC, type-B CSC, proposed type-C CSC, or proposed type-D CSC as defined by ISO 14443;
detecting a modulation in the RF field indicating that a first contactless smart card (CSC) is within the RF field and has responded to the first poll signal;
inspecting the modulation for a collision, wherein the collision occurs if more than one CSC within the RF field responds to the first poll signal;
determining that the modulation does not contain the collision;
transmitting a halt command to the first CSC in response to determining that the modulation does not contain the collision, wherein the halt command instructs the first CSC to only respond to a wakeup command; and
transmitting a second poll signal for the particular type of CSC in the RF field after transmitting the halt command to the first CSC and before conducting a transaction, wherein the first CSC does not respond to the second poll signal.
16. The non-transitory computer-readable medium of claim 15 , having further instructions stored therein, which when executed cause the computer to perform a set of operations comprising:
increasing a power level of the RF field after transmitting the halt command and before transmitting the second poll signal.
17. The non-transitory computer-readable medium of claim 15 , having further instructions stored therein, which when executed cause the computer to perform a set of operations comprising:
reducing a power level of the RF field after transmitting the halt command and before transmitting the second poll signal.
18. The non-transitory computer-readable medium of claim 15 , having further instructions stored therein, which when executed cause the computer to perform a set of operations comprising:
transmitting the second poll signal in the RF field for a preset period of time;
transmitting the wakeup command to the first CSC after the preset period of time has passed; and
selecting the first CSC for conducting a transaction.
19. The non-transitory computer-readable medium of claim 15 , having further instructions stored therein, which when executed cause the computer to perform a set of operations comprising:
detecting that a second CSC is within the RF field; and
generating at least one of a visual notification and an audio notification for a user, the notification informing the user that more than one CSC has been presented.
20. The non-transitory computer-readable medium of claim 15 , having further instructions stored therein, which when executed cause the computer to perform a set of operations comprising:
detecting that a second CSC is within the RF field; and
selecting one of the first CSC and the second CSC for conducting a transaction based on a predefined criteria.