Optimization of NFC Tag for Different Battery Levels

• US 20150334518A1
• Filed: 07/28/2015
• Published: 11/19/2015
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Hall, Steven Deane, Awad, Mohamed, Trost, Theodore
• Granted Patent: US 10,341,882 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
• CPC Class Codes: H04W 52/0277 according to available power supply, e.g. switching off when a low battery condition is detected
• CPC Class Codes: H04W 52/028 switching on or off only a part of the equipment circuit blocks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A mobile communication device has a processor, a radio, a near field communication (NFC) device, a battery, and memory for storing data. The power level of the battery is measured. When the measured power level is above a first predetermined level, power is provided to the radio to allow communication. Sufficient power is provided to operate the NFC device as a reader and a tag. When the measured power level of the battery falls below the first predetermined level, battery power to the radio is shut off. Sufficient power is maintained to the NFC device to allow it to operate only as a tag. Sufficient power is maintained to the memory to retain the data stored in the memory. When the measured power level of the battery falls below a second predetermined level, the NFC device is required to harvest all of its power from the field.

Claims

1. A method of controlling operation of a mobile device, the method comprising:

measuring a power level of a battery;

configuring the mobile device to operate in a first operating mode when the measured power level of the battery is above a first threshold;

configuring the mobile device to operate in a second operating mode when the measured power level of the battery falls below the first threshold; and

configuring the mobile device to operate in a third operating mode when the measured power level of the battery falls below a second threshold, the second threshold being less than the first threshold.

2. The method of claim 1, wherein the configuring the mobile device to operate in the first operating mode comprises configuring the mobile device to operate as a reader or a tag.

3. The method of claim 1, wherein the configuring the mobile device to operate in the second operating mode comprises configuring the mobile device to operate only as a tag.

4. The method of claim 1, wherein the configuring the mobile device to operate in the second operating mode comprises disabling a communication function of the mobile device.

5. The method of claim 1, further comprising:

transitioning from the first operating mode to the second operating mode or from the second operating mode to the third operating mode, the transitioning being based on a number of transactions performed by the mobile device.

6. The method of claim 1, further comprising:

transitioning from the first operating mode to the second operating mode or from the second operating mode to the third operating mode, the transitioning being based on an amount of time the mobile device has been active.

7. The method of claim 1, wherein the configuring the mobile device to operate in the third operating mode comprises:

operating the mobile device as a tag; and

harvesting power for the mobile device from a magnetic field.

8. The method of claim 7, wherein the configuring the mobile device to operate in the third operating mode further comprises providing sufficient battery power to maintain a secure element in an active state.

9. A mobile communication device, comprising:

a central processing unit (CPU) configured to measure a power level of a battery; and

a near field communication (NFC) circuit, coupled to the CPU, configured to;

operate in a first operating mode when the power level of the battery is above a first predetermined level,

operate in a second operating mode when the power level of the battery falls below the first predetermined level, and

operate in a third operating mode when the power level of the battery falls below a second predetermined level lower than the first predetermined level.

10. The mobile communication device of claim 9, wherein, in the first operating mode, the NFC circuit is configured to operate as a reader or a tag.

11. The mobile communication device of claim 9, wherein, in the second operating mode, the NFC circuit is configured to operate only as a tag.

12. The mobile communication device of claim 9, wherein, in the second operating mode, the CPU is configured to disable a communication function of the mobile device.

13. The mobile communication device of claim 9, wherein the NFC circuit is further configured to transition from the first operating mode to the second operating mode or from the second operating mode to the third operating mode, the transitioning being based on a number of transactions performed by the mobile device.

14. The mobile communication device of claim 9, wherein the NFC circuit is further configured to transition from the first operating mode to the second operating mode or from the second operating mode to the third operating mode, the transitioning being based on an amount of time the mobile device has been active.

15. The mobile communication device of claim 9, wherein, in the third operating mode, the NFC circuit is configured to operate as a tag and to harvest power from a magnetic field.

16. The mobile communication device of claim 15, wherein, in the third operating mode, the NFC circuit is further configured to provide sufficient battery power to maintain a secure element in an active state.

17. An article of manufacture including a non-transitory computer readable medium having computer program logic stored thereon that, when executed by a computing device, causes the computing device to perform operations in a mobile communication device, the operations comprising:

measuring a power level of a battery;

configuring the mobile device to operate in a first operating mode when the measured power level of the battery is above a first threshold;

configuring the mobile device to operate in a second operating mode when the measured power level of the battery falls below the first threshold; and

configuring the mobile device to operate in a third operating mode when the measured power level of the battery falls below a second threshold, the second threshold being less than the first threshold.

18. The article of manufacture according to claim 17, wherein the configuring the mobile device to operate in the first operating mode comprises configuring the mobile device to operate as a reader or a tag.

19. The article of manufacture according to claim 17, wherein the configuring the mobile device to operate in the second operating mode comprises configuring the mobile device to operate only as a tag and disabling a communication function of the mobile device.

20. The article of manufacture according to claim 18, wherein the configuring the mobile device to operate in the third operating mode comprises:

providing sufficient battery power to maintain a secure element in an active state; and

harvesting power for the mobile device from a magnetic field.