Optimization of NFC tag for different battery levels

• US 9,119,160 B2
• Filed: 09/30/2011
• Issued: 08/25/2015
• 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, Awad, Mohamed, Trost, Theodore
• Primary Examiner(s): Urban, Edward
• Assistant Examiner(s): Justus, Ralph H
• Application Number:
  US13/250,356
• Publication Number:
  US 20130084803A1
• Time in Patent Office: 1,425 Days
• Field of Search: 455/41.1, 320/124, 320/137, 320/127, 320/132
• 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 communication device, the method comprising:

measuring a power level of a battery;

configuring a near field communication (NFC) capable device to operate as a reader or a tag when the measured power level of the battery is above a first predetermined level;

configuring the NFC capable device to operate only as the tag when the measured power level of the battery falls below the first predetermined level; and

configuring the NFC capable device to operate only as the tag, harvesting power for the NFC capable device from a magnetic field, and providing power to a memory to retain data stored in the memory when the measured power level of the battery falls below a second predetermined level lower than the first predetermined level.

2. The method of claim 1, further comprising:

determining a number of transactions made with the mobile communication device; and

transitioning from a first power mode to a second power mode as a function of the determined number of transactions.

3. The method of claim 1, further comprising:

determining a length of time that the mobile communication device has been on; and

transitioning from a first power mode to a second power mode as a function of the determined length of time.

4. The method of claim 1, further comprising:

determining a number of data bits that have been transferred between the NFC capable device and an external tag or reader during a given period of time; and

transitioning from a first power mode to a second power mode as a function of the determined number of data bits.

5. The method of claim 1, further comprising:

providing power to a radio to allow communication when the measured power level of the battery is above the first predetermined level; and

shutting off battery power to the radio when the measured power level of the battery falls below the first predetermined level.

6. 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) device, coupled to the CPU, configured to;

operate as a reader or a tag when the power level of the battery is above a first predetermined level,

operate only as the tag when the power level of the battery falls below the first predetermined level, and

operate using power harvested from a magnetic field when the power level of the battery falls below a second predetermined level lower than the first predetermined level.

7. The mobile communication device of claim 6, wherein the NFC device is further configured to be transitioned from a first operating mode to a second operating mode as a function of a number of transactions made with the mobile communication device.

8. The mobile communication device of claim 6, wherein the NFC device is further configured to be transitioned from a first operating mode to a second operating mode as a function of a length of time that the mobile communication device has been on.

9. The mobile communication device of claim 6, wherein the NFC device is further configured to be transitioned from a first operating mode to a second operating mode as a function of a number of data bits that have been transferred between the NFC device and an external tag or reader during a given period of time.

10. The mobile communication device of claim 6, further comprising:

a radio, coupled to the CPU, configured to enable the mobile communication device to conduct wireless communications, the radio being further coupled to the battery to draw power from the battery when battery power is above the first predetermined level, wherein power to the radio is shut off when the battery power falls below the first predetermined level.

11. The mobile communication device of claim 6, further comprising:

a memory that draws power from the battery to retain data stored in the memory when the power level of the battery falls below the second predetermined level.

12. 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 communication device to operate as a reader or a tag when the measured power level of the battery is above a first predetermined level;

configuring the mobile communication device to operate only as the tag when the measured power level of the battery falls below the first predetermined level; and

configuring the mobile communication device to operate only as the tag, harvesting power for the mobile communication device from a magnetic field, and providing power to a memory to retain data stored in the memory when the measured power level of the battery falls below a second predetermined level lower than the first predetermined level.

13. The article of manufacture of claim 12, wherein the operations further comprise:

determining a number of transactions made with the mobile communication device, and

transitioning from a first power mode to a second power mode as a function of the determined number of transactions.

14. The article of manufacture of claim 12, wherein the operations further comprise:

determining a length of time that the mobile communication device has been on; and

transitioning from a first power mode to a second power mode as a function of the determined length of time.

15. The article of manufacture of claim 12, wherein the operations further comprise:

determining a number of data bits that have been transferred between the mobile communication device and an external tag or reader during a given period of time; and

transitioning from a first power mode to a second power mode as a function of the determined number of data bits.

16. The article of manufacture of claim 12, wherein the operations further comprise:

providing power to a radio to allow communication when the measured power level of the battery is above the first predetermined level; and

shutting off battery power to the radio when the measured power level of the battery falls below the first predetermined level.