Reducing power consumption through reduced measurement frequency

• US 9,549,359 B2
• Filed: 03/15/2016
• Issued: 01/17/2017
• Est. Priority Date: 01/13/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Vangala, Sarma V., Balakrishnan, Swaminathan, Barakat, Wael S., Damji, Navid, Tabet, Tarik
• Primary Examiner(s): TAYLOR, BARRY W
• Application Number:
  US15/071,112
• Publication Number:
  US 20160198386A1
• Time in Patent Office: 308 Days
• US Class Current: 1/1
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 36/0061 of neighbour cell information
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/0088 Scheduling hand-off measurements
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 36/324 by mobility data, e.g. speed data
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 52/0254 detecting a user operation or a tactile contact or a motion of the device
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method for reducing power consumption by a wireless communication device is disclosed. The method can include the wireless communication device performing a first measurement of an alternative cell during a first measurement gap; sending a first measurement report generated based on the first measurement to the serving cell; storing the first measurement report; determining a mobility state of the wireless communication device; comparing the mobility state to a mobility threshold criterion; resending the first measurement report to the serving network as a report for a second measurement gap in an instance in which the mobility state satisfies the mobility criterion; and performing a second measurement of the alternative cell during the second measurement gap and sending a second measurement report generated based on the second measurement to the serving cell in an instance in which the mobility state does not satisfy the mobility threshold criterion.

Claims

1. A method for reducing power consumption through reduced measurement frequency by a wireless device, the method comprising:

by an apparatus of the wireless device;

performing a first measurement of an alternative cell during a first measurement gap;

generating a first measurement report for the first measurement gap based at least in part on the first measurement of the alternative cell;

determining a mobility state of the wireless device, wherein the mobility state indicates a state of motion of the wireless device;

comparing the mobility state to a mobility threshold criterion, wherein the mobility state satisfies the mobility threshold criterion when mobility of the wireless device does not exceed a mobility threshold;

in an instance in which the mobility state satisfies the mobility threshold criterion for less than a threshold period of time, reusing the first measurement report as a measurement report for a second measurement gap; and

in an instance in which (i) the mobility state does not satisfy the mobility threshold criterion or (ii) the mobility state satisfies the mobility threshold criterion for at least the threshold period of time, performing a second measurement of the alternative cell during the second measurement gap and generating a second measurement report based at least in part on the second measurement of the alternative cell,

wherein the threshold period of time corresponds to a maximum threshold number of consecutive measurement gaps.

2. The method of claim 1, wherein:

determining the mobility state of the wireless device comprises determining a change in position of the wireless device since performance of the first measurement;

the mobility threshold criterion comprises a threshold change in position; and

the mobility state satisfies the mobility threshold criterion in an instance in which the change in position of the wireless device since performance of the first measurement does not exceed the threshold change in position.

3. The method of claim 1, wherein:

determining the mobility state of the wireless device comprises determining a velocity of the wireless device;

the mobility threshold criterion comprises a threshold velocity; and

the mobility state satisfies the mobility threshold criterion in an instance in which the velocity of the wireless device does not exceed the threshold velocity.

4. The method of claim 1, wherein:

determining the mobility state of the wireless device comprises determining a change in signal quality of a serving cell;

the mobility threshold criterion comprises a threshold change in signal quality; and

the mobility state satisfies the mobility threshold criterion in an instance in which the change in signal quality of the serving cell does not exceed the threshold change in signal quality.

5. The method of claim 1, wherein:

a serving network of the wireless device uses a first radio access technology (RAT),

the alternative cell uses a second RAT, and

the first measurement report comprises an inter-RAT (iRAT) measurement report.

6. The method of claim 5, further comprising:

by the apparatus of the wireless device;

maintaining a second stack associated with the second RAT in a deactivated state during the second measurement gap in an instance in which the mobility state satisfies the mobility threshold criterion; and

transitioning from a first stack associated with the first RAT to the second stack associated with the second RAT during the second measurement gap in an instance in which the mobility state does not satisfy the mobility threshold criterion.

7. The method of claim 5, wherein:

the first RAT is a Long Term Evolution (LTE) RAT, and

the second RAT is a second generation (2G) RAT or a third generation (3G) RAT.

8. The method of claim 1, wherein:

the alternative cell comprises a neighboring cell of a serving network, and

the first measurement report comprises an inter-frequency measurement report.

9. The method of claim 1, further comprising:

by the apparatus of the wireless device;

defining the maximum threshold number of consecutive measurement gaps based at least in part on the mobility state of the wireless device.

10. The method of claim 1, wherein the apparatus generates measurement reports while the wireless device operates in a connected mode on a serving network.

11. An apparatus configurable for reducing power consumption of a wireless device, the apparatus comprising processing circuitry configured to cause the wireless device to:

perform a first measurement of an alternative cell during a first measurement gap;

generate a first measurement report for the first measurement gap based at least in part on the first measurement of the alternative cell;

determine a mobility state of the wireless device, wherein the mobility state indicates a state of motion of the wireless device;

compare the mobility state to a mobility threshold criterion;

in an instance in which the mobility state satisfies the mobility threshold criterion for less than a threshold period of time, reuse the first measurement report as a measurement report for a second measurement gap; and

in an instance in which (i) the mobility state does not satisfy the mobility threshold criterion or (ii) the mobility state satisfies the mobility threshold criterion for at least the threshold period of time, perform a second measurement of the alternative cell during the second measurement gap and generate a second measurement report based at least in part on the second measurement of the alternative cell,

wherein the threshold period of time corresponds to a maximum threshold number of consecutive measurement gaps.

12. The apparatus of claim 11, wherein the processing circuitry is further configured to cause the wireless device to:

determine the mobility state of the wireless device at least in part by determining a change in position of the wireless device since performance of the first measurement;

wherein;

the mobility threshold criterion comprises a threshold change in position; and

the mobility state satisfies the mobility threshold criterion in an instance in which the change in position of the wireless device since performance of the first measurement does not exceed the threshold change in position.

13. The apparatus of claim 11, wherein the processing circuitry is further configured to cause the wireless device to:

determine the mobility state of the wireless device at least in part by determining a velocity of the wireless device;

wherein;

the mobility threshold criterion comprises a threshold velocity; and

the mobility state satisfies the mobility threshold criterion in an instance in which the velocity of the wireless device does not exceed the threshold velocity.

14. The apparatus of claim 11, wherein the processing circuitry is further configured to cause the wireless device to:

determine the mobility state of the wireless device at least in part by determining a change in signal quality of a serving cell;

wherein;

the mobility threshold criterion comprises a threshold change in signal quality; and

the mobility state satisfies the mobility threshold criterion in an instance in which the change in signal quality of the serving cell does not exceed the threshold change in signal quality.

15. The apparatus of claim 11, wherein:

a serving network of the wireless device uses a first radio access technology (RAT),

the alternative cell uses a second RAT, and

the first measurement report comprises an inter-RAT (iRAT) measurement report.

16. The apparatus of claim 15, wherein the processing circuitry is further configured to cause the wireless device to:

maintain a second stack associated with the second RAT in a deactivated state during the second measurement gap in an instance in which the mobility state satisfies the mobility threshold criterion; and

transition from a first stack associated with the first RAT to the second stack associated with the second RAT during the second measurement gap in an instance in which the mobility state does not satisfy the mobility threshold criterion.

17. The apparatus of claim 11, wherein:

the alternative cell comprises a neighboring cell of a serving network, and

the first measurement report comprises an inter-frequency measurement report.

18. The apparatus of claim 11, wherein the maximum threshold number of consecutive measurement gaps is based at least in part on the mobility state of the wireless device.

19. A non-transitory computer readable storage medium having computer program code stored thereon that, when executed by processing circuitry implemented on a wireless device, causes the wireless device to perform a method comprising:

performing a first measurement of an alternative cell during a first measurement gap;

generating a first measurement report based at least in part on the first measurement;

determining a mobility state of the wireless device, wherein the mobility state indicates a state of motion of the wireless device;

comparing the mobility state to a mobility threshold criterion;

in an instance in which the mobility state satisfies the mobility threshold criterion for less than a threshold period of time, reusing the first measurement report as a measurement report for a second measurement gap; and

in an instance in which (i) the mobility state does not satisfy the mobility threshold criterion or (ii) the mobility state satisfies the mobility threshold criterion for at least the threshold period of time, performing a second measurement of the alternative cell during the second measurement gap and generating a second measurement report based at least in part on the second measurement of the alternative cell,

wherein the threshold period of time corresponds to a maximum threshold number of consecutive measurement gaps.

20. The non-transitory computer readable storage medium of claim 19, wherein the maximum threshold number of consecutive measurement gaps is based at least in part on the mobility state of the wireless device.