Reducing power consumption through reduced measurement frequency

• US 9,319,985 B2
• Filed: 01/10/2014
• Issued: 04/19/2016
• 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
• Application Number:
  US14/151,969
• Publication Number:
  US 20140200002A1
• Time in Patent Office: 830 Days
• Field of Search: 455/436
• 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, the method comprising:

by a wireless communication device;

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

sending a first measurement report generated based at least in part on the first measurement to a serving cell of a serving network;

determining a mobility state of the wireless communication device;

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

in an instance in which the mobility state satisfies the mobility threshold criterion and the first measurement report has not been resent for a maximum threshold number of consecutive measurement gaps, resending the first measurement report to the serving cell 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 first measurement report has been resent for the maximum threshold number of consecutive measurement gaps, performing a second measurement of the alternative cell during the second measurement gap and sending a second measurement report generated based at least in part on the second measurement to the serving cell.

2. The method of claim 1, wherein:

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

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

the determined mobility state satisfies the mobility threshold criterion in an instance in which the change in position of the wireless communication 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 communication device comprises determining a velocity of the wireless communication device;

the mobility threshold criterion comprises a threshold velocity; and

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

4. The method of claim 1, wherein:

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

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

the determined 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 the serving network uses a first radio access technology (RAT), wherein the alternative cell uses a second RAT, and wherein the first measurement report comprises an inter-RAT (iRAT) measurement report.

6. The method of claim 5, further comprising the wireless communication 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 determined mobility state satisfies a mobility threshold criterion; and

transitioning from a first stack associated with the first RAT to the second stack during the second measurement gap in an instance in which the determined 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 wherein the second RAT is one of 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 the serving network, and wherein the first measurement report comprises an inter-frequency measurement report.

9. The method of claim 1, further comprising the wireless communication device defining the maximum threshold number of consecutive measurement gaps based at least in part on the mobility state.

10. The method of claim 1, wherein the wireless communication device is in connected mode on the serving network.

11. A wireless communication device comprising processing circuitry configured to cause the wireless communication device to at least:

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

send a first measurement report generated based at least in part on the first measurement to a serving cell of a serving network;

determine a mobility state of the wireless communication device;

compare the mobility state to a mobility threshold criterion;

in an instance in which the mobility state satisfies the mobility threshold criterion and the first measurement report has not been resent for a maximum threshold number of consecutive measurement gaps, resend the first measurement report to the serving cell 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 first measurement report has been resent for the maximum threshold number of consecutive measurement gaps, perform a second measurement of the alternative cell during the second measurement gap and send a second measurement report generated based at least in part on the second measurement to the serving cell.

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

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

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

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

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

determine the mobility state of the wireless communication device at least in part by causing the wireless communication device to determine a velocity of the wireless communication device;

wherein the mobility threshold criterion comprises a threshold velocity; and

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

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

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

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

wherein the determined 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 wireless communication device of claim 11, wherein the serving network uses a first radio access technology (RAT), wherein the alternative cell uses a second RAT, and wherein the first measurement report comprises an inter-RAT (iRAT) measurement report.

16. The wireless communication device of claim 15, wherein the processing circuitry is further configured to cause the wireless communication 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 determined mobility state satisfies a mobility threshold criterion; and

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

17. The wireless communication device of claim 11, wherein the alternative cell comprises a neighboring cell of the serving network, and wherein the first measurement report comprises an inter-frequency measurement report.

18. A non-transitory computer readable storage medium having computer program code stored thereon, the computer program code comprising program code, which, when executed by one or more processors implemented on a wireless communication device, is configured to cause the wireless communication device to perform a method comprising:

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

sending a first measurement report generated based at least in part on the first measurement to a serving cell of a serving network;

determining a mobility state of the wireless communication device;

comparing the mobility state to a mobility threshold criterion;

in an instance in which the mobility state satisfies the mobility threshold criterion and the first measurement report has not been resent for a maximum threshold number of consecutive measurement gaps, resending the first measurement report to the serving cell 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 first measurement report has been resent for the maximum threshold number of consecutive measurement gaps, performing a second measurement of the alternative cell during the second measurement gap and sending a second measurement report generated based at least in part on the second measurement to the serving cell.