Mitigating handover issues for ground-aerial hybrid networks

• US 10,531,315 B2
• Filed: 05/17/2018
• Issued: 01/07/2020
• Est. Priority Date: 05/17/2018
• Status: Active Grant

• Current Assignee: AT&T Technical Services Company, Inc. (AT&T, Inc.)
• Original Assignee: AT&T Technical Services Company, Inc. (AT&T, Inc.)
• Inventors: Vivanco, Daniel
• Primary Examiner(s): Kim, Minjung
• Application Number:
  US15/982,158
• Publication Number:
  US 20190357061A1
• Time in Patent Office: 600 Days
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 36/0083 Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/165 for reducing network power consumption H04W36/18 - H04W36/22 take precedence
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 76/19 Connection re-establishment

Abstract

In modern networks, frequent handovers (e.g., ping-pong) from one AP device to another is a situation that can lead to increased latency, excessive resource utilization, poor quality of service, or radio link failure (RLF). Conventional networks employ mobility robustness optimization (MRO) procedures to balance tradeoffs between setting low thresholds before initiating a handover procedure, thereby increasing the likelihood of ping-pong issues, and setting those thresholds to higher values, thereby increasing the likelihood of RLF. Conventional MRO procedures are tailored to terrestrial-only networks and furthermore merely react to existing issues. Hybrid networks, having both terrestrial and aerial AP devices often witness ping-pong issues and may be implemented with urgency not conducive to using MRO procedures. An architecture is presented that can predict and mitigate ping-pong and other issues in connection with hybrid networks before those issues occur.

Claims

1. A device, comprising:

a processor; and

a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising;

determining that a cell edge of a first service area provided by a first access point device is overlapped by a second service area provided by a second access point device;

determining that the second access point device is a mobile access point device that is configured to transit from a first physical location to a second physical location during operation;

determining location distribution data representative of a first percentage of user equipment devices served by the first access point device that are located within a first defined distance from the cell edge;

determining mobility data representative of a second percentage of user equipment devices served by the first access point device that are moving toward the second service area; and

updating handover trigger data based on the location distribution data, wherein the handover trigger data comprises a condition that, when satisfied, triggers a handover procedure.

2. The device of claim 1, wherein the condition is satisfied when a user equipment of the user equipment devices determines that a first signal strength metric of a neighbor access point device, which neighbors a serving access point device, exceeds a second signal strength metric of the serving access point device by a hysteresis value of the handover trigger data.

3. The device of claim 2, wherein the condition is satisfied when the user equipment determines that the first signal strength metric exceeds the second signal strength metric by the hysteresis value for a period that exceeds a time-to-trigger value of the handover trigger data.

4. The device of claim 1, wherein the operations further comprise:

updating the handover trigger data based on the location distribution data and the mobility data.

5. The device of claim 4, wherein the updating the handover trigger data comprises:

generating, as a function of the location distribution data and the mobility data, a first adjustment value indicative of a first amount by which to adjust a hysteresis value of the handover trigger data; and

generating, as a function of the location distribution data and the mobility data, a second adjustment value indicative of a second amount by which to adjust a time-to-trigger value of the handover trigger data.

6. The device of claim 5, wherein the first adjustment value and the second adjustment value are large, characterized as being determined to respectively exceed first corresponding defined thresholds, in response to the first percentage being determined to be above a first defined threshold and the second percentage being determined to be below a second defined threshold.

7. The device of claim 5, wherein the first adjustment value and the second adjustment value are near-zero, characterized as respectively being determined to be less than first corresponding defined thresholds, in response to the first percentage and the second percentage being respectively determined to exceed second corresponding defined thresholds.

8. The device of claim 5, wherein the first adjustment value and the second adjustment value are medium, characterized as respectively being determined to be less than corresponding defined high thresholds and greater than corresponding defined low thresholds, in response to the first percentage and the second percentage being respectively determined to be less than second corresponding defined thresholds.

9. The device of claim 5, wherein the first adjustment value and the second adjustment value are small, characterized as respectively being determined to be less than first corresponding defined thresholds, in response to the first percentage being determined to be below a first defined threshold and the second percentage being determined to be above a second defined threshold.

10. The device of claim 1, wherein the determining that the cell edge is overlapped by the second service area is in response to receiving, from a user equipment device served by the first access point device, an A3 event report that indicates conditions to trigger a handover to the second access point device have been satisfied.

11. The device of claim 1, wherein the determining that the second access point device is the mobile access point device is based on a value of a physical cell identity that is assigned to the second access point device.

12. The device of claim 1, wherein the cell edge is representative of portions of the first service area in which a signal strength metric determined by a user equipment device is below a defined threshold.

13. A non-transitory machine-readable storage medium, comprising executable instructions that, when executed by a processor, facilitate performance of operations, comprising:

determining that a cell edge of a first service area provided by a first access point device is overlapped by a second service area provided by a second access point device;

determining that the first access point device is a terrestrial access point device configured to remain stationary while providing service, and that the second access point device is an aerial access point device that is configured to provide service while in motion;

determining location data representative of a first percentage of user equipment devices served by the first access point device that are located within a first defined distance from the cell edge;

determining mobility data representative of a second percentage of user equipment devices served by the first access point device that are moving toward the second service area; and

updating handover trigger data based on the first percentage, wherein the handover trigger data comprises a condition that, when satisfied, triggers a handover procedure.

14. The non-transitory machine-readable storage medium of claim 13, wherein the updating the handover trigger data is based on the location data and the mobility data.

15. The non-transitory machine-readable storage medium of claim 13, wherein the updating the handover trigger data comprises:

updating a hysteresis value of the handover trigger data by a first amount that is determined based on the location data and the mobility data, and wherein the hysteresis value is an amount by which a first signal strength metric of a neighbor access point device is to exceed a second signal strength metric of a serving access point device in order to trigger the handover procedure; and

updating a time-to-trigger value of the handover trigger data by a second amount that is determined based on the location data and the mobility data, and wherein the time-to-trigger value is a length of time the first signal strength metric is to exceed the second signal strength metric by the hysteresis value in order to trigger the handover procedure.

16. The non-transitory machine-readable storage medium of claim 13, wherein the location data is representative of the first percentage of user equipment devices served by the first access point device that are located within a first defined distance from the cell edge and located outside of the second service area.

17. A method, comprising:

determining, by a device comprising a processor, that a cell edge of a first service area facilitated by a first access point device is overlapped by a second service area facilitated by a second access point device;

determining, by the device, that the second access point device is an aerial access point device that is configured to transit from a first physical location to a second physical location during operation;

determining, by the device, location data representative of a first percentage of user equipment devices served by the first access point device that are located within a defined distance from the cell edge;

determining, by the device, mobility data representative of a second percentage of user equipment devices served by the first access point device that are moving toward the second service area; and

updating, by the device, handover trigger data based on the first percentage, wherein the handover trigger data comprises condition data representative of a condition, and wherein a handover procedure is triggered in respect to the condition being determined to be satisfied.

18. The method of claim 17, wherein the operations further comprise receiving, from a user equipment device served by the first access point device, an A3 event report that indicates a handover to the second access point device is recommended, and wherein the receiving the A3 event report triggers the determining that the cell edge is overlapped by the second service area.

19. The method of claim 17, wherein the updating the handover trigger data is based on the location data and further based on the mobility data.

20. The method of claim 17, wherein the determining the location data further comprises determining the first percentage of user equipment devices served by the first access point device that are located within a defined distance from the cell edge and located outside of the second service area.