Methods and apparatus for improving coverage and capacity in a wireless network

• US 9,113,353 B1
• Filed: 02/27/2015
• Issued: 08/18/2015
• Est. Priority Date: 02/27/2015
• Status: Active Grant

• Current Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Original Assignee: Reverb Networks
• Inventors: Cotanis, Nicolae G., Jeon, Hyoung Suk
• Primary Examiner(s): Appiah, Charles
• Assistant Examiner(s): HOLLIDAY, JAIME MICHELE
• Application Number:
  US14/634,316
• Time in Patent Office: 172 Days
• Field of Search: 455/421, 455/422.1, 455/446
• US Class Current: 1/1
• CPC Class Codes: H04W 16/00 Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level

Abstract

A non-transitory processor-readable medium stores code to cause a processor to receive a performance indicator associated with a first mode. The code causes the processor to calculate, using the performance indicator associated with the first mode, a first metric value associated with a first metric and an objective of the first mode. The code causes the processor to calculate, using the first metric value, a second metric value associated with a second metric and an objective of a second mode. The second metric value partially compensates for a change in a performance indicator associated with the second mode when the first metric value is implemented. The code causes the processor to send a signal associated with the first metric value and a signal associated with the second metric value to an antenna module such that the antenna module implements the first metric value and the second metric value.

Claims

1. An apparatus, comprising:

a coverage hole detection module implemented in at least one of a memory or a processing device, the coverage hole detection module configured to receive, at a first time, a value associated with each key performance indicator from a set of key performance indicators associated with a wireless network,

the coverage hole detection module configured to identify, based on the value associated with each key performance indicator from the set of key performance indicators, a geographic area having a network performance problem at the first time,

the coverage hole detection module configured to send, in response to identifying the network performance problem and to a down cell detection module, an inactive cell request to identify inactive antenna cells from a set of antenna cells associated with the geographic area,

the coverage hole detection module configured to receive, from the down cell detection module and in response to the inactive cell request, an indication that each antenna cell from the set of antenna cells is active,

the coverage hole detection module configured to send, in response to the geographic area having the network performance problem at the first time and to a neighbor relation module, a neighbor relation update request for each antenna cell from the set of antenna cells to update at a second time after the first time a neighbor list associated with that antenna cell,

the coverage hole detection module configured to classify the network performance problem as a coverage hole in response to the coverage hole detection module identifying the network performance problem at a third time, the third time being a predetermined time after the second time, and

a coverage hole mitigation module operatively coupled to the coverage hole detection module, the coverage hole mitigation module configured to send a signal to modify at least one of a power or an antenna tilt associated with at least one antenna cell from the set of antenna cells based on the coverage hole detection module classifying the network performance problem as a coverage hole.

2. The apparatus of claim 1, wherein the set of key performance indicators includes a drop call rate, an indication of received signal power at a set of user devices, an estimate of propagation time between the set of user devices and an access point associated with an antenna cell from the set of antenna cells, available resources at the access point, available resources at the set of user devices, a radio resource utilization rate at the access point, and an indication of devices changing technology within the geographic area.

3. The apparatus of claim 1, wherein the coverage hole detection module is configured to send the neighbor relation update request in response to receiving the indication that each antenna cell from the set of antenna cells is active.

4. The apparatus of claim 1, wherein the at least one antenna cell from the set of antenna cells is a first antenna cell,

the coverage hole mitigation module is configured to, for each antenna cell from the set of antenna cells, detect a set of potential victim antenna cells within an area covered by that antenna cell from the set of antenna cells if that antenna cell from the set of antenna cells were used to mitigate the coverage hole,

the coverage hole mitigation module configured to select the first antenna cell from the set of antenna cells to use to mitigate the coverage hole,

the coverage hole mitigation module configured to not use a second antenna cell from the set of antenna cells to mitigate the coverage hole based on an antenna cell from the set of potential victim antenna cells within the area covered by the second antenna cell being within the set of potential victim antenna cells within the area covered by the first antenna cell.

5. The apparatus of claim 1, wherein the at least one antenna cell from the set of antenna cells is a first antenna cell,

the coverage hole mitigation module configured to, for each antenna cell from the set of antenna cells, detect a set of potential victim antenna cells within an area covered by that antenna cell from the set of antenna cells if that antenna cell from the set of antenna cells were used to mitigate the coverage hole,

the coverage hole mitigation module configured to select the first antenna cell from the set of antenna cells to use to mitigate the coverage hole,

the coverage hole mitigation module configured to send a signal to modify a configuration associated with a second antenna cell from the set of antenna cells based on each antenna cell from the set of potential victim antenna cells within the area covered by the second antenna cell not being within the set of potential victim antenna cells within the area covered by the first antenna cell.

6. The apparatus of claim 1, wherein:

the coverage hole mitigation module is configured to rank the set of antenna cells based on a cost value to modify a configuration of each antenna cell from the set of antenna cells,

the coverage hole mitigation module is configured to, at a fourth time after the third time, send a signal to change a configuration associated with a first antenna cell from the set of antenna cells to mitigate the coverage hole based on the first antenna cell having a rank meeting a first predetermined criterion, and

the coverage hole mitigation module is configured to, at a fifth time after the fourth time, send a signal to change a configuration associated with a second antenna cell from the set of antenna cells to mitigate the coverage hole based on (1) the second antenna cell from the set of antenna cells having a rank meeting a second predetermined criterion and (2) the first antenna cell from the set of antenna cells not meeting a third predetermined criterion.

7. The apparatus of claim 1,

wherein the coverage hole mitigation module is configured to select the at least one antenna cell from the set of antenna cells to use to at least partially mitigate the coverage hole based on a portion of the coverage hole associated with the at least one antenna cell from the set of antenna cells being greater than a portion of the coverage hole associated with each remaining antenna cell from the set of antenna cells.

8. An apparatus, comprising:

a coverage hole mitigation module implemented in at least one of a memory or a processing device, the coverage hole mitigation module configured to receive an indication of a coverage hole within a geographic area and associated with a plurality of antenna cells associated with an antenna,

the coverage hole mitigation module configured to identify a first antenna cell (1) from the plurality of antenna cells and (2) to use to mitigate the coverage hole,

the coverage hole mitigation module configured to send a signal to change a tilt of the antenna from a first position to a second position at a first time,

the coverage hole mitigation module configured to send, at a second time after the first time, a signal to increase power of the first antenna cell from a first power level to a second power level in response to at least one of (1) an adverse effect on a coverage area associated with a second antenna cell from the plurality of antenna cells and during a predetermined time period after the first time, or (2) a limit associated with the tilt of the antenna,

a time period to change the power of the first antenna cell from the second power level to the first power level after the second time based on an adverse effect on at least one antenna cell from the plurality of antenna cells is less than a time period to further increase the power of the first antenna cell from the second power level to a third power level after the second time based on an improvement in a value of at least one key performance indicator from a plurality of key performance indicators.

9. The apparatus of claim 8, wherein the coverage hole mitigation module is configured to, at a third time after the second time, send a signal to change the power of the first antenna cell from the second power level to the first power level if a value of at least one key performance indicator from the plurality of key performance indicators indicates from the second time to the third time a decrease in performance of at least one antenna cell from the plurality of antenna cells,

the coverage hole mitigation module configured to not send, at the third time, a signal to increase the power of the first antenna cell from the second power level to the third power level if a value of at least one key performance indicator from the plurality of key performance indicators indicates from the second time to the third time no decrease in performance of each antenna cell from the plurality of antenna cells.

10. The apparatus of claim 8, further comprising:

a coverage hole detection module operatively coupled to the coverage hole mitigation module, the coverage hole detection module configured to detect a network performance problem within the geographic area and identify the network performance problem as the coverage hole based on the network performance problem not being associated with an inactive antenna cell or an outdated neighbor list.

11. The apparatus of claim 8, wherein coverage hole mitigation module is configured to identify the adverse effect on the coverage area associated with the second antenna cell based on a value for each key performance indicator from the plurality of key performance indicators,

the plurality of key performance indicators includes at least one of a drop call rate, an indication of received signal power at a set of user devices, an estimate of propagation time between the set of user devices and an access point associated with the second antenna cell, available resources at the set of user devices, a radio resource utilization rate at the access point, and an indication of devices changing technology within the geographic area.

12. The apparatus of claim 8, wherein the coverage hole mitigation module configured to send a signal to change the tilt from the second position to the first position at a third time after the first time but before the second time and in response to a value for at least one key performance indicator from the plurality of key performance indicators indicating the adverse effect on the coverage area associated with the second antenna cell from the plurality of antenna cells and during a predetermined time period between the first time and the third time.

13. The apparatus of claim 8, wherein the coverage hole mitigation module is configured to send, at a third time after the first time, a signal to change the tilt of the antenna from the second position to a third position based on a limit associated with the power of the first antenna cell.

14. The apparatus of claim 8, wherein the coverage hole mitigation module is configured to, at a third time after the second time, send a signal to change the power of the first antenna cell from the second power level to the first power level if a value associated with a capacity of the first antenna cell meets a capacity limit criterion after the second time and before the third time.

15. A method, comprising:

analyzing, periodically and upon expiration of a detection timer for a wireless network, a first value of each key performance indicator from a set of key performance indicators for the wireless network;

identifying, based on the first value associated with at least one key performance indicator from the set of key performance indicators, a geographic area having a network performance problem at a time;

sending, in response to the geographic area having the network performance problem at the time, a neighbor relation request to update a neighbor list associated with at least one antenna cell from a set of antenna cells associated with the geographic area;

initiating a neighbor relation timer associated with the at least one antenna cell based on the sending the neighbor relation request;

upon expiration of the neighbor relation timer, identifying the network performance problem as a coverage hole if a second value associated with the at least one key performance indicator does not meet a first predetermined criterion;

sending, in response to the identifying the network performance problem as the coverage hole, a signal to modify at least one of a power associated with the at least one antenna cell from the set of antenna cells or a tilt of an antenna including the at least one antenna cell from the set of antenna cells;

initiating a monitor timer and an action timer for the antenna in relation to the signal to modify at least one of the power or the antenna tilt, a duration associated with the monitor timer being less than a duration associated with the action timer;

upon expiration of the monitor timer, receiving a third value of each key performance indicator from the set of key performance indicators and determining improvement or decrease in performance associated with the antenna based on the third value of the at least one key performance indicator from the set of key performance indicators; and

upon expiration of the action timer, sending a signal to further modify at least one of the power associated with the at least one antenna cell from the set of antenna cells or the tilt of the antenna if a fourth value of the at least one key performance indicator from the set of key performance indicators meets a second predetermined criterion.

16. The method of claim 15, wherein the set of key performance indicators includes a drop call rate, an indication of received signal power at a set of user devices, an estimate of propagation time between the set of user devices and an access point associated with an antenna cell from the plurality of antenna cells, available resources at the access point, a radio resource utilization rate, and an indication of devices changing technology within the geographic area.

17. The method of claim 15, further comprising:

upon expiration of the monitor timer, before expiration of the action timer, and based on determining a decrease in performance associated with the antenna, sending a signal to revert the at least one of the power associated with the at least one antenna cell from the set of antenna cells or the tilt of the antenna to a prior configuration.

18. The method of claim 15, wherein the second predetermined criterion is at least one of a decrease in a drop call rate, a decrease in received signal power at a set of user devices, an increase in propagation time between the set of user devices and an access point associated with the antenna, a decrease in available resources at the access point, or a decrease in a rate of devices changing technology within the geographic area.

19. The method of claim 15, wherein the initiating the monitor timer and the action timer for the antenna is based on an initial coverage hole detection associated with the antenna.

20. The method of claim 15, wherein the the third value is from a set of third values, each third value from the set of third values being associated with a unique antenna cell of the antenna,

the determining improvement or decrease in performance associated with the antenna is based on:

(1) the third value from the set of third values for each antenna cell of the antenna meeting a third predetermined criterion if the power of the at least one antenna cell is modified, or (2) a combination of each third value from the set of third values meeting a fourth predetermined criterion if the antenna tilt associated with the at least one antenna cell is modified.

21. The method of claim 15, wherein the geographic area is a first geographic area, the time is a first time, and the at least one antenna cell is a first antenna cell included in the antenna, the method further comprising:

identifying a second geographic area having a network performance problem at a second time after the first time and prior to expiration of the action timer, the second geographic area being associated with a second antenna cell included in the antenna; and

waiting until expiration of the action timer to modify at least one of a power of the second antenna cell included in the antenna or the tilt of the antenna based on the second geographic area having the network performance problem.