Antenna tilt optimization in a wireless communications network

1. A method for adjusting an antenna of a base station in a cellular telecommunications network, the method comprising:

collecting at least one of an activity metric, a transmit power, and an interference value for each of a plurality of target cells neighboring a source cell;

calculating respective first scores for each cell of a portion of the plurality of target cells based on the collected information;

calculating a tilt score based on the first scores;

comparing the tilt score to a predetermined value, and when the tilt score exceeds the predetermined value, adjusting at least one of a tilt angle and a transmission power of an antenna of the source cell based on the tilt score.

2. The method of claim 1 , wherein collecting the information for the plurality of target cells comprises:

comparing an activity metric for each cell on a neighbor cell list (NCL) of the source cell to a threshold value; and

when the activity metric exceeds the threshold value, adding the cell associated with the activity metric to a mobility neighbor list,

wherein the portion of the plurality of target cells includes cells of the mobility neighbor list.

3. The method of claim 2 , further comprising:

sorting cells on the mobility neighbor list in descending order according to a signal strength value; and

truncating the mobility neighbor list.

4. The method of claim 1 , wherein collecting the information for the plurality of target cells comprises:

receiving detected set reports (DSR) at the source cell; and

creating a DSR neighbor list from the received DSRs.

5. The method of claim 4 , wherein creating the DSR neighbor list comprises:

comparing an activity metric for each cell on the DSRs to a threshold value; and

when the activity metric exceeds the threshold value, adding the cell associated with the activity metric to the DSR neighbor list.

6. The method of claim 5 , wherein creating the DSR neighbor list further comprises:

sorting cells on the DSRs in descending order according to a signal strength value; and

truncating the list of sorted cells.

7. The method of claim 4 , wherein creating the DSR neighbor list comprises associating cell identifiers with scrambling codes of the DSR.

8. The method of claim 1 , wherein collecting the information for the plurality of target cells comprises:

creating a first neighbor list including a first set of performance metrics; and

creating a second neighbor list including a second set of performance metrics.

9. The method of claim 8 , wherein the first neighbor list is a mobility neighbor list, and the second neighbor list is a DSR neighbor list.

10. The method of claim 8 , wherein calculating the tilt score includes calculating a first tilt score for the first neighbor list, calculating a second tilt score for the second neighbor list, and adding the first tilt score and the second tilt score.

11. The method of claim 10 , further comprising weighting the first tilt score before adding the first tilt score and the second tilt score.

12. The method of claim 1 , wherein the collected information includes distance information, signal strength information, and activity information.

13. The method of claim 1 , wherein collecting information for the plurality of target cells neighboring a source cell comprises:

determining a set of intra-frequency cells neighboring the source cell;

comparing a metric associated with each cell of the set of source cells to a threshold value; and

when the metric exceeds the threshold value, adding the cell associated with the metric to a list.

14. The method of claim 13 , wherein the metric is an activity metric indicating a level of activity with respect to the associated cell.

15. The method of claim 1 , wherein adjusting the antenna comprises adjusting one of a transmit power and a tilt angle of the source cell.

16. A wireless communications system comprising:

a processor;

a memory; and

a non-transitory computer readable medium with computer executable instructions stored thereon which, when executed by the processor, perform the following steps:

collecting information for a plurality of target cells neighboring a source cell;

calculating respective first scores for each cell of a portion of the plurality of target cells based on the collected information;

calculating a tilt score based on the first scores; and

comparing the tilt score to a predetermined value, and when the tilt score exceeds the predetermined value, adjusting an antenna of the source cell based on the tilt score.

17. The system of claim 16 , wherein collecting the information for the plurality of target cells comprises:

comparing an activity metric for each cell on a neighbor cell list (NCL) of the source cell to a threshold value; and

when the activity metric exceeds the threshold value, adding the cell associated with the activity metric to a mobility neighbor list.

18. The system of claim 17 , wherein the non-transitory computer readable medium further comprises instructions for performing steps of:

sorting cells on the mobility neighbor list in descending order according to a signal strength value; and

truncating the mobility neighbor list.

19. The system of claim 16 , wherein collecting the information for the plurality of target cells comprises:

receiving detected set reports (DSR) at the source cell; and

creating a DSR neighbor list from the received DSRs.

20. The system of claim 19 , wherein creating the DSR neighbor list comprises:

comparing an activity metric for each cell on the DSRs to a threshold value; and

when the activity metric exceeds the threshold value, adding the cell associated with the activity metric to the DSR neighbor list.

21. The system of claim 20 , wherein creating the DSR neighbor list further comprises:

sorting cells on the DSRs in descending order according to a signal strength value; and

truncating the list of sorted cells.

22. The system of claim 19 , wherein creating the DSR neighbor list comprises associating cell identifiers with scrambling codes of the DSR.

23. The system of claim 16 , wherein collecting the information for the plurality of target cells comprises:

creating a first neighbor list including a first set of performance metrics; and

creating a second neighbor list including a second set of performance metrics.

24. The system of claim 23 , wherein the first neighbor list is a mobility neighbor list, and the second neighbor list is a DSR neighbor list.

25. The system of claim 23 , wherein calculating the tilt score includes calculating a first tilt score for the first neighbor list, calculating a second tilt score for the second neighbor list, and adding the first tilt score and the second tilt score.

26. The system of claim 25 , wherein the first tilt score is weighted before adding the first tilt score and the second tilt score.

27. The system of claim 16 , wherein the collected information includes distance information, signal strength information, and activity information.

28. The system of claim 16 , wherein collecting information for the plurality of target cells neighboring a source cell comprises:

determining a set of intra-frequency cells neighboring the source cell;

comparing a metric associated with each cell of the set of source cells to a threshold value; and

when the metric exceeds the threshold value, adding the cell associated with the metric to a list.

29. The system of claim 28 , wherein the metric is an activity metric indicating a level of activity with respect to the associated cell.

30. The system of claim 16 , wherein adjusting the antenna comprises adjusting one of a transmit power and a tilt angle of the source cell.

31. The system of claim 16 , wherein the tilt score is calculated based on interference metrics, signal strength metrics, and activity metrics for the plurality of target cells.