EFFICIENT NEIGHBOR LIST CREATION FOR CELLULAR NETWORKS

• US 20090124262A1
• Filed: 12/31/2007
• Published: 05/14/2009
• Est. Priority Date: 11/09/2007
• Status: Active Grant

• Current Assignee: United States Cellular Corporation (Telephone & Data Systems, Inc.)
• Original Assignee: United States Cellular Corporation (Telephone & Data Systems, Inc.)
• Inventors: Vela, Mario, Saxena, Narothum, Irizarry, Michael
• Granted Patent: US 8,086,237 B2
• Time in Patent Office: Days
• US Class Current: 455/442
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists

Abstract

A method of constructing a neighbor list for a plurality of sectors in a cellular communication environment sorts reference neighbor pairs in the network by number of occurrences based on data derived from one or more PSMM transmissions, analyzes pairs in the sorted list and determines for each pair whether a percentage of occurrence exceeds a first threshold and whether a measure of direct transition statistics exceeds a second threshold. If the percentage of occurrence exceeds a first threshold and the measure of direct transition statistics exceeds a second threshold, then if the reference'"'"'s neighbor list and reciprocal neighbor list have fewer than a predetermined number of neighbors, the process adds neighbors to the reference'"'"'s NL and reciprocal NL in order of occurrence percentage to create a final neighbor list.

Claims

1. A method of constructing a neighbor list associated with a plurality of sectors in a cellular communication environment the process comprising:

sorting reference neighbor pairs in the network by number of occurrences;

adding softer hand-off sectors to each reference sector;

analyzing pairs in the sorted list and determining for each pair whether a percentage of occurrence exceeds a first threshold and whether a measure of direct transition statistics exceeds a second threshold; and

if the percentage of occurrence exceeds a first threshold and the measure of direct transition statistics exceeds a second threshold, then determining whether the reference'"'"'s neighbor list and reciprocal neighbor list have fewer than a predetermined number of neighbors and if so, adding neighbors to the reference'"'"'s NL and reciprocal NL in order of occurrence percentage to create a final neighbor list.

2. The method according to claim 1, wherein sorting reference neighbor pairs in the network by number of occurrences comprises sorting reference neighbor pairs in descending order.

3. The method according to claim 1, wherein sorting reference neighbor pairs in the network by number of occurrences comprises sorting reference neighbor pairs globally.

4. The method according to claim 1, wherein the final neighbor list includes neighbors that are physically adjacent.

5. The method according to claim 4, wherein the final neighbor list also includes neighbors that are physically nonadjacent.

6. The method according to claim 1, wherein the final neighbor list includes at least a plurality of neighbors that are associated with a single base station.

7. The method according to claim 1, wherein the final neighbor list includes a list of one or more reference sectors associated with respective neighbor sectors.

8. The method according to claim 1, wherein data related to reference neighbor pairs usable to identify pairs and their frequency of occurrence of pairs is derived from a plurality of PSMM transmissions received from one or more mobile devices.

9. The method according to claim 8, wherein each PSMM transmission includes signal strength data in the form of a pilot strength record for each sector from which the mobile device is receiving a substantial signal.

10. The method according to claim 9, wherein each pilot strength record includes a PILOT_STRENGTH field that is used to compute the strength of a received pilot by measuring the ratio of the pilot energy to the total received spectral density.

11. A computer-readable medium having thereon computer-executable instructions for constructing a neighbor list associated with a plurality of sectors in a cellular communication environment the instructions comprising:

instructions for sorting reference neighbor pairs in the network by number of occurrences;

instructions for adding softer hand-off sectors to each reference sector;

instructions for analyzing pairs in the sorted list and determining for each pair whether a percentage of occurrence exceeds a first threshold and whether a measure of direct transition statistics exceeds a second threshold; and

instructions for determining whether the reference'"'"'s neighbor list and reciprocal neighbor list have fewer than a predetermined number of neighbors and if so, adding neighbors to the reference'"'"'s NL and reciprocal NL in order of occurrence percentage to create a final neighbor list if the percentage of occurrence exceeds a first threshold and the measure of direct transition statistics exceeds a second threshold.

12. The computer-readable medium according to claim 11, wherein the computer-executable instructions for sorting reference neighbor pairs in the network by number of occurrences comprise instructions for sorting reference neighbor pairs in descending order.

13. The computer-readable medium according to claim 11, wherein the computer-executable instructions for sorting reference neighbor pairs in the network by number of occurrences comprise instructions for sorting reference neighbor pairs globally.

14. The computer-readable medium according to claim 11, wherein the final neighbor list includes neighbors that are physically adjacent.

15. The computer-readable medium according to claim 14, wherein the final neighbor list also includes neighbors that are physically nonadjacent.

16. The computer-readable medium according to claim 11, wherein the final neighbor list includes at least a plurality of neighbors that are associated with a single base station.

17. The computer-readable medium according to claim 11, wherein the final neighbor list includes a list of one or more reference sectors associated with respective neighbor sectors.

18. The computer-readable medium according to claim 11, wherein data related to reference neighbor pairs usable to identify pairs and their frequency of occurrence of pairs is derived from a plurality of PSMM transmissions received from one or more mobile devices.

19. The computer-readable medium according to claim 18, wherein each PSMM transmission includes signal strength data in the form of a pilot strength record for each sector from which the mobile device is receiving a substantial signal.

20. The computer-readable medium according to claim 19, wherein each pilot strength record includes a PILOT_STRENGTH field that is used to compute the strength of a received pilot by measuring the ratio of the pilot energy to the total received spectral density.