Method and system for optimizing cell-neighbor lists

• US 20030190916A1
• Filed: 01/03/2003
• Published: 10/09/2003
• Est. Priority Date: 04/05/2002
• Status: Active Grant

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Shah, Ali, Velo, Julio, Inman, Dwight, Celedon, Rafael
• Granted Patent: US 7,050,803 B2
• Time in Patent Office: Days
• US Class Current: 455/437
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/0085 Hand-off measurements

Abstract

A count is made of the number of mobile assisted handoff (MAHO) attempts between a service cell and a targeted cell. A count is also made of the number of times the targeted cell is considered a Best Candidate (BestCand) for handoff from the service cell. If the targeted cell is not included in the service cell'"'"'s neighbor list, a potential neighbor cell (PNC), hysteresis is added to the targeted cell to prevent handoffs to the targeted cell. The MAHO and BestCand counts are determined and if the counts meet or exceed predetermined threshold values the targeted cell is added to the list. If the targeted cell is on the neighbor list, no hysteresis is added. If the count data does not meet or exceed the threshold values, the target is removed from the list

Claims

1. A method for adding a cell to a neighbor list comprising the steps of:

selecting a potential neighbor-cell (PNC);

adding said PNC to said neighbor list;

preventing handoffs to said PNC; and

retrieving count data that establishes the number of times that said PNC receives a request for access and is considered a best candidate for adding to said neighbor list.

2. The method of claim 1 wherein preventing handoffs to said PNC includes the step of applying a hysteresis value to said PNC to prevent any mobile station handoffs to said PNC.

3. The method of claim 1 wherein said step of retrieving count data further comprises the step of counting the number of mobile assisted handoff attempts to said PNC.

4. The method of claim 3 further comprising the step of counting the number of times that said PNC is a best candidate for handoff.

5. The method of claim 1 further comprising the steps of:

correlating said count data with predetermined threshold values; and

adjusting said hysteresis value to a level that will allow mobile station handoff to said PNC if said best candidate count and mobile assisted handoff attempts data exceeds a predetermined set of threshold values.

6. A base station in a wireless telecommunications system, comprising:

an operating support system (OSS) associated with said base station;

a database associated with said OSS for storing count data associated with said cells wherein said count data comprises mobile assisted handoff (MAHO) counts and best candidate counts;

a receiver for receiving said count data from a mobile station (MS);

a first counter for determining the number of times one of said cells in said telecommunications system is a best candidate for handoff between said one of said cells and a neighbor-cell;

a second counter for determining the number of mobile assisted handoff attempts between said one of said cells and said neighbor-cell; and

instructions within said OSS for one of removing said one of said cells from a neighbor list if said count data does not correlate with a predetermined threshold value and adding a potential neighbor-cell (PNC) to said neighbor list if said count data meets or exceeds said predetermined threshold value.

7. The base station of claim 6 wherein said OSS is capable of selecting a first potential neighbor-cell (PNC).

8. The base station of claim 6 wherein said OSS is capable of applying a hysteresis value to said PNC, said hysteresis value preventing MS handoffs to said PNC.

9. The base station of claim 6, wherein said database is communicably coupled with a mobile switching center (MSC), said MSC being capable of processing and storing said count data in said database.

10. The base station of claim 6 wherein said count data is accumulated in said database according to a predetermined time period.

11. The base station of claim 6 wherein said OSS is capable of correlating said count data with said predetermined threshold value.

12. The base station of claim 6, wherein said OSS is further capable of selecting succeeding PNCs for addition to said neighbor list.

13. A method for modifying a neighbor list in a cellular telecommunications network, comprising the steps of:

measuring data received from a mobile station;

storing and processing said data; and

adding and removing cells from said neighbor list wherein removing a cell from said neighbor list comprises the steps of;

a) selecting a neighbor-cell to pair with a service cell;

b) counting the number of times that said neighbor-cell is a best candidate for handoff between said service cell and said neighbor-cell;

c) counting the number of mobile assisted handoff (MAHO) attempts between said service cell and said neighbor-cell;

d) analyzing the count data of said best candidate count and said MAHO attempts; and

e) removing said neighbor-cell from said neighbor list if said count data does not meet or exceed a predetermined threshold value; and

wherein adding a potential neighbor-cell (PNC) to said neighbor list comprises the steps of;

a1) selecting a potential neighbor-cell (PNC) to said neighbor list;

b1) applying a hysteresis value to said PNC that prevents the possibility of a mobile station handoff to said PNC;

c1) adding said PNC to said neighbor list;

d1) counting the number of mobile assisted handoff attempts on said PNC;

e1) counting the number of times that said PNC is a best candidate for handoff;

f1) analyzing the count data of said best candidate count and said mobile assisted handoff attempts; and

g1) adjusting said hysteresis value to a level that will allow mobile station handoff to said PNC if said best candidate count data and said mobile assisted handoff attempts meet or exceed a predetermined set of threshold values.

14. The method of claim 13, further comprising the step of accumulating said best candidate count data in a database according to a preset time period.

15. The method of claim 14, further comprising the step of accumulating said MAHO attempts count data in said database according to said preset time period.

16. The method of claim 13, wherein the step of analyzing said best candidate count data and said MAHO attempts count data further comprises comparing said count data to a predetermined threshold value.

17. The method of claim 13, further comprising the step of selecting another cell in said neighbor list for removal and repeating steps a)-f).

18. The method of claim 17, further comprising repeating steps a1)-g1) for adding another PNC to said neighbor list.

19. The method of claim 13, wherein said step of counting the number of times that said neighbor-cell is a best candidate for handoff between said cell and neighbor-cell is performed by one of an originating base station and a mobile station.

20. The method of claim 13, wherein said step of maintaining said hysteresis value to prevent mobile station handoff to said PNC if said best candidate count data and said mobile assisted handoff attempts do not exceed a predetermined set of threshold values.