Method and system of identifying cells in which to apply a carrier frequency

• US 6,973,312 B1
• Filed: 07/18/2002
• Issued: 12/06/2005
• Est. Priority Date: 07/18/2002
• Status: Active Grant

• Current Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: Ngan, John Cheong-Wai, Narayanabhatla, Shiva
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Miller, Brandon J.
• Application Number:
  US10/198,382
• Time in Patent Office: 1,237 Days
• Field of Search: 455442-443, 455445-448, 455/452.2, 455/453, 455/436, 455437-438, 370331-332, 370/334
• US Class Current: 455/442
• CPC Class Codes: H04W 16/04 Traffic adaptive resource partitioning
• CPC Class Codes: H04W 36/00 Hand-off or reselection arrangements

Abstract

A method and system of identifying cells in which to apply a carrier frequency. A wireless communication system may be comprised of cells, which are divided into sectors. A list of sectors of the system that require additional capacity may be compiled and a carrier frequency may be applied to a selected group of those sectors. The sectors may be selected based on a distance between each other and/or based on a probability of handoff from one another, for instance.

Claims

1. In a wireless communication system comprising a plurality of base stations each having a respective radiation pattern defining a cell encompassing one or more sectors, a method comprising:

receiving a first list of sectors each deemed to require additional capacity;

establishing a second list of all sectors in the first list that are each within a predefined distance of at least one other sector in the first list;

improving wireless signal traffic capacity of all cells that encompass at least one sector in the second list;

determining neighboring cells of all of the cells that encompass at least one sector in the second list, wherein the neighboring cells comprise a first outer surrounding tier of cells; and

improving wireless signal traffic capacity of the neighboring cells.

2. In a wireless communication system comprising a plurality of base stations each having a respective radiation pattern defining a cell encompassing one or more sectors, a method comprising:

receiving a first list of sectors each deemed to require additional capacity;

establishing a second list of all sectors in the first list that are each within a predefined distance of at least one other sector in the first list;

determining neighboring sectors of all sectors in the second list, the neighboring sectors being nearest adjacent surrounding sectors of a given sector; and

applying a predetermined carrier frequency in all cells that encompass at least one sector in the second list and at least one neighboring sector.

3. A computer readable medium having stored therein instructions for causing a central processing unit to execute the method of claim 2.

4. The method of claim 2, wherein establishing the second list of all sectors in the first list that are within the predefined distance of at least one other sector in the first list comprises determining a distance between each sector in the first list and each other sector in the first list and selecting pairs of sectors that are within the predefined distance of each other.

5. The method of claim 2, wherein applying the predetermined carrier frequency in all cells that encompass the at least one sector in the second list comprises, for each such cell, causing the base station of the cell to communicate on the predetermined carrier frequency.

6. The method of claim 2, wherein each sector in the first list of sectors has an assigned carrier frequency.

7. The method of claim 6, wherein applying the predetermined carrier frequency in all cells that encompass the at least one sector in the second list comprises re-tuning at least one of the assigned carrier frequencies.

8. The method of claim 6, wherein applying the predetermined carrier frequency in all cells that encompass the at least one sector in the second list comprises designating a frequency to transmit signals, the frequency being different from the assigned carrier frequencies.

9. The method of claim 2, wherein each respective cell of the cells that encompass at least one sector in the second list has one or more neighboring cells, the method further comprising identifying the one or more neighboring cells and applying the predetermined carrier frequency to the one or more neighboring cells.

10. The method of claim 9, wherein identifying the one or more neighboring cells comprises identifying cells that each have a predetermined probability of handoff from at least one of the cells that encompass the at least one sector in the second list.

11. In a wireless communication system comprising a plurality of base stations each having a respective radiation pattern defining a cell encompassing one or more sectors, a method comprising:

receiving a list of sectors, each given sector in the list having a respective neighbor set defining neighbor sectors each having a respective probability of handoff from the given sector; and

for each given sector in the list;

identifying a subset of the given sectors neighbor set, the subset defining sectors (i) that do not share a common cell with the given sector, (ii) that have at least a predetermined probability of handoff from the given sector, and (iii) that are not in the list of sectors, and

improving wireless signal traffic capacity of all cells that encompass at least one sector in the subset.

12. In a wireless communication system comprising a plurality of base stations each having a respective radiation pattern defining a cell encompassing one or more sectors, a method comprising:

receiving a list of sectors, each given sector in the list having a respective neighbor set defining neighbor sectors each having a respective probability of handoff from the given sector; and

for each given sector in the list;

identifying a subset of the given sector'"'"'s neighbor set, the subset defining sectors (i) that do not share a common cell with the given sector, (ii) that have at least a predetermined probability of handoff from the given sector, and (iii) that are not in the list of sectors, and

applying a predetermined carrier frequency in all cells that encompass at least one sector in the subset.

13. A computer readable medium having stored therein instructions for causing a central processing unit to execute the method of claim 12.

14. The method of claim 12, wherein the list of sectors comprises sectors that are deemed to require additional capacity.

15. The method of claim 12, wherein receiving the list of sectors comprises identifying the neighbor sectors that have a respective distance between each other that is less than a predefined distance.

16. The method of claim 12, wherein each sector of the list of sectors has an assigned carrier frequency.

17. The method of claim 16, wherein applying the predetermined carrier frequency in all cells that encompass the at least one sector in the subset comprises re-tuning at least one of the assigned carrier frequencies.

18. The method of claim 16, wherein applying the predetermined carrier frequency in all cells that encompass the at least one sector in the subset comprises adding a frequency to transmit signals, the frequency being different from the assigned carrier frequencies.

19. The method of claim 12, further comprising applying the predetermined carrier frequency in all cells that encompass at least one sector in the list of sectors.

20. In a wireless communication system comprising a plurality of base stations each having a respective radiation pattern defining a cell encompassing one or more sectors, a method comprising:

(a) receiving a first list of sectors, each given sector in the first list being deemed to require additional capacity and having a respective neighbor set defining neighbor sectors each having a respective probability of handoff from the given sector;

(b) establishing a second list of all sectors in the first list that are within a predefined distance of at least one other sector in the first list; and

(c) for each given sector in the second list;

(i) identifying a subset of the given sector'"'"'s neighbor set, the subset defining sectors that do not share a common cell with the given sector, that have at least a predetermined probability of handoff from the given sector, and that are not in the first list of sectors, and

(ii) applying a predetermined carrier frequency in all cells that encompass at least one sector in the subset.

21. A computer readable medium having stored therein instructions for causing a central processing unit to execute the method of claim 20.

22. The method of claim 20, wherein establishing the second list of all sectors in the first list that are within the predefined distance of at least one other sector in the first list comprises determining a distance between each sector in the first list and each other sector in the first list and selecting pairs of sectors that are within the predefined distance of each other.

23. The method of claim 22, wherein, for each given sector in the second list, identifying the subset of the given sectors neighbor set comprises identifying the pairs of sectors that each have neighbor sectors that are within a second predefined distance of the given sector.

24. A system comprising:

a processing unit; and

machine language instructions stored in data storage executable by the processing unit to perform functions including;

receiving a first list of sectors each deemed to require additional capacity, each sector in the first list being included in a cell that is defined by a respective radiation pattern;

establishing a second list of all sectors in the first list that are each within a predefined distance of at least one other sector in the first list;

applying a predetermined carrier frequency in all cells that encompass at least one sector in the second list;

determining neighboring cells of all of the cells that encompass at least one sector in the second list, wherein the neighboring cells comprise a first outer surrounding tier of cells; and

improving wireless signal traffic capacity of the neighboring cells.

25. A system comprising:

a processing unit; and

machine language instructions stored in data storage executable by the processing unit to perform functions including;

receiving a list of sectors, each given sector in the list being included in a cell that is defined by a respective radiation pattern, each given sector in the list having a respective neighbor set defining neighbor sectors each having a respective probability of handoff from the given sector; and

for each given sector in the list;

identifying a subset of the given sector'"'"'s neighbor set, the subset defining sectors (i) that do not share a common cell with the given sector, (ii) that have at least a predetermined probability of handoff from the given sector, and (iii) that are not in the list of sectors, and

applying a predetermined carrier frequency in all cells that encompass at least one sector in the subset.

26. A system comprising:

a processing unit; and

machine language instructions stored in data storage executable by the processing unit to perform functions including;

(a) receiving a first list of sectors, each sector in the first list being included in a cell that is defined by a respective radiation pattern, each given sector in the first list being deemed to require additional capacity and having a respective neighbor set defining neighbor sectors each having a respective probability of handoff from the given sector;

(b) establishing a second list of all sectors in the first list that are within a predefined distance of at least one other sector in the first list; and

(c) for each given sector in the second list;

(i) identifying a subset of the given sector'"'"'s neighbor set, the subset defining sectors that do not share a common cell with the given sector, that have at least a predetermined probability of handoff from the given sector, and that are not in the first list of sectors, and

(ii) applying a predetermined carrier frequency in all cells that encompass at least one sector in the subset.

27. A system comprising:

a base station having a number of antenna-arrangements each operable to provide a respective radiation pattern that defines a respective sector;

means for determining which of the respective sectors require additional capacity;

means for establishing a first list of sectors that are each within a predefined distance of at least one of the sectors that require additional capacity;

means for identifying a second list of sectors that each have a predetermined probability of handoff from the first list of sectors;

means for determining neighboring sectors of all sectors in the second list, the neighboring sectors being nearest adjacent surrounding sectors of a given sector; and

means for applying a carrier frequency to the sectors that require additional capacity, to the first list of sectors, to the second list of sectors, and to at least one neighboring sectors.

28. The system of claim 27, wherein at least one of (i) the means for determining which of the respective sectors require additional capacity, (ii) the means for establishing the first list of sectors that are each within the predefined distance of the at least one of the sectors that require additional capacity, (iii) the means for identifying the second list of sectors that have the predetermined probability of handoff from the sectors that require additional capacity, and (iv) the means for applying the carrier frequency to the sectors that require additional capacity, to the first list of sectors, and to the second list of sectors is a processing unit operable to execute machine language instructions.