Cost-function-based dynamic channel assignment for a cellular system

• US 6,119,011 A
• Filed: 03/05/1998
• Issued: 09/12/2000
• Est. Priority Date: 03/05/1998
• Status: Expired due to Fees

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Kahn, Colin L., Kumaran, Krishnan, Grandhi, Sudheer A., Borst, Simon C., Huang, Joe, Zhang, Bulin B.
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): PEREZ GUTIERREZ, RAFAEL
• Application Number:
  US09/035,453
• Time in Patent Office: 922 Days
• Field of Search: 455/450, 455/451, 455/452, 455/509, 455/514, 455/447, 455/453, 455/513, 455/62, 370/329, 370/330
• US Class Current: 455/452.2
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]

Abstract

In a cellular system, channels are assigned for new calls using a cost-function-based dynamic channel assignment (CFBDCA) algorithm. In one embodiment, the CFBDCA algorithm is implemented in the cellular system'"'"'s mobile switching center (MSC), which maintains a database containing one or more cost tables and a busy channel table. The entries in the cost tables reflect the costs of using a candidate channel in one particular cell of the cellular system, assuming that the channel is already being used in another particular cell. The entries in the busy channel table identify which channels are currently being used in which cells. The CFBDCA algorithm uses the cost tables and the busy channel table to generate cost of reusing the channel (CORC) values. Depending on the implementation, the CFBDCA algorithm of the present invention may or may not be used in conjunction with a measurement-based DCA (MBDCA) algorithm. If so, then the CFBDCA algorithm may be applied to a list of candidate channels generated using the MBDCA algorithm.

Claims

1. A method for allocating channels in a cellular system, comprising the steps of:

(a) generating one or more cost tables for the cellular system, wherein each entry in the cost tables is a cost value corresponding to a cost of allocating a particular channel to a first sector or cell in the cellular system assuming that the particular channel is already being used in a second sector or cell in the cellular system;

(b) maintaining a busy channel table, wherein each entry in the busy channel table indicates whether a particular channel is currently being used in a particular sector or cell;

(c) generating one or more cost of reusing channel (CORC) values based on the cost tables and the busy channel table, wherein the CORC values correspond to costs of assigning a candidate channel to a candidate sector or cell for a new call; and

(d) determining whether the candidate channel is acceptable for the candidate sector or cell by comparing the CORC values to specified threshold values; and

(e) using the candidate channel for the new call depending on the determination of step (d).

2. The invention of claim 1, wherein steps (c) and (d) are applied sequentially to a list of candidate channels for the candidate sector or cell until an acceptable candidate channel is found.

3. The invention of claim 2, wherein the list of candidate channels is generated by a measurement-based dynamic channel assignment algorithm.

4. The invention of claim 1, wherein the cost values in the cost table are generated using a neighbor association algorithm.

5. The invention of claim 1, wherein the cost values in the cost table are generated using RF measurements.

6. The invention of claim 1, wherein the cost values in the cost table are generated using RF modeling.

7. The invention of claim 1, wherein the cost values in the cost table are generated using two or more of a neighbor association algorithm, RF measurement, and RF modeling.

8. The invention of claim 1, wherein a first CORC value corresponds to the cost of assigning the candidate channel to the candidate sector or cell and one or more additional CORC values correspond to the impacts adding the candidate channel to the candidate sector or cell would have on one or more other sectors or cells in which the candidate channel is already being used.

9. The invention of claim 1, wherein:

steps (c) and (d) are applied sequentially to a list of candidate channels for the candidate sector or cell until an acceptable candidate channel is found, wherein the list of candidate channels is generated by a measurement-based dynamic channel assignment algorithm;

the cost values in the cost table are generated using at least one of a neighbor association algorithm, RF measurements, and RF modeling; and

a first CORC value corresponds to the cost of assigning the candidate channel to the candidate sector or cell and one or more additional CORC values correspond to the impacts adding the candidate channel to the candidate sector or cell would have on one or more other sectors or cells in which the candidate channel is already being used.

10. A cellular system, comprising:

(a) a mobile switching center (MSC); and

(b) a plurality of cell sites, communicating with the MSC, wherein;

the MSC generates one or more cost tables for the cellular system, wherein each entry in the cost WE tables is a cost value corresponding to a cost of allocating a particular channel to a first sector or cell in the cellular system assuming that the particular channel is already being used in a second sector or cell in the cellular system;

the MSC maintains a busy channel table, wherein each entry in the busy channel table indicates whether a particular channel is currently being used in a particular sector or cell;

the MSC generates one or more cost of reusing channel (CORC) values based on the cost tables and the busy channel table, wherein the CORC values correspond to costs of assigning a candidate channel to a candidate sector or cell for a new call; and

the MSC determines whether the candidate channel is acceptable for the candidate sector or cell by comparing the CORC values to specified threshold values; and

the cell site uses the candidate channel for the new call depending on the determination of whether the candidate channel is acceptable.

11. The invention of claim 10, wherein the MSC generates the CORC values and determines whether the candidate channel is acceptable sequentially for a list of candidate channels for the candidate sector or cell until an acceptable candidate channel is found.

12. The invention of claim 11, wherein the list of candidate channels is generated by a measurement-based dynamic channel assignment algorithm.

13. The invention of claim 10, wherein the cost values in the cost table are generated using at least one of a neighbor association algorithm, RF measurement, and RF modeling.

14. The invention of claim 10, wherein a first CORC value corresponds to the cost of assigning the candidate channel to the candidate sector or cell and one or more additional CORC values correspond to the impacts adding the candidate channel to the candidate sector or cell would have on one or more other sectors or cells in which the candidate channel is already being used.

15. The invention of claim 10, wherein:

the MSC generates the CORC values and determines whether the candidate channel is acceptable sequentially for a list of candidate channels for the candidate sector or cell until an acceptable candidate channel is found, wherein the list of candidate channels is generated by a measurement-based dynamic channel assignment algorithm;

the cost values in the cost table are generated using at least one of a neighbor association algorithm, RF measurements, and RF modeling; and

a first CORC value corresponds to the cost of assigning the candidate channel to the candidate sector or cell and one or more additional CORC values correspond to the impacts adding the candidate channel to the candidate sector or cell would have on one or more other sectors or cells in which the candidate channel is already being used.

16. A mobile switching center (MSC) for a cellular system further comprising a plurality of cell sites, wherein:

the MSC generates one or more cost tables for the cellular system, wherein each entry in the cost tables is a cost value corresponding to a cost of allocating a particular channel to a first sector or cell in the cellular system assuming that the particular channel is already being used in a second sector or cell in the cellular system;

the MSC maintains a busy channel table, wherein each entry in the busy channel table indicates whether a particular channel is currently being used in a particular sector or cell;

the MSC generates one or more cost of reusing channel (CORC) values based on the cost tables and the busy channel table, wherein the CORC values correspond to costs of assigning a candidate channel to a candidate sector or cell for a new call; and

the MSC determines whether the candidate channel is acceptable for the candidate sector or cell by comparing the CORC values to specified threshold values; and

the cell site uses the candidate channel for the new call depending on the determination of whether the candidate channel is acceptable.

17. The invention of claim 16, wherein the MSC generates the CORC values and determines whether the candidate channel is acceptable sequentially for a list of candidate channels for the candidate sector or cell until an acceptable candidate channel is found.

18. The invention of claim 17, wherein the list of candidate channels is generated by a measurement-based dynamic channel assignment algorithm.

19. The invention of claim 16, wherein the cost values in the cost table are generated using at least one of a neighbor association algorithm, RF measurement, and RF modeling.

20. The invention of claim 16, wherein a first CORC value corresponds to the cost of assigning the candidate channel to the candidate sector or cell and one or more additional CORC values correspond to the impacts adding the candidate channel to the candidate sector or cell would have on one or more other sectors or cells in which the candidate channel is already being used.

21. The invention of claim 16, wherein:

the MSC generates the CORC values and determines whether the candidate channel is acceptable sequentially for a list of candidate channels for the candidate sector or cell until an acceptable candidate channel is found, wherein the list of candidate channels is generated by a measurement-based dynamic channel assignment algorithm;

the cost values in the cost table are generated using at least one of a neighbor association algorithm, RF measurements, and RF modeling; and

a first CORC value corresponds to the cost of assigning the candidate channel to the candidate sector or cell and one or more additional CORC values correspond to the impacts adding the candidate channel to the candidate sector or cell would have on one or more other sectors or cells in which the candidate channel is already being used.