System and method used in a mobile telecommunications network for load balancing ongoing calls between different base station controllers

• US 6,385,449 B2
• Filed: 03/06/1998
• Issued: 05/07/2002
• Est. Priority Date: 03/06/1998
• Status: Expired due to Term

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Olsson, Magnus, Helleberg, Anna, Eriksson, Erik H., Bhatia, Ranjit
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): BEAMER, TEMICA M
• Application Number:
  US09/036,391
• Publication Number:
  US 20010012778A1
• Time in Patent Office: 1,523 Days
• Field of Search: 455/436, 455/453, 455/450, 455/442, 455/443, 455/445, 455/440
• US Class Current: 455/436
• CPC Class Codes: H04W 28/0861 between base stations
• CPC Class Codes: H04W 36/20 for optimising the interference level

Abstract

A method and system for load balancing used in a mobile telecommunications network. The load balancing system includes a mobile services switching center and a first base station controller coupled to the mobile services switching center for managing a first plurality of cells. The load balancing system further includes a second base station controller coupled to the mobile services switching center for managing a second plurality of cells, where one cell of the first plurality of cells is adjacent to one cell of the second plurality of cells. The second base station controller includes a processor responsive to receiving a first load indication message from the first base station controller in order to determine whether to handover at least one ongoing call from the one cell of the second base station controller to the one cell of the first base station controller.

Claims

1. A load balancing system used in a mobile telecommunications network comprising:

a mobile services switching center;

a first base station controller coupled to the mobile services switching center for managing a first plurality of cells;

a second base station controller coupled to the mobile services switching center for managing a second plurality of cells, where one cell of the first plurality of cells is adjacent to one cell of the second plurality of cells, said second base station controller including;

a processor responsive to receiving a first load indication message from the first base station controller for determining whether to handover at least one ongoing call from the one cell of the second base station controller to the one cell of the first base station controller.

2. The load balancing system of claim 1, wherein said first base station controller including a processor responsive to receiving a second load indication message from the second base station controller for determining whether to handover at least one ongoing call from the one cell of the first base station controller to the one cell of the second base station controller.

3. The load balancing system of claim 2, wherein said processor of the first base station controller includes means for generating the first load indication message whenever a number of active traffic channels within the one cell of the first base station controller changes such as to exceed or fall below a predetermined threshold.

4. The load balancing system of claim 1, wherein said processor of the second base station controller includes means for generating the second load indication message whenever a number of active traffic channels within the one cell of the second base station controller changes such as to exceed or fall below a predetermined threshold.

5. The load balancing system of claim 2, wherein said processor of the first base station controller includes means for periodically generating the first load indication message.

6. The load balancing system of claim 1, wherein said processor of the second base station controller includes means for periodically generating the second load indicating message.

7. The load balancing system of claim 2, wherein said processor of the first base station controller further includes means for transferring the at least one ongoing call to the one cell of the second base station controller when the number of active traffic channels of the one cell associated with the first base station controller is greater than a predetermined threshold and the second base station controller can accept the at least one ongoing call.

8. The load balancing station of claim 1, wherein said processor of the second base station controller further includes means for transferring the at least one ongoing call to the one cell of the first base station controller when the number of active traffic channels of the one cell associated with the second base station controller is greater than a predetermined threshold and the first base station controller can accept the at least one ongoing call.

9. The load balancing system of claim 2, wherein the processor of the first base station controller further includes a load monitor for updating the number of active traffic channels.

10. The load balancing system of claim 9, wherein the processor of the first base station controller further includes a comparator for comparing the updated number of active traffic channels to the predetermined threshold.

11. The load balancing system of claim 1, wherein the processor of the second base station controller further includes a load monitor for updating the number of active traffic channels.

12. The load balancing system of claim 11, wherein the processor of the second base station controller further includes a comparator for comparing the updated number of active traffic channels to the predetermined threshold.

13. A mobile telecommunications network comprising:

a switching center;

a first base station having at least one first cell, said first base station controller coupled to the switching center; and

a second base station controller having at least one second cell adjacent to the first cell of the first base station controller, said second base station controller coupled to the switching center and including;

a second processor for transmitting a message to the first base station controller whenever a resource utilization number of the second cell changes as to exceed or fall below a predetermined threshold, where the second base station controller can accept at least one ongoing call from the first base station controller when the resource utilization number of the second base station controller is less than the predetermined threshold.

14. The mobile telecommunications network of claim 13, wherein said first base station controller including a first processor for transmitting a message to the second base station controller whenever a resource utilization number of the first cell changes as to exceed or fall below the predetermined threshold, where the first base station controller can accept at least one ongoing call from the second base station controller when the resource utilization number of the first base station controller is less than the predetermined threshold.

15. The mobile telecommunications network of claim 14, further comprising an operations and support system for submitting the predetermined threshold to the first processor and the second processor.

16. The mobile telecommunications network of claim 14, wherein said first processor includes means responsive to the transmitted message from the second base station controller for transferring the at least one ongoing call of the first cell to the second cell of the second base station controller when the resource utilization number of the first cell is greater than a predetermined threshold and the second base station controller can accept the at least one ongoing call from the first base station controller.

17. The mobile telecommunications network of claim 13, wherein said second processor includes means responsive to the transmitted message from the first base station controller for transferring the at least one ongoing call of the second cell to the first cell of the first base station controller when the resource utilization number of the second cell is greater than the predetermined threshold and the first base station controller can accept the at least one ongoing call from the second base station controller.

18. The mobile telecommunications network of claim 14, wherein the resource utilization number includes a number of active traffic channels.

19. The mobile telecommunications network of claim 14, wherein the resource utilization number includes a number of active traffic channels divided by a total number of traffic channels.

20. The mobile telecommunications network of claim 14, wherein the first and second processors each include a load monitor for updating the resource utilization number of the first cell and the second cell, respectively.

21. The mobile telecommunications network of claim 20, wherein the first and second processors each include a comparator for comparing the respective updated resource utilization number to the predetermined threshold.

22. A method used in a mobile telecommunications network for sharing loads between a first base station controller having at least one first cell and a second base station controller having at least one second cell adjacent to the first cell, said method comprising the steps of:

establishing and distributing a predetermined threshold to the first and second base station controllers;

generating a first load indication message within the first base station controller;

transmitting the first load indication message to the second base station controller; and

comparing the transmitted first load indication message to the distributed predetermined threshold to determine whether to handover at least one ongoing call from the second cell of the second base station controller to the first cell of the first base station controller.

23. The method of claim 22, further comprising the steps of:

generating a second load indication message within the second base station controller;

transmitting the second load indication message to the first base station controller; and

comparing the transmitted second load indication message to the distributed predetermined threshold to determine whether to handover at least one ongoing call from the first cell of the first base station controller to the second cell of the second base station controller.

24. The method of claim 22, wherein the step of generating a first load indication message includes updating the first load indication message whenever a number of active traffic channels within the first cell changes such as to exceed or fall below the predetermined threshold.

25. The method of claim 22, wherein the step of generating a first load indication message includes updating the first load indication message on a periodic basis.

26. The method of claim 23, wherein the step of generating a second load indication message includes updating the second load indication message whenever a number of active traffic channels within the second cell changes such as to exceed or fall below the predetermined threshold.

27. The method of claim 23, wherein the step of generating a second indication message includes periodically updating the second load indication message.

28. The method of claim 22, wherein the step of comparing the transmitted first load indication message further includes transferring the at least one ongoing call to the first cell when the number of active traffic channels of the second cell associated with the second base station controller is greater than the predetermined threshold and the first base station controller can accept the at least one ongoing call.

29. The method of claim 23, wherein the step of comparing the transmitted second load indication message further includes transferring the at least one ongoing call to the second cell when the number of active traffic channels of the first cell associated with the first base station controller is greater than the predetermined threshold and the second base station controller can accept the at least one ongoing call.