Overload cell control method in a CDMA mobile system

• US 5,912,884 A
• Filed: 02/05/1997
• Issued: 06/15/1999
• Est. Priority Date: 05/02/1996
• Status: Expired due to Term

• Current Assignee: Owens- Corning Fiberglas Technology Incorporated (Owens Corning)
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lee, Sook Jin, Ahn, Jee Hwan, Park, Woo Goo
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): NGO, RICKY QUOC
• Application Number:
  US08/796,024
• Time in Patent Office: 860 Days
• Field of Search: 370/252, 370/328, 370/329, 370/331, 370/335, 370/341, 370/342, 370/441, 455/446, 455/453, 455/522, 455/436, 455/422, 455/449
• US Class Current: 370/331
• CPC Class Codes: H04W 16/06 Hybrid resource partitioning, e.g. channel borrowing

Abstract

The method for controlling an overload cell in a CDMA Mobile System comprises the steps of: a first step of receiving information on the overload cell from an overload detection module within a base station controller to retrieve the information on the load of neighboring cells and calculating the information on the total overload of neighboring cells; a second step of determining whether or not the total overload of the neighboring cell in a second hierarchy is greater than the maximum value of the neighboring cells; a third step of informing the overload detection module of the impossibility of control and terminating the procedure when it is determined that the total overload of the neighboring cell in the second hierarchy is not greater than the maximum value of the neighboring cells; a fourth step of retrieving a cell group as a third hierarchy with minimum load when at the second step it is determined that the total overload of the neighboring cell in the second hierarchy is greater than the maximum value of the neighboring cells; and a fifth step of increasing forward power of the cell with minimum load to expand a service region and handoffing a moving subscriber call in the vicinity of the neighboring cell of the overload cell to the expanded cell.

Claims

1. A method for controlling an overload cell when a particular cell is overloaded in a CDMA mobile system, said method comprising the steps of:

a first step of receiving information on the overload cell from an overload detection module within a base station controller to retrieve the information on the load of neighboring cells and calculate the information on the total overload of said neighboring cells;

a second step of comparing the pre-defined total overload of said neighboring cells with a total load of said neighboring cells;

a third step of informing the overload detection module of the impossibility of control when it is determined that the total overload of said neighboring cells is not greater than the total load of said neighboring cells;

a fourth step of retrieving a cell group having a minimum load when at the second step it is determined as a result of the comparison that the total overload of the neighboring cell in the second hierarchy is less than the total load of said neighboring cells; and

a fifth step of increasing forward power of the cell having the minimum load to expand a service region and handing off a moving subscriber call in the vicinity of said neighboring cells of the overload cell to the expanded cell.

2. The method as set forth in claim 1, wherein said first step comprises the sub-steps of:

determining by said overload detection module within the base station controller when a load of a particular cell has a value greater than 50% of the overload;

proceeding to said step of determining if it is determined that the particular cell does not amount to the overload value;

receiving information on the overload cell from said overload detection module if it is determined that the particular cell has the overload value;

retrieving the load information of said neighboring cells positioned around the said overload cell; and

accumulating said load information on the load retrieved at said retrieving step.

3. The method as set forth in claim 1, wherein said third step comprises the sub-steps of:

selecting one of said neighboring cells positioned the overload cell;

retrieving the load information of other neighboring cells positioned around said selected neighboring cell;

summing said retrieved load information;

determining whether the operation of summing the load information has been completed;

proceeding to said step of selecting if it is determined that the operation of summing the load has not been completed; and

selecting a cell group having a minimum load if it is determined that the operation of summing the load has been completed.

4. The method as set forth in claim 1, wherein said fifth step comprises the sub-steps of:

enlarging a radius of the cell having a minimum load to expand a service region; and

handing off the moving subscriber call in the vicinity of said neighboring cells of the overload cell to the expanded cell.

5. The method as set forth in claim 1, wherein, in said step of enlarging the radius of the cell having a minimum load, the radius of the cell is enlarged by increasing the forward power of the cell having the minimum load.