Method for dividing traffic in a cellular radio network

• US 20020042276A1
• Filed: 09/04/2001
• Published: 04/11/2002
• Est. Priority Date: 03/05/1999
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Nokia Networks (Nokia Corporation)
• Inventors: Hulkkonen, Jari, Hakalin, Petteri
• Granted Patent: US 6,584,318 B2
• Time in Patent Office: Days
• US Class Current: 455/453
• CPC Class Codes: H04W 16/06 Hybrid resource partitioning, e.g. channel borrowing
• CPC Class Codes: H04W 16/08 Load shedding arrangements
• CPC Class Codes: H04W 36/22 for handling the traffic

Abstract

The invention relates to a method for dividing traffic between cells and a cellular radio system comprising at least a base station (300) of a particular cell (304), at least one subscriber terminal (322, 324) communicating with the base station (300), and cells (306) surrounding the particular cell (304), and subscriber terminals (332, 334) communicating therewith, the cellular radio system being arranged to measure the amount of traffic and interference in the system, and to calculate a weighting value for each cell based on the network measurements. In the method of the invention the base station (300) of the particular cell is arranged to adjust the size of its coverage area on the basis of the weighting value of the cell (304).

Claims

1. A method for dividing traffic between cells in a cellular radio network, comprising:

calculating for each cell a weighting value based on network measurements and the interference caused by each cell to the surrounding cells;

adjusting the size of each cell on the basis of the weighting value calculated for the cell.

2. A method as claimed in claim 1 further comprising the step of calculating the weighting value based on the amount of traffic of each cell.

3. A method as claimed in claim 2, further comprising the step of adjusting the size of each cell dynamically by changing the handover margin of the cell in relation to the surrounding cells.

4. A method as claimed in claim 3, further comprising the step of adjusting the handover margin independently for each surrounding cell.

5. A method as claimed in claim 3, where in the handover margin of the cell interfering with the surrounding cells is increased for the calls arriving at the cell and decreased for calls leaving the cell.

6. A method as claimed in claim 3, where in the handover margin is changed within pre-set limits.

7. A method as claimed in claim 3, where in the handover margin of the cell has a particular basic value, and the margin is changed with a correction factor depending on the amount of interference.

8. A method as claimed in claim 7, further comprising steps of measuring by a terminal in a determined cell in the cellular radio system the strengths of the broadcast control channels received from the surrounding cells;

reporting by the terminal the results to the base station;

determining the connections interfered by a particular cell of neighbouring cells using at least partly the same frequency set as the particular cell on the basis of the measurements of the subscriber terminals located in the neighbouring cells concerning the strongest neighbouring cells and on the basis of the common frequencies used by the neighbouring cells together with the particular cell and

selecting the correction factor of the handover margin on the basis of the quality measurements of the interfered connections of each surrounding cell.

9. A method as claimed in claim 8, where in a connection ratio depending on the quality measurements of the connections interfered by the cell to be examined is determined for the system cell, and the handover margin is adjusted on the basis of the ratio.

10. A cellular radio system comprising at least a base station of a particular cell, at least one subscriber terminal communicating with the base station, and cells surrounding the particular cell, and subscriber terminals communicating therewith, where in

the cellular radio system is arranged to measure the amount of traffic nd interference in the system, and to calculate a weighting value for each cell on the basis of the network measurements,

the base station of the particular cell is arranged to adjust the size of its coverage area on the basis of the weighting value of the cell

and the cellular radio system is arranged to calculate the weighting value for each cell depending on the interference caused by each cell to the neighbouring cells.

11. A system as claimed in claim 10, where in the cellular radio system is arranged to calculate the weighting value for each cell depending on the amount of traffic of each cell.

12. A cellular radio system as claimed in claim 10, where in the base station of the particular cell is arranged to adjust the size of its coverage area by dynamically changing the handover margin in relation to the surrounding cells.

13. A cellular radio system as claimed in claim 12, where in that the base station of the particular cell is arranged to independently adjust the handover margin between the particular cell and each surrounding cell.

14. A cellular radio system as claimed in claim 12, where in the handover margin of the base station of the particular cell has a certain basic value and that the base station is arranged to adjust the margin with a correction factor depending on the amount of interference.

15. A cellular radio system as claimed in claim 14, where in connections interfered by a particular cell of neighbouring cells using at least partly the same frequency set as the particular cell are determined on the basis of the measurements of the subscriber terminals located in the neighbouring cells concerning the strongest neighbouring cells and on the basis of the common frequencies used by the neighbouring cells together with the particular cell and in that the correction factor of the handover margin depends on the quality measurements of the interfered connections of each surrounding cell.