Cell selecting apparatus in mobile communication terminal and method thereof

• US 20060094452A1
• Filed: 11/01/2005
• Published: 05/04/2006
• Est. Priority Date: 11/03/2004
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kang, Woo-Sok
• Granted Patent: US 7,515,928 B2
• Time in Patent Office: Days
• US Class Current: 455/464
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The present invention provides a mobile communications terminal that may comprise: a transceiver to send and receive signals with a serving cell and one or more neighboring cells; a memory to store characteristic parameter values related to the signals; and a controller cooperating with the transceiver and the memory to perform the steps of, obtaining a difference value between a measured reception power quality value of the serving cell and a minimum reception power quality value of the serving cell; measuring an error rate of a reception quality of one or more messages received through a common channel during a certain time period; and performing further processing to determine cell section by using the measured error rate, if the obtained difference value is at or below a reference value. The controller can perform the further processing by, calculating a ranking value of the serving cell and a ranking value of one or more neighboring cells using reception power quality values of the serving cell and of the neighboring cells; comparing the measured error rate with a threshold value, if the ranking value of a neighboring cell is found to be greater than the ranking value of the serving cell during the duration of a timer; and performing cell selection if the measured error rate is greater than the threshold value.

Claims

1. A mobile communication terminal, comprising:

an error rate measuring unit for measuring an error rate of a message for a certain time period;

a checking unit for checking a size of the measured error rate and a size of a certain threshold value; and

a controller for controlling a cell selection by using the error rate and the threshold value.

2. The terminal of claim 1, further comprising a memory for storing the measured error rate.

3. The terminal of claim 1, further comprising a power quality measuring unit for measuring a power quality of a serving cell provided at the terminal.

4. The terminal of claim 1, wherein the controller performs a cell selection from a serving cell to a neighboring cell, if the error rate exceeds the preset threshold value.

5. The terminal of claim 1, further comprising a calculating unit for calculating a difference value between a reception power quality value of the serving cell and a minimum reception power quality value of the serving cell for providing service to the terminal.

6. The terminal of claim 5, wherein the calculating unit compares the difference value with a threshold value stored in the terminal for a connection between the terminal and the neighboring cell.

7. The terminal of claim 1, wherein the error rate is measured by using a message transmitted through a channel of a serving cell currently being served.

8. The terminal of claim 1, wherein the error rate comprises a signal to noise ratio.

9. The terminal of claim 1, wherein the certain time is a minimum time necessary to measure the error rate of a message, and can be varied.

10. The terminal of claim 1, wherein the threshold value is variable.

11. A mobile communications terminal comprising:

a transceiver to send and receive signals with a serving cell and one or more neighboring cells;

a memory to store characteristic parameter values related to the signals; and

a controller cooperating with the transceiver and the memory to perform the steps of,

obtaining a difference value between a measured reception power quality value of the serving cell and a minimum reception power quality value of the serving cell;

measuring an error rate of a reception quality of one or more messages received through a common channel during a certain time period; and

performing further processing to determine cell section by using the measured error rate, if the obtained difference value is at or below a reference value.

12. The terminal of claim 11, wherein the controller performs the further processing by,

calculating a ranking value of the serving cell and a ranking value of one or more neighboring cells using reception power quality values of the serving cell and of the neighboring cells;

comparing the measured error rate with a threshold value, if the ranking value of a neighboring cell is found to be greater than the ranking value of the serving cell during the duration of a timer; and

performing cell selection if the measured error rate is greater than the threshold value.

13. A cell selecting method in a mobile communication terminal, comprising:

measuring an error rate of a message for a certain time and then storing the error rate;

checking the stored error rate with a threshold value stored in the mobile communication terminal; and

performing a cell selection, if the stored error rate is greater than the threshold value.

14. The method of claim 13, wherein the error rate is measured by using a message transmitted through a channel of a serving cell.

15. The method of claim 13, wherein the error rate comprises a signal to noise ratio.

16. The method of claim 13, wherein the error rate is measured for a certain time provided by a timer.

17. The method of claim 13, wherein the threshold value is stored in the mobile communication terminal.

18. A cell selecting method in a mobile communication terminal, comprising:

calculating a difference value between a reception power quality value of a serving cell and a minimum reception power quality value of the serving cell;

measuring an error rate of a message transmitted from a channel of the serving cell for a certain time then storing, and comparing the calculated difference value with a reference value stored in the mobile communication terminal;

calculating each ranking value of the serving cell and a neighboring cell and then comparing the ranking values with each other for a certain time, if the difference value is less than the reference value; and

performing a cell selection, if the ranking value of the neighboring cell is greater than that of the serving cell and the stored error rate is greater than the threshold value.

19. The method of claim 18, wherein the serving cell channel is a channel for providing service to the mobile communication terminal by a base station.

20. The method of claim 18, wherein the error rate is measured by using a message transmitted through the channel.

21. The method of claim 18, wherein the error rate comprises a signal to noise ratio.

22. The method of claim 18, wherein the error rate is measured for a certain time provided by a timer.

23. The method of claim 18, wherein the threshold value is stored in the mobile communication terminal.