METHOD FOR RESELECTING A CELL AND DETECTING WHETHER A TERMINAL IS STATIONAY IN MOBILE TELECOMMUNICATIONS SYSTEM

• US 20100240356A1
• Filed: 09/27/2008
• Published: 09/23/2010
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Seon-Don, Yi, Seung-June, Park, Sung-Jun, Lee, Young-Dae, Chun, Sung-Duck
• Granted Patent: US 8,320,918 B2
• Time in Patent Office: Days
• US Class Current: 455/422.100
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination

Abstract

Disclosed is a method for determining, by a terminal, its mobility and deciding a time to select another cell in a mobile communication system, in which the terminal determines the mobility by using variation information in signal characteristic values of measurable specific cells, thereby appropriately controlling a size of a time restriction (e.g., Treselection) for a cell re-selection and preventing frequent occurrence of cell selection such as a ping-pong situation, thus to reduce an unnecessary service delay due to the cell re-selection and maximize a service quality for a user.

Claims

1. A method for selecting a cell according to terminal mobility in a mobile communication system comprised of a plurality of cells, comprising:

(a) determining whether or not a terminal is in a stationary state; and

(b) adjusting a control value for cell selection related to the terminal mobility according to the determination.

2. The method of claim 1, wherein the stationary state of the terminal is determined by the terminal based on a variation regarding the stationary state.

3. The method of claim 2, wherein the stationary state of the terminal is determined at a specific time point, for specific period of time or upon occurrence of a specific event.

4. The method of claim 1, wherein the control value for the cell selection is a timer value (Treselection) associated with the cell selection according to the terminal mobility.

5. The method of claim 2, wherein the variation is a value obtained based on a first measurement and a second measurement, and wherein, in the first measurement, the terminal measures each signal strength or each cell ID of neighboring cells for a timer time (TCRmax), and in the second measurement, the terminal measures each signal strength or each cell ID of neighboring cells for the timer time (TCRmax).

6. The method of claim 2, wherein the stationary state of terminal is determined by comparing the variation with a threshold.

7. The method of claim 1, wherein the control value for the cell selection is a measurement report transmitted from the terminal to a base station, and the measurement report includes each signal characteristic value of neighboring cells measured by the terminal.

8. The method of claim 1, wherein the step (a) is performed when the terminal is in an idle mode or in a connected mode.

9. The method of claim 2, wherein the variation is obtained from information about signal strength of searched cells for an operation time (TCRmax) of a specific timer, or obtained based on the number of the cell identifiers (ID) of the searched cells for the operation time (TCRmax) of the specific timer.

10. A method for detecting a stationary state of a terminal in a mobile communication system, in a method for selecting a cell according to terminal mobility in a mobile communication system comprised of a plurality of cells, comprising:

(A) obtaining a variation so as to determine whether or not the terminal positioned at a boundary of the plurality of cells is in a stationary state;

(B) determining the stationary state of the terminal by comparing the variation with a threshold; and

(C) if the terminal is determined to be in the stationary state, adjusting a value of a cell selection-related timer (Treselection).

11. The method of claim 10, wherein the variation in step (B) is obtained by measuring signal strength of neighboring cells or the number of cell IDs of searched neighboring cells for at least twice for an operation time (TCRmax) of a specific timer.

12. The method of claim 10, wherein the variation is calculated by measurement which the terminal measures signal variation of the neighboring cells periodically or upon occurrence of an event, or is calculated by applying weight for a condition when there is no change in the number of neighboring cells measured by the terminal or in a variation for a certain period of time.