MOBILE COMMUNICATION SYSTEM AND CELL RESELECTION METHOD THEREOF

• US 20110143752A1
• Filed: 07/02/2010
• Published: 06/16/2011
• Est. Priority Date: 12/16/2009
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: HONG, Tae Chul
• Granted Patent: US 8,391,856 B2
• Time in Patent Office: Days
• US Class Current: 455/428
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service

Abstract

Provided are a mobile communication system and a cell reselection method of a mobile communication terminal. The mobile communication system includes two or more communication systems using different transmission modes and a mobile communication terminal connectable to the two or more communication systems. The mobile communication terminal measures received signal strength of a satellite communication cell when being switched to an idle mode, divides priority of a satellite communication system using the measured received signal strength and location information of the mobile communication terminal, and sets a first threshold value necessary for cell reselection of the satellite communication system.

Claims

1. A cell reselection method of a terminal in a mobile communication system comprising:

measuring received signal strength of a satellite communication cell if the terminal is switched to an idle mode;

dividing priority of a satellite communication system using the measured received signal strength and location information of the terminal; and

setting a first threshold value necessary for cell reselection of the satellite communication system.

2. The cell reselection method of claim 1, further comprising:

comparing the received signal strength with the first threshold value; and

comparing a value representing power variation of a received signal according to shadowing determined by the location information of the terminal with a second threshold value when the received signal strength is greater than the first threshold value.

3. The cell reselection method of claim 1, wherein the measuring of received signal strength comprises determining a mean value of a result obtained by repeated performance for a certain time to be the received signal strength.

4. The cell reselection method of claim 1, wherein, in the measuring of received signal strength, the terminal is connected to a terrestrial communication cell.

5. The cell reselection method of claim 1, wherein, based on the location information of the terminal, the priority of the satellite communication system is determined:

to exclude the satellite communication system when the terminal is located in an urban area surrounded by terrestrial cells,

to be lower than priority of a terrestrial communication system when the terminal is located in a suburban area not only adjacent to terrestrial cells but also adjacent to areas that are not supported by terrestrial cells, and

to be higher than the priority of the terrestrial communication system when the terminal is located in an area not supported by terrestrial cells.

6. The cell reselection method of claim 1, wherein the priority of the satellite communication system is determined to be lower than the priority of the terrestrial communication system when a service provided by the satellite communication system plays an auxiliary role of a service provided by the terrestrial communication system.

7. The cell reselection method of claim 1, further comprising reselecting a cell according to the priority and the first threshold value.

8. The cell reselection method of claim 1, wherein the location information of the terminal is obtained by GPS or a cell ID of a terrestrial base station.

9. A cell reselection method of a terminal in a mobile communication system comprising:

determining whether the terminal connected to a satellite communication cell is switched to an idle mode;

dividing priority of a satellite communication system using location information of the terminal; and

setting a first threshold value necessary for cell reselection of the satellite communication system.

10. The cell reselection method of claim 9, wherein, based on the location information of the terminal, the priority of the satellite communication system is determined:

to exclude the satellite communication system when the terminal is located in an urban area surrounded by terrestrial cells,

to be lower than priority of a terrestrial communication system when the terminal is located in a suburban area not only adjacent to terrestrial cells but also adjacent to areas that are not supported by terrestrial cells, and

to be higher than the priority of the terrestrial communication system when the terminal is located in an area not supported by terrestrial cells.

11. The cell reselection method of claim 9, wherein the priority of the satellite communication system is determined to be lower than the priority of the terrestrial communication system when a service provided by the satellite communication system plays an auxiliary role of a service provided by the terrestrial communication system.

12. The cell reselection method of claim 9, further comprising reselecting a cell according to the priority and the first threshold value.

13. The cell reselection method of claim 9, wherein the location information of the terminal is obtained by GPS or a cell ID of a terrestrial base station.

14. A mobile communication system comprising:

two or more communication systems using different transmission modes; and

a mobile communication terminal connectable to the two or more communication systems,

wherein the mobile communication terminal measures received signal strength of a satellite communication cell when being switched to an idle mode, divides priority of a satellite communication system using the measured received signal strength and location information of the mobile communication terminal, and sets a first threshold value necessary for cell reselection of the satellite communication system.

15. The mobile communication system of claim 14, wherein the mobile communication terminal compares the received signal strength with the first threshold value, and, if the received signal strength is greater than the first threshold value, compares a value representing power variation of a received signal according to shadowing determined by the location information of the mobile communication terminal with a second threshold value.

16. The mobile communication system of claim 14, wherein the mobile communication terminal determines a mean value of a result obtained by repeating the measurement of the received signal strength for a certain time to be the received signal strength.

17. The mobile communication system of claim 14, wherein, based on the location information of the mobile communication terminal, the priority of the satellite communication system is determined:

to exclude the satellite communication system when the mobile communication terminal is located in an urban area surrounded by terrestrial cells,

to be lower than priority of a terrestrial communication system when the mobile communication terminal is located in a suburban area not only adjacent to terrestrial cells but also adjacent to areas that are not supported by terrestrial cells, and

to be higher than the priority of the terrestrial communication system when the mobile communication terminal is located in an area not supported by terrestrial cells.

18. The mobile communication system of claim 14, wherein the priority of the satellite communication system is determined to be lower than the priority of the terrestrial communication system when a service provided by the satellite communication system plays an auxiliary role of a service provided by the terrestrial communication system.

19. The mobile communication system of claim 14, wherein the mobile communication terminal reselects a cell according to the priority and the first threshold value.

20. The mobile communication system of claim 14, wherein the location information of the mobile communication terminal is obtained by GPS or a cell ID of a terrestrial base station.