WIRELESS COMMUNICATION TERMINAL, WIRELESS COMMUNICATION NETWORK SYSTEM AND HANDOVER TIMING DETERMINING METHOD

• US 20090270105A1
• Filed: 10/05/2007
• Published: 10/29/2009
• Est. Priority Date: 10/11/2006
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kakumaru, Takahiro
• Granted Patent: US 8,311,540 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/36 by user or terminal equipment

Abstract

A wireless communication terminal includes a first detecting section for detecting whether or not a reception signal level indicating a level of a received signal from a base station currently in connection as the first base station reduces to be equal to or lower than a first threshold level, a second detecting section for detecting whether or not a communication situation of a communication application program currently in communication is a situation suitable for handover, a third detecting section for detecting whether or not a predetermined handover forcedly performing condition is established, a determining section for determining whether or not the handover control is necessary, based on detection results of the first to third detecting section, and a communication control section for performing a handover control to switch from the first base station to a second base station when the switching to the handover control is necessary.

Claims

1. A wireless communication terminal comprising:

a communication control section connected with a first base station, and configured to perform a handover control to switch from said first base station to a second base station in response to a connection request;

a first detecting section configured to detect whether or not a reception signal level indicating a level of a received signal from a base station currently in connection as said first base station reduces to be equal to or lower than a first threshold level;

a second detecting section configured to detect whether or not a communication situation of a communication application program currently in communication is a situation suitable for handover;

a third detecting section configured to detect whether or not a predetermined handover forcedly performing condition is established; and

a determining section configured to determine whether or not the handover control is necessary, based on detection results of said first to third detecting sections and outputting a connection request when the handover control is determined to be necessary.

2. The wireless communication terminal according to claim 1, wherein said determining section determines that switching to the handover control is necessary when the reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than the first threshold level and the communication situation of the communication application program currently in communication becomes suitable for handover, or when the reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than the first threshold level and the handover forcedly performing condition is established.

3. The wireless communication terminal according to claim 2, wherein the handover forcedly performing condition is established when a passage time exceeds a preset time after said reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than the first threshold level.

4. The wireless communication terminal according to claim 2, wherein the handover forcedly performing condition is established when the reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than a second threshold level which is lower than the first threshold level.

5. The wireless communication terminal according to claim 1, wherein said second detecting section is provided in said communication application program, and

the communication application program detects whether or not the communication situation of the communication application program is suitable for the handover, by said second detecting section.

6. The wireless communication terminal according to claim 1, wherein said second detecting section is provided in a handover instructing application program different from said communication application program, and

the handover instructing application program detects whether or not the communication situation of the communication application program is suitable for the handover, by said second detecting section.

7. The wireless communication terminal according to claim 1, wherein when the communication application program is a speech communication application program, said second detecting section detects a silence period during data communication as a period suitable for the handover.

8. The wireless communication terminal according to claim 1, wherein said second detecting section detects a period other than a period for a process of a control protocol of the communication application program as a period suitable for the handover.

9. The wireless communication terminal according to claim 8, wherein the control protocol is a signaling protocol for a call control.

10. The wireless communication terminal according to claim 8, wherein the control protocol is a protocol to secure a communication path with VPN.

11. The wireless communication terminal according to claim 1, wherein when the communication application program is a software program which receives a content program distributed based on a predetermined content program list the program, said second detecting section detects whether or not the communication situation is suitable for the handover, based on the content program list.

12. The wireless communication terminal according to claim 1, wherein said second detecting section determines whether or not the communication situation is suitable for the handover, based on an operation situation of a physical button of said wireless communication terminal or a virtual button.

13. The wireless communication terminal according to claim 1, wherein said communication control section switches said first base station which is connected through one wireless communication interface section to said second base station, as the handover control.

14. The wireless communication terminal according to claim 1, wherein said communication control section switches said first base station which is connected through one wireless communication interface section to said second base station which is connected through another wireless communication interface section, as the handover control.

15. A wireless communication network system comprising:

a plurality of base stations;

a wireless communication terminal, which comprises;

a communication control section connected with a first base station, and configured to perform a handover control to switch from said first base station to a second base station in response to a connection request;

a first detecting section configured to detect whether or not a reception signal level indicating a level of a received signal from a base station currently in connection as said first base station reduces to be equal to or lower than a first threshold level;

a second detecting section configured to detect whether or not a communication situation of a communication application program currently in communication is a situation suitable for handover;

a third detecting section configured to detect whether or not a predetermined handover forcedly performing condition is established; and

a determining section configured to determine whether or not the handover control is necessary, based on detection results of said first to third detecting sections and outputting a connection request when the handover control is determined to be necessary,

wherein said wireless communication terminal is connected with a first base station of said plurality of base station and a connection destination is switched from said first base station to a second base station of said plurality of base stations, when a handover control is performed.

16. A method of determining a timing of a handover control to a wireless communication terminal for switching from a first base station to a second base station in response to a connection request, comprising:

performing a first detection of detecting whether or not a reception signal level indicating a level of a received signal from a base station currently in connection as said first base station reduces to be equal to or lower than a first threshold level;

performing a second detection of detecting whether or not a communication situation of a communication application program currently in communication is a situation suitable for handover;

performing a third detection of detecting whether or not a predetermined handover forcedly performing condition is established; and

determining whether or not the handover control is necessary, based on results of said first to third detections; and

outputting the connection request when the handover control is determined to be necessary.

17. The method according to claim 16, wherein said determining comprises:

determining that switching to the handover control is necessary when the reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than the first threshold level and the communication situation of the communication application program currently in communication becomes suitable for handover, or when the reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than the first threshold level and the handover forcedly performing condition is established.

18. The method according to claim 17, wherein the handover forcedly performing condition is established when a passage time exceeds a preset time after said reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than the first threshold level.

19. The method according to claim 17, wherein the handover forcedly performing condition is established when the reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than a second threshold level which is lower than the first threshold level.

20. A computer-readable recording medium in which a computer-readable program is stored to realize a method of determining a timing of a handover control to a wireless communication terminal which performs the handover control for switching from a first base station to a second base station in response to a connection request, wherein the method comprises:

performing a first detection of detecting whether or not a reception signal level indicating a level of a received signal from a base station currently in connection as said first base station reduces to be equal to or lower than a first threshold level;

performing a second detection of detecting whether or not a communication situation of a communication application program currently in communication is a situation suitable for handover;

performing a third detection of detecting whether or not a predetermined handover forcedly performing condition is established; and

determining whether or not the handover control is necessary, based on results of said first to third detections; and

outputting the connection request when the handover control is determined to be necessary.

21. The computer-readable recording medium according to claim 20, wherein said determining comprises:

determining that switching to the handover control is necessary when the reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than the first threshold level and the communication situation of the communication application program currently in communication becomes suitable for handover, or when the reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than the first threshold level and the handover forcedly performing condition is established.

22. The computer-readable recording medium according to claim 20, wherein the handover forcedly performing condition is established when a passage time exceeds a preset time after said reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than the first threshold level.

23. The computer-readable recording medium according to claim 21, wherein the handover forcedly performing condition is established when the reception signal level of the received signal from said base station currently in connection reduces to be equal to or lower than a second threshold level which is lower than the first threshold level.