Method of controlling handover in uplink synchronous transmission scheme

• US 7,184,419 B2
• Filed: 10/18/2001
• Issued: 02/27/2007
• Est. Priority Date: 10/18/2000
• Status: Active Grant

• Current Assignee: Thomson Licensing (Vantiva SA)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Hwang, Seung Hoon, Park, Jin Young, Kim, Eun Jung, Lee, So Young
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): MURPHY, RHONDA L
• Application Number:
  US09/978,550
• Publication Number:
  US 20020045451A1
• Time in Patent Office: 1,958 Days
• Field of Search: None
• US Class Current: 370/331
• CPC Class Codes: H04W 36/0072 of resource information of target access point

Abstract

A method of controlling a handover is disclosed that uses both a soft handover and a hard handover in an uplink synchronous transmission scheme to synchronize the reception timing between mobile stations in an area of a base station. The uplink synchronous timing of a mobile station established with respect to a first base station can be adjusted to the uplink synchronous timing of a second base station, after re-setting a radio link with the adjusted uplink synchronous information.

Claims

1. A method of controlling a handover of a communication link, comprising:

transmitting information for an uplink synchronous transmission from a radio network controller to a first base station and a second base station;

reconfiguring a radio link between a mobile station and the second base station, based on the information for the uplink synchronous transmission;

adjusting a base time for the uplink synchronous transmission of communication data by the mobile station to match the base time of an uplink synchronization scheme of the second base station when the mobile station moves from a first area corresponding to the first base station to a second area corresponding to the second base station;

transmitting the information on the uplink synchronous transmission from the radio network controller to another radio netxvork controller, if the first and second base stations are controlled by different radio network controllers;

reconfiguring the radio link based on the information for the uplink synchronous transmission transmitted from the radio network controlier; and

adjusting an uplink synchronous timing of the mobile station for the uplink synchronous transmission, on the basis of the reconfigured radio link, to match an uplink synchronous timing of the base station controlled by the another radio network controller.

2. The method of claim 1, wherein the information for the uplink synchronous transmission is an identifier of the uplink synchronous transmission scheme.

3. The method of claim 1, wherein the information for the uplink synchronous transmission is a scramble code of the uplink synchronous transmission scheme.

4. The method of claim 1, wherein the information for the uplink synchronous transmission is a channelizing code number of the uplink synchronous transmission scheme.

5. The method of claim 1, further comprising transmitting a measurement control command for measuring an uplink synchronous timing.

6. The method of claim 5, wherein the measurement control command includes a measurement type and a reporting characteristic.

7. The method of claim 1, wherein the radio link is reconfigured by converting a mode of the uplink synchronous transmission scheme.

8. A method of controUing a communication link, comprising:

measuring a first communication characteristic between a common terminal and a target terminal;

measuring a second communication characteristic between a current terminal and the common terminal;

determining whether to establish a synchronous communication link between the common terminal and the target terminal based on the measured first communication characteristic and the measured second communication characteristic;

establishing the synchronous communication link between the common terminal and the target terminal, the synchronous communication link established in accordance with a timing adjustment value derived from the first communication characteristic measurement; and

transitioning communication service support for the common terminal from the current terminal to the target terminal, using the synchronous communication link.

9. The method of claim 8, wherein the first communication characteristic is a commurncatlon propagation time.

10. The method of claim 8, wherein the second communication characteristic is a received quality of a signal transmitted separately by the target terminal and the current terminal and received by the common terminal.

11. The method of claim 8, wherein the second communication characteristic is the amount of communication traffic supported by the target terminal and by the current terminal.

12. The method of claim 8, wherein establishing the synchronous communication link includes:

activating a communication channel for the synchronous communication link between the target terminal and the common terminal;

synchronizing the common terminal with the synchronous communication link based on the timing adjustment value;

changing a mode of communication between the target terminal and the common terminal from an asynchronous mode to a synchronous mode; and

changing a mode of communication between the current terminal and the common terminal from the synchronous mode to the asynchronous mode.

13. The method of claim 8, further comprising:

establishing a communication channel between the common terminal and the target terminal through a soft handover procedure, prior to measuring the first communication characteristic; and

releasing a communication channel between the common terminal and the current terminal after transitioning the communication service support.

14. The method of claim 8, further comprising:

communicating a request from a source network controller to a target network controller for the target network controller to initiate the measurement of the first communication characteristic, wherein

the source network controller manages the operation of the current terminal and the target network controller manages the operation of the target terminal.

15. A system for managing a communication link, comprising:

a common terminal that communicates with both a target terminal and a current terminal and measures a communication characteristic between the common terminal and the target terminal; and

a network controller that manages the operation of the current terminal and the target terminal, the network controller establishes a synchronous communication link between the common terminal and the target terminal based on a timing adjustment value derived from the communication characteristic measurement and transitions communication service support for the common terminal from the current terminal to the target terminal, using the synchronous communication link, wherein the network controller establishing the synchronous communication link by changing a mode of communication between the target terminal and the common terminal from an asynchronous mode to a synchronous mode and changing a mode of communication between the current terminal and the common terminal from the synchronous mode to the asynchronous mode.

16. A method of controlling a communication link, comprising:

measuring a first communication characteristic between a common terminal and a target terminal;

establishing a synchronous communication link between the common terminal and the target terminal, the synchronous communication link established in accordance with a timing adjustment value derived from the first communication characteristic measurement, wherein establishing the synchronous communication link includes changing a mode of communication between the target terminal and the common terminal from an asynchronous mode to a synchronous mode and changing a mode of communication between a current terminal and the common terminal from the synchronous mode to the asynchronous mode; and

transitioning communication service support for the common terminal from the current terminal to the target terminal using the synchronous communication link.

17. The method of claim 16, wherein establishing the synchronous communication link includes:

activating a communication channel for the synchronous communication link between the target terminal and the common terminal; and

synchronizing the common terminal with the synchronous communication link based on the timing adjustment value.