Method and device for notifying handover failure indication information

• US 20110250925A1
• Filed: 03/25/2010
• Published: 10/13/2011
• Est. Priority Date: 07/15/2009
• Status: Active Grant

• Current Assignee: Advanced Standard Communication LLC
• Original Assignee: ZTE Corporation
• Inventors: Han, Lifeng
• Granted Patent: US 9,521,594 B2
• Time in Patent Office: Days
• US Class Current: 455/524
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 36/0079 in case of hand-off failure or rejection

Abstract

The invention discloses a method for notifying handover failure indication information, comprising: a first base station determines, according to radio link failure (RLF) information in a received radio resource control (RRC) re-establishment request message, the information about a cell in which an RLF happens before a UE initiates an RRC re-establishment, and sends the RLF information to a second base station to which the cell where the RLF happens belongs; and the second base station notifies, according to a notification condition set for the indication information of a too early handover or a handover selecting a wrong target handover cell, the base station initiating a handover of the indication information of a too early handover or a handover selecting a wrong target handover cell, both of which meet the notification condition; or upon determining the handover of the UE to a cell in which an RLF happens is a too early handover or a handover selecting a wrong target handover cell, the second base station notifies the base station initiating the handover of the indication information of the too early handover or the handover selecting a wrong target handover cell. The present invention also discloses a device for realizing the method. The invention increases the success rate of a cell handover.

Claims

1. A method for notifying handover failure indication information, comprising:

determining, by a first base station, according to radio link failure (RLF) information in a received radio resource control (RRC) re-establishment request message, the information about a cell in which an RLF happens before a user equipment (UE) initiates an RRC re-establishment, and sending the RLF information to a second base station to which the cell where an RLF happens belongs; and

notifying, by the second base station, upon determining that a handover of the UE to the cell in which an RLF happens is a too early handover or a handover selecting a wrong target handover cell, the base station initiating the handover of the indication information of the too early handover or the handover selecting a wrong target handover cell.

2. The method according to claim 1, wherein when the indication information of the is too early handover or the handover selecting a wrong target handover cell is notified to the base station initiating the handover, the method further comprising:

notifying, by the second base station, the base station initiating the handover of the cause for the handover of the UE.

3. The method according to claim 1, wherein the second base station determines that the handover of the UE to the cell in which an RLF happens is a too early handover if the second base station determines that before the RLF happens the UE has been switched from a current RRC re-establishment cell in the first base station to the cell where the RLF happens and the duration for the completion of the handover is smaller than a set threshold;

and the second base station determines that the handover of the UE to the cell in which an RLF happens is a handover selecting a wrong target handover cell if the second base station determines that before the RLF happens the UE has been switched to the cell in which the RLF happens from a cell in a third base station and the duration for completing the handover is smaller than a set threshold.

4. A method for notifying handover failure indication information, comprising:

determining, by a first base station, according to radio link failure (RLF) information in a received radio resource control (RRC) re-establishment request message, the information about a cell in which an RLF happens before a user equipment (UE) initiates an RRC re-establishment, and sending the RLF information to a second base station to which the cell where an RLF happens belongs; and

notifying, by the second base station, according to a notification condition set for the indication information of a too early handover or a handover selecting a wrong target handover cell, a base station initiating a handover of the indication information of a too early handover or a handover selecting a wrong target handover cell, both the two handovers here meeting the notification condition.

5. The method according to claim 4, wherein the notification condition for the to indication information of a too early handover or a handover selecting a wrong target handover cell is that:

only a handover initiated due to radio quality is notified;

upon determining that handover causes include the cause related to radio quality, the second base station notifies the base station initiating the handover of the indication information of a too early handover or a handover selecting a wrong target handover cell, both the two handovers here happening due to radio quality.

6. The method according to claim 4, wherein the second base station determines that the handover of the UE to the cell in which an RLF happens is a too early handover if the second base station determines that before the RLF happens the UE has been switched to the cell in which the RLF happens from a current RRC re-establishment cell in the first base station and the duration for the completion of the handover is smaller than a set threshold;

and the second base station determines that the handover of the UE to the cell in which an RLF happens is a handover selecting a wrong target handover cell if the second base station determines that before the RLF happens the UE has been switched to the cell in which the RLF happens from a cell in a third base station and the duration for completing the handover is smaller than a set threshold.

7. A device for notifying handover failure indication information, comprising a receiving unit for receiving an RRC re-establishment request message;

a first determining unit for determining the inclusion of RLF information in the RRC re-establishment request message;

a second determining unit for determining the information about a cell in which an RLF happens before a user equipment (UE) initiates an RRC re-establishment according to the RLF information;

a sending unit for sending the RLF information to the base station to which the cell where an RLF happens belongs;

a third determining unit for determining that the handover of the UE to the cell in which an RLF happens is a too early handover or a handover selecting a wrong target handover cell;

and a notifying unit is used for notifying the base station initiating the handover of the indication information of the too early handover or the handover selecting wrong target handover cell;

wherein the receiving unit, the first determining unit, the second determining unit and the sending unit belong to a first base station; and

the third determining unit and the notifying unit belong to a second base station.

8. The device according to claim 7, further comprising a searching unit for searching the cause for the handover of the UE;

the notifying unit notifies the base station initiating the handover of the cause found out by the searching unit;

wherein the searching unit belongs to the second base station.

9. A device for notifying handover failure indication information, comprising

a setting unit for setting a notification condition for the indication information of a too early handover or a handover selecting a wrong target handover cell;

a receiving unit for receiving an RRC re-establishment request message;

a first determining unit for determining the inclusion of RLF information in the RRC re-establishment request message;

a second determining unit for determining the information about a cell in which an RLF happens before a user equipment (UE) initiates an RRC re-establishment according to the RLF information;

a sending unit for sending the RLF information to the base station to which the cell where an RLF happens belongs;

a third determining unit for determining that the handover of the UE to the cell in which an RLF happens is a too early handover or a handover selecting a wrong target handover cell;

a judging unit for judging whether the too early handover or the handover selecting a wrong target handover cell determined by the third determining unit meets a notification condition for indication information, and triggering a notifying unit if the notification condition is met;

and the notifying unit for notifying the base station initiating the handover of the indication information of the too early handover or the handover selecting a wrong target handover cell, both the two handovers here meeting the notification condition;

wherein the setting unit, the receiving unit, the first determining unit, the second determining unit and the sending unit belong to a first base station; and

the third determining unit, the judging unit and the notifying unit belong to a second base station.

10. The device according to claim 9, wherein the notification condition for the indication information of a too early handover or a handover selecting a wrong target handover cell is that:

only a handover initiated due to radio quality is notified; and

upon determining that handover causes include the cause related to radio quality, the judging unit triggers the notifying unit to notify the base station initiating the handover of the indication information of the too early handover or the handover selecting a wrong target handover cell, both the two handovers here happening due to radio quality.