Granted Patent B2

US 12,628,228 · App. 17/890,900 · Granted May 12, 2026

Inventors: Liangliang Zhang (Beijing, CN); Junren Chang (Beijing, CN); Zhenhua Dai (Shanghai, CN)

Assignee: Huawei Technologies Co., Ltd.

H04W76/19H04W36/0055H04W76/18H04W76/27

Abstract

Claims (64)

1 . A re-establishment method, comprising:

receiving, by a terminal device, a handover command from a source network device, wherein the handover command indicates that the terminal device is to perform a dual active protocol stack (DAPS) handover from a source cell to a target cell, the handover command comprises first configuration information, and the first configuration information is configuration information used in the target cell;

performing, by the terminal device, the DAPS handover, and after successfully accessing the target cell and before receiving a first message from a target network device indicating to release the source cell, determining that link failure has occurred in the target cell;

releasing, by the terminal device, second configuration information, wherein the second configuration information is configuration information used in the source cell;

determining, by the terminal device, a first cell;

determining, by the terminal device, a radio resource control (RRC) re-establishment request message based on the first configuration information, wherein the RRC re-establishment request message comprises a cell-radio network temporary identifier (C-RNTI) used in the target cell and a short message authentication code for integrity (short MAC-I) used in the target cell; and

sending, by the terminal device, the RRC re-establishment request message in the first cell.

2 . The method according to claim 1 , wherein determining that link failure has occurred is further based on determining that one or more of the following cases occur in the target cell or the source cell:

an RRC connection reconfiguration failure occurs;

integrity check fails;

a quantity of radio link control (RLC) retransmissions reaches a preset threshold;

a timer T310 expires; or

random access fails and a timer T311 is not running.

3 . The method according to claim 1 , wherein determining that link failure has occurred is based on determining that an RRC connection reconfiguration failure occurs in the target cell, and wherein determining that the RRC connection reconfiguration failure occurs in the target cell comprises:

receiving a first reconfiguration message from the target network device, wherein the first reconfiguration message comprises third configuration information, and the third configuration information is new configuration information used in the target cell;

performing reconfiguration based on the first reconfiguration message; and

determining that the RRC connection reconfiguration failure occurs in the target cell.

4 . The method according to claim 3 , wherein the first reconfiguration message is received from the target network device in a DAPS handover procedure, after successfully accessing the target cell and before receiving the first message indicating to release the source cell from the target network device.

5 . The method according to claim 3 , wherein the first reconfiguration message further comprises first indication information, and the first indication information indicates to release the second configuration information.

6 . The method according to claim 1 , wherein determining that link failure has occurred is based on determining that one or more of the following cases occur in a handover procedure:

inter-system handover fails; or

intra-system handover fails.

7 . The method according to claim 1 , wherein the first cell is a cell to which the target network device belongs or a cell to which a non-source network device belongs.

8 . The method according to claim 1 , wherein the RRC re-establishment request message comprises second indication information, and the second indication information indicates the link failure.

9 . The method according to claim 1 , wherein the RRC re-establishment request message further comprises: a physical cell identifier (PCI) of the target cell.

10 . The method according to claim 1 , further comprising:

in a DAPS handover procedure, starting a timer after successfully accessing the target cell;

before receiving the first message indicating to release the source cell from the target network device, determining that the timer expires; and

sending a second message to the target network device, wherein the second message indicates that the first message has not been received or indicates that the first message failed to be received.

11 . An apparatus, comprising:

one or more processors; and

one or more memories coupled to the one or more processors and storing programming instructions;

wherein the one or more processors are configured to execute the programming instructions to facilitate performance of the following by the apparatus:

receiving a handover command from a source network device, wherein the handover command indicates that the apparatus is to perform a dual active protocol stack (DAPS) handover from a source cell to a target cell, the handover command comprises first configuration information, and the first configuration information is configuration information used in the target cell;

performing the DAPS handover, and after successfully accessing the target cell and before receiving a first message indicating to release the source cell from a target network device, determining that link failure has occurred in the target cell;

releasing second configuration information, wherein the second configuration information is configuration information used in the source cell;

determining a first cell;

determining a radio resource control (RRC) re-establishment request message based on the first configuration information, wherein the RRC re-establishment request message comprises a cell-radio network temporary identifier (C-RNTI) used in the target cell and a short message authentication code for integrity (short MAC-I) used in the target cell; and

sending the RRC re-establishment request message in the first cell.

12 . The apparatus according to claim 11 , wherein determining that link failure has occurred is further based on determining that one or more of the following cases occur in the target cell or the source cell:

an RRC connection reconfiguration failure occurs;

integrity check fails;

a quantity of radio link control (RLC) retransmissions reaches a preset threshold;

a timer T310 expires; or

random access fails and a timer T311 is not running.

13 . The apparatus according to claim 11 , wherein determining that link failure has occurred is based on determining that an RRC connection reconfiguration failure occurs in the target cell, wherein determining that the RRC connection reconfiguration failure occurs in the target cell comprises:

receiving a first reconfiguration message from the target network device, wherein the first reconfiguration message comprises third configuration information, and the third configuration information is new configuration information used in the target cell;

performing reconfiguration based on the first reconfiguration message; and

determining that the RRC connection reconfiguration failure occurs in the target cell.

14 . The apparatus according to claim 13 , wherein the first reconfiguration message is received from the target network device in a DAPS handover procedure, after successfully accessing the target cell and before receiving the first message indicating to release the source cell from the target network device.

15 . The apparatus according to claim 13 , wherein the first reconfiguration message further comprises first indication information, and the first indication information indicates to release the second configuration information.

16 . The apparatus according to claim 11 , wherein determining that link failure occurs is based on determining that one or more of the following cases occur in a handover procedure:

inter-system handover fails; or

intra-system handover fails.

17 . The apparatus according to claim 11 , wherein the first cell is a cell to which the target network device belongs or a cell to which a non-source network device belongs.

18 . The apparatus according to claim 11 , wherein the RRC re-establishment request message comprises second indication information, and the second indication information indicates the link failure.

19 . The apparatus according to claim 11 , wherein the RRC re-establishment request message further comprises: a physical cell identifier (PCI) of the target cell.

20 . A non-transitory computer-readable storage medium having processor-executable instructions stored thereon, wherein the processor-executable instructions, when executed, facilitate:

receiving a handover command from a source network device, wherein the handover command indicates a dual active protocol stack (DAPS) handover from a source cell to a target cell, the handover command comprises first configuration information, and the first configuration information is configuration information used in the target cell;

performing the DAPS handover, and after successfully accessing the target cell and before receiving a first message indicating to release the source cell from a target network device, determining that link failure has occurred in the target cell;

releasing second configuration information, wherein the second configuration information is configuration information used in the source cell;

determining a first cell;

determining a radio resource control (RRC) re-establishment request message based on the first configuration information, wherein the RRC re-establishment request message comprises a cell-radio network temporary identifier (C-RNTI) used in the target cell and a short message authentication code for integrity (short MAC-I) used in the target cell; and

sending the RRC re-establishment request message in the first cell.

Assignments (1)

Priority Claims (1)

Continuity (2)

References Cited (33)