# US 2021/0243661 A1 · Handover method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243661 A1 - Document ID: US20210243661A1 - Status: Published application - Kind: A1 - Application number: 17/237,151 - Filed: 2021-04-22 - Published: 2021-08-05 - Earliest claimed: 2018-05-14 - Assignees: Zte Corporation - Applicants: Zte Corporation - Inventors: Xiaojuan SHI; He HUANG; Jing LIU - Web page: https://patentgrep.com/patent/US20210243661A1 ## CPC - H04W 36/00: Hand-off or reselection arrangements - H04W 76/27: Transitions between radio resource control [RRC] states - H04W 36/0011: {for data sessions of end-to-end connection} - H04W 36/00838: {Resource reservation for handover} - H04W 36/0085: {Hand-off measurements} - H04W 36/08: Reselecting an access point - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Provided are a handover method and apparatus. The method includes following steps: a UE receives an RRC reconfiguration message sent by a source base station, where the RRC reconfiguration message includes a list of target cells for performing a conditional handover by the UE, information of each target cell in the list of the target cells for performing the conditional handover includes at least one of the following: frequency information of the target cell, a physical cell identifier of the target cell, a conditional handover command of the target cell generated by the target cell, or at least one piece of measurement configuration identifier information, and the at least one piece of measurement configuration identifier information is used for instructing an execution condition for the UE to perform a conditional handover in the target cell; and the UE performs a handover according to the RRC reconfiguration message. ## Claims ### Claim 1 A method, comprising: receiving, by a user equipment (UE), a radio resource control (RRC) reconfiguration message from a source base station, wherein the RRC reconfiguration message comprises a list of target cells for performing a conditional handover by the UE, and information of each target cell of the target cells which comprises at least one piece of measurement configuration identifier information to indicate an execution condition for the UE to perform a conditional handover to the target cell; and performing, by the UE, the conditional handover according to the RRC reconfiguration message. ### Claim 2 (depends on 1) The method of claim 1, wherein the at least one piece of the measurement configuration identifier information comprises two pieces of the measurement configuration identifier information. ### Claim 3 (depends on 1) The method of claim 1, comprising: responsive to a measurement result of at least a first target cell of the target cells meeting a reporting condition of a report configuration associated with the at least one piece of measurement configuration identifier information, determining that an execution condition for the UE to perform a conditional handover to the first target cell is met; and performing, by the UE, the conditional handover to the first target cell. ### Claim 4 (depends on 1) The method of claim 1, comprising: responsive to a radio link failure in a source cell, selecting, by the UE, a first target cell from the list of the target cells; and performing, by the UE, the conditional handover to the first target cell. ### Claim 5 (depends on 1) The method of claim 1, wherein after receiving, by the UE, the RRC reconfiguration message from the source base station, the method comprises: sending, by the UE, an RRC reconfiguration complete message to the source base station, wherein the RRC reconfiguration complete message includes an RRC message transaction identifier allocated to the RRC reconfiguration message by the source base station. ### Claim 6 A user equipment (UE), comprising: at least one processor configured to implement: receiving a radio resource control (RRC) reconfiguration message from a source base station, wherein the RRC reconfiguration message comprises a list of target cells for performing a conditional handover by the UE, and information of each target cell of the target cells which comprises at least one piece of measurement configuration identifier information to indicate an execution condition for the UE to perform a conditional handover to the target cell; and performing the conditional handover according to the RRC reconfiguration message. ### Claim 7 (depends on 6) The UE of claim 6, wherein the at least one piece of the measurement configuration identifier information comprises two pieces of the measurement configuration identifier information. ### Claim 8 (depends on 6) The UE of claim 6, wherein the at least one processor is configured to implement: responsive to a measurement result of at least a first target cell of the target cells meeting a reporting condition of a report configuration associated with the at least one piece of measurement configuration identifier information, determining that an execution condition for the UE to perform a conditional handover to the first target cell is met; and performing the conditional handover to the first target cell. ### Claim 9 (depends on 6) The UE of claim 6, wherein the at least one processor is configured to implement: responsive to a radio link failure in a source cell, selecting a first target cell from the list of the target cells; and performing the conditional handover to the first target cell. ### Claim 10 (depends on 6) The UE of claim 6, wherein the at least one processor is configured to implement: after receiving the RRC reconfiguration message from the source base station, sending an RRC reconfiguration complete message to the source base station, wherein the RRC reconfiguration complete message includes an RRC message transaction identifier allocated to the RRC reconfiguration message by the source base station. ### Claim 11 A method, comprising: transmitting, by a source base station to a user equipment (UE), a radio resource control (RRC) reconfiguration message, wherein the RRC reconfiguration message comprises a list of target cells for performing a conditional handover by the UE, and information of each target cell of the target cells which comprises at least one piece of measurement configuration identifier information to indicate an execution condition for the UE to perform a conditional handover to the target cell, and wherein the RRC reconfiguration message is used by the UE to perform the conditional handover. ### Claim 12 (depends on 11) The method of claim 11, wherein the at least one piece of the measurement configuration identifier information comprises two pieces of the measurement configuration identifier information. ### Claim 13 (depends on 11) The method of claim 11, wherein: responsive to a measurement result of at least a first target cell of the target cells meeting a reporting condition of a report configuration associated with the at least one piece of measurement configuration identifier information, the UE determines that an execution condition for the UE to perform a conditional handover to the first target cell is met, and performs the conditional handover to the first target cell. ### Claim 14 (depends on 11) The method of claim 11, wherein responsive to a radio link failure in a source cell, the UE selects a first target cell from the list of the target cells, and performs the conditional handover to the first target cell. ### Claim 15 (depends on 11) The method of claim 11, comprising: after the transmitting of the RRC reconfiguration message to the UE, receiving, by the source base station from the UE, an RRC reconfiguration complete message that includes an RRC message transaction identifier allocated to the RRC reconfiguration message by the source base station. ### Claim 16 A source base station, comprising: at least one processor configured to implement: transmitting, to a user equipment (UE), a radio resource control (RRC) reconfiguration message, wherein the RRC reconfiguration message comprises a list of target cells for performing a conditional handover by the UE, and information of each target cell of the target cells which comprises at least one piece of measurement configuration identifier information to indicate an execution condition for the UE to perform a conditional handover to the target cell, and wherein the RRC reconfiguration message is used by the UE to perform the conditional handover. ### Claim 17 (depends on 16) The source base station of claim 16, wherein the at least one piece of the measurement configuration identifier information comprises two pieces of the measurement configuration identifier information. ### Claim 18 (depends on 16) The source base station of claim 16, wherein: responsive to a measurement result of at least a first target cell of the target cells meeting a reporting condition of a report configuration associated with the at least one piece of measurement configuration identifier information, the UE determines that an execution condition for the UE to perform a conditional handover to the first target cell is met, and performs the conditional handover to the first target cell. ### Claim 19 (depends on 16) The source base station of claim 16, wherein responsive to a radio link failure in a source cell, the UE selects a first target cell from the list of the target cells, and performs the conditional handover to the first target cell. ### Claim 20 (depends on 16) The source base station of claim 16, wherein after the transmitting of the RRC reconfiguration message to the UE, the at least one processor is configured to implement: receiving from the UE an RRC reconfiguration complete message that includes an RRC message transaction identifier allocated to the RRC reconfiguration message by the source base station.