# US 12,004,034 B2 · 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 12,004,034 B2
- Document ID: US12004034B2
- Status: Granted
- Kind: B2
- Application number: 18/102,473
- Filed: 2023-01-27
- Published: 2023-06-08
- Granted: 2024-06-04
- Earliest claimed: 2018-05-14
- Assignees: Zte Corporation
- Applicants: Zte Corporation
- Inventors: Xiaojuan Shi; He Huang; Jing Liu
- Web page: https://patentgrep.com/patent/US12004034B2

## 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 handover 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 in the list of target cells for performing the conditional handover comprises: a conditional handover command of the target cell generated by the target cell, and a first measurement configuration identifier, wherein the first measurement configuration identifier is used to indicate a first execution condition for the UE to perform a conditional handover to the target cell; and
selecting, by the UE, responsive to detecting that a radio link failure has occurred with a source cell, a target cell from the list of target cells; and
initiating, based on the selecting, a handover to the target cell.

### Claim 2 (depends on 1)

The method of claim 1, wherein the information of each target cell in the list of target cells comprises a second measurement configuration identifier, wherein the second measurement configuration identifier is used to indicate a second execution condition for the UE to perform a conditional handover to the target cell.

### Claim 3 (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 4

A user equipment (UE), comprising:
at least one processor configured to:
receive 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 in the list of target cells for performing the conditional handover comprises: a conditional handover command of the target cell generated by the target cell, and a first measurement configuration identifier, wherein the first measurement configuration identifier is used to indicate a first execution condition for the UE to perform a conditional handover to the target cell; and
select, responsive to detecting that a radio link failure has occurred with a source cell, a target cell from the list of target cells; and
initiate, based on the selecting, a handover to the target cell.

### Claim 5 (depends on 4)

The UE of claim 4, wherein the information of each target cell in the list of target cells comprises a second measurement configuration identifier, wherein the second measurement configuration identifier is used to indicate a second execution condition for the UE to perform a conditional handover to the target cell.

### Claim 6 (depends on 4)

The UE of claim 4, wherein the at least one processor is further configured to:
send 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 7

A non-transitory computer readable medium storing program instructions for causing one or more processors to:
receive 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, and information of each target cell in the list of target cells for performing the conditional handover comprises: a conditional handover command of the target cell generated by the target cell, and a first measurement configuration identifier, wherein the first measurement configuration identifier is used to indicate a first execution condition to perform a conditional handover to the target cell; and
select responsive to detecting that a radio link failure has occurred with a source cell, a target cell from the list of target cells; and
initiate, based on the selecting, a handover to the target cell.

### Claim 8 (depends on 7)

The non-transitory computer-readable storage medium of claim 7, wherein the information of each target cell in the list of target cells comprises a second measurement configuration identifier, wherein the second measurement configuration identifier is used to indicate a second execution condition to perform a conditional handover to the target cell.

### Claim 9 (depends on 7)

The non-transitory computer-readable storage medium of claim 7, wherein the instructions cause the one or more processors to:
send 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.