Message transmission methods, and device and storage medium

Abstract

The embodiments of the present disclosure relate to message transmission methods, and a device and a storage medium. A message transmission method comprises: a first access network device receiving a first message sent by a terminal device, the first message comprising a second message; and determining a third access network device, and sending the second message to the third access network device, wherein the first access network device is an access network device to which a first cell belongs, the first cell is a primary cell (PCell) of the terminal device, the first message is a message sent when the terminal device executes a mobility operation, the mobility operation comprises a secondary cell group (SCG) mobility operation, the SCG mobility operation comprises a primary secondary cell (PSCell) change or a PSCell addition, the PSCell change comprising changing a PSCell of the terminal device from a second cell to a third cell, and the PSCell addition comprising adding the third cell as the PSCell of the terminal device, the first message comprises the second message, the second message is a message corresponding to the third cell, and the third access network device is an access network device to which the third cell belongs.

Description

Message transmission method, device and storage medium Technical Field

[0001] The present disclosure relates to the field of communication technologies, and in particular to a message transmission method, device, and storage medium. Background Art

[0002] With the development of wireless communication technology, the 3rd Generation Partnership Project (3GPP) has proposed Dual Connectivity (DC) technology. Based on DC, terminal devices can connect to two or more access network devices. By splitting traffic between different access network devices, the coverage and capacity of wireless communication systems can be improved.

[0003] Summary of the Invention

[0004] The embodiments of the present disclosure provide a message transmission method, device, and storage medium.

[0005] According to a first aspect of an embodiment of the present disclosure, a message transmission method is provided, which is performed by a first access network device, where the first access network device is an access network device to which a first cell belongs, and the first cell is a primary cell (PCell) of a terminal device. The method includes:

[0006] receiving a first message sent by the terminal device, where the first message is a message sent when the terminal device performs a mobility operation, the mobility operation includes a secondary cell group (SCG) mobility operation, the SCG mobility operation includes a primary / secondary cell (PSCell) change or a PSCell addition, the PSCell change includes changing the PSCell of the terminal device from a second cell to a third cell, and the PSCell addition includes adding a third cell as the PSCell of the terminal device, the first message includes a second message, and the second message is a message corresponding to the third cell;

[0007] Determine a third access network device, where the third access network device is an access network device to which the third cell belongs, and the third access network device is different from a second access network device to which the second cell belongs;

[0008] Send the second message to the third access network device.

[0009] According to a second aspect of an embodiment of the present disclosure, a message transmission method is proposed, which is executed by a terminal device. The method includes:

[0010] performing a mobility operation, the mobility operation including an SCG mobility operation, the SCG mobility operation including a primary / secondary cell (PSCell) change or a PSCell addition, the PSCell change including changing the primary / secondary cell (PSCell) of the terminal device from a second cell to a third cell, the PSCell addition including adding the third cell as the PSCell of the terminal device, the second cell belonging to a second access network device, the third cell belonging to a third access network device, and the second access network device being different from the third access network device;

[0011] A first message is sent to a first access network device, where the first access network device is an access network device to which a first cell belongs, and the first cell is the primary cell PCell of the terminal device. The first message includes a second message, and the second message is a configuration message corresponding to the third cell.

[0012] According to a third aspect of an embodiment of the present disclosure, a message transmission method is proposed, which is performed by a second access network device. The method includes:

[0013] Sending a first indication to a terminal device, where the first indication is used to instruct the terminal device to perform a mobility operation, where the mobility operation includes an SCG mobility operation, where the SCG mobility operation includes a primary / secondary cell (PSCell) change or a PSCell addition, where the PSCell change includes changing the primary / secondary cell (PSCell) of the terminal device from a second cell to a third cell, where the PSCell addition includes adding the third cell as the PSCell of the terminal device, where the second cell belongs to the second access network device, where the third cell belongs to a third access network device, and where the second access network device is different from the third access network device;

[0014] A third message is sent to the first access network device, where the third message is used to instruct the first access network device to determine a third access network device.

[0015] According to a fourth aspect of an embodiment of the present disclosure, a message transmission method is provided, which is performed by a fourth access network device. The method includes:

[0016] Sending a first indication to a terminal device, where the first indication is used to instruct the terminal device to perform a mobility operation, where the mobility operation includes a primary cell group (MCG) mobility operation and a secondary cell group (SCG) mobility operation, where the SCG mobility operation includes a primary or secondary cell (PSCell) change or a PSCell addition, where the PSCell change includes changing the primary or secondary cell (PSCell) of the terminal device from a second cell to a third cell, where the PSCell addition includes adding the third cell as the PSCell of the terminal device, where the second cell belongs to a second access network device, where the third cell belongs to a third access network device, and where the second access network device is different from the third access network device, and where the MCG mobility operation includes changing the primary cell (PCell) of the terminal device from a fourth cell to a first cell, where the first cell belongs to the first access network device, where the fourth cell belongs to the fourth access network device, and where the fourth access network device is different from the first access network device;

[0017] A fourth message is sent to the first access network device, where the fourth message is used to instruct the first access network device to determine the third access network device.

[0018] According to a fifth aspect of an embodiment of the present disclosure, a terminal device is provided, including:

[0019] a processing module configured to perform a mobility operation, the mobility operation including an SCG mobility operation, the SCG mobility operation including a primary / secondary cell (PSCell) change or a PSCell addition, the PSCell change including changing the primary / secondary cell (PSCell) of the terminal device from a second cell to a third cell, the PSCell addition including adding the third cell as the PSCell of the terminal device, the second cell belonging to a second access network device, the third cell belonging to a third access network device, and the second access network device being different from the third access network device;

[0020] The transceiver module is configured to send a first message to a first access network device, where the first access network device is an access network device to which a first cell belongs, and the first cell is the primary cell PCell of the terminal device. The first message includes a second message, and the second message is a configuration message corresponding to the third cell.

[0021] According to a sixth aspect of an embodiment of the present disclosure, a first access network device is provided. The first access network device is an access network device to which a first cell belongs, and the first cell is a primary cell (PCell) of a terminal device. The first access network device includes:

[0022] a transceiver module configured to receive a first message sent by the terminal device, where the first message is a message sent when the terminal device performs a mobility operation, the mobility operation includes a secondary cell group (SCG) mobility operation, the SCG mobility operation includes a primary or secondary cell (PSCell) change or a PSCell addition, the PSCell change includes changing the PSCell of the terminal device from a second cell to a third cell, the PSCell addition includes adding a third cell as the PSCell of the terminal device, and the first message includes a second message, where the second message is a message corresponding to the third cell;

[0023] a processing module configured to determine a third access network device, where the third access network device is an access network device to which the third cell belongs, and the third access network device is different from a second access network device to which the second cell belongs;

[0024] The transceiver module is further configured to send the second message to the third access network device.

[0025] According to a seventh aspect of an embodiment of the present disclosure, a second access network device is provided, including:

[0026] The transceiver module is configured to send a first indication to the terminal device, where the first indication is used to instruct the terminal device to perform a mobility operation, where the mobility operation includes an SCG mobility operation, where the SCG mobility operation includes a primary and secondary cell PSCell change or a PSCell addition, where the PSCell change includes a primary and secondary cell PSCell of the terminal device being changed from a second cell to a third cell, where the PSCell addition includes adding a third cell as the PSCell of the terminal device, where the second cell belongs to the second access network device, where the third cell belongs to a third access network device, and where the second access network device is different from the third access network device; and send a third message to the first access network device, where the third message is used to instruct the first access network device to determine a third access network device.

[0027] According to an eighth aspect of an embodiment of the present disclosure, a fourth access network device is provided, including:

[0028] The transceiver module is configured to send a first indication to the terminal device, wherein the first indication is used to instruct the terminal device to perform a mobility operation, wherein the mobility operation includes a main cell group MCG mobility operation and a secondary cell group SCG mobility operation, wherein the SCG mobility operation includes a main and secondary cell PSCell change or a PSCell addition, wherein the PSCell change includes changing the main and secondary cell PSCell of the terminal device from the second cell to the third cell, wherein the PSCell addition includes adding the third cell as the PSCell of the terminal device, wherein the second cell belongs to the second access network device, the third cell belongs to the third access network device, and the second access network device is different from the third access network device, and the MCG mobility operation includes changing the main cell PCell of the terminal device from the fourth cell to the first cell, wherein the first cell belongs to the first access network device, the fourth cell belongs to the fourth access network device, and the fourth access network device is different from the first access network device; and sending a fourth message to the first access network device, wherein the fourth message is used to instruct the first access network device to determine the third access network device.

[0029] According to a ninth aspect of an embodiment of the present disclosure, a communication device is proposed, comprising: one or more processors; wherein the communication device can be used to execute an optional implementation of the first aspect, the second aspect, the third aspect or the fourth aspect.

[0030] According to the tenth aspect of an embodiment of the present disclosure, a storage medium is proposed, which stores instructions. When the instructions are executed on a communication device, the communication device executes the method described in the optional implementation manner of the first aspect, the second aspect, the third aspect or the fourth aspect.

[0031] According to the eleventh aspect of an embodiment of the present disclosure, a computer program product is proposed, which includes a computer program and / or instructions. When the computer program and / or instructions are executed by a communication device, the communication device executes the method described in the optional implementation of the first aspect, the second aspect, the third aspect or the fourth aspect.

[0032] According to an eleventh aspect of an embodiment of the present disclosure, a communication system is proposed, which may include: a terminal device and an access network device, wherein the access network device includes at least one of the following: a first access network device, a second access network device, and a fourth access network device; wherein,

[0033] The terminal device is configured to execute the method described in the optional implementation manner of the second aspect;

[0034] The first access network device is configured to perform the method described in the optional implementation manner of the first aspect;

[0035] The second access network device is configured to perform the method described in the optional implementation manner of the third aspect;

[0036] The fourth access network device is configured to execute the method described in the optional implementation manner of the fourth aspect.

[0037] The technical solution provided by the embodiment of the present disclosure may include the following beneficial effects: a first access network device receives a first message sent by the terminal device, the first message includes a second message, determines a third access network device, and sends a second message to the third access network device; wherein, the first access network device is an access network device to which the first cell belongs, the first cell is the primary cell PCell of the terminal device, the first message is a message sent when the terminal device performs a mobility operation, the mobility operation includes a secondary cell group SCG mobility operation, the SCG mobility operation includes a primary and secondary cell PSCell change or a PSCell addition, the PSCell change includes changing the PSCell of the terminal device from the second cell to the third cell, the PSCell addition includes adding the third cell as the PSCell of the terminal device, the first message includes a second message, the second message is a message corresponding to the third cell; the third access network device is an access network device to which the third cell belongs, and the third access network device is different from the second access network device to which the second cell belongs. In this way, the first access network device can determine the third access network device and forward the second message to the third access network device, thereby improving the reliability and success rate of mobility operations and enhancing network performance.

[0038] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following drawings required for describing the embodiments are introduced. The following drawings are merely some embodiments of the present disclosure and do not impose specific limitations on the protection scope of the present disclosure.

[0040] FIG1A is a schematic diagram showing the architecture of a communication system according to an embodiment of the present disclosure.

[0041] FIG1B is a schematic diagram showing the architecture of a communication system according to an embodiment of the present disclosure.

[0042] FIG1C is a schematic diagram of a master cell group MCG and a secondary cell group SCG proposed in an embodiment of the present disclosure.

[0043] FIG2A is an interactive schematic diagram illustrating a message transmission method according to an embodiment of the present disclosure.

[0044] FIG2B is an interactive schematic diagram illustrating a message transmission method according to an embodiment of the present disclosure.

[0045] FIG2C is an interactive schematic diagram illustrating a message transmission method according to an embodiment of the present disclosure.

[0046] FIG2D is an interactive schematic diagram illustrating a message transmission method according to an embodiment of the present disclosure.

[0047] FIG2E is an interactive schematic diagram illustrating a message transmission method according to an embodiment of the present disclosure.

[0048] FIG2F is an interactive schematic diagram illustrating a message transmission method according to an embodiment of the present disclosure.

[0049] FIG3A is a schematic flow chart showing a message transmission method according to an embodiment of the present disclosure.

[0050] FIG3B is a flow chart showing a message transmission method according to an embodiment of the present disclosure.

[0051] FIG3C is a flow chart illustrating a message transmission method according to an embodiment of the present disclosure.

[0052] FIG4A is a schematic flow chart showing a message transmission method according to an embodiment of the present disclosure.

[0053] FIG4B is a flow chart showing a message transmission method according to an embodiment of the present disclosure.

[0054] FIG4C is a schematic flow chart of a message transmission method according to an embodiment of the present disclosure.

[0055] FIG5A is a schematic flow chart of a message transmission method according to an embodiment of the present disclosure.

[0056] FIG5B is a flow chart showing a message transmission method according to an embodiment of the present disclosure.

[0057] FIG6A is a schematic flow chart of a message transmission method according to an embodiment of the present disclosure.

[0058] FIG6B is a flow chart showing a message transmission method according to an embodiment of the present disclosure.

[0059] FIG7A is a flow chart showing a message transmission method according to an embodiment of the present disclosure.

[0060] FIG7B is a flow chart showing a message transmission method according to an embodiment of the present disclosure.

[0061] FIG8A is a schematic structural diagram of a terminal device according to an embodiment of the present disclosure.

[0062] FIG8B is a schematic structural diagram of a first access network device according to an embodiment of the present disclosure.

[0063] FIG8C is a schematic structural diagram of a second access network device according to an embodiment of the present disclosure.

[0064] FIG8D is a schematic structural diagram of a third access network device according to an embodiment of the present disclosure.

[0065] FIG8E is a schematic structural diagram of a fourth access network device according to an embodiment of the present disclosure.

[0066] FIG9A is a schematic structural diagram of a communication device according to an embodiment of the present disclosure.

[0067] FIG9B is a schematic structural diagram of a chip according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0068] The embodiments of the present disclosure provide a message transmission method, device, and storage medium.

[0069] In a first aspect, an embodiment of the present disclosure provides a message transmission method, which is performed by a first access network device, where the first access network device is an access network device to which a first cell belongs, and the first cell is a primary cell (PCell) of a terminal device; the method includes:

[0070] receiving a first message sent by the terminal device, where the first message is a message sent when the terminal device performs a mobility operation, the mobility operation includes a secondary cell group (SCG) mobility operation, the SCG mobility operation includes a primary / secondary cell (PSCell) change or a PSCell addition, the PSCell change includes changing the PSCell of the terminal device from a second cell to a third cell, and the PSCell addition includes adding a third cell as the PSCell of the terminal device, the first message includes a second message, and the second message is a message corresponding to the third cell;

[0071] Determine a third access network device, where the third access network device is an access network device to which the third cell belongs, and the third access network device is different from a second access network device to which the second cell belongs;

[0072] Send the second message to the third access network device.

[0073] In the above embodiment, the first access network device (MN) can determine the third access network device (target SN) and forward the second message to the third access network device, thereby improving the reliability and success rate of mobility operations and enhancing network performance.

[0074] In conjunction with some embodiments of the first aspect, in some embodiments, determining the third access network device includes at least one of the following:

[0075] Determining the third access network device according to the first message;

[0076] The third access network device is determined according to a third message, where the third message is a message sent by the second access network device to the first access network device.

[0077] In the above embodiment, the first access network device (MN) can determine the third access network device (target SN) according to the first message or the third message, thereby being able to flexibly determine the third access network device.

[0078] In conjunction with some embodiments of the first aspect, in some embodiments, the first message further includes at least one of the following:

[0079] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0080] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation.

[0081] In the above embodiment, the first access network device (MN) can flexibly determine the third access network device according to any one or more of the above items in the first message, thereby improving the flexibility of device determination.

[0082] In combination with some embodiments of the first aspect, in some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute the LTM configuration information corresponding to the SCG mobility operation.

[0083] In the above embodiment, for LTM-based mobility operations, the first access network device (MN) can determine the third access network device according to LTM configuration information, thereby adapting to the LTM scenario.

[0084] In combination with some embodiments of the first aspect, in some embodiments, the first message includes a first parameter and a second parameter, the first parameter is used to indicate whether the second parameter is used to determine the third access network device, and the second parameter is the primary and secondary cell selected based on the SCG LTM.

[0085] In the above embodiment, signaling consumption can be reduced by reusing parameters in related technologies.

[0086] In conjunction with some embodiments of the first aspect, in some embodiments, the third message includes at least one of the following:

[0087] an access network device identifier, where the access network device identifier is used to indicate the third access network device;

[0088] a target cell identifier, where the target cell identifier is used to indicate the third cell;

[0089] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0090] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0091] The transmission configuration indicates TCI status information, and the TCI status information is used to indicate the beam information of the third cell.

[0092] In the above embodiment, the first access network device (MN) can flexibly determine the third access network device according to any one or more of the above items in the third message, thereby improving the flexibility of device determination.

[0093] In combination with some embodiments of the first aspect, in some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute the LTM configuration information corresponding to the SCG mobility operation.

[0094] In combination with some embodiments of the first aspect, in some embodiments, the SCG mobility operation is triggered by the terminal device or the second access network device.

[0095] In the above embodiment, for the SCG mobility operation triggered by the terminal device or the second access network device (source SN), the first access network device (MN) can determine the third access network device (target SN) and forward the second information to improve the reliability of the mobility operation.

[0096] In combination with some embodiments of the first aspect, in some embodiments, the mobility operation also includes a main cell group MCG mobility operation, and the MCG mobility operation includes changing the main cell PCell of the terminal device from the fourth cell to the first cell, and the fourth cell belongs to a fourth access network device, and the fourth access network device is different from the first access network device.

[0097] In conjunction with some embodiments of the first aspect, in some embodiments, determining the third access network device includes at least one of the following:

[0098] Determining the third access network device according to the first message;

[0099] The third access network device is determined according to a fourth message, where the fourth message is a message sent by the fourth access network device to the first access network device.

[0100] In the above embodiment, the first access network device (MN) can determine the third access network device according to the fourth message sent by the fourth access network device (source MN), thereby improving the flexibility of device determination.

[0101] In conjunction with some embodiments of the first aspect, in some embodiments, the fourth message includes at least one of the following:

[0102] an access network device identifier, where the access network device identifier is used to indicate the third access network device;

[0103] a target cell identifier, where the target cell identifier is used to indicate the third cell;

[0104] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0105] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0106] The transmission configuration indicates TCI status information, and the TCI status information is used to indicate the beam information of the third cell.

[0107] In the above embodiment, the first access network device (MN) can flexibly determine the third access network device according to any one or more of the above items in the fourth message, thereby improving the flexibility of device determination.

[0108] In combination with some embodiments of the first aspect, in some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute the LTM configuration information corresponding to the SCG mobility operation.

[0109] In combination with some embodiments of the first aspect, in some embodiments, the mobility operation is triggered by the terminal device or the fourth access network device.

[0110] In the above embodiment, for the MCG mobility operation and SCG mobility operation triggered by the terminal device or the fourth access network device (source SN), the first access network device (MN) can determine the third access network device (target SN) and forward the second information to improve the reliability of the mobility operation.

[0111] In combination with some embodiments of the first aspect, in some embodiments, the mobility operation is a cell change or addition triggered based on LTM.

[0112] In combination with some embodiments of the first aspect, in some embodiments, the first message is a first RRC reconfiguration complete message, the second message is a second RRC reconfiguration complete message, and the first RRC reconfiguration complete message includes the second RRC reconfiguration complete message.

[0113] In a second aspect, an embodiment of the present disclosure provides a message transmission method, which is executed by a terminal device, and the method includes:

[0114] performing a mobility operation, the mobility operation including an SCG mobility operation, the SCG mobility operation including a primary / secondary cell (PSCell) change or a PSCell addition, the PSCell change including changing the primary / secondary cell (PSCell) of the terminal device from a second cell to a third cell, the PSCell addition including adding the third cell as the PSCell of the terminal device, the second cell belonging to a second access network device, the third cell belonging to a third access network device, and the second access network device being different from the third access network device;

[0115] A first message is sent to a first access network device, where the first access network device is an access network device to which a first cell belongs, and the first cell is the primary cell PCell of the terminal device. The first message includes a second message, and the second message is a configuration message corresponding to the third cell.

[0116] In the above embodiment, the terminal device can notify the first access network device (MN) of relevant information of the third access network device (target SN) through a first message, so that the first access network device forwards the second message to the third access network device, thereby improving the reliability and success rate of mobility operations and improving network performance.

[0117] In combination with some embodiments of the second aspect, in some embodiments, the first message is used to instruct the first access network device to determine a third access network device.

[0118] In conjunction with some embodiments of the second aspect, in some embodiments, the first message includes at least one of the following:

[0119] A layer 1 or layer 2 triggered mobility LTM configuration identifier, wherein the LTM configuration identifier is used to instruct the terminal device to perform the LTM configuration corresponding to the SCG mobility operation;

[0120] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0121] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation.

[0122] In combination with some embodiments of the second aspect, in some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute the LTM configuration information corresponding to the SCG mobility operation.

[0123] In combination with some embodiments of the second aspect, in some embodiments, the SCG mobility operation is triggered by the terminal device or the second access network device.

[0124] In conjunction with some embodiments of the second aspect, in some embodiments, the method further includes:

[0125] Receive a first indication sent by a second access network device, where the first indication is used to instruct the terminal device to perform the mobility operation.

[0126] In combination with some embodiments of the second aspect, in some embodiments, the mobility operation also includes a main cell group MCG mobility operation, and the MCG mobility operation includes changing the main cell PCell of the terminal device from the fourth cell to the first cell, and the fourth cell belongs to a fourth access network device, and the fourth access network device is different from the first access network device.

[0127] In combination with some embodiments of the second aspect, in some embodiments, the mobility operation is triggered by the terminal device or the fourth access network device.

[0128] In combination with some embodiments of the second aspect, in some embodiments, the mobility operation is a cell change or addition triggered based on LTM.

[0129] In combination with some embodiments of the second aspect, in some embodiments, the first message is a first RRC reconfiguration complete message, the second message is a second RRC reconfiguration complete message, and the first RRC reconfiguration complete message includes the second RRC reconfiguration complete message.

[0130] In a third aspect, an embodiment of the present disclosure provides a message transmission method, which is performed by a second access network device. The method includes:

[0131] A first indication is sent to a terminal device, where the first indication is used to instruct the terminal device to perform a mobility operation, where the mobility operation includes an SCG mobility operation, where the SCG mobility operation includes a primary and secondary cell PSCell change or a PSCell addition, where the PSCell change includes changing the primary and secondary cell PSCell of the terminal device from a second cell to a third cell, where the PSCell addition includes adding the third cell as the PSCell of the terminal device, where the second cell belongs to the second access network device, where the third cell belongs to the third access network device, and where the second access network device is different from the third access network device; and a third message is sent to the first access network device, where the third message is used to instruct the first access network device to determine the third access network device.

[0132] In the above embodiment, the second access network device (source SN) can notify the first access network device (MN) of relevant information of the third access network device (target SN) through the third message, so that the first access network device forwards the second message to the third access network device, thereby improving the reliability and success rate of mobility operations and enhancing network performance.

[0133] In conjunction with some embodiments of the third aspect, in some embodiments, the third message includes at least one of the following:

[0134] an access network device identifier, where the access network device identifier is used to indicate the third access network device;

[0135] a target cell identifier, where the target cell identifier is used to indicate the third cell;

[0136] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0137] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0138] The transmission configuration indicates TCI status information, and the TCI status information is used to indicate the beam information of the third cell.

[0139] In combination with some embodiments of the third aspect, in some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute the LTM configuration information corresponding to the SCG mobility operation.

[0140] In combination with some embodiments of the third aspect, in some embodiments, the SCG mobility operation is triggered by the terminal device or the second access network device.

[0141] In combination with some embodiments of the third aspect, in some embodiments, the mobility operation is a cell change or addition triggered based on LTM.

[0142] In the fourth aspect, an embodiment of the present disclosure proposes a message transmission method, sending a first indication to a terminal device, the first indication being used to instruct the terminal device to perform a mobility operation, the mobility operation including a main cell group MCG mobility operation and a secondary cell group SCG mobility operation, the SCG mobility operation including a main and secondary cell PSCell change or a PSCell addition, the PSCell change including the main and secondary cell PSCell of the terminal device being changed from a second cell to a third cell, the PSCell addition including adding the third cell as the PSCell of the terminal device, the second cell belonging to a second access network device, the third cell belonging to a third access network device, and the second access network device being different from the third access network device, the MCG mobility operation including the main cell PCell of the terminal device being changed from a fourth cell to a first cell, the first cell belonging to the first access network device, the fourth cell belonging to the fourth access network device, and the fourth access network device being different from the first access network device; sending a fourth message to the first access network device, the fourth message being used to instruct the first access network device to determine the third access network device.

[0143] In the above embodiment, the fourth access network device (source MN) can notify the first access network device (target MN) of relevant information of the third access network device (target SN) through the fourth message, so that the first access network device forwards the second message to the third access network device, thereby improving the reliability and success rate of mobility operations and enhancing network performance.

[0144] In conjunction with some embodiments of the fourth aspect, in some embodiments, the fourth message includes at least one of the following:

[0145] an access network device identifier, where the access network device identifier is used to indicate the third access network device;

[0146] a target cell identifier, where the target cell identifier is used to indicate the third cell;

[0147] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0148] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0149] The transmission configuration indicates TCI status information, and the TCI status information is used to indicate the beam information of the third cell.

[0150] In combination with some embodiments of the fourth aspect, in some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute the LTM configuration information corresponding to the SCG mobility operation.

[0151] In combination with some embodiments of the fourth aspect, in some embodiments, the mobility operation is triggered by the terminal device or the fourth access network device.

[0152] In combination with some embodiments of the fourth aspect, in some embodiments, the mobility operation is a cell change or addition triggered based on LTM.

[0153] In a fifth aspect, an embodiment of the present disclosure proposes a terminal device, which may include at least one of a transceiver module and a processing module; wherein the terminal device can be used to execute the optional implementation method of the second aspect.

[0154] In the sixth aspect, an embodiment of the present disclosure proposes a first access network device, which may include at least one of a transceiver module and a processing module; wherein the first access network device can be used to execute the optional implementation method of the first aspect.

[0155] In the seventh aspect, an embodiment of the present disclosure proposes a second access network device, and the first access network device may include at least one of a transceiver module and a processing module; wherein the first access network device can be used to execute the optional implementation method of the third aspect.

[0156] In the eighth aspect, an embodiment of the present disclosure proposes a fourth access network device, and the first access network device may include at least one of a transceiver module and a processing module; wherein the first access network device can be used to execute the optional implementation method of the fourth aspect.

[0157] In a ninth aspect, an embodiment of the present disclosure proposes a communication device, which may include: one or more processors; wherein the communication device can be used to execute optional implementation methods of the first aspect, the second aspect, the third aspect or the fourth aspect.

[0158] In the tenth aspect, an embodiment of the present disclosure proposes a storage medium storing instructions, which, when executed on a communication device, enables the communication device to execute the method described in the optional implementation of the first aspect, the second aspect, the third aspect or the fourth aspect.

[0159] In the eleventh aspect, an embodiment of the present disclosure proposes a computer program product, which includes a computer program and / or instructions. When the computer program and / or instructions are executed by a communication device, the communication device executes the method described in the optional implementation of the first aspect, the second aspect, the third aspect or the fourth aspect.

[0160] In a twelfth aspect, an embodiment of the present disclosure proposes a computer program, which, when executed on a computer, enables the computer to execute the method described in the optional implementation of the first, second, third or fourth aspects.

[0161] In a thirteenth aspect, an embodiment of the present disclosure provides a chip or a chip system, wherein the chip or chip system includes a processing circuit configured to execute the method described in the optional implementation of the first aspect, the second aspect, the third aspect, or the fourth aspect.

[0162] In the fourteenth aspect, an embodiment of the present disclosure proposes a communication system, which may include: a terminal device and a first access network device; wherein, the terminal device is configured to execute the method described in the optional implementation manner of the first aspect, and the first access network device is configured to execute the method described in the optional implementation manner of the second aspect.

[0163] It is understandable that the above-mentioned terminal device, access network device, first access network device, second access network device, fourth access network device, communication device, communication system, storage medium, computer program product, computer program, chip or chip system can all be used to perform the method proposed in the embodiments of the present disclosure. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects of the corresponding method and will not be repeated here.

[0164] The present disclosure provides a message transmission method, device, and storage medium. In some embodiments, the terms "message transmission method" and "information processing method" and "communication method" are interchangeable; "message transmission device" and "information processing device" and "communication device" are interchangeable; and "information processing system" and "communication system" are interchangeable.

[0165] The embodiments of the present disclosure are not exhaustive and are merely illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present disclosure. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a certain embodiment can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementation methods in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined. For example, some or all steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

[0166] In each embodiment of the present disclosure, unless otherwise specified or provided for by logic, the terms and / or descriptions between the embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form a new embodiment based on their inherent logical relationships.

[0167] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0168] In the embodiments of the present disclosure, unless otherwise specified, elements expressed in the singular, such as "a", "an", "the", "above", "said", "the", "the", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun following the article may be understood as a singular expression or a plural expression.

[0169] In some embodiments, "plurality" may refer to two or more.

[0170] In some embodiments, the terms "at least one," "one or more," "a plurality of," "multiple," etc. may be used interchangeably.

[0171] In some embodiments, descriptions such as "at least one of A and B," "A and / or B," "A in one case, B in another case," or "in response to one case A, in response to another case B" may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); and in some embodiments, A and B (both A and B are executed). The above is also applicable when there are more branches such as A, B, and C.

[0172] In some embodiments, "A or B" and other descriptions may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). The above is also applicable when there are more branches such as A, B, C, etc.

[0173] The prefixes such as "first" and "second" in the embodiments of the present disclosure are only used to distinguish different description objects and do not constitute any restriction on the position, order, priority, quantity or content of the description objects. For the statement of the description object, please refer to the description in the context of the claims or embodiments, and no unnecessary restriction should be constituted due to the use of prefixes. For example, if the description object is a "field", the ordinal number before the "field" in the "first field" and the "second field" does not limit the position or order between the "fields". "First" and "second" do not limit whether the "fields" they modify are in the same message, nor do they limit the order of the "first field" and the "second field". For another example, if the description object is a "level", the ordinal number before the "level" in the "first level" and the "second level" does not limit the priority between the "levels". For another example, the number of description objects is not limited by the ordinal number and can be one or more. Taking "first device" as an example, the number of "devices" can be one or more. In addition, the objects modified by different prefixes can be the same or different. For example, if the description object is "device", then the "first device" and the "second device" can be the same device or different devices, and their types can be the same or different; for another example, if the description object is "information", then the "first information" and the "second information" can be the same information or different information, and their contents can be the same or different.

[0174] In some embodiments, “including A,” “comprising A,” “used to indicate A,” and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0175] In some embodiments, terms such as "in response to...", "in response to determining...", "in the case of...", "at the time of...", "when...", "if...", "if...", etc. can be used interchangeably.

[0176] In some embodiments, terms such as "greater than", "greater than or equal to", "not less than", "more than", "more than or equal to", "not less than", "higher than", "higher than or equal to", "not less than", and "above" can be replaced with each other, and terms such as "less than", "less than or equal to", "not greater than", "less than", "less than or equal to", "not more than", "lower than", "lower than or equal to", "not higher than", and "below" can be replaced with each other.

[0177] In some embodiments, devices and the like may be interpreted as physical or virtual, and their names are not limited to those described in the embodiments. Terms such as "device," "equipment," "device," "circuit," "network element," "node," "function," "unit," "section," "system," "network," "chip," "chip system," "entity," and "subject" may be used interchangeably.

[0178] In some embodiments, "network" can be interpreted as devices included in the network (for example, first access network equipment, access network equipment, core network equipment, etc.).

[0179] In some embodiments, the network device may include at least one of an access network device and a core network device.

[0180] In some embodiments, the terms "Access Network Device (AN Device)", "Radio Access Network Device (RAN Device)", "Base Station (BS)", "Radio Base Station (Radio Base Station)", "Fixed Station (Fixed Station)", "Node (Node)", "Access Point (Access Point)", "Transmission Point (TP)", "Reception Point (RP)", "Transmission and / or Reception Point (TRP))", "Panel (Panel)", "Antenna Panel (Antenna Panel)", "Antenna Array (Antenna Array)" "Cell (Cell)", "Macro Cell (Macro Cell)", "Small Cell (Small Cell)", "Femto Cell (Femto Cell)", "Pico Cell (Pico Cell)" "Sector (Sector)" "Cell Group (Cell Group)" "Serving Cell" "Carrier (Carrier)", "Component Carrier (Component Carrier)" and "Bandwidth Part (BWP)" can be used interchangeably.

[0181] In some embodiments, the terms "terminal", "terminal device", "terminal side device", "user equipment (UE)", "user terminal" "mobile station (MS)", "mobile terminal (MT)", subscriber station (Subscriber Station), mobile unit (Mobile Unit), subscriber unit (Subscriber Unit), wireless unit (Wireless Unit), remote unit (Remote Unit), mobile device (Mobile Device), wireless device (Wireless Device), wireless communication device (Wireless Communication Device), remote device (Remote Device), mobile subscriber station (Mobile Subscriber Station), access terminal (Access Terminal), mobile terminal (Mobile Terminal), wireless terminal (Wireless Terminal), remote terminal (Remote Terminal), handset (Handset), user agent (User Agent), mobile client (Mobile Client), client (Client) and the like can be used interchangeably.

[0182] In some embodiments, the access network device, the core network device, or the first access network device can be replaced by a terminal device. For example, the various embodiments of the present disclosure can also be applied to a structure in which the communication between the access network device, the core network device, or the first access network device and the terminal device is replaced by communication between multiple terminal devices (for example, device-to-device (D2D), vehicle-to-everything (V2X), etc.). In this case, it can also be set as a structure in which the terminal device has all or part of the functions of the access network device. In addition, terms such as "uplink" and "downlink" can also be replaced by terms corresponding to communication between terminal devices (for example, "side"). For example, uplink channels, downlink channels, etc. can be replaced by side channels or direct channels, and uplinks, downlinks, etc. can be replaced by side links or direct links.

[0183] In some embodiments, the terminal device may be replaced by an access network device, a core network device, or a first access network device. In this case, the access network device, the core network device, or the first access network device may also be configured to have all or part of the functions of the terminal device.

[0184] In some embodiments, obtaining data, information, etc. may comply with the laws and regulations of the country where the data is obtained.

[0185] In some embodiments, data, information, etc. may be obtained with the user's consent.

[0186] In addition, each element, each row, or each column in the table of the embodiment of the present disclosure can be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns can also be implemented as an independent embodiment.

[0187] FIG1A is a schematic diagram illustrating an architecture of a communication system according to an embodiment of the present disclosure. As shown in FIG1A , the communication system 100 may include a terminal device 101 , an access network device 102 , and a core network device 103 .

[0188] In some embodiments, the terminal device 101 may include at least one of a mobile phone, a wearable device, an Internet of Things device, a car with communication function, a smart car, a vehicle-mounted terminal, a tablet computer, a computer with wireless transceiver function, a road side unit (RSU), a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in smart grid, a wireless terminal device in transportation safety, a wireless terminal device in smart city, and a wireless terminal device in smart home, but is not limited thereto.

[0189] In some embodiments, the access network device 102 may be a node or device that accesses a terminal device to a wireless network. The access network device may include an evolved NodeB (eNB), a next generation evolved NodeB (ng-eNB), a next generation NodeB (gNB), a NodeB (NB), a home NodeB (HNB), a home evolved NodeB (HeNB), a wireless backhaul device, a radio network controller (RNC), a base station controller (BSC), a base transceiver station (BTS), a base band unit (BBU), a mobile switching center, a base station in a 6G communication system, an open base station (Open RAN), a cloud base station (Cloud RAN), a base station in other communication systems, and at least one of an access node in a Wi-Fi system, but is not limited thereto.

[0190] In some embodiments, the technical solution of the present disclosure can be applied to the Open RAN architecture. In this case, the interfaces between or within the access network devices involved in the embodiments of the present disclosure can be transformed into internal interfaces of the Open RAN, and the processes and information interactions between these internal interfaces can be implemented through software or programs.

[0191] In some embodiments, the access network device can be composed of a centralized unit (CU) and a distributed unit (DU), where the CU can also be called a control unit (Control Unit). The CU-DU structure can be used to split the protocol layer of the access network device, with the functions of some protocol layers centrally controlled by the CU, and the functions of the remaining part or all of the protocol layers distributed in the DU, which is centrally controlled by the CU, but is not limited to this.

[0192] In some embodiments, the core network device 103 may be a single device, or may be multiple devices or a group of devices. The core network may include at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a 6G Core Network (5GCN), and a Next Generation Core (NGC).

[0193] It can be understood that the communication system described in the embodiment of the present disclosure is to more clearly illustrate the technical solution of the embodiment of the present disclosure, and does not constitute a limitation on the technical solution proposed in the embodiment of the present disclosure. Ordinary technicians in this field can know that with the evolution of system architecture and the emergence of new business scenarios, the technical solution proposed in the embodiment of the present disclosure is also applicable to similar technical problems.

[0194] The following embodiments of the present disclosure may be applied to the communication system 100 shown in FIG1A , or a portion thereof, but are not limited thereto. The entities shown in FIG1A are examples. The communication system may include all or part of the entities shown in FIG1A , or may include other entities outside of FIG1A . The number and form of the entities are arbitrary. The entities may be physical or virtual. The connection relationship between the entities is an example. The entities may be connected or disconnected. The connection may be in any manner, whether direct or indirect, and may be wired or wireless.

[0195] The embodiments of the present disclosure can be applied to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 5G New Radio (NR), Evolved Universal Terrestrial Radio Access (E-UTRA), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New Radio Access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), Public Land Mobile Network (PLMN) networks, Device-to-Device (D2D) systems, Machine-to-Machine (M2M) systems, Internet of Things (IoT) systems, Vehicle-to-Everything (V2X), systems utilizing other communication methods, and next-generation systems based on and extending these methods. Furthermore, multiple systems may be combined (for example, a combination of LTE or LTE-A with 5G).

[0196] In some embodiments, the communication system may support dual connectivity technology, which may enable traffic to be distributed between different access network devices via an X2 interface or an Xn interface, thereby improving the coverage and capacity of the communication system.

[0197] Figure 1B is a schematic diagram of the architecture of a communication system proposed in an embodiment of the present disclosure. The communication system 100 may include multiple terminal devices 101, or multiple access network devices 102, or multiple core network devices 103. As shown in Figure 1B, the access network devices 102 may include a first access network device 1021, a second access network device 1022, a third access network device 1023, a fourth access network device 1024, and the like. Optionally, the core network devices 103 may include a first core network device 1031, a second core network device 1032, and the like. It should be noted that the number of the above-mentioned access network devices and core network devices is for illustrative purposes only and is not limited to that shown in Figure 1B. For example, the access network device 102 may include only the first access network device 1021 and the second access network device 1022; for another example, the access network device 102 may also include other access network devices, such as a fifth access network device and a sixth access network device.

[0198] In some embodiments, different access network devices may be connected or not connected to each other, and the interface connecting the access network devices may include but is not limited to at least one of the following: an X2 interface and an Xn interface.

[0199] In some embodiments, an access network device may be connected to one or more core network devices. For example, a first access network device may be connected to a first core network device and a second core network device, or may be connected only to the first core network device. Alternatively, some access network devices may not be connected to a core network device, or may not be directly connected to a core network device. This disclosure is not limited to this.

[0200] In some embodiments, based on dual connectivity technology, a terminal device can connect to a first access network device serving as a master node (MN) and a second access network device serving as a secondary node (SN). The first access network device (i.e., the MN) can connect to a core network device, and the first access network device and the second access network device can be connected to each other. Optionally, the second access network device (i.e., the SN) can also connect to the core network device.

[0201] In one implementation, the interface between the first access network device (i.e., MN) and the core network device (e.g., 5GC) may be an NG interface, and the NG interface may include an NG-C (NG control plane) interface and an NG-U (NG data plane) interface. The first access network device and the second access network device may be connected via an Xn interface. The interface between the second access network device (i.e., SN) and the core network device may be an NG-U interface. In this way, NR-NR dual connectivity, i.e., NR-DC technology, may be implemented, wherein the terminal device may be connected to the first access network device serving as the MN and the second access network device serving as the SN, the first access network device may be connected to the core network device via the NG interface, and optionally the second access network device may also be connected to the 5GC via the NG-U interface. Optionally, the terminal device may also be connected to a single access network device, which may serve as both an MN and an SN at the same time, i.e., the first access network device and the second access network device may be the same access network device.

[0202] In one implementation, the interface between the first access network device (i.e., MN) and the core network device (e.g., EPC) can be an S1 interface, which can include an S1-C (S1 control plane) interface and an S1-U (S1 data plane) interface. The first access network device and the second access network device can be connected via an X2 interface. Optionally, the interface between the second access network device (i.e., SN) and the core network device can be an S1-U interface. In this way, MR-DC technology can be implemented. MR-DC is a generalized Intra-E-UTRA dual connection, in which a terminal device can utilize radio resources provided by two different schedulers, which are located on two different NG-RAN nodes, connected through non-ideal backhaul, one providing NR access and the other providing E-UTRA or NR access. One acts as an MN and the other as an SN. The MN and the SN are connected via a network interface, wherein at least the MN is connected to the core network device, and optionally, the SN can also be connected to the core network device.

[0203] In some embodiments, the above-mentioned access network device may also be referred to as a node (Node), a next generation NodeB (gNB), a NodeB (NB), etc.

[0204] In some embodiments, the first access network device 1021 may be a first node, for example, a master node MN, or a master node (MN) or a target master node (Target MN, T-MN for short) in a mobility operation (such as cell change, addition or deletion).

[0205] In some embodiments, the second access network device 1022 may be a second node, for example, a secondary node SN, or a source secondary node (Source SN, S-SN for short) in a mobility operation (eg, cell change, addition, or deletion).

[0206] In some embodiments, the third access network device 1023 may be a third node, for example, a secondary node SN, or a target secondary node (T-SN) in a mobility operation (eg, cell change, addition, or deletion).

[0207] In some embodiments, the fourth access network device 1024 may be a fourth node, for example, a master node MN, or a source master node (Source MN, S-MN for short) in a mobility operation (eg, cell change, addition, or deletion).

[0208] In some embodiments, based on dual connectivity technology, a terminal device can access multiple cells. For example, a terminal device can access two cells, namely a primary cell (PCell) and a secondary cell (SCell).

[0209] In some embodiments, based on dual connectivity technology, a terminal device can access multiple cell groups. For example, a terminal device can access two cell groups, namely a Master Cell Group (MCG) and a Secondary Cell Group (SCG).

[0210] In some embodiments, an MCG may correspond to a first access network device, for example, all cells in the MCG are cells under the first access network device, and the first access network device may serve as a master node MN. An SCG may correspond to a second access network device, for example, all cells in the SCG are cells under the second access network device, and the second access network device may serve as a secondary node SN.

[0211] Figure 1C is a schematic diagram of a primary cell group (MCG) and a secondary cell group (SCG) according to an embodiment of the present disclosure. As shown in Figure 1C, a terminal device can access two cell groups, the primary cell group (MCG) and the secondary cell group (SCG), based on dual connectivity technology.

[0212] In some embodiments, the MCG may include a primary cell PCell and one or more secondary cells SCell. Optionally, the PCell may be the cell to which the terminal device initially accesses, and the PCell is the most important cell in the MCG. Optionally, the MCG may not include an SCell. For example, the MCG may have only one PCell and no SCell. Optionally, all cells in the MCG except the PCell are SCells, and the PCell in the MCG and the SCell in the MCG are combined through carrier aggregation (CA), thereby improving the transmission rate and meeting the user's requirements for the rate.

[0213] In some embodiments, the SCG may include a primary secondary cell (PSCell), or the SCG may include a PSCell and one or more secondary cells (SCells). Optionally, the SCG may not include an SCell; for example, the SCG may have only one PSCell. Optionally, all cells in the SCG except the PSCell are SCells, and the PSCells and SCells in the MCG may be combined through carrier aggregation.

[0214] In some embodiments, a concept of a special primary cell (sPCell) is proposed, which may include the aforementioned primary cell PCell and / or primary secondary cell PSCell. Optionally, the main signaling of the terminal device may be transmitted via the sPCell.

[0215] In some embodiments of the present disclosure, the communication system may support mobility operations in dual connectivity scenarios. Optionally, the mobility operations may be triggered based on Layer 1 (L1) or Layer 2 (L2)-triggered mobility (L1 / L2-triggered Mobility, LTM) or other mobility methods. LTM can reduce mobility latency.

[0216] In some embodiments, LTM may be a process of PCell / PSCell cell change (cell switch) triggered by a network device through MAC CE based on L1 measurement results, which may be accompanied by a change of MCG / SCG.

[0217] In LTM, a network device (e.g., a gNB) receives Layer 1 (L1) measurement reports from a terminal device (UE). Based on these reports, the gNB issues a cell switch command (CSC) via a MAC CE to change the UE's serving cell. This CSC may indicate an LTM candidate cell configuration that the gNB has previously provided to the UE via RRC signaling. Based on the received CSC, the UE accesses the target cell indicated in the CSC. LTM can be used to reduce mobility latency.

[0218] The LTM candidate cell configuration can only be added, modified, and released by the network through RRC signaling. The LTM process can be used to reduce mobility delays.

[0219] LTM can support subsequent LTM (subsequent LTM), where Subsequent LTM can mean that the subsequent LTM cell switching process between candidate cells does not require RRC reconfiguration by the network device, that is, after performing the mobility operation, the UE will not autonomously delete the LTM configuration information. The LTM configuration information can continue to be used even if RRC reconfiguration and update are not performed to trigger subsequent LTM (Subsequent LTM).

[0220] LTM can support intra-gNB DU and inter-gNB CU mobility. LTM can support intra-frequency and inter-frequency mobility, including mobility to an inter-frequency cell that is not the current serving cell. For example, LTM can support at least one of the following scenarios:

[0221] Changes in PCell in non-CA and non-DC scenarios;

[0222] PCell changes in CA scenarios;

[0223] In dual connectivity scenarios, MCG PCell changes and SCG PSCell changes are performed without MN participation (i.e., PSCell changes within an SN). Simultaneous changes to the LTM of both PCell and PSCell are not supported.

[0224] In some embodiments, the communication system may support intra-DU and inter-DU intra-CU LTM.

[0225] In other embodiments, the communication system can be extended to support inter-CU (inter-CU, inter-node / gNB) LTM. Inter-CU LTM for SCG PSCell change can involve the participation of a master node (MN). The master node MN can be responsible for coordinating the configuration of candidate PSCells of different CUs.

[0226] In some embodiments, the LTM may configure LTM configuration information via LTM-Config.

[0227] The LTM configuration information may include, but is not limited to, one or more of the following:

[0228] LTM reference configuration;

[0229] One or more candidate cell configurations (candidate cell configurations can be added, modified, or deleted through ltm-CandidateToReleaseList and ltm-CandidateToAddModList);

[0230] LTM CSI resource configuration;

[0231] wait.

[0232] The candidate cell configuration can be configured through LTM-Candidate, which includes but is not limited to one or more of the following information:

[0233] Candidate configuration identifier;

[0234] Candidate cell identifier;

[0235] Candidate configuration (represented by RRCReconfiguration);

[0236] wait.

[0237] In some embodiments, the candidate cell configuration may be a configuration portion of an RRCReconfiguration message associated with the candidate cell, for example, for LTM or subsequent CPAC. The candidate configuration may be a complete candidate configuration or an incremental configuration relative to an LTM reference configuration.

[0238] In some embodiments, the LTM reference configuration information can be configured by the access network device to the terminal device, and the mobility reference configuration information can be common to all cells in the same cell group (for example, within an MCG or an SCG), and the cell group can be a candidate cell group.

[0239] In some embodiments, the mobility operation in the dual connectivity scenario may include an MCG mobility operation and / or an SCG mobility operation.

[0240] The MCG mobility operation may include at least one of the following: PCell change, SCell change, SCell addition, SCell deletion, and MCG change. PCell change may also be referred to as handover.

[0241] The SCG mobility operation may include at least one of the following: PSCell change, PSCell addition, PSCell deletion, SCell change, SCell addition, SCell deletion, SCG change, SCG addition, SCG deletion.

[0242] In some embodiments, the MCG mobility operation and the SCG mobility operation may be performed independently or in parallel. For example, a PSCell change may be triggered alone, or a PSCell addition may be triggered alone, or a PCell change and a PSCell change may be triggered simultaneously, or a PCell change and a PSCell addition may be triggered simultaneously, or a PCell change, an SCell change in the MCG, a PSCell change, and an SCell change in the SCG may be triggered simultaneously, or other individual or combined scenarios.

[0243] Optionally, terms such as "mobility operation", "mobility", "cell change (Cell Switch)", "cell group change", "serving cell change (Cell Switch), handover" etc. can be used interchangeably.

[0244] In some embodiments, the above mobility operation in the dual connectivity scenario may be triggered by LTM or other mobility methods, which is not limited in the present disclosure.

[0245] In some embodiments of the present disclosure, the communication system may support mobility operations. For example, the access network device may configure one or more mobility configuration identifiers corresponding to the mobility operation for the terminal device, and the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the mobility operation.

[0246] A mobility configuration identifier may correspond to a candidate cell. For example, a mobility configuration identifier may correspond to a cell identifier of a candidate cell, which may be a physical cell identifier (PCI) and / or a global cell identifier (CGI). The candidate cell may be a cell measured by a terminal device. Based on the measurement results of the candidate cell, the terminal device may determine a target cell from one or more candidate cells and trigger a mobility operation (such as cell change or cell addition) corresponding to the target cell.

[0247] A mobility configuration identifier may also correspond to mobility configuration information of a candidate cell.

[0248] In some embodiments, the access network device may configure configuration information for the terminal device for mobility operations, where the configuration information may include at least one of the following:

[0249] Mobility reference configuration information;

[0250] Mobility configuration information corresponding to one or more candidate cells;

[0251] Channel State Information (CSI) resource configuration, for example, LTM CSI resource configuration information.

[0252] Optionally, the configuration information can be configured through LTM-Config.

[0253] In some embodiments, the mobility reference configuration information can be configured by the access network device to the terminal device. The mobility reference configuration information can be common to all cells in the same cell group (for example, an MCG or an SCG), and the cell group can be a candidate cell group.

[0254] In some embodiments, the mobility configuration information corresponding to a candidate cell may include:

[0255] Mobility configuration identifier;

[0256] cell identifier of the candidate cell;

[0257] The candidate configuration information may be represented by RRC reconfiguration (RRCReconfiguration).

[0258] In one implementation, the candidate configuration information may be a configuration in an RRC reconfiguration message associated with the candidate cell.

[0259] For example, the candidate configuration may be incremental configuration information relative to the mobility reference configuration information. In this way, each cell only needs to configure the incremental configuration corresponding to the cell, thereby reducing the amount of information required to be configured in each cell and reducing the consumption of radio resources by air interface signaling.

[0260] For another example, the candidate configuration information may be complete configuration information including mobility reference configuration information and incremental configuration information.

[0261] In some embodiments, the mobility configuration information corresponding to the candidate cells may be configured for the terminal device by the access network device through RRC signaling, and the configuration may include at least one of addition, modification, and release.

[0262] Through the above configuration information, the terminal device can determine the cell identifier of the candidate cell corresponding to the mobility configuration identifier, and can also determine the corresponding mobility configuration identifier through the cell identifier of the candidate cell.

[0263] In some embodiments, the candidate cell may be a candidate primary cell PCell, a candidate primary secondary cell PSCell, or a candidate secondary cell SCell.

[0264] In some embodiments, the candidate cell group may be a candidate primary cell group MCG or a candidate secondary cell group SCG.

[0265] In some embodiments, the above-mentioned mobility operation may be an LTM-based mobility operation, the above-mentioned configuration information for the mobility operation may be the configuration information for LTM, the above-mentioned mobility configuration identifier may be the LTM configuration identifier, and the above-mentioned mobility configuration information corresponding to the candidate cell may be the LTM configuration information corresponding to the candidate cell. The LTM configuration information may be configured through the LTM-Candidate information element. For example, the candidate cell configuration may be added, modified or deleted through ltm-CandidateToReleaseList and ltm-CandidateToAddModList.

[0266] In some embodiments, the terminal device may measure the candidate cell based on the above-mentioned mobility configuration information to obtain a measurement result of the candidate cell. For example, based on the LTM mobility operation, the terminal device performs L1 measurement on the candidate cell and may obtain at least one of the following measurement results: physical layer reference signal receiving power (Layer 1 Reference Signal Receiving Power, L1-RSRP), physical layer signal to interference plus noise ratio (Layer 1 Signal to Interference plus Noise Ratio, L1-SINR), and physical layer reference signal receiving quality (Layer 1 Reference Signal Receiving Quality, L1-RSRQ).

[0267] In some embodiments, the terminal device may send a measurement result to the access network device, and the access network device may send a first indication to the terminal device based on the measurement result. The first indication may be used to instruct the terminal device to perform a mobility operation.

[0268] Optionally, the name of the first indication is not limited, for example, it can be "mobility operation indication", "mobility operation command", "cell change command (Cell Switch Command)", "cell change command", "cell add command", "cell deletion command", "cell change indication", "cell change indication", "cell add indication", "cell deletion indication", etc.

[0269] In one implementation, the first indication may indicate a mobility configuration identifier that an access network device provides to the terminal device in advance through RRC signaling. The terminal device determines the mobility configuration identifier based on the received first indication and accesses the candidate cell corresponding to the mobility configuration identifier.

[0270] In another implementation, the first indication may indicate a cell identifier of a candidate cell, and the terminal device may access the candidate cell corresponding to the cell identifier.

[0271] In some embodiments, the access network device may send the above-mentioned first indication through L1 signaling or L2 signaling, wherein the L1 signaling may include downlink control information (DCI) or other L1 signaling, and the L2 signaling may include a medium access control control element (MAC CE) or other L2 signaling.

[0272] In some embodiments, the communication system may also support subsequent LTM (Subsequent LTM), which refers to the subsequent LTM cell switching process between candidate cells without the need for RRC reconfiguration by the access network device. That is to say, after performing a mobility operation (such as cell switching), the terminal device will not autonomously delete the LTM configuration. The LTM configuration can continue to be used even without RRC reconfiguration and update, and is used to trigger subsequent LTM (Subsequent LTM).

[0273] In some embodiments, scenarios of LTM-based mobility operations may include at least one of the following:

[0274] Intra-DU mobility operations involve changing, adding, or deleting cells within the same DU, i.e., the target cell and the source cell belong to the same DU.

[0275] Inter-DU mobility operations involve changing, adding, or deleting cells between different DUs, i.e., the target cell and the source cell belong to different DUs;

[0276] Intra CU mobility operations involve changing, adding, or deleting cells within the same CU, i.e., the target cell and the source cell belong to the same CU;

[0277] Inter-CU mobility operations involve changing, adding, or deleting cells between different CUs, i.e., the target cell and the source cell belong to different CUs.

[0278] In some embodiments, the above-mentioned CUs can also be referred to as inter-node, inter-gNB or inter-access network devices, and the target cell and the source cell belong to different access network devices (nodes, base stations).

[0279] In some embodiments, the above intra-CU mobility operation scenario may include inter-DU mobility operation and / or intra-DU mobility operation within a CU.

[0280] In some embodiments, in the SCG PSCell cell change triggered based on inter-CU LTM, an access network device serving as a MN may participate, and the MN may be used to coordinate the configuration between candidate PSCells of different CUs.

[0281] In some embodiments, based on the correspondence between different cells and access network devices, the mobility operation in the dual connectivity scenario may include at least one of the following:

[0282] Intra-MN MCG mobility operations, for example, the PCell in the MCG changes from the fourth cell to the first cell, where the fourth cell and the first cell belong to the same access network device (the MN);

[0283] Inter-MN MCG mobility operations, for example, a PCell in an MCG changes from a fourth cell to a first cell, where the fourth cell belongs to a fourth access network device, which is a target MN, and the first cell belongs to a first access network device, which is a source MN;

[0284] Intra-SN SCG mobility operations, for example, a PSCell in an SCG changes from a second cell to a third cell, where the second and third cells belong to the same access network device (SN);

[0285] Inter-SN SCG mobility operations, for example, a PSCell in an SCG changes from a second cell to a third cell, where the second cell and the third cell belong to different access network devices (secondary SNs). For example, the second cell belongs to a second access network device, which is the source SN, and the third cell belongs to a third access network device, which is the target SN.

[0286] Inter-Node MCG mobility operations and SCG mobility operations, for example, the PCell in the MCG changes from the fourth cell to the first cell, and the PSCell in the SCG changes from the second cell to the third cell, the fourth cell belongs to the fourth access network device, the fourth access network device is the target MN, the first cell belongs to the first access network device, the first access network device is the source MN, the second cell belongs to the second access network device, the second access network device is the source SN, the third cell belongs to the third access network device, and the third access network device is the target SN.

[0287] In some embodiments, the mobility operation in the dual connectivity scenario (eg, LTM-based mobility operation) may be triggered by at least one of the MN, the SN, or the terminal device.

[0288] In some embodiments, for SCG mobility operations within a secondary node (intra-SN), mobility configuration information (eg, LTM configuration information) corresponding to the SCG mobility operations may be sent directly by the SN to the terminal device, or transparently transmitted by the SN to the terminal device via the MN.

[0289] Optionally, the SCG mobility operation within the secondary node (intra-SN) based on LTM can be performed without the participation of the MN. After the terminal device performs the cell change, the RRC reconfiguration complete message can be sent to the SN. For example, the RRC reconfiguration complete message can be sent directly to the SN via SRB3 or through MN transparent transmission.

[0290] In other embodiments, for scenarios of inter-SN SCG mobility operations, or inter-Node MCG mobility operations and SCG mobility operations, in order to implement inter-node PScell ​​changes or additions, the participation of the MN is required, and the MN needs to exchange information with the source SN and the candidate SN. The LTM configuration in this scenario can be configured to the terminal device by the MN. After the terminal device performs the cell change, the terminal device can send an MN RRC reconfiguration complete message carrying the SN RRC reconfiguration complete message to the MN, and then the MN can forward the SN RRC reconfiguration complete message therein to the target SN.

[0291] Optionally, the MN RRC reconfiguration complete message may be referred to as a first message or a first RRC reconfiguration complete message, and the SN RRC reconfiguration complete message may be referred to as a second message or a second RRC reconfiguration complete message.

[0292] In some embodiments, if the above-mentioned inter-SN SCG mobility operation, or inter-node MCG mobility operation and SCG mobility operation are triggered by the SN, or by the terminal device based on network configuration conditions, the MN does not know which candidate SN (i.e., target SN) the terminal device has accessed, and thus cannot forward the SN RRC reconfiguration complete message to the target SN. Therefore, how the MN determines the candidate SN to which the terminal device has accessed becomes an urgent problem to be solved.

[0293] FIG2A is an interactive schematic diagram illustrating a message transmission method according to an embodiment of the present disclosure.

[0294] In order to more clearly illustrate the optional technical solutions of the embodiments of the present disclosure, the scenarios and network elements involved in FIG2A are first described.

[0295] As shown in FIG2A , the access network device involved in this embodiment may include at least one of the following:

[0296] A first access network device, which may also be referred to as a first node or a master node MN (MN), includes a first cell, which may also be referred to as a primary cell (PCell);

[0297] A second access network device, which may also be referred to as a second node or a source secondary node SN (Source SN, S-SN for short), includes a second cell, which may also be referred to as a source primary secondary cell (Source PSCell);

[0298] A third access network device, which may also be referred to as a third node, a target secondary node SN (T-SN), or a first candidate secondary node, includes a third cell, which may also be referred to as a target primary and secondary cell (Target PSCell) or a first candidate primary and secondary cell;

[0299] The fifth access network device may also be referred to as a fifth node, other candidate secondary node SN (Other Candidate SN, abbreviated as C-SN), or a second candidate secondary node. The fifth access network device includes a fifth cell, which may also be referred to as other candidate primary and secondary cells (Other Candidate PSCell) or a second candidate primary and secondary cell. Optionally, the fifth access network device may be one or more, and the fifth cell may be one or more. The candidate secondary node SN may include a third access network device and a fifth access network device, that is, the fifth access network device may be one or more candidate secondary nodes other than the third access network device. In some embodiments, the names of the third access network device and the fifth access network device may be interchangeable. For example, during a mobility operation, if the third cell is determined as the target PSCell, the third access network device is the target SN. For another example, during a mobility operation, if the fifth cell is determined as the target PSCell, the fifth access network device is the target SN. In some embodiments, the candidate secondary node SN may include only one, for example, only the third access network device.

[0300] In some embodiments, the above-mentioned access network devices may all be different access network devices.

[0301] As shown in Figure 2A, the terminal device can be a terminal device supporting dual connectivity, and the terminal device can perform mobility operations, which may include SCG mobility operations, such as SCG mobility operations between secondary nodes (inter-SN), and the SCG mobility operations may include PSCell changes or PSCell additions.

[0302] In some embodiments, the mobility operation may be triggered by the terminal device or the second access network device (SN).

[0303] In some embodiments, the mobility may be LTM and the SCG mobility may be SCG LTM.

[0304] In some embodiments, the mobility operation may be a mobility operation triggered based on LTM (eg, cell change or addition), which may be referred to as LTM Cell Switch.

[0305] For example, the mobility operation may be a cell change or addition triggered by the terminal device based on LTM, or the mobility operation may be a cell change triggered by the second access network device based on LTM.

[0306] In some embodiments, the SCG mobility operation may include a PSCell change. Before performing the mobility operation, the terminal device may access the first MCG and the first SCG, the PCell of the first MCG may be the first cell, and the PSCell of the first SCG may be the second cell. The target SCG for the terminal device to perform the PSCell change is the second SCG, and the PSCell of the second SCG may be the third cell. That is, the scenario of this embodiment is that the terminal device expects to perform a PSCell change, changing the primary and secondary cell PSCells of the SCG from the second cell (source PSCell) under the second access network device to the third cell (target PSCell) under the third access network device, and the second access network device and the third access network device are different.

[0307] In other embodiments, the SCG mobility operation may include PSCell addition. Before performing the mobility operation, the terminal device may access the first MCG, and the PCell of the first MCG may be the first cell. The target SCG for the terminal device to perform PSCell addition is the second SCG, and the PSCell of the second SCG may be the third cell. That is, the scenario of this embodiment is that the terminal device expects to perform PSCell addition and add a second SCG, and the primary and secondary cell PSCell of the second SCG is the third cell (target PSCell) under the third access network device.

[0308] As shown in FIG2A , the message transmission method may be performed by a terminal device and / or an access network device in the above communication system. The method may include:

[0309] Step S2101: The second access network device sends a secondary node change request (SN Change Required) message to the first access network device.

[0310] In some embodiments, the first access network device may receive the secondary node change request message sent by the second access network device. For example, the first access network device may receive the secondary node change request message sent by the second access network device through an Xn interface.

[0311] In some embodiments, the secondary node change request message may be used to request a secondary node change.

[0312] In some embodiments, the secondary node change request message may be used to request triggering of an inter-secondary node (inter-SN) SCG mobility operation.

[0313] In some embodiments, the name of the secondary node change request message is not limited, for example, it can be "secondary node change request message", "SCG mobility operation request (SCG Change Required) message", "SCG change request message", etc.

[0314] In some embodiments, the term "message" can be used interchangeably with terms such as "information", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "parameter", "field", and "data".

[0315] Optionally, in the PSCell adding scenario, step S2101 can be omitted.

[0316] In some embodiments of the present disclosure, the secondary node change request message may include candidate information corresponding to at least one candidate primary and secondary cell. The candidate information corresponding to one candidate primary and secondary cell may include at least one of the following:

[0317] Cell identification information of candidate primary and secondary cells, such as physical cell identifier PCI and / or cell global identity CGI.

[0318] The device identifier of the access network device to which the candidate primary and secondary cells belong;

[0319] Cell measurement result information of the candidate primary and secondary cells, such as the signal strength of the candidate primary and secondary cells, where the signal strength may include at least one of RSRP, SINR, and RSRQ;

[0320] Cell configuration information of candidate primary and secondary cells, such as frequency, bandwidth, etc.

[0321] In some embodiments, the first access network device can determine at least one candidate primary and secondary cell corresponding to the terminal device performing the SCG mobility operation based on the secondary node change request message, and determine the candidate access network device corresponding to the candidate primary and secondary cell (for example, the third access network device and / or the fifth access network device).

[0322] In some other embodiments, for scenarios where a PSCell is added, the first access network device may independently determine the third access network device and / or the fifth access network device. Optionally, the first access network device may receive a measurement report sent by the terminal device, determine at least one candidate primary and secondary cell based on the measurement report, and determine the candidate access network devices corresponding to the candidate primary and secondary cells (e.g., the third access network device and / or the fifth access network device).

[0323] In some embodiments, the terminal device may send a measurement report to the second access network device, and the second access network device may send a secondary node change request message to the first access network device in response to receiving the measurement report.

[0324] Exemplarily, the measurement report may be obtained by the terminal device based on layer 3 measurements for radio resource management RRM.

[0325] Step S2102: The first access network device sends a secondary node addition request (SN Addition Request) message to the third access network device and / or the fifth access network device.

[0326] In some embodiments, the third access network device and / or the fifth access network device may receive the secondary node addition request message sent by the first access network device. For example, the third access network device and / or the fifth access network device may receive the secondary node addition request message sent by the first access network device via an Xn interface.

[0327] In some embodiments, the secondary node addition request message may be used to request the addition of a secondary node.

[0328] In some embodiments, the name of the secondary node adding request message is not limited, and may be, for example, a "secondary node adding indication message", a "secondary node changing request message", etc.

[0329] In some embodiments, the first access network device may send a secondary node add request message to the third access network device and / or the fifth access network device in response to the secondary node change request message. In this embodiment, the mobility operation is triggered by the second access network device (SN).

[0330] In some embodiments, the terminal device may send a measurement report to the first access network device. In response to receiving the measurement report, the first access network device may send a secondary node addition request message to the third access network device and / or the fifth access network device. In this embodiment, the mobility operation is triggered by the first access network device. In this case, step S2101 above may be omitted.

[0331] Exemplarily, the measurement report is obtained by the terminal device based on layer 3 measurement for radio resource management RRM.

[0332] In some embodiments, the third access network device and / or the fifth access network device can determine one or more candidate primary and secondary cells for the terminal device to perform mobility operations based on the secondary node addition request message, and determine candidate configurations of the candidate primary and secondary cells.

[0333] Exemplarily, the candidate configuration of the candidate primary and secondary cells can be carried in the secondary node SN RRC reconfiguration message, and the SN RRC reconfiguration message can include relevant configuration messages for the terminal device on the candidate primary and secondary cells to perform mobility operations (such as LTM-based SCG mobility operations).

[0334] For example, the SN RRC reconfiguration message may include mobility configuration information corresponding to the candidate primary and secondary cells, and the mobility configuration information may include at least one of the following: a mobility configuration identifier, a cell identifier of the candidate primary and secondary cells, and candidate configuration information.

[0335] Optionally, the candidate configuration information may include at least one of the following: wireless resource information allocated to the terminal device on the candidate cell (such as frequency, bandwidth, channel resources, etc.), transmission resources (such as bearer context), security-related information (such as encryption and integrity protection parameters required to establish a secure connection), triggering conditions for mobility operations (such as triggering events, triggering thresholds, etc.), mobility operation indications (such as addition, change, deletion), and other information.

[0336] Optionally, the mobility configuration information may include LMT configuration information.

[0337] Step S2103: The third access network device and / or the fifth access network device sends a secondary node addition request confirmation (SN Addition Request Acknowledge) message to the first access network device.

[0338] In some embodiments, the first access network device may receive a secondary node addition request confirmation message sent by the third access network device and / or the fifth access network device. For example, the first access network device may receive the secondary node addition request confirmation message sent by the third access network device and / or the fifth access network device via an Xn interface.

[0339] In some embodiments, the secondary node adding request confirmation message may be used to respond to the secondary node adding request message.

[0340] In some embodiments, the secondary node addition request confirmation message may confirm the secondary node addition.

[0341] In some embodiments, the name of the secondary node addition request confirmation message is not limited, and may be, for example, "Secondary Node Addition Response Message (SN Addition Response)".

[0342] In some embodiments, the secondary node addition request confirmation message may include the candidate primary and secondary cells.

[0343] In some embodiments, the secondary node addition request confirmation message may include candidate configurations corresponding to the one or more candidate primary and secondary cells.

[0344] In some embodiments, the secondary node addition request confirmation message may include the SN RRC reconfiguration message.

[0345] In some embodiments, in step S2102 and step S2103, the third access network device and the fifth access network device are not distinguished or can be interchanged. For example, the third access network device and the fifth access network device are both candidate SNs.

[0346] Step S2104: The first access network device sends an RRC reconfiguration message to the terminal device.

[0347] In some embodiments, the terminal device may receive an RRC reconfiguration message sent by the first access network device.

[0348] In some embodiments, the RRC reconfiguration message may be used to indicate that the terminal device is ready to perform a mobility operation.

[0349] In some embodiments, the RRC reconfiguration message may include the MN RRC reconfiguration message and the above-mentioned SN RRC reconfiguration message.

[0350] In some embodiments, the SN RRC reconfiguration message is included in the above-mentioned MN RRC reconfiguration message.

[0351] In some embodiments, the MN RRC reconfiguration message is included in the above-mentioned RRC reconfiguration message.

[0352] In some embodiments, the name of the RRC reconfiguration message is not limited, and may be, for example, "RRC reconfiguration message", "RRC message", "downlink message", "downlink signaling", etc.

[0353] In some embodiments, the terminal device may perform a preparation phase for a mobility operation (e.g., an SCG mobility operation) based on the RRC reconfiguration message. For example, the terminal device may measure candidate primary and secondary cells and determine whether to trigger a mobility operation based on the measurement results. For another example, the terminal device may measure candidate primary and secondary cells and, if conditions are met, report a measurement report to trigger a mobility operation. The measurement may be an L1 measurement based on LTM.

[0354] Optionally, if the terminal device detects that the RRC reconfiguration message is abnormal, or that mobility operations cannot be performed, the RRC reconfiguration failure process can be initiated, for example, it can fall back to the source configuration or start the RRC reconstruction process.

[0355] Step S2105: The terminal device sends an RRC reconfiguration completion message to the first access network device.

[0356] In some embodiments, the first access network device may receive an RRC reconfiguration completion message sent by the terminal device.

[0357] In some embodiments, the RRC reconfiguration complete message may be used to respond to the above-mentioned RRC reconfiguration message.

[0358] In some embodiments, the name of the RRC reconfiguration completion message is not limited, and may be, for example, "RRC message", "uplink message", "uplink signaling", etc.

[0359] Step S2106: The first access network device sends a secondary node change confirmation (SN Change Confirm) message to the second access network device.

[0360] In some embodiments, the second access network device may receive a secondary node change confirmation message sent by the first access network device.

[0361] In some embodiments, the secondary node change confirmation message may be used to respond to the secondary node change request message.

[0362] In some embodiments, the name of the secondary node change confirmation message is not limited, for example, it can be "SCG mobility operation confirmation message", "secondary node change confirmation message", "secondary node change response message", "SCG mobility operation response message", "secondary node change response message", etc.

[0363] In some embodiments, the second access network device receives the secondary node change confirmation message and can determine that the terminal device has started to perform the preparatory stage of the secondary node change or SCG mobility operation (for example, performing LTM-based measurements).

[0364] Optionally, step S2101 and step S2106 are specific steps of the inter-SN SCG mobility operation triggered by the SN.

[0365] In some embodiments, when the SCG mobility operation may be triggered by a second access network device (SN), steps S2101 and S2106 may be performed.

[0366] In other embodiments, when the SCG mobility operation can be triggered by a terminal device, step S2101 and step S2106 may not be performed.

[0367] Step S2107: The terminal device performs measurement.

[0368] In some embodiments, the terminal device may perform LTM-based measurements according to the LTM configuration configured via the RRC reconfiguration message.

[0369] In some embodiments, the terminal device may perform L1 measurement on the candidate primary and secondary cells according to the LTM configuration configured through the RRC reconfiguration message, for example, performing downlink L1 measurement and / or uplink synchronous L1 measurement.

[0370] In some embodiments, the terminal device may obtain a measurement result, which may include at least one of the following: L1-RSRP, L1-SINR, and L1-RSRQ.

[0371] Step S2108: The terminal device sends a measurement report to the first access network device and / or the first access network device and / or the second access network device.

[0372] In some embodiments, the first access network device and / or the second access network device may receive a measurement report sent by the terminal device.

[0373] In some embodiments, the measurement report may be used by the first access network device and / or the second access network device to determine whether to instruct the terminal device to initiate execution of a mobility operation.

[0374] In some embodiments, the name of the measurement report is not limited, and may be, for example, "measurement result report", "measurement result information", etc.

[0375] In some embodiments, the measurement report may include the above measurement results.

[0376] Step S2109: The first access network device and / or the second access network device sends a first indication to the terminal device.

[0377] In some embodiments, the terminal device may receive a first indication sent by the first access network device and / or the second access network device.

[0378] In some embodiments, the first indication may be used to instruct the terminal device to perform a mobility operation (eg, an SCG mobility operation).

[0379] In some embodiments, the name of the first indication is not limited, for example, it can be "mobility operation indication", "mobility operation command", "cell change command (Cell Switch Command)", "cell change command", "cell add command", "cell deletion command", "cell change indication", "cell change indication", "cell add indication", "cell deletion indication", etc.

[0380] In some embodiments, the first indication may be a MAC CE message.

[0381] In some embodiments, the first indication can be used to determine the third cell. The terminal device can determine the third cell and the third access network device to which the third cell belongs based on the first indication, and use the third cell as the target PSCell to perform mobility operations.

[0382] In some embodiments, the above mobility operation may be actively triggered by the terminal device based on a condition. For example, the mobility operation may be a conditional LTM (LTM).

[0383] For example, the first access network device may configure candidate cells and trigger conditions for the terminal device. For example, the candidate cells and trigger conditions may be configured for the terminal device through the RRC reconfiguration message of step S2104. The terminal device may perform measurements, determine a third cell (i.e., a target PSCell) based on the trigger conditions, and actively trigger a PSCell change or addition.

[0384] Optionally, if the above mobility operation can be actively triggered by the terminal device based on conditions, the above steps S2108 and S2109 can be omitted.

[0385] Step S2110: The second access network device sends a third message to the first access network device.

[0386] In some embodiments, the first access network may receive the third message sent by the second access network device. Alternatively, the first access network may receive the third message sent by the second access network device via an Xn interface.

[0387] In some embodiments, the third message may be used to determine a third access network device. The third access network device is an access network device to which a third cell belongs, and the third cell is a target cell for PSCell change or addition. The third access network device may also be referred to as a target secondary node (Targe SN).

[0388] In some embodiments, the third access network device may be a target SN determined in the candidate SNs, and the candidate SNs may include a third access network device and a fifth access network device. Optionally, the third access network device may be a target SN determined by the terminal device in the candidate SNs, or the third access network device may be a target SN determined by the second access network device (source SN) in the candidate SNs, or the third access network device may be a target SN determined by the first access network device (MN) in the candidate SNs.

[0389] In some embodiments, the name of the third message is not limited, and may be, for example, "Cell Switch Notification", "Cell Change Notification", etc.

[0390] In some embodiments, the third message may be an Xn message between access network devices. In some embodiments, the third message may directly or indirectly include at least one of the following:

[0391] an access network device identifier, where the access network device identifier is used to indicate a third access network device;

[0392] a target cell identifier, where the target cell identifier is used to indicate a third cell;

[0393] target cell information, where the target cell information includes frequency information and / or a cell identifier corresponding to the third cell, where the frequency information may include a frequency point and / or a frequency band, and where the cell identifier may include a physical cell identifier (PCI) and / or a global cell identity (CGI);

[0394] Mobility configuration identifier, which is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0395] Transmission configuration indication TCI state information, where the TCI state information is used to indicate beam information of the third cell;

[0396] A first inter-node RRC message.

[0397] Exemplarily, indirect inclusion means that the third message may include certain information or messages, and the information may include at least one of the above items.

[0398] In one embodiment, the first inter-node RRC message includes at least one of the following information:

[0399] a target cell identifier, where the target cell identifier is used to indicate a third cell;

[0400] target cell information, where the target cell information includes frequency information and / or a cell identifier corresponding to the third cell, where the frequency information may include a frequency point and / or a frequency band, and where the cell identifier may include a physical cell identifier (PCI) and / or a global cell identity (CGI);

[0401] Mobility configuration identifier, which is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0402] The transmission configuration indicates TCI status information, which is used to indicate the beam information of the third cell.

[0403] Exemplarily, the third message includes a first inter-node RRC message, and this message includes the above-mentioned information related to the target node or cell to which the terminal device is to access.

[0404] In one implementation, the mobility configuration identifier may include an LTM configuration identifier (eg, LTM Configuration ID), which is used to instruct the terminal device to perform LTM configuration information corresponding to the SCG mobility operation. Optionally, the LTM configuration information may correspond to the third cell.

[0405] Optionally, the above-mentioned access network device identifier may also be referred to as the target access network node identifier (Target S-NG-RAN node ID), the above-mentioned target cell identifier may also be referred to as the primary and secondary cell identifier (PSCell ID), the above-mentioned target cell information may also be referred to as LTM cell change information (LTM Cell Switch Information), and the above-mentioned transmission configuration indication TCI state information may include a TCI state identifier (TCI State ID).

[0406] Optionally, the third message may further include at least one of the following:

[0407] Message type, which is used to indicate the type of the Xn message and can be used to define the purpose and function of the message;

[0408] A first node identifier, where the first node identifier is used to indicate a UE XnAP identifier of a multi-connection master node NG-RAN (M-NG-RAN node UE XnAP ID);

[0409] The second node identifier is used to indicate the UE XnAP identifier of the multi-connection slave node NG-RAN (S-NG-RAN node UE XnAP ID).

[0410] In this way, the cell or the third access network device can be determined through the third message.

[0411] Optionally, step S2110 may also be a specific step of an inter-SN SCG mobility operation triggered by an SN.

[0412] In some embodiments, step S2110 may be performed when the SCG mobility operation is triggered by the second access network device (SN).

[0413] In some embodiments, when the SCG mobility operation is triggered by the second access network device (SN), step S2110 may not be performed.

[0414] In some embodiments, when the SCG mobility operation can be triggered by a terminal device, step S2110 may not be performed.

[0415] Step S2111: The terminal device sends a first message to the first access network device.

[0416] In some embodiments, the first access network device may receive a first message sent by the terminal device.

[0417] In some embodiments, the first message may be a response of the terminal device to the MN RRC reconfiguration message in step S2104.

[0418] Exemplarily, the first message may be a response to a MN RRC reconfiguration message corresponding to the third cell.

[0419] In some embodiments, the first message may be a response of the terminal device to the candidate configuration of the third cell. When the terminal device performs LTM to access the third cell, the candidate configuration of the third cell is applied to generate the first message.

[0420] In some embodiments, the first message can be used to request the first access network device to send the second message to the third access network device so that the terminal device can access the third cell under the third access network device.

[0421] In some embodiments, the name of the first message is not limited, for example, it can be "first RRC reconfiguration completion message", "MN RRC reconfiguration completion message", "RRC message", "uplink message", "uplink signaling", etc.

[0422] In some embodiments, the first message may include a second message, where the second message is a message corresponding to the third cell, and the third cell is a target cell for PSCell change or addition.

[0423] In some embodiments, the second message may be a response of the terminal device to the SN RRC reconfiguration message in step S2104.

[0424] In some embodiments, the second message can be used to request a third access network device corresponding to the third cell to allocate resources and configure related parameters for the terminal device.

[0425] In some embodiments, the name of the second message is not limited, for example, it can be "second RRC reconfiguration completion message", "SN RRC reconfiguration completion message", "RRC message", "uplink message", "uplink signaling", etc.

[0426] In some embodiments, the first message may further include at least one of the following:

[0427] target cell information, where the target cell information includes frequency information and / or a cell identifier corresponding to the third cell, where the frequency information may include a frequency point and / or a frequency band, and where the cell identifier may include a physical cell identifier (PCI) and / or a global cell identity (CGI);

[0428] Mobility configuration identifier, which is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation.

[0429] In one implementation, the mobility configuration identifier may include an LTM configuration identifier, which is used to instruct the terminal device to perform LTM configuration information corresponding to the SCG mobility operation.

[0430] Optionally, the LTM configuration information may correspond to the third cell mentioned above.

[0431] In this way, the cell or the third access network device can be determined through any item in the first message.

[0432] In some embodiments, the first message is an RRC reconfiguration complete message, and a new parameter may be added to the RRC reconfiguration complete message to carry the above-mentioned target cell information and / or mobility configuration identifier.

[0433] For example, a new parameter selectedLTMCandidate may be added to the RRC reconfiguration complete message. The parameter selectedLTMCandidate may be the above-mentioned LTM configuration identifier, that is, the LTM configuration identifier of the LTM configuration information applied when performing the SCG mobility operation.

[0434] For example, the name of the parameter selectedLTMCandidate is only used as an example and is not limited in this disclosure. Any parameters with similar functions or contents to this parameter are within the scope of this disclosure.

[0435] Optionally, the LTM configuration information may be LTM configuration information sent by the first access network device to the terminal device. Optionally, the selectedLTMCandidate is an optional parameter.

[0436] For another example, a parameter selectedPSCellForSCGLTM may be added to the RRC reconfiguration complete message. The parameter selectedPSCellForSCGLTM may be the target cell information. For example, the parameter selectedPSCellForSCGLTM may include frequency information ssbFrequency and / or a cell identifier CellId. Optionally, the cell identifier may include a physical cell identifier physCellId. Optionally, the parameter selectedPSCellForSCGLTM is optional.

[0437] For example, the name of the parameter selectedPSCellForSCGLTM is only used as an example and is not limited in this disclosure. Any parameters with similar functions or contents to this parameter are within the scope of this disclosure.

[0438] In some embodiments, the first message may include a first parameter and a second parameter, and the first parameter is used to indicate whether the second parameter is used to determine the third access network device.

[0439] For example, when the value of the first parameter is a preset value (eg, TRUE or 1), the second parameter can be used to determine the third access network device. For example, the second parameter can be used to carry the above-mentioned target cell information and / or mobility configuration identifier.

[0440] Optionally, the first message is an RRC reconfiguration completion message, the first parameter is a newly added parameter, the first parameter can occupy one bit, and the second parameter can reuse existing parameters in the RRC reconfiguration completion message, such as the primary and secondary cells selected based on SCG LTM selectedPSCellForSCGLTM.

[0441] In this way, messages in related protocols can be reused to determine the third access network device, saving signaling overhead of the first message.

[0442] For example, the names of the above parameters, first parameter, second parameter, and selectedPSCellForSCGLTM, are only used as examples and are not limited in this disclosure. Any parameters with similar functions or contents to these parameters are within the scope of this disclosure.

[0443] Step S2112: The first access network device determines a third access network device.

[0444] In some embodiments, the first access network device may determine the third access network device based on the first message.

[0445] Optionally, the first access network device may determine the third access network device according to at least one of the target cell information and the mobility configuration identifier of the first message.

[0446] For example, the first access network device may determine the third access network device corresponding to the third cell according to the target cell information.

[0447] For example, the first access network device may determine the target cell corresponding to the mobility configuration according to the mobility configuration identifier, and use the access network device to which the target cell belongs as the third access network device.

[0448] In other embodiments, the first access network device may determine the third access network device based on the third message.

[0449] Optionally, the first access network device can determine the third access network device based on at least one of the access network device identifier, target cell identifier, target cell information, mobility configuration identifier, and transmission configuration indication TCI status information of the third message.

[0450] For example, the first access network device may use the access network device corresponding to the access network device identifier as the third access network device.

[0451] For example, the first access network device may determine the third access network device corresponding to the third cell according to the target cell identifier or target cell information.

[0452] For example, the first access network device can determine the target cell corresponding to the mobility configuration or TCI status information based on the mobility configuration identifier, and use the access network device to which the target cell belongs as the third access network device.

[0453] In some embodiments, when the above-mentioned step S2110 is omitted, the first access network device may determine the third access network device based on the first message.

[0454] Step S2113: The first access network device sends a second message to the third access network device.

[0455] In some embodiments, the third access network device may receive the second message sent by the first access network device. For example, the third access network device may receive the second message sent by the first access network device through an Xn interface.

[0456] In some embodiments, the name of the second message is not limited, for example, it can be "second RRC reconfiguration completion message", "SN RRC reconfiguration completion message", "RRC message", "uplink message", "uplink signaling", etc.

[0457] In some embodiments, the second message may be encapsulated in a message container of the Xn interface.

[0458] In some embodiments, the third access network device may allocate wireless resources to the terminal device in the third cell according to the second message to implement PSCell change or addition.

[0459] Step S2114: The terminal device accesses the third cell.

[0460] In some embodiments, the terminal device may perform random access and access the third cell.

[0461] Optionally, if the SCG mobility operation is a PSCell change, that is, changing the PSCell of the terminal device from the second cell to the third cell, the terminal device may also disconnect from the second cell.

[0462] The method involved in the embodiment of the present disclosure may include at least one of the above steps S2101 to S2114. For example, step S2110 can be implemented as an independent embodiment, step S2111 can be implemented as an independent embodiment, step S2112 can be implemented as an independent embodiment, steps S2110+S2112 can be implemented as an independent embodiment, steps S2111+S2112 can be implemented as an independent embodiment, steps S2111+S2112+S2113 can be implemented as an independent embodiment, and steps S2110+S2111+S2112+S2113 can be implemented as an independent embodiment. Steps S2119+S2110+S2111+S2112+S2113 can be implemented as independent embodiments, steps S2119+S2110+S2111+S2112+S2113+S2114 can be implemented as independent embodiments, and steps S2102+S2103+S2104+S2105+S2107+S2108+S2109+S2110+S2111+S2112+S2113+S2114 can be implemented as independent embodiments, but are not limited to these.

[0463] In some embodiments, steps S2101 to S2114 can be performed in a swapped order or simultaneously. For example, steps S2109 and S2110 can be performed in a swapped order or simultaneously. For another example, steps S2110 and S2111 can be performed in a swapped order or simultaneously. For another example, steps S2111 and S2114 can be performed in a swapped order or simultaneously.

[0464] In some embodiments, the above steps S2101 to S2114 are all optional steps.

[0465] In some embodiments, reference may be made to other optional implementations described before or after the description corresponding to FIG. 2A .

[0466] FIG2B is an interactive schematic diagram illustrating a message transmission method according to an embodiment of the present disclosure.

[0467] In order to more clearly illustrate the optional technical solutions of the embodiments of the present disclosure, the scenarios and network elements involved in FIG2B are first described.

[0468] As shown in FIG2B , the access network device involved in this embodiment includes at least one of the following:

[0469] A first access network device, which may also be referred to as a first node, a target primary node MN (T-MN), or a first candidate primary node, includes a first cell, which may also be referred to as a target primary cell (Target PCell) or a first candidate primary cell;

[0470] A second access network device, which may also be referred to as a second node or a source secondary node SN (Source SN, S-SN for short), includes a second cell, which may also be referred to as a source primary secondary cell (Source PSCell);

[0471] A third access network device, which may also be referred to as a third node, a target secondary node SN (Target SN, T-SN for short), or a first candidate SN, includes a third cell, which may also be referred to as a target primary and secondary cell (Target PSCell) or a first candidate primary and secondary cell;

[0472] A fourth access network device, which may also be referred to as a fourth node or a source master node MN (Source MN, S-MN for short), includes a fourth cell, which may also be referred to as a source primary cell (Source PCell);

[0473] The fifth access network device may also be referred to as a fifth node, another candidate secondary node SN (Other Candidate SN, C-SN for short), or a second candidate secondary node. The fifth access network device includes a fifth cell, which may also be referred to as another candidate primary and secondary cell (Other Candidate PSCell) or a second candidate primary and secondary cell. Optionally, the fifth access network device may be one or more, and the fifth cell may be one or more. The candidate secondary node SN may include a third access network device and a fifth access network device, that is, the fifth access network device is a candidate secondary node other than the third access network device.

[0474] The sixth access network device may also be referred to as the sixth node, other candidate master node MN (Other Candidate MN, C-MN for short) or the second candidate master node. The sixth access network device includes the sixth cell, which may also be referred to as other candidate master cell (Other Candidate PCell) or the second candidate master cell. Optionally, the sixth access network device may be one or more, and the sixth cell may also be one or more. The candidate master node MN may include the first access network device and the sixth access network device, that is, the sixth access network device is another candidate master node other than the first access network device.

[0475] In some embodiments, the names of the third access network device and the fifth access network device may be interchangeable. For example, during a mobility operation, if the third cell is determined as the target PSCell, the third access network device is the target SN. For another example, during a mobility operation, if the fifth cell is determined as the target PSCell, the fifth access network device is the target SN. In some embodiments, the candidate secondary node SN may include only one, for example, only the third access network device.

[0476] In some embodiments, the names of the first access network device and the sixth access network device can be interchangeable. For example, during a mobility operation, if the first cell is determined as the target PCell, the first access network device is the target MN. For another example, during a mobility operation, if the sixth cell is determined as the target PCell, the sixth access network device is the target MN. In some embodiments, the candidate master node MN may include only one, for example, the first access network device.

[0477] In some embodiments, the above-mentioned access network devices may all be different access network devices.

[0478] As shown in Figure 2B, the terminal device may be a terminal device supporting dual connectivity, and the terminal device may perform mobility operations, the mobility operations may include MCG mobility operations and SCG mobility operations, such as MCG mobility operations between master nodes (inter-MN) and SCG mobility operations between secondary nodes (inter-SN), the MCG mobility operations may include PCell changes, and the SCG mobility operations may include PSCell changes or PSCell additions. For example, the mobility operations involved in Figure 2B may include PCell changes and PSCell changes; or, the mobility operations involved in Figure 2B may include PCell changes and PSCell additions.

[0479] In some embodiments, the mobility operation may be triggered by a terminal device or a fourth access network device (S-MN).

[0480] In some embodiments, the mobility may be LTM, the MCG mobility may be MCG LTM, and the SCG mobility may be SCG LTM.

[0481] In some embodiments, the mobility operation may be a mobility operation triggered based on LTM (eg, cell change or addition), which may be referred to as LTM Cell Switch.

[0482] For example, the mobility operation may be a mobility operation triggered by the terminal device based on LTM, or the mobility operation may be a mobility operation triggered by the fourth access network device based on LTM.

[0483] In some embodiments, the MCG mobility operation may include a PCell change, and the SCG mobility operation may include a PSCell change, that is, the mobility operation involved in Figure 2B includes a PCell change and a PSCell change. For example, before performing the mobility operation, the terminal device may access the second MCG and the first SCG, the PCell of the second MCG may be the fourth cell mentioned above, and the PSCell of the first SCG may be the second cell. The target MCG for the terminal device to perform the PCell change is the first MCG, the PSCell of the first MCG may be the first cell, the target SCG for the terminal device to perform the PSCell change is the second SCG, and the PSCell of the second SCG may be the third cell. That is, the scenario of this embodiment is that the terminal device expects to perform PCell change and PSCell change, changing the main cell PCell of MCG from the fourth cell (source PCell) under the fourth access network device to the first cell (target PCell) under the first access network device, and changing the main and auxiliary cell PSCell of SCG from the second cell (source PSCell) under the second access network device to the third cell (target PSCell) under the third access network device. The fourth access network device is different from the first access network device, and the second access network device is different from the third access network device.

[0484] In some embodiments, the MCG mobility operation may include a PCell change, and the SCG mobility operation may include a PSCell addition, that is, the mobility operation involved in Figure 2B includes a PCell change and a PSCell addition. For example, before performing the mobility operation, the terminal device may access a second MCG, and the PCell of the second MCG may be the fourth cell mentioned above. The target MCG for the terminal device to perform the PCell change is the first MCG, and the PSCell of the first MCG may be the first cell. The target SCG for the terminal device to perform the PSCell addition is the second SCG, and the PSCell of the second SCG may be the third cell. That is, the scenario of this embodiment is that the terminal device expects to perform a PCell change and a PSCell addition, and change the main cell PCell of the MCG from the fourth cell (source PCell) under the fourth access network device to the first cell (target PCell) under the first access network device, and add a second SCG. The main and auxiliary cell PSCells of the second SCG are the third cell (target PSCell) under the third access network device, and the fourth access network device is different from the first access network device.

[0485] As shown in FIG2B , the message transmission method may be performed by a terminal device and / or an access network device in the above communication system. The method may include:

[0486] Step S2201: The fourth access network device sends a handover request (Handover Request) message to the first access network device and / or the sixth access network device.

[0487] In some embodiments, the first access network device and / or the sixth access network device may receive the handover request message sent by the fourth access network device. For example, the first access network device and / or the sixth access network device may receive the handover request message sent by the fourth access network device via an Xn interface.

[0488] In some embodiments, the handover request message may be used to request the above-mentioned mobility operation.

[0489] In some embodiments, the name of the handover request message is not limited, and may be, for example, a "mobility operation request message", a "node change request message", etc.

[0490] In some embodiments, the terminal device may send a measurement report to the fourth access network device, and the fourth access network device may send the handover request message to the first access network device in response to receiving the measurement report.

[0491] Exemplarily, the measurement report may be obtained by the terminal device based on layer 3 measurements for radio resource management RRM.

[0492] Step S2202: The first access network device and / or the sixth access network device sends a secondary node addition request (SN Addition Request) message to the third access network device and / or the fifth access network device.

[0493] In some embodiments, the first access network device may send a secondary node addition request message to the third access network device and / or the fifth access network device. In some embodiments, the sixth access network device may send a secondary node addition request message to the third access network device and / or the fifth access network device.

[0494] In some embodiments, the third access network device and / or the fifth access network device may receive the secondary node adding request message. For example, the third access network device and / or the fifth access network device may receive the secondary node adding request message via an Xn interface.

[0495] In some embodiments, the optional implementation of the secondary node adding request message can refer to the optional implementation of FIG2A , which will not be described in detail here.

[0496] Step S2203: The third access network device and / or the fifth access network device sends a secondary node addition request confirmation (SN Addition Request Acknowledge) message to the first access network device and / or the sixth access network device.

[0497] In some embodiments, the third access network device may send a secondary node addition request confirmation (SN Addition Request Acknowledge) message to the first access network device and / or the sixth access network device. In some embodiments, the fifth access network device sends a secondary node addition request confirmation (SN Addition Request Acknowledge) message to the first access network device and / or the sixth access network device.

[0498] In some embodiments, the first access network device and / or the sixth access network device may receive the secondary node addition request confirmation message. For example, the first access network device and / or the sixth access network device may receive the secondary node addition request confirmation message via an Xn interface.

[0499] In some embodiments, the optional implementation of the secondary node addition request confirmation message can refer to the optional implementation of Figure 2A, which will not be repeated here.

[0500] In some embodiments, in step S2202 and step S2203, the third access network device and the fifth access network device are not distinguished or can be interchanged. For example, the third access network device and the fifth access network device are both candidate SNs.

[0501] Step S2204: The first access network device and / or the sixth access network device sends a handover request acknowledgement (Handover Request Acknowledge) message to the fourth access network device.

[0502] In some embodiments, the fourth access network device may receive a handover request confirmation message sent by the first access network device and / or the sixth access network device.

[0503] In some embodiments, the handover request confirmation message may be used to respond to the handover request message.

[0504] In some embodiments, after receiving the switching request message, the fourth access network device may determine that the first access network device and / or the sixth access network device can serve as the target master node for switching, and may continue to execute step S2205.

[0505] In some embodiments, in steps S2201-S2104, the first access network device and the sixth access network device are not distinguished or can be interchanged. For example, the first access network device and the sixth access network device are both candidate MNs.

[0506] Step S2205: The fourth access network device sends an RRC reconfiguration message to the terminal device.

[0507] In some embodiments, the terminal device may receive an RRC reconfiguration message sent by the fourth access network device.

[0508] In some embodiments, the optional implementation of the RRC reconfiguration message can refer to the optional implementation of Figure 2A, which will not be repeated here.

[0509] Step S2206: The terminal device sends an RRC reconfiguration completion message to the fourth access network device.

[0510] In some embodiments, the fourth access network device may receive an RRC reconfiguration completion message sent by the terminal device.

[0511] In some embodiments, the optional implementation of the RRC reconfiguration complete message can refer to the optional implementation of Figure 2A, which will not be repeated here.

[0512] Step S2207: The terminal device performs measurement

[0513] In some embodiments, the terminal device may perform LTM-based measurements according to the RRC reconfiguration message.

[0514] In some embodiments, the terminal device may perform L1 measurement on the candidate primary and secondary cells according to the RRC reconfiguration message, for example, perform downlink L1 measurement and / or uplink synchronous L1 measurement.

[0515] In some embodiments, the terminal device may obtain a measurement result, which may include at least one of the following: L1-RSRP, L1-SINR, and L1-RSRQ.

[0516] Step S2208: The terminal device sends a measurement report to the fourth access network device.

[0517] In some embodiments, the fourth access network device may receive a measurement report sent by the terminal device.

[0518] In some embodiments, the optional implementation of the measurement report can refer to the optional implementation of Figure 2A, which will not be repeated here.

[0519] Step S2209: The fourth access network device sends a first indication to the terminal device.

[0520] In some embodiments, the terminal device may receive a first indication sent by a fourth access network device.

[0521] In some embodiments, the first indication may be used to instruct the terminal device to perform a mobility operation (eg, an SCG mobility operation).

[0522] In some embodiments, the name of the first indication is not limited, for example, it can be "mobility operation indication", "mobility operation command", "cell change command (Cell Switch Command)", "cell change command", "cell add command", "cell deletion command", "cell change indication", "cell change indication", "cell add indication", "cell deletion indication", etc.

[0523] In some embodiments, the above mobility operation may be actively triggered by the terminal device based on a condition. For example, the mobility operation may be a conditional LTM (LTM).

[0524] For example, the first access network device may configure candidate cells and trigger conditions for the terminal device. For example, the candidate cells and trigger conditions may be configured for the terminal device through the RRC reconfiguration message of step S2204. The terminal device may perform measurements and determine the first cell (target PCell) and the third cell (target PSCell) based on the trigger conditions, and actively trigger a PCell change and a PSCell change or addition.

[0525] Optionally, if the above mobility operation can be actively triggered by the terminal device based on conditions, the above steps S2208 and S2209 can be omitted.

[0526] Step S2210: The fourth access network device sends a fourth message to the first access network device.

[0527] In some embodiments, the first access network may receive the fourth message sent by the fourth access network device. Alternatively, the first access network may receive the fourth message sent by the fourth access network device through an Xn interface.

[0528] In some embodiments, the first access network device may be a target MN determined among candidate MNs, and the candidate MNs may include the first access network device and a sixth access network device. Alternatively, the first access network device may be a target MN determined by the terminal device among candidate MNs, or the first access network device may be a target MN determined by the fourth access network device (source MN) among candidate MNs.

[0529] In some embodiments, the fourth message may be used to determine a third access network device. The third access network device is an access network device to which a third cell belongs, and the third cell is a target cell for PSCell change or addition. The third access network device may also be referred to as a target secondary node (Targe SN).

[0530] In some embodiments, the third access network device may be a target SN determined in the candidate SNs, and the candidate SNs may include a third access network device and a fifth access network device. Optionally, the third access network device may be a target SN determined by the terminal device in the candidate SNs, or the third access network device may be a target SN determined by the second access network device (source SN) in the candidate SNs, or the third access network device may be a target SN determined by the first access network device (MN) in the candidate SNs.

[0531] In some embodiments, the name of the fourth message is not limited, and may be, for example, "Cell Switch Notification", "Cell Change Notification", etc.

[0532] In some embodiments, the fourth message may be an Xn message between access network devices.

[0533] In some embodiments, the fourth message may directly or indirectly include at least one of the following:

[0534] an access network device identifier, where the access network device identifier is used to indicate a third access network device;

[0535] a target cell identifier, where the target cell identifier is used to indicate a third cell;

[0536] target cell information, where the target cell information includes frequency information and / or a cell identifier corresponding to the third cell, where the frequency information may include a frequency point and / or a frequency band, and where the cell identifier may include a physical cell identifier (PCI) and / or a global cell identity (CGI);

[0537] Mobility configuration identifier, which is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0538] Transmission configuration indication TCI state information, where the TCI state information is used to indicate beam information of the third cell;

[0539] The second inter-node RRC message.

[0540] Exemplarily, indirect inclusion means that the fourth message may include certain information or messages, and the information may include at least one of the above items.

[0541] In one embodiment, the second inter-node RRC message includes at least one of the following information:

[0542] a target cell identifier, where the target cell identifier is used to indicate a third cell;

[0543] target cell information, where the target cell information includes frequency information and / or a cell identifier corresponding to the third cell, where the frequency information may include a frequency point and / or a frequency band, and where the cell identifier may include a physical cell identifier (PCI) and / or a global cell identity (CGI);

[0544] Mobility configuration identifier, which is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0545] The transmission configuration indicates TCI status information, which is used to indicate the beam information of the third cell.

[0546] Exemplarily, the fourth message includes a second inter-node RRC message, and this message includes the above-mentioned information related to the target node or cell to which the terminal device is to access.

[0547] In one implementation, the mobility configuration identifier may include an LTM configuration identifier (LTM Configuration ID), which is used to indicate to the terminal device the LTM configuration information corresponding to the SCG mobility operation. Optionally, the LTM configuration information may correspond to the third cell.

[0548] Optionally, the above-mentioned access network device identifier may also be referred to as the target access network node identifier (Target S-NG-RAN node ID), the above-mentioned target cell identifier may also be referred to as the primary and secondary cell identifier (PSCell ID), the above-mentioned target cell information may also be referred to as LTM cell change information (LTM Cell Switch Information), and the above-mentioned transmission configuration indication TCI state information may include a TCI state identifier (TCI State ID).

[0549] Optionally, the fourth message may further include at least one of the following:

[0550] Message type, which is used to indicate the type of the Xn message and can be used to define the purpose and function of the message;

[0551] A first node identifier, where the first node identifier is used to indicate a UE XnAP identifier of a multi-connection master node NG-RAN (M-NG-RAN node UE XnAP ID);

[0552] The second node identifier is used to indicate the UE XnAP identifier of the multi-connection slave node NG-RAN (S-NG-RAN node UE XnAP ID).

[0553] In this way, the cell or the third access network device can be determined through the fourth message.

[0554] Optionally, the fourth message and the third message in the embodiment of FIG. 2A may be Xn messages of the same type.

[0555] Step S2211: The terminal device sends a first message to the first access network device.

[0556] In some embodiments, the first access network device may receive a first message sent by the terminal device.

[0557] In some embodiments, the optional implementation of the first message can refer to the optional implementation of Figure 2A, which will not be repeated here.

[0558] Step S2212: The first access network device determines a third access network device.

[0559] In some embodiments, the first access network device may determine the third access network device based on the first message.

[0560] Optionally, the first access network device may determine the third access network device according to at least one of the target cell information and the mobility configuration identifier of the first message.

[0561] For example, the first access network device may determine the third access network device corresponding to the third cell according to the target cell information.

[0562] For example, the first access network device may determine the target cell corresponding to the mobility configuration according to the mobility configuration identifier, and use the access network device to which the target cell belongs as the third access network device.

[0563] In other embodiments, the first access network device may determine the third access network device based on the fourth message.

[0564] Optionally, the first access network device can determine the third access network device based on at least one of the access network device identifier, target cell identifier, target cell information, mobility configuration identifier, and transmission configuration indication TCI status information of the fourth message.

[0565] For example, the first access network device may use the access network device corresponding to the access network device identifier as the third access network device.

[0566] For example, the first access network device may determine the third access network device corresponding to the third cell according to the target cell identifier or target cell information.

[0567] For example, the first access network device can determine the target cell corresponding to the mobility configuration or TCI status information based on the mobility configuration identifier, and use the access network device to which the target cell belongs as the third access network device.

[0568] Step S2213: The first access network device sends a second message to the third access network device.

[0569] In some embodiments, the third access network device may receive the second message sent by the first access network device. For example, the third access network device may receive the second message sent by the first access network device through an Xn interface.

[0570] In some embodiments, the name of the second message is not limited, for example, it can be "second RRC reconfiguration completion message", "SN RRC reconfiguration completion message", "RRC message", "uplink message", "uplink signaling", etc.

[0571] In some embodiments, the second message may be encapsulated in a message container of the Xn interface.

[0572] In some embodiments, the third access network device may allocate wireless resources to the terminal device in the third cell according to the second message to implement PSCell change or addition.

[0573] Step S2214: The terminal device accesses the first cell and the third cell

[0574] In some embodiments, the terminal device may perform random access and access the first cell.

[0575] In some embodiments, the terminal device may perform random access and access the third cell.

[0576] Optionally, if the above mobility operation includes a PCell change, that is, changing the PCell of the terminal device from the fourth cell to the first cell, the terminal device may also disconnect from the fourth cell.

[0577] Optionally, if the above mobility operation includes a PSCell change, that is, changing the PSCell of the terminal device from the second cell to the third cell, the terminal device may also disconnect from the second cell.

[0578] The method involved in the embodiment of the present disclosure may include at least one of the above steps S2201 to S2214. For example, step S2210 can be implemented as an independent embodiment, step S2211 can be implemented as an independent embodiment, step S2212 can be implemented as an independent embodiment, steps S2210+S2212 can be implemented as an independent embodiment, steps S2211+S2212 can be implemented as an independent embodiment, steps S2211+S2212+S2213 can be implemented as an independent embodiment, and steps S2210+S2211+S2212+S2213 can be implemented as an independent embodiment. Steps S2219+S2210+S2211+S2212+S2213 can be implemented as independent embodiments, steps S2219+S2210+S2211+S2212+S2213+S2214 can be implemented as independent embodiments, and steps S2202+S2203+S2204+S2205+S2207+S2208+S2209+S2210+S2211+S2212+S2213+S2214 can be implemented as independent embodiments, but are not limited to these.

[0579] In some embodiments, steps S2201 to S2214 can be performed in a swapped order or simultaneously. For example, steps S2209 and S2210 can be performed in a swapped order or simultaneously. For another example, steps S2210 and S2211 can be performed in a swapped order or simultaneously. For another example, steps S2211 and S2214 can be performed in a swapped order or simultaneously.

[0580] In some embodiments, the above steps S2201 to S2214 are all optional steps.

[0581] In some embodiments, reference may be made to other optional implementations described before or after the description corresponding to FIG. 2A .

[0582] Figure 2C is an interactive diagram of a message transmission method according to an embodiment of the present disclosure. As shown in Figure 2C, the embodiment of the present disclosure relates to a message transmission method, which can be executed by a communication system and may include:

[0583] Step S2301: The second access network device triggers the SCG mobility operation.

[0584] Optional implementations of step S2301 may include one or more steps from steps S2101 to S2108 of Figure 2A. For example, step S2301 may include steps S2201+S2202+S2203+S2204+S2205+S2206+S2207+S2208; or, for another example, step S2301 may include steps S2201+S2206+S2207+S2208.

[0585] Step S2302: The second access network device sends a first indication to the terminal device.

[0586] The optional implementation of step S2302 can refer to the optional implementation of step S2109 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0587] Step S2303: The second access network device sends a third message to the first access network device.

[0588] The optional implementation of step S2303 can refer to the optional implementation of step S2110 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0589] In some embodiments, step S2303 may be omitted.

[0590] Step S2304: The terminal device sends a first message to the first access network device.

[0591] The optional implementation of step S2304 can refer to the optional implementation of step S2111 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0592] Step S2305: The first access network device determines a third access network device.

[0593] The optional implementation of step S2305 can refer to the optional implementation of step S2112 in FIG. 2A and other related parts in the embodiment involved in FIG. 2A , which will not be described in detail here.

[0594] Step S2306: The first access network device sends a second message to the third access network device.

[0595] The optional implementation of step S2306 can refer to the optional implementation of step S2113 in FIG2A and other related parts in the embodiment involved in FIG2A , which will not be described in detail here.

[0596] In some embodiments, the above steps are all optional steps.

[0597] In some embodiments, the embodiment shown in FIG. 2C may also be combined with any one or more steps in the embodiment shown in FIG. 2A to form a new embodiment.

[0598] Figure 2D is an interactive diagram of a message transmission method according to an embodiment of the present disclosure. As shown in Figure 2D, the embodiment of the present disclosure relates to a message transmission method, which can be executed by a communication system and may include:

[0599] Step S2401: The terminal device triggers the SCG mobility operation.

[0600] In some embodiments, optional implementations of step S2401 may include one or more of steps S2102 to S2105 in Figure 2A. For example, step S2401 may include steps S2102+S2103+S2104+S2105; for another example, step S2401 may include steps S2104+S2105; and for another example, step S2401 may include step S2104.

[0601] Step S2402: The terminal device sends a first message to the first access network device.

[0602] The optional implementation of step S2402 can refer to the optional implementation of step S2111 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0603] Step S2403: The first access network device determines a third access network device.

[0604] The optional implementation of step S2403 can refer to the optional implementation of step S2112 in FIG. 2A and other related parts in the embodiment involved in FIG. 2A , which will not be described in detail here.

[0605] Step S2404: The first access network device sends a second message to the third access network device.

[0606] The optional implementation of step S2404 can refer to the optional implementation of step S2113 in FIG. 2A and other related parts in the embodiment involved in FIG. 2A , which will not be described in detail here.

[0607] In some embodiments, the above steps are all optional steps.

[0608] In some embodiments, the embodiment shown in FIG. 2D may also be combined with any one or more steps in the embodiment shown in FIG. 2A to form a new embodiment.

[0609] Figure 2E is an interactive diagram of a message transmission method according to an embodiment of the present disclosure. As shown in Figure 2E, the embodiment of the present disclosure relates to a message transmission method, which can be executed by a communication system and can include:

[0610] Step S2501: The fourth access network device triggers a mobility operation.

[0611] Optionally, the mobility operation includes MCG mobility operation and SCG mobility operation.

[0612] Optional implementations of step S2501 may include one or more steps of steps S2201 to S2208 of Figure 2B. For example, step S2501 may include steps S2201+S2202+S2203+S2204+S2205+S2206+S2207+S2208; or, for another example, step S2501 may include steps S2201+S2206+S2207+S2208.

[0613] Step S2502: The fourth access network device sends a first indication to the terminal device.

[0614] The optional implementation of step S2502 can refer to the optional implementation of step S2209 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0615] Step S2503: The fourth access network device sends a fourth message to the first access network device.

[0616] The optional implementation of step S2503 can refer to the optional implementation of step S2210 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0617] Step S2504: The terminal device sends a first message to the first access network device.

[0618] The optional implementation of step S2504 can refer to the optional implementation of step S2211 in FIG. 2B and other related parts in the embodiment involved in FIG. 2B , which will not be described in detail here.

[0619] Step S2505: The first access network device determines a third access network device.

[0620] The optional implementation of step S2505 can refer to the optional implementation of step S2210 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0621] Step S2506: The first access network device sends a second message to the third access network device.

[0622] The optional implementation of step S2506 can refer to the optional implementation of step S2212 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0623] In some embodiments, the above steps are all optional steps.

[0624] In some embodiments, the embodiment shown in FIG. 2E may also be combined with any one or more steps in the embodiment shown in FIG. 2B to form a new embodiment.

[0625] Figure 2F is an interactive diagram of a message transmission method according to an embodiment of the present disclosure. As shown in Figure 2F, the embodiment of the present disclosure relates to a message transmission method, which can be executed by a communication system and can include:

[0626] Step S2601: The terminal device triggers a mobility operation.

[0627] Optionally, the mobility operation includes MCG mobility operation and SCG mobility operation.

[0628] Optional implementations of step S2601 may include one or more steps of steps S2201 to S2208 of Figure 2B. For example, step S2601 may include steps S2201+S2202+S2203+S2204+S2205+S2206+S2207+S2208; or, for another example, step S2601 may include steps S2201+S2206+S2207+S2208.

[0629] Step S2602: The terminal device sends a first message to the first access network device.

[0630] The optional implementation of step S2602 can refer to the optional implementation of step S2211 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0631] Step S2603: The first access network device determines a third access network device.

[0632] The optional implementation of step S2603 can refer to the optional implementation of step S2212 in FIG. 2B and other related parts in the embodiment involved in FIG. 2B , which will not be described in detail here.

[0633] Step S2604: The first access network device sends a second message to the third access network device.

[0634] The optional implementation of step S2604 can refer to the optional implementation of step S2213 in FIG2B and other related parts in the embodiment involved in FIG2B , which will not be described in detail here.

[0635] In some embodiments, the above steps are all optional steps.

[0636] In some embodiments, the embodiment shown in FIG. 2F may also be combined with any one or more steps in the embodiment shown in FIG. 2B as a new embodiment.

[0637] FIG3A is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG3A , the embodiment of the present disclosure relates to a message transmission method, which can be executed by a terminal device. The method may include:

[0638] Step S3101: Obtain RRC reconfiguration message.

[0639] The optional implementation of step S3101 can refer to the optional implementation of step S2104 in FIG2A and other related parts in the embodiment involved in FIG2A , which will not be described in detail here.

[0640] In some embodiments, the terminal device may receive an RRC reconfiguration message sent by the first access network device, but is not limited thereto. The terminal device may also receive an RRC reconfiguration message sent by other entities.

[0641] In some embodiments, the terminal device may obtain an RRC reconfiguration message specified by the protocol.

[0642] In some embodiments, the terminal device may obtain the RRC reconfiguration message from upper layer(s).

[0643] In some embodiments, the terminal device may perform processing to obtain an RRC reconfiguration message.

[0644] In some embodiments, step S3101 may be omitted, and the terminal device may autonomously implement the functions indicated by the RRC reconfiguration message, or the above functions may be default or by default.

[0645] Step S3102: Send an RRC reconfiguration completion message.

[0646] The optional implementation of step S3102 can refer to the optional implementation of step S2105 in FIG2A and other related parts in the embodiment involved in FIG2A , which will not be described in detail here.

[0647] In some embodiments, the terminal device may send the RRC reconfiguration completion message to the first access network device, but is not limited thereto. The terminal device may also send the RRC reconfiguration completion message to other entities.

[0648] Step S3103: perform measurement.

[0649] The optional implementation of step S3103 can refer to the optional implementation of step S2107 in FIG2A and other related parts in the embodiment involved in FIG2A , which will not be described in detail here.

[0650] Step S3104: Send a measurement report.

[0651] The optional implementation of step S3104 can refer to the optional implementation of step S2108 in FIG2A and other related parts in the embodiment involved in FIG2A , which will not be described in detail here.

[0652] In some embodiments, the terminal device can send the measurement report to the second access network device, but is not limited to this. The terminal device can also send the measurement report to other entities. For example, the terminal device can send the measurement report to the first access network device, and the first access network device forwards the measurement report to the second access network device.

[0653] Step S3105: Obtain a first indication.

[0654] The optional implementation of step S3105 can refer to the optional implementation of step S2109 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0655] In some embodiments, the terminal device may receive the first indication sent by the second access network device, but is not limited thereto. The terminal device may also receive the first indication sent by other entities.

[0656] In some embodiments, the terminal device may obtain a first indication specified by the protocol.

[0657] In some embodiments, the terminal device may obtain the first indication from upper layer(s).

[0658] In some embodiments, the terminal device may perform processing to obtain the first indication.

[0659] In some embodiments, step S3105 may be omitted, and the terminal device may autonomously implement the function indicated by the first indication, or the above function may be default or acquiescent.

[0660] Step S3106: Send the first message.

[0661] The optional implementation of step S3106 can refer to the optional implementation of step S2111 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0662] In some embodiments, the terminal device may send the first message to the first access network device, but is not limited thereto. The terminal device may also send the first message to other entities.

[0663] Step S3107: Access the third cell.

[0664] The optional implementation of step S3107 can refer to the optional implementation of step S2114 in FIG2A and other related parts in the embodiment involved in FIG2A , which will not be described in detail here.

[0665] The method according to the embodiments of the present disclosure may include at least one of steps S3101 to S3107. For example, step S3106 may be implemented as an independent embodiment, steps S3105+S3106 may be implemented as an independent embodiment, steps S3106+S3107 may be implemented as an independent embodiment, steps S3101+S3102+S3103+S3105+S3106 may be implemented as an independent embodiment, and steps S3101+S3102+S3103+S3104+S3105+S3106 may be implemented as an independent embodiment, but the present invention is not limited thereto.

[0666] In some embodiments, the above steps S3101 to S3107 can be executed in a swapped order or simultaneously.

[0667] In some embodiments, the above steps S3101 to S3107 are all optional steps.

[0668] FIG3B is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG3B , the embodiment of the present disclosure relates to a message transmission method, which can be executed by a terminal device. The method may include:

[0669] Step S3201: Obtain RRC reconfiguration message.

[0670] The optional implementation of step S3201 can refer to the optional implementation of step S2205 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0671] In some embodiments, the terminal device may receive an RRC reconfiguration message sent by the fourth access network device, but is not limited thereto. The terminal device may also receive an RRC reconfiguration message sent by other entities.

[0672] In some embodiments, the terminal device may obtain an RRC reconfiguration message specified by the protocol.

[0673] In some embodiments, the terminal device may obtain the RRC reconfiguration message from upper layer(s).

[0674] In some embodiments, the terminal device may perform processing to obtain an RRC reconfiguration message.

[0675] In some embodiments, step S3201 may be omitted, and the terminal device may autonomously implement the functions indicated by the RRC reconfiguration message, or the above functions may be default or by default.

[0676] Step S3202: Send an RRC reconfiguration completion message.

[0677] The optional implementation of step S3202 can refer to the optional implementation of step S2206 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0678] In some embodiments, the terminal device may send the RRC reconfiguration completion message to the fourth access network device, but is not limited thereto. The terminal device may also send the RRC reconfiguration completion message to other entities.

[0679] Step S3203: perform measurement.

[0680] The optional implementation of step S3203 can refer to the optional implementation of step S2207 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0681] Step S3204: Send a measurement report.

[0682] The optional implementation of step S3204 can refer to the optional implementation of step S2208 in FIG2B and other related parts in the embodiment involved in FIG2B , which will not be described in detail here.

[0683] In some embodiments, the terminal device may send the measurement report to the fourth access network device, but is not limited thereto. The terminal device may also send the measurement report to other entities.

[0684] Step S3205: Obtain a first indication.

[0685] The optional implementation of step S3205 can refer to the optional implementation of step S2209 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0686] In some embodiments, the terminal device may receive the first indication sent by the fourth access network device, but is not limited thereto. The terminal device may also receive the first indication sent by other entities.

[0687] In some embodiments, the terminal device may obtain a first indication specified by the protocol.

[0688] In some embodiments, the terminal device may obtain the first indication from upper layer(s).

[0689] In some embodiments, the terminal device may perform processing to obtain the first indication.

[0690] In some embodiments, step S3205 may be omitted, and the terminal device may autonomously implement the function indicated by the first indication, or the above function may be default or by default.

[0691] Step S3206: Send the first message.

[0692] The optional implementation of step S3206 can refer to the optional implementation of step S2211 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0693] In some embodiments, the terminal device may send the first message to the first access network device, but is not limited thereto. The terminal device may also send the first message to other entities.

[0694] Step S3207: Access the first cell and the third cell.

[0695] The optional implementation of step S3207 can refer to the optional implementation of step S2214 in FIG2B and other related parts in the embodiment involved in FIG2B , which will not be described in detail here.

[0696] The method according to the embodiments of the present disclosure may include at least one of steps S3201 to S3207. For example, step S3206 may be implemented as an independent embodiment, steps S3205+S3206 may be implemented as an independent embodiment, steps S3206+S3207 may be implemented as an independent embodiment, steps S3201+S3202+S3203+S3205+S3206 may be implemented as an independent embodiment, and steps S3201+S3202+S3203+S3204+S3205+S3206 may be implemented as an independent embodiment, but the present invention is not limited thereto.

[0697] In some embodiments, the above steps S3201 to S3207 can be executed in a swapped order or simultaneously.

[0698] In some embodiments, the above steps S3201 to S3207 are all optional steps.

[0699] FIG3C is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG3C , the embodiment of the present disclosure relates to a message transmission method, which can be executed by a terminal device. The method may include:

[0700] Step S3301: Perform mobility operations.

[0701] In some embodiments, the mobility operation may include an SCG mobility operation triggered by the terminal device itself.

[0702] For example, optional implementations of step S3301 may include one or more of steps S2102 to S2105, and S2107 to S2109 in FIG2A . For example, step S3301 may include steps S2104+S2105+S2107; for another example, step S3301 may include steps S2104+S2105; for another example, step S3301 may include steps S2104+S2107, without limitation thereto.

[0703] In some embodiments, the mobility operation may include an SCG mobility operation triggered by a second access network device (SN).

[0704] For example, an optional implementation of step S3301 may include one or more steps from steps S2101 to S2110 in FIG2A . For example, step S3301 may include steps S2104+S2105+S2107+S2108+S2109; for another example, step S3301 may include steps S2104+S2105+S2108+S2109; for another example, step S3301 may include steps S2104+S2108+S2109, without limitation thereto.

[0705] In some embodiments, the mobility operation may include an MCG mobility operation and an SCG mobility operation triggered by the terminal device itself.

[0706] For example, an optional implementation of step S3301 may include one or more steps of steps S2201 to S2210 in FIG2B . For example, step S3301 may include steps S2205+S2206+S2207; for another example, step S3301 may include steps S2205+S2206; for another example, step S3301 may include steps S2205+S2207, without limitation thereto.

[0707] In some embodiments, the mobility operation may include an MCG mobility operation and an SCG mobility operation triggered by a fourth access network device (MN).

[0708] For example, an optional implementation of step S3301 may include one or more steps of steps S2201 to S2210 in FIG2B . For example, step S3301 may include steps S2205+S2206+S2207+S2208+S2209; for another example, step S3301 may include steps S2205+S2206+S2208+S2209; for another example, step S3301 may include steps S2205+S2208+S2209, without limitation thereto.

[0709] Step S3302: Send the first message.

[0710] The optional implementation of step S3302 can be found in step S2111 of Figure 2A, step S2211 of Figure 2B, step S3106 of Figure 3A, the optional implementation of step S3206 of Figure 3B, and other related parts in the embodiments involved in Figures 2A, 2B, 3A, and 3B, which will not be repeated here.

[0711] In some embodiments, the above steps are all optional steps.

[0712] In some embodiments, the embodiment shown in FIG. 3C may also be combined with any one or more steps in the embodiment shown in FIG. 3A to form a new embodiment.

[0713] In some embodiments, the embodiment shown in FIG. 3C may also be combined with any one or more steps in the embodiment shown in FIG. 3B to form a new embodiment.

[0714] In some embodiments, the mobility operation includes an SCG mobility operation, the SCG mobility operation includes a primary / secondary cell (PSCell) change or a PSCell addition, the PSCell change includes changing the primary / secondary cell (PSCell) of the terminal device from a second cell to a third cell, the PSCell addition includes adding the third cell as the PSCell of the terminal device, the second cell belongs to a second access network device, the third cell belongs to a third access network device, and the second access network device is different from the third access network device;

[0715] In some embodiments, the first access network device is an access network device to which the first cell belongs, the first cell is the primary cell PCell of the terminal device, the first message includes a second message, and the second message is a configuration message corresponding to the third cell.

[0716] In some embodiments, the first message is used to instruct the first access network device to determine a third access network device.

[0717] In some embodiments, the first message includes at least one of the following:

[0718] A layer 1 or layer 2 triggered mobility LTM configuration identifier, wherein the LTM configuration identifier is used to instruct the terminal device to perform the LTM configuration corresponding to the SCG mobility operation;

[0719] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0720] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation.

[0721] In some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute LTM configuration information corresponding to the SCG mobility operation.

[0722] In some embodiments, the SCG mobility operation is triggered by the terminal device or the second access network device.

[0723] In some embodiments, the method further comprises:

[0724] Receive a first indication sent by a second access network device, where the first indication is used to instruct the terminal device to perform the mobility operation.

[0725] In some embodiments, the mobility operation also includes a main cell group MCG mobility operation, and the MCG mobility operation includes changing the main cell PCell of the terminal device from a fourth cell to the first cell, the fourth cell belongs to a fourth access network device, and the fourth access network device is different from the first access network device.

[0726] In some embodiments, the mobility operation is triggered by the terminal device or the fourth access network device.

[0727] In some embodiments, the mobility operation is a cell change or addition triggered based on LTM.

[0728] In some embodiments, the first message is a first RRC reconfiguration complete message, the second message is a second RRC reconfiguration complete message, and the first RRC reconfiguration complete message includes the second RRC reconfiguration complete message.

[0729] FIG4A is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG4A , the embodiment of the present disclosure relates to a message transmission method, which can be executed by a first access network device, and the method includes:

[0730] Step S4101: Obtain a secondary node change request message.

[0731] The optional implementation of step S4101 can refer to the optional implementation of step S2101 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0732] In some embodiments, the first access network device may receive a secondary node change request message sent by the second access network device, but is not limited thereto. The first access network device may also receive a secondary node change request message sent by other entities.

[0733] In some embodiments, the first access network device may perform processing to obtain a secondary node change request message.

[0734] In some embodiments, step S4101 may be omitted, and the first access network device may autonomously implement the function indicated by the secondary node change request message, or the above function may be default or acquiescent.

[0735] Step S4102: Send a secondary node adding request message.

[0736] The optional implementation of step S4102 can refer to the optional implementation of step S2102 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0737] In some embodiments, the first access network device may send the secondary node adding request message to the third access network device and / or the fifth access network device, but is not limited thereto. The first access network device may also send the secondary node adding request message to other entities.

[0738] Step S4103: Obtain confirmation of the secondary node addition request.

[0739] The optional implementation of step S4103 can refer to the optional implementation of step S2103 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0740] In some embodiments, the first access network device may receive a secondary node adding request confirmation sent by the third access network device and / or the fifth access network device, but is not limited thereto. The first access network device may also receive a secondary node adding request confirmation sent by other entities.

[0741] In some embodiments, the first access network device may perform processing to obtain confirmation of the secondary node adding request.

[0742] Step S4104: Send an RRC reconfiguration message.

[0743] The optional implementation of step S4104 can refer to the optional implementation of step S2104 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0744] In some embodiments, the first access network device may send the RRC reconfiguration message to the terminal device, but is not limited thereto. The first access network device may also send the RRC reconfiguration message to other entities.

[0745] Step S4105: Obtain RRC reconfiguration completion message.

[0746] The optional implementation of step S4105 can refer to the optional implementation of step S2105 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0747] In some embodiments, the first access network device may receive an RRC reconfiguration completion message sent by the terminal device, but is not limited thereto. The first access network device may also receive an RRC reconfiguration completion message sent by other entities.

[0748] In some embodiments, the first access network device may perform processing to obtain an RRC reconfiguration completion message.

[0749] Step S4106: Send a secondary node change confirmation message.

[0750] The optional implementation of step S4106 can refer to the optional implementation of step S2106 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0751] In some embodiments, the first access network device may send the secondary node change confirmation message to the second access network device, but is not limited thereto. The first access network device may also send the secondary node change confirmation message to other entities.

[0752] Step S4107: Obtain a measurement report.

[0753] The optional implementation of step S4107 can refer to the optional implementation of step S2108 in FIG2A and other related parts in the embodiment involved in FIG2A , which will not be described in detail here.

[0754] In some embodiments, the first access network device may receive a measurement report sent by a terminal device, but is not limited thereto. The first access network device may also receive a measurement report sent by other entities.

[0755] In some embodiments, the first access network device may perform processing to obtain a measurement report.

[0756] Step S4108: Send a first instruction.

[0757] The optional implementation of step S4108 can refer to the optional implementation of step S2109 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0758] In some embodiments, the first access network device may send the first indication to the terminal device, but is not limited thereto. The first access network device may also send the first indication to other entities.

[0759] Step S4109: Get the third message.

[0760] The optional implementation of step S4109 can refer to the optional implementation of step S2110 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0761] In some embodiments, the first access network device may receive the third message sent by the second access network device, but is not limited thereto. The first access network device may also receive the third message sent by other entities.

[0762] In some embodiments, the first access network device may perform processing to obtain the third message.

[0763] Step S4110: Get the first message.

[0764] The optional implementation of step S4110 can refer to the optional implementation of step S2111 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0765] In some embodiments, the first access network device may receive a first message sent by a terminal device, but is not limited thereto. The first access network device may also receive a first message sent by other entities.

[0766] In some embodiments, the first access network device may perform processing to obtain the first message.

[0767] Step S4111: Determine the third access network device.

[0768] The optional implementation of step S4111 can refer to the optional implementation of step S2112 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0769] Step S4112: Send the second message.

[0770] The optional implementation of step S4112 can refer to the optional implementation of step S2113 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0771] In some embodiments, the first access network device may send the second message to the third access network device, but is not limited thereto. The first access network device may also send the second message to other entities.

[0772] The method involved in the embodiment of the present disclosure may include at least one of the above steps S4101 to S4112. For example, step S4111 can be implemented as an independent embodiment, steps S4111+S4112 can be implemented as an independent embodiment, steps S4110+S4111 can be implemented as an independent embodiment, steps S4109+S4111 can be implemented as an independent embodiment, steps S4109+S4110+S4111 can be implemented as an independent embodiment, steps S4109+S4110+S4111+S4112 can be implemented as an independent embodiment, and steps S4102+S4103+S4104+S4105 can be implemented as an independent embodiment. 105+S4107+S4108+S4109+S4110+S4111+S4112 can be implemented as an independent embodiment, steps S4102+S4103+S4104+S4105+S4109+S4110+S4111+S4112 can be implemented as an independent embodiment, and steps S4101+S4102+S4103+S4104+S4105+S4106+S4109+S4110+S4111+S4112 can be implemented as an independent embodiment, but are not limited to this.

[0773] In some embodiments, the above steps S4101 to S4112 can be executed in a swapped order or simultaneously.

[0774] In some embodiments, the above steps S4101 to S4112 are all optional steps.

[0775] FIG4B is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG4B , the embodiment of the present disclosure relates to a message transmission method, which can be executed by a first access network device, and the method includes:

[0776] Step S4201: Obtain a switching request message.

[0777] The optional implementation of step S4201 can refer to the optional implementation of step S2201 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0778] In some embodiments, the first access network device may receive a handover request message sent by the fourth access network device, but is not limited thereto. The first access network device may also receive a handover request message sent by other entities.

[0779] In some embodiments, the first access network device may perform processing to obtain a handover request message.

[0780] In some embodiments, step S4201 may be omitted, and the first access network device may autonomously implement the function indicated by the switching request message, or the above function may be default or acquiescent.

[0781] Step S4202: Send a secondary node adding request message.

[0782] The optional implementation of step S4202 can refer to the optional implementation of step S2202 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0783] In some embodiments, the first access network device may send the secondary node adding request message to the third access network device and / or the fifth access network device, but is not limited thereto. The first access network device may also send the secondary node adding request message to other entities.

[0784] Step S4203: Obtain confirmation of the secondary node addition request.

[0785] The optional implementation of step S4203 can refer to the optional implementation of step S2203 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0786] In some embodiments, the first access network device may receive a secondary node adding request confirmation sent by the third access network device and / or the fifth access network device, but is not limited thereto. The first access network device may also receive a secondary node adding request confirmation sent by other entities.

[0787] In some embodiments, the first access network device may perform processing to obtain confirmation of the secondary node adding request.

[0788] Step S4204: Send a handover request confirmation message.

[0789] The optional implementation of step S4204 can refer to the optional implementation of step S2204 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0790] In some embodiments, the first access network device may send the switching request confirmation message to the fourth access network device, but is not limited thereto. The first access network device may also send the switching request confirmation message to other entities.

[0791] Step S4205: Get the fourth message.

[0792] The optional implementation of step S4205 can refer to the optional implementation of step S2210 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0793] In some embodiments, the first access network device may receive the fourth message sent by the second access network device, but is not limited thereto. The first access network device may also receive the fourth message sent by other entities.

[0794] In some embodiments, the first access network device may perform processing to obtain the fourth message.

[0795] Step S4206: Get the first message.

[0796] The optional implementation of step S4206 can refer to the optional implementation of step S2211 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0797] In some embodiments, the first access network device may receive a first message sent by a terminal device, but is not limited thereto. The first access network device may also receive a first message sent by other entities.

[0798] In some embodiments, the first access network device may perform processing to obtain the first message.

[0799] Step S4207: Determine the third access network device.

[0800] The optional implementation of step S4207 can refer to the optional implementation of step S2212 in FIG2B and other related parts in the embodiment involved in FIG2B , which will not be described in detail here.

[0801] Step S4208: Send the second message.

[0802] The optional implementation of step S4208 can refer to the optional implementation of step S2213 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0803] In some embodiments, the first access network device may send the second message to the third access network device, but is not limited thereto. The first access network device may also send the second message to other entities.

[0804] The method involved in the embodiments of the present disclosure may include at least one of the above steps S4201 to S4208. For example, step S4207 can be implemented as an independent embodiment, steps S4207 + S4208 can be implemented as an independent embodiment, steps S4206 + S4207 can be implemented as an independent embodiment, steps S4205 + S4207 can be implemented as an independent embodiment, steps S4205 + S4206 + S4207 can be implemented as an independent embodiment, steps S4205 + S4206 + S4207 + S4208 can be implemented as an independent embodiment, steps S4201 + S4202 + S4203 + S4204 can be implemented as an independent embodiment, and steps S4201 + S4202 + S4203 + S4204 + S4207 can be implemented as an independent embodiment, but the present invention is not limited thereto.

[0805] In some embodiments, the above steps S4201 to S4208 can be executed in a swapped order or simultaneously.

[0806] In some embodiments, the above steps S4201 to S4208 are all optional steps.

[0807] FIG4C is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG4C , the embodiment of the present disclosure relates to a message transmission method, which can be performed by a first access network device. The method may include:

[0808] Step S4301: Get the first message.

[0809] The optional implementation of step S4301 can be found in step S2111 of Figure 2A, step S2211 of Figure 2B, step S4110 of Figure 4A, step S4206 of Figure 4B, and other related parts in the embodiments involved in Figures 2A, 2B, 4A, and 4B, which will not be repeated here.

[0810] Step S4302: Determine the third access network device.

[0811] The optional implementation of step S4302 can be found in step S2112 of Figure 2A, step S2212 of Figure 2B, step S4111 of Figure 4A, step S4206 of Figure 4B, and other related parts in the embodiments involved in Figures 2A, 2B, 4A, and 4B, which will not be repeated here.

[0812] Step S4303: Send the second message.

[0813] The optional implementation of step S4303 can be found in step S2113 of Figure 2A, step S2213 of Figure 2B, step S4112 of Figure 4A, step S4206 of Figure 4B, and other related parts in the embodiments involved in Figures 2A, 2B, 4A, and 4B, which will not be repeated here.

[0814] In some embodiments, the above steps are all optional steps.

[0815] In some embodiments, the embodiment shown in FIG. 4C may also be combined with any one or more steps in the embodiment shown in FIG. 4A to form a new embodiment.

[0816] In some embodiments, the embodiment shown in FIG. 4C may also be combined with any one or more steps in the embodiment shown in FIG. 4B to form a new embodiment.

[0817] In some embodiments, the first message is a message sent when the terminal device performs a mobility operation, the mobility operation includes a secondary cell group SCG mobility operation, the SCG mobility operation includes a primary and secondary cell PSCell change or PSCell addition, the PSCell change includes the PSCell of the terminal device being changed from a second cell to a third cell, the PSCell addition includes adding a third cell as the PSCell of the terminal device, the first message includes a second message, and the second message is a message corresponding to the third cell.

[0818] In some embodiments, the third access network device is an access network device to which the third cell belongs, and the third access network device is different from the second access network device to which the second cell belongs.

[0819] In some embodiments, determining the third access network device includes at least one of the following:

[0820] Determining the third access network device according to the first message;

[0821] The third access network device is determined according to a third message, where the third message is a message sent by the second access network device to the first access network device.

[0822] In some embodiments, the first message further includes at least one of the following:

[0823] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0824] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation.

[0825] In some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute LTM configuration information corresponding to the SCG mobility operation.

[0826] In some embodiments, the first message includes a first parameter and a second parameter, the first parameter is used to indicate whether the second parameter is used to determine the third access network device, and the second parameter is a primary and secondary cell selected based on the SCG LTM.

[0827] In some embodiments, the third message includes at least one of the following:

[0828] an access network device identifier, where the access network device identifier is used to indicate the third access network device;

[0829] a target cell identifier, where the target cell identifier is used to indicate the third cell;

[0830] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0831] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0832] The transmission configuration indicates TCI status information, and the TCI status information is used to indicate the beam information of the third cell.

[0833] In some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute LTM configuration information corresponding to the SCG mobility operation.

[0834] In some embodiments, the SCG mobility operation is triggered by the terminal device or the second access network device.

[0835] In some embodiments, the mobility operation also includes a main cell group MCG mobility operation, and the MCG mobility operation includes changing the main cell PCell of the terminal device from a fourth cell to the first cell, the fourth cell belongs to a fourth access network device, and the fourth access network device is different from the first access network device.

[0836] In some embodiments, determining the third access network device includes at least one of the following:

[0837] Determining the third access network device according to the first message;

[0838] The third access network device is determined according to a fourth message, where the fourth message is a message sent by the fourth access network device to the first access network device.

[0839] In some embodiments, the fourth message includes at least one of the following:

[0840] an access network device identifier, where the access network device identifier is used to indicate the third access network device;

[0841] a target cell identifier, where the target cell identifier is used to indicate the third cell;

[0842] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0843] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0844] The transmission configuration indicates TCI status information, and the TCI status information is used to indicate the beam information of the third cell.

[0845] In some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute LTM configuration information corresponding to the SCG mobility operation.

[0846] In some embodiments, the mobility operation is triggered by the terminal device or the fourth access network device.

[0847] In some embodiments, the mobility operation is a cell change or addition triggered by LTM.

[0848] In some embodiments, the first message is a first RRC reconfiguration complete message, the second message is a second RRC reconfiguration complete message, and the first RRC reconfiguration complete message includes the second RRC reconfiguration complete message.

[0849] FIG5A is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG5A , the embodiment of the present disclosure relates to a message transmission method, which can be executed by a second access network device, and the method includes:

[0850] Step S5101: Send a secondary node change request message.

[0851] The optional implementation of step S5101 can refer to the optional implementation of step S2101 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0852] In some embodiments, the second access network device may send the secondary node change request message to the first access network device, but is not limited thereto. The second access network device may also send the secondary node change request message to other entities.

[0853] Step S5102: Obtain a secondary node change confirmation message.

[0854] The optional implementation of step S5102 can refer to the optional implementation of step S2106 in FIG2A and other related parts in the embodiment involved in FIG2A , which will not be described in detail here.

[0855] In some embodiments, the second access network device may receive a secondary node change confirmation message sent by the first access network device, but is not limited thereto. The second access network device may also receive a secondary node change confirmation message sent by other entities.

[0856] In some embodiments, the second access network device may perform processing to obtain a secondary node change confirmation message.

[0857] Step S5103: Obtain a measurement report.

[0858] The optional implementation of step S5103 can refer to the optional implementation of step S2108 in FIG2A and other related parts in the embodiment involved in FIG2A , which will not be described in detail here.

[0859] In some embodiments, the second access network device may receive a measurement report sent by the terminal device, but is not limited thereto. The second access network device may also receive a measurement report sent by other entities.

[0860] In some embodiments, the second access network device may perform processing to obtain a measurement report.

[0861] Step S5104: Send a first instruction.

[0862] The optional implementation of step S5104 can refer to the optional implementation of step S2109 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0863] In some embodiments, the second access network device may send the first indication to the terminal device, but is not limited thereto. The second access network device may also send the first indication to other entities.

[0864] Step S5105: Send the third message.

[0865] The optional implementation of step S5105 can refer to the optional implementation of step S2110 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0866] In some embodiments, the second access network device may send the third message to the first access network device, but is not limited thereto. The second access network device may also send the third message to other entities.

[0867] The method according to the embodiments of the present disclosure may include at least one of steps S5101 to S5105. For example, step S5105 may be implemented as an independent embodiment, steps S5104 + S5105 may be implemented as an independent embodiment, steps S5103 + S5104 + S5105 may be implemented as an independent embodiment, and steps S5101 + S5102 may be implemented as an independent embodiment, but the present invention is not limited thereto.

[0868] In some embodiments, the above steps S5101 to S5105 can be executed in a swapped order or simultaneously.

[0869] In some embodiments, the above steps S5101 to S5105 are all optional steps.

[0870] FIG5B is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG5B , the embodiment of the present disclosure relates to a message transmission method, which can be performed by a second access network device. The method may include:

[0871] Step S5201: Send a first instruction.

[0872] The optional implementation of step S5201 can be found in step S2109 of FIG. 2A , the optional implementation of step S5104 of FIG. 5A , and other related parts in the embodiments involved in FIG. 2A and FIG. 5A , which will not be described in detail here.

[0873] Step S5202: Send the third message.

[0874] The optional implementation of step S5202 can be found in step S2110 of FIG. 2A , the optional implementation of step S5105 of FIG. 5A , and other related parts in the embodiments involved in FIG. 2A and FIG. 5A , which will not be described in detail here.

[0875] In some embodiments, the above steps are all optional steps.

[0876] In some embodiments, the embodiment shown in FIG. 5B may also be combined with any one or more steps in the embodiment shown in FIG. 5A to form a new embodiment.

[0877] In some embodiments, the first indication is used to instruct the terminal device to perform a mobility operation, the mobility operation includes an SCG mobility operation, the SCG mobility operation includes a primary and secondary cell PSCell change or a PSCell addition, the PSCell change includes the primary and secondary cell PSCell of the terminal device being changed from a second cell to a third cell, the PSCell addition includes adding a third cell as the PSCell of the terminal device, the second cell belongs to the second access network device, the third cell belongs to a third access network device, and the second access network device is different from the third access network device.

[0878] In some embodiments, the third message is used to instruct the first access network device to determine a third access network device.

[0879] In some embodiments, the third message includes at least one of the following:

[0880] an access network device identifier, where the access network device identifier is used to indicate the third access network device;

[0881] a target cell identifier, where the target cell identifier is used to indicate the third cell;

[0882] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0883] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0884] The transmission configuration indicates TCI status information, and the TCI status information is used to indicate the beam information of the third cell.

[0885] In some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute LTM configuration information corresponding to the SCG mobility operation.

[0886] In some embodiments, the SCG mobility operation is triggered by the terminal device or the second access network device.

[0887] In some embodiments, the mobility operation is a cell change or addition triggered by LTM.

[0888] FIG6A is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG6A , the embodiment of the present disclosure relates to a message transmission method, which can be executed by a fourth access network device, and the method includes:

[0889] Step S6101: Send a handover request message.

[0890] The optional implementation of step S6101 can refer to the optional implementation of step S2201 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0891] In some embodiments, the fourth access network device may send the switching request message to the first access network device, but is not limited thereto. The fourth access network device may also send the switching request message to other entities.

[0892] Step S6102: Obtain a handover request confirmation message.

[0893] The optional implementation of step S6102 can refer to the optional implementation of step S2204 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0894] In some embodiments, the fourth access network device may receive a handover request confirmation message sent by the first access network device, but is not limited thereto. The fourth access network device may also receive a handover request confirmation message sent by other entities.

[0895] In some embodiments, the fourth access network device may perform processing to obtain a handover request confirmation message.

[0896] Step S6103: Send an RRC reconfiguration message.

[0897] The optional implementation of step S6103 can refer to the optional implementation of step S2205 in FIG2B and other related parts in the embodiment involved in FIG2B , which will not be described in detail here.

[0898] In some embodiments, the fourth access network device may send the RRC reconfiguration message to the terminal device, but is not limited thereto. The fourth access network device may also send the RRC reconfiguration message to other entities.

[0899] Step S6104: Obtain RRC reconfiguration completion message.

[0900] The optional implementation of step S6104 can refer to the optional implementation of step S2206 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0901] In some embodiments, the fourth access network device may receive an RRC reconfiguration completion message sent by the terminal device, but is not limited thereto. The fourth access network device may also receive an RRC reconfiguration completion message sent by other entities.

[0902] In some embodiments, the fourth access network device may perform processing to obtain an RRC reconfiguration completion message.

[0903] Step S6105: Obtain a measurement report.

[0904] The optional implementation of step S6105 can refer to the optional implementation of step S2208 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0905] In some embodiments, the fourth access network device may receive a measurement report sent by the terminal device, but is not limited thereto. The fourth access network device may also receive a measurement report sent by other entities.

[0906] In some embodiments, the fourth access network device may perform processing to obtain a measurement report.

[0907] Step S6106: Send a first instruction.

[0908] The optional implementation of step S6106 can refer to the optional implementation of step S2209 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0909] In some embodiments, the fourth access network device may send the first indication to the terminal device, but is not limited thereto. The fourth access network device may also send the first indication to other entities.

[0910] Step S6107: Send the fourth message.

[0911] The optional implementation of step S6107 can refer to the optional implementation of step S2210 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0912] In some embodiments, the fourth access network device may send the fourth message to the first access network device, but is not limited thereto. The fourth access network device may also send the fourth message to other entities.

[0913] The method according to the embodiments of the present disclosure may include at least one of steps S6101 to S6107. For example, step S6107 may be implemented as an independent embodiment, steps S6106 + S6107 may be implemented as an independent embodiment, steps S6101 + S6102 may be implemented as an independent embodiment, steps S6101 + S6102 + S6103 + S6104 may be implemented as an independent embodiment, and steps S6101 + S6102 + S6103 + S6104 + S6106 + S6107 may be implemented as an independent embodiment, but the present invention is not limited thereto.

[0914] In some embodiments, the above steps S6101 to S6107 can be executed in a swapped order or simultaneously.

[0915] In some embodiments, the above steps S6101 to S6107 are all optional steps.

[0916] FIG6B is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG6B , the embodiment of the present disclosure relates to a message transmission method, which can be performed by a fourth access network device. The method may include:

[0917] Step S6201: Send a first instruction.

[0918] The optional implementation of step S6201 can be found in step S2209 of FIG. 2B , the optional implementation of step S6106 of FIG. 6A , and other related parts in the embodiments involved in FIG. 2A and FIG. 6A , which will not be described in detail here.

[0919] Step S6202: Send the fourth message.

[0920] The optional implementation of step S6202 can be found in step S2210 of FIG. 2B , the optional implementation of step S6107 of FIG. 6A , and other related parts in the embodiments involved in FIG. 2A and FIG. 6A , which will not be described in detail here.

[0921] In some embodiments, the above steps are all optional steps.

[0922] In some embodiments, the embodiment shown in FIG. 6B may be combined with any one or more steps in the embodiment shown in FIG. 6A to form a new embodiment.

[0923] In some embodiments, the first indication is used to instruct the terminal device to perform a mobility operation, the mobility operation including a main cell group MCG mobility operation and a secondary cell group SCG mobility operation, the SCG mobility operation including a main and secondary cell PSCell change or a PSCell addition, the PSCell change including the main and secondary cell PSCell of the terminal device changing from the second cell to the third cell, the PSCell addition including adding the third cell as the PSCell of the terminal device, the second cell belonging to the second access network device, the third cell belonging to the third access network device, the second access network device being different from the third access network device, the MCG mobility operation including the main cell PCell of the terminal device changing from the fourth cell to the first cell, the first cell belonging to the first access network device, the fourth cell belonging to the fourth access network device, the fourth access network device being different from the first access network device.

[0924] In some embodiments, the fourth message is used to instruct the first access network device to determine the third access network device.

[0925] In some embodiments, the fourth message includes at least one of the following:

[0926] an access network device identifier, where the access network device identifier is used to indicate the third access network device;

[0927] a target cell identifier, where the target cell identifier is used to indicate the third cell;

[0928] target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell;

[0929] A mobility configuration identifier, wherein the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the SCG mobility operation;

[0930] The transmission configuration indicates TCI status information, and the TCI status information is used to indicate the beam information of the third cell.

[0931] In some embodiments, the mobility configuration identifier includes a mobility LTM configuration identifier triggered by layer 1 or layer 2, and the LTM configuration identifier is used to instruct the terminal device to execute LTM configuration information corresponding to the SCG mobility operation.

[0932] In some embodiments, the mobility operation is triggered by the terminal device or the fourth access network device.

[0933] In some embodiments, the mobility operation is a cell change or addition triggered based on LTM.

[0934] FIG7A is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG7A , the embodiment of the present disclosure relates to a message transmission method, which can be executed by a third access network device, and the method includes:

[0935] Step S7101: Obtain a secondary node adding request message.

[0936] The optional implementation of step S7101 can be found in the optional implementation of step S2102 in FIG. 2A , step S2202 in FIG. 2B , and other related parts in the embodiments involved in FIG. 2A and FIG. 2B , which will not be described in detail here.

[0937] In some embodiments, the third access network device may receive a secondary node adding request message sent by the first access network device, but is not limited thereto. The third access network device may also receive a secondary node adding request message sent by other entities.

[0938] Step S7102: Send a secondary node adding request confirmation message.

[0939] The optional implementation of step S7102 can be found in the optional implementation of step S2103 in FIG. 2A , step S2203 in FIG. 2B , and other related parts in the embodiments involved in FIG. 2A and FIG. 2B , which will not be described in detail here.

[0940] In some embodiments, the third access network device may send the secondary node adding request confirmation message to the first access network device, but is not limited thereto. The third access network device may also send the secondary node adding request confirmation message to other entities.

[0941] Step S7103: Get the second message.

[0942] The optional implementation of step S7103 can be found in the optional implementation of step S2113 in FIG. 2A , step S2213 in FIG. 2B , and other related parts in the embodiments involved in FIG. 2A and FIG. 2B , which will not be described in detail here.

[0943] In some embodiments, the third access network device may receive the second message sent by the first access network device, but is not limited thereto. The third access network device may also receive the second message sent by other entities.

[0944] The method involved in the embodiment of the present disclosure may include at least one of the above steps S7101 to S7103. For example, step S7103 may be implemented as an independent embodiment, and steps S7101+S7102 may be implemented as independent embodiments, but are not limited thereto.

[0945] In some embodiments, the above steps S7101 to S7103 can be executed in a swapped order or simultaneously.

[0946] In some embodiments, the above steps S7101 to S7103 are all optional steps.

[0947] FIG7B is a flow chart of a message transmission method according to an embodiment of the present disclosure. As shown in FIG7B , the embodiment of the present disclosure relates to a message transmission method, which can be performed by a third access network device. The method may include:

[0948] Step S7201: Get the second message.

[0949] The optional implementation of step S7201 can be found in step S2113 of FIG. 2A , step S2213 of FIG. 2B , the optional implementation of step S7103 of FIG. 7A , and other related parts in the embodiments involved in FIG. 2A , FIG. 2B , and FIG. 7A , which will not be repeated here.

[0950] In some embodiments, the embodiment shown in FIG. 7B may also be combined with any one or more steps in the embodiment shown in FIG. 7A to form a new embodiment.

[0951] In some embodiments of the present disclosure, a method for indicating an LTM candidate configuration (or candidate cell) for access by a terminal device (UE) is proposed, which can be indicated by the UE in an RRC reconfiguration completion message sent to the MN, or the source secondary node (S-SN) that sends a cell change command (Cell Switch Command) can send corresponding indication information to the MN.

[0952] In some embodiments, the RRC reconfiguration complete message sent by the UE to the master node MN includes information indicating the LTM candidate configuration accessed by the UE or the LTM target cell accessed by the UE. For example, the RRC reconfiguration complete message sent by the UE to the MN includes an identifier corresponding to the LTM candidate configuration executed by the UE. For another example, the RRC reconfiguration complete message sent by the UE to the MN includes relevant information regarding the UE's access to the LTM target cell, such as the LTM target cell identifier and the corresponding frequency.

[0953] In some embodiments, after sending the Cell Switch Command to the UE, the source secondary node (S-SN) may send an Xn message to notify the MN. The Xn message may include the LTM candidate configuration or LTM target cell or LTM target SN corresponding to the LTM triggered by the S-SN.

[0954] In some embodiments, for LTM for MCG and SCG change, after sending the Cell Switch Command to the UE, the source MN (S-MN) sends an Xn message to notify the target MN (T-MN). The message may include the target PSCell identifier or LTM target SN in the LTM candidate configuration corresponding to the S-MN triggering the LTM.

[0955] In some embodiments, MN and / or T-MN can determine the LTM target PSCell accessed by the UE and the corresponding target SN based on at least one of the above messages (for example, the RRC reconfiguration completion message sent by the UE to the MN, the Xn message sent by the S-SN, and the Xn message sent by the S-MN), so as to forward the SN RRC reconfiguration completion message to the corresponding target SN.

[0956] In some embodiments of the present disclosure, for the inter-node SCG LTM (inter-SN SCG LTM) scenario, the UE receives the Cell Switch Command sent by the S-SN to start the SCG LTM, or the UE starts the SCG LTM based on preconfigured execution conditions. The UE sends a first RRC reconfiguration completion message to the MN, and the first RRC reconfiguration completion message includes a second RRC reconfiguration completion message that needs to be forwarded to the C-SN accessed by the UE. Since the SCG LTM is not triggered by the MN, the MN cannot know which C-SN the UE has accessed. The problem in this scenario can be solved by the following embodiments 1 and 2. Optionally, embodiment 1 is only applicable to SCG LTM triggered by the S-SN, and is not applicable to SCG LTM autonomously initiated by the UE.

[0957] Embodiment 1: The RRC reconfiguration complete message sent by the UE to the MN includes information indicating the LTM candidate configuration to be accessed by the UE or the LTM target cell to be accessed by the UE.

[0958] Optionally, referring to Figure 2A, the UE receives the Cell Switch Command sent by the S-SN (for example, the first indication in Figure 2A) to start the SCG LTM, or the UE meets the pre-configured execution conditions to start the SCG LTM, and accesses the target PSCell corresponding to the LTM candidate configuration identifier indicated in the Cell Switch Command or the target PSCell corresponding to the satisfied execution conditions.

[0959] Optionally, referring to step S2111 of Figure 2A, the UE sends a first RRC reconfiguration completion message (e.g., the first message in Figure 2A) to the MN (e.g., the first access network device in Figure 2A), which includes a second RRC reconfiguration completion message (e.g., the second message) corresponding to the accessed target PSCell that needs to be forwarded to the SN.

[0960] In one implementation, the first RRC reconfiguration complete message may include an LTM candidate configuration identifier corresponding to the SCG LTM executed by the UE. Based on the LTM candidate configuration identifier, the MN determines the target PSCell corresponding to the SCG LTM executed by the UE, thereby determining the target SN accessed by the UE, and sends the second RRC reconfiguration complete message to be sent to the SN to the target SN. The SCG LTM executed by the UE may include one or more of inter-SN SCG LTM and intra-SN SCG LTM in MN format, that is, the SCG LTM configured by the MN.

[0961] Exemplarily, the first RRC reconfiguration complete message may include at least one of the following:

[0962] Among them, the selectedLTMCandidate field can be used to indicate the selected LTM candidate configuration identifier applied by the UE when executing SCG LTM.

[0963] In one implementation, the first RRC reconfiguration completion message may include relevant information of the LTM target cell corresponding to the SCG LTM executed by the UE, such as the LTM target cell identifier (such as PCI or CGI) and the corresponding frequency information (ARFCN). Based on the received information related to the LTM target cell, the MN can determine the target PSCell (such as the third cell) corresponding to the SCG LTM executed by the UE, thereby determining the target SN (such as the third access network device) to which the UE accesses, and send the second RRC reconfiguration completion message to be sent to the SN contained therein to the target SN.

[0964] Optional implementation method 1: A new parameter may be added to the first RRC reconfiguration complete message to indicate relevant information of the LTM target cell.

[0965] Exemplarily, the first RRC reconfiguration complete message may include at least one of the following:

[0966] Among them, the selectedPSCellForSCGLTM field can be used to indicate the information of the target PSCell selected when executing SCG LTM.

[0967] Optionally, selectedPSCellForSCGLTM may include at least one of ssbFrequency-r18 and physCellId-r18, wherein the ssbFrequency-r18 field may be used to indicate the frequency information of the target cell, and the physCellId-r18 field may be used to indicate the PCI of the target cell. Optionally, the above-mentioned selectedPSCellForSCGLTM field, ssbFrequency-r18 field, and physCellId-r18 field are optional fields.

[0968] Optional implementation method 2 may indicate in the first RRC reconfiguration complete message that the relevant information of the target PSCell for transmitting UE access in the existing parameters indicates the target PSCell corresponding to the SCG LTM.

[0969] Exemplarily, the first RRC reconfiguration complete message may include at least one of the following:

[0970] Optionally, the ltm-indicator field can be used to indicate the execution of LTM, or the ltm-indicator field can be used to indicate whether the selectedPSCellForCHO-WithSCG-r18 field contains the target PSCell information corresponding to the SCG LTM. The selectedPSCellForCHO-WithSCG-r18 field can be used to indicate the selected target PSCell, which can be the target PSCell selected by the mobility operation (such as SCG LTM).

[0971] Optionally, if the value of the ltm-indicator field is "true", the selectedPSCellForCHO-WithSCG-r18 field contains the target PSCell information corresponding to the SCG LTM; conversely, if the value of the ltm-indicator field is not "true", or the first RRC reconfiguration completion message does not include the ltm-indicator field, the selectedPSCellForCHO-WithSCG-r18 field does not contain the target PSCell information corresponding to the SCG LTM.

[0972] Optionally, the ltm-indicator field may be the above-mentioned first parameter, and the selectedPSCellForCHO-WithSCG-r18 field may be the above-mentioned second parameter.

[0973] Embodiment 2: After sending the Cell Switch Command to the UE, the source secondary node (S-SN) sends an Xn message to inform the MN of the LTM candidate configuration or LTM target cell or LTM target node corresponding to the LTM triggered by the S-SN.

[0974] In some embodiments, the UE receives the Cell Switch Command sent by the S-SN and starts the SCG LTM, accesses the candidate PSCell corresponding to the LTM candidate configuration identifier indicated in the Cell Switch Command, and the UE sends a first RRC reconfiguration completion message carrying the second RRC reconfiguration completion message sent to the SN to the UE.

[0975] Optionally, after the S-SN sends a Cell Switch Command to the UE to initiate SCG LTM, the S-SN may send a first notification message to the MN. The first notification message may be, for example, the third message or the Cell Switch Notification message shown in FIG. 2A , or another existing XnAP message sent by the SN to the MN, or a newly introduced XnAP message, which is not limited in this disclosure.

[0976] Optionally, the S-SN may indicate information related to the SCG LTM initiated by the S-SN in the first notification message. Based on the relevant information in the received first notification message, the MN determines the target PSCell (for example, the third cell) corresponding to the SCG LTM executed by the UE, thereby determining the target SN (for example, the third access network device) to which the UE accesses, and sends the second RRC reconfiguration completion message contained therein to be sent to the SN to the target SN.

[0977] The information related to the SCG LTM initiated by the S-SN may include, but is not limited to, one or more of the following information:

[0978] The target SN identifier to which the UE is to access;

[0979] ID of the target cell to which the UE is to access;

[0980] LTM configuration identifier corresponding to the SCG LTM executed by the UE;

[0981] Frequency information and PCI corresponding to the target cell accessed by the UE;

[0982] Information related to the TCI state ID contained in the Cell Switch command.

[0983] Exemplarily, the first notification message (Cell Switch Notification message) may include, but is not limited to, any one or more of the information in Table 1 below:

[0984] Table 1

[0985] As shown in Table 1, the first notification message (Cell Switch Notification message) may include but is not limited to at least one of the following:

[0986] Message type, which is used to indicate the type of the Xn message and can be used to define the purpose and function of the message;

[0987] a first node identifier, where the first node identifier is used to indicate a UE XnAP identifier of a multi-connectivity master node NG-RAN (M-NG-RAN node UE XnAP ID), and the first node identifier may be allocated by the M-NG-RAN node;

[0988] a second node identifier, where the second node identifier is used to indicate a UE XnAP identifier of a multi-connection slave node NG-RAN (S-NG-RAN node UE XnAP ID), where the second node identifier may be allocated by the S-NG-RAN node;

[0989] an access network device identifier, where the access network device identifier is used to indicate a third access network device and may also be referred to as a target node identifier or a target S-NG-RAN node identifier (Target S-NG-RAN node ID);

[0990] a target cell identifier, where the target cell identifier is used to indicate a third cell and may be referred to as a PSCell ID;

[0991] target cell information, where the target cell information includes frequency information and / or a cell identifier corresponding to the third cell, where the frequency information may include a frequency point and / or a frequency band, and where the cell identifier may include a physical cell identifier (PCI) and / or a global cell identity (CGI);

[0992] LTM configuration identifier, which may be used to instruct the terminal device to perform LTM configuration information corresponding to the SCG mobility operation. For example, the LTM configuration identifier may be an LTM candidate identifier field (LTM CandidateId IE);

[0993] LTM cell change information, the LTM cell change information may include TCI status information, the TCI status information may be used to indicate the beam information of the third cell; for example, the TCI status information may be a TCI status identifier (beam identifier), and the LTM configuration identifier may be a candidate TCI state identifier field (CandidateTCI-StatesId IE).

[0994] Optionally, "Whether to perform error handling" in the above table is used to indicate whether to perform error handling in the event of information errors (such as verification errors). YES means that error handling needs to be performed, and "Error handling method" is "reject", which means that after an error occurs in the information of this row, the processing of the message is rejected; "Error handling method" is "ignore", which means that after an error occurs in the information of this row, the information of this row can be ignored, but other information in the message can continue to be processed.

[0995] In some embodiments, each element, each row, or each column in Table 1 above can be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns can also be implemented as an independent embodiment.

[0996] In some embodiments of the present disclosure, for the MCG and SCG LTM (LTM for MCG and SCG change) scenario, the UE receives the Cell Switch Command sent by the source master node (S-MN) to start LTM to execute the simultaneous change of MCG and SCG, or the UE starts LTM of MCG and SCG based on pre-configured execution conditions. The UE sends a first RRC reconfiguration completion message to the target master node (T-MN), and the first RRC reconfiguration completion message includes a second RRC reconfiguration completion message that needs to be forwarded to the target secondary node (T-SN) accessed by the UE. Since a T-MN may be configured with multiple candidate secondary nodes (C-SN) at the same time, the MN cannot know which C-SN the UE has accessed. The problems existing in this scenario can be solved by using Embodiments 3 and 4. Optionally, Embodiment 3 may only be applicable to LTM for MCG and SCG change triggered by S-MN, and is not applicable to LTM for MCG and SCG change initiated autonomously by the UE.

[0997] Embodiment 3: After sending the Cell Switch Command to the UE, the source master node (S-MN) sends an Xn message to inform the target master node (T-MN), informing the T-MN to trigger the LTM candidate configuration or LTM target cell or LTM target node corresponding to the LTM.

[0998] In some embodiments, the UE receives the Cell Switch Command sent by the S-MN and starts the MCG&SCG LTM, accesses the candidate PSCell corresponding to the LTM candidate configuration identifier indicated in the Cell Switch Command, and the UE sends a first RRC reconfiguration completion message carrying the second RRC reconfiguration completion message sent to the SN to the UE.

[0999] Optionally, after the S-MN sends a Cell Switch Command to the UE to start the MCG & SCG LTM, the S-MN may send a second notification message to the MN. The second notification message may be, for example, the fourth message or the Cell Switch Notification message shown in FIG. 2B , or another existing XnAP message sent by the SN to the MN, or a newly introduced XnAP message, which is not limited in this disclosure.

[1000] Optionally, the specific implementation of this embodiment 3 is similar to that of the embodiment 2 of the inter-SN SCG LTM scenario, except that in embodiment 2, the message is sent from the S-SN to the MN, while in embodiment 3, the message is sent from the S-MN to the T-MN.

[1001] The content of the second notification message is similar to that of the first notification message. For example, the second notification message (Cell Switch Notification message) may include, but is not limited to, any one or more of the information in Table 2 below:

[1002] Table 2

[1003] As shown in Table 2, the second notification message may include but is not limited to at least one of the following:

[1004] Message type, which is used to indicate the type of the Xn message and can be used to define the purpose and function of the message;

[1005] a first node identifier, where the first node identifier is used to indicate a UE XnAP identifier of a multi-connectivity master node NG-RAN (M-NG-RAN node UE XnAP ID), and the first node identifier may be allocated by the M-NG-RAN node;

[1006] a second node identifier, where the second node identifier is used to indicate a UE XnAP identifier of a multi-connection slave node NG-RAN (S-NG-RAN node UE XnAP ID), where the second node identifier may be allocated by the S-NG-RAN node;

[1007] an access network device identifier, where the access network device identifier is used to indicate a third access network device and may also be referred to as a target node identifier or a target S-NG-RAN node identifier (Target S-NG-RAN node ID);

[1008] a target cell identifier, where the target cell identifier is used to indicate a third cell and may be referred to as a PSCell ID;

[1009] target cell information, where the target cell information includes frequency information and / or a cell identifier corresponding to the third cell, where the frequency information may include a frequency point and / or a frequency band, and where the cell identifier may include a physical cell identifier (PCI) and / or a global cell identity (CGI);

[1010] LTM configuration identifier, which may be used to instruct the terminal device to perform LTM configuration information corresponding to the SCG mobility operation. For example, the LTM configuration identifier may be an LTM candidate identifier field (LTM CandidateId IE);

[1011] LTM cell change information, which may include first TCI state information and second TCI state information. The first TCI state information may be used to indicate beam information of the first cell (target PCell); exemplarily, the first TCI state information may be a first TCI state identifier (beam identifier), and the LTM configuration identifier may be a candidate TCI state identifier field (CandidateTCI-StatesId IE). The second TCI state information may be used to indicate beam information of the third cell (target PSCell); exemplarily, the second TCI state information may be a second TCI state identifier (beam identifier), and the LTM configuration identifier may be a candidate TCI state identifier field (CandidateTCI-StatesId IE).

[1012] Optionally, "Whether to perform error handling" in the above table is used to indicate whether to perform error handling in the event of information errors (such as verification errors). YES means that error handling needs to be performed, and "Error handling method" is "reject", which means that after an error occurs in the information of this row, the processing of the message is rejected; "Error handling method" is "ignore", which means that after an error occurs in the information of this row, the information of this row can be ignored, but other information in the message can continue to be processed.

[1013] In some embodiments, each element, each row, or each column in Table 2 above can be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns can also be implemented as an independent embodiment.

[1014] In some embodiments, the second notification message and the first notification message may be the same Xn message, which may be sent by the SN to the MN, or by the source MN to the target MN.

[1015] Embodiment 4: The RRC reconfiguration complete message sent by the UE to the T-MN includes information indicating the LTM candidate configuration to be accessed by the UE or the LTM target cell to be accessed by the UE.

[1016] Optionally, the specific implementation of Example 4 may refer to the description of Example 1 of the above-mentioned inter-node SCG LTM (inter-SN SCG LTM) scenario, which will not be repeated here.

[1017] Optionally, if an LTM candidate configuration is associated with a candidate PCell and multiple candidate PSCells, the first RRC reconfiguration complete message sent by the UE to the T-MN needs to include not only the LTM candidate configuration identifier but also information related to the candidate PSCell, such as PCI and frequency information.

[1018] In some embodiments of the present disclosure, a communication system is provided, which may include a terminal device and a first access network device, wherein the terminal device can execute the message transmission method executed by the terminal device in the aforementioned embodiment of the present disclosure; the first access network device can execute the message transmission method executed by the first access network device in the aforementioned embodiment of the present disclosure.

[1019] The embodiments of the present disclosure further provide an apparatus for implementing any of the above methods. For example, an apparatus is provided, comprising units or modules for implementing each step performed by a terminal device in any of the above methods. For another example, another apparatus is provided, comprising units or modules for implementing each step performed by a first access network device (e.g., an access network device, a core network function node, a core network device, etc.) in any of the above methods.

[1020] It should be understood that the division of the various units or modules in the above device is merely a division of logical functions. In actual implementation, they may be fully or partially integrated into a physical entity, or they may be physically separated. In addition, the units or modules in the device may be implemented in the form of a processor calling software: for example, the device includes a processor, the processor is connected to a memory, and the memory stores instructions. The processor calls the instructions stored in the memory to implement any of the above methods or implement the functions of the various units or modules of the above device, wherein the processor is, for example, a general-purpose processor, such as a central processing unit (CPU) or a microprocessor, and the memory is a memory within the device or a memory outside the device. Alternatively, the units or modules in the device can be implemented in the form of hardware circuits, and the functions of some or all of the units or modules can be realized by designing the hardware circuits. The above-mentioned hardware circuits can be understood as one or more processors; for example, in one implementation, the above-mentioned hardware circuit is an application-specific integrated circuit (ASIC), and the functions of some or all of the above units or modules are realized by designing the logical relationship of the components in the circuit; for example, in another implementation, the above-mentioned hardware circuit can be realized by a programmable logic device (PLD). Taking a field programmable gate array (FPGA) as an example, it can include a large number of logic gate circuits, and the connection relationship between the logic gate circuits is configured by configuring the configuration file, thereby realizing the functions of some or all of the above units or modules. All units or modules of the above devices can be realized in the form of software called by the processor, or in the form of hardware circuits, or in part by the form of software called by the processor, and the rest by hardware circuits.

[1021] In the embodiments of the present disclosure, the processor is a circuit with signal processing capabilities. In one implementation, the processor can be a circuit with instruction reading and execution capabilities, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which can be understood as a microprocessor), or a digital signal processor (DSP); in another implementation, the processor can implement certain functions through the logical relationship of the hardware circuit, and the logical relationship of the above hardware circuit is fixed or reconfigurable, such as a hardware circuit implemented by a processor as an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document to implement the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units or modules. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), a deep learning processing unit (DPU), etc.

[1022] Figure 8A is a schematic diagram of the structure of a terminal device proposed in an embodiment of the present disclosure. As shown in Figure 8A, the terminal device 101 may include: at least one of a transceiver module 211, a processing module 212, etc. In some embodiments, the transceiver module 211 is configured to send a first message to a first access network device, the first access network device is an access network device to which a first cell belongs, the first cell is a primary cell (PCell) of the terminal device, the first message includes a second message, and the second message is a configuration message corresponding to the third cell; the processing module 212 is configured to perform a mobility operation, the mobility operation includes an SCG mobility operation, the SCG mobility operation includes a primary / secondary cell (PSCell) change or a PSCell addition, the PSCell change includes changing the primary / secondary cell (PSCell) of the terminal device from a second cell to a third cell, the PSCell addition includes adding the third cell as the PSCell of the terminal device, the second cell belongs to a second access network device, the third cell belongs to a third access network device, and the second access network device is different from the third access network device. Optionally, the transceiver module 211 can be used to execute at least one of the communication steps such as sending and / or receiving performed by the terminal device in any of the above methods (for example, step S2101, step S2102, step S2103, step S2104, step S2105, step S2106, step S2108, step S2109, step S2110, step S2111, step S2113, step S2201, step S2202, step S2203, step S2204, step S2205, step S2206, step S2208, step S2209, step S2210, step S2211, step S2213, but not limited to these), which will not be repeated here. Optionally, the processing module 212 can be used to execute at least one of the other steps performed by the terminal device in any of the above methods (for example, step S2107, step S2112, step S2114, step S2207, step S2212, step S2214, but not limited to these), which will not be repeated here.

[1023] Figure 8B is a schematic structural diagram of a first access network device proposed in an embodiment of the present disclosure. As shown in Figure 8B, the first access network device 1021 may include at least one of a transceiver module 231 and a processing module 232. In some embodiments, the transceiver module 231 is configured to receive a first message sent by the terminal device, the first message being a message sent when the terminal device performs a mobility operation, the mobility operation including a secondary cell group (SCG) mobility operation, the SCG mobility operation including a primary / secondary cell (PSCell) change or a PSCell addition, the PSCell change including changing the PSCell of the terminal device from a second cell to a third cell, the PSCell addition including adding the third cell as the PSCell of the terminal device, the first message including a second message corresponding to the third cell, and the second message being sent to a third access network device; the processing module 232 is configured to determine a third access network device, the third access network device being the access network device to which the third cell belongs, and the third access network device being different from the second access network device to which the second cell belongs. Optionally, the transceiver module 231 can be used to execute at least one of the communication steps such as sending and / or receiving performed by the first access network device in any of the above methods (for example, step S2101, step S2102, step S2103, step S2104, step S2105, step S2106, step S2108, step S2109, step S2110, step S2111, step S2113, step S2201, step S2202, step S2203, step S2204, step S2205, step S2206, step S2208, step S2209, step S2210, step S2211, step S2213, but not limited to these), which will not be repeated here. Optionally, the processing module 232 can be used to execute at least one of the other steps performed by the first access network device in any of the above methods (for example, step S2107, step S2112, step S2114, step S2207, step S2212, step S2214, but not limited to these), which will not be repeated here.

[1024] Figure 8C is a schematic structural diagram of a second access network device proposed in an embodiment of the present disclosure. As shown in Figure 8C, the second access network device 1022 may include: at least one of a transceiver module 241, a processing module 242, etc. In some embodiments, the transceiver module 241 is configured to send a first indication to the terminal device, the first indication being used to instruct the terminal device to perform a mobility operation, the mobility operation including an SCG mobility operation, the SCG mobility operation including a primary / secondary cell (PSCell) change or a PSCell addition, the PSCell change including the primary / secondary cell (PSCell) of the terminal device being changed from a second cell to a third cell, the PSCell addition including adding the third cell as the PSCell of the terminal device, the second cell belonging to the second access network device, the third cell belonging to a third access network device, and the second access network device being different from the third access network device; and send a third message to the first access network device, the third message being used to instruct the first access network device to determine the third access network device. Optionally, the transceiver module 241 can be used to execute at least one of the communication steps such as sending and / or receiving performed by the first access network device in any of the above methods (for example, step S2101, step S2102, step S2103, step S2104, step S2105, step S2106, step S2108, step S2109, step S2110, step S2111, step S2113, step S2201, step S2202, step S2203, step S2204, step S2205, step S2206, step S2208, step S2209, step S2210, step S2211, step S2213, but not limited to these), which will not be repeated here. Optionally, the processing module 242 can be used to execute at least one of the other steps performed by the second access network device in any of the above methods (for example, step S2107, step S2112, step S2114, step S2207, step S2212, step S2214, but not limited to these), which will not be repeated here.

[1025] Figure 8D is a schematic diagram of the structure of a third access network device proposed in an embodiment of the present disclosure. As shown in Figure 8D, the third access network device 1023 may include at least one of a transceiver module 251 and a processing module 252. In some embodiments, the transceiver module 261 is configured to receive a second message. Optionally, the transceiver module 251 can be used to execute at least one of the communication steps such as sending and / or receiving performed by the first access network device in any of the above methods (for example, step S2101, step S2102, step S2103, step S2104, step S2105, step S2106, step S2108, step S2109, step S2110, step S2111, step S2113, step S2201, step S2202, step S2203, step S2204, step S2205, step S2206, step S2208, step S2209, step S2210, step S2211, step S2213, but not limited to these), which will not be repeated here. Optionally, the processing module 252 can be used to execute at least one of the other steps performed by the third access network device in any of the above methods (for example, step S2107, step S2112, step S2114, step S2207, step S2212, step S2214, but not limited to these), which will not be repeated here.

[1026] FIG8E is a schematic diagram of the structure of a fourth access network device proposed in an embodiment of the present disclosure. As shown in FIG8E , the fourth access network device 1024 may include: at least one of a transceiver module 261 and a processing module 262 . In some embodiments, the transceiver module 261 is configured to send a first indication to the terminal device, wherein the first indication is used to instruct the terminal device to perform a mobility operation, wherein the mobility operation includes a main cell group MCG mobility operation and a secondary cell group SCG mobility operation, wherein the SCG mobility operation includes a main and secondary cell PSCell change or a PSCell addition, wherein the PSCell change includes changing the main and secondary cell PSCell of the terminal device from the second cell to the third cell, wherein the PSCell addition includes adding the third cell as the PSCell of the terminal device, wherein the second cell belongs to the second access network device, the third cell belongs to the third access network device, and the second access network device is different from the third access network device, and the MCG mobility operation includes changing the main cell PCell of the terminal device from the fourth cell to the first cell, wherein the first cell belongs to the first access network device, the fourth cell belongs to the fourth access network device, and the fourth access network device is different from the first access network device; and sending a fourth message to the first access network device, wherein the fourth message is used to instruct the first access network device to determine the third access network device. Optionally, the transceiver module 261 can be used to execute at least one of the communication steps such as sending and / or receiving performed by the first access network device in any of the above methods (for example, step S2101, step S2102, step S2103, step S2104, step S2105, step S2106, step S2108, step S2109, step S2110, step S2111, step S2113, step S2201, step S2202, step S2203, step S2204, step S2205, step S2206, step S2208, step S2209, step S2210, step S2211, step S2213, but not limited to these), which will not be repeated here. Optionally, the processing module 262 can be used to execute at least one of the other steps performed by the fourth access network device in any of the above methods (for example, step S2107, step S2112, step S2114, step S2207, step S2212, step S2214, but not limited to these), which are not repeated here.

[1027] In some embodiments, the transceiver module may include a transmitting module and / or a receiving module, and the transmitting module and the receiving module may be separate or integrated. Optionally, the transceiver module may be interchangeable with the transceiver.

[1028] In some embodiments, the processing module can be a single module or can include multiple submodules. Optionally, the multiple submodules each execute all or part of the steps required to be executed by the processing module. Optionally, the processing module can be interchangeable with the processor.

[1029] Figure 9A is a schematic diagram of the structure of a communication device proposed in an embodiment of the present disclosure. The communication device 300 can be a terminal device or an access network device. The access network device can be at least one of the following: a first access network device, a second access network device, a third access network device, or a fourth access network device. It can also be a chip, a chip system, or a processor that supports the terminal device or access network device to implement any of the above methods. The communication device 300 can be used to implement the methods described in the above method embodiments. For details, please refer to the description of the above method embodiments.

[1030] As shown in Figure 9A, the communication device 300 includes one or more processors 301. The processor 301 can be a general-purpose processor or a dedicated processor, for example, a baseband processor or a central processing unit. The baseband processor can be used to process the communication protocol and communication data, and the central processing unit can be used to control the communication device (such as a base station, a baseband chip, a terminal device, a terminal device chip, a DU or a CU, etc.), execute programs, and process program data. Optionally, the communication device 300 can be used to perform any of the above methods. Optionally, one or more processors 301 are used to call instructions to enable the communication device 300 to perform any of the above methods.

[1031] In some embodiments, the communication device 300 may further include one or more transceivers 302. When the communication device 300 includes one or more transceivers 302, the transceiver 302 may perform the communication steps of sending and / or receiving in the above method (e.g., step S2101, step S2102, step S2103, step S2104, step S2105, step S2106, step S2108, step S2109, step S2110, step S2111, step S2113, step S2201, step S2 ... S2203, step S2204, step S2205, step S2206, step S2208, step S2209, step S2210, step S2211, step S2213, but not limited to these), the processor 301 may execute at least one of the other steps (for example, step S2107, step S2112, step S2114, step S2207, step S2212, step S2214, but not limited to these).

[1032] In some embodiments, a transceiver may include a receiver and / or a transmitter. The receiver and transmitter may be separate or integrated. Optionally, the terms transceiver, transceiver unit, transceiver, transceiver circuit, interface circuit, and interface may be used interchangeably; the terms transmitter, transmitting unit, transmitter, and transmitting circuit may be used interchangeably; and the terms receiver, receiving unit, receiver, and receiving circuit may be used interchangeably.

[1033] In some embodiments, the communication device 300 also includes one or more memories 303 for storing data. Alternatively, all or part of the memories 303 may be located outside the communication device 300. In alternative embodiments, the communication device 300 may include one or more interface circuits 304. Optionally, the interface circuits 304 are connected to the memories 303 and can be used to receive data from the memories 303 or other devices, or to send data to the memories 303 or other devices. For example, the interface circuits 304 can read data stored in the memories 303 and send the data to the processor 301.

[1034] The communication device 300 described in the above embodiment may be a first access network device or a terminal device, but the scope of the communication device 300 described in the present disclosure is not limited thereto, and the structure of the communication device 300 may not be limited by FIG. 9A. The communication device may be an independent device or may be part of a larger device. For example, the communication device 300 may be: 1) an independent integrated circuit IC, or a chip, or a chip system or subsystem; (2) a collection of one or more ICs, optionally, the above IC collection may also include a storage component for storing data and programs; (3) an ASIC, such as a modem; (4) a module that can be embedded in other devices; (5) a receiver, a terminal device, an intelligent terminal device, a cellular phone, a wireless device, a handheld device, a mobile unit, an in-vehicle device, a first access network device, a cloud device, an artificial intelligence device, etc.; (6) others, etc.

[1035] FIG9B is a schematic diagram of the structure of the chip 400 proposed in an embodiment of the present disclosure. If the communication device 300 can be a chip or a chip system, please refer to the schematic diagram of the structure of the chip 400 shown in FIG9B , but the present disclosure is not limited thereto.

[1036] The chip 400 includes one or more processors 401 , and the chip 400 is configured to execute any of the above methods.

[1037] In some embodiments, chip 400 further includes one or more interface circuits 404. Alternatively, the terms interface circuit, interface, and transceiver pins may be used interchangeably. In some embodiments, chip 400 further includes one or more memories 403 for storing data. Alternatively, all or part of memories 403 may be located external to chip 400.

[1038] Optionally, the interface circuit 404 is connected to the memory 403. The interface circuit 404 can be used to receive data from the memory 403 or other devices, and the interface circuit 404 can be used to send data to the memory 403 or other devices. For example, the interface circuit 404 can read data stored in the memory 403 and send the data to the processor 401.

[1039] In some embodiments, the interface circuit 404 performs at least one of the communication steps such as sending and / or receiving in the above method (e.g., step S2101, step S2102, step S2103, step S2104, step S2105, step S2106, step S2108, step S2109, step S2110, step S2111, step S2113, step S2201, step S2202, step S2203, step S2204, step S2205, step S2206, step S2208, step S2209, step S2210, step S2211, and step S2213, but not limited thereto). The interface circuit 404 performing the communication steps such as sending and / or receiving in the above method, for example, means that the interface circuit 404 performs data exchange between the processor 401, chip 400, memory 403, or transceiver device. In some embodiments, the processor 401 may execute at least one of the other steps (eg, step S2107, step S2112, step S2114, step S2207, step S2212, step S2214, but not limited thereto).

[1040] The modules and / or devices described in various embodiments, such as virtual devices, physical devices, and chips, can be arbitrarily combined or separated according to circumstances. Optionally, some or all steps can also be performed collaboratively by multiple modules and / or devices, which is not limited here.

[1041] The embodiments of the present disclosure further provide a storage medium having instructions stored thereon. When the instructions are executed on the communication device 300, the communication device 300 executes any of the above methods. Optionally, the storage medium is an electronic storage medium. Optionally, the storage medium is a computer-readable storage medium, but is not limited thereto and may also be a storage medium readable by other devices. Optionally, the storage medium may be a non-transitory storage medium, but is not limited thereto and may also be a transient storage medium.

[1042] The embodiments of the present disclosure also provide a program product. When executed by the communication device 300, the program product causes the communication device 300 to perform any of the above methods. Optionally, the program product may be a computer program product. Optionally, the computer program product may include a computer program and / or instructions that, when executed by the communication device, implement any of the above optional message transmission methods.

[1043] The embodiments of the present disclosure also provide a computer program, which, when executed on a computer, enables the computer to execute any one of the above methods.

Claims

1. A message transmission method, characterized in that Performed by a first access network device, where the first access network device is the access network device to which a first cell belongs, and the first cell is the primary cell (PCell) of a terminal device; the method includes: Receiving a first message sent by the terminal device, where the first message is a message sent when the terminal device performs a mobility operation, the mobility operation includes a secondary cell group (SCG) mobility operation, the SCG mobility operation includes a primary secondary cell (PSCell) change or PSCell addition, the PSCell change includes the PSCell of the terminal device changing from a second cell to a third cell, the PSCell addition includes adding the third cell as the PSCell of the terminal device, the first message includes a second message, and the second message is a message corresponding to the third cell; Determining a third access network device, where the third access network device is the access network device to which the third cell belongs, and the third access network device is different from a second access network device to which the second cell belongs; Sending the second message to the third access network device.

2. The method according to claim 1, wherein The determining the third access network device includes at least one of the following: Determining the third access network device according to the first message; Determining the third access network device according to a third message, where the third message is a message sent by the second access network device to the first access network device.

3. The method according to claim 2, wherein The first message further includes at least one of the following: Target cell information, where the target cell information includes frequency information and / or a cell identifier corresponding to the third cell; A mobility configuration identifier, where the mobility configuration identifier is used to indicate mobility configuration information corresponding to the SCG mobility operation performed by the terminal device.

4. The method according to claim 3, characterized in that, The mobility configuration identifier includes a layer 1 or layer 2 triggered mobility (LTM) configuration identifier, and the LTM configuration identifier is used to indicate LTM configuration information corresponding to the SCG mobility operation performed by the terminal device.

5. The method according to claim 2, wherein The first message includes a first parameter and a second parameter, where the first parameter is used to indicate whether the second parameter is used to determine the third access network device, and the second parameter is a primary secondary cell selected based on SCG LTM.

6. The method according to claim 2, wherein The third message includes at least one of the following: An access network device identifier, where the access network device identifier is used to indicate the third access network device; A target cell identifier, where the target cell identifier is used to indicate the third cell; Target cell information, where the target cell information includes frequency information and / or a cell identifier corresponding to the third cell; A mobility configuration identifier, where the mobility configuration identifier is used to indicate mobility configuration information corresponding to the SCG mobility operation performed by the terminal device; Transmission configuration indication (TCI) status information, where the TCI status information is used to indicate beam information of the third cell.

7. The method according to claim 6, characterized in that, The mobility configuration identifier includes a layer 1 or layer 2 triggered mobility (LTM) configuration identifier, and the LTM configuration identifier is used to indicate LTM configuration information corresponding to the SCG mobility operation performed by the terminal device.

8. The method according to any one of claims 1 to 7, characterized in that The SCG mobility operation is triggered by the terminal device or the second access network device.

9. The method according to claim 1, wherein The mobility operation further includes a master cell group (MCG) mobility operation, and the MCG mobility operation includes changing the primary cell (PCell) of the terminal device from a fourth cell to the first cell, where the fourth cell belongs to a fourth access network device, and the fourth access network device is different from the first access network device.

10. The method according to claim 9, characterized in that, The determining of the third access network device includes at least one of the following: Determining the third access network device according to the first message; Determining the third access network device according to a fourth message, where the fourth message is a message sent by the fourth access network device to the first access network device.

11. The method according to claim 10, wherein The fourth message includes at least one of the following: An access network device identifier for indicating the third access network device; A target cell identifier for indicating the third cell; Target cell information including frequency information and / or cell identifier corresponding to the third cell; A mobility configuration identifier for indicating mobility configuration information corresponding to the terminal device performing the SCG mobility operation; Transmission configuration indication (TCI) status information for indicating beam information of the third cell.

12. The method according to claim 11, wherein The mobility configuration identifier includes a layer 1 or layer 2 triggered mobility (LTM) configuration identifier for indicating LTM configuration information corresponding to the terminal device performing the SCG mobility operation.

13. The method according to any one of claims 9 to 12, characterized in that, The mobility operation is triggered by the terminal device or the fourth access network device.

14. The method according to any one of claims 1 to 13, characterized in that, The mobility operation is a cell change or addition triggered by LTM.

15. The method according to any one of claims 1 to 14, characterized in that, The first message is a first RRC reconfiguration complete message, the second message is a second RRC reconfiguration complete message, and the first RRC reconfiguration complete message contains the second RRC reconfiguration complete message.

16. A message transmission method, characterized in that, Performed by the terminal device, the method includes: Performing a mobility operation, where the mobility operation includes an SCG mobility operation, and the SCG mobility operation includes a primary secondary cell (PSCell) change or PSCell addition. The PSCell change includes changing the PSCell of the terminal device from a second cell to a third cell, and the PSCell addition includes adding the third cell as the PSCell of the terminal device. The second cell belongs to a second access network device, the third cell belongs to a third access network device, and the second access network device is different from the third access network device; Sending a first message to a first access network device, where the first access network device is the access network device to which the first cell belongs, the first cell is the PCell of the terminal device, and the first message includes a second message, and the second message is a configuration message corresponding to the third cell.

17. The method according to claim 16, wherein The first message is used to instruct the first access network device to determine the third access network device.

18. The method according to claim 17, characterized in that The first message includes at least one of the following: A layer 1 or layer 2 triggered mobility (LTM) configuration identifier for indicating the LTM configuration corresponding to the terminal device performing the SCG mobility operation; Target cell information, where the target cell information includes frequency information and / or cell identifier corresponding to the third cell; Mobility configuration identifier, where the mobility configuration identifier is used to indicate mobility configuration information corresponding to the terminal device performing the SCG mobility operation.

19. The method according to claim 18, characterized in that, The mobility configuration identifier includes a layer 1 or layer 2 triggered mobility LTM configuration identifier, and the LTM configuration identifier is used to indicate LTM configuration information corresponding to the terminal device performing the SCG mobility operation.

20. The method according to any one of claims 16 to 19, characterized in that, The SCG mobility operation is triggered by the terminal device or the second access network device.

21. The method according to any one of claims 16 to 19, characterized in that, The method further includes: Receiving a first indication sent by the second access network device, where the first indication is used to indicate the terminal device to perform the mobility operation.

22. The method according to claim 16, wherein The mobility operation further includes a master cell group MCG mobility operation, and the MCG mobility operation includes changing the primary cell PCell of the terminal device from the fourth cell to the first cell, where the fourth cell belongs to the fourth access network device, and the fourth access network device is different from the first access network device.

23. The method according to claim 22, characterized in that, The mobility operation is triggered by the terminal device or the fourth access network device.

24. The method according to any one of claims 16 to 23, characterized in that The mobility operation is a cell change or addition triggered based on LTM.

25. The method according to any one of claims 16 to 24, characterized in that, The first message is a first RRC reconfiguration complete message, the second message is a second RRC reconfiguration complete message, and the first RRC reconfiguration complete message contains the second RRC reconfiguration complete message.

26. A message transmission method, characterized in that, Performed by the second access network device, the method includes: Sending a first indication to the terminal device, where the first indication is used to indicate the terminal device to perform a mobility operation, and the mobility operation includes an SCG mobility operation, and the SCG mobility operation includes a primary secondary cell PSCell change or PSCell addition. The PSCell change includes changing the primary secondary cell PSCell of the terminal device from the second cell to the third cell, and the PSCell addition includes adding the third cell as the PSCell of the terminal device. The second cell belongs to the second access network device, the third cell belongs to the third access network device, and the second access network device is different from the third access network device; Sending a third message to the first access network device, where the third message is used to indicate the first access network device to determine the third access network device.

27. The method according to claim 26, wherein The third message includes at least one of the following: Access network device identifier, where the access network device identifier is used to indicate the third access network device; Target cell identifier, where the target cell identifier is used to indicate the third cell; Target cell information, where the target cell information includes frequency information and / or cell identifier corresponding to the third cell; Mobility configuration identifier, where the mobility configuration identifier is used to indicate mobility configuration information corresponding to the terminal device performing the SCG mobility operation; Transmission configuration indication TCI status information, where the TCI status information is used to indicate beam information of the third cell.

28. The method according to claim 27, wherein The mobility configuration identifier includes a layer 1 or layer 2 triggered mobility LTM configuration identifier, and the LTM configuration identifier is used to indicate the LTM configuration information corresponding to the terminal device performing the SCG mobility operation.

29. The method according to any one of claims 26 to 28, characterized in that, The SCG mobility operation is triggered by the terminal device or the second access network device.

30. The method according to any one of claims 26 to 29, characterized in that, The mobility operation is a cell change or addition triggered based on LTM.

31. A message transmission method, characterized in that, Performed by a fourth access network device, the method includes: Sending a first indication to the terminal device, the first indication being used to indicate that the terminal device performs a mobility operation, the mobility operation including a master cell group (MCG) mobility operation and a secondary cell group (SCG) mobility operation, the SCG mobility operation including a primary-secondary cell (PSCell) change or PSCell addition, the PSCell change including the PSCell of the terminal device changing from a second cell to a third cell, the PSCell addition including adding the third cell as the PSCell of the terminal device, the second cell belonging to a second access network device, the third cell belonging to a third access network device, the second access network device being different from the third access network device, the MCG mobility operation including the primary cell (PCell) of the terminal device changing from a fourth cell to a first cell, the first cell belonging to a first access network device, the fourth cell belonging to the fourth access network device, the fourth access network device being different from the first access network device; Sending a fourth message to the first access network device, the fourth message being used to indicate that the first access network device determines the third access network device.

32. The method according to claim 31, wherein The fourth message includes at least one of the following: An access network device identifier, the access network device identifier being used to indicate the third access network device; A target cell identifier, the target cell identifier being used to indicate the third cell; Target cell information, the target cell information including frequency information and / or cell identifier corresponding to the third cell; A mobility configuration identifier, the mobility configuration identifier being used to indicate the mobility configuration information corresponding to the terminal device performing the SCG mobility operation; Transmission configuration indication (TCI) state information, the TCI state information being used to indicate the beam information of the third cell.

33. The method according to claim 32, wherein The mobility configuration identifier includes a layer 1 or layer 2 triggered mobility LTM configuration identifier, and the LTM configuration identifier is used to indicate the LTM configuration information corresponding to the terminal device performing the SCG mobility operation.

34. The method according to any one of claims 31 to 33, characterized in that, The mobility operation is triggered by the terminal device or the fourth access network device.

35. The method according to any one of claims 31 to 34, characterized in that, The mobility operation is a cell change or addition triggered based on LTM.

36. A terminal device, characterized in that, Including: A processing module, configured to perform mobility operations, where the mobility operations include SCG mobility operations, the SCG mobility operations include a primary secondary cell (PSCell) change or a PSCell addition, the PSCell change includes changing the PSCell of the terminal device from a second cell to a third cell, the PSCell addition includes adding the third cell as the PSCell of the terminal device, the second cell belongs to a second access network device, the third cell belongs to a third access network device, and the second access network device is different from the third access network device; A transceiver module, configured to send a first message to a first access network device, where the first access network device is the access network device to which a first cell belongs, the first cell is the primary cell (PCell) of the terminal device, and the first message includes a second message, and the second message is a configuration message corresponding to the third cell.

37. A first access network device, characterized in that, The first access network device is the access network device to which the first cell belongs, and the first cell is the primary cell (PCell) of the terminal device; The first access network device includes: A transceiver module, configured to receive the first message sent by the terminal device, where the first message is a message sent when the terminal device performs mobility operations, the mobility operations include secondary cell group (SCG) mobility operations, the SCG mobility operations include a PSCell change or a PSCell addition, the PSCell change includes changing the PSCell of the terminal device from a second cell to a third cell, the PSCell addition includes adding the third cell as the PSCell of the terminal device, and the first message includes a second message, and the second message is a message corresponding to the third cell; A processing module, configured to determine a third access network device, where the third access network device is the access network device to which the third cell belongs, and the third access network device is different from the second access network device to which the second cell belongs; The transceiver module is further configured to send the second message to the third access network device.

38. A second access network device, characterized in that It includes: A transceiver module, configured to send a first indication to the terminal device, where the first indication is used to instruct the terminal device to perform mobility operations, the mobility operations include SCG mobility operations, the SCG mobility operations include a PSCell change or a PSCell addition, the PSCell change includes changing the PSCell of the terminal device from a second cell to a third cell, the PSCell addition includes adding the third cell as the PSCell of the terminal device, the second cell belongs to the second access network device, the third cell belongs to the third access network device, and the second access network device is different from the third access network device; Sending a third message to the first access network device, where the third message is used to instruct the first access network device to determine a third access network device.

39. A fourth access network device, characterized in that, It includes: A transceiver module, configured to send a first indication to a terminal device, where the first indication is used to instruct the terminal device to perform mobility operations, and the mobility operations include master cell group (MCG) mobility operations and secondary cell group (SCG) mobility operations. The SCG mobility operations include primary-secondary cell (PSCell) change or PSCell addition. The PSCell change includes changing the PSCell of the terminal device from a second cell to a third cell, and the PSCell addition includes adding the third cell as the PSCell of the terminal device. The second cell belongs to a second access network device, and the third cell belongs to a third access network device, and the second access network device is different from the third access network device. The MCG mobility operations include changing the primary cell (PCell) of the terminal device from a fourth cell to a first cell. The first cell belongs to a first access network device, the fourth cell belongs to a fourth access network device, and the fourth access network device is different from the first access network device; Send a fourth message to the first access network device, where the fourth message is used to instruct the first access network device to determine the third access network device.

40. A communication device, characterized in that, Comprising: One or more processors; Wherein, the communication device is used to execute the message transmission method according to any one of claims 1 to 15, claims 16 to 25, claims 26 to 30, or claims 31 to 35.

41. A storage medium storing instructions, characterized in that, When the instruction runs on the communication device, the communication device is caused to execute the message transmission method according to any one of claims 1 to 15, claims 16 to 25, claims 26 to 30, or claims 31 to 35.

42. A computer program product comprising a computer program and / or instructions, characterized in that, When the computer program and / or instruction is executed by the communication device, it implements the message transmission method according to any one of claims 1 to 15, claims 16 to 25, claims 26 to 30, or claims 31 to 35.

43. A communication system, characterized in that, The communication system includes a terminal device and access network devices, and the access network devices include at least one of the following: a first access network device, a second access network device, and a fourth access network device. Wherein, the terminal device is configured to implement the message transmission method according to any one of claims 16 to 25, the first access network device is configured to implement the message transmission method according to any one of claims 1 to 15, the second access network device is configured to implement the message transmission method according to any one of claims 26 to 30, and the fourth access network device is configured to implement the message transmission method according to any one of claims 31 to 35.

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