Conditional primary-secondary cell change method and device

Abstract

The present application provides a conditional primary-secondary cell change method and apparatus to solve a problem that a secondary cell group radio link failure may occur in a scenario of successive CPC change. The method includes: a UE receiving a first RRC reconfiguration message from a network device, the first RRC reconfiguration message including first information corresponding to M candidate PSCells and a second RRC message, the second RRC message including second information corresponding to N candidate PSCells among the M candidate PSCells, the first information and the second information including at least one of an execution trigger condition and measurement configuration information, the UE evaluating whether the execution trigger condition of the M candidate PSCells is satisfied based on the first information, and when the UE determines through the evaluation that the execution trigger condition of the first candidate PSCell is satisfied, the UE applying the second RRC message corresponding to the first candidate PSCell.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 202310157032.1, entitled "CONDITIONAL PRIMARY SECONDARY CELL CHANGE METHOD AND APPARATUS," filed with the State Intellectual Property Office of the People's Republic of China on February 17, 2023, which is incorporated herein by reference in its entirety.

[0002] The present application relates to the field of communication technologies, and in particular to a conditional primary-secondary cell change method and apparatus. [Background technology]

[0003] In a 5G communication system, a conditional primary secondary cell (PSCell) change (CPC) function can be used to support secondary station mobility for dual connectivity. The primary secondary cell change can be triggered by either the primary base station or the secondary base station. Currently, after successfully performing CPC based on the source PSCell, a user equipment (UE) can store the configuration information of one or more candidate PSCells to continue evaluating whether the execution trigger conditions for the candidate PSCells are met and perform continuous CPC. This eliminates the need for the network side to deliver CPC configurations to the UE again for continuous CPC. For example, the source PSCell may be PSCell 0. After CPC is performed based on PSCell 0, the source PSCell is changed from PSCell 0 to PSCell 1. After continuous CPC is performed, the source PSCell is changed from PSCell 1 to PSCell 2. After the continuous CPC is performed, the source PSCell is changed from PSCell 2 to PSCell 3.

[0004] When the UE evaluates another candidate cell in the source PSCell 0, the execution trigger condition of the other candidate cell is determined by the trigger node based on the source PSCell 0. After the UE changes from source PSCell 0 to PSCell 1, the UE continues to use the execution trigger condition of the candidate cell determined by the trigger node, which may result in a secondary cell group (SCG) radio link failure (RLF) issue. Summary of the Invention [Means for solving the problem]

[0005] Embodiments of the present application provide a conditional primary-secondary cell change method and apparatus that improves successive CPC change accuracy and timeliness, avoids SCG RLF, reduces evaluation of whether invalid neighbor cell execution trigger conditions are met, and saves energy.

[0006] According to a first aspect, the present application provides a CPC method. The method may be applied to a UE, a chip, a chip group, a functional module implementing the method within a chip, etc. A UE is used as an example. The method includes: a UE receives a first RRC reconfiguration message from a network device, the first RRC reconfiguration message includes first information corresponding to M candidate PSCells and a second RRC message, where M is a positive integer; the second RRC message includes second information corresponding to N candidate PSCells among the M candidate PSCells, the first information and the second information including one or more of an execution trigger condition and measurement configuration information; the UE evaluates whether the execution trigger condition of the M candidate PSCells is satisfied based on the first information; and when the UE determines through the evaluation that the execution trigger condition of the first candidate PSCell among the M candidate PSCells satisfies the execution trigger condition, the UE applies the second RRC message corresponding to the first candidate PSCell.

[0007] In this method, the first RRC reconfiguration message includes a second RRC message for the candidate PSCell, which allows the UE to update the applied CPC configuration in the process of continuous CPC. In this way, in the process of implementing continuous CPC, the UE may apply one or more of the execution trigger conditions and measurement configuration information corresponding to the candidate PSCell corresponding to the newly accessed PSCell in time. Therefore, according to this method, the accuracy and timeliness of continuous CPC can be improved, SCG RLF caused by inaccurate CPC configuration can be avoided, and evaluation of whether the execution trigger conditions of invalid neighboring cells are met can be reduced, thereby saving energy.

[0008] In one possible design, after the UE applies the second RRC message corresponding to the first candidate PSCell, the method further includes: the UE evaluating, based on the second information, whether execution trigger conditions of the N candidate PSCells are satisfied. In this design, the first RRC reconfiguration message includes the second RRC message of the first candidate PSCell, and the execution trigger conditions and measurement configurations corresponding to the N candidate PSCells in the second RRC message may be implemented in a complete manner to avoid increasing the computational complexity of the UE.

[0009] In one possible design, after the UE applies the second RRC message corresponding to the first candidate PSCell, the method further includes: the UE determining third information corresponding to the N PSCells based on the first information and the second information, where the third information includes one or more of an execution trigger condition and measurement configuration information; and the UE evaluating whether the execution trigger condition of the N candidate PSCells is satisfied based on the third information.

[0010] In this design, the first RRC reconfiguration message includes a second RRC message for the first candidate PSCell, and the execution trigger conditions and measurement configurations corresponding to the N candidate PSCells in the second RRC message may be implemented in an incremental manner to reduce overhead.

[0011] In one possible design, the second RRC message further includes first indication information, where the first indication information indicates that the UE does not evaluate whether the execution trigger conditions of the P candidate PSCells are met when accessing the first candidate PSCell, and the M candidate PSCells include the P candidate PSCells.

[0012] In this design, based on the indication of the first indication information, the UE can be prevented from evaluating the execution trigger conditions of invalid neighboring cells, and valid neighboring cells of the PSCell to which the UE is currently accessed can be accurately evaluated, thereby saving energy.

[0013] In one possible design, the first RRC reconfiguration message further includes a reference configuration, where the reference configuration includes a secondary cell group SCG configuration and a master cell group MCG configuration; the second RRC message further includes SCG configurations corresponding to the N candidate PSCells; and the UE applying the second RRC message corresponding to the first candidate PSCell includes: the UE obtaining the MCG configuration and the SCG configuration corresponding to the first candidate PSCell based on the reference configuration and the second RRC message.

[0014] In this design, the reference configuration between the network device and the candidate secondary base station and the information indicated by the reference configuration stored by the UE are clarified, so that continuous CPC can be implemented accurately and the occurrence of SCG RLF can be reduced.

[0015] In one possible design, the second RRC message further includes an MCG configuration corresponding to the first candidate PSCell.

[0016] In one possible design, the first information is included in a reference configuration.

[0017] According to a second aspect, the present application provides a CPC method. The method can be applied to a network device, a chip, a chipset, a functional module in a chip that implements the method, etc. A network device is used as an example. The method includes: a network device determining a first message or receiving a first message from a source secondary base station, the first message including identifiers of L candidate PSCells and corresponding first information, where L is a positive integer; a network device sending a second message to at least one candidate secondary base station, the second message being used to request adding a secondary base station; a network device receiving a second RRC message from the at least one candidate secondary base station, the second RRC message including second information corresponding to M candidate PSCells, where M is a positive integer, and N candidate PSCells among the M candidate PSCells; a network device sending a first RRC reconfiguration message to the UE, the first RRC reconfiguration message including the first information and the second RRC message corresponding to the M candidate PSCells, the first information and the second information including one or more of an execution trigger condition and measurement configuration information. For example, the network device may be a primary base station.

[0018] In one possible design, the second message includes first information corresponding to the L candidate PSCells, and the first information is used by the at least one candidate secondary base station to determine the second information.

[0019] In one possible design, the first message includes a first reference configuration, and the first reference configuration includes an SCG configuration.

[0020] In one possible design, the second message includes a first reference configuration, which is an SCG configuration used by the at least one candidate secondary base station to determine the second RRC message.

[0021] In one possible design, the second RRC message further includes an MCG configuration.

[0022] In one possible design, the first RRC reconfiguration message further includes a reference configuration, which includes the first reference configuration and an MCG configuration, and the reference configuration is used by the UE to obtain the MCG configuration and the SCG configuration corresponding to the first candidate PSCell based on the second RRC message.

[0023] According to a third aspect, the present application provides a CPC method. The method may be applied to a candidate secondary base station, a chip, a chip group, a functional module implementing the method within a chip, etc. A candidate secondary base station is used as an example. The method includes: the candidate secondary base station receives a second message from a primary base station, the second message is used to request adding a secondary base station, and the candidate secondary base station sends a third message to the primary base station, the third message indicating a second RRC message corresponding to at least one candidate PSCell, the second RRC message including second information corresponding to N candidate PSCells, and the second information including one or more of an execution trigger condition and measurement configuration information.

[0024] In one possible design, the second message includes first information corresponding to the L candidate PSCells, the first information being one or more of an execution trigger condition and measurement configuration information, and the first information being used by the candidate secondary base station to determine the second information.

[0025] In one possible design, the second message includes a first reference configuration, the first reference configuration includes an SCG configuration, and the first reference configuration is an SCG configuration used by the candidate secondary base station to determine the second RRC message.

[0026] According to a fourth aspect, an embodiment of the present application provides a communication device. The device may be a communication device, or a chip or chipset within the communication device. The communication device may be a UE or a network device, for example, a base station. The base station may be a primary base station or a secondary base station. The device may include a processing unit, a transceiver unit, and a receiving unit. It should be understood that the transmitting unit and the receiving unit herein may alternatively be transceiver units. When the device is a communication device, the processing unit may be a processor, and the transmitting unit and the receiving unit may be transceivers. The communication device may further include a storage unit, and the storage unit may be a memory. The storage unit is configured to store instructions, and the processing unit executes the instructions stored in the storage unit, such that the UE performs a method according to the first aspect or any one of its possible designs, or the network device performs a method according to the second aspect or any one of its possible designs, or the candidate secondary base station performs a method according to the third aspect or any one of its possible designs. When the apparatus is a chip in a communication device, the processing unit may be a processor, and the transmitting unit and the receiving unit may be input / output interfaces, pins, circuits, etc. The processing unit executes the instructions stored in the storage unit, such that the chip performs a method according to the first aspect or any one of its possible designs, or the chip performs a method according to the second aspect or any one of its possible designs, or the chip performs a method according to the third aspect or any one of its possible designs. The storage unit is configured to store instructions. The storage unit may be a storage unit within the chip (e.g., a register or cache) or may be a storage unit located within the UE and external to the chip (e.g., a read-only memory or a random access memory).

[0027] According to a fifth aspect, an embodiment of the present application further provides a computer-readable storage medium storing a computer program, which, when running on a computer, enables the computer to perform the methods according to the first to third aspects.

[0028] According to a sixth aspect, an embodiment of the present application further provides a computer program product comprising a program that, when run on a computer, enables the computer to perform the methods according to the first to third aspects. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a diagrammatic representation of the MR-DC control plane architecture. [Figure 2a] 1 is a schematic flow diagram of a basic PSCell addition. [Figure 2b] 10 is a schematic flow diagram of a basic PSCell change triggered by an MN. [Figure 2c] 10 is a schematic flow diagram of a basic PSCell change triggered by a source SN. [Figure 3a] 1 is a schematic flow diagram of CPA. [Figure 3b] 1 is a schematic flow diagram of a CPC triggered by an MN; [Figure 3c] 1 is a schematic flow diagram of a CPC triggered by a source SN; [Figure 4a] 1 is a diagrammatic representation of a network architecture of a communication system to which the present application is applicable; [Figure 4b] 1 is a diagrammatic representation of a network architecture of a (wireless) access network device to which the present application is applicable; [Figure 5] 1 is a diagrammatic representation of a communication system scenario to which the present application is applicable; [Figure 6a] FIG. 1 is a diagram of an A3 event scenario diagram according to an embodiment of the present application. [Figure 6b] FIG. 1 is a diagram of an A5 event scenario diagram according to an embodiment of the present application. [Figure 7] FIG. 1 is a diagram of the interaction procedure of the CPC method according to an embodiment of the present application. [Figure 8] FIG. 2 is an exemplary diagram of a first RRC reconfiguration message according to an embodiment of the present application. [Figure 9] FIG. 2 is a diagram of the interaction procedure of the CPC method according to an embodiment of the present application. [Figure 10] FIG. 3 is a diagram of the interaction procedure of the CPC method according to an embodiment of the present application. [Figure 11] FIG. 4 is a diagram of the interaction procedure of the CPC method according to an embodiment of the present application. [Figure 12] 1 is a diagrammatic view of the structure of a communication device according to an embodiment of the present application; [Figure 13] FIG. 2 is a diagrammatic view of the structure of a base station according to an embodiment of the present application; [Figure 14] FIG. 2 is a diagram of the structure of a terminal device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0030] To facilitate understanding of the embodiments of the present application, terms or background art related to the embodiments of the present application are explained below.

[0031] (1) Multi-radio dual connectivity (MR-DC) In a wireless network, one UE may communicate with multiple base stations. This is called MR-DC (sometimes referred to as "DC"). The multiple base stations may belong to the same radio access technology (RAT), for example, all base stations are fourth-generation (4G) base stations, or all base stations are fifth-generation (5G) base stations, or may belong to different RATs, for example, some base stations are 4G base stations and other base stations are 5G base stations. The network side may provide communication services to the UE by using resources of the multiple base stations to provide high-rate transmission to the UE.

[0032] A primary base station (master node, MN) is a base station that exchanges control plane signaling with the core network in a DC. A secondary base station (secondary node, SN) is a base station other than an MN in a DC. Each base station has various radio link control (RLC) / media access control (MAC) entities.

[0033] In DC, data radio bearers (DRBs) are classified into master cell group (MCG) bearers, secondary cell group (SCG) bearers, and split bearers. An MCG bearer means that the RLC / MAC entity of the DRB resides only in the primary base station, an SCG bearer means that the RLC / MAC entity of the DRB resides only in the secondary base station, and a split bearer means that the RLC / MAC entity of the DRB resides in both the primary and secondary base stations. In addition, a bearer in which the packet data convergence protocol (PDCP) is terminated on the MN is called an MN-terminated bearer. Specifically, downlink (DL) data arrives directly from the core network to the MN, is processed by the MN's PDCP or service data adaptation protocol (SDAP), and then transmitted to the UE via RLC and MAC. Uplink (UL) data is processed by the PDCP or SDAP of the MN and then sent to the core network. Similarly, a bearer whose PDCP is terminated on the SN is called an SN terminated bearer. Specifically, DL data arrives directly from the core network to the SN, is processed by the PDCP / SDAP of the SN, and then sent to the UE through RLC / MAC. UL data is processed by the PDCP / SDAP of the SN and then sent to the core network.

[0034] In addition, Figure 1 is a diagram of the architecture of the MR-DC control plane. It can be seen from Figure 1 that in DC, both the primary base station and the secondary base station have a radio resource control (RRC) entity, and each may generate an RRC message, which may be, for example, a measurement message. In one scenario, the secondary base station may directly transmit the RRC message generated by the secondary base station to the UE. In this case, the RRC message transmitted by the UE to the secondary base station is also directly transmitted to the secondary base station, and the RRC message directly exchanged between the secondary base station and the UE is called an SRB3. In another scenario, the secondary base station may also notify the primary base station of the RRC message generated by the secondary base station, and the primary base station then transmits the RRC message to the UE. In this case, the UE also forwards the RRC message transmitted to the secondary base station to the secondary base station through the primary base station. Specifically, the UE transmits an RRC message to the primary base station, and the primary base station forwards the message to the secondary base station. The control plane interface of the primary base station is called the NG-C interface, the control plane interface between the primary base station and the secondary base station is called the Xn-C interface, and the interface between the primary base station and the UE and the interface between the secondary base station and the UE are called the Uu interface.

[0035] The DC architecture may include, but is not limited to, the following four types:

[0036] The first type is E-UTRA-NR dual connectivity (EN-DC). A long-term evolution (LTE) base station (e.g., eNB) functions as the MN, also called the anchor, and a new radio (NR) base station (e.g., gNB) functions as the SN to implement DC. Both the MN and the SN are connected to a 4G core network (evolved packet core, EPC) to provide air interface transmission resources for data between the UE and the EPC. EN-DC is also called non-standalone (NSA) networking. In the early stages of 5G, in an EN-DC network, a UE cannot camp on an NR cell. An NR base station that a UE can camp on may be called a SA NR base station.

[0037] The second type is NR-E-UTRA dual connectivity (NE-DC). An NR base station (e.g., gNB) functions as the MN, and an LTE base station (e.g., ng-eNB) functions as the SN. Both the MN and the SN are connected to a 5G core (5GC) network to provide air interface transmission resources for data between the UE and the 5GC.

[0038] The third type is NGEN-DC (NG-RAN E-UTRA-NR dual connectivity). Specifically, an LTE base station (e.g., ng-eNB) functions as a MN, and an NR base station (e.g., gNB) functions as a SN to implement DC. Both the MN and the SN are connected to the 5GC to provide air interface transmission resources for data between the UE and the 5GC.

[0039] Type 4: In addition to the above three types of LTE-NR DC, 5G also supports NR-NR DC (NR-DC). Specifically, both the MN and the SN are NR base stations, and both the primary and secondary base stations are connected to 5GC.

[0040] For a UE in MR-DC, the user plane of the secondary base station may be connected to a core network connected to the primary base station. In other words, the core network may transmit data directly to the UE through the secondary base station.

[0041] (2) Primary cell (PCell) and primary secondary cell (PSCell) In MR-DC, there is one PCell in the primary base station and one PSCell in the secondary base station. The PCell is deployed on the dominant frequency and is the cell where the UE initiates the initial connection establishment process or connection re-establishment process, or is designated as the primary cell in the handover process. The PSCell is the cell where the UE initiates the random access procedure in the secondary base station, or where the UE skips the random access procedure and initiates data transmission in the secondary base station change process, or where the UE initiates random access in the process of performing synchronous reconfiguration.

[0042] Because a UE can simultaneously receive services from multiple cells under one base station, the serving cell group provided by the MN for the UE can also be called a master cell group (MCG). Similarly, the serving cell group provided by the SN for the UE can also be called a secondary cell group (SCG). The MCG and SCG each contain at least one cell. When there is only one cell in the MCG, that cell is the UE's PCell. When there is only one cell in the SCG, that cell is the UE's PSCell. In addition, in NR, to unify various terminologies, the PCell and PSCell are collectively called a special cell (SPCell). When there are multiple cells in the MCG or SCG, the cells other than the SPCell are called SCells. In this case, carrier aggregation (CA) is implemented between the SCell and SPCell in each cell group. The following explains some important terms.

[0043] In CA technology, multiple carriers (also called "cells") are configured to allow a single UE to perform data transmission together. In this way, the UE can simultaneously perform uplink and downlink communications by using multiple carriers to support high-speed data transmission and jointly provide transmission resources for the UE.

[0044] The PCell is a cell operating on the primary carrier. The UE performs the initial connection setup process or initiates the connection re-establishment process in the cell. In the handover process, the cell is referred to as the primary cell.

[0045] A PSCell is a cell that belongs to a cell of an SCG and is indicated for a UE to perform random access or initial physical uplink shared channel (PUSCH) transmission, e.g., the random access procedure is omitted in the SCG change procedure.

[0046] An SCell is a cell operating on a secondary carrier. When an RRC connection is established, the secondary cell may be configured to provide additional radio resources. In addition, it should be noted that in the DC architecture, cells other than the PCell in the MCG and SCG may be referred to as SCells.

[0047] For a UE in RRC connected mode, the serving cell is the PCell if CA / DC is not configured and there is only one serving cell, or the serving cell set includes the PCell and SCells if CA / DC is configured. Each component carrier (CC) corresponds to one independent cell. A UE configured with CA / DC is connected to one PCell and up to 31 SCells. The PCell and all SCells of the UE form the serving cell set of the UE. The serving cell may be either a PCell or an SCell.

[0048] (3) Basic PSCell addition / modification When the UE is not configured with a PSCell, the network side triggers the PSCell addition. The network side directly indicates the target PSCell to the UE, and the UE adds the target PSCell. It will be understood that in a scenario where the network side configures MR-DC for the UE, the PSCell addition can only be triggered by the MN. For example, Figure 2a is a schematic flow chart of a basic PSCell addition. The basic PSCell addition may include the following steps.

[0049] S201: The MN sends an SN addition request message to the target SN.

[0050] S202: The target SN returns an SN addition request confirmation message to the MN. The SN addition request confirmation message carries the target SCG information configured by the target SN for the UE.

[0051] S204: The MN sends an RRC reconfiguration message to the UE, which carries target SCG information and is used to deliver an SN or SCG addition instruction to the UE.

[0052] S205: The UE sends an RRC reconfiguration complete message to the MN.

[0053] S207: The MN sends an SN RRC reconfiguration complete message to the target SN.

[0054] S208: The UE and the target SN perform a random access procedure. In the random access procedure, the UE may access the target PSCell.

[0055] The execution order of S207 and S208 is not limited and may be determined based on the implementation of the UE.

[0056] When a PSCell is configured for a UE, due to the mobility of the UE, the network side may trigger a PSCell change, which may be triggered by the MN or the SN. The network side directly indicates a target PSCell to the UE, and the UE is handed over from the current PSCell to the target PSCell. For example, Figure 2b is a schematic flow diagram of a basic PSCell change triggered by an MN. Compared with the procedure shown in Figure 2a, the basic PSCell change triggered by an MN may further include the following steps.

[0057] After S202, S203a: the MN sends an SN release request message to the source SN, which may indicate to the source SN to release resources and stop data transmission with the UE.

[0058] S203b: The source SN sends an SN release request confirmation message to the MN.

[0059] In another example, Figure 2c is a schematic flow chart of a basic PSCell change triggered by a source SN. Compared with the procedure shown in Figure 2a, the basic PSCell change triggered by a source SN may further include the following steps:

[0060] Before S201, S200: The source SN sends an SN change request message to the MN.

[0061] After S205, S206: The MN sends an SN change confirmation message to the source SN.

[0062] (4) Conditional Primary Secondary Cell Addition / Change (CPAC) In CPAC, the MN or SN prepares multiple candidate PSCells, and the network side sends a CPAC configuration to the UE. The CPAC configuration includes candidate PSCell information, measurement configuration information, and handover trigger conditions. After receiving the CAPC configuration information, if the UE confirms that the signal quality of the candidate PSCell satisfies the handover trigger conditions, the UE performs random access by using the candidate PSCell as the target PSCell and performs a PSCell addition or modification procedure. CPAC differs from basic PSCell addition / modification. In basic PSCell addition / modification, the target candidate PSCell is indicated by the network side. In CPAC, the network side indicates multiple candidate PSCells, and the UE determines the candidate PSCell that satisfies the trigger conditions as the target PSCell through evaluation.

[0063] CPAC can be categorized into conditional primary secondary cell addition (CPA) and conditional primary secondary cell change (CPC), which are described below.

[0064] When the UE is not configured with a PSCell, the network side triggers the PSCell addition. It will be understood that in a scenario where the network side configures MR-DC for the UE, the PSCell addition can only be triggered by the MN. For example, Figure 3a is a schematic flow chart of CPA. CPA may include the following steps:

[0065] S301: The MN sends an SN addition request message to a first candidate SN and a second candidate SN. Note that the first candidate SN and the second candidate SN are used as an example in FIG. 3a. In actual implementation, the MN may send an SN addition request message to one or more candidate SNs. The SN addition request message may include a CPAC configuration, one or more recommended candidate PSCells, and measurement results to assist the candidate SN in configuring an SCG cell.

[0066] S302: The first candidate SN and the second candidate SN each return an SN addition request confirmation message to the MN. The SN addition request confirmation message includes one or more prepared candidate PSCells, where the one or more prepared candidate PSCells are PSCells determined by the candidate SNs and can be accessed by the UE. In addition, the candidate SN reserves radio resources for the UE until an SN release request message is received from the MN.

[0067] S305: The MN sends an RRC reconfiguration message to the UE. The RRC reconfiguration message includes a CPA configuration, and the CPA configuration may indicate the radio air interface configuration and an execution trigger condition of each of the first candidate SN and the second candidate SN.

[0068] S306: The UE sends an RRC reconfiguration complete message to the MN. Note that in this case, the UE does not add a candidate PSCell, and continues to determine whether there is a candidate PSCell that meets the execution trigger condition.

[0069] S309: When the UE detects that the candidate PSCell satisfies the execution trigger condition, the UE uses the candidate PSCell that satisfies the execution trigger condition as a target PSCell, and the UE sends an RRC reconfiguration complete message to the MN. It should be understood that the RRC reconfiguration complete message indicates the target PSCell selected by the UE. For example, the target PSCell is the PSCell of the first candidate SN.

[0070] S3010a: The MN sends an SN release request message to a second candidate SN. The SN release request message is used to request an SN to release reserved radio resources, buffered data, etc. It should be understood that the second candidate SN is another candidate SN other than the SN where the target PSCell is located.

[0071] S3010b: The second candidate SN sends an SN release confirmation message to the MN.

[0072] S3011. The MN sends an SN RRC reconfiguration complete message to the first candidate SN.

[0073] S3012. The UE and the first candidate SN perform a random access procedure. In the random access procedure, the UE may access the first candidate PSCell.

[0074] The execution order of S309 and S3012 is not limited and may be determined based on the implementation of the UE.

[0075] When a PSCell is configured for a UE, due to the mobility of the UE, the network side may trigger a PSCell change, which may be triggered by the MN or the source SN. For example, Figure 3b is a schematic flow diagram of CPC triggered by the MN. Compared with the procedure shown in Figure 3a, CPC triggered by the MN may further include the following steps:

[0076] Before S301, S300a: The MN sends an SN change request message to the source SN. Optionally, the SN change request message may be used to request the current SCG configuration. The SCG configuration may be used to implement incremental configuration on the SCG in the CPC.

[0077] S300b: The source SN sends an SN change confirmation message to the MN. Optionally, the SN change confirmation message may include the current SCG configuration.

[0078] After S306, S307: the MN sends a user plane address indication message to the source SN, which is used to perform early data transfer.

[0079] Compared with S3010a, S3010a': the MN further sends an SN release request message to the source SN. The SN release request message is used to request the source SN to stop data transmission with the UE and perform a delayed data transfer with the SN corresponding to the target PSCell (e.g., the first candidate SN in FIG. 3b).

[0080] Compared with S3010b, S3010b': the source SN further sends an SN release request message to the MN.

[0081] In another example, Figure 3c is a schematic flow diagram of CPC triggered by the source SN. Compared with the procedure shown in Figure 3a, the CPC triggered by the source SN may further include the following steps:

[0082] Before S301, S300: The source SN sends an SN change request message to the MN. The SN change request message may include, but is not limited to, a CPAC configuration, one or more recommended candidate PSCells, and an SCG configuration, where the CPAC configuration and one or more recommended candidate PSCells may be used to assist the candidate SN in configuring an SCG cell, and the SCG configuration may be used to implement incremental configuration on the SCG within the CPC.

[0083] Optionally, after S302, S303: the MN sends an SN change request message to the source SN. The SN change request message may indicate a candidate PSCell prepared by the candidate SN, where the prepared candidate PSCell is a PSCell determined by the candidate SN and can be accessed by the UE.

[0084] Optionally, S304: The source SN sends a source SN triggered update message to the MN. The source SN triggered update message may include, but is not limited to, one or any combination of updated measurement configuration information, updated execution trigger conditions, etc.

[0085] After S306, S307': the MN sends an SN change confirmation message to the source SN. The SN change confirmation message may indicate that the MN has configured a CPC for the UE to indicate that the source SN will perform early data transfer. Optionally, if S303 and S304 are not performed, the SN change confirmation message may further indicate a candidate PSCell prepared by the candidate SN. The prepared candidate PSCell is a PSCell determined by the candidate SN and may be accessed by the UE.

[0086] Optionally, S308: The source SN sends a source SN triggered update message to the MN. The source SN triggered update message may include, but is not limited to, one or any combination of updated measurement configuration, updated execution trigger condition, etc. It will be understood that after the MN receives the source SN triggered update message sent by the source SN, S305 and S306 refer to the manner of implementing the reconfiguration for the UE.

[0087] The measurement configuration information in the above example mainly includes measurement objects, measurement reports, and other parameters. For example, the measurement configuration information may be shown in Table 1 below.

[0088] [Table 1]

[0089] Referring to Table 1, it can be seen that a measurement ID is associated with a measurement object and a reporting configuration, and the reporting configuration may include a measurement event configuration. It can also be understood that an execution trigger condition primarily refers to the configuration of one or more measurement events. For example, the execution trigger condition of a CPAC may be an A3, A4, A5, or B1 event. For example, the measurement events may be as shown in Table 2 below.

[0090] [Table 2]

[0091] From the contents shown in Table 2, it can be seen that an event report can be triggered after the UE detects that a corresponding measurement event in Table 2 is satisfied through measurement. For example, the measurement event of the execution trigger condition is an A3 event, and the execution trigger condition is that a PSCell change can be performed when the UE measures that the reference signal received power (RSRP) of a neighboring cell is 3 dB higher than that of the source PSCell. After finding a target PSCell that satisfies the execution trigger condition in a candidate PSCell, the UE can autonomously decide to perform a PSCell change. In another example, the measurement event of the execution trigger condition is an A4 event, and the execution trigger condition is that the UE can perform a PSCell change when the UE measures that the signal quality of the candidate PSCell is higher than a threshold. Therefore, when evaluating candidate PSCells, after finding a target PSCell that satisfies the execution trigger condition, the UE can autonomously decide to perform a PSCell change.

[0092] Generally, in CPA and CPC scenarios triggered by the MN, the execution trigger condition is generally at least one of an A4 event and a B1 event. For the A4 and B1 events, the signal quality of the candidate PSCell only needs to be greater than the corresponding threshold. In CPC triggered by the SN, the execution trigger condition is generally at least one of an A3 event and an A5 event. For the A3 and A5 events, the signal quality of the current serving PSCell and the signal quality of the candidate PSCell need to be evaluated simultaneously.

[0093] It should be noted that with the continuous development of technology, the terms in the embodiments of the present application may change, but all of them fall within the protection scope of the present application.

[0094] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following further describes the embodiments of the present application in detail with reference to the accompanying drawings.

[0095] The technical solutions in the embodiments of the present application may be applied to various communication systems, for example, a satellite communication system, a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD) system, a fifth generation (5G) mobile communication system or a new radio (NR) system, or an integrated communication system of satellite communication and a 5G mobile communication system, or may be applied to a future communication system or another similar communication system.

[0096] 4a is a diagram of a network architecture of a communication system to which the present application is applicable. According to the requirements of the 3rd generation partnership project (3GPP®) protocol standard, the network architecture includes four components: a user equipment (UE), an access network (AN), a core network, and a data network (DN). The access network may be a radio access network (RAN).

[0097] The UE, (radio) access network, and core network are the main parts of the network architecture, which can be logically divided into two parts: the user plane and the control plane. The control plane is responsible for mobile network management, and the user plane is responsible for service data transmission. For example, as shown in Figure 4a, in a 5G communication system, two next-generation (NG) reference points are located between the (radio) access network control plane and the core network control plane, the NG3 reference point is located between the (radio) access network user plane and the core network user plane, and the NG6 reference point is located between the core network user plane and the data network.

[0098] Each component of the network architecture is described in detail below.

[0099] 1. UE is a device with radio transceiver capabilities and is the gateway for mobile users to interact with the network. The UE provides basic computing and storage capabilities, displays service windows to the user, and receives operational inputs from the user. The UE communicates with a core network or a data network through a (radio) access network and may exchange voice and / or data with the (radio) access network. For example, in a 5G communication system, a next-generation UE (nextgen UE, NG UE) may establish a signaling connection and a data connection to the (radio) access network by using new radio (NR) technology to transmit control signals and service data to the network.

[0100] For example, a UE may include a wireless UE, a mobile UE, a device-to-device (D2D) UE, a vehicle-to-everything (V2X) UE, a machine-to-machine / machine-type communications (M2M / MTC) UE, an internet of things (IoT) UE, a subscriber unit, a subscriber station, a mobile station, a remote station, an access point (AP), a remote terminal, an access terminal, a user terminal, a user agent, or a user device. For example, a UE may be a mobile phone, a tablet computer (PAD), a computer with wireless transceiver capabilities, a portable, pocket-sized, handheld, or computer-embedded mobile device, etc. In another example, the UE may alternatively be a virtual reality (VR) UE, an augmented reality (AR) UE, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a UE in a future public land mobile network (PLMN), a vehicle device in V2X, or customer premises equipment (CPE).In another example, the UE may be a device such as a personal communication service (PCS) phone, a cordless telephone set, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, or a personal digital assistant (PDA).

[0101] By way of example and not limitation, the UE may alternatively be a wearable device. Wearable devices, also sometimes referred to as wearable intelligent devices or intelligent wearable devices, are a collective term for wearable devices, such as eyeglasses, gloves, watches, clothing, and shoes, that are intelligently designed and developed for everyday wear using wearable technology. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not only hardware devices but also implement powerful functions through software support, data exchange, and cloud interaction. In a broad sense, wearable intelligent devices include both full-featured, large devices, such as smart watches or smart glasses, that can implement full or partial functionality without relying on a smartphone, and devices that are specialized for only one type of application function and require cooperation with other devices, such as smartphones, such as various smart bands, smart helmets, or smart jewelry that monitor physical symptoms. However, when the various UEs described above are located in a vehicle (e.g., placed within or mounted on a vehicle), the UEs may be considered to be on-board UEs, which may also be referred to as, for example, on-board units (OBUs).

[0102] The UE may be deployed on land, including indoor or outdoor devices, handheld devices, or wearable or vehicle-mounted devices, on water (e.g., on a ship), or in the air (e.g., on an airplane, balloon, or satellite). The specific technologies, device forms, application scenarios, and names used by the UE are not limited in the embodiments of the present application.

[0103] 2. The (radio) access network is deployed near the UE, provides network access functions for authorized users within a specific area, and can determine transmission tunnels of various qualities to transmit user data based on user level, service requirements, etc. The (radio) access network can manage and appropriately use its resources, provide access services to the UE upon request, and transfer control signals and service data between the UE and the core network.

[0104] (Radio) access network devices are deployed in (radio) access networks and are configured to connect UEs to the wireless network. (Radio) access network devices are generally connected to the core network through wired links (e.g., fiber optic cables). (Radio) access network devices may also be referred to as RAN devices / nodes or base stations.

[0105] For example, a (radio) access network device may include a base station, an evolved NodeB (eNodeB) in an LTE system or an LTE-Advanced (LTE-A) system, a next generation NodeB (gNB) in a 5G communication system, a transmission reception point (TRP), a baseband unit (BBU), an access point (AP) in a wireless local area network (WLAN), an integrated access and backhaul (IAB) node, a base station in a future mobile communication system, an access node in a Wi-Fi system, etc. Alternatively, a radio access network device may be a module or unit that completes some functions of a base station, such as a central unit (CU) or a distributed unit (DU).

[0106] For example, in a network structure, the (radio) access network device may be a CU node, a DU node, or a (radio) access network device including a CU node and a DU node. Figure 4b is a diagram of a network architecture of (radio) access network devices to which the present application is applicable. The CU node is configured to support protocols such as the radio resource control (RRC) protocol, the packet data convergence protocol (PDCP), and the service data adaptation protocol (SDAP). The DU node is configured to support the radio link control (RLC) layer protocol, the medium access control (MAC) layer protocol, and the physical layer protocol.

[0107] Radio access network devices may be deployed on land, including indoor or outdoor devices, handheld devices, or wearable or vehicle-mounted devices; on water (e.g., ships); or in the air (e.g., on airplanes, balloons, or satellites). For example, some gNBs can currently be deployed on satellites. The specific technologies, device forms, application scenarios, and names used by (radio) access network devices are not limited in the embodiments of this application. In the embodiments of this application, (radio) access network devices may be referred to as access network (AN) devices for short. Unless otherwise specified, all access network devices below may be (radio) access network devices.

[0108] For example, the CPC method provided in the embodiments of the present application may be applied to the communication system shown in FIG. 5. The communication system may include one UE and two network devices. The UE and the two network devices are in a DC relationship. The two network devices are the MN and SN described in the above embodiments, respectively. In CPC, the SN may implement the change. For the connection architecture of the two network devices, please refer to the four DC architectures described above. It should be understood that the connection architecture of the two network devices in the present application is not limited to the four DC architectures described above, and may alternatively be another DC architecture that appears in future communication developments. It should be understood that FIG. 5 is merely an example for explanation and does not particularly limit the number of UEs and network devices included in the communication system.

[0109] 3. The core network is responsible for maintaining subscription data of the mobile network, managing network elements of the mobile network, and providing functions such as session management, mobility management, policy management, and security authentication to the UE. Specifically, when the UE is connected, network access authentication is provided to the UE; when the UE has a service request, network resources are allocated to the UE; when the UE moves, network resources are updated for the UE; when the UE is idle, a fast recovery mechanism is provided to the UE; when the UE is disconnected, network resources are released for the UE; and when the UE has service data, a data routing function is provided to the UE. For example, uplink data is forwarded to the data network, or downlink data is received from the data network and sent to the (radio) access network, and the data is sent to the UE.

[0110] The network elements of the core network may be deployed on land, including indoor or outdoor devices, handheld devices, or wearable or vehicle-mounted devices, on water (e.g., ships), or in the air (e.g., airplanes, balloons, or satellites). For example, in some current scenarios, user plane function (UPF) network elements may be deployed on satellites. The specific technologies, device forms, application scenarios, and names used by the network elements of the core network are not limited in the embodiments of the present application.

[0111] 4. The data network is configured to provide services to users. In the actual communication process, the client is usually located in the UE, and the server is usually located in the data network. The data network may be a private network, such as a local area network, or an external network not managed or controlled by the operator, such as the Internet, or a dedicated network jointly deployed by operators, such as a network providing IP multimedia network subsystem (IMS) services.

[0112] The network architectures and service scenarios described in the embodiments of the present application are intended to clearly illustrate the technical solutions of the embodiments of the present application, but are not intended to limit the technical solutions provided in the embodiments of the present application. Those skilled in the art may know that with the evolution of network architectures and the emergence of new service scenarios, the technical solutions provided in the embodiments of the present application can also be applied to similar technical problems.

[0113] In the embodiments of the present application, it should be understood that "at least one" refers to one or more, and "multiple" refers to two or more. The term "and / or" describes an association relationship between related objects and indicates that three relationships may exist. For example, A and / or B may indicate that only A is present, that both A and B are present, and that only B is present, and A and B may be singular or plural. The symbol " / " typically indicates an "or" relationship between related objects. "At least one of the following moieties (items)" or similar expressions refers to any combination of these items, including a single item (moiety) or any combination of multiple items (moieties). For example, at least one of a, b, or c may refer to a, b, c, a and b, a and c, b and c, or a, b, and c, and a, b, and c may be singular or plural.

[0114] It is to be understood that the terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a," "the," and "this" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0115] Additionally, although terms such as first, second, and third may be used in the present application to describe various pieces of information, the information should not be limited to these terms. These terms are used only to distinguish between the same types of information. For example, without departing from the scope of the present application, first information may also be referred to as second information. Similarly, second information may also be referred to as first information. Depending on the context, for example, the term "if" used in this specification may be explained as "while," "when," or "in response to determining."

[0116] The DC scenario may include procedures such as SN addition (e.g., PSCell addition) and SN change (including intra-station PSCell change, inter-station PSCell change, etc.) procedures. The existing standard implementation not only supports a conditional execution mechanism, i.e., a CPC mechanism, that supports PSCell addition and change, but also supports continuous CPC. It should be understood that in continuous CPC, a UE may acquire configuration information for one or more candidate PSCells after performing CPC, and the UE may continue to perform measurements based on the configuration information to continue performing CPC. However, in current communication technologies, when a UE evaluates one or more candidate PSCells, the execution trigger conditions for the one or more candidate PSCells to be used are generated based on the source PSCell. After CPC is performed, the serving PSCell is changed, but the one or more candidate PSCells and the corresponding execution trigger conditions are still determined by the trigger node (MN / SN) based on the source PSCell. This may cause some problems. Below, Figures 6a and 6b are used as examples for explanation. In a scenario where the source serving PSCell is PSCell 0, after CPC is performed based on PSCell 0, the serving PSCell changes from PSCell 0 to PSCell 1, and after a subsequent CPC is performed again, the serving PSCell changes from PSCell 1 to PSCell 2. It will be understood that the serving PSCell is the PSCell currently accessed by the UE through the random access procedure.

[0117] The A3 offset value is used as an example. It can be seen from FIG. 6a that the A3 offset value for changing from PSCell 0 to PSCell 1 is 2 dB (power unit), the A3 offset value for changing from PSCell 0 to PSCell 2 is 4 dB, and the A3 offset value for changing from PSCell 1 to PSCell 2 is 2 dB. In current communication technologies, both the candidate PSCells evaluated by the UE and the corresponding execution trigger conditions are configured by a trigger node (SN) based on PSCell 0 and used for CPC evaluation from PSCell 0 to another candidate PSCell. Therefore, after CPC is implemented and PSCell 0 is changed to PSCell 1, when the UE still uses the CPC configuration based on PSCell 0 to evaluate whether the execution trigger conditions of the candidate PSCells are met, PSCell 1 may be changed to PSCell 2 too late, which may result in a radio link failure.

[0118] The A5 threshold is used as an example. From Figure 6b, it can be seen that for a change from PSCell 0 to PSCell 1, threshold 1 is -90 dBm (power units) and threshold 2 is -85 dBm, for a change from PSCell 0 to PSCell 2, threshold 1 is -92 dBm and threshold 2 is -88 dBm, and for a change from PSCell 1 to PSCell 2, threshold 1 is -89 dBm and threshold 2 is -86 dBm. In current communication technologies, both the candidate PSCells evaluated by the UE and the corresponding execution trigger conditions are set by a trigger node (SN) based on PSCell 0. Therefore, after CPC is implemented and PSCell 0 is changed to PSCell 1, when the UE is still using the CPC configuration based on PSCell 0 to evaluate whether the execution trigger conditions of the candidate PSCell are met, PSCell 1 may be changed to PSCell 2 too late, too early or incorrectly, which may result in a radio link failure.

[0119] The A4 threshold is used as an example. It can be seen from Figure 6b that the threshold for changing from PSCell 0 to PSCell 1 is -85 dBm, the threshold for changing from PSCell 0 to PSCell 2 is -88 dBm, and the threshold for changing from PSCell 1 to PSCell 2 is -86 dBm. In current communication technologies, both the candidate PSCells evaluated by the UE and the corresponding execution trigger conditions are set by a trigger node (MN) based on PSCell 0. Therefore, after CPC is implemented and PSCell 0 is changed to PSCell 1, when the UE still uses the CPC configuration based on PSCell 0 to evaluate whether the execution trigger conditions of the candidate PSCells are met, PSCell 1 may be changed to PSCell 2 too early, which may result in a radio link failure.

[0120] From the examples described in Figures 6a and 6b, it can be seen that for A3 and A5 events, candidate PSCells need to be evaluated, and the serving PSCell currently accessed by the UE needs to be evaluated. For continuous CPC triggered by an SN or MN in the current standard, the RRC reconfiguration message delivered by the network side only includes candidate PSCells determined based on the PSCell currently accessed by the UE (source PSCell) and the corresponding execution trigger conditions. Even if the serving PSCell is changed, the UE still uses the CPC configuration based on the source PSCell to evaluate whether the execution trigger conditions of the candidate PSCells are met. Therefore, in a scenario in which the UE performs continuous CPC, radio link failure problems such as changing too late, changing too late, or changing to the wrong cell described in Figure 6a or 6b may occur.

[0121] Based on this, the embodiments of the present application provide a CPC method and apparatus to solve the problem that radio link failure may occur in a continuous CPC scenario. The method and apparatus are based on the same inventive concept. Because the principles for solving the problem by using the method and apparatus are similar, cross-references may be made between the implementations of the apparatus and method, and repeated descriptions will be omitted.

[0122] The CPC method provided in the present application will be specifically described below with reference to the accompanying drawings.

[0123] Embodiment 1 7 is a diagram of an interaction procedure of a CPC method according to an embodiment of the present application. This method can be applied between a UE and a network device, and this method can be applied to a continuous CPC scenario. This method can include the following detailed steps:

[0124] S701: The MN obtains identifiers of L candidate PSCells and corresponding first information.

[0125] In one possible implementation, the MN functions as a trigger node, and the MN determines identifiers of the L candidate PSCells and the corresponding first information.

[0126] In another possible implementation, the MN obtains identifiers of L candidate PSCells and corresponding first information from a source SN, and the source SN functions as a trigger node. For example, the MN receives an SN change request message from the source SN. The SN change request message indicates a request for a continuous CPC procedure and includes identifiers of the L candidate PSCells and corresponding first information.

[0127] (1) Identifiers of L candidate PSCells. The L candidate PSCells may be understood as candidate PSCells recommended by the source SN based on measurement results. For example, the PSCell currently accessed by the UE (source PSCell) may be PSCell 0, and the L candidate PSCells may include PSCell 1, PSCell 2, PSCell 3, ..., PSCell L.

[0128] (2) First information corresponding to the L candidate PSCells. For example, the first information may include one or more of an execution trigger condition and measurement configuration information. It will be understood that the execution trigger condition corresponding to each of the L candidate PSCells indicates an execution trigger condition for handover from PSCell 0 to PSCell 1, or PSCell 2, ..., or PSCell L. The measurement configuration information may indicate to the UE to perform cell measurement and evaluation, thereby causing the UE to implement CPC.

[0129] It should be noted that in this embodiment of the present application, the information format of each piece of information included in the SN change request message is not limited. For example, the SN change request message may also include, but is not limited to, one or more of identifiers of L candidate PSCells, execution trigger conditions corresponding to the identifiers of the L candidate PSCells, and measurement configuration information corresponding to the identifiers of the L candidate PSCells. In other words, the information may be displayed in a parallel manner, an embedded manner, an aggregated manner, etc. This is not limited in the present application. In addition, the information format of one or more pieces of information included in various messages described in other embodiments is not limited in the present application, and will not be described in detail below.

[0130] S702: The MN sends an SN addition request message to at least one candidate SN to which the L candidate PSCells belong. Note that in FIG. 7, an example is used in which at least one candidate SN is a first candidate SN and a second candidate SN is used. In actual implementation, the MN may send an SN addition request message to more or fewer candidate SNs, and the candidate SN may be determined based on the L candidate PSCells or may be determined by the MN. This is not limited in the present application. For example, the MN determines one or more candidate SNs to which the L candidate PSCells belong in response to an SN change request message sent by the source SN.

[0131] The SN addition request message is used to request the addition of a candidate SN. In this way, the candidate SN can allocate radio resources of the candidate PSCell to the UE in response to the SN addition request message. For example, the SN addition request message sent by the MN to the first candidate SN is used as an example and may include, but is not limited to, one or more of the following information:

[0132] (1) At least one recommended candidate PSCell. For example, the candidate PSCells transmitted by the MN to a first candidate SN may include PSCell 1 and PSCell 3 belonging to the first candidate SN. In another example, the candidate PSCells transmitted by the MN to a second candidate SN may include PSCell 2 and PSCell 4 belonging to the second candidate SN. It will be understood that based on information about the L candidate PSCells determined by the MN or recommended by the source SN, the MN may separately transmit SN addition request messages to the candidate SNs in which the candidate PSCells are located.

[0133] (2) First information corresponding to at least one recommended candidate PSCell. For example, the first information may include one or more of an execution trigger condition and measurement configuration information.

[0134] It will be understood that the MN may send one or more of the acquired candidate PSCell, the corresponding execution trigger condition, and the measurement configuration information to the candidate SN. In this way, the candidate SN may update / modify one or more information in the execution trigger condition and the measurement configuration information based on the SN addition request message sent by the MN.

[0135] S703: The first candidate SN and the second candidate SN each return an SN addition request confirmation message to the MN. The SN addition request confirmation message indicates that each candidate SN responds separately to the SN addition request message from the MN. The SN addition request confirmation message returned by the first candidate SN is used as an example and may include one or more of the following information:

[0136] (1) First information corresponding to at least one prepared candidate PSCell. The at least one prepared candidate PSCell may be understood as a candidate PSCell that is determined by a first candidate SN and that may be allowed to be accessed by a UE. Optionally, when an SN addition request message received by the first candidate SN from an MN includes at least one recommended candidate PSCell, the first candidate SN may sequentially determine at least one recommended candidate PSCell and feed back to the MN the candidate PSCell that is determined to be allowed to be accessed by the UE, as well as execution trigger conditions and measurement configuration information corresponding to the one or more candidate PSCells.

[0137] (2) A second RRC message corresponding to at least one prepared candidate PSCell. For example, the second RRC message may include an SCG configuration and second information corresponding to one or more candidate PSCells. The second information may also include one or more of an execution trigger condition and measurement configuration information for the candidate PSCell. It will be understood that one or more candidate PSCells included in the second RRC message are determined for each prepared candidate PSCell. For example, if the prepared candidate PSCell is PSCell 1, one or more candidate PSCells included in the second RRC message for PSCell 1 may be understood as neighbor cells of PSCell 1. For example, the neighbor cells may include PSCell 2, PSCell 3, ..., and PSCell L.

[0138] For example, the second RRC message corresponding to each candidate PSCell indicates updating the CPC configuration applied by the UE to accurately perform continuous CPC after the UE accesses the candidate PSCell. For example, PSCell 1 is used as an example, and the second RRC message corresponding to PSCell 1 may include an execution trigger condition for the candidate PSCell. In the second RRC message, the execution trigger condition for the candidate PSCell indicates an execution trigger condition for handover from PSCell 1 to PSCell 2, or PSCell 3, ..., or PSCell L.

[0139] In this embodiment of the present application, the second information included in the second RRC message may be a complete information scheme or an incremental information scheme. In this embodiment, the implementation of incremental information is described first. It should be understood that when the incremental information scheme is used, corresponding reference information needs to be further configured. The reference information may be determined by the source SN or the candidate SN. Scheme A1 and Scheme A2 below will be described separately.

[0140] Scheme A1: The reference information may be first information, which is determined by a trigger node (MN or source SN). For example, the reference information may be the first information corresponding to a candidate PSCell and obtained by the MN in the above embodiment description. It should be understood that the first information corresponding to a candidate PSCell is one or more of the execution trigger condition and measurement configuration information of the candidate PSCell and obtained based on the UE's current PSCell (assumed to be PSCell 0). In this case, the candidate SN may directly use the first information of the candidate PSCell received from the MN as reference information.

[0141] Furthermore, the candidate SN may first determine the actual execution trigger conditions of a handover from each candidate PSCell to another candidate PSCell, for example, the execution trigger conditions of a handover from PSCell 1 to PSCell 2 and the execution trigger conditions of a handover from PSCell 1 to PSCell 3. Then, the candidate SN may obtain incremental information of the execution trigger conditions of a handover from each candidate PSCell to another candidate PSCell based on the reference information and the actual execution trigger conditions, which may be understood as the second information corresponding to the candidate PSCell described in the above embodiment. In this way, based on the concept that complete information can be obtained based on the reference information and the incremental information, after receiving the first information corresponding to the candidate PSCell and the second information corresponding to the candidate PSCell, the UE may determine third information corresponding to the candidate PSCell. The third information may indicate the indirectly obtained actual execution trigger conditions of a handover from each candidate PSCell to another candidate PSCell. In addition, message overhead can be reduced based on the incremental information, and the complexity of applying an updated CPC by the UE can be reduced. It will be appreciated that, similar to the first information and the second information, the third message may also include one or more of an execution trigger condition and measurement configuration information.

[0142] For example, candidate PSCell 1 is used as an example. The second RRC message of PSCell 1 may include second information of PSCell 2, second information of PSCell 3, etc. It will be understood that in order for the UE to implement CPC after accessing PSCell 1, the second RRC message of PSCell 1 includes second information corresponding to the candidate PSCells.

[0143] Scheme A2: The reference information may be determined based on the candidate SN. Similar to Scheme 1, when the candidate SN does not receive the first information corresponding to the candidate PSCell from the MN, or even if the candidate SN receives the first information corresponding to the candidate PSCell from the MN, the candidate SN may customize the reference information instead of using the first information from the source SN corresponding to the candidate PSCell as reference information. For example, the candidate SN may customize the reference information and then determine the actual execution trigger condition of a handover from each candidate PSCell to another candidate PSCell. In this way, the candidate SN may indicate the customized reference information to the UE, and the UE may also indirectly obtain the actual execution trigger condition of a handover from each candidate PSCell to another candidate PSCell based on the reference information of each candidate SN and the second RRC message of the candidate PSCell. In addition, different candidate SNs may correspond to different customized reference information.

[0144] Scheme A2: The candidate SN determines the second information in a complete information manner. Similar to Scheme 1, when the candidate SN does not receive the first information corresponding to the candidate PSCell from the MN, or even when the candidate SN receives the first information corresponding to the candidate PSCell from the MN, the candidate SN may customize the reference information without using the first information from the source SN corresponding to the candidate PSCell as reference information. For example, the candidate SN determines an actual execution trigger condition for handover from each candidate PSCell to another candidate PSCell, and the actual execution trigger condition is included in the second information of the second RRC message. In this way, the UE may directly obtain the actual execution trigger condition for handover from each candidate PSCell to another candidate PSCell based on the second RRC message of the candidate PSCell.

[0145] The second message may include one or more of the following information in an incremental information manner:

[0146] (1) Updated measurement identifier information. For example, the measurement ID listed in the execution trigger condition in Table 1 above may be modified.

[0147] (2) Updated measurement events. For example, the measurement events listed in the execution trigger conditions in Table 1 above may be modified.

[0148] (3) Updated measurement objects. For example, the measurement objects listed in the execution trigger conditions in Table 1 above may be modified.

[0149] (4) The information about the P PSCells may be information about identifiers of the P PSCells, information about identifiers of PSCells other than the P PSCells among the M candidate PSCells, or corresponding execution trigger conditions that indicate to the UE to release the P PSCells. The P PSCells are not candidate PSCells for the UE, and P is a positive integer. It can be understood that, because the cell distribution is different, neighboring cells obtained when the UE accesses PSCell 0 may be different from neighboring cells obtained when the UE accesses PSCell 1. For example, candidate PSCells for PSCell 0 may include PSCell 1, PSCell 2, and PSCell 3, and candidate PSCells for PSCell 1 may include PSCell 2. In other words, PSCell 3 may be used as a neighboring cell of PSCell 0 but may not be used as a neighboring cell of PSCell 1. In this scenario, the information about PSCell 3 indicated in the second RRC message of PSCell 1 may indicate that whether the execution trigger condition of PSCell 3 is satisfied is not evaluated, or the execution trigger condition of PSCell 3 may be released, when CPC is performed in a scenario in which the UE accesses PSCell 1. In this way, the UE does not need to evaluate whether the execution trigger condition of an invalid neighbor cell is satisfied when accessing PSCell 1, in order to save overhead.

[0150] The second message may include one or more of the following information in a complete information manner:

[0151] (1) Determine Q candidate primary and secondary cells and set corresponding execution trigger conditions. After the UE accesses the candidate PSCells, the Q candidate primary and secondary cells are the candidate primary and secondary PSCells on which CPC evaluation is performed. For example, the measurement IDs listed in the execution trigger conditions in Table 1 above may be set.

[0152] (2) Set a measurement event. For example, a measurement event listed in the execution trigger conditions in Table 1 above may be set.

[0153] (3) Set the measurement target. For example, the measurement target listed in the execution trigger conditions in Table 1 above may be set.

[0154] S705: The MN sends a first RRC reconfiguration message to the UE. The first RRC reconfiguration message includes first information of the M candidate PSCells, and the first RRC reconfiguration message further includes second RRC messages of the M candidate PSCells. The first information may include, but is not limited to, one or more of an execution trigger condition and measurement configuration information.

[0155] For example, Figure 8 is an example diagram of a first RRC reconfiguration message according to an embodiment of the present application. From Figure 8, it can be seen that the first RRC reconfiguration message may include, but is not limited to, first information corresponding to M candidate PSCells and a second RRC message corresponding to the M candidate PSCells. For example, the first information corresponding to the M candidate PSCells may include an execution trigger condition for a change from PSCell 0 to PSCell 1, an execution trigger condition for a change from PSCell 0 to PSCell 2, ..., an execution trigger condition for a change from PSCell 0 to PSCell M. When the execution trigger condition for PSCell 1 is satisfied, the second RRC message corresponding to PSCell 1 may be applied. The second RRC message may include second information corresponding to the N candidate PSCells. For example, the second information corresponding to PSCell 1 among the M candidate PSCells may include an execution trigger condition for a change from PSCell 1 to PSCell 2, an execution trigger condition for a change from PSCell 1 to PSCell 3, ..., an execution trigger condition for a change from PSCell 1 to PSCell N1. Considering that neighboring cells of PSCell 0 may be different from neighboring cells of PSCell 1, PSCell 1 may include execution trigger conditions for N1 candidate PSCells, where N1 is a positive integer less than or equal to M. Similarly, PSCell 2 may include execution trigger conditions for N2 candidate PSCells, PSCell 3 may include execution trigger conditions for N3 candidate PSCells, and PSCell 4 may include execution trigger conditions for N4 candidate PSCells. The values ​​of N1, N2, N3, and N4 may be determined based on the number of neighboring cells of the corresponding candidate PSCell.

[0156] Additionally, in another optional implementation, the first RRC reconfiguration message may include the reference information described in S703. In another optional implementation, the MN may alternatively indicate the reference information to the UE through a separate RRC reconfiguration message. In this case, it will be understood that the second information in the second RRC message of the M candidate PSCells is obtained in the form of incremental information.

[0157] S706: The UE sends an RRC reconfiguration complete message to the MN. Note that in this case, the UE does not add a candidate PSCell, but continues to determine whether there is a candidate PSCell that satisfies the execution trigger condition. It should be understood that the RRC reconfiguration complete message in this step may indicate that the UE receives the first RRC reconfiguration message.

[0158] Optionally, S707: The MN or the source SN initiates an SN modification procedure (to update incremental second information based on the first information). The MN or the source SN may update one or more of information such as an execution trigger condition, measurement configuration information, and reference information. In this case, the MN may rebroadcast the first RRC reconfiguration message to the UE. Based on this, the UE may evaluate whether the execution trigger condition of the candidate PSCell is satisfied based on the latest first RRC reconfiguration message.

[0159] S708: The UE evaluates candidate PSCells. It should be understood that the UE evaluates whether there is a candidate PSCell that satisfies the corresponding execution trigger condition based on the execution trigger conditions included in the first RRC reconfiguration message and belonging to the M PSCells therein. For example, when the UE detects that PSCell 1 satisfies the corresponding execution trigger condition, the UE applies the second RRC message for PSCell 1. In addition, the UE may further send an RRC reconfiguration complete message to the MN to indicate PSCell 1 or the second RRC message corresponding to PSCell 1 to the MN.

[0160] It will be appreciated that in this embodiment of the present application, the first RRC reconfiguration message further includes and applies a second RRC message for each candidate PSCell, so that when the UE performs the continuous CPC procedure, the CPC configuration applied by the UE can be updated, and the UE can perform accurate CPC to avoid the occurrence of radio link failure problems caused by non-updated information.

[0161] S709: The UE performs a random access procedure with a first candidate SN where the first candidate PSCell is located. An example in which PSCell 1 satisfies the corresponding execution trigger condition is still used. The UE changes access from PSCell 0 to PSCell 1, and performs a random access procedure with the candidate SN where PSCell 1 is located to access PSCell 1. For the random access procedure, please refer to the content defined in the current standard. Details will not be described here.

[0162] S710: The UE continues to evaluate candidate PSCells. It will be understood that the difference from S708 is that the CPC configuration applied by the UE in this case is determined based on the second RRC message of PSCell 1 and is different from the CPC configuration applied in S708. Therefore, in this embodiment of the present application, the UE continues to evaluate candidate PSCells after changing from PSCell 0 to PSCell 1 is performed based on the trigger condition for executing handover from PSCell 1 to each candidate PSCell. Compared with the current communication technology in which the trigger condition for executing handover from PSCell 0 to each candidate PSCell is still used, the present application can improve the accuracy of continuous CPC.

[0163] It will be appreciated that, based on the execution trigger conditions of the N1 PSCells and included in the second RRC message of PSCell 1, the UE evaluates whether there is a candidate PSCell that satisfies the corresponding execution trigger condition. For example, when the UE detects that PSCell 2 satisfies the execution trigger condition that belongs to PSCell 2 and corresponds to the second RRC message of PSCell 1, the UE continues to apply the second RRC message of PSCell 2. It will be appreciated that the UE may further retransmit an RRC reconfiguration complete message to the MN to indicate the second RRC message of PSCell 2 or PSCell 2 to the MN.

[0164] S711: The UE performs a random access procedure with a second candidate SN where the second candidate PSCell is located. An example in which PSCell 2 satisfies an execution trigger condition corresponding to the second RRC message of PSCell 1 is still used. The UE changes from accessing PSCell 1 to accessing PSCell 2, and performs a random access procedure with the candidate SN where PSCell 2 is located to access PSCell 2.

[0165] It will be understood that the UE may continue to further evaluate candidate PSCells based on the second RRC message for PSCell 2. For subsequent procedures, refer to the procedures described in S710 and S711 until the UE detects that the network side indicates to the UE to release the CPC configuration.

[0166] From the content described in embodiment 1, it can be seen that according to the CPC method provided in this embodiment of the present application, the CPC configuration applied by the UE can be updated, so that the execution trigger condition used when the UE performs cell measurement and evaluation can be generated based on the currently accessed serving PSCell. In this way, the accuracy of the continuous CPC performed by the UE can be improved, and the occurrence of radio link failure problems caused by inaccurate CPC configuration can be avoided.

[0167] Embodiment 2 9 is a diagram of an interaction procedure of a CPC method according to an embodiment of the present application. This method can be applied between a UE and a network device, and this method can be applied to a continuous CPC scenario. This method can include the following detailed steps:

[0168] S701: If the SN triggers the procedure, the source SN sends an SN change request message to the MN. If the MN triggers the procedure, S701 is skipped.

[0169] S702: N sends an SN addition request message to at least one candidate SN to which the L candidate PSCells belong.

[0170] S703: The first candidate SN and the second candidate SN each return an SN addition request confirmation message to the MN. Based on the content described in embodiment 1, the candidate SN may generate second information corresponding to the candidate PSCell, which is included in the second RRC message in an incremental information manner or a complete information manner. Embodiment 2 describes an implementation form of the complete information. It should be understood that, compared with the incremental information, the corresponding reference information does not need to be set for the complete information.

[0171] Optionally, when a candidate SN receives the first information corresponding to a candidate PSCell through the SN addition request confirmation message, the candidate SN may determine the actual execution trigger conditions for handover from each candidate PSCell to another candidate PSCell based on the first information or not based on the first information.

[0172] In another optional manner, when a candidate SN does not receive the first information corresponding to a candidate PSCell through the SN addition request confirmation message, the candidate SN may alternatively directly determine the actual execution trigger conditions for handover from each candidate PSCell to another candidate PSCell.

[0173] It will be understood that the second information corresponding to the candidate PSCell and included in the second RRC message corresponding to the candidate PSCell in embodiment 2 is one or more of an actual execution trigger condition and actual measurement configuration information.

[0174] Optionally, in S704, the MN or source SN may initiate the SN modification procedure (to update complete information) to update only the N candidate PSCells indicated in the second RRC message for the candidate PSCell.

[0175] S705: The MN sends a first RRC reconfiguration message to the UE. The first RRC reconfiguration message may include, but is not limited to, first information corresponding to the M candidate PSCells and second RRC messages corresponding to the M candidate PSCells. The second RRC messages corresponding to each candidate PSCell further include second information corresponding to the N candidate PSCells and within the M candidate PSCells.

[0176] S706: The UE sends an RRC reconfiguration complete message to the MN.

[0177] S708: The UE evaluates the candidate PSCell. The subsequent steps use an example in which the UE determines through evaluation that the first candidate PSCell satisfies the execution trigger condition indicated by the first information and included in the first RRC reconfiguration message. It can be understood that the UE applies the second RRC message corresponding to the first candidate PSCell.

[0178] S709: The UE performs a random access procedure with the first candidate SN in which the first candidate PSCell is located.

[0179] S910A: The UE continues to evaluate the candidate PSCell. In the subsequent procedure, an example is used in which the UE determines through evaluation that the second candidate PSCell satisfies the execution trigger condition indicated by the second information and contained in the second RRC message. It will be understood that the UE updates the second RRC message corresponding to the second candidate PSCell.

[0180] S910B: The UE releases one or more of the currently applied execution trigger condition and measurement configuration information. It will be understood based on embodiment 2 that the second information included in the second RRC message and corresponding to the candidate PSCell generated by the candidate SN is implemented based on the complete information. The UE releases the currently applied third information. The second information may be part or all of the first information currently applied by the UE, or may be the second information included in the second RRC message of the first candidate PSCell. The second RRC message of the first candidate PSCell is applied, and the second information included in the second RRC message of the second candidate PSCell is used to evaluate the candidate PSCell, thereby enabling accurate CPC to be implemented.

[0181] S711: The UE performs a random access procedure with a second candidate SN in which the second candidate PSCell is located.

[0182] It should be noted that the implementation process of embodiment 2 is similar to that of embodiment 1, and the details will not be described again here. For details, please refer to the contents described in embodiment 1.

[0183] Embodiment 3 Embodiment 1 and Embodiment 2 describe two optional implementation forms for updating / resetting one or more of the execution trigger condition and the measurement configuration information. In a continuous CPC scenario, the message exchanged between the UE and the network device may further include an SCG configuration. Generally, considering factors such as reducing message overhead, the SCG configuration is usually an incremental configuration. It should be understood that Embodiment 3 can be combined with Embodiment 1 or Embodiment 2, and the specific implementation process will not be described again here.

[0184] 10 is a diagram of an interaction procedure of a CPC method according to an embodiment of the present application. This method can be applied between a UE and a network device, and this method can be applied to a continuous CPC scenario. This method can include the following detailed steps:

[0185] S1001: A source SN sends an SN change request message to an MN. The SN change request message includes a reference configuration, and the reference configuration includes an SCG configuration. For example, the SCG configuration from the source SN may be used as the reference configuration.

[0186] Referring to the description of S701 in the first embodiment, it should be noted that the information format of each piece of information is not limited in this embodiment of the present application. For example, the reference configuration may include only the SCG configuration. As another example, the reference configuration may further include, in addition to the SCG configuration, first information corresponding to the L candidate cells in the first embodiment. The first information includes one or more of an execution trigger condition and measurement configuration information. In this case, it should be understood that the first information included in the reference configuration may also be used as reference measurement configuration information, thereby causing the candidate SN to generate one or more of incremental measurement configuration information and incremental execution trigger conditions.

[0187] In addition, the reference configuration may be a newly added information element in the SN change request message or may be a new message, which is not limited in this application.

[0188] S1002: The MN sends an SN addition request message to at least one candidate SN to which the L candidate PSCells belong. The SN addition request message includes a reference configuration.

[0189] S1003: The first candidate SN and the second candidate SN each return an SN addition request confirmation message to the MN.

[0190] For example, based on the actual SCG configuration corresponding to each candidate PSCell when the candidate SN accesses each candidate PSCell, the reference configuration, and the actual SCG configuration corresponding to each candidate PSCell, the candidate SN may obtain an incremental SCG configuration corresponding to each PSCell. In addition, the candidate SN may also determine an MCG configuration corresponding to each PSCell.

[0191] S1004: The MN sends a first RRC reconfiguration message to the UE. As described in embodiment 1 or embodiment 2, the first RRC reconfiguration message may include, but is not limited to, first information corresponding to the M candidate PSCells and second RRC messages corresponding to the M candidate PSCells. The second RRC messages corresponding to each candidate PSCell further include second information corresponding to the N candidate PSCells and located in the M candidate PSCells.

[0192] In embodiment 3, the first RRC reconfiguration message may further include a reference configuration. Optionally, the reference configuration may include an SCG configuration. In another optional implementation, the reference configuration may further include an SCG configuration and an MCG configuration. The UE may store the reference configuration.

[0193] Based on this, the second RRC message may further include an incremental SCG configuration corresponding to each candidate PSCell, or may further include an incremental SCG configuration and an MCG configuration corresponding to each candidate PSCell.

[0194] S1005: The UE sends an RRC reconfiguration complete message to the MN.

[0195] S1006A: The UE evaluates the candidate PSCell. The subsequent procedure uses an example in which the UE determines through evaluation that the first candidate PSCell satisfies the execution trigger condition indicated by the first information and included in the first RRC reconfiguration message.

[0196] S1006B: The UE applies an incremental configuration in addition to the stored reference configuration. For example, to access a first candidate PSCell, the UE first applies the reference configuration and then applies a second RRC message corresponding to the first candidate PSCell. In this way, the UE may apply a complete SCG configuration corresponding to the first candidate PSCell based on the SCG configuration included in the reference configuration and the incremental SCG configuration indicated in the second RRC message corresponding to the first candidate PSCell. In the SCG configuration implementation process, the UE may also apply a complete MCG configuration corresponding to the first candidate PSCell based on the MCG configuration included in the reference configuration and the MCG configuration indicated in the second RRC message corresponding to the first candidate PSCell.

[0197] S1007: The UE performs a random access procedure with the first candidate SN in which the first candidate PSCell is located.

[0198] S1008A: The UE continues to evaluate the candidate PSCell. In the subsequent procedure, an example is used in which the UE determines through evaluation that the second candidate PSCell satisfies the execution trigger condition indicated by the second information and contained in the second RRC message.

[0199] S1008B: The UE applies an incremental configuration in addition to the stored reference configuration. For example, the UE applies the reference configuration based on the first RRC reconfiguration message, and then applies a second RRC message corresponding to the second candidate PSCell. In this way, the UE may apply a complete SCG configuration corresponding to the second candidate PSCell based on the SCG configuration included in the reference configuration and the incremental SCG configuration indicated in the second RRC message corresponding to the second candidate PSCell. In the SCG configuration implementation process, the UE may also apply a complete MCG configuration corresponding to the second candidate PSCell based on the MCG configuration included in the reference configuration and the MCG configuration indicated in the second RRC message corresponding to the second candidate PSCell.

[0200] S1009: The UE performs a random access procedure with a second candidate SN in which the second candidate PSCell is located.

[0201] From the content described in embodiment 3, it can be seen that according to the CPC method provided in this embodiment of the present application, the CPC configuration applied by the UE can be updated, so that the SCG configuration used when the UE performs cell measurement and evaluation can be generated based on the currently accessed serving PSCell. In this way, the accuracy of the continuous CPC performed by the UE can be improved, and the occurrence of radio link failure problems caused by an inaccurate CPC configuration can be avoided.

[0202] In some other embodiments, Figure 11 is a schematic flow diagram of a CPC method according to an embodiment of the present application. This procedure may include the following steps:

[0203] S1101: A UE receives a first RRC reconfiguration message from a network device, the first RRC reconfiguration message including first information corresponding to M candidate PSCells and a second RRC message, where M is a positive integer, and the second RRC message includes second information corresponding to N candidate PSCells among the M candidate PSCells, the first information and the second information including one or more of an execution trigger condition and measurement configuration information. The network device may be, for example, the MN in the above-mentioned embodiment, or may be another network device.

[0204] S1102: The UE evaluates whether the execution trigger conditions of the M candidate PSCells are satisfied based on the first information.

[0205] S1103: When the UE determines through evaluation that the execution trigger condition of a first candidate PSCell among the M candidate PSCells satisfies the execution trigger condition, the UE applies a second RRC message corresponding to the first candidate PSCell.

[0206] For the implementation process of Figure 11, please refer to the contents described in Figures 7 to 10. The details will not be described again here.

[0207] Based on the same inventive concept as the method embodiment, one embodiment of the present application provides a communication device (which may also be referred to as a "CPC device"). The structure of the communication device may be shown in Figure 12. The communication device includes a transceiver unit 1201 and a processing unit 1202.

[0208] In certain implementations, the communication device may be specifically configured to implement the methods performed by the UE in the embodiments of Figures 7-11. The device may be a UE, or may be part of a chip or chipset within the UE, or a chip configured to perform the relevant method functions. The transceiver unit 1201 is configured to receive and transmit messages. The processing unit 1202 is configured to control the transceiver unit 1201 to perform the following operations: receiving a first RRC reconfiguration message from a network device, where the first RRC reconfiguration message includes first information and a second RRC message corresponding to M candidate PSCells, where M is a positive integer, and the second RRC message includes second information corresponding to N candidate PSCells among the M candidate PSCells, where the first information and the second information include one or more of an execution trigger condition and measurement configuration information; and evaluating whether the execution trigger condition of the M candidate PSCells is satisfied based on the first information, where when it is determined through the evaluation that the execution trigger condition of a first candidate PSCell among the M candidate PSCells satisfies the execution trigger condition, the UE applies the second RRC message corresponding to the first candidate PSCell.

[0209] In one possible design, after being configured to apply the second RRC message corresponding to the first candidate PSCell, the processing unit 1202 is further configured to evaluate, based on the second information, whether execution trigger conditions for the N candidate PSCells are met.

[0210] In one possible design, after being configured to apply the second RRC message corresponding to the first candidate PSCell, the processing unit 1202 is further configured to: determine third information corresponding to the N PSCells based on the first information and the second information, where the third information includes one or more of an execution trigger condition and measurement configuration information; and evaluate whether the execution trigger condition of the N candidate PSCells is satisfied based on the third information.

[0211] In one possible design, the second RRC message further includes first indication information, where the first indication information indicates that when the UE accesses the first candidate PSCell, it should not evaluate whether the execution trigger conditions of the P candidate PSCells are met, and the M candidate PSCells include the P candidate PSCells.

[0212] In one possible design, the first RRC reconfiguration message further includes a reference configuration, where the reference configuration includes a secondary cell group (SCG) configuration and a master cell group (MCG) configuration. The second RRC reconfiguration message further includes SCG configurations corresponding to the N candidate PSCells. The processing unit 1202 is configured to apply the second RRC message corresponding to the first candidate PSCell and is particularly configured to obtain the MCG configuration and the SCG configuration corresponding to the first candidate PSCell based on the reference configuration and the second RRC message.

[0213] In one possible design, the second RRC reconfiguration message further includes MCG configurations corresponding to the N candidate PSCells.

[0214] In one possible design, the first information is included in a reference configuration.

[0215] In another specific implementation, a communication device may be specifically configured to implement the methods performed by the network devices in the embodiments of Figures 7 to 11. The device may be the network device, or a chip or chipset within the network device, or part of a chip configured to perform the functions of the associated method. For example, the network device may be the primary base station of the aforementioned embodiment. The transceiver unit 1201 is configured to receive and transmit messages. The processing unit 1202 is configured to control the transceiver unit 1201 to perform the following operations: receiving a first message from a source secondary base station, where the first message includes identifiers of L candidate PSCells and corresponding first information, where L is a positive integer; sending a second message to at least one candidate secondary base station, where the second message is used to request adding a secondary base station; receiving a second RRC message corresponding to M candidate PSCells from the at least one candidate secondary base station, where M is a positive integer and the second RRC message includes second information corresponding to N candidate PSCells within the M candidate PSCells; and sending a first RRC reconfiguration message to the UE, where the first RRC reconfiguration message includes the first information and the second RRC message corresponding to the M candidate PSCells, where the first information and the second information include one or more of an execution trigger condition and measurement configuration information.

[0216] In one possible design, the second message includes first information corresponding to the L candidate PSCells, and the first information is used by the at least one candidate secondary base station to determine the second information.

[0217] In one possible design, the first message includes a first reference configuration, and the first reference configuration includes an SCG configuration.

[0218] In one possible design, the second message includes a first reference configuration, which is an SCG configuration used by the at least one candidate secondary base station to determine the second RRC message.

[0219] In one possible design, the second RRC reconfiguration message further includes the MCG configuration.

[0220] In one possible design, the first RRC reconfiguration message further includes a reference configuration, which includes the first reference configuration and an MCG configuration, and the reference configuration is used by the UE to obtain the MCG configuration and the SCG configuration corresponding to the first candidate PSCell based on the second RRC message.

[0221] In another specific implementation, a communications device may be specifically configured to implement the methods performed by the candidate secondary base stations in the embodiments of Figures 7 to 11. The device may be a candidate secondary base station, or may be part of a chip or chipset within the candidate secondary base station, or a chip configured to perform associated method functions. The transceiver unit 1201 is configured to receive and transmit messages. The processing unit 1202 is configured to control the transceiver unit 1201 to perform the following operations: receive a second message from the primary base station, where the second message is used to request adding a secondary base station; and send a third message to the primary base station, where the third message indicates a second RRC message corresponding to at least one candidate PSCell, where the second RRC message includes second information corresponding to the N candidate PSCells, and where the second information includes one or more of an execution trigger condition and measurement configuration information.

[0222] In one possible design, the second message includes first information corresponding to the L candidate PSCells, the first information being one or more of an execution trigger condition and measurement configuration information, and the first information being used by the candidate secondary base station to determine the second information.

[0223] In one possible design, the second message includes a first reference configuration, the first reference configuration includes an SCG configuration, and the first reference configuration is an SCG configuration used by the candidate secondary base station to determine the second RRC message.

[0224] The division into modules in the embodiments of the present application is merely an example and is a logical division of functions. In actual implementation, other division methods may be used. In addition, the functional modules in the embodiments of the present application may be integrated into one processor, or each module may exist physically alone, or two or more modules may be integrated into one module. The integrated module may be implemented in the form of hardware or in the form of a software functional module. It will be understood that for the functions or implementation methods of the modules in the embodiments of the present application, reference is further made to the relevant descriptions in the method embodiments.

[0225] FIG. 13 is a diagram of the structure of a network device (e.g., MN, or source SN, or candidate SN) according to one embodiment of the present application, e.g., a diagram of the structure of a base station. As shown in FIG. 13, the base station may perform the functions of the MN, source SN, or candidate SN in the method embodiments of FIGS. 7 to 11. The base station 130 may include one or more distributed units (DUs) 1301 and one or more centralized units (CUs) 1302. The DU 1301 may include at least one antenna 13011, at least one radio frequency unit 13012, at least one processor 13013, and at least one memory 13014. The DU 1301 is mainly configured to receive and transmit radio frequency signals, perform conversion between radio frequency signals and baseband signals, and perform some baseband processing. The CU 1302 may include at least one processor 13022 and at least one memory 13021. The CU 1302 and the DU 1301 may communicate with each other through interfaces. The control plane interface may be Fs-C, for example, F1-C, and the user plane interface may be Fs-U, for example, F1-U.

[0226] The CU 1302 is mainly configured to perform baseband processing, control the base station, etc. The DU 1301 and the CU 1302 may be physically co-located or physically separated, i.e., a distributed base station. The CU 1302 is the control center of the base station and may also be called a processing unit, and is mainly configured to implement baseband processing functions.

[0227] Specifically, the baseband processing of the CU and the DU may be divided based on the protocol layers of the wireless network. For example, the functions of the PDCP layer and protocol layers above the PDCP layer are configured in the CU, and the functions of protocol layers below the PDCP layer, such as the RLC layer and MAC layer, are configured in the DU. In another example, the CU implements the functions of the RRC layer and the PDCP layer, and the DU implements the functions of the RLC layer, MAC layer, and physical (PHY) layer.

[0228] Additionally, optionally, the base station 130 may include one or more radio frequency units (RUs), one or more DUs, and one or more CUs. The DU may include at least one processor 13013 and at least one memory 13014, the RU may include at least one antenna 13011 and at least one radio frequency unit 13012, and the CU may include at least one processor 13022 and at least one memory 13021.

[0229] In one example, the CU 1302 may include one or more boards, and the multiple boards may jointly support a radio access network of a single access standard (e.g., a 5G network) or separately support radio access networks of different access standards (e.g., an LTE network, a 5G network, or another network). The memory 13021 and the processor 13022 may serve one or more boards. In other words, the memory and the processor may be located on each board. Alternatively, multiple boards may share the same memory and the same processor. In addition, necessary circuits may be further located on each board. The DU 1301 may include one or more boards, and the multiple boards may jointly support a radio access network of a single access standard (e.g., a 5G network) or separately support radio access networks of different access standards (e.g., an LTE network, a 5G network, or another access network). The memory 13014 and the processor 13013 may serve one or more boards. In other words, the memory and the processor may be located on each board. Alternatively, multiple boards may share the same memory and the same processor, and each board may further include the necessary circuitry.

[0230] FIG. 14 is a diagram of the structure of a UE according to one embodiment of the present application. The UE may perform the functions of the UE in the method embodiments of FIGS. 7 to 11. For ease of explanation, FIG. 14 shows only the main components of the UE. As shown in FIG. 14, the UE 140 includes a processor, a memory, a control circuit, an antenna, and an input / output device. The processor is primarily configured to process communication protocols and communication data, control the entire UE, execute software programs, and process data of the software programs, for example, to support the UE in performing the operations described in the method embodiments in FIGS. 7 to 11. The memory is primarily configured to store software programs and data. The control circuit is primarily configured to convert baseband signals and radio frequency signals and process radio frequency signals. The control circuit and antenna together may be referred to as a transceiver and are primarily configured to receive and transmit radio frequency signals in the form of electromagnetic waves. The input / output device, such as a touchscreen, display, or keyboard, is primarily configured to receive data input by a user and output data to the user.

[0231] After the UE is powered on, the processor can read the software program in the memory, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be transmitted wirelessly, the processor performs baseband processing on the data to be transmitted and then outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then transmits the radio frequency signal to the outside in the form of electromagnetic waves through an antenna. When data is transmitted to the UE, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal to a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal to data and processes the data.

[0232] Those skilled in the art will understand that for ease of explanation, FIG. 14 shows only one memory and only one processor. In an actual UE, there may be multiple processors and multiple memories. The memory may be referred to as a storage medium, a storage device, etc. The memory may be a storage element on the same chip as the processor, i.e., an on-chip storage element, or may be an independent storage element. This is not limited in this embodiment of the present application.

[0233] In one optional implementation, the UE may include a baseband processor and a central processing unit. The baseband processor is primarily configured to process communication protocols and communication data. The central processing unit is primarily configured to control the entire UE, execute software programs, and process data of the software programs. The functions of the baseband processor and the central processing unit may be integrated into the processor in FIG. 14. Those skilled in the art may understand that the baseband processor and the central processing unit may each be an independent processor or may be interconnected using technology such as a bus. Those skilled in the art may understand that the UE may include multiple baseband processors to adapt to various network standards, or multiple central processing units to enhance the UE's processing capabilities. The components of the UE may be connected using various buses. The baseband processor may also be referred to as a baseband processing circuit or a baseband processing chip. The central processing unit may alternatively be referred to as a central processing circuit or a central processing chip. The function of processing communication protocols and communication data may be built into the processor or stored in memory in the form of a software program, and the processor executes the software program to implement the baseband processing function.

[0234] In this embodiment of the present application, an antenna and control circuitry having receiving and transmitting capabilities may be considered, for example, as a transceiver unit 1401 of the UE 140, configured to support the UE in performing receiving and transmitting functions. A processor 1402 having processing capabilities may be considered as a processing unit 1402 of the UE 140. As shown in FIG. 14, the UE 140 includes a transceiver unit 1401 and a processing unit 1402. The transceiver unit may also be referred to as a transceiver, a transceiver machine, a transceiver device, or the like. Optionally, components within the transceiver unit 1401 configured to implement receiving capabilities may be considered receiving units, and components within the transceiver unit 1401 configured to implement transmitting capabilities may be considered transmitting units. In other words, the transceiver unit 1401 includes a receiving unit and a transmitting unit. The receiving unit may be referred to as a receiver, an input port, a receiving circuit, or the like. The transmitting unit may be referred to as a transmitter, a transmission circuit, or the like.

[0235] The processor 1402 may be configured to execute instructions stored in the memory and control the transceiver unit 1401 to receive and / or transmit signals to complete the functions of the UE in the aforementioned method embodiments. The processing unit 1402 further includes an interface configured to implement signal input / output functions. In one implementation, it may be considered that the functions of the transceiver unit 1401 are implemented by using a transceiver circuit or a dedicated transceiver chip.

[0236] An embodiment of the present invention further provides a computer-readable storage medium configured to store computer software instructions that need to be executed for execution of the above-mentioned processor, the computer-readable storage medium including a program that needs to be executed for execution of the above-mentioned processor.

[0237] Those skilled in the art will appreciate that the embodiments of the present application may be provided as a method, a system, or a computer program product. Therefore, the present application may utilize hardware-only, software-only, or a combination of software and hardware. Additionally, the present application may utilize the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0238] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the present application. It will be understood that computer program instructions can be used to implement each process and / or each block in the flowcharts and / or block diagrams, and combinations of processes and / or blocks in the flowcharts and / or block diagrams. These computer program instructions may be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or some other programmable data processing device to create a machine, whereby the instructions executed by the processor of the computer or some other programmable data processing device create an apparatus that implements the particular functionality in one or more processes in the flowcharts and / or one or more blocks in the block diagrams.

[0239] These computer program instructions may be stored in a computer-readable memory that may direct a computer or other programmable data processing device to operate in a particular manner, whereby the instructions stored in the computer-readable memory generate an artifact that includes an instruction apparatus that implements a particular function in one or more processes of the flowcharts and / or one or more blocks of the block diagrams.

[0240] The computer program instructions may alternatively be loaded into a computer or other programmable data processing device and cause a sequence of operations and steps to be performed on the computer or other programmable device, thereby generating a computer-implemented process. Thus, the instructions that execute on the computer or other programmable device provide steps for implementing a particular function in one or more procedures of the flowcharts and / or one or more blocks of the block diagrams.

[0241] It is obvious that those skilled in the art may make various modifications and variations to this application without departing from the spirit and scope of this application. This application intends to cover these modifications and variations of this application as long as they fall within the scope of protection defined by the following claims and their equivalent technologies. [Explanation of symbols]

[0242] 130 base station 140 UE 1201 Transceiver Unit 1202 Processing Unit 1301 Distributed Unit 1302 Centralized Unit 13011 Antenna 13012 Radio Frequency Unit 13013 processor 13014 memory 13021 memory 13022 processor 1401 Transceiver Unit 1402 processor

Claims

1. A conditional primary-secondary cell change CPC method, comprising: receiving, by the UE, a first RRC reconfiguration message from a network device, the first RRC reconfiguration message including first information and second configuration information corresponding to M candidate PSCells, where M is a positive integer, and the second configuration information including second information corresponding to N candidate PSCells among the M candidate PSCells, and the first information and the second information including one or more of an execution trigger condition and measurement configuration information; evaluating, by the UE based on the first information, whether an execution trigger condition of the M candidate PSCells is met; applying, by the UE, second configuration information corresponding to the first candidate PSCell when the UE determines through evaluation that an execution trigger condition of a first candidate PSCell among the M candidate PSCells satisfies the execution trigger condition; A conditional primary-secondary cell change CPC method, including:

2. After the step of applying, by the UE, the second configuration information corresponding to the first candidate PSCell, the method further comprises: evaluating, by the UE based on the second information, whether execution trigger conditions of the N candidate PSCells are met; The method of claim 1 further comprising:

3. After the step of applying, by the UE, the second configuration information corresponding to the first candidate PSCell, the method further comprises: determining, by the UE, third information corresponding to the N PSCells based on the first information and the second information, wherein the third information includes one or more of an execution trigger condition and measurement configuration information; evaluating, by the UE based on the third information, whether an execution trigger condition of the N candidate PSCells is satisfied; The method of claim 1 further comprising:

4. 2. The method of claim 1, wherein the second configuration information further includes first instruction information, the first instruction information indicating not to evaluate whether execution trigger conditions of P candidate PSCells are satisfied when the UE accesses the first candidate PSCell, and the M candidate PSCells comprise the P candidate PSCells.

5. the first RRC reconfiguration message further includes a reference configuration, the reference configuration including a secondary cell group (SCG) configuration and a master cell group (MCG) configuration; the second RRC reconfiguration message further includes an SCG configuration corresponding to the N candidate PSCells; applying, by the UE, the second configuration information corresponding to the first candidate PSCell; 5. The method of claim 1, comprising: obtaining, by the UE, an MCG configuration and an SCG configuration corresponding to the first candidate PSCell based on the reference configuration and the second configuration information.

6. The method of claim 5 , wherein the second configuration information further includes the MCG configuration corresponding to the first candidate PSCell.

7. The method of claim 5 or 6, wherein the first information is included in the reference configuration.

8. The method according to claim 1 , wherein the second configuration information is a second RRC message.

9. 1. A CPC method, comprising: obtaining, by a network device, a first message, the first message including identifiers of L candidate PSCells and corresponding first information, where L is a positive integer; and transmitting, by the network device, a second message to at least one candidate secondary base station, the second message being used to request adding a secondary base station, the first message being determined by the network device or the first message being a message received from a source secondary base station; receiving, by the network device, second configuration information corresponding to M candidate PSCells from the at least one candidate secondary base station, where M is a positive integer, and the second configuration information includes second information corresponding to N candidate PSCells among the M candidate PSCells; sending, by the network device, a first RRC reconfiguration message to a UE, the first RRC reconfiguration message including first information and the second configuration information corresponding to the M candidate PSCells, and the first information and the second information including one or more of an execution trigger condition and measurement configuration information; CPC methods, including:

10. 10. The method of claim 9, wherein the second message includes the first information corresponding to the L candidate PSCells, and the first information is used by the at least one candidate secondary base station to determine the second information.

11. The method of claim 9 , wherein the first message includes a first reference configuration, and the first reference configuration includes an SCG configuration.

12. 10. The method of claim 9, wherein the second message includes the first reference configuration, and the first reference configuration is an SCG configuration used by the at least one candidate secondary base station to determine the second configuration information.

13. The method of claim 12 , wherein the second configuration information further includes an MCG configuration.

14. the first RRC reconfiguration message further includes a reference configuration, the reference configuration including the first reference configuration and the MCG configuration; The method of claim 12 or 13, wherein the reference configuration is used by the UE to obtain an MCG configuration and an SCG configuration corresponding to a first candidate PSCell based on the second configuration information.

15. 15. The method of claim 9, wherein the second configuration information is a second RRC message.

16. 1. A CPC method, comprising: receiving, by the candidate secondary base station, a second message from the primary base station, the second message being used to request adding a secondary base station; sending, by the candidate secondary base station, a third message to the primary base station, the third message indicating second configuration information corresponding to at least one candidate PSCell, the second configuration information including second information corresponding to N candidate PSCells, and the second information including one or more of an execution trigger condition and measurement configuration information; CPC methods, including:

17. 17. The method of claim 16, wherein the second message includes first information corresponding to L candidate PSCells, the first information being one or more of an execution trigger condition and measurement configuration information, and the first information is used by the candidate secondary base station to determine the second information.

18. 17. The method of claim 16, wherein the second message includes a first reference configuration, the first reference configuration includes an SCG configuration, and the first reference configuration is an SCG configuration used by the candidate secondary base station to determine the second configuration information.

19. 19. The method of claim 16, wherein the second configuration information is a second RRC message.

20. A conditional primary-secondary cell change CPC device, the device comprising: a transceiver unit; and a processing unit; the transceiver unit is configured to receive a first RRC reconfiguration message from a network device, the first RRC reconfiguration message including first information and second configuration information corresponding to M candidate PSCells, where M is a positive integer, the second configuration information including second information corresponding to N candidate PSCells among the M candidate PSCells, and the first information and the second information including one or more of an execution trigger condition and measurement configuration information; the processing unit is configured to evaluate whether an execution trigger condition of the M candidate PSCells is satisfied based on the first information; and wherein the processing unit is further configured to: when the UE determines through evaluation that an execution trigger condition of a first candidate PSCell among the M candidate PSCells satisfies the execution trigger condition, the UE applies second configuration information corresponding to the first candidate PSCell.

21. After being configured to apply the second configuration information corresponding to the first candidate PSCell, the processing unit: The apparatus of claim 20 , further configured to: evaluate whether an execution trigger condition of the N candidate PSCells is satisfied based on the second information.

22. After being configured to apply the second configuration information corresponding to the first candidate PSCell, the processing unit: determining third information corresponding to the N PSCells based on the first information and the second information, wherein the third information includes one or more of an execution trigger condition and measurement configuration information; evaluating whether execution trigger conditions of the N candidate PSCells are satisfied based on the third information; 21. The apparatus of claim 20, further configured to:

23. 23. The apparatus of claim 21 or 22, wherein the second configuration information is a second RRC message.

24. A CPC device, a transceiver unit configured to receive and transmit messages; Through said transceiver unit, the following operations are performed: determining a first message or receiving a first message sent by a source secondary base station, the first message including identifiers of L candidate PSCells and corresponding first information, where L is a positive integer; sending a second message to at least one candidate secondary base station, the second message being used to request adding a secondary base station; receiving, from the at least one candidate secondary base station, second configuration information corresponding to M candidate PSCells, where M is a positive integer, and the second configuration information includes second information corresponding to N candidate PSCells among the M candidate PSCells; sending a first RRC reconfiguration message to a UE, the first RRC reconfiguration message including first information and the second configuration information corresponding to the M candidate PSCells, the first information and the second information including one or more of an execution trigger condition and measurement configuration information; a processing unit configured to perform A CPC device comprising:

25. 25. The apparatus of claim 24, wherein the second configuration information is a second RRC message.

26. A CPC device, a transceiver unit configured to receive and transmit messages; Through said transceiver unit, the following operations are performed: receiving a second message from the primary base station, the second message being used to request adding a secondary base station; sending a third message to the primary base station, the third message indicating second configuration information corresponding to at least one candidate PSCell, the second configuration information including second information corresponding to N candidate PSCells, and the second information including one or more of an execution trigger condition and measurement configuration information; a processing unit configured to perform A CPC device comprising:

27. 27. The apparatus of claim 26, wherein the second configuration information is a second RRC message.

28. 20. A communications device comprising a transceiver, a processor, and a memory, wherein the memory stores program instructions that, when executed, enable the communications device to perform a method according to any one of claims 1 to 8, or enable the communications device to perform a method according to any one of claims 9 to 15, or enable the communications device to perform a method according to any one of claims 16 to 19.

29. A chip coupled to a memory in an electronic device such that, when executed, the chip invokes program instructions stored in the memory to implement a method according to any one of claims 1 to 8, or to implement a method according to any one of claims 9 to 15, or to implement a method according to any one of claims 16 to 19.

30. 20. A computer-readable storage medium comprising program instructions that, when executed on a device, enable the device to perform the method of any one of claims 1 to 19.

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