Communication processing method and device, chip and storage medium

Abstract

Disclosed are a communication processing method and apparatus, a chip and a storage medium, the method comprising: receiving a radio resource control (RRC) reconfiguration message, the RRC reconfiguration message comprising pre-configuration information of a second primary network device or a second secondary network device; receiving a layer 1 / layer 2 trigger mobility LTM switching command, wherein the LTM switching command is used for indicating switching from the first main network equipment to the second main network equipment or switching from the first auxiliary network equipment to the second auxiliary network equipment; determining a change in a bearer type based on the RRC reconfiguration message and the LTM handover command; on the basis of the determined change in the bearer type, the processing of Layer 2 is executed. According to the method provided by the invention, the terminal equipment performs processing of a layer 2 based on the change of the bearing type, thereby facilitating protocol stack reconstruction based on bearing change adaptability in a dual-connection LTM process, facilitating realization of continuity of data transmission, reducing service interruption and improving LTM efficiency under dual connection.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication processing method, device, chip and storage medium. Background Art

[0002] In a wireless communication system, when a user equipment (UE) is in a service connection state and maintains service, it moves from one cell to another. In order to ensure the continuity of UE communication, cell switching is required.

[0003] At present, in the fifth-generation mobile communication technology (5th-generation, 5G) radio access network (RAN) architecture, and in the base station deployment with separation of centralized unit (CU) and distributed unit (DU), in order to reduce the switching delay and further enhance the service continuity, the 5G system considers using layer 1 / layer 2 (L1 / L2) triggered mobility (L1 / L2-triggered mobility, LTM). Among them, layer 1 includes the physical (physical layer, PHY) layer, and layer 2 includes the radio link control (radio link control, RLC) layer, the media access control (media access control, MAC) layer and the packet data convergence protocol (packet data convergence protocol, PDCP) layer.

[0004] In the dual-connectivity (DC) scenario, the terminal device can communicate with multiple access network devices, such as the terminal device can simultaneously communicate with the master cell group (MCG) on the MN (master node) and the secondary cell group (SCG) on the SN (secondary node). At present, how to improve the efficiency of LTM switching under dual connectivity has become an urgent problem to be solved. Summary of the invention

[0005] The embodiments of the present application provide a communication processing method, device, chip and storage medium. Based on the method described in the present application, the protocol stack can be rebuilt based on the adaptability of bearer changes, which is conducive to achieving the continuity of data transmission, reducing service interruptions, and improving the efficiency of LTM under dual connections.

[0006] In a first aspect, the present application provides a communication processing method, applied to a terminal device, the method comprising: receiving a radio resource control RRC reconfiguration message, the RRC reconfiguration message including pre-configuration information of one or more second primary network devices or one or more second secondary network devices; receiving a layer 1 / layer 2 triggered mobility LTM switching command, the LTM switching command being used to indicate switching from a first primary network device to one of one or more second primary network devices, or indicating switching from a first secondary network device to one of one or more second secondary network devices; determining a change in bearer type based on the RRC reconfiguration message and the LTM switching command; and performing layer 2 processing based on the determined change in bearer type.

[0007] Based on the method described in the first aspect, the terminal device can determine the change of the bearer type based on the RRC reconfiguration message and the LTM switching command by receiving the pre-configuration information of the target network device, and execute layer 2 processing based on the change of the bearer type. This is beneficial to rebuild the protocol stack based on the adaptability of bearer changes during the dual-connection LTM process, which is beneficial to achieving continuity of data transmission, reducing service interruptions, and improving the efficiency of LTM under dual connections.

[0008] In one possible implementation, an RRC reconfiguration message and an LTM switching command are received from a first main network device, the RRC reconfiguration message includes pre-configuration information of one or more second main network devices, the LTM switching command indicates switching from the first main network device to one of the one or more second main network devices, and the method also includes: receiving first indication information from the first main network device, the first indication information is used to indicate a processing strategy for the secondary cell group SCG configuration in the LTM, the processing strategy including retaining or releasing the SCG configuration; determining a change in the bearer type based on the RRC reconfiguration message and the LTM switching command, including: determining a change in the bearer type based on the RRC reconfiguration message, the LTM switching command and the first indication information.

[0009] Based on this implementation method, the change of bearer type can be determined according to the processing strategy indication information of the SCG configuration. There is no need to wait for LTM to determine whether the SCG configuration is to retain or release and determine the change of growth type. This is conducive to timely L2 processing and reconstruction of the protocol stack, which is conducive to achieving data transmission continuity, reducing service interruptions, and improving the efficiency of LTM under dual connections.

[0010] In a possible implementation, the first indication information is carried by any one of the following signalings: RRC signaling; downlink control information DCI signaling; physical downlink control channel PDCCH signaling; physical downlink shared channel PDSCH signaling.

[0011] In a possible implementation, the first indication information instructs the LTM to retain the SCG configuration and perform layer 2 processing, including: performing layer 2 processing corresponding to the main cell group MCG and SCG.

[0012] Based on this implementation, the protocol stack can be adaptively rebuilt according to the change of the bearer type during the LTM switching process to ensure the continuity of data transmission.

[0013] In a possible implementation, the first indication information instructs the LTM to release the SCG configuration and execute layer 2 processing, including: executing layer 2 processing corresponding to the MCG.

[0014] Based on this implementation, the protocol stack can be adaptively rebuilt according to the change of the bearer type during the LTM switching process to ensure the continuity of data transmission.

[0015] In one possible implementation, an RRC reconfiguration message and an LTM switching command are received from a first primary network device or a first secondary network device, the RRC reconfiguration message includes preconfiguration information of one or more second secondary network devices, the LTM switching command indicates switching from the first secondary network device to one of the one or more second secondary network devices, and performing layer 2 processing, including: performing layer 2 processing corresponding to the SCG.

[0016] Based on this implementation, the protocol stack can be adaptively rebuilt according to the change of the bearer type during the LTM switching process to ensure the continuity of data transmission.

[0017] In a possible implementation, the pre-configuration information includes a bearer type configuration, and the bearer type includes at least one of the following items: a main cell group MCG bearer; a secondary cell group SCG bearer; a split bearer.

[0018] In one possible implementation, the change of bearer type includes at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

[0019] In a possible implementation, the processing of layer 2 includes at least one of the following: medium access control MAC layer resetting; radio link control RLC layer reestablishment; packet data convergence protocol PDCP layer reestablishment.

[0020] In the second aspect, the present application provides a communication processing method, which is applied to a first main network device or a first auxiliary network device, and the method includes: sending a radio resource control RRC reconfiguration message to a terminal device, the RRC reconfiguration message includes pre-configuration information of one or more second main network devices or one or more second auxiliary network devices; sending a layer 1 / layer 2 triggered mobility LTM switching command to the terminal device, the LTM switching command is used to indicate switching from the first main network device to one of one or more second main network devices, or to indicate switching from the first auxiliary network device to one of one or more second auxiliary network devices.

[0021] Based on the method described in the second aspect, by sending an RRC reconfiguration message and an LTM switching command including pre-configuration information of the target network device to the terminal device, the terminal device is facilitated to determine the change of the bearer type based on the RRC reconfiguration message and the LTM switching command, and execute layer 2 processing based on the change of the bearer type, which is conducive to rebuilding the protocol stack based on the adaptability of bearer changes during the dual-connection LTM process, and is conducive to achieving continuity of data transmission, reducing service interruptions, and improving the efficiency of LTM under dual connections.

[0022] In a possible implementation, the pre-configuration information includes a bearer type configuration, and the bearer type includes at least one of the following items: a main cell group MCG bearer; a secondary cell group SCG bearer; a split bearer.

[0023] In one possible implementation, the RRC reconfiguration message includes pre-configuration information of one or more second main network devices, and the LTM switching command is used to indicate switching from the first main network device to one of the one or more second main network devices. The method also includes: sending first indication information to the terminal device, and the first indication information is used to indicate the processing strategy for the secondary cell group SCG configuration in the LTM, and the processing strategy includes retaining or releasing the SCG configuration.

[0024] Based on this implementation method, the processing strategy indication information of the SCG configuration can be used to indicate the change of the bearer type to the terminal device, so that the terminal device does not need to wait for LTM to determine whether the SCG configuration is to retain or release and determine the change of the growth type. This is conducive to timely L2 processing and reconstruction of the protocol stack, which is conducive to achieving data transmission continuity, reducing service interruptions, and improving the efficiency of LTM under dual connections.

[0025] In a possible implementation, the first indication information is carried by any one of the following signalings: RRC signaling; downlink control information DCI signaling; physical downlink control channel PDCCH signaling; physical downlink shared channel PDSCH signaling.

[0026] In a possible implementation, the first indication information is determined based on a measurement report received from the terminal device, wherein the measurement report includes a layer 3 measurement report and / or a layer 1 measurement report.

[0027] Based on this implementation method, the source main network device can flexibly determine the processing strategy of the SCG configuration, which is conducive to flexible configuration of the dual connection of the terminal device according to the communication environment.

[0028] In one possible implementation, the method also includes: sending first processing information to one of one or more second main network devices, the first processing information is used to indicate a processing strategy regarding the SCG configuration in the LTM, and the processing strategy regarding the SCG configuration indicated by the first processing information is the same as the processing strategy regarding the SCG configuration indicated by the first indication information.

[0029] Based on this implementation method, the target main network device can be instructed about the processing strategy of the SCG configuration, which is conducive to the target main network device to configure the auxiliary network device in time and is conducive to improving the efficiency of LTM under dual connection.

[0030] In a possible implementation manner, the first processing information is transmitted through an Xn interface.

[0031] In a possible implementation, the first indication information is determined based on an LTM switching request response received from one or more second master network devices, where the LTM switching request response includes an indication of a processing policy configured for the SCG.

[0032] In a possible implementation, the method further includes: sending second indication information to one of the one or more second primary network devices, the second indication information is used to indicate a target cell for switching, and the target cell is determined based on a layer 1 measurement report received from the terminal device.

[0033] Based on this implementation method, the source main network device can determine the cell to which the terminal device wants to switch according to the communication environment, and indicate the target cell to the target main network device, which is conducive to the target main network device to configure the auxiliary network device in a timely manner and is conducive to improving the efficiency of LTM under dual connection.

[0034] In a possible implementation manner, the method further includes: sending third indication information to the secondary network device SN, where the third indication information is used to indicate updating of the SN configuration.

[0035] Based on this implementation, the primary network device can instruct the secondary network device to update the configuration of the terminal device, which is beneficial to improving the efficiency of LTM under dual connections.

[0036] In one possible implementation, the third indication information indicates at least one of the following items: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

[0037] In a possible implementation, the method further includes: sending fourth indication information, where the fourth indication information is used to indicate status information of the SCG configuration after LTM.

[0038] Based on this implementation method, it is beneficial for all candidate network devices in the communication system to update the status of the SCG-related configuration of the terminal device, thereby avoiding possible failures or errors in the subsequent LTM due to inconsistent status of the SCG configuration.

[0039] In one possible implementation, the RRC reconfiguration message includes pre-configuration information of one or more second auxiliary network devices, the LTM switching command is used to indicate switching from the first auxiliary network device to one of the one or more second auxiliary network devices, and the method also includes: sending fifth indication information to the main network device MN, and the fifth indication information is used to indicate an update to the MN configuration.

[0040] Based on this implementation, the auxiliary network device can notify the primary network device about the terminal device update configuration, which is beneficial to improving the efficiency of LTM under dual connection.

[0041] In a possible implementation manner, sending a radio resource control (RRC) reconfiguration message to a terminal device includes: sending the RRC reconfiguration message to the terminal device via a MN.

[0042] In one possible implementation, the fifth indication information indicates at least one of the following items: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

[0043] In the third aspect, the present application provides a communication processing method, which is applied to a second main network device, and the method includes: receiving a layer 1 / layer 2 triggered mobility LTM switching request from a first main network device; sending an LTM switching request response to the first main network device, the LTM switching request response including pre-configuration information; determining a processing strategy for a secondary cell group SCG configuration in the LTM, the processing strategy including retaining or releasing the SCG configuration; based on the processing strategy of the SCG configuration, sending an SN add request or a terminal device context release request to the secondary network device SN.

[0044] Based on the method described in the third aspect, the target main network device can determine the processing strategy for the SCG configuration, and configure the auxiliary network device in a timely manner according to the corresponding processing strategy, which is conducive to improving the efficiency of LTM under dual connections.

[0045] In a possible implementation, the pre-configuration information includes a bearer type configuration, and the bearer type includes at least one of the following items: a main cell group MCG bearer; a secondary cell group SCG bearer; a split bearer.

[0046] In a possible implementation, the method further includes: the processing strategy of the SCG configuration is determined based on first processing information received from the first master network device, and the first processing information is used to indicate the processing strategy regarding the SCG configuration in the LTM.

[0047] In a possible implementation manner, the first processing information is transmitted through an Xn interface.

[0048] In one possible implementation, the processing strategy configured by the SCG is preconfigured, or determined in response to an LTM switching request received from a first main network device, and based on the processing strategy configured by the SCG, an SN addition request or a terminal device context release request is sent to the secondary network device SN, including: receiving second indication information from the first main network device, the second indication information is used to indicate a target cell for switching; based on the processing strategy configured by the SCG and the second indication information, an SN addition request or a terminal device context release request is sent to the SN.

[0049] Based on this implementation method, the target primary network device can configure the secondary network device in a timely manner, which is conducive to improving the efficiency of LTM under dual connections.

[0050] In a possible implementation manner, the method further includes: sending third indication information to the SN, where the third indication information is used to indicate updating of the SN configuration.

[0051] Based on this implementation, the target primary network device can instruct the secondary network device to update the configuration of the terminal device, which is beneficial to improving the efficiency of LTM under dual connections.

[0052] In one possible implementation, the third indication information indicates at least one of the following items: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

[0053] In a possible implementation, the method further includes: sending fourth indication information, where the fourth indication information is used to indicate status information of the SCG configuration after LTM.

[0054] Based on this implementation method, it is beneficial for all candidate network devices in the communication system to update the status of the SCG-related configuration of the terminal device, thereby avoiding possible failures or errors in the subsequent LTM due to inconsistent status of the SCG configuration.

[0055] In a fourth aspect, the present application provides a communication device, which may be a terminal device, or a device in a terminal device, or a device that can be used in combination with a terminal device; wherein the communication device may also be a chip system, and the communication device may execute the method executed by the terminal device in the first aspect. The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more units corresponding to the above functions. The unit may be software and / or hardware. The operations and beneficial effects performed by the communication device may refer to the method and beneficial effects of the first aspect above, and the repeated parts will not be repeated.

[0056] In a fifth aspect, the present application provides a communication device, which may be a network device, or a device in a network device, or a device that can be used in combination with a network device; wherein the communication device may also be a chip system, and the communication device may execute the method executed by the network device in the second aspect. The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above functions. The unit may be software and / or hardware. The operations and beneficial effects performed by the communication device may refer to the method and beneficial effects of the second aspect above, and the repeated parts will not be repeated.

[0057] In a sixth aspect, the present application provides a communication device, which may be a network device, or a device in a network device, or a device that can be used in combination with a network device; wherein the communication device may also be a chip system, and the communication device may execute the method executed by the network device in the third aspect. The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above functions. The unit may be software and / or hardware. The operations and beneficial effects performed by the communication device may refer to the method and beneficial effects of the second aspect above, and the repeated parts will not be repeated.

[0058] In a seventh aspect, the present application provides a communication device, which includes a processor. When the processor calls a computer program in a memory, the method performed by a terminal device or a network device in the method of the first aspect, the second aspect, or the third aspect is executed.

[0059] In an eighth aspect, the present application provides a communication device, which includes a processor and a memory, the memory being used to store computer execution instructions; the processor being used to execute the computer execution instructions stored in the memory so that the communication device executes the method executed by a terminal device or a network device in the method of the first aspect, the second aspect, or the third aspect.

[0060] In the ninth aspect, the present application provides a communication device, which includes a processor, a memory and a transceiver, the transceiver is used to receive or send signals; the memory is used to store a computer program; the processor is used to call the computer program from the memory to execute the method executed by the terminal device or network device in the method of the first aspect, the second aspect or the third aspect.

[0061] In the tenth aspect, the present application provides a communication device, which includes a processor and an interface circuit, wherein the interface circuit is used to receive computer execution instructions and transmit them to the processor; the processor runs the computer execution instructions to execute the method performed by the terminal device or network device in the method of the first aspect, the second aspect, or the third aspect.

[0062] In the eleventh aspect, the present application provides a computer-readable storage medium for storing computer-executable instructions, which, when executed, enables a terminal device or a network device to execute a method as in the first aspect, the second aspect, or the third aspect.

[0063] In a twelfth aspect, the present application provides a communication device, which includes a function or unit for executing any method in the first aspect, the second aspect, or the third aspect.

[0064] In a thirteenth aspect, the present application provides a computer program product comprising a computer program, which, when executed, enables the method performed by a terminal device or a network device in the method of the first aspect, the second aspect, or the third aspect to be implemented.

[0065] In a fourteenth aspect, the present application provides a communication system, which includes a terminal device and a network device; wherein the terminal device is used to execute the method of the first aspect above, and the network device is used to execute the method of the second aspect or the third aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is a schematic diagram of the architecture of a communication system under dual connection provided by an embodiment of the present application;

[0067] Figure 2 A schematic diagram of a network architecture of a network device provided in an embodiment of the present application;

[0068] Figure 3 This is a schematic diagram of CU-DU separation of a network device provided in an embodiment of the present application;

[0069] Figure 4 1 is a schematic diagram of a control plane architecture of a communication system supporting dual connections provided in an embodiment of the present application;

[0070] Figure 5 1 is a schematic diagram of a user plane architecture of a communication system supporting dual connectivity provided by an embodiment of the present application;

[0071] Figure 6 1 is a schematic diagram of a user plane architecture of a communication system supporting dual connectivity provided by an embodiment of the present application;

[0072] Figure 7 is a schematic diagram of a dual-connectivity (DC) scenario provided in an embodiment of the present application;

[0073] Figure 8 is a switching interaction schematic diagram provided in an embodiment of the present application;

[0074] Fig. 9 It is a schematic diagram of an interaction of L1 / L2 triggered mobility (LTM) provided in an embodiment of the present application;

[0075] Fig.10 This is a schematic diagram of interaction of L1 / L2 triggered mobility between DUs within a CU provided by an embodiment of the present application;

[0076] Fig.11 This is a schematic diagram of an interaction of intra-CU and intra-DU L1 / L2 triggered mobility provided by an embodiment of the present application;

[0077] Fig.12 This is a schematic diagram of LTM interaction between CUs under dual connection provided in an embodiment of the present application;

[0078] Fig.13 This is a schematic diagram of LTM interaction between CUs under dual connection provided in an embodiment of the present application;

[0079] Fig.14 This is a schematic diagram of LTM interaction between CUs under dual connection provided in an embodiment of the present application;

[0080] Fig.15 This is a schematic diagram of LTM interaction between CUs under dual connection provided in an embodiment of the present application;

[0081] Fig.16 This is a schematic diagram of LTM interaction between CUs under dual connection provided in an embodiment of the present application;

[0082] Fig.17 This is a schematic diagram of LTM interaction between CUs under dual connection provided in an embodiment of the present application;

[0083] Fig.18 It is a flow chart of a communication method provided in an embodiment of the present application;

[0084] Fig.19 It is a flow chart of a communication method provided in an embodiment of the present application;

[0085] Fig. 20 It is a flow chart of a communication method provided in an embodiment of the present application;

[0086] Fig.21 is a structural diagram of a communication device provided in an embodiment of the present application;

[0087] Fig. 22 is a structural diagram of a communication device provided in an embodiment of the present application;

[0088] Fig.23 It is a schematic diagram of the structure of a chip provided in an embodiment of the present application. DETAILED DESCRIPTION

[0089] The terms "first" and "second" and the like in the specification, claims and drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0090] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0091] In the present application, "at least one (item)" means one or more, "more than one" means two or more, "at least two (items)" means two or three and more than three, and "and / or" is used to describe the corresponding relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0092] The terms "including" and "having" and any variations thereof mentioned in the following description of the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes other steps or units that are not listed, or optionally includes other steps or units that are inherent to these processes, methods, products or devices. It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any method or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other methods or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way. In order to better understand the embodiments of the present application, the system architecture involved in the embodiments of the present application is first introduced below:

[0093] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), worldwide interoperability for microwave access (WiMAX) or wireless local area network (WLAN) system, new radio (NR), the 3rd generation partner project (3GPP) service-based network architecture (SBA) and other fifth generation (5G) communication systems or sixth generation (6G) communication systems and other communication systems evolved after 5G.

[0094] Figure 1 Schematic diagram of the architecture of a dual-connection communication system provided in an embodiment of the present application. Figure 1 The communication system shown in FIG. 1 is used as an example to explain in detail the communication system applicable to the embodiment of the present application. It should be noted that the solution in the embodiment of the present application can also be applied to other mobile communication systems, and the corresponding names can also be replaced by the names of corresponding functions in other mobile communication systems.

[0095] like Figure 1 As shown, the communication system includes a terminal device, a master node (MN), a secondary node (SN), and a core network composed of one or more core network elements.

[0096] The terminal device may have a wireless connection with the MN and the SN respectively, that is, the wireless network may communicate with the terminal device in a dual connection manner to provide high-speed data transmission for the terminal device. Depending on the communication standards supported by the MN and the SN, the dual connection may be implemented in a variety of ways, as illustrated below.

[0097] EN-DC (E-UTRA-NR dual connectivity), the terminal device is connected to the evolved Node B (eNB) of LTE as MN and the g Node B (gNB) of NR as SN. Among them, MN is the eNB connected to the fourth generation core network (CN), such as the evolved packet core network (EPC).

[0098] NGEN-DC (next generation E-UTRA-NR dual connectivity), the terminal device is connected to the evolved Node B (evolved Node B, eNB) of the LTE standard as the MN and the g NodeB (gNB) of the NR standard as the SN. The MN is an eNB connected to the fifth generation core network (5th generation core, 5GC), which can also be called the next generation evolved node (next generation-eNB, ng-eNB).

[0099] NE-DC (NR-E-UTRAdual connectivity), the terminal device is connected to the NR standard gNB as MN and the LTE standard eNB as SN. Among them, MN is the gNB connected to 5GC, and SN is the eNB that provides data interaction between the terminal device and 5GC, also known as ng-eNB.

[0100] NR-DC (NR-NR dual connectivity), the terminal device is connected to the NR gNB as MN and the NR gNB as SN. The MN is connected to the gNB of 5GC.

[0101] It should be understood that there may be other implementations of dual connectivity, which are not listed one by one in the embodiments of the present application.

[0102] Generally speaking, MN can also be called a primary network device, and SN can also be called a secondary network device. This application does not limit the specific names. Figure 1 The network equipment (including main network equipment and auxiliary network equipment) and terminal equipment involved in the communication system are described in detail.

[0103] The network device can provide wireless access services for the terminal device, that is, the network device is an access device that enables the terminal device to access the communication system wirelessly. The network device can be an evolved Node B (eNB or eNodeB) in LTE; or a base station in a 5G network, a broadband network gateway (BNG), an aggregation switch or a non-third generation partnership project (3GPP) access device, etc., which is not specifically limited in the embodiments of the present application. The network device can also be called an access network device, an access node (AN), a radio access node (RAN), etc. Exemplarily, the base station in the embodiments of the present application may include various forms of base stations, such as: macro base stations, micro base stations (also called small stations), relay stations, access points, next-generation base stations (gNodeB, gNB), radio network controllers (radio network controller, RNC), node B (node ​​B, NB), base station controllers (base station controller, BSC), base transceiver stations (base transceiver station, BTS), home base stations (for example, home evolved node B, or home node B, HNB), base band units (base band unit, BBU), transmission and receiving points (transmitting and receiving point, TRP), transmitting points (transmitting point, TP), mobile switching centers, and devices to devices (Device-to-Device, D2D), vehicle external links (vehicle-to-everything, V2X), machine-to-machine (machine-to-machine, M2M) communication, Internet of Things (Internet of Things) communication in the function of base stations, etc., the embodiments of the present application do not specifically limit this. Alternatively, the network device 110 may also be a centralized unit (CU), a distributed unit (DU), a centralized unit control plane (CU control plane, CU-CP) node, or a centralized unit user plane (CU user plane, CU-UP) node.

[0104] It is understood that in the embodiments of the present application, the device for implementing the network device function may be the network device itself, or may be a device that can support the network device to implement the function, such as a chip system or a combination device or component that can implement the network device function, and the device may be installed in the network device. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network device.

[0105] The terminal device includes a device that provides voice and / or data connectivity to the user. For example, the terminal device is a device with wireless transceiver function, which can be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted; it can also be deployed on the water surface (such as ships, etc.); it can also be deployed in the air (such as airplanes, balloons and satellites, etc.). The terminal device can be a mobile phone, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a vehicle-mounted terminal, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a wearable terminal, etc. The embodiments of the present application do not limit the application scenarios. The terminal device 120 may also sometimes be referred to as a terminal, user equipment (UE), mobile station (MS), mobile terminal (MT), access terminal, vehicle terminal, industrial control terminal, UE unit, UE station, mobile station, mobile station, remote station, remote terminal, mobile device, UE terminal, wireless communication device, UE agent or UE device, etc. The terminal device may be fixed or mobile.

[0106] It can be understood that in the embodiments of the present application, all or part of the functions of the terminal device can also be implemented by software functions running on hardware, or by virtualization functions instantiated on a platform (such as a cloud platform). The terminal device in this application can be a terminal for 5G or a 6G terminal, and this application does not limit this. In the embodiments of the present application, the device for implementing the function of the terminal device can be a terminal device, or it can be a device that can support the terminal device to implement the function, such as a chip system or a combination device or component that can implement the function of the terminal device, and the device can be installed in the terminal device.

[0107] It should be noted that Figure 1 This is just a schematic diagram of the architecture of a communication system. The communication system may also include other devices, such as wireless relay devices, wireless backhaul devices, etc. Figure 1 The embodiments of the present application do not limit the number of various devices included in the communication system.

[0108] Figure 2 Schematic diagram of a network architecture of a network device provided in an embodiment of the present application. Figure 2 As shown, the network equipment can also be called access network equipment, and the access network equipment can include a node gNB. The access network equipment can be connected to the core network equipment through the NG interface, and the nodes gNB can be connected through the Xn-C interface. Among them, the gNB can adopt a CU-DU separation structure, and the CU and DU can be connected through the F1 interface.

[0109] Figure 3 Schematic diagram of CU-DU separation of a network device provided in an embodiment of the present application. Figure 3 As shown, the CU includes a radio resource control (RRC) layer and a PDCP layer, and the DU includes a radio link control (RLC) layer, a medium access control (MAC) layer, and a physical layer (PHY). The core network equipment may include an access and mobility management function (AMF) network element and a user plane function (UPF) network element.

[0110] The gNB may also include an active antenna unit (AAU). The CU implements some functions of the gNB, and the DU implements some functions of the gNB. For example, the CU is responsible for processing non-real-time protocols and services. The DU is responsible for processing physical layer protocols and real-time services. The AAU implements some physical layer processing functions, radio frequency processing, and related functions of active antennas. Since the information of the RRC layer will eventually become the information of the PHY layer, or be converted from the information of the PHY layer, therefore, under this architecture, high-level signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or by the DU and the CU. It can be understood that the network device can be a device including one or more of a CU node, a DU node, and an AAU node. In addition, the CU can be divided into a network device in the access network (radio access network, RAN), and the CU can also be divided into a network device in the core network (core network, CN), and this application does not limit this.

[0111] Figure 4 1 is a schematic diagram of a control plane architecture of a communication system supporting dual connectivity provided by an embodiment of the present application. Figure 4 As shown, in dual connectivity, the node that directly interacts with the core network through control plane signaling (through the NG-C interface) is called MN (usually one), and the node that does not directly interact with the core network through control plane signaling is called SN (there can be one or more, Figure 4 Only one is shown in the figure). It should be understood that the SN can implement indirect control plane signaling interaction with the core network through control plane signaling interaction with the MN, such as through the Xn-C interface, that is, the control plane signaling between the SN and the core network can be forwarded by the MN.

[0112] It should be understood that Figure 4 The control plane architecture diagram of the communication system supporting dual connectivity is illustrated by taking the core network as 5GC and the interface between the MN and the SN as the Xn interface as an example. Figure 4 The core network shown in the figure may also be a 4G core network, such as the EPC in the LTE system, and the control plane signaling interaction between the MN and the core network may be performed through the S1-C interface. Optionally, the interface between the MN and the SN may also be an X2 interface, and the control plane signaling interaction between the SN and the MN may be performed through the X2-C interface. The embodiment of the present application does not specifically limit the implementation method of the core network and the implementation method of the interface between the MN and the SN.

[0113] In addition, the control plane signaling interaction between the terminal device and the MN and SN can be performed through the Uu interface. Figure 4As shown, in the dual link, both MN and SN have radio resource control (RRC) layer entities, and can generate control plane signaling, that is, various RRC messages, such as RRC establishment / re-establishment messages, RRC configuration / re-configuration messages, RRC release messages, measurement request messages, etc. Among them, MN can directly send RRC messages generated by MN to the terminal device through the Uu port. The terminal device can also directly send RRC messages generated by the terminal device to MN through the Uu port, such as RRC establishment / re-establishment completion messages, RRC configuration / re-configuration completion messages, and measurement reports.

[0114] Optionally, the SN may directly send an RRC message generated by the SN to the terminal device through the Uu port. At this time, the terminal device may also directly send an RRC message generated by the terminal device to the SN through the Uu port, such as an RRC establishment / re-establishment completion message, an RRC configuration / reconfiguration completion message, and a measurement report. Alternatively, optionally, the SN may first send the RRC message generated by the SN to the MN through the control plane interface between the SN and the MN, such as the Xn-C interface or the X2-C interface, and then the MN sends it to the terminal device through the Uu port. Among them, the RRC message directly transmitted between the SN and the terminal device may be carried in, for example, a signaling radio bearer (SRB) 3. The embodiment of the present application does not specifically limit the interaction method of the control plane signaling between the SN and the terminal device.

[0115] Furthermore, in addition to the control plane signaling interaction described above, there is also user plane (CP) data interaction between the MN and the core network, and between the MN and the SN. Optionally, there may also be user plane data interaction between the SN and the core network. The following is an example.

[0116] For example, Figure 5 1 is a schematic diagram of a user plane architecture of a communication system supporting dual connectivity provided by an embodiment of the present application, which is applicable to the dual connectivity architecture of the EN-DC described above. Figure 5As shown, both MN and SN have multiple radio link control (RLC) layer entities and media access control (MAC) layer entities, and the data radio bearer (DRB) in the dual connection may include one or more of MCG bearer, SCG bearer, and split bearer. Among them, MCG bearer means that the RLC layer entity and MAC layer entity of the DRB only exist on MN, SCG bearer means that the RLC layer entity and MAC layer entity of the DRB only exist on SN, and split bearer means that the RLC layer entity and MAC layer entity of the DRB exist on both MN and SN.

[0117] In addition, the bearer whose PDCP is terminated on the MN is called an MN-terminated bearer, that is, the downlink (DL) data reaches the MN directly from the core network, and after being processed by the PDCP layer entity of the MN, it is sent to the terminal device after being processed by the RLC layer entity and MAC layer entity of the MN and / or SN; accordingly, the uplink (UL) data reaches the MN and / or SN from the terminal device, and is sent to the core network after being processed by the PDCP layer entity of the MN.

[0118] Similarly, the bearer whose PDCP terminates on the SN is called an SN terminated bearer, that is, the downlink data reaches the SN directly from the core network, and after being processed by the PDCP layer entity of the SN, it is sent to the terminal device after being processed by the RLC layer entity and MAC layer entity of the MN and / or SN; accordingly, the uplink data reaches the MN and / or SN from the terminal device, and is sent to the core network after being processed by the PDCP layer entity of the SN.

[0119] For example, Figure 6 This is a schematic diagram of a user plane architecture of a communication system supporting dual connectivity provided by an embodiment of the present application, which is applicable to the dual connectivity architectures of the above-mentioned NGEN-DC, NE-DC, and NR-DC, that is, the dual connectivity architecture of the core network being 5GC. Figure 6 As shown, except Figure 5In addition to the above-mentioned protocol layer entities also involved in the present invention, MN and SN also include service data adaptation protocol (SDAP) layer entities. Among them, the SDAP layer entity is used to map the quality of service (QoS) flow (QoS flow) of the core network to the above-mentioned DRBs and send it to the terminal device when the MN or SN exchanges data with the core network, or to map the data carried by the above-mentioned DRBs to the QoS flow and send it to the core network. Regarding the mapping between QoS flows and DRBs, reference can be made to the existing implementation methods, and the embodiments of the present application will not be repeated here.

[0120] In addition, for a terminal device in dual connection, the user plane of the SN may be connected to the core network to which the MN is connected, that is, the core network can exchange data with the terminal device through the SN.

[0121] Figure 7 This is a schematic diagram of a dual-connectivity (DC) scenario provided in an embodiment of the present application. Dual-connectivity or Multi-Radio Dual Connectivity (MR-DC) means that a terminal device can communicate with two network devices at the same time, and one of the two network devices can be an NR network device and the other can be an LTE network device, or both can be NR network devices. One network device is an MN and the other is an SN.

[0122] like Figure 7 As shown, when dual connectivity is combined with carrier aggregation (CA), each network device may include a cell group (CG). Among them, the cell group under the MN is a master cell group (MCG), and the cell group under the SN is a secondary cell group (SCG). The master cell group may include a primary cell (PCell) and at least one secondary cell (SCell), and the secondary cell group may include a primary secondary cell (PSCell) and at least one secondary cell (SCell).

[0123] It should be understood that when dual connectivity is not combined with CA, there is only one primary cell under the MN and only one primary and secondary cell under the SN. This scenario is also applicable to the embodiments of the present application.

[0124] It should be understood that for ease of description, Figure 7The example in which each cell group includes 2 SCells is used for explanation.

[0125] The embodiments of the present application can be applicable to downlink signal transmission, uplink signal transmission, and sidelink communication (such as device-to-device (D2D) signal transmission). For downlink signal transmission, the sending device is a network device, and the corresponding receiving device is a terminal device. For uplink signal transmission, the sending device is a terminal device, and the corresponding receiving device is a network device. For D2D signal transmission, the sending device is a terminal device, and the corresponding receiving device is also a terminal device. The transmission direction of the signal in the embodiments of the present application is not limited.

[0126] The network device and the terminal device can communicate through the licensed spectrum, or through the unlicensed spectrum, or through both the licensed spectrum and the unlicensed spectrum. The network device and the terminal device can communicate through the spectrum below 6 gigahertz (GHz), or through the spectrum above 6 GHz, or through the spectrum below 6 GHz and the spectrum above 6 GHz at the same time. The embodiments of the present application do not limit the spectrum resources used between the network device and the terminal device.

[0127] In the embodiments of the present application, the time domain symbol may be an orthogonal frequency division multiplexing (OFDM) symbol or a discrete Fourier transform spread OFDM (DFT-s-OFDM) symbol. Unless otherwise specified, the symbols in the embodiments of the present application refer to time domain symbols.

[0128] It can be understood that in the embodiments of the present application, the physical downlink shared channel (PDSCH), the physical downlink control channel (PDCCH) and the physical uplink shared channel (PUSCH) are merely examples of downlink data channels, downlink control channels and uplink data channels, respectively. In different systems and different scenarios, data channels and control channels may have different names, and the embodiments of the present application do not limit this.

[0129] The following is a definition of technical terms that may appear in the embodiments of the present application. The terms used in the implementation method of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0130] (1) Cell, source cell, target cell, candidate cell

[0131] The network device may configure or deploy or control at least one cell.

[0132] In a handover scenario, the cell that the terminal device accesses before the handover is called the source cell, and the cell that the terminal device accesses after the handover is called the target cell. The source cell and the target cell may be cells configured by the same network device, or may be cells configured by different network devices.

[0133] For example, the network device is a base station. One example is that the source cell is cell 11 configured by base station 1, and the target cell is cell 12 configured by base station 1. Another example is that the source cell is cell 11 configured by base station 1, and the target cell is cell 21 configured by base station 2.

[0134] For another example, in a CU-DU separation architecture, the network device includes a CU and a DU. In one example, the source cell is cell 11 configured for DU1, and the target cell is cell 12 configured for DU1. In another example, the source cell is cell 11 configured for DU1, and the target cell is cell 21 configured for DU2. DU1 and DU2 may belong to the same CU or different CUs.

[0135] In another example, the terminal may perform a change in the PSCell. In this example, the primary cell under the primary base station may remain unchanged. In one example, the source cell is cell 11 configured by secondary base station 1, and the target cell is cell 12 configured by secondary base station 1. In another example, the source cell is cell 11 configured by secondary base station 1, and the target cell is cell 21 configured by secondary base station 2.

[0136] The candidate cell is also referred to as a switching candidate cell or a target candidate cell or a candidate target cell, and the names are not limited in the embodiments of the present application. In some switching modes, for example, in the L1 / L2-triggered mobility (LTM) process introduced later, the network device can configure at least one candidate cell for the terminal device. In these switching modes, the target cell is a candidate cell in at least one candidate cell.

[0137] (2) Source network device, target network device, candidate network device

[0138] In a switching scenario, the network device that the terminal device communicates with before switching is called the source network device, and the network device that the terminal device communicates with after switching is called the target network device.

[0139] The source network device and the target network device can be the same or different.

[0140] When the source network device and the target network device are the same, it is called intra-network device switching.

[0141] For example, the network device is a base station, the source network device and the target network device are both base station 1, the source cell is cell 11 configured by base station 1, the target cell is cell 12 configured by base station 1, and the handover is an intra-base station handover.

[0142] For another example, the network device includes a CU and a DU. The source network device and the target network device are both DU1, the source cell is cell 11 configured in DU1, the target cell is cell 12 configured in DU1, and the handover is an intra-DU handover.

[0143] For another example, the network device is a secondary base station, the source network device and the target network device are both secondary base station 1, the source cell is cell 11 configured by secondary base station 1, the target cell is cell 12 configured by secondary base station 1, and the handover is an intra-secondary base station handover.

[0144] When the source network device and the target network device are different, it is called inter-network device switching or switching between different network devices.

[0145] For example, the network device is a base station, the source cell is cell 11 configured by base station 1, the source network device is base station 1, the target cell is cell 21 configured by base station 2, the target network device is base station 2, and the switching is an inter-base station switching.

[0146] For another example, the network device includes a CU and a DU. The source cell is cell 11 configured for DU1, the source network device is DU1, the target cell is cell 21 configured for DU2, the target network device is DU2, and the handover is an inter-DU handover. DU1 and DU2 may belong to the same CU or different CUs.

[0147] For another example, the network device is a secondary base station, the source cell is cell 11 configured by secondary base station 1, the source network device is secondary base station 1, the target cell is cell 21 configured by secondary base station 2, the target network device is secondary base station 2, and the handover is an inter-secondary base station handover.

[0148] In some switching modes, such as the L1 / L2 triggered mobility described later, the network device communicates with at least one candidate network device to negotiate at least one candidate cell configured for the terminal device. In these switching modes, the target network device is one of the at least one candidate network device.

[0149] (3) Switch

[0150] In a wireless communication system, when a terminal device moves from one cell to another, or due to network reasons, business load adjustment, equipment failure, etc., the terminal device may leave the source cell and access the target cell to ensure the continuity of communication between the terminal device and the network. The above process is called "handover".

[0151] In one possible implementation, the handover can be controlled by layer 3, namely the RRC layer. Figure 8 , Figure 8 is a schematic diagram of a switching interaction provided by an embodiment of the present application. Figure 8 As shown, the switching process can be as follows:

[0152] 801. The source base station performs measurement configuration on the terminal device, and the terminal device performs measurement according to the measurement configuration and submits a measurement report.

[0153] 802. The source base station makes a handover decision. The source base station may refer to the measurement results reported by the terminal device and / or its own handover algorithm to make a handover decision. For example, when the signal quality of the source cell is poor, but the signal quality of the target cell is good, the source base station determines to perform a handover.

[0154] 803. The source base station sends a handover request message to the target base station. The request message transmits necessary information for handover preparation, which at least includes the target cell identifier, key, the terminal identifier in the source cell, basic access layer configuration, etc.

[0155] 804. The target base station performs admission control.

[0156] 805. The target base station sends a handover request response message to the source base station. If the target base station confirms that the terminal device can access, it replies a handover request response message to the source cell, wherein the handover command sent to the terminal device can be included in the confirmation message in the form of an RRC container.

[0157] 806. The source base station sends an RRC reconfiguration message (or handover command) to the terminal device. The message contains information required for accessing the target cell, including at least the target cell identifier, the new terminal device identifier, the target cell security algorithm identifier, and may also carry dedicated RACH resources for accessing the target cell.

[0158] 807. After receiving the switching command, the terminal device performs synchronization with the target cell, for example, through a random access procedure (RACH).

[0159] 808. The terminal device sends an RRC reconfiguration completion message to the target base station, which is used to confirm the successful completion of the RRC reconfiguration. The RRC reconfiguration completion message includes the information required by the target base station to configure the terminal device after the terminal device accesses, which can help the target base station better configure the resources or measurements of the terminal device.

[0160] (4) L1 / L2 Triggered Mobility (LTM)

[0161] In a possible implementation, the switching can be completed by L1 / L2 triggered mobility. L1 / L2 triggered mobility may also be referred to as L1 / L2 switching, L1 / L2 mobility, lower layer switching, lower layer mobility or L2 triggered mobility, etc., and the embodiments of the present application do not limit the names.

[0162] For scenarios with large amounts of data (such as extended reality (XR) services) or scenarios with frequent switching (such as frequency range 2 (FR2)), in order to reduce switching delay and interruption time and improve the user experience of the terminal, layer 1 / layer 2 triggered mobility is proposed. L1 / L2 triggered mobility instructs the terminal to perform switching through L1 signaling or L2 signaling. Among them, L1 signaling can be downlink control information (DCI), and L2 signaling can be MAC control element (Media Access Control control element, MAC CE).

[0163] The main idea of ​​L1 / L2 triggered mobility is: the network device selects one or more candidate cell configurations based on the measurement report reported by the terminal device, where the measurement report can be a layer 3 (L3) measurement report, and provides the terminal device with one or more candidate cell configuration information through pre-configuration information (which can be included in the RRC reconfiguration message). After receiving the configuration information of L1 / L2 triggered mobility, the terminal device does not perform switching immediately. The source network device determines to trigger L1 / L2 triggered mobility based on the measurement report (such as L1 measurement report) reported by the terminal device. The source network device sends an L1 / L2 triggered mobility cell change (cell switch) command to the terminal device through L1 / L2 signaling, which indicates the target cell identifier or target cell configuration of the terminal device switching, and optionally can also include the target beam information of the target cell. The L1 / L2 triggered mobility cell change command can also be called an L1 / L2 switching command, or an L1 / L2 triggered mobility command, or an L1 / L2 triggered mobility MAC CE / DCI. The terminal device performs the switching process based on the indication in the cell change command.

[0164] Fig. 9 FIG. 1 is a schematic diagram of an interaction of L1 / L2 triggered mobility (LTM) provided in an embodiment of the present application. Fig. 9 As shown, the LTM process can be as follows:

[0165] 901. The terminal device may perform measurement reporting according to the configured candidate cell. The measurement reporting may include any measurement reporting such as layer 1 measurement reporting, layer 2 measurement reporting or layer 3 measurement reporting. The present application does not impose too many restrictions on the method of performing measurement reporting.

[0166] The candidate cell may refer to all neighboring cells that the terminal device can access. The source cell receives the measurement report sent by the terminal device and decides to perform the LTM cell change.

[0167] 902. During the LTM handover preparation, the source cell may send an LTM handover request to the target cell and potential target cell in the candidate cells. The target cell and potential target cell may respond to the LTM handover request of the source cell. The source cell receives the LTM handover request response.

[0168] 903. The source cell may also send the configuration information of the target cell and the potential target cell to the terminal device via an RRC reconfiguration message.

[0169] 904. After receiving the configuration information of the candidate cells, the terminal device can perform downlink synchronization and uplink synchronization for each candidate cell respectively.

[0170] 905. The source cell reports L1 / L2 measurements of the source cell and candidate cells to determine the target cell.

[0171] 906. The source cell sends an LTM switching command to the terminal device. The LTM switching command may be carried in the MAC CE signaling. The MAC CE may include at least the following information: timing advance (TA), transmission configuration indication state (TCI state) identity document (ID), CFRA resource information, and candidate cell configuration information identity. Candidate cell configuration information identity.

[0172] 907. After receiving the MAC CE, the terminal device may disconnect from the source cell, perform a random access procedure, connect to the target cell, and perform data transmission through the target cell.

[0173] 908. Confirm that the LTM cell switching is completed.

[0174] In some implementations, the network device of the source cell and the network device of the target cell may be the same device, or in other words, the source cell and the target cell may be co-located.

[0175] In some implementations, the network device of the source cell and the network device of the target cell may be different devices, or in other words, the source cell and the target cell may not be co-located.

[0176] The handover message and the above-mentioned RRC message indicating the handover are described from different perspectives. The handover message is described from a functional perspective, aiming to express that the message is used to instruct the terminal device to switch. The RRC message is described from the perspective of the message type, aiming to express that the message is a high-level signaling. Among them, the RRC reconfiguration message is an enumeration of RRC messages. In other words, the handover message is sent to the terminal device via high-level signaling.

[0177] Different RRC messages are listed above, such as the RRC connection reconfiguration message in LTE, the RRC reconfiguration message in NR, etc. These messages are only examples for ease of understanding and should not constitute any limitation to this application. This application does not limit the specific name of the handover message used to instruct the terminal device to send a handover process.

[0178] When the network device of the source cell and the network device of the target cell are the same device, L1 / L2 triggered mobility can be limited to the same CU. At this time, the implementation of L1 / L2 triggered mobility includes multiple technical solutions, and the following are exemplary examples, among which:

[0179] Solution 1: L1 / L2 triggered mobility between DUs within a CU (intra-CU inter-DU).

[0180] See also Fig.10 , Fig.10 1 is a schematic diagram of an interaction of L1 / L2 triggered mobility between DUs in a CU provided by an embodiment of the present application. Fig.10 As shown, the process of L1 / L2 triggered mobility between DUs within a CU includes:

[0181] 1001. The terminal device performs measurement according to the measurement configuration and submits a measurement report.

[0182] The measurement configuration and report may be, for example, an L3 measurement configuration and report, and may be configured by a CU.

[0183] 1002. The base station (eg, CU) determines an L1 / L2 triggered mobility configuration decision (or a handover preparation decision). The base station determines to perform L1 / L2 triggered mobility and determines a plurality of candidate DUs.

[0184] 1003. The CU sends an LTM handover request to one or more candidate DUs. The one or more candidate DUs may be DUs to which one or more candidate cells belong.

[0185] 1004. The candidate DU sends a terminal device LTM handover request response to the CU and determines a candidate cell for L1 / L2 triggered mobility. The base station may refer to the reporting result of the terminal device and / or its own handover algorithm to determine the configuration decision or candidate cell.

[0186] If the candidate DU confirms that the terminal device can be connected, it replies to the CU with an LTM handover request response, which may include the configuration information of the candidate cell.

[0187] 1005. The CU sends an RRC reconfiguration message to the source DU, which includes L1 / L2 triggered mobility pre-configuration information. The L1 / L2 triggered mobility pre-configuration information includes configuration information of one or more candidate cells.

[0188] 1006. The source DU sends an RRC reconfiguration message to the terminal device.

[0189] Optionally, the source DU may send the RRC reconfiguration message received from the CU to the terminal device.

[0190] Optionally, the RRC reconfiguration message sent by the source DU to the terminal device may also include configuration information of the source cell.

[0191] The configuration information of each candidate cell may be sent in one of the following ways:

[0192] a) The configuration information of each candidate cell is included in an RRC reconfiguration message. That is, the RRC reconfiguration message sent by the base station to the terminal device in 1005 includes one or more RRC reconfiguration messages, each including the configuration information of one or more candidate cells;

[0193] b) The configuration information of each candidate cell is included in an information element (IE). That is, the RRC reconfiguration message sent by the base station to the terminal device in 1005 includes one or more IEs, each including the configuration information of one or more candidate cells. For example, the IE may be a cell group configuration (CellGroupConfig) IE.

[0194] In some embodiments, the RRC reconfiguration message may be sent directly by the CU to the terminal device. That is, the CU does not send the RRC reconfiguration message to the terminal device via the source DU, but directly sends the RRC reconfiguration message to the terminal device.

[0195] 1007. After receiving the RRC reconfiguration message, the terminal device sends an RRC reconfiguration completion message to the source DU. The RRC reconfiguration completion message is used to confirm the RRC reconfiguration message sent by the source DU in 1006.

[0196] 1008. The source DU sends an RRC reconfiguration completion message to the CU so that the CU confirms that the terminal device has received the RRC reconfiguration message.

[0197] In some embodiments, the RRC reconfiguration completion message may be sent directly by the terminal device to the CU. That is, the terminal device does not send the RRC reconfiguration completion message to the CU via the source DU, but directly sends the RRC reconfiguration completion message to the CU.

[0198] 1009. The terminal device performs L1 measurement based on the L1 measurement configuration and sends an L1 measurement report. The L1 measurement configuration may be included in the RRC reconfiguration message in 1005.

[0199] 1010. The base station (eg, source DU) determines to trigger L1 / L2 triggered mobility based on the L1 measurement report sent by the terminal device.

[0200] 1011. The base station (e.g., source DU) sends an L1 / L2 triggered mobility cell change command, or LTM switching command, to the terminal device. The cell change command may be carried on a MAC CE or DCI. The cell change command indicates the target cell identifier of the terminal device switching, or indicates the target cell configuration identifier of the terminal device switching. The target cell is included in the above-mentioned candidate cells.

[0201] 1012. The terminal device accesses the target cell. The terminal device may perform synchronization with the base station (eg, target DU) to which the target cell belongs. The synchronization process may be implemented through a RACH process or through other processes (eg, RACH-less).

[0202] 1013. Determine that the LTM switching is completed. The terminal device may determine that the LTM switching is completed by sending an RRC reconfiguration completion message to the base station (eg, the target DU).

[0203] In some embodiments, the RRC reconfiguration completion message may be sent by the terminal device to the CU via the target DU. That is, the terminal device first sends the RRC reconfiguration completion message to the target DU, and then the target DU sends the RRC reconfiguration completion message to the CU.

[0204] Solution 2: L1 / L2 triggered mobility within CU and DU (intra-CU intra-DU).

[0205] See also Fig.11 , Fig.11 1 is a schematic diagram of an interaction of L1 / L2 triggering mobility within a CU and within a DU provided in an embodiment of the present application. Fig.11 As shown, the process of triggering mobility of L1 / L2 within CU and DU includes:

[0206] 1101. The terminal device performs measurement according to the measurement configuration and reports a measurement report; the measurement configuration and report may be an L3 measurement configuration and report, and may be configured by the CU.

[0207] 1102. The base station (e.g., CU) determines an L1 / L2 triggered mobility configuration decision (or a handover preparation decision). The base station determines that the L1 / L2 triggered mobility is to be performed, and determines a candidate cell for the L1 / L2 triggered mobility. The base station may refer to the reporting result of the terminal device and / or its own handover algorithm to determine the configuration decision or the candidate cell.

[0208] 1103. The CU sends an RRC reconfiguration message to the DU, which includes L1 / L2 triggered mobility preconfiguration information. The L1 / L2 triggered mobility preconfiguration information includes configuration information of one or more candidate cells.

[0209] 1104.DU sends an RRC reconfiguration message to the terminal device.

[0210] Optionally, the DU may send the RRC reconfiguration message received from the CU to the terminal device.

[0211] Optionally, the RRC reconfiguration message sent by the DU to the terminal device may also include configuration information of the source cell.

[0212] The configuration information of each candidate cell may be sent in one of the following ways:

[0213] a) The configuration information of each candidate cell is included in an RRC reconfiguration message. That is, the RRC reconfiguration message sent by the base station to the terminal device in 1105 includes one or more RRC reconfiguration messages, each including the configuration information of one or more candidate cells;

[0214] b) The configuration information of each candidate cell is included in an IE. That is, the RRC reconfiguration message sent by the base station to the terminal device in 1105 includes one or more IEs, each including the configuration information of one or more candidate cells. For example, the IE may be a cell group configuration IE.

[0215] In some embodiments, the RRC reconfiguration message may be sent directly by the CU to the terminal device. That is, the CU does not send the RRC reconfiguration message to the terminal device via the DU, but directly sends the RRC reconfiguration message to the terminal device.

[0216] 1105. After receiving the RRC reconfiguration message, the terminal device sends an RRC reconfiguration completion message to the DU. The RRC reconfiguration completion message is used to confirm the RRC reconfiguration message sent by the base station in 1105.

[0217] 1006. DU sends an RRC reconfiguration completion message to CU so that CU confirms that the terminal device has received the RRC reconfiguration message.

[0218] In some embodiments, the RRC reconfiguration completion message may be sent directly by the terminal device to the CU. That is, the terminal device does not send the RRC reconfiguration completion message to the CU via the DU, but directly sends the RRC reconfiguration completion message to the CU.

[0219] 1107. The terminal device performs L1 measurement based on the L1 measurement configuration and sends an L1 measurement report. The L1 measurement configuration may be included in the RRC reconfiguration message in 1105.

[0220] 1108. The base station (eg, DU) determines to trigger L1 / L2 triggered mobility based on the L1 measurement report sent by the terminal device.

[0221] 1109. The base station (e.g., DU) sends an L1 / L2 triggered mobility cell change command, or LTM switching command, to the terminal device. The cell change command may be carried on a MAC CE or a DCI. The cell change command indicates the target cell identifier of the terminal device switching, or indicates the target cell configuration identifier of the terminal device switching. The target cell is included in the candidate cells.

[0222] 1110. The terminal device accesses the target cell. The terminal device may perform synchronization with the base station (eg, DU). The synchronization process may be implemented through a RACH process, or through other processes (eg, RACH-less).

[0223] 1111. Determine that the LTM switching is completed. The terminal device may determine that the LTM switching is completed by sending an RRC reconfiguration completion message to the base station (eg, DU).

[0224] In some embodiments, the RRC reconfiguration completion message may be sent by the terminal device to the CU via the DU. That is, the terminal device first sends the RRC reconfiguration completion message to the DU, and then the DU sends the RRC reconfiguration completion message to the CU.

[0225] The network device of the source cell and the network device of the target cell can be different devices, that is, L1 / L2 triggered mobility can occur between different CUs. When L1 / L2 triggered mobility between CUs under dual connectivity, due to changes in base stations and bearers, both the network side and the terminal side in LTM will involve related processing of resource configuration and related processing of the protocol stack.

[0226] In the dual connectivity scenario, L1 / L2 triggered mobility (LTM) between CUs may generally include two scenarios: scenario one is LTM between MNs; scenario two is LTM between SNs.

[0227] The embodiment of the present application further proposes a communication method to ensure the stability and continuity of LTM between CUs under dual connectivity and improve the efficiency of LTM.

[0228] Scenario 1: Inter-MN LTM

[0229] See also Fig.12 , Fig.12 1 is a schematic diagram of LTM interaction between CUs under dual connection provided by an embodiment of the present application. Fig.12 As shown, the LTM process between MNs may include:

[0230] 1201. The terminal device reports the measurement to the source MN.

[0231] The terminal device may perform measurement according to the measurement configuration and report a measurement report; the measurement configuration and report may be an L3 measurement configuration and report, and may be configured by the source MN.

[0232] 1202. The source MN sends an LTM switching request to one or more candidate MNs (including the target MN).

[0233] The source MN may determine one or more candidate MNs for LTM by referring to the reporting results of the terminal device and / or its own switching algorithm. The target MN for subsequent switching may be included in the determined one or more candidate MNs. The one or more candidate MNs may be MNs to which one or more candidate PCells belong.

[0234] 1203. The candidate MN sends an LTM handover request response to the source MN.

[0235] The candidate MN may pre-configure the LTM pre-configuration information of the candidate MN / candidate PCell, and the LTM handover request response may include the LTM pre-configuration information. The LTM pre-configuration information may include configuration information related to measurement reporting, cell identification, handover conditions, and other information, and may also be configured to indicate the configuration information of the layer 2 processing of the terminal after the handover occurs, wherein the layer 2 processing may include MAC layer reset, RLC layer re-establishment, and PDCP layer re-establishment.

[0236] 1204. The source MN sends an RRC reconfiguration message to the terminal device.

[0237] The RRC reconfiguration message may include LTM preconfiguration information received from the candidate MN. The LTM preconfiguration information includes configuration information of one or more candidate MNs.

[0238] In some embodiments, the RRC reconfiguration message includes a bearer type configuration for one or more candidate MNs.

[0239] In some embodiments, the bearer type includes at least one of the following: a primary cell group (MCG) bearer; a secondary cell group (SCG) bearer; a split bearer.

[0240] Optionally, the RRC reconfiguration message may further include configuration information of the source MN, and the configuration information of the source MN may include the bearer type configuration of the source MN.

[0241] In some embodiments, the configuration information of each candidate MN may be included in one RRC reconfiguration message. That is, the RRC reconfiguration message sent by the source MN to the terminal device in 1204 includes one or more RRC reconfiguration messages, each including the configuration information of one or more candidate MNs.

[0242] In some embodiments, the configuration information of each candidate MN may be included in one IE. That is, the RRC reconfiguration message sent by the source MN to the terminal device in 1204 includes one or more IEs, each including the configuration information of one or more candidate MNs.

[0243] 1205. After receiving the RRC reconfiguration message, the terminal device sends an RRC reconfiguration completion message to the source MN. The RRC reconfiguration completion message is used to confirm the RRC reconfiguration message sent by the source MN in 1204.

[0244] 1206. The terminal device reports L1 measurement to the source MN.

[0245] The terminal device may perform L1 measurement based on the L1 measurement configuration and send an L1 measurement report. The L1 measurement configuration may be included in the RRC reconfiguration message in 1204 .

[0246] 1207. The source MN sends an LTM switching command to the terminal device.

[0247] The LTM handover command may be used to instruct handover from a source MN to one of one or more candidate MNs, ie, a target MN.

[0248] The LTM handover command may be carried on a MAC CE or a DCI. The LTM handover command indicates the target cell identifier of the terminal device handover, or indicates the target cell configuration identifier of the terminal device handover. The candidate MNs include the MN to which the target cell belongs, namely, the target MN.

[0249] In some embodiments, the target MN may be determined by the source MN based on a measurement report received from the terminal device, wherein the measurement report may include, for example, the L3 measurement report in 1201 and / or the L1 measurement report in 1206 .

[0250] 1208. The source MN sends first indication information to the terminal device.

[0251] The first indication information is used to indicate the processing strategy regarding the SCG configuration in the LTM, where the processing strategy includes retaining or releasing the SCG configuration.

[0252] In the LTM between MNs, the source MN can indicate to the terminal device through the first indication information whether the SCG configuration is to be retained or released, so that the terminal device can determine the change in bearer type after switching from the source MN to the target MN based on the RRC reconfiguration message, the LTM switching command and the first indication information.

[0253] In some embodiments, the first indication information may be dedicated signaling sent separately as shown in 1208 .

[0254] In some embodiments, the first indication information may be carried by the LTM switching command in 1207, that is, 1207 and 1208 may be one step.

[0255] In some embodiments, the first indication information may be included in the LTM pre-configuration information, for example, 1203 and 1204, and carried by an RRC message, for example, an RRC reconfiguration message.

[0256] In some embodiments, the first indication information may be carried by DCI signaling.

[0257] In some embodiments, the first indication information may be carried by PDCCH signaling.

[0258] In some embodiments, the first indication information may be carried by PDSCH signaling.

[0259] In some embodiments, the first indication information may be determined by the source MN based on a measurement report received from the terminal device, wherein the measurement report may include the L3 measurement report in 1201 and / or the L1 measurement report in 1206 .

[0260] In some embodiments, the first indication information may be determined by the source MN based on LTM handover request responses received from one or more candidate MNs, where the LTM handover request responses include an indication of a processing policy configured by the SCG.

[0261] 1209. The source MN sends first processing information to the target MN, indicating the processing strategy configured by the SCG to the target MN.

[0262] The first processing information is used to indicate the processing strategy for the SCG configuration in the LTM, and the processing strategy includes retaining or releasing the SCG configuration. Moreover, the processing strategy for the SCG configuration indicated by the first processing information is the same as the processing strategy for the SCG configuration indicated by the first indication information in 1208.

[0263] In some embodiments, the first processing information may be transmitted via an Xn interface.

[0264] 1210. The target MN sends an SN add request or a terminal device context release request to the SN based on the processing policy configured by the SCG.

[0265] The target MN may determine the processing strategy regarding the SCG configuration in the LTM according to the received first processing information.

[0266] In some embodiments, the first processing information indicates the release of the SCG configuration, and the target MN may send a terminal device context release request or a release indication of the SCG configuration information to the SN.

[0267] In some embodiments, the first processing information indicates to retain the SCG configuration, and the target MN can perform the SN adding process, that is, send an SN adding request to the SN and receive an SN adding request response from the SN, thereby implementing the adding of the SN.

[0268] In some embodiments, if the first indication information indicates to release the SCG configuration, the source MN may directly send the first processing information to the SN to indicate to release the SCG configuration and to indicate to the SN to release the terminal device context.

[0269] 1211. The terminal device determines the change in bearer type and performs L2 processing.

[0270] The terminal device can determine the change of the bearer type after switching from the source MN to the target MN based on the RRC reconfiguration message and the LTM switching command received from the source MN, and perform L2 processing accordingly.

[0271] In some embodiments, the change of bearer type may include at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer.

[0272] In some embodiments, the L2 processing may include at least one of the following: MAC layer reset; RLC layer re-establishment; PDCP layer re-establishment.

[0273] In some embodiments, if the terminal device also receives first indication information for indicating a processing strategy for SCG configuration in LTM, the terminal device can determine the change in bearer type after switching from the source MN to the target MN based on the RRC reconfiguration message, the LTM switching command and the first indication information, and perform L2 processing.

[0274] In some embodiments, the first indication information indicates that the SCG configuration is retained in the LTM. The terminal device can determine the change in the bearer type corresponding to the MCG in the MN and the SCG in the SN after switching from the source MN to the target MN, and perform L2 processing, including: executing layer 2 processing corresponding to the MCG and SCG.

[0275] In some embodiments, the first indication information indicates that the SCG configuration in the LTM is released. The terminal device can determine that the SCG configuration is no longer retained after switching from the source MN to the target MN. Therefore, it is only necessary to determine the change of the bearer type corresponding to the MCG in the MN and perform L2 processing, including: executing the layer 2 processing corresponding to the MCG.

[0276] In some embodiments, the source MN or the target MN may send third indication information to the SN, where the third indication information is used to instruct to update the SN configuration.

[0277] In some embodiments, the third indication information indicates at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer. Based on this, the SN can be informed of the change of the bearer type in the LTM.

[0278] In some embodiments, the source MN or the target MN may send a fourth indication information, and the fourth indication information is used to indicate the status information of the SCG configuration after LTM. For example, the source MN or the target MN notifies other candidate MNs that the SCG configuration information is released or is in a reserved state, so that the candidate MN updates the status of the SCG-related configuration of the terminal device.

[0279] See also Fig.13 , Fig.13 1 is a schematic diagram of LTM interaction between CUs under dual connection provided by an embodiment of the present application. Fig.13 As shown, the LTM process between MNs may include:

[0280] 1301. The terminal device reports the measurement to the source MN.

[0281] The terminal device may perform measurement according to the measurement configuration and report a measurement report; the measurement configuration and report may be an L3 measurement configuration and report, and may be configured by the source MN.

[0282] 1302. The source MN sends an LTM switching request to one or more candidate MNs (including the target MN).

[0283] The source MN may determine one or more candidate MNs for LTM by referring to the reporting results of the terminal device and / or its own switching algorithm. The target MN for subsequent switching may be included in the determined one or more candidate MNs. The one or more candidate MNs may be MNs to which one or more candidate PCells belong.

[0284] 1303. The candidate MN sends an LTM handover request response to the source MN.

[0285] The candidate MN may pre-configure the LTM pre-configuration information of the candidate MN / candidate PCell, and the LTM handover request response may include the LTM pre-configuration information. The LTM pre-configuration information may include configuration information related to measurement reporting, cell identification, handover conditions, and other information, and may also be configured to indicate the configuration information of the layer 2 processing of the terminal after the handover occurs, wherein the layer 2 processing may include MAC layer reset, RLC layer re-establishment, and PDCP layer re-establishment.

[0286] 1304. The source MN sends an RRC reconfiguration message to the terminal device.

[0287] The RRC reconfiguration message may include LTM preconfiguration information received from the candidate MN. The LTM preconfiguration information includes configuration information of one or more candidate MNs.

[0288] In some embodiments, the RRC reconfiguration message includes a bearer type configuration for one or more candidate MNs.

[0289] In some embodiments, the bearer type includes at least one of the following: a primary cell group (MCG) bearer; a secondary cell group (SCG) bearer; a split bearer.

[0290] Optionally, the RRC reconfiguration message may further include configuration information of the source MN, and the configuration information of the source MN may include the bearer type configuration of the source MN.

[0291] In some embodiments, the configuration information of each candidate MN may be included in one RRC reconfiguration message. That is, the RRC reconfiguration message sent by the source MN to the terminal device in 1304 includes one or more RRC reconfiguration messages, each including the configuration information of one or more candidate MNs.

[0292] In some embodiments, the configuration information of each candidate MN may be included in one IE. That is, the RRC reconfiguration message sent by the source MN to the terminal device in 1304 includes one or more IEs, each including the configuration information of one or more candidate MNs.

[0293] 1305. After receiving the RRC reconfiguration message, the terminal device sends an RRC reconfiguration completion message to the source MN. The RRC reconfiguration completion message is used to confirm the RRC reconfiguration message sent by the source MN in 1304.

[0294] 1306. The terminal device reports L1 measurement to the source MN.

[0295] The terminal device may perform L1 measurement based on the L1 measurement configuration and send an L1 measurement report. The L1 measurement configuration may be included in the RRC reconfiguration message in 1304 .

[0296] 1307. The source MN sends first processing information to the target MN, indicating the processing strategy configured by the SCG to the target MN.

[0297] In some embodiments, the first processing information may be transmitted via an Xn interface.

[0298] In some embodiments, the target MN may be determined by the source MN based on a measurement report received from the terminal device, wherein the measurement report may include, for example, the L3 measurement report in 1301 and / or the L1 measurement report in 1306 .

[0299] 1308. The target MN sends an SN add request or a terminal device context release request to the SN based on the processing policy configured by the SCG.

[0300] The target MN may determine the processing strategy regarding the SCG configuration in the LTM according to the received first processing information.

[0301] In some embodiments, the first processing information indicates the release of the SCG configuration, and the target MN may send a terminal device context release request or a release indication of the SCG configuration information to the SN.

[0302] In some embodiments, the first processing information indicates that the SCG configuration is to be maintained, and the target MN may perform the SN adding process, ie, send an SN adding request to the SN and receive an SN adding request response from the SN, thereby implementing the adding of the SN.

[0303] In some embodiments, if the first indication information indicates to release the SCG configuration, the source MN may directly send the first indication information to the SN to indicate to release the SCG configuration, thereby indicating to the SN to release the terminal device context.

[0304] 1309. The source MN sends an LTM switching command to the terminal device.

[0305] The LTM handover command may be used to instruct handover from a source MN to one of one or more candidate MNs, ie, a target MN.

[0306] The LTM handover command may be carried on a MAC CE or a DCI. The LTM handover command indicates the target cell identifier of the terminal device handover, or indicates the target cell configuration identifier of the terminal device handover. The candidate MNs include the MN to which the target cell belongs, namely, the target MN.

[0307] 1310. The source MN sends first indication information to the terminal device.

[0308] The first indication information is used to indicate the processing strategy for the SCG configuration in the LTM, and the processing strategy includes retaining or releasing the SCG configuration. Moreover, the processing strategy for the SCG configuration indicated by the first processing information is the same as the processing strategy for the SCG configuration indicated by the first indication information in 1208.

[0309] In the LTM between MNs, the source MN can indicate to the terminal device through the first indication information whether the SCG configuration is to be retained or released, so that the terminal device can determine the change in bearer type after switching from the source MN to the target MN based on the RRC reconfiguration message, the LTM switching command and the first indication information.

[0310] In some embodiments, the first indication information may be dedicated signaling sent separately as shown in 1310 .

[0311] In some embodiments, the first indication information may be carried by the LTM switching command in 1309 , that is, 1309 and 1310 may be one step.

[0312] In some embodiments, the first indication information may be included in the LTM pre-configuration information, for example, 1303 and 1304, and carried by an RRC message, for example, an RRC reconfiguration message.

[0313] In some embodiments, the first indication information may be carried by DCI signaling.

[0314] In some embodiments, the first indication information may be carried by PDCCH signaling.

[0315] In some embodiments, the first indication information may be carried by PDSCH signaling.

[0316] In some embodiments, the first indication information may be determined by the source MN based on a measurement report received from the terminal device, wherein the measurement report may include the L3 measurement report in 1301 and / or the L1 measurement report in 1306 .

[0317] In some embodiments, the first indication information may be determined by the source MN based on LTM handover request responses received from one or more candidate MNs, where the LTM handover request responses include an indication of a processing policy configured by the SCG.

[0318] 1311. The terminal device determines the change in bearer type and performs L2 processing.

[0319] The terminal device can determine the change of the bearer type after switching from the source MN to the target MN based on the RRC reconfiguration message and the LTM switching command received from the source MN, and perform L2 processing accordingly.

[0320] In some embodiments, the change of bearer type may include at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer.

[0321] In some embodiments, the L2 processing may include at least one of the following: MAC layer reset; RLC layer re-establishment; PDCP layer re-establishment.

[0322] In some embodiments, if the terminal device also receives first indication information for indicating a processing strategy for SCG configuration in LTM, the terminal device can determine the change in bearer type after switching from the source MN to the target MN based on the RRC reconfiguration message, the LTM switching command and the first indication information, and perform L2 processing.

[0323] In some embodiments, the first indication information indicates that the SCG configuration is retained in the LTM. The terminal device can determine the change in the bearer type corresponding to the MCG in the MN and the SCG in the SN after switching from the source MN to the target MN, and perform L2 processing, including: executing layer 2 processing corresponding to the MCG and SCG.

[0324] In some embodiments, the first indication information indicates that the SCG configuration in the LTM is released. The terminal device can determine that the SCG configuration is no longer retained after switching from the source MN to the target MN. Therefore, it is only necessary to determine the change of the bearer type corresponding to the MCG in the MN and perform L2 processing, including: executing the layer 2 processing corresponding to the MCG.

[0325] In some embodiments, the source MN or the target MN may send third indication information to the SN, where the third indication information is used to instruct to update the SN configuration.

[0326] In some embodiments, the third indication information indicates at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer. Based on this, the SN can be informed of the change of the bearer type in the LTM.

[0327] In some embodiments, the source MN or the target MN may send a fourth indication information, and the fourth indication information is used to indicate the status information of the SCG configuration after LTM. For example, the source MN or the target MN notifies other candidate MNs that the SCG configuration information is released or is in a reserved state, so that the candidate MN updates the status of the SCG-related configuration of the terminal device.

[0328] See also Fig.14 , Fig.14 1 is a schematic diagram of LTM interaction between CUs under dual connection provided by an embodiment of the present application. Fig.14 As shown, the LTM process between MNs may include:

[0329] 1401. The terminal device reports the measurement to the source MN.

[0330] The terminal device may perform measurement according to the measurement configuration and report a measurement report; the measurement configuration and report may be an L3 measurement configuration and report, and may be configured by the source MN.

[0331] 1402. The source MN sends an LTM switching request to one or more candidate MNs (including the target MN).

[0332] The source MN may determine one or more candidate MNs for LTM by referring to the reporting results of the terminal device and / or its own switching algorithm. The target MN for subsequent switching may be included in the determined one or more candidate MNs. The one or more candidate MNs may be MNs to which one or more candidate PCells belong.

[0333] 1403. The candidate MN sends an LTM handover request response to the source MN.

[0334] The candidate MN may pre-configure the LTM pre-configuration information of the candidate MN / candidate PCell, and the LTM handover request response may include the LTM pre-configuration information. The LTM pre-configuration information may include configuration information related to measurement reporting, cell identification, handover conditions, and other information, and may also be configured to indicate the configuration information of the layer 2 processing of the terminal after the handover occurs, wherein the layer 2 processing may include MAC layer reset, RLC layer re-establishment, and PDCP layer re-establishment.

[0335] In some embodiments, the LTM switching request response sent by the candidate MN to the source MN also includes first indication information, where the first indication information is used to indicate a processing strategy regarding the SCG configuration in the LTM, where the processing strategy includes retaining or releasing the SCG configuration.

[0336] In some embodiments, the processing policy configured by the SCG may be pre-configured.

[0337] In some embodiments, since the LTM switching request in 1402 may include terminal device context information, bearer type and data path information, time synchronization and timing information, SCG configuration information, MAC and RLC layer resource information and other information, the processing strategy configured by the SCG may be determined by the candidate MN in response to the LTM switching request received from the source MN in 1402.

[0338] In some embodiments, the processing strategy configured by the candidate MN according to the respective base station SCG is applied to all candidate cells configured by the candidate MN, that is, each candidate MN is configured with the same processing strategy for all candidate cells to which it belongs.

[0339] In some embodiments, the candidate MN configures a processing strategy for each candidate cell to which it belongs.

[0340] 1404. The source MN sends an RRC reconfiguration message to the terminal device.

[0341] The RRC reconfiguration message may include LTM preconfiguration information received from the candidate MN. The LTM preconfiguration information includes configuration information of one or more candidate MNs.

[0342] The RRC reconfiguration message may also include first indication information related to each of the one or more candidate MNs.

[0343] In some embodiments, the RRC reconfiguration message includes a bearer type configuration for one or more candidate MNs.

[0344] In some embodiments, the bearer type includes at least one of the following: a primary cell group (MCG) bearer; a secondary cell group (SCG) bearer; a split bearer.

[0345] Optionally, the RRC reconfiguration message may further include configuration information of the source MN, and the configuration information of the source MN may include the bearer type configuration of the source MN.

[0346] In some embodiments, the configuration information of each candidate MN may be included in one RRC reconfiguration message, that is, the RRC reconfiguration message sent by the source MN to the terminal device in 1404 includes one or more RRC reconfiguration messages, each including the configuration information of one or more candidate MNs.

[0347] In some embodiments, the configuration information of each candidate MN may be included in one IE. That is, the RRC reconfiguration message sent by the source MN to the terminal device in 1404 includes one or more IEs, each including the configuration information of one or more candidate MNs.

[0348] 1405. After receiving the RRC reconfiguration message, the terminal device sends an RRC reconfiguration completion message to the source MN. The RRC reconfiguration completion message is used to confirm the RRC reconfiguration message sent by the source MN in 1404.

[0349] 1406. The terminal device reports L1 measurement to the source MN.

[0350] The terminal device may perform L1 measurement based on the L1 measurement configuration and send an L1 measurement report. The L1 measurement configuration may be included in the RRC reconfiguration message in 1404 .

[0351] 1407. The source MN sends an LTM switching command to the terminal device.

[0352] The LTM handover command may be used to instruct handover from a source MN to one of one or more candidate MNs, ie, a target MN.

[0353] The LTM handover command may be carried on a MAC CE or a DCI. The LTM handover command indicates the target cell identifier of the terminal device handover, or indicates the target cell configuration identifier of the terminal device handover. The candidate MNs include the MN to which the target cell belongs, namely, the target MN.

[0354] In some embodiments, the target MN may be determined by the source MN based on a measurement report received from the terminal device, wherein the measurement report may include, for example, the L3 measurement report in 1401 and / or the L1 measurement report in 1406 .

[0355] 1408. The source MN sends second indication information to the target MN, where the second indication information is used to indicate the target cell for switching.

[0356] In some embodiments, the target cell may be determined based on the L1 measurement report in 1406 .

[0357] 1409. The target MN sends an SN adding request or a terminal device context releasing request to the SN based on the processing strategy configured by the SCG and the second indication information.

[0358] After receiving the second indication information, the target MN can determine the subsequent execution action according to the processing strategy configured by the SCG corresponding to the target cell.

[0359] In some embodiments, the processing strategy of the SCG configuration is to release the SCG configuration, then the target MN sends a terminal device context release request or a release indication of the SCG configuration information to the SN.

[0360] In some embodiments, the processing strategy of the SCG configuration is to retain the SCG configuration, and the target MN can execute the SN adding process, that is, send an SN adding request to the SN and receive an SN adding request response from the SN, thereby realizing the adding of the SN.

[0361] In some embodiments, if the first indication information indicates to release the SCG configuration, the source MN may directly send the first indication information to the SN to indicate to release the SCG configuration, thereby indicating to the SN to release the terminal device context.

[0362] 1410. The terminal device determines the change in bearer type and performs L2 processing.

[0363] The terminal device can determine the change of the bearer type after switching from the source MN to the target MN based on the RRC reconfiguration message and the LTM switching command received from the source MN, and perform L2 processing accordingly.

[0364] In some embodiments, the change of bearer type may include at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer.

[0365] In some embodiments, the L2 processing may include at least one of the following: MAC layer reset; RLC layer re-establishment; PDCP layer re-establishment.

[0366] In some embodiments, if the terminal device also receives first indication information for indicating a processing strategy for SCG configuration in LTM, the terminal device can determine the change in bearer type after switching from the source MN to the target MN based on the RRC reconfiguration message, the LTM switching command and the first indication information, and perform L2 processing.

[0367] In some embodiments, the first indication information indicates that the SCG configuration is retained in the LTM. The terminal device can determine the change in the bearer type corresponding to the MCG in the MN and the SCG in the SN after switching from the source MN to the target MN, and perform L2 processing, including: executing layer 2 processing corresponding to the MCG and SCG.

[0368] In some embodiments, the first indication information indicates that the SCG configuration in the LTM is released. The terminal device can determine that the SCG configuration is no longer retained after switching from the source MN to the target MN. Therefore, it is only necessary to determine the change of the bearer type corresponding to the MCG in the MN and perform L2 processing, including: executing the layer 2 processing corresponding to the MCG.

[0369] In some embodiments, the source MN or the target MN may send third indication information to the SN, where the third indication information is used to instruct to update the SN configuration.

[0370] In some embodiments, the third indication information indicates at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer. Based on this, the SN can be informed of the change of the bearer type in the LTM.

[0371] In some embodiments, the source MN or the target MN may send a fourth indication information, and the fourth indication information is used to indicate the status information of the SCG configuration after LTM. For example, the source MN or the target MN notifies other candidate MNs that the SCG configuration information is released or is in a reserved state, so that the candidate MN updates the status of the SCG-related configuration of the terminal device.

[0372] See also Fig.15 , Fig.15 1 is a schematic diagram of LTM interaction between CUs under dual connection provided by an embodiment of the present application. Fig.15 As shown, the LTM process between MNs may include:

[0373] 1501. The terminal device reports the measurement to the source MN.

[0374] The terminal device may perform measurement according to the measurement configuration and report a measurement report; the measurement configuration and report may be, for example, an L3 measurement configuration and report, and may be configured by the source MN.

[0375] 1502. The source MN sends an LTM switching request to one or more candidate MNs (including the target MN).

[0376] The source MN may determine one or more candidate MNs for LTM by referring to the reporting results of the terminal device and / or its own switching algorithm. The target MN for subsequent switching may be included in the determined one or more candidate MNs. The one or more candidate MNs may be MNs to which one or more candidate PCells belong.

[0377] 1503. The candidate MN determines the processing strategy configured by the SCG and sends an SN add request or a terminal device context release request to the SN.

[0378] The candidate MN may determine a processing strategy regarding the SCG configuration in the LTM, which processing strategy includes retaining or releasing the SCG configuration.

[0379] In some embodiments, the processing policy configured by the SCG may be pre-configured.

[0380] In some embodiments, since the LTM switching request in 1502 may include terminal device context information, bearer type and data path information, time synchronization and timing information, SCG configuration information, MAC and RLC layer resource information and other information, the processing strategy configured by the SCG may be determined by the candidate MN in response to the LTM switching request received from the source MN in 1502.

[0381] In some embodiments, the processing strategy configured by the candidate MN according to the respective base station SCG is applied to all candidate cells configured by the candidate MN, that is, each candidate MN is configured with the same processing strategy for all candidate cells to which it belongs.

[0382] In some embodiments, the candidate MN configures a processing strategy for each candidate cell to which it belongs.

[0383] The candidate MN can determine the subsequent execution actions based on the processing strategy configured by the SCG.

[0384] In some embodiments, the processing strategy of the SCG configuration is to release the SCG configuration, then the candidate MN sends a terminal device context release request or a release indication of the SCG configuration information to the SN.

[0385] In some embodiments, the processing strategy of the SCG configuration is to retain the SCG configuration, and the candidate MN can execute the SN adding process, that is, send an SN adding request to the SN and receive an SN adding request response from the SN, thereby realizing the adding of the SN.

[0386] 1504. The candidate MN sends an LTM switching request response to the source MN.

[0387] The candidate MN may pre-configure the LTM pre-configuration information of the candidate MN / candidate PCell, and the LTM handover request response may include the LTM pre-configuration information. The LTM pre-configuration information may include configuration information related to measurement reporting, cell identification, handover conditions, and other information, and may also be configured to indicate the configuration information of the layer 2 processing of the terminal after the handover occurs, wherein the layer 2 processing may include MAC layer reset, RLC layer re-establishment, and PDCP layer re-establishment.

[0388] In some embodiments, the LTM switching request response sent by the candidate MN to the source MN also includes first indication information, and the first indication information is used to indicate the processing strategy for the SCG configuration in the LTM determined in 1503, and the processing strategy includes retaining or releasing the SCG configuration.

[0389] 1505. The source MN sends an RRC reconfiguration message to the terminal device.

[0390] The RRC reconfiguration message may include LTM preconfiguration information received from the candidate MN. The LTM preconfiguration information includes configuration information of one or more candidate MNs.

[0391] The RRC reconfiguration message may also include first indication information related to each of the one or more candidate MNs.

[0392] In some embodiments, the RRC reconfiguration message includes a bearer type configuration for one or more candidate MNs.

[0393] In some embodiments, the bearer type includes at least one of the following: a primary cell group (MCG) bearer; a secondary cell group (SCG) bearer; a split bearer.

[0394] Optionally, the RRC reconfiguration message may further include configuration information of the source MN, and the configuration information of the source MN may include the bearer type configuration of the source MN.

[0395] In some embodiments, the configuration information of each candidate MN may be included in one RRC reconfiguration message, that is, the RRC reconfiguration message sent by the source MN to the terminal device in 1505 includes one or more RRC reconfiguration messages, each including the configuration information of one or more candidate MNs.

[0396] In some embodiments, the configuration information of each candidate MN may be included in one IE. That is, the RRC reconfiguration message sent by the source MN to the terminal device in 1505 includes one or more IEs, each including the configuration information of one or more candidate MNs.

[0397] 1506. After receiving the RRC reconfiguration message, the terminal device sends an RRC reconfiguration completion message to the source MN. The RRC reconfiguration completion message is used to confirm the RRC reconfiguration message sent by the source MN in 1505.

[0398] 1507. The terminal device reports L1 measurement to the source MN.

[0399] The terminal device may perform L1 measurement based on the L1 measurement configuration and send an L1 measurement report. The L1 measurement configuration may be included in the RRC reconfiguration message in 1505 .

[0400] 1508. The source MN sends an LTM switching command to the terminal device.

[0401] The LTM handover command may be used to instruct handover from a source MN to one of one or more candidate MNs, ie, a target MN.

[0402] The LTM handover command may be carried on a MAC CE or a DCI. The LTM handover command indicates the target cell identifier of the terminal device handover, or indicates the target cell configuration identifier of the terminal device handover. The candidate MNs include the MN to which the target cell belongs, namely, the target MN.

[0403] In some embodiments, the target MN may be determined by the source MN based on a measurement report received from the terminal device, wherein the measurement report may include the L3 measurement report in 1501 and / or the L1 measurement report in 1507 .

[0404] 1509. The source MN sends second indication information to the target MN, where the second indication information is used to indicate the target cell for switching.

[0405] In some embodiments, the target cell may be determined based on the L1 measurement report in 1507 .

[0406] 1510. The terminal device determines the change in bearer type and performs L2 processing.

[0407] The terminal device can determine the change of the bearer type after switching from the source MN to the target MN based on the RRC reconfiguration message and the LTM switching command received from the source MN, and perform L2 processing accordingly.

[0408] In some embodiments, the change of bearer type may include at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer.

[0409] In some embodiments, the L2 processing may include at least one of the following: MAC layer reset; RLC layer re-establishment; PDCP layer re-establishment.

[0410] In some embodiments, if the terminal device also receives first indication information for indicating a processing strategy for SCG configuration in LTM, the terminal device can determine the change in bearer type after switching from the source MN to the target MN based on the RRC reconfiguration message, the LTM switching command and the first indication information, and perform L2 processing.

[0411] In some embodiments, the first indication information indicates that the SCG configuration is retained in the LTM. The terminal device can determine the change in the bearer type corresponding to the MCG in the MN and the SCG in the SN after switching from the source MN to the target MN, and perform L2 processing, including: executing layer 2 processing corresponding to the MCG and SCG.

[0412] In some embodiments, the first indication information indicates that the SCG configuration in the LTM is released. The terminal device can determine that the SCG configuration is no longer retained after switching from the source MN to the target MN. Therefore, it is only necessary to determine the change of the bearer type corresponding to the MCG in the MN and perform L2 processing, including: executing the layer 2 processing corresponding to the MCG.

[0413] In some embodiments, the source MN or the target MN may send third indication information to the SN, where the third indication information is used to instruct to update the SN configuration.

[0414] In some embodiments, the third indication information indicates at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer. Based on this, the SN can be informed of the change of the bearer type in the LTM.

[0415] In some embodiments, the source MN or the target MN may send a fourth indication information, and the fourth indication information is used to indicate the status information of the SCG configuration after LTM. For example, the source MN or the target MN notifies other candidate MNs that the SCG configuration information is released or is in a reserved state, so that the candidate MN updates the status of the SCG-related configuration of the terminal device.

[0416] Scenario 2: Inter-SN LTM

[0417] See also Fig.16 , Fig.16 1 is a schematic diagram of LTM interaction between CUs under dual connection provided by an embodiment of the present application. Fig.16 As shown, the LTM process between SNs may include:

[0418] 1601. The terminal device reports the measurement to the source SN.

[0419] The terminal device may perform measurement according to the measurement configuration and report a measurement report; the measurement configuration and report may be an L3 measurement configuration and report, and may be configured by the source MN.

[0420] 1602. The source SN sends an LTM switching request to one or more candidate SNs (including the target SN).

[0421] The source SN can determine one or more candidate SNs of LTM by referring to the reporting results of the terminal device and / or its own switching algorithm. The target SN of subsequent switching can be included in the determined one or more candidate SNs. The one or more candidate SNs can be the SNs to which one or more candidate PSCells belong.

[0422] 1603. The candidate SN sends an LTM switching request response to the source SN.

[0423] The candidate SN may pre-configure the LTM pre-configuration information of the candidate SN / candidate PSCell, and the LTM handover request response may include the LTM pre-configuration information. The LTM pre-configuration information may include configuration information related to measurement reporting, cell identification, handover conditions, and other information, and may also be configured to indicate the configuration information for the terminal to perform layer 2 processing after the handover occurs, wherein the layer 2 processing may include MAC layer reset, RLC layer re-establishment, and PDCP layer re-establishment.

[0424] 1604. The source SN sends an RRC reconfiguration message to the MN.

[0425] 1605.MN sends an RRC reconfiguration message to the terminal device.

[0426] The RRC reconfiguration message may include LTM preconfiguration information sent by the candidate SN. The LTM preconfiguration information includes configuration information of one or more candidate SNs.

[0427] In some embodiments, the RRC reconfiguration message includes a bearer type configuration of one or more candidate SNs.

[0428] In some embodiments, the bearer type includes at least one of the following: a primary cell group (MCG) bearer; a secondary cell group (SCG) bearer; a split bearer.

[0429] Optionally, the RRC reconfiguration message may further include configuration information of the source SN, and the configuration information of the source SN may include the bearer type configuration of the source SN.

[0430] In some embodiments, the configuration information of each candidate SN may be included in an RRC reconfiguration message. That is, the RRC reconfiguration message sent by the source SN to the MN in 1604 and the RRC reconfiguration message sent by the MN to the terminal device in 1605 include one or more RRC reconfiguration messages, each including the configuration information of one or more candidate SNs.

[0431] In some embodiments, the configuration information of each candidate MN may be included in one IE. That is, the RRC reconfiguration message sent by the source SN to the MN in 1604 and the RRC reconfiguration message sent by the MN to the terminal device in 1605 include one or more IEs, respectively including the configuration information of one or more candidate SNs.

[0432] In some embodiments, the source SN may send an RRC reconfiguration message directly to the terminal device without going through the MN.

[0433] 1606. After receiving the RRC reconfiguration message, the terminal device sends an RRC reconfiguration completion message to the MN. The RRC reconfiguration completion message is used to confirm the RRC reconfiguration message sent by the MN in 1605.

[0434] 1607. The terminal device reports L1 measurement to the source SN.

[0435] The terminal device may perform L1 measurement and send an L1 measurement report based on the L1 measurement configuration. The L1 measurement configuration may be included in the RRC reconfiguration message in 1604 and 1605 .

[0436] 1608. The source SN sends an LTM switching command to the terminal device.

[0437] The LTM handover command may be used to instruct handover from a source SN to one of one or more candidate SNs, ie, a target SN.

[0438] The LTM switching command may be carried on a MAC CE or a DCI. The LTM switching command indicates the target cell identifier of the terminal device switching, or indicates the target cell configuration identifier of the terminal device switching. The candidate SNs include the SN to which the target cell belongs, namely the target SN.

[0439] In some embodiments, the target SN may be determined by the source SN based on a measurement report received from the terminal device, wherein the measurement report may include the L3 measurement report in 1601 and / or the L1 measurement report in 1607 .

[0440] 1609. The source SN sends second indication information to the target SN, where the second indication information is used to indicate the target cell for switching.

[0441] In some embodiments, the target cell may be determined based on the L1 measurement report in 1607 .

[0442] 1610. The terminal device determines the change in bearer type and performs L2 processing.

[0443] The terminal device can determine the change of the bearer type after switching from the source SN to the target SN based on the RRC reconfiguration message and LTM switching command received from the MN or the source SN, and perform L2 processing accordingly.

[0444] In some embodiments, the change of bearer type may include at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer.

[0445] In some embodiments, the L2 processing may include at least one of the following: MAC layer reset; RLC layer re-establishment; PDCP layer re-establishment.

[0446] In some embodiments, the source SN or the target SN may send fifth indication information to the MN, where the fifth indication information is used to indicate that the MN configuration is to be updated.

[0447] In some embodiments, the fifth indication information indicates at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer. Based on this, the MN can learn about the change of the bearer type in the LTM.

[0448] See also Fig.17 , Fig.17 1 is a schematic diagram of LTM interaction between CUs under dual connection provided by an embodiment of the present application. Fig.17 As shown, the LTM process between SNs may include:

[0449] 1701. The source SN sends an SN change request to the MN.

[0450] The source SN may determine the need for switching based on the communication environment, for example, by referring to the reporting result of the terminal device and / or its own switching algorithm, and send an SN change request to the MN, requesting the MN to switch between SNs.

[0451] 1702. MN sends an SN adding request to one or more candidate SNs (including the target SN).

[0452] In response to the SN change request received from the source SN, the MN can refer to the reporting results of the terminal device and / or its own switching algorithm to determine one or more candidate SNs for the LTM. The target SN for subsequent switching may be included in the determined one or more candidate SNs, and the one or more candidate SNs may be the SNs to which one or more candidate PSCells belong.

[0453] 1703. The candidate SN sends an SN add request response to the MN.

[0454] The candidate SN may pre-configure the LTM pre-configuration information of the candidate SN / candidate PSCell, and the SN add request response may include the LTM pre-configuration information. The LTM pre-configuration information may include configuration information related to measurement reporting, cell identification, switching conditions, and other information, and may also be configured to indicate the configuration information of the layer 2 processing of the terminal after the switching occurs, wherein the layer 2 processing may include MAC layer reset, RLC layer re-establishment, and PDCP layer re-establishment.

[0455] 1704.MN sends an RRC reconfiguration message to the terminal device.

[0456] The RRC reconfiguration message may include LTM preconfiguration information sent by the candidate SN. The LTM preconfiguration information includes configuration information of one or more candidate SNs.

[0457] In some embodiments, the RRC reconfiguration message includes a bearer type configuration of one or more candidate SNs.

[0458] In some embodiments, the bearer type includes at least one of the following: a primary cell group (MCG) bearer; a secondary cell group (SCG) bearer; a split bearer.

[0459] Optionally, the RRC reconfiguration message may further include configuration information of the source SN, and the configuration information of the source SN may include the bearer type configuration of the source SN.

[0460] In some embodiments, the configuration information of each candidate SN may be included in one RRC reconfiguration message. That is, the RRC reconfiguration message sent by the MN to the terminal device in 1704 includes one or more RRC reconfiguration messages, each including the configuration information of one or more candidate SNs.

[0461] In some embodiments, the configuration information of each candidate MN may be included in one IE. That is, the RRC reconfiguration message sent by the MN to the terminal device in 1704 includes one or more IEs, each including the configuration information of one or more candidate SNs.

[0462] 1705. After receiving the RRC reconfiguration message, the terminal device sends an RRC reconfiguration completion message to the MN. The RRC reconfiguration completion message is used to confirm the RRC reconfiguration message sent by the MN in 1704.

[0463] 1706. The terminal device reports L1 measurement to the source SN.

[0464] The terminal device may perform L1 measurement based on the L1 measurement configuration and send an L1 measurement report. The L1 measurement configuration may be included in the RRC reconfiguration message in 1704 .

[0465] 1707. The source SN sends an LTM switching command to the terminal device.

[0466] The LTM handover command may be used to instruct handover from a source SN to one of one or more candidate SNs, ie, a target SN.

[0467] The LTM switching command may be carried on a MAC CE or a DCI. The LTM switching command indicates the target cell identifier of the terminal device switching, or indicates the target cell configuration identifier of the terminal device switching. The candidate SNs include the SN to which the target cell belongs, namely the target SN.

[0468] In some embodiments, the target SN may be determined by the source SN based on a measurement report received from the terminal device, wherein the measurement report may include an L3 measurement report and / or an L1 measurement report in 1706 .

[0469] 1708. The source SN sends second indication information to the target SN, where the second indication information is used to indicate the target cell for switching.

[0470] In some embodiments, the target cell may be determined based on the L1 measurement report in 1706 .

[0471] 1709. The terminal device determines the change in bearer type and performs L2 processing.

[0472] The terminal device can determine the change of the bearer type after switching from the source SN to the target SN based on the RRC reconfiguration message received from the MN and the LTM switching command of the source SN, and perform L2 processing accordingly.

[0473] In some embodiments, the change of bearer type may include at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer.

[0474] In some embodiments, the L2 processing may include at least one of the following: MAC layer reset; RLC layer re-establishment; PDCP layer re-establishment.

[0475] In some embodiments, the source SN or the target SN may send fifth indication information to the MN, where the fifth indication information is used to indicate that the MN configuration is to be updated.

[0476] In some embodiments, the fifth indication information indicates at least one of the following: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between an MN terminated bearer and an SN terminated bearer. Based on this, the MN can learn about the change of the bearer type in the LTM.

[0477] It is understood that multiple embodiments are described in detail above in conjunction with multiple flow charts, but it should be understood that these flow charts and the related descriptions of their corresponding embodiments are only examples for ease of understanding and should not constitute any limitation to this application. Each step in each flow chart is not necessarily required to be executed, for example, some steps can be skipped. Moreover, the execution order of each step is not fixed and is not limited to that shown in each flow chart. The execution order of each step should be determined by its function and internal logic.

[0478] It can also be understood that the LTM between MNs in scenario 1 and the LTM between SNs in scenario 2 described above regarding the LTM between CUs under dual connectivity are not mutually exclusive events. That is, when executing LTM between MNs, LTM between SNs may also occur; or when executing LTM between SNs, LTM between MNs may also occur. The terminal device may perform layer 2 processing on the MN and SN sides respectively according to the specific circumstances. The layer 2 processing may include one or more of PDCP re-establishment, RLC re-establishment, and MAC layer reset.

[0479] Fig.18 It is a flow chart of a communication method provided in an embodiment of the present application. Fig.18 The method shown may be performed by a terminal device, or the subject may be a chip in the terminal device.

[0480] S1801. Receive a radio resource control RRC reconfiguration message, where the RRC reconfiguration message includes preconfiguration information of one or more second primary network devices or one or more second secondary network devices.

[0481] S1802. Receive a layer 1 / layer 2 triggered mobility LTM handover command, where the LTM handover command is used to instruct handover from a first primary network device to one of the one or more second primary network devices, or to instruct handover from a first secondary network device to one of the one or more second secondary network devices.

[0482] S1803. Determine the change of the bearer type based on the RRC reconfiguration message and the LTM switching command.

[0483] S1804. Execute layer 2 processing based on the determined bearer type change.

[0484] Based on Fig.18 According to the method shown, the terminal device receives an RRC reconfiguration message including pre-configuration information of the target network device and an LTM switching command, and can determine the change of the bearer type based on the RRC reconfiguration message and the LTM switching command, and execute layer 2 processing based on the change of the bearer type. This is beneficial to rebuild the protocol stack based on the adaptability of the bearer change during the dual-connection LTM process, which is beneficial to achieving the continuity of data transmission, reducing service interruptions, and improving the efficiency of LTM under dual connections.

[0485] In a possible implementation, the pre-configuration information includes a bearer type configuration, and the bearer type includes at least one of the following items: a main cell group MCG bearer; a secondary cell group SCG bearer; a split bearer.

[0486] In one possible implementation, an RRC reconfiguration message and an LTM switching command are received from a first main network device, the RRC reconfiguration message includes pre-configuration information of one or more second main network devices, the LTM switching command indicates switching from the first main network device to one of the one or more second main network devices, and the method also includes: receiving first indication information from the first main network device, the first indication information is used to indicate a processing strategy for the secondary cell group SCG configuration in the LTM, the processing strategy including retaining or releasing the SCG configuration; determining a change in the bearer type based on the RRC reconfiguration message and the LTM switching command, including: determining a change in the bearer type based on the RRC reconfiguration message, the LTM switching command and the first indication information.

[0487] In some embodiments, the second master network device indicated by the LTM switching command may be determined by the first master network device from one or more second master network devices based on a measurement report received from the terminal device, wherein the measurement report may include an L3 measurement report and / or an L1 measurement report.

[0488] In some embodiments, the first indication information may be dedicated signaling sent separately.

[0489] In some embodiments, the first indication information may be carried by the LTM switching command.

[0490] In some embodiments, the first indication information may be preconfigured, for example, may be included in LTM preconfiguration information, and may be carried by an RRC reconfiguration message.

[0491] In some embodiments, the first indication information may be carried by DCI signaling.

[0492] In some embodiments, the first indication information may be carried by PDCCH signaling.

[0493] In some embodiments, the first indication information may be carried by PDSCH signaling.

[0494] Based on this implementation method, the change of bearer type can be determined according to the processing strategy indication information of the SCG configuration. There is no need to wait for LTM to determine whether the SCG configuration is to retain or release and determine the change of growth type. This is conducive to timely L2 processing and reconstruction of the protocol stack, which is conducive to achieving data transmission continuity, reducing service interruptions, and improving the efficiency of LTM under dual connections.

[0495] In a possible implementation, the first indication information instructs the LTM to retain the SCG configuration and perform layer 2 processing, including: performing layer 2 processing corresponding to the main cell group MCG and SCG.

[0496] Based on this implementation, the protocol stack can be adaptively rebuilt according to the change of the bearer type during the LTM switching process to ensure the continuity of data transmission.

[0497] In a possible implementation, the first indication information instructs the LTM to release the SCG configuration and execute layer 2 processing, including: executing layer 2 processing corresponding to the MCG.

[0498] Based on this implementation, the protocol stack can be adaptively rebuilt according to the change of the bearer type during the LTM switching process to ensure the continuity of data transmission.

[0499] In one possible implementation, an RRC reconfiguration message and an LTM switching command are received from a first primary network device or a first secondary network device, the RRC reconfiguration message includes preconfiguration information of one or more second secondary network devices, the LTM switching command indicates switching from the first secondary network device to one of the one or more second secondary network devices, and performing layer 2 processing, including: performing layer 2 processing corresponding to the SCG.

[0500] Based on this implementation, the protocol stack can be adaptively rebuilt according to the change of the bearer type during the LTM switching process to ensure the continuity of data transmission.

[0501] In some embodiments, the second secondary network device indicated by the LTM switching command may be determined by the first secondary network device from one or more second secondary network devices based on a measurement report received from the terminal device, wherein the measurement report may include an L3 measurement report and / or an L1 measurement report.

[0502] In a possible implementation, it is characterized in that the change of bearer type includes at least one of the following items: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between a primary network device MN terminated type bearer and a secondary network device SN terminated type bearer.

[0503] In a possible implementation, the processing of layer 2 includes at least one of the following: medium access control MAC layer resetting; radio link control RLC layer reestablishment; packet data convergence protocol PDCP layer reestablishment.

[0504] Fig.19 It is a flow chart of a communication processing method provided in an embodiment of the present application. Fig.19 The method shown may be performed by a network device, or by a chip in the network device.

[0505] S1901. Send a radio resource control RRC reconfiguration message to the terminal device, where the RRC reconfiguration message includes preconfiguration information of one or more second primary network devices or one or more second secondary network devices.

[0506] S1902. Send a layer 1 / layer 2 triggered mobility LTM switching command to the terminal device, where the LTM switching command is used to indicate switching from a first primary network device to one of one or more second primary network devices, or to indicate switching from a first secondary network device to one of one or more second secondary network devices.

[0507] Based on the method described in the second aspect, by sending an RRC reconfiguration message and an LTM switching command including pre-configuration information of the target network device to the terminal device, the terminal device is facilitated to determine the change of the bearer type based on the RRC reconfiguration message and the LTM switching command, and execute layer 2 processing based on the change of the bearer type, which is conducive to rebuilding the protocol stack based on the adaptability of bearer changes during the dual-connection LTM process, and is conducive to achieving continuity of data transmission, reducing service interruptions, and improving the efficiency of LTM under dual connections.

[0508] In a possible implementation, the pre-configuration information includes a bearer type configuration, and the bearer type includes at least one of the following items: a main cell group MCG bearer; a secondary cell group SCG bearer; a split bearer.

[0509] In one possible implementation, the RRC reconfiguration message includes pre-configuration information of one or more second main network devices, and the LTM switching command is used to indicate switching from the first main network device to one of the one or more second main network devices. The method also includes: sending first indication information to the terminal device, and the first indication information is used to indicate the processing strategy for the secondary cell group SCG configuration in the LTM, and the processing strategy includes retaining or releasing the SCG configuration.

[0510] In some embodiments, the second master network device indicated by the LTM switching command may be determined by the first master network device from one or more second master network devices based on a measurement report received from the terminal device, wherein the measurement report may include an L3 measurement report and / or an L1 measurement report.

[0511] In some embodiments, the first indication information may be dedicated signaling sent separately.

[0512] In some embodiments, the first indication information may be carried by the LTM switching command.

[0513] In some embodiments, the first indication information may be preconfigured, for example, may be included in LTM preconfiguration information, and may be carried by an RRC reconfiguration message.

[0514] In some embodiments, the first indication information may be carried by DCI signaling.

[0515] In some embodiments, the first indication information may be carried by PDCCH signaling.

[0516] In some embodiments, the first indication information may be carried by PDSCH signaling.

[0517] Based on this implementation method, the processing strategy indication information of the SCG configuration can be used to indicate the change of the bearer type to the terminal device, so that the terminal device does not need to wait for LTM to determine whether the SCG configuration is to retain or release and determine the change of the growth type. This is conducive to timely L2 processing and reconstruction of the protocol stack, which is conducive to achieving data transmission continuity, reducing service interruptions, and improving the efficiency of LTM under dual connections.

[0518] In a possible implementation, the first indication information is determined based on a measurement report received from the terminal device, wherein the measurement report includes a layer 3 measurement report and / or a layer 1 measurement report.

[0519] Based on this implementation method, the source main network device can flexibly determine the processing strategy of the SCG configuration, which is conducive to flexible configuration of the dual connection of the terminal device according to the communication environment.

[0520] In one possible implementation, the method also includes: sending first processing information to one of one or more second main network devices, the first processing information is used to indicate a processing strategy regarding the SCG configuration in the LTM, and the processing strategy regarding the SCG configuration indicated by the first processing information is the same as the processing strategy regarding the SCG configuration indicated by the first indication information.

[0521] Based on this implementation method, the target main network device can be instructed about the processing strategy of the SCG configuration, which is conducive to the target main network device to configure the auxiliary network device in time and is conducive to improving the efficiency of LTM under dual connection.

[0522] In a possible implementation manner, the first processing information is transmitted through an Xn interface.

[0523] In a possible implementation, the first indication information is determined based on an LTM switching request response received from one or more second master network devices, where the LTM switching request response includes an indication of a processing policy configured for the SCG.

[0524] In a possible implementation, the method further includes: sending second indication information to one of the one or more second primary network devices, the second indication information is used to indicate a target cell for switching, and the target cell is determined based on a layer 1 measurement report received from the terminal device.

[0525] Based on this implementation method, the source main network device can determine the cell to which the terminal device wants to switch according to the communication environment, and indicate the target cell to the target main network device, which is conducive to the target main network device to configure the auxiliary network device in a timely manner and is conducive to improving the efficiency of LTM under dual connection.

[0526] In a possible implementation manner, the method further includes: sending third indication information to the secondary network device SN, where the third indication information is used to indicate updating of the SN configuration.

[0527] Based on this implementation, the primary network device can instruct the secondary network device to update the configuration of the terminal device, which is beneficial to improving the efficiency of LTM under dual connections.

[0528] In one possible implementation, the third indication information indicates at least one of the following items: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

[0529] In a possible implementation, the method further includes: sending fourth indication information, where the fourth indication information is used to indicate status information of the SCG configuration after LTM.

[0530] Based on this implementation method, it is beneficial for all candidate network devices in the communication system to update the status of the SCG-related configuration of the terminal device, thereby avoiding possible failures or errors in the subsequent LTM due to inconsistent status of the SCG configuration.

[0531] In one possible implementation, the RRC reconfiguration message includes pre-configuration information of one or more second auxiliary network devices, the LTM switching command is used to indicate switching from the first auxiliary network device to one of the one or more second auxiliary network devices, and the method also includes: sending fifth indication information to the main network device MN, and the fifth indication information is used to indicate an update to the MN configuration.

[0532] In some embodiments, the second secondary network device indicated by the LTM switching command may be determined by the first secondary network device from one or more second secondary network devices based on a measurement report received from the terminal device, wherein the measurement report may include an L3 measurement report and / or an L1 measurement report.

[0533] Based on this implementation, the auxiliary network device can notify the primary network device about the terminal device update configuration, which is beneficial to improving the efficiency of LTM under dual connection.

[0534] In a possible implementation manner, sending a radio resource control (RRC) reconfiguration message to a terminal device includes: sending the RRC reconfiguration message to the terminal device via a MN.

[0535] In one possible implementation, the fifth indication information indicates at least one of the following items: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

[0536] Fig. 20 It is a flow chart of a communication processing method provided in an embodiment of the present application. Fig. 20 The method shown may be performed by a network device, or by a chip in the network device.

[0537] S2001. Receive a layer 1 / layer 2 triggered mobility LTM switching request from a first primary network device.

[0538] S2002. Send an LTM switch request response to the first master network device, where the LTM switch request response includes pre-configuration information.

[0539] S2003. Determine a processing strategy for the secondary cell group SCG configuration in the LTM, where the processing strategy includes retaining or releasing the SCG configuration.

[0540] S2004. Based on the processing strategy configured by the SCG, an SN adding request or a terminal device context releasing request is sent to the secondary network device SN.

[0541] Based on the method described in the third aspect, the target main network device can determine the processing strategy for the SCG configuration, and configure the auxiliary network device in a timely manner according to the corresponding processing strategy, which is conducive to improving the efficiency of LTM under dual connections.

[0542] In a possible implementation, the pre-configuration information includes a bearer type configuration, and the bearer type includes at least one of the following items: a main cell group MCG bearer; a secondary cell group SCG bearer; a split bearer.

[0543] In a possible implementation, the method further includes: the processing strategy of the SCG configuration is determined based on first processing information received from the first master network device, and the first processing information is used to indicate the processing strategy regarding the SCG configuration in the LTM.

[0544] In a possible implementation manner, the first processing information is transmitted through an Xn interface.

[0545] In one possible implementation, the processing strategy configured by the SCG is preconfigured, or determined in response to an LTM switching request received from a first main network device, and based on the processing strategy configured by the SCG, an SN addition request or a terminal device context release request is sent to the secondary network device SN, including: receiving second indication information from the first main network device, the second indication information is used to indicate a target cell for switching; based on the processing strategy configured by the SCG and the second indication information, an SN addition request or a terminal device context release request is sent to the SN.

[0546] Based on this implementation method, the target primary network device can configure the secondary network device in a timely manner, which is conducive to improving the efficiency of LTM under dual connections.

[0547] In a possible implementation manner, the method further includes: sending third indication information to the SN, where the third indication information is used to indicate updating of the SN configuration.

[0548] Based on this implementation, the target primary network device can instruct the secondary network device to update the configuration of the terminal device, which is beneficial to improving the efficiency of LTM under dual connections.

[0549] In one possible implementation, the third indication information indicates at least one of the following items: a change between an MCG bearer and an SCG bearer; a change between an MCG bearer and a split bearer; a change between an SCG bearer and a split bearer; a change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

[0550] In a possible implementation, the method further includes: sending fourth indication information, where the fourth indication information is used to indicate status information of the SCG configuration after LTM.

[0551] Based on this implementation method, it is beneficial for all candidate network devices in the communication system to update the status of the SCG-related configuration of the terminal device, thereby avoiding possible failures or errors in the subsequent LTM due to inconsistent status of the SCG configuration.

[0552] Fig.21 It is a structural diagram of a communication device according to an embodiment of the present application. Fig.21 The communication device 2100 shown may be a terminal device, or a device in a terminal device, or a device that can be used in conjunction with a terminal device; or Fig.21 The communication device shown may be a network device, or a device in a network device, or a device that can be used in conjunction with a network device.

[0553] Fig.21 The communication device 2100 shown may include a communication unit 2101 and a processing unit 2102. Specifically, the processing unit 2102 is used to process data, which may be data received by the communication unit 2101, and the processed data may also be sent by the communication unit 2101.

[0554] Specifically, the processing unit 2102 is used to execute the function of processing data of the terminal device or network device in the above method embodiment. For other possible implementations of the communication device, please refer to the above Figures 18 to 20 The relevant description of the functions of the terminal device or network device in the corresponding method embodiment will not be repeated here.

[0555] Fig. 22 2200 may be a terminal device or a network device in the above method embodiment, or a chip, a chip system, or a processor that supports the terminal device or the network device to implement the above method. The communication device may be used to implement the method described in the above method embodiment, and the details may refer to the description in the above method embodiment.

[0556] The communication device 2200 may include one or more processors 2201. The processor 2201 may be a general-purpose processor or a dedicated processor, etc. For example, it may be a baseband processor or a central processing unit. The baseband processor may be used to process the communication protocol and communication data, and the central processing unit may be used to control the communication device (such as a base station, a baseband chip, a terminal, a terminal chip, a DU or a CU, etc.), execute a software program, and process the data of the software program.

[0557] Optionally, the communication device 2200 may include one or more memories 2202, on which instructions 2204 may be stored, and the instructions may be executed on the processor 2201, so that the communication device 2200 performs the method described in the above method embodiment. Optionally, data may also be stored in the memory 2202. The processor 2201 and the memory 2202 may be provided separately or integrated together.

[0558] Optionally, the communication device 2200 may further include a transceiver 2205 and an antenna 2206. The transceiver 2205 may be referred to as a transceiver unit, a transceiver, or a transceiver circuit, etc., and is used to implement a transceiver function. The transceiver 2205 may include a receiver and a transmitter, the receiver may be referred to as a receiver or a receiving circuit, etc., and is used to implement a receiving function; the transmitter may be referred to as a transmitter or a transmitting circuit, etc., and is used to implement a transmitting function. Fig.21 The processing unit 2102 shown may be a processor 2201. The communication unit 2101 may be a transceiver 2205.

[0559] In another possible design, the processor 2201 may include a transceiver for implementing the receiving and sending functions. For example, the transceiver may be a transceiver circuit, or an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing the receiving and sending functions may be separate or integrated. The above-mentioned transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or the above-mentioned transceiver circuit, interface, or interface circuit may be used for transmitting or delivering signals.

[0560] In another possible design, optionally, the processor 2201 may store an instruction 2203, and the instruction 2203 runs on the processor 2201, so that the communication device 2200 can execute the method described in the above method embodiment. The instruction 2203 may be solidified in the processor 2201, in which case the processor 2201 may be implemented by hardware.

[0561] The communication device described in the above embodiments may be a terminal device or a network device, but the scope of the communication device described in the embodiments of the present application is not limited thereto, and the structure of the communication device may not be limited thereto. Fig. 22The communication device may be an independent device or may be part of a larger device. For example, the communication device may be:

[0562] (1) Independent integrated circuit IC, or chip, or chip system or subsystem;

[0563] (2) having a set of one or more ICs, and optionally, the IC set may also include a storage component for storing data and instructions;

[0564] (3) ASIC, such as modem (MSM);

[0565] (4) Modules that can be embedded in other devices;

[0566] (5) Receivers, terminals, smart terminals, cellular phones, wireless devices, handheld devices, mobile units, vehicle-mounted devices, network devices, cloud devices, artificial intelligence devices, etc.;

[0567] (6)Others

[0568] For the case where the communication device may be a chip or a chip system, see Fig.23 Schematic diagram of the chip structure shown. Fig.23 The chip 2300 shown includes a processor 2301 and an interface 2302. Optionally, it may also include a memory 2303. The number of the processor 2301 may be one or more, and the number of the interface 2302 may be multiple.

[0569] For the case where the chip is used to implement a terminal device or a network device in the embodiment of the present application:

[0570] Interface 2302, used to receive or output signals;

[0571] Processor 2301 is used to execute data processing operations of terminal equipment or network equipment.

[0572] It is understandable that some optional features in the embodiments of the present application may be implemented independently in certain scenarios without relying on other features, such as the solution on which they are currently based, to solve corresponding technical problems and achieve corresponding effects, and may also be combined with other features according to needs in certain scenarios. Accordingly, the communication device provided in the embodiments of the present application may also implement these features or functions accordingly, which will not be elaborated here.

[0573] It should be understood that the processor in the embodiment of the present application can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiment can be completed by an integrated logic circuit of hardware in the processor or an instruction in the form of software. The above processor can be a general-purpose processor, a digital signal processor (digital signal processor, DSP), an application specific integrated circuit (application specific integrated circuit, ASIC), a field programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components.

[0574] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0575] The present application also provides a computer-readable medium, in which a computer program or instruction is stored. When the computer program or instruction is executed by a communication device, the functions of any of the above method embodiments are implemented.

[0576] The present application also provides a computer program product including instructions, and when a computer reads and executes the computer program product, the computer implements the functions of any of the above method embodiments.

[0577] The present application provides a communication system, which includes a terminal device and a network device; wherein the terminal device is used to execute the method executed by the terminal device in the above embodiment, and the network device is used to execute the method executed by the network device in the above embodiment.

[0578] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on the computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that can be accessed by the computer or a data storage device such as a server or data center that contains one or more available media integrated. Available media may be magnetic media (eg, floppy disks, hard disks, tapes), optical media (eg, high-density digital video discs (DVD)), or semiconductor media (eg, solid state disks (SSD)).

[0579] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain operations can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0580] The descriptions of the various embodiments provided in this application can refer to each other, and the descriptions of the various embodiments have different focuses. For parts that are not described in detail in a certain embodiment, refer to the relevant descriptions of other embodiments. For the convenience and simplicity of description, for example, the functions of the various devices and equipment provided in the embodiments of this application and the operations performed can refer to the relevant descriptions of the method embodiments of this application, and the various method embodiments and the various device embodiments can also refer to, combine or quote each other.

[0581] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A communication processing method, applied to a terminal device, characterized in that: The method comprises: Receiving a radio resource control RRC reconfiguration message, where the RRC reconfiguration message includes preconfiguration information of one or more second primary network devices or one or more second secondary network devices; Receiving a layer 1 / layer 2 triggered mobility LTM handover command, the LTM handover command being used to instruct a handover from a first primary network device to one of the one or more second primary network devices, or to instruct a handover from a first secondary network device to one of the one or more second secondary network devices; Determining a change in bearer type based on the RRC reconfiguration message and the LTM switching command; Based on the determined change in bearer type, layer 2 processing is performed.

2. The method according to claim 1, characterized in that The RRC reconfiguration message and the LTM switching command are received from the first master network device, the RRC reconfiguration message includes preconfiguration information of the one or more second master network devices, the LTM switching command indicates switching from the first master network device to one of the one or more second master network devices, and the method further includes: receiving first indication information from the first master network device, where the first indication information is used to indicate a processing strategy for a secondary cell group SCG configuration in the LTM, where the processing strategy includes retaining or releasing the SCG configuration; Determining a change in a bearer type based on the RRC reconfiguration message and the LTM switching command includes: A change in the bearer type is determined based on the RRC reconfiguration message, the LTM switching command and the first indication information.

3. The method according to claim 2, characterized in that The first indication information is carried by any one of the following signalings: RRC signaling; Downlink control information DCI signaling; Physical downlink control channel PDCCH signaling; Physical Downlink Shared Channel PDSCH signaling.

4. The method according to claim 2, characterized in that: The first indication information indicates that the SCG configuration is retained in the LTM, and the execution layer 2 processing includes: Execute layer 2 processing corresponding to the main cell groups MCG and SCG.

5. The method according to claim 2, characterized in that: The first indication information indicates that the SCG configuration is released in the LTM, and the processing of the execution layer 2 includes: Execute layer 2 processing corresponding to MCG.

6. The method according to claim 1, characterized in that The RRC reconfiguration message and the LTM switching command are received from the first primary network device or the first secondary network device, the RRC reconfiguration message includes preconfiguration information of the one or more second secondary network devices, the LTM switching command indicates switching from the first secondary network device to one of the one or more second secondary network devices, and the performing layer 2 processing includes: Execute layer 2 processing corresponding to SCG.

7. The method according to any one of claims 1 to 6, characterized in that The pre-configuration information includes a bearer type configuration, and the bearer class includes at least one of the following: Main cell group MCG bearer; Secondary cell group SCG bearer; Separate split bearer.

8. The method according to claim 7, characterized in that The change of the bearer type includes at least one of the following: Changes between MCG bearer and SCG bearer; Changes between MCG bearer and split bearer; Changes between SCG bearer and split bearer; Change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

9. The method according to claim 7, characterized in that: The processing of layer 2 includes at least one of the following: Medium Access Control MAC layer reset; Radio link control RLC layer re-establishment; The Packet Data Convergence Protocol PDCP layer is re-established.

10. A communication processing method, applied to a first primary network device or a first secondary network device, characterized in that: The method comprises: Sending a radio resource control RRC reconfiguration message to the terminal device, wherein the RRC reconfiguration message includes preconfiguration information of one or more second primary network devices or one or more second secondary network devices; A layer 1 / layer 2 triggered mobility LTM switching command is sent to the terminal device, where the LTM switching command is used to indicate switching from the first primary network device to one of the one or more second primary network devices, or to indicate switching from the first secondary network device to one of the one or more second secondary network devices.

11. The method according to claim 10, characterized in that The pre-configuration information includes a bearer type configuration, and the bearer class includes at least one of the following: Main cell group MCG bearer; Secondary cell group SCG bearer; Separate split bearer.

12. The method according to claim 10, characterized in that The RRC reconfiguration message includes preconfiguration information of the one or more second master network devices, the LTM switching command is used to instruct switching from the first master network device to one of the one or more second master network devices, and the method further includes: A first indication message is sent to the terminal device, where the first indication message is used to indicate a processing strategy for the secondary cell group SCG configuration in the LTM, where the processing strategy includes retaining or releasing the SCG configuration.

13. The method according to claim 12, characterized in that The first indication information is carried by any one of the following signalings: RRC signaling; Downlink control information DCI signaling; Physical downlink control channel PDCCH signaling; Physical Downlink Shared Channel PDSCH signaling.

14. The method according to claim 12, characterized in that The first indication information is determined based on a measurement report received from the terminal device, wherein the measurement report includes a layer 3 measurement report and / or a layer 1 measurement report.

15. The method according to claim 14, characterized in that The method further comprises: Sending first processing information to one of the one or more second main network devices, wherein the first processing information is used to indicate a processing policy regarding the SCG configuration in the LTM, and the processing policy regarding the SCG configuration indicated by the first processing information is the same as the processing policy regarding the SCG configuration indicated by the first indication information.

16. The method according to claim 15, characterized in that The first processing information is transmitted via the Xn interface.

17. The method according to claim 12, characterized in that The first indication information is determined based on an LTM switch request response received from the one or more second master network devices, wherein the LTM switch request response includes an indication of a processing policy configured for the SCG.

18. The method according to claim 17, characterized in that The method further comprises: Sending second indication information to one of the one or more second primary network devices, where the second indication information is used to indicate a target cell for switching, where the target cell is determined based on a layer 1 measurement report received from the terminal device.

19. The method according to any one of claims 12 to 18, characterized in that: The method further comprises: Sending third indication information to the secondary network device SN, where the third indication information is used to instruct to update the SN configuration.

20. The method according to claim 19, characterized in that The third indication information indicates at least one of the following items: Changes between MCG bearer and SCG bearer; Changes between MCG bearer and split bearer; Changes between SCG bearer and split bearer; Change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

21. The method according to any one of claims 12 to 18, characterized in that: The method further comprises: Send fourth indication information, where the fourth indication information is used to indicate status information of the SCG configuration after LTM.

22. The method according to claim 10, characterized in that The RRC reconfiguration message includes a bearer type configuration of one or more second auxiliary network devices, the LTM switching command is used to instruct switching from the first auxiliary network device to one of the one or more second auxiliary network devices, and the method further includes: Send fifth indication information to the master network device MN, where the fifth indication information is used to instruct to update the MN configuration.

23. The method according to claim 22, characterized in that The sending of a radio resource control (RRC) reconfiguration message to the terminal device includes: Send an RRC reconfiguration message to the terminal device via the MN.

24. The method according to claim 22 or 23, characterized in that The fifth indication information indicates at least one of the following items: Changes between MCG bearer and SCG bearer; Changes between MCG bearer and split bearer; Changes between SCG bearer and split bearer; Change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

25. A communication processing method, applied to a second main network device, characterized in that: The method comprises: receiving a layer 1 / layer 2 triggered mobility LTM handover request from a first primary network device; Sending an LTM switching request response to the first master network device, wherein the LTM switching request response includes pre-configuration information; Determine a processing strategy for a secondary cell group SCG configuration in the LTM, wherein the processing strategy includes retaining or releasing the SCG configuration; Based on the processing strategy configured by the SCG, an SN adding request or a terminal device context releasing request is sent to the auxiliary network device SN.

26. The method according to claim 25, characterized in that The pre-configuration information includes a bearer type configuration, and the bearer class includes at least one of the following: Main cell group MCG bearer; Secondary cell group SCG bearer; Separate split bearer.

27. The method according to claim 25, characterized in that The processing strategy of the SCG configuration is determined based on first processing information received from the first master network device, where the first processing information is used to indicate the processing strategy regarding the SCG configuration in the LTM.

28. The method according to claim 27, characterized in that The first processing information is transmitted via the Xn interface.

29. The method according to claim 25, characterized in that The processing strategy configured by the SCG is preconfigured or determined in response to the LTM switching request received from the first primary network device, and the sending of the SN adding request or the terminal device context releasing request to the secondary network device SN based on the processing strategy configured by the SCG includes: receiving second indication information from the first master network device, where the second indication information is used to indicate a target cell for handover; Based on the processing strategy configured by the SCG and the second indication information, an SN addition request or a terminal device context release request is sent to the SN.

30. The method according to any one of claims 25 to 29, characterized in that: The method further comprises: Send third indication information to the SN, where the third indication information is used to indicate that the SN configuration is to be updated.

31. The method according to claim 30, characterized in that The third indication information indicates at least one of the following items: Changes between MCG bearer and SCG bearer; Changes between MCG bearer and split bearer; Changes between SCG bearer and split bearer; Change between a primary network device MN terminated bearer and a secondary network device SN terminated bearer.

32. The method according to any one of claims 25 to 29, characterized in that: The method further comprises: Send fourth indication information, where the fourth indication information is used to indicate status information of the SCG configuration after LTM.

33. A communication device, characterized in that: The method comprises a unit for executing the method according to any one of claims 1 to 9, or comprises a unit for executing the method according to any one of claims 10 to 24, or comprises a unit for executing the method according to any one of claims 25 to 32.

34. A communication device, characterized in that: The method comprises a processor and a memory, wherein the processor and the memory are coupled, and the processor is used to implement the method according to any one of claims 1 to 9, or the processor is used to implement the method according to any one of claims 10 to 24, or the processor is used to implement the method according to any one of claims 25 to 32.

35. A chip, characterized in that: It comprises a processor and an interface, wherein the processor and the interface are coupled; the interface is used to receive or output signals, and the processor is used to execute code instructions so that the method described in any one of claims 1 to 9 is executed, or the method described in any one of claims 10 to 24 is executed, or the method described in any one of claims 25 to 32 is executed.

36. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which, when called by the computer, enable the computer to execute the method described in any one of claims 1 to 9, or the method described in any one of claims 10 to 24, or the method described in any one of claims 25 to 32.

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