Communication method and apparatus

Abstract

The present application relates to the technical field of communications. Provided are a communication method and apparatus. The method comprises: when a terminal fails to switch from a first cell to a second cell, executing a cell selection operation to determine a third cell; and when the terminal accesses the third cell, determining a protocol stack processing behavior on the basis of a protocol stack processing operation group identifier of the first cell, a protocol stack processing operation group identifier of the second cell, and a protocol stack processing operation group identifier of the third cell. The terminal determines a protocol stack processing behavior with reference to the protocol stack processing operation group identifier of the first cell, a protocol stack processing operation group identifier of a cell failing to switch to (i.e., the second cell), and a protocol stack operation group identifier of a cell determined by executing the cell selection operation after the switching fails (i.e., the third cell), so that access failure caused by the fact that a protocol stack processing behavior is not aligned with a first network device (i.e., a network device which manages the third cell) when accessing the third cell is avoided, and an interruption time caused by switching failure can be shortened, thereby improving service experience of a UE.

Description

Communication method and device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on November 30, 2023, with application number 202311636786.1 and application name “A Communication Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The embodiments of the present application relate to the field of communication technology, and in particular to a communication method and apparatus. Background Art

[0004] In a mobile communication system, when user equipment (UE) moves from the coverage of one cell to the coverage of another, a cell handover process is required. In the scenario where the cell handover fails, the UE's L2 (Layer 2) behavior (e.g., radio link control (RLC) behavior) is unclear, and the corresponding L2 behavior of the network device (e.g., RLC behavior) is also unclear, which will cause the UE's L2 behavior and the network device's L2 behavior to be misaligned. Based on this, when the cell handover fails, clarifying the L2 behavior of the UE and the network device can reduce the interruption time caused by the handover failure, which is conducive to improving the UE's service experience.

[0005] Summary of the Invention

[0006] The present application provides a communication method and apparatus to ensure that, in a scenario where cell handover fails, the L2 behavior of a UE is aligned with the L2 behavior of a network device.

[0007] In a first aspect, the present application provides a communication method that can be applied to a terminal or a terminal chip, which is not specifically limited here. The terminal can be a mobile phone, a vehicle-mounted device, an Internet of Things device, etc. The method can be applied to the 5th generation (5G) communication system or a communication system above 5G, and can also be applied to non-terrestrial communication systems, which is not specifically limited here. In actual application, the method is performed as follows:

[0008] When the terminal fails to switch from the first cell to the second cell, a cell selection operation is performed to determine the third cell; when the terminal accesses the third cell, the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are used to determine the protocol stack processing behavior.

[0009] In the present application, the terminal determines the protocol stack processing behavior by referring to the protocol stack processing operation group identifier of the source cell (i.e., the first cell), the protocol stack processing operation group identifier of the cell where the handover failed (i.e., the second cell), and the protocol stack operation group identifier of the cell (i.e., the third cell) determined by the cell selection operation after the handover failed. This avoids access failure caused by the misalignment of the protocol stack processing behavior with the first network device (i.e., the network device that manages the third cell) when accessing the third cell. This can reduce the interruption time caused by the handover failure, which is beneficial to improving the UE's service experience.

[0010] In an optional manner, if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different, the first protocol stack processing behavior is executed; or, if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are all the same, the second protocol stack processing behavior is executed.

[0011] In this application, the first protocol stack processing behavior is executed only when the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different. It is necessary to make a judgment based on the protocol stack processing operation identifiers of the three cells to avoid inconsistency with the protocol stack processing behavior on the first network device side.

[0012] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0013] RLC re-establishment, media access control protocol (MAC) reset, packet data convergence protocol (PDCP) re-establishment.

[0014] Specifically, the second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, and PDCP data recovery.

[0015] In the second aspect, the present application provides a communication method, which can be applied to a first network device or a chip of the first network device, which is not specifically limited here. The first network device can be a base station, an access point, etc. The first network device can be a centralized unit (CU) or a distributed unit (DU), or a device that combines CU and DU, and can also be a 5G base station (gNodeB, gNB), etc. The method can be applied to a 5G communication system or a communication system above 5G, and can also be applied to a non-terrestrial communication system, which is not specifically limited here. In actual application, the following is performed:

[0016] Determine that the terminal accesses a third cell, which is managed by the first network device; determine the protocol stack processing behavior based on reference information; wherein the reference information includes at least one of the following: storage status of the protocol stack processing state in the first network device; or access information of the terminal.

[0017] In the present application, the first network device refers to the storage status of the protocol stack processing status in the first network device; or, the access information of the terminal determines the protocol stack processing behavior. When the terminal accesses the third cell, the first network device adopts the protocol stack processing behavior aligned with the terminal, which can reduce the interruption time caused by the switching failure, which is beneficial to improving the UE's service experience.

[0018] In an optional manner, when the reference information includes a protocol stack processing operation group identifier of the first cell, a protocol stack processing operation group identifier of the second cell, and a protocol stack processing operation group identifier of the third cell, determining the protocol stack processing behavior according to the reference information includes:

[0019] If the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different, the first protocol stack processing behavior is executed; or, if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are all the same, the second protocol stack processing behavior is executed.

[0020] In this application, the first protocol stack processing behavior is executed only when the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different. It is necessary to combine the protocol stack processing operation identifiers of the three cells to make a judgment that is consistent with the judgment logic on the terminal side, which can avoid inconsistencies with the protocol stack processing behavior on the terminal side.

[0021] In an optional manner, when the reference information includes storage status of a protocol stack processing state in the first network device, determining the protocol stack processing behavior according to the reference information includes:

[0022] If it is determined that the protocol stack processing status is not stored in the first network device, the first protocol stack processing behavior is executed; or, if it is determined that the protocol stack processing status is stored in the first network device, and the protocol stack processing operation group identifier of the cell corresponding to the stored protocol stack processing status is the same as the protocol stack group identifier of the third cell, the second protocol stack processing behavior is executed; or, if it is determined that the protocol stack processing status is stored in the first network device, and the protocol stack processing operation group identifier of the cell corresponding to the stored protocol stack processing status is different from the protocol stack group identifier of the third cell, the first protocol stack processing behavior is executed.

[0023] In the present application, the first network device determines the protocol stack processing behavior by referring to the storage status of the protocol stack processing state in the first network device, which can avoid inconsistency with the protocol stack processing behavior on the terminal side.

[0024] In an optional manner, when the reference information includes access information of the terminal, determining the protocol stack processing behavior according to the reference information includes:

[0025] If it is determined based on the access information of the terminal that the terminal has not switched from the cell managed by the first network device to the third cell, the first protocol stack processing behavior is executed; or, if it is determined based on the access information of the terminal that the terminal has switched from the cell managed by the first network device to the third cell, and the protocol stack processing operation group identifier of the cell managed by the first network device is the same as the protocol stack group identifier of the third cell, the second protocol stack processing behavior is executed; or, if it is determined based on the access information of the terminal that the terminal has switched from the cell managed by the first network device to the third cell, and the protocol stack processing operation group identifier of the cell managed by the first network device is different from the protocol stack group identifier of the third cell, the first protocol stack processing behavior is executed.

[0026] In the present application, the first network device determines the protocol stack processing behavior with reference to the access information of the terminal, which can avoid inconsistencies with the protocol stack processing behavior on the terminal side.

[0027] In an optional manner, when at least one of the following conditions is met, the first network device deletes the protocol stack processing state:

[0028] The terminal switches to a cell managed by a second network device; or the protocol stack processing operation group identifier of the switching cell of the terminal is different from the protocol stack processing operation group identifier of the source cell of the terminal; or, it is determined that the terminal executes the first protocol stack processing behavior.

[0029] This approach can prevent the first network device from storing the protocol stack processing state for a long time, thereby preventing storage pressure from occurring.

[0030] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0031] RLC re-establishment, MAC reset, PDCP re-establishment.

[0032] Specifically, the second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, and PDCP data recovery.

[0033] In a third aspect, the present application provides a communication method that can be applied to a first network device or a chip of the first network device, which is not specifically limited herein. The first network device can be a base station, an access point, etc. The first network device can be a CU or DU, or a device that combines a CU and a DU, or a gNB, etc. The method can be applied to 5G communication systems or communication systems above 5G, and can also be applied to non-terrestrial communication systems, which is not specifically limited herein. In actual application, the method is performed as follows:

[0034] Instructing a terminal to switch from a first cell to a second cell; determining that the terminal accesses a third cell, where both the first cell and the third cell are managed by a first network device; and determining a protocol stack processing behavior based on reference information, wherein the reference information includes at least one of the following:

[0035] The protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell; the storage status of the protocol stack processing state in the first network device; or the access information of the terminal.

[0036] In the present application, the first network device refers to the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell to determine the storage status of the protocol stack processing state in the first network device; or, the access information of the terminal determines the protocol stack processing behavior. When the terminal accesses the third cell, the first network device adopts the protocol stack processing behavior aligned with the terminal, which can reduce the interruption time caused by switching failure, which is beneficial to improving the UE's service experience.

[0037] In an optional manner, when the reference information includes a protocol stack processing operation group identifier of the first cell, a protocol stack processing operation group identifier of the second cell, and a protocol stack processing operation group identifier of the third cell, determining the protocol stack processing behavior according to the reference information includes:

[0038] If the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different, the first protocol stack processing behavior is executed; or, if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are all the same, the second protocol stack processing behavior is executed.

[0039] In this application, the first protocol stack processing behavior is executed only when the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different. It is necessary to combine the protocol stack processing operation identifiers of the three cells to make a judgment that is consistent with the judgment logic on the terminal side, which can avoid inconsistencies with the protocol stack processing behavior on the terminal side.

[0040] In an optional manner, when the reference information includes storage status of a protocol stack processing state in the first network device, determining the protocol stack processing behavior according to the reference information includes:

[0041] If it is determined that the protocol stack processing status is not stored in the first network device, the first protocol stack processing behavior is executed; or, if it is determined that the protocol stack processing status is stored in the first network device, and the protocol stack processing operation group identifier of the cell corresponding to the stored protocol stack processing status is the same as the protocol stack group identifier of the third cell, the second protocol stack processing behavior is executed; or, if it is determined that the protocol stack processing status is stored in the first network device, and the protocol stack processing operation group identifier of the cell corresponding to the stored protocol stack processing status is different from the protocol stack group identifier of the third cell, the first protocol stack processing behavior is executed.

[0042] In the present application, the first network device determines the protocol stack processing behavior by referring to the storage status of the protocol stack processing state in the first network device, which can avoid inconsistency with the protocol stack processing behavior on the terminal side.

[0043] In an optional manner, when the reference information includes access information of the terminal, determining the protocol stack processing behavior according to the reference information includes:

[0044] If it is determined based on the access information of the terminal that the terminal has not switched from the cell managed by the first network device to the third cell, the first protocol stack processing behavior is executed; or, if it is determined based on the access information of the terminal that the terminal has switched from the cell managed by the first network device to the third cell, and the protocol stack processing operation group identifier of the cell managed by the first network device is the same as the protocol stack group identifier of the third cell, the second protocol stack processing behavior is executed; or, if it is determined based on the access information of the terminal that the terminal has switched from the cell managed by the first network device to the third cell, and the protocol stack processing operation group identifier of the cell managed by the first network device is different from the protocol stack group identifier of the third cell, the first protocol stack processing behavior is executed.

[0045] In the present application, the first network device determines the protocol stack processing behavior with reference to the access information of the terminal, which can avoid inconsistencies with the protocol stack processing behavior on the terminal side.

[0046] In an optional manner, when at least one of the following conditions is met, the first network device deletes the protocol stack processing state:

[0047] The terminal switches to a cell managed by a second network device; or the protocol stack processing operation group identifier of the switching cell of the terminal is different from the protocol stack processing operation group identifier of the source cell of the terminal; or, it is determined that the terminal executes the first protocol stack processing behavior.

[0048] This approach can prevent the first network device from storing the protocol stack processing state for a long time, thereby preventing storage pressure from occurring.

[0049] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0050] RLC re-establishment, MAC reset, PDCP re-establishment.

[0051] Specifically, the second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, and PDCP data recovery.

[0052] Fourthly, the present application provides a communication method that can be applied to a terminal or a terminal chip, which is not specifically limited here. The terminal can be a mobile phone, a vehicle-mounted device, an Internet of Things device, etc. The method can be applied to 5G communication systems or communication systems above 5G, and can also be applied to non-terrestrial communication systems, which is not specifically limited here. In actual application, the method is performed as follows:

[0053] When the terminal fails to switch from the first cell to the second cell, a cell selection operation is performed to determine a third cell; when the terminal accesses the third cell, a first protocol stack processing behavior is executed; wherein the first protocol stack processing behavior includes at least one of the following: RLC re-establishment, MAC reset, or PDCP re-establishment.

[0054] In the present application, once a cell switching behavior occurs, the terminal executes the first protocol stack processing behavior, which can avoid the occurrence of inconsistencies with the protocol stack processing behavior on the first network device side.

[0055] In a fifth aspect, the present application provides a communication method, which can be applied to a first network device or a chip of the first network device, which is not specifically limited here. The first network device can be a base station, an access point, etc. The first network device can be a CU or DU, or a device equipped with a CU and DU, or a gNB, etc. The method can be applied to 5G communication systems or communication systems above 5G, and can also be applied to non-terrestrial communication systems, which is not specifically limited here. In actual application, the method is performed as follows:

[0056] Determine that the terminal accesses a third cell, which is managed by a first network device; execute a first protocol stack processing behavior according to reference information; wherein the reference information satisfies at least one of the following: the protocol stack processing status is not stored in the first network device; the first network device determines that the terminal accesses the third cell from the cell managed by the second network device; the first network device determines that the terminal accesses the third cell after a cell handover fails; wherein the first protocol stack processing behavior includes at least one of the following: RLC re-establishment, MAC reset, or PDCP re-establishment.

[0057] In the present application, when the first network device determines that one of the above reference information is satisfied, it executes the first protocol stack processing behavior, which can avoid the occurrence of inconsistency with the terminal side protocol stack processing behavior.

[0058] In a sixth aspect, the present application provides a communication method that can be applied to a terminal or a chip of a terminal, which is not specifically limited here. The terminal can be a mobile phone, a vehicle-mounted device, an Internet of Things device, etc. The method can be applied to a 5G communication system or a communication system above 5G, and can also be applied to a non-terrestrial communication system, which is not specifically limited here. In actual application, the method is performed as follows:

[0059] When the terminal fails to switch from the first cell to the second cell, the protocol stack processing state is called back to the protocol stack processing state corresponding to the first cell; when the terminal accesses the third cell, the protocol stack processing behavior is determined according to the protocol stack processing operation group identifier of the first cell and the protocol stack processing operation group identifier of the third cell. The third cell is the cell determined after the terminal performs the cell selection operation.

[0060] In the present application, the terminal determines the protocol stack processing behavior by referring to the protocol stack processing operation group identifier of the source cell (i.e., the first cell) and the protocol stack operation group identifier of the cell (i.e., the third cell) determined by the cell selection operation after the handover fails, so as to avoid access failure caused by the misalignment of the protocol stack processing behavior with the first network device (i.e., the network device that manages the third cell) when accessing the third cell. This can reduce the interruption time caused by the handover failure, which is beneficial to improving the service experience of the UE.

[0061] In an optional manner, determining the protocol stack processing behavior according to the protocol stack processing operation group identifier of the first cell and the protocol stack processing operation group identifier of the third cell includes:

[0062] If the protocol stack processing operation group identifier of the first cell is different from the protocol stack processing operation group identifier of the third cell, the first protocol stack processing behavior is executed; or, if the protocol stack processing operation group identifier of the first cell is the same as the protocol stack processing operation group identifier of the third cell, the second protocol stack processing behavior is executed.

[0063] In this application, the first protocol stack processing behavior is only executed when the protocol stack processing operation group identifier of the first cell is different from the protocol stack processing operation group identifier of the third cell, so as to avoid inconsistency with the protocol stack processing behavior on the first network device side.

[0064] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0065] RLC re-establishment, MAC reset, or PDCP re-establishment.

[0066] Specifically, the second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, or PDCP data recovery.

[0067] In a seventh aspect, the present application provides a communication method, which can be applied to a first network device or a chip of the first network device, which is not specifically limited here. The first network device can be a base station, an access point, etc. The first network device can be a CU or DU, or a device that combines a CU and DU, and can also be a gNB, etc. The method can be applied to 5G communication systems or communication systems above 5G, and can also be applied to non-terrestrial communication systems, which is not specifically limited here. In actual application, the method is performed as follows:

[0068] Determine that the terminal accesses a third cell, which is managed by a first network device; determine a protocol stack processing behavior based on first reference information; wherein the first reference information indicates at least one of the following: access information of the terminal; or second reference information of the protocol stack processing behavior reported by the terminal.

[0069] In the present application, the first network device determines the protocol stack processing behavior by referring to the access information of the terminal or the second reference information of the protocol stack processing behavior reported by the terminal, which can reduce the interruption time caused by the switching failure and is conducive to improving the service experience of the UE.

[0070] In an optional manner, the first reference information indicates access information of the terminal, and determining a protocol stack processing behavior according to the first reference information includes:

[0071] If it is determined according to the access information that the terminal accesses the third cell from the second cell managed by the second network device, the first protocol stack processing behavior is executed; or, if it is determined according to the access information that the terminal accesses the third cell from the first cell managed by the first network device, and the protocol stack processing operation group identifier of the first cell is different from the protocol stack group identifier of the third cell, the first protocol stack processing behavior is executed; or, if it is determined according to the access information that the terminal accesses the third cell from the first cell managed by the first network device, and the protocol stack processing operation group identifier of the first cell is the same as the protocol stack group identifier of the third cell, the second protocol stack processing behavior is executed.

[0072] In the present application, the first network device determines the protocol stack processing behavior with reference to the access information of the terminal, which can avoid inconsistencies with the protocol stack processing behavior on the terminal side.

[0073] In an optional manner, the access information is determined by third reference information, and the third reference information includes at least one of the following:

[0074] A first notification message from the second network device for switching to the third cell, and a second notification message for the terminal successfully switching from the first cell to the second cell. The first cell is managed by the first network device, and the second cell is managed by the second network device.

[0075] In this application, data processing efficiency can be improved by determining access information through third reference information.

[0076] In an optional manner, the first reference information indicates second reference information of the protocol stack processing behavior reported by the terminal; the second reference information includes at least one of the following: execution status of the protocol stack processing behavior in the terminal; or access mode of the terminal; determining the protocol stack processing behavior based on the first reference information includes:

[0077] If the execution status of the protocol stack processing behavior in the terminal indicates that the terminal executes the first protocol stack processing behavior, the first protocol stack processing behavior is executed; or, if the execution status of the protocol stack processing behavior in the terminal indicates that the terminal executes the second protocol stack processing behavior, the second protocol stack processing behavior is executed; or, if the access method of the terminal indicates that the terminal is switching the cell after a successful cell switching, the first protocol stack processing behavior is executed; or, if the access method of the terminal indicates that the terminal is selecting a cell after a cell switching failure, the second protocol stack processing behavior is executed.

[0078] In the present application, the first network device determines the protocol stack processing behavior by referring to the second reference information of the protocol stack processing behavior reported by the terminal, which can avoid inconsistency with the protocol stack processing behavior on the terminal side.

[0079] In an optional manner, when at least one of the following conditions is met, the first network device stores the protocol stack processing status:

[0080] The protocol stack processing operation group identifier of the candidate cell managed by the first network device contains the same protocol stack processing operation group identifier as the protocol stack processing operation group identifier of the first cell; the first network device determines that the terminal leaves the first cell within a set timer duration.

[0081] This approach can prevent the first network device from storing the protocol stack processing state for a long time, thereby preventing storage pressure from occurring.

[0082] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0083] RLC re-establishment, MAC reset, PDCP re-establishment.

[0084] Specifically, the second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, and PDCP data recovery.

[0085] In an eighth aspect, an embodiment of the present application provides a communication device, which may be a terminal (such as the terminal in the first aspect or a chip disposed inside the terminal, a first network device or a chip disposed inside the first network device). The communication device has the functions of implementing the above-mentioned first to seventh aspects. For example, the communication device includes modules or units or means corresponding to the steps involved in the above-mentioned first to seventh aspects. The functions or units or means may be implemented by software, or by hardware, or the corresponding software implementation may be executed by hardware.

[0086] In one possible design, the communication device includes a processing unit and a transceiver unit, wherein the transceiver unit can be used to send and receive signals to achieve communication between the communication device and other devices, for example, the transceiver unit is used to receive a first message; the processing unit can be used to perform some internal operations of the communication device. The transceiver unit can be called an input / output unit, a communication unit, etc., and the transceiver unit can be a transceiver; the processing unit can be a processor. When the communication device is a module (such as a chip) in a communication device, the transceiver unit can be an input / output interface, an input / output circuit, or an input / output pin, etc., and can also be called an interface, a communication interface, or an interface circuit, etc.; the processing unit can be a processor, a processing circuit, or a logic circuit, etc.

[0087] In another possible design, the communication device includes a processor and may also include a transceiver, the transceiver is used to send and receive signals, and the processor executes program instructions to complete the method in any possible design or implementation of the first to seventh aspects above. The communication device may also include one or more memories, the memory is used to couple with the processor, and the memory can store the necessary computer programs or instructions for implementing the functions involved in the first aspect above. The processor can execute the computer program or instructions stored in the memory, and when the computer program or instructions are executed, the communication device implements the method in any possible design or implementation of the first to seventh aspects above.

[0088] In another possible design, the communication device includes a processor, which can be coupled to a memory. The memory can store the necessary computer programs or instructions for implementing the functions of the first to seventh aspects described above. The processor can execute the computer programs or instructions stored in the memory. When the computer programs or instructions are executed, the communication device implements the method in any possible design or implementation of the first to seventh aspects described above.

[0089] In another possible design, the communication device includes a processor and an interface circuit, wherein the processor is used to communicate with other devices through the interface circuit and execute the method in any possible design or implementation of the first to seventh aspects above.

[0090] It can be understood that in the eighth aspect above, the processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading the software code stored in the memory. In addition, the above processors can be one or more, and the memories can be one or more. The memory can be integrated with the processor, or the memory and the processor can be set separately. In the specific implementation process, the memory can be integrated with the processor on the same chip, or can be set on different chips respectively. The embodiment of the present application does not limit the type of memory and the setting method of the memory and the processor.

[0091] In a ninth aspect, an embodiment of the present application provides a communication system, which includes the above-mentioned terminal and a first network device.

[0092] In a tenth aspect, the present application provides a chip system, which includes a processor and may also include a memory, for implementing the methods described in aspects 1 to 7. The chip system may be composed of a chip, or may include a chip and other discrete devices.

[0093] In the eleventh aspect, the present application also provides a computer-readable storage medium, in which computer-readable instructions are stored. When the computer-readable instructions are executed on a computer, the computer executes the methods in the first to seventh aspects.

[0094] In a twelfth aspect, the present application provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the methods of the embodiments of the first to seventh aspects described above.

[0095] For the technical effects that can be achieved in the above-mentioned second to twelfth aspects, please refer to the description of the technical effects that can be achieved by the corresponding possible design schemes in the above-mentioned first aspect, and this application will not repeat them here. BRIEF DESCRIPTION OF THE DRAWINGS

[0096] FIG1 shows a schematic diagram of a communication system provided by an embodiment of the present application;

[0097] FIG2A shows a schematic diagram of cell selection after a cell handover failure;

[0098] FIG2B shows a schematic diagram of a cell handover process flow;

[0099] FIG3 shows a flow chart of a communication method provided in an embodiment of the present application;

[0100] FIG4 shows a schematic diagram of cell selection after a cell handover failure;

[0101] FIG5 shows a flow chart of a communication method provided in an embodiment of the present application;

[0102] FIG6 shows a flow chart of a communication method provided in an embodiment of the present application;

[0103] FIG7 shows a flow chart of a communication method provided in an embodiment of the present application;

[0104] FIG8 shows a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0105] FIG9 shows a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0106] FIG10 shows a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0107] In order to make the purpose, technical solutions and advantages of this application clearer, the present application will be further described in detail below with reference to the accompanying drawings. The specific operating methods in the method embodiments can also be applied to the device embodiments or system embodiments. In the description of this application, unless otherwise specified, "multiple" means two or more. Therefore, the implementation of the device and method can refer to each other, and the repeated parts will not be repeated.

[0108] The technical solutions provided in the embodiments of the present application can be applied to 5G systems, or to future communication systems or other similar communication systems. In addition, the technical solutions provided in the embodiments of the present application can be applied to cellular links, public land mobile networks (PLMN), machine to machine (M2M) networks, Internet of Things (IoT) networks or other networks. It can also be applied to links between devices, such as device to device (D2D) links. D2D links can also be called sidelinks, where sidelinks can also be called side links or side links, etc. In the embodiments of the present application, the above terms all refer to links established between devices of the same type, and their meanings are the same. The so-called devices of the same type can be links between terminal devices, links between base stations, links between relay nodes, etc., and the embodiments of the present application do not limit this. For links between terminal devices, there are D2D links defined in Release (Rel) 12 / 13 of the Third Generation Partnership Project (3GPP), as well as V2X links defined for vehicle-to-vehicle, vehicle-to-mobile phone, or vehicle-to-any-entity (V2X) for the Internet of Vehicles (IoV), including Rel-14 / 15. Also included are V2X links based on the New Radio (NR) system defined in Rel-18 and later.

[0109] Reference is made to Figure 1, which is a schematic diagram of a wireless communication system applicable to the present invention. The wireless communication system may include at least one network device, such as network device 111, network device 112, and network device 113 shown in Figure 1. The wireless communication system may also include at least one terminal device, such as terminal device 121, terminal device 122, terminal device 123, terminal device 124, terminal device 125, terminal device 126, and terminal device 127 shown in Figure 1. Network devices and terminal devices can communicate with each other, such as in multi-site transmission as shown in Figure 1, where network device 112 can communicate with terminal devices 121, 122, and 123; or in enhanced mobile broadband (eMBB) transmission as shown in Figure 1, where network devices 112 and 113 can communicate with terminal device 124. Network devices can also communicate with each other, such as in backhaul as shown in Figure 1, where network device 111 can communicate with network devices 112 and 113. Terminal devices may also communicate with each other, such as the D2D transmission shown in FIG. 1 , where, for example, terminal device 122 may communicate with terminal device 125 .

[0110] A terminal device may be a wireless terminal device capable of receiving network device scheduling and instruction information. A wireless terminal device may be a device that provides voice and / or data connectivity to a user, or a handheld device with wireless connection capabilities, or other processing devices connected to a wireless modem. A wireless terminal device may communicate with one or more core networks or the Internet via a radio access network (RAN). A wireless terminal device may be a mobile terminal device, such as a mobile phone (also known as a "cellular" phone, mobile phone), a computer, and a data card. For example, a mobile device may be portable, pocket-sized, handheld, built-in, or in-vehicle, and may exchange voice and / or data with a radio access network. Examples include personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, PDAs, tablet computers, and computers with wireless transceiver capabilities. A wireless terminal device may also be referred to as a system, a subscriber unit, a subscriber station, a mobile station, a mobile station (MS), a remote station, an access point (AP), a remote terminal, an access terminal, a user terminal, a user agent, a subscriber station (SS), a customer premises equipment (CPE), a terminal, a user equipment (UE), a mobile terminal (MT), etc. A wireless terminal device may also be a wearable device and a next-generation communication system, for example, a terminal device in a 5G network or a terminal device in a future evolved public land mobile network (PLMN) network, a terminal device in an NR communication system, etc.

[0111] A network device is an entity on the network side used to transmit or receive signals, such as a transmission reception point (TRP) or gNB. A network device can be a device used to communicate with mobile devices. A network device can be an access point (AP) in a wireless local area network (WLAN), a base transceiver station (BTS) in a global system for mobile communication (GSM) or code division multiple access (CDMA), a base station (NodeB) in wideband code division multiple access (WCDMA), an evolutionary Node B (eNB or eNodeB) in long-term evolution (LTE), a relay station or access point, or a network device in an in-vehicle device, wearable device, future 5G network, or future evolved PLMN, or a gNodeB / gNB in ​​a NR system. In some deployments, a gNB can include a CU and DU. A gNB can also include an active antenna unit (AAU). The CU implements some gNB functions, while the DU implements some gNB functions. For example, the CU is responsible for processing non-real-time protocols and services, such as radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP). The DU is responsible for processing physical layer protocols and real-time services, such as radio link control (RLC), medium access control (MAC), and physical (PHY) layer functions. The AAU implements some physical layer processing functions, RF processing, and active antenna-related functions. Because RRC layer information ultimately becomes PHY layer information, or is converted from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or by both the DU and the AAU. It is understood that a network device can be a device that includes one or more of a CU node, a DU node, or an AAU node.In addition, the CU can be divided into a network device in the access network (radio access network, RAN), or the CU can be divided into a network device in the core network (core network, CN), which is not limited in this application. In addition, in an embodiment of the present application, the network device provides services for a cell, and the terminal device communicates with the network device through the transmission resources used by the cell (for example, frequency domain resources, or spectrum resources). The cell can be a cell corresponding to the network device (for example, a base station). The cell can belong to a macro base station or a base station corresponding to a small cell. The small cell here can include: a metro cell, a micro cell, a pico cell, a femto cell, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services. In addition, in other possible cases, the network device may be other devices that provide wireless communication functions for terminal devices. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network device. For the convenience of description, in the embodiments of the present application, the device that provides wireless communication functions for terminal devices is referred to as a network device.

[0112] The following describes the operations of a terminal performing cell handover and cell selection with reference to Figures 2A and 2B. This description uses the example of a terminal being a UE, a network device including a CU and a DU, and a CU managing DU1 and DU2. Figure 2A shows that DU1 manages cells 1 and 3, and DU2 manages cell 2. This is merely an example and does not specifically limit the cells managed by each DU. In Figure 2A, the UE fails to successfully handover from cell 1 to cell 2 and, after cell selection, accesses cell 3. Referring to Figure 2B, the following operations are performed:

[0113] Step 201: The CU establishes a UE context with the target DU and obtains configuration information of the cell managed by the target DU.

[0114] Among them, the target DU can also be called a candidate DU before performing cell switching; when the switching decision determines that the target cell is a cell managed by a candidate DU, the candidate DU can be called a target DU. In the example of Figure 2A, the target DU is DU2.

[0115] Step 202: The CU sends the configuration information of the candidate cells to the UE via the source DU.

[0116] In the example of FIG2A , Cell1 is the source cell of UE1 , DU1 is the source DU, and Cell2 and Cell3 are candidate cells.

[0117] Step 203: The UE sends L1 (layer 1) measurement results of different cells to the source DU via the communication resources of the source cell.

[0118] The L1 measurement result includes at least one of the following: the L1 measurement result of the source cell and the L1 measurement result of at least one candidate cell. The L1 measurement result may be a cell-level measurement result or a beam-level measurement result, which is not specifically limited herein. Based on the example of FIG. 2A , the L1 measurement result includes at least one of the following: the measurement results of cell 1, cell 2, and cell 3.

[0119] In step 204, the source DU determines that the UE should perform L1 / L2 Triggered Mobility (LTM) handover based on the L1 measurement results of different cells, and sends the identification information of the associated target cell to the UE through LTM handover signaling.

[0120] The LTM handover signaling is still sent by the communication resources of the source cell. Furthermore, the LTM handover signaling may indicate the beam direction information that the UE should use when communicating with the target cell.

[0121] In the example in the figure, the target cell indicated by the LTM handover command is Cell2.

[0122] Step 205A: The source DU sends a notification message to the CU.

[0123] The notification message indicates that the UE has performed LTM switching.

[0124] Optionally, step 205B may also be performed.

[0125] Step 205B: The CU sends a notification message to the target DU.

[0126] The notification message indicates that the UE has performed LTM switching.

[0127] In step 206, the UE performs LTM handover and accesses the target cell using the configuration information of the target cell received in step 202. After successful access, the UE starts uplink and downlink data transmission with the target cell.

[0128] Furthermore, the UE may use the beam direction information indicated in step 204 to perform uplink and downlink data transmission with the target cell.

[0129] Step 207: After the UE successfully accesses the target DU, the target DU sends a notification message of successful access to the CU.

[0130] The above step 207 only exists when the handover is successful. For the handover failure scenario that this application focuses on, step 206 is not successfully executed, so step 207 will not be executed.

[0131] Step 208: When the UE recognizes that the handover fails, the UE performs cell selection.

[0132] In the example of FIG2A , the UE selects Cell3 managed by DU1 , and Cell3 is a candidate cell configured in step 202 , and the UE applies the configuration information of the cell and accesses Cell3 .

[0133] Step 209: The UE accesses Cell 3.

[0134] In step 210, the DU (ie, DU1) of the cell to which the UE successfully accesses sends a notification message of successful access to the CU.

[0135] Maintaining L2 behavior when a UE switches from a source cell to a target cell facilitates data transmission continuity after the cell handover. The following description uses RLC behavior as an example of L2 behavior. In actual applications, other protocol stack processing behaviors, such as MAC and PCDP, may also be included. In conjunction with the scenario in Figure 2A above, the network device can be configured to perform RLC re-establishment when switching from Cell 1 to Cell 2, perform RLC maintenance when switching from Cell 1 to Cell 3, and perform RLC re-establishment when switching from Cell 2 to Cell 3.

[0136] However, when steps 208 to 209 in FIG. 2B are executed, the UE switches from Cell 1 to Cell 3 and performs RLC maintenance. However, the network device (DU1) believes that the UE is switching from Cell 2 to Cell 3 and performs RLC re-establishment. In addition, if the UE successfully performs steps 206 to 207 in FIG. 2B and switches from Cell 1 to Cell 2, and then DU2 instructs the UE to switch from Cell 2 to Cell 3, during the switching process from Cell 2 to Cell 3, the UE performs RLC re-establishment, but the network device (DU1) mistakenly believes that the UE is performing cell handover failure recovery in steps 208 to 209 in FIG. 2B. Therefore, DU1 believes that the UE is switching from Cell 1 to Cell 3, and DU1 performs RLC maintenance. The above will result in misalignment of the RLC behavior of the UE and the network device, resulting in problems in the RLC transmission and reception process.

[0137] Based on this, the present application provides a communication method to ensure that in the scenario of cell switching failure, the L2 behavior of the UE is aligned with the L2 behavior of the network device. The present application determines the protocol stack processing behavior of the terminal and the network device with reference to the protocol stack processing operation identifier of the cell, the storage of the protocol stack processing status, and the access information of the terminal. In order to better illustrate the scheme of the present application, it is introduced below with reference to three specific implementation methods. The terminal in the following specific implementation method can be the terminal itself or the chip inside the terminal. The following description takes the terminal as a UE as an example. The first network device can be the first network device itself or the chip inside the first network device. The following first network device and the second network device can be a device that is a combination of CU and DU, can be CU or DU, or can be gNB, etc., which is not specifically limited here. The specific form of the first network device is only specifically described below.

[0138] Implementation Method 1:

[0139] The technical solution of the present application is described in detail below with reference to a specific method embodiment in conjunction with Figure 3. It should be noted that Figure 3 is a schematic flow chart of a method embodiment of the present application, which shows the detailed communication steps or operations of the method, but these steps or operations are only examples. The embodiment of the present application can also perform other operations or variations of the various operations in Figure 3. In addition, the various steps in Figure 3 can be performed in a different order from that presented in Figure 3, and it is possible that not all operations in Figure 3 need to be performed. In Figure 3, the terminal is UE, the network device includes CU and DU as an example, and the CU governs DU1 (first network device) and DU2 (second network device) as an example. As shown in Figure 3, the method is performed as follows:

[0140] Step 301: CU establishes a UE context with DU2 and obtains configuration information of the cell managed by DU2.

[0141] The above configuration information may include the protocol stack processing operation identifier of the cell.

[0142] Step 302: The CU sends the configuration information of the candidate cell to the UE via DU1.

[0143] In step 303, the UE sends L1 (layer 1) measurement results of different cells to DU1 via the communication resources of the source cell (first cell).

[0144] Step 304: DU1 determines that the UE should perform LTM-based handover based on the L1 measurement results of different cells, and sends the identification information of the associated target cell (second cell) to the UE through LTM handover signaling.

[0145] It can be understood that DU1 instructs the terminal to switch from the first cell to the second cell.

[0146] Step 305A: DU1 sends a notification message to CU.

[0147] Optionally, step 305B may also be performed.

[0148] Step 305B: CU sends a notification message to DU2.

[0149] The above steps 301 to 305B can be understood by referring to steps 201 to 205B in FIG. 2B , and are not described in detail here.

[0150] Step 306: The UE performs LTM handover from the first cell to the second cell.

[0151] The first cell is managed by DU1, and the second cell is managed by DU2. In the above step 306, when executing the handover from the first cell to the second cell, the UE determines whether the protocol stack processing operation identifiers of the first cell and the second cell are the same. If they are the same, the first protocol stack processing behavior is executed; if they are different, the second protocol stack processing behavior is executed. The first protocol stack processing behavior includes at least one of the following: RLC re-establishment, MAC reset, or PDCP re-establishment. The second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, or PDCP data recovery. It can be understood with reference to the existing protocol and will not be repeated here. The following parts involving the first protocol stack processing behavior and the second protocol stack processing behavior can be understood with reference to this understanding and will not be repeated. For example, RLC re-establishment can be understood as the re-establishment of the RLC processing state, and MAC reset can be understood as the reset of the MAC state. For example, in Figure 2A above, the protocol stack processing operation identifiers of Cell1 and Cell2 are different, so the UE executes RLC re-establishment.

[0152] Step 307: When the UE fails to switch from the first cell to the second cell, the UE performs a cell selection operation to determine a third cell.

[0153] Specifically, when the UE determines to perform LTM handover, it may start a timer (referred to as timer T304). If the UE has not successfully accessed the second cell after the timer expires, the UE determines that a cell handover failure has occurred. The third cell is managed by DU1 and is also a candidate cell provided to the UE in step 302.

[0154] Step 308: When the UE accesses the third cell, the protocol stack processing behavior is determined according to the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell.

[0155] The above-mentioned first cell and third cell are managed by DU1 and may have the same protocol stack processing operation group identifier, such as ID=1. The above-mentioned second cell is managed by DU2, and its protocol stack processing operation group identifier may be ID=2. This is only an illustrative description and does not specifically limit the protocol stack processing operation group identifier. The protocol stack group identifiers of the cells managed by the same DU may be the same or different. For example, the protocol stack group identifier of the cell Cell1 managed by DU1 is ID=1-1, and the protocol stack group identifier of the cell Cell3 managed by DU1 is ID=1-3. This is only an illustrative description.

[0156] When executing step 308, the UE may directly compare the protocol stack processing operation identifiers of the first cell, the second cell, and the third cell, and determine the protocol stack processing behavior based on whether the protocol stack processing operation identifiers are the same.

[0157] Specifically, if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different, the first protocol stack processing behavior is executed; or, if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are all the same, the second protocol stack processing behavior is executed.

[0158] For example, in Figure 2A above, the protocol stack processing operation group identifier of Cell1 is ID=1, the protocol stack processing operation group identifier of Cell2 is ID=2, and the protocol stack processing operation identifier of Cell3 is ID=1. If the protocol stack processing operation group identifiers of Cell1, Cell2, and Cell3 are different, the first protocol stack processing behavior is executed. In Figure 4, the cells managed by DU1 include Cell1, Cell2, and Cell3. The UE fails to switch from Cell1 to Cell2 and performs a cell selection operation to select Cell3. If the protocol stack processing operation group identifier of Cell1 is ID=1, the protocol stack processing operation group identifier of Cell2 is ID=1, and the protocol stack processing operation identifier of Cell3 is ID=1, then the protocol stack processing operation group identifiers of Cell1, Cell2, and Cell3 are the same, and the second protocol stack processing behavior is executed.

[0159] In one possible implementation, when a cell handover failure occurs, the UE first calls back (which may also be referred to as fallback, recovery, adjustment, etc., which are not specifically limited herein) to the protocol stack processing state of the source cell (i.e., the first cell), such as the RLC processing state, and then executes the first protocol stack processing behavior or the second protocol stack processing behavior when accessing the third cell through failure recovery. Optionally, in another possible implementation, when a handover failure occurs, the UE does not need to call back to the protocol stack processing state of the source cell, and then executes the first protocol stack processing behavior or the second protocol stack processing behavior when accessing the third cell through failure recovery. The above-mentioned callback RLC processing status may include at least one of the following: rolling back the sending-related state variables to the variable values ​​of the source cell (i.e., the first cell) (sending-related state variables such as: TX_Next_Ack-Acknowledgement state variable sending side confirmation state variable, TX_Next-Send state variable sending side sending state variable, POLL_SN-Poll send state variable polling sending state variable); rolling back the sending-related counters to the count values ​​of the source cell (i.e., the first cell) (sending-related counters such as: PDU_WITHOUT_POLL-Counter unpolled packet counter, BYTE_WITHOUT_POLL-Counter unpolled byte counter, RETX_COUNT-Counter retransmission counter); rolling back the receiving-related state variables to the variable values ​​of the source cell (i.e., the first cell) (receiving-related state variables such as: RX_Next-Receive state variable receiving side receiving state variable); rolling back the sending or receiving-related timers (such as: t-PollRetransmit polling retransmission timer, t-Reassembly receiving reassembly timer) to the timing values ​​of the source cell. The operation of calling back to the protocol stack processing status of the source cell may be performed with reference to the existing protocol description, which will not be described in detail here.

[0160] Step 309: DU1 determines that the terminal has accessed the third cell, and determines a protocol stack processing behavior based on the reference information.

[0161] The reference information includes at least one of the following: a protocol stack processing operation group identifier of the first cell, a protocol stack processing operation group identifier of the second cell, and a protocol stack processing operation group identifier of the third cell; storage information of the protocol stack processing state in the first network device; or terminal access information. Based on different reference information, DU1 can perform different protocol stack processing behaviors. The following describes the solution of this application based on different reference information.

[0162] Case 1: The reference information includes the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell.

[0163] If the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different, the first protocol stack processing behavior is executed; or, if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are all the same, the first protocol stack processing behavior is executed.

[0164] The judgment logic of DU1 in case 1 is the same as that in the above step 308 and can be understood by reference. Therefore, when the reference information is case 1, the consistency of the protocol stack processing behaviors on the UE and DU1 sides can be guaranteed.

[0165] Case 2: The reference information includes the storage of the protocol stack processing status in the first network device

[0166] If it is determined that the protocol stack processing state is not stored in the first network device, the first protocol stack processing behavior is executed; or, if it is determined that the protocol stack processing state is stored in the first network device, and the protocol stack processing operation group identifier of the cell corresponding to the stored protocol stack processing state (that is, the first cell) is the same as the protocol stack group identifier of the third cell, the second protocol stack processing behavior is executed; or, if it is determined that the protocol stack processing state is stored in the first network device, and the protocol stack processing operation group identifier of the cell corresponding to the stored protocol stack processing state is different from the protocol stack group identifier of the third cell, the first protocol stack processing behavior is executed.

[0167] Among them, when DU1 determines that the UE needs to switch from the first cell managed by DU1 to the second cell managed by DU2 (this can be determined by comparing the protocol stack processing identifier of the first cell and the protocol stack processing identifier of the second cell, that is, the protocol stack processing identifier of the first cell is different from the protocol stack processing identifier of the second cell), or when the UE needs to perform the first protocol stack behavior when switching from the first cell to the second cell, DU1 deletes the processing status of the protocol stack, such as the RLC status, and the protocol stack processing status is not stored in DU1. Referring to Figure 2A, when the UE accesses Cell3, it performs the first protocol stack processing behavior. DU1 determines that the UE needs to switch from cell1 to cell2, so the protocol stack processing status is not stored. When the UE accesses Cell3, the first protocol stack processing behavior is also performed. Referring to Figure 4, when the UE accesses Cell3, it performs the second protocol stack processing behavior. Since the UE has not left the cell managed by DU1, DU1 stores the protocol stack processing status, and the protocol stack group identifiers of cell1 and cell3 are the same, then when the UE accesses Cell3, the second protocol stack processing behavior is performed. Referring to Figure 4 , if the protocol stack processing operation group identifier of Cell1 is different from the protocol stack processing operation group identifier of Cell2, but is the same as the protocol stack processing operation group identifier of Cell3, the UE executes the first protocol stack processing behavior when accessing Cell3. Since the UE executed the first protocol stack processing behavior when switching from Cell1 to Cell2, DU1 has deleted the protocol stack processing state. Therefore, when the UE accesses Cell3, DU1 executes the first protocol stack processing behavior. This approach ensures consistency of protocol stack processing behavior on the UE and DU1 sides.

[0168] In addition, when at least one of the following conditions is met, the first network device deletes the protocol stack processing state (e.g., RLC processing state, MAC processing state) to avoid maintaining the protocol stack processing state for a long time and causing storage pressure:

[0169] The terminal switches to a cell managed by the second network device (for example, in FIG2A above, the terminal switches from cell 1 managed by DU1 to cell 2 managed by DU2); or, the protocol stack processing operation group identifier of the terminal's switching cell is different from the protocol stack processing operation group identifier of the terminal's source cell (for example, in FIG2A above, the protocol stack processing operation identifiers of the terminal's source cell cell1 and the terminal's switching cell cell2 are different); or, it is determined that the terminal executes the first protocol stack processing behavior (that is, it is determined that the terminal executes the reconstruction or reset of the protocol stack).

[0170] Case 3: Reference information includes terminal access information

[0171] If it is determined according to the access information of the terminal that the terminal has not switched from the cell managed by the first network device to the third cell, the first protocol stack processing behavior is executed (for example, in Figure 2A above, the terminal fails to successfully switch from the cell cell1 managed by DU1 to the cell cell2 managed by DU2, and then accesses the cell cell3 through cell selection, then DU1 can determine that the terminal is not switched from the cell managed by the first network device, and the first protocol stack processing behavior is executed, which is consistent with the protocol stack processing behavior on the UE side); or, if it is determined according to the access information of the terminal that the terminal is switched from the cell managed by the first network device to the third cell, and the protocol stack processing operation group identifier of the cell managed by the first network device is the same as the protocol stack group identifier of the third cell, the second protocol stack processing behavior is executed (for example, in Figure 4 above, the terminal successfully switches from the cell cell1 managed by DU1 to the cell cell managed by DU2 2, and then switches to cell cell3. If the protocol stack processing operation identifiers of cell1 and cell3 are the same, the second protocol stack processing behavior is executed, which is consistent with the protocol stack processing behavior on the UE side); or, if it is determined according to the access information of the terminal that the terminal switches from the cell managed by the first network device to the third cell, and the protocol stack processing operation group identifier of the cell managed by the first network device is different from the protocol stack group identifier of the third cell, the first protocol stack processing behavior is executed (for example, in Figure 4 above, the terminal successfully switches from the cell cell1 managed by DU1 to the cell cell2 managed by DU2, and then switches to the cell cell3. If the protocol stack processing operation identifiers of cell1 and cell3 are different, the first protocol stack processing behavior is executed, which is consistent with the protocol stack processing behavior on the UE side (the first protocol stack processing behavior is executed if it is determined that the protocol stack processing operation identifiers are different).

[0172] Therefore, when the reference information is case 3, the consistency of the protocol stack processing behaviors on the UE and DU1 sides can be guaranteed.

[0173] Step 310: DU1 sends a notification message of successful access to CU.

[0174] In actual application, the first network device may only know that a terminal has accessed the cell it manages. It is not clear whether the terminal is switching cells or selecting cells after cell switching fails. The technical solution of the present application is described in detail with reference to a specific method embodiment in conjunction with Figure 5. In Figure 5, the terminal is UE, the network device includes CU and DU as an example, and the CU governs DU1, DU2 and DU3 (the first network device) as an example. The second network device can be other network devices other than the first network device, which can be one or more. As shown in Figure 5, the method is performed as follows:

[0175] Step 501: CU establishes a UE context with DU2 and obtains configuration information of the cell managed by DU2.

[0176] Step 502: The CU sends the configuration information of the candidate cell to the UE via DU1.

[0177] In step 503, the UE sends L1 (layer 1) measurement results of different cells to DU1 via the communication resources of the source cell (first cell).

[0178] Step 504: DU1 determines that the UE should perform LTM-based handover based on the L1 measurement results of different cells, and sends the identification information of the associated target cell (second cell) to the UE through LTM handover signaling.

[0179] It can be understood that DU1 instructs the terminal to switch from the first cell to the second cell.

[0180] Step 505A: DU1 sends a notification message to CU.

[0181] Optionally, step 505B may also be performed.

[0182] Step 505B: CU sends a notification message to DU2.

[0183] Step 506: The UE performs LTM handover from the first cell to the second cell.

[0184] The first cell is managed by DU1, and the second cell is managed by DU2. The above steps 501 to 506 can be understood with reference to steps 301 to 306 in FIG3 , and are not described in detail here.

[0185] Step 507: When the UE fails to switch from the first cell to the second cell, the UE performs a cell selection operation to determine a third cell.

[0186] Specifically, when the UE determines to perform LTM handover, it may start a timer (referred to as timer T304). If the UE has not successfully accessed the second cell after the timer expires, the UE determines that a cell handover failure has occurred. The third cell is managed by DU3 and is also a candidate cell provided to the UE in step 302.

[0187] Step 508: When the UE accesses the third cell, the protocol stack processing behavior is determined according to the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell.

[0188] This can be understood with reference to the description of step 308 in FIG. 3 , and will not be further described here. For example, the first protocol stack processing behavior or the second protocol stack processing behavior, wherein the first protocol stack processing behavior includes at least one of the following: RLC re-establishment, MAC reset, or PDCP re-establishment. The second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, MAC partial reset, PDCP maintenance, or PDCP data recovery.

[0189] In FIG5 , the first cell is managed by DU1, the second cell is managed by DU2, and the third cell is managed by DU3. Therefore, the first cell, the second cell, and the third cell have different protocol stack processing operation group identifiers, and the first protocol stack processing behavior is executed.

[0190] Step 509: DU3 determines that the terminal has accessed the third cell and determines a protocol stack processing behavior based on the reference information.

[0191] The reference information includes at least one of the following: storage status of the protocol stack processing state in the first network device; or access information of the terminal. Based on different reference information, DU3 can perform different protocol stack processing behaviors. The following describes the solution of this application based on different reference information situations.

[0192] Case 1: The reference information includes the storage of the protocol stack processing status in the first network device

[0193] If it is determined that the protocol stack processing state is not stored in the first network device, the first protocol stack processing behavior is executed. In Figure 5, since DU3 determines that the UE has not been handed over from the cell it manages to the third cell, DU3 does not store the protocol stack processing state, such as RLC behavior, and executes the first protocol stack processing behavior, such as RLC re-establishment.

[0194] In addition, when at least one of the following conditions is met, the first network device deletes the protocol stack processing state to avoid maintaining the protocol stack processing state for a long time and causing storage pressure:

[0195] The terminal switches to the cell managed by the second network device (the terminal switches from the cell managed by DU3 to the cell managed by DU2); or, determines that the terminal executes the first protocol stack processing behavior (that is, determines that the terminal executes the reconstruction or reset of the protocol stack).

[0196] Case 2: Reference information includes terminal access information

[0197] According to the access information of the terminal, it is determined that the terminal has not switched from the cell managed by the first network device to the third cell, and the first protocol stack processing behavior is executed. Since in Figure 5, DU3 determines that the UE has not switched from the cell it manages to the third cell, the first protocol stack processing behavior is executed, such as RLC re-establishment.

[0198] Therefore, when the reference information is Case 1 and Case 2 above, the consistency of the protocol stack processing behaviors on the UE and DU1 sides can be guaranteed.

[0199] Step 510: DU3 sends a notification message of successful access to CU.

[0200] Implementation Method 2:

[0201] The technical solution of the present application is described in detail below with reference to a specific method embodiment in conjunction with Figure 6. The first network device and the second network device described below can be devices jointly provided by CU and DU, can be CU or DU, can also be gNB, etc. In Figure 6, the terminal is UE, the first network device is CU1, and the second network device is CU2 as an example. The DU under the jurisdiction of CU1 is different from the DU under the jurisdiction of CU2. The cell managed by CU1 is also the cell managed by all DUs under the jurisdiction of CU1, and the cell managed by CU2 is also the cell managed by all DUs under the jurisdiction of CU2. Among them, the second network device can be other network devices except the first network device, which can be one or more. As shown in Figure 6, the method is performed as follows:

[0202] Step 601: CU1 obtains configuration information of candidate cells.

[0203] The candidate cell configuration information may include a protocol stack processing operation identifier of the candidate cell, wherein the candidate cell may include a source cell (ie, the first cell).

[0204] Step 602: CU1 sends the configuration information of the candidate cells to the UE via the DU under its jurisdiction.

[0205] Step 603: The UE sends the L1 measurement results of different cells to CU1 via the communication resources of the source cell (the first cell).

[0206] Step 604: CU1 determines that the UE should perform LTM-based handover based on the L1 measurement results of different cells, and sends the identification information of the associated target cell (second cell) to the UE through LTM handover signaling.

[0207] Step 605: The UE performs LTM handover from the first cell to the second cell.

[0208] The first cell is managed by CU1 and the second cell is managed by CU2. In the above step 605, when executing the handover from the first cell to the second cell, the UE determines whether the protocol stack processing operation identifiers of the first cell and the second cell are the same. If they are the same, the first protocol stack processing behavior is executed; if they are different, the second protocol stack processing behavior is executed. The first protocol stack processing behavior includes at least one of the following: RLC re-establishment, MAC reset, or PDCP re-establishment. The second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, or PDCP data recovery.

[0209] Step 606: When the UE fails to switch from the first cell to the second cell, the UE performs a cell selection operation to determine a third cell.

[0210] Specifically, when the UE determines to perform LTM handover, it may start a timer (referred to as timer T304). If the UE has not successfully accessed the second cell after the timer expires, the UE determines that a cell handover failure has occurred. The third cell is managed by CU1 and is also a candidate cell provided to the UE in step 601.

[0211] Step 607: When the UE accesses the third cell, the first protocol stack processing behavior is executed.

[0212] Step 608: CU1 determines that the terminal has accessed the third cell, and executes the first protocol stack processing behavior according to the reference information.

[0213] The reference information satisfies at least one of the following conditions:

[0214] Reference Information 1: The first network device does not store the protocol stack processing status.

[0215] Reference Information 2: The first network device determines that the terminal accesses the third cell from the cell managed by the second network device.

[0216] Reference information 3: The first network device determines that the terminal accesses the third cell after the cell handover fails.

[0217] Because the terminal switches from the first cell to the second cell, which is not managed by CU1, CU1 does not store a protocol stack processing state that is consistent with reference information 1. CU1 determines that the terminal's access to the third cell from the cell managed by CU1 is inconsistent with reference information 2. CU1 cannot determine that the terminal's access to the third cell after the cell handover failure is inconsistent with reference information 3, so it executes the first protocol stack processing behavior. For example, the protocol stack processing state includes the PDCP processing state, the RLC processing state, and the MAC processing state.

[0218] In the above Figure 4, since the UE fails to switch from Cell1 to Cell2, the cell selection operation is performed to select Cell3, so the first protocol stack processing behavior is executed. At this time, since Cell1, Cell2 and Cell3 are managed by DU1, the protocol stack processing status stored in DU1 is inconsistent with the reference information 1. DU1 determines that the UE does not access the third cell from the cell managed by the second network device, so it is inconsistent with the reference information 2. DU1 determines that the UE accesses the third cell after the cell switching fails, so it is consistent with the reference information 3, and therefore the first protocol stack processing behavior is executed.

[0219] Based on this, the consistency of protocol stack processing behaviors on the UE and CU1 sides can be guaranteed.

[0220] Implementation Method 3:

[0221] The following detailed description of the technical solution of the present application is provided with reference to FIG7 , using a specific method embodiment. The first network device and the second network device described below can be devices that are a combination of a CU and a DU, can be a CU or a DU, or can be a gNB, etc. FIG7 illustrates this using an example in which a terminal is a UE, the first network device is gNB1, and the second network device is gNB2. The second network device can be any other network device other than the first network device, and can be one or more. As shown in FIG7 , the method is performed as follows:

[0222] Step 701: gNB1 obtains the configuration information of the candidate cell.

[0223] The candidate cell configuration information may include a protocol stack processing operation identifier of the candidate cell, wherein the candidate cell may include a source cell (ie, the first cell).

[0224] In step 702, gNB1 sends the configuration information of the candidate cell to the UE.

[0225] In step 703, the UE sends the L1 measurement results of different cells to gNB1 through the communication resources of the source cell (first cell).

[0226] In step 704, gNB1 determines that the UE should perform LTM-based switching based on the L1 measurement results of different cells, and sends the identification information of the associated target cell (second cell) to the UE through LTM switching signaling.

[0227] Optionally, gNB1 may instruct the terminal to switch from the first cell to the second cell.

[0228] Step 705: The UE performs LTM handover from the first cell to the second cell.

[0229] The first cell is managed by gNB1, and the second cell is managed by gNB2. In step 705, during handover from the first cell to the second cell, the UE determines whether the protocol stack processing operation identifiers for the first and second cells are the same. If they are the same, the UE performs the first protocol stack processing action; if they are different, the UE performs the second protocol stack processing action. The first protocol stack processing action includes at least one of the following: RLC re-establishment, MAC reset, or PDCP re-establishment. The second protocol stack processing action includes at least one of the following: RLC maintenance, MAC maintenance, partial MAC reset, PDCP maintenance, or PDCP data recovery.

[0230] Step 706: When the UE fails to switch from the first cell to the second cell, the protocol stack processing state is called back to the protocol stack processing state corresponding to the first cell, and a cell selection operation is performed to determine a third cell.

[0231] Step 707: When the UE accesses the third cell, the protocol stack processing behavior is determined according to the protocol stack processing operation group identifier of the first cell and the protocol stack processing operation group identifier of the third cell.

[0232] Specifically, when the UE determines to perform LTM handover, it may start a timer (referred to as timer T304). If the UE has not successfully accessed the second cell after the timer expires, the UE determines that a cell handover failure has occurred. The third cell is managed by gNB1 and is also a candidate cell provided to the UE in step 601.

[0233] Specifically, if the protocol stack processing operation group identifier of the first cell is different from the protocol stack processing operation group identifier of the third cell, the first protocol stack processing behavior is executed; or, if the protocol stack processing operation group identifier of the first cell is the same as the protocol stack processing operation group identifier of the third cell, the second protocol stack processing behavior is executed.

[0234] For example, referring to FIG2A above, the protocol stack processing operation group identifier of Cell1 is ID=1, the protocol stack processing operation group identifier of Cell2 is ID=2, and the protocol stack processing operation group identifier of Cell3 is ID=1. Then, the protocol stack processing operation group identifier of Cell1 is the same as the protocol stack processing operation group identifier of Cell3, and the second protocol stack processing behavior is executed.

[0235] In step 708, gNB1 determines that the terminal accesses the third cell and determines the protocol stack processing behavior based on the first reference information.

[0236] The first reference information indicates at least one of the following: terminal access information; or second reference information indicating a protocol stack processing behavior reported by the terminal. Based on the first reference information, gNB1 may perform different protocol stack processing behaviors. The following describes the solution of this application based on different scenarios of the first reference information.

[0237] Case 1: The first reference information indicates the access information of the terminal

[0238] The access information is determined by third reference information, and the third reference information includes at least one of the following:

[0239] A first notification message from the second network device regarding handover to the third cell (e.g., notification information sent by gNB2 indicating that the UE performed LTM handover to Cell2) and a second notification message regarding successful handover from the first cell to the second cell (e.g., notification information sent by gNB2 indicating that the terminal successfully handed over from the first cell to the second cell. Furthermore, if the terminal did not successfully handover from the first cell to the second cell, gNB2 may not send the notification message or may send a notification message indicating handover failure, which is not specifically limited here) are received. The first cell is managed by gNB1, and the second cell is managed by gNB2. If gNB1 receives the first notification message or the second notification message, gNB1 no longer stores the protocol stack processing status of the UE.

[0240] If it is determined according to the access information that the terminal accesses the third cell from the second cell managed by the second network device (for example, if the first notification message or the second notification message is received, it is determined that the terminal accesses the third cell from the second cell managed by the second network device (gNB2 in Figure 7 above)), the first protocol stack processing behavior is executed; or, if it is determined according to the access information that the terminal accesses the third cell from the first cell managed by the first network device (for example, if the first notification message or the second notification message is not received, it is determined that the terminal accesses the third cell from the first cell, that is, recovery of cell switching failure), and the protocol stack processing operation group identifier of the first cell is different from the protocol stack group identifier of the third cell, the first protocol stack processing behavior is executed; or, if it is determined according to the access information that the terminal accesses the third cell from the first cell managed by the first network device, and the protocol stack processing operation group identifier of the first cell is the same as the protocol stack group identifier of the third cell, the second protocol stack processing behavior is executed.

[0241] Case 2: The first reference information indicates the second reference information of the protocol stack processing behavior reported by the terminal

[0242] The second reference information includes at least one of the following: an execution status of a protocol stack processing behavior in the terminal; or an access mode of the terminal.

[0243] If the execution status of the protocol stack processing behavior in the terminal indicates that the terminal executes the first protocol stack processing behavior, the first protocol stack processing behavior is executed (for example, if the UE executes RLC re-establishment, then gNB1 also executes RLC re-establishment); or, if the execution status of the protocol stack processing behavior in the terminal indicates that the terminal executes the second protocol stack processing behavior, the second protocol stack processing behavior is executed (for example, if the UE executes partial reset of MAC, then gNB1 also executes partial reset of MAC); or, if the access mode of the terminal indicates that the terminal is performing cell switching after a successful cell switching, the first protocol stack processing behavior is executed; or, if the access mode of the terminal indicates that the terminal is selecting a cell after a failed cell switching, the second protocol stack processing behavior is executed.

[0244] The above-mentioned second reference information can be reported through an L1 message, such as uplink control information (UCI), or an L2 message, such as a media access control control element (MAC CE), or an L3 message, such as a radio resource control (RRC) message.

[0245] When at least one of the following conditions is met, the first network device stores the protocol stack processing status:

[0246] The protocol stack processing operation group identifiers of the candidate cells managed by the first network device contain the same protocol stack processing operation group identifier as the protocol stack processing operation group identifier of the first cell (for example, if gNB1's candidate cells include the first cell, the second cell, and the third cell, and the first cell has the same protocol stack processing operation group identifier as the first cell, gNB1 stores the protocol stack processing state; if gNB1's candidate cells include the second cell and the third cell, and the third cell has the same protocol stack processing operation group identifier as the first cell, gNB1 stores the protocol stack processing state); the first network device determines that the terminal has not left the first cell for more than a set timer duration (for example, after sending a handover command to the UE to leave the first cell, gNB1 starts a timer. When the timer expires, gNB1 no longer stores the protocol stack processing state. No longer storing the protocol stack processing state can also be understood as deleting the previously stored protocol stack processing state. If the set timer duration has not expired, gNB1 stores the protocol stack processing state). The protocol stack processing state includes, for example, the PDCP processing state, the RLC processing state, and the MAC processing state.

[0247] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of device interaction. It is understandable that, in order to implement the above functions, each device may include a hardware structure and / or software module that performs each function. Those skilled in the art should easily appreciate that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in a hardware or computer software driven hardware manner depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0248] In the embodiments of the present application, the functional units of the device can be divided according to the above method examples. For example, each functional unit can be divided according to each function, or two or more functions can be integrated into one unit. The above integrated unit can be implemented in the form of hardware or software functional units.

[0249] In the case of an integrated unit, Figure 8 shows a possible exemplary block diagram of a communication device involved in an embodiment of the present application. As shown in Figure 8, the communication device 800 may include: a processing unit 801 and a transceiver unit 802. The processing unit 801 is used to control and manage the operations of the communication device 800. The transceiver unit 802 is used to support communication between the communication device 800 and other devices. Optionally, the transceiver unit 802 may include a receiving unit and / or a transmitting unit, respectively, for performing receiving and transmitting operations. Optionally, the communication device 800 may also include a storage unit for storing program code and / or data of the communication device 800. The transceiver unit may be referred to as an input / output unit, a communication unit, etc., and the transceiver unit may be a transceiver; the processing unit may be a processor. When the communication device is a module (e.g., a chip) in a communication device, the transceiver unit may be an input / output interface, an input / output circuit, or an input / output pin, etc., and may also be referred to as an interface, a communication interface, or an interface circuit, etc.; the processing unit may be a processor, a processing circuit, or a logic circuit, etc. Specifically, the device may be the above-mentioned terminal device, the first network device, etc.

[0250] In one embodiment, the communication device 800 is a terminal, and the processing unit 801 is used to perform a cell selection operation to determine a third cell when the terminal fails to switch from the first cell to the second cell; when the terminal accesses the third cell, the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are used to determine the protocol stack processing behavior.

[0251] Accordingly, when the communication device 800 is a first network device, the processing unit 801 is used to determine that the terminal accesses the third cell, and the third cell is managed by the first network device; determine the protocol stack processing behavior based on the reference information; wherein the reference information includes at least one of the following: the storage status of the protocol stack processing status in the first network device; or, the access information of the terminal.

[0252] Based on this, the consistency of the processing behavior of the terminal and the first network device protocol stack can be guaranteed.

[0253] In addition, when the communication device 800 is a first network device, the transceiver unit 802 is used to instruct the terminal to switch from the first cell to the second cell; determine that the terminal accesses the third cell, and the first cell and the third cell are both managed by the first network device; the processing unit 801 is used to determine the protocol stack processing behavior based on the reference information; wherein the reference information includes at least one of the following: the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell; the storage status of the protocol stack processing status in the first network device; or, the access information of the terminal.

[0254] Based on this, the consistency of the processing behavior of the terminal and the first network device protocol stack can also be guaranteed.

[0255] In order to avoid inconsistency with the protocol stack processing behavior on the first network device side, when the communication device 800 is a terminal, the processing unit 801 is used to execute the first protocol stack processing behavior if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different; or, if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are all the same, execute the second protocol stack processing behavior.

[0256] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0257] RLC re-establishment, MAC reset, or PDCP re-establishment.

[0258] Specifically, the second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, or PDCP data recovery.

[0259] In an optional manner, when the reference information includes the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell, when the communication device 800 is a first network device, the processing unit 801 is used to execute the first protocol stack processing behavior if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different; or, if the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are all the same, execute the second protocol stack processing behavior.

[0260] In an optional manner, when the reference information includes the storage status of the protocol stack processing state in the first network device, when the communication device 800 is the first network device, the processing unit 801 is used to execute the first protocol stack processing behavior if it is determined that the protocol stack processing state is not stored in the first network device; or, if it is determined that the protocol stack processing state is stored in the first network device, and the protocol stack processing operation group identifier of the cell corresponding to the stored protocol stack processing state is the same as the protocol stack group identifier of the third cell, then execute the second protocol stack processing behavior; or, if it is determined that the protocol stack processing state is stored in the first network device, and the protocol stack processing operation group identifier of the cell corresponding to the stored protocol stack processing state is different from the protocol stack group identifier of the third cell, then execute the first protocol stack processing behavior.

[0261] In an optional manner, when the reference information includes the access information of the terminal, when the communication device 800 is a first network device, the processing unit 801 is used to execute the first protocol stack processing behavior if it is determined based on the access information of the terminal that the terminal has not switched from the cell managed by the first network device to the third cell; or, if it is determined based on the access information of the terminal that the terminal is switched from the cell managed by the first network device to the third cell, and the protocol stack processing operation group identifier of the cell managed by the first network device is the same as the protocol stack group identifier of the third cell, then execute the second protocol stack processing behavior; or, if it is determined based on the access information of the terminal that the terminal is switched from the cell managed by the first network device to the third cell, and the protocol stack processing operation group identifier of the cell managed by the first network device is different from the protocol stack group identifier of the third cell, then execute the first protocol stack processing behavior.

[0262] In an optional manner, when the communication device 800 is a first network device, the processing unit 801 is used to delete the protocol stack processing state when it is determined that at least one of the following conditions is met: the terminal switches to a cell managed by a second network device; or, the protocol stack processing operation group identifier of the terminal's switching cell is different from the protocol stack processing operation group identifier of the terminal's source cell; or, it is determined that the terminal executes the first protocol stack processing behavior.

[0263] In another embodiment, the communication device 800 is a terminal, and the processing unit 801 is used to perform a cell selection operation to determine a third cell when the terminal fails to switch from the first cell to the second cell; when the terminal accesses the third cell, execute the first protocol stack processing behavior; wherein the first protocol stack processing behavior includes at least one of the following: RLC re-establishment, MAC reset, and PDCP re-establishment.

[0264] Accordingly, the communication device 800 is a first network device, and the processing unit 801 is used to determine that the terminal accesses the third cell, which is managed by the first network device; and execute the first protocol stack processing behavior according to the reference information; wherein the reference information satisfies at least one of the following: the protocol stack processing status is not stored in the first network device, the first network device determines that the terminal accesses the third cell from the cell managed by the second network device, and the first network device determines that the terminal accesses the third cell after the cell switching fails; wherein the first protocol stack processing behavior includes at least one of the following: RLC re-establishment, MAC reset, PDCP re-establishment.

[0265] In another embodiment, the communication device 800 is a terminal, and the processing unit 801 is used to call back the protocol stack processing state to the protocol stack processing state corresponding to the first cell when the terminal fails to switch from the first cell to the second cell; when the terminal accesses the third cell, the protocol stack processing behavior is determined according to the protocol stack processing operation group identifier of the first cell and the protocol stack processing operation group identifier of the third cell, and the third cell is the cell determined after the terminal performs the cell selection operation.

[0266] Accordingly, the communication device 800 is a first network device, and the processing unit 801 is used to determine that the terminal accesses the third cell, which is managed by the first network device; determine the protocol stack processing behavior based on the first reference information; wherein the first reference information indicates at least one of the following: the access information of the terminal; or, the second reference information of the protocol stack processing behavior reported by the terminal.

[0267] In an optional manner, when the communication device 800 is a terminal, the processing unit 801 is used to execute the first protocol stack processing behavior if the protocol stack processing operation group identifier of the first cell is different from the protocol stack processing operation group identifier of the third cell; or, if the protocol stack processing operation group identifier of the first cell is the same as the protocol stack processing operation group identifier of the third cell, execute the second protocol stack processing behavior.

[0268] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0269] RLC re-establishment, MAC reset, or PDCP re-establishment.

[0270] Specifically, the second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, or PDCP data recovery.

[0271] In an optional manner, the first reference information indicates the access information of the terminal. When the communication device 800 is a first network device, the processing unit 801 is used to execute the first protocol stack processing behavior if it is determined according to the access information that the terminal accesses the third cell from the second cell managed by the second network device; or, if it is determined according to the access information that the terminal accesses the third cell from the first cell managed by the first network device, and the protocol stack processing operation group identifier of the first cell is different from the protocol stack group identifier of the third cell, then execute the first protocol stack processing behavior; or, if it is determined according to the access information that the terminal accesses the third cell from the first cell managed by the first network device, and the protocol stack processing operation group identifier of the first cell is the same as the protocol stack group identifier of the third cell, then execute the second protocol stack processing behavior.

[0272] In an optional manner, the access information is determined by third reference information, and the third reference information includes at least one of the following:

[0273] A first notification message from the second network device for switching to the third cell, and a second notification message for the terminal successfully switching from the first cell to the second cell. The first cell is managed by the first network device, and the second cell is managed by the second network device.

[0274] In an optional manner, the first reference information indicates second reference information of the protocol stack processing behavior reported by the terminal; the second reference information includes at least one of the following: the execution status of the protocol stack processing behavior in the terminal; or, the access method of the terminal; when the communication device 800 is a first network device, the processing unit 801 is used to execute the first protocol stack processing behavior if the execution status of the protocol stack processing behavior in the terminal indicates that the terminal executes the first protocol stack processing behavior; or, if the execution status of the protocol stack processing behavior in the terminal indicates that the terminal executes the second protocol stack processing behavior, then execute the second protocol stack processing behavior; or, if the access method of the terminal indicates that the terminal is a cell switch after a successful cell switch, then execute the first protocol stack processing behavior; or, if the access method of the terminal indicates that the terminal is a cell selection after a cell switch fails, then execute the second protocol stack processing behavior.

[0275] In an optional manner, when the communication apparatus 800 is a first network device, the processing unit 801 is configured to store the protocol stack processing state of the first network device when determining that at least one of the following conditions is met:

[0276] The protocol stack processing operation group identifier of the candidate cell managed by the first network device contains the same protocol stack processing operation group identifier as the protocol stack processing operation group identifier of the first cell; the first network device determines that the terminal leaves the first cell within a set timer duration.

[0277] In addition, Figure 9 shows a simplified schematic diagram of the structure of a terminal device provided by this application. For ease of understanding and illustration, Figure 9 uses a mobile phone as an example of a terminal. As shown in Figure 9, the terminal includes a processor, memory, radio frequency circuitry, an antenna, and input / output devices.

[0278] The processor is mainly used to process communication protocols and communication data, as well as control terminal devices, execute software programs, process software program data, etc.

[0279] Memory is mainly used to store software programs and data.

[0280] Radio frequency circuits are mainly used for conversion between baseband signals and radio frequency signals and for processing radio frequency signals.

[0281] Antennas are mainly used to send and receive radio frequency signals in the form of electromagnetic waves.

[0282] Input and output devices, such as touch screens, display screens, keyboards, etc., are mainly used to receive data input by users and output data to users.

[0283] It should be noted that some types of terminal devices may not have input and output devices.

[0284] When data needs to be sent, the processor performs baseband processing on the data to be transmitted and outputs the baseband signal to the RF circuit. The RF circuit then performs RF processing on the baseband signal and transmits it via the antenna in the form of electromagnetic waves. When data is sent to a terminal device, the RF circuit receives the RF signal via the antenna, converts it into a baseband signal, and outputs the baseband signal to the processor, which converts the baseband signal into data and processes it.

[0285] For ease of explanation, Figure 9 shows only one memory and processor. In actual terminal device products, one or more processors and one or more memories may exist. Memory may also be referred to as a storage medium or storage device. The memory may be provided independently of the processor or integrated with the processor, and this embodiment of the application does not impose any restrictions on this.

[0286] In the embodiment of the present application, the antenna and radio frequency circuit with transceiver functions can be regarded as the transceiver unit of the terminal device, and the processor with processing function can be regarded as the processing unit of the terminal device.

[0287] As shown in Figure 9, terminal 900 includes a transceiver unit 910 and a processing unit 920. Transceiver unit 910 may also be called a transceiver, a transceiver, a transceiver device, etc. Processing unit 920 may also be called a processor, a processing board, a processing module, a processing device, etc.

[0288] Alternatively, the device in the transceiver unit 910 that implements the receiving function may be considered a receiving unit, and the device in the transceiver unit 910 that implements the transmitting function may be considered a transmitting unit. That is, the transceiver unit 910 includes a receiving unit and a transmitting unit. The transceiver unit may also be sometimes referred to as a transceiver, a transceiver, or a transceiver circuit. The receiving unit may also be sometimes referred to as a receiver, a receiver, or a receiving circuit. The transmitting unit may also be sometimes referred to as a transmitter, a transmitter, or a transmitting circuit.

[0289] It should be understood that the transceiver unit 910 is used to perform the sending and receiving operations of the terminal device in the above method embodiment, and the processing unit 920 is used to perform other operations except the sending and receiving operations on the terminal device in the above method embodiment.

[0290] When the terminal device is a chip, the chip includes a transceiver unit 910 and a processing unit 920. The transceiver unit 910 may be an input / output circuit or a communication interface; the processing unit 920 may be a processor, microprocessor, integrated circuit, or logic circuit integrated on the chip.

[0291] This application also provides a network device. Figure 10 shows a schematic diagram of the structure of a network device 1000 provided in an embodiment of this application. This network device 1000 can be applied to the system shown in Figure 1. For example, network device 1000 can be a network device in the system shown in Figure 1, configured to perform the functions of the network device in the above-described method embodiment. It should be understood that the following is merely an example, and in future communication systems, network devices may have other forms and configurations.

[0292] For example, in a 5G communication system, the network device 1000 may include a CU, a DU, and an AAU. Compared to the network device in an LTE communication system, which consists of one or more radio frequency units, such as a remote radio unit (RRU) and one or more building base band units (BBU):

[0293] The non-real-time portion of the original BBU will be separated and redefined as a CU, responsible for handling non-real-time protocols and services. Some of the BBU's physical layer processing functions will be merged with the original RRU and passive antennas into the AAU. The remaining BBU functions will be redefined as a DU, responsible for handling physical layer protocols and real-time services. In short, the CU and DU are differentiated by the real-time nature of their processing, and the AAU is a combination of the RRU and antenna.

[0294] The CU, DU, and AAU can be deployed separately or together, resulting in a variety of network deployment configurations. One possible deployment configuration, shown in Figure 10, is consistent with traditional 4G network equipment, with the CU and DU deployed on shared hardware. It should be understood that Figure 10 is merely an example and does not limit the scope of protection of this application. For example, the deployment configuration may also include the DU being deployed in the BBU room, the CU being deployed centrally, or the DU being deployed centrally, with the CU being centralized at a higher level.

[0295] The AAU 1100 can implement transceiver functions and correspond to the transceiver unit 802 in Figure 8. Optionally, the AAU 1100 can also be called a transceiver, a transceiver circuit, or a transceiver, and can include at least one antenna 1101 and a radio frequency unit 1102. Optionally, the AAU 1100 can include a receiving unit and a transmitting unit. The receiving unit can correspond to a receiver (or a receiver, a receiving circuit), and the transmitting unit can correspond to a transmitter (or a transmitter, a transmitting circuit). The CU and DU 1200 can implement internal processing functions and correspond to the processing unit 801 in Figure 8. Optionally, the CU and DU 1200 can control network devices and can be called controllers. The AAU, CU, and DU can be physically arranged together or physically separated.

[0296] In addition, the first network device is not limited to the form shown in Figure 10, but can also be other forms: for example: including a BBU and an adaptive radio unit (ARU), or including a BBU and an AAU; it can also be customer premises equipment (CPE), or it can be other forms, which is not limited in this application.

[0297] In one example, the CU and DU1200 can be composed of one or more single boards, and multiple single boards can jointly support a wireless access network with a single access standard (such as an LTE network), or can respectively support wireless access networks with different access standards (such as an LTE network, a 5G network, a future network or other networks). The CU and DU1200 also include a memory 1201 and a processor 1202. The memory 1101 is used to store necessary instructions and data. The processor 1202 is used to control the first network device to perform necessary actions, such as controlling the network device to execute the operation process of the network device in the above method embodiment. The memory 1201 and the processor 1202 can serve one or more single boards. That is, a memory and a processor can be set separately on each single board. Alternatively, multiple single boards can share the same memory and processor. In addition, necessary circuits can also be set on each single board.

[0298] It should be understood that the network device 1000 shown in Figure 10 is capable of implementing the network device functions involved in the method embodiment of Figure 5. The operations and / or functions of each unit in the network device 1000 are respectively for implementing the corresponding processes performed by the network device in the method embodiment of the present application. To avoid repetition, detailed description is appropriately omitted here. The structure of the network device illustrated in Figure 10 is only one possible form and should not constitute any limitation on the embodiments of the present application. The present application does not exclude the possibility of other forms of network device structures that may appear in the future.

[0299] The CU and DU 1200 can be used to perform the actions implemented within the network device described in the previous method embodiments, while the AAU 1100 can be used to perform the actions described in the previous method embodiments in which the network device sends or receives data to or from the terminal device. For details, please refer to the description in the previous method embodiments and will not be repeated here.

[0300] The present application also provides a communication system including a terminal device and a network device. The terminal device is configured to execute all or part of the steps performed by the terminal device in the embodiments shown in Figures 3-7. The network device is configured to execute all or part of the steps performed by the network device in the embodiments shown in Figures 3-7.

[0301] Based on the above embodiments, embodiments of the present application further provide a readable storage medium storing instructions that, when executed, implement the method of any of the above embodiments. The readable storage medium may include a USB flash drive, a mobile hard drive, a read-only memory, a random access memory, a magnetic disk, or an optical disk, among other media capable of storing program code.

[0302] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, compact disc read-only memory (CD-ROM), optical storage, etc.) containing computer-usable program code.

[0303] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0304] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0305] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

Claims

1. A communication method, characterized in that: A chip applied to a terminal or the terminal, comprising: When the terminal fails to switch from the first cell to the second cell, performing a cell selection operation to determine a third cell; When the terminal accesses the third cell, a protocol stack processing behavior is determined according to the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell.

2. The method according to claim 1, characterized in that The determining the protocol stack processing behavior according to the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell includes: If the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different, then executing the first protocol stack processing behavior; or, If the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are all the same, the second protocol stack processing behavior is executed.

3. The method according to claim 2, characterized in that The first protocol stack processing behavior includes at least one of the following: Radio link control RLC is re-established, medium access control protocol MAC is reset, and packet data convergence protocol PDCP is re-established.

4. The method according to claim 2, characterized in that: The second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, PDCP data recovery.

5. A communication method, characterized in that: A chip applied to a first network device or the first network device includes: Determining that the terminal accesses a third cell, where the third cell is managed by the first network device; Determine the protocol stack processing behavior based on the reference information; The reference information includes at least one of the following: the storage status of the protocol stack processing status in the first network device; or, The access information of the terminal.

6. A communication method, characterized in that: A chip applied to a first network device or the first network device includes: Instructing the terminal to switch from the first cell to the second cell; Determining that the terminal accesses a third cell, where both the first cell and the third cell are managed by the first network device; Determine the protocol stack processing behavior based on the reference information; The reference information includes at least one of the following: The protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell; Storage status of the protocol stack processing status in the first network device; The access information of the terminal.

7. The method according to claim 6, characterized in that When the reference information includes a protocol stack processing operation group identifier of the first cell, a protocol stack processing operation group identifier of the second cell, and a protocol stack processing operation group identifier of the third cell, determining a protocol stack processing behavior according to the reference information includes: If the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are different, then executing the first protocol stack processing behavior; or, If the protocol stack processing operation group identifier of the first cell, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell are all the same, the second protocol stack processing behavior is executed.

8. The method according to claim 5 or 6, characterized in that: When the reference information includes storage status of a protocol stack processing state in the first network device, determining a protocol stack processing behavior according to the reference information includes: If it is determined that the protocol stack processing state is not stored in the first network device, then executing the first protocol stack processing behavior; or, If it is determined that the protocol stack processing state is stored in the first network device, and the protocol stack processing operation group identifier of the cell corresponding to the stored protocol stack processing state is the same as the protocol stack group identifier of the third cell, then the second protocol stack processing behavior is executed; or, If it is determined that the protocol stack processing state is stored in the first network device, and the protocol stack processing operation group identifier of the cell corresponding to the stored protocol stack processing state is different from the protocol stack group identifier of the third cell, the first protocol stack processing behavior is executed.

9. The method according to claim 5 or 6, characterized in that: When the reference information includes access information of the terminal, determining a protocol stack processing behavior according to the reference information includes: If it is determined according to the access information of the terminal that the terminal has not switched from the cell managed by the first network device to the third cell, executing the first protocol stack processing behavior; or, If it is determined according to the access information of the terminal that the terminal switches from the cell managed by the first network device to the third cell, and the protocol stack processing operation group identifier of the cell managed by the first network device is the same as the protocol stack group identifier of the third cell, then executing the second protocol stack processing behavior; or, If it is determined based on the access information of the terminal that the terminal switches from the cell managed by the first network device to the third cell, and the protocol stack processing operation group identifier of the cell managed by the first network device is different from the protocol stack group identifier of the third cell, the first protocol stack processing behavior is executed.

10. The method according to claim 5, 6 or 8, characterized in that Also includes: When at least one of the following conditions is met, the protocol stack processing state is deleted: The terminal switches to a cell managed by a second network device; The protocol stack processing operation group identifier of the switching cell of the terminal is different from the protocol stack processing operation group identifier of the source cell of the terminal; Determine that the terminal executes a first protocol stack processing behavior.

11. The method according to any one of claims 7 to 10, characterized in that: The first protocol stack processing behavior includes at least one of the following: Radio Link Control RLC re-establishment, Medium Access Control Protocol MAC reset, or Packet Data Convergence Protocol PDCP re-establishment.

12. The method according to any one of claims 7 to 10, characterized in that: The second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, PDCP data recovery.

13. A communication method, characterized in that: A chip applied to a terminal or the terminal, comprising: When the terminal fails to switch from the first cell to the second cell, performing a cell selection operation to determine a third cell; When the terminal accesses the third cell, a first protocol stack processing behavior is executed; wherein the first protocol stack processing behavior includes at least one of the following: Radio Link Control RLC re-establishment, Medium Access Control Protocol MAC reset, or Packet Data Convergence Protocol PDCP re-establishment.

14. A communication method, characterized in that: A chip applied to a first network device or the first network device includes: Determining that the terminal accesses a third cell, where the third cell is managed by the first network device; Execute a first protocol stack processing behavior according to the reference information; The reference information satisfies at least one of the following: The first network device does not store a protocol stack processing state; The first network device determines that the terminal accesses the third cell from the cell managed by the second network device; The first network device determines that the terminal accesses the third cell after the cell handover fails; The first protocol stack processing behavior includes at least one of the following: radio link control RLC re-establishment, medium access control protocol MAC reset, or packet data convergence protocol PDCP re-establishment.

15. A communication method, characterized in that: A chip applied to a terminal or the terminal, comprising: When the terminal fails to switch from the first cell to the second cell, calling back the protocol stack processing state to the protocol stack processing state corresponding to the first cell; When the terminal accesses a third cell, a protocol stack processing behavior is determined according to the protocol stack processing operation group identifier of the first cell and the protocol stack processing operation group identifier of the third cell, and the third cell is a cell determined after the terminal performs a cell selection operation.

16. The method according to claim 15, characterized in that The determining the protocol stack processing behavior according to the protocol stack processing operation group identifier of the first cell and the protocol stack processing operation group identifier of the third cell includes: If the protocol stack processing operation group identifier of the first cell is different from the protocol stack processing operation group identifier of the third cell, executing the first protocol stack processing behavior; or, If the protocol stack processing operation group identifier of the first cell is the same as the protocol stack processing operation group identifier of the third cell, the second protocol stack processing behavior is executed.

17. The method according to claim 16, characterized in that The first protocol stack processing behavior includes at least one of the following: Radio link control RLC is re-established, medium access control protocol MAC is reset, and packet data convergence protocol PDCP is re-established.

18. The method according to claim 16, characterized in that The second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, PDCP data recovery.

19. A communication method, characterized in that: A chip applied to a first network device or the first network device includes: Determining that the terminal accesses a third cell, where the third cell is managed by the first network device; Determine a protocol stack processing behavior according to the first reference information; The first reference information indicates at least one of the following: access information of the terminal; or Second reference information of the protocol stack processing behavior reported by the terminal.

20. The method according to claim 19, characterized in that The first reference information indicates access information of the terminal, and determining a protocol stack processing behavior according to the first reference information includes: If it is determined according to the access information that the terminal accesses the third cell from the second cell managed by the second network device, then executing the first protocol stack processing behavior; or, If it is determined according to the access information that the terminal accesses the third cell from the first cell managed by the first network device, and the protocol stack processing operation group identifier of the first cell is different from the protocol stack group identifier of the third cell, then the first protocol stack processing behavior is executed; or, If it is determined according to the access information that the terminal accesses the third cell from the first cell managed by the first network device, and the protocol stack processing operation group identifier of the first cell is the same as the protocol stack group identifier of the third cell, the second protocol stack processing behavior is executed.

21. The method according to claim 19 or 20, characterized in that The access information is determined by third reference information, and the third reference information includes at least one of the following: A first notification message from the second network device for switching to the third cell, and a second notification message for the terminal to successfully switch from the first cell to the second cell, the first cell is managed by the first network device, and the second cell is managed by the second network device.

22. The method according to claim 19, characterized in that The first reference information indicates second reference information of the protocol stack processing behavior reported by the terminal; the second reference information includes at least one of the following: execution status of the protocol stack processing behavior in the terminal; or, an access mode of the terminal; and determining a protocol stack processing behavior according to the first reference information, comprising: If the execution status of the protocol stack processing behavior in the terminal indicates that the terminal executes the first protocol stack processing behavior, then the first protocol stack processing behavior is executed; or, If the execution status of the protocol stack processing behavior in the terminal indicates that the terminal executes the second protocol stack processing behavior, then the second protocol stack processing behavior is executed; or, If the access mode of the terminal indicates that the terminal is a cell handover after a successful cell handover, executing the first protocol stack processing behavior; or, If the access mode of the terminal indicates that the terminal is selecting a cell after a cell handover failure, the second protocol stack processing behavior is executed.

23. The method according to claim 20 or 21, characterized in that When at least one of the following conditions is met, the protocol stack processing state is stored: The protocol stack processing operation group identifier of the candidate cell managed by the first network device includes a protocol stack processing operation group identifier that is the same as the protocol stack processing operation group identifier of the first cell; The first network device determines that the terminal has not left the first cell for more than a set duration of the timer.

24. The method according to any one of claims 20 to 23, characterized in that: The first protocol stack processing behavior includes at least one of the following: Radio link control RLC is re-established, medium access control protocol MAC is reset, and packet data convergence protocol PDCP is re-established.

25. The method according to any one of claims 20 to 23, characterized in that: The second protocol stack processing behavior includes at least one of the following: RLC maintenance, MAC maintenance, partial reset of MAC, PDCP maintenance, PDCP data recovery.

26. A communication device, characterized in that: include: A functional module for implementing the method according to any one of claims 1 to 25.

27. A communication device, characterized in that: include: at least one processor and memory; The memory is used to store computer programs or instructions; The at least one processor is configured to execute the computer program or instructions so that the method according to any one of claims 1 to 25 is performed.

28. A chip system, characterized in that: The chip system comprises: a processing circuit; the processing circuit is coupled to a storage medium; The processing circuit is used to execute part or all of the computer programs or instructions in the storage medium. When the computer program or instruction is executed, it is used to implement the method according to any one of claims 1 to 25.

29. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed by a computer, the method according to any one of claims 1 to 25 is executed.

30. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed on a computer, the method according to any one of claims 1 to 25 is executed.

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