Communication method and device

Abstract

The invention provides a communication method and device, and relates to the technical field of communication, and the method comprises the steps: executing a cell selection operation to determine a third cell when a terminal fails to switch from a first cell to a second cell; and when the terminal accesses a third cell, determining a 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. A terminal determines a protocol stack processing behavior by referring to a protocol stack processing operation group identifier of a first cell, a protocol stack processing operation group identifier of a switching failure cell (i.e., a second cell), and a protocol stack operation group identifier of a cell (i.e., a third cell) determined by executing cell selection operation after switching failure; therefore, access failure caused by the fact that the protocol stack processing behavior is not aligned with the first network equipment (namely the network equipment for managing the third cell) when the third cell is accessed is avoided, interruption time caused by switching failure can be shortened, and the service experience of the UE can be improved.

Description

Technical Field

[0001] Embodiments of this application relate to the field of communication technologies, and in particular, to a communication method and apparatus. Background Art

[0002] In a mobile communication system, when a user equipment (UE) moves from the coverage area of one cell to that of another cell, a cell handover process is required. In the scenario of cell handover failure, the L2 (Layer 2) behavior of the UE (such as radio link control (RLC) behavior) is not clear, and the corresponding L2 behavior of the network device (such as RLC behavior) is also not clear, which will result in misalignment between the L2 behavior of the UE and the L2 behavior of the network device. Based on this, when the cell handover fails, clarifying the L2 behavior of the UE and the network device and reducing the interruption time caused by the handover failure are beneficial to improving the service experience of the UE. Summary of the Invention

[0003] This application provides a communication method and apparatus to ensure that in the scenario of cell handover failure, the L2 behavior of the UE is aligned with the L2 behavior of the network device.

[0004] In a first aspect, this application provides a communication method. This method can be applied to a terminal or a chip of the terminal, which is not specifically limited herein. The terminal can be a mobile phone, a vehicle-mounted device, an Internet of Things device, etc. This method can be applied to a 5th generation (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 herein. In practical applications, the following operations are performed:

[0005] When the terminal fails to hand over from a first cell to a second cell, a cell selection operation is performed to determine a third 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, the protocol stack processing operation group identifier of the second cell, and the protocol stack processing operation group identifier of the third cell.

[0006] In this 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 fails (i.e., the second cell), and the protocol stack operation group identifier of the cell determined by performing the cell selection operation after the handover fails (i.e., the third cell), which can avoid access failure caused by misalignment of the protocol stack processing behavior with the first network device (i.e., the network device managing the third cell) when accessing the third cell, reduce the interruption time caused by the handover failure, and is beneficial to improving the service experience of the UE.

[0007] In an alternative manner, if there are differences in the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell, then perform a first protocol stack processing behavior; or, if the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell are all the same, then perform a second protocol stack processing behavior.

[0008] In this application, the first protocol stack processing behavior is only performed when there are differences in the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell. It is necessary to make a judgment by combining the protocol stack processing operation identifiers of the three cells to avoid situations inconsistent with the protocol stack processing behavior on the first network device side.

[0009] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0010] RLC re - establishment, media access control protocol (MAC) reset, packet data convergence protocol (PDCP) re - establishment.

[0011] Specifically, 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.

[0012] In a second aspect, this application provides a communication method. This method 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 with both CU and DU integrated, and can also be a 5G base station (gNodeB, gNB), etc. This 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 in this application. In actual application, the following is executed:

[0013] 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 according to the reference information; where the reference information includes at least one of the following: the storage situation of the protocol stack processing state in the first network device; or, the access information of the terminal.

[0014] In this application, the first network device refers to the storage situation 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 a protocol stack processing behavior aligned with the terminal, which can reduce the interruption time caused by handover failure and is beneficial to improving the service experience of the UE.

[0015] 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, determining the protocol stack processing behavior according to the reference information includes:

[0016] If there are differences among 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, then execute 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, then execute the second protocol stack processing behavior.

[0017] In this application, only when there are differences among 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 first protocol stack processing behavior is executed. It is necessary to combine the protocol stack processing operation identifiers of the three cells for judgment, which is consistent with the judgment logic on the terminal side and can avoid the situation of inconsistent protocol stack processing behavior with the terminal side.

[0018] In an optional manner, when the reference information includes the storage situation of the protocol stack processing status in the first network device, determining the protocol stack processing behavior according to the reference information includes:

[0019] If it is determined that the protocol stack processing status is not stored in the first network device, then execute the first protocol stack processing behavior; 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, then execute the second protocol stack processing behavior; 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, then execute the first protocol stack processing behavior.

[0020] In this application, the first network device determines the protocol stack processing behavior by referring to the storage situation of the protocol stack processing status in the first network device, which can avoid the situation of inconsistent protocol stack processing behavior with the terminal side.

[0021] In an optional manner, when the reference information includes the access information of the terminal, determining the protocol stack processing behavior according to the reference information includes:

[0022] 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, then perform the first protocol stack processing behavior; or, if it is determined according to 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, then perform the second protocol stack processing behavior; or, if it is determined according to 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, then perform the first protocol stack processing behavior.

[0023] In this application, the first network device determines the protocol stack processing behavior with reference to the access information of the terminal, which can avoid the situation of inconsistent protocol stack processing behavior with the terminal side.

[0024] In an optional manner, when at least one of the following conditions is met, the first network device deletes the protocol stack processing status:

[0025] The terminal switches to the cell managed by the second network device; or, the protocol stack processing operation group identifier of the cell to which the terminal switches is different from the protocol stack processing operation group identifier of the source cell of the terminal; or, it is determined that the terminal performs the first protocol stack processing behavior.

[0026] By this method, it is possible to avoid the situation where the first network device stores the protocol stack processing status for a long time, resulting in storage pressure.

[0027] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0028] RLC re - establishment, MAC reset, PDCP re - establishment.

[0029] Specifically, 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.

[0030] In a third aspect, this application provides a communication method, which can be applied to the first network device or the chip of the first network device, without specific limitation here. The first network device can be a base station, an access point, etc. The first network device can be a CU or a DU, or a device combining CU and DU, or a gNB, etc. This 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. This application does not specifically limit here. In actual application, the following is executed:

[0031] Instruct the terminal to hand over from the first cell to the second cell; determine that the terminal accesses the third cell, and both the first cell and the third cell are managed by the first network device; determine the protocol stack processing behavior according to the reference information; where the reference information includes at least one of the following:

[0032] 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 situation of the protocol stack processing status in the first network device; or, the access information of the terminal.

[0033] In this 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, the storage situation of the protocol stack processing status in the first network device; or, the access information of the terminal to determine the protocol stack processing behavior. When the terminal accesses the third cell, the first network device adopts a protocol stack processing behavior aligned with the terminal, which can reduce the interruption time caused by handover failure and is beneficial to improving the UE's service experience.

[0034] 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, determining the protocol stack processing behavior according to the reference information includes:

[0035] If there are differences in 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, then execute 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, then execute the second protocol stack processing behavior.

[0036] In this application, only when there are differences in 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 first protocol stack processing behavior is executed. It is necessary to combine the protocol stack processing operation identifiers of the three cells for judgment, which is consistent with the judgment logic on the terminal side and can avoid the situation of inconsistent protocol stack processing behavior with the terminal side.

[0037] In an optional manner, when the reference information includes the storage situation of the protocol stack processing status in the first network device, determining the protocol stack processing behavior according to the reference information includes:

[0038] If it is determined that the protocol stack processing status is not stored in the first network device, perform the first protocol stack processing behavior; 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, perform the second protocol stack processing behavior; 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, perform the first protocol stack processing behavior.

[0039] In this application, the first network device determines the protocol stack processing behavior with reference to the storage situation of the protocol stack processing status in the first network device, which can avoid the situation of inconsistent protocol stack processing behavior with the terminal side.

[0040] In an optional manner, when the reference information includes the access information of the terminal, determining the protocol stack processing behavior according to the reference information includes:

[0041] 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, perform the first protocol stack processing behavior; or, if it is determined according to 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, perform the second protocol stack processing behavior; or, if it is determined according to 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, perform the first protocol stack processing behavior.

[0042] In this application, the first network device determines the protocol stack processing behavior with reference to the access information of the terminal, which can avoid the situation of inconsistent protocol stack processing behavior with the terminal side.

[0043] In an optional manner, when at least one of the following conditions is met, the first network device deletes the protocol stack processing status:

[0044] The terminal switches to the cell managed by the second network device; or, the protocol stack processing operation group identifier of the cell to which the terminal switches is different from the protocol stack processing operation group identifier of the source cell of the terminal; or, it is determined that the terminal performs the first protocol stack processing behavior.

[0045] Through this method, it is possible to avoid the situation where the first network device stores the protocol stack processing status for a long time, resulting in storage pressure.

[0046] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0047] RLC re - establishment, MAC reset, PDCP re - establishment.

[0048] Specifically, 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.

[0049] In a fourth aspect, the present application provides a communication method, which can be applied to a terminal or a chip of the terminal, without specific limitation here. The terminal can be a mobile phone, a vehicle - mounted device, an Internet of Things device, etc. This 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. The present application does not specifically limit this here. In actual application, the following is executed:

[0050] 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, a first protocol stack processing behavior is performed; wherein, the first protocol stack processing behavior includes at least one of the following: RLC re - establishment, MAC reset, or PDCP re - establishment.

[0051] In the present application, once the terminal has a cell switching behavior, the first protocol stack processing behavior is executed, which can avoid the situation of inconsistency with the protocol stack processing behavior on the first network device side.

[0052] 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, without specific limitation here. The first network device can be a base station, an access point, etc. The first network device can be a CU or a DU, or a device with both CU and DU integrated, or a gNB, etc. This 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. The present application does not specifically limit this here. In actual application, the following is executed:

[0053] Determine that the terminal accesses the third cell, and the third cell is managed by the first network device; 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; the first network device determines that the terminal accesses the third cell after a cell switching failure; 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, when the first network device determines that one of the above - mentioned reference information is satisfied, the first protocol stack processing behavior is executed, which can avoid the situation of inconsistency with the protocol stack processing behavior on the terminal side.

[0055] Sixthly, the present application provides a communication method, which can be applied to a terminal or a chip of the terminal, without specific limitation here. The terminal can be a mobile phone, a vehicle-mounted device, an Internet of Things device, etc. This 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, without specific limitation here in the present application. In practical applications, the following steps are performed:

[0056] 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, where the third cell is the cell determined after the terminal performs a cell selection operation.

[0057] In the present application, the terminal determines the protocol stack processing behavior with reference 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 after performing a cell selection operation after a handover failure, avoiding access failure caused by misalignment of the protocol stack processing behavior with the first network device (i.e., the network device managing the third cell), which can reduce the interruption time caused by a handover failure and is beneficial to improving the service experience of the UE.

[0058] 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:

[0059] 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, then perform a 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, then perform a second protocol stack processing behavior.

[0060] In the present application, the first protocol stack processing behavior is only performed 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, avoiding the situation of inconsistent protocol stack processing behavior with the first network device side.

[0061] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0062] RLC re-establishment, MAC reset, or PDCP re-establishment.

[0063] 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.

[0064] 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, without specific limitation here. The first network device can be a base station, an access point, etc. The first network device can be a CU or a DU, or a device integrating CU and DU, or a gNB, etc. This 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. The present application does not specifically limit this here. In actual application, the following steps are performed:

[0065] Determine that the terminal accesses a third cell, and the third cell is managed by the first network device; determine the protocol stack processing behavior according to first reference information; wherein, the first reference information indicates at least one of the following: the access information of the terminal; or, second reference information of the protocol stack processing behavior reported by the terminal.

[0066] In the present application, the first network device determines the protocol stack processing behavior with reference 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 handover failure and is beneficial to improving the service experience of the UE.

[0067] In an optional manner, the first reference information indicates the access information of the terminal. Determining the protocol stack processing behavior according to the first reference information includes:

[0068] If it is determined according to the access information that the terminal accesses the third cell from a second cell managed by a second network device, then perform a first protocol stack processing behavior; or, if it is determined according to the access information that the terminal accesses the third cell from a 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 perform the first protocol stack processing behavior; or, if it is determined according to the access information that the terminal accesses the third cell from a 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 perform a second protocol stack processing behavior.

[0069] 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 the situation of inconsistency with the protocol stack processing behavior on the terminal side.

[0070] In an optional manner, the access information is determined through third reference information, and the third reference information includes at least one of the following:

[0071] A first notification message for switching to the third cell from the second network device, 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.

[0072] In the present application, determining the access information through the third reference information can improve data processing efficiency.

[0073] In an alternative 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 mode of the terminal; determining the protocol stack processing behavior according to the first reference information includes:

[0074] 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 execute 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 mode of the terminal indicates that the terminal is cell handover after successful cell handover, then execute the first protocol stack processing behavior; or, if the access mode of the terminal indicates that the terminal is cell selection after failed cell handover, then execute the second protocol stack processing behavior.

[0075] In this application, the first network device determines the protocol stack processing behavior with reference to the second reference information of the protocol stack processing behavior reported by the terminal, which can avoid the situation inconsistent with the protocol stack processing behavior on the terminal side.

[0076] In an alternative manner, when at least one of the following conditions is met, the first network device stores the protocol stack processing status:

[0077] There is a protocol stack processing operation group identifier in the protocol stack processing operation group identifiers of the candidate cells managed by the first network device 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 left the first cell and has not exceeded the set duration of the timer.

[0078] By this means, it is possible to avoid the situation that the first network device stores the protocol stack processing status for a long time, resulting in storage pressure.

[0079] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0080] RLC re-establishment, MAC reset, PDCP re-establishment.

[0081] Specifically, 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.

[0082] In an eighth aspect, embodiments of the present application provide a communication device, which may be a terminal (such as the terminal in the first aspect or a chip disposed inside the terminal, the first network device or a chip disposed inside the first network device). The communication device has the functions of implementing the above first aspect to the seventh aspect. For example, the communication device includes modules or units or means corresponding to the steps involved in the above first aspect to the seventh aspect. The functions or units or means may be implemented by software, or by hardware, or by hardware executing corresponding software.

[0083] In a possible design, the communication device includes a processing unit and a transceiver unit. The transceiver unit may be used to transmit and receive signals to implement communication between the communication device and other devices. For example, the transceiver unit is used to receive a first message. The processing unit may be used to perform some internal operations of the communication device. The transceiver unit may be referred to as an input / output unit, a communication unit, etc. The transceiver unit may be a transceiver. The processing unit may be a processor. When the communication device is a module (such as a chip) in a communication device, the transceiver unit may be an input / output interface, an input / output circuit, or input / output pins, 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.

[0084] In another possible design, the communication device includes a processor and may further include a transceiver. The transceiver is used to transmit and receive signals. The processor executes program instructions to complete the methods in any possible design or implementation manner in the above first aspect to the seventh aspect. The communication device may further include one or more memories, which are used to be coupled to the processor. The memories may store necessary computer programs or instructions for implementing the functions involved in the above first aspect. The processor may execute the computer programs or instructions stored in the memories. When the computer programs or instructions are executed, the communication device implements the methods in any possible design or implementation manner in the above first aspect to the seventh aspect.

[0085] In another possible design, the communication device includes a processor, and the processor may be used to be coupled to a memory. The memory may store necessary computer programs or instructions for implementing the functions involved in the above first aspect to the seventh aspect. The processor may execute the computer programs or instructions stored in the memory. When the computer programs or instructions are executed, the communication device implements the methods in any possible design or implementation manner in the above first aspect to the seventh aspect.

[0086] In yet another possible design, the communication device includes a processor and an interface circuit. The processor is configured to communicate with other devices through the interface circuit and execute the methods in any possible design or implementation manner of the above first aspect to the seventh aspect.

[0087] It can be understood that in the above eighth aspect, 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 that implements by reading software code stored in a 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 are separately arranged. In a specific implementation process, the memory can be integrated with the processor on the same chip, or can be separately arranged on different chips. The embodiments of the present application do not limit the type of the memory and the setting manner of the memory and the processor.

[0088] In a ninth aspect, an embodiment of the present application provides a communication system, which includes the above terminal and a first network device.

[0089] In a tenth aspect, the present application provides a chip system, which includes a processor and may further include a memory, and is configured to implement the methods described in the above first aspect to the seventh aspect. The chip system can be composed of chips, or can include chips and other discrete devices.

[0090] In an eleventh aspect, the present application further provides a computer-readable storage medium, in which computer-readable instructions are stored. When the computer-readable instructions run on a computer, the computer is caused to execute the methods in the first aspect to the seventh aspect.

[0091] In a twelfth aspect, the present application provides a computer program product including instructions, which when running on a computer, causes the computer to execute the methods of the embodiments in the above first aspect to the seventh aspect.

[0092] For the technical effects that can be achieved by the above second aspect to the twelfth aspect, please refer to the technical effects that can be achieved by the corresponding possible design solutions in the above first aspect, and the present application will not repeat them here. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 FIG. shows a schematic diagram of a communication system provided by an embodiment of the present application;

[0094] Figure 2A FIG. shows a schematic diagram of cell selection after cell handover failure;

[0095] Figure 2BShows a schematic diagram of the processing flow of cell handover;

[0096] Figure 3 Shows a schematic diagram of the flow of a communication method provided by an embodiment of the present application;

[0097] Figure 4 Shows a schematic diagram of cell selection after cell handover failure;

[0098] Figure 5 Shows a schematic diagram of the flow of a communication method provided by an embodiment of the present application;

[0099] Figure 6 Shows a schematic diagram of the flow of a communication method provided by an embodiment of the present application;

[0100] Figure 7 Shows a schematic diagram of the flow of a communication method provided by an embodiment of the present application;

[0101] Figure 8 Shows a schematic diagram of the structure of a communication device provided by an embodiment of the present application;

[0102] Figure 9 Shows a schematic diagram of the structure of a communication device provided by an embodiment of the present application;

[0103] Figure 10 Shows a schematic diagram of the structure of a communication device provided by an embodiment of the present application. Detailed implementation manners

[0104] In order to make the objectives, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. The specific operation methods in the method embodiments can also be applied to the device embodiments or system embodiments. Among them, in the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more. Therefore, the implementations of the device and the method can be referred to each other, and the repeated parts will not be described again.

[0105] The technical solutions provided by the embodiments of the present application can be applied to a 5G system, or to future communication systems or other similar communication systems. Additionally, the technical solutions provided by the embodiments of the present application can be applied to cellular links, public land mobile networks (PLMNs), machine-to-machine (M2M) networks, Internet of Things (IoT) networks, or other networks. They can also be applied to links between devices, such as device-to-device (D2D) links. A D2D link can also be referred to as a sidelink, where the sidelink can also be called a side link or a secondary link, etc. In the embodiments of the present application, the above terms all refer to links established between the same type of devices and have the same meaning. The so-called same type of devices can be a link between terminal devices, a link between base stations, or a link between relay nodes, etc. The embodiments of the present application do not limit this. For the link between terminal devices, there is the D2D link defined in Release 12 / 13 of the third generation partnership project (3GPP), and there is also the vehicle-to-vehicle, vehicle-to-phone, or vehicle-to-any entity V2X link defined by 3GPP for vehicle networking, including Release 14 / 15. It also includes the V2X link based on the new radio (NR) system in Release 18 and subsequent versions, etc.

[0106] Reference Figure 1 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 Figure 1 the network devices 111, 112, and 113 shown. The wireless communication system may further include at least one terminal device, such as Figure 1 the terminal devices 121, 122, 123, 124, 125, 126, and 127 shown. Communication can occur between the network device and the terminal device, such as Figure 1 the multi-site transmission shown, such as communication can occur between network device 112 and terminal devices 121, 122, and 123; or Figure 1 the enhanced mobile broadband (eMBB) transmission shown, such as network devices 112 and 113 can communicate with terminal device 124. Communication can also occur between network devices, such as Figure 1The backhaul shown, for example, the network devices 111 and 112, 113 can communicate with each other. Communication can also be carried out between terminal devices, such as Figure 1 the D2D transmission shown, for example, the terminal device 122 can communicate with the terminal device 125.

[0107] The terminal device can be a wireless terminal device capable of receiving scheduling and indication information from a network device. The wireless terminal device can be a device that provides voice and / or data connectivity to users, or a handheld device with wireless connection capabilities, or other processing devices connected to a wireless modem. The wireless terminal device can communicate with one or more core networks or the Internet via a radio access network (such as a radio access network, RAN). The wireless terminal device can be a mobile terminal device, such as a mobile phone (or "cellular" phone, mobile phone), computer, and data card. For example, it can be a portable, pocket-sized, handheld, computer-integrated, or vehicle-mounted mobile device that exchanges voice and / or data with the radio access network. For example, personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, PDAs, tablets (Pad), computers with wireless transceiver functions, and other devices. The wireless terminal device can also be referred to as a system, subscriber unit, subscriber station, mobile station, mobile station (MS), remote station, access point (AP), remote terminal device, access terminal device, user terminal device, user agent, user station (SS), customer premises equipment (CPE), terminal, user equipment (UE), mobile terminal (MT), etc. The wireless terminal device can also be a wearable device and the next-generation communication system. For example, the terminal device in a 5G network or the terminal device in a future evolved public land mobile network (PLMN) network, the terminal device in an NR communication system, etc.

[0108] A network device is an entity in the network side used to transmit or receive signals, such as a transmission reception point (TRP), gNB. The network device can be a device for communicating with a mobile device. The network device can be an 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, NB) in wideband code division multiple access (WCDMA), an evolved base station (evolutional Node B, eNB or eNodeB) in long term evolution (LTE), or a relay station or access point, or a vehicle-mounted device, a wearable device, and a network device in a future 5G network or a network device in a future evolved PLMN, or a gNodeB / gNB in an NR system, etc.; in some deployments, a gNB can include a CU and a DU. A gNB can also include an active antenna unit (AAU). The CU implements part of the functions of the gNB, and the DU implements part of the functions of the gNB. For example, the CU is responsible for processing non-real-time protocols and services, such as implementing radio resource control (RRC), service data adaptation protocol (SDAP) functions, and the functions of the packet data convergence protocol (PDCP) layer. The DU is responsible for processing physical layer protocols and real-time services, such as implementing the functions of the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical (PHY) layer. The AAU implements part of the physical layer processing functions, radio frequency processing, and related functions of active antennas. Since the information in the RRC layer will ultimately become the information in the PHY layer, or is transformed from the information in the PHY layer, thus, in this architecture, high-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or sent by the DU and the AAU. It can be understood that the network device can be a device including one or more of a CU node, a DU node, and an AAU node.In addition, the CU can be divided into network devices in the radio access network (RAN), or the CU can be divided into network devices in the core network (CN). This application does not make any limitations in this regard. Additionally, in the embodiments of this application, the network device provides services for a cell, and the terminal device communicates with the network device through the transmission resources used by this cell (for example, frequency domain resources, or in other words, spectrum resources). This cell can be the cell corresponding to the network device (such as a base station). The cell can belong to a macro base station or a base station corresponding to a small cell. Here, small cells can include: Metro cell, Micro cell, Pico cell, Femto cell, etc. These small cells have the characteristics of small coverage range and low transmission power, and are suitable for providing high-rate data transmission services. In addition, in other possible cases, the network device can be other devices that provide wireless communication functions for the terminal device. The embodiments of this application do not make any limitations on the specific technologies and specific device forms adopted by the network device. For the convenience of description, in the embodiments of this application, the device that provides wireless communication functions for the terminal device is referred to as the network device.

[0109] The following refers to Figure 2A and Figure 2B to introduce the operations of the terminal for cell handover and cell selection. Here, taking the terminal as a UE and the network device including a CU and a DU as an example, and taking the CU governing DU1 and DU2 as an example to illustrate, Figure 2A it is shown in Figure 2A that the cells managed by DU1 are cell1 and cell3; the cells managed by DU2 are cell2. Here, only an example is given and the cells managed by each DU are not specifically limited. In Figure 2B UE fails to successfully hand over from cell1 to cell2 and accesses cell3 after cell selection. Referring to

[0110] Step 201, the CU establishes a UE context with the target DU and obtains the configuration information of the cells managed by the target DU.

[0111] Among them, before the target DU performs cell handover, it can also be called a candidate DU; when the handover decision determines that the target cell is a cell managed by a certain candidate DU, this candidate DU can be called the target DU. Figure 2A In the example of

[0112] the target DU is DU2.

[0113] In Figure 2AIn the example, if Cell1 is the source cell of UE1, then DU1 is the source DU, and Cell2 and Cell3 are candidate cells.

[0114] Step 203: The UE sends the L1 (Layer 1) measurement results of different cells to the source DU through the communication resources of the source cell.

[0115] Among them, the L1 measurement results include at least one of the following: the L1 measurement results of the source cell, the L1 measurement results of at least one candidate cell. The above L1 measurement results can be cell-level measurement results or beam-level measurement results, which are not specifically limited here. Based on the above Figure 2A example, the L1 measurement results include at least one of the following: the measurement results of cell1, cell2, and cell3.

[0116] Step 204: The source DU determines whether the UE should perform a Layer 1 / Layer 2 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 the LTM handover signaling.

[0117] Among them, the LTM handover signaling is still sent through the communication resources of the source cell. Further, in this LTM handover signaling, the beam direction information that the UE should use when communicating with the target cell can be indicated.

[0118] In the example in the figure, the target cell indicated by the LTM handover command is Cell2.

[0119] Step 205A: The source DU sends a notification message to the CU.

[0120] Among them, this notification message indicates that the UE has performed an LTM handover.

[0121] Optionally, step 205B can also be executed.

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

[0123] Among them, this notification message indicates that the UE has performed an LTM handover.

[0124] Step 206: The UE performs an LTM handover, accesses the target cell using the configuration information of the target cell received in step 202, and starts the uplink and downlink data transmission with the target cell after successful access.

[0125] Further, the UE can use the beam direction information indicated in step 204 to perform the uplink and downlink data transmission with the target cell.

[0126] Step 207: After the UE successfully accesses, the target DU sends a notification message of successful access to the CU.

[0127] The above step 207 only exists when the handover is successful. For the handover failure scenario concerned in this application, step 206 is not successfully executed, so step 207 will not be executed either.

[0128] Step 208: When the UE recognizes a handover failure, the UE performs cell selection.

[0129] In Figure 2A the example, if the UE selects Cell3 managed by DU1 and Cell3 is a candidate cell configured in step 202, the UE applies the configuration information of this cell and accesses Cell3.

[0130] Step 209: The UE accesses Cell3.

[0131] Step 210: The DU (i.e., DU1) of the cell to which the UE successfully accesses sends a notification message of successful access to the CU.

[0132] When the UE handovers from the source cell to the target cell, if the L2 behavior is maintained, it is beneficial to the continuity of data transmission after the cell handover. The following takes the RLC behavior as an example of the L2 behavior for description. In actual applications, it also includes the processing behaviors of other protocol stacks, such as: MAC, PCDP. Combining the above Figure 2A scenarios, the network device can be configured to perform RLC re - establishment when handover from Cell1 to Cell2; perform RLC maintenance when handover from Cell1 to Cell3; and perform RLC re - establishment when handover from Cell2 to Cell3.

[0133] However, when steps 208 - 209 above Figure 2B are executed, when the UE handovers from Cell1 to Cell3, it performs the RLC maintenance behavior; but the network device (DU1) thinks that the UE handovers from Cell2 to Cell3, so it performs the RLC re - establishment behavior. In addition, if the UE successfully executes the handover of steps 206 - 207 above Figure 2B from Cell1 to Cell2; then DU2 instructs the UE to handover from Cell2 to Cell3. During the process of handover from Cell2 to Cell3, the UE performs RLC re - establishment, but the network device (DU1) mistakenly thinks that the UE performs the cell handover failure recovery of steps 208 - 209 above Figure 2B so DU1 thinks that the UE handovers from Cell1 to Cell3, and then DU1 performs RLC maintenance. All of the above will result in the misalignment of the RLC behaviors between the UE and the network device, causing problems in the RLC transceiver process.

[0134] Based on this, the present application provides a communication method to ensure that in the scenario of cell handover 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 by referring to the operation identifier of the protocol stack processing of the cell, the storage status of the protocol stack processing status, and the access information of the terminal, etc. To better illustrate the solution of the present application, the following will introduce it with reference to three specific embodiments. The terminal in the following specific embodiments can be the terminal itself or a chip inside the terminal. The following takes the terminal as the UE as an example to illustrate. The first network device can be the first network device itself or a chip inside the first network device. The first network device and the second network device below can be a device integrating the CU and the DU, can be the CU or the DU, or can also be a gNB, etc. Here, it is not specifically limited. The specific form of the first network device will only be specifically described below.

[0135] Embodiment 1

[0136] The following combines Figure 3 , and uses a specific method embodiment to detail the technical solution of the present application. It should be noted that Figure 3 is a schematic flowchart of the method embodiment of the present application, showing the detailed communication steps or operations of the method. However, these steps or operations are only examples. The embodiments of the present application can also perform other operations or Figure 3 variations of various operations in Figure 3 . In addition, Figure 3 each step in Figure 3 can be executed in a different order from that presented in Figure 3 , and it is possible that not all the operations in Figure 3 need to be executed.

[0137] Step 301, the CU establishes a UE context with the DU2 and obtains the configuration information of the cell managed by the DU2.

[0138] The above configuration information may include the operation identifier of the protocol stack processing of the cell.

[0139] Step 302, the CU sends the configuration information of the candidate cell to the UE via the DU1.

[0140] Step 303, the UE sends the L1 (Layer 1) measurement results of different cells to the DU1 through the communication resources of the source cell (the first cell).

[0141] Step 304: DU1 determines, based on the L1 measurement results of different cells, whether the UE should perform an LTM handover, and sends the identification information of the associated target cell (the second cell) to the UE through the LTM handover signaling.

[0142] It can be understood that DU1 instructs the terminal to hand over from the first cell to the second cell.

[0143] Step 305A: DU1 sends a notification message to the CU.

[0144] Optionally, step 305B can also be executed.

[0145] Step 305B: The CU sends a notification message to DU2.

[0146] Steps 301 to 305B above can be understood with reference to steps 201 to 205B in the above Figure 2B and will not be elaborated here.

[0147] Step 306: The UE performs an LTM handover and hands over from the first cell to the second cell.

[0148] Among them, the first cell is managed by DU1, and the second cell is managed by DU2. In step 306 above, when the UE performs the handover from the first cell to the second cell, it determines whether the protocol stack processing operation identifiers of the first cell and the second cell are the same. If they are the same, it performs the first protocol stack processing behavior; if they are different, it performs the second protocol stack processing behavior. Among them, 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 elaborated here. The following parts related to the first protocol stack processing behavior and the second protocol stack processing behavior can be understood with reference to this 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 the above Figure 2A , the protocol stack processing operation identifiers of Cell1 and Cell2 are different, so the UE performs RLC re-establishment.

[0149] Step 307: When the UE fails to hand over from the first cell to the second cell, it performs a cell selection operation to determine the third cell.

[0150] Specifically, when the UE determines to perform an LTM handover, it can start a timer (denoted as the T304 timer). When the timer expires, if the UE still fails to successfully access the second cell, the UE determines that a cell handover failure has occurred. Among them, the third cell is managed by DU1. The third cell is also one of the candidate cells provided to the UE in step 302.

[0151] Step 308: When the UE accesses the third cell, determine 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.

[0152] The above-mentioned first cell and third cell managed by DU1 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 can be ID = 2. This is only an exemplary description here and does not specifically limit the protocol stack processing operation group identifier. Among them, the protocol stack group identifiers of the cells managed by the same DU can be the same or different. For example, the protocol stack group identifier of cell Cell1 managed by DU1 is ID = 1-1, and the protocol stack group identifier of cell Cell3 managed by DU1 is ID = 1-3. This is only an exemplary description here.

[0153] When performing the above step 308, the UE can 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.

[0154] Specifically, if the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell are different, then perform the first protocol stack processing behavior; or, if the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell are all the same, then perform the second protocol stack processing behavior.

[0155] For example, the above Figure 2A 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. Then, since the protocol stack processing operation group identifiers of Cell1, Cell2, and Cell3 are different, the first protocol stack processing behavior is performed. In Figure 4 DU1 manages cells including 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 since the protocol stack processing operation group identifiers of Cell1, Cell2, and Cell3 are all the same, the second protocol stack processing behavior is performed.

[0156] In a possible implementation, when a cell handover fails for a UE, it first callbacks (which can also be referred to as fallback, recovery, adjustment, etc., not specifically defined here) to the protocol stack processing state of the source cell (i.e., the first cell), such as the RLC processing state. When it then accesses the third cell through failure recovery, it performs the first protocol stack processing behavior or the second protocol stack processing behavior. Optionally, in another possible implementation, when a handover fails for the UE, it does not need to callback to the protocol stack processing state of the source cell. When it accesses the third cell through failure recovery, it performs the first protocol stack processing behavior or the second protocol stack processing behavior. The above callback of the RLC processing state may include at least one of the following: reverting the state variables related to transmission to the variable values of the source cell (i.e., the first cell) (state variables related to transmission such as: TX_Next_Ack - Acknowledgement state variable for the sending side, TX_Next - Send state variable for the sending side, POLL_SN - Poll send state variable); reverting the counters related to transmission to the counter values of the source cell (i.e., the first cell) (counters related to transmission such as: PDU_WITHOUT_POLL - Counter for non - polled packets, BYTE_WITHOUT_POLL - Counter for non - polled bytes, RETX_COUNT - Counter for retransmission); reverting the state variables related to reception to the variable values of the source cell (i.e., the first cell) (state variables related to reception such as: RX_Next - Receive state variable for the receiving side); reverting the timers related to transmission or reception (such as: t - PollRetransmit for poll retransmission timer, t - Reassembly for receive reassembly timer) to the timing values of the source cell. The operation of callback to the protocol stack processing state of the source cell can be performed with reference to the existing protocol descriptions, which will not be elaborated here.

[0157] Step 309, DU1 determines that the terminal accesses the third cell and determines the protocol stack processing behavior according to the reference information.

[0158] Among them, 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, the protocol stack processing operation group identifier of the third cell; the storage situation of the protocol stack processing state in the first network device; or, the access information of the terminal. Based on different reference information, DU1 can perform different protocol stack processing behaviors. Next, the solution of this application will be described based on different situations of the reference information.

[0159] 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

[0160] If the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell are different, then perform the first protocol stack processing behavior; or, if the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell are all the same, then perform the first protocol stack processing behavior.

[0161] In Case 1, the judgment logic of DU1 is the same as the judgment logic in step 308 above and can be understood by reference. Therefore, when the reference information is Case 1, the consistency of the protocol stack processing behavior between the UE side and the DU1 side can be ensured.

[0162] Case 2: The reference information includes the storage situation of the protocol stack processing state in the first network device

[0163] If it is determined that the protocol stack processing state is not stored in the first network device, then perform 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 (i.e., the first cell) is the same as the protocol stack group identifier of the third cell, then perform 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 perform the first protocol stack processing behavior.

[0164] 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 (which can be judged 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 state of the protocol stack, such as the RLC state. Then, the protocol stack processing state is not stored in DU1. Refer to Figure 2A , when the UE accesses Cell3, the first protocol stack processing behavior is performed. DU1 determines that the UE needs to switch from cell1 to cell2, so the protocol stack processing state is not stored. When the UE accesses Cell3, the first protocol stack processing behavior is also performed. Refer to Figure 4When 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. Therefore, when the UE accesses Cell3, it performs the second protocol stack processing behavior. Refer to Figure 4 , if the protocol stack processing operation group identifier of Cell1 is different from that of Cell2 and the same as that of Cell3, when the UE accesses Cell3, it performs the first protocol stack processing behavior. Since the UE performed the first protocol stack processing behavior when switching from Cell1 to Cell2, DU1 has deleted the protocol stack processing status. Therefore, when the UE accesses Cell3, DU1 performs the first protocol stack processing behavior. This method ensures the consistency of the protocol stack processing behavior on the UE and DU1 sides.

[0165] In addition, when at least one of the following conditions is met, the first network device deletes the protocol stack processing status (such as RLC processing status, MAC processing status) to avoid storage pressure caused by long-term maintenance of the protocol stack processing status:

[0166] The terminal switches to the cell managed by the second network device (for example, in the above Figure 2A , the terminal switches from the cell cell1 managed by DU1 to the cell cell2 managed by DU2); or, the protocol stack processing operation group identifier of the cell to which the terminal switches is different from the protocol stack processing operation group identifier of the source cell of the terminal (for example, in the above Figure 2A , the protocol stack processing operation identifier of the source cell cell1 of the terminal is different from that of the cell cell2 to which the terminal switches); or, it is determined that the terminal performs the first protocol stack processing behavior (that is, it is determined that the terminal performs the re-establishment or reset of the protocol stack).

[0167] Case 3. The reference information includes the access information of the terminal

[0168] 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 performed (for example, in the above Figure 2A , 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 does not switch from the cell managed by the first network device and performs the first protocol stack processing behavior, 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 the same as the protocol stack group identifier of the third cell, the second protocol stack processing behavior is performed (for example, in the above Figure 4In the case where 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, and 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 the above Figure 4 In the case where 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 (judging that the first protocol stack processing behavior is executed if there are different protocol stack processing operation identifiers)).

[0169] Therefore, when the reference information is in Case 3, the consistency of the protocol stack processing behavior between the UE and DU1 sides can be ensured.

[0170] Step 310, DU1 sends a successful access notification message to the CU.

[0171] In practical applications, the first network device may only learn that a certain terminal accesses the cell it manages, and it is not clear whether the terminal is cell switching or cell selection after cell switching failure. The following combines Figure 5 to illustrate the technical solution of the present application in detail with specific method embodiments. Figure 5 Taking the terminal as the UE and the network device including the CU and DU as an example for illustration, taking the CU governing DU1, DU2, and DU3 (the first network device) as an example for illustration, where the second network device may be other network devices except the first network device, and may be one or more. As Figure 5 shown, the method is executed as follows:

[0172] Step 501, the CU establishes a UE context with DU2 and obtains the configuration information of the cell managed by DU2.

[0173] Step 502, the CU sends the configuration information of the candidate cell to the UE via DU1.

[0174] Step 503, the UE sends the L1 (layer 1) measurement results of different cells to DU1 through the communication resources of the source cell (the first cell).

[0175] Step 504: DU1 determines whether the UE should perform an LTM handover based on the L1 measurement results of different cells, and sends the identification information of the associated target cell (the second cell) to the UE through the LTM handover signaling.

[0176] It can be understood that DU1 instructs the terminal to hand over from the first cell to the second cell.

[0177] Step 505A: DU1 sends a notification message to the CU.

[0178] Optionally, step 505B can also be executed.

[0179] Step 505B: The CU sends a notification message to DU2.

[0180] Step 506: The UE performs an LTM handover and hands over from the first cell to the second cell.

[0181] Among them, 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 above, and will not be elaborated here. Figure 3 in the steps 301 to 306, and will not be elaborated here.

[0182] Step 507: When the UE fails to hand over from the first cell to the second cell, it performs a cell selection operation to determine the third cell.

[0183] Specifically, when the UE determines to perform an LTM handover, it can start a timer (denoted as the T304 timer). When the timer expires, if the UE still fails to successfully access the second cell, the UE determines that a cell handover failure has occurred. Among them, the third cell is managed by DU3. The third cell is also a candidate cell provided to the UE in step 302.

[0184] Step 508: When the UE accesses the third cell, it determines 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.

[0185] It can be understood with reference to the description of step 308 above, and will not be elaborated here. For example, the first protocol stack processing behavior or the second protocol stack processing behavior, where 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. Figure 3 in the steps 301 to 306, and will not be elaborated here. For example, the first protocol stack processing behavior or the second protocol stack processing behavior, where 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.

[0186] The above Figure 5The 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 then the first protocol stack processing behavior is executed.

[0187] Step 509, DU3 determines that the terminal accesses the third cell and determines the protocol stack processing behavior according to the reference information.

[0188] Among them, the reference information includes at least one of the following: the storage situation of the protocol stack processing state in the first network device; or, the access information of the terminal. Based on different reference information, DU3 can execute different protocol stack processing behaviors. Next, the solution of this application will be described based on different situations of the reference information.

[0189] Situation 1: The reference information includes the storage situation of the protocol stack processing state in the first network device

[0190] If it is determined that the protocol stack processing state is not stored in the first network device, then the first protocol stack processing behavior is executed. Since Figure 5 in, DU3 determines that the UE has not switched from the cell it manages to the third cell. Therefore, DU3 does not store the protocol stack processing state, such as RLC behavior, etc., and executes the first protocol stack processing behavior, such as RLC re-establishment.

[0191] In addition, when at least one of the following conditions is met, the first network device deletes the protocol stack processing state to avoid long-term maintenance of the protocol stack processing state and causing storage pressure:

[0192] 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, it is determined that the terminal executes the first protocol stack processing behavior (that is, it is determined that the terminal executes the re-establishment or reset of the protocol stack).

[0193] Situation 2: The reference information includes the access information of the terminal

[0194] 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, then the first protocol stack processing behavior is executed. Since Figure 5 in, DU3 determines that the UE has not switched from the cell it manages to the third cell. Therefore, the first protocol stack processing behavior, such as RLC re-establishment, is executed.

[0195] Therefore, when the reference information is the above Situation 1 and Situation 2, the consistency of the protocol stack processing behavior between the UE and the DU1 side can be ensured.

[0196] Step 510, DU3 sends a notification message of successful access to the CU.

[0197] Embodiment 2

[0198] The following combines Figure 6 , and uses specific method embodiments to describe the technical solution of this application in detail. The following first network device and second network device can be a device integrating CU and DU, can be a CU or a DU, or can also be a gNB, etc. Figure 6 Taking the terminal as a UE, the first network device as CU1, and the second network device as CU2 as an example, the DUs under the jurisdiction of CU1 are different from those under the jurisdiction of CU2. The cells managed by CU1 are all the cells managed by the DUs under the jurisdiction of CU1, and the cells managed by CU2 are all the cells managed by the DUs under the jurisdiction of CU2. Among them, the second network device can be other network devices except the first network device, and can be one or more. As Figure 6 shown, this method is executed as follows:

[0199] Step 601, CU1 obtains the configuration information of the candidate cell.

[0200] The above-mentioned candidate cell configuration information may include the protocol stack processing operation identifier of the candidate cell, where the candidate cell may include the source cell (i.e., the first cell).

[0201] Step 602, CU1 sends the configuration information of the candidate cell to the UE via the DU under its jurisdiction.

[0202] Step 603, the UE sends the L1 measurement results of different cells to CU1 through the communication resources of the source cell (the first cell).

[0203] Step 604, CU1 determines whether the UE should perform an LTM handover according to the L1 measurement results of different cells, and sends the identification information of the associated target cell (the second cell) to the UE through the LTM handover signaling.

[0204] Step 605, the UE performs an LTM handover and switches from the first cell to the second cell.

[0205] Among them, the first cell is managed by CU1, and the second cell is managed by CU2. In the above step 605, when the UE performs the handover from the first cell to the second cell, it determines whether the protocol stack processing operation identifiers of the first cell and the second cell are the same. If they are the same, it performs the first protocol stack processing behavior; if they are different, it performs the second protocol stack processing behavior. Among them, 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.

[0206] Step 606: When the UE fails to hand over from the first cell to the second cell, it performs a cell selection operation to determine the third cell.

[0207] Specifically, when the UE determines to perform an LTM handover, it can start a timer (denoted as the T304 timer). When the timer expires, if the UE still fails to successfully access the second cell, the UE determines that a cell handover failure has occurred. Among them, the third cell is managed by CU1. The third cell is also one of the candidate cells provided to the UE in step 601.

[0208] Step 607: When the UE accesses the third cell, it performs the first protocol stack processing behavior.

[0209] Step 608: When CU1 determines that the terminal accesses the third cell, it performs the first protocol stack processing behavior according to the reference information.

[0210] Among them, the reference information satisfies at least one of the following:

[0211] Reference information 1: The protocol stack processing status is not stored in the first network device.

[0212] Reference information 2: The first network device determines that the terminal accesses the third cell from the cell managed by the second network device.

[0213] Reference information 3: The first network device determines that the terminal accesses the third cell after a cell handover failure.

[0214] Since the terminal hands over from the first cell to the second cell, and the second cell is not the cell managed by CU1, it is consistent that CU1 does not store the protocol stack processing status with reference information 1. It is inconsistent that CU1 determines that the terminal accesses the third cell from the cell managed by CU1 with reference information 2. It is inconsistent that CU1 cannot determine that the terminal accesses the third cell after a cell handover failure with reference information 3. Therefore, the first protocol stack processing behavior is performed. For example, the protocol stack processing status includes PDCP processing status, RLC processing status, and MAC processing status.

[0215] In the above Figure 4 Since the UE fails to hand over from Cell1 to Cell2 and performs a cell selection operation to select Cell3, the first protocol stack processing behavior is performed. At this time, since Cell1, Cell2, and Cell3 are managed by DU1, it is inconsistent that DU1 stores the protocol stack processing status with 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 reference information 2. DU1 determines that the UE accesses the third cell after a cell handover failure, so it is consistent with reference information 3. Therefore, the first protocol stack processing behavior is performed.

[0216] Based on this, the consistency of the protocol stack processing behaviors on the UE and CU1 sides can be ensured.

[0217] Embodiment 3

[0218] Next, in combination with Figure 7 , the technical solution of the present application will be described in detail by specific method embodiments. The following first network device and second network device can be a device integrating CU and DU, can be a CU or a DU, or can also be a gNB, etc. Figure 7 In Figure 7 , the terminal is taken as the UE, the first network device is taken as gNB1, and the second network device is taken as gNB2 as an example for illustration. Among them, the second network device can be other network devices except the first network device, and can be one or more. As

[0219] Step 701, gNB1 obtains the configuration information of the candidate cell.

[0220] The above candidate cell configuration information may include the protocol stack processing operation identifier of the candidate cell, where the candidate cell may include the source cell (i.e., the first cell).

[0221] Step 702, gNB1 sends the configuration information of the candidate cell to the UE.

[0222] Step 703, the UE sends the L1 measurement results of different cells to gNB1 through the communication resources of the source cell (the first cell).

[0223] Step 704, gNB1 determines whether the UE should perform an LTM handover according to the L1 measurement results of different cells, and sends the identification information of the associated target cell (the second cell) to the UE through the LTM handover signaling.

[0224] Optionally, gNB1 may instruct the terminal to hand over from the first cell to the second cell.

[0225] Step 705, the UE performs an LTM handover and hands over from the first cell to the second cell.

[0226] Among them, the first cell is managed by gNB1, and the second cell is managed by gNB2. In the above step 705, when the UE performs the handover from the first cell to the second cell, it determines whether the protocol stack processing operation identifiers of the first cell and the second cell are the same. If they are the same, it performs the first protocol stack processing behavior; if they are different, it performs the second protocol stack processing behavior. Among them, 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.

[0227] In step 706, when the UE fails to hand over from the first cell to the second cell, the protocol stack processing status is called back to the protocol stack processing status corresponding to the first cell, and a cell selection operation is performed to determine a third cell.

[0228] In 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.

[0229] Specifically, when the UE determines to perform an LTM handover, a timer (denoted as the T304 timer) can be started. When the timer expires, if the UE still fails to successfully access the second cell, the UE determines that a cell handover failure has occurred. Among them, the third cell is managed by gNB1. The third cell is also a candidate cell provided to the UE in step 601.

[0230] 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 performed; 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 performed.

[0231] For example, referring to the above Figure 2A 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. Then, since the protocol stack processing operation group identifier of Cell1 is the same as that of Cell3, the second protocol stack processing behavior is performed.

[0232] In step 708, when gNB1 determines that the terminal accesses the third cell, the protocol stack processing behavior is determined according to the first reference information.

[0233] Among them, 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. Based on the difference of the first reference information, gNB1 can perform different protocol stack processing behaviors. Next, the solution of this application will be described based on different situations of the first reference information.

[0234] Situation 1: The first reference information indicates the access information of the terminal

[0235] Among them, the access information is determined through the third reference information, and the third reference information includes at least one of the following:

[0236] The first notification message for switching to the third cell from the second network device (e.g., the notification message for the UE to perform LTM handover to Cell2 sent by gNB2), the second notification message for the terminal to successfully handover from the first cell to the second cell (e.g., the notification message sent by gNB2 for the terminal to successfully handover from the first cell to the second cell. In addition, if the terminal fails to successfully handover from the first cell to the second cell, gNB2 may not send a notification message or send a notification message indicating handover failure, which is not specifically defined here). The first cell is managed by gNB1, and the second cell is managed by gNB2. If gNB1 receives the above first notification message or second notification message, gNB1 no longer stores the protocol stack processing status of this UE.

[0237] 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 (e.g., receives the first notification message or the second notification message, then it is determined that the terminal accesses the third cell from the second cell managed by the second network device (gNB2 in the above Figure 7 ), then perform 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 (e.g., does not receive the first notification message or the second notification message, then it is determined that the terminal accesses the third cell from the first cell, that is, the recovery of a failed cell handover), 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 perform 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 perform the second protocol stack processing behavior.

[0238] Case 2: The second reference information of the protocol stack processing behavior reported by the first reference information indicating the terminal

[0239] Among them, 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 mode of the terminal.

[0240] If the execution status of the protocol stack processing behavior in the terminal indicates that the terminal performs the first protocol stack processing behavior, then perform the first protocol stack processing behavior (e.g., if the UE performs RLC reconstruction, then gNB1 also performs RLC reconstruction); or, if the execution status of the protocol stack processing behavior in the terminal indicates that the terminal performs the second protocol stack processing behavior, then perform the second protocol stack processing behavior (e.g., if the UE performs partial reset of MAC, then gNB1 also performs partial reset of MAC); or, if the access mode of the terminal indicates that the terminal is cell handover after successful cell handover, then perform the first protocol stack processing behavior; or, if the access mode of the terminal indicates that the terminal is cell selection after failed cell handover, then perform the second protocol stack processing behavior.

[0241] The second reference information described above may be reported via 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.

[0242] When at least one of the following conditions is met, the first network device stores the protocol stack processing state:

[0243] There is a protocol stack processing operation group identifier in the protocol stack processing operation group identifiers of the candidate cells managed by the first network device that is the same as the protocol stack processing operation group identifier of the first cell (for example, the candidate cells of gNB1 include the first cell, the second cell, and the third cell. Among them, the first cell has the same protocol stack processing operation group identifier as the first cell. At this time, gNB1 stores the protocol stack processing state; the candidate cells of gNB1 include the second cell and the third cell. Among them, the third cell has the same protocol stack processing operation group identifier as the first cell. At this time, gNB1 stores the protocol stack processing state); The first network device determines that the terminal has left the first cell for no more than the set duration of the timer (for example, after gNB1 sends a handover command to the UE to leave the first cell, a timer is started. When the timer expires, gNB1 no longer stores the protocol stack processing state. Not storing the protocol stack processing state can also be understood as deleting the previously stored protocol stack processing state; if it does not exceed the set duration of the timer, 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.

[0244] The above mainly introduces the solution provided by the embodiments of the present application from the perspective of device interaction. It can be understood that, in order to implement the above functions, each device may include a corresponding hardware structure and / or software module for executing each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of the examples described in the embodiments disclosed in this article, the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0245] Embodiments of the present application can divide the device into functional units according to the above method examples. For example, each functional unit can be divided corresponding 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 in the form of a software functional unit.

[0246] In the case of adopting an integrated unit, Figure 8 FIG. shows a possible exemplary block diagram of a communication device involved in an embodiment of the present application. As Figure 8 shown, 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 the communication between the communication device 800 and other devices. Optionally, the transceiver unit 802 may include a receiving unit and / or a transmitting unit, which are respectively used to perform receiving and transmitting operations. Optionally, the communication device 800 may further include a storage unit, which is used to store the 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 (such as 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 terminal device, the first network device, etc.

[0247] In one embodiment, when the communication device 800 is a terminal, 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, determine 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.

[0248] Correspondingly, 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 according to the reference information; where the reference information includes at least one of the following: the storage situation of the protocol stack processing state in the first network device; or, the access information of the terminal.

[0249] Based on this, the consistency of the protocol stack processing behavior of the terminal and the first network device can be ensured.

[0250] In addition, when the communication device 800 is the 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 both the first cell and the third cell are managed by the first network device; the processing unit 801 is used to determine the protocol stack processing behavior according to 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, the protocol stack processing operation group identifier of the third cell; the storage situation of the protocol stack processing state in the first network device; or, the access information of the terminal.

[0251] Based on this, the consistency of the protocol stack processing behavior of the terminal and the first network device can also be ensured.

[0252] In order to avoid the situation of inconsistent protocol stack processing behavior with the first network device side, when the communication device 800 is the terminal, the processing unit 801 is used to execute the first protocol stack processing behavior if there are differences in the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell; or, execute the second protocol stack processing behavior if the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell are all the same.

[0253] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0254] RLC re - establishment, MAC reset, or PDCP re - establishment.

[0255] 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.

[0256] In an optional manner, when the reference information includes the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell, 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 there are differences in the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell; or, execute the second protocol stack processing behavior if the protocol stack processing operation group identifiers of the first cell, the second cell, and the third cell are all the same.

[0257] In an alternative manner, when the reference information includes the storage status of the protocol stack processing status in the first network device, when the communication device 800 is the first network device, the processing unit 801 is configured to, if it is determined that the protocol stack processing status is not stored in the first network device, perform a first protocol stack processing behavior; 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, perform a second protocol stack processing behavior; 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, perform a first protocol stack processing behavior.

[0258] In an alternative manner, when the reference information includes the access information of the terminal, when the communication device 800 is the first network device, the processing unit 801 is configured to, 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, perform a first protocol stack processing behavior; or, if it is determined according to 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, perform a second protocol stack processing behavior; or, if it is determined according to 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, perform a first protocol stack processing behavior.

[0259] In an alternative manner, when the communication device 800 is the first network device, the processing unit 801 is configured to delete the protocol stack processing status when it is determined that at least one of the following conditions is met: the terminal has switched to the cell managed by the second network device; or, the protocol stack processing operation group identifier of the cell to which the terminal has switched is different from the protocol stack processing operation group identifier of the source cell of the terminal; or, it is determined that the terminal performs a first protocol stack processing behavior.

[0260] In yet another embodiment, the communication device 800 is a terminal, and the processing unit 801 is configured to determine a third cell by performing a cell selection operation when the terminal fails to switch from the first cell to the second cell; when the terminal accesses the third cell, perform a first protocol stack processing behavior; wherein, the first protocol stack processing behavior includes at least one of the following: RLC re-establishment, MAC reset, PDCP re-establishment.

[0261] Correspondingly, the communication device 800 is a first network device, and the processing unit 801 is configured to determine that a terminal accesses a third cell, where the third cell is managed by the first network device; perform a first protocol stack processing behavior according to reference information; where 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 a cell managed by a second network device, and the first network device determines that the terminal accesses the third cell after a cell handover fails; where the first protocol stack processing behavior includes at least one of the following: RLC re - establishment, MAC reset, and PDCP re - establishment.

[0262] In another embodiment, the communication device 800 is a terminal, and the processing unit 801 is configured to, when the terminal fails to handover from a first cell to a second cell, callback the protocol stack processing status to the protocol stack processing status corresponding to the first cell; when the terminal accesses a third cell, determine a 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, where the third cell is a cell determined after the terminal performs a cell selection operation.

[0263] Correspondingly, the communication device 800 is a first network device, and the processing unit 801 is configured to determine that a terminal accesses a third cell, where the third cell is managed by the first network device; determine a protocol stack processing behavior according to first reference information; where the first reference information indicates at least one of the following: the access information of the terminal; or, second reference information of the protocol stack processing behavior reported by the terminal.

[0264] In an optional manner, when the communication device 800 is a terminal, the processing unit 801 is configured to, 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, perform a 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, perform a second protocol stack processing behavior.

[0265] Specifically, the first protocol stack processing behavior includes at least one of the following:

[0266] RLC re - establishment, MAC reset, or PDCP re - establishment.

[0267] 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.

[0268] In an alternative manner, the first reference information indicates access information of the terminal. When the communication device 800 is the first network device, the processing unit 801 is configured to perform a 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, perform a 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, perform a second protocol stack processing behavior.

[0269] In an alternative manner, the access information is determined by a third reference information, and the third reference information includes at least one of the following:

[0270] A first notification message for switching to the third cell from the second network device, a second notification message that the terminal has successfully switched from the first cell to the second cell, the first cell being managed by the first network device and the second cell being managed by the second network device.

[0271] In an alternative manner, the first reference information indicates second reference information of 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 mode of the terminal. When the communication device 800 is the first network device, the processing unit 801 is configured to perform a first protocol stack processing behavior if the execution status of the protocol stack processing behavior in the terminal indicates that the terminal performs the first protocol stack processing behavior; or, if the execution status of the protocol stack processing behavior in the terminal indicates that the terminal performs the second protocol stack processing behavior, perform the second protocol stack processing behavior; or, if the access mode of the terminal indicates that the terminal is a cell handover after successful cell handover, perform the first protocol stack processing behavior; or, if the access mode of the terminal indicates that the terminal is a cell selection after failed cell handover, perform the second protocol stack processing behavior.

[0272] In an alternative manner, when the communication device 800 is the first network device, the processing unit 801 is configured to store the protocol stack processing status in the first network device when determining that at least one of the following conditions is met:

[0273] There is a protocol stack processing operation group identifier in the protocol stack processing operation group identifiers of the candidate cells managed by the first network device 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 left the first cell and has not exceeded the set duration of the timer.

[0274] In addition, as Figure 9As shown, it is a schematic structural diagram of a simplified terminal device provided by the present application. For the convenience of understanding and in the form of illustration, Figure 9 in which, a mobile phone is taken as an example for the terminal. As Figure 9 shown, the terminal includes a processor, a memory, a radio frequency circuit, an antenna, and an input / output device.

[0275] The processor is mainly used to process communication protocols and communication data, control the terminal device, execute software programs, process data of software programs, etc.

[0276] The memory is mainly used to store software programs and data.

[0277] The radio frequency circuit is mainly used for the conversion between baseband signals and radio frequency signals and the processing of radio frequency signals.

[0278] The antenna is mainly used to receive and transmit radio frequency signals in the form of electromagnetic waves.

[0279] The input / output device, such as a touch screen, a display screen, a keyboard, etc., is mainly used to receive data input by the user and output data to the user.

[0280] It should be noted that some types of terminal devices may not have an input / output device.

[0281] When data needs to be sent, after the processor performs baseband processing on the data to be sent, it outputs a baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then sends the radio frequency signal outwards in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data.

[0282] For the convenience of description, Figure 9 only one memory and one processor are shown in the figure. In an actual terminal device product, there may be one or more processors and one or more memories. The memory can also be referred to as a storage medium or a storage device, etc. The memory can be set independently of the processor or integrated with the processor. The embodiments of the present application do not limit this.

[0283] In the embodiments of the present application, the antenna and the radio frequency circuit with transceiver functions can be regarded as the transceiver unit of the terminal device, and the processor with processing functions can be regarded as the processing unit of the terminal device.

[0284] As Figure 9 shown, the terminal 900 includes a transceiver unit 910 and a processing unit 920. The transceiver unit 910 can also be referred to as a transceiver, a transceiver machine, a transceiver device, etc. The processing unit 920 can also be referred to as a processor, a processing board, a processing module, a processing device, etc.

[0285] Optionally, the devices in the transceiver unit 910 for implementing the receiving function can be regarded as the receiving unit, and the devices in the transceiver unit 910 for implementing the transmitting function can be regarded as the transmitting unit, that is, the transceiver unit 910 includes a receiving unit and a transmitting unit. The transceiver unit can sometimes also be referred to as a transceiver, transceiver, or transceiver circuit, etc. The receiving unit can sometimes also be referred to as a receiver, receiver, or receiving circuit, etc. The transmitting unit can sometimes also be referred to as a transmitter, transmitter, or transmitting circuit, etc.

[0286] It should be understood that the transceiver unit 910 is used to perform the sending operation and receiving operation of the terminal device in the above method embodiments, and the processing unit 920 is used to perform other operations of the terminal device except the sending and receiving operations in the above method embodiments.

[0287] When the terminal device is a chip, the chip includes a transceiver unit 910 and a processing unit 920. Among them, the transceiver unit 910 can be an input / output circuit or a communication interface; the processing unit 920 is a processor, microprocessor, integrated circuit, or logic circuit integrated on the chip.

[0288] This application also provides a network device. As Figure 10 shown, it is a schematic structural diagram of the network device 1000 provided by the embodiments of this application. The network device 1000 can be applied to a system as Figure 1 shown. For example, the network device 1000 can be Figure 1 the network device in the system, and is used to perform the functions of the network device in the above method embodiments. It should be understood that the following is only an example. In future communication systems, the network device can have other forms and compositions.

[0289] For example, in a 5G communication system, the network device 1000 can include a CU, a DU, and an AAU. Compared with the network device in an LTE communication system, which consists of one or more radio frequency units, such as remote radio units (RRUs) and one or more indoor baseband processing units (BBUs):

[0290] The non-real-time part of the original BBU will be split out and redefined as the CU, which is responsible for processing non-real-time protocols and services. The part of the physical layer processing function of the BBU, the original RRU, and the passive antenna are combined into the AAU. The remaining function of the BBU is redefined as the DU, which is responsible for processing physical layer protocols and real-time services. In short, the CU and the DU are distinguished by the real-time nature of the processed content, and the AAU is a combination of the RRU and the antenna.

[0291] The CU, DU, and AAU can be deployed separately or integrated, so there will be various network deployment forms. One possible deployment form is as shown in Figure 10 , which is the same as the traditional 4G network equipment, and the CU and DU share the same hardware for deployment. It should be understood that Figure 10 is just an example and does not limit the protection scope of this application. For example, the deployment form can also be that the DU is deployed in the BBU computer room, the CU is centrally deployed or the DU is centrally deployed, and the CU is more highly centralized, etc.

[0292] The AAU 1100 can implement the transceiver function corresponding to the transceiver unit 802 in Figure 8 . Optionally, the AAU 1100 can also be referred to as a transceiver, a transceiver circuit, or a transceiver, etc. It 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 the internal processing function corresponding to the processing unit 801 in Figure 8 . Optionally, the CU and DU 1200 can control the network device, etc., and can be referred to as a controller. The AAU, CU, and DU can be physically set together or physically separated.

[0293] In addition, the first network device is not limited to the Figure 10 shown form, and can also be in other forms: for example, it includes a BBU and an adaptive radio unit (ARU), or includes a BBU and an AAU; it can also be a customer premises equipment (CPE), or in other forms, which is not limited in this application.

[0294] In one example, the CU and DU 1200 can be composed of one or more single boards. The multiple single boards can jointly support a radio access network of a single access mode (such as an LTE network), or can separately support radio access networks of different access modes (such as an LTE network, a 5G network, a future network, or other networks). The CU and DU 1200 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 embodiments. The memory 1201 and the processor 1202 can serve one or more single boards. That is to say, a memory and a processor can be separately set on each single board. It can also be that multiple single boards share the same memory and processor. In addition, necessary circuits can also be set on each single board.

[0295] It should be understood that Figure 10 the network device 1000 shown is capable of implementing Figure 5 the network device functions involved in the method embodiments described above. The operations and / or functions of each unit in the network device 1000 respectively implement the corresponding processes executed by the network device in the method embodiments of this application. To avoid repetition, the detailed description is appropriately omitted here. Figure 10 The structure of the exemplary network device is only one possible form and should not impose any limitation on the embodiments of this application. This application does not exclude the possibility of other forms of network device structures that may appear in the future.

[0296] The above-mentioned CU and DU 1200 can be used to execute the actions implemented inside the network device described in the previous method embodiments, while the AAU 1100 can be used to execute the actions of the network device sending to or receiving from the terminal device described in the previous method embodiments. For specific details, please refer to the description in the previous method embodiments and will not be elaborated here.

[0297] The embodiments of this application also provide a communication system, which includes a terminal device and a network device. The terminal device is used to execute all or part of the steps executed by the terminal device in the above-mentioned Figures 3 - 7 illustrated embodiments. The network device is used to execute all or part of the steps executed by the network device in the Figures 3 - 7 illustrated embodiments.

[0298] Based on the above embodiments, the embodiments of this application also provide a readable storage medium, which stores instructions that, when executed, implement the methods in any of the above embodiments. The readable storage medium may include: various media that can store program codes such as USB flash drives, mobile hard disks, read-only memories, random access memories, magnetic disks, or optical discs.

[0299] Those skilled in the art should understand that the embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, compact disc read-only memories (CD-ROMs), optical memories, etc.) that contain computer-usable program codes.

[0300] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0301] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0302] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate 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 flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

Claims

1. A communication method, characterized in that, applied to a terminal or a chip of the terminal, includes: when the terminal fails to switch from a first cell to a second cell, performing a cell selection operation to determine a third cell; when the terminal accesses the third cell, determining a 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.

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 there are differences among 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, performing a 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, performing a second protocol stack processing behavior.

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) re - establishment, medium access control (MAC) protocol reset, packet data convergence protocol (PDCP) re - establishment.

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, applied to a first network device or a chip of the first network device, includes: determining that a terminal accesses a third cell, where the third cell is managed by the first network device; determining a protocol stack processing behavior according to reference information; wherein, the reference information includes at least one of the following: the storage situation of the protocol stack processing state in the first network device; or, the access information of the terminal.

6. A communication method, characterized in that, applied to a first network device or a chip of the first network device, includes: instructing the 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 the first network device; determining a protocol stack processing behavior according to 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 situation of the protocol stack processing state 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 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, determining the 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, perform a 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, perform a second protocol stack processing behavior.

8. The method according to claim 5 or 6, wherein, When the reference information includes the storage situation of the protocol stack processing state in the first network device, determining the 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, perform a 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, perform a 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, perform the first protocol stack processing behavior.

9. The method according to claim 5 or 6, wherein, When the reference information includes the access information of the terminal, determining the 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, perform a first protocol stack processing behavior; or, If it is determined according to 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, perform a second protocol stack processing behavior; or, If it is determined according to 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, perform the first protocol stack processing behavior.

10. The method according to claim 5, 6 or 8, wherein, further includes: When at least one of the following conditions is met, delete the protocol stack processing state: The terminal switches to the cell managed by the second network device; The protocol stack processing operation group identifier of the cell to which the terminal switches is different from the protocol stack processing operation group identifier of the source cell of the terminal; It is determined that the terminal performs a first protocol stack processing behavior.

11. The method according to any one of claims 7-10, It is 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 (MAC) protocol reset, or packet data convergence protocol (PDCP) re - establishment.

12. The method according to any one of claims 7 - 10, It is 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, It is characterized in that applied to a terminal or a chip of the terminal, includes: when the terminal fails to switch from a first cell to a second cell, performing a cell selection operation to determine a third cell; when the terminal accesses the third cell, performing a first protocol stack processing behavior; wherein, the first protocol stack processing behavior includes at least one of the following: radio link control (RLC) re - establishment, medium access control (MAC) protocol reset, or packet data convergence protocol (PDCP) re - establishment.

14. A communication method, It is characterized in that applied to a first network device or a chip of the first network device, includes: determining that a terminal accesses a third cell, where the third cell is managed by the first network device; performing 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 state is not stored in the first network device; the first network device determines that the terminal accesses the third cell from a cell managed by a 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: radio link control (RLC) re - establishment, medium access control (MAC) protocol reset, or packet data convergence protocol (PDCP) re - establishment.

15. A communication method, It is characterized in that applied to a terminal or a chip of the terminal, includes: when the terminal fails to switch from a first cell to a 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, determining a 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, where the third cell is the cell determined by the terminal after performing a cell selection operation.

16. The method according to claim 15, It is characterized in that the determining a 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, then performing a 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, then performing a second protocol stack processing behavior.

17. The method according to claim 16, It is 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 (MAC) protocol reset, Packet Data Convergence Protocol (PDCP) re - establishment.

18. The method according to claim 16, wherein, 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, wherein, applied to a first network device or a chip of the first network device, includes: determining that a terminal accesses a third cell, where the third cell is managed by the first network device; determining a protocol stack processing behavior according to 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.

20. The method according to claim 19, wherein, the first reference information indicates the access information of the terminal, and the determining the 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 a second cell managed by a second network device, then perform a first protocol stack processing behavior; or, if it is determined according to the access information that the terminal accesses the third cell from a 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 perform the first protocol stack processing behavior; or, if it is determined according to the access information that the terminal accesses the third cell from a 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 perform a second protocol stack processing behavior.

21. The method according to claim 19 or 20, wherein, 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, a second notification message that the terminal successfully switches from the first cell to the second cell, where 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, wherein, the first reference information indicates the 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 situation of the protocol stack processing behavior in the terminal; or, the access mode of the terminal; the determining the protocol stack processing behavior according to the first reference information includes: if the execution situation of the protocol stack processing behavior in the terminal indicates that the terminal performs a first protocol stack processing behavior, then perform the first protocol stack processing behavior; or, if the execution situation of the protocol stack processing behavior in the terminal indicates that the terminal performs a second protocol stack processing behavior, then perform the second protocol stack processing behavior; or, if the access mode of the terminal indicates that the terminal is a cell handover after successful cell handover, then perform the first protocol stack processing behavior; or, If the access mode of the terminal indicates that the terminal is cell selection after cell handover failure, then perform the second protocol stack processing behavior.

23. The method according to claim 20 or 21, wherein, when at least one of the following conditions is satisfied, store the protocol stack processing status: there is a protocol stack processing operation group identifier in the protocol stack processing operation group identifiers of the candidate cells managed by the first network device 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 left the first cell and has not exceeded the set duration of the timer.

24. The method according to any one of claims 20-23, wherein, the first protocol stack processing behavior includes at least one of the following: Radio Link Control (RLC) re-establishment, Medium Access Control (MAC) protocol reset, Packet Data Convergence Protocol (PDCP) re-establishment.

25. The method according to any one of claims 20-23, wherein, 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, wherein, comprising: a functional module for implementing the method according to any one of claims 1-25.

27. A communication device, wherein, comprising: at least one processor and a memory; the memory for storing computer programs or instructions; the at least one processor for executing the computer programs or instructions so that the method according to any one of claims 1-25 is executed.

28. A chip system, wherein, the chip system comprises: a processing circuit; the processing circuit is coupled to a storage medium; the processing circuit for executing some or all of the computer programs or instructions in the storage medium, and when the some or all of the computer programs or instructions are executed, for implementing the method according to any one of claims 1-25.

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

30. A computer program product comprising computer programs or instructions, wherein, when the computer programs or instructions run on a computer, the method according to any one of claims 1-25 is executed.

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