Communication method and communication device

Abstract

The present application provides a communication method and communication apparatus that can obtain more accurate mobility history information of a terminal device. The method includes: a first network device determines that a terminal device changes to a first cell, where the change includes a dual-activation protocol stack (DAPS) handover, a conditional handover (CHO), or a radio resource control (RRC) re-establishment; and the first network device begins recording first mobility history information at or after determining that the terminal device changes to the first cell, where the first mobility history information is historical information of the terminal device in the first cell.

Description

Technical Field

[0001] The present application relates to the field of communications, and more particularly, to a communication method and a communication device. Background Art

[0002] Currently, to optimize the mobility of terminal devices, terminal devices or network devices record the terminal device's movement history. During a handover, the target network device begins recording the terminal device's movement history upon receiving a handover request message. However, at the time the target network device receives the handover request message, the terminal device may not have yet been switched to the target network device. Therefore, it is not reasonable for the target network device to begin recording the terminal device's movement history upon receiving the handover request message.

[0003] For example. In the conditional handover (CHO) mechanism, the time when the source network device sends a handover request message to the target network device and the time when the terminal device selects the target cell (i.e., a candidate cell) for access may be quite different. It is not reasonable for the target network device to start recording the terminal device's mobility history information from the moment it receives the handover request message. For another example, in the dual active protocol stack handover (DAPS HO) process, the terminal device is connected to both the source network device (or source cell) and the target network device (or target cell) for a period of time. Therefore, it is not reasonable for the target network device to start recording the terminal device's mobility history information after receiving the handover request message. Summary of the Invention

[0004] The present application provides a communication method to obtain more accurate movement history information of a terminal device.

[0005] In a first aspect, a communication method is provided, the method comprising: a first network device determines that a terminal device changes to a first cell, the change comprising dual activation protocol stack DAPS switching, conditional switching CHO or radio resource control RRC re-establishment; the first network device starts recording first mobility history information at or after determining that the terminal device changes to the first cell, the first mobility history information being historical information of the terminal device in the first cell.

[0006] Based on the above technical solution, when the terminal device performs CHO switching, DAPS switching or RRC re-establishment, the target network device (i.e., the first network device) or the target cell (the first cell) determines that the terminal device has changed to the target cell (i.e., the first cell), and starts recording the terminal device's movement history information, that is, starts recording the terminal device's historical information in the target cell, so that more accurate terminal device movement history information can be recorded, so that the target network device can obtain more accurate terminal device movement status, so as to facilitate more accurate optimization.

[0007] In combination with the first aspect, in certain implementations of the first aspect, the first network device determines that the terminal device changes to the first cell, including: the first network device determines that the terminal device changes to the first cell when it is determined that the terminal device successfully randomly accesses the first cell; the first network device starts recording the first mobile history information at or after determining that the terminal device changes to the first cell, including: the first network device starts recording the first mobile history information at or after determining that the terminal device successfully randomly accesses the first cell.

[0008] In combination with the first aspect, in certain implementations of the first aspect, if the change is a DAPS switch, the first network device determines that the terminal device changes to the first cell, including: the first network device determines that the terminal device changes to the first cell after sending a first indication message, and the first indication message is used to instruct the terminal device to disconnect from the second cell; the first network device starts recording the first mobile history information at or after determining that the terminal device changes to the first cell, including: the first network device starts recording the first mobile history information at or after sending the first indication message.

[0009] In combination with the first aspect, in certain implementations of the first aspect, if the change is a DAPS switch, the first network device determines that the terminal device changes to the first cell, including: the first network device determines that the terminal device changes to the first cell after sending a second indication message, and the second indication message is used to instruct the second cell or the second network device to release the context of the terminal device; the first network device starts recording the first mobile history information at or after determining that the terminal device changes to the first cell, including: the first network device starts recording the first mobile history information at or after sending the second indication message.

[0010] In combination with the first aspect, in some implementations of the first aspect, the first mobility history information further includes third indication information, and the third indication information is used to instruct the terminal device to switch from the first cell to the third cell using DAPS switching.

[0011] In combination with the first aspect, in some implementations of the first aspect, the third indication information is also used to indicate a first time period, which represents the length of time that the terminal device stays in the first cell and the third cell at the same time during the DAPS switching process.

[0012] In combination with the first aspect, in certain implementations of the first aspect, if the change is CHO, the first network device determines that the terminal device changes to the first cell, including: the first network device determines that the terminal device changes to the first cell when sending a switching success message; the first network device starts recording the first mobile history information at or after determining that the terminal device changes to the first cell, including: the first network device starts recording the first mobile history information at or after sending the switching success message.

[0013] In combination with the first aspect, in certain implementations of the first aspect, if the change is CHO, the first network device determines that the terminal device has changed to the first cell, including: the first network device determines that the terminal device has changed to the first cell when receiving a serial number status transfer message; the first network device starts recording the first mobile history information at or after determining that the terminal device has changed to the first cell, including: the first network device starts recording the first mobile history information at or after receiving the serial number status transfer message.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the method further includes: the first network device sends the first mobility history information to the third network device, the first mobility history information includes a second time period, and the second time period is the length of time the terminal device stays in the first cell.

[0015] In combination with the first aspect, in certain implementations of the first aspect, before the first network device determines that the terminal device has changed to the first cell, the method also includes: the first network device receives a switching request message from the second network device, the switching request message includes second mobile history information, the second mobile history information is recorded by the second network device, and the second mobile history information includes a third time period, which is the length of time the terminal device stays in the second cell; the first network device compensates the time from receiving the switching request message to determining that the terminal device has changed to the first cell into the third time period.

[0016] Based on the above technical solution, the target network device can modify the time that the terminal device receives in the switching request message and stays in the source cell (second cell), that is, the time from receiving the switching request message to the terminal device successfully switching to the target cell is compensated to the time the terminal device stays in the source cell, so that the target network device can obtain more accurate historical information of the terminal device in the source cell, so as to facilitate more accurate optimization.

[0017] In a second aspect, a communication method is provided, which is applied to a dual-activation protocol stack switching process, the method including: a terminal device determines to switch from a second cell to a first cell; the terminal device records fourth mobility history information at or after the moment of determining to switch from the second cell to the first cell, the fourth mobility history information being the historical information of the terminal device in the second cell, the fourth mobility history information including a fourth time period, the fourth time period being the time spent in the second cell; the terminal device determines to switch from the first cell to the second cell including: the terminal device determines to switch from the second cell to the first cell upon receiving first indication information, the first indication information being used to instruct the terminal device to disconnect from the second cell; the terminal device records the fourth mobility history information at or after determining to switch from the second cell to the first cell including: the terminal device records the fourth mobility history information at or after receiving the first indication information.

[0018] Based on the above technical solution, during the process of the terminal device executing the handover, when the terminal device determines that it has successfully switched from the source cell (the second cell) to the target cell (the first cell), it records the historical information of the source cell (i.e., the third mobile history information), thereby recording more accurate mobile history information of the terminal device, so that the network device can obtain more accurate terminal device movement information, so as to facilitate more accurate optimization.

[0019] In combination with the second aspect, in some implementations of the second aspect, the fourth time period includes the time the terminal device stays in the second cell before receiving the first indication information.

[0020] In conjunction with the second aspect, in certain implementations of the second aspect, the method further includes:

[0021] When the terminal device determines that the random access to the first cell is successful, the terminal device starts recording the fifth time period, and the fifth time period is the time the terminal device stays in the first cell.

[0022] In conjunction with the second aspect, in certain implementations of the second aspect, the method further includes:

[0023] When the terminal device receives the first indication information, it starts to record the fifth time period, and the fifth time period is the time the terminal device stays in the first cell.

[0024] In combination with the second aspect, in some implementations of the second aspect, the fourth mobility history information further includes fourth indication information, and the fourth indication information is used to instruct the terminal device to switch from the second cell to the first cell using DAPS switching.

[0025] In combination with the second aspect, in some implementations of the second aspect, the fourth indication information is also used to indicate a sixth time period, which represents the length of time that the terminal device stays in the first cell and the second cell at the same time during the DAPS switching process.

[0026] In a third aspect, a communication method is provided, the method comprising: a centralized unit CU-control plane CP entity sending a minimization of drive test (MDT) measurement result to a tracking collection entity TCE or a core network CN;

[0027] The CU-CP entity sends the coexistence IDC information within the device detected by the terminal device to the TCE or the CN.

[0028] Based on the above technical solution, in the CU / DU architecture, the CU-CP sends MDT measurement results and IDC information to the TCE. At the same time, the TCE can obtain whether these MDT measurement results are affected by IDC interference, thereby enabling more accurate analysis of these MDT measurement results.

[0029] In combination with the third aspect, in certain implementations of the third aspect, the method also includes: the CU-CP entity receives a cell service tracking message from the distributed unit DU or the CU-user plane UP entity; the CU-CP entity sends the coexistence IDC information within the device detected by the terminal device to the TCE or the CN, including: upon receiving the cell service tracking message, the CU-CP entity sends the IDC information detected by the terminal device to the TCE or the CN.

[0030] In combination with the third aspect, in certain implementations of the third aspect, the cell service tracking message includes the MDT measurement result.

[0031] In combination with the third aspect, in certain implementations of the third aspect, the IDC information includes at least one of the following: whether the terminal device detects IDC, the frequency points corresponding to the cells in which the terminal device detects IDC, the start time and end time of the detected IDC, and the duration of the detected IDC.

[0032] With reference to the third aspect, in certain implementations of the third aspect, the MDT measurement result includes a start time and an end time for collecting the MDT measurement result.

[0033] In combination with the third aspect, in certain implementations of the third aspect, the cell service tracing message includes a tracing identifier and an Internet Protocol (IP) address of the TCE entity, and the tracing identifier includes a tracing reference and a tracing record session reference.

[0034] In combination with the third aspect, in certain implementations of the third aspect, the cell service tracking message includes a request message for requesting the CU-CP entity to report IDC information detected by the terminal device.

[0035] In combination with the third aspect, in certain implementations of the third aspect, the CU-CP entity receives indication information from a terminal device, where the indication information is used to indicate IDC information detected by the terminal device.

[0036] In combination with the third aspect, in certain implementations of the third aspect, the indication information is further used to indicate frequency information corresponding to the frequency at which the terminal device detects IDC interference, or the indication information is used to indicate at which frequencies IDC interference is detected.

[0037] In combination with the third aspect, in certain implementations of the third aspect, the indication information is further used to indicate information about a direction in which the terminal device detects IDC interference.

[0038] In a fourth aspect, a communication device is provided. The communication device may be a network device or a component of a network device. The communication device may include modules or units for executing the method of the first aspect and any possible implementation of the first aspect.

[0039] In a fifth aspect, a communication device is provided, comprising a processor. The processor is coupled to a memory and configured to execute instructions in the memory to implement the method of any possible implementation of the first aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface, the communication interface being configured to input and / or output information, the information comprising at least one of instructions and data.

[0040] In one implementation, the communication device is a network device. When the communication device is a network device, the communication interface may be a transceiver or an input / output interface.

[0041] Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0042] In another implementation, the communication device is a chip or chip system configured in a network device. When the communication device is a chip or chip system configured in a network device, the communication interface can be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or related circuits. The processor can also be embodied as a processing circuit or a logic circuit.

[0043] In a sixth aspect, a communication device is provided. The communication device may be a terminal device or a component in a terminal device. The communication device may include various modules or units for executing the method in the second aspect and any possible implementation of the second aspect.

[0044] In a seventh aspect, a communication device is provided, comprising a processor. The processor is coupled to a memory and configured to execute instructions in the memory to implement the method of any possible implementation of the second aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface, the communication interface being configured to input and / or output information, the information comprising at least one of instructions and data.

[0045] In one implementation, the communication device is a terminal device. When the communication device is a terminal device, the communication interface may be a transceiver, or an input / output interface.

[0046] Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0047] In another implementation, the communication device is a chip or chip system configured in a terminal device. When the communication device is a chip or chip system configured in a terminal device, the communication interface can be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or related circuits. The processor can also be embodied as a processing circuit or a logic circuit.

[0048] In an eighth aspect, a communication device is provided. The communication device may be a network device or a component in a network device. The communication device may include modules or units for executing the method in the third aspect and any possible implementation of the third aspect.

[0049] In a ninth aspect, a communication device is provided, comprising a processor. The processor is coupled to a memory and configured to execute instructions in the memory to implement the method of any possible implementation of the third aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface, the communication interface being configured to input and / or output information, the information comprising at least one of instructions and data.

[0050] In one implementation, the communication device is a CU-CP entity. When the communication device is a CU-CP entity, the communication interface may be a transceiver, or an input / output interface.

[0051] Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0052] In another implementation, the communication device is a chip or chip system configured in a CU-CP entity. When the communication device is a chip or chip system configured in a CU-CP entity, the communication interface may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or related circuits. The processor may also be embodied as a processing circuit or a logic circuit.

[0053] In a tenth aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is configured to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor executes the method of any possible implementation of the first to third aspects.

[0054] In a specific implementation, the processor may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a trigger, or various logic circuits. The input signal received by the input circuit may be, for example, but not limited to, received and input by a receiver, and the signal output by the output circuit may be, for example, but not limited to, output to and transmitted by a transmitter. The input circuit and the output circuit may be the same circuit, which functions as an input circuit and an output circuit at different times. The embodiments of the present application do not limit the specific implementation of the processor and various circuits.

[0055] In an eleventh aspect, a processing device is provided, comprising a communication interface and a processor. The communication interface is coupled to the processor. The communication interface is configured to input and / or output information. The information includes at least one of instructions and data. The processor is configured to execute a computer program to cause the processing device to perform the method of any possible implementation of aspects 1 to 3.

[0056] Optionally, there are one or more processors and one or more memories.

[0057] In a twelfth aspect, a processing device is provided, comprising a processor and a memory. The processor is configured to read instructions stored in the memory and to receive signals via a receiver and transmit signals via a transmitter, so that the processing device executes the method of any possible implementation of aspects 1 to 3.

[0058] Optionally, there are one or more processors and one or more memories.

[0059] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0060] In the specific implementation process, the memory can be a non-transitory memory, such as a read-only memory (ROM), which can be integrated with the processor on the same chip or can be set on different chips. The embodiments of the present application do not limit the type of memory and the setting method of the memory and the processor.

[0061] It should be understood that the relevant information exchange process, such as sending indication information, can be the process of outputting the indication information from the processor, and receiving indication information can be the process of inputting the received indication information into the processor. Specifically, the information output by the processor can be output to the transmitter, and the input information received by the processor can come from the receiver. The transmitter and receiver can be collectively referred to as a transceiver.

[0062] The device in the above-mentioned eleventh and twelfth aspects can be a chip, and the processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading the software code stored in the memory. The memory can be integrated in the processor or can be located outside the processor and exist independently.

[0063] In the thirteenth aspect, a computer program product is provided, which includes: a computer program (also referred to as code, or instructions), which, when executed, enables a computer to execute a method in any possible implementation of the first to third aspects above.

[0064] In the fourteenth aspect, a computer-readable medium is provided, which stores a computer program (also referred to as code, or instructions) which, when run on a computer, enables the computer to execute the method in any possible implementation of the above-mentioned first to third aspects.

[0065] In a fifteenth aspect, a communication system is provided, comprising the aforementioned terminal device and network device. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a schematic diagram of a communication system applicable to the communication method provided in the embodiment of the present application.

[0067] Figures 2 to 5 It is a schematic flowchart of the communication method provided in an embodiment of the present application.

[0068] Figure 6 and Figure 7 It is a schematic block diagram of a communication device provided in an embodiment of the present application.

[0069] Figure 8 It is a structural diagram of the terminal device provided in an embodiment of the present application.

[0070] Figure 9 It is a structural diagram of the network device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0071] The technical solution in this application will be described below with reference to the accompanying drawings.

[0072] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Long Term Evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) communication system or new radio access technology (NR), vehicle-to-X (V2X), where V2X may include vehicle-to-network (V2N), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), etc., Long Term Evolution-Vehicle (LTE-V), Internet of Vehicles, machine type communication (MTC), Internet of Things (IoT), etc. things, IoT), Long Term Evolution-Machine (LTE-M), machine to machine (M2M), etc.

[0073] In the embodiment of the present application, the network device can be any device with wireless transceiver function. The device includes but is not limited to: an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., home evolved NodeB, or homeNode B, HNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (WIFI) system, a wireless relay node, a wireless backhaul node, a transmission point (TP) or a transmission and reception point (TRP), etc. It can also be a gNB in a 5G, such as NR, system, or a transmission point (TRP or TP), one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU) or a distributed unit (DU), etc.

[0074] In some deployments, the gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some gNB functions, while the DU implements some gNB functions. For example, the CU is responsible for processing non-real-time protocols and services, implementing the functions of the radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP). The DU is responsible for processing physical layer protocols and real-time services, implementing the functions of the radio link control (RLC), media access control (MAC), and physical (PHY) layers. The AAU implements some physical layer processing functions, RF processing, and active antenna-related functions. Because RRC layer information ultimately becomes PHY layer information, or is converted from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or by both the DU and the AAU. It is understood that the network device may include one or more of a CU node, a DU node, and an AAU node. In addition, the CU may be classified as a network device in an access network (RAN) or a network device in a core network (CN), which is not limited in this application.

[0075] The functions of the CU entity can be implemented by one or more entities. For example, the functions of the CU entity can be further divided, for example, the functions of the control plane (CP) and the user plane (UP) can be separated, that is, the CU entity includes the CU control plane (CU-CP) entity and the CU user plane (CU-UP) entity. The CU-CP entity and the CU-UP entity can be coupled with the DU entity to jointly complete the functions of the network device. In one possible approach, the CU-CP entity is responsible for control plane functions, mainly including the RRC protocol layer and the PDCP control plane (PDCP-C) protocol layer. The PDCP-C protocol layer is mainly responsible for encryption and decryption, integrity protection, and data transmission of control plane data. The CU-UP entity is responsible for user plane functions, mainly including the SDAP protocol layer and the PDCP user plane (PDCP-U) protocol layer. Among them, the SDAP protocol layer is mainly responsible for mapping core network data flows to bearers. The PDCP-U protocol layer is mainly responsible for encryption and decryption, integrity protection, header compression, sequence number maintenance, and data transmission of the data plane. Among them, in an embodiment of the present application, the CU-CP entity and the CU-UP entity are connected through an interface (for example, an E1 interface). The CU-CP entity is connected to the DU entity through F1-C (control plane), and the CU-UP entity is connected to the DU entity through F1-U (user plane). In addition, the CU-CP entity represents the connection between the network device and the control plane of the core network (such as the mobility management entity (MME) of the fourth generation (4G) core network, or the access and mobility management function (AMF) network element of the 5G core network (5G core, 5GC)); the CU-UP entity represents the connection between the network device and the user plane of the core network (such as the serving gateway (SGW) of the 4G core network, or the user plane function (UPF) network element of the 5G core network); and the DU entity represents the connection between the network device and the terminal device.

[0076] The network equipment provides services for the cell, and the terminal device communicates with the cell through the transmission resources (for example, frequency domain resources, or spectrum resources) allocated by the network equipment. The cell can belong to a macro base station (for example, macro eNB or macro gNB, etc.) or a base station corresponding to a small cell. The small cells here can include: metrocell, microcell, picocell, femtocell, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services.

[0077] In an embodiment of the present application, the terminal device includes user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in a future evolved public land mobile communication network (PLMN), etc.

[0078] Wearable devices, also known as wearable smart devices, are a general term for wearable devices that use wearable technology to intelligently design and develop wearable devices for daily wear, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not just hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. In a broad sense, wearable smart devices include those that are fully functional, large in size, and can achieve full or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0079] Furthermore, the terminal device can also be a terminal device in the Internet of Things (IoT) system. IoT is an important component of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network that interconnects people, machines, and things.

[0080] This application does not limit the specific form of the terminal device.

[0081] To facilitate understanding of the embodiments of this application, first Figure 1 A communication system applicable to an embodiment of the present application is described in detail. Figure 1 Schematic diagram of a communication system applicable to the communication method and communication device of the embodiment of the present application is shown. Figure 1 As shown, the communication system 100 may include at least two network devices, such as Figure 1 The network device 110 and the network device 120 shown; the communication system 100 may also include at least one terminal device, such as Figure 1 The terminal device 130 is shown. The terminal device 130 can be mobile or fixed. Network device 110 and network device 120 are both devices that can communicate with terminal device 130 via wireless links, such as base stations or base station controllers. Each network device can provide communication coverage for a specific geographic area and can communicate with terminal devices located within the coverage area (cell).

[0082] Figure 1 Two network devices and one terminal device are shown exemplarily. Optionally, the communication system 100 may include at least one network device and each network device may include other number of terminal devices within its coverage area, which is not limited in the embodiments of the present application.

[0083] The above-mentioned communication devices, such as Figure 1The network device 110, network device 120, or terminal device 130 in the embodiment may be configured with multiple antennas. The multiple antennas may include at least one transmitting antenna for sending signals and at least one receiving antenna for receiving signals. In addition, each communication device also includes a transmitter chain and a receiver chain. Those skilled in the art will appreciate that each of these may include multiple components related to signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, or antennas, etc.). Therefore, the network device and the terminal device can communicate using multi-antenna technology.

[0084] Optionally, the wireless communication system 100 may further include other network entities such as a network controller and a mobility management entity, but the embodiments of the present application are not limited thereto.

[0085] To facilitate understanding of the embodiments of the present application, a brief explanation of the terms involved in the present application is first given.

[0086] 1. Dual active protocol stack handover (DAPS HO): To ensure zero interruption during the handover process of terminal devices, DAPS handover was introduced into the communications industry standard.

[0087] In a traditional handover process, the terminal device disconnects from the source cell and connects to the target cell after receiving the handover command from the source network device. Unlike traditional handover, in a DAPS handover process, the terminal device connects to the target cell after receiving the handover command from the source network device, while maintaining communication with the source cell link until the target network device notifies the terminal device to completely release the source cell configuration. At this point, the terminal device stops communicating with the source cell and releases the communication link with the source cell.

[0088] The DAPS handover process is similar to the traditional handover process. The source network device decides to perform the handover, and then the source network device sends a handover request to the target network device. Furthermore, the target network device replies to the source network device with a handover confirmation message, instructing the receiving terminal to switch to the target cell. Furthermore, the source network device sends a handover command to the terminal device, instructing the terminal device to switch to the target cell. The terminal device then maintains the connection between the source cell and the target cell at the same time. When the terminal device successfully accesses the target cell, the target cell sends a message to the core network, which converts the downlink data flow and switches it to the target network device, and simultaneously sends an end marker data packet to the source network device. Subsequently, the source network device forwards the data to the target network device. After the terminal device successfully accesses the target cell, the target network device can notify the terminal device to release the source cell connection, thereby completing the DAPS handover process.

[0089] During the DAPS handover process, after the terminal device successfully connects to the target network device, the terminal device will stop sending new uplink data to the source network device. After the terminal device successfully releases the connection with the source cell, the terminal device stops all communication with the source network device. After the terminal device successfully connects to the target network device, the source network device receives a handover success indication message from the target network device, and the source network device stops sending new downlink data to the terminal device.

[0090] 2. Condition handover (CHO):

[0091] In the traditional switching process, the mobility management of the connected terminal device is controlled by the network device, that is, the network device instructs the terminal device to which cell to switch to and how to switch by sending a switching message. Specifically, the source network device sends a switching message to the terminal device to control the terminal device to switch from the source cell to the target cell. After receiving the switching message, the terminal device accesses the target cell according to the content contained in the switching message. Therefore, the successful sending of the switching message is a necessary condition to ensure successful switching under the traditional switching mechanism. However, in the LTE system or NR system or other systems, the rapid attenuation of signal quality, or the rapid movement of the terminal device and the obstruction of objects, the long duration of the switching preparation, etc. will cause the failure of the switching message to be sent, and then cause the switching failure, reducing the switching success rate. In addition, in the traditional switching process, the network device generally determines whether to instruct the terminal device to switch based on the signal quality reported by the terminal device. For example, when the terminal device detects that the signal quality of the neighboring cell is better than the signal quality of the current serving cell by a certain threshold, the terminal device reports the measurement result. However, in LTE systems, NR systems, or other systems, rapid attenuation of signal quality, rapid movement of terminal devices, and obstruction by objects may lead to failure in sending measurement reports, which in turn may cause handover failure and reduce the handover success rate.

[0092] In view of the above problems, the CHO mechanism is introduced into the communication industry standard to improve the handover success rate.

[0093] In the CHO mechanism, when the source link quality is good, the source cell sends CHO configuration information to the terminal device. The CHO configuration information may include CHO trigger conditions and information of one or more candidate cells, wherein the information of the candidate cell may include the cell global identifier (CGI) of the candidate cell, or may include the physical cell identifier (PCI) of the candidate cell and the frequency information corresponding to the candidate cell. After receiving the CHO configuration information, the terminal device determines whether the candidate cell meets the CHO trigger condition based on the CHO configuration information, and uses a candidate cell that meets the CHO trigger condition as the target cell. Then, the terminal device performs a random access process with the determined target cell. When the random access is successfully completed, the terminal device sends an RRC message (such as an RRC reconfiguration completion message) to the target cell to notify the target cell that the conditional switching is completed.

[0094] 3. Mobile history information of terminal devices:

[0095] One of the purposes of introducing the mobility history information of terminal devices in the prior art is to optimize the mobility of terminal devices. For example, in a macro-micro network (i.e., some cells have a relatively large coverage area (e.g., using frequency f1) and other cells have a relatively small coverage area (e.g., using frequency f2)), terminal devices are preferably switched only within macro base stations (cells with large coverage areas) to reduce the number of RRC messages exchanged between the terminal device and network devices. Because the coverage area of micro cells is relatively small, if a terminal device switches within a micro cell, it may switch between multiple cells in a very short period of time, resulting in a relatively large number of RRC messages exchanged between the terminal device and network devices.

[0096] Another purpose of incorporating a terminal device's mobility history information in existing technologies is to allow network equipment to estimate the terminal device's speed or historical cell location based on the terminal device's mobility history information when the terminal device switches between cells, thereby configuring different measurement parameters for the terminal device. For example, based on the terminal device's mobility history information, the network equipment can determine whether the terminal device is likely to perform a ping-pong handover between different cells, thereby adjusting the corresponding handover parameters.

[0097] The movement history information of the terminal device can be recorded by the terminal device or by the network device.

[0098] If the terminal device supports storing movement history information, the terminal device records movement history information in the following manner:

[0099] (1) When the cell changes (i.e., the primary cell of the terminal device in the RRC connected state or the serving cell in the RRC idle state changes to another cell of the same system or a cell of a different system, or the terminal device enters a non-serving cell), the terminal device includes or adds an entity recording the mobile history in a variable for storing the mobile history. The entity includes the visited cell information visitedCellInfo, and the visited cell information includes visitedCellId (the number of entities that the terminal device can store is limited. If the number exceeds the maximum number, the first saved entity is deleted first), and records the relevant content in the following manner:

[0100] a. If the CGI of the previous primary cell or serving cell is available, the CGI is carried in this entity; if the VGI of the previous primary cell or serving cell is not available, the PCI and frequency of the primary cell or serving cell are carried in this entity.

[0101] b. The time the terminal device spent in the previous primary cell or serving cell is stored in this entity.

[0102] (2) When the terminal device enters the current radio access technology (RAT) from another radio access technology (RAT), or the terminal device enters the current RAT from a non-service area, the terminal device includes or adds an entity recording the mobile history in a variable that stores the mobile history. The entity includes the information of the visited cell, visitedCellInfo (the number of entities that the terminal device can store is limited. If the number exceeds the maximum number, the earliest stored entity is deleted first), and records the time spent outside the current RAT in the entity.

[0103] When the terminal device re-accesses the network from an inactive state (inactive) or an idle state (idle), the terminal device will indicate to the network device when accessing the network that the terminal device has saved the mobility history information. For example, the terminal device may carry an indication information in an RRC connection setup complete (RRCConnection setupcomplete) message or an RRC connection setup recovery complete (RRCConnectionResumeComplete) message to indicate that the terminal device has saved the mobility history information. Furthermore, the network device may request the terminal device to report the mobility history information. For example, the network device may carry a request for mobility history information indication in a terminal device information request (UEInformationResquest) message. Furthermore, after receiving the request from the network device, the terminal device may report the mobility history information to the network device. For example, the terminal device may carry the mobility history information in a terminal device information response (UEInformationResponse) message.

[0104] If a terminal device switches between different cells or network devices, the source cell / network device will send the terminal device's reported mobility history information to the target cell / network device. For example, the source cell / network device may include the terminal device's mobility history information in a handover request message.

[0105] If the network device supports storing the terminal device's movement history information, the network device records the terminal device's movement history information in the following manner:

[0106] When the terminal device is in the RRC connection state, the network device can also record the mobility history information of the terminal device. For example, if the service cell corresponding to the terminal device changes, the network device can record the cell corresponding to the service cell before the change, such as the CGI of the cell, the type of cell (such as the size of the cell, which can be very small, small, medium, or large) and the time the terminal device stays in the cell. If the terminal device undergoes a network device switch, the source network device will send the previously recorded mobility history information of the terminal device to the target network device. For example, the source network device carries the mobility history information of the terminal device in a switching request message and sends it to the target network device. Furthermore, the target network device can perform some mobility optimization based on the mobility history information and start recording the mobility history information of the terminal device.

[0107] The network device can also achieve other purposes based on the terminal device's mobility history information. For example, the network device can reduce the number of times the terminal device measures cells or frequencies based on the terminal device's mobility history information, thereby saving power of the terminal device.

[0108] As previously mentioned, when a terminal device performs a handover between network devices, the source network device can include the terminal device's mobility history information in a handover request message and send it to the target network device. Accordingly, upon receiving the handover request message from the source network device, the target network device begins collecting and storing the terminal device's mobility history information. In other words, the handover request message sent by the source network device to the target network device can trigger the target network device to begin collecting and storing the terminal device's mobility history information (e.g., to begin recording the time the terminal device spent in the target network device's cell).

[0109] However, in the CHO mechanism, the time when the source network device sends a switching request message to the target network device and the time when the terminal device selects the target cell (i.e., a candidate cell) for access may be quite different. It is not reasonable for the target network device to start recording the terminal device's mobility history information from the moment it receives the switching request message.

[0110] In addition, in the prior art, after the source network device sends a handover message carrying the terminal device's mobility history information to the target network device, it stops recording the terminal device's mobility history information. However, during the DAPS handover process, the terminal device is connected to both the source network device (or source cell) and the target network device (or target cell) for a period of time. Therefore, it is not reasonable for the source network device to stop recording the terminal device's mobility history information after sending the handover request message, because the terminal device is actually still connected to the source cell. At the same time, for the terminal device, during the DAPS handover process, it is also necessary to clearly specify the time when the access cell (i.e., source cell) information is generated.

[0111] Based on this, the present application provides a communication method, in which the terminal device and the network device can reasonably record the movement history information of the terminal device during the terminal device switching process.

[0112] The method provided in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0113] It should be understood that the following description is only for ease of understanding and explanation, and the method provided in the embodiment of the present application is described in detail using the interaction between a terminal device and a network device as an example. However, this does not constitute any limitation on the execution subject of the method provided in the present application. For example, the terminal device shown in the embodiment below can be replaced by a component (such as a chip or circuit) configured in the terminal device. The network device shown in the embodiment below can also be replaced by a component (such as a chip or circuit) configured in the network device.

[0114] The embodiments shown below do not particularly limit the specific structure of the execution subject of the method provided in the embodiments of the present application. As long as it is possible to communicate according to the method provided in the embodiments of the present application by running a program that records the code of the method provided in the embodiments of the present application, for example, the execution subject of the method provided in the embodiments of the present application can be a terminal device or a network device, or a functional module in the terminal device or the network device that can call and execute the program.

[0115] Figure 2 This is a schematic flow chart of a communication method 200 provided by an embodiment of the present application, shown from the perspective of device interaction. Each step in the method 200 is described in detail below.

[0116] In S201, network device #2 (an example of the second network device) sends a CHO request message to network device #1 (an example of the first network device). Accordingly, in S201, network device #1 receives the CHO request message from network device #2.

[0117] Network device #1 is a network device belonging to cell #1 (an example of the first cell). Cell #1 is the cell that the terminal device is about to access. Cell #1 can also be called a candidate cell or a target cell, and network device #1 can also be called a target network device.

[0118] Network device #2 is a network device to which cell #2 belongs. Cell #2 is a cell that provides services to the terminal device before CHO. Cell #2 may also be referred to as a source cell, and network device #2 may also be referred to as a source network device.

[0119] Network device #1 and network device #2 can be the same network device or different network devices, and this embodiment of the application does not limit this.

[0120] In S201 , cell # 2 may transmit a CHO request message (an example of a handover request message) to cell # 1 .

[0121] Optionally, the CHO request message may carry movement history information #1 (an example of second movement history information).

[0122] Mobility history information #1 is the mobility history information of the terminal device recorded by network device #2 before sending the CHO request message. Mobility history information #1 includes the historical information of the terminal device in cell #2. For example, mobility history information #1 may include one or more of the following: CGI of cell #2, PCI of cell #2, central frequency of cell #2, time period #1 (an example of the third time period), and time period #1 indicates the time the terminal device stayed in cell #2. Since mobility history information #1 is the information recorded by network device #2 before sending the CHO request message, time period #1 included in mobility history information #1 is the time the terminal device stayed in cell #2 before network device #2 sent the CHO request message.

[0123] It can be understood that if network device #1 and network device #2 are the same network device, the CHO request message may not carry movement history information #1.

[0124] Optionally, the CHO request message may be a handover request message. In this case, the handover request message may further include indication information #1, where the indication information #1 is used to indicate that the handover request message is a handover request message under the CHO handover mechanism.

[0125] S202: Network device #1 sends a CHO request confirmation message to network device #2. Accordingly, in S202, network device #2 receives the CHO request confirmation message from network device #1.

[0126] The CHO request confirmation message includes the RRC configuration information configured by network device #1 for the terminal device. Specifically, the CHO request confirmation message includes the RRC configuration information configured by cell #1 for the terminal device. For more description of the RRC configuration information, please refer to the prior art. For the sake of brevity, this embodiment of the application will not be repeated.

[0127] S203: Network device #2 sends CHO configuration information to the terminal device. Accordingly, in S203, the terminal device receives the CHO configuration information from network device #2.

[0128] The CHO configuration information includes the RRC configuration information configured by network device #1 for the terminal device. Specifically, the CHO configuration information includes the RRC configuration information configured by cell #1 for the terminal device. The CHO configuration information also includes the triggering conditions for the terminal device to access cell #1.

[0129] S204, the terminal device determines whether the triggering condition of cell #1 is met.

[0130] When the triggering conditions of cell #1 are met, the terminal device can switch to cell #1, that is, switch from cell #2 to cell #1, for example, by initiating a random access procedure or sending an RRC reconfiguration complete message to cell #1.

[0131] For example, the trigger condition for the terminal device to access cell #1 is that the signal quality of cell #1 is greater than a preset threshold. Then, when the signal quality of cell #1 is greater than the preset threshold, the terminal device initiates random access to cell #1.

[0132] When the triggering condition of cell #1 is not met, when the terminal device detects that a radio link failure occurs in cell #2, the terminal device performs an RRC reconstruction process. During the RRC reconstruction process, the terminal device performs cell selection. If the selected cell is a candidate cell in the CHO configuration information sent by network device #2 to the terminal device, and network device #2 sends an indication message to the terminal device, the indication message indicates that the terminal device can perform conditional reconfiguration (i.e., execute the RRC configuration information corresponding to the candidate cell) if the selected cell is a candidate cell when a radio link failure is detected. The terminal device then switches to the candidate cell (such as cell #1), that is, switches from cell #2 to the candidate cell (the terminal device sends an RRC reconfiguration completion message to the candidate cell. Optionally, before the terminal device sends an RRC reconfiguration completion message to the candidate cell, the terminal device performs a random access process with the candidate cell).

[0133] S210: The terminal device is changed to cell #1. Accordingly, in S210, network device #1 determines that the terminal device is changed to cell #1.

[0134] It should be understood that in S210, the terminal device is changed to cell #1, which means that the terminal device is successfully changed to cell #1, that is, the terminal device successfully establishes a connection with cell #1.

[0135] The terminal device changes to cell #1, which may be that the terminal device successfully switches from cell #2 to cell #1, or that the terminal device successfully initiates RRC re-establishment in cell #1 (here, it means that the terminal device selects a candidate cell in CHO during the RRC re-establishment process after detecting a radio link failure). This application does not limit this.

[0136] In S210, cell #1 may also determine that the terminal device is changed to cell #1.

[0137] S220, network device #1 starts recording movement history information #2 (an example of first movement history information) at or after determining that the terminal device has changed to cell #1. Movement history information #2 is historical information of the terminal device in cell #1.

[0138] In S220 , cell # 1 may also start recording movement history information # 2 when or after determining that the terminal has switched to cell # 1 .

[0139] Mobile history information #2 may include one or more of the following: CGI of cell #1, PCI of cell #1, central frequency of cell #1, time period #2 (an example of the second time period), where time period #2 is the time the terminal device stays in cell #1.

[0140] Network device #1 starts recording mobile history information #2, which can be understood as network device #1 starts recording the time the terminal device stays in cell #1. That is, network device #1 determines that the terminal device starts staying in cell #1 at or after the moment when the terminal device changes to cell #1. Optionally, network device #1 can also start recording the CGI of cell #1 or the PCI and center frequency of cell #1. It should be noted that the moment when network device #1 generates mobile history information #2 is not limited in itself. Network device #1 can generate mobile history information #2 after determining that the terminal device switches from cell #1 to other cells. Network device #1 starts recording mobile history information #2, which can also be understood as network device #1 starts collecting mobile history information #2. Recording mobile history information in this application can be understood as collecting mobile history information.

[0141] The embodiments of the present application do not limit how network device #1 determines whether the terminal device has changed to cell #1. It should be understood that, in different methods, the time when network device #1 determines that the terminal device has changed to cell #1 may be different, and further, the time when network device #1 begins recording movement history information #2 may also be different.

[0142] Network device #1 can determine whether the terminal device has changed to cell #1 in the following manner:

[0143] Method 1: When determining that the terminal device has successfully randomly accessed cell #1, network device #1 determines that the terminal device is switched to cell #1.

[0144] For example, if the terminal device adopts two-step random access, network device #1 determines that the terminal device has successfully performed random access in cell #1 after sending random access response signaling to the terminal device.

[0145] For another example, if the terminal device adopts four-step random access, network device #1 determines that the terminal device has successfully randomly accessed cell #1 after sending conflict resolution signaling to the terminal device.

[0146] Furthermore, network device #1 may start recording movement history information #2 at or after determining that the terminal device has successfully randomly accessed cell #1.

[0147] Method 2: When network device #1 sends a handover success (HO success) message to the terminal device, network device #1 determines that the terminal device has been switched to cell #1.

[0148] Furthermore, network device #1 may start recording movement history information #2 at the time of sending the handover success message or thereafter.

[0149] Method 3: Network device #1 may determine that the terminal device has been switched to cell #1 upon receiving a sequence number status transfer message.

[0150] Furthermore, network device #1 may start recording movement history information #2 at or after receiving the sequence number state transition message.

[0151] Optionally, after S210 , method 200 may further include S230 : network device # 2 sends movement history information # 3 to network device # 1 .

[0152] Movement history information #3 is the movement history information of the terminal device recorded by network device #2. Movement history information #3 includes historical information about the terminal device in cell #2. For example, movement history information #3 may include one or more of the following: the CGI of cell #2, the PCI of cell #2, the center frequency of cell #2, and time period #3, where time period #3 represents the time the terminal device spent in cell #2.

[0153] As described above, network device #1 can start recording the terminal device's mobility history information when it determines that the terminal device has changed to cell #1. Correspondingly, network device #2 can stop recording the terminal device's mobility history information when it determines that the terminal device has changed to cell #1, and send the recorded terminal device's mobility history information (i.e., mobility history information #3) to network device #1. Therefore, time period #3 included in mobility history information #3 is the time the terminal device spent in cell #2 before changing to cell #1.

[0154] Network device #2 can determine whether the terminal device has changed to cell #1 in the following manner:

[0155] Method 1: Network device #2 can determine that the terminal device has been moved to cell #1 upon receiving the handover success message from network device #1. That is, upon receiving the handover success message, network device #2 can stop recording the terminal device's movement history information and send movement history information #3 to network device #1.

[0156] Method 2: Network device #2 can determine that the terminal device has moved to cell #1 when sending the sequence number state transition message. That is, network device #2 can stop recording the terminal device's movement history information when sending the sequence number state transition message and send movement history information #3 to network device #1.

[0157] Optionally, network device #2 may carry movement history information #3 in a sequence number state transfer message and send it to network device #1; or, network device #2 may carry movement history information #3 in other messages and send it to network device #1, for example, a new message may be defined.

[0158] Optionally, if in S201, the CHO request message sent by network device #2 to network device #1 carries movement history information #1, then after S210, method 200 may further include: upon determining that the terminal device has moved to cell #1, network device #1 modifying movement history information #1. Specifically, network device #1 modifies the duration of time period #1 included in movement history information #1, i.e., network device #1 may compensate time period #1 for the period from receiving the CHO request message to determining that the terminal device has moved to cell #1.

[0159] As mentioned above, under the CHO mechanism, after network device #2 sends a CHO request message to network device #1, the terminal device does not switch immediately, that is, the terminal device may continue to stay in cell #2, and time period #1 is the time the terminal device stays in cell #2 before network device #2 sends the CHO request message, that is, time period #1 may not be the time the terminal device actually stays in cell #2.

[0160] The actual time the terminal device spends in cell #2 is equal to time period #1 plus the time between network device #2 sending a CHO request message and network device #2 determining that the terminal device has moved to cell #1. For example, if time period #1 included in movement history information #1 is t1, and the time between network device #2 sending a CHO request message (or network device #1 receiving a CHO request message) and determining that the terminal device has moved to cell #1 is t2, network device #1 can modify time period #1 to t1 + t2.

[0161] Optionally, after S220, if the terminal device changes from cell #1 to cell #3, method 200 may further include S240: network device #1 sends movement history information #2 to network device #3 (an example of a third network device). Network device #3 is the network device to which cell #3 belongs. It will be understood that, during the process of the terminal device changing from cell #1 to cell #3, cell #1 may be referred to as the source cell, network device #1 may be referred to as the source network device, and correspondingly, cell #3 may be referred to as the target cell or candidate cell, and network device #3 may be referred to as the target network device.

[0162] According to an embodiment of the present application, when the terminal device performs CHO switching or RRC re-establishment, the target network device (i.e., network device #1) or the target cell (cell #1) starts recording the terminal device's mobility history information when determining that the terminal device has changed to the target cell, i.e., starts recording the terminal device's historical information in the target cell, thereby recording more accurate terminal device mobility history information, so that the target network device can obtain more accurate terminal device mobility information, so as to facilitate more accurate optimization.

[0163] In addition, the target network device can modify the time that the terminal device receives in the switching request message and stays in the source cell (cell #2), that is, the time from receiving the switching request message to the terminal device successfully switching to the target cell is compensated to the time the terminal device stays in the source cell, so that the target network device can obtain more accurate historical information of the terminal device in the source cell, so as to facilitate more accurate optimization.

[0164] Figure 3 This is a schematic flow chart of the communication method 200 provided by the embodiment of the present application from the perspective of device interaction. The steps in the method 300 are described in detail below.

[0165] In S301, network device #2 (an example of a second network device) sends a handover request message to network device #1 (an example of a first network device). Accordingly, in S301, network device #1 receives the handover request message from network device #2.

[0166] Network device #1 is a network device belonging to cell #1 (an example of the first cell). Cell #1 is the cell that the terminal device is about to access. Cell #1 can also be called a candidate cell or a target cell, and network device #1 can also be called a target network device.

[0167] Network device #2 is a network device to which cell #2 belongs. Cell #2 is a cell that provides services to the terminal device before DAPS switching. Cell #2 can also be called a source cell, and network device #2 can also be called a source network device.

[0168] Network device #1 and network device #2 can be the same network device or different network devices, and this embodiment of the application does not limit this.

[0169] In S301 , cell # 2 may send a handover request message to cell # 1 .

[0170] Optionally, the handover request message may carry movement history information #1 (an example of second movement history information).

[0171] Mobility history information #1 is the mobility history information of the terminal device recorded by network device #2 before sending the switching request message. Mobility history information #1 includes the historical information of the terminal device in cell #2. For example, mobility history information #1 may include one or more of the following: CGI of cell #2, PCI of cell #2, central frequency of cell #2, time period #1 (an example of the third time period), and time period #1 indicates the time the terminal device stayed in cell #2. Since mobility history information #1 is the information recorded by network device #2 before sending the switching request message, time period #1 included in mobility history information #1 is the time the terminal device stayed in cell #2 before network device #2 sent the switching request message.

[0172] Optionally, the movement history information #1 may further include indication information #2, where the indication information #2 is used to instruct the terminal device to switch from cell #2 to cell #1 using DAPS switching.

[0173] It can be understood that if network device #1 and network device #2 are the same network device, the handover request message may not carry movement history information #1.

[0174] S302: Network device #1 sends a handover request confirmation message to network device #2. Accordingly, in S302, network device #2 receives the handover request confirmation message from network device #1.

[0175] The handover request confirmation message includes the RRC configuration information configured by network device #1 for the terminal device. Specifically, the handover request confirmation message includes the RRC configuration information configured by cell #1 for the terminal device. Optionally, the RRC configuration information may also carry indication information, indicating which data radio bearers (DRBs) perform DAPS operations, that is, DAPS switching may only be performed on certain DRBs, and other DRBs are still processed according to traditional switching. For more descriptions of RRC configuration information, please refer to the prior art. For the sake of brevity, the embodiments of the present application will not be repeated.

[0176] S303: Network device #2 sends a switching command to the terminal device. Accordingly, in S303, the terminal device receives the switching command from network device #2.

[0177] The handover command sent by network device #2 to the terminal device may be in the form of an RRC reconfiguration message, which includes the RRC configuration information configured for the terminal device by network device #1. Specifically, the RRC reconfiguration message includes the RRC configuration information configured for the terminal device by cell #1.

[0178] S310: The terminal device is changed to cell #1. Accordingly, in S310, network device #1 determines that the terminal device is changed to cell #1.

[0179] It should be understood that in S310, the terminal device is changed to cell #1, which means that the terminal device is successfully changed to cell #1, that is, the terminal device successfully establishes a connection with cell #1.

[0180] The terminal device being switched to cell #1 may be the terminal device successfully switching from cell #2 to cell #1, which is not limited in this application.

[0181] In S310, cell #1 may also determine that the terminal device is changed to cell #1.

[0182] S320, network device #1 starts recording movement history information #2 (an example of first movement history information) at or after determining that the terminal device has changed to cell #1. Movement history information #2 is historical information of the terminal device in cell #1.

[0183] In S320 , cell # 1 may also start recording movement history information # 2 when or after determining that the terminal has switched to cell # 1 .

[0184] Mobile history information #2 may include one or more of the following: CGI of cell #1, PCI of cell #1, central frequency of cell #1, time period #2 (an example of the second time period), where time period #2 is the time the terminal device stays in cell #1.

[0185] Optionally, the mobility history information #2 may further include indication information #3 (an example of the third indication information), and the indication information #3 is used to instruct the terminal device to switch from cell #1 to cell #3 (an example of the third cell) using DAPS switching.

[0186] Optionally, indication information #3 is also used to indicate time period #5, where time period #5 represents the length of time that the terminal device stays in cell #1 and cell #3 simultaneously during the DAPS switching process.

[0187] Network device #1 starts recording mobile history information #2, which can be understood as network device #1 starts recording the time the terminal device stays in cell #1. That is, network device #1 determines that the terminal device starts staying in cell #1 at or after the moment when the terminal device changes to cell #1. Optionally, network device #1 can also start recording the CGI of cell #1 or the PCI and center frequency of cell #1. It should be noted that the present application does not limit the moment when network device #1 generates mobile history information #2. Network device #1 can generate mobile history information #2 after determining that the terminal device switches from cell #1 to other cells. Network device #1 starts recording mobile history information #2, which can also be understood as network device #1 starts collecting mobile history information #2. Recording mobile history information in the present application can be understood as collecting mobile history information.

[0188] The embodiments of the present application do not limit how network device #1 determines whether the terminal device has changed to cell #1. It should be understood that, in different methods, the time when network device #1 determines that the terminal device has changed to cell #1 may be different, and further, the time when network device #1 begins recording movement history information #2 may also be different.

[0189] Network device #1 can determine whether the terminal device has changed to cell #1 in the following manner:

[0190] Method 1: When determining that the terminal device has successfully randomly accessed cell #1, network device #1 determines that the terminal device is switched to cell #1.

[0191] For example, if the terminal device adopts the two-step access method, network device #1 determines that the terminal device has successfully randomly accessed cell #1 after sending random access response signaling to the terminal device.

[0192] For another example, if the terminal device adopts the four-step access method, network device #1 determines that the terminal device has successfully randomly accessed cell #1 after sending a conflict resolution signaling to the terminal device.

[0193] Furthermore, network device #1 may start recording movement history information #2 at or after determining that the terminal device has successfully randomly accessed cell #1.

[0194] Method 2: When network device #1 sends indication information #4 (an example of the first indication information) to the terminal device, it determines that the terminal device has changed to cell #1. Indication information #4 is used to instruct the terminal device to disconnect from cell #2. Indication information #4 can also be used to instruct the terminal device to stop DAPS operation in cell #2 and release the terminal device's configuration information in cell #2.

[0195] Furthermore, network device #1 may start recording movement history information #2 at or after the time of sending instruction information #4.

[0196] Method three: Network device #1 can determine that the terminal device is switched to cell #1 after sending indication information #5 (an example of the second indication information). Indication information #5 is used to instruct cell #2 or network device #2 to release the context of the terminal device.

[0197] Furthermore, network device #1 may start recording movement history information #2 at or after the time of sending instruction information #5.

[0198] Optionally, if network device #1 and network device #2 are different network devices, after S310 , method 300 may further include S330 : network device #2 sends movement history information #3 to network device 1 .

[0199] Movement history information #3 is the movement history information of the terminal device recorded by network device #2. Movement history information #3 includes historical information about the terminal device in cell #2. For example, movement history information #3 may include one or more of the following: the CGI of cell #2, the PCI of cell #2, the center frequency of cell #2, and time period #3, where time period #3 represents the time the terminal device spent in cell #2.

[0200] As described above, network device #1 can start recording the terminal device's mobility history information when it determines that the terminal device has changed to cell #1. Correspondingly, network device #2 can stop recording the terminal device's mobility history information when it determines that the terminal device has changed to cell #1, and send the recorded terminal device's mobility history information (i.e., mobility history information #3) to network device #1. Therefore, time period #3 included in mobility history information #3 is the time the terminal device spent in cell #2 before changing to cell #1.

[0201] Network device #2 can determine that the terminal device has moved to cell #1 upon receiving indication information #5. That is, network device #2 can stop recording the terminal device's movement history information upon receiving indication information #5 and send movement history information #3 to network device #1.

[0202] Optionally, the movement history information #3 may further include indication information #2, where the indication information #2 is used to instruct the terminal device to switch from cell #2 to cell #1 using DAPS switching.

[0203] Optionally, indication information #2 is also used to indicate time period #4, where time period #4 represents the length of time that the terminal device stays in cell #2 and cell #1 simultaneously during the DAPS switching process.

[0204] Optionally, network device #2 may carry movement history information #3 in a sequence number state transfer message and send it to network device #1; or, network device #2 may carry movement history information #3 in other messages and send it to network device #1, for example, a new message may be defined.

[0205] Optionally, if in S301, the handover request message sent by network device #2 to network device #1 carries movement history information #1, then after S310, method 300 may further include: upon determining that the terminal device has changed to cell #1, network device #1 modifying movement history information #1. Specifically, network device #1 modifies the duration of time period #1 included in movement history information #1, i.e., network device #1 may compensate time period #1 for the time from receiving the handover request message to the time when the terminal device changes to cell #1.

[0206] As mentioned above, under the DAPS switching mechanism, after network device #2 sends a switching request message to network device #1, the terminal device still remains connected to cell #2, and time period #1 is the time the terminal device stays in cell #2 before network device #2 sends the switching request message. In other words, time period #1 is not the actual time the terminal device stays in cell #2.

[0207] The actual time the terminal device spends in cell #2 is equal to time period #1 plus the time from when network device #2 sends the handover request message to when the terminal device switches to cell #1. For example, if time period #1 included in mobility history information #1 is t1, and the time from when network device #2 sends the handover request message (or when network device #1 receives the handover request message) to when the terminal device switches to cell #1 is t2, network device #1 can modify time period #1 to t1 + t2.

[0208] Optionally, after S320, if the terminal device changes from cell #1 to cell #3, method 300 may further include S340: network device #1 sends movement history information #2 to network device #3 (an example of a third network device). Network device #3 is the network device to which cell #3 belongs. It will be understood that, during the process of the terminal device changing from cell #1 to cell #3, cell #1 may be referred to as the source cell, network device #1 may be referred to as the source network device, and correspondingly, cell #3 may be referred to as the target cell or candidate cell, and network device #3 may be referred to as the target network device.

[0209] According to an embodiment of the present application, when the terminal device performs DAPS switching or RRC re-establishment, the target network device (i.e., network device #1) or the target cell (cell #1) starts recording the terminal device's mobility history information when determining that the terminal device has changed to the target cell, i.e., starts recording the terminal device's historical information in the target cell, thereby recording more accurate terminal device mobility history information, so that the target network device can obtain more accurate terminal device mobility information, so as to facilitate more accurate optimization.

[0210] In addition, the target network device can modify the time that the terminal device receives in the switching request message and stays in the source cell (cell #2), that is, the time from receiving the switching request message to the terminal device successfully switching to the target cell is compensated to the time the terminal device stays in the source cell, so that the target network device can obtain more accurate historical information of the terminal device in the source cell, so as to facilitate more accurate optimization.

[0211] Figure 4 It is a schematic flow chart of a communication method 400 provided by an embodiment of the present application, shown from the perspective of device interaction. Figure 4 The method shown is described by taking an example where a terminal device switches from a source cell to a target cell using a DAPS switching mechanism. Each step in the method 400 is described in detail below.

[0212] S401: Network device #2 sends a handover request message to network device #1.

[0213] This is the same as S301 in method 300 and will not be described in detail here.

[0214] S402: Network device #1 sends a handover request confirmation message to network device #2.

[0215] This is the same as S302 in method 300 and will not be described in detail here.

[0216] S403, network device #2 sends a switching command to the terminal device.

[0217] This is the same as S303 in method 300 and will not be described in detail here.

[0218] S410, the terminal device is changed to cell #1.

[0219] This is the same as S310 in method 300 and will not be described in detail here.

[0220] S420, the terminal device records movement history information #4 at or after the moment of determining to switch from cell #2 (an example of the second cell) to cell #1 (an example of the first cell). Movement history information #4 is the historical information of the terminal device in cell #2.

[0221] Mobile history information #4 may include one or more of the following: CGI of cell #2, PCI of cell #2, central frequency of cell #2, time period #6 (an example of the fourth time period), where time period #6 is the time the terminal device stays in cell #2.

[0222] The terminal device records the mobile history information #4, which can be understood as the terminal device adding the mobile history information #4 to a variable that stores the mobile history information, that is, adding the CGI of cell #2 or the PCI and center frequency of cell #2, and adding time period #6. Time period #6 can be the time the terminal device stays in cell #2 before switching to cell #1.

[0223] The embodiments of the present application do not limit how the terminal device determines whether to switch from cell #2 to cell #1. It should be understood that in different methods, the time when the terminal device determines that it has successfully switched to cell #1 may be different, and further, the time when the terminal device records movement history information #4 may also be different.

[0224] As an example, when the terminal device determines that random access to cell #1 is successful, it determines that switching from cell #2 to cell #1 is successful.

[0225] For example, if the terminal device adopts two-step random access, the terminal device determines that the random access in cell #1 is successful when receiving the random access response signaling.

[0226] For another example, if the terminal device adopts four-step random access, the terminal device determines that the terminal device has successfully performed random access in cell #1 when receiving the conflict resolution signaling.

[0227] Furthermore, the terminal device may record movement history information #4 at or after determining that random access to cell #1 is successful.

[0228] Optionally, when the terminal device determines that random access is successful in cell #1, it starts recording time period #7 (an example of the fifth time period), where time period #7 is the time the terminal device stays in cell #1. That is, before the terminal device successfully accesses cell #1, it is considered that the terminal device is staying in cell #2, and after the terminal device successfully accesses cell #1, it is considered that the terminal device is staying in cell #1.

[0229] As another example, upon receiving indication information #4 sent by network device #1, the terminal device determines to switch to cell #1, where indication information #4 is used to instruct the terminal device to disconnect from cell #2.

[0230] Furthermore, the terminal device may record movement history information #4 at the moment of receiving indication information #4 or thereafter.

[0231] Optionally, the terminal device starts recording time period #7 at the moment when it determines that random access in cell #1 is successful. That is, before the terminal device receives indication information #4, it is considered that the terminal device is still in cell #2, and after the terminal device determines that random access in cell #1 is successful, it is considered that the terminal device is staying in cell #1. That is, from the time when the terminal device determines that random access in cell #1 is successful to the time when indication information #4 is received, it is considered that the terminal device is staying in both cell #2 and cell #1. That is, the end point of the time the terminal device stays in cell #2 is when the terminal device receives indication information #4, and the starting point of the time it stays in cell #1 is when the terminal device determines that random access in cell #1 is successful.

[0232] Optionally, the terminal device starts recording period #7 when receiving indication information #4. That is, before the terminal device receives indication information #4, it is considered that the terminal device is staying in cell #2, and after the terminal device receives indication information #4, it is considered that the terminal device is staying in cell #1.

[0233] Optionally, the movement history information #4 may further include indication information #6, where the indication information #6 is used to instruct the terminal device to switch from cell #2 to cell #1 using the DAPS switching mechanism.

[0234] Optionally, indication information #6 is also used to indicate time period #8 (an example of the sixth time period), where time period #8 represents the length of time that the terminal device stays in cell #2 and cell #1 at the same time during the DAPS switching process.

[0235] Optionally, when the terminal device re-accesses cell #3 from an inactive state or an idle state, the method 400 may further include: S430, the terminal device sends movement history information #4 to the network device #3. The network device #3 is the network device to which the cell #3 belongs.

[0236] According to an embodiment of the present application, during the process of the terminal device performing a handover, when the terminal device determines that it has successfully switched from the source cell (cell #2) to the target cell (cell #1), it records the historical information of the source cell (i.e., the mobile history information #4), thereby being able to record more accurate mobile history information of the terminal device, so that the network device can obtain more accurate terminal device movement information, so as to facilitate more accurate optimization.

[0237] To reduce data collection costs, existing technologies have introduced minimization of drive tests (MDT) technology, which automatically collects measurements, to partially complete traditional drive testing tasks, thereby detecting and optimizing wireless network issues or faults. Application scenarios for MDT technology include, for example, the monthly routine network coverage drive tests typically performed by operators, or the area-specific network coverage drive tests performed in response to user complaints.

[0238] Currently, MDT technology can be applied to automatic measurement collection at base stations, such as quality of service (QoS) measurement collection, cell signal quality measurement collection, or accessibility measurement collection. The measurement types of MDT technology can be divided into the following categories:

[0239] First, signal level measurement: The terminal device measures the signal level of the wireless signal, such as reference signal receiving power (RSRP) or reference signal receiving quality (RSRQ), and reports the measurement collection results to the network device.

[0240] Second, QoS measurement: QoS measurement is usually performed by network equipment, such as service traffic, service Internet Protocol (IP) throughput, service packet loss rate, or service processing delay, etc.; of course, QoS measurement can also be performed by terminal equipment, such as uplink processing delay, which is not specifically limited in the embodiments of the present application.

[0241] Third, accessibility measurement: The terminal device records random access channel (RACH) failure statistics, radio link failure (RLF) statistics, RRC connection access failure statistics and other information, and reports it to the network device.

[0242] MDT includes logged MDT (or log MDT) and immediate MDT. Immediate MDT is mainly used to collect measurements for terminal devices in the RRC connected state (RRC_CONNECTED), while logged MDT is mainly used to collect measurements for terminal devices in the idle state (RRC_IDLE) or the RRC inactive state (RRC_INACTIVE) (for example, a terminal device in the idle state or the inactive state measures the cell with the frequency corresponding to the currently resident cell and the inter-frequency / inter-system adjacent cell corresponding to the cell reselection broadcast in the currently resident cell, and the terminal device records and reports these measurement results). Immediate MDT is generally used to measure the data volume, IP throughput, packet transmission delay, packet loss rate, processing delay, etc. of the terminal device. Logged MDT generally refers to the UE's measurement of the received signal strength.

[0243] Wireless also defines some Layer 2 measurements for network-side statistics on network performance, enabling functions such as radio link management, radio resource management, and network maintenance. Some of these Layer 2 measurements are specific to a terminal device, such as service throughput, service flow, terminal device processing latency, and terminal device air interface latency.

[0244] Access network devices initiate MDT measurement collection tasks in two scenarios. One is signaling-based MDT (MDT), and the other is management-based MDT (MDT). Signaling-based MDT is MDT targeted at a specific terminal device. The access network device receives a message from the core network (CN) requesting MDT for a specific terminal device. Management-based MDT is not MDT targeted at a specific terminal device. The access network device receives an MDT request from the operation administration and maintenance (OAM) or element manager (EM). For management-based MDT, the access network device selects terminal devices from its network based on a specific policy for MDT measurement collection. For signaling-based MDT, the CN does not initiate signaling MDT for a UE unless the UE has consented to MDT. For management-based MDT, the access network device can consider whether the terminal device has consented to MDT when selecting the terminal device, for example, only selecting those terminal devices that have consented to MDT for MDT measurement collection. In the CU / DU architecture, OAM can independently send management-based MDT measurement collection tasks to the CU-CP / CU-UP / CU-DU. For signaling-based MDT measurement collection tasks, if the task corresponding to the measurement type required in the MDT measurement collection task requires CU-UP / DU participation, when the CU-CP receives the MDT measurement collection task from the CN, the CU-CP will send the corresponding measurement task to the CU-UP or DU, thereby triggering the CU-UP or DU to perform MDT measurements. After the access network device or CU-CP / CU-UP / DU receives the MDT measurement results, it will send the MDT measurement results to the trace collection entity (TCE).

[0245] In practice, when a terminal device performs MDT measurements, it may detect in-device coexistence problems (IDC). An IDC problem refers to interference problems detected by the terminal device in some subframes / time slots during wireless communication with network-side devices. For frequencies corresponding to activated service cells, the IDC problem means that the terminal device is unable to resolve these interference problems by itself. For frequencies corresponding to inactivated service cells, the IDC problem means that when these service cells are activated, the terminal device is expected to detect interference problems and be unable to resolve them by itself. For frequencies corresponding to non-service cells, the IDC problem means that when the frequencies corresponding to these non-service cells become frequencies corresponding to service cells, the terminal device is expected to detect interference problems and be unable to resolve them by itself. These IDC problems may affect the communication performance of the terminal device. If the network equipment cannot know whether the terminal device detected an IDC problem when collecting MDT measurement results, it may obtain incorrect conclusions when analyzing these MDT measurement results (for example, IDC interference will affect the accuracy of the MDT measurement results. If IDC interference is detected, the wireless signal quality of the cell in the base station detected in the MDT measurement results may be degraded, which will not reflect the actual wireless performance).

[0246] Based on this, an embodiment of the present application proposes a communication method, which can associate the MDT measurement results and IDC results obtained by CU-CP / CU-UP / DU in the CU / DU architecture.

[0247] Figure 5 The communication method provided by an embodiment of the present application is shown. As shown in the figure, the method 500 may include S501 and S502. Each step is described in detail below.

[0248] In S501, a DU or CU-UP sends a cell traffic trace message to a CU-CP. Accordingly, in S501, the CU-CP receives the cell traffic trace message from the DU or CU-UP.

[0249] It is understandable that the name of the above-mentioned cell service tracing message is for illustration only, and the embodiment of the present application does not limit the message name. The message carries a tracing identifier and a TCE IP address. The tracing identifier may include a trace reference and a trace recording session reference. Optionally, the cell service tracing message may also carry a request message requesting the CU-CP to report the IDC information detected by the terminal device.

[0250] Optionally, when performing MDT measurement, the DU or CU-UP obtains the corresponding MDT measurement result and sends the corresponding MDT measurement result to the TCE.

[0251] Optionally, when the DU or CU-UP sends the MDT measurement results to the TCE, the DU or CU-UP also carries the time information corresponding to the collection of the MDT measurement results (such as the start time and end time of the MDT measurement corresponding to the MDT measurement results).

[0252] S502: CU-CP sends IDC information to TCE or CN.

[0253] Here, the CU-CP may send the IDC information to the TCE directly or through the CN.

[0254] After the CU-CP receives the cell service tracking message from the DU or CU-UP, the CU-CP sends the IDC information detected by the terminal device to the TCE or CN.

[0255] It is understood that when the cell service tracking message carries a request message requesting reporting of the IDC information detected by the terminal device, the CU-CP sends the IDC information to the TCE or CN. Alternatively, the CU-CP may proactively send the IDC information to the TCE or CN, which is not limited in this embodiment of the present application. In other words, step S501 is optional.

[0256] Optionally, the CU-CP can obtain information that the terminal device has detected IDC interference based on the message received from the terminal device. For example, the terminal device sends an RRC message (such as a terminal device auxiliary information message) to the CU-CP, and the RRC message includes information for determining whether IDC interference is detected (for example, the RRC message carries a Boolean variable, when the value is 1, it means that the terminal device has detected IDC interference, and when the value is 0, it means that the terminal device has not detected IDC interference. For another example, the RRC message carries an indication information, when the indication information is carried, it means that the terminal device has detected IDC interference; when the indication information is not carried, it means that the terminal device has not detected IDC interference). Optionally, the RRC message may also include frequency information corresponding to the frequency point where IDC interference is detected or frequency information affected by IDC interference. That is, the terminal device can indicate to the network device whether interference is detected and at which frequencies the IDC problem is detected (for example, the RRC message carries a frequency list, indicating that the IDC problem is detected at these frequencies). Optionally, the RRC message may also include information about the direction in which the IDC interference is detected, where the direction of the IDC interference may refer to who is the victim in the IDC interference, such as NR being the victim of the IDC interference, or other wireless (such as industrial, scientific, and medical bands) or global navigation satellite systems (GNSS) being the victims of the IDC interference. For example, the RRC message includes information indicating which frequency points are detected for IDC problems and a method for detecting IDC interference in these frequency points. It will be understood that the above-mentioned information for determining whether IDC interference is detected, the frequency point information indicating the frequency point in which the IDC interference is detected, and the information indicating the direction in which the IDC interference is detected can all be referred to as IDC information. It will be understood that in the embodiment of the present application, IDC interference may also be referred to as an IDC problem.

[0257] Optionally, the terminal device may send the RRC message to the network device based on a notification or instruction from the network device. For example, the network device may notify or instruct the terminal device through a message or instruction that the frequency points are subject to IDC interference. Then, when the terminal device detects IDC interference, it may report to the network device that the frequency points are subject to IDC interference.

[0258] Optionally, the IDC information detected by the terminal device sent by the CU-CP to the TCE or CN includes at least one of the following: whether the terminal device detects IDC, the frequency points corresponding to the cells in which the terminal device detects IDC, the start time and end time of IDC detection (or the duration of IDC detection). It should be noted that the terminal device may not detect IDC continuously, that is, it may detect IDC for a period of time, then not detect IDC for a period of time, and then detect IDC again for a period of time. Therefore, the CU-CP may send multiple start and end times of IDC detection (or the duration of IDC detection).

[0259] Optionally, the CU-CP may carry IDC information in the cell service tracking message sent to the CN. After receiving the IDC information, the CN sends the corresponding IDC information to the TCE.

[0260] When performing MDT measurement, the CU-CP obtains the corresponding MDT measurement result and sends the corresponding MDT measurement result to the TCE.

[0261] The TCE knows whether the corresponding MDT measurement result is affected by IDC interference based on the MDT measurement result received from the CU-CP, DU or CU-UP, the received IDC information, and the time information corresponding to the MDT measurement result.

[0262] According to an embodiment of the present application, in a CU / DU architecture, the CU-CP or CU-UP or DU sends MDT measurement results to the TCE, and the TCE can obtain whether these MDT measurement results are affected by IDC interference, thereby being able to more accurately analyze these MDT measurement results.

[0263] It should be understood that in each of the above embodiments, the terminal device and / or the network device can perform some or all of the steps in each embodiment. These steps or operations are merely examples, and the embodiments of the present application can also perform other operations or variations of various operations. In addition, each step can be performed in the different orders presented in each embodiment, and it is possible not to perform all of the operations in the embodiments of the present application. Moreover, the size of the sequence number of each step does not mean the order of execution, and the execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0264] Figure 6 : is a schematic block diagram of a communication device provided in an embodiment of the present application. Figure 6 As shown, the communication device 1000 may include a processing unit 1100 and a transceiver unit 1200 .

[0265] Optionally, the communication device 1000 may correspond to the terminal device in the above method embodiment, for example, it may be a terminal device, or a component configured in the terminal device (such as a circuit, a chip or a chip system, etc.).

[0266] It should be understood that the communication device 1000 may correspond to the terminal device in the methods 200 to 400 according to the embodiments of the present application, and the communication device 1000 may include a Figure 2 Method 200, Figure 3 Method 300, Figure 4 The units of the method executed by the terminal device in the method 400. In addition, the units in the communication device 1000 and the above-mentioned other operations and / or functions are respectively for implementing Figure 2 Method 200, Figure 3 Method 300, Figure 4 It should be understood that the specific process of each unit performing the above steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0267] It should be understood that when the communication device 1000 is a terminal device, the transceiver unit 1200 in the communication device 1000 can be implemented by a transceiver, for example, corresponding to Figure 7 The transceiver 2020 or the communication device 2000 shown in FIG. Figure 8 The processing unit 1100 in the communication device 1000 can be implemented by at least one processor, for example, corresponding to Figure 7 The processor 2010 or the processor 2010 in the communication device 2000 shown in FIG. Figure 8 The processor 3010 in the terminal device 3000 is shown.

[0268] It should also be understood that when the communication device 1000 is a chip or chip system configured in a terminal device, the transceiver unit 1200 in the communication device 1000 can be implemented through an input / output interface, circuit, etc., and the processing unit 1100 in the communication device 1000 can be implemented through a processor, microprocessor or integrated circuit integrated on the chip or chip system.

[0269] Optionally, the communication device 1000 may correspond to the network device in the above method embodiment, for example, it may be a network device, or a component configured in the network device (such as a circuit, a chip or a chip system, etc.).

[0270] It should be understood that the communication device 1000 may correspond to the network device in the method 200 to the method 400 according to the embodiment of the present application, and the communication device 1000 may include a Figure 2 Method 200, Figure 3 Method 300, Figure 4 The units of the method performed by the network device in the method 400 are respectively for implementing Figure 2 Method 200, Figure 3 Method 300, Figure 4 It should be understood that the specific process of each unit performing the above steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0271] It should be understood that when the communication device 1000 is a network device, the transceiver unit 1200 in the communication device 1000 can be implemented by a transceiver, for example, corresponding to Figure 7 The transceiver 2020 or the communication device 2000 shown in FIG. Figure 9 The RRU 4100 in the base station 4000 shown in FIG. 1 , the processing unit 1100 in the communication device 1000 may be implemented by at least one processor, for example, corresponding to Figure 7 The processor 2010 or the processor 2010 in the communication device 2000 shown in FIG. Figure 8 The processing unit 4200 or processor 4202 in the base station 4000 is shown.

[0272] It should also be understood that when the communication device 1000 is a chip or chip system configured in a network device, the transceiver unit 1200 in the communication device 1000 can be implemented through an input / output interface, circuit, etc., and the processing unit 1100 in the communication device 1000 can be implemented through a processor, microprocessor or integrated circuit integrated on the chip or chip system.

[0273] Optionally, the communication device 1000 may correspond to the DU in the above method embodiment, for example, it may be a DU, or a component configured in the DU (such as a circuit, a chip, or a chip system, etc.).

[0274] It should be understood that the communication device 1000 may correspond to the DU in the method 500 according to the embodiment of the present application, and the communication device 1000 may include a Figure 5 The units of the method performed by the DU in the method 500 are respectively Figure 5 It should be understood that the specific process of each unit performing the above steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0275] Optionally, the communication device 1000 may correspond to the CU-UP in the above method embodiment, for example, it may be a CU-UP, or a component configured in the CU-UP (such as a circuit, chip or chip system, etc.).

[0276] It should be understood that the communication device 1000 may correspond to the CU-UP in the method 500 according to the embodiment of the present application, and the communication device 1000 may include a Figure 5 The units of the method performed by the CU-UP in the method 500 are respectively for implementing Figure 5 It should be understood that the specific process of each unit performing the above steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0277] Optionally, the communication device 1000 may correspond to the CU-CP in the above method embodiment, for example, it may be a CU-CP, or a component configured in the CU-CP (such as a circuit, a chip, or a chip system, etc.).

[0278] It should be understood that the communication device 1000 may correspond to the DU in the method 500 according to the embodiment of the present application, and the communication device 1000 may include a Figure 5 The units of the method performed by the CU-CP in the method 500 are respectively for implementing Figure 5 It should be understood that the specific process of each unit performing the above steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0279] Optionally, the communication device 1000 may correspond to the TCE in the above method embodiment, for example, it may be a TCE, or a component configured in the TCE (such as a circuit, a chip, or a chip system, etc.).

[0280] It should be understood that the communication device 1000 may correspond to the TCE in the method 500 according to the embodiment of the present application, and the communication device 1000 may include a Figure 5 The units of the method performed by the TCE in the method 500 are respectively for implementing Figure 5 It should be understood that the specific process of each unit performing the above steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0281] Optionally, the communication device 1000 may correspond to the CN in the above method embodiment, for example, it may be a CN, or a component configured in the CN (such as a circuit, a chip, or a chip system, etc.).

[0282] It should be understood that the communication device 1000 may correspond to the CN in the method 500 according to the embodiment of the present application, and the communication device 1000 may include a method for executing Figure 5 The units of the method performed by the CN in the method 500 are respectively for implementing Figure 5 It should be understood that the specific process of each unit performing the above steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0283] Figure 7 2 is another schematic block diagram of the communication device 2000 provided in an embodiment of the present application. Figure 7 As shown, the communication device 2000 includes a processor 2010, a transceiver 2020, and a memory 2030. The processor 2010, the transceiver 2020, and the memory 2030 communicate with each other via an internal connection path. The memory 2030 is used to store instructions, and the processor 2010 is used to execute the instructions stored in the memory 2030 to control the transceiver 2020 to send and / or receive signals.

[0284] It should be understood that the communication device 2000 can correspond to the terminal device in the above-mentioned method embodiment and can be used to execute the various steps and / or processes performed by the network device or terminal device in the above-mentioned method embodiment. Optionally, the memory 2030 may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. The memory 2030 can be a separate device or integrated into the processor 2010. The processor 2010 can be used to execute the instructions stored in the memory 2030, and when the processor 2010 executes the instructions stored in the memory, the processor 2010 is used to execute the various steps and / or processes of the above-mentioned method embodiment corresponding to the network device or terminal device.

[0285] Optionally, the communication device 2000 is the terminal device in the above embodiment.

[0286] Optionally, the communication device 2000 is the network device in the above embodiment.

[0287] The transceiver 2020 may include a transmitter and a receiver. The transceiver 2020 may further include an antenna, which may be one or more. The processor 2010, memory 2030, and transceiver 2020 may be integrated on different chips. For example, the processor 2010 and memory 2030 may be integrated in a baseband chip, and the transceiver 2020 may be integrated in a radio frequency chip. The processor 2010, memory 2030, and transceiver 2020 may also be integrated on the same chip. This application is not limited to this.

[0288] Optionally, the communication device 2000 is a component configured in a terminal device, such as a circuit, a chip, a chip system, etc.

[0289] Optionally, the communication device 2000 is a component configured in a network device, such as a circuit, a chip, a chip system, etc.

[0290] Optionally, the communication device 2000 is a component configured in a DU, such as a circuit, a chip, a chip system, etc.

[0291] Optionally, the communication device 2000 is a component configured in a CU-UP, such as a circuit, a chip, a chip system, etc.

[0292] Optionally, the communication device 2000 is a component configured in a CU-CP, such as a circuit, a chip, a chip system, etc.

[0293] Optionally, the communication device 2000 is a component configured in a TCE, such as a circuit, a chip, a chip system, etc.

[0294] Optionally, the communication device 2000 is a component configured in the CN, such as a circuit, a chip, a chip system, etc.

[0295] The transceiver 2020 may also be a communication interface, such as an input / output interface, a circuit, etc. The transceiver 2020, the processor 2010, and the memory 2020 may all be integrated into the same chip, such as a baseband chip.

[0296] Figure 8 This is a schematic diagram of the structure of the terminal device 3000 provided in the embodiment of the present application. The terminal device 3000 can be applied to Figure 1In the system shown, the functions of the terminal device in the above-mentioned method embodiment are performed. As shown in the figure, the terminal device 3000 includes a processor 3010 and a transceiver 3020. Optionally, the terminal device 3000 also includes a memory 3030. The processor 3010, the transceiver 3020, and the memory 3030 can communicate with each other via an internal connection path to transmit control and / or data signals. The memory 3030 is used to store a computer program, and the processor 3010 is used to call and execute the computer program from the memory 3030 to control the transceiver 3020 to transmit and receive signals. Optionally, the terminal device 3000 may also include an antenna 3040 for transmitting uplink data or uplink control signaling output by the transceiver 3020 via wireless signals.

[0297] The processor 3010 and the memory 3030 can be combined into a processing device, and the processor 3010 is used to execute the program code stored in the memory 3030 to implement the above functions. In specific implementation, the memory 3030 can also be integrated into the processor 3010, or independent of the processor 3010. The processor 3010 can be combined with the memory 3030 to form a processing device. Figure 6 The processing unit 1100 or Figure 7 Corresponding to the processor 2010 in.

[0298] The transceiver 3020 can be used with Figure 6 The transceiver unit 1200 or Figure 7 The transceiver 3020 may include a receiver (or receiver, receiving circuit) and a transmitter (or transmitter, transmitting circuit). The receiver is used to receive signals, and the transmitter is used to transmit signals.

[0299] It should be understood that Figure 8 The terminal device 3000 shown can realize Figures 2 to 4 The illustrated method embodiments involve various processes of the terminal device. The operations and / or functions of the various modules in the terminal device 3000 are respectively for implementing the corresponding processes in the aforementioned method embodiments. For details, please refer to the description of the aforementioned method embodiments. To avoid repetition, detailed descriptions are appropriately omitted here.

[0300] The processor 3010 can be used to execute the actions implemented within the terminal device described in the previous method embodiments, while the transceiver 3020 can be used to execute the actions of the terminal device sending to or receiving from the network device described in the previous method embodiments. For details, please refer to the description of the previous method embodiments and will not be repeated here.

[0301] Optionally, the terminal device 3000 may further include a power supply 3050 for providing power to various devices or circuits in the terminal device.

[0302] In addition, in order to make the functions of the terminal device more complete, the terminal device 3000 may also include one or more of an input unit 3060, a display unit 3070, an audio circuit 3080, a camera 3090 and a sensor 3100, and the audio circuit may also include a speaker 3082, a microphone 3084, etc.

[0303] Figure 9 This is a schematic diagram of the structure of the network device provided in the embodiment of the present application, for example, a schematic diagram of the structure of a base station. The base station 4000 can be applied to Figure 1 In the system shown in FIG. 1 , the functions of the network device in the above method embodiment are performed. As shown in the figure, the base station 4000 may include one or more radio frequency units, such as a remote radio unit (RRU) 4100 and one or more baseband units (BBU) (also known as distributed units (DU)) 4200. The RRU 4100 may be called a transceiver unit and may be connected to the base station 4000. Figure 6 The transceiver unit 1200 or Figure 7 . Optionally, the RRU4100 may also be referred to as a transceiver, a transceiver circuit, or a transceiver, etc., and may include at least one antenna 4101 and a radio frequency unit 4102. Optionally, the RRU 4100 may include a receiving unit and a transmitting unit, the receiving unit may correspond to a receiver (or receiver, receiving circuit), and the transmitting unit may correspond to a transmitter (or transmitter, transmitting circuit). The RRU4100 part is mainly used for receiving and transmitting radio frequency signals and converting radio frequency signals into baseband signals, for example, for sending indication information to terminal devices. The BBU 4200 part is mainly used for baseband processing, controlling the base station, etc. The RRU4100 and BBU 4200 may be physically arranged together or physically separated, that is, a distributed base station.

[0304] The BBU 4200 is the control center of the base station, which can also be called a processing unit. Figure 6 The processing unit 1100 or Figure 7 The processor 2010 in the embodiment corresponds to the baseband processor 2010, which is mainly used to perform baseband processing functions such as channel coding, multiplexing, modulation, spread spectrum, etc. For example, the BBU (processing unit) can be used to control the base station to execute the operation process of the network device in the above method embodiment, for example, to generate the above indication information.

[0305] In one example, the BBU 4200 may be composed of one or more single boards, and the multiple single boards may jointly support a wireless access network of a single access standard (such as an LTE network), or may separately support wireless access networks of different access standards (such as an LTE network, a 5G network, or other networks). The BBU 4200 also includes a memory 4201 and a processor 4202. The memory 4201 is used to store necessary instructions and data. The processor 4202 is used to control the base station to perform necessary actions, such as controlling the base station to execute the operation process of the network device in the above method embodiment. The memory 4201 and the processor 4202 can serve one or more single boards. That is, a memory and a processor can be set separately on each single board. Alternatively, multiple single boards may share the same memory and processor. In addition, necessary circuits may also be set on each single board.

[0306] It should be understood that Figure 9 The base station 4000 shown is capable of Figures 2 to 4 The illustrated method embodiments involve various processes of network devices. The operations and / or functions of the various modules in base station 4000 are respectively for implementing the corresponding processes in the aforementioned method embodiments. For details, please refer to the description of the aforementioned method embodiments. To avoid repetition, detailed descriptions are appropriately omitted here.

[0307] The BBU 4200 can be used to perform the actions implemented within the network device described in the previous method embodiments, while the RRU 4100 can be used to perform the actions described in the previous method embodiments, where the network device sends or receives data to or from a terminal device. For details, please refer to the description in the previous method embodiments and will not be repeated here.

[0308] It should be understood that Figure 9 The base station 4000 shown is only one possible form of network equipment and should not constitute any limitation to this application. The method provided in this application is applicable to network equipment in other forms. For example, it may include an AAU, and may also include a CU and / or DU, or include a BBU and an adaptive radio unit (ARU), or a BBU; it may also be customer premises equipment (CPE), or it may be in other forms. This application does not limit the specific form of the network equipment.

[0309] The CU and / or DU can be used to perform the actions implemented within the network device described in the previous method embodiments, while the AAU can be used to perform the actions described in the previous method embodiments where the network device sends or receives information to or from the terminal device. For details, please refer to the description in the previous method embodiments and will not be repeated here.

[0310] The present application also provides a processing device, comprising at least one processor, wherein the at least one processor is configured to execute a computer program stored in a memory, so that the processing device executes the method executed by the terminal device or network device in any of the above method embodiments.

[0311] An embodiment of the present application further provides a processing device, comprising a processor and a communication interface. The communication interface is coupled to the processor. The communication interface is configured to input and / or output information. The information includes at least one of instructions and data. The processor is configured to execute a computer program to cause the processing device to perform the method performed by the terminal device or network device in any of the above method embodiments.

[0312] The present application also provides a processing device including a processor and a memory. The memory is configured to store a computer program, and the processor is configured to call and execute the computer program from the memory, so that the processing device executes the method executed by the terminal device or network device in any of the above method embodiments.

[0313] It should be understood that the above-mentioned processing device may be one or more chips. For example, the processing device may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0314] During implementation, each step of the above method can be completed by an integrated logic circuit of the hardware in the processor or by instructions in the form of software. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it will not be described in detail here.

[0315] It should be noted that the processor in the embodiments of the present application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment can be completed by an integrated logic circuit of the hardware in the processor or by instructions in the form of software. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0316] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0317] According to the method provided in the embodiment of the present application, the present application also provides a computer program product, which includes: a computer program code, which, when executed on a computer, causes the computer to execute Figures 2 to 5 The method executed by the terminal device or the method executed by the network device in the illustrated embodiment.

[0318] According to the method provided in the embodiment of the present application, the present application also provides a computer-readable storage medium, which stores a program code, and when the program code is run on a computer, the computer executes Figures 2 to 5 The method executed by the terminal device or the method executed by the network device in the illustrated embodiment.

[0319] According to the method provided in the embodiment of the present application, the present application also provides a system, which includes one or more of the aforementioned terminal devices and one or more of the aforementioned network devices.

[0320] The network devices in the above-mentioned various apparatus embodiments completely correspond to the network devices or terminal devices in the terminal devices and method embodiments, and the corresponding steps are performed by the corresponding modules or units. For example, the communication unit (transceiver) performs the receiving or sending steps in the method embodiments, and other steps except sending and receiving can be performed by the processing unit (processor). The functions of the specific units can be referred to the corresponding method embodiments. Among them, there can be one or more processors.

[0321] In the above embodiments, a terminal device can be used as an example of a receiving device, and a network device can be used as an example of a sending device. However, this does not constitute any limitation on the present application. For example, both the sending device and the receiving device can be terminal devices. The present application does not limit the specific types of the sending device and the receiving device.

[0322] As used in this specification, the terms "component," "module," "system," and the like are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. By way of illustration, both an application running on a computing device and a computing device can be a component. One or more components can reside in a process and / or an execution thread, and a component can be located on a computer and / or distributed between two or more computers. In addition, these components can be executed from various computer-readable media having various data structures stored thereon. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component on a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0323] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0324] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0325] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0326] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0327] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0328] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0329] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: include: The first network device receives a handover request message from the second network device, where the handover request message includes second mobility history information, where the second mobility history information is recorded by the second network device, and where the second mobility history information includes a third time period, where the third time period is a duration for which the terminal device stays in the second cell. The first network device determines that the terminal device is changed to the first cell, and the change includes dual activation protocol stack DAPS switching, conditional switching CHO or radio resource control RRC re-establishment. The first network device will compensate the time from receiving the switching request message to determining that the terminal device is changed to the first cell into the third time period.

2. The method according to claim 1, wherein Also includes: The first network device starts recording first movement history information at or after determining that the terminal device changes to the first cell. The first movement history information is historical information of the terminal device in the first cell.

3. The method according to claim 2, wherein The first network device determining that the terminal device is switched to the first cell includes: When determining that the terminal device has successfully randomly accessed the first cell, the first network device determines that the terminal device is switched to the first cell; The first network device starting to record the first movement history information at or after determining that the terminal device changes to the first cell includes: The first network device starts recording the first movement history information at or after determining that the terminal device has successfully randomly accessed the first cell.

4. The method according to claim 2, characterized in that If the change is a DAPS handover, then the first network device determining that the terminal device is switched to the first cell includes: The first network device determines that the terminal device changes to the first cell when sending the first indication information, where the first indication information is used to instruct the terminal device to disconnect from the second cell; The first network device starting to record the first movement history information at or after determining that the terminal device changes to the first cell includes: The first network device starts recording the first movement history information at or after sending the first indication information.

5. The method according to claim 2, characterized in that If the change is a DAPS handover, then the first network device determining that the terminal device is switched to the first cell includes: The first network device determines that the terminal device is switched to the first cell when sending the second indication information, where the second indication information is used to instruct the second cell or the second network device to release the context of the terminal device; The first network device starting to record the first movement history information at or after determining that the terminal device changes to the first cell includes: The first network device starts recording the first movement history information at or after sending the second indication information.

6. The method according to any one of claims 2 to 5, characterized in that The first movement history information further includes third indication information, and the third indication information is used to instruct the terminal device to switch from the first cell to the third cell using DAPS switching.

7. The method according to claim 6, characterized in that The third indication information is also used to indicate a first time period, where the first time period represents the length of time that the terminal device stays in the first cell and the third cell at the same time during the DAPS switching process.

8. The method according to claim 2, characterized in that If the change is CHO, then the first network device determining that the terminal device changes to the first cell includes: The first network device determines, when sending a handover success message, that the terminal device is switched to the first cell; The first network device starting to record the first movement history information at or after determining that the terminal device changes to the first cell includes: The first network device starts recording the first movement history information at or after sending the handover success message.

9. The method according to claim 2, characterized in that If the change is CHO, then the first network device determining that the terminal device changes to the first cell includes: Upon receiving the sequence number state transfer message, the first network device determines that the terminal device has been switched to the first cell; The first network device starting to record the first movement history information at or after determining that the terminal device changes to the first cell includes: The first network device starts recording the first movement history information at or after receiving the sequence number state transfer message.

10. The method according to any one of claims 1 to 5 and 7 to 9, characterized in that The first network device determining that the terminal device is switched to the first cell includes: Upon receiving the RRC reconfiguration completion message from the terminal device, the first network device determines that the terminal device has switched to the first cell.

11. The method according to any one of claims 2 to 5 and 7 to 9, characterized in that The method further comprises: The first network device sends the first mobility history information to the third network device, where the first mobility history information includes a second time period, and the second time period is the length of time the terminal device stays in the first cell.

12. The method according to any one of claims 1 to 5 and 7 to 9, characterized in that The first network device compensating the time from receiving the handover request message to determining that the terminal device switches to the first cell into the third time period includes: The first network device adds the third time period to the time from when the first network device receives the switching request message to when the first network device determines that the terminal device switches to the first cell.

13. A communication method, applied in a dual-active protocol stack switching process, characterized in that: include: The terminal device determines to switch from the second cell to the first cell; The terminal device records fourth mobility history information at or after determining to switch from the second cell to the first cell, where the fourth mobility history information is historical information of the terminal device in the second cell, and the fourth mobility history information includes a fourth time period, where the fourth time period is the time spent in the second cell; The terminal device determining to switch from the first cell to the second cell includes: The terminal device determines to switch from the second cell to the first cell when receiving the first indication information, where the first indication information is used to instruct the terminal device to disconnect from the second cell; The terminal device recording the fourth movement history information at or after determining to switch from the second cell to the first cell includes: The terminal device records the fourth movement history information at the moment of receiving the first indication information or thereafter.

14. The method according to claim 13, characterized in that The fourth time period includes the time the terminal device stays in the second cell before receiving the first indication information.

15. The method according to claim 13 or 14, characterized in that The method further comprises: When the terminal device determines that random access to the first cell is successful, the terminal device starts recording a fifth time period, where the fifth time period is the time the terminal device stays in the first cell.

16. The method according to claim 13 or 14, characterized in that The method further comprises: When the terminal device receives the first indication information, it starts to record the fifth time period, and the fifth time period is the time the terminal device stays in the first cell.

17. The method according to claim 13 or 14, characterized in that The fourth movement history information further includes fourth indication information, and the fourth indication information is used to instruct the terminal device to switch from the second cell to the first cell using a DAPS switching method.

18. The method according to claim 17, characterized in that The fourth indication information is further used to indicate a sixth time period, where the sixth time period represents the length of time that the terminal device stays in the first cell and the second cell at the same time during the DAPS switching process.

19. A communication device, characterized in that: include: a transceiver unit, configured to receive a handover request message from a second network device, the handover request message including second mobility history information, the second mobility history information being recorded by the second network device, the second mobility history information including a third time period, the third time period being the length of time the terminal device stays in the second cell; A processing unit is used to determine that the terminal device is changed to the first cell, and the change includes dual activation protocol stack DAPS switching, conditional switching CHO or radio resource control RRC re-establishment; the processing unit is also used to compensate the time from receiving the switching request message to determining that the terminal device is changed to the first cell into the third time period.

20. The communication device according to claim 19, wherein The processing unit is further configured to start recording first movement history information at or after determining that the terminal device changes to the first cell, where the first movement history information is historical information of the terminal device in the first cell.

21. The communication device according to claim 20, wherein: The processing unit is specifically configured to: If it is determined that the terminal device has successfully randomly accessed the first cell, determining that the terminal device is switched to the first cell; At or after determining that the terminal device has successfully randomly accessed the first cell, the first movement history information begins to be recorded.

22. The communication device according to claim 20, wherein: If the replacement is DAPS switching, the processing unit is specifically configured to: In a case where the first indication information is sent, determining that the terminal device is changed to the first cell, the first indication information being used to instruct the terminal device to disconnect from the second cell; At or after the first indication information is sent, the first movement history information starts to be recorded.

23. The communication device according to claim 20, wherein: If the replacement is DAPS switching, the processing unit is specifically configured to: In a case where the second indication information is sent, determining that the terminal device is changed to the first cell, the second indication information is used to instruct the second cell or the second network device to release the context of the terminal device; At or after the second indication information is sent, the first movement history information starts to be recorded.

24. The communication device according to any one of claims 20 to 23, characterized in that The first movement history information further includes third indication information, and the third indication information is used to instruct the terminal device to switch from the first cell to the third cell using DAPS switching.

25. The communication device according to claim 24, characterized in that The third indication information is also used to indicate a first time period, where the first time period represents the length of time that the terminal device stays in the first cell and the third cell at the same time during the DAPS switching process.

26. The communication device according to claim 20, wherein: If the replacement is CHO, the processing unit is specifically used to: In the case where a handover success message is sent, determining that the terminal device is switched to the first cell; At or after the switching success message is sent, the first movement history information starts to be recorded.

27. The communication device according to claim 20, wherein: If the replacement is CHO, the processing unit is specifically used to: Upon receiving the sequence number state transfer message, determining that the terminal device is switched to the first cell; At or after the moment the sequence number state transfer message is received, the first movement history information starts to be recorded.

28. The communication device according to any one of claims 19 to 23 and 25 to 27, characterized in that: The processing unit is specifically configured to: Upon receiving the RRC reconfiguration completion message from the terminal device, it is determined that the terminal device is switched to the first cell.

29. The communication device according to any one of claims 20 to 23 and 25 to 27, characterized in that: The communication device further includes: The transceiver unit is used to send the first mobility history information to the third network device, where the first mobility history information includes a second time period, and the second time period is the length of time the terminal device stays in the first cell.

30. The communication device according to any one of claims 19 to 23 and 25 to 27, characterized in that: The processing unit is specifically configured to: The third time period is added to the time period from receiving the switching request message to determining that the terminal equipment is switched to the first cell.

31. A communication device, used in a dual-active protocol stack switching process, characterized in that: include: a processing unit, configured to determine handover from the second cell to the first cell; The processing unit is further configured to record fourth mobility history information at or after determining a moment of switching from the second cell to the first cell, the fourth mobility history information being historical information of the terminal device in the second cell, the fourth mobility history information including a fourth time period, the fourth time period being the time spent in the second cell; The processing unit is further configured to determine, upon receiving first indication information, to switch from the second cell to the first cell, where the first indication information is used to instruct the terminal device to disconnect from the second cell; The processing unit is further configured to record the fourth movement history information at or after receiving the first indication information.

32. The communication device according to claim 31, wherein: The fourth time period includes the time the terminal device stays in the second cell before receiving the first indication information.

33. The communication device according to claim 31 or 32, characterized in that The processing unit is further configured to start recording a fifth time period when determining that random access to the first cell is successful, the fifth time period being the time the terminal device stays in the first cell.

34. The communication device according to claim 31 or 32, characterized in that The processing unit is further configured to start recording a fifth time period upon receiving the first indication information, where the fifth time period is the time the terminal device stays in the first cell.

35. The communication device according to claim 31 or 32, characterized in that The fourth movement history information further includes fourth indication information, and the fourth indication information is used to instruct the terminal device to switch from the second cell to the first cell using a DAPS switching method.

36. The communication device according to claim 35, characterized in that The fourth indication information is further used to indicate a sixth time period, where the sixth time period represents the length of time that the terminal device stays in the first cell and the second cell at the same time during the DAPS switching process.

37. A communication device, characterized in that: include: A processor and a communication interface, wherein the processor is configured to execute computer instructions received through the communication interface, so that the apparatus implements the method according to any one of claims 1 to 18.

38. A computer-readable storage medium, characterized in that A computer program is stored thereon, which, when executed, causes the method according to any one of claims 1 to 18 to be performed.

39. A computer program product, characterized in that The invention comprises a computer program which, when running on a computer, causes the computer to perform the method according to any one of claims 1 to 18.

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