Cell handover method and apparatus, terminal, and network side device

Abstract

The present application relates to the technical field of communications, and discloses a cell handover method and apparatus, a terminal, and a network side device. The cell handover method of embodiments of the present application comprises: a terminal receives a first message sent by a network side device, wherein the first message is used for triggering cell handover; and the terminal performs a first operation on the basis of the first message, wherein the execution of the first operation comprises any one of the following: when the first message satisfies a first condition, performing random access channel (RACH)-less cell handover, the first condition being a condition corresponding to the RACH-less cell handover; when the first message satisfies a second condition, performing contention-free random access (CFRA)-based cell handover, the second condition being a condition corresponding to the CFRA-based cell handover; and when the first message satisfies a third condition, performing contention-based random access (CBRA)-based cell handover, the third condition being a condition corresponding to the CBRA-based cell handover.

Description

Cell switching method, device, terminal and network side equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202310972876.1 filed in China on August 3, 2023, and this application claims priority to Chinese patent application No. 202311067856.6 filed in China on August 23, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application belongs to the field of communication technology, and specifically relates to a cell switching method, apparatus, terminal and network-side equipment. Background Art

[0004] In related technologies, Layer 1 (L1) / Layer 2 (L2)-based cell switching (L1 / L2 Triggered Mobility, LTM) supports two cell switching modes: random access channel (Rach-based) and Rach-less. The Rach-based switching mode includes cell switching based on non-contention random access (CFRA) and cell switching based on contention random access (CBRA). In related technologies, when selecting a cell switching mode, the terminal performs cell switching according to a fixed cell switching mode, resulting in poor flexibility in cell switching for the terminal.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a cell switching method, apparatus, terminal, and network-side equipment, which can solve the problem of poor flexibility of the terminal in performing cell switching.

[0007] In a first aspect, a cell handover method is provided, comprising:

[0008] The terminal receives a first message sent by a network-side device, where the first message is used to trigger a cell handover;

[0009] The terminal performs a first operation based on the first message;

[0010] The performing of the first operation includes any one of the following:

[0011] If the first message satisfies a first condition, performing a cell handover without a random access channel (RACH), where the first condition is a condition corresponding to a cell handover without a RACH;

[0012] If the first message satisfies a second condition, performing cell switching based on non-contention random access (CFRA), where the second condition is a condition corresponding to cell switching based on CFRA;

[0013] In a case where the first message satisfies a third condition, a cell handover of contention-based random access (CBRA) is performed, where the third condition is a condition corresponding to the cell handover of CBRA.

[0014] In a second aspect, a cell handover method is provided, including:

[0015] The network-side device sends a first message to the terminal, where the first message is used to instruct execution of a first operation;

[0016] The first message is used to instruct the execution of the first operation, including any one of the following:

[0017] When the first message satisfies a first condition, the first message is used to instruct execution of a cell handover without RACH, and the first condition is a condition corresponding to the cell handover without RACH;

[0018] When the first message satisfies a second condition, the first message is used to instruct execution of cell switching based on non-contention random access (CFRA), and the second condition is a condition corresponding to cell switching based on CFRA;

[0019] In a case where the first message satisfies a third condition, the first message is used to instruct execution of a cell handover based on contention-based random access (CBRA), and the third condition is a condition corresponding to the cell handover based on CBRA.

[0020] According to a third aspect, a cell switching device is provided. The terminal includes the cell switching device, including:

[0021] A receiving module, configured to receive a first message sent by a network-side device, where the first message is used to trigger a cell handover;

[0022] An execution operation, configured to execute a first operation based on the first message;

[0023] The performing of the first operation includes any one of the following:

[0024] If the first message satisfies a first condition, performing a cell handover without a random access channel (RACH), where the first condition is a condition corresponding to a cell handover without a RACH;

[0025] If the first message satisfies a second condition, performing cell switching based on non-contention random access (CFRA), where the second condition is a condition corresponding to cell switching based on CFRA;

[0026] In a case where the first message satisfies a third condition, a cell handover of contention-based random access (CBRA) is performed, where the third condition is a condition corresponding to the cell handover of CBRA.

[0027] In a fourth aspect, a cell switching device is provided, wherein a network-side device includes the cell switching device, including:

[0028] A sending module, configured to send a first message to a terminal, where the first message is used to instruct execution of a first operation;

[0029] The first message is used to instruct the execution of the first operation, including any one of the following:

[0030] When the first message satisfies a first condition, the first message is used to instruct execution of a cell handover without RACH, and the first condition is a condition corresponding to the cell handover without RACH;

[0031] When the first message satisfies a second condition, the first message is used to instruct execution of cell switching based on non-contention random access (CFRA), and the second condition is a condition corresponding to cell switching based on CFRA;

[0032] In a case where the first message satisfies a third condition, the first message is used to instruct execution of a cell handover based on contention-based random access (CBRA), and the third condition is a condition corresponding to the cell handover based on CBRA.

[0033] In a fifth aspect, a terminal is provided, comprising a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the method described in the first aspect are implemented.

[0034] In a sixth aspect, a network side device is provided, which includes a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the method described in the second aspect are implemented.

[0035] In a seventh aspect, a terminal is provided, comprising a processor and a communication interface, wherein the communication interface is configured to: receive a first message sent by a network-side device, the first message being configured to trigger a cell handover; and the processor is configured to: perform a first operation based on the first message;

[0036] The performing of the first operation includes any one of the following:

[0037] If the first message satisfies a first condition, performing a cell handover without a random access channel (RACH), where the first condition is a condition corresponding to a cell handover without a RACH;

[0038] If the first message satisfies a second condition, performing cell switching based on non-contention random access (CFRA), where the second condition is a condition corresponding to cell switching based on CFRA;

[0039] In a case where the first message satisfies a third condition, a cell handover of contention-based random access (CBRA) is performed, where the third condition is a condition corresponding to the cell handover of CBRA.

[0040] In an eighth aspect, a network-side device is provided, including a processor and a communication interface, wherein the communication interface is configured to: send a first message to a terminal, the first message being configured to instruct execution of a first operation;

[0041] The first message is used to instruct the execution of the first operation, including any one of the following:

[0042] When the first message satisfies a first condition, the first message is used to instruct execution of a cell handover without RACH, and the first condition is a condition corresponding to the cell handover without RACH;

[0043] When the first message satisfies a second condition, the first message is used to instruct execution of cell switching based on non-contention random access (CFRA), and the second condition is a condition corresponding to cell switching based on CFRA;

[0044] In a case where the first message satisfies a third condition, the first message is used to instruct execution of a cell handover based on contention-based random access (CBRA), and the third condition is a condition corresponding to the cell handover based on CBRA.

[0045] In the ninth aspect, a cell switching system is provided, comprising: a terminal and a network side device, wherein the terminal can be used to execute the steps of the method described in the first aspect, and the network side device can be used to execute the steps of the method described in the second aspect.

[0046] In the tenth aspect, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method described in the first aspect are implemented, or the steps of the method described in the second aspect are implemented.

[0047] In the eleventh aspect, a chip is provided, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the method as described in the first aspect, or to implement the method as described in the second aspect.

[0048] In the twelfth aspect, a computer program / program product is provided, which is stored in a storage medium and is executed by at least one processor to implement the steps of the method described in the first aspect, or to implement the steps of the method described in the second aspect.

[0049] In an embodiment of the present application, a terminal receives a first message sent by a network-side device, where the first message is used to trigger a cell handover; the terminal performs a first operation based on the first message; wherein the performing of the first operation includes any one of the following: performing a cell handover without a random access channel (RACH) when the first message satisfies a first condition, where the first condition is a condition corresponding to a cell handover without RACH; performing a cell handover based on non-contention random access (CFRA) when the first message satisfies a second condition, where the second condition is a condition corresponding to a cell handover based on CFRA; performing a cell handover based on contention random access (CBRA) when the first message satisfies a third condition, where the third condition is a condition corresponding to a cell handover based on CBRA. In this way, the terminal performs the corresponding cell handover based on the condition satisfied by the first message for triggering the cell handover, thereby improving the flexibility of the terminal in performing cell handover. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG1 is a block diagram of a wireless communication system to which embodiments of the present application may be applied;

[0051] FIG2 is a diagram of an embodiment of the present application.

[0052] FIG3 is a flowchart of a cell switching method according to an embodiment of the present application;

[0053] FIG4 is a second flowchart of a cell switching method provided in an embodiment of the present application;

[0054] FIG5 is a schematic diagram of a cell switching device according to an embodiment of the present application;

[0055] FIG6 is a second structural diagram of a cell switching device provided in an embodiment of the present application;

[0056] FIG7 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0057] FIG8 is a schematic structural diagram of a terminal provided in an embodiment of the present application;

[0058] FIG9 is a schematic structural diagram of a network-side device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] The following will be combined with the accompanying drawings in the embodiments of this application to clearly describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0060] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same type, and do not limit the number of objects, for example, the first object can be one or more. In addition, "or" in this application represents at least one of the connected objects. For example, "A or B" covers three options, namely, Option 1: including A but not including B; Option 2: including B but not including A; Option 3: including both A and B. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0061] The term "indication" in this application can be either a direct indication (or explicit indication) or an indirect indication (or implicit indication). A direct indication can be understood as the sender explicitly informing the receiver of specific information, the operation to be performed, or the requested result, etc. in the instruction sent; an indirect indication can be understood as the receiver determining the corresponding information based on the instruction sent by the sender, or making a judgment and determining the operation to be performed or the requested result, etc. based on the judgment result.

[0062] It is worth noting that the technology described in the embodiments of the present application is not limited to the Long Term Evolution (LTE) / LTE-Advanced (LTE-A) system, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency Division Multiple Access (SC-FDMA) or other systems. The terms "system" and "network" in the embodiments of the present application are often used interchangeably, and the described technology can be used for the systems and radio technologies mentioned above, as well as for other systems and radio technologies. The following description describes a New Radio (NR) system for example purposes, and NR terminology is used in most of the following description, but these technologies can also be applied to systems other than NR systems, such as 6th Generation (6G) communication systems.

[0063] FIG1 is a block diagram of a wireless communication system applicable to an embodiment of the present application. The wireless communication system includes a terminal 11 and a network-side device 12. The terminal 11 may be a mobile phone, a tablet computer (Tablet Personal Computer), a laptop computer (Laptop Computer), a notebook computer, a personal digital assistant (PDA), a handheld computer, a netbook, an ultra-mobile personal computer (UMPC), a mobile internet device (MID), an augmented reality (AR), a virtual reality (VR) device, a robot, a wearable device (Wearable Device), an aircraft (Flight Vehicle), a vehicle-mounted device (VUE), a ship-mounted device, a pedestrian user equipment (PUE), a smart home (home appliances with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), a game console, a personal computer (PC), an ATM, or a self-service machine, or other terminal-side devices. Wearable devices include: smart watches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart bracelets, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among them, the vehicle-mounted device can also be called a vehicle-mounted terminal, a vehicle-mounted controller, a vehicle-mounted module, a vehicle-mounted component, a vehicle-mounted chip or a vehicle-mounted unit, etc. In addition to the above-mentioned terminal devices, it can also be a chip in the terminal, such as a modem chip, a system-on-chip (SoC). It should be noted that the specific type of the terminal 11 is not limited in the embodiment of the present application. The network side device 12 may include an access network device or a core network device, wherein the access network device may also be called a radio access network (RAN) device, a radio access network function or a radio access network unit. The access network device may include a base station, a wireless local area network (WLAN) access point (AS) or a wireless fidelity (WiFi) node, etc.Among them, the base station can be referred to as Node B (NB), Evolved Node B (eNB), the next generation Node B (gNB), New Radio Node B (NR Node B), access point, Relay Base Station (RBS), Serving Base Station (SBS), Base Transceiver Station (BTS), radio base station, radio transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Home Node B (HNB), Home Evolved Node B (home evolved Node B), Transmission Reception Point (TRP) or other appropriate terms in the field. As long as the same technical effect is achieved, the base station is not limited to specific technical vocabulary. It should be noted that in the embodiment of the present application, only the base station in the NR system is used as an example for introduction, and the specific type of the base station is not limited.

[0064] The core network equipment may include but is not limited to at least one of the following: core network node, core network function, mobility management entity (MME), access mobility management function (AMF), session management function (SMF), user plane function (UPF), policy control function (PCF), policy and charging rules function unit (PCRF), edge application service discovery function (EASDF), unified data management (UDM), unified data repository (UDR), home user server (HSS), centralized network configuration (CNC), network storage function (NRF), network exposure function (NEF), local NEF (L-NEF), binding support function (BSF), application function ( It should be noted that in the embodiments of the present application, only the core network device in the NR system is introduced as an example, and the specific type of the core network device is not limited.

[0065] For ease of understanding, some of the contents involved in the embodiments of this application are described below:

[0066] 1. LTM switching process

[0067] As shown in Figure 2, the LTM switching process is as follows:

[0068] (1) Radio Resource Control (RRC) pre-configuration: The terminal receives the pre-configuration information of candidate cells sent by the network side;

[0069] (2) Measurement reporting: The terminal obtains L1 measurement results by measuring the reference signals (RS) (such as synchronization signal blocks (SSB)) of the current serving cell and neighboring cells and reports them;

[0070] (3) Handover command: The terminal receives the cell handover command sent by the network side and applies the RRC configuration information of the target cell. The LTM uses the Medium Access Control (MAC) Control Element (CE) as the carrier of the cell handover command.

[0071] (4) Downlink synchronization and automatic gain control (AGC) adjustment: The terminal decodes the demodulation reference signal (DMRS) and physical broadcast channel (PBCH) of the first SSB of the target cell after RRC reconfiguration, obtains the system frame number, half-frame indicator, and SSB index, performs downlink synchronization at the frame level, timeslot level, and symbol level, and adjusts the automatic gain control (AGC) parameters according to the received power of the SSB.

[0072] (5) Uplink synchronization: After downlink synchronization, the terminal performs uplink synchronization through the Random Access Channel (RACH) until it receives the Random Access Response (RAR) and obtains the TA. The uplink synchronization is completed.

[0073] 2. Timing Advance (TA)

[0074] In the LTM process, TA acquisition is implemented in the uplink synchronization step. In related technologies, LTM supports rach-less handover and rach-based handover.

[0075] Rach-less handover means that neither the network nor the terminal triggers the RACH process during the handover process. There are three ways to implement uplink synchronization for rach-less handover. The first is early RACH. To address the issue of long handover latency caused by the RACH process, LTM introduces a Physical Downlink Control Channel (PDCCH) order that triggers the terminal to send a preamble to the candidate cell before the handover command is issued. The candidate cell detects the preamble and calculates the TA, which it then sends to the source cell via a higher-layer interface. The source cell then notifies the terminal via a handover command or a Random Access Response (RAR). After receiving the handover command, the terminal sends uplink data based on the TA value of the target cell. The second is LLTE rach-less, which means the target cell's TA value is zero or the target cell's TA value is the same as the serving cell's TA value. The third is UE-based TA measurement, in which the terminal determines its TA value in the target cell based on the downlink reception time difference between the target and source cells and its TA value in the source cell.

[0076] In contrast to rach-less handover, rach-based handover requires initiating a RACH procedure during the handover process. Related technologies, such as LTM, have not yet discussed the details of rach-based handover, such as whether it is triggered by the network or the user equipment (UE), and whether it is CFRA or CBRA.

[0077] 3. Beam pointing mechanism

[0078] After the traditional cell switching or initial access is completed, if the network does not configure a beam indication information list, or configures a beam indication information list and the number of beam indication information in the list is greater than 1, but the network does not activate the beam indication information, the terminal will determine the downlink receive beam for data reception based on the SSB associated with the most recent physical random access channel (PRACH) transmission or the PRACH transmission initiated by the initial access, and use the uplink transmit beam corresponding to the most recent PRACH transmission or the PRACH transmission initiated by the initial access as the uplink transmit beam for data transmission.

[0079] In LTM, the related art only supports a unified TCI framework, that is, the same beam is used for uplink and / or downlink. It is also agreed in the related art that a cell handover command can carry a TCI state index (for the case where the beam information corresponding to the target cell is configured as joint TCI), or a pair of uplink (UL) and downlink (DL) TCI state indexes (for the case where the beam information corresponding to the target cell is configured as separate TCI mode), so that the terminal can use a determined beam for data transmission after switching to the target cell. However, there is no clear conclusion on whether the cell handover command always carries beam indication information.

[0080] The cell switching method, apparatus, terminal, and network-side equipment provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings through some embodiments and their application scenarios.

[0081] Referring to FIG3 , FIG3 is a flow chart of a cell switching method provided in an embodiment of the present application. As shown in FIG3 , the cell switching method includes the following steps:

[0082] Step 101: A terminal receives a first message sent by a network-side device, where the first message is used to trigger a cell handover.

[0083] The first message may be a cell switch command (cell switch command). For example, the first message may be a cell switch command carried by a MAC CE, and the cell switch command may be an LTM switch command.

[0084] Step 102: The terminal performs a first operation based on the first message;

[0085] The performing of the first operation includes any one of the following:

[0086] If the first message satisfies a first condition, performing a cell handover without a random access channel (RACH), where the first condition is a condition corresponding to a cell handover without a RACH;

[0087] If the first message satisfies a second condition, performing cell switching based on non-contention random access (CFRA), where the second condition is a condition corresponding to cell switching based on CFRA;

[0088] In a case where the first message satisfies a third condition, a cell handover of contention-based random access (CBRA) is performed, where the third condition is a condition corresponding to the cell handover of CBRA.

[0089] In one embodiment, the first message is a cell handover command. After receiving the cell handover command, the terminal performs a first operation. The cell handover command carries at least target object indication information. The first operation includes, but is not limited to, at least one of the following: CBRA-based cell handover, CFRA-based cell handover, and RACH-free cell handover. The target object may include at least one of the following: a transmission reception point (TRP), a cell, a cell group, or a primary cell in a cell group.

[0090] In one implementation, the target object may be a target cell for cell handover.

[0091] In one implementation, the first message is a cell handover command. After the terminal receives the cell handover command that meets the first condition, the terminal performs a RACH-free cell handover.

[0092] In one implementation, the first message is a cell switching command. After the terminal receives the cell switching command that meets the second condition, the terminal performs a CFRA-based cell switching.

[0093] In one implementation, the first message is a cell switching command. After the terminal receives the cell switching command that meets the third condition, the terminal performs CBRA-based cell switching.

[0094] In an embodiment of the present application, a terminal receives a first message sent by a network-side device, where the first message is used to trigger a cell handover; the terminal performs a first operation based on the first message; wherein the performing of the first operation includes any one of the following: performing a cell handover without a random access channel (RACH) when the first message satisfies a first condition, where the first condition is a condition corresponding to a cell handover without RACH; performing a cell handover based on non-contention random access (CFRA) when the first message satisfies a second condition, where the second condition is a condition corresponding to a cell handover based on CFRA; performing a cell handover based on contention random access (CBRA) when the first message satisfies a third condition, where the third condition is a condition corresponding to a cell handover based on CBRA. In this way, the terminal can perform a corresponding cell handover based on the condition satisfied by the first message for triggering a cell handover, thereby improving the flexibility of the terminal in performing cell handover.

[0095] Optionally, the first condition includes at least one of the following:

[0096] The first message carries timing advance TA information;

[0097] The first message carries beam indication information;

[0098] The first message carries indication information indicating that there is no RACH;

[0099] The first message carries indication information indicating a target object, and the TA of the terminal under the target object is configured by a network side device or is instructed by the network side device to be acquired by the terminal according to a second operation.

[0100] In which, the first message carries beam indication information. When the beam information corresponding to the target object is configured as joint TCI mode, the beam indication information may include a TCI state index; or, when the beam information corresponding to the target object is configured as separate TCI mode, the beam indication information may include a pair of UL and DL TCI state indexes.

[0101] The first message carrying indication information indicating no RACH may include: the first message carrying indication information indicating LTErach-less like, such as TA=0 or an identity document (ID) of a timing advance group (TAG) of a source object (such as a source cell). The source object may include at least one of the following: a transmitting and receiving point (TRP), a cell, a cell group, and a primary cell in a cell group. In one embodiment, the source object may be a source cell of a cell handover.

[0102] It should be noted that the indication information indicating the target object may be indication information that explicitly indicates the target object, for example, the indication information directly indicates the target object, such as a physical cell identifier (PCI); or it may be indication information that implicitly indicates the target object, and the indication information indicates the target object, such as the configuration identifier of the target object. The terminal can determine the configuration information of the target object based on the configuration identifier, wherein the configuration information of the target object includes the physical cell identifier PCI, wherein the target object may include at least one of the following: a transmitting and receiving point (TRP), a cell, a cell group, and a main cell in a cell group. The target cell can be uniquely determined through the target object.

[0103] The TA of the target object is configured by a network device or instructed by the network device to be acquired by the terminal according to a second operation. The second operation may include: acquiring the TA of the terminal under the target object based on at least one of the downlink reception time difference between the terminal under the source object and the target object, the timing difference between the source object and the target object, and the TA indication information sent by the source object. For example, the second operation may be a UE-based TA measurement operation, and the second operation may include: acquiring the TA value of the terminal under the target object based on at least one of the reception time difference between the terminal under the source object (e.g., source cell) and the target object (e.g., target cell), the timing difference between the source object (e.g., source cell) and the target object (e.g., target cell), and a TA command (command) MAC CE sent by the source object (e.g., source cell). In the case of a timing difference between the source object (e.g., source cell) and the target object (e.g., target cell), the timing difference may be determined based on an absolute timing advance command (TAC) sent by the network after the terminal sends a PRACH to the source object (e.g., source cell) and the target object (e.g., target cell), respectively.

[0104] In this implementation, the terminal can perform cell switching without RACH based on the first condition satisfied by the first message for triggering cell switching, thereby improving the flexibility of the terminal in performing cell switching.

[0105] Optionally, the first condition also includes: the TA of the target object is valid.

[0106] The TA of the target object can be considered valid if the TA of the target object meets at least one of the following conditions:

[0107] The TA timer has not timed out;

[0108] The TA value does not exceed the preset threshold;

[0109] The terminal updates the TA value within a preset time.

[0110] Optionally, the method further comprises at least one of the following:

[0111] Detecting or measuring, by the terminal, a reference signal corresponding to the beam indication information carried in the first message;

[0112] The terminal determines a downlink receive beam based on the beam indication information carried in the first message and receives downlink data;

[0113] The terminal determines the target uplink resource based on the TA information and the first uplink resource carried by the first message, and determines the uplink transmission beam based on the beam indication information carried in the first message, and sends uplink data based on the uplink transmission beam in the target uplink resource. The first uplink resource is an uplink resource pre-configured or scheduled by the network.

[0114] It should be noted that before the terminal sends and receives data based on the beam indication information carried in the first message, it is necessary to detect or measure the reference signal corresponding to the beam indication information carried in the first message. The reference signal corresponding to the beam indication information is at least one of SSB, CSI-RS for tracking, and CSI-RS for beam management. Among them, when the TCI state indicating the downlink beam or the quasi-co-located source reference signal indicating the TCI state of the uplink and downlink beams in the beam indication information is the CSI-RS for tracking, and the terminal has not detected or measured it within the preset time, the terminal needs to detect or measure the CSI-RS for tracking before using the downlink beam or the uplink and downlink beams for data transmission or reception. Similarly, SSB and CSI-RS for beam management. Among them, when the beam indication information indicates the TCI-UL-state of the uplink beam or the path loss reference signal associated with the TCI state of the uplink and downlink beams, and the terminal has not detected or measured it within the preset time, the terminal needs to detect or measure the path loss reference signal before using the uplink beam or the uplink and downlink beams for data transmission or reception.

[0115] It should be noted that the operation of the terminal determining the downlink receiving beam and receiving downlink data based on the beam indication information carried in the first message can be performed during the terminal performing a cell switching without RACH, or can be performed after the terminal performs a cell switching without RACH and before the terminal receives a command sent by the network side to update the beam indication information. This embodiment does not limit this.

[0116] It should be noted that the terminal determines the target uplink resource based on the TA information and the first uplink resource carried by the first message, and determines the uplink transmission beam based on the beam indication information carried in the first message. The operation of sending uplink data based on the uplink transmission beam on the target uplink resource can be performed during the cell switching process without RACH performed by the terminal, or can be performed after the terminal performs the cell switching without RACH and before the terminal receives the command sent by the network side for updating the beam indication information or TA, wherein the TA and beam information are decoupled, that is, after receiving the command sent by the network side for updating the TA, the terminal can still determine the uplink beam for data transmission according to the beam indication information carried in the cell switching command; after receiving the command sent by the network side for updating the beam indication information, the terminal can still determine the target uplink resource according to the TA information carried in the cell switching command. This embodiment does not limit this.

[0117] In one embodiment, the first message is a cell switching command, and the terminal performs a cell switching without RACH, which may include: after a first preset time after receiving the cell switching command, the terminal uses the beam indication information carried in the cell switching command to determine a downlink receive beam and receive downlink data, uses the TA-related information indicated in the cell switching command and the first uplink resource to determine a target uplink resource, and uses the beam indication information carried in the cell switching command to determine an uplink transmit beam and transmit uplink data on the target uplink resource, wherein the first uplink resource is an uplink resource pre-configured or scheduled by the network. In this way, the resource location where the terminal actually sends data can be determined based on the pre-configured or network-scheduled PUSCH resource and the TA value indicated in the cell switching command (CSC).

[0118] In this embodiment, the terminal detects or measures the reference signal corresponding to the beam indication information carried in the first message; the terminal determines a downlink receive beam based on the beam indication information carried in the first message and receives downlink data; the terminal determines a target uplink resource based on the TA information carried in the first message and a first uplink resource, and determines an uplink transmit beam based on the beam indication information carried in the first message, and transmits uplink data based on the uplink transmit beam on the target uplink resource, where the first uplink resource is an uplink resource preconfigured or scheduled by the network. In this way, the terminal can determine the resource location where the terminal actually transmits data based on the TA information carried in the first message and the first uplink resource.

[0119] Optionally, the second condition includes at least one of the following:

[0120] The first message does not carry TA information;

[0121] The first message carries beam indication information;

[0122] The first message does not carry indication information indicating that there is no RACH;

[0123] The first message carries indication information indicating a target object, and the TA of the target object is not configured by the network side device or is not instructed by the network side device to be acquired by the terminal according to the second operation;

[0124] The first message carries indication information indicating a target object, the TA of the target object is configured by a network-side device or is instructed by the network-side device to be acquired by the terminal according to a second operation, and the TA of the target object is invalid;

[0125] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes CFRA resource configuration information;

[0126] The first message carries indication information of RACH resources.

[0127] The TA of the target object may be considered invalid if the TA of the target object meets the following conditions:

[0128] TA timer times out;

[0129] The TA value exceeds the preset threshold;

[0130] The terminal does not update the TA value within a preset time.

[0131] In one implementation, when the first message carries indication information of RACH resources, the value of the preamble index is non-zero.

[0132] The fact that the first message does not carry indication information indicating that there is no RACH may include: the first message does not carry indication information indicating LTeRach-less-like, such as TA=0 or a TAG id of a source object.

[0133] The first message carries indication information of RACH resources, and the indication information of RACH resources may include at least one of the following: an identity of a target object; a reference signal index; a preamble index; and a preamble mask index.

[0134] The second operation may include: obtaining the TA of the terminal at the target object based on at least one of the downlink reception time difference of the terminal at the source object and the target object, the timing difference between the source object and the target object, and the TA indication information sent by the source object. For example, the second operation may be a UE-based TA measurement operation, and the second operation may include: obtaining the TA value of the terminal at the target object based on at least one of the reception time difference of the terminal at the source object (e.g., source cell) and the target object (e.g., target cell), the timing difference between the source object (e.g., source cell) and the target object (e.g., target cell), and the TA command (command) MAC CE sent by the source object (e.g., source cell). In the case of the timing difference between the source object (e.g., source cell) and the target object (e.g., target cell), the timing difference may be determined based on the absolute TAC sent by the network side after the terminal sends a PRACH to the source object (e.g., source cell) and the target object (e.g., target cell), respectively.

[0135] In this implementation, the terminal can perform CFRA-based cell switching based on the second condition satisfied by the first message for triggering cell switching, thereby improving the flexibility of the terminal in performing cell switching.

[0136] Optionally, the RACH resource indication information includes at least one of the following:

[0137] Target object identification; reference signal index; preamble index; preamble mask index.

[0138] The reference signal index may be an RS identifier.

[0139] Optionally, the method further comprises at least one of the following:

[0140] The terminal determines a target RACH resource according to the beam indication information carried in the first message, sends a preamble on the target RACH resource, and after the RACH process ends, determines an uplink beam or a downlink beam for data transmission according to the beam indication information carried in the first message;

[0141] The terminal performs a RACH process based on the CFRA resources included in the pre-configuration information corresponding to the target object indicated by the first message. If the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission.

[0142] In one embodiment, determining the uplink beam or downlink beam used for data transmission based on the beam indication information carried in the first message may include: determining the uplink beam used for data transmission based on the beam indication information carried in the first message; or, determining the downlink beam used for data transmission based on the beam indication information carried in the first message; or, determining the uplink beam and downlink beam used for data transmission based on the beam indication information carried in the first message.

[0143] It should be noted that the terminal determines the target RACH resource based on the beam indication information carried in the first message, and sends a preamble code on the target RACH resource. After the RACH process is completed, the terminal determines the uplink beam or downlink beam used for data transmission based on the beam indication information carried in the first message. The operation can be performed during the terminal's CFRA-based cell switching process, or can be performed after the terminal performs CFRA-based cell switching and before the terminal receives a command sent by the network side to update the beam indication information. This embodiment does not limit this.

[0144] When the terminal performs the RACH process based on the CFRA resources contained in the pre-configuration information corresponding to the target object indicated by the first message during the cell switching process based on CFRA, the terminal does not use the beam corresponding to the beam indication information carried by the first message for data transmission.

[0145] In one embodiment, the first message is a cell handover command, and the terminal performs a cell handover based on CFRA, including at least one of the following operations:

[0146] After a second preset time after receiving the cell handover command, the terminal sends a preamble on a target RACH resource determined according to the beam indication information carried in the cell handover command; after the RACH process is completed, the terminal uses the beam indication information carried in the cell handover command to determine the uplink and downlink beams and perform subsequent data transmission and reception;

[0147] After the third preset time after receiving the cell switching command, the terminal executes the RACH process according to the CFRA resources contained in the pre-configuration information corresponding to the target object indicated in the cell switching command, that is, the CFRA process of legacy cell switching is used. During the RACH process, the terminal needs to perform beam measurement and selection; in this case, if the cell switching command carries beam indication information, the terminal does not use the uplink and downlink beams corresponding to the beam indication information to send and receive data.

[0148] It should be noted that in rach-based handover, which performs a RACH process based on the CFRA resources included in the pre-configured information corresponding to the target object, the terminal actually performs a beam measurement and selection during the RACH process. Assuming that the beam selected during the RACH process is different from the beam indicated in the cell handover command, for example, when the terminal moves, a new beam is selected based on the RACH process, and the real-time performance of the new beam is better than that of the beam indicated in the cell handover command. After the RACH process ends (i.e., the handover is completed), if the terminal uses the beam information indicated in the cell handover command, data reception performance may be greatly reduced, or even unable to receive data correctly.

[0149] In an embodiment of the present application, the terminal performs a RACH process based on the CFRA resources contained in the pre-configuration information corresponding to the target object indicated by the first message. If the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission, but uses the new beam selected in the RACH process for data transmission, which can increase the probability of the terminal successfully transmitting data.

[0150] Optionally, the third condition includes at least one of the following:

[0151] The first message does not carry TA information;

[0152] The first message does not carry indication information indicating that there is no RACH;

[0153] The first message carries indication information indicating a target object, and the TA of the target object is not configured by the network side device or is not instructed by the network side device to be acquired by the terminal according to the second operation;

[0154] The first message carries indication information indicating a target object, the TA of the target object is configured by a network-side device or is instructed by the network-side device to be acquired by the terminal according to a second operation, and the TA of the target object is invalid;

[0155] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object does not include CFRA resource configuration information;

[0156] The first message does not carry indication information of RACH resources;

[0157] The first message carries indication information of RACH resources, wherein the indication information of the RACH resources does not include a preamble index or the preamble index value is 0;

[0158] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes common RACH resource configuration information.

[0159] The fact that the first message does not carry indication information indicating no RACH may include: the first message does not carry indication information indicating LTE RACH-less like, such as TA=0 or a TAG id of a source object.

[0160] The second operation may include: obtaining the TA of the terminal at the target object based on at least one of the downlink reception time difference of the terminal at the source object and the target object, the timing difference between the source object and the target object, and the TA indication information sent by the source object. For example, the second operation may be a UE-based TA measurement operation, and the second operation may include: obtaining the TA value of the terminal at the target object based on at least one of the reception time difference of the terminal at the source object (e.g., source cell) and the target object (e.g., target cell), the timing difference between the source object (e.g., source cell) and the target object (e.g., target cell), and the TA command (command) MAC CE sent by the source object (e.g., source cell). In the case of the timing difference between the source object (e.g., source cell) and the target object (e.g., target cell), the timing difference may be determined based on the absolute TAC sent by the network side after the terminal sends a PRACH to the source object (e.g., source cell) and the target object (e.g., target cell), respectively.

[0161] The TA of the target object may be considered invalid if the TA of the target object meets the following conditions:

[0162] TA timer times out;

[0163] The TA value exceeds the preset threshold;

[0164] The terminal does not update the TA value within a preset time.

[0165] The first message carries indication information of RACH resources, and the indication information of RACH resources may include at least one of the following: an identity of a target object; a reference signal index; a preamble index; and a preamble mask index.

[0166] In this implementation, the terminal can perform CBRA-based cell switching based on the third condition satisfied by the first message for triggering cell switching, thereby improving the flexibility of the terminal in performing cell switching.

[0167] Optionally, the second operation includes:

[0168] The TA of the terminal under the target object is obtained according to at least one of the downlink reception time difference of the terminal under the source object and the target object, the timing difference between the source object and the target object, and the TA indication information sent by the source object.

[0169] Optionally, the method further comprises at least one of the following:

[0170] The terminal determines the target RACH resource and performs the RACH process according to at least one of the common RACH resource configuration information contained in the pre-configuration information corresponding to the target object indicated by the first message and the RACH resource indication information carried by the first message;

[0171] In which, when the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission.

[0172] It should be noted that the terminal determines the target RACH resource and performs the RACH process according to at least one of the common RACH resource configuration information included in the pre-configuration information corresponding to the target object indicated by the first message and the RACH resource indication information carried by the first message.

[0173] It should be noted that, during the terminal executing the RACH process, the terminal does not use the beam corresponding to the beam indication information carried by the first message for data transmission; or, after the terminal executes the RACH process, the terminal does not use the beam corresponding to the beam indication information carried by the first message for data transmission.

[0174] In one embodiment, the first message is a cell switching command, and the terminal performs a cell switching based on CBRA, including: after a fourth preset time after receiving the cell switching command, the terminal performs a RACH process, i.e., a CBRA process, according to the public RACH resources contained in the pre-configuration information corresponding to the target object indicated in the cell switching command. During the CBRA process, the terminal needs to perform beam measurement and selection; if the cell switching command carries beam indication information, the terminal does not use the uplink and downlink beams corresponding to the beam indication information to send and receive data.

[0175] It should be noted that for rach-based handover (especially CBRA-based cell handover), the terminal actually performs beam measurement and selection during the RACH process. If the beam selected during the RACH process is different from the beam indicated in the cell handover command, for example, when the terminal moves, a new beam is selected based on the RACH process. The real-time performance of the new beam is better than that of the beam indicated in the cell handover command. After the RACH process ends (i.e., the handover is complete), if the terminal uses the beam information indicated in the cell handover command, data reception performance may be significantly degraded, or even unable to receive data correctly.

[0176] In an embodiment of the present application, when the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission, but uses the new beam selected in the RACH process for data transmission, which can increase the probability of the terminal successfully transmitting data.

[0177] Optionally, when the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission, including:

[0178] The terminal does not detect or measure the reference signal corresponding to the beam indication information.

[0179] It should be noted that the reference signal corresponding to the beam indication information is at least one of SSB, CSI-RS for tracking, CSI-RS for beam management, and path loss reference signal.

[0180] Referring to FIG. 4 , FIG. 4 is a flow chart of a cell switching method provided in an embodiment of the present application. As shown in FIG. 4 , the cell switching method includes the following steps:

[0181] Step 201: A network-side device sends a first message to a terminal, where the first message is used to instruct the terminal to perform a first operation.

[0182] The first message is used to instruct the execution of the first operation, including any one of the following:

[0183] When the first message satisfies a first condition, the first message is used to instruct execution of a cell handover without RACH, and the first condition is a condition corresponding to the cell handover without RACH;

[0184] When the first message satisfies a second condition, the first message is used to instruct execution of cell switching based on non-contention random access (CFRA), and the second condition is a condition corresponding to cell switching based on CFRA;

[0185] In a case where the first message satisfies a third condition, the first message is used to instruct execution of a cell handover based on contention-based random access (CBRA), and the third condition is a condition corresponding to the cell handover based on CBRA.

[0186] Optionally, when the first message meets the fourth condition, the first message carries beam indication information;

[0187] The fourth condition includes at least one of the following:

[0188] The first message carries TA information;

[0189] The first message carries indication information indicating that there is no RACH;

[0190] The first message carries indication information indicating a target object, and the TA of the target object is configured by a network-side device or is instructed by the network-side device to be acquired by the terminal according to a second operation;

[0191] Optionally, the first message carries indication information of RACH resources;

[0192] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes CFRA resource configuration information.

[0193] In one implementation, when the first message carries indication information of RACH resources, the value of the preamble index is non-zero.

[0194] In one embodiment, the first message is a cell switching command, and the network side device sends a cell switching command to the terminal. When the fourth condition is met, the cell switching hit carries beam indication information.

[0195] In the related art, LTM supports two switching modes: rach-based and rach-less. The network triggers the terminal to perform cell switching by sending a cell switching command carried by MAC CE. The cell switching command may include information such as the target object configuration index. For example, for rach-based switching (especially CBRA), the terminal actually performs a beam measurement and selection during the RACH process. Assuming that the beam selected during the RACH process is different from the beam indicated in the cell switching command, such as when the terminal moves, a new beam is selected based on the RACH process. The real-time performance of the new beam is better than the real-time performance of the beam indicated in the cell switching command. After the RACH process ends (that is, the switching is completed), if the terminal uses the beam information indicated in the cell switching command, the data reception performance may be greatly reduced, or even the data may not be received correctly. The embodiment of the present application is designed to clarify the content carried in the cell switching command on the network side in different cell switching scenarios, and the terminal performs the corresponding behavior after receiving the corresponding cell switching command, which can improve the success rate of the terminal in cell switching and the reliability of data transmission after cell switching.

[0196] The cell switching method provided in the embodiment of the present application is described below through several specific embodiments:

[0197] Example 1:

[0198] This embodiment is used for rach-less based handover, that is, rach-less based cell handover.

[0199] Step (11): The network side sends a cell handover command, wherein the cell handover command includes: a target object identifier, beam indication information, and first indication information; the first indication information is at least one of the following: the TA value of the terminal under the target object (including TA=0); the TAG id of the source object;

[0200] When the following conditions are met, the indication field corresponding to the first indication information may be ignored or defaulted:

[0201] The TA of the target object indicated in the cell handover command is configured by the network or instructed by the terminal to be obtained according to a second operation (e.g., UE-based TA measurement). Optionally, the TA of the target object is valid; the second operation is that the terminal determines the TA value of the terminal under the target object according to at least one of the reception time difference of the terminal under the source object (e.g., source cell) and the target object (e.g., target cell), the timing difference between the source object (e.g., source cell) and the target object (e.g., target cell), and the TA command (command) MAC CE sent by the source object (e.g., source cell). In the case of a timing difference between the source object (e.g., source cell) and the target object (e.g., target cell), the timing difference can be determined based on the absolute TAC sent by the network side after the terminal sends PRACH to the source object (e.g., source cell) and the target object (e.g., target cell), respectively.

[0202] Step (12): The terminal receives a cell switching command, and after a first preset time after receiving the cell switching command, uses the beam indication information carried in the cell switching command to determine the downlink receiving beam and receives downlink data, uses the TA-related information indicated in the cell switching command and the first uplink resource to determine the target uplink resource, and uses the beam indication information carried in the cell switching command to determine the uplink transmitting beam and transmits uplink data on the target uplink resource, wherein the first uplink resource is an uplink resource pre-configured or scheduled by the network. The first preset time is specified by the network configuration or protocol, and includes but is not limited to at least one of the following: beam effective time, radio frequency (RF) retuning time, and cell switching time (for example, target object RRC configuration effective time).

[0203] Example 2:

[0204] This embodiment is used for CFRA-based handover, that is, cell handover based on CFRA.

[0205] Step (21): The network side sends a cell switching command, which includes:

[0206] Case-1: Target object identification and beam indication information;

[0207] Case-2: Target object identifier, SSB index or CSI reference signal (CSI-RS) resource identifier (resource ID), Preamble index, Preamble Mask index;

[0208] Case-3: Target object identification.

[0209] Step (22): The terminal receives the cell handover command and performs the corresponding first operation (case-1 in step (21) corresponds to case1-1 and case1-2 below, and the other cases correspond one to one):

[0210] Case 1-1: The terminal side determines the target RACH resource based on the source reference signal (reference signal associated with the downlink beam) corresponding to the beam indication information and the CFRA resource configuration of the associated target object, and sends a preamble for the first time on the target RACH resource. The preamble is configured by the network side. After sending the preamble, the RAR is detected within the RAR window. If the RAR is detected, the RACH process ends. Otherwise, the terminal side retransmits PRACH until the number of PRACH transmissions reaches the maximum number configured by the network side. Regardless of whether PRACH is transmitted for the first time or PRACH is retransmitted, the RS associated with the target RACH resource on the terminal side remains unchanged, that is, the associated downlink beam remains unchanged. After the RACH process ends, the terminal uses the beam indication information carried in the cell switching command to determine the uplink and downlink beams and perform subsequent data transmission and reception;

[0211] Case 1-2: The terminal side determines the target RACH resource based on the source reference signal (reference signal associated with the downlink beam) corresponding to the beam indication information and the CFRA resource configuration of the associated target object, and sends the target preamble for the first time on the target RACH resource. The target preamble is configured by the network side. After sending the Preamble, the RAR is detected within the RAR window. If the RACH process is detected, the RACH process ends; otherwise, the terminal side reselects the RS or resource for PRACH retransmission until the number of PRACH transmissions reaches the maximum number configured by the network side. Among them, the RS, RACH resources corresponding to the PRACH retransmission may be different in PRACH and Preamble from the first PRACH transmission. During the entire RACH process and after the RACH is successful, the terminal does not use the beam indication information carried in the cell switching command to determine the uplink and downlink beams for subsequent data transmission and reception.

[0212] When the cell switching command includes the target object identifier and beam indication information, and the pre-configuration information corresponding to the target object includes CFRA resource configuration information, the terminal executes Case 1-1 or Case 1-2 in this embodiment.

[0213] Case-2: The terminal determines the target RACH resource according to the SSB index or CSI-RS resource ID carried in the cell handover command and the RACH resource configuration of the associated target object, and sends a target preamble on the target RACH resource, where the target preamble is determined by the Preamble index indication carried in the cell handover command; before the third operation, the terminal determines the uplink and downlink beams according to the SSB index or CSI-RS resource ID carried in the cell handover command and performs subsequent data transmission and reception; the third operation includes at least one of the following:

[0214] The terminal receives the beam-related configuration information corresponding to the target object, or the beam-related configuration information corresponding to the target object takes effect; optionally, the beam-related configuration information corresponding to the target object includes only one beam information, namely TCI state or TCI-UL-State.

[0215] The terminal receives a command for activating the TCI state and / or TCI-UL-State of the associated target object, or the TCI state and / or TCI-UL-State of the associated target object is activated;

[0216] The terminal receives a command for indicating a TCI state and / or TCI-UL-State of an associated target object, or the TCI state and / or TCI-UL-State of the associated target object takes effect.

[0217] When the cell switching command includes a target object identifier, an SSB index or a CSI-RS resource Id, a Preamble index, and a Preamble Mask index, and the pre-configuration information corresponding to the target object includes CFRA resource configuration information, the terminal executes Case-2 in this embodiment.

[0218] Case-3: The terminal side performs beam measurement and selection based on the CFRA resource configuration information of the associated target object, selects a CSI-RS or SSB with a measurement value greater than a certain threshold, determines the target RACH resource based on the selected CSI-RS or SSB, and performs the first PRACH transmission on the target RACH resource. After sending the Preamble, the RAR is detected within the RAR window. If the RACH process is detected, the RACH process ends; otherwise, the terminal side reselects the RS or RACH resource for PRACH retransmission until the number of PRACH transmissions reaches the maximum number configured on the network side. After the RACH is successful, before the fourth operation, the terminal performs subsequent data transmission and reception according to the uplink and downlink beams determined in the RACH process. The fourth operation includes at least one of the following:

[0219] The terminal receives the beam-related configuration information corresponding to the target object, or the beam-related configuration information corresponding to the target object takes effect; optionally, the beam-related configuration information corresponding to the target object includes only one beam information, namely TCI state or TCI-UL-State.

[0220] The terminal receives a command for activating the TCI state and / or TCI-UL-State of the associated target object, or the TCI state and / or TCI-UL-State of the associated target object is activated;

[0221] The terminal receives a command for indicating a TCI state and / or TCI-UL-State of an associated target object, or the TCI state and / or TCI-UL-State of the associated target object takes effect.

[0222] In a case where the cell handover command includes a target object identifier and the pre-configuration information corresponding to the target object includes CFRA resource configuration information, the terminal executes Case-3 in this embodiment.

[0223] Example 3:

[0224] This embodiment is used for CBRA-based handover, that is, cell handover based on CBRA.

[0225] Step (31): The network side sends a cell switching command, which includes:

[0226] Case-1: Target object identification and beam indication information;

[0227] Case-2: Target object identification.

[0228] Step (32): The terminal receives the cell handover command and performs the corresponding first operation (case-1 in step (31) corresponds to case 1-1 and case 1-2 of this embodiment, and the other cases correspond one to one):

[0229] Case 1-1: The terminal determines the target RACH resource based on the source reference signal (reference signal associated with the downlink beam) corresponding to the beam indication information and the RACH common resource configuration of the associated target object, and sends the target preamble code for the first time on the target RACH resource. The target preamble code is configured by the network side; after sending the Preamble, the RAR is detected within the RAR window. If the RACH process is detected, the RACH process ends; otherwise, the terminal side reselects the RS or RACH resource for PRACH retransmission until the number of PRACH transmissions reaches the maximum number configured by the network side. Regardless of whether the PRACH is transmitted for the first time or the PRACH is retransmitted, the RS associated with the target RACH resource remains unchanged, that is, the downlink beam remains unchanged. After the RACH process ends, the terminal uses the beam indication information carried in the cell switching command to determine the uplink and downlink beams and perform subsequent data transmission and reception;

[0230] Case 1-2: The terminal determines the target RACH resource based on the source reference signal (reference signal associated with the downlink beam) corresponding to the beam indication information and the RACH common resource configuration of the associated target object, and sends the target preamble code for the first time on the target RACH resource. The target preamble code is configured by the network side. After sending the preamble, the RAR is detected within the RAR window. If the RAR is detected, the RACH process ends; otherwise, the terminal reselects the RS or RACH resource for PRACH retransmission until the number of PRACH transmissions reaches the maximum number configured by the network side. During the PRACH retransmission process and after the RACH is successful, the terminal does not use the beam indication information carried in the cell handover command to determine the uplink and downlink beams for subsequent data transmission and reception.

[0231] When the cell handover command includes the target object identifier and beam indication information, and the pre-configuration information corresponding to the target object includes CBRA resource configuration information, the terminal executes Case 1-1 or Case 1-2 in this embodiment.

[0232] Case-2: The terminal performs beam measurement and selection based on the RACH public resource configuration information of the associated target object, selects a CSI-RS or SSB with a measurement value greater than a certain threshold, determines the target RACH resource based on the selected CSI-RS or SSB, and performs the first PRACH transmission on the target RACH resource. After sending the Preamble, the RAR is detected within the RAR window. If the RACH process is detected, the RACH process ends; otherwise, the terminal reselects the RS or RACH resource for PRACH retransmission until the number of PRACH transmissions reaches the maximum number configured on the network side. After the RACH is successful, before the fifth operation, the terminal performs subsequent data transmission and reception according to the uplink and downlink beams determined in the RACH process. The fifth operation includes at least one of the following:

[0233] The terminal receives the beam-related configuration information corresponding to the target object, or the beam-related configuration information corresponding to the target object takes effect; optionally, the beam-related configuration information corresponding to the target object includes only one beam information, namely TCI state or TCI-UL-State.

[0234] The terminal receives a command for activating the TCI state and / or TCI-UL-State of the associated target object, or the TCI state and / or TCI-UL-State of the associated target object is activated;

[0235] The terminal receives a command for indicating a TCI state and / or TCI-UL-State of an associated target object, or the TCI state and / or TCI-UL-State of the associated target object takes effect.

[0236] In a case where the cell handover command includes a target object identifier and the pre-configuration information corresponding to the target object includes CBRA resource configuration information, the terminal executes Case-2 in this embodiment.

[0237] It should be noted that for high-speed mobile scenarios, in order to reduce switching delay, Release 18 introduced L1 / L2-based cell switching (LTM for short). In the related technology, LTM supports two switching modes: rach-based and rach-less. The network triggers the terminal to perform cell switching by sending a cell switching command with MAC CE as the carrier. The cell switching command may include the target cell configuration index, TA indication information, beam indication information, etc. However, whether the above content always appears in the cell switching command, how the cell switching command instructs the terminal to perform rach-less or rach-based switching, and whether the terminal uses the beam indicated in the cell switching command to send and receive data after rach-based switching has not yet been discussed and resolved.

[0238] An embodiment of the present application implements a cell handover indication method to ensure that the terminal can perform a correct cell handover operation after receiving a cell handover command. For example, when the UE receives a cell handover command and executes CBRA, after completing the handover, the UE does not send or receive data or signals according to the TCI state indicated in the handover command; when the UE receives a cell handover command and executes CBRA, the UE does not expect the cell handover command to carry the TCI state id. When the cell handover command does not carry TA indication information, and the terminal receives indication information that meets the following conditions, the terminal executes CFRA; otherwise, it executes CBRA; the condition includes: the cell handover hit carries the TCI state id; or the condition includes: the pre-configuration information of the target object contains CFRA configuration information.

[0239] It should be noted that this embodiment is an implementation of the network side device corresponding to the embodiment shown in Figure 3. Its specific implementation can refer to the relevant description of the embodiment shown in Figure 3. To avoid repetition, this embodiment will not be repeated.

[0240] The cell switching method provided in the embodiment of the present application can be executed by a cell switching device. In the embodiment of the present application, the cell switching device executing the cell switching method is taken as an example to illustrate the cell switching device provided in the embodiment of the present application.

[0241] Please refer to FIG5 , which is a structural diagram of a cell switching device provided in an embodiment of the present application. A terminal includes the cell switching device. As shown in FIG5 , the cell switching device 300 includes:

[0242] A receiving module 301 is configured to receive a first message sent by a network-side device, where the first message is used to trigger a cell handover;

[0243] Executing operation 302 for performing a first operation based on the first message;

[0244] The performing of the first operation includes any one of the following:

[0245] If the first message satisfies a first condition, performing a cell handover without a random access channel (RACH), where the first condition is a condition corresponding to a cell handover without a RACH;

[0246] If the first message satisfies a second condition, performing cell switching based on non-contention random access (CFRA), where the second condition is a condition corresponding to cell switching based on CFRA;

[0247] In a case where the first message satisfies a third condition, a cell handover of contention-based random access (CBRA) is performed, where the third condition is a condition corresponding to the cell handover of CBRA.

[0248] Optionally, the first condition includes at least one of the following:

[0249] The first message carries timing advance TA information;

[0250] The first message carries beam indication information;

[0251] The first message carries indication information indicating that there is no RACH;

[0252] The first message carries indication information indicating a target object, and the TA of the target object is configured by a network-side device or is instructed by the network-side device to be acquired by the terminal according to a second operation.

[0253] Optionally, the first condition also includes: the TA of the target object is valid.

[0254] Optionally, the device further includes a first processing module, wherein the first processing module is configured to perform at least one of the following:

[0255] Detecting or measuring a reference signal corresponding to the beam indication information carried in the first message;

[0256] Determine a downlink receive beam based on the beam indication information carried in the first message and receive downlink data;

[0257] The target uplink resource is determined based on the TA information and the first uplink resource carried by the first message, and the uplink transmission beam is determined based on the beam indication information carried in the first message. Uplink data is sent based on the uplink transmission beam in the target uplink resource. The first uplink resource is an uplink resource pre-configured or scheduled by the network.

[0258] Optionally, the second condition includes at least one of the following:

[0259] The first message does not carry TA information;

[0260] The first message carries beam indication information;

[0261] The first message does not carry indication information indicating that there is no RACH;

[0262] The first message carries indication information indicating a target object, and the TA of the target object is not configured by the network side device or is not instructed by the network side device to be acquired by the terminal according to the second operation;

[0263] The first message carries indication information indicating a target object, the TA of the target object is configured by a network-side device or is instructed by the network-side device to be acquired by the terminal according to a second operation, and the TA of the target object is invalid;

[0264] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes CFRA resource configuration information;

[0265] The first message carries indication information of RACH resources.

[0266] Optionally, the RACH resource indication information includes at least one of the following:

[0267] Target object identification; reference signal index; preamble index; preamble mask index.

[0268] Optionally, the device further includes a second processing module, wherein the second processing module is configured to perform at least one of the following:

[0269] Determining a target RACH resource according to the beam indication information carried in the first message, sending a preamble on the target RACH resource, and after the RACH process ends, determining an uplink beam or a downlink beam for data transmission according to the beam indication information carried in the first message;

[0270] The RACH process is performed based on the CFRA resources included in the pre-configuration information corresponding to the target object indicated by the first message. If the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission.

[0271] Optionally, the third condition includes at least one of the following:

[0272] The first message does not carry TA information;

[0273] The first message does not carry indication information indicating that there is no RACH;

[0274] The first message carries indication information indicating a target object, and the TA of the target object is not configured by the network side device or is not instructed by the network side device to be acquired by the terminal according to the second operation;

[0275] The first message carries indication information indicating a target object, the TA of the target object is configured by a network-side device or is instructed by the network-side device to be acquired by the terminal according to a second operation, and the TA of the target object is invalid;

[0276] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object does not include CFRA resource configuration information;

[0277] The first message does not carry indication information of RACH resources;

[0278] The first message carries indication information of RACH resources, wherein the indication information of the RACH resources does not include a preamble index or the preamble index value is 0;

[0279] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes common RACH resource configuration information.

[0280] Optionally, the second operation includes:

[0281] The TA of the terminal under the target object is obtained according to at least one of the downlink reception time difference of the terminal under the source object and the target object, the TA indication information sent by the source object, and the timing difference between the source object and the target object.

[0282] Optionally, the device further includes a third processing module, wherein the third processing module is configured to perform at least one of the following:

[0283] Determine a target RACH resource and perform a RACH process according to at least one of the common RACH resource configuration information contained in the pre-configuration information corresponding to the target object indicated by the first message and the RACH resource indication information carried by the first message;

[0284] In which, when the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission.

[0285] Optionally, when the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission, including:

[0286] The terminal does not detect or measure the reference signal corresponding to the beam indication information. The cell switching device in the embodiment of the present application can be an electronic device, such as an electronic device with an operating system, or a component in an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other device other than a terminal. For example, the terminal can include but is not limited to the types of terminals 11 listed above, and other devices can be servers, network attached storage (NAS), etc., which are not specifically limited in the embodiment of the present application.

[0287] The cell switching device provided in the embodiment of the present application can implement each process implemented in the method embodiment of Figure 3 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0288] Please refer to FIG6 , which is a structural diagram of a cell switching device provided in an embodiment of the present application. The network-side device includes the cell switching device. As shown in FIG6 , the cell switching device 400 includes:

[0289] A sending module 401 is configured to send a first message to a terminal, where the first message is used to instruct execution of a first operation;

[0290] The first message is used to instruct the execution of the first operation, including any one of the following:

[0291] When the first message satisfies a first condition, the first message is used to instruct execution of a cell handover without RACH, and the first condition is a condition corresponding to the cell handover without RACH;

[0292] When the first message satisfies a second condition, the first message is used to instruct execution of cell switching based on non-contention random access (CFRA), and the second condition is a condition corresponding to cell switching based on CFRA;

[0293] In a case where the first message satisfies a third condition, the first message is used to instruct execution of a cell handover based on contention-based random access (CBRA), and the third condition is a condition corresponding to the cell handover based on CBRA.

[0294] Optionally, when the first message meets the fourth condition, the first message carries beam indication information;

[0295] The fourth condition includes at least one of the following:

[0296] The first message carries TA information;

[0297] The first message carries indication information indicating that there is no RACH;

[0298] The first message carries indication information indicating a target object, and the TA of the target object is configured by a network-side device or is instructed by the network-side device to be acquired by the terminal according to a second operation;

[0299] Optionally, the first message carries indication information of RACH resources;

[0300] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes CFRA resource configuration information.

[0301] The cell switching device in the embodiments of the present application can be an electronic device, such as an electronic device with an operating system, or a component of an electronic device, such as an integrated circuit or chip. The electronic device can be a terminal, or it can be other devices other than a terminal. For example, the terminal can include but is not limited to the types of terminal 11 listed above, and other devices can be servers, network attached storage (NAS), etc., which are not specifically limited in the embodiments of the present application.

[0302] The cell switching device provided in the embodiment of the present application can implement the various processes implemented in the method embodiment of Figure 4 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0303] Optionally, as shown in FIG7 , an embodiment of the present application further provides a communication device 500, comprising a processor 501 and a memory 502, wherein the memory 502 stores a program or instruction that can be run on the processor 501. For example, when the communication device 500 is a terminal, the program or instruction is executed by the processor 501 to implement the various steps of the cell switching method embodiment applied to the terminal, and can achieve the same technical effect. To avoid repetition, it is not described here. When the communication device 500 is a network side device, the program or instruction is executed by the processor 501 to implement the various steps of the cell switching method embodiment applied to the network side device, and can achieve the same technical effect. To avoid repetition, it is not described here.

[0304] The present application also provides a terminal including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to execute a program or instruction to implement the steps in the method embodiment shown in FIG3 . This terminal embodiment corresponds to the above-mentioned terminal-side method embodiment, and each implementation process and implementation method of the above-mentioned method embodiment are applicable to this terminal embodiment and can achieve the same technical effects.

[0305] Specifically, FIG8 is a schematic diagram of the hardware structure of a terminal implementing an embodiment of the present application.

[0306] The terminal 600 includes but is not limited to: a radio frequency unit 601, a network module 602, an audio output unit 603, an input unit 604, a sensor 605, a display unit 606, a user input unit 607, an interface unit 608, a memory 609 and at least some of the components of the processor 610.

[0307] Those skilled in the art will appreciate that the terminal 600 may also include a power supply (such as a battery) to power various components. The power supply may be logically connected to the processor 610 via a power management system, thereby enabling the power management system to manage charging, discharging, and power consumption. The terminal structure shown in FIG8 does not limit the terminal. The terminal may include more or fewer components than shown, or combine certain components, or arrange the components differently, which will not be described in detail here.

[0308] It should be understood that in an embodiment of the present application, the input unit 604 may include a graphics processing unit (GPU) 6041 and a microphone 6042, and the GPU 6041 processes the image data of a static picture or video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 606 may include a display panel 6061, and the display panel 6061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 607 includes a touch panel 6071 and at least one of other input devices 6072. The touch panel 6071 is also called a touch screen. The touch panel 6071 may include two parts: a touch detection device and a touch controller. Other input devices 6072 may include, but are not limited to, a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, and an operating stick, which will not be repeated here.

[0309] In the embodiment of the present application, after receiving downlink data from a network-side device, the radio frequency unit 601 may transmit the data to the processor 610 for processing. Furthermore, the radio frequency unit 601 may send uplink data to the network-side device. Typically, the radio frequency unit 601 includes, but is not limited to, an antenna, an amplifier, a transceiver, a coupler, a low-noise amplifier, a duplexer, and the like.

[0310] The memory 609 can be used to store software programs or instructions and various data. The memory 609 may mainly include a first storage area for storing programs or instructions and a second storage area for storing data, wherein the first storage area may store an operating system, applications or instructions required for at least one function (such as a sound playback function, an image playback function, etc.). In addition, the memory 609 may include a volatile memory or a non-volatile memory, or the memory 609 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), a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDRSDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synchronous link dynamic random access memory (SLDRAM), and a direct memory bus random access memory (DRRAM). The memory 609 in the embodiment of the present application includes but is not limited to these and any other suitable types of memory.

[0311] Processor 610 may include one or more processing units. Optionally, processor 610 integrates an application processor and a modem processor. The application processor primarily handles operations related to the operating system, user interface, and application programs, while the modem processor primarily processes wireless communication signals, such as a baseband processor. It is understood that the modem processor may not be integrated into processor 610.

[0312] The radio frequency unit 601 is used for:

[0313] receiving a first message sent by a network-side device, where the first message is used to trigger a cell handover;

[0314] The terminal performs a first operation based on the first message;

[0315] The performing of the first operation includes any one of the following:

[0316] If the first message satisfies a first condition, performing a cell handover without a random access channel (RACH), where the first condition is a condition corresponding to a cell handover without a RACH;

[0317] If the first message satisfies a second condition, performing cell switching based on non-contention random access (CFRA), where the second condition is a condition corresponding to cell switching based on CFRA;

[0318] In a case where the first message satisfies a third condition, a cell handover of contention-based random access (CBRA) is performed, where the third condition is a condition corresponding to the cell handover of CBRA.

[0319] Optionally, the first condition includes at least one of the following:

[0320] The first message carries timing advance TA information;

[0321] The first message carries beam indication information;

[0322] The first message carries indication information indicating that there is no RACH;

[0323] The first message carries indication information indicating a target object, and the TA of the target object is configured by a network-side device or is instructed by the network-side device to be acquired by the terminal according to a second operation.

[0324] Optionally, the first condition also includes: the TA of the target object is valid.

[0325] Optionally, the processor 610 is configured to perform at least one of the following:

[0326] The terminal detects or measures a reference signal corresponding to the beam indication information carried in the first message; the terminal determines a downlink receive beam based on the beam indication information carried in the first message and receives downlink data;

[0327] The terminal determines the target uplink resource based on the TA information and the first uplink resource carried by the first message, and determines the uplink transmission beam based on the beam indication information carried in the first message, and sends uplink data based on the uplink transmission beam in the target uplink resource. The first uplink resource is an uplink resource pre-configured or scheduled by the network.

[0328] Optionally, the second condition includes at least one of the following:

[0329] The first message does not carry TA information;

[0330] The first message carries beam indication information;

[0331] The first message does not carry indication information indicating that there is no RACH;

[0332] The first message carries indication information indicating a target object, and the TA of the target object is not configured by the network side device or is not instructed by the network side device to be acquired by the terminal according to the second operation;

[0333] The first message carries indication information indicating a target object, the TA of the target object is configured by a network-side device or is instructed by the network-side device to be acquired by the terminal according to a second operation, and the TA of the target object is invalid;

[0334] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes CFRA resource configuration information;

[0335] The first message carries indication information of RACH resources.

[0336] Optionally, the RACH resource indication information includes at least one of the following:

[0337] Target object identification; reference signal index; preamble index; preamble mask index.

[0338] Optionally, the processor 610 is configured to perform at least one of the following:

[0339] The terminal determines a target RACH resource according to the beam indication information carried in the first message, sends a preamble on the target RACH resource, and after the RACH process ends, determines an uplink beam or a downlink beam for data transmission according to the beam indication information carried in the first message;

[0340] The terminal performs a RACH process based on the CFRA resources included in the pre-configuration information corresponding to the target object indicated by the first message. If the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission.

[0341] Optionally, the third condition includes at least one of the following:

[0342] The first message does not carry TA information;

[0343] The first message does not carry indication information indicating that there is no RACH;

[0344] The first message carries indication information indicating a target object, and the TA of the target object is not configured by the network side device or is not instructed by the network side device to be acquired by the terminal according to the second operation;

[0345] The first message carries indication information indicating a target object, the TA of the target object is configured by a network-side device or is instructed by the network-side device to be acquired by the terminal according to a second operation, and the TA of the target object is invalid;

[0346] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object does not include CFRA resource configuration information;

[0347] The first message does not carry indication information of RACH resources;

[0348] The first message carries indication information of RACH resources, wherein the indication information of the RACH resources does not include a preamble index or the preamble index value is 0;

[0349] The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes common RACH resource configuration information.

[0350] Optionally, the second operation includes:

[0351] The TA of the terminal under the target object is obtained according to at least one of the downlink reception time difference of the terminal under the source object and the target object, the TA indication information sent by the source object, and the timing difference between the source object and the target object.

[0352] Optionally, the processor 610 is configured to perform at least one of the following:

[0353] The terminal determines the target RACH resource and performs the RACH process according to at least one of the common RACH resource configuration information contained in the pre-configuration information corresponding to the target object indicated by the first message and the RACH resource indication information carried by the first message;

[0354] In which, when the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission.

[0355] Optionally, when the first message carries beam indication information, the terminal not using the beam corresponding to the beam indication information for data transmission includes:

[0356] The terminal does not detect or measure a reference signal corresponding to the beam indication information;

[0357] It can be understood that the implementation process of each implementation method mentioned in this embodiment can refer to the relevant description of the method embodiment Figure 6, and achieve the same or corresponding technical effects. To avoid repetition, it will not be repeated here.

[0358] Specifically, the terminal of the embodiment of the present application also includes: instructions or programs stored in the memory 609 and can be run on the processor 610. The processor 610 calls the instructions or programs in the memory 609 to execute the method of execution of each module shown in Figure 5 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0359] The present application also provides a network-side device, including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to execute a program or instruction to implement the steps of the method embodiment shown in FIG3 . This network-side device embodiment corresponds to the above-described method embodiment, and each implementation process and implementation method of the above-described method embodiment are applicable to this network-side device embodiment and can achieve the same technical effects.

[0360] Specifically, an embodiment of the present application further provides a network-side device. The network-side device can be a first node, a second node, or a data providing node. As shown in Figure 9, the network-side device 700 includes: an antenna 701, a radio frequency device 702, a baseband device 703, a processor 704, and a memory 705. The antenna 701 is connected to the radio frequency device 702. In the uplink direction, the radio frequency device 702 receives information through the antenna 701 and sends the received information to the baseband device 703 for processing. In the downlink direction, the baseband device 703 processes the information to be sent and sends it to the radio frequency device 702. The radio frequency device 702 processes the received information and sends it out through the antenna 701.

[0361] The method executed by the network-side device in the above embodiment may be implemented in the baseband device 703 , which includes a baseband processor.

[0362] The baseband device 703 may include, for example, at least one baseband board, on which multiple chips are arranged, as shown in Figure 9, one of which is, for example, a baseband processor, which is connected to the memory 705 through a bus interface to call the program in the memory 705 and execute the network device operations shown in the above method embodiment.

[0363] The network side device may further include a network interface 706 , which is, for example, a Common Public Radio Interface (CPRI).

[0364] Specifically, the network side device 700 of the embodiment of the present application also includes: instructions or programs stored in the memory 705 and can be run on the processor 704. The processor 704 calls the instructions or programs in the memory 705 to execute the method of execution of each module shown in Figure 6 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0365] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the various processes of the above-mentioned cell switching method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0366] The processor is the processor in the terminal described in the above embodiment. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. In some examples, the readable storage medium may be a non-transitory readable storage medium.

[0367] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned cell switching method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0368] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0369] An embodiment of the present application further provides a computer program / program product, which is stored in a storage medium. The computer program / program product is executed by at least one processor to implement the various processes of the above-mentioned cell switching method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0370] An embodiment of the present application also provides a cell switching system, including: a terminal and a network side device, wherein the terminal can be used to execute the steps of the cell switching method applied to the terminal as described above, and the network side device can be used to execute the steps of the cell switching method applied to the network side device as described above.

[0371] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0372] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of a computer software product plus a necessary general-purpose hardware platform, or of course, by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes a number of instructions for enabling a terminal or network-side device to execute the methods described in each embodiment of the present application.

[0373] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms of implementation methods without departing from the purpose of this application and the scope of protection of the claims. These implementation methods are all within the protection of this application.

Claims

1. A cell switching method, comprising: The terminal receives a first message sent by a network side device, where the first message is used to trigger a cell switching; The terminal performs a first operation based on the first message; The performing of the first operation includes any one of the following: When the first message satisfies a first condition, performing a cell handover without a random access channel RACH, the first condition being a condition corresponding to a cell handover without RACH; When the first message satisfies a second condition, performing cell switching based on non-contention random access CFRA, where the second condition is a condition corresponding to cell switching based on CFRA; In the case where the first message satisfies a third condition, a cell switching based on contention-based random access (CBRA) is performed, and the third condition is a condition corresponding to the cell switching based on CBRA.

2. The method according to claim 1, wherein: The first condition includes at least one of the following: The first message carries timing advance TA information; The first message carries beam indication information; The first message carries indication information indicating that there is no RACH; The first message carries indication information indicating a target object, and the TA of the target object is configured by a network side device or is indicated by the network side device to be acquired by the terminal according to a second operation.

3. The method according to claim 2, wherein: The first condition also includes: the TA of the target object is valid.

4. The method according to any one of claims 1 to 3, wherein: The method further comprises at least one of the following: The terminal detects or measures a reference signal corresponding to the beam indication information carried in the first message; The terminal determines a downlink receiving beam based on the beam indication information carried in the first message and receives downlink data; The terminal determines a target uplink resource based on the TA information and the first uplink resource carried by the first message, and determines an uplink transmit beam based on the beam indication information carried in the first message, and sends uplink data based on the uplink transmit beam on the target uplink resource, where the first uplink resource is an uplink resource preconfigured or scheduled by the network.

5. The method according to any one of claims 1 to 4, wherein: The second condition includes at least one of the following: The first message does not carry TA information; The first message carries beam indication information; The first message does not carry indication information indicating that there is no RACH; The first message carries indication information indicating a target object, and the TA of the target object is not configured by the network side device or is not indicated by the network side device to be acquired by the terminal according to the second operation; The first message carries indication information indicating a target object, and the TA of the target object is configured or The terminal is instructed by the network side device to obtain the TA according to the second operation, and the TA of the target object is invalid; The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes CFRA resource configuration information; The first message carries indication information of RACH resources.

6. The method according to claim 5, wherein: The indication information of the RACH resource includes at least one of the following: Target object identification; reference signal index; preamble index; preamble mask index.

7. The method according to any one of claims 1 to 6, wherein: The method further comprises at least one of the following: The terminal determines a target RACH resource according to the beam indication information carried in the first message, sends a preamble on the target RACH resource, and after the RACH process ends, the terminal determines an uplink beam or a downlink beam for data transmission according to the beam indication information carried in the first message; The terminal performs a RACH process based on the CFRA resources included in the pre-configuration information corresponding to the target object indicated by the first message. If the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission.

8. The method according to any one of claims 1 to 7, wherein: The third condition includes at least one of the following: The first message does not carry TA information; The first message does not carry indication information indicating that there is no RACH; The first message carries indication information indicating a target object, and the TA of the target object is not configured by the network side device or is not indicated by the network side device to be acquired by the terminal according to the second operation; The first message carries indication information indicating a target object, the TA of the target object is configured by a network side device or is indicated by the network side device to be acquired by the terminal according to a second operation, and the TA of the target object is invalid; The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object does not include CFRA resource configuration information; The first message does not carry indication information of RACH resources; The first message carries indication information of RACH resources, wherein the indication information of RACH resources does not include a preamble index or the preamble index value is 0; The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes common RACH resource configuration information.

9. The method according to claim 2, 5 or 8, wherein: The second operation includes: The TA of the terminal under the target object is obtained according to at least one of the downlink reception time difference of the terminal under the source object and the target object, the TA indication information sent by the source object, and the timing difference between the source object and the target object.

10. The method according to any one of claims 1 to 9, wherein: The method further comprises at least one of the following: The terminal determines the target RACH resource and performs the RACH process according to at least one of the common RACH resource configuration information contained in the pre-configuration information corresponding to the target object indicated by the first message and the indication information of the RACH resource carried by the first message; In which, when the first message carries beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission.

11. The method according to any one of claims 1 to 10, wherein: When the first message carries the beam indication information, the terminal does not use the beam corresponding to the beam indication information for data transmission, including: The terminal does not detect or measure the reference signal corresponding to the beam indication information.

12. A cell switching method, comprising: The network side device sends a first message to the terminal, where the first message is used to instruct to perform a first operation; The first message is used to indicate that the first operation is to be performed, including any one of the following: In a case where the first message satisfies a first condition, the first message is used to instruct execution of a cell handover without RACH, and the first condition is a condition corresponding to the cell handover without RACH; In a case where the first message satisfies a second condition, the first message is used to instruct execution of a cell switching based on non-contention random access CFRA, and the second condition is a condition corresponding to the cell switching based on CFRA; In the case where the first message satisfies a third condition, the first message is used to instruct execution of a cell switching based on contention-based random access (CBRA), and the third condition is a condition corresponding to the cell switching based on CBRA.

13. The method according to claim 12, wherein: When the first message satisfies the fourth condition, the first message carries beam indication information; The fourth condition includes at least one of the following: The first message carries TA information; The first message carries indication information indicating that there is no RACH; The first message carries indication information indicating a target object, and the TA of the target object is configured by a network side device or is indicated by the network side device to be acquired by the terminal according to a second operation; The first message carries indication information of RACH resources; The first message carries indication information indicating a target object, and the pre-configuration information corresponding to the target object includes CFRA resource configuration information.

14. A cell switching device, wherein a terminal comprises the cell switching device, comprising: A receiving module, used to receive a first message sent by a network side device, where the first message is used to trigger a cell handover; An execution operation is used to execute a first operation based on the first message; The performing of the first operation includes any one of the following: When the first message satisfies a first condition, performing a cell handover without a random access channel RACH, the first condition being a condition corresponding to a cell handover without RACH; When the first message satisfies a second condition, performing cell switching based on non-contention random access CFRA, where the second condition is a condition corresponding to cell switching based on CFRA; In the case where the first message satisfies a third condition, a cell switching based on contention-based random access (CBRA) is performed, and the third condition is a condition corresponding to the cell switching based on CBRA.

15. A cell switching device, wherein a network side device includes the cell switching device, comprising: A sending module, used for sending a first message to a terminal, where the first message is used for instructing to perform a first operation; The first message is used to indicate that the first operation is to be performed, including any one of the following: In a case where the first message satisfies a first condition, the first message is used to instruct execution of a cell handover without RACH, and the first condition is a condition corresponding to the cell handover without RACH; In a case where the first message satisfies a second condition, the first message is used to instruct execution of a cell switching based on non-contention random access CFRA, and the second condition is a condition corresponding to the cell switching based on CFRA; In the case where the first message satisfies a third condition, the first message is used to instruct execution of a cell switching based on contention-based random access (CBRA), and the third condition is a condition corresponding to the cell switching based on CBRA.

16. A terminal comprising a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the cell switching method according to any one of claims 1 to 11 are implemented.

17. A network side device, comprising a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the cell switching method according to any one of claims 12 to 13 are implemented.

18. A chip, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the steps of the cell switching method as described in any one of claims 1 to 11, or to implement the steps of the cell switching method as described in any one of claims 12 to 13.

19. A readable storage medium storing a program or instruction, wherein the program or instruction, when executed by a processor, implements the steps of the cell switching method as described in any one of claims 1 to 11, or implements the steps of the cell switching method as described in any one of claims 12 to 13.

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