WO2025232279A1 - Communication method and apparatus - Google Patents

Abstract

A communication method and apparatus, which are used for improving the communication stability of a terminal device during a handover process. In the present application, the method comprises: a terminal device acquiring first information, the first information being prediction information for indicating that a first abnormal event is predicted to occur in the future between the terminal device and a serving cell; and when it is determined on the basis of the first information that a preset condition is met, the terminal device accessing a first cell before a first time, the first time being a predicted occurrence time of the first abnormal event, wherein the first cell is different from the serving cell.

Description

A communication method and apparatus

Cross-reference to related applications

This application claims priority to Chinese Patent Application No. 202410574520.7, filed on May 9, 2024, entitled "A Communication Method and Apparatus", the entire contents of which are incorporated herein by reference.

Technical Field

This application relates to the field of wireless communication, and more particularly to a communication method and apparatus.

Background Technology

Cell handover (or handover) of terminal devices is controlled by access network equipment. For example, a terminal device accesses cell 1 of the access network equipment. The access network equipment sends a measurement configuration to the terminal device. The terminal device measures the downlink reference signals of multiple cells according to the measurement configuration to obtain measurement results for multiple cells, and sends these measurement results back to the access network equipment. Based on the measurement results of multiple cells, the access network equipment can select cell 2 with better signal quality from among the multiple cells, and then send a handover command message to the terminal device. The handover command message instructs the terminal device to hand over from cell 1 to cell 2. In response to the handover command message, the terminal device hands over from cell 1 to cell 2.

In the above handover process, if the signal quality received by the terminal device from cell 1 deteriorates, causing a radio link failure (RLF) between the terminal device and cell 1, and the terminal device has not received a handover command message from the access network device, then the terminal device needs to initiate a radio resource control (RRC) re-establishment request process to request access to other cells (e.g., cell 3).

This leads to instability in the communication of terminal devices.

Summary of the Invention

This application provides a communication method and apparatus for improving the stability of terminal device communication during the handover process.

Firstly, this application provides a communication method, which can be executed by a first communication device, which may be a terminal device or a module within the terminal device, such as a chip. Further, when the first communication device is a module within the terminal device, the module can send information (e.g., a measurement report) to other modules within the terminal device (e.g., an RF module or an antenna), the measurement report being sent by the terminal device to an access network device; of course, the module can also receive information (e.g., a measurement configuration) from other modules (e.g., an RF module or an antenna), the measurement configuration being sent by the access network device to the terminal device. For ease of description, the following explanation uses the terminal device as an example.

The method includes: a terminal device acquiring first information, which is prediction information (or inference information) used to indicate that a first abnormal event will occur between the terminal device and the serving cell in the future; the terminal device accessing the first cell before a first time when it determines that a preset condition is met based on the first information, where the first time is the predicted occurrence time of the first abnormal event; wherein, the first cell is different from the serving cell.

In the above technical solution, the terminal device obtains prediction information about the first abnormal event that will occur between the terminal device and the serving cell in the future, and connects to the first cell in advance based on this prediction information. This avoids the terminal device failing to connect to the first cell before receiving the handover command message (or conditional handover (CHO) configuration information) before the RLF occurs between the terminal device and the serving cell. This helps improve the stability of terminal device communication.

In one possible implementation, when the terminal device accesses the first cell, it may specifically send a measurement report to the first access network device, the measurement report including signal quality information of multiple second cells, of which the first cell is included, and the first access network device is associated with the serving cell; the terminal device receives configuration information of the first cell from the first access network device; and the terminal device switches to the first cell according to the configuration information of the first cell.

In the above technical solution, the terminal device can trigger the first access network device to send configuration information of the first cell to the terminal device by sending a measurement report to the first access network device. Thus, the terminal device can switch to the first cell before an RLF occurs with the serving cell.

In one possible implementation, the measurement report also includes prediction information of second abnormal events occurring when multiple second cells are used as target cells for terminal equipment handover. In one possible implementation, the second abnormal event (or type of second abnormal event) includes one or more of the following: handover failure, RLF, ping-pong handover, unnecessary handover, handover too late, or handover too early.

In the above technical solution, when the first access network device selects a target cell/candidate cell for the terminal device, it considers the prediction information of a second abnormal event that might occur when the second cell is used as the target cell for handover of the terminal device. This helps to ensure the stability of terminal device communication.

In one possible implementation, the measurement report also includes initial information.

In the above technical solution, the first access network device can determine the reason why the terminal device sends the measurement report based on the first information in the measurement report, and then quickly select a suitable target cell/candidate cell for the terminal device.

In one possible implementation, when the terminal device accesses the first cell, it may specifically send second information to the second access network device. The second information indicates access to the first cell (or, the second information indicates access to the first cell via RRC re-establishment). The first cell is determined by measuring the signals of multiple third cells, including the first cell. The second access network device is associated with the first cell. The second information may be, for example, an RRC re-establishment request message.

In the above technical solution, the terminal device can select the first cell and initiate an RRC re-establishment process to the second access network device associated with the first cell. Thus, the terminal device can access the first cell before an RLF occurs with the serving cell.

In one possible implementation, before accessing the first cell, the terminal device also receives third information (e.g., CHO configuration information) from the first access network device. This third information indicates the configuration information of multiple fourth cells, and the first access network device is associated with the serving cell. Specifically, when accessing the first cell, the terminal device may determine the first cell from among the multiple fourth cells by measuring the signals from the multiple fourth cells; and then switch to the first cell based on its configuration information.

In the above technical solution, the terminal device can automatically execute the CHO handover process and select the first cell from multiple fourth cells. Thus, the terminal device can access the first cell before an RLF occurs with the serving cell.

In one possible implementation, when the terminal device determines that a preset condition is met based on the first information, it can specifically determine that the preset condition is met when the first information indicates that a first abnormal event will occur in the future. Alternatively, it can determine that the preset condition is met when the probability of the first abnormal event occurring in the future, as indicated by the first information, is greater than a first threshold. Or, it can determine that the preset condition is met when the probability of the first abnormal event occurring in the future, as indicated by the first information, is greater than the first threshold, and the accuracy of the probability of the first abnormal event occurring in the future is greater than a second threshold.

In one possible implementation, the first exception event includes RLF.

RLF includes one or more of the following: RLF caused by physical layer problem causing timer timeout, RLF caused by timer timeout triggered when radio problem timer runs and triggers measurement reporting, RLF caused by random access procedure failure, RLF caused by radio link control failure, RLF caused by detection of continuous uplink READ failure, or RLF caused by receiving backhaul radio link failure from parent node.

In one possible implementation, when the terminal device acquires the first information, it may specifically receive fourth information from the first access network device, the fourth information indicating at least one measurement item. The terminal device measures the reference signal of the serving cell to obtain measurement results corresponding to each of the at least one measurement item; the terminal device determines the first information based on the measurement results corresponding to each of the at least one measurement item. In one possible implementation, the at least one measurement item includes at least one of: a measurement identifier, a measurement object, a report configuration, or a measurement event.

In the above technical solution, the terminal device can determine at least one measurement item that needs to be measured based on the fourth information, and then determine the first information based on the measurement results corresponding to the at least one measurement item, which helps to improve the accuracy of the terminal device in determining the first information.

Secondly, this application provides a communication method, which can be executed by a second communication device. The second communication device can be an access network device or a module within the access network device, such as a chip. Further, when the second communication device is a module within the access network device, the module can send information (e.g., measurement configuration) to other modules within the access network device (e.g., an RF module or an antenna), the measurement configuration being sent by the access network device to a terminal device; of course, the module can also receive information (e.g., a measurement report) from other modules (e.g., an RF module or an antenna), the measurement report being sent by the terminal device to the access network device. For ease of description, the following explanation uses an access network device as an example.

The method includes: an access network device (or a first access network device) receiving a measurement report, the measurement report including signal quality information of multiple second cells, the measurement report being sent by a terminal device when it determines that a prediction condition is met based on first information, the first information being prediction information used to indicate that a first abnormal event will occur between the terminal device and the serving cell in the future, the access network device being associated with the serving cell; the access network device sending configuration information of the first cell or configuration information corresponding to one or more candidate cells, the first cell being one of multiple second cells, the configuration information of the first cell or the configuration information corresponding to one or more candidate cells being determined based on the measurement report; the configuration information of the first cell being used by the terminal device to access the first cell, and the configuration information corresponding to one or more candidate cells being used by the terminal device to select from one or more candidate cells and access the first cell.

In one possible implementation, when the access network device sends the configuration information of the first cell, it may specifically send fifth information. This fifth information includes the configuration information of the first cell and is used to instruct the terminal device to switch to the first cell based on that configuration information. The fifth information could be, for example, a handover command message, equivalent to an RRC reconfiguration message carrying the `reconfigurationWithSync` field.

Alternatively, when the access network device sends configuration information corresponding to one or more candidate cells, specifically, the access network device sends sixth information. This sixth information includes configuration information corresponding to one or more candidate cells. The sixth information instructs the terminal device to select a first cell from the one or more candidate cells based on the configuration information corresponding to each candidate cell, and then switch to the first cell. The sixth information could be, for example, CHO configuration information, which is carried in the RRC reconfiguration message.

In one possible implementation, the measurement report also includes prediction information of second abnormal events occurring when multiple second cells are used as target cells for terminal equipment handover. In one possible implementation, the second abnormal event includes one or more of the following: handover failure, RLF, ping-pong handover, unnecessary handover, handover too late, or handover too early.

In one possible implementation, the measurement report also includes initial information.

In one possible implementation, the first exception event includes RLF.

RLF includes one or more of the following: RLF caused by physical layer problem causing timer timeout, RLF caused by timer timeout triggered when radio problem timer runs and triggers measurement reporting, RLF caused by random access procedure failure, RLF caused by radio link control failure, RLF caused by detection of continuous uplink READ failure, or RLF caused by receiving backhaul radio link failure from parent node.

Thirdly, embodiments of this application provide a communication device that has the function of implementing the terminal device in the first aspect or any possible implementation of the first aspect. The device can be a terminal device or a chip included in the terminal device.

The communication device may also have the function of an access network device in the second aspect or any possible implementation of the second aspect described above. The device may be an access network device or a chip included in the access network device.

The functions of the aforementioned communication device can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules, units, or means corresponding to the aforementioned functions.

In one possible implementation, the device includes a processing module and a transceiver module. The processing module is configured to support the device in performing the functions of a terminal device as described in the first aspect or any implementation thereof, or in performing the functions of an access network device as described in the second aspect or any implementation thereof. The transceiver module supports communication between the device and other communication devices; for example, when the device is a terminal device, it can receive measurement configurations from the access network device. The communication device may also include a storage module coupled to the processing module, which stores necessary program instructions and data for the device. As an example, the processing module may be a processor, the communication module may be a transceiver, and the storage module may be a memory. The memory may be integrated with the processor or separated from it.

In another possible implementation, the device includes a processor and may also include a memory. The processor is coupled to the memory and can be used to execute computer program instructions stored in the memory to cause the device to perform the methods in the first aspect or any possible implementation thereof, or to perform the methods in the second aspect or any possible implementation thereof. Optionally, the device also includes a communication interface, with the processor coupled to the communication interface. When the device is an access network device or a terminal device, the communication interface may be a transceiver or an input/output interface; when the device is a chip included in an access network device or a chip included in a terminal device, the communication interface may be the chip's input/output interface. Optionally, the transceiver may be a transceiver circuit, and the input/output interface may be an input/output circuit.

Fourthly, embodiments of this application provide a chip system, including: a processor and a memory, the processor being coupled to the memory, the memory being used to store programs or instructions, and when the program or instructions are executed by the processor, causing the chip system to implement the methods in the first aspect or any possible implementation of the first aspect, or to implement the methods in the second aspect or any possible implementation of the second aspect.

Optionally, the chip system also includes an interface circuit for exchanging code instructions with the processor.

Optionally, the chip system may include one or more processors, which can be implemented in hardware or software. When implemented in hardware, the processor may be a logic circuit, integrated circuit, etc. When implemented in software, the processor may be a general-purpose processor that reads software code stored in memory.

Optionally, the chip system may contain one or more memories. These memories may be integrated with the processor or disposed separately. For example, the memory may be a non-transitory processor, such as read-only memory (ROM), which may be integrated with the processor on the same chip or disposed on separate chips.

Fifthly, this application provides a computer-readable storage medium storing a computer program or instructions that, when executed by a communication device, cause the communication device to perform the method of the first aspect or any possible implementation thereof, or cause the communication device to perform the method of the second aspect or any possible implementation thereof.

Sixthly, this application provides a computer program product comprising a computer program or instructions that, when executed by a communication device, implement the method in the first aspect or any possible implementation thereof, or implement the method in the second aspect or any possible implementation thereof.

In a seventh aspect, embodiments of this application provide a communication system including an access network device and at least one terminal device. The terminal device is used to execute the method in the first aspect or any possible implementation thereof, and the access network device is used to execute the method in the second aspect or any possible implementation thereof.

The technical effects that can be achieved by any of the second to seventh aspects mentioned above can be referred to the description of the beneficial effects in the first aspect mentioned above, and will not be repeated here.

Attached Figure Description

Figure 1A is a schematic diagram of a communication system architecture;

Figure 1B is a schematic diagram of the functions of a CU and a DU;

Figure 2 is a schematic diagram of an application architecture for an AI model;

Figure 3 is a schematic diagram of a traditional switching process;

Figure 4 is a flowchart illustrating the communication method exemplarily provided in this application;

Figure 5 is a flowchart illustrating the communication method provided by this application in a first specific scenario;

Figure 6 is a flowchart illustrating the communication method provided by this application in a second specific scenario;

Figure 7 is a flowchart illustrating the communication method provided by this application in a third specific scenario;

Figure 8 is a flowchart illustrating the communication method provided by this application in a fourth specific scenario;

Figure 9 is a schematic diagram illustrating the interaction between modules within a first base station in an O-RAN scenario provided by this application;

Figure 10 is a schematic diagram illustrating the interaction between modules within a second base station in an O-RAN scenario provided by this application;

Figure 11 is a schematic diagram of the structure of a communication device provided by example in this application;

Figure 12 is a schematic diagram of another communication device provided by example in this application.

Detailed Implementation

The relevant technical features involved in the embodiments of this application will be explained below. It should be noted that these explanations are for the purpose of making the embodiments of this application easier to understand, and should not be regarded as a limitation on the scope of protection claimed by this application.

I. Architecture of the Communication System

Based on the above description, Figure 1A is a schematic diagram of the architecture of a communication system.

The communication system includes a wireless access network 100 and a core network 200. Optionally, the communication system may also include an Internet 300.

The wireless access network 100 may include at least one wireless access network device (110a and 110b in Figure 1A) and at least one terminal device (120a-120j in Figure 1A). The terminal devices are connected wirelessly to the wireless access network devices, and the wireless access network devices are connected to the core network wirelessly or via a wired connection. The core network devices and the wireless access network devices may be independent physical devices, or the functions of the core network devices and the logical functions of the wireless access network devices may be integrated into the same physical device, or a single physical device may integrate some of the functions of the core network devices and some of the functions of the wireless access network devices. Terminal devices and wireless access network devices can be interconnected via wired or wireless connections. Figure 1A is only a schematic diagram; this communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1A.

Wireless access network equipment can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation NodeB (gNB) in a 5G mobile communication system, a next-generation base station in a 6G mobile communication system, a base station in a future mobile communication system, or an access node in a Wireless Fidelity (WiFi) system, etc. Wireless access network equipment can be a macro base station (as shown in Figure 1A, 110a), a micro base station or an indoor station (as shown in Figure 1A, 110b), or a relay node or donor node, etc.

In another possible scenario, multiple wireless access network (UART) devices collaborate to assist terminal devices in achieving wireless access, with each UART device performing a specific function. For example, the UART devices can be a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be separate entities or included in the same network element, such as a baseband unit (BBU). The RU can be included in radio frequency (RF) devices or RF units, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). The CU and DU are connected via an F1 interface; the DU and RU are connected via a fronthaul interface.

In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an open radio access network (O-RAN) system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software modules and hardware modules.

For example, Figure 1B illustrates the functions of a CU and DU. The CU implements the Radio Resource Control (RRC) layer, the Packet Data Convergence Protocol (PDCP) layer, the Service Data Adaptation Protocol (SDAP) layer, and other control functions. The DU implements the Radio Link Control (RLC) layer, the Media Access Control (MAC) layer, and higher layers of the Physical Layer (PHY) (closest to the MAC layer). Higher-layer functions of the Physical Layer include one or more of the following: feedforward error correction coding/decoding, scrambling/descrambling, or modulation/demodulation.

The embodiments of this application do not limit the specific technology or device form used in the wireless access network equipment.

Terminal devices can also be called terminals, user equipment (UE), mobile stations, mobile terminal devices, etc. They can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), the Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, and smart cities. Terminal devices can include mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, and smart home devices.

The embodiments of this application do not limit the specific technology or device form used in the terminal device.

Access network equipment and terminal equipment can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the access network equipment and terminal equipment.

The roles of access network devices and terminal devices can be relative. For example, the helicopter or drone 120i in Figure 1A can be configured as a mobile access network device. For terminal devices 120j that access the wireless access network 100 via 120i, terminal device 120i is an access network device; however, for access network device 110a, 120i is a terminal device. That is, 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via an interface protocol between access network devices. In this case, relative to 110a, 120i is also an access network device. Therefore, both access network devices and terminal devices can be collectively referred to as communication devices. 110a and 110b in Figure 1A can be called communication devices with access network device functions, and 120a-120j in Figure 1A can be called communication devices with terminal device functions.

Communication between access network devices and terminal devices, between access network devices, and between terminal devices can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

In the embodiments of this application, the functions of the access network device can be executed by modules (such as chips) within the access network device, or by a control subsystem that includes the functions of the access network device. This control subsystem, including the functions of the access network device, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal device can be executed by modules (such as chips or modems) within the terminal device, or by a device that includes the functions of the terminal device.

In this application, the access network device sends downlink signals or downlink information to the terminal device, with the downlink information carried on the downlink channel; the terminal device sends uplink signals or uplink information to the access network device, with the uplink information carried on the uplink channel. To communicate with the access network device, the terminal device needs to establish a radio connection with the cell controlled by the access network device. The cell with which the terminal device has established a radio connection is called the serving cell of the terminal device. When the terminal device communicates with this serving cell, it is also subject to interference from signals from neighboring cells.

For ease of description, the following description uses the base station as an example of a wireless access network device and the UE as an example of a terminal device.

II. Model

The model is, for example, an artificial intelligence (AI) model or a machine learning (ML) model.

Figure 2 illustrates a schematic diagram of an AI model application architecture. The data source stores training and inference data. The AI model training host analyzes or trains the AI model using the training data provided by the data source and deploys the AI model on the AI model inference host. Optionally, the AI model training host can also update the AI model already deployed on the AI model inference host. The AI model inference host can also feed back relevant information about the deployed AI model to the AI model training host, enabling the training host to optimize or update the deployed AI model.

In this process, the AI model is learned through the AI model training nodes, which essentially learn the mapping relationship between the AI model's input and output using training data. The AI model inference nodes use the AI model to perform inference based on the inference data provided by the data source, and obtain the inference result. This method can also be described as follows: the AI model inference nodes input the inference data into the AI model, and the AI model outputs the inference result.

The inference result can indicate the configuration parameters used (executed) by the executing object, and/or the operations performed by the executing object. The inference result can be uniformly planned by the actor entity and sent to one or more executing objects (e.g., network entities) for execution. Optionally, the executing entity or executing object can feed back the parameters or measurements it collects to the data source; this process can be called performance feedback, and the fed-back parameters can serve as training data or inference data. Optionally, the executing entity or executing object can also determine AI model performance-related feedback information based on the inference result output by the AI model inference node, and feed this feedback information back to the AI model inference node. The AI model inference node can then use this feedback information to feed back the AI model's performance information to the AI model training node, enabling the AI model training node to optimize or update the deployed AI model; this process can be called AI model feedback.

III. Measurement and Measurement Configuration

Connectivity-state measurements are generally used for cell selection during the handover preparation process.

After the base station sends the measurement configuration to the UE, the UE detects changes in the signal status of neighboring cells based on the measurement objects and reporting configuration parameters indicated in the measurement configuration. The measurement configuration is generally transmitted via RRC reconfiguration messages. The UE performs relevant measurements according to the content of the measurement configuration and sends the measurement results to the base station through a measurement report.

The measurement configuration includes the measurement object, report configuration, measurement identities, measurement quantity configuration, and measurement interval configuration. The measurement identity can be associated with both the measurement object and the report configuration.

1. Measurement object

The measurement objects include the subcarrier spacing of the synchronization signal block (SSB), the SSB-based measurement timing configuration (SMTC), whitelisted cells, and blacklisted cells. Whitelisted cells can also be called allowed cells; blacklisted cells can also be called excluded cells. The network can configure specific lists of cells to be measured, namely blacklisted cell lists and whitelisted cell lists. For cells on the blacklist, the UE will no longer perform event measurements or report measurements. Whitelisted cells are those on the measurement frequency that the UE will perform event measurements and report measurements on.

2. Report Configuration

The report configuration specifies the criteria and format that trigger the UE to report measurement reports. For example, the measurement report is based on measurements of signals such as SSB or Channel State Information-Reference Signal (CSI-RS). Each reporting configuration has a unique identifier (which may be referred to as the report configuration identifier).

When a UE reports a measurement report, it can do so through either event-triggered reporting or periodic-triggered reporting. Event-triggered reporting configuration includes various measurement events (as shown in Table 1) and threshold values. Under normal circumstances, the UE needs to continuously meet the entry conditions for measurement reporting within a defined hysteresis time (TimeToTrigger) before triggering a measurement report. Periodic-triggered reporting configuration includes the reporting period, etc.

Table 1

The specific meanings of the relevant variables in Table 1 above are as follows:

Ms and Mn represent the measurement results of the serving cell and the neighboring cell, respectively;

Hys indicates amplitude hysteresis in the measurement result;

TimeToTrigger represents the duration for which the event entry condition is continuously met, i.e., time delay;

Thresh, Thresh1, and Thresh2 represent threshold values;

Ofs and Ofn represent the frequency offset of the serving cell and the neighboring cell, respectively.

Ocs and Ocn represent the cell individual offset (CIO) of the serving cell and neighboring cell, respectively.

Off indicates the bias of the measurement result.

Signal quality can be represented by one or more of the following four parameters:

(1) Reference signal received power (RSRP) is used to reflect the received strength of the reference signal.

(2) Received signal strength indication (RSSI) is used to reflect the total signal strength of the current channel.

(3) Reference signal received quality (RSRQ) is used to reflect the signal-to-noise ratio and interference level of the current channel quality, and is approximately the ratio of RSRP to RSSI.

(4) Signal to interference and noise ratio (SINR) is used to reflect the signal-to-interference ratio of the current channel and is an important indicator for measuring UE performance.

When different signal qualities are used as the triggering conditions for an event, the measurement results in the above event are the corresponding measured triggering results.

3. Measurement markings

Measurement identifiers are used to associate measurement objects with measurement configurations. If a UE reaches a measurement activation threshold, it determines whether to perform the measurement based on the presence or absence of a measurement identifier. When a UE sends a measurement report to the base station, it only needs to indicate the measurement identifier. The base station can then use the measurement identifier to find the corresponding measurement object identifier and report configuration identifier, and thus determine what event the measurement report refers to. The base station can configure multiple measurement identifiers to link multiple measurement objects to the same report configuration, or multiple report configurations to the same measurement object.

IV. Handover (HO)

Handover (also known as cell handover) refers to the migration of the radio link connection of a UE from a source cell to a target cell. Handover includes traditional handover and conditional handover (CHO), which are explained below:

In this application, the base station used to manage the source cell is referred to as the source base station, the base station used to manage the target cell is referred to as the target base station, the base station used to manage the candidate cell is referred to as the candidate base station, and the base station used to manage the serving cell is referred to as the serving base station. The base station used to manage the cell can also be considered as the base station to which the cell belongs, the base station covering the cell, or the base station associated with (corresponding to) the cell, etc.

Furthermore, when the source cell and the target cell are managed by the same base station, the source base station and the target base station are the same; when the source cell and the candidate cell are managed by the same base station, the source base station and the candidate base station are the same, and so on.

1. Traditional switching

The source base station sends a handover command message to the UE (specifically, an RRC reconfiguration message carrying the reconfigurationWithSync field (or information element, IE)). This handover command message instructs the UE which target cell to hand over to and how to perform the handover. For example, the handover command message includes the target cell's identification information and configuration information. The UE releases the connection with the source cell, stops data transmission with the source cell, and then accesses the target cell. In traditional handover scenarios, successful transmission of the handover command message is a necessary condition for a successful handover. The cell identification information includes, for example, the cell index and cell identifier (physical cell identifier (PCI), cell global identifier (CGI), etc.).

Figure 3 is a schematic diagram of a traditional switching process:

Step 301: The source base station sends a handover request message to the target base station.

Step 302: The target base station performs permission control, for example, the target base station allocates one or more of the following information to the UE: cell radio network temporary identifier (C-RNTI), random access channel (RACH) resources required for the UE to access the target cell, the RACH resources can be dedicated RACH resources or public RACH resources.

Step 303: The target base station sends a handover request acknowledgement message to the source base station.

The handover request confirmation message includes the target cell configuration information generated by the target base station after performing permission control. The target cell configuration information includes the target cell parameter configuration and/or resource configuration. The parameter configuration may specifically be RRC parameter configuration, which may include the C-RNTI generated for the UE. The resource configuration may be the location of resources, which may include dedicated RACH resources and/or public RACH resources.

Step 304: The source base station sends an RRC reconfiguration message (i.e., a handover command message) to the UE.

The RRC reconfiguration message includes the target cell's identification and configuration information.

Step 305: The UE sends a random access request message to the target base station. For example, the UE sends a random access request message to the target base station based on the target cell's identification information and configuration information to request access to the target cell.

Step 306: The UE sends an RRC reconfiguration complete message to the target base station.

2. CHO

Compared to traditional switching, CHO can improve the success rate of switching.

When the communication link between the source base station and the UE is of good quality, the source base station sends CHO configuration information to the UE (which may be included in the RRC reconfiguration message). The CHO configuration information includes configuration information and execution trigger conditions for one or more candidate cells. After receiving the CHO configuration information, the UE will not immediately initiate a handover to any candidate cell, but will continue to maintain the connection and data transmission with the source cell. Furthermore, after finding a candidate cell that meets the execution trigger conditions, the UE will autonomously decide to handover to that candidate cell (at this time, the candidate cell can also be referred to as the target cell).

The CHO process is similar to that shown in Figure 3, except that the source base station needs to send a handover request message to the candidate base station, receive the configuration information of the candidate cell from the candidate base station, and when the source base station sends the CHO configuration information to the UE, the CHO configuration information includes the configuration information of the candidate cell. Therefore, when the UE selects a candidate cell as the target cell, it can handover to that candidate cell based on its configuration information.

V. Measurement-based switching mechanism

In traditional handover scenarios, the UE receives measurement configuration from the source base station. Based on this configuration, the UE measures signals from multiple neighboring cells to obtain measurement results. When the UE determines that the measurement results of a neighboring cell meet the aforementioned reporting conditions (event-triggered reporting or periodic-triggered reporting), it sends the neighboring cell's measurement results to the source base station via a measurement report. The source base station makes a handover decision based on the measurement results reported by the UE to determine the target cell and target base station, and requests the target cell's configuration information from the target base station. The target base station then sends the target cell's configuration information to the source base station. Finally, the source base station sends a handover command message to the UE, which includes the target cell's configuration information.

In the CHO scenario, the source base station sends the CHO configuration information to the UE in advance. The UE determines that the measurement result of a candidate cell meets the entry threshold of a certain measurement event and continues for a period of time (e.g., after a hysteresis time), and then uses the candidate cell as the target cell for handover. Here, the triggering condition corresponds to the reporting condition of the aforementioned measurement report or the execution triggering condition of the candidate cell.

VI. Carrier aggregation (CA)

CA (Carrier Aggregator) technology is used to aggregate two or more component carriers (CCs) to support greater transmission bandwidth. For example, the maximum bandwidth can be 100 MHz, and the bandwidth of each carrier unit can be 5 MHz, 10 MHz, 15 MHz, or 20 MHz. CA technology involves primary cells (PCells) and secondary cells (SCells). The primary cell is the cell used when the UE initially establishes a connection, or when re-establishing a connection via RRC (Reconnection Reconfiguration), or the primary cell designated during handover; the carrier unit corresponding to the primary cell is called the primary component carrier (PCC). Secondary cells are added during RRC reconfiguration to provide additional radio resources. The carrier unit corresponding to the secondary cell is called the secondary component carrier (SCC).

In traditional handover scenarios, if the signal quality of the serving cell received by the UE deteriorates, causing an RLF (Recurrent Link Request) between the UE and the serving cell, the UE may not receive a handover command message beforehand. Alternatively, in CHO (Confirmation of Hazard) scenarios, if the signal quality of the serving cell received by the UE deteriorates, causing an RLF between the UE and the serving cell, the UE may not receive CHO configuration information beforehand. In such cases, the UE must initiate an RRC (Re-establishment Call) procedure to request access to another cell. This leads to instability in UE communication.

Therefore, this application provides a communication method to improve the stability of UE communication.

Figure 4 is a flowchart illustrating a communication method provided by this application:

Step 401, the UE obtains the first information.

The first information is prediction information used to indicate that a first abnormal event will occur in the UE and the serving cell in the future. This prediction information can also be referred to as prediction information of a first abnormal event occurring in the serving cell (in the future or soon), prediction information of the serving cell, prediction information corresponding to the serving cell, etc., and may have other names, which are not limited in this application.

The service area can be one or more.

For example, in a CA scenario, there are multiple serving cells (e.g., including one primary cell and one or more secondary cells). The first information can be used to indicate the predicted information of a first abnormal event that will occur between the UE and each serving cell in the future, or the first information can be used to indicate the predicted information of a first abnormal event that will occur between the UE and the primary cell (equivalent to a serving cell). In a non-CA scenario, there is one serving cell.

In this application, when the UE switches from the serving cell to the first cell (see the description in step 402 below), the serving cell can be considered as the source cell, and the first cell can be considered as the target cell. "Prediction information" can also be called "inference information," and "prediction" can also be called "inference." Of course, "prediction information" and "prediction" can have other names, and this application is not limited to any of them.

The first abnormal event includes at least RLF and/or the first HOF.

RLF includes at least one or more of the following:

(1) Physical layer issues cause RLF timeouts.

For example, when the UE's RRC layer receives n consecutive out-of-synchronization indications from the physical layer, or when the UE determines that the signal quality (e.g., channel quality indicator (CQI) or signal-to-interference-plus-noise ratio (SINR)) is less than a preset threshold, a radio problem timer (e.g., T310 in 5G) is started. If the RRC layer still has not received m consecutive synchronization indications from the physical layer by the time the radio problem timer expires, where n and m are positive integers. Furthermore, if the UE's RRC layer receives m synchronization indications from the physical layer before the radio problem timer expires, the UE stops the radio problem timer. Here, the cells are, for example, the primary cell.

(2) RLF that runs on a wireless problem timer (e.g., T310 in 5G) and timed out when a timer (e.g., T312 in 5G) that was started when the measurement was reported.

(3) RLF for a failed random access procedure. For example, a random access procedure fails in a cell group, such as the primary cell group.

(4) Radio link control (RLC) failure RLF. For example, the UE's RRC layer receives an indication from the RLC layer of the cell group that the maximum number of retransmissions has been reached, such as the primary cell group.

(5) Detected consecutive uplink listen before talk (LBT) failures of RLF.

(6) For integrated access and backhaul mobile termination (IAB MT), the backhaul radio link failure (BH RLF) received from the parent node.

The first HOF includes at least one or more of the following:

(1) Within the first time period from when the UE meets the measurement event entry condition to when the UE successfully receives the handover command message from the source cell (e.g., an RRC reconfiguration message carrying the reconfigurationWithSync field), an RLF occurs (e.g., an RLF occurs in the source cell).

Among them, the time point at which the UE determines that the measurement event entry condition is met is time point 1, and the time point at which the UE successfully receives the handover command message from the source cell is time point 2. The first time period is specifically the time period between time point 1 and time point 2.

(2) Within the first time period from when the measurement event entry condition is met to when the UE successfully receives the handover command message from the source cell (e.g., an RRC reconfiguration message carrying the reconfigurationWithSync field), the UE detects a failure of the physical downlink control channel (PDCCH) (e.g., detects a failure of the PDCCH of the source cell).

The definition of the first time period is given in (1) of the first HOF above.

Of course, the RLF may also include other RLFs, and this application does not limit the specific definition of the RLF. Similarly, the first HOF may also include other handover failure modes, and this application does not limit the specific definition of the first HOF.

The first information can be presented in the following three ways:

Method 1: The first information includes the probability that a first abnormal event will occur in the UE and the serving cell in the future. Furthermore, when there are multiple first abnormal events, the first information includes the probability of each first abnormal event occurring.

For example, the first anomalous event is an RLF where a physical layer problem causes a timer timeout, and the first information includes {RLF where a physical layer problem causes a timer timeout, probability of occurrence 30%}. As another example, the first anomalous event is an RLF where a physical layer problem causes a timer timeout and an RLF where the random access procedure fails, and the first information includes {RLF where a physical layer problem causes a timer timeout, probability of occurrence 30%} and {RLF where the random access procedure fails, probability of occurrence 20%}.

The probability of the first abnormal event occurring can also be referred to as the likelihood of the first abnormal event occurring, the accuracy of the occurrence of the first abnormal event, etc. This application does not limit the specific names.

In addition, the first information may also include the start time and/or end time of each first abnormal event that will occur between the UE and the serving cell in the future.

Method 2: The first information includes the probability of a first abnormal event occurring in the UE and the serving cell in the future, and the accuracy of the probability of the first abnormal event occurring (which can be simply referred to as the probability accuracy). Furthermore, when there are multiple first abnormal events, the first information includes the probability of each first abnormal event occurring and the accuracy of the probability of that first abnormal event occurring.

For example, the first anomalous event is an RLF where a physical layer problem causes a timer timeout. The first information includes {RLF where a physical layer problem causes a timer timeout, probability of occurrence 30%, accuracy 90%}. As another example, the first anomalous event is an RLF where a physical layer problem causes a timer timeout and an RLF where the random access procedure fails. The first information includes {RLF where a physical layer problem causes a timer timeout, probability of occurrence 30%, accuracy 90%} and {RLF where the random access procedure fails, probability of occurrence 20%, accuracy 90%}.

The accuracy of the probability of the first abnormal event occurring can also be referred to as the accuracy of the probability of the first abnormal event occurring, etc. This application does not limit the specific name.

It's important to clarify that the accuracy rate of the probability of the first anomalous event occurring is different from the aforementioned "accuracy rate of the first anomalous event." "Accuracy rate of the probability of the first anomalous event occurring" refers to the probability of the first anomalous event occurring, while "accuracy rate of the probability of the first anomalous event occurring" can also be considered the "accuracy rate of the accuracy rate of the first anomalous event." Furthermore, a 100% probability of the first abnormal event occurring is equivalent to the first abnormal event occurring 100% of the time; a 0% probability of the first abnormal event occurring is equivalent to the first abnormal event not occurring 100% of the time. The 100% occurrence or non-occurrence of the first abnormal event corresponds to an accuracy rate, which can be converted into the probability of the first abnormal event occurring. For example, if the accuracy rate of the first abnormal event occurring 100% of the time is 90%, then the probability of the first abnormal event occurring can also be considered to be 90%. If the accuracy rate of the first abnormal event not occurring 100% of the time is 90%, then the probability of the first abnormal event occurring can also be considered to be 10% (or the probability of the first abnormal event not occurring is 90%).

The accuracy of the probability of the first anomalous event occurring in the serving cell is determined by the model used by the UE.

In one possible example, the UE includes one or more models, each corresponding to its own accuracy rate. When the UE determines the probability of the first abnormal event occurring in the serving cell based on a certain model, the accuracy rate of the probability of the first abnormal event occurring in the serving cell is the accuracy rate corresponding to that model. For example, the UE includes model 1 and model 2, where model 1 corresponds to accuracy rate 1 and model 2 corresponds to accuracy rate 2. When the UE determines the probability of the first abnormal event occurring in the serving cell based on model 1, the accuracy rate is accuracy rate 1; when the UE determines the probability of the first abnormal event occurring in the serving cell based on model 2, the accuracy rate is accuracy rate 2.

In another possible example, the model can be used by the UE to determine the probability of different first anomalous events occurring in the serving cell, and the model's accuracy in predicting the probability of different first anomalous events may differ. For example, the model is used to determine the probability of anomalous events 1 through 7 occurring in the serving cell, and the accuracy rates for the probabilities of anomalous events 1 through 7 are accuracy rates 1 through 7, respectively.

In addition, the first information may also include the start time and/or end time of each first abnormal event that will occur between the UE and the serving cell in the future.

Method 3: The first information includes whether the UE and the serving cell will experience a first abnormal event in the future.

For example, the first information includes indication information, which occupies 1 bit. When the value of this bit is 0, it indicates that the UE and the serving cell will not experience the first abnormal event in the future; when the value of this bit is 0, it indicates that the UE and the serving cell will experience the first abnormal event in the future.

Example 3-1: The first abnormal event is one or more, and the indication information corresponds to the serving cell. This indication information is used to indicate whether the serving cell can continue to serve as the UE's serving cell. This can be interpreted as follows: when the indication information indicates that the first abnormal event will occur between the UE and the serving cell in the future, it is equivalent to the serving cell being unable to continue serving as the UE's serving cell, and the UE needs to perform the subsequent step 402; when the indication information indicates that the first abnormal event will not occur between the UE and the serving cell in the future, it is equivalent to the serving cell being able to continue serving as the UE's serving cell, and the UE does not need to perform the subsequent step 402.

Example 3-2: There are one or more first abnormal events. When there are multiple first abnormal events, each first abnormal event corresponds to its own indication information, that is, it is used to indicate whether each first abnormal event has occurred. For example, the first abnormal events include RLFs where a physical layer problem causes a timer to time out and RLFs where a random access procedure fails. The first information includes {RLF where a physical layer problem causes a timer to time out, indication information equals 1}, {RLF where a random access procedure fails, indication information equals 0}. In addition, the first information may also include the start time and/or the end time of each first abnormal event.

In one possible approach, the UE determines the first information itself. For example, the UE includes a model (e.g., an AI model), and the UE determines the first information based on the model. Another example is that the UE includes a preset algorithm, and the UE determines the first information based on the preset algorithm. Furthermore, the UE may also determine the first information based on a prediction system or other methods. For ease of description, the following explanation uses a model as an example.

When determining the first information, the UE may input one or more of the following parameters into the model: the measurement results of the serving cell, the UE's movement information (e.g., movement speed, movement direction, geographical location), prediction information of other UEs and the serving cell in the future occurrence of the first abnormal event, and historical abnormal event information of the serving cell.

Accordingly, the UE obtains the first information output by the model, which can be any one of the above methods 1 to 3.

Alternatively, the model outputs the probability of a first abnormal event occurring between the UE and the serving cell in the future. The UE then determines the first information based on the probability of the first abnormal event occurring between the UE and the serving cell and a first threshold. The first information can be method 3 described above. For example, when the UE determines that the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than the first threshold, the first information is determined to include the possibility of a first abnormal event occurring between the UE and the serving cell in the future; when the UE determines that the probability of a first abnormal event occurring between the UE and the serving cell in the future is less than or equal to the first threshold, the first information is determined to include the possibility that a first abnormal event will not occur between the UE and the serving cell in the future.

Alternatively, the model outputs the probability and accuracy of the first abnormal event occurring between the UE and the serving cell in the future. The UE then determines the first information based on the probability, accuracy, first threshold, and second threshold of the first abnormal event occurring between the UE and the serving cell in the future. The first information can be as described in method 3 above. For example, when the UE determines that the probability of the first abnormal event occurring between the UE and the serving cell in the future is greater than the first threshold and the accuracy of the probability is greater than the second threshold, the first information is determined to include the occurrence of the first abnormal event between the UE and the serving cell in the future. When the UE determines that the probability of the first abnormal event occurring between the UE and the serving cell in the future is less than or equal to the first threshold, and/or the accuracy of the probability is less than or equal to the second threshold, the first information is determined to include the absence of the first abnormal event between the UE and the serving cell in the future.

The first threshold can also be called the possibility threshold, probability threshold, accuracy threshold, etc., and the second threshold can also be called the accuracy threshold, etc. This application does not limit the specific names.

The configuration granularity of the first threshold can be determined based on the model configuration or the measurement configuration.

When the configuration granularity of the first threshold is determined based on the model configuration, there are two specific examples:

Example 1: The UE includes one or more models, all of which correspond to the same first threshold. For example, the UE includes models 1 to 5, all of which correspond to the same first threshold 1.

Example 2: The UE includes multiple models, one or more of which correspond to a first threshold. For example, the UE includes models 1 to 5, which correspond to first thresholds 1 to 5 respectively; or, models 1 to 3 correspond to first thresholds 1 to 3 respectively, and models 4 and 5 together correspond to first threshold 4.

When the configuration granularity of the first threshold is determined based on the measurement configuration, there are two specific examples:

Example 3: The UE receives a measurement configuration from a first base station (also known as a serving base station, or the first access network device). The measurement configuration includes one or more measurement identifiers, each corresponding to the same first threshold. For example, the measurement configuration includes measurement identifiers 1 to 5, each corresponding to the same first threshold 1.

Example 4: The UE receives a measurement configuration from a first base station. The measurement configuration includes multiple measurement identifiers, one or more of which correspond to a first threshold. For example, the UE includes measurement identifiers 1 to 5, which correspond to first thresholds 1 to 5 respectively; or, measurement identifiers 1 to 3 correspond to first thresholds 1 to 3 respectively, and measurement identifiers 4 and 5 together correspond to first threshold 4.

It is understandable that in the scenario where the configuration granularity of the first threshold is determined based on the measurement configuration, "measurement identifier" can be replaced with "measurement object", "report configuration" or "measurement event", or "measurement identifier" can be replaced with any combination of "measurement identifier", "measurement object", "report configuration" or "measurement event".

For ease of description, the following explanation uses a single first threshold as an example. That is, different models, different measurement identifiers, different measurement objects, different measurement reports, and different measurement events all correspond to the same first threshold. This first threshold is, for example, 60%.

The configuration granularity of the second threshold can be determined based on the model configuration or the measurement configuration.

When the configuration granularity of the second threshold is determined based on the model configuration, there are two specific examples:

Example (1): The UE includes one or more models, all of which correspond to the same second threshold. For a specific example, please refer to Example 1 above.

Example (2): The UE includes multiple models, one or more of which correspond to a second threshold. For a specific example, please refer to Example 2 above.

When the configuration granularity of the second threshold is determined based on the measurement configuration, there are two specific examples:

Example (3): The UE receives a measurement configuration from the first base station. The measurement configuration includes one or more measurement identifiers, all of which correspond to the same second threshold. For a specific example, please refer to Example 3 above.

Example (4): The UE receives a measurement configuration from the first base station. The measurement configuration includes multiple measurement identifiers, one or more of which correspond to a second threshold. For a specific example, please refer to Example 4 above.

It is understandable that in scenarios where the configuration granularity of the second threshold is determined based on the measurement configuration, "measurement identifier" can be replaced with "measurement object", "report configuration" or "measurement event", or "measurement identifier" can be replaced with any combination of "measurement identifier", "measurement object", "report configuration" or "measurement event".

For ease of description, the following explanation uses a single second threshold as an example. That is, different models, different measurement identifiers, different measurement objects, different measurement reports, and different measurement events all correspond to the same second threshold. This second threshold is, for example, 90%.

For example, the UE may also pre-configure or pre-define first indication information and/or second indication information. As another example, the UE may also obtain the first indication information and/or second indication information from the first base station.

The first indication information is used to indicate what the first abnormal event (or the type of the first abnormal event) specifically is.

In one possible approach, the first indication information includes an identifier of a first abnormal event that the UE needs to predict. For example, if the first indication information includes identifiers of three abnormal events: a physical layer problem causing a timer timeout, a random access procedure failure, and an LBT failure detection, then the first abnormal event includes the physical layer problem causing a timer timeout, the random access procedure failure, and the LBT failure detection.

In another possible approach, the first indication information includes identifiers of multiple abnormal events and corresponding indication information for those abnormal events. The indication information is used by the UE to determine whether to predict the abnormal event. For example, the indication information is one bit; when the bit is 0, the UE determines not to predict the abnormal event; when the bit is 1, the UE determines to predict the abnormal event. As another example, if the first indication information includes {identifier of RLF causing timer timeout due to physical layer problem, 1}, {identifier of RLF causing random access procedure failure, 1}, {identifier of RLF detecting LBT failure, 1}, and {identifier of BH RLF, 0}, then the first abnormal event includes RLF causing timer timeout due to physical layer problem, RLF causing random access procedure failure, and RLF detecting LBT failure.

In one example, the model can determine the probabilities (or probabilities and their accuracy, or whether an abnormal event has occurred) of which abnormal events are included in the first information based on the first abnormal event indicated by the first indication information. In another example, the UE determines the first information from the probabilities (or probabilities and their accuracy, or whether an abnormal event has occurred) of multiple abnormal events output by the model based on the first indication information.

The second indication information is used to indicate at least one measurement item. The at least one measurement item includes at least one of: a measurement identifier, a measurement object, a report configuration, or a measurement event.

The UE can measure the reference signal of the serving cell according to the second indication information to obtain the measurement results corresponding to at least one measurement item. Subsequently, the UE can determine first information based on the measurement results corresponding to at least one measurement item. For example, the UE inputs the measurement results corresponding to at least one measurement item (i.e., as the measurement results of the serving cell) into the model, and the model outputs the first information, or the probability of a first abnormal event occurring between the UE and the serving cell in the future, or the probability of a first abnormal event occurring between the UE and the serving cell in the future and the accuracy of the probability.

In another possible approach, the UE obtains the first information from other devices. These other devices could be, for example, other UEs.

In step 402, when the UE determines that the first preset condition is met based on the first information, it accesses the first cell before a first time. The first time is determined based on the occurrence time of the first abnormal event predicted by the UE. Here, the first cell is different from the serving cell.

The following explains how the UE determines that the first preset condition is met based on the first information, in two scenarios:

Scenario 1, when there is only one serving cell, or when there are multiple serving cells and the first information is used to indicate the predicted information of the first abnormal event that will occur between the UE and the primary cell (i.e., one serving cell) in the future, can be illustrated by the following examples 1 to 3:

Example 1: When the UE determines that the first information indicates that a first abnormal event will occur between the UE and the serving cell in the future, it determines that the first preset condition is met.

Furthermore, when the UE determines that the first information indicates that the UE and the serving cell will not experience a first abnormal event in the future, it determines that the first preset condition is not met. For example, the first preset condition is that the UE and the serving cell will experience a first abnormal event in the future. For example, the first information includes indication information used to indicate whether the UE and the serving cell will experience a first abnormal event in the future (e.g., method 3 described above).

It should be added that when there are multiple first exception events, there are two possible examples:

Example a (corresponding to Example 3-1 above), the first information includes indication information, which corresponds to the serving cell. This indication information is used to indicate that when the UE and the serving cell experience a first abnormal event in the future, the first preset condition is met.

Example b (corresponding to Example 3-2 above): The first information includes indication information corresponding to multiple first abnormal events, and the indication information corresponding to each first abnormal event is used to indicate whether the first abnormal event has occurred. Further, when the UE determines that a first abnormal event greater than or equal to a preset percentage of 1 will occur in the future, it determines that the first preset condition is met; otherwise, it determines that the first preset condition is not met. For example, if there are 3 first abnormal events (denoted as first abnormal event 1 to first abnormal event 3), the preset percentage of 1 is 50%, and the first information indicates that first abnormal event 1 occurs, first abnormal event 2 occurs, and first abnormal event 3 does not occur, then the UE determines that the first preset condition is met. In addition, the preset percentage of 1 can also be replaced with a preset quantity of 1. For example, the preset quantity of 1 is equal to 0, that is, when the first information indicates that one or more first abnormal events will occur in the future, it determines that the first preset condition is met. Of course, there are other methods, which are not limited in this application.

Example 2: When the UE determines that the probability of a first abnormal event occurring between the UE and the serving cell in the future, as indicated by the first information, is greater than a first threshold, the UE determines that the first preset condition is met. Conversely, when the UE determines that the probability of a first abnormal event occurring between the UE and the serving cell in the future, as indicated by the first information, is less than or equal to the first threshold, the UE determines that the first preset condition is not met.

For example, the first preset condition is that the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than a first threshold. This application may also replace "greater than" with "greater than or equal to", and the corresponding "less than or equal to" with "less than". For example, the first information includes the probability of a first abnormal event occurring between the UE and the serving cell in the future (e.g., method 1 above).

For example, the first preset condition is that a first abnormal event will occur between the UE and the serving cell in the future. That is, when the UE determines that the probability of the first information indicating that the first abnormal event will occur between the UE and the serving cell in the future is greater than a first threshold (e.g., in method 1 above), it is equivalent to determining that the first information indicates that the first abnormal event will occur between the UE and the serving cell in the future, and thus determining that the first preset condition is met. When the UE determines that the probability of the first information indicating that the first abnormal event will occur between the UE and the serving cell in the future is less than or equal to the first threshold, it is equivalent to determining that the first information indicates that the first abnormal event will not occur between the UE and the serving cell in the future, and thus determining that the first preset condition is not met.

It should be added that when there are multiple first abnormal events, the first information includes the probability corresponding to each of the multiple first abnormal events. Furthermore, when the UE determines that the probability corresponding to a first abnormal event greater than or equal to a preset percentage 2 is greater than a first threshold, it determines that the first preset condition is met; otherwise, it determines that the first preset condition is not met. For example, if there are three first abnormal events (denoted as first abnormal event 1 to first abnormal event 3), the preset percentage 2 is 50%, the first threshold is 60%, and the first information indicates that the probability of first abnormal event 1 occurring is 90%, the probability of first abnormal event 2 occurring is 90%, and the probability of first abnormal event 3 occurring is 20%, then the UE determines that the first preset condition is met. In addition, the preset percentage 2 can also be replaced with a preset quantity 2. For example, the preset quantity 2 is equal to 0, that is, when the first information indicates that the probability of one or more first abnormal events occurring is greater than the first threshold, it determines that the first preset condition is met. There are other methods as well, which are not limited in this application.

The configuration granularity of the first threshold can be determined based on the model configuration or the measurement configuration. For an explanation of the first threshold, please refer to the description in the above-mentioned embodiments related to "UE determining first information".

Example 3: When the UE determines that the first preset condition is met, the probability of the first abnormal event occurring between the UE and the serving cell in the future, as indicated by the first information, is greater than a first threshold, and the accuracy of the probability of the first abnormal event occurring between the UE and the serving cell in the future is greater than a second threshold.

Furthermore, when the UE determines that the probability of the first abnormal event occurring between the UE and the serving cell in the future is less than or equal to a first threshold, and/or when the accuracy of the UE in determining the probability of the first abnormal event occurring between the UE and the serving cell in the future is less than or equal to a second threshold, the UE determines that the first preset condition is not met.

For example, the first preset condition is that the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than a first threshold, and the accuracy of the probability of the first abnormal event occurring between the UE and the serving cell in the future is greater than a second threshold. This application may also replace "greater than" with "greater than or equal to", and the corresponding "less than or equal to" with "less than". For example, the first information includes the probability of a first abnormal event occurring between the UE and the serving cell in the future and the accuracy of the probability of the first abnormal event occurring (e.g., method 2 above).

For example, the first preset condition is that a first abnormal event will occur between the UE and the serving cell in the future. That is, when the UE determines that the probability of the first information indicating that the UE and the serving cell will experience a first abnormal event in the future is greater than a first threshold, and the accuracy of the probability of the UE and the serving cell experiencing a first abnormal event in the future is greater than a second threshold (e.g., in method 2 above), it is equivalent to determining that the first information indicates that the UE and the serving cell will experience a first abnormal event in the future, and thus the first preset condition is satisfied. When the UE determines that the probability of the first information indicating that the UE and the serving cell will experience a first abnormal event in the future is less than or equal to the first threshold, and/or when the UE determines that the accuracy of the probability of the first information indicating that the UE and the serving cell will experience a first abnormal event in the future is less than or equal to the second threshold, it is equivalent to determining that the first information indicates that the UE and the serving cell will not experience a first abnormal event in the future, and thus the first preset condition is not satisfied.

It should be added that when there are multiple first abnormal events, the first information includes the probability and accuracy of each first abnormal event. Further, when the UE determines that the probability of a first abnormal event greater than or equal to a preset percentage of 3 is greater than a first threshold, and the accuracy of these probabilities greater than or equal to a preset percentage of 4 is greater than a second threshold. For example, if there are 4 first abnormal events, the preset percentage of 3 is 50%, the preset percentage of 4 is 50%, the probability of 3 first abnormal events in the first information is greater than the first threshold, and the accuracy of 2 of these 3 probabilities is greater than the second threshold. In addition, the preset percentage of 3 can be replaced with a preset quantity of 3, and the preset percentage of 4 can be replaced with a preset quantity of 4. For example, both the preset quantity of 3 and the preset quantity of 4 are equal to 0, that is, when the first information indicates that the probability of a first abnormal event is greater than the first threshold and the accuracy of the probability is greater than the second threshold, the first preset condition is determined to be met. Other methods exist, but this application does not limit them.

The configuration granularity of the first threshold can be determined based on the model configuration or the measurement configuration. The configuration granularity of the second threshold can also be determined based on the model configuration or the measurement configuration. For a description of the first and second thresholds, please refer to the descriptions in the above-mentioned embodiments related to "UE determining first information".

Scenario 2: When there are multiple serving cells, and the first information is used to indicate the predicted information of the first abnormal event that will occur between the UE and multiple serving cells in the future, the specific examples are as follows (I) to (III):

Example (1): When the UE determines that the proportion of the first serving cell among multiple serving cells indicated by the first information is greater than the first preset proportion, it determines that the first preset condition is met. Here, the first serving cell is the serving cell where the first abnormal event will occur with the UE in the future.

For example, the first preset percentage is 50%, and the UE accesses serving cell 1 to serving cell 3. The first information indicates that the UE and serving cell 1 will experience a first abnormal event in the future, the UE and serving cell 2 will experience a first abnormal event in the future, and the UE and serving cell 3 will experience a first abnormal event in the future. That is, serving cell 1 to serving cell 3 are all the first serving cells, and the UE determines that the first preset condition is met.

Furthermore, when the UE determines that the proportion of the first serving cell among multiple serving cells is less than or equal to the first preset proportion, the UE determines that the first preset condition is not met.

For example, the first preset percentage is 50%, and the UE accesses serving cell 1 to serving cell 3. The first information indicates that the UE and serving cell 1 will experience a first abnormal event in the future, the UE and serving cell 2 will not experience a first abnormal event in the future, and the UE and serving cell 3 will not experience a first abnormal event in the future. That is, serving cell 1 is the first serving cell, and the UE determines that the first preset condition is not met.

For example, the first preset condition is that the proportion of the first serving cell among multiple serving cells is greater than the first preset proportion.

The first preset percentage can also be replaced by a first preset quantity. That is, when the UE determines that the number of first serving cells indicated by the first information is greater than the first preset quantity, the first preset condition is satisfied; when the UE determines that the number of first serving cells indicated by the first information is less than or equal to the first preset quantity, the first preset condition is not satisfied. In a specific scenario, the first preset quantity is equal to 0. This can be understood as the UE determining that the first preset condition is satisfied when it determines that the first serving cell exists among multiple serving cells; and the UE determining that the first preset condition is not satisfied when it determines that none of the multiple serving cells are the first serving cell.

It should be added that when there are multiple first abnormal events, there are two possible approaches: Approach a: The first information includes indication information corresponding to each serving cell. The UE determines whether each serving cell is the first serving cell based on the indication information corresponding to each serving cell (corresponding to example a above). Approach b: The first information includes indication information corresponding to each of the multiple first abnormal events when multiple first abnormal events occur in each serving cell. The UE determines whether each serving cell is the first serving cell based on the indication information corresponding to each of the multiple first abnormal events (corresponding to example b above). For a more detailed implementation, please refer to Example 1 above.

Example (2): When the UE determines that the proportion of the second serving cell among multiple serving cells indicated by the first information is greater than the second preset proportion, it determines that the first preset condition is met. The second serving cell is a serving cell whose probability of a first abnormal event occurring with the UE in the future is greater than a first threshold.

Furthermore, when the UE determines that the proportion of the second serving cell among multiple serving cells indicated by the first information is less than or equal to the second preset proportion, it determines that the first preset condition is not met.

For example, the first preset condition is that the proportion of the second serving cell among multiple serving cells is greater than the second preset proportion.

The second preset percentage can also be replaced by a second preset quantity. That is, when the UE determines that the number of second serving cells indicated by the first information is greater than the second preset quantity, the first preset condition is satisfied; when the UE determines that the number of second serving cells indicated by the first information is less than or equal to the second preset quantity, the first preset condition is not satisfied. In a specific scenario, the second preset quantity is equal to 0. This can be understood as the UE determining that the first preset condition is satisfied when it determines that a second serving cell exists among multiple serving cells, and that the first preset condition is not satisfied when it determines that none of the multiple serving cells are the second serving cell.

It should be added that when there are multiple first abnormal events, the UE can determine whether each serving cell is a second serving cell based on the probability of each of the multiple first abnormal events occurring in each serving cell in the first information. For details, please refer to Example 2 above.

The configuration granularity of the first threshold can be determined based on the model configuration or the measurement configuration. For an explanation of the first threshold, please refer to the description in the above-mentioned embodiments related to "UE determining first information".

Example (3): When the UE determines that the proportion of the third serving cell among multiple serving cells indicated by the first information is greater than the third preset proportion, it determines that the first preset condition is met. Here, the third serving cell is a serving cell whose probability of a first abnormal event occurring with the UE in the future is greater than a first threshold, and whose accuracy in predicting the probability of a first abnormal event occurring with the UE is greater than a second threshold.

For example, the first preset condition is that the proportion of the third serving cell among multiple serving cells is greater than the third preset proportion.

The third preset percentage can also be replaced by a third preset quantity. That is, when the UE determines that the number of third serving cells indicated by the first information is greater than the third preset quantity, the first preset condition is satisfied; when the UE determines that the number of third serving cells indicated by the first information is less than or equal to the third preset quantity, the first preset condition is not satisfied. In a specific scenario, the third preset quantity is equal to 0. This can be understood as the UE determining that the first preset condition is satisfied when it determines that a third serving cell exists among multiple serving cells, and that the first preset condition is not satisfied when it determines that none of the multiple serving cells are third serving cells.

It should be added that when there are multiple first abnormal events, the UE can determine whether each serving cell is the third serving cell based on the probability and accuracy of each first abnormal event occurring in each serving cell in the first information. For details, please refer to Example 3 above.

The configuration granularity of the first threshold can be determined based on the model configuration or the measurement configuration. The configuration granularity of the second threshold can also be determined based on the model configuration or the measurement configuration. The configuration granularity of the first threshold can be determined based on either the model configuration or the measurement configuration. For a description of the first and second thresholds, please refer to the description in the above-mentioned embodiments related to "UE determining first information".

For example, the UE may have a first preset condition pre-configured or pre-defined. Also for example, the UE may obtain the first preset condition from the first base station.

The first preset condition, the first instruction information, and the second instruction information (also known as the fourth information) can be collectively referred to as the seventh information.

In one possible example, the first base station sends the seventh information to the UE, and correspondingly, the UE receives the seventh information from the first base station. Exemplarily, the seventh information is carried in an RRC message. For example, the RRC message includes a measurement configuration, which includes the seventh information; or, for another example, the RRC message is an RRC reconfiguration message, which includes the seventh information.

In another possible example, the UE has pre-configured or pre-defined seventh information. Specifically, the UE's memory stores the seventh information, and the UE's processor can read (or retrieve) the seventh information from the memory.

It should be added that the triggering conditions for the UE to determine the first information can be as follows: The UE periodically determines the first information, which can be configured by the first base station (e.g., carried in the seventh information) or pre-configured. Alternatively, the UE determines the first information in response to the seventh information received from the first base station. Alternatively, the UE determines the first information after determining the measurement result of a neighboring cell. Alternatively, the UE determines the first information before performing neighboring cell measurements. Of course, the UE can also determine the first information under other triggering conditions, which are not limited in this application.

Furthermore, when the UE determines the first time, there are two specific scenarios:

When there is only one serving cell, the UE can determine the first time based on the occurrence time of the first abnormal event that will occur between the UE and the serving cell in the future. For example, when there is only one first abnormal event, the UE can determine the first time as the occurrence time of the first abnormal event that will occur between the UE and the serving cell in the future; when there are multiple first abnormal events, the UE can take the earliest (or latest) occurrence time among the multiple first abnormal events that will occur between the UE and the serving cell in the future as the first time.

When there are multiple serving cells, the UE can determine the first time based on the occurrence time of the first abnormal event between the UE and the primary cell in the future (see the previous embodiment for details). Alternatively, the UE can determine the first time based on the occurrence time of the first abnormal event between the UE and each of the multiple serving cells in the future. For example, the UE can use the earliest (or latest) occurrence time among the occurrence times of the first abnormal event between the UE and each of the multiple serving cells in the future as the first time.

UE access to the first cell can be implemented in the following ways, from Method 1 to Method 4:

Implementation method 1: The UE sends a measurement report to the first base station, and the measurement report is used to trigger the first base station to select a target cell for the UE.

The UE sends a measurement report to the first base station, which includes signal quality information (or measurement results) of multiple second cells. The first base station receives the measurement report from the UE and, based on the signal quality information of the multiple second cells in the report, selects a first cell (equivalent to a target cell) from among the multiple second cells. Subsequently, the first base station sends the configuration information of the first cell to the UE. The UE receives the configuration information of the first cell from the first base station and, based on the configuration information, switches to the first cell.

The multiple second cells can specifically be multiple neighboring cells of the serving cell. For example, before the UE sends a measurement report to the first base station, the first base station also sends a measurement configuration to the UE, which can be used to indicate multiple second cells. For example, the measurement configuration includes third indication information, which is used to indicate multiple second cells. For instance, the third indication information includes identification information of multiple second cells; or, for example, the third indication information includes a measurement frequency point, which the UE can use to determine multiple second cells covering that measurement frequency point.

Specifically, the signal quality information of the second cell can be obtained by the UE measuring the downlink reference signal of the second cell. The downlink reference signal can be, for example, one or more of CSI-RS and SSB. Signal quality information can be, for example, RSRP, RSSI, RSRQ, and SINR.

The configuration information of the first cell is used for UE handover (access) to the first cell. The configuration information of the first cell includes the parameter configuration and resource configuration of the first cell. Among them, the parameter configuration of the first cell includes the C-RNTI generated by its associated base station for the UE; the resources of the first cell include the resources required for the UE to randomly access the first cell, such as dedicated RACH resources and/or public RACH resources.

When the first base station sends the configuration information of the first cell to the UE, specifically, the first base station sends fifth information to the UE. This fifth information includes the configuration information of the first cell and is used to instruct the UE to switch to the first cell according to the configuration information. For example, the fifth information is a handover command message, which may be an RRC reconfiguration message carrying the `reconfigurationWithSync` field.

Before sending the configuration information of the first cell to the UE, the first base station can also obtain the configuration information of the first cell. Based on whether the first cell is associated with the first base station, two operations for the first base station are provided below. Operation 1 applies to scenarios where the first cell and the serving cell are managed by the same base station; operation 2 applies to scenarios where the first cell and the serving cell are managed by two different base stations, i.e., the first cell is managed by a second base station (i.e., a second access network device) and the first and second base stations are different.

Operation 1: The first base station determines the configuration information of the first cell.

Operation 2: The first base station sends a handover request message to the second base station. The second base station determines the configuration information of the first cell and sends the configuration information of the first cell to the first base station through a handover request confirmation message.

Optionally, the measurement report may also include signal quality information of the serving cell. The serving cell may be one or more.

Optionally, the measurement report may also include first information or a portion of first information. For example, if the first information includes the probability of a first abnormal event occurring between the UE and the serving cell in the future, and the start and end times of the first abnormal event, the measurement report may carry the probability of the first abnormal event occurring between the UE and the serving cell (i.e., a portion of the first information). In this way, the first base station can determine the reason why the UE sends the measurement report based on the first information, select a suitable first cell for the UE, and instruct the UE to hand over to the first cell.

Optionally, the measurement report may also include eighth information, which is used to indicate the second cell (which may be referred to as the fifth cell) among multiple second cells whose prediction information meets the second preset condition.

Specifically, the prediction information for the second cell refers to the prediction information of a second abnormal event occurring when the second cell serves as the target cell for UE handover. The prediction information for the second cell may include one or more of the following: whether a second abnormal event occurs in the second cell, the probability of a second abnormal event occurring in the second cell, the accuracy of the probability of a second abnormal event occurring in the second cell, the start time of the second abnormal event occurring in the second cell, and the end time of the second abnormal event occurring in the second cell. The method by which the UE determines the prediction information of a second abnormal event occurring in the second cell is the same as the method described above for the UE to determine the prediction information of a first abnormal event occurring in the serving cell.

The second preset condition is that no second abnormal event occurs when the second cell is the target cell; or, the second preset condition is that the probability of the second abnormal event occurring when the second cell is the target cell is less than the first threshold; or, the second preset condition is that the probability of the second abnormal event occurring when the second cell is the target cell is less than the first threshold and the accuracy of the probability is greater than the second threshold. The configuration granularity of the first and second thresholds can be found in the descriptions of the first and second thresholds above.

For example, the second information includes the identification information of the fifth cell.

Alternatively, the second information may include the combination corresponding to the fifth cell, which includes the identification information of the fifth cell and the probability of the second abnormal event occurring (or the probability of the second abnormal event occurring and the accuracy of the probability of the second abnormal event occurring). Optionally, the combination corresponding to the fifth cell may also include the start time and/or end time of the second abnormal event occurring.

Alternatively, the second information may include the combination corresponding to the fifth cell, which includes the identification information of the fifth cell and the absence of the second abnormal event.

Alternatively, the second information may include the prediction information corresponding to the fifth cell.

Alternatively, the second information may include combinations corresponding to the second cell. For example, each combination corresponding to the second cell may include the identification information of the second cell and the probability of the second abnormal event occurring (or the probability of the second abnormal event occurring and the accuracy of the probability of the second abnormal event occurring). Optionally, the combination corresponding to the second cell may also include the start time and/or end time of the second abnormal event.

The second abnormal event can specifically be a mobility abnormal event, including one or more of the following: too late handover, too early handover, handover to the wrong cell, unnecessary handover, ping-pong handover, RLF, and second HOF. Specific details are as follows:

1. Late Handover: After a UE has been connected to the serving cell for a period of time, a Relationship Default (RLF) may occur between the UE and the serving cell. The UE then attempts to re-establish a connection with another cell. This situation mainly refers to a deterioration in the signal quality of the serving cell, where the UE does not receive a handover command message from the serving base station. Therefore, the UE attempts to re-establish a connection with another cell only after the serving cell detects the RLF.

2. Premature handover: After the UE successfully hands over from the source cell to the target cell, the UE quickly experiences an RLF with the target cell; or, the UE fails to handover during the process of handover from the source cell to the target cell, and the UE attempts to rebuild the connection in the source cell.

3. Handover to the wrong cell: After the UE successfully hands over from the source cell to the target cell, the UE quickly experiences an RLF with the target cell, or the UE fails to handover during the handover process from the source cell to the target cell, and the UE attempts to rebuild the connection in other cells (the other cells here are different from the source cell and the target cell).

4. Unnecessary Handover: Even if the coverage quality of the source system is sufficient to meet the services used by the UE, the UE may still hand over from a cell in the source system to a cell in the target system. The source system could be, for example, a New Radio (NR) system, and the target system could be, for example, an Evolution UMTS Terrestrial Radio Access Network (E-UTRAN) system. Therefore, this handover may be considered unnecessary, or referred to as an unnecessary cross-system handover, or a premature cross-system handover without connection failure.

Alternatively, if the coverage of the source cell is sufficient to meet the UE's service needs, the UE can switch from the source cell to the target cell.

5. Ping-Pong Handover: The UE switches from a cell in the source system to a cell in the target system. Within a predefined limited time, the UE switches back to a cell in the source system, where the coverage of the source system is sufficient to meet the UE's service needs. The source system could be an NR system, and the target system could be an E-UTRAN system. Alternatively, the UE switches from a source cell to a target cell, and within a predefined limited time, switches back to the source cell, where the coverage of the source cell is sufficient to meet the UE's service needs.

6. RLF includes at least one or more of the following:

(1) RLF caused by physical layer problem leading to timer timeout. (2) RLF caused by timer timeout triggered when wireless problem timer is running and measurement reporting is initiated. (3) RLF caused by random access procedure failure. (4) RLF caused by RLC failure. (5) RLF caused by detection of continuous uplink LBT failure. (6) RLF caused by receiving BH RLF from the parent node for IAB MT. See step 401 above for details.

7. The second HOF includes at least one or more of the following:

(1) During the handover process, after receiving a handover command message from the source cell (e.g., an RRC reconfiguration message carrying the reconfigurationWithSync field), the UE starts a handover timer (e.g., T304 in 5G). If the UE successfully completes random access in the target cell before the handover timer expires, it indicates that the UE has successfully handed over from the source cell to the target cell, and the UE stops the handover timer. If the UE still fails to successfully complete random access in the target cell when the handover timer expires, it indicates that the UE has not successfully handed over from the source cell to the target cell, i.e., the handover has failed.

(2) Within the first time period from when the UE meets the measurement event entry condition to when the UE successfully receives the handover command message from the source cell, an RLF occurs. See the description in step 401 above for details.

(3) During the first time period from when the UE meets the measurement event entry condition to when the UE successfully receives the handover command message from the source cell, the UE detects a PDCCH failure. See step 401 above for details.

(4) During the second time period between the UE receiving the handover command message from the source cell (e.g., an RRC reconfiguration message carrying the reconfigurationWithSync field) and the UE successfully transmitting the handover completion message (e.g., an RRC reconfiguration completion message), the UE detects a PDCCH failure (e.g., detects a PDCCH failure in the target cell). The transmission of the handover completion message is the UE's response to the handover command message.

Specifically, the time point at which the UE determines that it has received the handover command message from the source cell is time point 3, and the time point at which the UE successfully transmits the handover completion message is time point 4. The second time period is specifically the time period between time point 3 and time point 4.

Of course, the second HOF may also include other switching failure modes, and this application does not limit the specific definition of the second HOF.

Thus, when selecting a first cell for the UE, the first base station considers not only the signal quality of multiple second cells, but also the predicted information of the second abnormal event occurring when the second cell is used as the target cell for UE handover. For example, the first cell could be a second cell with good signal quality and no second abnormal event, or a second cell with good signal quality and a relatively low probability of the second abnormal event occurring, or a second cell with good signal quality, a relatively low probability of the second abnormal event occurring, and a relatively high accuracy rate in predicting the probability. This helps ensure the stability of UE communication.

Optionally, the measurement report may also include a first timeframe, during which the first base station may send the configuration information of the first cell to the UE at a second timeframe. The second timeframe is earlier than the first timeframe; in other words, the second timeframe must ensure that the UE can access the first cell before the first timeframe.

In the above technical solution, once the UE determines that the first preset condition is met, it can send a measurement report to the first base station. That is, this application defines a new way to trigger the reporting of measurement reports: the UE determines that the first preset condition is met. In other words, the UE uses "determining that the first preset condition is met" as a trigger condition for sending a measurement report, or as a newly defined measurement event. This helps to trigger the first base station to send a handover command message to the UE as quickly as possible, thus helping to ensure the stability of UE communication.

Method 2: The UE sends a measurement report to the first base station, which triggers the first base station to select a candidate cell for the UE.

Specifically, the UE sends a measurement report to the first base station, which includes signal quality information from multiple second cells. The first base station receives the measurement report from the UE, selects candidate cells from the multiple second cells based on the measurement report, and sends the configuration information of the candidate cells to the UE. The UE receives the configuration information of the candidate cells from the first base station, selects a first cell from the candidate cells based on the downlink reference signal of the candidate cells, and then switches to the first cell according to the configuration information of the first cell. There can be one or more candidate cells.

The multiple second cells can specifically be multiple neighboring cells of the serving cell. For example, before the UE sends a measurement report to the first base station, the first base station sends a measurement configuration to the UE, which indicates the multiple second cells. See the description in Implementation Method 1 for details.

Specifically, the signal quality information of the second cell can be obtained by the UE measuring the downlink reference signal of the second cell. The downlink reference signal may be one or more of CSI-RS and SSB. Signal quality information may include RSRP, RSSI, RSRQ, and SINR.

The configuration information of a candidate cell is used by the UE to hand over to that candidate cell. The configuration information includes the candidate cell's parameter configuration and resource configuration. The candidate cell's parameter configuration includes the C-RNTI generated by its base station for the UE; the candidate cell's resources include the resources required for the UE to randomly access the candidate cell, such as dedicated RACH resources and/or public RACH resources. Optionally, the candidate cell's configuration information also includes the candidate cell's execution triggering conditions. When the UE determines that the downlink reference signal (or signal quality information) of the candidate cell meets the candidate cell's execution triggering conditions, it autonomously decides to hand over to that candidate cell.

When the first base station sends the configuration information of candidate cells to the UE, it may specifically send sixth information to the UE. This sixth information includes the configuration information of the candidate cells and is used to instruct the UE to select a first cell from the candidate cells based on the configuration information corresponding to each candidate cell, and then switch to the first cell. For example, the sixth information may specifically be CHO configuration information, which may be carried in an RRC reconfiguration message. There may be one or more candidate cells.

Before sending the candidate cell configuration information to the UE, the first base station can first obtain the candidate cell configuration information. Based on whether the candidate cell is associated with the first base station, the following two operations of the first base station are provided. Operation 1 is applicable to the scenario where the candidate cell and the serving cell are managed by the same base station, that is, the candidate cell is managed by the first base station; Operation 2 is applicable to the scenario where the candidate cell and the serving cell are managed by two different base stations, that is, the candidate cell is managed by the candidate base station and the first base station and the candidate base station are different.

Operation 1: The first base station determines the configuration information of the candidate cells. For example, the first base station may also determine the execution triggering conditions of the candidate cells and send the execution triggering conditions of the candidate cells to the UE along with the configuration information of the candidate cells.

In operation 2, the first base station sends a handover request message to the candidate base station. The candidate base station determines the configuration information of the candidate cell and sends the configuration information of the candidate cell to the first base station via a handover request confirmation message. For example, after receiving the configuration information of the candidate cell from the candidate base station, the first base station can also determine the execution triggering conditions of the candidate cell and send the execution triggering conditions of the candidate cell to the UE along with the configuration information of the candidate cell.

Optionally, the measurement report may also include signal quality information of the serving cell. The serving cell may be one or more. Optionally, the measurement report may also include first information or a portion of the first information. Optionally, the measurement report may also include prediction information of second abnormal events occurring when multiple second cells are respectively used as target cells for UE handover. Specific implementations can be found in the description of Implementation Method 1.

Thus, when the first base station selects a candidate cell for the UE, it considers not only the signal quality of multiple second cells, but also the predicted information of the second abnormal event occurring when the second cell is used as the target cell during UE handover. For example, a candidate cell could be a second cell with good signal quality that does not experience the second abnormal event, or a second cell with good signal quality and a relatively low probability of experiencing the second abnormal event, or a second cell with good signal quality, a relatively low probability of experiencing the second abnormal event, and a relatively high accuracy in probability calculation. This helps ensure the stability of UE communication.

Optionally, the measurement report may also include a first timeframe, during which the first base station may send the configuration information of the first cell to the UE at a second timeframe. The second timeframe is earlier than the first timeframe; in other words, the second timeframe must ensure that the UE can access the first cell before the first timeframe.

In the above technical solution, once the UE determines that the first preset condition is met, it can send a measurement report to the first base station. That is, this application defines a new way to trigger the reporting of measurement reports: the UE determines that the first preset condition is met. In other words, the UE uses "determining that the first preset condition is met" as a trigger condition for sending a measurement report, or as a newly defined measurement event. This helps to trigger the first base station to send a handover command message to the UE as quickly as possible, thus helping to ensure the stability of UE communication.

Implementation Method 3: The UE initiates the RRC re-establishment process itself.

Specifically, the UE measures the downlink reference signals of multiple third cells to obtain signal quality information for these cells. Based on this signal quality information, the UE selects a first cell from among the third cells. The UE then sends second information to the base station associated with the first cell (referred to as the second base station, equivalent to a second access network device), whereby the second information is used to indicate (or request) access to the first cell.

For example, the second information may be an RRC re-establishment request message. Further, the RRC re-establishment request message may carry reconstruction reason information. For example, the reconstruction reason information may include prediction information about a first abnormal event occurring between the UE and the serving cell in the future, or the reconstruction reason information may be the UE's prediction of a first abnormal event occurring with the serving cell in the future, or the UE's prediction of a first abnormal event occurring with the serving cell in the future based on a model, or the reconstruction reason information may be the UE's prediction of an RLF (Recurrent Leak) occurring with the serving cell in the future, etc.

Multiple third cells can specifically be multiple neighboring cells of the serving cell. For example, before the UE initiates the RRC re-establishment procedure itself, the first base station sends a measurement configuration to the UE, which is used to indicate multiple third cells.

The first cell can be the cell with better signal quality among multiple third cells.

For example, the UE also predicts the occurrence of a second abnormal event when multiple third cells are used as the target cell during UE handover. For details, please refer to the description in Implementation Method 1 above. Furthermore, when the UE selects a first cell from multiple third cells, the first cell can be a third cell with good signal quality and no second abnormal event, or a third cell with good signal quality and a relatively low probability of a second abnormal event, or a third cell with good signal quality, a relatively low probability of a second abnormal event, and a relatively high accuracy rate in predicting the probability. This helps ensure the stability of UE communication.

Implementation Method 4: The UE selects a candidate cell for handover.

In one possible approach, before accessing the first cell, the UE also receives third information from the first base station, which indicates configuration information for multiple fourth cells. For example, the third information includes configuration information for multiple fourth cells. The UE measures the downlink reference signals of the multiple fourth cells to obtain signal quality information for each fourth cell. Based on the signal quality information of the multiple fourth cells, the UE determines the first cell from among the multiple fourth cells. Then, the UE switches to the first cell based on its configuration information.

For example, the fourth cell is a candidate cell determined by the first base station for the UE, and the third information is CHO configuration information. The CHO configuration information includes configuration information for multiple fourth cells. The CHO configuration information is, for example, carried in an RRC reconfiguration message.

The configuration information of the fourth cell is used for UE handover to this fourth cell. The configuration information of the fourth cell includes parameter configuration and resource configuration. Specifically, the parameter configuration of the fourth cell includes the C-RNTI generated by its associated base station for the UE; the resources of the fourth cell include the resources required for the UE to randomly access the fourth cell, such as dedicated RACH resources and/or public RACH resources. For example, the configuration information of the fourth cell also includes the execution triggering conditions of the fourth cell. For example, when the UE determines that the downlink reference signal (or signal quality information) of the fourth cell meets the execution triggering conditions of the fourth cell, it autonomously decides to handover to this fourth cell.

The first cell can be the cell with better signal quality among multiple fourth cells.

For example, the UE also predicts the occurrence of a second abnormal event when multiple fourth cells are used as the target cell during UE handover, as detailed in the description of Implementation Method 1 above. Furthermore, when the UE selects a first cell from multiple fourth cells, the first cell can be a fourth cell with good signal quality and no second abnormal event, or a fourth cell with good signal quality and a relatively low probability of the second abnormal event, or a fourth cell with good signal quality, a relatively low probability of the second abnormal event, and a relatively high accuracy rate in predicting the probability. This helps ensure the stability of UE communication.

It should be noted that when the UE determines that the downlink reference signal (or signal quality information) of each fourth cell does not meet its corresponding execution triggering condition based on the configuration information of each fourth cell, the UE may also disregard the execution triggering condition and select the first cell from multiple fourth cells, thereby avoiding the UE failing to select the first cell and affecting the stability of UE communication.

Based on the relevant embodiments in Figure 4, the following are communication methods in several specific scenarios.

Figure 5 illustrates the implementation of the communication method provided in this application in a first specific scenario. During the measurement process, the UE predicts a first abnormal event that may occur between the UE and the serving cell in the future, and when it determines that a first preset condition is met, it sends the measurement result to the first base station. The first base station then sends a handover command message (an example of the fifth information) to the UE based on the measurement result.

Step 501: The first base station sends a measurement configuration to the UE. The measurement configuration includes seventh information and third indication information.

Furthermore, step 501 can be replaced by: step 501a, the serving base station sends a measurement configuration to the UE, the measurement configuration including third indication information; step 501b, the serving base station sends seventh information to the UE. Alternatively, step 501 can be replaced by: step 501a, the serving base station sends a measurement configuration to the UE, the measurement configuration including third indication information; step 501b, the UE obtains predefined (or pre-configured) seventh information. Of course, there may be other methods, which will not be listed in this application.

The seventh information includes one or more of the first preset condition, the first instruction information, and the second instruction information.

For example, the first preset condition is that a first abnormal event will occur between the UE and the serving cell in the future.

For example, the first preset condition is that the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than a first threshold.

For another example, the first preset condition is that the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than a first threshold, and the accuracy of the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than a second threshold.

The first indication information is used to indicate a first abnormal event, which includes at least an RLF and/or a first HOF.

The second indication information is used to indicate at least one measurement item, which includes at least one of the following: measurement identifier, measurement object, report configuration, or measurement event.

The third indication information is used to indicate multiple second cells. For example, the third indication information includes identification information of multiple second cells, or, for example, measurement frequency points associated with multiple second cells.

Step 502: The UE determines the first information based on the model.

The first information is the prediction information of the first abnormal event that will occur between the UE and the serving cell in the future.

Step 503: The UE determines that the first preset condition is met based on the first information.

For example, when the UE determines that the first information indicates that a first abnormal event will occur between the UE and the serving cell in the future, it determines that the first preset condition is met.

For another example, when the UE determines that the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than a first threshold, the UE determines that the first preset condition is met.

For another example, when the UE determines that the first preset condition is met, the probability that the first abnormal event will occur between the UE and the serving cell in the future is greater than a first threshold, and the accuracy of the probability that the first abnormal event will occur between the UE and the serving cell in the future is greater than a second threshold.

Step 504: The UE measures the downlink reference signals of multiple second cells to obtain signal quality information of multiple second cells. Step 504 is located after step 501, but the order of step 504 and step 502 (or step 503) is not limited.

Step 505: The UE sends a measurement report to the first base station.

The measurement report includes signal quality information for multiple second cells.

Optionally, the measurement report may also include first information. Optionally, the measurement report may also include eighth information, which is used to indicate the second cell (i.e., the fifth cell) among the multiple second cells whose prediction information meets the second preset condition.

It can be understood that step 503 is the trigger condition for step 505. That is, once the UE determines that the first preset condition is met, it can send a measurement report to the first base station. This helps to trigger the first base station to send a handover command message to the UE as soon as possible.

Step 506: The first base station selects a target cell (equivalent to the first cell) from multiple second cells based on the measurement report.

For example, the first base station selects the second cell with better signal quality from the multiple second cells as the target cell based on the signal quality information of the multiple second cells.

For example, the measurement report also includes eighth information, which is used to indicate the second cell among the multiple second cells whose prediction information meets the second preset condition. The first base station selects the second cell with better signal quality and no second abnormal event as the target cell based on the signal quality information of the multiple second cells and the eighth information, or the first base station selects the second cell with better signal quality and a relatively low probability of the second abnormal event (or a relatively low probability of the second abnormal event and a relatively high accuracy of the probability) as the target cell.

Step 507: The first base station sends a handover request message to the base station associated with the first cell (i.e., the target base station, or the second base station).

Step 508: The second base station sends a handover request confirmation message to the first base station. Specifically, the second base station generates the configuration information of the first cell and sends a handover request confirmation message to the first base station, the handover request confirmation message including the configuration information of the first cell.

Step 509: The first base station sends a handover command message to the UE. The handover command message includes the configuration information of the first cell.

Step 510: The UE sends a random access request message to the second base station to request access to the first cell.

All the terms and technical solutions mentioned above can be found in the descriptions of the relevant embodiments in Figure 4. For example, the contents not described in detail in steps 501 to 502 can be found in step 401 above; the contents not described in detail in steps 503 to 510 can be found in step 402 above, and the implementation method one after step 402.

Figure 6 illustrates the implementation of the communication method provided in this application in a second specific scenario. During the measurement process, the UE predicts a first abnormal event that may occur between the UE and the serving cell in the future, and sends the measurement result to the first base station when it determines that a first preset condition is met. The first base station then sends CHO configuration information (an example of the sixth information) to the UE based on the measurement result.

Steps 601 to 605 are similar to steps 501 to 505.

Step 606: The first base station selects a candidate cell from multiple second cells based on the measurement report.

There can be K candidate cells, where K is an integer greater than 1.

For example, the first base station selects a second cell with better signal quality from multiple second cells as a candidate cell based on the signal quality information of multiple second cells.

For example, the measurement report also includes eighth information, which is used to indicate the second cell among the multiple second cells whose prediction information meets the second preset condition. The first base station selects the second cell with better signal quality and no second abnormal event as a candidate cell based on the signal quality information of the multiple second cells and the eighth information, or the first base station selects the second cell with better signal quality and a relatively low probability of the second abnormal event (the probability of the second abnormal event is relatively low and the accuracy of the probability is relatively high) as a candidate cell.

Step 607: The first base station sends a handover request message to the base station associated with the candidate cell. Further, for clarity, Figure 6 shows a second base station and a third base station, each associated with one of the two candidate cells.

Here, it is assumed that the base stations used to manage different candidate cells are different; that is, there are also K base stations used to manage K candidate cells, and these K base stations are all different from each other. Of course, in another possible approach, if a base station manages multiple candidate cells, the number of base stations will be less than the number of candidate cells. For example, if there are 10 candidate cells (represented as candidate cell 1 to candidate cell 10), candidate cells 1 to 5 are managed by base station 1, and candidate cells 6 to 10 are managed by base station 2. In this case, the number of base stations used to manage the 10 candidate cells is 2. For ease of description, this application uses the first implementation method as an example, and this description can also be used in other embodiments.

Step 608: The base station associated with the candidate cell sends a handover request confirmation message to the first base station. This message includes configuration information of the candidate cell, which is used by the UE to access the candidate cell. Further, for clarity, Figure 6 shows the second and third base stations sending handover request confirmation messages to the first base station.

Furthermore, in step 606 above, the first base station may select K’ candidate cells. Correspondingly, in step 607, the first base station sends handover request messages to each of the K’ base stations. In step 608, K of the K’ base stations send handover request confirmation messages to the first base station, while the other K’-K base stations send handover request rejection messages to the first base station. For example, if a base station determines that the number of UEs accessing a candidate cell exceeds a preset number, it sends a handover request rejection message to the first base station. Here, K’ is a positive integer greater than K. This explanation can also be applied to other examples; for ease of description, the following examples all use the interaction between the first base station and the K base stations as an example.

Step 609: The first base station sends CHO configuration information to the UE.

Specifically, the CHO configuration information includes the configuration information of K candidate cells. The K candidate cells include the first cell.

Step 610: The UE selects the target cell (equivalent to the first cell) from the candidate cells.

For example, the UE continues to measure the downlink reference signals of K candidate cells to obtain the signal quality information of the K candidate cells. Based on the signal quality information of the K candidate cells, the UE selects the candidate cell with better signal quality from the K candidate cells as the first cell.

For example, in step 609, the configuration information of each candidate cell may further include the execution triggering condition of the candidate cell, which may be determined by the first base station based on the signal quality information of the candidate cell. Thus, in step 610, the UE continues to measure the downlink reference signals of the K candidate cells to obtain the signal quality information of the K candidate cells. Subsequently, the UE can select the candidate cell whose signal quality information meets the execution triggering condition of the candidate cell from the K candidate cells as the target cell.

Step 611: The UE sends a random access request message to the second base station to request access to the first cell.

The second base station is associated with the first cell.

All the terms and technical solutions mentioned above can be found in the descriptions of the relevant embodiments in Figure 4. For example, the contents not described in detail in steps 601 to 602 can be found in step 401 above; the contents not described in detail in steps 603 to 611 can be found in step 402 above, and the second implementation method after step 402.

Figure 7 illustrates the implementation of the communication method provided in this application in a third specific scenario. The UE predicts the occurrence of a first abnormal event between the UE and the serving cell in the future, and initiates an RRC re-establishment process when it is determined that the first preset condition is met.

Step 701: The first base station sends the seventh information to the UE. Correspondingly, the UE receives the seventh information from the first base station.

Step 701 is an optional step. In other possible ways, the UE may also pre-configure (or pre-define) the seventh information.

The seventh information includes one or more of the first preset condition, the first instruction information, and the second instruction information.

For example, the first preset condition is that a first abnormal event will occur between the UE and the serving cell in the future.

For example, the first preset condition is that the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than a first threshold.

For another example, the first preset condition is that the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than a first threshold, and the accuracy of the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than a second threshold.

The first indication information is used to indicate a first abnormal event, which includes at least an RLF and/or a first HOF.

The second indication information is used to indicate at least one measurement item, which includes at least one of the following: measurement identifier, measurement object, report configuration, or measurement event.

Step 702: The UE determines the first information based on the model.

The first information is the prediction information of the first abnormal event that will occur between the UE and the serving cell in the future.

Step 703: The UE determines that the first preset condition is met based on the first information.

For example, when the UE determines that the first information indicates that a first abnormal event will occur between the UE and the serving cell in the future, it determines that the first preset condition is met.

For another example, when the UE determines that the probability of a first abnormal event occurring between the UE and the serving cell in the future is greater than a first threshold, the UE determines that the first preset condition is met.

For another example, when the UE determines that the first preset condition is met, the probability that the first abnormal event will occur in the UE and the serving cell in the future is greater than a first threshold, and the accuracy of the probability that the first abnormal event will occur in the UE and the serving cell in the future is greater than a second threshold.

Step 704: The UE measures the downlink reference signals of multiple third cells to obtain signal quality information of multiple third cells. Based on the signal quality information of multiple third cells, the UE selects the third cell with better signal quality from the multiple third cells as the first cell.

Step 705: The UE sends an RRC re-establishment request message (an example of the second information) to the second base station to access the first cell.

The second base station is associated with the first cell.

Furthermore, the RRC Re-establishment Request message can carry reconstruction reason information.

For example, the reconstruction reason information may include prediction information of a first abnormal event occurring between the UE and the serving cell in the future, or the reconstruction reason information may be the UE predicting that a first abnormal event will occur between the UE and the serving cell in the future, or the reconstruction reason information may be the UE predicting that a first abnormal event will occur between the UE and the serving cell in the future through a model, or the reconstruction reason information may be the UE predicting that an RLF will occur between the UE and the serving cell in the future, etc.

All the terms and technical solutions mentioned above can be found in the descriptions of the relevant embodiments in Figure 4. For example, the contents not described in detail in steps 701 to 702 can be found in step 401 above; the contents not described in detail in steps 703 to 705 can be found in step 402 above, and the implementation method three after step 402.

Figure 8 illustrates the implementation of the communication method provided in this application in a fourth specific scenario. The UE predicts the occurrence of a first abnormal event between the UE and the serving cell in the future, and selects a candidate cell for handover when it is determined that the first preset condition is met.

Steps 801 to 803 are similar to steps 701 to 703.

Step 804: The first base station sends CHO configuration information (an example of third information) to the UE.

Step 804 occurs before step 805, but the order of step 804 with step 801 (or step 802/step 803) is not limited. For example, the seventh message and CHO configuration information can be carried in the same RRC reconfiguration message (in which case, steps 801 and 804 can be considered to occur simultaneously), or they can be carried in different RRC reconfiguration messages.

Specifically, the CHO configuration information includes configuration information for multiple fourth cells. These multiple fourth cells include the first cell.

In one possible example, before the first base station sends the CHO configuration information to the UE, the first base station sends a handover request message to the base station associated with each fourth cell. Subsequently, the base station associated with the fourth cell sends a handover request confirmation message to the first base station. The handover request confirmation message includes the configuration information of the fourth cell, which is used by the UE to access the fourth cell. In this way, the first base station obtains the configuration information of multiple fourth cells, and thus obtains the CHO configuration information.

Step 805: The UE selects the first cell from multiple fourth cells based on the CHO configuration information.

For example, the UE measures the downlink reference signals of multiple fourth cells to obtain signal quality information of multiple fourth cells, and selects the fourth cell with better signal quality from the multiple fourth cells as the first cell based on the signal quality information of multiple fourth cells.

It should be noted that when the UE determines that the downlink reference signal (or signal quality information) of each fourth cell does not meet its corresponding execution triggering condition based on the configuration information of each fourth cell, the UE may also disregard the execution triggering condition and select the first cell from multiple fourth cells, thereby avoiding the UE failing to select the first cell and affecting the stability of UE communication.

Step 806: The UE sends a random access request message to the second base station to request access to the first cell.

The second base station is associated with the first cell.

All the terms and technical solutions mentioned above can be found in the descriptions of the relevant embodiments in Figure 4. For example, the contents not described in detail in steps 801 to 802 can be found in step 401 above; the contents not described in detail in steps 803 to 806 can be found in step 402 above, and the fourth implementation method after step 402.

It should be added that, in the embodiments of Figures 4 to 8, the base station processing operation can be performed by the CU, and the base station transmit and receive operation can be performed by the DU or RU; or, the base station processing operation can be performed by the CU-CP, and the base station transmit and receive operation can be performed by the DU or RU.

Referring to the interaction flow between the first base station and the UE in Figure 5:

For example, the CU can generate a measurement configuration, which it can then send to the DU. The DU can then send the measurement configuration to the UE, or the DU can send the measurement configuration to the RU, which in turn sends it to the UE. Similarly, the DU can receive measurement reports from the UE, or the RU can receive measurement reports from the UE and send them to the DU. Subsequently, the DU sends the measurement reports back to the CU. The CU then determines the handover command message based on the measurement reports.

For example, the CU-CP can generate a measurement configuration, which it can then send to the DU. The DU can then send the measurement configuration to the UE, or it can send it to the RU, which in turn sends it to the UE. Similarly, the DU can receive measurement reports from the UE, or the RU can receive measurement reports from the UE and send them to the DU. The DU then sends the measurement reports back to the CU-CP. The CU-CP determines the handover command message based on the measurement reports.

Of course, CU, DU, RU, and CU-CP can also perform other operations, which will not be listed in this application.

Furthermore, in the O-RAN scenario, the operations performed by the CU can be performed by the O-CU, the operations performed by the DU can be performed by the O-DU, the operations performed by the RU can be performed by the O-RU, and the operations performed by the CU-CP can be performed by the O-CU-CP. Referring to the flow in Figure 5, Figure 9 is a schematic diagram illustrating the interaction flow of various modules within the first base station in an O-RAN scenario provided by this application.

Referring to the interaction flow between the second base station and the UE in Figure 5:

For example, the DU can receive a random access request message from the UE, or the RU can receive a random access request message from the UE and send the random access request message to the DU. Subsequently, the DU sends the random access request message to the CU.

For example, the DU can receive a random access request message from the UE, or the RU can receive a random access request message from the UE and send the random access request message to the DU. Subsequently, the DU sends the random access request message to the CU-CP.

Of course, CU, DU, RU, and CU-CP can also perform other operations, which will not be listed in this application.

Furthermore, in the O-RAN scenario, the operations performed by the CU can be performed by the O-CU, the operations performed by the DU can be performed by the O-DU, the operations performed by the RU can be performed by the O-RU, and the operations performed by the CU-CP can be performed by the O-CU-CP. Referring to the flow in Figure 5, Figure 10 is a schematic diagram illustrating the interaction flow of various modules within a second base station in an O-RAN scenario provided by this application.

It should be noted that the step numbers in the above flowcharts are merely examples of the execution flow and do not constitute a restriction on the order of step execution. In this embodiment, there is no strict execution order between steps that do not have temporal dependencies. Not all steps shown in the flowcharts are mandatory. Some steps can be deleted from the flowcharts as needed, or other possible steps can be added to the flowcharts as needed.

The above focuses on describing the differences between the various implementation methods. Apart from the differences, the implementation methods can be referenced from each other. In addition, different examples of the same implementation method can also be referenced from each other.

It is understood that, in order to implement the functions in the above embodiments, the base station and UE include hardware structures and/or software modules corresponding to perform each function. Those skilled in the art should readily recognize that, based on the units and method steps described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

Figures 11 and 12 are schematic diagrams of possible communication devices provided in embodiments of this application. These communication devices can be used to implement the functions of the UE or base station in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be one of the UEs 120a-120j shown in Figure 1A, or the base station 110a or 110b shown in Figure 1A, or a module (such as a chip) applied to the UE or base station.

As shown in Figure 11, the communication device 1100 includes a processing module 1101 and a transceiver module 1102. The communication device 1100 is used to implement the functions of the UE or base station in the method embodiments shown in Figures 4 to 8 above.

When the communication device 1100 is used to implement the functions of the UE in the method embodiments shown in Figures 4 to 8:

The processing module 1101 is used to acquire first information, which is prediction information for indicating that a first abnormal event will occur between the terminal device and the serving cell in the future; when a preset condition is determined to be met according to the first information, the terminal device accesses the first cell before a first time, where the first time is the predicted occurrence time of the first abnormal event; wherein, the first cell is different from the serving cell.

In one possible implementation, when the processing module 1101 accesses the first cell, it is specifically configured to: control the transceiver module 1102 to send a measurement report to the first access network device, the measurement report including signal quality information of multiple second cells, of which the first cell is included, and the first access network device is associated with the serving cell; control the transceiver module 1102 to receive configuration information of the first cell from the first access network device; and, according to the configuration information of the first cell, switch to the first cell.

In one possible implementation, when the processing module 1101 accesses the first cell, it is specifically used to: control the transceiver module 1102 to send second information to the second access network device; the second information is used to indicate access to the first cell, the first cell is determined by measuring the signals of multiple third cells, the multiple third cells include the first cell, and the second access network device is associated with the first cell.

In one possible implementation, before accessing the first cell, the processing module 1101 is further configured to: control the transceiver module 1102 to receive third information from the first access network device, the third information indicating the configuration information of multiple fourth cells, and the first access network device being associated with the serving cell; when accessing the first cell, the processing module 1101 is specifically configured to: determine the first cell from the multiple fourth cells, the first cell being determined by measuring the signals of the multiple fourth cells; and switch to the first cell according to the configuration information of the first cell.

In one possible implementation, when the processing module 1101 determines that the preset condition is met based on the first information, it is specifically used to: determine that the preset condition is met when the first information indicates that a first abnormal event will occur in the future.

In one possible implementation, when the processing module 1101 determines that the preset condition is met based on the first information, it is specifically used to: determine that the preset condition is met when the first information indicates that the probability of the first abnormal event occurring in the future is greater than the first threshold.

In one possible implementation, when the processing module 1101 determines that the preset condition is met based on the first information, it is specifically used to: determine that the preset condition is met when the first information indicates that the probability of the first abnormal event occurring in the future is greater than a first threshold and the accuracy of the probability of the first abnormal event occurring in the future is greater than a second threshold.

In one possible implementation, when the processing module 1101 acquires the first information, it is specifically configured to: control the transceiver module 1102 to receive fourth information from the first access network device, the fourth information being used to indicate at least one measurement item, the first access network device being associated with the serving cell; measure the reference signal of the serving cell to obtain the measurement results corresponding to the at least one measurement item; and determine the first information based on the measurement results corresponding to the at least one measurement item.

When the communication device 1100 is used to implement the function of the base station in the method embodiment shown in FIG5 or FIG6:

The processing module 1101 is configured to: control the transceiver module 1102 to receive a measurement report, the measurement report including signal quality information of multiple second cells, the measurement report being sent by the terminal device when it determines that the prediction conditions are met based on first information, the first information being prediction information used to indicate that a first abnormal event will occur between the terminal device and the serving cell in the future, and the access network device being associated with the serving cell; and control the transceiver module 1102 to send configuration information of the first cell or configuration information corresponding to one or more candidate cells, the first cell being one of multiple second cells, the configuration information of the first cell or the configuration information corresponding to one or more candidate cells being determined based on the measurement report; the configuration information of the first cell being used by the terminal device to access the first cell, and the configuration information corresponding to one or more candidate cells being used by the terminal device to select from one or more candidate cells and access the first cell.

In one possible implementation, when the transceiver module 1102 sends the configuration information of the first cell, it is specifically used to: send fifth information, the fifth information including the configuration information of the first cell, the fifth information being used to instruct the terminal device to switch to the first cell according to the configuration information of the first cell; or, when the transceiver module 1102 sends the configuration information corresponding to one or more candidate cells respectively, it is specifically used to: send sixth information, the sixth information including the configuration information corresponding to one or more candidate cells respectively, the sixth information being used to instruct the terminal device to select the first cell from one or more candidate cells according to the configuration information corresponding to one or more candidate cells respectively, and switch to the first cell, the one or more candidate cells including the first cell.

A more detailed description of the above-mentioned processing module 1101 and transceiver module 1102 can be obtained directly from the relevant description in the method embodiment shown in Figure 12, and will not be repeated here.

As shown in Figure 12, the communication device 1200 includes a processor 1210 and an interface circuit 1220. The processor 1210 and the interface circuit 1220 are coupled to each other. It is understood that the interface circuit 1220 can be a transceiver or an input/output interface. Optionally, the communication device 1200 may also include a memory 1230 for storing instructions executed by the processor 1210, or storing input data required by the processor 1210 to execute instructions, or storing data generated after the processor 1210 executes instructions.

When the communication device 1200 is used to implement the method shown in any of Figures 4 to 8, the processor 1210 is used to implement the function of the processing module 1101, and the interface circuit 1220 is used to implement the function of the transceiver module 1102.

When the aforementioned communication device is a chip applied to the UE, the UE chip implements the functions of the UE in the above method embodiments. The UE chip receives information from other modules in the UE (such as radio frequency modules or antennas), which is sent to the UE by the base station; or, the UE chip sends information to other modules in the UE (such as radio frequency modules or antennas), which is sent to the base station by the UE.

When the aforementioned communication device is a module applied to a base station, the base station module implements the functions of the base station in the above method embodiments. The base station module receives information from other modules (such as radio frequency modules or antennas) in the base station, which is information sent by the UE to the base station; or, the base station module sends information to other modules (such as radio frequency modules or antennas) in the base station, which is information sent by the base station to the UE. Here, the base station module can be the baseband chip of the base station, or it can be a DU or other modules, where the DU can be a DU under the O-RAN architecture.

It is understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

The method steps in the embodiments of this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a base station or UE. Of course, the processor and storage medium can also exist as discrete components in the base station or UE.

In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer programs or instructions. When a computer program or instruction is loaded and executed on a computer, all or part of the processes or functions of the embodiments of this application are performed. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, a computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or a combination of both.

In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and/or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

In this application, "at least one" means one or more, and "more than one" means two or more. "And/or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and/or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. In the textual description of this application, the character "/" generally indicates an "or" relationship between the preceding and following related objects; in the formulas of this application, the character "/" indicates a "division" relationship between the preceding and following related objects. "Including at least one of A, B, and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B, and C.

It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims (23)

A communication method, characterized in that it is applied to a terminal device and includes: Obtain first information, which is prediction information used to indicate that a first abnormal event will occur between the terminal device and the serving cell in the future; When the preset conditions are met based on the first information, the first cell is accessed before the first time, where the first time is the predicted time of occurrence of the first abnormal event. The first cell is different from the serving cell. The method as described in claim 1, wherein accessing the first cell comprises: A measurement report is sent to a first access network device. The measurement report includes signal quality information of multiple second cells, including the first cell. The first access network device is associated with the serving cell. Receive configuration information of the first cell from the first access network device; Switch to the first cell based on the configuration information of the first cell. The method as described in claim 2, wherein the measurement report further includes prediction information of a second abnormal event occurring when the plurality of second cells are respectively used as target cells for handover of the terminal device. The method as described in claim 3, wherein the second abnormal event includes one or more of the following: handover failure, wireless link failure, ping-pong handover, unnecessary handover, handover too late, or handover too early. The method according to any one of claims 2-4, wherein the measurement report further includes the first information. The method as described in claim 1, wherein accessing the first cell comprises: Send the second information to the second access network device; The second information is used to indicate access to the first cell, which is determined by measuring the signals of a plurality of third cells, including the first cell, and the second access network device is associated with the first cell. The method as described in claim 1, characterized in that, before accessing the first cell, it further includes: Receive third information from a first access network device, the third information indicating configuration information of a plurality of fourth cells, the first access network device being associated with the serving cell; The access to the first cell includes: A first cell is determined from the plurality of fourth cells, wherein the first cell is determined by measuring the signals of the plurality of fourth cells; Switch to the first cell based on the configuration information of the first cell. The method as described in any one of claims 1-7, characterized in that determining that the preset condition is met based on the first information includes: When the first information indicates that a first abnormal event will occur in the future, it is determined that the preset condition is met. The method as described in any one of claims 1-7, characterized in that determining that the preset condition is met based on the first information includes: When the first information indicates that the probability of the first abnormal event occurring in the future is greater than the first threshold, it is determined that the preset condition is met. The method as described in any one of claims 1-7, characterized in that determining that the preset condition is met based on the first information includes: When the first information indicates that the probability of the first abnormal event occurring in the future is greater than a first threshold, and the accuracy of the probability of the first abnormal event occurring in the future is greater than a second threshold, it is determined that the preset condition is met. The method according to any one of claims 1-10, wherein the first abnormal event includes a wireless link failure. The method according to any one of claims 1-11, wherein obtaining the first information includes: Receive fourth information from a first access network device, the fourth information being used to indicate at least one measurement item, the first access network device being associated with the serving cell; Measure the reference signal of the serving cell to obtain the measurement results corresponding to each of the at least one measurement item; The first information is determined based on the measurement results corresponding to the at least one measurement item. The method of claim 12, wherein the at least one measurement item includes at least one of: measurement identifier, measurement object, report configuration, or measurement event. A communication method, characterized in that it is applied to an access network device, comprising: The device receives a measurement report, which includes signal quality information of multiple second cells. The measurement report is sent by the terminal device when it determines that the prediction conditions are met based on first information. The first information is prediction information used to indicate that a first abnormal event will occur between the terminal device and the serving cell in the future. The access network device is associated with the serving cell. The configuration information of the first cell or the configuration information corresponding to one or more candidate cells are sent. The first cell is one of the plurality of second cells. The configuration information of the first cell or the configuration information corresponding to one or more candidate cells is determined according to the measurement report. The configuration information of the first cell is used for the terminal device to access the first cell. The configuration information corresponding to one or more candidate cells is used for the terminal device to select from one or more candidate cells and access the first cell. The method as described in claim 14, wherein sending the configuration information of the first cell includes: Send a fifth message, the fifth message including the configuration information of the first cell, the fifth message being used to instruct the terminal device to switch to the first cell according to the configuration information of the first cell; or, Sending configuration information corresponding to one or more candidate cells includes: Send a sixth message, the sixth message including configuration information corresponding to the one or more candidate cells respectively, the sixth message being used to instruct the terminal device to select the first cell from the one or more candidate cells according to the configuration information corresponding to the one or more candidate cells respectively, and switch to the first cell, the one or more candidate cells including the first cell. The method as described in claim 14 or 15 is characterized in that the measurement report further includes prediction information of a second abnormal event occurring when the plurality of second cells are respectively used as target cells for handover of the terminal device. The method as described in claim 16, wherein the second abnormal event includes one or more of the following: handover failure, wireless link failure, ping-pong handover, unnecessary handover, handover too late, or handover too early. The method according to any one of claims 14-17, wherein the measurement report further includes the first information. The method according to any one of claims 14-18, wherein the first abnormal event includes a wireless link failure. A communication device, characterized in that it includes a module for performing the method as described in any one of claims 1-13, or includes a module for performing the method as described in any one of claims 14-19. A communication device, characterized in that it includes a processor and an interface circuit, the interface circuit being configured to receive signals from other communication devices outside the communication device and transmit them to the processor, or to send signals from the processor to other communication devices outside the communication device, the processor being configured to implement the method as described in any one of claims 1-13 via logic circuits or executable code instructions, or the processor being configured to implement the method as described in any one of claims 14-19 via logic circuits or executable code instructions. A computer-readable storage medium, characterized in that the storage medium stores a computer program or instructions that, when executed by a communication device, implement the method as described in any one of claims 1-13, or implement the method as described in any one of claims 14-19. A computer program product, characterized in that the computer program product includes a computer program or instructions, which, when executed by a communication device, implement the method as described in any one of claims 1-13, or implement the method as described in any one of claims 14-19.