Cell access method and related apparatus

Abstract

A cell access method and a related apparatus, which relate to the technical field of communications. In the method, a network side may issue to a terminal an SSB measurement configuration used for cell access; the terminal obtains a measurement result for SSBs on the basis of the SSB measurement configuration, and selects a first SSB from among the SSBs; and when autonomously determining that the first SSB belongs to a neighboring cell of the same network device, the terminal may directly access the neighboring cell without reporting the measurement result and exchanging inter-network signaling. In this way, signaling overheads and power consumption of terminal sides and network sides are greatly reduced.

Description

Cell access methods and related devices

[0001] This application claims priority to Chinese Patent Application No. 202411653905.9, filed with the China National Intellectual Property Administration on November 18, 2024, entitled “Cell Access Method and Related Apparatus”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a cell access method and related apparatus. Background Technology

[0003] Non-terrestrial networks (NTNs) refer to networks that use radio frequency resources on satellite platforms (including low-, medium-, and high-orbit satellites, unmanned aerial vehicle (UAV) platforms, or high-altitude communication platforms) to provide communication services. Compared to terrestrial communication systems, satellite communication systems are characterized by wider coverage areas per satellite, greater transmission loss, and faster mobility. Unlike terrestrial systems where a maximum of 8 or 64 synchronization signal blocks can cover the service area of ​​a single base station, satellite communication systems may require hundreds or even thousands of synchronization signal block beams. Even with some beam widening, hundreds of beams are still needed to maintain the gain level to achieve coverage. Using a multi-cell approach with a single satellite can increase the number of beams providing coverage.

[0004] The typical cell handover process in terrestrial communication systems generally includes the terminal taking measurements based on reference signals and reporting the results to the source base station, the source base station making a handover decision, and signaling interaction between the source and target base stations. It is evident that the current cell handover process incurs significant signaling overhead and power consumption. Summary of the Invention

[0005] This application provides a cell access method and related apparatus, which can reduce signaling overhead and power consumption on the terminal side and the network side.

[0006] Firstly, this application provides a cell access method, which is executed by a terminal device. For example, the terminal device may be a terminal equipment, or it may be executed by a component of the terminal equipment (e.g., a chip, chip system, processor, or circuit), or it may be executed by hardware and / or software implementing all or part of the terminal equipment's functions; this application does not limit the scope of the method. In this method, the terminal device receives a Synchronization Signal Block (SSB) measurement configuration for cell access, where cell access includes cell reselection or cell handover; the terminal device obtains the SSB measurement result based on the SSB measurement configuration; the terminal device selects a first SSB based on the SSB measurement result; the terminal device determines that the first SSB belongs to a neighboring cell of the current serving cell, and performs cell access in the neighboring cell.

[0007] Based on this method, when the terminal device determines that the first SSB it maintains belongs to a neighboring cell of the current serving cell based on SSB measurement, it can directly access the cell without measurement reporting and a series of signaling interactions between the terminal side and the network side, thus reducing the signaling overhead and power consumption between the terminal side and the network side.

[0008] In one possible design, the cell access method further includes: the terminal device determining that the first SSB belongs to the current serving cell and maintaining access in the current serving cell.

[0009] Based on this method, the terminal device determines that the first SSB it maintains is still the current serving cell, and can continue to maintain access in the current serving cell.

[0010] In one possible design, the current serving cell and neighboring cells belong to the same network device.

[0011] Using this method for cell access also saves signaling interaction between network devices, further reducing signaling overhead and power consumption on the network device side.

[0012] In one possible implementation, the SSB measurement configuration includes measurement information of at least one SSB, and the at least one SSB includes a first SSB.

[0013] Based on this implementation method, the terminal device can determine whether the first SSB belongs to the current serving cell or a neighboring cell of the current serving cell based on the measurement information of the SSB.

[0014] This measurement information includes, but is not limited to, the following possible designs:

[0015] In one possible design, the measurement information includes an index of at least one SSB. Based on this method, the terminal device can directly determine the SSB to be measured.

[0016] In another possible design, the measurement information includes a waveform identifier corresponding to at least one SSB. Based on this method, the terminal device can calculate the index of each SSB based on its corresponding waveform identifier to determine the SSB to be measured.

[0017] In another possible design, the measurement information includes a time offset and duration for determining the time window in which the at least one SSB is located. Optionally, the time offset is the time offset of the start time position of the SSB to be measured relative to the SSB of the current serving cell; the duration is the duration of the time window of the SSB to be measured. In this method, the terminal device determines the time window of the SSB to be measured based on the time offset and duration, thereby obtaining the SSB to be measured.

[0018] In one possible implementation, the SSB measurement configuration also includes identifiers of multiple cells (such as physical cell identifiers (PCIs)), including neighboring cells.

[0019] Based on this implementation method, the terminal device can determine whether the first SSB belongs to the current serving cell or a neighboring cell of the current serving cell based on the cell identifier corresponding to the first SSB.

[0020] In one possible implementation, the SSB measurement configuration further includes: a maximum number of cycles for filtering and averaging multiple measurement results of the same SSB for at least one SSB in multiple cycles, and a minimum level threshold. Filtering and averaging refers to averaging the measurement results of the same SSB across multiple cycles, such as signal quality indicators used to characterize signal quality, and using the average value as the measurement result of the SSB. The maximum number of cycles is the maximum number of cycles for averaging the measurement results of the same SSB. The minimum level threshold is the lowest level threshold of the measurement results of the same SSB across multiple cycles that can be used for filtering and averaging; that is, among the measurement results of the same SSB across multiple cycles, the measurement results of SSBs with levels lower than the minimum level threshold cannot be used to calculate the average value of the measurement results of that SSB. Optionally, the terminal device may not retain the measurement results of SSBs with levels lower than the minimum level threshold. Optionally, this implementation is mainly applied to situations where the transmission gain on the network side does not change drastically.

[0021] Based on this implementation method, by designing the filtering period and minimum level threshold configured on the network side, the terminal side can merge the measurement results of multiple periods, thereby improving the stability and accuracy of the measurement results.

[0022] In one possible implementation, the terminal device selects a first SSB based on the SSB measurement results. This first SSB can be the SSB with the best or optimal signal quality among the measured SSBs, or it can be an SSB whose signaling quality meets a certain threshold requirement and certain conditions. These certain conditions can be predefined or configured on the network side or the terminal side; this embodiment does not limit the specific conditions.

[0023] In one possible implementation, the information included in the SSB measurement configuration is carried in at least one of the following: a system message block or a main information block. In another possible implementation, the information included in the SSB measurement configuration is carried in Radio Resource Control (RRC) public signaling or RRC private signaling.

[0024] In one possible implementation, the terminal device receives a mobility measurement configuration in addition to the SSB measurement configuration for cell access. This mobility measurement configuration is used by the terminal device to execute mobility management procedures for neighboring network devices of the currently accessing network device.

[0025] Based on this method, it is beneficial for terminal devices to use the cell access method described in this application for neighboring cells of the same network device without reporting measurement results or conducting signaling interactions between network devices; for neighboring cells of adjacent network devices, mobility management procedures can be executed based on mobility measurement configuration to perform cell handover or cell reselection.

[0026] Secondly, this application also provides a cell access method, which is executed by a network device. For example, the network device may be a network equipment, or it may be executed by a component of the network equipment (e.g., a chip, chip system, processor, or circuit), or it may be executed by hardware and / or software implementing all or part of the functions of the network equipment; this application does not limit this. In this method, the network device determines and sends a Synchronization Signal Block (SSB) measurement configuration for cell access, which includes cell reselection or cell handover. This SSB measurement configuration is used by the terminal device to select a first SSB based on the SSB measurement result. When it is determined that the first SSB belongs to a neighboring cell of the current serving cell, cell access is performed in the neighboring cell.

[0027] Based on this method, when a terminal device determines that the first SSB it maintains belongs to a neighboring cell of the current serving cell, it can directly access the cell without performing measurement reporting and a series of signaling interactions between the terminal side and the network side, thus reducing the signaling overhead and power consumption between the terminal side and the network side.

[0028] Optionally, other alternative implementations of the SSB measurement configuration and other alternative implementations of this aspect, and their beneficial effects, can be found in the relevant content described in the first aspect, which will not be detailed here.

[0029] Thirdly, this application provides a cell access method, which is executed by a terminal device. For example, the terminal device may be a terminal equipment, or it may be executed by a component of the terminal equipment (e.g., a chip, chip system, processor, or circuit), or it may be executed by hardware and / or software implementing all or part of the terminal equipment's functions; this application does not limit this. In this method, the terminal device receives a Synchronization Signal Block (SSB) measurement configuration for cell access. Cell access includes cell reselection or cell handover. The SSB measurement configuration includes measurement information of at least one SSB in neighboring cells. The terminal device obtains the measurement results of at least one SSB in the neighboring cells according to the SSB measurement configuration. The terminal device selects a first SSB based on the measurement results of at least one SSB in the neighboring cells. Cell access is then performed in the neighboring cell based on the first SSB.

[0030] Based on this method, since the SSB measurement configuration includes measurement information of at least one SSB in the neighboring cells, and the first SSB is selected from at least one SSB in the neighboring cells, the terminal device can directly access the cell in the neighboring cell according to the first SSB, without the need for measurement reporting and a series of signaling interactions between the terminal side and the network side, thus reducing the signaling overhead and power consumption between the terminal side and the network side.

[0031] In one possible design, the current serving cell and neighboring cells belong to the same network device.

[0032] Using this method for cell access also saves signaling interaction between network devices, further reducing signaling overhead and power consumption on the network device side.

[0033] In one optional implementation, if the measurement results of at least one SSB do not meet the selection conditions (e.g., the signal quality is all below a certain threshold) and the first SSB cannot be obtained, the terminal device can maintain access to the current serving cell without performing cell handover or cell reselection.

[0034] Based on this method, signaling interaction between the terminal side and the network side can be avoided, reducing signaling overhead and power consumption.

[0035] In one optional implementation, the terminal device receives a mobility measurement configuration in addition to the SSB measurement configuration for cell access. This mobility measurement configuration is used by the terminal device to execute mobility management procedures for neighboring network devices of the currently accessing network device.

[0036] Based on this method, it is beneficial for terminal devices to use the cell access method described in this application for neighboring cells of the same network device without reporting measurement results or conducting signaling interactions between network devices; for neighboring cells of adjacent network devices, mobility management procedures can be executed based on mobility measurement configuration to perform cell handover or cell reselection.

[0037] In this regard, possible design methods for measurement information and optional implementation methods for SSB measurement configurations can be found in the relevant content described in the first aspect, and will not be detailed here.

[0038] Fourthly, this application provides a cell access method, which is executed by a network device. For example, the network device may be a network equipment, or it may be executed by a component of the network equipment (e.g., a chip, chip system, processor, or circuit), or it may be executed by hardware and / or software implementing all or part of the functions of the network equipment; this application does not limit this. In this method, the network device determines and sends a Synchronization Signal Block (SSB) measurement configuration for cell access. Cell access includes cell reselection or cell handover. The SSB measurement configuration includes measurement information of at least one SSB in neighboring cells. The SSB measurement configuration is used by a terminal device to obtain the measurement results of at least one SSB in a neighboring cell and, based on a first SSB selected therefrom, perform cell access in the neighboring cell.

[0039] Based on this method, since the SSB measurement configuration includes measurement information of at least one SSB in the neighboring cells, and the first SSB is selected by the terminal device from at least one SSB in the neighboring cells, the terminal device can directly access the neighboring cells according to the first SSB without performing measurement reporting and a series of signaling interactions between the terminal side and the network side, thereby reducing the signaling overhead and power consumption between the terminal side and the network side.

[0040] In another optional implementation, the network configuration, in addition to determining and sending the SSB measurement configuration for cell access, also determines and sends mobility measurement configurations for other network devices (such as neighboring satellites). This mobility measurement configuration is used by the terminal device to execute mobility management procedures for neighboring network devices of the currently accessed network device.

[0041] Based on this method, when a terminal device determines that the first SSB does not belong to the current serving cell or a neighboring cell of the same network device, it can execute the mobility management process based on mobility measurement configuration to perform cell handover or cell reselection.

[0042] In this regard, possible design methods for measurement information and optional implementation methods for SSB measurement configurations can be found in the relevant content described in the first aspect, and will not be detailed here.

[0043] Fifthly, this application also provides a cell access method, which is executed by a terminal device. For example, the terminal device may be a terminal equipment, or it may be executed by a component of the terminal equipment (e.g., a chip, chip system, processor, or circuit), or it may be executed by hardware and / or software implementing all or part of the terminal equipment's functions; this application does not limit this. In this method, the terminal device receives a Measurement Timing Configuration (SMTC) based on a synchronization signal block. The SMTC includes first information indicating that the SMTC belongs to the currently accessed network device. Based on the first information and the SMTC, the terminal device obtains the measurement results of at least one cell in the network device, where the at least one cell includes neighboring cells of the currently serving cell. Based on the measurement results of the at least one cell, the terminal device selects a first cell. The terminal device determines that the first cell belongs to a neighboring cell and performs cell access in the neighboring cell.

[0044] Based on this method, after the terminal device obtains the SMTC and performs SSB measurement, it can independently determine whether it needs to perform measurement reporting and execute a complete cell handover or cell reselection process. When the SMTC belongs to the network device it is currently accessing and the terminal device determines that the first cell belongs to a neighboring cell, it can directly access the cell without measurement reporting and other related processes, thereby reducing the signaling overhead and power consumption between the terminal side and the network side.

[0045] In one possible design, the terminal device determines that the first cell belongs to the current serving cell and maintains access in the current serving cell.

[0046] In one possible design, the terminal device receives not only the SMTC belonging to the currently accessed network device, but also the SMTC belonging to the neighboring network devices of the currently accessed network device. The SMTC of the neighboring network device is used by the terminal device to perform mobility management procedures on that neighboring network device.

[0047] Based on this method, it is beneficial for terminal devices to use the cell access method described in this application for the same network device without reporting measurement results or conducting signaling interactions between network devices; for adjacent network devices, it is possible to execute mobility management procedures based on mobility measurement configuration to perform cell handover or cell reselection.

[0048] In one possible design, the terminal device receives an SMTC and determines whether the SMTC belongs to the currently accessed network device or a neighboring network device. If it belongs to the currently accessed network device, the terminal device executes a process to obtain the measurement results of at least one cell in the network device based on the first information and the SMTC, and directly accesses the cell in the neighboring cell. If it belongs to a neighboring network device, the terminal device executes a mobility management process based on the SMTC of the neighboring network device to perform cell handover or cell reselection.

[0049] Sixthly, this application also provides a cell access method, which is executed by a network device. For example, the network device may be a network equipment, or it may be executed by a component of the network equipment (e.g., a chip, chip system, processor, or circuit), or it may be executed by hardware and / or software implementing all or part of the functions of the network equipment; this application does not limit this. In this method, the network device determines and sends an SMTC, which includes first information indicating that the SMTC belongs to the currently accessing network equipment. The SMTC is used by the terminal device to obtain measurement results of at least one cell in the network equipment and select a first cell from among them. If the first cell belongs to a neighboring cell, cell access is performed in the neighboring cell.

[0050] Based on this method, after the terminal device performs SSB measurement based on SMTC, it can independently determine whether it needs to perform measurement reporting and execute the complete cell handover or cell reselection process. This allows the terminal device to directly access the cell when SMTC belongs to the network device it is currently accessing and the first cell is determined to be a neighboring cell, without the need for measurement reporting and other related processes, thereby reducing the signaling overhead and power consumption between the terminal side and the network side.

[0051] In one possible design, in addition to determining and sending the SMTC belonging to the currently accessed network device, the network device also determines and sends the SMTCs of neighboring network devices belonging to the currently accessed network device. The SMTC of the neighboring network device is used by the terminal device to perform mobility management procedures on that neighboring network device.

[0052] Based on this method, when the terminal device cannot select the first cell that meets the cell access conditions, it can perform the mobility management process based on the SMTC of the adjacent network device to perform cell handover or cell reselection.

[0053] In one possible design, the network device determines and sends an SMTC, which is used by the terminal device to determine whether it belongs to the currently accessed network device or a neighboring network device. If it belongs to the currently accessed network device, the terminal device executes a process of obtaining the measurement results of at least one cell in the network device based on the first information and the SMTC, and directly performs cell access in the neighboring cell. If it belongs to a neighboring network device, the terminal device executes a mobility management process based on the SMTC of the neighboring network device to perform cell handover or cell reselection.

[0054] Seventhly, this application also provides a cell access method, which is executed by a terminal device. For example, the terminal device may be a terminal equipment, or it may be executed by a component of the terminal equipment (e.g., a chip, chip system, processor, or circuit), or it may be executed by hardware and / or software implementing all or part of the terminal equipment's functions; this application does not limit this. In this method, the terminal device receives a Measurement Timing Configuration (SMTC) based on a synchronization signal block. The SMTC includes first information indicating that the SMTC belongs to a neighboring cell of the current serving cell, and the neighboring cell and the serving cell belong to the same network device. The terminal device obtains the measurement results of at least one cell in the network device based on the first information and the SMTC. The terminal device selects a first cell based on the measurement results of the at least one cell. The terminal device performs cell access in the first cell.

[0055] Based on this method, after the terminal device obtains the SMTC and performs SSB measurement, it can independently determine whether it needs to perform measurement reporting and execute a complete cell handover or cell reselection process. When the SMTC belongs to a neighboring cell of the current serving cell and the terminal device selects the first cell based on the measurement results of at least one cell, it can directly access the cell in the first cell without the need for measurement reporting and other related processes, thereby reducing the signaling overhead and power consumption between the terminal side and the network side.

[0056] In one possible design, the terminal device receives not only the SMTC of neighboring cells belonging to the current serving cell, but also the SMTC of neighboring network devices. The SMTC of the neighboring network devices is used by the terminal device to perform mobility management procedures on those neighboring network devices.

[0057] Based on this method, when the terminal device cannot select the first cell that meets the cell access conditions, it can perform the mobility management process based on the SMTC of the adjacent network device to perform cell handover or cell reselection.

[0058] In one possible design, the terminal device receives the SMTC and determines whether the SMTC belongs to a neighboring cell of the same network device or to an adjacent network device. If it belongs to a neighboring cell of the same network device, the process of obtaining the measurement results of at least one cell in the network device is performed, and cell access is directly performed in the selected first cell. If it belongs to an adjacent network device, the mobility management process is performed based on the SMTC of the adjacent network device to perform cell handover or cell reselection.

[0059] Eighthly, this application also provides a cell access method, which is executed by a network device. For example, the network device may be a network equipment, or it may be executed by a component of the network equipment (e.g., a chip, chip system, processor, or circuit), or it may be executed by hardware and / or software implementing all or part of the functions of the network equipment; this application does not limit this. In this method, the network device determines and sends a Measurement Timing Configuration (SMTC) based on a synchronization signal block. The SMTC includes first information indicating that the SMTC belongs to a neighboring cell of the current serving cell, and the neighboring cell and the serving cell belong to the same network equipment. The SMTC is used by a terminal device to obtain measurement results of at least one cell in the network equipment, select a first cell from among them, and perform cell access in the first cell.

[0060] Based on this method, after the terminal device obtains the SMTC and performs SSB measurement, it can independently determine whether it needs to perform measurement reporting and execute a complete cell handover or cell reselection process. When the SMTC belongs to a neighboring cell of the current serving cell and the terminal device selects the first cell based on the measurement results of at least one cell, it can directly access the cell in the first cell without the need for measurement reporting and other related processes, thereby reducing the signaling overhead and power consumption between the terminal side and the network side.

[0061] In one possible design, in addition to identifying and sending the SMTC of neighboring cells belonging to the current serving cell, the network device also identifies and sends the SMTC of neighboring network devices. The SMTC of the neighboring network device is used by the terminal device to perform mobility management procedures on that neighboring network device.

[0062] Based on this method, it is beneficial for terminal devices to use the cell access method described in this application for neighboring cells of the same network device without reporting measurement results or conducting signaling interactions between network devices; for neighboring cells of adjacent network devices, mobility management procedures can be executed based on mobility measurement configuration to perform cell handover or cell reselection.

[0063] Ninthly, this application provides a communication device that has the function of implementing any one of the first to eighth aspects or any optional implementation of any one aspect. For example, the communication device includes modules, units or means corresponding to the operations involved in any one of the first to eighth aspects or any optional implementation of any one aspect. The modules, units or means can be implemented by software, or by hardware, or by a combination of software and hardware.

[0064] Tenthly, this application provides a communication device including one or more processors. The one or more processors are coupled to a memory. The memory is used to store part or all of a computer program or instructions necessary for implementing the functions involved in any one of the first to eighth aspects or any optional implementation of any one of the aspects. The one or more processors are capable of executing the computer program or instructions, which, when executed, cause the communication device to implement the methods in any one of the first to eighth aspects or any possible design or implementation of any one of the aspects.

[0065] In one possible design, the communication device may also include the memory.

[0066] In one possible design, the communication device further includes an interface circuit for implementing communication functions within the communication device and / or communication functions between the communication device and other devices or components. For example, the processor communicates with other devices or components through the interface circuit.

[0067] The aforementioned communication device may be a terminal, or a component of a terminal (such as a chip, chip system, processor, or circuit).

[0068] The aforementioned communication device may be a network device or a component of a network device (such as a chip, chip system, processor, or circuit).

[0069] Eleventhly, this application provides a communication system comprising a terminal device and a network device; the terminal device is configured to execute the method described in the first aspect or any possible embodiment of the first aspect, and the network device is configured to execute the method described in the second aspect or any possible embodiment of the second aspect. Alternatively, the terminal device is configured to execute the method described in the third aspect or any possible embodiment of the third aspect, and the network device is configured to execute the method described in the fourth aspect or any possible embodiment of the fourth aspect. Alternatively, the terminal device is configured to execute the method described in the fifth aspect or any possible embodiment of the fifth aspect, and the network device is configured to execute the method described in the sixth aspect or any possible embodiment of the sixth aspect. Alternatively, the terminal device is configured to execute the method described in the seventh aspect or any possible embodiment of the seventh aspect, and the network device is configured to execute the method described in the eighth aspect or any possible embodiment of the eighth aspect.

[0070] In a twelfth aspect, this application provides a computer-readable storage medium storing computer-readable instructions that, when read and executed by a computer, cause the computer to perform any one of the first to eighth aspects or any possible design of any one of the aspects.

[0071] In a thirteenth aspect, this application provides a computer program product that, when read and executed by a computer, causes the computer to perform any one of the first to eighth aspects or any one of the possible designs in any one aspect. Attached Figure Description

[0072] Figure 1 is a schematic diagram of a measurement time window;

[0073] Figure 2 is a schematic diagram of a typical handover process;

[0074] Figure 3 is a schematic diagram of a condition switching process;

[0075] Figure 4 is a schematic diagram of an LTM switching process;

[0076] Figure 5 is a schematic diagram of an NTN scenario based on transparent load transmission;

[0077] Figure 6 is a schematic diagram of an NTN scenario based on regenerative load;

[0078] Figure 7 is a schematic diagram of the architecture of a communication system;

[0079] Figure 8 is a schematic diagram of the SSB (Satellite Service Bus) of a satellite in a satellite communication system;

[0080] Figure 9 is a schematic diagram of a single satellite with multiple cells in a satellite communication system;

[0081] Figure 10 is a flowchart illustrating a cell handover method provided in an embodiment of this application;

[0082] Figure 11 is a schematic diagram of determining the SSB to be measured according to an embodiment of this application;

[0083] Figure 12 is a flowchart illustrating another cell handover method provided in an embodiment of this application;

[0084] Figure 13 is a flowchart illustrating another cell handover method provided in an embodiment of this application;

[0085] Figure 14 is a schematic diagram of determining SMTC according to an embodiment of this application;

[0086] Figure 15 is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0087] Figure 16 is a schematic diagram of the structure of a terminal provided in an embodiment of this application. Detailed Implementation

[0088] To facilitate a clear description of the technical solutions of the embodiments of this application, the following points will be explained before introducing the solutions of this application.

[0089] (1) "And / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone, where A and B can be singular or plural. In the description of this application, unless otherwise stated, "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0090] (2) “Instruction” can include direct instruction, indirect instruction, explicit instruction, and implicit instruction. When describing a certain instruction information or when an instruction is used to instruct A, it can be understood that the instruction information carries A, directly instructs A, or indirectly instructs A.

[0091] The instruction information, or the information that the instruction indicates, is called the instruction-to-instruction information. In practical implementation, there are many ways to instruct the instruction-to-instruction information, such as, but not limited to, directly instructing the instruction-to-instruction information itself or its index. It can also indirectly instruct the instruction-to-instruction information by instructing other information, where there is a correlation between the other information and the instruction-to-instruction information. Furthermore, it can instruct only a part of the instruction-to-instruction information, while the other parts are known or pre-agreed upon. For example, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing instruction overhead to some extent. In addition, the instruction-to-instruction information can be sent as a whole or divided into multiple sub-information pieces, and the sending period and / or timing of these sub-information pieces can be the same or different.

[0092] (3) "Send" and "receive" indicate the direction of signal transmission. For example, "send information to XX" can be understood as the destination of the information being XX, which can include sending directly through the air interface or sending indirectly through the air interface by other units or modules. "receive information from YY" can be understood as the source of the information being YY, which can include receiving directly from YY through the air interface or receiving indirectly from YY through the air interface by other units or modules.

[0093] "Sending" can also be understood as the "output" of a chip interface, and "receiving" can be understood as the "input" of a chip interface. In other words, sending and receiving can occur between devices, such as between network devices and terminal devices, or within a device, such as between components, modules, chips, software modules, or hardware modules within the device via buses, traces, or interfaces. Furthermore, unless otherwise specified, "transmission" includes receiving and / or sending. For example, transmitting signals can include receiving signals and / or sending signals.

[0094] For example, in this application, "sending information" can be understood as one device sending information to another device, or it can also be understood as one logical module within a device sending information to another logical module. For example, "terminal sending information" can be understood as a terminal sending information to another device (such as an access network device), or it can be understood as logical module 1 in the terminal sending information to logical module 2 in the terminal.

[0095] For example, in this application, "receiving information" can be understood as one device receiving information from another device, or it can also be understood as a logical module within a device receiving information from another logical module. For example, "terminal device receiving information" can be understood as a terminal device receiving information from another device (such as a network device), or it can be understood as logical module 1 in the terminal receiving information from logical module 2 in the network device.

[0096] In this application, the phrase "sending information to... (e.g., a terminal device)" or the related illustrations in the accompanying drawings can be understood as the destination of the information being an access network device. This can include sending information directly or indirectly to an access network device. Similarly, the phrases "receiving information from... (e.g., a network device)," "receiving information from... (e.g., a network device)," or "receiving information sent (e.g., by a network device)," or the related illustrations in the accompanying drawings, can be understood as the source of the information being a network device. This can include receiving information directly or indirectly from a network device. Information may undergo necessary processing between the source and destination, such as format changes, but the destination can understand the valid information from the source. Similar expressions in this application can be interpreted similarly, and will not be elaborated further here.

[0097] (4) Information C is used to determine information D, which includes both information D being determined solely based on information C and information D being determined based on information C and other information. In addition, information C can also be used to determine information D indirectly, for example, information D is determined based on information E, and information E is determined based on information C.

[0098] (5) "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.

[0099] (6) In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terms 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.

[0100] (7) In this application, "first" and "second" are used for convenience of description to distinguish objects and are not intended to limit the scope of the embodiments of this application, nor are they used to describe the order or sequence of features. It should be understood that the objects described in this way can be interchanged where appropriate so as to describe solutions other than those in the embodiments of this application.

[0101] (8) The words “exemplary” or “for example” are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as “exemplary” or “for example” in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words “exemplary” or “for example” is intended to present the relevant concepts in a specific manner.

[0102] (9) "Information", such as first information, can be a message or the content of a message.

[0103] (10) “The network device sends to the terminal device”, correspondingly, “the terminal device receives from the network device” or “the terminal device receives the network device sending”; similarly, “the network device receives the terminal device sending”, correspondingly, “the terminal device sends to the network device” or “the network device receives the terminal device sending”, which will not be elaborated here.

[0104] For ease of understanding, examples are provided to illustrate some concepts related to the embodiments of this application, as shown below.

[0105] 1. Beam Management

[0106] In communication systems, the movement of a terminal causes it to select and switch between different beams of network equipment. Specifically, when the terminal is in a disconnected state (e.g., idle or inactive), movement causes beam reselection; when the terminal is in a connected state, movement causes beam switching. The determination of beam reselection and switching generally relies on beam management.

[0107] Beam management refers to the beam pairing process where communicating parties align and obtain the optimal transmit and receive beams. Through beam management, the terminal obtains the transmit and receive beam directions for data transmission, signal reception, link recovery, and other related processes. There are two main types of reference signals used for beam management: synchronization signal blocks (SSBs) and channel state information-reference signals (CSI-RS). For example, taking SSB-based beam management as an example, the SSB is associated with the physical random access channel (PRACH) occasion and the preamble index within each PRACH occasion. The network device transmits SSBs using beam scanning. The terminal measures each SSB and selects one with the strongest or best signal quality. It then uses the preamble corresponding to the selected SSB for random access. The network device detects this preamble to determine the beam selected by the terminal, thus completing the management of the transmit beam on the network device side and the receive beam on the terminal side.

[0108] In beam management, SSB measurement is primarily enabled by configuring reference signal resources on the network side, allowing terminals to perform measurements in both connected and disconnected states. In beam management, for terminals in a disconnected state, the SSB resources to be measured are indicated by ssb-PositionsInBurst in system information block 1 (SIB1) (by default, the terminal measures all SSBs within one cycle); for terminals in a connected state, the SSB index to be measured can be indicated by the measurement resource configuration in RRC signaling.

[0109] The measurement results of the SSB obtained by the terminal measurement may include, but are not limited to, at least one of the following indicators used to characterize signal quality: reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-noise ratio (SINR), and received signal strengthen indicator (RSSI). Accordingly, the SSB with the larger signal strength or the best signal quality can be determined based on the above indicators.

[0110] 2. Mobility Management

[0111] In communication systems, terminal movement causes the terminal to select and switch access between different network devices. Specifically, when the terminal is in a disconnected state (e.g., idle or inactive), movement causes cell reselection; when the terminal is in a connected state, movement causes handover between cells. The determination of cell reselection and handover states generally relies on mobility management procedures.

[0112] Mobility management processes mainly refer to measurement processes related to radio resource management (RRM) and mobility signaling processes triggered by measurement results. In mobility management, the network side issues RRM measurement tasks to the terminal, including two basic measurement configurations: (1) Measurement object: specifying the frequency band to be measured, the form of the reference signal, and the time domain location of the reference signal to be measured, etc. (2) Measurement reporting: specifying the conditions for triggering the measurement and the method of reporting the measurement results, etc. Similar to beam management, the reference signals used for RRM measurements are mainly SSB and CSI-RS.

[0113] In mobility management (MRM), SSB (Security Shield) measurement is primarily enabled by SSB-based measurement timing configuration (SMTC), allowing terminals to perform measurements in both connected and disconnected states. In SSB-based mobility management, SSBs are often not continuous in the time domain. Therefore, terminals do not need to continuously search for and measure SSBs in the time domain; instead, they can operate within a time window where these SSBs are located. This is why SMTC is introduced in RRM-related measurement configurations. SMTC is configured with intervals in the time domain based on a certain period (e.g., new radio access technology (NR) defines a minimum period of 5ms and a maximum period of 160ms). The measurement window of SMTC maintains a fixed duration (e.g., NR defines a minimum of 1ms and a maximum of 5ms). From a measurement perspective, the terminal searches for and measures SSBs within the SMTC's measurement window and assumes that SSBs outside the SMTC do not exist. Optionally, the network side configures a Single-Mode Controller (SMTC) for each SSB measurement frequency. For intra-frequency measurements, the SSBs to be measured in multiple cells are all included in this single SMTC, which is sent to the terminal by the network side of the serving cell. Additionally, for individual cells with the same center frequency for the SSB, the network side can configure another SMTC with a shorter period, but the measurement windows of the two SMTCs must remain consistent over a long period. When the center frequencies and subcarrier spacing of the SSBs measured in two cells are the same, the RRM measurement between these two cells is called intra-frequency measurement.

[0114] In SSB-based mobility management, the SMTC for terminals in non-connected state is mainly configured in the intraFreqCellReselectionInfo of SIB2 and the InterFreqCarrierFreqInfo of SIB4; the SMTC for terminals in RRC connected state is mainly configured in the MeasObjectNR of RRC signaling. System messages SIB2 / SIB4 can be configured at the cell or region level and broadcast via the network side, while RRC signaling can be configured at the user level, meaning each user has different configured parameters.

[0115] For example, the four SMTCs defined based on SSB mobility management are SMTC1 to 4, where:

[0116] SMTC1 is defined as the primary measurement configuration, comprising three parameters: periodicity, offset, and duration. The periodicity specifies the frequency at which the terminal measures SSBs, and the offset specifies the starting time position of the terminal's SSB measurement. The starting time position of the SSB measurement equals the starting frame number of the measurement period plus the offset time, and cannot exceed the configured period. The duration controls the length of the time window for the terminal to measure SSBs.

[0117] SMTC2 mainly includes a cell list (pci-list) and a period. Compared with SMTC1, SMTC2 only performs SSB measurements on some specific cells, and the period is generally shorter than that of SMTC1, but it reuses the same bias and duration as SMTC1.

[0118] SMTC3 not only configures the period, offset, duration, and cell list separately, but also specifies the SSB index to be measured. However, it is generally used in integrated access and backhaul (IAB) scenarios. In actual NTN scenarios, where the number of satellite SSB beams is relatively large, the values ​​of SMTC's period, offset, and duration can be appropriately expanded to ensure that the SSB to be measured can be included in the configured SMTC window.

[0119] SMTC4 is configured to address the varying arrival times of different satellites. For example, in an NTN scenario, the arrival times of serving satellites and neighboring satellites to the terminal differ. If the same offset configuration is used, the SSBs of neighboring satellites may not be measured within the configured duration, leading to measurement failure. As shown in Figure 1, if the measurement time window includes SSBs transmitted by the serving satellite but not those transmitted by neighboring satellites, the terminal will be unable to measure the SSBs of neighboring satellites. SMTC4 includes a cell list and offsets. For each cell list, one offset can be configured, allowing for a maximum of three cell lists. Compared to SMTC1, the network side typically calculates the arrival times of different satellites based on their locations and the terminal's location, and configures the corresponding satellite cell list and offset in SMTC4 to ensure that the SSBs of neighboring satellites can be detected by the terminal at the corresponding time and location. The period and duration are shared between SMTC4 and SMTC1.

[0120] Optionally, the NR protocol also considers configuring the ssb-ToMeasure parameter on top of the SMTC window to specify the index of the SSB to be measured, thereby further reducing the number of SSBs that need to be measured.

[0121] 3. Cell handover process

[0122] Mobility signaling procedures triggered by measurement results mainly include cell reselection procedures and cell handover procedures.

[0123] 3.1 Community Reselection Process

[0124] When a terminal is in a disconnected state (e.g., idle or inactive), its movement will cause cell reselection. For example, the cell reselection process involves: the network device obtaining the SSB measurement configuration of the serving cell and neighboring cells via system messages SIB2 / SIB4; the terminal selecting the optimal SSB based on the SSB measurement configuration, and autonomously initiating an access request based on this optimal SSB and parameters issued by the network side (such as reselection thresholds), thus reselecting to the target neighboring cell.

[0125] 3.2 Cell handover process

[0126] When a terminal is in a connected state, its movement will cause it to hand over between cells. The typical handover process mainly involves when, where, and how the terminal hands over. The following describes some of the main cell handover procedures:

[0127] 3.2.1 Normal handover process

[0128] For example, Figure 2 is a schematic diagram of a normal handover process. As shown in Figure 2, taking the network device currently accessed by the terminal as gNobeB as an example, this normal handover process mainly includes the following steps:

[0129] Triggering point (when):

[0130] 101.gNodeB determines whether to initiate a cell handover process based on the signal quality of the serving cell of the terminal; if the cell handover process is initiated, step 102 is executed.

[0131] Measurement process:

[0132] The 102.gNodeB sends measurement configuration information to the terminal via Radio Resource Control Reconfiguration (RRCReconfiguration) messages. The measurement configuration information includes measurement configurations for multiple cells.

[0133] 103. The terminal generates measurement results for multiple cells based on the measurement configuration information;

[0134] 104. The terminal reports the measurement results to gNodeB via a measurement report.

[0135] Switching between decision-making stages (where, how):

[0136] 105.gNobeB determines whether there is a suitable target cell or target frequency, and the corresponding target gNobeB, based on the measurement report; if so, proceed to step 106.

[0137] Switching execution phase:

[0138] The 106.gNodeB exchanges context information related to terminal handover and reserved resources with the identified target gNobeB.

[0139] 107.gNodeB sends handover-related control information to the terminal, enabling the terminal to complete the cell access process at the target gNobeB.

[0140] 3.2.2 Conditional Handover (CHO) Procedure

[0141] In this CHO process, the network side will prepare radio resources corresponding to the candidate cell for the terminal in advance and notify the terminal of the triggering conditions for switching to the candidate cell; when the terminal determines that the triggering conditions are met, the terminal will directly switch to the candidate cell.

[0142] Terrestrial networks (TN) introduce a signal quality-based handover procedure (CHO). In TN systems, Responsive Relationship Management (RRM) measurements are the primary basis for handover. Handover strategies triggered by signal strength are well-suited for terrestrial cells because when a terminal moves away from the center of the cell, the signal strength drops sharply, allowing the terminal to easily distinguish whether it is located at the center or the edge of the cell.

[0143] In non-terrestrial network (NTN) systems, the primary consideration for handover is how to utilize ephemeris and terminal location information to ensure handover reliability. In NTN systems, such as satellite systems, due to the very high orbits of satellites, signals from satellites reach the ground almost vertically, resulting in only a small difference in signal strength between the center and edges of an NTN cell. Therefore, in satellite systems, handover relies not only on RRM measurements but also on fully utilizing the terminal's location and satellite beam movement patterns. For example, the Call-Only (CHO) technology introduced in NTN systems pre-configures terminal-to-point autonomous handover based on satellite movement patterns and certain conditions. These trigger conditions include signal strength-based, time-based, and location-based trigger conditions. Time-based trigger conditions define the time window during which the terminal can perform CHO on candidate cells; location-based trigger conditions define two distance thresholds: one from the terminal to the source cell and the other from the terminal to the candidate cell. The terminal performs CHO based on these distance thresholds.

[0144] Triggering conditions based on signal strength include, but are not limited to, at least one of the following: A3 (the neighboring cell signal quality is better than the current serving cell signal quality by a certain threshold), A5 (the neighboring cell signal quality is better than threshold 1, while the current serving cell signal quality is worse than threshold 2), and A4 (the current serving cell signal quality is worse than a certain threshold).

[0145] For example, Figure 3 is a schematic diagram of a conditional handover process. As shown in Figure 3, taking the network device currently accessed by the terminal as gNobeB as an example, this conditional handover process mainly includes the following steps:

[0146] 201. The source base station configures the RRM measurement settings for the terminal, enabling the terminal to find a list of candidate cells that are likely to be handed over, and then reports this list to the source base station.

[0147] Optionally, the information reported by the terminal to the source base station includes: the identifier of the serving cell, the signal quality (or signal strength) of the serving cell, the identifier of the neighboring cell, and the signal quality (or signal strength) of the neighboring cell.

[0148] 202. Based on the reported list of candidate cells, the source base station selects the target base station and exchanges with the target base station context information related to terminal handover and reserved resources.

[0149] 203. The source base station sends handover-related control information to the terminal, such as the parameter configuration related to the handover command and the triggering conditions for handover to the target base station.

[0150] 204. The terminal evaluates whether the triggering conditions for switching to the target base station are met. At this time, it still maintains the connection and data transmission with the source base station, but does not need to send the RRM measurement results to the source base station. If the conditions are met, the terminal executes step 205.

[0151] 205. When a terminal performs a handover autonomously, it needs to synchronize with the target cell of the target base station and perform random access to establish an RRC connection, while deleting the connection with the source base station.

[0152] 206. The target cell of the target base station notifies the source cell, and the terminal handover is complete.

[0153] 3.2.3 Layer 1 or Layer 2 Triggered Mobility (LTM) Switching

[0154] LTM handover is based on L1 / L2 measurement results to determine handover. The source network device will send the handover configuration of candidate cells in advance. The terminal reports the handover request based on the measurement results according to the handover configuration. The source network device sends the handover command according to the handover request.

[0155] For example, Figure 4 is a schematic diagram of an LTM handover process. As shown in Figure 4, the LTM handover process includes, but is not limited to, the following steps:

[0156] LTM preparation process:

[0157] 301. The base station triggers the LTM preparation process, exchanges signaling with the base stations of multiple candidate cells, and configures the LTM candidate configurations of multiple candidate cells to the terminal.

[0158] Initial synchronization phase:

[0159] 302. The terminal stores LTM candidate configurations and performs uplink and downlink synchronization with all candidate cells based on the LTM candidate configurations.

[0160] LTM execution phase:

[0161] 303. The terminal performs L1 measurement on the configured candidate cells and reports the L1 measurement results to the base station. The base station makes a handover decision. If the handover is decided, the base station sends a cell handover command to the terminal (which includes the candidate configuration index of the target cell to which the handover is made).

[0162] 304. The terminal receives the cell handover command, disconnects from the source cell, and performs cell access in the target cell according to the configuration of the target cell.

[0163] The following provides examples of the communication systems that are the main applications of this application.

[0164] For example, embodiments of this application can be applied to communication systems using various radio access technologies (RATs), such as narrowband Internet of Things (NB-IoT) systems, long term evolution (LTE) communication systems, 5G (or new radio (NR)) communication systems, transitional systems between LTE and 5G communication systems (also known as 4.5G communication systems), and future communication systems. Embodiments of this application can also be applied to non-terrestrial networks (NTN), vehicle-to-everything (V2X), long term evolution-vehicle (LTE-V), vehicle-to-vehicle (V2V), machine-type communications (MTC), Internet of Things (IoT), long term evolution-machine-to-machine (LTE-M), machine-to-machine (M2M), or future mobile communication systems, etc.

[0165] For example, an NTN system can include a satellite system. Based on satellite altitude, i.e., orbital altitude, satellite systems are categorized into highly elliptical orbit (HEO) satellites, geosynchronous orbit (GEO) satellites, medium Earth orbit (MEO) satellites, and low-earth orbit (LEO) satellites. Furthermore, an NTN system can also include high altitude platform station (HAPS) communication systems. Compared to communication infrastructure such as terrestrial cellular networks and submarine fiber optic cables, NTN offers significant cost advantages. Modern small satellites have low R&D and manufacturing costs, and software-defined technologies can further extend the on-orbit lifespan of satellites. With a large number of satellites deployed in low Earth orbit, the round-trip latency of data transmission between satellites and ground terminals is greatly reduced, reaching a low latency of tens of milliseconds. The use of technologies such as high-frequency bands, multi-beamforming, and frequency reuse significantly improves satellite communication capabilities, reduces unit broadband costs, and meets the demands of high-data-rate services. NTN networks can be used for global coverage (such as remote areas and ocean-going vessels), emergency relief (such as disaster monitoring and emergency communications), the Internet of Things, and high-speed mobility (such as high-speed rail and airplanes).

[0166] For example, a network device is an access network (AN) device, such as a base station, that a terminal wirelessly accesses a mobile communication system. A network device can also refer to a device that communicates with a terminal device over the air interface. Network equipment may include evolved NodeB (eNodeB or eNB) transmission reception points (TRPs) in long term evolution (LTE) systems or long term evolution-advanced (LTE-A) systems, next generation NodeB (gNB) in 5th generation (5G) mobile communication systems, access network equipment in open radio access networks (O-RAN or open RAN), base stations in future mobile communication systems, or access nodes in wireless fidelity (WiFi) systems; alternatively, network equipment may be relay stations, vehicle-mounted equipment, and equipment in future evolved public land mobile networks (PLMNs), devices in device-to-device (D2D) networks, devices in M2M networks, devices in IoT networks, or network equipment in public land mobile networks (PLMNs).

[0167] Taking a base station as an example, a network device can communicate with terminal devices, either directly or via relay stations. A terminal can communicate with multiple base stations using different access technologies. A network device can be a module or unit that performs some of the functions of a base station; for example, it can be a central unit (CU), a distributed unit (DU), a CU control plane (CU-CP) module, or a CU user plane (CU-UP) module. Multiple DUs can be centrally controlled by a single CU. CUs and DUs can be distinguished based on their protocol layer functions within the wireless network. For example, functions at the Packet Data Convergence Protocol (PDCP) layer and above are located in the CU, while functions at lower protocol layers, such as Radio Link Control (RLC) and Medium Access Control (MAC), are located in the DU. It should be noted that this protocol layer division is merely an example; other protocol layer divisions are also possible. The radio frequency (RF) device can be remotely located, not placed within the DU, or integrated into the DU, or partially remote and partially integrated into the DU; this application does not impose any limitations on the embodiments. Additionally, in some embodiments, the control plane (CP) and user plane (UP) of the CU can be separated and implemented as different entities, namely the control plane CU entity (CU-CP entity) and the user plane CU entity (CU-UP entity). In this network architecture, signaling generated by the CU can be sent to the terminal device through the DU, or signaling generated by the terminal device can be sent to the CU through the DU. The DU can directly encapsulate the signaling through the protocol layer and transmit it to the terminal device or CU without parsing it. In this network architecture, the CU is classified as a network device on the radio access network (RAN) side. Alternatively, the CU can also be classified as a network device on the core network (CN) side; this application does not impose any limitations on this. Optionally, the access network device can be a server, for example, the network device in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). Optionally, network devices can also be various devices that constitute access nodes, such as active antenna unit (AAU) and baseband unit (BBU).

[0168] In different systems, RAN nodes may have different names. For example, in an O-RAN system, a CU can be called an open CU (O-CU), a DU can be called an open DU (O-DU), and an RU can be called an open RU (O-RU). The RAN nodes in the embodiments of this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. For example, a RAN node can be a server loaded with the corresponding software modules. The embodiments of this application do not limit the specific technology or device form used in the RAN nodes.

[0169] For example, network devices in an NTN system can be deployed on high-altitude platforms or satellites, such as satellites or satellite base stations. NTN systems can provide terminal access in scenarios including transparent payloads and regenerative payloads. A transparent payload is a payload that changes the frequency carrier of the uplink radio frequency signal, filtering and amplifying it before downlink transmission. This type of payload only has a radio frequency processing unit and lacks baseband demodulation, decoding, and other processing. Therefore, the signal waveform remains unchanged and is repeated. A regenerative payload is a payload that transforms and amplifies the uplink radio frequency signal before downlink transmission. Signal transformation refers to digital processing, which can include demodulation, decoding, re-encoding, remodulation, and / or filtering, equivalent to having all or part of the base station functions (such as a gNB) on a satellite (or unmanned aircraft system platform, UAS platform).

[0170] Figure 5 is a schematic diagram of an NTN scenario based on transparent payload. This NTN scenario is also known as a transparent forwarding scenario for satellite communication. As shown in Figure 5, there are one or more gateway stations connecting the NTN network and the public data network. The feeder link is the wireless link between the gateway station and the satellite (or UAS platform). The service link is the wireless link between the terminal and the satellite (or UAS platform). The satellite (or UAS platform) can implement transparent payloads.

[0171] Figure 6 is a schematic diagram of an NTN scenario based on regenerative payloads. This NTN scenario is also known as the regenerative mode scenario for satellite communication. As shown in Figure 6, this NTN scenario includes a feeder link and a service link. Whether or not there is an inter-satellite link (ISL) between the satellites shown in Figure 6 is optional. If there is no ISL, the satellites must have a feeder link (mandatory if no ISL). An inter-satellite link requires the satellite to be a regenerative payload (i.e., if there is an inter-satellite link, the satellite is a regenerative payload). The ISL can operate at radio frequency or optical band. User equipment is served by satellites (or UAS platforms) within the target service area. This target service area is the geographical area where the satellites can provide services.

[0172] Optionally, the network equipment can be a macro base station (also known as a large station), a micro base station or an indoor station (also known as a small station), or a relay node or donor node, etc. For example, Figure 7 is a schematic diagram of a communication system architecture. Taking the number of network devices and terminals shown in Figure 7 as an example, this application does not limit the number of network devices and terminals. In Figure 7, the network devices are satellite 110a, macro base station 110b, and micro base station or indoor station 110c; the terminals are mobile phone 120a accessing the network via macro base station 110b, vehicle 120b accessing the network via satellite 110a, aircraft 120c accessing the network via satellite 110a, mobile phone 120d accessing the network via satellite 110a, and printer 120e, mobile phone 120f, and computer 120g accessing the network via micro base station or indoor station 110c. Optionally, mobile phone 120d can communicate with satellite 110a using aircraft 120c as a relay. The mobile phone 120f can communicate with the micro base station or indoor station 110c by using the computer 120g as a relay.

[0173] Optionally, a terminal, also known as a terminal device, user equipment (UE), mobile station (MS), or mobile terminal (MT), is a device with wireless transceiver capabilities. It can send signals to or receive signals from network devices. Terminal devices may include user equipment (UE) and are sometimes also called terminals, access stations, UE stations, remote stations, wireless communication devices, or user devices, etc. These terminal devices are used to connect people, objects, and machines, and can be widely used in various scenarios, including but not limited to: cellular communication, D2D, V2X, M2M / MTC, IoT, virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical care, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, drones, and robots. For example, a terminal can be a mobile phone, tablet, computer with wireless transceiver capabilities, VR terminal, AR terminal, wireless terminal in industrial control, wireless terminal in autonomous driving, smart speaker in IoT networks, wireless terminal device in telemedicine, wireless terminal device in smart grids, wireless terminal device in transportation safety, wireless terminal device in smart cities, or wireless terminal device in smart homes, etc. As an example and not a limitation, the terminal can also be a wearable device, also known as wearable smart device or smart wearable device, etc. It is a general term for devices that apply wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. All the terminals described above, if located in a vehicle (e.g., placed inside or installed inside a vehicle), can be considered in-vehicle terminal devices, also known as on-board units (OBUs). The terminal may also be an on-board module, on-board component, on-board chip, or on-board unit that is built into the vehicle as one or more components or units. The vehicle can implement the methods described in the embodiments of this application through the built-in on-board module, on-board component, on-board chip, or on-board unit.

[0174] Network devices and / or terminal devices can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; or on water; or in the air on aircraft, balloons, and satellites. This application does not limit the environment / scenario in which the network devices and terminal devices are located. Network devices and terminal devices can be deployed in the same or different environments / scenarios; for example, both network devices and terminal devices can be deployed on land simultaneously; or, the network device can be deployed on land and the terminal device on water, etc., and so on.

[0175] In this application embodiment, taking a network device as an example of the apparatus used to implement the functions of an access network node, the technical solutions provided by the embodiments of this application are described. The embodiments of this application do not limit the specific technology or specific device form adopted by the network device. The functions of the network device can also be executed by modules (such as chips, chip systems, processors, or circuits) within the network device, or by a control subsystem containing network device functions. Here, the control subsystem containing network device functions can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Correspondingly, taking a terminal device as an example of the apparatus used to implement wireless transceiver functions, the functions of the terminal device can also be executed by modules (such as chips, chip systems, processors, or circuits) within the terminal device.

[0176] The aforementioned functions can be network elements in hardware devices, software functions running on dedicated hardware, a combination of hardware and software, or virtualization functions instantiated on a platform (e.g., a cloud platform).

[0177] In NTN satellite communication systems, satellites are being researched as access network devices (such as base stations) for mobile communication systems due to their advantages, such as resistance to natural disasters or external damage. This is intended to provide communication services to areas like oceans and forests. Unlike terrestrial base stations, satellites move at higher speeds relative to the ground and travel longer distances, resulting in greater signal path loss when used as base stations. Current communication mechanisms designed for communication between terminal devices and terrestrial base stations cannot be directly applied to communication between terminal devices and satellite base stations.

[0178] Compared to terrestrial communication systems, satellite communication systems are characterized by wider coverage areas, greater transmission losses, and faster mobility. Unlike terrestrial systems where a maximum of 8 SSBs (frequency range, FR1) or 64 SSBs (FR2) are sufficient to cover the service area of ​​a single base station, satellite communication systems may require hundreds or even thousands of SSBs. As shown in Figure 8, taking a satellite communication system with an orbital altitude of 600 km as an example, the service area of ​​a single satellite can reach hundreds of thousands of square kilometers. To overcome the path loss caused by transmission distance and ensure communication service quality, satellites generally use large-scale antenna arrays to provide higher array gain, but this also results in narrower beam main lobes. For example, a coverage radius of only a few dozen kilometers with a 3dB beamwidth covers an area of ​​about several hundred square kilometers. Therefore, using narrow beams to achieve seamless coverage of a single satellite's service area would require thousands of beams. Furthermore, even with some beam widening, hundreds of beams are still needed to maintain the gain level to achieve coverage. When hundreds of scanning beams are used, a complete scan takes approximately several hundred milliseconds.

[0179] Since the number of beams required for the entire coverage area can reach hundreds, the number of beams providing coverage can be increased by using a single satellite with multiple cells. As shown in Figure 9, when each cell has 8 SSBs (e.g., SSB0 to SSB7), and N cells (e.g., cells PCI#1 to PCI#N) provide services, the coverage area of ​​8*N SSB beams can be achieved, thereby increasing the number of beams that a single cell can serve and increasing the coverage area.

[0180] Although different handover modes are defined, the general procedure involves using SMTC for SSB measurement, the terminal obtaining the measurement results, reporting the signal quality of candidate cells, interacting with the source base station for handover decision, and signaling interaction between the source and target base stations. However, in a single-satellite multi-cell scenario, intra-satellite cell handover does not involve the source and target base stations, therefore a complete handover procedure is unnecessary, and measurement result reporting is also unnecessary. In a single-satellite multi-cell scenario, if the inter-cell frame headers are aligned, the UE does not even need to resynchronize. Furthermore, using SMTC configuration for SSB measurement is not flexible enough, and terminals in connected mode need to obtain SMTC via additional RRC signaling, increasing power consumption on both the network and UE sides. Therefore, using the existing handover procedure introduces unnecessary handover overhead in a single-satellite multi-cell scenario, requiring redesign to reduce power consumption on both the network and terminal sides.

[0181] This application provides a cell access method in which the terminal device determines that the selected first SSB belongs to a neighboring cell of the current serving cell and can directly access the cell in the neighboring cell to which the first SSB belongs. This eliminates the need for measurement reporting and a series of signaling interactions between the terminal and the network, thereby reducing the signaling overhead and power consumption between the terminal and the network.

[0182] The network device issues an SSB measurement configuration to the terminal device. When the terminal device is in a connected state, this SSB measurement configuration is used for cell handover; when the terminal device is in a disconnected state, this SSB measurement configuration is used for cell reselection. Figure 10 is a flowchart illustrating a cell handover method provided in an embodiment of this application. As shown in Figure 10, the cell handover method includes, but is not limited to, the following steps:

[0183] S101. The network device sends an SSB measurement configuration for cell handover; correspondingly, the terminal device receives the SSB measurement configuration.

[0184] Optionally, the SSB measurement configuration is carried in at least one of the following: SIB1 or master indication block (MIB). Optionally, the network device can broadcast SIB1 at the radii level or cell level within the cell. The radii level SIB1 is broadcast within a partial coverage area, while the cell level SIB1 is broadcast throughout the cell.

[0185] In another possible implementation, the information included in the SSB measurement configuration is carried in either the Radio Resource Control (RRC) common signaling or the RRC dedicated signaling. The RRC common signaling is signaling applicable to the entire domain, while the RRC dedicated signaling is signaling specific to a particular terminal.

[0186] The SSB measurement configuration includes measurement information for at least one SSB, indicating the specific SSB information to be measured. This measurement information includes, but is not limited to, the following possible designs:

[0187] (1) The measurement information includes the index of at least one SSB. Based on this method, the terminal device can directly determine the SSB to be measured. For example, as shown in Figure 11, the terminal is located within the coverage area of ​​SSB#25, and the network device is configured to measure the SSBs that need to be measured, including its own SSB#25 and the surrounding SSBs#{8,9,10,24,26,40,41,42}. Therefore, the indication of these nine SSB indices can be added to the SIB1 transmitted by the broadcast beam corresponding to SSB#25.

[0188] (2) The measurement information includes at least one wave position identifier corresponding to an SSB. Based on this method, the terminal device can calculate the index of each SSB based on its corresponding wave position identifier to determine the SSB to be measured. For example, for the terminal shown in Figure 11 located within the coverage area of ​​SSB#25, the SSBs to be measured configured by the network device include its own SSB#25 and the surrounding SSBs#{8,9,10,24,26,40,41,42}. Therefore, wave position indicators for these nine SSBs can be added to the SIB1 transmitted by the broadcast beam corresponding to SSB#25.

[0189] (3) The measurement information includes the time offset and duration (or duration) of the time window in which the at least one SSB is located. Optionally, the time offset is the time offset of the start time position of the SSB to be measured relative to the SSB of the current serving cell; the duration is the duration of the time window of the SSB to be measured; or, the time offset is the time offset of the start time position of the SSB to be measured relative to the default or specified SSB. In this method, the terminal device determines the time window of the SSB to be measured based on the time offset and duration, and then obtains the SSB to be measured. For example, in the satellite communication shown in Figure 11, as the satellite moves, the terminal will perform cell handover, where satellite cell PCI#2 and satellite cell PCI#1 belong to the satellite currently accessed by the terminal; satellite cell PCI#0 belongs to the neighboring satellite. The SSBs to be measured configured by the network device may include SSB#25 where the terminal is located (i.e., the terminal's current location) and the surrounding SSBs#{8,9,10,24,26,40,41,42}. Therefore, in SIB1 transmitted by the broadcast beam corresponding to SSB#25, the added time offset can be 620ms with a duration of 200ms. In this way, the time window for SSB measurement determined by the terminal can include the SSBs that need to be measured.

[0190] In one optional implementation, the terminal device determines the cell identifier to which each SSB belongs based on the aforementioned SSB measurement information. In another optional implementation, the SSB measurement configuration further includes the identifier of the cell to which the SSB belongs, such as identifiers of multiple cells, including the currently serving cell and neighboring cells. Optionally, the terminal device can determine whether the SSB measurement configuration belongs to another cell of the same network device currently accessed by the terminal by distinguishing it through cell identifiers or the index of the SSB to be measured, etc.

[0191] In an optional implementation, the SSB measurement configuration further includes: a maximum number of cycles for filtering and averaging multiple measurement results of the same SSB for at least one SSB in multiple cycles, and a minimum level threshold. Filtering and averaging refers to averaging the measurement results of the same SSB in multiple cycles, such as signal quality indicators used to characterize signal quality, and using the average value as the measurement result of the SSB. The maximum number of cycles is the maximum number of cycles for averaging the measurement results of the same SSB. The minimum level threshold is the lowest level threshold of the measurement results of the same SSB in multiple cycles that can be used for filtering and averaging; that is, among the measurement results of the same SSB in multiple cycles, the measurement results of SSBs with a level lower than the minimum level threshold cannot be used to calculate the average value of the measurement results of the SSB. Optionally, the terminal device may not retain the measurement results of SSBs with a level lower than the minimum level threshold. It can be seen that this implementation mainly considers that with the movement of network equipment (such as satellites), the beam gain and channel level of the same coverage area may change to some extent. This implementation allows the measurement results obtained by the terminal based on the SSB measurement configuration to be merged, and can be applied to situations where the transmission gain on the network side does not change drastically.

[0192] For example, for the SSB measurement configuration configured on the network side, the following information element can be added to SIB1, taking the cell corresponding to SSB#25 where the terminal is located as an example, wherein the SSB to be measured is determined by carrying time offset and duration:

[0193] For example, the SSB measurement configuration carries the SSB index to identify the SSB to be measured:

[0194] Among them, ssbConfigforCS represents the beam management of this parameter for cell handover; ssbTargetOffset represents the time domain offset of the SSB to be measured in the neighboring cell relative to this cell; ssbTargetIndex represents the SSB index to be measured in the neighboring cell; Pci is the cell identifier corresponding to this beam management; nrofPeriodToAvg represents the maximum number of periods that can be used for filtering among the measurement results of the same SSB index in multiple periods (here it is assumed to be configured as 10 periods); ssbThreshold represents the lowest level (unit such as dB) corresponding to the measurement result of the SSB that can be used for filtering.

[0195] S102. The terminal device acquires the SSB measurement results according to the SSB measurement configuration.

[0196] In the SSB measurement results, the indicator used to characterize the signal quality for each SSB index may include, but is not limited to, at least one of the following: RSRP, RSRQ, SINR, RSSI. Optionally, the value of the indicator used to characterize the signal quality for each SSB index may be the average value of a multi-cycle filter.

[0197] S103. The terminal device selects the first SSB based on the measurement results of the SSB.

[0198] In one optional implementation, the terminal device selects a first SSB based on the measurement results of the SSBs, including: the terminal device selecting the SSB with the highest signal strength or the best signal quality from the SSB measurement results. The SSB with the highest signal strength or the best signal quality can be determined based on indicators used to characterize signal quality.

[0199] In one optional implementation, the terminal device selects a first SSB based on the measurement results of the SSBs, including: the terminal device selecting an SSB whose signal strength or signal quality meets a certain threshold and certain conditions from the SSB measurement results, as the first SSB. The certain conditions may be predefined or configured on the network side or the terminal side, and are not limited in this embodiment.

[0200] In one possible implementation, the terminal device selects the first SSB based on the measurement results of the SSB. This first SSB may be the SSB with the best or optimal signal quality among the measured SSBs, or it may be an SSB whose signaling quality meets a certain threshold requirement and certain conditions.

[0201] Optionally, the terminal device executes step S104 based on the first SSB maintained, to determine whether it has entered the beam coverage range of the SSB of other cells in the same network device.

[0202] S104. The terminal device determines whether the first SSB belongs to the current serving cell or a neighboring cell of the current serving cell; if it belongs to a neighboring cell of the current serving cell, then proceed to step S105; if it belongs to the current serving cell, then maintain access in the current serving cell.

[0203] The terminal device determines whether the first SSB belongs to the current serving cell or a neighboring cell of the current serving cell based on the measurement information of the SSB. For example, the terminal device can determine whether the first SSB belongs to the current serving cell or a neighboring cell based on the index of the first SSB. Alternatively, the terminal device can determine whether the first SSB belongs to the current serving cell or a neighboring cell based on the cell identifier corresponding to the first SSB.

[0204] In another optional implementation, the SSB measurement configuration issued by the network side specifies that the SSB to be measured is an SSB of a neighboring cell of the same network device. As shown in Figure 11, the SSB#25 where the terminal device is located and the SSB#{8,9,10} to be measured are both cells PCI#2 adjacent to cell PCI#1 to which SSB#25 belongs and belong to the same satellite. Therefore, the first SSB selected by the terminal device does not need to perform step S104 to determine whether it is a neighboring cell of the current serving cell, and can directly perform step S105.

[0205] S105. The terminal device performs cell handover in the neighboring cell corresponding to the first SSB.

[0206] In one optional implementation, the terminal device performs cell handover in a neighboring cell, including: synchronizing with the neighboring cell corresponding to the first SSB and performing random access to establish a radio resource control connection, while simultaneously deleting the connection with the source cell. The source cell is the serving cell accessed by the terminal before step S105. Therefore, in this embodiment, since the beam management process corresponding to steps S101 to S104 is used to achieve cell handover, it does not involve the source network device and the target network device. Thus, a complete handover process is unnecessary, and measurement result reporting is also unnecessary, reducing signaling overhead and power consumption on both the network and terminal sides.

[0207] In another optional implementation, the terminal device performs cell handover in the neighboring cell corresponding to the first SSB, including: the terminal device performing random access to establish a radio resource control connection in the neighboring cell corresponding to the first SSB, while simultaneously deleting the connection with the source cell. This implementation is applicable when the frame headers of the neighboring cell and the source cell are aligned, so the terminal device does not need to resynchronize. Therefore, this implementation can further save the terminal's power consumption.

[0208] Based on the cell handover method described in Figure 10, when the terminal device determines that the first SSB it maintains belongs to a neighboring cell of the current serving cell based on the SSB measurement configuration, it can directly perform cell handover without measurement reporting and a series of signaling interactions between the terminal side and the network side, thus reducing the signaling overhead and power consumption between the terminal side and the network side.

[0209] Furthermore, in the cell handover method described in Figure 10, the SSB to be measured in the SSB measurement configuration is the SSB of another cell within the same network device (such as a neighboring cell of the current serving cell). This SSB measurement configuration can be added to SIB1 or MIB, eliminating the need for the network side to specifically notify the terminal of the SSB measurement configuration via RRC signaling. When the terminal discovers that the SSB it maintains (such as the first SSB) belongs to another cell within the same network device based on the SSB measurement configuration, it can directly access the network without the need for measurement reporting and a series of signaling interactions between network devices. This greatly simplifies the SSB measurement and cell handover process, saving power consumption on both the network side and the UE side.

[0210] Figure 12 is a flowchart illustrating another cell handover method provided in an embodiment of this application. Based on the beam management process defined in Figure 10 for cell handover, Figure 12 defines the design of a new handover process. As shown in Figure 12, this cell handover method includes, but is not limited to, the following steps:

[0211] S201. The network device broadcasts SIB1, which carries SSB measurement configuration for cell handover and also sends out mobility measurement configuration. Correspondingly, the terminal device receives SIB1 and the mobility measurement configuration.

[0212] The mobility measurement configuration is broadcast using SIB2 / SIB4 when the terminal is in a disconnected state, and sent using RRC signaling when the terminal is in a connected state.

[0213] S202. The terminal device performs measurements of neighboring cells in the same network device according to the SSB measurement configuration, and obtains the measurement results of the SSB of neighboring cells in the same network device; and performs measurements of adjacent network devices according to the mobility measurement configuration, and obtains the measurement results of the SSB of neighboring cells in adjacent network devices.

[0214] S203. Based on the measurement results of the SSB of the neighboring cell in the same network device, the terminal device can directly switch to the neighboring cell of the same network device without performing a measurement reporting procedure; or, based on the measurement results of the neighboring cell in the adjacent network device, the terminal device can execute a mobility management procedure and switch to the neighboring cell of the adjacent network device.

[0215] In step S203, the terminal device may use the handover method described in FIG10 to switch to a neighboring cell of the same network device, or execute a mobility management procedure to switch to a neighboring cell of an adjacent network device. This may include, but is not limited to, at least one of the following optional implementation methods:

[0216] In Implementation 1, the network side configures indication information to determine the method. For example, the indication information may instruct the terminal device to use the handover method described in FIG10 to switch to a neighboring cell of the same network device; or, the indication information may instruct the terminal device to use a mobility management procedure to switch to a neighboring cell of an adjacent network device.

[0217] Implementation method 2 determines the signal strength or signal quality of the first SSB selected by the terminal device based on the measurement results of the neighboring cells in the same network device and the measurement results of the neighboring cells in adjacent network devices. For example, if the signal strength or signal quality of the first SSB selected by the terminal device based on the measurement results of the neighboring cells in the same network device is better than the signal strength or signal quality of the neighboring cells in adjacent network devices or better than a certain threshold, then the handover method described in Figure 10 is used to hand over to the neighboring cell of the same network device; otherwise, the mobility management process is used to hand over to the neighboring cell of the adjacent network device.

[0218] Implementation method 3 involves pre-definition on the terminal side and the network side. For example, the terminal side and the network side pre-define the selection of the first SSB based on the measurement results of the neighboring SSBs in the same network device. When the first SSB belongs to a neighboring cell of the same network device (e.g., the terminal determines that its optimal beam has changed and switches to the beam of another cell in the same network device), there is no need to perform a measurement reporting process, and access is directly performed in the neighboring cell to which the first SSB belongs. When the first SSB belongs to the currently serving cell of the same network device, a mobility management process is then executed to switch to the neighboring cell of the adjacent network device.

[0219] As can be seen, in the cell handover method described in Figure 12, by using the beam management process to measure the SSBs of multiple cells in the same network device, the terminal device can determine whether it is within the SSB coverage area of ​​other cells in the same network device through the SSB measurement configuration carried by the SIB1 broadcast by the cell. There is no need for the network side to send terminal-level RRC signaling. When the optimal SSB maintained by itself is located in other cells in the same network device, it can directly re-access, eliminating the need for measurement reporting and a series of signaling interactions between base stations. Therefore, the power overhead on both the network side and the UE side is greatly reduced.

[0220] The embodiment described in Figure 10 can also be applied to cell reselection scenarios. When the terminal device is in a disconnected state, after selecting the first SSB, it can autonomously determine whether it belongs to a neighboring cell of the current serving cell. If it does, it can directly reselect to the neighboring cell to which the first SSB belongs. The embodiment described in Figure 12 can also be applied to cell reselection scenarios. By using beam management procedures to measure SSBs of multiple cells within the same network device, the terminal device can configure SSB measurement through the SSB carried by the SIB1 broadcast by the cell. When the selected first SSB belongs to another cell within the same network device, it can directly reselect to the cell to which the first SSB belongs, eliminating the need for measurement reporting and a series of signaling interactions between base stations. Therefore, the power overhead on both the network side and the UE side is significantly reduced. Specifically, the relevant procedures and optional implementation methods of the cell reselection method can be found in the cell handover method described in the embodiments of this application, and will not be detailed here.

[0221] This application also provides a cell access method. The SMTC acquired by the terminal device includes first information, which indicates that the SMTC belongs to the currently accessing network device or to a neighboring cell of the currently serving cell, wherein the neighboring cell and the serving cell belong to the same network device. When the measurement results obtained by the terminal device based on the first information and the SMTC meet the cell handover conditions, it can directly access the cell without reporting measurements, thereby reducing power consumption and signaling overhead on both the terminal and network sides. Optionally, this application can reuse SMTC1 to SMTC4, adding the first information within them. For example, for satellite communication systems, considering satellite latency, SMTC4 can be reused. For a description of other information elements or data in the SMTC, please refer to the preceding text; details will not be elaborated here.

[0222] The SMTC issued by the network device to the terminal device can be used for cell handover or cell reselection. For example, when the terminal device is in a connected state, the SMTC is used for cell handover; when the terminal device is in a disconnected state, the SMTC is used for cell reselection. Figure 13 is a flowchart illustrating another cell handover method provided in an embodiment of this application. This cell handover method reuses the SMTC design by adding an information element to the SMTC to indicate whether the measurement configuration belongs to the same network device currently accessed by the terminal, enabling subsequent cell handover processes that do not require reporting or interaction with network devices. As shown in Figure 13, this cell handover method includes, but is not limited to, the following steps:

[0223] S301. The network device sends an SMTC, which includes first information indicating that the SMTC belongs to the network device currently accessed by the terminal; the terminal device receives the SMTC.

[0224] In one optional implementation, an information element `servingsatelite` is added to the SMTC to indicate whether the SSB measurement configuration indicated by the SMTC belongs to the same network device currently accessed by the terminal. If the value of the information element `servingsatelite` is true, it means that the SSB measurement configuration indicated by the SMTC belongs to the same network device currently accessed by the terminal; if the value of the information element `servingsatelite` is false, it means that the SSB measurement configuration indicated by the SMTC does not belong to the same network device currently accessed by the terminal, but belongs to an adjacent network device.

[0225] For example, the SSBs included in each satellite cell shown in Figure 14 are as follows: the satellite cell currently accessed by the terminal is PCI#1, and the neighboring cells of satellite cell PCI#1 are another satellite cell PCI#2 of the satellite currently accessed by the terminal (referred to as local PCI#2) and the satellite cell PCI#2 of the adjacent satellite of the currently accessed satellite (referred to as neighboring satellite PCI#2).

[0226] Assuming the SMTC received by the terminal is as shown below, it indicates the cell PCI2 to which the SMTC belongs. It also uses the value of the information cell servingsatelite to indicate that the SSB measurement configuration indicated by the SMTC belongs to the same satellite that the terminal is currently accessing. Therefore, the SMTC belongs to the local satellite and to the local satellite PCI#2.

[0227] Assuming the SMTC received by the terminal is as follows, it indicates the cell PCI2 to which the SMTC belongs. It also uses the value false of the information cell servingsatelite to indicate that the SSB measurement configuration indicated by the SMTC does not belong to the same satellite that the terminal is currently accessing. Therefore, the SMTC belongs to a neighboring satellite and belongs to the neighboring satellite PCI#2.

[0228] In another optional implementation, the information element servingsatelite is added to the SMTC to indicate that the SSB measurement configuration indicated by the SMTC belongs to the same network device currently accessed by the terminal. If the information element servingsatelite is not added to the SMTC, it means that the SSB measurement configuration indicated by the SMTC does not belong to the same network device currently accessed by the terminal, but belongs to an adjacent network device.

[0229] S302. The terminal device obtains the measurement results of at least one cell in the network device based on the first information and SMTC.

[0230] Optionally, the terminal device obtains the signal quality after filtering by multiple SSBs based on the SMTC, and determines the signal quality of at least one cell based on the signal quality after filtering by multiple SSBs, as the measurement result of at least one cell. This application does not limit the optional implementation methods for performing cell measurements based on SSBs to obtain the signal quality or measurement results of the cell.

[0231] S303. The terminal device selects a first cell based on the measurement results of at least one cell.

[0232] The first cell selected by the terminal device is a cell that meets the cell handover conditions. These cell handover conditions can be referenced from the signal quality requirements in A3, A4, or A5, or the cell handover or triggering conditions in the NTN network, and will not be detailed here.

[0233] S304. The terminal device determines that the first cell belongs to a neighboring cell of the current serving cell and executes step S305; if the first cell belongs to the current serving cell, then it remains in the current serving cell.

[0234] S305. The terminal device switches to the first cell.

[0235] Optionally, if the first information not only indicates that the SMTC belongs to the network device currently accessed by the terminal, but also indicates that the SMTC belongs to another cell of the network device currently accessed by the terminal (such as a neighboring cell of the current serving cell), then step S304 can be skipped and the terminal can be directly switched to the first cell.

[0236] In step S305, the terminal device does not need to perform measurement reporting and subsequent complete handover procedures in the mobility management process; it can directly access the first cell, thereby reducing power consumption and signaling overhead on both the terminal and network sides.

[0237] In one optional implementation of this application, the network side not only issues the corresponding SMTC as needed, but also issues instruction information to enable the terminal to perform a mechanism for multi-cell handover under the same network device without measurement reporting and without interaction between network devices (i.e., the cell handover method described in the embodiments of this application).

[0238] The cell handover method described in Figure 13 uses the first information configured in the SMTC to reuse the SMTC design and perform neighbor cell SSB measurements. If the neighboring cells belong to the same network device and the measurement results meet the cell handover conditions (e.g., exceeding a preset threshold), no measurement reporting is performed, and re-access is initiated directly, completing the cell handover independently on the terminal side. If the neighboring cells belong to adjacent network devices, the cell handover method in the existing mobility management process is reused. Accordingly, in step S301, the network side not only issues SMTCs for the same network device but also SMTCs for adjacent network devices. The terminal side uses the first information carried in the SMTC to determine whether the SMTC belongs to the same network device or an adjacent network device.

[0239] In addition, the cell handover method described in Figure 13 can also be applied to the case where the cell identifier of the currently accessed network device is the same as that of the neighboring network device. The first information carried in the SMTC can be used to determine whether the SMTC belongs to the currently accessed network device or the neighboring network device.

[0240] The embodiment described in Figure 13 can also be applied to cell reselection scenarios. When the terminal device is in a disconnected state, it selects a first cell based on SMTC. If it can autonomously determine that the first cell belongs to a neighboring cell of the same network device, it can directly reselect to the first cell, eliminating the need for measurement reporting and a series of signaling interactions between base stations. Therefore, the power overhead on both the network side and the UE side is greatly reduced. Specifically, the relevant process and optional implementation methods of the cell reselection method can be found in the relevant content of the cell handover method in the embodiments of this application, and will not be detailed here.

[0241] The cell access method provided by the embodiments of this application has been described above with reference to Figures 10 to 14. In the various embodiments of this application, unless otherwise specified or logically conflicting, the terms and / or descriptions between the various embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0242] The communication device provided in the embodiments of this application will be described below with reference to Figures 15 and 16. It should be understood that the description of the device embodiments corresponds to the description of the method embodiments. Therefore, for content not described in detail, please refer to the method embodiments above. For the sake of brevity, it will not be repeated here.

[0243] For example, FIG15 shows a possible exemplary block diagram of a communication device involved in an embodiment of this application. As shown in FIG15, the communication device may include modules or units for implementing the method embodiments described above. In one possible design, the communication device includes a communication unit 401 and a processing unit 402. Optionally, the communication device may further include a storage unit 403 for storing device program code and / or data.

[0244] The communication device can be the terminal device in the above embodiments, such as a terminal or a communication module in a terminal, or a circuit or chip in a terminal that is responsible for communication functions.

[0245] For example, in one embodiment, the communication unit 401 is configured to: receive a Synchronization Signal Block (SSB) measurement configuration for cell access, wherein the cell access includes cell reselection or cell handover. The processing unit 402 is configured to: obtain the measurement result of the SSB according to the SSB measurement configuration; select a first SSB according to the SSB measurement result; determine that the first SSB belongs to a neighboring cell of the current serving cell, and perform cell access in the neighboring cell.

[0246] In one possible design, the SSB measurement configuration includes measurement information for at least one SSB, wherein the at least one SSB includes a first SSB; the measurement information includes an index of at least one SSB, or a wave position identifier corresponding to at least one SSB, or includes a time offset and duration for determining the time window in which the at least one SSB is located.

[0247] In one possible design, the SSB measurement configuration also includes the identification of multiple cells, including neighboring cells.

[0248] In one possible design, the SSB measurement configuration also includes: multiple measurements of the same SSB for at least one SSB in multiple cycles, a maximum number of cycles for filtered averaging, and a minimum level threshold.

[0249] In one possible design, the information included in the SSB measurement configuration is carried in at least one of the following: a system message block or a main information block.

[0250] For example, in another embodiment, the communication unit 401 is configured to: receive an SMTC, the SMTC including first information, the first information indicating that the SMTC belongs to the currently accessed network device. The processing unit 402 is configured to: obtain the measurement results of at least one cell in the network device based on the first information and the SMTC; select a first cell based on the measurement results of at least one cell; and determine that the first cell belongs to a neighboring cell of the current serving cell, and perform cell access in the neighboring cell.

[0251] In one possible design, the processing unit 402 is also used to: determine that the first cell belongs to the current serving cell and maintain access in the current serving cell.

[0252] For example, in another embodiment, the communication unit 401 is configured to: receive an SMTC, the SMTC including first information, the first information indicating that the SMTC belongs to a neighboring cell of the current serving cell, the neighboring cell and the serving cell belong to the same network device; the processing unit 402 is configured to: obtain the measurement results of at least one cell in the network device according to the first information and the SMTC, the at least one cell including the neighboring cell; and select a first cell according to the measurement results of the at least one cell; and perform cell access in the first cell.

[0253] In one possible design, when the communication device is a terminal or a communication module within a terminal, the functionality of the processing unit 402 can be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-a-chip (SoC) chip or a SIP chip containing a modem core. The functionality of the communication unit 401 can be implemented by transceiver circuitry.

[0254] In one possible design, when the communication device is a circuit or chip in a terminal responsible for communication functions, such as a modem chip or a system-on-a-chip (SoC) or SIP chip containing a modem core, the function of the processing unit 402 can be implemented by a circuit system in the aforementioned chip that includes one or more processors or processor cores. The function of the communication unit 401 can be implemented by an interface circuit or data transceiver circuit on the aforementioned chip.

[0255] In one possible design, when the communication device is a terminal or a processing module within a terminal, the functionality of the processing unit 402 can be implemented by one or more processors. Specifically, the processor may include a GPU, or a system-on-a-chip (SoC) or SIP chip containing a GPU. The functionality of the communication unit 401 can be implemented by transceiver circuitry.

[0256] In one possible design, when the communication device is a circuit or chip in the terminal responsible for processing functions, such as a GPU or a system-on-a-chip (SoC) or SIP chip containing a GPU, the function of the processing unit 402 can be implemented by a circuit system in the aforementioned chip that includes one or more processors or processor cores. The function of the communication unit 401 can be implemented by interface circuitry or data transceiver circuitry on the aforementioned chip.

[0257] The communication device can be a network-side device as described in the above embodiments, such as a network device or network apparatus.

[0258] For example, in one embodiment, the processing unit 402 is configured to: determine an SSB measurement configuration for cell access, the cell access including cell reselection or cell handover; and the communication unit 401 is configured to: send the SSB measurement configuration.

[0259] For example, in another embodiment, the processing unit 402 is used to: determine the SMTC, the SMTC including first information, the first information being used to indicate that the SMTC belongs to the currently accessed network device; the communication unit 401 is used to: send the SMTC.

[0260] For example, in another embodiment, the processing unit 402 is used to: determine the SMTC, the SMTC including first information, the first information being used to indicate that the SMTC belongs to a neighboring cell of the current serving cell, and the neighboring cell and the serving cell belong to the same network device; the communication unit 401 is used to: send the SMTC.

[0261] It is understood that the division of units in the above-described device is a logical functional division. One function can correspond to one functional unit, or two or more functions can be integrated into one functional unit. In actual implementation, all or some units can be integrated into one physical entity, or distributed across different physical entities. Furthermore, the aforementioned functional units can be implemented in hardware, software, or a combination of both. Whether a function is executed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for specific applications, but such implementations should not be considered beyond the scope of this application.

[0262] In one example, the functional unit in any of the above devices may be one or more integrated circuits configured to implement the above methods, such as: one or more application-specific integrated circuits (ASICs), or one or more central processing units (CPUs), one or more microcontroller units (MCUs), one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms.

[0263] In one example, storage unit 403 may include random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory and / or registers, etc.

[0264] For example, Figure 16 is a schematic diagram of the structure of a terminal provided in an embodiment of this application. This terminal can correspond to the terminal or terminal device shown in Figures 1 to 14 and is used to implement the operation of the terminal or terminal device in the above embodiments. As shown in Figure 16, the terminal includes: one or more antennas 510, a radio frequency processing system 520, and a processor system 530.

[0265] In the downlink or sidelink direction, the RF processing system 520 receives RF signals through the antenna 510 and sends the RF-processed signals to the processor system 530 for further processing. In the uplink or sidelink direction, the processor system 530 processes the terminal-side information and sends it to the RF processing system 520, which then processes the signal and transmits it through the antenna 510.

[0266] In one example, the radio frequency (RF) processing system 520 serves as the communication interface for external communication of the terminal and may include a radio frequency front end (RFFE) 521 and a radio frequency transceiver 522. The RFFE 521 is primarily used for one or more processing operations, such as shaping, passband selection, or gain adjustment, on the RF signals received by the antenna or the RF signals to be transmitted through the antenna. It may include one or more components such as RF switches, duplexers, filters, power amplifiers, antenna tuners, and low-noise amplifiers. The RFFE 521 can be a circuit system composed of multiple discrete devices or integrated into one or more chips. The RF transceiver 522 processes the RF signals received by the RFFE 521 into baseband / IF signals for further processing by the processor system 530, and processes the baseband / IF signals provided by the processor system 530 into RF signals for transmission to the RFFE 521. The baseband / IF signals transmitted between the RF transceiver 522 and the processor system 530 can be digital or analog signals. The radio frequency transceiver 522 can be implemented by one or more chips, which are usually referred to as radio frequency integrated circuits (RFICs).

[0267] In one example, processor system 530 may include one or more processors for processing signals and executing one or more communication protocols. Optionally, processor system 530 may also include memory 536. In one example, the one or more processors include at least one baseband processor 531 (also known as a modem processor). Memory 536 is used to store data and / or computer program instructions. Optionally, processor system 530 may also include one or more application processors 532 for implementing processing of the terminal operating system and application layer. Application processor 532 may include, for example, a GPU. Optionally, processor system 530 may also include one or more of a voice subsystem 533, a multimedia subsystem 534, or an interface circuit 535. The voice subsystem 533 is used to process voice signals, the multimedia subsystem 534 is used to handle multimedia-related operations, such as video encoding / decoding, image processing, etc., and the interface circuit 535 is used to implement communication with other terminal components, such as a display 540, an input device 550, memory 560, etc. The above-mentioned components in processor system 530 can communicate with each other via a bus or communication interface circuit.

[0268] In one example, the processor system 530 can be packaged as a single processor chip, such as a SoC chip or a SIP chip. In another example, the processor system 530 can be a system of multiple chips, for example, the baseband processor 531 can be packaged as a single chip, or packaged with part or all of the circuitry of the radio frequency processing system into a single chip.

[0269] In one example, memory 536 can be on-chip memory, i.e., located on the processor system 530 chip. In another example, memory 560 can be off-chip memory, i.e. located outside the processor system 530 chip.

[0270] In one example, the baseband processor 531 may include one or more processor cores 5311 and interface circuitry 5314. The one or more processor cores 5311 are used to process signals and execute one or more communication protocols. Optionally, the baseband processor 531 may also include a memory 5312 for storing at least a portion of the corresponding computer program instructions and / or data. In one example, the one or more processor cores 5311 execute the computer program instructions stored in the memory 5312 to implement the relevant operations (such as generating and sending first information) in the above method embodiments. In this application, the memory 5312 storing the corresponding computer program instructions and / or data may mean that the memory 5312 stores all the corresponding computer program instructions and / or data for the processor core 5311 to execute; or it may mean that the memory 5312 stores a portion of the corresponding computer program instructions and / or data, which includes the computer program instructions and / or data that the processor core 5311 currently needs to execute. The memory 5312 can store different portions of computer program instructions and / or data multiple times for the processor core 5311 to execute in order to implement the relevant operations in the above method embodiments. Interface circuit 5314 serves as a communication interface for communication with other components, such as transmitting signals with RF processing system 520, communicating with other subsystems and related components of processor system 530 via bus, such as transmitting data control signals with application processor 532, and transmitting data or computer program instructions with memory 536 or memory 560. Optionally, to reduce the load on the processor core, baseband signal processing circuit 5313 can also be provided to perform at least some baseband signal processing, including one or more of signal demodulation, modulation, encoding, or decoding.

[0271] The processor, processor system, application processor, baseband processor, processor circuit, or processor core mentioned above can be collectively referred to as a processor. The processor may include one or more of the following: central processing unit (CPU), digital signal processor (DSP), microprocessor unit (MPU), microcontroller unit (MCU), graphics processing unit (GPU), field programmable gate array (FPGA), artificial intelligence processor (AI processor), or neural processing unit (NPU).

[0272] The aforementioned memory may include one or more of the following storage media: random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), phase-change memory (PCM), resistive random access memory (RERAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), cache, register, read-only memory (ROM), flash memory, erasable programmable read-only memory (EPROM), hard disk, etc. In one example, computer program instructions for executing the above embodiments may be stored in non-volatile memory, such as at least a portion of the aforementioned memory 560 (e.g., one or more of ROM, flash memory, EPROM, or hard disk). When the terminal is running, the corresponding computer program instructions may be partially or wholly loaded onto a memory with a faster transfer speed than the processor, such as at least a portion of memory 536 and / or memory 5312 (e.g., one or more of RAM, SRAM, DRAM, PCM, RERAM, MRAM, FRAM, cache, or register), for the processor to execute in order to implement the steps in the above method embodiments.

[0273] In one example, the RF transceiver 522 and the RF front-end 521 can also be packaged in a single chip. In another example, the RF transceiver 522, the RF front-end 521, and the baseband processor 531 can also be packaged in a single chip.

[0274] The terms "system" and "network" in the embodiments of this application may be used interchangeably. "At least one" means one or more, and "multiple" means two or more.

[0275] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, etc.) containing computer-usable program code.

[0276] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0277] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0278] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0279] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A cell access method, characterized in that, The method includes: Receive synchronization signal block (SSB) measurement configuration for cell access, which includes cell reselection or cell handover; Based on the SSB measurement configuration, obtain the SSB measurement results; Based on the measurement results of the SSB, the first SSB is selected; If the first SSB is determined to be a neighboring cell of the current serving cell, then cell access is performed in the neighboring cell.

2. The method according to claim 1, characterized in that, The method further includes: If the first SSB is determined to belong to the current serving cell, the access to the current serving cell is maintained.

3. The method according to claim 1 or 2, characterized in that, The SSB measurement configuration includes measurement information of at least one SSB, and the at least one SSB includes the first SSB; The measurement information includes the index of the at least one SSB, or the wave position identifier corresponding to the at least one SSB, or the time offset and duration for determining the time window in which the at least one SSB is located.

4. The method according to claim 3, characterized in that, The SSB measurement configuration also includes identifiers for multiple cells, including the neighboring cells.

5. The method according to claim 3 or 4, characterized in that, The SSB measurement configuration also includes: multiple measurement results for the same SSB for at least one SSB in multiple cycles, a maximum number of cycles for filtering and averaging, and a minimum level threshold.

6. The method according to any one of claims 1 to 5, characterized in that, The information included in the SSB measurement configuration is carried in at least one of the following: System message block SIB1; or In the main information block (MIB).

7. A cell access method, characterized in that, The method includes: Receive Measurement Timing Configuration (SMTC) based on synchronization signal block. The SMTC includes first information, which indicates that the SMTC belongs to the currently accessed network device. Based on the first information and the SMTC, obtain the measurement results of at least one cell in the network device; Based on the measurement results of the at least one cell, a first cell is selected; If the first cell is determined to be a neighboring cell of the current serving cell, cell access is performed in the neighboring cell.

8. The method according to claim 7, characterized in that, The method further includes: If the first cell is determined to belong to the current serving cell, the access to the current serving cell is maintained.

9. A cell access method, characterized in that, The method includes: Receive Measurement Timing Configuration (SMTC) based on synchronization signal block. The SMTC includes first information, which indicates that the SMTC belongs to a neighboring cell of the current serving cell, and the neighboring cell and the serving cell belong to the same network device. Based on the first information and the SMTC, the measurement results of at least one cell in the network device are obtained, and the at least one cell includes the neighboring cell; Based on the measurement results of the at least one cell, a first cell is selected; Cell access is performed in the first cell.

10. A communication device, characterized in that, Includes units or modules for implementing the method as described in any one of claims 1 to 9.

11. A communication device, characterized in that, The communication device includes at least one processor; the at least one processor is configured to enable the communication device to implement the method as described in any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed, cause the computer to perform the method as described in any one of claims 1 to 9.

13. A communication system, characterized in that, The communication system includes at least a network device and a terminal device; The network device is used to determine and transmit the Synchronization Signal Block (SSB) measurement configuration for cell access; The terminal device is used to perform the method as described in any one of claims 1 to 6; or, The network device is used to determine and transmit measurement timing configuration based on synchronization signal blocks; The terminal device is used to perform the method as described in any one of claims 7 to 9.

14. A computer program product, characterized in that, The computer program product includes: computer program code, which, when executed by a computer, causes the computer to perform the method as described in any one of claims 1 to 9.

15. A communication device, characterized in that, The communication device includes logic circuitry and an interface, the interface being used for inputting and / or outputting information, and the logic circuitry being used to cause the communication device to perform the method as described in any one of claims 1 to 9.

16. A chip, characterized in that, It includes at least one processor, the processor being configured to execute instructions to cause a communication device including the chip to perform the cell access method as described in any one of claims 1 to 9.

17. The chip according to claim 16, characterized in that, The chip also includes an interface circuit, which is used to receive the executed instructions and transmit them to the processor, or to output information from the processor.

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