Communication method, user equipment and network node

Abstract

A communication method used in a mobile communication system includes performing, at a user equipment, wireless communication with a network node using one or more network slices; and transmitting, at the user equipment, slice-related information for performing mobility control of the user equipment to the network node. The slice-related information includes at least one item selected from a group consisting of first information indicating a probability of use of each of the network slices, second information indicating a priority of each of the network slices, and third information indicating a traffic mode of each of the network slices.

Description

Technical Field

[0001] This disclosure relates to communication methods, user equipment, and network nodes used in mobile communication systems. Background Technology

[0002] The 3rd Generation Partnership Project (3GPP), a standardization project for mobile communication systems, has explored the application of artificial intelligence or machine learning (also known as artificial intelligence / machine learning (AI / ML)) technologies to the air interface of mobile communication systems.

[0003] Reference List

[0004] Non-patent literature

[0005] Non-patent literature 1: 3GPP Technical Report: TR 38.843 V0.1.0 (2023-05), "Study on Artificial Intelligence (AI) / Machine Learning (ML) for NR air interface (Release 18)" Summary of the Invention

[0006] In a first aspect, the communication method is a method used in a mobile communication system. The communication method includes: at a user equipment, performing wireless communication with a network node using one or more network slices; and at the user equipment, sending slice-related information to the network node for performing mobility control of the user equipment. The slice-related information includes at least one selected from the group consisting of: first information indicating the probability of use of each of the network slices, second information indicating the priority of each of the network slices, and third information indicating the service mode of each of the network slices.

[0007] In a second aspect, the user equipment is a device used in a mobile communication system. The user equipment includes: a controller configured to perform wireless communication with a network node using one or more network slices; and a transmitter configured to transmit slice-related information to the network node for performing mobility control of the user equipment. The slice-related information includes at least one selected from the group consisting of: first information indicating the probability of use of each of the network slices, second information indicating the priority of each of the network slices, and third information indicating the service mode of each of the network slices.

[0008] In a third aspect, the network node is a node used in a mobile communication system. The network node includes: a controller configured to perform wireless communication with a user equipment using one or more network slices; and a receiver configured to receive slice-related information from the user equipment for performing mobility control of the user equipment. The slice-related information includes at least one selected from the group consisting of: first information indicating the probability of use of each of the network slices, second information indicating the priority of each of the network slices, and third information indicating the service mode of each of the network slices.

[0009] In the fourth aspect, a network node is a node used in a mobile communication system. The network node includes: a communicator configured to transmit slice load information indicating the load status of each in a network slice to another network node. The slice load information includes at least one selected from the group consisting of: information about the number of user equipments in a Radio Resource Control (RRC) connected state, information about the number of user equipments in a Radio Resource Control (RRC) connected state and active, and information about the communication load for each user equipment regarding each in the network slice. Attached Figure Description

[0010] Figure 1 This is a diagram illustrating the configuration of a mobile communication system according to an embodiment.

[0011] Figure 2 This is a diagram illustrating the configuration of a user equipment (UE) according to an embodiment.

[0012] Figure 3 This is a diagram illustrating the configuration of a gNB (network node) according to an embodiment.

[0013] Figure 4 This is a diagram illustrating the configuration of the protocol stack for the user plane radio interface that processes data.

[0014] Figure 5 This is a diagram showing the configuration of the protocol stack of the radio interface of the control plane that processes signaling (control signals).

[0015] Figure 6 This is a diagram illustrating the functional block configuration of AI / ML technology in a mobile communication system according to an embodiment.

[0016] Figure 7 This is a diagram used to describe an overview of network slicing technology.

[0017] Figure 8 This is a diagram illustrating an example of an operational scenario of a mobile communication system according to an embodiment.

[0018] Figure 9 This is a diagram used to describe a first operating mode of a mobile communication system according to an embodiment.

[0019] Figure 10 This is a diagram illustrating an example of a first operating mode of a mobile communication system according to an embodiment.

[0020] Figure 11 This is a diagram used to describe a second operating mode of a mobile communication system according to an embodiment.

[0021] Figure 12 This is a diagram illustrating an example of a second operating mode of a mobile communication system according to an embodiment. Detailed Implementation

[0022] As a use case for AI / ML technologies, mobility control for user equipment (e.g., handover control) is conceivable. For example, with network slicing technology, determining the network nodes of the target cell for user equipment handover through model inference could allow for more appropriate target cell determination by considering network slicing. However, no technology has yet been established to combine network slicing technology to achieve such AI / ML-based mobility control.

[0023] This disclosure provides a way to facilitate the implementation of AI / ML-based mobility control by taking network slicing into account.

[0024] According to embodiments, a mobile communication system is described herein with reference to the accompanying drawings. In the description of the drawings, the same or similar reference numerals denote the same or similar parts.

[0025] (1) Configuration of mobile communication system

[0026] First, the configuration of the mobile communication system according to an embodiment is described. Figure 1 This is a diagram illustrating the configuration of a mobile communication system 1 according to an embodiment. The mobile communication system 1 conforms to the 3GPP standard for a fifth-generation system (5GS). The following description uses 5GS as an example, but a Long Term Evolution (LTE) system can be at least partially applied to the mobile communication system. Alternatively, a sixth-generation (6G) system can be at least partially applied to this mobile communication system.

[0027] Mobile communication system 1 includes user equipment (UE) 100, a 5G radio access network (Next Generation Radio Access Network (NG-RAN)) 10, and a 5G core network (5GC) 20. In the following text, NG-RAN 10 may be simply referred to as RAN 10. 5GC 20 may be simply referred to as core network (CN) 20. RAN 10 and CN 20 configure network 5 of mobile communication system 1. UE 100 performs wireless communication with network 5.

[0028] UE 100 is a mobile wireless communication device. UE 100 can be any device as long as it is used by a user. Examples of UE 100 include mobile phone terminals (which may be smartphones) or tablet terminals, laptop PCs, communication modules (which may be communication cards or chipsets), sensors or devices mounted on sensors, vehicles or devices mounted on vehicles (vehicle UE), and flying objects or devices mounted on flying objects (airborne UE).

[0029] NG-RAN 10 includes base stations 200 (also referred to as "gNBs" or "NG-RAN nodes" in 5G systems) as network nodes. gNBs 200 are interconnected via the Xn interface, which serves as an inter-base station interface. Each gNB 200 manages one or more cells. gNBs 200 perform wireless communication with UE 100, which has established a connection with a cell of the gNB 200. gNBs 200 have radio resource management (RRM) functions, functions for routing user data (hereinafter referred to as "data"), measurement and control functions for mobility control and scheduling, etc. "Cell" is used as a term to represent the smallest unit of a wireless communication area. "Cell" is also used as a term to represent the functions or resources used to perform wireless communication with UE 100. A cell belongs to a carrier frequency (hereinafter referred to as "frequency").

[0030] Note that a gNB can connect to the Evolved Packet Core (EPC) corresponding to the LTE core network. LTE base stations can also connect to the 5GC. LTE base stations and gNBs can connect via an inter-base station interface.

[0031] The 5GC 20 includes Access and Mobility Management Functions (AMF) and User Plane Functions (UPF) 300. The AMF performs various types of mobility control for the UE 100. The AMF manages the mobility of the UE 100 by communicating with it using Non-Access Stratum (NAS) signaling. The UPF controls data transmission. The AMF and UPF are connected to the gNB 200 via the NG interface, which serves as the interface between the base station and the core network.

[0032] Figure 2 This diagram illustrates the configuration of a UE 100 (User Equipment) according to an embodiment. UE 100 includes a receiver 110, a transmitter 120, and a controller 130. The receiver 110 and transmitter 120 constitute a communicator for performing wireless communication with the gNB 200. UE 100 is an example of a communication device.

[0033] Receiver 110 performs various reception functions under the control of controller 130. Receiver 110 includes an antenna and receiving equipment. The receiving equipment converts the radio signals or terahertz wave signals received through the antenna into baseband signals (received signals) and outputs the resulting signals to controller 130.

[0034] Transmitter 120 performs various transmissions under the control of controller 130. Transmitter 120 includes an antenna and a transmitting device. The transmitting device converts the baseband signal (transmit signal) output by controller 130 into a radio signal or a terahertz wave signal, and transmits the obtained signal through the antenna.

[0035] Controller 130 performs various control and processing operations within UE 100. The operation of UE 100, as described above and below, can also be performed under the control of controller 130. Controller 130 includes at least one processor and at least one memory. The memory stores programs to be executed by the processor and information to be used for processing within the processor. The processor may include a baseband processor and a central processing unit (CPU). The baseband processor performs modulation and demodulation, encoding and decoding of baseband signals, etc. The CPU executes programs stored in the memory, thereby performing various types of processing.

[0036] Figure 3 This diagram illustrates the configuration of a gNB 200 (network node) according to an embodiment. The gNB 200 includes a transmitter 210, a receiver 220, a controller 230, and a backhaul communicator 240. The transmitter 210 and receiver 220 constitute a communicator for wireless communication with the user equipment 100. The backhaul communicator 240 constitutes a network communicator for communication with the CN 20. The gNB 200 is another example of a communication device.

[0037] Transmitter 210 performs various transmissions under the control of controller 230. Transmitter 210 includes an antenna and a transmitting device. The transmitting device converts the baseband signal (transmit signal) output by controller 230 into a radio signal or a terahertz wave signal, and transmits the obtained signal through the antenna.

[0038] Receiver 220 performs various types of reception under the control of controller 230. Receiver 220 includes an antenna and receiving equipment. The receiving equipment converts the radio signals or terahertz wave signals received through the antenna into baseband signals (received signals) and outputs the resulting signals to controller 230.

[0039] Controller 230 performs various types of control and processing within gNB 200. The operations of gNB 200 described above and below can also be performed under the control of controller 230. Controller 230 includes at least one processor and at least one memory. The memory stores programs to be executed by the processor and information to be used for processing within the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation and demodulation, encoding and decoding of baseband signals, etc. The CPU executes programs stored in the memory, thereby performing various types of processing.

[0040] The backhaul communicator 240 is connected to an adjacent base station via the Xn interface, which serves as an inter-base station interface. The backhaul communicator 240 is connected to the AMF / UPF 300 via the NG interface, which is the interface between the base station and the core network. Note that the gNB 200 may include a central unit (CU) and a distributed unit (DU) (i.e., functions are divided), and these two units can be connected via the F1 interface, which serves as a fronthaul interface.

[0041] Figure 4 This is a diagram illustrating the configuration of the protocol stack for the user plane radio interface that processes data.

[0042] The user plane radio interface protocol includes the physical layer (PHY), media access control layer (MAC), radio link control layer (RLC), packet data convergence protocol (PDCP) layer, and service data adaptation protocol (SDAP) layer.

[0043] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the PHY layer of UE 100 and the PHY layer of gNB 200 via the physical channel. Note that the PHY layer of UE 100 receives downlink control information (DCI) transmitted from gNB 200 via the physical downlink control channel (PDCCH). Specifically, UE 100 performs blind decoding of the PDCCH using the radio network temporary identifier (RNTI) and obtains the successfully decoded DCI as the DCI addressing the UE. The DCI transmitted from gNB 200 is appended with cyclic redundancy check (CRC) bits scrambled by the RNTI.

[0044] In an NR system, UE 100 can use a bandwidth narrower than the system bandwidth (i.e., cell bandwidth). The gNB 200 configures a bandwidth portion (BWP) for UE 100, consisting of contiguous physical resource blocks (PRBs). UE 100 transmits and receives data and control signals within an active BWP. For example, up to four BWPs can be configured for UE 100. Each BWP can have a different subcarrier spacing. The frequencies of the BWPs can overlap. When multiple BWPs are configured for UE 100, the gNB 200 can specify which BWP to apply by controlling the downlink. By doing so, the gNB 200 dynamically adjusts the UE bandwidth based on factors such as data traffic volume in UE 100 to reduce UE power consumption.

[0045] For example, gNB 200 can configure up to three control resource sets (CORESETs) for each of up to four BWPs on the serving cell. A CORESET is a radio resource used for control information to be received by UE 100. Up to 12 or more CORESETs can be configured for UE 100 on the serving cell. Each CORESET can have an index of 0 to 11 or greater. A CORESET can include six resource blocks (PRBs) and one, two, or three consecutive orthogonal frequency division multiplexing (OFDM) symbols in the time domain.

[0046] The MAC layer performs data priority control, retransmission processing via Hybrid ARQ (HARQ: Hybrid Automatic Repeat Request), and random access procedures. Data and control information are transmitted between the MAC layer of UE 100 and the MAC layer of gNB 200 via the transport channel. The MAC layer of gNB 200 includes a scheduler. The scheduler determines the transport format (transport block size, modulation and coding scheme (MCS)) in the uplink and downlink, as well as the resource blocks to be assigned to UE 100.

[0047] The RLC layer transmits data to the receiving RLC layer using the functions of the MAC layer and PHY layer. Data and control information are transmitted between the RLC layer of UE 100 and the RLC layer of gNB 200 via logical channels.

[0048] The PDCP layer performs header compression / decompression, encryption / decryption, etc.

[0049] The SDAP layer performs the mapping between IP flows (which are the units used for Quality of Service (QoS) control by the core network) and radio bearers (which are the units used for QoS control by the access layer (AS)). Note that SDAP is not required when the RAN is connected to the EPC.

[0050] Figure 5This is a diagram showing the configuration of the protocol stack of the radio interface of the control plane that processes signaling (control signals).

[0051] The protocol stack for the control plane's radio interface includes the Radio Resource Control (RRC) layer and the Non-Access Layer (NAS), rather than... Figure 4 The SDAP layer is shown.

[0052] RRC signaling for various configurations is transmitted between the RRC layer of UE 100 and the RRC layer of gNB 200. The RRC layer controls logical channels, transport channels, and physical channels based on the establishment, reconstruction, and release of radio bearers. UE 100 is in an RRC connected state when a connection exists between the RRC of UE 100 and the RRC of gNB 200 (RRC connected). UE 100 is in an RRC idle state when no connection exists between the RRC of UE 100 and the RRC of gNB 200 (RRC connected). UE 100 is in an RRC inactive state when the connection between the RRC of UE 100 and the RRC of gNB 200 is suspended.

[0053] The NAS, located above the RRC, performs session management, mobility management, etc. NAS signaling is transmitted between the UE 100's NAS and the AMF 300A's NAS. In addition to the radio interface protocol, the UE 100 includes the application layer. The layer below the NAS is called the access layer (AS).

[0054] (2) Overview of AI / ML technologies

[0055] This article provides an overview of AI / ML technologies. Figure 6 This is a diagram illustrating the functional block configuration of AI / ML technology in a mobile communication system 1 according to an embodiment.

[0056] Figure 6 The functional module configuration shown includes a data collector A1, a model training unit A2, a model inference unit A3, and a data processor A4.

[0057] Data collector A1 collects input data (specifically, training data and inference data), and outputs the training data to model training unit A2 and the inference data to model inference unit A3. Data collector A1 can acquire data as input data from a device in which it is located. Data collector A1 can also acquire data as input data from another device.

[0058] Model training unit A2 performs model training (also known as "learning processing"). Specifically, model training unit A2 uses training data to optimize the parameters of the trained model (also referred to below as the "model" or "AI / ML model") through machine learning, derives (generates or updates) the trained model, and outputs the trained model to model inference unit A3. This model is a data-driven algorithm that uses AI / ML techniques to generate an output set based on an input set. For example, consider y = ax + b, where a (slope) and b (intercept) are parameters, and optimizing these parameters corresponds to machine learning. Generally, machine learning includes supervised learning, unsupervised learning, and reinforcement learning. Supervised learning is a method that uses correct answer data as training data. Unsupervised learning is a method that does not use correct answer data as training data. For example, in unsupervised learning, feature points are learned from a large amount of training data, and correct answer determination (range estimation) is performed. Reinforcement learning is a method that assigns a score to an output and learns a way to maximize that score.

[0059] Model inference unit A3 performs model inference (also known as "inference processing"). Specifically, model inference unit A3 infers outputs from the inference data using a trained model and outputs the inference result data to data processor A4. For example, consider y=ax+b, where x is the inference data and y corresponds to the inference result data. Note that "y=ax+b" is the model. The model where the slope and intercept are optimized (e.g., "y=5x+3") is the trained model. Here, various techniques for the model are used, such as linear regression analysis, neural networks, and decision tree analysis. The "y=ax+b" above can be considered a type of linear regression analysis. Model inference unit A3 can perform model performance feedback to model training unit A2.

[0060] Data processor A4 receives inference result data and performs processing using the inference result data.

[0061] (3) Overview of network slicing technology

[0062] This article provides an overview of network slicing technology. Figure 7 This is a diagram used to describe an overview of network slicing technology.

[0063] In network slicing, network 5 is logically divided into configuration network slices (hereinafter referred to as "slices"). Each slice corresponds to different service requirements. In the example shown, network 5 has four slices (slices 1 to 4).

[0064] Network slicing comprises the RAN (Radio Router) and CN (Network Network) components. Support for network slicing is based on the principle that services in different slices are handled by different Protocol Data Unit (PDU) sessions. Network 5 can implement various network slices through scheduling and by providing different Layer 1 / Layer 2 (L1 / L2) configurations.

[0065] Each network slice is uniquely identified by a single Network Slice Selection Auxiliary Information (S-NSSAI). Note that an NSSAI consists of either a single S-NSSAI or a list of S-NSSAIs. An S-NSSAI has a mandatory Slice / Service Type (SST) field to identify the slice type and an optional Slice Distinguisor (SD) field to distinguish slices with the same SST field.

[0066] When the NAS provides the NSSAI, the UE 100 provides the NSSAI for network slice selection to Network 5 (NG-RAN 10 / gNB 200) in the RRC setup completion message. Network 5 can support a large number of slices, but the UE 100 does not need to support more than 8 slices simultaneously. NG-RAN 10 supports selecting the RAN portion of a network slice via the NSSAI provided by the UE 100 or 5GC 20. Note that a gNB 200 (NG-RAN node) can support multiple slices.

[0067] NG-RAN 10 supports resource isolation between slices and can dedicate NG-RAN resources to a specific slice. Certain Random Access Channel (RACH) resources are associated with a specific Network Slice AS Group (NSAG). An NSAG identifies the association with a slice or set of slices. That is, an NSAG indicates a slice group consisting of at least one slice. NSAGs are defined within the Tracking Area (TA) and are used for slice-based cell reselection and / or slice-based random access (slice-based RACH configuration).

[0068] (4) Operation of mobile communication systems

[0069] In this embodiment, the operation of mobile communication system 1 is described. In this embodiment, AI / ML technology is applied to the mobility control of UE 100. Specifically, in this embodiment, AI / ML technology is applied to cell switching from the source cell to the target cell, specifically, the switching of the serving cell of UE 100. As an example, this embodiment mainly describes the handover for switching the primary cell (PCell) of UE 100 when UE 100 is in an RRC connection state, initiated actively by the RRC layer.

[0070] In addition to handover, cell switching when UE 100 is in RRC connected state also includes PSCell changes for exchanging UE 100's primary and secondary cells (PSCells) initiated at the RRC layer, and L1 / L2 triggered mobility (LTM) as cell switching initiated at Layer 1 and / or Layer 2 (L1 / L2). Although the embodiments primarily describe examples of applying AI / ML technology to handover, AI / ML technology can also be applied to LTM or PSCell changes. In other words, the term "handover" below can be understood as "LTM" or "PSCell change". Note that in LTM, for example, gNB 200 pre-configures one or more candidate cells for UE 100 in an RRC message, UE 100 reports cell measurement results to gNB 200 in L1, gNB 200 instructs UE 100 to perform cell switching to a target cell in a MAC control element (CE), and UE 100 accesses the target cell in response to this instruction.

[0071] Handover includes normal handover (also known as "HO") and conditional handover (CHO). In normal handover, UE 100 sends a measurement report message, which is a type of RRC message, to gNB 200. gNB 200 determines the target cell based on the measurement report message, instructs UE 100 to handover to the target cell in the RRC message, and UE 100 responds by accessing the target cell. In contrast, in conditional handover, gNB 200 pre-configures one or more candidate cells and the handover execution conditions for UE 100 in the RRC message. UE 100 evaluates whether the execution conditions for handover to any candidate cell are met, and UE 100 determines the candidate cell that meets the handover execution conditions as the target cell and accesses that target cell. Note that the cell determined for UE 100 to access is called the target cell, and the cell that is a candidate for the target cell is called a candidate cell; however, in the following description, the terms "target cell" and "candidate cell" can be used synonymously.

[0072] From the perspective of network 5, handover includes intra-gNB (CU) handover when the source cell and the target cell belong to the same gNB (CU), and inter-gNB (CU) handover when the source cell and the target cell belong to different gNBs (CUs). In this embodiment, inter-gNB handover is mainly assumed, but intra-gNB handover can also be assumed.

[0073] Furthermore, the following embodiments primarily describe an example where AI / ML-related signaling is an RRC message, which is signaling at the RRC layer (i.e., layer 3). However, AI / ML-related signaling can be MAC CE as MAC layer signaling (i.e., layer 2) or downlink control information (DCI) and / or uplink control information (UCI) as PHY layer signaling (i.e., L1). Downlink AI / ML-related signaling can be UE-specific signaling (dedicated signaling) or broadcast signaling (e.g., system information block (SIB)). AI / ML-related signaling can also be signaling in a new layer specifically used for artificial intelligence or machine learning (e.g., the AI / ML layer).

[0074] Figure 8 This is a diagram illustrating an example of an operational scenario of a mobile communication system 1 according to an embodiment.

[0075] In the example shown, UE 100 is in an RRC connection state, where cell a, managed by gNB 200a, is the serving cell. In other words, UE 100 establishes an RRC connection with gNB 200a and wirelessly communicates with gNB 200a. Neighboring cells of cell a include cells b and c. Cell b is managed by gNB 200b, and cell c is managed by gNB 200c. gNB 200a communicatively connects to gNB 200b and gNB 200c via an inter-node interface (Xn interface).

[0076] In response to UE 100's movement, a handover of UE 100 needs to be performed from cell a to a neighboring cell. In the example shown, the neighboring cells are cell b and cell c, and cell b and cell c are candidate cells for handover.

[0077] For normal handover, gNB 200 sends a measurement report message as an RRC message. Based on the measurement report message, gNB 200 determines either cell b or c as the target cell. In the RRC message, gNB 200 indicates the handover to the target cell to UE 100, and UE 100 responds to the instruction and accesses the target cell.

[0078] For conditional handover, gNB 200 pre-configures one or more candidate cells (cells b and c) and the handover execution conditions of UE 100 in the RRC message. UE 100 evaluates whether the execution conditions for handover to any candidate cell are met, and UE 100 determines the candidate cell that meets the handover execution conditions as the target cell and accesses the target cell.

[0079] In such handovers (normal handover and conditional handover), issues such as service interruptions may occur when the target cell (target gNB) does not support the network slice that UE 100 is using or will use. Even if the target cell (target gNB) supports the network slice that UE 100 is using, the required quality of service may not be required if the target cell (target gNB) has insufficient network slice resources during handover.

[0080] Here, determining the target cell (target gNB) for UE 100 handover through model inference (gNB 200a) allows for more appropriate target cell determination by considering network slicing. The embodiments describe a first and second operating mode of the mobile communication system 1 to facilitate AI / ML-based mobility control by considering network slicing.

[0081] (4.1) Example of the first operation

[0082] Figure 9 This is a diagram used to describe a first operating mode of the mobile communication system 1 according to an embodiment.

[0083] UE 100 is in RRC connected state, where cell a, managed by gNB 200a, is the serving cell. UE 100 performs wireless communication with gNB 200a using one or more network slices. In a first operating mode, UE 100 sends slice-related information to gNB 200 for performing mobility control of UE 100. The slice-related information includes at least one selected from the group consisting of: first information indicating the usage probability of each network slice, second information indicating the priority of each network slice, and third information indicating the service mode of each network slice. That is, UE 100 notifies gNB 200a of at least one selected from the group consisting of the usage probability of each slice, the priority of each slice, and the service mode (resource utilization) of each slice.

[0084] This enables the gNB 200a (source gNB) to appropriately determine the target cell (target gNB) based on the slice-related information provided from the UE 100, taking into account network slices.

[0085] The UE 100 performing this operation includes: a controller 130 configured to perform wireless communication with the gNB 200a using one or more network slices; and a transmitter 120 configured to send slice-related information to the gNB 200a for performing mobility control of the UE 100. Conversely, the gNB 200a includes: a controller 230 configured to perform wireless communication with the UE 100 using one or more network slices; and a receiver 220 configured to receive slice-related information from the UE 100 for performing mobility control of the UE 100.

[0086] In the first operating mode, UE 100 can receive signaling from gNB 200 for requesting or configuring the transmission of slice-related information. UE 100 can then send slice-related information to gNB 200a in response to this signaling.

[0087] In the first operating mode, the UE 100 can use the tracking records of each of the network slices to derive at least one item selected from the group consisting of first information, second information and third information through statistical processing.

[0088] In the first operating mode, the UE 100 can derive at least one item selected from the group consisting of first information, second information, and third information by using an artificial intelligence or machine learning (AI / ML) model, based on the tracking records of the UE 100 using each of the network slices, through inference processing (model inference). Here, the AI / ML model can be a trained model that has been trained on the tracking records of the UE 100 using each of the network slices.

[0089] In the first operating mode, at least one item selected from the group consisting of the first information, the second information, and the third information can be information from the S-NSSAI unit or information from the NSAG unit.

[0090] Figure 10 This is a diagram illustrating an example of a first operating mode of the mobile communication system 1 according to an embodiment. Note that information about network slices allowed for use by the UE 100 (e.g., allowing NSSAI or configuring NSSAI) can be provided from the AMF 300A to the gNB 200a.

[0091] In step S101, UE 100 is in RRC connected state, where cell a managed by gNB 200a is the serving cell. UE 100 uses one or more network slices to perform wireless communication with cell a (gNB 200a).

[0092] In step S102, gNB 200a may send a transmission configuration or transmission request (also referred to as a "slice information request") for slice-related information to UE 100. UE 100 receives the slice information request.

[0093] The gNB 200a can send an RRC reconfiguration message to the UE 100 as an RRC message, which includes a slice information request. The RRC reconfiguration message can include a measurement configuration for configuring measurements and a measurement report for handover of the UE 100. That is, the gNB 200 can send the slice information request along with the measurement configuration to the UE 100. The slice information request can be included in the measurement configuration.

[0094] gNB 200 may include information indicating network slices intended for use in slice-related information (or not intended for use in slice-related information) in the slice information request. This information may be an S-NSSAI list or an NSAG list.

[0095] The gNB 200 may include information indicating the type of slice-related information requested from the UE 100 in the slice information request. For example, the gNB 200 may include information indicating the type of information to be exported and sent by the UE 100 among the first to third information in the slice information request.

[0096] When gNB 200 requests statistics based on past history (tracking records) from UE 100, gNB 200 can include information indicating the expected time period (e.g., the past day) in the slice information request.

[0097] When gNB 200 requests future predicted values ​​from UE 100 for use of model inference, gNB 200 may include the identification information (model ID or function ID) of the AI / ML model used for model inference in the slice information request. Alternatively, gNB 200 may include the AI / ML model itself in the slice information request.

[0098] In step S103, UE 100 sends slice-related information to gNB 200a. gNB 200a receives the slice-related information. UE 100 may send a measurement report message or a UE assistance information message, which is a type of RRC message, to gNB 200a, and includes the slice-related information to be sent. The slice-related information includes at least one piece of information selected from the group consisting of the first to third pieces of information described below.

[0099] 1) Information indicating the probability of using each network slice (first information):

[0100] For each network slice, the first information may include the S-NSSAI indicating the network slice and information indicating the probability that the UE100 will use the network slice. For example, the first information may be such as S-NSSAI#1: 30%, S-NSSAI#2: 15%, S-NSSAI#3: 60%... However, the information indicating the probability may be an index indicating the probability, rather than a probability value. For example, the first information may be such as S-NSSAI#1: High probability (high), S-NSSAI#2: Low probability (low), S-NSSAI#3: Medium probability (medium)...

[0101] For each set (group) of network slices, the first information may include information indicating the NSAG of that set and information indicating the probability that the UE100 uses that set. For example, the first information may be information such as NSAG#1:30%, NSAG#2:15%, NSAG#3:60%...

[0102] UE 100 can derive the usage probability of each network slice based on the tracking records of each network slice using statistical processing (e.g., maximum, minimum, or average values). UE 100 can also derive the usage probability of each network slice through model inference using an AI / ML model (trained model) that has already been trained on the tracking records of each network slice for UE 100.

[0103] 2) Information indicating the priority of each network slice (secondary information):

[0104] For each network slice, the second information may include information indicating the S-NSSAI of that network slice and information indicating the priority (priority order) derived by the UE100 for that network slice. For example, the first information may be information such as S-NSSAI#1: priority "3", S-NSSAI#2: priority "1", S-NSSAI#3: priority "2", and so on.

[0105] For each set (group) of network slices, the second information may include information indicating the NSAG of that set and information indicating the priority (priority order) derived by the UE100 for that set. For example, the second information may be information such as NSAG#1: priority "3", NSAG#2: priority "1", NSAG#3: priority "2", and so on.

[0106] UE 100 can derive the priority of each network slice based on the tracking records of each network slice used by UE 100 through statistical processing. For example, UE 100 can calculate the usage probability of each network slice through the statistical processing described above, and then derive the priority, with higher usage probabilities resulting in higher priorities. UE 100 can also derive the priority of each network slice through model inference using an AI / ML model (trained model) that has already been trained on the records of each network slice used by UE 100.

[0107] 3) Information indicating the service mode of each network slice (third information):

[0108] The service pattern can be selected from at least one of the following groups: service cycle (generation cycle), data volume of a burst (throughput), and duration of a burst (duration). A burst can be each piece of data sent (or received). Third information can be information indicating different service patterns for the uplink and downlink as the service pattern for each network slice.

[0109] For each network slice, the third information may include the S-NSSAI indicating the network slice and information indicating the service mode exported by UE 100 for that network slice. For each set (group) of network slices, the third information may include the NSAG indicating the set and information indicating the service mode exported by UE 100 for that set.

[0110] UE 100 can derive the business patterns of each network slice based on the tracking records of each network slice using statistical processing (e.g., maximum, minimum, or average values). UE 100 can also derive the business patterns of each network slice through model inference using an AI / ML model (trained model) that has already been trained on the records of each network slice.

[0111] In step S104, gNB 200a determines the target cell for UE 100 handover based on the slice-related information received from UE 100 in step S103. gNB 200a can use an AI / ML model to determine the target cell through model inference based on the slice-related information. Here, it is assumed that cell b is determined to be the target cell.

[0112] The gNB 200a can pre-acquire the network slices to be supported and / or the traffic of each network slice for each candidate cell. Here, the candidate cells can be cells (neighboring cells) that meet predetermined radio quality standards. The gNB 200a can determine the candidate cells based on measurement report messages from the UE 100. The gNB 200a can determine the candidate cells that support network slices with high usage probability and / or high priority in the UE 100 as target cells based on first and / or second information included in the slice-related information. The gNB 200a can estimate the radio resource load (ratio) of each candidate cell based on third information included in the slice-related information and select the candidate cell whose traffic can withstand the load as the target cell.

[0113] In step S105, gNB 200a sends a HO request message to gNB 200b requesting UE 100 to hand over to managing cell b. gNB 200b receives the HO request message. gNB 200a may send the HO request message to gNB 200b, which includes at least a portion of the slice-related information received from UE 100 in step S103 and / or information indicating the estimated radio resource load based on the slice-related information.

[0114] In step S106, gNB 200b sends an HO request response message to gNB 200a in response to receiving the HO request message. The HO request response message includes the configuration information (RRC configuration information) required for UE 100 to access the target cell (cell b).

[0115] In step S107, in response to receiving the HO request response message in step S106, gNB 200a sends an RRC reconfiguration message to UE 100 as a HO command. This RRC reconfiguration message includes the RRC configuration information from the HO request response message. UE 100 receives the HO command.

[0116] In step S108, in response to receiving the HO command from step S107, UE 100 performs access (connection processing) to the target cell b. For example, UE 100 may initiate a random access procedure for cell b and send a random access preamble to cell b. Then, UE 100 may send an RRC reconfiguration complete message to cell b. Upon completion of this connection processing, UE 100 continues to communicate with cell b as the new serving cell.

[0117] Note that this example describes a normal handover as an example, but it can also be applied to conditional handovers. For instance, gNB 200a can determine one or more candidate cells based on slice-related information from UE 100, and configure these candidate cells and the handover execution conditions for UE 100 in the RRC message. When the execution conditions for handover to any candidate cell are met, UE 100 can access the target cell by determining the candidate cell that meets the handover execution conditions as the target cell.

[0118] (4.2) Example of the second operation

[0119] Figure 11 This is a diagram illustrating a second operating mode of the mobile communication system 1 according to an embodiment. Note that the second operating mode can be performed in conjunction with the first operating mode.

[0120] In the second operating mode, gNB 200a obtains slice load information from another gNB 200 (neighboring gNB), indicating the load status of each network slice of that other gNB 200. In the example shown, gNB 200a obtains slice load information from gNB 200b, indicating the load status of each network slice of gNB 200b (cell b), and from gNB 200c, indicating the load status of each network slice associated with gNB 200c (cell c). gNB 200a performs mobility control from gNB 200a to that other gNB 200 (target cell) based on the obtained slice load information. For example, gNB 200a determines the target (target cell and / or target gNB) for the handover of UE 100 based on the obtained slice load information. The gNB 200a can predict whether slicing services will be appropriately provided in the target after a handover of UE 100, and can perform a handover of UE 100 to the target where slicing services are predicted to be appropriately provided.

[0121] Figure 12 This is a diagram illustrating an example of a second operating mode of a mobile communication system 1 according to an embodiment. Here, the differences from the first operating mode are mainly described.

[0122] In step S201, UE 100 is in RRC connected state, where cell a managed by gNB 200a is the serving cell. UE 100 uses one or more network slices to perform wireless communication with cell a (gNB 200a).

[0123] In step S202, gNB 200a can send a slice information request to UE 100.

[0124] In step S203, gNB 200a may send a "Resource Status Request" message to gNB 200b to request a report on the resource load status of gNB 200b, which is a neighboring gNB. The "Resource Status Request" message may include information indicating the cell to be reported (e.g., cell b), information for requesting the start of resource load status measurement, and information indicating the reporting period. In the second operating mode, the "Resource Status Request" message may include information indicating the type of slice load information to be reported and / or information indicating the slice to be reported.

[0125] In step S204, gNB 200b may send a "Resource Status Response" message to gNB 200a in response to receiving the "Resource Status Request" message in step S203, and start the measurement requested from gNB 200a.

[0126] In step S205, UE 100 can send slice-related information to gNB 200a.

[0127] In step S206, gNB 200b sends a "Resource Status Update" message containing slice load information (information about the load of each slice) to gNB 200a. gNB 200a receives the "Resource Status Update" message. The "Resource Status Update" message may include cell identification information indicating the cell (cell b) to be reported, and slice load information associated with that cell identification information. The slice load information includes at least one of the following information 1) to 3).

[0128] 1) For each network slice, information regarding the number of UE 100s in RRC connection state (RRC connection quantity information):

[0129] RRC connection quantity information is information about the number of RRC connections for each slice of the cell. This information can include a value (integer type) for the number of RRC connections for each slice of the cell and a value for the available RRC connection capacity for each slice of the cell. The value (integer type) for the number of RRC connections for each slice of the cell can be the number of RRC connections for which a PDU session has been established with that slice (the number of UEs 100 in an RRC connection state). The available RRC connection capacity value for each slice of the cell is the percentage of the current number of RRC connections for that slice relative to the maximum number of RRC connections supported by that slice. For example, when the maximum number of RRC connections supported by slice #1 is 100 and the current number of RRC connections for that slice is 25, the available RRC connection capacity value is 75%.

[0130] For example, RRC connection quantity information can be such as S-NSSAI#1: RRC connection quantity "25" and available RRC connection capacity 30 [%], S-NSSAI#2: RRC connection quantity "20" and available RRC connection capacity 45 [%], and so on.

[0131] Note that the number of RRC connections (the number of UE 100s in RRC connected state) can be replaced with the number of RRC inactive UEs (the number of UE 100s in RRC inactive state), or it can be the sum of the number of RRC connections and the number of RRC inactive UEs.

[0132] 2) For each network slice, information regarding the number of UEs 100 that are in RRC connected state and active (active UE count information):

[0133] The number of active UEs can be the average number of active UEs per slice of the cell (integer type). This number of active UEs can be UEs with data available for transmission. The number of active UEs information can be, for example, information such as S-NSSAI#1: Number of active UEs "25", S-NSSAI#2: Number of active UEs "20", and so on.

[0134] 3) For each network slice, information regarding the communication load (resource usage) for each UE:

[0135] This information could be the average resource (load) consumed by each UE for each slice of the cell. For example, this information could be an integer (0 to 100) and could indicate that the (average) resources consumed by each UE are 2% of the total capacity of the slice. This information could be, for example, such as S-NSSAI#1: Average resource usage per UE 2% [%], S-NSSAI#2: Average resource usage per UE 5% [%], and so on.

[0136] In step S207, gNB 200a determines whether to identify cell b as the target cell based on the slice load information received from gNB 200a in step S206. For example, gNB 200a identifies candidate cells that support the network slice being used by UE 100 and whose network slice has low load as target cells. gNB 200a can further identify the target cell based on the slice-related information received from UE 100 in step S205. For example, gNB 200a can use model inference from an AI / ML model to estimate the load increase per slice of each candidate cell (the amount of resources consumed by UE 100) after the handover of UE 100, and identify the candidate cell with the lowest estimated load as the target cell.

[0137] In step S208, gNB 200a sends a HO request message to gNB 200b requesting UE 100 to hand over to managing cell b. gNB 200b receives the HO request message. gNB 200a may send the HO request message to gNB 200b, which includes at least a portion of the slice-related information received from UE 100 in step S205 and / or information indicating the estimated load in step S207.

[0138] In step S209, gNB 200b sends an HO request response message to gNB 200a in response to receiving the HO request message. The HO request response message includes the configuration information (RRC configuration information) required for UE 100 to access the target cell (cell b).

[0139] In step 210, in response to receiving the HO request response message in step 209, gNB 200a sends an RRC reconfiguration message as an HO command to UE 100. This RRC reconfiguration message includes the RRC configuration information from the HO request response message. UE 100 receives the HO command.

[0140] In step S211, UE 100, in response to receiving the HO command from step S107, performs access (connection processing) to the target cell b. For example, UE 100 may initiate a random access procedure for cell b and send a random access preamble to cell b. Then, UE 100 may send an RRC reconfiguration complete message to cell b. Upon completion of this connection processing, UE 100 continues to communicate with cell b as the new serving cell.

[0141] In step S212, gNB 200b may send a "Resource Status Update" message containing slice load information (information about the load of each slice) to gNB 200a. As a supplement or alternative to the information in the "Resource Status Update" message of step S206, the "Resource Status Update" message of step S212 may include information about the amount of load change in gNB 200b (cell b) caused by the handover of UE 100. This information includes at least one of the following 1) and 2). gNB 200a may use the information in the "Resource Status Update" message of step S212 to perform model training for an AI / ML model.

[0142] 1) Information indicating the amount of resources (load) consumed by the switched UE 100 for each slice:

[0143] This information could be information indicating the amount of resources (load) consumed by UE 100 in cell b after handover for each slice.

[0144] 2) Information regarding the estimated load and actual load sent in step S208:

[0145] This information could be the difference between these loads. This information could also be an indication of whether the estimate is correct.

[0146] Note that this example describes a normal handover as an example, but it can also be applied to conditional handovers. For instance, gNB 200a can determine one or more candidate cells based on slice load information from neighboring gNBs, and configure these candidate cells and the handover execution conditions for UE 100 in the RRC message. When the execution conditions for handover to any candidate cell are met, UE 100 can access the target cell by determining the candidate cell that meets the handover execution conditions as the target cell.

[0147] (5) Other embodiments

[0148] The above operational procedures can be implemented separately and independently, or they can be implemented as a combination of two or more operational procedures. For example, some steps in one operational procedure can be added to another, or some steps in one operational procedure can be replaced by some steps in another. In each procedure, not all steps are required to be executed; only some steps may be executed.

[0149] In the above embodiments, an example of an NR base station (gNB) has been described, but the base station can also be an LTE base station (eNB). The base station can be a relay node, such as an Integrated Access and Backhaul (IAB) node. The base station can be a Distributed Unit (DU) of an IAB node. User equipment (terminal device) can be a relay node, such as an IAB node or a mobile terminal (MT) of an IAB node.

[0150] In other words, UE 100 can be a terminal functional unit (a type of communication module) used by the base station to control repeaters that perform signal relay. This type of terminal functional unit is called MT. In addition to IAB-MT, examples of MT include Network Control Repeater (NCR)-MT and Reconfigurable Smart Surface (RIS)-MT.

[0151] The term "network node" primarily refers to a base station, but can also refer to core network equipment or a portion of a base station (CU, DU, or RU). A network node can be a combination of at least a portion of core network equipment and at least a portion of a base station.

[0152] A program may be provided that enables a computer to perform each process executed by a communication device (e.g., UE 100 or gNB 200). This program may be recorded on a computer-readable medium. The computer-readable medium allows the program to be installed on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not specifically limited and may, for example, be a recording medium such as a CD-ROM or DVD-ROM. Circuitry for performing each process executed by the communication device may be integrated, and at least a portion of the communication device may be configured as a semiconductor integrated circuit (chipset, system-on-chip (SoC)).

[0153] The functions implemented by UE 100 and gNB 200 (network nodes) can be implemented in circuitry or processing circuitry programmed to perform the functions, including general-purpose processors, application-specific processors, integrated circuits, application-specific integrated circuits (ASICs), central processing units (CPUs), conventional circuitry, and / or combinations thereof. A processor may include transistors and other circuitry and may be considered as a circuit or processing circuitry. A processor may be a programmed processor that executes a program stored in memory. As used herein, a circuit, unit, or device is hardware programmed to implement the functions or hardware that performs the functions. The hardware may be any hardware disclosed herein or any hardware programmed to implement the functions or any hardware known to perform the functions. When the hardware is a processor considered as a type of circuit, the circuit, device, or unit is a combination of the hardware and software used to configure the hardware and / or the processor.

[0154] Unless otherwise specified, the terms “based on” and “depending on” as used in this disclosure do not mean “based on only” or “depending on only”. The phrase “based on” means “based on only” and “at least partially based on” both. Similarly, the phrase “depending on” means “depending on only” and “at least partially dependent on”. “Obtaining” or “getting” can mean obtaining information from stored information, obtaining information from information received from another node, or obtaining information by generating information. The terms “comprising,” “including,” and variations thereof do not mean “including only the said items,” but rather mean “may include only the said items” or “may include not only the said items but also other items.” The term “or” as used in this disclosure is not intended to be an “exclusive or.” Any reference to elements in this disclosure using names such as “first” and “second” does not generally limit the number or order of those elements. These names may be used herein as a convenient way to distinguish two or more elements. Therefore, references to a first element and a second element do not imply that only the two elements may be used there or that the first element needs to precede the second element in some way. For example, when English articles such as “a,” “one,” and “the” are added in this disclosure by translation, these articles include plural forms unless otherwise explicitly stated in the context.

[0155] The embodiments have been described in detail above with reference to the accompanying drawings, but the specific configurations are not limited to those described above, and various design changes can be made without departing from the spirit of this disclosure.

[0156] This application claims priority to Japanese Patent Application No. 2023-133595 (filed on August 18, 2023), the entire contents of which are incorporated herein by reference.

[0157] (6) Supplementary Notes

[0158] The features related to the above embodiments are described below as supplementary notes.

[0159] Supplementary Note 1

[0160] A communication method for use in a mobile communication system, the communication method comprising:

[0161] At the user equipment, wireless communication is performed with network nodes using one or more network slices; and

[0162] At the user equipment, slice-related information for performing mobility control of the user equipment is sent to the network node.

[0163] The slice-related information includes at least one selected from the group consisting of: first information indicating the probability of use of each of the network slices, second information indicating the priority of each of the network slices, and third information indicating the service mode of each of the network slices.

[0164] Supplementary Note 2

[0165] The communication method described in Supplementary Note 1 further includes the following steps:

[0166] At the user equipment, signaling is received from the network node for requesting or configuring the transmission of information related to the slice.

[0167] Sending the slice-related information includes sending the slice-related information to the network node in response to the signaling.

[0168] Supplementary Note 3

[0169] The communication method described in Supplementary Note 1 or 2 also includes:

[0170] At the user equipment, based on the tracking records of each of the network slices used by the user equipment, at least one item selected from the group consisting of the first information, the second information and the third information is derived through statistical processing.

[0171] Supplementary Note 4

[0172] The communication method according to any one of Supplementary Notes 1 to 3 further includes:

[0173] At the user equipment, at least one item selected from the group consisting of the first information, the second information, and the third information is derived through inference processing based on the tracking records of each of the network slices used by the user equipment using artificial intelligence or machine learning AI / ML models.

[0174] Supplementary Note 5

[0175] According to any one of Supplementary Notes 1 to 4, in the communication method, wherein,

[0176] At least one of the information selected from the group consisting of the first information, the second information, and the third information is information in a single network slice selection auxiliary information (S-NSSAI) unit or information in a network slice AS group (NSAG) unit.

[0177] Supplementary Note 6

[0178] The communication method according to any one of Supplementary Notes 1 to 5 further includes:

[0179] At the network node, the slice-related information is received from the user equipment;

[0180] At the network node, slice load information is obtained, which is obtained from another network node and indicates the load status of each of the network slices of that other network node; and

[0181] At the network node, mobility control from the network node to the other network node is performed based on the slice-related information and the slice load information.

[0182] Supplementary Note 7

[0183] According to the communication method described in Supplementary Note 6, wherein,

[0184] Slice load information for each network slice includes information about the number of user equipment in Radio Resource Control (RRC) connected state.

[0185] Supplementary Note 8

[0186] According to the communication method described in supplementary note 6 or 7, wherein,

[0187] Slice load information for each network slice includes information about the number of user equipment that is in Radio Resource Control (RRC) connected and active.

[0188] Supplementary Note 9

[0189] According to any one of Supplementary Notes 6 to 8, in the communication method, wherein,

[0190] Slice load information includes information about the communication load of each user device for each network slice.

[0191] Supplementary Note 10

[0192] According to any one of Supplementary Notes 6 to 9, in the communication method, wherein,

[0193] Mobility control involves determining the target for user equipment handover based on slice-related information and slice load information.

[0194] Supplementary Note 11

[0195] A user equipment for use in a mobile communication system, the user equipment comprising:

[0196] The controller is configured to perform wireless communication with network nodes using one or more network slices; and

[0197] The transmitter is configured to send slice-related information to the network node for performing mobility control of the user equipment.

[0198] The slice-related information includes at least one selected from the group consisting of: first information indicating the probability of use of each of the network slices, second information indicating the priority of each of the network slices, and third information indicating the service mode of each of the network slices.

[0199] Supplementary Note 12

[0200] A network node used in a mobile communication system, the network node comprising:

[0201] The controller is configured to perform wireless communication with the user equipment using one or more network slices; and

[0202] The receiver is configured to receive slice-related information from the user equipment for performing mobility control of the user equipment.

[0203] The slice-related information includes at least one selected from the group consisting of: first information indicating the probability of use of each of the network slices, second information indicating the priority of each of the network slices, and third information indicating the service mode of each of the network slices.

[0204] Supplementary Note 13

[0205] A network node used in a mobile communication system, the network node comprising:

[0206] The communicator is configured to send slice load information, indicating the load status of each segment in the network slice, to another network node.

[0207] The slice load information includes at least one selected from the group consisting of: information about the number of user equipments in the Radio Resource Control (RRC) connected state, information about the number of user equipments in the RRC connected state and active state, and information about the communication load of each user equipment in each of the network slices.

[0208] Figure Labels

[0209] 1: Mobile communication system

[0210] 5: Network

[0211] 10: RAN (NG-RAN)

[0212] 20:CN (5GC)

[0213] 100:UE

[0214] 110: Receiver

[0215] 120: Transmitter

[0216] 130: Controller

[0217] 200: gNB

[0218] 210: Transmitter

[0219] 220: Receiver

[0220] 230: Controller

[0221] 240: Backhaul Communicator

[0222] A1: Data Collector

[0223] A2: Model Training Unit

[0224] A3: Model Inference Unit

[0225] A4: Data processor.

Claims

1. A communication method used in a mobile communication system, the communication method comprising: At the user equipment, one or more network slices are used to perform wireless communication with network nodes; as well as At the user equipment, slice-related information for performing mobility control of the user equipment is sent to the network node. The slice-related information includes at least one selected from the group consisting of: first information indicating the probability of use of each of the network slices, second information indicating the priority of each of the network slices, and third information indicating the service mode of each of the network slices.

2. The communication method according to claim 1 further includes: At the user equipment, signaling is received from the network node for requesting or configuring the transmission of information related to the slice. Sending the slice-related information includes sending the slice-related information to the network node in response to the signaling.

3. The communication method according to claim 1 further includes: At the user equipment, based on the tracking records of each of the network slices used by the user equipment, at least one item selected from the group consisting of the first information, the second information and the third information is derived through statistical processing.

4. The communication method according to claim 1 further includes: At the user equipment, at least one item selected from the group consisting of the first information, the second information, and the third information is derived through inference processing based on the tracking records of each of the network slices used by the user equipment using artificial intelligence or machine learning AI / ML models.

5. The communication method according to any one of claims 1 to 4, wherein, At least one item selected from the group consisting of the first information, the second information, and the third information is information in the single network slice selection auxiliary information S-NSSAI unit or information in the network slice AS group NSAG unit.

6. The communication method according to claim 1, further comprising: At the network node, the slice-related information is received from the user equipment; At the network node, slice load information is obtained, which is obtained from another network node and indicates the load status of each of the network slices of the other network node; as well as At the network node, mobility control from the network node to the other network node is performed based on the slice-related information and the slice load information.

7. The communication method according to claim 6, wherein, The slice load information for each network slice includes information about the number of user equipment in Radio Resource Control (RRC) connected state.

8. The communication method according to claim 6, wherein, The slice load information for each network slice includes information about the number of user equipment that is in Radio Resource Control (RRC) connected and active.

9. The communication method according to claim 6, wherein, The slice load information for each network slice includes information about the communication load of each user device.

10. The communication method according to claim 6, wherein, Performing mobility control includes determining the handover target of the user equipment based on the slice-related information and the slice load information.

11. A user equipment for use in a mobile communication system, the user equipment comprising: The controller is configured to perform wireless communication with network nodes using one or more network slices; as well as The transmitter is configured to send slice-related information to the network node for performing mobility control of the user equipment. The slice-related information includes at least one selected from the group consisting of: first information indicating the probability of use of each of the network slices, second information indicating the priority of each of the network slices, and third information indicating the service mode of each of the network slices.

12. A network node used in a mobile communication system, the network node comprising: The controller is configured to perform wireless communication with the user equipment using one or more network slices; as well as The receiver is configured to receive slice-related information from the user equipment for performing mobility control of the user equipment. The slice-related information includes at least one selected from the group consisting of: first information indicating the probability of use of each of the network slices, second information indicating the priority of each of the network slices, and third information indicating the service mode of each of the network slices.

13. A network node used in a mobile communication system, the network node comprising: The communicator is configured to send slice load information, indicating the load status of each segment in the network slice, to another network node. The slice load information for each of the network slices includes at least one selected from the group consisting of: information about the number of user equipments in the Radio Resource Control (RRC) connected state, information about the number of user equipments in the RRC connected state and active state, and information about the communication load of each user equipment.

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