Electronic device and operation method thereof

Abstract

This method for operating an electronic device may comprise the steps of: setting a label for each of a plurality of medium access control (MAC) contexts; identifying an allowable degree of radio link failure (RLF) occurrence; identifying information about a target DU; determining the shortest duration for which an RLF associated with a MAC layer can occur in a target cell; determining an allowable MAC scheduling stop duration; predicting the maximum transmittable data size between a source DU and a target DU; and determining the priority of at least one UE among the plurality of UEs, and transferring a portion of the data of the MAC contexts for the target cell from the source DU to the target DU on the basis of the priority and label of the at least one UE.

Description

Electronic devices and their operating methods

[0001] The present disclosure relates to a method and an electronic device for migrating a medium access control (MAC) context from a source DU (distributed unit) to a target DU.

[0002] In the communications industry, technology for virtualized radio access networks (RANs), or vRANs (virtualized RANs), is rapidly growing. Conventional hardware-based RANs require specific hardware to perform each communication function. Mobile carriers, due to hardware compatibility issues, have had to build RANs using hardware configurations from the same manufacturer. However, vRANs are software-based, not hardware-based. Their communication functions can be performed by software configurations. In other words, vRANs do not require specialized hardware to perform communication functions, and their software configurations can be run on general-purpose server devices to perform communication functions. Consequently, mobile carriers can build vRANs using products from various manufacturers, rather than being tied to a single manufacturer's product.

[0003] The present disclosure can be implemented in various ways, including as a method, system, device, or computer program stored on a computer-readable storage medium.

[0004] In one embodiment of the present disclosure, a method of operating an electronic device may include a step of setting a label for each of a plurality of medium access control (MAC) contexts. In one embodiment of the present disclosure, the method may include a step of identifying a degree of tolerance for occurrence of a radio link failure (RLF). In one embodiment of the present disclosure, the method may include a step of identifying information about a target DU. In one embodiment of the present disclosure, the method may include a step of determining a shortest duration during which an RLF associated with a MAC layer in a target cell may occur, based on information about a plurality of user equipments (UEs) associated with the target cell. In one embodiment of the present disclosure, the method may include a step of determining an allowable MAC scheduling interruption time based on the shortest duration. In one embodiment of the present disclosure, the method may include a step of predicting a maximum transmittable data size between a source DU and the target DU, based on the allowable MAC scheduling interruption time and the information about the target DU. In one embodiment of the present disclosure, the method may include determining a priority of one or more UEs among the plurality of UEs based on determining that a data size of MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label.

[0005] In one embodiment of the present disclosure, a computer-readable recording medium having recorded thereon a program for performing the above method on a computer may be provided.

[0006] In one embodiment of the present disclosure, an electronic device may include a memory storing one or more instructions and at least one processor executing the one or more instructions stored in the memory. In one embodiment of the present disclosure, the at least one processor may set a label for each of a plurality of medium access control (MAC) contexts by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor may identify a tolerance level of occurrence of a radio link failure (RLF) by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor may identify information about a target DU (330) by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor may determine a shortest time in which an RLF associated with a MAC layer in the target cell can occur based on information about a plurality of user equipments (UEs) associated with the target cell by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor can determine an allowable MAC scheduling interruption duration based on the shortest time by executing the one or more commands. In one embodiment of the present disclosure, the at least one processor can predict a maximum transmittable data size between a source DU and the target DU based on the allowable MAC scheduling interruption duration and information about the target DU by executing the one or more commands.In one embodiment of the present disclosure, the at least one processor may determine a priority of one or more UEs among the plurality of UEs based on determining that a data size of MAC contexts for the target cell exceeds the maximum transmittable data size by executing the one or more commands, and may transfer some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label.

[0007] FIG. 1 is a diagram showing an example of a wireless communication system structure according to one embodiment of the present disclosure.

[0008] FIG. 2 is a flowchart illustrating an example of a cell transfer method from a source DU to a target DU according to one embodiment of the present disclosure.

[0009] FIG. 3A is a diagram illustrating an example of a source DU and a target DU before MAC context transfer from the source DU to the target DU according to one embodiment of the present disclosure.

[0010] FIG. 3b is a diagram illustrating an example of a source DU and a target DU after MAC context transfer from the source DU to the target DU according to one embodiment of the present disclosure.

[0011] FIG. 4 is a diagram illustrating an example of determining a reference label for each UE for MAC context transfer from a source DU to a target DU according to one embodiment of the present disclosure.

[0012] FIG. 5A is a diagram illustrating an example of determining reference labels for multiple UEs in one embodiment of the present disclosure.

[0013] FIG. 5b is a diagram illustrating an example of determining reference labels for multiple UEs in one embodiment of the present disclosure.

[0014] FIG. 6A is a diagram illustrating an example of determining reference labels for multiple UEs in one embodiment of the present disclosure.

[0015] FIG. 6b is a diagram illustrating an example of determining reference labels for multiple UEs in one embodiment of the present disclosure.

[0016] FIG. 7 is a diagram illustrating an example of transferring a MAC context from a source DU to a target DU based on a label of each MAC context and a reference label for each UE in one embodiment of the present disclosure.

[0017] FIG. 8 is a diagram illustrating an example in which transfer of MAC context fails in one embodiment of the present disclosure.

[0018] FIG. 9 is a drawing showing an example of an operating method of an electronic device according to one embodiment of the present disclosure.

[0019] FIG. 10 is a drawing showing an example of an electronic device according to one embodiment of the present disclosure.

[0020] This disclosure may be subject to various modifications and various embodiments. Specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the disclosure to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the disclosure.

[0021] When describing embodiments, detailed descriptions of related known technologies are omitted if they are deemed to unnecessarily obscure the main point. Furthermore, numbers (e.g., "first," "second," etc.) used in the description of embodiments are merely identifiers used to distinguish one component from another. Furthermore, unless the context clearly indicates otherwise, the singular forms "a," "an," and "the" are understood to include plural references.

[0022] It should also be understood that the blocks and combinations of flowcharts in each flowchart can be executed by one or more computer programs containing computer-executable instructions. The one or more computer programs may be stored entirely in a single memory, or may be stored in separate portions across multiple different memories.

[0023] All functions or operations described in this document may be performed by a single processor or a combination of processors. A single processor or a combination of processors is a circuitry that performs processing, and may include circuitry such as an Application Processor (AP), a Communication Processor (CP), a Graphical Processing Unit (GPU), a Neural Processing Unit (NPU), a Microprocessor Unit (MPU), a System on Chip (SoC), or an Integrated Chip (IC).

[0024] Below, with reference to the attached drawings, embodiments of the present disclosure are described in detail to facilitate implementation by those skilled in the art. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein. Before proceeding with a detailed description of the invention, the terms used herein are defined or understood as follows.

[0025] When a component is referred to herein as being "connected" or "connected" to another component, it should be understood that the component may be directly connected to or connected to the other component, but may also be connected or connected via another component in between, unless otherwise specifically stated. Furthermore, "connection" may include a wireless connection or a wired connection.

[0026] In addition, in this specification, components expressed as 'unit', 'module', etc. may be two or more components combined into one component, or one component may be divided into two or more components with more detailed functions. In addition, each component described below may additionally perform some or all of the functions performed by other components in addition to its own main function, and of course, some of the main functions performed by each component may be performed exclusively by other components.

[0027] In this disclosure, the expression "at least one of a, b, or c" can refer to "a", "b", "c", "a and b", "a and c", "b and c", "all of a, b, and c", or variations thereof. In this disclosure, the expression "a or b" can refer to "a", "b", "a and b", or variations thereof. In this disclosure, the expression "a (or, b, c)" or the expression "a, b, or c" can refer to "a", "b", "c", "a and b", "a and c", "b and c", "all of a, b, and c", or variations thereof.

[0028] In one embodiment of the present disclosure, the term "transfer" may include moving, copying, duplicating, or synchronizing previous target information contained in any logical or physical space to any other space. In one embodiment of the present disclosure, the term "transfer from A to B" may include causing previous target information (e.g., context information) contained, stored, or set in space A (or device A, module A) to be contained, stored, or set in space B (or device B, module B). In one embodiment of the present disclosure, "transfer from A to B" may include causing previous target information contained, stored, or set in space A (or device A, module A) to be contained, stored, or set in space B (device B or module B), and removing, deleting, or releasing the previous target information in space A (device A or module A). In one embodiment of the present disclosure, "transfer from A to B" may include making information used by module A (or device A) available to module B (or device B).

[0029] In one embodiment of the present disclosure, a "cell transfer" may include transferring at least one of information, context, or interface associated with a cell. For example, a "cell transfer" may include transferring cell configuration information. For example, a "cell transfer" may be a cell-by-cell transfer, and may include transferring cell configuration information and a UE context of a UE (user equipment) associated with the cell. For example, a "cell transfer" may be a UE-by-UE transfer, and may include transferring a UE context of a UE (user equipment) associated with the cell. For example, a "cell transfer" may be a UE-by-UE transfer, and may include transferring an interface for user data (e.g., an F1-U interface).

[0030] In one embodiment of the present disclosure, a "MAC (medium access control) context" may include configuration information or context included in the MAC layer. For example, the MAC context may include cell configuration information (or cell context) included (or configured, stored) in the MAC layer. For example, the MAC context may include UE context (or UE configuration information) included (or configured, stored) in the MAC layer.

[0031] In one embodiment of the present disclosure, "cell configuration information" may include information about basic settings, operation methods, configurations or parameters of each cell in a wireless communication system. For example, "cell configuration information" may include information about frequency bands, channel bands, frequency allocation information, transmission output power settings, cell identifiers, settings in time and frequency domains, interference management with other cells and base stations, scheduling information (e.g., DL (downlink) / UL (uplink) Max Resource Block, PDSCH (physical downlink shared channel), PUSCH (physical uplink shared channel), SSB (synchronization signal block), etc.), or timing information (e.g., number of slots per flame), UE information associated with a cell (e.g., number of UEs associated with a cell).

[0032] In one embodiment of the present disclosure, a "UE context" may include information for wireless communication of a UE in a wireless communication system. For example, the "UE context" may include location information of a UE, a UE identifier, a status of the UE, service requirements, information on the network and cell currently in use, performance information, function information, security information, or authentication information of the UE. For example, the "UE context" may include a unique number for each situation of UEs connected to a base station (e.g., a radio network temporary identifier (RNTI)), information on DL Data Volume per UE (e.g., a buffer occupancy (BO)), information on UL Data Volume per UE (e.g., a buffer status report (BSR)), a physical downlink control channel (PDCCH) monitoring period for the UE to transmit and receive new DL / UL traffic (e.g., discontinuous reception (DRX)), and retransmission information per UE (e.g., hybrid automatic repeat request (HARQ) information). For example, a "UE context" may include different parameter values ​​or data for each of multiple UEs associated with the same cell. For example, a "UE context" may include common or shared parameter values ​​or data for multiple UEs associated with the same cell.

[0033] In one embodiment of the present disclosure, "connection relationship" may include the meaning of "connection relationship," "inclusion relationship," "attachment relationship," or "matching relationship." For example, "connected" may include the meaning of "connected," "inclusion," "attachment," or "matched." In one embodiment of the present disclosure, "connection" may include the meaning of data communication being possible, either wired or wireless. For example, "A and B are connected" may include the meaning that A and B are capable of data communication, i.e., can transmit and receive data with each other.

[0034] In one embodiment of the present disclosure, “A performing action B” may include “A directly performing action B,” “A instructing C to perform action B,” or “A controlling C to perform action B.”

[0035] In one embodiment of the present disclosure, a “UE associated with a cell” may include a UE associated with a cell, a UE attached to a cell, a UE communicating with an RU including a cell (i.e., transmitting and receiving data), a UE receiving a communication service via a cell, a UE transmitting and receiving data via a cell, a UE accessing a network via a cell, a UE included in a range (e.g., effective range, communication range) of a cell, a UE requesting a radio resource of a cell, or a UE allocated a radio resource of a cell, etc. For example, one or more UEs associated with a target cell may have a connection established and managed based on cell configuration information for the target cell.

[0036] In one embodiment of the present disclosure, "path" or "interface" may include the meaning of a module (e.g., a software module, a hardware module) that enables data transmission and reception. In one embodiment of the present disclosure, "path" or "interface" may include the meaning of a logical or physical connection relationship. In one embodiment of the present disclosure, "path" or "interface" may include the meaning of a data transmission and reception path. In one embodiment of the present disclosure, "establishing an interface between A and B" may include the meaning of establishing a connection so that A and B can transmit and receive data with each other and process the received data.

[0037] In one embodiment of the present disclosure, "scale-out for a DU" and "scaling-out for a DU" may include adding a new DU to a DU pool containing DUs. In one embodiment of the present disclosure, "scale-out for a DU" and "scaling-out for a DU" may include migrating cells contained in a DU to another DU (e.g., a newly added DU).

[0038] In one embodiment of the present disclosure, “scale-in for a DU” and “scaling-in for a DU” may include removing the DU from the DU pool. In one embodiment of the present disclosure, “scale-in for a DU” and “scaling-in for a DU” may include transferring cells included in the DU to another DU (e.g., an existing DU).

[0039] In one embodiment of the present disclosure, the "reference label" may include a label that serves as a criterion for selecting a MAC context to be transferred from among MAC contexts. For example, a MAC context corresponding to a label having an importance higher than the "reference label" may be selected (or selected, determined) as the MAC context to be transferred. For example, the "reference label for the UE" may include a label having the lowest importance among the labels of the MAC contexts to be transferred from among the MAC contexts for the UE. For example, the electronic device may determine the reference label for the UE and select MAC contexts having an importance higher than the reference label for the UE as the MAC contexts to be transferred. For example, if a first reference label is determined (or set) for a first UE and a second reference label is determined (or set) for a second UE, the electronic device may transfer a MAC context for the first UE having an importance higher than the first reference label and a MAC context for the second UE having an importance higher than the second reference label.

[0040] In one embodiment of the present disclosure, a "radio resource control (RRC) idle state" may include a state in which there is no DL / UL data stream. For example, a UE may transition from an RRC connected state (or an RRC active state) or an RRC inactive state to an RRC idle state. In one embodiment of the present disclosure, an "RRC inactive state" may include a state in which a base station and a UE are connected, but signaling between the base station and the UE is minimized to minimize power consumption. For example, a UE may transition from an RRC connected state to an RRC inactive state. For example, when transitioning to an RRC inactive state (e.g., RRC connection suspend), the base station and the UE may not discard but retain an AS context (UE Inactive AS Context) containing configuration information required for the RRC connection (e.g., C-RNTI, cellIdentity, etc.). Therefore, a UE in an RRC inactive state may quickly transition to an RRC connected state. In one embodiment of the present disclosure, an "RRC inactive state" or an "RRC connected state" may include a state in which a base station is connected and DL / UL data streams are present. In the present disclosure, the terms "RRC inactive state" and "RRC connected state" may be used interchangeably. FIG. 1 is a diagram illustrating an example of a wireless communication system structure according to one embodiment of the present disclosure.

[0041] In one embodiment of the present disclosure, a wireless communication system may include a core network (110) and a radio access network (RAN) (120). The core network (110) may include user authentication information for each telecommunications company, and may be a platform network that is wired and connected to servers and systems of various service providers via optical cables.

[0042] In one embodiment of the present disclosure, the RAN (120) may include at least one radio unit (RU) (128_1, 128_2, 128_3, 128_4, 128_5, 128_6), at least one distributed unit (DU) (124_1, 124_2, 124_3, 124_4), and a centralized unit (CU) (122). In one embodiment of the present disclosure, the RAN (120) may include, but is not limited to, a vRAN (virtualized radio access network) system. For example, the RAN (120) may include a 5GS (5G system), a 4GS, or other wireless communication system, and may also refer to a wireless communication system to be developed in the future.

[0043] In one embodiment of the present disclosure, the CU (122) may be an entity that performs functions of some layers among the protocol layers of a network. For example, the CU (122) may be an entity that performs network functions of the RRC (radio resource control) layer and the PDCP (packet data convergence protocol) layer, but the functions that the CU (122) can process are not limited to the functions of the RRC layer and the PDCP layer described above. For example, the CU (122) may perform functions such as setting quality of service (QoS), reordering packets, etc., setting and processing security, etc. As an example, the CU (122) may mean a vCU (virtualized-CU) of a vRAN system, but is not limited thereto.

[0044] One CU (122) can be connected to N DUs, where N can be any integer greater than 1. The CU (122) and the DUs (124_1, 124_2, 124_3, 124_4) can be connected by an interface. For example, the interface between the CU (122) and the DUs (124_1, 124_2, 124_3, 124_4) can be an F1 interface (or a mid-hole interface). For example, the F1 interface can include F1-C, which is an F1 interface of a control plane, and F1-U, which is an F1 interface of a user plane.

[0045] RAN (120) may include DU (124_1), DU (124_2), and DU (124_3). DU (124_1), DU (124_2), and DU (124_3) may perform the same function, but DU (124_3) is described as an example below.

[0046] In one embodiment of the present disclosure, DU (124_3) may be an entity that performs functions of some layers among the protocol layers of the network except for some layers performed by CU (122). For example, DU (124_3) may be an entity that performs network functions (e.g., baseband functions) of RLC (radio link control) layer, MAC (medium access control) layer, and PHY (physical) layer, but the functions that DU (124_3) can process are not limited to the functions of the RLC layer, MAC layer, and PHY layer described above. For example, DU (124_3) may perform a buffer function, a radio resource scheduling function, a data reprocessing function, etc. For example, DU (124_3) may be a vDU (virtualized-DU) of a vRAN system, but is not limited thereto. For example, DU (124_3) may correspond to a component module, an arbitrary processing operation unit, a distribution unit performing arbitrary processing, software, etc. For example, DU (124_3) may correspond to one server.

[0047] One DU can be connected to N RUs, where N can be any integer greater than 1. Referring to FIG. 1, DU (124_1) can be connected to RU (128_1), ..., and RU (128_2), DU (124_2) can be connected to RU (128_3), ..., and RU (128_4), and DU (124_3) can be connected to RU (128_5), ..., and RU (128_6). In one embodiment of the present disclosure, DU (124_3) and RU (128_5, 128_6) can be connected by an interface. For example, the interface between DU (124_3) and RU (128_5, 128_6) can be a front haul interface.

[0048] RU(128_1), RU(128_2), RU(128_3), RU(128_4), RU(128_5) and RU(128_6) can perform the same function, but RU(128_6) is described as an example below.

[0049] In one embodiment of the present disclosure, RU (128_6) may be an entity that performs some functions of the PHY layer other than those handled by DU (124_3). For example, DU (124_3) may perform the function of the high-PHY layer, and RU (128_6) may perform the function of the low-PHY layer. For example, RU (128_6) may perform a data transmission and reception function via an RF antenna.

[0050] In existing RAN systems, a DU can be connected 1:1 to a cell site containing one or more RUs, and the DU's processing capacity can be determined based on the maximum traffic that can enter the cell site. Based on traffic trends over time, the peak traffic hours are limited (e.g., 5:00 PM to 9:00 PM), and outside of these hours, unused DU resources, i.e., remaining available resources, may exist.

[0051] According to one embodiment of the present disclosure, a vRAN system may employ a virtualized DU (vDU) pooling technology that breaks the 1:1 relationship between existing DUs and cell sites (a collection of RUs) and virtualizes DUs by pooling them. This can reduce the number of servers required to build a RAN system and reduce capital expenditures (CAPEX). Furthermore, compared to existing RAN systems, power consumption can be reduced and operating expenditures (OPEX) can be reduced.

[0052] A vRAN system according to one embodiment of the present disclosure may employ vCU pooling technology, which pools and virtualizes CUs. This can reduce the number of servers required to build a RAN system and reduce capital expenditures (CAPEX). Furthermore, compared to existing RAN systems, power consumption can be reduced and operating expenditures (OPEX) can be reduced.

[0053] In one embodiment of the present disclosure, a vDU scaling method may be used in the RAN (120) to efficiently utilize server resources by dynamically scaling out or in a DU depending on the current traffic situation. In the case of scaling out, a DU (124_4) may be newly created in the RAN (120), but is not limited thereto. For example, the DU (124_4) may already exist in the RAN (120). In the case of scaling in, the DU (124_4) may already exist in the RAN (120).

[0054] Hereinafter, DU (124_3) may be denoted as the first DU (124_3), and DU (124_4) may be denoted as the second DU (124_4). In the case of scale-out in FIG. 1, the first DU (124_3) may correspond to the source DU, and the second DU (124_4) may correspond to the target DU. In the case of scale-in in FIG. 1, the first DU (124_3) may correspond to the target DU, and the second DU (124_4) may correspond to the source DU. The first DU (124_3) and the second DU (124_4) may be connected via an inter DU interface (Xd interface) (126).

[0055] In one embodiment of the present disclosure, scale-out may include adding a new DU (e.g., a second DU (124_4)) to the DU pool for the CU (122). For example, if the amount of traffic that a first DU (124_3) included in the DU pool must process increases, a second DU (124_4) may be added to the DU pool. For example, adding the second DU (124_4) to the DU pool may include adding a module corresponding to the second DU (124_4) to the DU pool. For example, adding the second DU (124_4) to the DU pool may include initiating operation of an additional server capable of processing data. When the capacity or performance of processing data of the first DU (124_3) (e.g., an existing server) reaches its limit, a second DU (124_4) (a non-limiting example, a server with similar specifications) can be added to the communication system using scale-out. In this case, the cell whose data is being processed by the first DU (124_3) can be migrated from the first DU (124_3) to the second DU (124_4), so that the cell's data can be processed by the second DU (124_4).

[0056] In an embodiment of the present disclosure, scale-in may include removing a second DU (124_4) included in a DU pool. For example, when the amount of traffic that DUs included in the DU pool must process decreases, the second DU (124_4) may be removed from the DU pool. For example, removing the second DU (124_4) from the DU pool may include removing a module corresponding to the second DU (124_4). For example, removing the second DU (124_4) from the DU pool may include stopping the operation of a server that was processing data. By using scale-in, the number of servers that are no longer needed to operate can be reduced, and resources can be saved. For scale-in, a cell whose data is processed by the second DU (124_4) may be transferred from the second DU (124_4) to the first DU (124_3), so that the cell's data is processed by the first DU (124_3).

[0057] In one embodiment of the present disclosure, in addition to the case of scaling by adding or removing the second DU (124_4) from the DU pool, a cell whose data is processed by the second DU (124_4) may be moved from the second DU (124_4) to the first DU (124_3) so that the cell's data is processed by the first DU (124_3), or a cell whose data is processed by the first DU (124_3) may be moved from the first DU (124_3) to the second DU (124_4) so ​​that the cell's data is processed by the second DU (124_4). For example, a cell may be moved from the first DU (124_3) with a large traffic volume to the second DU (124_4) with a relatively small traffic volume so that the cell's data is processed by the second DU (124_4).

[0058] To prevent UE connection disruption during cell transfer, it is necessary to minimize the time during which scheduling for UE data traffic is interrupted. In one embodiment of the present disclosure, a transfer method can be provided to minimize malfunctions and performance degradation in the MAC layer (L2 layer) that schedules radio resource allocation.

[0059] The MAC layer of a DU can perform scheduling based on information about the cells and UEs associated with (e.g., attached to) the DU. Therefore, to ensure uninterrupted scheduling operation even after scaling in or out, the target DU requires data managed by the source DU. However, transferring all MAC contexts during DU scaling takes a long time, and MAC scheduling must be suspended during the transfer time. Therefore, a longer scheduling suspension time may cause a problem in which RLF occurs simultaneously for multiple UEs associated with the target cell.

[0060] When RLF occurs for multiple UEs simultaneously in a target cell, the UEs that have experienced RLF must perform RA (random access) again to transmit traffic, which may cause overhead in neighboring cells and degrade the QoS of the network. Therefore, in one embodiment of the present disclosure, rather than migrating all MAC contexts of a previous target cell, a method may be provided that considers various scenarios in which RLF may occur, determines a time point at which RLF occurrence can be minimized, and selects the target MAC context to be migrated at that time point to perform scaling in / out.

[0061] FIG. 2 is a flowchart illustrating an example of a cell transfer method from a source DU to a target DU according to one embodiment of the present disclosure.

[0062] In explaining Fig. 2, any explanation that overlaps with the explanation given above in Fig. 1 may be omitted.

[0063] FIG. 2 illustrates an example of a method (200) in which an electronic device transfers a target cell from a source DU to a target DU. In one embodiment of the present disclosure, the electronic device performing the method (200) may include a cell transfer module (e.g., a scaling agent module) that manages, controls, or processes cell transfer. In one embodiment of the present disclosure, the electronic device performing the method (200) may include a device of the source DU, a device of the target DU, or another separate device. For example, the source DU (or the device of the source DU) may include a cell transfer module. For example, the target DU (or the device of the target DU) may include a cell transfer module. For example, another device separate from the source DU and the target DU may include a cell transfer module.

[0064] Referring to FIG. 2, a method (200) according to one embodiment of the present disclosure may include steps 210 to 260. In one embodiment of the present disclosure, steps 210 to 260 of the method (200) may be executed by a cell transfer module included in an electronic device. In one embodiment of the present disclosure, steps 210 to 260 of the method (200) may be executed by at least one processor included in the electronic device. The method (200) is not limited to that illustrated in FIG. 2, and in one or more embodiments, steps not illustrated in FIG. 2 may be further included, or some steps may be omitted.

[0065] In one embodiment of the present disclosure, the electronic device can perform the method (200) upon identifying (or receiving) a DU scaling (e.g., scaling out, scaling in) request (or instruction) from an operations, administration, and maintenance (OAM) module. In one embodiment of the present disclosure, the electronic device can perform the method (200) upon identifying (or receiving) a cell transfer request (or instruction) from the OAM module. For example, the electronic device can identify (or receive) a cell transfer request (or instruction) from a source DU to a target DU from the OAM module. For example, the electronic device can identify (or receive) a transfer request (or instruction) for a target cell from the OAM module.

[0066] In one embodiment of the present disclosure, the electronic device may perform the method (200) based on determining DU scaling. In one embodiment of the present disclosure, the electronic device may perform the method (200) based on determining cell migration. For example, the electronic device may determine cell migration from a source DU to a target DU. For example, the electronic device may determine migration of a source DU to a target cell.

[0067] In step 210, the electronic device may transfer cell configuration information for the target cell of the source DU to the target DU. In one embodiment of the present disclosure, the electronic device may copy cell configuration information for the target cell included (or configured, stored) in the source DU to the target DU. The cell configuration information for the target cell may include information about the frequency band of the target cell, a radio resource scheduling method, a common signal transmitted to one or more UEs associated with the target cell, and the like.

[0068] In one embodiment of the present disclosure, the transfer of cell configuration information may include transferring or duplicating data of the cell configuration information. For example, the transfer of cell configuration information for a target cell from a source DU to a target DU may include setting or determining a value corresponding to specific cell configuration information for the target cell in the source DU as a value of specific cell configuration information in the target DU. For example, the transfer of cell configuration information for a target cell from a source DU to a target DU may include setting or determining a value of specific cell configuration information for the target cell in the target DU as a value of specific cell configuration information for the target cell stored in the source DU.

[0069] In one embodiment of the present disclosure, the electronic device can transfer cell configuration information for a target cell included (or set, stored) in at least one of an RLC layer, a MAC layer, or a PHY layer of a source DU to at least one of an RLC layer, a MAC layer, or a PHY layer of a target DU. For example, the electronic device can transfer cell configuration information included in an RLC layer of the source DU to an RLC layer of the target DU. For example, the electronic device can transfer cell configuration information included in a MAC layer of the source DU to a MAC layer of the target DU. For example, the electronic device can transfer cell configuration information included in a PHY layer of the source DU to a PHY layer of the target DU. In one embodiment of the present disclosure, the cell configuration information included in each of the RLC layer, the MAC layer, and the PHY layer of the source DU may be different from each other, may be partially different from each other, or may be the same from each other.

[0070] In one embodiment of the present disclosure, the electronic device can transfer a target cell from a source DU to a target DU by setting the target cell in the target DU using information (e.g., data, parameters) used to set the target cell in the source DU. For example, the electronic device can create (or set) cell configuration information for the target cell in the target DU using parameters used to create (or set) cell configuration information for the target cell in the source DU.

[0071] In one embodiment of the present disclosure, the electronic device can copy (or replicate) the cell configuration information for the target cell contained in the source DU to the target DU. For example, the cell configuration information for the target cell can be transferred, copied, or replicated from the source DU to the target DU through an interface between the DUs. For example, the electronic device can control the source DU to copy the cell configuration information for the target cell and provide it to the target DU. For example, the electronic device can obtain the cell configuration information for the target cell from the source DU and provide the obtained cell configuration information to the target DU.

[0072] In step 220, the electronic device may transfer (or copy, replicate) one or more UE contexts for the target cell of the source DU to the target DU. In one embodiment of the present disclosure, the electronic device may transfer one or more UE contexts for the target cell from the source DU (e.g., the MAC layer of the source DU) to the target DU (e.g., the MAC layer of the target DU). For example, the electronic device may transfer one or more UE contexts for the target cell, which are included (or stored, set) in the MAC layer of the source DU, to the MAC layer of the target DU.

[0073] In one embodiment of the present disclosure, transferring a UE context may include transferring or duplicating data of the UE context. For example, transferring a UE context for a target cell from a source DU to a target DU may include setting or determining a value corresponding to a specific UE context for the target cell in the source DU to a value of a specific UE context in the target DU. For example, transferring a UE context for a target cell from a source DU to a target DU may include setting or determining a value corresponding to a specific UE context for a specific UE associated with the target cell in the source DU to a value of a specific UE context for a specific UE in the target DU.

[0074] The UE context for the target cell may include UE contexts for UEs associated with the target cell that are included (or stored, configured) in the source DU. For example, the UE context for the target cell may include contexts for each of the UEs associated with the target cell or contexts that are common (or shared) for the UEs associated with the target cell. For example, the UE context for the target cell may include at least a portion of a MAC context configured (or stored, configured) for the target cell in the MAC layer of the DU. For example, the UE context for the target cell may include UE contexts that are generated (or stored, configured), accumulated, or updated (or changed) in the source DU (e.g., in the MAC layer of the source DU) before step 220 is performed.

[0075] In one embodiment of the present disclosure, the electronic device may use information (e.g., data, parameters) used to create (or store, set), accumulate, or update (or change) one or more UE contexts for a target cell in a target DU (e.g., MAC layer of the target DU) to create (or store, set), accumulate, or update (or change) one or more UE contexts for a target cell in a source DU (e.g., MAC layer of the source DU).

[0076] In one embodiment of the present disclosure, an electronic device can copy (or replicate) one or more UE contexts for a target cell, which are included in a source DU (e.g., a MAC layer of the source DU), to a target DU (e.g., a MAC layer of the target DU). For example, one or more UE contexts for the target cell can be transferred (or copied, replicated) from the source DU to the target DU via an inter-DU interface. For example, the electronic device can control the source DU to copy (or replicate) one or more UE contexts for the target cell, which are included in the MAC layer, and provide them to the target DU. For example, the electronic device can obtain one or more UE contexts for the target cell from the source DU and provide the obtained one or more UE contexts to the target DU.

[0077] In step 230, the electronic device may switch (or change) the fronthaul interface from the source DU to the target DU, switch (or change) at least one control path from the source DU to the target DU, and transfer one or more MAC contexts for the target cell from the source DU to the target DU. In one embodiment of the present disclosure, the electronic device may stop MAC scheduling of the source DU and perform step 230. For example, the electronic device may buffer the fronthaul message queue and perform step 230.

[0078] In one embodiment of the present disclosure, the electronic device can switch (or change) the fronthaul interface, i.e., the RU-PHY layer interface, from 'RU of target cell' - 'PHY layer of source DU' to 'RU of target cell' - 'PHY layer of target DU'. In one embodiment of the present disclosure, the electronic device can switch (or change) the control path of the MAC layer or PHY layer from the source DU to the target DU. For example, the control path may include a path through which control messages, data, or traffic for the target cell are processed or transmitted / received. For example, the electronic device can switch the RLC layer-MAC layer path from the RLC layer of the source DU-MAC layer path to the RLC layer of the source DU-MAC layer path.

[0079] In one embodiment of the present disclosure, an electronic device may transfer one or more MAC contexts for a target cell, which are included (or set) in a source DU (e.g., a MAC layer of the source DU), to a target DU (e.g., a MAC layer of the target DU). For example, the electronic device may transfer at least some data among the MAC contexts for the target cell from the source DU to the target DU. For example, the electronic device may synchronize at least some data among the MAC contexts for the target cell included in the source DU to the target DU.

[0080] In one embodiment of the present disclosure, the electronic device may use information (e.g., data, parameters) used to create (or store, set), accumulate, or update (or change) one or more MAC contexts for the target cell in the target DU (e.g., MAC layer of the target DU) to create (or store, set), accumulate, or update (or change) one or more MAC contexts for the target cell in the target DU (e.g., MAC layer of the target DU).

[0081] In one embodiment of the present disclosure, an electronic device can copy (or replicate) one or more MAC contexts for a target cell, which are included in a source DU (e.g., a MAC layer of the source DU), to a target DU (e.g., a MAC layer of the target DU). For example, one or more MAC contexts for the target cell can be transferred (or copied, replicated) from the source DU to the target DU via an inter-DU interface. For example, the electronic device can control the source DU to copy (or replicate) one or more MAC contexts for the target cell, which are included in the MAC layer, and provide them to the target DU. For example, the electronic device can obtain one or more MAC contexts for the target cell from the source DU and provide the obtained one or more MAC contexts to the target DU.

[0082] In one embodiment of the present disclosure, the MAC context for the target cell may include configuration information or context set (or stored, included) in the MAC layer of the DU for the target cell. For example, the MAC context for the target cell may include cell configuration information or cell context for the target cell included (or set, stored) in the MAC layer of the source DU. For example, the MAC context for the target cell may include configuration information (e.g., UE configuration information) or context (e.g., UE context) included (or stored, set) in the MAC layer for each of a plurality of UEs associated with the target cell. For example, the MAC context for the target cell may include contexts (or configuration information) specific to a plurality of UEs associated with the target cell or contexts (or configuration information) common to a plurality of UEs.

[0083] In one embodiment of the present disclosure, the MAC context for the target cell in step 230 of FIG. 2 may include a MAC context for the target cell of a source DU that is not included in (or set, stored) the target DU. For example, the MAC context for the target cell in step 230 of FIG. 2 may include a MAC context that is not transferred (or copied) from the source DU to the target DU. For example, the MAC context for the target cell in step 230 of FIG. 2 may include a MAC context that is generated (or set) in the source DU (e.g., MAC layer) after step 210 or 220.

[0084] In one embodiment of the present disclosure, at least some of the data of the MAC context for the target cell in step 230 of FIG. 2 may be different from data of at least some of the MAC context for the target cell included (or set, stored) in the target DU. For example, cell configuration information or UE context included in the MAC layer of the DU may be included in the MAC context, and after the cell configuration information or UE context for the target cell is transferred to the MAC layer of the target DU, at least some of the data of the MAC context for the target cell may be generated, accumulated, or updated (or changed) in the MAC layer of the source DU. For example, at least some of the data (e.g., values) of the MAC context for the target cell of the source DU may be generated (or set), accumulated, or updated (or changed) in the source DU (e.g., MAC layer) after step 210 or 220. For example, the data update cycle of the MAC context may be different for each MAC context.

[0085] In one embodiment of the present disclosure, the transfer of a MAC context may include transferring or duplicating data of the MAC context. For example, the transfer of a MAC context for a target cell from a source DU to a target DU may include setting or determining a value corresponding to a specific MAC context for the target cell in the source DU to a value of a specific MAC context in the target DU. For example, the transfer of a MAC context for a target cell from a source DU to a target DU may include setting or determining a value of a specific MAC context for the target cell in the target DU to a value of a specific MAC context for the target cell stored in the source DU.

[0086] In one embodiment of the present disclosure, the electronic device may perform step 230 and restart the buffered fronthaul message queue. As the fronthaul interface switches from the source DU to the target DU, the buffered fronthaul message queue may be transmitted to the target DU. For example, data may be transmitted and received between the PHY layer of the RU and the target DU.

[0087] In step 240, the electronic device may control (or perform) cell release processing for the PHY layer and MAC layer of the source DU. In one embodiment of the present disclosure, the electronic device may release a target cell for the PHY layer and MAC layer of the source DU. For example, the electronic device may remove (or release) configuration information or context for the target cell included (or set) in the PHY layer or MAC layer of the source DU. For example, the electronic device may remove (or release) configuration information or context for each of a plurality of UEs associated with the target cell included (or set) in the PHY layer or MAC layer of the source DU. For example, the electronic device may remove (or release) at least some of the cell configuration information, UE context, or MAC context transferred to the target DU from the PHY layer or MAC layer of the source DU.

[0088] For example, if the data of the fronthaul message queue and RU are smoothly transmitted to the target DU, the electronic device can perform cell release processing for the PHY layer and MAC layer of the source DU. For example, if communication between UEs associated with the target cell is possible, the electronic device can perform cell release processing for the PHY layer and MAC layer of the source DU. For example, the electronic device can identify that the communication state of the target cell is a communication-possible state, and remove (or delete) the cell context or UE context transferred from the PHY layer or MAC layer of the source DU. The communication-possible state may include a communication state that satisfies any criteria such as delay and data processing speed.

[0089] In step 250, the electronic device may transfer one or more RLC contexts for the target cell of the source DU to the target DU, and switch one or more F1 paths (e.g., midhaul interfaces) for the target cell from the source DU to the target DU. For example, the one or more RLC contexts for the target cell of the source DU may include configuration information or contexts for the target cell, which are included (or configured, stored) in the RLC layer of the source DU. For example, the one or more RLC contexts for the target cell of the source DU may include configuration information or contexts for each of a plurality of UEs associated with the target cell, which are included (or configured, stored) in the RLC layer of the source DU. In one embodiment of the present disclosure, the electronic device may transfer one or more RLC contexts for the target cell from the source DU (e.g., the RLC layer of the source DU) to the target DU (e.g., the RLC layer of the target DU) on a per-UE basis.

[0090] An F1 path may include a path (or interface) between a DU (e.g., an RLC layer of the DU) and a CU. For one UE associated with a target cell, one or more F1 paths may be established between the source DU and the CU. In one embodiment of the present disclosure, the electronic device may switch one or more F1 paths for each of a plurality of UEs associated with the target cell from the source DU to the target DU on a per-UE basis. For example, the electronic device may switch the F1 path for each of a plurality of UEs associated with the target cell from 'RLC layer of the source DU' to 'RLC layer of the target DU' to 'CU' on a per-UE basis.

[0091] In one embodiment of the present disclosure, the electronic device may transfer the RLC context and switch the F1 path multiple times per UE (e.g., per UE group) rather than transferring the RLC context or switching the F1 path for multiple UEs associated with the target cell at once. For example, the electronic device may transfer the RLC context of a UE group including at least one of the multiple UEs associated with the target cell from a source DU to a target DU, and switch one or more F1 paths for the corresponding UE group from the source DU to the target DU. For example, the electronic device may sequentially transfer the RLC context and change the F1 path for multiple UE groups.

[0092] In step 260, the electronic device may control (or perform) cell release processing for the RLC layer of the source DU. In one embodiment of the present disclosure, the electronic device may release a target cell for the RLC layer of the source DU. For example, the electronic device may remove (or release) an RLC context for a target cell included (or configured, stored) in the RLC layer of the source DU. For example, the electronic device may remove (or release) configuration information or context for a target cell included (or configured, stored) in the RLC layer of the source DU. For example, the electronic device may remove (or release) configuration information or context for a plurality of UEs associated with a target cell included (or configured, stored) in the RLC layer of the source DU.

[0093] FIG. 3A is a diagram illustrating an example of a source DU and a target DU before MAC context transfer from the source DU to the target DU according to one embodiment of the present disclosure.

[0094] In explaining Fig. 3a, any explanation that overlaps with the explanation given above in Fig. 1 or Fig. 2 may be omitted.

[0095] FIG. 3A is a diagram illustrating an example of a RAN including a source DU and a target DU before switching of a fronthaul interface, switching of a control path (e.g., an RLC layer-MAC layer path), and transfer of a MAC context are performed in one embodiment of the present disclosure. For example, FIG. 3A may illustrate a path and MAC context for a target cell prior to step 230 of FIG. 2 described above.

[0096] Referring to FIG. 3A, an RU (340) for a target cell may be connected to a source DU (320) via a fronthaul interface, and the source DU (320) may be connected to a CU (310) via a midhaul interface. For example, the RU (340) and the source DU (320) may transmit and receive data for the target cell via the fronthaul interface. For example, the source DU (320) and the CU (310) may transmit and receive data for the target cell via the midhaul interface. Accordingly, a plurality of UEs (342) associated with the target cell may wirelessly communicate with the RU (340) for the target cell, thereby accessing a core network via the RU (340), the source DU (320), and the CU (310), and receiving wireless communication services.

[0097] Referring to FIG. 3A, the MAC layer (334) of the target DU (330) may include (or set, store) first data (350) of MAC contexts for the target cell. For example, the first data (350) of the MAC contexts for the target cell may include data transferred in step 210 or 220 of FIG. 2 described above. For example, the first data (350) of the MAC contexts for the target cell may include cell configuration information for the target cell (or context for the target cell) transferred in step 210 of FIG. 2 described above, or UE contexts for a plurality of UEs associated with the target cell (or configuration information for a plurality of UEs) transferred in step 220 of FIG. 2 described above.

[0098] For example, step 210 or 220 of the above-described FIG. 2 can be performed without interrupting the MAC scheduling of the source DU (320). For example, the first data (350) of the MAC contexts included in the target DU (330) may be transferred (or copied) from the source DU (320) while the MAC scheduling of the source DU (320) is not interrupted. Accordingly, even after step 210 or 220 of the above-described FIG. 2, data of a new MAC context may be generated, data of an existing MAC context may be updated (or changed), or additional data of an existing MAC context may be accumulated or updated (or changed) by the MAC scheduling operation of the source DU (320).

[0099] Referring to FIG. 3A, the MAC layer (324) of the source DU (320) may include (or set, store) second data (352) of MAC contexts for a target cell. In one embodiment of the present disclosure, the second data (352) of the MAC contexts for the target cell included in the source DU (320) may include updated (or changed) or accumulated data for the same MAC context as at least one MAC context included in the target DU (330). For example, the second data (352) of the MAC contexts may include MAC context data of the source DU (320) that has not been transferred to the target DU (330). For example, the first data (350) included in the target DU (330) may include UE RNTI (radio network temporary identifier) ​​information of the first UE at a first time point, and the second data (352) included in the source DU (320) may include UE RNTI information (e.g., updated UE RNTI information) of the first UE at a second time point after the first time point.

[0100] In one embodiment of the present disclosure, the second data (352) of the MAC contexts for the target cell included in the source DU (320) may include data of a new MAC context not included in the target DU (330). For example, the second data (352) of the MAC contexts for the target cell included in the source DU (320) may include UE RNTI information of a second UE not included in the target DU (330).

[0101] In one embodiment of the present disclosure, at least some of the second data (352) of the MAC contexts for the target cell included in the source DU (320) may be identically included in the target DU (330). For example, for at least one MAC context that has not been updated (or changed) since step 210 or 220 of FIG. 2 described above, the same data (e.g., value) may be set (or stored, included) in the source DU (320) and the target DU (330). For example, at least some of the second data (352) of the MAC contexts for the target cell may be identical to at least some of the first data (350) of the MAC contexts for the target cell. For example, UE RNTI (radio network temporary identifier) ​​information of a first UE at a first time point included in the target DU (330) and UE RNTI information of the first UE at a second time point after the first time point included in the source DU (320) may be identical.

[0102] In one embodiment of the present disclosure, the electronic device may suspend MAC scheduling for a target cell in order to switch a fronthaul interface, switch a control path, or transfer a MAC context. For example, the electronic device may suspend MAC scheduling for the target cell of the source DU (320). For example, the electronic device may perform switching of the fronthaul interface, switching of the control path, or transfer of the MAC context while the MAC scheduling for the target cell is suspended. Referring to FIG. 3A, the second data (352) of the MAC contexts may include data of MAC contexts that are generated, stored, acquired, determined, updated (or changed), or accumulated after the operation of step 210 or step 220 of FIG. 2 described above until the MAC scheduling for the target cell of the source DU (320) is stopped.

[0103] FIG. 3b is a diagram illustrating an example of a source DU and a target DU after MAC context transfer from the source DU to the target DU according to one embodiment of the present disclosure.

[0104] In explaining Fig. 3b, any explanation that overlaps with the explanations given above in Figs. 1 to 3a may be omitted.

[0105] FIG. 3b is a diagram illustrating an example of a RAN including a source DU and a target DU after switching of a fronthaul interface, switching of a control path (e.g., an RLC layer-MAC layer path), and transfer of a MAC context are performed in one embodiment of the present disclosure. For example, FIG. 3b may illustrate a path and MAC context for a target cell after step 230 of FIG. 2 described above.

[0106] In one embodiment of the present disclosure, the electronic device can transfer a MAC context for a target cell from a source DU (320) to a target DU (330). For example, the MAC context for the target cell may include configuration information (or context) for the target cell configured (or included, stored) in the MAC layer or contexts (or configuration information) for a plurality of UEs associated with the target cell. For example, the MAC context for the target cell may include information used for communication of a plurality of UEs associated with the target cell or information generated (or updated, determined) by communication of the plurality of UEs. Referring to FIG. 3B, the electronic device can transfer second data (352) of MAC contexts for the target cell included in the source DU (320) to the target DU (330).

[0107] In one embodiment of the present disclosure, the electronic device may use parameters used to generate (or set, store) the second data (352) of the MAC contexts for the target cell in the MAC layer (334) of the source DU (320) to generate (or set, store) the second data (352) of the MAC contexts for the target cell in the MAC layer (334) of the target DU (330). In one embodiment of the present disclosure, the electronic device may copy (or replicate) the second data (352) of the MAC contexts for the target cell itself, included in the MAC layer (324) of the source DU (320), to the MAC layer (334) of the target DU (330). For example, the electronic device may control the source DU (320) to copy (or replicate) the second data (352) of the MAC contexts for the target cell and provide the copy to the MAC layer (334) of the target DU (330). For example, the second data (352) of MAC contexts for the target cell can be copied or replicated from the source DU (320) to the target DU (330) via the DU-to-DU interface. For example, the electronic device can obtain the second data (352) of MAC contexts for the target cell from the source DU (320) and provide it to the MAC layer (334) of the target DU (330).

[0108] In one embodiment of the present disclosure, the electronic device can switch the fronthaul interface from the source DU (320) to the target DU (330). For example, the electronic device can release (or disconnect, remove, deactivate) the fronthaul interface between the RU (340) of the target cell and the PHY layer (326) of the source DU (320), and establish (or connect, create, activate) the fronthaul interface between the RU (340) of the target cell and the PHY layer (336) of the target DU (330).

[0109] In one embodiment of the present disclosure, the electronic device can switch a control path (e.g., a control path of a MAC layer, a control path of a PHY layer) from a source DU (320) to a target DU (330). For example, the electronic device can switch a path (or connection, interface) of an RLC layer-MAC layer for a target cell from a path of an RLC layer (322) of the source DU (320) - a MAC layer (324) of the source DU (320) to a path of an RLC layer (322) of the source DU (320) - a MAC layer (334) of the target DU (330). For example, the electronic device can release (or disconnect, remove, disable) the RLC layer (322) of the source DU (320) - MAC layer (324) of the source DU (320) path for the target cell, and set (or establish, create, activate) the RLC layer (322) of the source DU (320) - MAC layer (334) of the target DU (330) path.

[0110] For example, at least some of the transfer of the MAC context, the switching of the fronthaul interface, or the switching of the control path (e.g., the RLC layer-to-MAC layer path) may be performed while MAC scheduling for the target cell is suspended. For example, at least some of the transfer of the MAC context, the switching of the fronthaul interface, or the switching of the control path may be performed concurrently. For example, at least some of the transfer of the MAC context, the switching of the fronthaul interface, or the switching of the control path may be performed in parallel. For example, at least some of the transfer of the MAC context, the switching of the fronthaul interface, or the switching of the control path may be performed sequentially.

[0111] Referring to FIG. 3b, as the MAC context is transferred from the source DU (320) to the target DU (330), the second data (352) of the MAC contexts for the target cell may be included (or set, transferred) in the MAC layer (334) of the target DU (330). For example, at least one MAC context for the target cell in the target DU (330) may be set, updated, or synchronized with the transferred data (e.g., the second data (352)). As illustrated in FIG. 3b, a fronthaul interface between the RU (340) of the target cell and the PHY layer (336) of the target DU (330) may be set (or, connected, created, activated), and a path between the RLC layer (322) of the source DU (320) and the MAC layer (334) of the target DU (330) may be set (or, connected, created, activated).

[0112] In one embodiment of the present disclosure, after at least one of switching of a fronthaul interface, switching of a control path, or transfer of a MAC context is processed, MAC scheduling for a target cell of a target DU (330) may start. As MAC scheduling for a target cell of a target DU (330) starts, the RU (340) of the target cell and the PHY layer (336) of the target DU (330) may transmit and receive data for the target cell, and the RLC layer (322) of the source DU (320) and the MAC layer (334) of the target DU (330) may transmit and receive data for the target cell. Data for communication of a plurality of UEs (342) associated with the target cell may be processed by the PHY layer (336), the MAC layer (334) of the target DU (330) and the RLC layer (322) of the source DU (320). Accordingly, a plurality of UEs (342) associated with a target cell can access a core network through the RU (340), the PHY layer (336) of the target DU (330), the MAC layer (334), the RLC layer (322) of the source DU (320), and the CU (310) by wirelessly communicating with the RU (340) for the target cell, and can receive wireless communication services.

[0113] FIG. 3b illustrates an example in which all second data (352) of MAC contexts for target cells included in the source DU (320) are transferred to the target DU (330), but is not limited thereto. For example, some of the second data (352) of the MAC contexts for the target cells included in the source DU (320) may be transferred to the target DU (330), and some of the first data (350) of the MAC contexts for the target cells included in the target DU (330) may be maintained. For example, when the second data of a previous target MAC context among the MAC contexts for the target cells included in the source DU (320) is transferred to the target DU (330), the data of the previous target MAC context in the target DU (330) may be updated with the second data (e.g., the transferred data), and the first data (e.g., the existing data) may be maintained for the remaining MAC contexts in the target DU (330). For example, if the value of a specific UE context for a first UE is transferred and the value of a specific UE context for a second UE is not transferred, the value of the specific UE context for the first UE in the target DU (330) may be updated to the transferred value, and the value of the specific context for the second UE in the target DU (330) may be maintained at the existing value.

[0114] FIG. 4 is a diagram illustrating an example of determining a reference label for each UE for MAC context transfer from a source DU to a target DU according to one embodiment of the present disclosure.

[0115] In explaining Fig. 4, any explanation that overlaps with the explanation given above in any one of Figs. 1 to 3b may be omitted.

[0116] In one embodiment of the present disclosure, an electronic device can transfer a target cell from a source DU (320) to a target DU (330). The electronic device can transfer a MAC context for the target cell from the source DU (320) to the target DU (330) for the transfer of the target cell. For example, the electronic device can transfer, transmit, or replicate a MAC context from a MAC layer of the source DU (320) to a MAC layer of the target DU (330) for the transfer of the target cell.

[0117] In one embodiment of the present disclosure, the electronic device for transferring the MAC context may include a device including (or configured with) the source DU (320), a device including (or configured with) the target DU (330), or a device separate from the source DU (320) and the target DU (330). For example, the electronic device may include a device separate from the source DU (320) and the target DU (330) that controls the transfer of a target cell or MAC context from the source DU (320) to the target DU (330).

[0118] In one embodiment of the present disclosure, an electronic device can set a label for each of a plurality of MAC contexts. For example, the electronic device can label the plurality of MAC contexts by type. For example, the electronic device can label each of the plurality of MAC contexts with at least one of the plurality of labels. For example, the electronic device can group the plurality of MAC contexts into a plurality of groups and assign a label to each group. For example, the electronic device can set which label among the plurality of labels corresponds to each of the various MAC contexts.

[0119] In one embodiment of the present disclosure, an electronic device may label multiple MAC contexts based on their influence on UE traffic. For example, the electronic device may classify each MAC context into at least one label based on the influence that the presence or absence of data in each MAC context has on UE communication. In one embodiment of the present disclosure, the electronic device may label each MAC context based on its influence or importance in the MAC scheduling process.

[0120] In one embodiment of the present disclosure, an electronic device may obtain information (e.g., labeling information) regarding a label corresponding to (or matching) each of a plurality of MAC contexts, and may set or assign a label to each MAC context. For example, the electronic device may set a predefined label for each of the plurality of MAC contexts. For example, the label set for each MAC context may be defined or determined based on the importance of the presence or absence of the MAC context on UE traffic.

[0121] For example, the electronic device may set a label for each MAC context as shown in Table 1 below, but is not limited thereto.

[0122] Examples of Label MAC Contexts: Label 3 Slot configuration, etc. Label 2 UE RNTI, Attach information, etc. Label 1 BO (buffer occupancy) information, BSR (buffer status report) information, HARQ (hybrid automatic repeat request) information, scheduling information of the previous slot, etc. Label 0 System time, statistical data, etc.

[0123]

[0124] In Table 1 above, Label 3 can correspond to a context in which the communication system for the target cell may malfunction if not transferred. Label 2 can correspond to a context in which the communication system for the target cell may operate normally even if not transferred, but a radio link failure (RLF) may occur in the associated UE. Label 1 can correspond to a context in which the communication system for the target cell may operate normally even if not transferred, but a throughput degradation, i.e., performance degradation, may occur in the associated UE. Label 0 is updated on a slot-by-slot basis, so it can correspond to a context that does not need to be transferred.

[0125] Table 1 above shows an example corresponding to a MAC context in which the importance increases as the label value increases, but is not limited thereto.

[0126] In one embodiment of the present disclosure, an electronic device can identify an RLF generation tolerance level. For example, the electronic device can obtain or determine an RLF generation tolerance level. For example, the electronic device can receive information indicating an RLF generation tolerance level from another device or another module (400). For example, the electronic device can obtain an RLF generation tolerance level input through an input device connected to or built into the electronic device.

[0127] In one embodiment of the present disclosure, the RLF occurrence tolerance may include information indicating the level to which RLF that may occur during a transfer process of a target cell (e.g., a transfer process of a MAC context) is allowed. For example, the RLF occurrence tolerance may include an allowable degree of RLF occurring among UEs associated with the target cell. For example, the RLF occurrence tolerance may include a maximum allowable RLF occurrence tolerance used in an RLF occurrence condition. For example, the RLF occurrence tolerance may include a maximum allowable RLF occurrence tolerance during a MAC context transfer. For example, the RLF occurrence tolerance may include at least one of an allowable RLF occurrence rate, an allowable number of RLF occurrences, or an allowable number of UEs that generate RLF.

[0128] In one embodiment of the present disclosure, the electronic device can identify information about the target DU (330) and / or information about the source DU (320). For example, the electronic device can obtain information about the target DU (330) and / or information about the source DU (320). For example, the electronic device can obtain information about the target DU (330) and / or information about the source DU (320) input through an input device connected to or built into the electronic device. For example, the electronic device can receive information about the target DU (330) and / or information about the source DU (320) from another device or another module (400). For example, the electronic device may request information about the target DU (330) and / or information about the source DU (320) from another device or another module (400), and may receive information about the target DU (330) and / or information about the source DU (320) from another device or another module (400).

[0129] In one embodiment of the present disclosure, the information about the target DU (330) may include information used to predict, determine, or calculate the maximum transmittable data size (or amount) between the source DU (320) (e.g., the MAC layer of the source DU) and the target DU (330) (e.g., the MAC layer of the target DU) during a specific period of time. In one embodiment of the present disclosure, the information about the target DU (330) may include information about the communication of the target DU (330) (e.g., network information, frequency resource information). For example, the information about the target DU (330) may include frequency resource information of a network interface card (NIC) used before a MAC context. In one embodiment of the present disclosure, the information about the target DU (330) may include performance information of the target DU (330) (e.g., processing capacity information). For example, information about the target DU (330) may include processing capacity information of a Read / Write operation prior to the MAC context.

[0130] In one embodiment of the present disclosure, the information about the source DU (320) may include information used to predict, determine, or calculate the maximum transmittable data size (or amount) between the source DU (320) (e.g., the MAC layer of the source DU) and the target DU (330) (e.g., the MAC layer of the target DU) during a specific period of time. In one embodiment of the present disclosure, the information about the source DU (320) may include information about the communication of the source DU (320) (e.g., network information, frequency resource information). For example, the information about the source DU (320) may include frequency resource information of a network interface card (NIC) used before a MAC context. In one embodiment of the present disclosure, the information about the source DU (320) may include performance information about the source DU (320) (e.g., processing capacity information). For example, the information about the source DU (320) may include processing capacity information of a Read / Write operation before a MAC context.

[0131] In one embodiment of the present disclosure, an electronic device may determine (or predict, calculate) a shortest duration of time in which an RLF associated with a MAC layer in a target cell may occur based on information about a plurality of UEs associated with the target cell. For example, the electronic device may determine the shortest duration of time in which an RLF may occur in the target cell during MAC context transfer. For example, since UEs in an RRC idle state are not affected by RLF occurrence, the electronic device may predict the shortest duration of time in which an RLF may occur based on UEs whose RRC state is not in an RRC idle state among the plurality of UEs associated with the target cell. For example, the electronic device may calculate a possible RLF occurrence time for each of the plurality of UEs associated with the target cell (e.g., UEs in an RRC inactive state or an RRC active state), and determine the shortest time among the calculated possible RLF occurrence times for each of the plurality of UEs as the shortest duration of time in which an RLF may occur in the target cell.

[0132] In one embodiment of the present disclosure, the electronic device can determine (or predict, calculate) the shortest possible RLF occurrence time of the target cell by considering RLF occurrence scenarios associated with the MAC layer (e.g., RLF occurrence scenarios associated with MAC context transfer). For example, the electronic device can determine the shortest possible RLF occurrence time of the target cell based on RLF occurrence times calculated for a plurality of UEs (e.g., UEs in an RRC inactive state or an RRC active state) associated with the target cell in each scenario. For example, the electronic device can determine the smallest value among the predicted RLF occurrence times for a plurality of UEs associated with the target cell in each scenario as the shortest possible RLF occurrence time of the target cell.

[0133] For example, scenarios in which RLF may occur during MAC context transfer may include a RACH (random access channel) failure scenario or an RLC failure scenario. A RACH failure scenario may include a scenario in which an RRC idle state or an RRC inactive state attempts a RACH while changing to an RRC connected (or active) state by receiving a paging message, and an RAR (random access response) message is not received within a specific time, resulting in an RLF. An RLC failure scenario may include an AM (acknowledge mode) DRB (data radio bearer) max retransmission exceeded scenario in which an RLF occurs for a UE in an RRC connected state performing RLC AM mode transmission.

[0134] For example, in a RACH failure scenario, an electronic device can calculate the possible RLF occurrence times for multiple UEs associated with a target cell. For example, the electronic device can calculate the possible RLF occurrence times for each of the multiple UEs in a RACH failure scenario using the following mathematical expression 1.

[0135] Mathematical formula 1

[0136] DL(Downlink) RLF occurrence time = SR(scheduling request) cycle * sr-TransMax + PRACH cycle * preambleTransMax

[0137] UP(Uplink) RLF occurrence time = retxBSR trigger + SR period * sr-TransMax(64) + PRACH period * preambleTransMax(10)

[0138] In the above mathematical expression 1, SR period may represent a scheduling request period, sr-TransMax may represent the maximum number of transmissions of scheduling requests, and preambleTransMax may represent the maximum number of transmissions of a preamble. In addition, retxBSR trigger may represent a parameter that sets a trigger for retransmitting a buffer status report, sr-TransMax(64) may represent that sr-TransMax is set to 64, and preambleTransMax(10) may represent that preambleTransMax is set to 10. The parameter values ​​of the above mathematical expression 1 may be different for each of a plurality of UEs or may be common for a plurality of UEs.

[0139] For example, an electronic device can calculate the RLF occurrence time for multiple UEs associated with a target cell in an RLC failure scenario. For example, the electronic device can calculate the RLF occurrence time for each of multiple UEs in an RLC failure scenario using the following mathematical expression 2.

[0140] Mathematical formula 2

[0141] DL or UL RLF occurrence possible time = t-PollRetransmit * maxRetxThreshold

[0142] In the above mathematical expression 2, t-PollRetransmit represents the time interval at which the UE polls the network, and maxRetxThreshold may represent the maximum number of retransmissions allowed in the HARQ (hybrid automatic repeat request) process. The parameter values ​​of the above mathematical expression 2 may be different for each UE or may be common to multiple UEs.

[0143] In one embodiment of the present disclosure, parameters (e.g., RRC parameters) used to calculate the RLF occurrence time for each of a plurality of UEs may be transmitted to the MAC layer (e.g., the MAC layer of a DU associated with a target cell) during a UE setup or UE modify process. For example, the parameters used to calculate the RLF occurrence time may be included in a context managed for each UE. In one embodiment of the present disclosure, the parameters used to calculate the RLF occurrence time for each of a plurality of UEs may be changed depending on base station operation or may be set differently for each UE. In one embodiment of the present disclosure, since the RRC parameter values ​​that determine RLF occurrence may differ for each operator or UE, the RLF occurrence time (or the shortest possible RLF occurrence time) may be predicted based on the RRC parameters at the time of operation rather than a fixed value.

[0144] In one embodiment of the present disclosure, the electronic device may determine an allowable MAC scheduling interruption time based on the shortest possible RLF occurrence time in the target cell. For example, the MAC scheduling interruption time may include N-slot, i.e., slot unit time. The time corresponding to one slot may vary depending on the value of subcarrier spacing (SCS) (e.g., 15, 30, 60, 120, 240). For example, in order to minimize the probability of RLF occurrence, the MAC scheduling interruption of the source DU (320), the MAC context transfer, and the MAC scheduling start of the target DU (330) may need to be performed within the allowable MAC scheduling interruption time, i.e., within N-slot.

[0145] In one embodiment of the present disclosure, the electronic device can predict (or determine, calculate) the maximum transmittable data amount (or size) between the source DU (320) and the target DU (330) based on the allowable MAC scheduling interruption time and the information about the target DU (330). For example, the electronic device can predict the available time before the MAC context by considering the allowable MAC scheduling interruption time and the time required to interrupt the MAC scheduling of the source DU (320) and / or start the MAC scheduling of the target DU (330). For example, the electronic device can predict the maximum transmittable data size between the source DU (320) and the target DU (330) based on the available time before the MAC context and the information about the target DU (330).

[0146] For example, the electronic device can use information about the target DU (330) to predict the size (or amount) of data that can be transferred between the source DU (320) and the target DU (330) during a specific period of time, and can use the allowable MAC scheduling interruption time (or the time available before the MAC context) to predict the maximum transferable data size between the source DU (320) and the target DU (330) during the MAC context transfer. For example, the electronic device can predict, calculate, or determine the amount of data of the MAC context that can be transferred from the source DU (320) to the target DU (330) during the MAC scheduling interruption.

[0147] In one embodiment of the present disclosure, the electronic device can predict or determine whether all MAC contexts for a target cell can be transferred from a source DU (320) to a target DU (330) within an allowable MAC scheduling interruption time (or, time available for MAC context transfer). For example, the electronic device can predict or determine whether MAC scheduling interruption of the source DU (320), transfer of all MAC contexts for the target cell, and MAC scheduling start of the target DU (330) can be performed within the allowable MAC scheduling interruption time.

[0148] In one embodiment of the present disclosure, the electronic device can determine whether the data size of MAC contexts for a target cell exceeds the maximum transmittable data size. For example, the MAC context for the target cell may include a context set in the MAC layer of the source DU (320) for the target cell. For example, the MAC context for the target cell may include a MAC context that needs to be transferred to the target DU (330) for the transfer of the target cell. For example, the MAC context for the target cell may include a MAC context that has not been transferred to the target DU (330). For example, the MAC context for the target cell may include a MAC context that is newly created, accumulated, or updated (or changed) after the cell configuration information or UE context of the target cell is transferred to the target DU (330). For example, the MAC context for the target cell may include a MAC context for each of a plurality of UEs associated with the target cell.

[0149] In one embodiment of the present disclosure, if it is determined that all target MAC contexts of a target cell are transferable within an allowable MAC scheduling interruption time (or MAC context transferable time), the electronic device may transfer all MAC contexts for the target cell from the source DU (320) to the target DU (330) to minimize the impact of the transfer. In one embodiment of the present disclosure, if it is determined that the data size of the MAC contexts for the target cell does not exceed the maximum transferable data size, the electronic device may transfer all MAC contexts for the target cell from the source DU (320) to the target DU (330). For example, the electronic device may transfer MAC contexts of all labels from the source DU (320) to the target DU (330), regardless of the label to which each MAC context for the target cell corresponds.

[0150] In one embodiment of the present disclosure, if it is determined that not all MAC contexts for the target cell can be transferred within the allowable MAC scheduling interruption time (or the time available for transferring MAC contexts), the electronic device may determine a priority of one or more UEs (e.g., UEs in RRC active state) among a plurality of UEs associated with the target cell to select (or determine) some of the MAC contexts for the target cell as the transfer target MAC contexts. In one embodiment of the present disclosure, if it is determined that the data size of the MAC context for the target cell exceeds the maximum transmittable data size, the electronic device may determine a priority of one or more UEs among a plurality of UEs associated with the target cell to select (or determine) some of the MAC contexts for the target cell as the transfer target MAC contexts.

[0151] In one embodiment of the present disclosure, an electronic device may determine a priority of one or more UEs based on at least one of RRC state information of a plurality of UEs associated with a target cell or traffic information of one or more UEs. For example, the electronic device may group the plurality of UEs based on the RRC state. For example, the electronic device may classify the plurality of UEs into one of an RRC idle state group, an RRC inactive state group, or an RRC active state group. For example, the electronic device may determine a priority of a UE included in an RRC idle state group to be lower than a priority of a UE included in an RRC inactive state group or an RRC active state group. For example, the electronic device may determine a priority of a UE included in an RRC inactive state group to be lower than a priority of a UE included in an RRC active state group.

[0152] For example, the electronic device may identify one or more UEs in an RRC active state (e.g., UEs included in an RRC active state group) based on RRC state information of multiple UEs, and determine a priority of the identified one or more UEs based on traffic information (e.g., bearer QoS, recent DL / UL throughput, or BO / BSR information) of the identified one or more UEs. For example, the electronic device may determine the priorities of UEs in an RRC active state group based on UE traffic information within the RRC active state group. For example, the electronic device may assign a higher priority to a UE that is more affected by a service interruption time.

[0153] In one embodiment of the present disclosure, an electronic device may determine a reference label for each of a plurality of UEs associated with a target cell in order to select some MAC contexts to be transferred from among MAC contexts for the target cell. In one embodiment of the present disclosure, the electronic device may determine a priority of one or more UEs among the plurality of UEs associated with the target cell, and determine a reference label for each of the plurality of UEs based on the determined priority of the one or more UEs. The reference label for a specific UE may indicate a label with the lowest importance among the MAC contexts for the specific UE to be transferred. Accordingly, when transferring a MAC context, among the MAC contexts for a specific UE included in the source DU (320), a MAC context corresponding to the reference label of the specific UE or a MAC context corresponding to a label indicating a higher importance than the reference label may be selected (or determined) as a MAC context to be transferred.

[0154] In one embodiment of the present disclosure, the electronic device may determine or adjust a reference label for one or more of a plurality of UEs associated with a target cell so as to transfer more MAC contexts to a UE with a higher priority than to a UE with a lower priority. For example, the electronic device may determine a reference label for one or more UEs based on a priority of the one or more UEs in an RRC active state. For example, the electronic device may determine a reference label for one or more UEs by upwardly adjusting a reference label of a second UE in an RRC active state, which has a lower priority than a first UE in an RRC active state. For example, the importance of the reference label for the second UE, which has a lower priority than the first UE, may be higher than the importance of the reference label for the first UE.

[0155] For example, an electronic device may determine (or adjust) a label corresponding to a high importance as a reference label for a UE in an RRC active state with a low priority. In this case, for the UE, RLF may occur because MAC contexts corresponding to labels with a lower importance than the reference label are not transferred. However, if the RLF occurrence rate for the entire target cell does not exceed the RLF occurrence allowable rate, the electronic device may assign (or set) the label corresponding to a high importance as a reference label for the UE in an RRC active state with a low priority for transfer to the target cell.

[0156] In one embodiment of the present disclosure, an electronic device may determine a reference label for at least one UE based on RRC state information of at least one UE among a plurality of UEs. For example, the electronic device may determine a reference label for a UE in an RRC idle state as a predefined label for the RRC idle state. For example, the electronic device may determine a predefined highest label (e.g., label 3) for the RRC idle state as a reference label so that a malfunction does not occur for a UE in an RRC idle state (e.g., a UE included in an RRC idle state group). For example, the electronic device may determine a reference label for a UE in an RRC inactive state as a predefined label for the RRC inactive state. For example, the electronic device may determine a predefined label (e.g., label 2) for the RRC inactive state as a reference label so that a contention free based random access (CFRA) process can be performed without a malfunction for a UE in an RRC inactive state (e.g., a UE included in an RRC inactive state group).

[0157] In one embodiment of the present disclosure, an electronic device may determine reference labels for a plurality of UEs that satisfy an RLF occurrence condition or a data size condition. For example, the electronic device may determine whether a condition for RLF occurrence or a condition for data size is satisfied in various cases through a loop operation to determine reference labels for the plurality of UEs. For example, the condition for RLF occurrence may include a condition that the degree of RLF occurrence prediction does not exceed an allowable degree of RLF occurrence. For example, the condition for data size may include a condition that the data size of a previous target MAC context does not exceed a maximum transmittable data size. For example, the condition for data size may include a condition that the previous target MAC context can be transferred within an allowable MAC scheduling interruption time (or, the time available for transfer of the MAC context). In one embodiment of the present disclosure, the electronic device may determine reference labels for a plurality of UEs that minimize the degree of RLF occurrence prediction while satisfying the condition for RLF occurrence or the condition for data size.

[0158] In one embodiment of the present disclosure, the electronic device can determine a reference label for each of a plurality of UEs associated with the target cell such that the predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence and the data size of a previous target MAC contest does not exceed the maximum transmittable data size. For example, the electronic device can determine a reference label for each UE such that the predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence and the data size of a previous target MAC contest does not exceed the maximum transmittable data size by repeatedly adjusting (or updating) the reference labels for at least some of the plurality of UEs.

[0159] In one embodiment of the present disclosure, the electronic device can determine a reference label for each of a plurality of UEs associated with a target cell, such that a predicted degree of RLF occurrence does not exceed a permitted degree of RLF occurrence and a transferable target MAC contest can be selected within an allowable MAC scheduling interruption time (or a previously available time of MAC context). For example, the electronic device can determine a reference label for each UE, such that a predicted degree of RLF occurrence does not exceed a permitted degree of RLF occurrence and a transferable target MAC contest can be selected within an allowable MAC scheduling interruption time (or a previously available time of MAC context), by repeatedly adjusting (or updating) the reference labels for at least some of the plurality of UEs.

[0160] Referring to FIG. 4, the source DU (320) may perform labeling (410) for each MAC context. For example, the source DU (320) may assign at least one label among multiple labels to each MAC context at the initial execution time of the MAC process. For example, the source DU (320) may set (or assign) a label to each MAC context based on labeling information defined based on importance.

[0161] The source DU (320) may perform a MAC scheduling operation (420) for the target cell. For example, the MAC layer of the source DU (320) may perform MAC scheduling for communication of multiple UEs associated with the target cell. For example, data of at least one MAC context may be generated, accumulated, or updated (or changed) in the source DU (320) by the MAC scheduling operation (420) for the target cell.

[0162] The source DU (320) can receive a cell transfer request (430) from another device or another module (400). For example, the source DU (320) can receive a message, signal, or information requesting (or instructing) cell transfer. For example, the source DU (320) can receive a cell transfer request (430) from another module of an electronic device including the source DU (320). The cell transfer request (430) can include at least one of information about a target DU that will process the transfer target cell (e.g., an identifier, location, hardware information of the target DU), information about a target cell to be transferred to the target DU (e.g., an identifier of the target cell), or information about the degree to which RLF occurrence is allowed (e.g., an allowable RLF occurrence rate).

[0163] In one embodiment of the present disclosure, a source DU (320) and a target DU (330) may exchange information used to predict a maximum transmittable data size between the source DU (320) (e.g., a MAC layer of the source DU) and the target DU (330) (e.g., a MAC layer of the target DU) for a specific period of time. For example, the source DU and the target DU may exchange network information, frequency band information, or processing capacity information prior to a MAC context.

[0164] Referring to FIG. 4, the source DU (320) can request (440) information about the target DU (330) to the target DU (330) and obtain information about the target DU (330) from the target DU (330). As illustrated in FIG. 4, the target DU (330) can transmit a return response (442) in response to receiving the request from the source DU (320). For example, the target DU (330) can provide information about the target DU (330) to the source DU (320) together with the return response (442), before the return response (442), or after the return response (442).

[0165] The source DU (320) can calculate (450) (or predict, determine) the shortest possible RLF occurrence time for the MAC context transfer of the target cell. For example, the source DU (320) can calculate the possible RLF occurrence time for each of a plurality of UEs associated with the target cell, and determine the shortest time among the calculated times as the shortest possible RLF occurrence time for the target cell.

[0166] The source DU (320) can calculate (460) the time during which MAC context transfer is possible (or the time available for MAC context transfer, the time during which MAC scheduling can be suspended) based on the calculated shortest possible RLF occurrence time. For example, the source DU (320) can calculate (or determine) the number of slots during which MAC context transfer is possible (or the time during which MAC scheduling can be suspended), i.e., the time per slot, using the calculated shortest possible RLF occurrence time. For example, the source DU (320) can calculate (460) the time during which MAC context transfer is possible by considering the calculated shortest possible RLF occurrence time, the time required for MAC scheduling suspension of the source DU (320) and the MAC scheduling start of the target DU (330).

[0167] If all MAC contexts for the target cell can be transferred within the MAC context transfer possible time (or MAC scheduling suspension possible time), the source DU (320) can transfer (or transfer, copy) data of all MAC contexts for the target cell to the target DU (330). For example, when transferring all MAC contexts for the target cell to the target DU (330) regardless of the label of each MAC context, the source DU (320) can batch-transfer (or transfer, copy) data of the MAC contexts for the target cell to the target DU (330) using a memory dump method without a process of obtaining / setting data of contexts of a specific label. For example, the source DU (320) can transfer memory area data of all MAC contexts for the target cell to the target DU (330), and the target DU (330) can copy data of the MAC contexts received to the memory area of ​​the target cell.

[0168] Referring to FIG. 4, if not all MAC contexts for a target cell can be transferred within the MAC context transfer possible time (or MAC scheduling suspension possible time), the source DU (320) may determine (470) a reference label for each of a plurality of UEs associated with the target cell to select a transfer target MAC context. For example, the source DU (320) may determine a priority of one or more UEs among the plurality of UEs and determine a reference label for each of the plurality of UEs based on the determined priority. For example, a UE with a higher priority may be assigned a reference label with a lower importance than a UE with a lower priority.

[0169] FIG. 4 illustrates an example of a source DU (320) receiving a cell transfer request (430), but is not limited thereto. In one embodiment of the present disclosure, the source DU (320) may determine a cell transfer. For example, the source DU (320) may receive a DU scaling (e.g., scaling in or scaling out) request and determine a cell transfer. For example, the source DU (320) may determine DU scaling and then determine a cell transfer.

[0170] FIG. 5A is a diagram illustrating an example of determining reference labels for multiple UEs in one embodiment of the present disclosure. FIG. 5B is a diagram illustrating an example of determining reference labels for multiple UEs in one embodiment of the present disclosure.

[0171] In explaining Fig. 5a or Fig. 5b, any explanation that overlaps with the explanation given above in any one of Figs. 1 to 4 may be omitted.

[0172] In one embodiment of the present disclosure, the electronic device may determine a reference label for one or more UEs based on a priority of one or more UEs among a plurality of UEs associated with a target cell. For example, the electronic device may determine a reference label for each of the plurality of UEs such that a predicted RLF occurrence does not exceed a permitted RLF occurrence and transfer of a target MAC context is possible within a MAC context transfer time (or a MAC scheduling interruption allowed time). For example, the electronic device may determine a reference label for each of the plurality of UEs such that a predicted RLF occurrence does not exceed a permitted RLF occurrence and a data size of a target MAC context for transfer does not exceed a maximum transmittable data size.

[0173] For example, the electronic device may determine a reference label for each of the plurality of UEs such that the data size of the previous target MAC context does not exceed the maximum transmittable data size and RLF occurrence is minimized. For example, the electronic device may determine a reference label for each of the plurality of UEs such that the data size of the previous target MAC context does not exceed the maximum transmittable data size and communication performance (e.g., throughput) degradation for the target cell is minimized.

[0174] In one embodiment of the present disclosure, an electronic device can determine a reference label for each of a plurality of UEs by repeatedly (or one-time) adjusting (or updating) reference labels for at least some of the plurality of UEs. For example, the electronic device can obtain reference labels for a plurality of UEs that satisfy conditions for RLF occurrence and conditions for data size by adjusting reference labels for at least some of the plurality of UEs using a predefined algorithm operation or learning model. For example, the electronic device can obtain reference labels for a plurality of UEs that satisfy conditions for RLF occurrence and conditions for data size by adjusting reference labels for at least some of the plurality of UEs through a repetitive loop operation.

[0175] In one embodiment of the present disclosure, the electronic device can obtain a final reference label for the plurality of UEs by adjusting a reference label for at least one UE among the plurality of UEs until a condition for RLF generation and a condition for data size are satisfied. For example, the electronic device can assign a label with a low priority as a reference label to one or more UEs in an RRC active state among the plurality of UEs as an initial setting (or assumption), and can preferentially adjust upward the reference label for a UE with a lower priority among the one or more UEs. For example, the electronic device can set (or determine, assign) a reference label for one or more UEs in an RRC active state among the plurality of UEs as a label predefined for the RRC active state in an initial setting (or assumption) step, and can preferentially adjust upward the reference label for a UE with a lower priority among the one or more UEs.

[0176] Referring to FIG. 5A, the UE list-reference label table (510) may indicate reference labels for n UEs in the initial setup (or assumption) step or the ith (where i is a natural number) adjustment step. In the table (510), the n UEs may be sequentially displayed from top to bottom in order of priority. For example, they may be sequentially displayed in the table (510) from UE 1 with the highest priority to UE n with the lowest priority. As illustrated in FIG. 5A, in the initial setup (or assumption) step or the ith adjustment step, the reference labels for UE 1 and UE 2 may be set (or assigned, assumed) as Label 0, and the reference labels for UE 3 to UE n may be set (or assigned, assumed) as Label 1.

[0177] The electronic device can predict (or determine) whether the MAC context transfer will be successful when the reference labels for UE 1 to UE n are set (or assigned, assumed) as shown in Table (510). For example, the electronic device can predict (or determine) that the predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence, but that the target MAC context cannot be transferred within the MAC context transfer possible time (or MAC scheduling interruption allowed time), when the reference labels for UE 1 to UE n are set (or assigned, assumed) as shown in Table (510). For example, the electronic device can predict (or determine) that the predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence, but that the size of the target MAC context to be transferred exceeds the maximum transmittable data size, when the reference labels for UE 1 to UE n are set (or assigned, assumed) as shown in Table (510).

[0178] Accordingly, the electronic device may adjust the reference labels for at least some of the n UEs. Referring to FIG. 5B, the UE list-reference label table (520) may indicate the reference labels for the n UEs in the first adjustment step or the (i+1)th adjustment step. As illustrated in the table (520) of FIG. 5B, in the first adjustment step or the (i+1)th adjustment step, the electronic device may adjust the reference label for the UE n having a lower priority from Label 1 to Label 2. As the reference label for the UE n is adjusted from Label 1 to Label 2, the MAC contest for the UE n corresponding to Label 1 may be excluded from the previous target MAC context.

[0179] The electronic device can predict (or determine) whether the MAC context transfer is successful when the reference labels for UE 1 to UE n are set (or assigned, assumed) as shown in Table (520). For example, the electronic device can predict (or determine) that the degree of RLF occurrence prediction does not exceed the degree of RLF occurrence tolerance when the reference labels for UE 1 to UE n are set (or assigned, assumed) as shown in Table (520), and that the target MAC context can be transferred within the MAC context transfer possible time (or MAC scheduling interruption tolerance time). For example, the electronic device can predict (or determine) that the degree of RLF occurrence prediction does not exceed the degree of RLF occurrence tolerance when the reference labels for UE 1 to UE n are set (or assigned, assumed) as shown in Table (520), and that the size of the target MAC context to be transferred does not exceed the maximum transmittable data size. Accordingly, the electronic device can finally determine the reference labels for multiple UEs, as shown in table (520).

[0180] The algorithms, parameters, reference values, operations, or models used in each adjustment step may be different or identical. FIG. 5b illustrates an example of determining reference labels for multiple UEs by upwardly adjusting the reference labels for lower-priority UEs in one embodiment of the present disclosure, but is not limited thereto. For example, an electronic device may determine reference labels for multiple UEs by setting labels with high priority as reference labels for UEs during the initial setup step and downwardly adjusting the reference labels for higher-priority UEs.

[0181] For example, UEs (e.g., UE 1, UE 2, ..., UE n) listed in order of priority in table (510) of FIG. 5A and table (520) of FIG. 5B may include UEs in an RRC active state, UEs in an RRC inactive state, or UEs in an RRC idle state. For example, the priority of a UE in an RRC inactive state may be set (or determined) lower than the priority of a UE in an RRC active state and higher than the priority of a UE in an RRC idle state. For example, a reference label for a UE in an RRC inactive state or a UE in an RRC idle state may be determined as a label predefined for each RRC state.

[0182] FIG. 6A is a diagram illustrating an example of determining reference labels for multiple UEs in one embodiment of the present disclosure. FIG. 6B is a diagram illustrating an example of determining reference labels for multiple UEs in one embodiment of the present disclosure.

[0183] In explaining Fig. 6a or Fig. 6b, any explanation that overlaps with the explanation given above in any one of Figs. 1 to 5b may be omitted.

[0184] In one embodiment of the present disclosure, the electronic device may classify one or more UEs among a plurality of UEs associated with a target cell into multiple groups (e.g., m, where m is a natural number). For example, the electronic device may include one or more UEs among the plurality of UEs in an RRC active state. In one embodiment of the present disclosure, the electronic device may classify one or more UEs among the plurality of UEs associated with the target cell into multiple groups based on traffic information or priorities. For example, the electronic device may classify one or more UEs into multiple groups based on traffic information or priorities, or based on the degree of impact caused by service interruption time.

[0185] In one embodiment of the present disclosure, the electronic device may determine priorities of one or more UEs among a plurality of UEs associated with a target cell, and then classify the one or more UEs into a plurality of groups based on the priorities. For example, UEs with priorities within the upper x may be determined as a first UE group, and UEs with priorities from x+1 to y may be determined as a second UE group. For example, UEs with the same priority may be classified into one group. In terms of priorities between UE groups, the priority of a group including a UE with a high priority may be higher than the priority of a group including a UE with a relatively low priority.

[0186] In one embodiment of the present disclosure, an electronic device may classify multiple UEs associated with a target cell into multiple groups based on traffic information of one or more UEs. For example, UEs included in the same group may correspond to the same priority. Based on traffic information of one or more UEs, a priority of a first group of UEs predicted to be significantly affected by service interruption time may be higher than a priority of a second group of UEs predicted to be relatively less affected by service interruption time.

[0187] In one embodiment of the present disclosure, the electronic device can determine a reference label for one or more UEs among a plurality of UEs associated with a target cell by determining a reference label for each UE group. For example, the electronic device can determine the reference labels of the UEs included in each UE group by determining the reference labels for each UE group. For example, determining the reference label for a first UE group as Label 0 may include determining the reference labels for the UEs included in the first UE group as Label 0. For example, the same reference label may be determined (or set) for UEs included in the same UE group.

[0188] In one embodiment of the present disclosure, the electronic device can determine a reference label for each of the plurality of UE groups by repeatedly (or one-time) adjusting (or updating) the reference labels for at least some of the plurality of UE groups. For example, the electronic device can obtain reference labels for the plurality of UE groups that satisfy conditions for RLF occurrence and conditions for data size by adjusting the reference labels for at least some of the plurality of UE groups using a predefined algorithm operation or learning model. For example, the electronic device can obtain reference labels for the plurality of UE groups that satisfy conditions for RLF occurrence and conditions for data size by adjusting the reference labels for at least some of the plurality of UE groups through a repetitive loop operation.

[0189] In one embodiment of the present disclosure, the electronic device can obtain a final reference label for the plurality of UE groups by adjusting the reference label for at least one UE group among the plurality of UE groups until the conditions for RLF occurrence and the conditions for data size are satisfied. For example, the electronic device can assign a label with a low importance as the reference label to the plurality of UE groups as an initial setting (or assumption), and can preferentially adjust the reference label for a UE group with a low priority. For example, the electronic device can set (or determine, assign) the reference label for the plurality of UE groups to a label predefined for an RRC state in the initial setting (or assumption) step, and preferentially adjust the reference label for a UE group with a low priority.

[0190] Referring to FIG. 6A, the UE group list-reference label table (610) may indicate reference labels for m UE groups in the initial setup (or assumption) step or the j-th (j is a natural number) adjustment step. In the table (610), the m UE groups may be sequentially displayed from top to bottom according to priority. For example, the table (610) may sequentially display the m-th UE group from the first UE group with the highest priority to the m-th UE group with the lowest priority. As illustrated in FIG. 6A, in the initial setup (or assumption) step or the j-th adjustment step, the reference labels for the first UE group and the second UE group may be set (or assigned, assumed) as Label 0, and the reference labels for the third UE group to the m-th UE group may be set (or assigned, assumed) as Label 1.

[0191] The electronic device can predict (or determine) whether the MAC context transfer is successful when the reference labels for the first UE group to the m-th UE group are set (or assigned, assumed) as shown in the table (610). For example, the electronic device can predict (or determine) that the predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence, but that the target MAC context cannot be transferred within the MAC context transfer possible time (or MAC scheduling interruption allowed time), when the reference labels for the first UE group to the m-th UE group are set (or assigned, assumed) as shown in the table (610). For example, the electronic device can predict (or determine) that the predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence, but that the size of the target MAC context to be transferred exceeds the maximum transmittable data size, when the reference labels for the first UE group to the m-th UE group are set (or assigned, assumed) as shown in the table (610).

[0192] Accordingly, the electronic device may adjust the reference labels for at least some of the m UE groups. Referring to FIG. 6B, the UE group list-reference label table (620) may indicate reference labels for the m UE groups in the first adjustment step or the (j+1)th adjustment step. As illustrated in the table (620) of FIG. 6B, in the first adjustment step or the (j+1)th adjustment step, the electronic device may adjust the reference label for the m-th UE group with a lower priority from Label 1 to Label 2. As the reference label for the m-th UE group is adjusted from Label 1 to Label 2, the MAC context for the m-th UE group corresponding to Label 1 (e.g., the MAC context for UEs corresponding to Label 1 and included in the m-th UE group) may be excluded from the previous target MAC context.

[0193] The electronic device can predict (or determine) whether the MAC context transfer is successful when the reference labels for the first UE group to the m-th UE group are set (or assigned, assumed) as shown in the table (620). For example, the electronic device can predict (or determine) that the degree of RLF occurrence prediction does not exceed the degree of RLF occurrence tolerance and that the target MAC context can be transferred within the MAC context transfer possible time (or MAC scheduling interruption tolerance time) when the reference labels for the first UE group to the m-th UE group are set (or assigned, assumed) as shown in the table (620). For example, the electronic device can predict (or determine) that the degree of RLF occurrence prediction does not exceed the degree of RLF occurrence tolerance and that the size of the target MAC context to be transferred does not exceed the maximum transmittable data size when the reference labels for the first UE group to the m-th UE group are set (or assigned, assumed) as shown in the table (620). Accordingly, the electronic device can finally determine the reference labels for multiple UE groups, as shown in table (620).

[0194] For example, the algorithms, parameters, reference values, operations, or models used in each adjustment step may be different or the same. FIG. 6b illustrates an example of determining reference labels for multiple UE groups by upwardly adjusting the reference label for a UE group with a low priority in one embodiment of the present disclosure, but is not limited thereto. For example, the electronic device may determine reference labels for multiple UE groups by setting labels with high importance as reference labels for the UE groups in the initial setup step and downwardly adjusting the reference label for a UE group with a high priority.

[0195] For example, the UE groups (e.g., the first UE group, the second UE group, ..., the mth UE group) listed in order of priority in the table (610) of FIG. 6a and the table (620) of FIG. 6b may include UEs in an RRC active state, UEs in an RRC inactive state, or UEs in an RRC idle state. For example, the priority of a UE group composed of UEs in an RRC inactive state may be set (or determined) lower than the priority of a UE group composed of UEs in an RRC active state and higher than the priority of a UE group composed of UEs in an RRC idle state. For example, a reference label for a UE group composed of UEs in an RRC inactive state or a UE group composed of UEs in an RRC idle state may be determined as a label predefined for each RRC state.

[0196] FIG. 7 is a diagram illustrating an example of transferring a MAC context from a source DU to a target DU based on a label of each MAC context and a reference label for each UE in one embodiment of the present disclosure.

[0197] In explaining Fig. 7, any explanation that overlaps with the explanation given above in any one of Figs. 1 to 6b may be omitted.

[0198] FIG. 7 illustrates an example of identifying (or determining, selecting) a previous target MAC context among MAC contexts based on a label of each MAC context and a reference label for each UE in one embodiment of the present disclosure, and transferring the previous target MAC context from a source DU (320) to a target DU (330).

[0199] In one embodiment of the present disclosure, the electronic device may suspend MAC scheduling of the source DU (320) for the target cell in order to transfer at least a portion of data of MAC contexts for the target cell included in the source DU (320). Due to the suspension of MAC scheduling of the source DU (320) for the target cell, communication services of a plurality of UEs associated with the target cell may be disconnected. For example, after the suspension of MAC scheduling of the source DU (320) for the target cell, communication services of a plurality of UEs associated with the target cell may be disconnected until the source DU (320) resumes MAC scheduling for the target cell or the target DU (330) initiates MAC scheduling for the target cell.

[0200] To prevent the connection (or attach) between multiple UEs and the target cell from being released (or disconnected) or to prevent multiple RLFs from occurring in the target cell, it is necessary to resume MAC scheduling for the target cell in the source DU (320) or to start MAC scheduling for the target cell in the target DU (330) within the MAC scheduling interruption allowance time. For example, it is necessary to transfer MAC contexts for communication of multiple UEs to the target DU (330) within the MAC scheduling interruption allowance time, and to start MAC scheduling for the target cell in the target DU (330).

[0201] Meanwhile, transferring all MAC contexts for the target cell may require more time than the MAC scheduling interruption allowance time (or the time available for MAC context transfer). In this case, in order to minimize RLF occurrence in the target cell, the time for which MAC scheduling is interrupted is limited to within the MAC scheduling interruption allowance time, and the electronic device may select at least some of the MAC contexts for the target cell as target MAC contexts to be transferred during the MAC scheduling interruption time. In this case, since some MAC contexts for the target cell are not transferred, RLF may occur for some UEs among the plurality of UEs associated with the target cell, but RLF occurrence can be minimized for the entire target cell.

[0202] In one embodiment of the present disclosure, the electronic device may transfer at least some of the data of MAC contexts for a target cell from a source DU (320) to a target DU (330) based on a label set for each MAC context and a reference label determined for each UE. For example, the electronic device may identify (or determine, select) at least some of the MAC contexts for the target cell included in the source DU (320) as transfer target MAC contexts based on a label set for each MAC context and a reference label determined for each UE.

[0203] In one embodiment of the present disclosure, each MAC context for a target cell may correspond to at least one label, depending on the label set for each MAC context. For example, if a label is set (or assigned) for each MAC context according to the labeling information of Table 1 described above, the UE RNTI of the first UE and the UE RNTI of the second UE included in the MAC context for the target cell may correspond to Label 2.

[0204] In one embodiment of the present disclosure, the electronic device may identify (or determine, select) as the transfer target MAC context a MAC context for the first UE, which corresponds to at least one of a first reference label for the first UE or a label having a higher importance than the first reference label. In one embodiment of the present disclosure, the electronic device may identify (or determine, select) as the transfer target MAC context a MAC context for the second UE, which corresponds to at least one of a second reference label for the second UE or a label having a higher importance than the second reference label.

[0205] In one embodiment of the present disclosure, the electronic device can transfer (or replicate) data of a previous target MAC context from a source DU (320) to a target DU (330). For example, the electronic device can control the source DU (320) or the target DU (330) to transfer (or replicate) data of the previous target MAC context. For example, the electronic device can transmit a message requesting (or instructing) a transfer or information (or data) used for transfer to the source DU (320) or the target DU (330) to transfer (or replicate) data of the previous target MAC context. For example, the electronic device can obtain information (e.g., parameter values) used to set (or include, or store) data of the previous target MAC context in the source DU (320) and use the obtained information to set (or store) data of the previous target MAC context in the target DU (330). For example, the electronic device can transfer data of a previous target MAC context to a target DU (330) by replicating the data of the previous target MAC context itself, which is set (or included, stored) in the source DU (320), to the target DU (330).

[0206] In one embodiment of the present disclosure, the electronic device may cause the target DU (330) to initiate MAC scheduling for the target cell. For example, if an allowable MAC scheduling interruption time has elapsed since the MAC scheduling of the source DU (320) was interrupted, the target DU (330) (e.g., the electronic device including the target DU (330)) may initiate MAC scheduling for the target cell. For example, after data of a previous target MAC context is copied (or transferred) from the source DU (320) to the target DU (330), the target DU (330) (e.g., the electronic device including the target DU (330)) may initiate MAC scheduling for the target cell. For example, after the previous target MAC context is copied (or transferred) from the source DU (320) to the target DU (330) and the fronthaul interface and control path are switched from the source DU (320) to the target DU (330), the target DU (330) can start MAC scheduling for the target cell. Accordingly, after the data of the previous target MAC context is copied (or transferred) from the source DU (320) to the target DU (330), the MAC scheduling operation for communication services for multiple UEs associated with the target cell can be performed by the target DU (330) rather than the source DU (320).

[0207] Referring to FIG. 7, the source DU (320) may stop (710) MAC scheduling for the target cell. The source DU (320) may transfer (720) a MAC context to the target DU (330). For example, the source DU (320) may provide at least a portion of data of MAC contexts for the target cell (e.g., data of the transferred target MAC context) to the target DU (330) based on a reference label for each UE. For example, the source DU (320) may transfer data of a MAC context for the first UE corresponding to a first reference label for the first UE or a label having a higher importance than the first reference label to the target DU (330).

[0208] The target DU (330) can receive data of a previous target MAC context from the source DU (320) and store (or set) it in the MAC layer of the target DU (330). As the transfer of the data of the previous target MAC context is successful (or completed), the target DU (330) can provide a return response to the source DU (320). As the transfer of the data of the previous target MAC context is successful (or completed), the target DU (330) can start (730) MAC scheduling for the target cell.

[0209] The source DU (320) may receive a return response from the target DU (330) and provide information indicating the success of the MAC context transfer to another device or another module (400). For example, the source DU (320) may provide information indicating the success of the MAC context transfer to an administrator client device or a user client device.

[0210] FIG. 7 illustrates, but is not limited to, an example in which a source DU (320) provides information indicating the success of a MAC context transfer to another device or another module (400). For example, the source DU (320) may output information indicating the success of a MAC context transfer through an output device connected to, attached to, or built into an electronic device including the source DU (320). For example, a target DU (330) may transmit information indicating the success of a MAC context transfer to another device or another module (400). For example, the target DU (330) may output information indicating the success of a MAC context transfer through an output device connected to, attached to, or built into an electronic device including the target DU (330).

[0211] For example, the source DU (320) can transmit information indicating the success of the MAC context transfer independently of whether the target DU (330) starts MAC scheduling for the target cell. For example, the source DU (320) can transmit information indicating the success of the MAC context transfer after transferring the previous target MAC context to the target DU (330). For example, the source DU (320) can transmit information indicating the success of the MAC context transfer upon receiving a response (e.g., a return response) from the target DU (330) regarding the completion (or success) of the previous target MAC context transfer.

[0212] FIG. 8 is a diagram illustrating an example in which transfer of MAC context fails in one embodiment of the present disclosure.

[0213] In explaining Fig. 8, any description that overlaps with the descriptions given above in any one of Figs. 1 to 7 may be omitted. For example, among the multiple operations illustrated in Fig. 8, the description of steps 410 to 460, which overlap with those in Fig. 4, may be omitted.

[0214] In one embodiment of the present disclosure, the electronic device can identify (or determine) a failure of a MAC context transfer based on identifying (or determining) that the predicted degree of RLF occurrence exceeds the allowed degree of RLF occurrence. For example, the electronic device can identify (or determine) a failure of a MAC context transfer based on identifying (or determining) that there is no case in which the predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence. For example, the electronic device can determine a failure of a MAC context transfer based on identifying (or determining) that there is no case in which the predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence in cases in which data of a previous target MAC context having a size less than or equal to the maximum transmittable data size is predicted to occur more than the allowed degree of RLF occurrence. For example, the electronic device can identify (or determine) a failure of a MAC context transfer based on identifying (or determining) that there is no case in which the predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence while the data size of the previous target MAC context does not exceed the maximum transmittable data size.

[0215] In one embodiment of the present disclosure, the electronic device may perform an operation to determine a reference label for each of a plurality of UEs such that the predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence and the data size of the previous target MAC context does not exceed the maximum transmittable data size. For example, the electronic device may determine whether the condition for RLF occurrence or the condition for data size is satisfied in various cases through a loop operation to determine the reference label for the plurality of UEs that satisfy the condition for RLF occurrence and the condition for data size. In one embodiment of the present disclosure, the electronic device may fail to determine (or select, identify) the reference label for the plurality of UEs that satisfy both the condition for RLF occurrence and the condition for data size. For example, the electronic device may perform at least some of the operations performed in step 470 of FIG. 4 described above, but may fail to determine the reference label for the plurality of UEs that satisfy the condition for RLF occurrence and the condition for data size.

[0216] In one embodiment of the present disclosure, the electronic device can identify (or determine) a failure in MAC context transfer based on a failure to determine reference labels of a plurality of UEs that satisfy conditions for RLF occurrence and conditions for data size. For example, the electronic device can identify (or determine) a failure in MAC context transfer by identifying that reference labels of a plurality of UEs that satisfy conditions for RLF occurrence and conditions for data size do not exist.

[0217] In one embodiment of the present disclosure, the electronic device may provide information indicating a failure of a MAC context transfer to another device or another module (400). For example, the other device may include an administrator client device or a user client device. In one embodiment of the present disclosure, the electronic device may output information indicating a failure of a MAC context transfer through an output device connected to, attached to, or built into the electronic device.

[0218] Referring to FIG. 8, the source DU (320) can identify (or determine) that the predicted RLF occurrence degree exceeds the RLF occurrence tolerance based on the MAC context transfer possible time (or, allowable MAC scheduling interruption time) and the RLF occurrence tolerance. For example, the source DU (320) can identify (or determine) that the conditions for RLF occurrence and the conditions for data size cannot be met based on the MAC context transfer possible time (or, allowable MAC scheduling interruption time) and the RLF occurrence tolerance. Accordingly, the source DU (320) can identify (or determine) (810) a failure of the MAC context transfer. Upon identifying (or in response to identifying) the failure of the MAC context transfer, the source DU (320) can provide (820) information indicating the failure of the MAC context transfer to another device or another module (400).

[0219] In one embodiment of the present disclosure, after a MAC context transfer failure, the electronic device can periodically or aperiodically identify (or determine) whether a transfer of a MAC context for which an RLF occurrence is expected to not exceed a tolerance for RLF occurrence is possible. For example, the electronic device can determine, at a predetermined cycle (e.g., a cycle that does not affect performance), whether a transfer of a MAC context for which an RLF occurrence is expected to not exceed a tolerance for RLF occurrence is possible. For example, the electronic device can periodically or aperiodically determine whether a transfer of a MAC context that satisfies a condition for RLF occurrence and a condition for data size is possible.

[0220] In one embodiment of the present disclosure, based on identifying (or determining) that a transfer of a MAC context in which an RLF occurrence is predicted to occur without exceeding an RLF occurrence tolerance is possible, an electronic device (e.g., an electronic device of a source DU (320)) may provide information indicating that the MAC context transfer is possible to another device or another module (400). For example, when a time point at which a transfer of a MAC context satisfying a condition for RLF occurrence is possible is reached, the electronic device may provide information indicating that the MAC context transfer is possible to another device or another module (400). For example, when identifying (or determining) that a transfer of a MAC context satisfying a condition for RLF occurrence and a condition for data size is possible is reached, the electronic device may provide information indicating that the MAC context transfer is possible to another device or another module (400).

[0221] In one embodiment of the present disclosure, based on identifying (or determining) that a transfer of a MAC context is possible in which an RLF occurrence is predicted to not exceed an RLF occurrence tolerance, an electronic device (e.g., an electronic device of a source DU (320)) may output information indicating the success of the transfer of the MAC context through an output device connected to, attached to, or built into the electronic device. For example, when identifying (or determining) that a transfer of a MAC context that satisfies a condition for RLF occurrence and a condition for data size is possible, the electronic device may output information indicating the success of the transfer of the MAC context through an output device connected to, attached to, or built into the electronic device.

[0222] In one embodiment of the present disclosure, based on identifying (or determining) that a transfer of a MAC context is possible in which an RLF occurrence is predicted to occur without exceeding an RLF occurrence tolerance, an electronic device (e.g., an electronic device of a source DU (320)) can resume (or retry) a target cell transfer or a MAC context transfer. For example, if identifying (or determining) that a transfer of a MAC context that satisfies a condition for RLF occurrence and a condition for data size is possible, the electronic device can resume (or retry) a target cell transfer or a MAC context transfer.

[0223] FIG. 9 is a drawing showing an example of an operating method of an electronic device according to one embodiment of the present disclosure.

[0224] In explaining Fig. 9, any explanation that overlaps with the explanation given above in any one of Figs. 1 to 8 may be omitted.

[0225] FIG. 9 may illustrate an example of an operating method (900) of an electronic device. In one embodiment of the present disclosure, the electronic device performing the method (900) may include a cell transfer module (e.g., a scaling agent module) that manages, controls, or processes cell transfer. In one embodiment of the present disclosure, the electronic device performing the method (900) may include a device of a source DU, a device of a target DU, and / or another separate device. For example, the source DU (or the device of the source DU) may include a cell transfer module. For example, the target DU (or the device of the target DU) may include a cell transfer module. For example, another device separate from the source DU and the target DU may include a cell transfer module.

[0226] Referring to FIG. 9, a method (900) according to one embodiment of the present disclosure may include steps 910 to 970. In one embodiment of the present disclosure, steps 910 to 970 of the method (900) may be executed by at least one processor included in an electronic device. The method (900) is not limited to that illustrated in FIG. 9, and in one or more embodiments, steps not illustrated in FIG. 9 may be further included, or some steps may be omitted.

[0227] In step 910, the electronic device may set a label for each of the plurality of MAC contexts. For example, the electronic device may set a label for each of the plurality of MAC contexts based on labeling information. For example, the MAC context corresponding to the highest importance among the plurality of labels (e.g., Label 3) may always be included in the previous target MAC context. In one embodiment of the present disclosure, the label set for each of the plurality of MAC contexts may indicate an importance based on the influence of the presence or absence of the MAC context corresponding to the label on UE traffic. For example, the label set for each of the plurality of MAC contexts may correspond to an importance based on the influence of each MAC context on UE traffic.

[0228] In step 920, the electronic device may identify the level of RLF occurrence tolerance. For example, the level of RLF occurrence tolerance may include conditions or levels regarding the level of RLF that may occur during the transfer process among UEs belonging to the transfer target cell.

[0229] At step 930, the electronic device can identify information about the target DU.

[0230] In step 940, the electronic device may determine a shortest duration during which an RLF associated with a MAC layer in the target cell can occur based on information about a plurality of UEs associated with the target cell.

[0231] At step 950, the electronic device may determine an allowable MAC scheduling outage time based on a shortest possible time for an RLF associated with the MAC layer in the target cell to occur.

[0232] At step 960, the electronic device can predict the maximum transmittable data size between the source DU and the target DU based on the information about the allowable MAC scheduling interruption time and the target DU.

[0233] In step 970, the electronic device determines a priority of one or more UEs among the plurality of UEs based on determining that the data size of the MAC contexts for the target cell exceeds the maximum transmittable data size, and may transfer some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label for each MAC context. For example, the MAC context for the target cell may include a MAC context for a first UE associated with the target cell and a MAC context for a second UE associated with the target cell. In one embodiment of the present disclosure, the electronic device may stop MAC scheduling of the source DU and transfer some of the data of the MAC contexts for the target cell from the source DU to the target DU.

[0234] In one embodiment of the present disclosure, an electronic device may determine the priority of one or more UEs based on at least one of RRC state information of a plurality of UEs or traffic information of one or more UEs. For example, the electronic device may identify one or more UEs in an RRC active state among a plurality of UEs based on the RRC state information of the plurality of UEs, and determine the priority of the one or more UEs in an RRC active state based on the traffic information of the one or more UEs.

[0235] In one embodiment of the present disclosure, an electronic device may determine a reference label for one or more UEs based on priorities of the one or more UEs. The electronic device may transfer data of a MAC context for a first UE, which corresponds to at least one of a first reference label for the first UE included in a plurality of UEs or a label having a higher priority than the first reference label, from a source DU to a target DU.

[0236] In one embodiment of the present disclosure, the electronic device may adjust a second reference label for a second UE included in a plurality of UEs and having a lower priority than the first UE, such that the predicted RLF occurrence degree does not exceed the allowed RLF occurrence degree and the data size of the previous target MAC context does not exceed the maximum transmittable data size. The electronic device may transfer data of the MAC context for the second UE corresponding to at least one of the second reference label or a label having a higher priority than the second reference label from the source DU to the target DU. For example, the priority of the first reference label for the first UE may be lower than the priority of the second reference label for the second UE.

[0237] In one embodiment of the present disclosure, the electronic device may determine a third reference label for a third UE included in a plurality of UEs in an RRC idle state or an RRC inactive state as a label predefined for the RRC idle state or the RRC inactive state. The electronic device may transfer data of a MAC context for the third UE corresponding to at least one of the third reference label for the third UE or a label having a higher priority than the third reference label from a source DU to a target DU.

[0238] In one embodiment of the present disclosure, the electronic device can transfer data of all MAC contexts for the target cell from a source DU to a target DU based on determining that the data size of the MAC contexts for the target cell is less than or equal to a maximum transmittable data size.

[0239] In one embodiment of the present disclosure, the electronic device can determine a previous failure of a MAC context based on determining that a predicted degree of RLF occurrence exceeds a permitted degree of RLF occurrence.

[0240] FIG. 10 is a drawing showing an example of an electronic device according to one embodiment of the present disclosure.

[0241] In explaining Fig. 10, any explanation that overlaps with the explanation given above in any one of Figs. 1 to 9 may be omitted.

[0242] The electronic device (1000) illustrated in FIG. 10 is an electronic device that performs a cell transfer operation for a DU, and may be a server device. For example, the electronic device (100) may be a communication device that constitutes a RAN, such as a server device that performs an RU function, a server device that performs a DU function, a server device that performs a CU function, a server device that performs an OAM function, or a server device that constitutes an existing RAN, or may be a separate server device that controls cell transfer (e.g., a scaling agent device, etc.).

[0243] In one embodiment of the present disclosure, the electronic device (1000) may include, but is not limited to, at least one processor (1010) and memory (1020).

[0244] The processor (1010) is electrically connected to the components included in the electronic device (1000) and can execute operations or data processing related to control and / or communication of the components included in the electronic device (1000). In one embodiment of the present disclosure, the processor (1010) can load and process requests, commands, or data received from at least one of the other components into a memory and store the processing result data in the memory. The processor (1010) is a component that controls a series of processes so that the electronic device (1000) operates according to the above-described embodiments, and may be configured with one or more processors.

[0245] One or more processors included in the processor (1010) may be circuitry such as a System on Chip (SoC), an Integrated Circuit (IC), etc. One or more processors included in the processor (1010) may include at least one of a general-purpose processor such as a central processing unit (CPU), a Micro Processor Unit (MPU), an application processor (AP), a Digital Signal Processor (DSP), a graphics-only processor such as a GPU (graphic processing unit) or a VPU (vision processing unit), an artificial intelligence-only processor such as an NPU (neural processing unit), or a communication-only processor such as a CP (communication processor). When one or more processors included in the processor (1010) are artificial intelligence-only processors, the artificial intelligence-only processor may be designed with a hardware structure specialized for processing a specific artificial intelligence model.

[0246] The processor (1010) may include various processing circuits and / or multiple processors. For example, the term "processor" as used in this disclosure, including the claims, may include various processing circuits including at least one processor. One or more of the at least one processor may be configured to perform one or more functions of the present disclosure, individually and / or collectively in a distributed manner. In this disclosure, when "processor," "at least one processor," or "one or more processors" is described as being configured to perform multiple functions, this may include situations where one processor performs some of the functions and other processor(s) perform other parts of the functions, and situations where a single processor performs all of the functions. Furthermore, the at least one processor may include a combination of processors that perform various functions in a distributed manner. The at least one processor may execute program instructions to achieve or perform various functions.

[0247] The processor (1010) can write data to the memory (1020) or read data stored in the memory (1020), and in particular, process data according to predefined operation rules or artificial intelligence models by executing a program or at least one instruction stored in the memory (1020). The processor (1010) can be controlled to process input data according to predefined operation rules, algorithms, methods, or models stored in the memory (1020). The processor (1010) can be controlled to process input data based on data stored in the memory (1020). The processor (1010) can perform operations of predefined operation rules, algorithms, methods, or models stored in the memory (1020) using the input data.

[0248] The memory (1020) is electrically connected to the processor (1010) and may store one or more modules, algorithms, operating rules, models, programs, instructions, or data related to the operation of components included in the electronic device (1000). For example, the memory (1020) may store one or more modules, algorithms, operating rules, models, programs, instructions, or data for processing and controlling the processor (1010).

[0249] The memory (1020) may be configured as a storage medium or a combination of storage media such as a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (e.g., SD or XD memory, etc.), a RAM (Random Access Memory), a SRAM (Static Random Access Memory), a ROM (Read-Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), a PROM (Programmable Read-Only Memory), a magnetic memory, a magnetic disk, an optical disk, etc., but is not limited thereto. The memory (1020) may not exist separately and may be configured to be included in the processor (1010). The memory (1020) may be configured as a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. A program or at least one instruction for performing operations according to the above-described embodiments may be stored in the memory (1020). The memory (1020) may also provide stored data to the processor (1010) at the request of the processor (1010).

[0250] In one embodiment of the present disclosure, the memory (1020) may store data or information identified, acquired, generated, or determined by the electronic device (1000). The memory (1020) may store data or information identified, acquired, generated, or determined by the electronic device (1000) in a compressed form.

[0251] Some modules (e.g., cell transfer modules) that perform at least one operation of the electronic device (1000) may be implemented as hardware modules, software modules, and / or a combination thereof. The memory (1020) may include software modules that perform at least some of the operations of the electronic device (1000) described above. In one embodiment of the present disclosure, the modules included in the memory (1020) may be executed by the processor (1010) to perform the operations. For example, the modules (i.e., software modules) included in the memory (1020) may include programs, models, or algorithms that are executed according to the control or command of the processor (1010) and are configured to perform operations that derive output data for input data. Some modules that perform at least one operation of the electronic device (1000) may be configured as a plurality of sub-modules or may constitute a single module.

[0252] The electronic device (1000) may include more components than those illustrated in FIG. 10. In one embodiment of the present disclosure, the electronic device (1000) may further include a communication interface (or communication module) for communicating with an external device. In one embodiment of the present disclosure, the electronic device (1000) may further include an input / output device and / or an input / output interface.

[0253] In one embodiment of the present disclosure, the electronic device (1000) may include a communication module for communicating with an external device. For example, the communication module of the electronic device (1000) may support establishing a wired or wireless communication channel with another external device or server and performing communication through the established communication channel. For example, the electronic device (1000) may communicate with devices constituting an existing RAN, such as a device performing an RU function, a device performing a DU function, a device performing a CU function, a device performing an OAM function, or a separate device controlling cell transfer (e.g., a scaling agent device, etc.) through the communication module.

[0254] In one embodiment of the present disclosure, the communication module may receive signals, information, requests, and / or data from another external electronic device or server via wired communication or wireless communication, or transmit signals, information, requests, and / or data to another external electronic device or server. According to one embodiment of the present disclosure, the communication module may include a wireless communication module (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module (e.g., a local area network (LAN) communication module, or a power line communication module), and may communicate with the external electronic device or server via at least one network, for example, a short-range communication network (e.g., Bluetooth, WiFi direct, or IrDA (infrared data association)) or a long-range communication network (e.g., a cellular network, the Internet, or a computer network (e.g., a LAN or a WAN)) using any one of the communication modules.

[0255] In one embodiment of the present disclosure, the electronic device (1000) can exchange signals, data, requests, and / or information with an external device via a network and communication module. For example, the electronic device (1000) and the external device can directly exchange signals, data, requests, and / or information, but this is not limited to the above. For example, the electronic device (1000) and the external device can also indirectly exchange signals, data, requests, and / or information via another device.

[0256] In any of FIGS. 1 to 10, the operations described as being performed by the electronic device may be performed by a cell transfer module of the electronic device. For example, the operations described as being performed by the electronic device may be performed by at least one processor of the electronic device.

[0257] In any of FIGS. 1 to 10, the operations described as being performed by the source DU may be performed by an electronic device that includes (or is configured with) the source DU. For example, the operations described as being performed by the source DU may be performed by at least one processor of the electronic device that includes (or is configured with) the source DU.

[0258] In any one of FIGS. 1 to 10, the operations described as being performed by the target DU may be performed by an electronic device in which the target DU is included (or set up). For example, the operations described as being performed by the target DU may be performed by at least one processor of the electronic device in which the target DU is included (or set up).

[0259] Any one or more of the embodiments described for the MAC layer in any of FIGS. 1 to 10 may also be applied to other units or layers.

[0260] In one embodiment of the present disclosure, a method of operating an electronic device may include a step of setting a label for each of a plurality of medium access control (MAC) contexts. In one embodiment of the present disclosure, the method may include a step of identifying a degree of tolerance for occurrence of a radio link failure (RLF). In one embodiment of the present disclosure, the method may include a step of identifying information about a target DU. In one embodiment of the present disclosure, the method may include a step of determining a shortest duration during which an RLF associated with a MAC layer in a target cell may occur, based on information about a plurality of user equipments (UEs) associated with the target cell. In one embodiment of the present disclosure, the method may include a step of determining an allowable MAC scheduling interruption time based on the shortest duration. In one embodiment of the present disclosure, the method may include a step of predicting a maximum transmittable data size between a source DU and the target DU, based on the allowable MAC scheduling interruption time and the information about the target DU. In one embodiment of the present disclosure, the method may include determining a priority of one or more UEs among the plurality of UEs based on determining that a data size of MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label.

[0261] In one embodiment of the present disclosure, an operating method of an electronic device may include a step of transferring data of all MAC contexts for the target cell from the source DU to the target DU based on determining that the data size of the MAC contexts for the target cell is less than or equal to the maximum transmittable data size.

[0262] In one embodiment of the present disclosure, the step of determining a priority of one or more UEs among the plurality of UEs based on determining that a data size of MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label may include the step of determining a priority of the one or more UEs based on at least one of radio resource control (RRC) state information of the plurality of UEs or traffic information of the one or more UEs.

[0263] In one embodiment of the present disclosure, the step of determining the priority of the one or more UEs based on at least one of RRC state information of the plurality of UEs or traffic information of the one or more UEs may include the step of identifying the one or more UEs in an RRC active state among the plurality of UEs based on the RRC state information of the plurality of UEs. In one embodiment of the present disclosure, the step of determining the priority of the one or more UEs based on at least one of RRC state information of the plurality of UEs or traffic information of the one or more UEs may include the step of determining the priority of the one or more UEs in an RRC active state based on the traffic information of the one or more UEs.

[0264] In one embodiment of the present disclosure, the step of determining a priority of one or more UEs among the plurality of UEs based on determining that a data size of MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label may include the step of determining a reference label for the one or more UEs based on the priority of the one or more UEs. In one embodiment of the present disclosure, the step of determining a priority of one or more UEs among the plurality of UEs based on determining that a data size of MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label may include the step of transferring data of a MAC context for the first UE corresponding to at least one of a first reference label for the first UE included in the plurality of UEs or a label having a higher importance than the first reference label from the source DU to the target DU.

[0265] In one embodiment of the present disclosure, the step of determining a reference label for the one or more UEs based on the priorities of the one or more UEs may include the step of adjusting a second reference label for a second UE included in the plurality of UEs and having a lower priority than the first UE such that a predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence and a data size of a transfer target MAC context does not exceed the maximum transmittable data size. In one embodiment of the present disclosure, the step of transferring data of a MAC context for the first UE corresponding to at least one of a first reference label or a label having a higher priority than the first reference label for the first UE included in the plurality of UEs from the source DU to the target DU may include the step of transferring data of a MAC context for the first UE corresponding to at least one of the first reference label or a label having a higher priority than the first reference label and data of a MAC context for the second UE corresponding to at least one of the second reference label or a label having a higher priority than the second reference label from the source DU to the target DU. In one embodiment of the present disclosure, the importance of the first reference label for the first UE may be lower than the importance of the second reference label for the second UE.

[0266] In one embodiment of the present disclosure, the step of determining a priority of one or more UEs among the plurality of UEs based on determining that a data size of MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label may include the step of determining a third reference label for a third UE included in the plurality of UEs in an RRC idle state or an RRC inactive state as a label predefined for the RRC idle state or the RRC inactive state. In one embodiment of the present disclosure, the step of determining a priority of one or more UEs among the plurality of UEs based on determining that a data size of MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label may include the step of transferring data of the MAC context for the third UE corresponding to at least one of a third reference label for the third UE or a label having a higher importance than the third reference label from the source DU to the target DU.

[0267] In one embodiment of the present disclosure, the step of determining a priority of one or more UEs among the plurality of UEs based on determining that a data size of MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label may include the step of stopping MAC scheduling of the source DU and transferring some of the data of the MAC contexts for the target cell from the source DU to the target DU.

[0268] In one embodiment of the present disclosure, a method of operating an electronic device may include a step of determining a previous failure of a MAC context based on determining that a predicted degree of RLF occurrence exceeds the allowed degree of RLF occurrence.

[0269] In one embodiment of the present disclosure, a label set for each of the plurality of MAC contexts may indicate an importance based on the influence that the presence or absence of a MAC context corresponding to the label has on UE traffic.

[0270] In one embodiment of the present disclosure, a computer-readable recording medium having recorded thereon a program for performing the above method on a computer may be provided.

[0271] In one embodiment of the present disclosure, an electronic device may include a memory storing one or more instructions and at least one processor executing the one or more instructions stored in the memory. In one embodiment of the present disclosure, the at least one processor may set a label for each of a plurality of medium access control (MAC) contexts by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor may identify a tolerable degree of occurrence of a radio link failure (RLF) by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor may identify information about a target DU by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor may determine a shortest time during which an RLF associated with a MAC layer in the target cell can occur based on information about a plurality of user equipments (UEs) associated with the target cell by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor may determine an allowable MAC scheduling interruption duration based on the shortest time by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor can predict a maximum transmittable data size between a source DU and the target DU based on the information about the allowable MAC scheduling interruption time and the target DU by executing the one or more instructions.In one embodiment of the present disclosure, the at least one processor may determine a priority of one or more UEs among the plurality of UEs based on determining that a data size of MAC contexts for the target cell exceeds the maximum transmittable data size by executing the one or more commands, and may transfer some of the data of the MAC contexts for the target cell from the source DU to the target DU based on the priority of the one or more UEs and the label.

[0272] In one embodiment of the present disclosure, the at least one processor may transfer data of all MAC contexts for the target cell from the source DU to the target DU based on determining that the data size of the MAC contexts for the target cell is less than or equal to the maximum transmittable data size.

[0273] In one embodiment of the present disclosure, the at least one processor may determine the priority of the one or more UEs based on at least one of radio resource control (RRC) state information of the plurality of UEs or traffic information of the one or more UEs.

[0274] In one embodiment of the present disclosure, the at least one processor can identify one or more UEs in an RRC active state among the plurality of UEs based on RRC state information of the plurality of UEs. In one embodiment of the present disclosure, the at least one processor can determine the priority of the one or more UEs in an RRC active state based on traffic information of the one or more UEs.

[0275] In one embodiment of the present disclosure, the at least one processor may determine a reference label for the one or more UEs based on priorities of the one or more UEs. In one embodiment of the present disclosure, the at least one processor may transfer data of a MAC context for the first UE, corresponding to at least one of a first reference label for the first UE included in the plurality of UEs or a label having a higher priority than the first reference label, from the source DU to the target DU.

[0276] In one embodiment of the present disclosure, the at least one processor may adjust a second reference label for a second UE included in the plurality of UEs and having a lower priority than the first UE, such that a predicted degree of RLF occurrence does not exceed the allowed degree of RLF occurrence and a data size of a previous target MAC context does not exceed the maximum transmittable data size. In one embodiment of the present disclosure, the at least one processor may transfer data of a MAC context for the first UE corresponding to at least one of the first reference label or a label having a higher priority than the first reference label and data of a MAC context for the second UE corresponding to at least one of the second reference label or a label having a higher priority than the second reference label from the source DU to the target DU. In one embodiment of the present disclosure, an importance of the first reference label for the first UE may be lower than an importance of the second reference label for the second UE.

[0277] In one embodiment of the present disclosure, the at least one processor may determine a third reference label for a third UE included in the plurality of UEs in an RRC idle state or an RRC inactive state as a label predefined for the RRC idle state or the RRC inactive state. In one embodiment of the present disclosure, the at least one processor may transfer data of a MAC context for the third UE corresponding to at least one of the third reference label for the third UE or a label having a higher priority than the third reference label from the source DU to the target DU.

[0278] In one embodiment of the present disclosure, the at least one processor may stop MAC scheduling of the source DU and transfer some of the data of the MAC contexts for the target cell from the source DU to the target DU.

[0279] In one embodiment of the present disclosure, the at least one processor may determine a previous failure of the MAC context based on determining that the predicted degree of RLF occurrence exceeds the allowed degree of RLF occurrence.

[0280] A device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, the term "non-transitory storage medium" simply means a tangible device that does not contain signals (e.g., electromagnetic waves). This term does not distinguish between cases where data is permanently stored in the storage medium and cases where data is temporarily stored. For example, a "non-transitory storage medium" may include a buffer in which data is temporarily stored.

[0281] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

Claims

1. In the method of operating an electronic device, A step of setting a label for each of multiple MAC (medium access control) contexts; Step for identifying the tolerance level of RLF (radio link failure) occurrence; Step of identifying information about target DU (330); A step of determining the shortest time (duration) during which an RLF associated with a MAC layer in a target cell can occur based on information about a plurality of user equipment (UEs) associated with the target cell; A step of determining an allowable MAC scheduling interruption time based on the above shortest time; A step of predicting the maximum transmittable data size between the source DU (320) and the target DU (330) based on the allowable MAC scheduling interruption time and information about the target DU (330); and A method comprising: determining a priority of one or more UEs among the plurality of UEs based on determining that the data size of the MAC contexts for the target cell exceeds the maximum transmittable data size; and transferring some of the data of the MAC contexts for the target cell from the source DU (320) to the target DU (330) based on the priority of the one or more UEs and the label.

2. In paragraph 1, A method comprising the step of transferring data of all MAC contexts for the target cell from the source DU (320) to the target DU (330) based on determining that the data size of the MAC contexts for the target cell is less than or equal to the maximum transmittable data size.

3. In paragraph 1 or 2, A step of determining a priority of one or more UEs among the plurality of UEs based on determining that the data size of the MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU (320) to the target DU (330) based on the priority of the one or more UEs and the label, A method comprising a step of determining a priority of one or more UEs based on at least one of RRC (radio resource control) state information of the plurality of UEs or traffic information of the one or more UEs.

4. In paragraph 3, The step of determining the priority of one or more UEs based on at least one of RRC state information of the plurality of UEs or traffic information of the one or more UEs is as follows: A step of identifying at least one UE in an RRC active state among the plurality of UEs based on RRC state information of the plurality of UEs; and A method comprising the step of determining a priority of one or more UEs in an RRC active state based on traffic information of the one or more UEs.

5. In any one of paragraphs 1 to 4, A step of determining a priority of one or more UEs among the plurality of UEs based on determining that the data size of the MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU (320) to the target DU (330) based on the priority of the one or more UEs and the label, A step of determining a reference label for one or more UEs based on the priorities of the one or more UEs; and A method comprising the step of transferring data of a MAC context for a first UE corresponding to at least one of a first reference label for the first UE included in the plurality of UEs or a label having a higher priority than the first reference label from the source DU (320) to the target DU (330).

6. In paragraph 5, The step of determining a reference label for the one or more UEs based on the priorities of the one or more UEs is: Including a step of adjusting a second reference label for a second UE included in the plurality of UEs and having a lower priority than the first UE, such that the predicted RLF occurrence degree does not exceed the RLF occurrence allowable degree and the data size of the previous target MAC context does not exceed the maximum transmittable data size; The step of transferring data of a MAC context for the first UE corresponding to at least one of a first reference label for the first UE included in the plurality of UEs or a label having a higher priority than the first reference label from the source DU (320) to the target DU (330) is as follows. A step of transferring data of a MAC context for the first UE corresponding to at least one of the first reference label or a label having a higher importance than the first reference label and data of a MAC context for the second UE corresponding to at least one of the second reference label or a label having a higher importance than the second reference label from the source DU (320) to the target DU (330), A method wherein the importance of the first reference label for the first UE is lower than the importance of the second reference label for the second UE.

7. In any one of paragraphs 1 to 6, A step of determining a priority of one or more UEs among the plurality of UEs based on determining that the data size of the MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU (320) to the target DU (330) based on the priority of the one or more UEs and the label, A step of determining a third reference label for a third UE in an RRC idle state or an RRC inactive state included in the plurality of UEs as a label predefined for the RRC idle state or the RRC inactive state; and A method comprising the step of transferring data of a MAC context for the third UE corresponding to at least one of a third reference label for the third UE or a label having a higher importance than the third reference label from the source DU (320) to the target DU (330).

8. In any one of paragraphs 1 to 7, A step of determining a priority of one or more UEs among the plurality of UEs based on determining that the data size of the MAC contexts for the target cell exceeds the maximum transmittable data size, and transferring some of the data of the MAC contexts for the target cell from the source DU (320) to the target DU (330) based on the priority of the one or more UEs and the label, A method comprising the step of stopping MAC scheduling of the source DU (320) and transferring some of the data of MAC contexts for the target cell from the source DU (320) to the target DU (330).

9. In any one of paragraphs 1 to 8, A method comprising the step of determining a previous failure of a MAC context based on determining that the predicted degree of RLF occurrence exceeds the allowed degree of RLF occurrence.

10. In any one of paragraphs 1 to 9, A method in which a label set for each of the above plurality of MAC contexts indicates importance based on the influence that the presence or absence of a MAC context corresponding to the label has on UE traffic.

11. A computer-readable recording medium having recorded thereon a program for performing the method of any one of claims 1 to 10 on a computer.

12. In an electronic device (1000), A memory (1020) storing one or more instructions; and At least one processor (1010) for executing one or more instructions stored in the memory (1020), The at least one processor (1010) executes the one or more instructions, Set a label for each of the multiple MAC (medium access control) contexts, Identify the tolerance level of RLF (radio link failure) occurrence, Identify information about the target DU (330), Based on information about multiple UEs (user equipment) associated with a target cell, the shortest time during which an RLF associated with a MAC layer can occur in the target cell is determined, Based on the above shortest time, determine the allowable MAC scheduling interruption time (duration), Based on the above allowable MAC scheduling interruption time and information about the target DU (330), the maximum transmittable data size between the source DU (320) and the target DU (330) is predicted, An electronic device, which determines the priority of one or more UEs among the plurality of UEs based on determining that the data size of the MAC contexts for the target cell exceeds the maximum transmittable data size, and transfers some of the data of the MAC contexts for the target cell from the source DU (320) to the target DU (330) based on the priority of the one or more UEs and the label.

13. In paragraph 12, At least one processor (1010) above, An electronic device that transfers data of all MAC contexts for the target cell from the source DU (320) to the target DU (330) based on determining that the data size of the MAC contexts for the target cell is less than or equal to the maximum transmittable data size.

14. In paragraph 12 or 13, At least one processor (1010) above, An electronic device that determines the priority of one or more UEs based on at least one of RRC (radio resource control) state information of the plurality of UEs or traffic information of the one or more UEs.

15. In any one of paragraphs 12 to 14, At least one processor (1010) above, Based on the priorities of the one or more UEs, a reference label for the one or more UEs is determined, An electronic device that transfers data of a MAC context for a first UE corresponding to at least one of a first reference label for the first UE included in the plurality of UEs or a label having a higher priority than the first reference label from the source DU (320) to the target DU (330).

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