Method and electronic device for performing migration operation for distributed unit (DU) scaling

Abstract

This method performed by an electronic device may comprise the steps of: migrating, to a second distributed unit (DU), a cell context for a target cell included in a first DU; configuring a connection between an RLC layer of the first DU and a MAC layer of the second DU with respect to the target cell, and migrating, to an RLC layer of the second DU, a user equipment (UE) context for a target UE from among UE contexts for a plurality of UEs associated with the target cell, included in the RLC layer of the first DU; and switching an F1-U interface for the target UE from the first DU to the second DU, and configuring a connection between the RLC layer and the MAC layer of the second DU for the target UE.

Description

Method and electronic device for performing the previous operation for DU(DISTRIBUTED UNIT) scaling

[0001] The present disclosure relates to a method and an electronic device for performing a previous operation for DU (distributed unit) scaling.

[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 performed by an electronic device may include a step of migrating a cell context for a target cell included in at least one of a radio link control (RLC) layer, a medium access control (MAC) layer, or a physical (PHY) layer of a first distributed unit (DU) to at least one of an RLC layer, a MAC layer, or a PHY layer of a second DU. In one embodiment of the present disclosure, the method may include a step of configuring a connection between an RLC layer of the first DU and a MAC layer of the second DU for the target cell, and identifying that a communication state of the target cell is a communication-capable state. In one embodiment of the present disclosure, the method may include a step of migrating a UE context for at least one target UE among a plurality of UE contexts for the target cell included in an RLC layer of the first DU, to an RLC layer of the second DU. In one embodiment of the present disclosure, the method may include switching an F1-U interface for the one or more target UEs from a first DU to a second DU, and establishing a connection between an RLC layer and a MAC layer of the second DU for the one or more target UEs.

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

[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 transfer a cell context for a target cell included in at least one of an RLC layer, a MAC layer, or a PHY layer of a first DU to at least one of an RLC layer, a MAC layer, or a PHY layer of a second DU by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor may establish a connection between an RLC layer of the first DU and a MAC layer of the second DU for the target cell, and identify that the communication state of the target cell is a communication-capable state by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor may transfer a UE context for one or more target UEs among UE contexts for a plurality of UEs associated with the target cell included in the RLC layer of the first DU to the RLC layer of the second DU by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor can switch the F1-U interface for the one or more target UEs from the first DU to the second DU by executing the one or more commands, and establish a connection between the RLC layer and the MAC layer of the second DU for the one or more target UEs.

[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 diagram illustrating an example of performing DU scaling in a radio access network (RAN) according to one embodiment of the present disclosure.

[0009] FIG. 3 is a diagram illustrating an example of performing DU scaling out in a RAN according to one embodiment of the present disclosure.

[0010] FIG. 4 is a diagram illustrating an example of an electronic device determining scaling out for a first DU according to one embodiment of the present disclosure.

[0011] FIGS. 5 to 7 are diagrams illustrating an example of an electronic device performing cell transfer for DU scaling out according to one embodiment of the present disclosure.

[0012] FIG. 8 is a diagram illustrating an example of performing DU scaling in a RAN according to one embodiment of the present disclosure.

[0013] FIG. 9 is a flowchart illustrating an example of a method for performing a cell transfer operation for a DU according to one embodiment of the present disclosure.

[0014] FIG. 10 is a flowchart illustrating an example of a method for performing a cell transfer operation for a DU according to one embodiment of the present disclosure.

[0015] FIG. 11 is a diagram illustrating an example of an electronic device performing a cell transfer operation for a DU according to one embodiment of the present disclosure.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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).

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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)" can refer to "a", "b", "c", "a and b", "a and c", "b and c", "all of a, b, and c", or variations thereof.

[0024] In one embodiment of the present disclosure, the term "transfer" may include moving, copying, duplicating, or synchronizing previous target information contained in any space to another space. In one embodiment of the present disclosure, the term "transfer" 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" 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).

[0025] In one embodiment of the present disclosure, a "cell transfer" may include transferring at least one of a context associated with a cell or an interface associated with a cell. For example, a "cell transfer" may include transferring a cell context. For example, a "cell transfer" may be a cell-by-cell transfer, and may include transferring a cell context and a UE context of a user equipment (UE) associated with the cell. In one embodiment of the present disclosure, a "UE transfer" may be a UE-by-UE transfer, and may include transferring a UE context. In one embodiment of the present disclosure, a "UE transfer" may include transferring an interface for user data (e.g., an F1-U interface).

[0026] 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.

[0027] In one embodiment of the present disclosure, “configure” may include the meaning of “create,” “activate,” “connect,” “establish,” or “initiate.”

[0028] In one embodiment of the present disclosure, “releasing” may include “removing,” “deactivating,” “stopping / suspending,” or “disconnecting.”

[0029] In one embodiment of the present disclosure, “module A performing operation B” may include “module A directly performing operation B” or “module A controls module C to perform operation B.”

[0030] In one embodiment of the present disclosure, a “UE associated with a cell” may include a UE connected to a cell, a UE communicating with an RU including a cell (i.e., transmitting and receiving data), a UE receiving communication services through a cell, a UE transmitting and receiving data through a cell, a UE accessing a core network through a cell, a UE included in the range of a cell, a UE requesting radio resources of a cell, or a UE allocated radio resources of a cell.

[0031] In one embodiment of the present disclosure, "interface" may include the meaning of a module that enables data transmission and reception. In one embodiment of the present disclosure, "interface" may include the meaning of a connection relationship. In one embodiment of the present disclosure, "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 and process the received data.

[0032] 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).

[0033] 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).

[0034] FIG. 1 is a diagram showing an example of a wireless communication system structure according to one embodiment of the present disclosure.

[0035] 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.

[0036] In one embodiment of the present disclosure, the RAN (120) may include at least one RU (Radio Unit) (128_1, 128_2, 128_3, 128_4, 128_5, 128_6), at least one DU (Distributed Unit) (124_1, 124_2, 124_3, 124_4), and a CU (centralized unit) (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), 4GS, or other wireless communication system, and may also refer to a wireless communication system to be developed in the future.

[0037] 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 QoS (Quality of Service) setting, packet reordering, and security setting and processing. For example, the CU (122) may mean a vCU (virtualized-CU) of a vRAN system, but is not limited thereto.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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 scaling in DUs according to current traffic conditions. 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).

[0048] 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).

[0049] 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, when 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).

[0050] 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 the 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 migrated 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).

[0051] 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 migrated 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 migrated 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 migrated 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).

[0052] FIG. 2 is a diagram illustrating an example of performing DU scaling in a radio access network (RAN) according to one embodiment of the present disclosure.

[0053] The OAM module (210) can determine scaling out or scaling in for the first DU (240). In one embodiment of the present disclosure, the OAM module (210) can determine scaling out, which adds a new DU to the DU pool including the first DU (240). In one embodiment of the present disclosure, the OAM module (210) can determine scaling in, which removes the first DU (240) from the DU pool including the first DU (240).

[0054] The OAM module (210) may generate a second DU (250) as it determines scaling out for the first DU (240) (212). In one embodiment of the present disclosure, the OAM module (210) may configure a new DU, the second DU (250), in the DU pool including the first DU (240). In one embodiment of the present disclosure, the OAM module (210) may activate a deactivated second DU (250). In one embodiment of the present disclosure, the OAM module (210) may configure the second DU (250) in an existing operating server device. In one embodiment of the present disclosure, the OAM module (210) may initiate operation of an additional server device and configure the second DU (250) in the additional server device.

[0055] The OAM module (210) can transfer a target cell associated with the first DU (240) to the second DU (250). The OAM module (210) can configure a connection between the second DU (250) and the CU (220). In one embodiment of the present disclosure, the OAM module (210) can register the second DU (250) with the mid-haul splitter module (230) for the CU (220) (214). For example, the OAM module (210) can configure (or create) a mid-haul interface for connecting the second DU (250) and the CU (220). In FIG. 2, the mid-haul splitter module (230) is illustrated as a separate module from the CU (220), but is not limited thereto. For example, a mid-hole splitter module (230) may be included in the CU (220).

[0056] The OAM module (210) can configure a connection between the second DU (250) and the RU (270). In one embodiment of the present disclosure, the OAM module (210) can register the second DU (250) with the fronthaul splitter module (260) for the RU (270) (216). For example, the OAM module (210) can configure (or create) a fronthaul interface for connecting the second DU (250) and the RU (270). In FIG. 2, the fronthaul splitter module (260) is illustrated as a separate module from the RU (270), but is not limited thereto. For example, the fronthaul splitter module (260) can be included in the RU (270).

[0057] The OAM module (210) can transfer contexts included in the first DU (240) to the second DU (250) (218). The contexts included in the DU can include system information, scheduling context, control information, frequency resource information, spatial resource information, UE context, and RU context. In one embodiment of the present disclosure, the OAM module (210) can transfer cell context and UE context for a target cell to the second DU (250). For example, the OAM module (210) can synchronize the cell context and UE context of the first DU (240) to the second DU (250).

[0058] While the target cell is being transferred from the first DU (240) to the second DU (250), UEs associated with the target cell may be disconnected from the wireless communication system. For example, while the fronthaul interface is being transferred, UEs associated with the cell may not be provided with communication services through the target cell. If the transfer time of the fronthaul interface is long, i.e., if the time that the UEs associated with the target cell are disconnected from the wireless communication system exceeds a reference time, the UEs associated with the target cell may search for other cells and perform connection operations, and a large amount of computing resources may be used in the process of the UEs searching for other cells and connecting. Therefore, a cell transfer method may be required that ensures that the time that the UEs associated with the target cell are disconnected from the wireless communication system does not exceed the reference time. The reference time may be a short time that the UE user cannot recognize the disconnection from the communication system. The reference time may be a time determined by the mobile carrier.

[0059] In one embodiment of the present disclosure, the OAM module (210) can quickly switch over the target cell from the first DU (240) to the second DU (250) within a predetermined time (e.g., a reference time). For example, the OAM module (210) can simultaneously transfer all cell contexts and UE contexts included in the midhaul interface, the fronthaul interface, and each layer of the first DU (240) from the first DU (240) to the second DU (250) within a predetermined time. That is, the OAM module (210) can simultaneously perform the above-described operations (214, 216, 218) for cell transfer within a predetermined time. In this case, the transfer operation timings of all modules associated with the transfer operation must be synchronized, and if the synchronization of the operation timings is not guaranteed, it may cause overall system instability. In addition, transferring a large amount of data at once within a predetermined time may be difficult to implement in practice in the system.

[0060] In one embodiment of the present disclosure, the OAM module (210) can transfer a target cell from the first DU (240) to the second DU (250) on a UE-by-UE basis. For example, the OAM module (210) can transfer a plurality of UEs included in the target cell from the first DU (240) to the second DU (250) on a UE-by-UE basis. In this case, while the target cell is being transferred, the first UE of the target cell is connected to the first DU (240) and data of the first UE is processed by the first DU (240), and the second UE of the target cell is connected to the second DU (250) and data of the second UE is processed by the second DU (250). Therefore, referring to FIG. 2, the RU (270) can be connected to both the first DU (240) and the second DU (250) via the fronthaul splitter module (260) to transmit and receive data.

[0061] When transferring the target cell on a UE-by-UE basis, the fronthaul splitter module (260) can transmit data from the first UE to the first DU (240) and data from the second UE to the second DU (250). For example, when transmitting data of the first UE to the first DU (240) or data from the first DU (240) to the RU (270), the fronthaul interface between the first DU (240) and the RU (270) can be activated, and when transmitting data of the second UE to the second DU (250) or data from the second DU (250) to the RU (270), the fronthaul interface between the second DU (250) and the RU (270) can be activated. Therefore, in order to process data of multiple UEs associated with a target cell, the fronthaul splitter module (260) must quickly switch the path (or interface activation) between DU-RUs, and for high-speed switching, the fronthaul splitter module (260) may require a large amount of computing resources. In addition, high-speed switching may degrade system stability and cause operational instability.

[0062] In addition, when moving a target cell on a UE basis, the first DU (240) and the second DU (250) are connected to one RU (240) until the moving of the target cell is completed, and the MAC layer of the first DU (240) and the MAC layer of the second DU (250) can schedule the radio resources of the target cell simultaneously. Therefore, the implementation complexity in the system may increase, and the system stability may decrease.

[0063] One or more of the operations described as being performed by a module or unit in FIG. 2 may be performed by an electronic device (or at least one processor of the electronic device) including the module or unit.

[0064] FIG. 3 is a diagram illustrating an example of performing DU scaling out in a RAN according to one embodiment of the present disclosure.

[0065] The OAM module (310) may determine scaling out for the first DU (350). For example, the OAM module (310) may determine scaling out by adding a new DU to the DU pool including the first DU (350). In one embodiment of the present disclosure, the OAM module (310) may identify that scaling out is required for the first DU (350) based on information about the first DU (350). For example, the OAM module (310) may determine scaling out for the first DU (350) based on traffic of the first DU (350), processing capacity of the first DU (350) (e.g., maximum amount of available resources), current available resources of the first DU (350) (e.g., remaining amount of resources), etc.

[0066] The OAM module (310) may initiate (312) a second DU (360). In one embodiment of the present disclosure, the OAM module (310) may initiate the second DU (360) by creating the second DU (360). In one embodiment of the present disclosure, the OAM module (310) may configure the second DU (360), which is a new DU. In one embodiment of the present disclosure, the OAM module (310) may initiate the second DU (360) by activating an inactive second DU (360). In one embodiment of the present disclosure, the OAM module (310) may configure the second DU (360) in an existing operating server device. In one embodiment of the present disclosure, the OAM module (310) may initiate an additional server device to operate and configure the second DU (360) in the additional server device.

[0067] The OAM module (310) can configure a connection between the second DU (360) and the CU (330). For example, the OAM module (310) can configure a mid-hole interface for connecting the second DU (360) and the CU (330). For example, the OAM module (310) can generate a mid-hole interface for connecting the generated second DU (360) and the CU (330). As illustrated in FIG. 3, the CU (330) can be connected to multiple DUs, i.e., the first DU (350) and the second DU (360), through a mid-hole splitter module (340) and multiple mid-hole interfaces.

[0068] The OAM module (310) can transmit information about a scaling-out decision for the first DU (350) to the scaling agent module (320) that manages / processes DU scaling or cell transfer. In one embodiment of the present disclosure, the OAM module (310) can instruct the scaling agent module (320) to perform a transfer operation from the first DU (350) to the second DU (360) for scaling out. For example, the OAM module (310) can provide the scaling agent module (320) with information necessary to perform the transfer operation.

[0069] The scaling agent module (320) can identify a scaling-out decision for the first DU (350) and perform a cell transfer operation from the first DU (350) to the second DU (360). In one embodiment of the present disclosure, the scaling agent module (320) can control at least one of the first DU (350), the second DU (360), the RU (370), or an inter-unit interface as the cell transfer operation. For example, the scaling agent module (320) can transmit a command to at least one of the first DU (350), the second DU (360), or the RU (370). For example, the scaling agent module (320) may control at least a portion of the RLC layer (352), the MAC layer (354), the PHY layer (356) of the first DU (350), the RLC layer (362), the MAC layer (364), or the PHY layer (366) of the second DU (360).

[0070] The scaling agent module (320) can identify a target cell to be transferred from the first DU (350) to the second DU (360). In one embodiment of the present disclosure, the target cell may be selected from one or more cells associated with the first DU (350) by the scaling agent module (320) or the OAM module (310), but is not limited thereto. For example, the target cell may be selected based on information about the first DU (350) (e.g., processing capacity, remaining resources, traffic, etc.), information about the second DU (360), information about each cell associated with the first DU (350) (e.g., traffic), etc. For example, the target cell may be randomly selected from one or more cells associated with the first DU (350).

[0071] The scaling agent module (320) may transfer a context associated with a target cell from the first DU (350) to the second DU (360) for scaling out (322). For example, the scaling agent module (320) may control at least one of the first DU (350) or the second DU (360) to transfer the context associated with the target cell from the first DU (350) to the second DU (360). The context associated with the target cell may include a cell context for the target cell itself and a UE context for a UE associated with the target cell. In one embodiment of the present disclosure, the scaling agent module (320) can transfer a context associated with a target cell included in at least one of the RLC layer (352), the MAC layer (354), or the PHY layer (356) of the first DU (350) to at least one of the RLC layer (362), the MAC layer (364), or the PHY layer (366) of the second DU (360).

[0072] The scaling agent module (320) can switch the fronthaul interface between the RU (370) and the DU from the first DU (350) to the second DU (360) for the target cell (324). For example, the scaling agent module (320) can control at least one of the first DU (350), the second DU (360), or the RU (370) to switch the fronthaul interface from the first DU (350) to the second DU (360) for the target cell. In one embodiment of the present disclosure, the scaling agent module (320) can release the fronthaul interface between the first DU (350) and the RU (370) for the target cell, and establish the fronthaul interface between the second DU (360) and the RU (370). That is, the RU (370) can be connected to one DU for the target cell through the fronthaul interface. Accordingly, the RAN of FIG. 3 may not include a fronthaul splitter module for providing multiple fronthaul interfaces between the RU (370) and multiple DUs for the target cell.

[0073] Meanwhile, in one embodiment of the present disclosure, an RU (370) may be connected to one DU for a target cell, but an RU associated with multiple cells may be connected to a first DU for a first cell and a second DU for a second cell. That is, an RU may be connected to multiple DUs through multiple fronthaul interfaces on a cell-by-cell basis. Furthermore, in one embodiment of the present disclosure, one DU may be connected to multiple RUs through multiple fronthaul interfaces.

[0074] The specific operations of the scaling agent module (320) for transferring the context associated with the target cell (322) and switching the fronthaul interface (324) to transfer the target cell from the first DU (350) to the second DU (360) can be described later with reference to FIGS. 5 to 7.

[0075] Although FIG. 3 illustrates a scaling agent module (320) and an OAM module (310), the present invention is not limited thereto. For example, the scaling agent module (320) and the OAM module (310) are one and the same module and can perform the functions and operations of the scaling agent module (320) and the OAM module (310) described above.

[0076] Each module and unit of FIG. 3 may be a software module, a hardware module, and / or a combination thereof. For example, the first DU (350) and the second DU (360) may be software modules, and may be included / stored and executed on a single piece of hardware. For example, the first DU (350) and the second DU (360) may be included / stored and executed on different pieces of hardware.

[0077] One or more of the operations described as being performed by a module or unit in FIG. 3 may be performed by an electronic device (or at least one processor of the electronic device) including the module or unit.

[0078] FIG. 4 is a diagram illustrating an example of an electronic device determining scaling out for a first DU according to one embodiment of the present disclosure.

[0079] FIG. 4 may illustrate an example of a RAN before a target cell is transferred. Referring to FIG. 4, one or more UEs (450) may be connected (or connected, included, or attached) to an RU (380). For example, one or more UEs (450) may be connected (or connected, included, or attached) to a target cell of the RU (380) and may perform data communication through the target cell. For example, one or more UEs (450) may be wirelessly connected to the RU (380) and may exchange information, data, packets, signals, etc. with the RAN. For example, one or more UEs (450) may be connected (or connected, included, or attached) to a target cell of the RU (380) and may be connected (or connected, included, or attached) to a core network through the RU (380), the first DU (350), and the CU (330).

[0080] In one embodiment of the present disclosure, the CU (330) may include a PDCP layer (410), and the PDCP layer (410) may include UE contexts (412_1, 412_2, 412_3) for one or more UEs (450). For example, UE contexts (412_1, 412_2, 412_3) for one or more UEs (450) may be configured in the PDCP layer (410). The UE contexts (412_1, 412_2, 412_3) for one or more UEs (450) may include one or more radio bearers (RBs). As illustrated in FIG. 4, the UE context (412_1) for a first UE may include multiple RBs. The number of RBs may correspond to the number of applications and services running on the UE.

[0081] In one embodiment of the present disclosure, the first DU (350) may include an RLC layer (352), a MAC layer (354), and a high-physical (H-PHY) layer (356). The RLC layer (352) may include UE contexts (440_1, 440_2, 440_3) for one or more UEs (450). For example, UE contexts (440_1, 440_2, 440_3) for one or more UEs (450) may be configured in the RLC layer (352). The UE contexts (440_1, 440_2, 440_3) for one or more UEs (450) may include one or more radio bearers (RBs). One or more RBs may include a buffer. As illustrated in FIG. 4, the UE context (440_1) for the first UE may include multiple RBs.

[0082] The CU (330) may be connected to the first DU (350) via a mid-hole interface (i.e., an F1 interface). In one embodiment of the present disclosure, the CU (330) includes an F1 message handler module (420), the first DU (350) includes an F1 message handler module (430), and the CU (330) and the first DU (350) may be connected via the F1 message handler modules (420, 430) and the mid-hole splitter module (340). For example, the F1-C interface between the CU (330) and the first DU (350) may be formed via the F1 message handler modules (420, 430) and the mid-hole splitter module (340).

[0083] The mid-hole splitter module (340) can transmit F1 messages received from multiple DUs to the CU (330) and distribute the F1 messages received from the CU (330) to the multiple DUs. The F1 message handler modules (420, 430) can process the F1 messages input through the mid-hole splitter module (340). The F1 messages can include information, data, signals, packets, etc. that are transmitted and received between the DU and the CU (330). For example, the F1 message can include control information.

[0084] In one embodiment of the present disclosure, the CU (330) and the first DU (350) can directly transmit and receive user data to and from each other without going through the mid-haul splitter module (340). For example, the PDCP layer (410) of the CU (330) and the RLC layer (352) of the first DU (350) can directly communicate user data through the F1-U interface. Therefore, inefficient use of network resources by the mid-haul splitter module (340) can be prevented. As illustrated in FIG. 4, the F1-U interface (or F1-U path) can provide user data communication between the PDCP layer (410) of the CU (330) and the RLC layer (352) of the first DU (350) without going through the mid-haul splitter module (340).

[0085] In one embodiment of the present disclosure, multiple F1-U interfaces may be configured (or established, created) for a single UE. For example, the number of F1-U interfaces for a single UE may be equal to the number of RBs configured for the UE. For example, an F1-U interface may be configured for each RB between a CU (330) (e.g., a PDCP layer (410)) and a first DU (350) (e.g., an RLC layer (352)).

[0086] Referring to FIG. 4, before the cell is transferred from the first DU (350) to the second DU (360), a fronthaul interface may be set (or established, created) between the RU (380) and the first DU (350), so as to perform processing for communication between the RU (380) and the first DU (350). That is, the RU (380) may be connected to the first DU (350) (e.g., H-PHY layer (356)) via the fronthaul interface. In one embodiment of the present disclosure, the RU (380) and the first DU (350) (e.g., H-PHY layer (356)) may transmit and receive information, data, packets, signals, etc. to and from each other via the fronthaul interface.

[0087] In one embodiment of the present disclosure, an electronic device (e.g., a device on which an OAM module is executed) may determine scaling out for a first DU (350). For example, the electronic device may determine scaling out from the first DU (350) to a new DU, a second DU (360), and generate (or form, initiate, activate) the second DU (360). The second DU (360) may include an RLC layer (362), a MAC layer (364), and an H-PHY layer (366). As illustrated in FIG. 4, the first DU (350) and the second DU (360) may be connected via an inter-DU interface (e.g., an Xd interface).

[0088] In one embodiment of the present disclosure, the electronic device can generate a second DU (360) and set (or establish, create) a mid-hole interface (510) between the second DU (360) and the CU (330). The mid-hole interface (510) between the second DU (360) and the CU (330) is set via a mid-hole splitter module (340) and can perform processing for communication between the second DU (360) and the CU (330).

[0089] FIGS. 5 to 7 are diagrams illustrating an example of an electronic device performing cell transfer for DU scaling out according to one embodiment of the present disclosure.

[0090] The electronic device performing the operations described below in FIGS. 5 to 7 may be a different device from or the same as the electronic device performing the operations described above in FIG. 4. FIGS. 5 and 6 illustrate an example of an electronic device (e.g., a device executing a scaling agent module) transferring a cell context and fronthaul interface to a target cell, according to one embodiment of the present disclosure.

[0091] The electronic device can identify a scaling out decision for the first DU (350). In one embodiment of the present disclosure, the electronic device can identify a scaling out decision from the first DU (350) to the second DU (360) of the OAM module. The electronic device can identify a target cell to be transferred from the first DU (350) to the second DU (360). In one embodiment of the present disclosure, the electronic device can identify a target cell determined as a transfer target by the OAM module. In one embodiment of the present disclosure, the electronic device can determine the target cell from among cells associated (or included, connected) with the first DU (350). The cells associated with the first DU (350) can include cells of an RU (380) connected with the first DU (350).

[0092] Referring to FIG. 5, the first DU (350) may include cell contexts (520, 530, 540) for a target cell. The cell contexts (520, 530, 540) for the target cell may include configuration information regarding a frequency band of the target cell, a radio resource scheduling method, a common signal transmitted to one or more UEs (450) associated with the target cell, etc. One or more UEs (450) associated with the target cell may have a connection established and managed based on the cell context for the target cell. The one or more UEs (450) associated with the target cell may include a UE included in the effective range of the target cell, a UE connected to the target cell, a UE attached to the target cell, a UE provided with a communication service through the target cell, a UE accessing a network through the target cell, etc. The cell contexts included in each of the RLC layer (352), MAC layer (354), and H-PHY layer (356) of the first DU (350) may be different from each other, partially different, or identical to each other.

[0093] An electronic device can transfer a target cell from a first DU (350) to a second DU (360). Referring to FIG. 5, the electronic device can transfer a cell context (520, 530, 540) for a target cell included in the first DU (350) to the second DU (360). In one embodiment of the present disclosure, the electronic device can transfer a cell context (520, 530, 540) for a target cell included in at least one of an RLC layer (352), a MAC layer (354), or an H-PHY layer (356) of the first DU (350) to at least one of an RLC layer (362), a MAC layer (364), or an H-PHY layer (366) of the second DU (360). For example, the electronic device can transfer a cell context (520) included in the RLC layer (352) of the first DU (350) to the RLC layer (362) of the second DU (360). For example, the electronic device can transfer a cell context (530) included in the MAC layer (354) of the first DU (350) to the MAC layer (364) of the second DU (360). For example, the electronic device can transfer a cell context (540) included in the H-PHY layer (356) of the first DU (350) to the H-PHY layer (366) of the second DU (360).

[0094] According to one embodiment of the present disclosure, even while the electronic device transfers the cell context (520, 530, 540) for the target cell from the first DU (350) to the second DU (360), since the first DU (350) includes the cell context (520, 530, 540) for the target cell, the first DU (350) can process data for the target cell (e.g., data for communication of a UE associated with the target cell), and communication of one or more UEs (450) associated with the target cell may not be interrupted. That is, even while the cell context (520, 530, 540) for the target cell is being transferred, the communication service through the target cell may be maintained without interruption. Accordingly, the transfer of the cell context (520, 530, 540) for the target cell may be performed without time constraints.

[0095] In one embodiment of the present disclosure, the electronic device can transfer the target cell by setting the target cell in the second DU (360) using the parameters used to set the target cell in the first DU (350). For example, the electronic device can use the parameters used to create (or set) the cell contexts (520, 530, 540) for the target cell in the first DU (350) to create (or set) the cell contexts (520, 530, 540) for the target cell in the second DU (360). For example, the electronic device can use the parameters used to create the cell context (520) for the target cell in the RLC layer (352) of the first DU (350) to create the cell context (520) for the target cell in the RLC layer (362) of the second DU (360). For example, the electronic device may generate a cell context (530) for the target cell in the MAC layer (364) of the second DU (360) based on the parameters used to generate the cell context (530) for the target cell in the MAC layer (354) of the first DU (350). For example, the electronic device may generate a cell context (540) for the target cell in the H-PHY layer (364) of the second DU (360) based on the parameters used to generate the cell context (540) for the target cell in the H-PHY layer (354) of the first DU (350).

[0096] In one embodiment of the present disclosure, the electronic device can copy (or replicate) the cell context (520, 530, 540) for the target cell contained in the first DU (350) to the second DU (360). For example, the electronic device can control the first DU (350) to copy (or replicate) the cell context (520, 530, 540) for the target cell and provide it to the second DU (360). For example, the cell context (520, 530, 540) for the target cell can be copied / replicated from the first DU (350) to the second DU (360) through an inter-DU interface.

[0097] Referring to FIGS. 5 and 6, the electronic device may transfer UE contexts (550) for one or more UEs (450) included in the MAC layer (354) of the first DU (350) to the MAC layer (364) of the second DU (360). In one embodiment of the present disclosure, the electronic device may use parameters used to create (or set) the UE contexts (550) for one or more UEs (450) in the MAC layer (364) of the second DU (360) to create (or set) the UE contexts (550) for one or more UEs (450). In one embodiment of the present disclosure, the electronic device may copy (or replicate) the UE context (550) for one or more UEs (450) included in the MAC layer (354) of the first DU (350) to the MAC layer (364) of the second DU (360). For example, the electronic device may control the first DU (350) to copy (or replicate) the UE context (550) for one or more UEs (450) included in the MAC layer (354) and provide it to the MAC layer (364) of the second DU (360). For example, the UE context (550) for one or more UEs (450) may be copied / replicated from the first DU (350) to the second DU (360) through an inter-DU interface.

[0098] Referring to FIG. 6, the electronic device can set up (or establish, create, activate) a connection between the RLC layer (352) of the first DU (350) and the MAC layer (364) of the second DU (360) for DU scaling or target cell transfer. That is, the electronic device can set up (or activate) an interface (e.g., an inter-DU interface) for the connection between the RLC layer (352) of the first DU (350) and the MAC layer (364) of the second DU (360). For example, the electronic device may transfer a UE context (550) for one or more UEs (450) included in the MAC layer (354) of the first DU (350) to the MAC layer (364) of the second DU (360), and then establish a connection between the RLC layer (352) of the first DU (350) and the MAC layer (364) of the second DU (360).

[0099] Referring to FIGS. 5 and 6, the electronic device can switch the fronthaul interface of the RU (380) for the target cell from the first DU (350) to the second DU (360). For example, after transferring the cell contexts (520, 530, 540) for the target cell from the first DU (350) to the second DU (360), the electronic device can release (or disconnect, stop, deactivate) the fronthaul interface between the RU (380) and the first DU (350) and establish (or initiate, activate) the fronthaul interface between the RU (380) and the second DU (360). For example, while simultaneously transferring cell contexts (520, 530, 540) for a target cell from a first DU (350) to a second DU (360), the electronic device can release the fronthaul interface between the RU (380) and the first DU (350) and establish the fronthaul interface between the RU (380) and the second DU (360). For example, while simultaneously transferring UE contexts (550) for one or more UEs (450) to the MAC layer (364) of the second DU (360), the electronic device can switch the fronthaul interface of the RU (380) for the target cell from the first DU (350) to the second DU (360). For example, after transferring the UE context (550) for one or more UEs (450) to the MAC layer (364) of the second DU (360), the electronic device may switch the fronthaul interface of the RU (380) from the first DU (350) to the second DU (360) for the target cell.

[0100] In one embodiment of the present disclosure, the release of the fronthaul interface between the RU (380) and the first DU (350) and the establishment of the fronthaul interface between the RU (380) and the second DU (360) may be performed simultaneously. In one embodiment of the present disclosure, there may be a time difference between the release of the fronthaul interface between the RU (380) and the first DU (350) and the establishment of the fronthaul interface between the RU (380) and the second DU (360). For example, the electronic device may establish the fronthaul interface between the RU (380) and the second DU (360) after releasing the fronthaul interface between the RU (380) and the first DU (350). In this case, a time may occur during which the RU (380) is disconnected from the RAN, but it may be a very short time during which the user of the UE cannot recognize the disconnection of communication within a reference time. For example, the electronic device may set up a fronthaul interface between the RU (380) and the second DU (360), and then release the fronthaul interface between the RU (380) and the first DU (350).

[0101] Referring to FIG. 6, if communication of one or more UEs (450) through the target cell is possible after transfer of cell contexts (520, 530, 540) for the target cell described above, transfer of UE contexts (550) for one or more UEs (450), and switching of the fronthaul interface, the electronic device may remove (or delete) the transferred cell contexts (530, 540) and the UE context (550) in the MAC layer (354) and the H-PHY layer (356) of the first DU (350). In one embodiment of the present disclosure, the electronic device may identify that the communication state of the target cell is a communication-capable state, and accordingly, remove (or delete) the transferred cell contexts (530, 540) and the UE context (550) in the MAC layer (354) and the H-PHY layer (356) of the first DU (350). A communication state may include a communication state that satisfies any criteria such as delay, data processing speed, etc.

[0102] Referring to FIG. 6, one or more UEs (450) included in the target cell can receive communication services through the RU (380), the H-PHY layer (366) of the second DU (360), the MAC layer (364), the RLC layer (352) of the first DU (350), and the CU (330). That is, one or more UEs (450) included in the target cell can be connected (or accessed) to the core network through the RU (380), the H-PHY layer (366) of the second DU (360), the MAC layer (364), the RLC layer (352) of the first DU (350), and the CU (330). That is, data for communication of one or more UEs (450) associated with the target cell can be processed by the H-PHY layer (366) and MAC layer (364) of the second DU (360) and the RLC layer (352) of the first DU (350).

[0103] FIG. 7 is a diagram illustrating an example of an electronic device transferring a UE context and an F1-U interface to one or more UEs included in an RLC layer according to one embodiment of the present disclosure.

[0104] The electronic device can transfer UE contexts (440_1, 440_2, 440_3) for one or more UEs (450) included in the RLC layer (352) of the first DU (350) to the RLC layer (362) of the second DU (360) on a per-UE basis. In one embodiment of the present disclosure, the electronic device can use information (e.g., parameters, data) used to create (or set) the UE contexts (440_1, 440_2, 440_3) in the RLC layer (352) of the first DU (350) to create (or set) the UE contexts (440_1, 440_2, 440_3) in the RLC layer (352) of the second DU (360). In one embodiment of the present disclosure, the electronic device can copy (or replicate) the UE contexts (440_1, 440_2, 440_3) of the RLC layer (352) of the first DU (350) to the RLC layer (362) of the second DU (360). For example, the electronic device can control the first DU (350) to copy (or replicate) the UE contexts (440_1, 440_2, 440_3) included in the RLC layer (352) and provide them to the RLC layer (362) of the second DU (360) on a per-UE basis. For example, the UE contexts (440_1, 440_2, 440_3) can be copied / replicated from the first DU (350) to the second DU (360) on a per-UE basis through the DU-to-DU interface.

[0105] In one embodiment of the present disclosure, the electronic device may sequentially transfer a plurality of UE groups, including at least some of one or more UEs (450) associated with a target cell, from an RLC layer (352) of a first DU (350) to an RLC layer (362) of a second DU (360). For example, the electronic device may sequentially transfer the plurality of UE groups at multiple times (or points in time). For example, the electronic device may transfer UE contexts for one or more first target UEs, which are at least some of one or more UEs (450) associated with the target cell, and then transfer UE contexts for one or more second target UEs, which are at least some of the UEs to which UE contexts have not been transferred. The electronic device may transfer UE contexts from the RLC layer (352) of the first DU (350) to the RLC layer (362) of the second DU (360) on a UE-by-UE basis until all of the one or more UEs (450) associated with the target cell are transferred.

[0106] In one embodiment of the present disclosure, the electronic device may identify one or more target UEs (450) to be transferred in the current round (or time point) from among one or more UEs (450) associated with the target cell. For example, the electronic device may select (or determine) one or more target UEs to be transferred in the current round (or time point) from among one or more UEs (450) associated with the target cell. For example, the electronic device may determine the transfer order of the UEs (or groups of UEs). For example, the electronic device may identify one or more target UEs determined by another electronic device.

[0107] In one embodiment of the present disclosure, the electronic device can switch the F1-U interface for one or more target UEs from the first DU (350) to the second DU (360). For example, the electronic device can transfer the UE context for one or more target UEs from the RLC layer (352) of the first DU (350) to the RLC layer (362) of the second DU (360), and then switch the F1-U interface for one or more target UEs from the first DU (350) to the second DU (360). For example, the electronic device can release (or deactivate, disconnect, suspend, remove) the F1-U interface between the CU (330) and the first DU (350) for the UE to which the UE context is transferred, and establish (or activate, establish, create) the F1-U interface between the CU (330) and the second DU (360). For example, the establishment of the F1-U interface between the CU (330) and the second DU (360) and the release of the F1-U interface between the CU (330) and the first DU (350) can be performed simultaneously. For example, the establishment of the F1-U interface between the CU (330) and the second DU (360) can be performed after the release of the F1-U interface between the CU (330) and the first DU (350). Meanwhile, the F1-U interface between the CU (330) and the first DU (350) can be maintained for one or more UEs (450) for the target cell to which the UE context has not been transferred.

[0108] In one embodiment of the present disclosure, the electronic device can change (or switch) the RLC layer-MAC layer path for one or more target UEs from the first DU (350) - second DU (360) path to the second DU (360) - second DU (360) path. For example, the electronic device can change (or switch) the RLC layer (352) of the first DU (350) - MAC layer (364) of the second DU (360) path to the RLC layer (362) of the second DU (360) - MAC layer (364) of the second DU (360) path for one or more target UEs. Among one or more UEs (450) for the target cell, the RLC layer-MAC layer path for a UE whose UE context has not been transferred may be maintained as a first DU (350)-second DU (360) path (i.e., an RLC layer (352) of the first DU (350)-MAC layer (364) of the second DU (360) path).

[0109] As illustrated in FIG. 7, a first UE, to which a UE context (440_1), an F1-U interface, and an RLC-MAC path have not been transferred, can be connected (or, connected) to a core network through an RU (380), an H-PHY layer (366) of a second DU (360), a MAC layer (364), an RLC layer (352) of a first DU (350), and a CU (330), and can receive communication services. On the other hand, a second UE, to which a UE context (440_3), an F1-U interface, and an RLC-MAC path have been transferred, can be connected (or, connected) to a core network through an RU (380), an H-PHY layer (366) of a second DU (360), a MAC layer (364), an RLC layer (362) of a second DU (360), and a CU (330), and can receive communication services. That is, among the data for the target cell, data for the UE that has not been transferred may be processed by the RLC layer (352) of the first DU (350), and data for the UE that has been transferred may be processed by the RLC layer (362) of the second DU (360).

[0110] In one embodiment of the present disclosure, the electronic device may remove the UE context (440_3) for the UE to which the F1-U interface and RLC-MAC path are transferred from the RLC layer (352) of the first DU (350). For example, after transferring the UE context for one or more target UEs, switching the F1-U interface, and changing the RLC-MAC path, the electronic device may remove the UE context for one or more target UEs from the RLC layer (352) of the first DU (350) regardless of the transfer of other UE contexts. For example, after transferring UE contexts for one or more target UEs, switching the F1-U interface, and changing the RLC-MAC path, the electronic device may remove UE contexts for one or more target UEs from the RLC layer (352) of the first DU (350) before transferring UE contexts for other UEs to the RLC layer (352) of the first DU (350). For example, after completing the transfer of UE contexts, switching of the F1-U interface, and changing of the RLC-MAC path for all of the plurality of UEs associated with the target cell, the electronic device may remove UE contexts for the plurality of UEs associated with the target cell from the RLC layer (352) of the first DU (350). For example, the electronic device may periodically or aperiodically remove UE contexts for the UEs for which transfer has been completed from the RLC layer (352) of the first DU (350).

[0111] The electronic device can transfer UE contexts of all UEs associated with a target cell from the RLC layer (352) of the first DU (350) to the RLC layer (362) of the second DU (360). In one embodiment of the present disclosure, the electronic device can select a target UE to be transferred until the UE contexts for all UEs associated with the target cell are transferred to the second DU (360), transfer the UE context for the selected target UE from the RLC layer (352) to the RLC layer (362), switch the F1-U interface for the selected target UE, and change the RLC-MAC path. When there are no more UEs to be transferred, i.e., when the transfer of the UE contexts for all UEs associated with the target cell is completed, the electronic device can remove (or delete) information about the target cell from the first DU (350). For example, as the migration of the target cell is completed, the electronic device can remove the cell context (520) for the target cell from the RLC layer (352). For example, as the migration of the target cell is completed, the electronic device can remove the UE contexts (440_1, 440_2, 440_3) from the RLC layer (352).

[0112] In one embodiment of the present disclosure, as the transfer of the target cell is completed, the electronic device can release (or, suspend, disconnect, deactivate) the connection between the RLC layer (352) of the first DU (350) and the MAC layer (364) of the second DU (360). In one embodiment of the present disclosure, as the transfer of the target cell is completed, the electronic device can release (or, suspend, disconnect, deactivate) the interface between the first DU (350) and the second DU (360). Data for communication of one or more UEs (450) associated with the target cell, which are previously processed by the first DU (350), can be processed by the second DU (36) as the target cell is transferred.

[0113] FIG. 8 is a diagram illustrating an example of performing DU scaling in a RAN according to one embodiment of the present disclosure.

[0114] The OAM module (810) may determine a scaling-in for the first DU (850). For example, the OAM module (810) may determine a scaling-in that removes the first DU (850) from the DU pool that includes the first DU (850). In one embodiment of the present disclosure, the OAM module (810) may identify that a scaling-in is required based on information about the DU pool that includes the first DU (850). For example, the OAM module (810) may determine a scaling-in for the first DU (850) based on traffic, processing capacity (e.g., maximum available resource amount), currently available resources (e.g., remaining resource amount), etc. of the DU pool that includes the first DU (850).

[0115] As illustrated in FIG. 8, the CU (830) can be connected to multiple DUs, i.e., the first DU (850) and the second DU (860), through multiple mid-haul interfaces via the mid-haul splitter module (840). In one embodiment of the present disclosure, the OAM module (810) can configure a connection (or mid-haul interface) between the second DU (860) and the CU (830) for the previous target cell.

[0116] The OAM module (810) can transmit information about a scaling-in decision for the first DU (850) to the scaling agent module (820). In one embodiment of the present disclosure, the OAM module (810) can instruct the scaling agent module (820) to perform a transfer operation from the first DU (850) to the second DU (860) for scaling-in. For example, the OAM module (810) can provide the scaling agent module (820) with information necessary to perform the transfer operation.

[0117] The scaling agent module (820) can identify a scaling-in decision for the first DU (850) and perform a cell transfer operation from the first DU (850) to the second DU (860) for scaling-in. In one embodiment of the present disclosure, the scaling agent module (820) can control at least one of the first DU (850), the second DU (860), the RU (870), or an inter-unit interface as the transfer operation for scaling-in. For example, the scaling agent module (820) can transmit a command to at least one of the first DU (850), the second DU (860), or the RU (870). For example, the scaling agent module (820) may control at least a portion of the RLC layer (852), the MAC layer (854), the PHY layer (856) of the first DU (850), the RLC layer (862), the MAC layer (864), or the PHY layer (866) of the second DU (860).

[0118] The scaling agent module (820) can identify a target cell to be transferred from the first DU (850) to the second DU (860). In one embodiment of the present disclosure, the target cell may be selected from one or more cells associated with the first DU (850) by the scaling agent module (820) or the OAM module (810), but is not limited thereto. For example, the target cell may be selected based on information about the first DU (850) (e.g., processing capacity, remaining resources, traffic, etc.), information about the second DU (860), information about each cell associated with the first DU (850) (e.g., traffic), etc. For example, the target cell may be randomly selected from one or more cells associated with the first DU (850). In one embodiment of the present disclosure, in the case of scaling in, all cells associated with the first DU (850) may be transferred to the second DU (860) as target cells.

[0119] The scaling agent module (820) may transfer (822) a context associated with a target cell from the first DU (850) to the second DU (860) for scaling in. For example, the scaling agent module (820) may control at least one of the first DU (850) or the second DU (860) to transfer the context associated with the target cell from the first DU (850) to the second DU (860). The context associated with the target cell may include a cell context for the target cell itself and a UE context for a UE associated with the target cell. In one embodiment of the present disclosure, the scaling agent module (820) can transfer a context associated with a target cell included in at least one of the RLC layer (852), the MAC layer (854), or the PHY layer (856) of the first DU (850) to at least one of the RLC layer (862), the MAC layer (864), or the PHY layer (866) of the second DU (860).

[0120] The scaling agent module (820) can switch the fronthaul interface between the RU (870) and the DU from the first DU (850) to the second DU (860) for the target cell (824). For example, the scaling agent module (820) can control at least one of the first DU (850), the second DU (860), or the RU (870) to switch the fronthaul interface from the first DU (850) to the second DU (860) for the target cell. In one embodiment of the present disclosure, the scaling agent module (820) can release the fronthaul interface between the first DU (850) and the RU (870) for the target cell, and establish the fronthaul interface between the second DU (860) and the RU (870). That is, the RU (870) can be connected to one DU for the target cell through the fronthaul interface. Accordingly, the RAN system of FIG. 8 may not require a fronthaul splitter module to provide multiple fronthaul interfaces between the RU (870) and multiple DUs for the target cell.

[0121] Meanwhile, in one embodiment of the present disclosure, an RU (870) may be connected to one DU for a target cell, but an RU associated with multiple cells may be connected to a first DU for a first cell and a second DU for a second cell. That is, an RU may be connected to multiple DUs through multiple fronthaul interfaces on a cell-by-cell basis. Furthermore, in one embodiment of the present disclosure, one DU may be connected to multiple RUs through multiple fronthaul interfaces.

[0122] In one embodiment of the present disclosure, as the target cell migration is completed, the first DU (850) may be removed from the DU pool. In one embodiment of the present disclosure, as the target cell migration is completed, the mid-hole interface between the first DU (850) and the CU (830) may be released. In one embodiment of the present disclosure, as all cells included in the first DU (850) are migrated to the second DU (860), the first DU (850) may be removed from the DU pool, and the scaling-in operation may be completed.

[0123] The specific operations of the scaling agent module (820) for transferring a context associated with the target cell (822) and switching the fronthaul interface (824) to transfer the target cell from the first DU (850) to the second DU (860) may be performed according to one or more of the embodiments described above with reference to FIGS. 5 to 7 . For example, one or more of the embodiments described in the present disclosure for target cell transfer for scaling out may also be applied to target cell transfer for scaling in. Similarly, one or more of the embodiments described in the present disclosure for target cell transfer for scaling in may also be applied to target cell transfer for scaling out. Furthermore, one or more of the embodiments described in the present disclosure for target cell transfer for scaling in or scaling out may also be applied to target cell transfer in cases other than scaling in and scaling out.

[0124] Although FIG. 8 illustrates a scaling agent module (820) and an OAM module (810), the present invention is not limited thereto. For example, the scaling agent module (820) and the OAM module (810) may be one and the same module and may perform the functions and operations of the scaling agent module (820) and the OAM module (810) described above.

[0125] Each module and entity of FIG. 8 may be a software module, a hardware module, and / or a combination thereof. For example, the first DU (850) and the second DU (860) may be software modules, and may be included / stored and executed on a single piece of hardware (e.g., a server device). For example, the first DU (850) and the second DU (860) may be included / stored and executed on different pieces of hardware.

[0126] FIG. 9 is a flowchart illustrating an example of a method for performing a cell transfer operation for a DU according to one embodiment of the present disclosure.

[0127] Referring to FIG. 9, a method (900) for performing a cell transfer operation for a DU by an electronic device according to one embodiment may include steps 910 to 940. In one embodiment of the present disclosure, steps 910 to 940 may be executed by at least one processor included in the electronic device. In one embodiment of the present disclosure, steps 910 to 940 may be executed by an electronic device (e.g., at least one processor of the electronic device) in which a scaling agent module is included or executed. The method (900) for performing a cell transfer operation for a DU by an electronic device 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.

[0128] In step 910, the electronic device can transfer a cell context for a target cell included in at least one of the RLC layer, the MAC layer, or the PHY layer of the first DU to at least one of the RLC layer, the MAC layer, or the PHY layer of the second DU.

[0129] In step 920, the electronic device may establish a connection between the RLC layer of the first DU and the MAC layer of the second DU for the target cell, and may identify that the communication status of the target cell is a communication-enabled state. In one embodiment of the present disclosure, the communication-enabled state may include a state in which communication through the target cell satisfies any criteria. For example, the communication-enabled state may include a state in which criteria for communication delay, communication performance, processing capability, throughput, etc. are satisfied.

[0130] In step 930, the electronic device may transfer UE contexts for one or more target UEs among the UE contexts for the plurality of UEs associated with the target cell included in the RLC layer of the first DU to the RLC layer of the second DU. That is, the electronic device may transfer UE contexts on a per-UE basis.

[0131] In step 940, the electronic device may switch the F1-U interface for the one or more target UEs from the first DU to the second DU, and establish a connection (or, path, interface) between the RLC layer and the MAC layer of the second DU for the one or more target UEs. For example, a connection between the RLC layer and the MAC layer of the second DU may be established for the transferred UE, and a connection between the RLC layer of the first DU and the MAC layer of the second DU may be established for the non-transferred UE. Since the number of F1-U interfaces is as many as the number of radio bearers of the UE, it may be difficult to transfer from the first DU to the second DU for all UEs at once. Therefore, the electronic device may transfer the UE context of the RLC layer and the F1-U interface on a per-UE basis, rather than on a per-cell basis.

[0132] FIG. 10 is a flowchart illustrating an example of a method for performing a cell transfer operation for a DU according to one embodiment of the present disclosure.

[0133] Referring to FIG. 10 , a method (1000) for performing a cell transfer operation for a DU by an electronic device according to one embodiment may include steps 1010 to 1032. In one embodiment of the present disclosure, steps 1010 to 1032 may be executed by at least one processor included in the electronic device. In one embodiment of the present disclosure, steps 1010 to 1032 may be executed by an electronic device (e.g., at least one processor of the electronic device) in which a scaling agent module is included or executed. The method (1000) for performing a cell transfer operation for a DU by an electronic device is not limited to that illustrated in FIG. 10 , and in one or more embodiments, steps not illustrated in FIG. 10 may be further included, or some steps may be omitted.

[0134] In step 1010, the electronic device may transfer the cell context for the target cell of the RLC layer, MAC layer, and PHY layer of the first DU to the RLC layer, MAC layer, and PHY layer of the second DU.

[0135] In step 1012, the electronic device may switch the fronthaul interface for the target cell from the first DU to the second DU based on the transfer of the cell context for the target cell. For example, the electronic device may switch the fronthaul interface for the target cell from the first DU to the second DU after the transfer of the cell context for the target cell.

[0136] In step 1014, the electronic device may transfer UE contexts for multiple UEs (e.g., all UEs) in the target cell of the MAC layer and PHY layer of the first DU to the MAC layer and PHY layer of the second DU based on the transfer of cell contexts for the target cell. For example, after the transfer of cell contexts for the target cell, the electronic device may transfer UE contexts for all UEs in the target cell of the MAC layer and PHY layer of the first DU to the MAC layer and PHY layer of the second DU.

[0137] In step 1016, the electronic device may establish a connection between the RLC layer of the first DU and the MAC layer of the second DU based on the transfer of the UE context to the MAC layer and PHY layer of the second DU. For example, the electronic device may establish a connection between the RLC layer of the first DU and the MAC layer of the second DU after the transfer of the UE context to the MAC layer and PHY layer of the second DU.

[0138] In one embodiment of the present disclosure, the electronic device can perform steps 1014 and 1016 and step 1012 in parallel. For example, the electronic device can perform steps 1014 and 1016 and step 1012 simultaneously.

[0139] In step 1018, the electronic device can identify whether the communication service of the target cell is successfully provided. In one embodiment of the present disclosure, the electronic device can identify whether a UE associated with the target cell can successfully access a communication network via the target cell. In one embodiment of the present disclosure, the electronic device can identify whether the communication status of the target cell is a communication-enabled state. In one embodiment of the present disclosure, it can be determined whether the communication service of the target cell is successfully provided. In one embodiment of the present disclosure, information regarding whether the communication service of the target cell is successfully provided can be received.

[0140] Based on identifying that the communication service of the target cell is not successfully provided, the electronic device may perform at least one of steps 1010 to 1016 again.

[0141] In step 1020, the electronic device may remove the cell context and UE context for the transferred target cell from the MAC layer and PHY layer of the first DU based on the identification that the communication service of the target cell is successfully provided. For example, the electronic device may remove the cell context and UE context for the transferred target cell from the MAC layer and PHY layer of the first DU after (or in response to) the identification that the communication service of the target cell is successfully provided.

[0142] In step 1022, the electronic device may select one or more target UEs to be transferred to the second DU from among one or more UEs within the target cell existing (or included) in the RLC layer of the first DU. In one embodiment of the present disclosure, the electronic device may select one or more target UEs to be transferred to the RLC layer of the second DU from among one or more UEs that have not been transferred to the RLC layer of the second DU.

[0143] At step 1024, the electronic device may transfer the UE context for one or more selected target UEs to the RLC layer of the second DU.

[0144] At step 1026, the electronic device may change (or switch) the F1-U path (i.e., F1-U interface) of one or more target UEs transferred to the RLC layer of the second DU from the first DU to the second DU.

[0145] In step 1028, the electronic device may change (or switch) the RLC layer-MAC layer path of one or more target UEs transferred to the RLC layer of the second DU from the first DU-second DU path (i.e., the RLC layer of the first DU-MAC layer path of the second DU) to the second DU-second DU path (i.e., the RLC layer of the second DU-MAC layer path of the second DU). For example, the electronic device may establish a connection between the RLC layer and the MAC layer of the second DU for the one or more target UEs transferred.

[0146] In step 1030, the electronic device can identify whether there are any UEs remaining in the target cell that are to be transferred to the RLC layer of the first DU, i.e., one or more UEs within the target cell that have not been transferred. In one embodiment of the present disclosure, the electronic device can identify whether there are any remaining UEs remaining in the RLC layer of the first DU that are to be transferred.

[0147] Based on identifying that there is a UE to be transferred, the electronic device may perform at least one of steps 1022 to 1028 again.

[0148] In step 1032, the electronic device may delete (or remove) information related to the transferred target cell within the RLC layer of the first DU based on identifying that there is no UE to be transferred, i.e., that the UE contexts for all UEs within the target cell have been transferred to the RLC layer of the second DU. For example, the electronic device may delete cell contexts and UE contexts for the target cell included in the RLC layer of the first DU.

[0149] In one embodiment of the present disclosure, upon completion of the cell transfer, the electronic device may transmit information indicating that the cell transfer has been completed to a network element management system (EMS) (or a configuration module managed by a mobile operator).

[0150] In FIG. 10, the electronic device is illustrated as sequentially performing steps 1024 to 1028, but this is not limited thereto. For example, the electronic device may perform at least some of steps 1024 to 1028 simultaneously.

[0151] Although FIG. 10 illustrates that the electronic device deletes the UE context included in the RLC layer of the first DU after transferring all UEs from the first DU to the second DU, the present invention is not limited thereto. For example, the electronic device may delete (or remove) the UE context transferred to the RLC layer of the second DU after at least one of steps 1024, 1026, or 1028. That is, the electronic device may delete the UE context for the transferred UE every time the UE is transferred to the second DU. For example, the electronic device may delete the UE context for the transferred UE periodically or aperiodically.

[0152] As illustrated in FIG. 10, a method (1000) for an electronic device to perform a cell migration operation for a DU may include migration steps 1010 to 1020 for a MAC layer, a PHY layer, and a fronthaul interface, and migration steps 1022 to 1032 for a midhaul interface and an RLC layer. According to one embodiment of the present disclosure, in vDU scaling, a migration method for the MAC layer, the PHY layer, and the fronthaul interface may be different from a migration method for the midhaul interface and the RLC layer. For example, in order to reduce the complexity that may occur when operating two fronthaul interfaces and a MAC Scheduler, the electronic device may migrate information at once on a cell basis in each step for the migration of the MAC layer, the PHY layer, and the fronthaul interface, whereas in each step for the migration of the midhaul interface and the RLC layer, the electronic device may perform the migration on a UE basis for a stable migration operation.

[0153] FIG. 11 is a diagram illustrating an example of an electronic device performing a cell transfer operation for a DU according to one embodiment of the present disclosure.

[0154] The electronic device (1100) illustrated in FIG. 11 is an electronic device that performs cell transfer operations for a DU, and may be a server device. For example, the electronic device (1100) 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.).

[0155] In one embodiment of the present disclosure, the electronic device (1100) may include, but is not limited to, at least one processor (1110) and memory (1120).

[0156] The processor (1110) is electrically connected to components included in the electronic device (1100) and can execute operations or data processing related to control and / or communication of the components included in the electronic device (1100). In one embodiment of the present disclosure, the processor (1110) 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 (1110) is a component that controls a series of processes so that the electronic device (1100) operates according to the above-described embodiments, and may be configured with one or more processors.

[0157] One or more processors included in the processor (1110) may be circuitry such as a System on Chip (SoC), an Integrated Circuit (IC), etc. One or more processors included in the processor (1110) 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 (1110) 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.

[0158] The processor (1110) 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.

[0159] The processor (1110) can write data to the memory (1120) or read data stored in the memory (1120), 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 (1120). The processor (1110) can be controlled to process input data according to predefined operation rules, algorithms, methods, or models stored in the memory (1120). The processor (1110) can be controlled to process input data based on data stored in the memory (1120). The processor (1110) can perform operations of predefined operation rules, algorithms, methods, or models stored in the memory (1120) using the input data.

[0160] The memory (1120) is electrically connected to the processor (1110) and may store one or more modules, algorithms, operating rules, models, programs, commands, or data related to the operation of components included in the electronic device (1100). For example, the memory (1120) may store one or more modules, algorithms, operating rules, models, programs, commands, or data for processing and controlling the processor (1110).

[0161] The memory (1120) 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 (1120) may not exist separately and may be configured to be included in the processor (1110). The memory (1120) 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 (1120). The memory (1120) may also provide stored data to the processor (1110) at the request of the processor (1110).

[0162] In one embodiment of the present disclosure, the memory (1120) may store data or information identified, acquired, generated, or determined by the electronic device (1100). The memory (1120) may store data or information identified, acquired, generated, or determined by the electronic device (1100) in a compressed form.

[0163] Some modules that perform at least one operation of the electronic device (1100) may be implemented as hardware modules, software modules, and / or a combination thereof. The memory (1120) may include software modules that perform at least some of the operations of the electronic device (1100) described above. In one embodiment of the present disclosure, the modules included in the memory (1120) may perform operations by being executed by the processor (1110). For example, the modules (i.e., software modules) included in the memory (1120) may include programs, models, or algorithms that are executed according to the control or command of the processor (1110) 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 (1100) may be composed of a plurality of sub-modules or may constitute a single module.

[0164] The electronic device (1100) may include more components than those illustrated in FIG. 11. In one embodiment of the present disclosure, the electronic device (1100) 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 (1100) may further include an input / output device and / or an input / output interface.

[0165] In the present disclosure, overlapping descriptions in FIGS. 1 to 11 may be omitted, and one or more embodiments described above in FIGS. 1 to 11 may be applied / implemented in combination with each other. In the present disclosure, an operation described as being performed by a module may be executed / performed by an electronic device in which the module is included or stored, or may be executed / performed by the control of at least one processor of the electronic device in which the module is included. An operation described as being performed by an electronic device may be executed / performed by a module included or stored in the electronic device, or may be performed by the control of at least one processor of the electronic device using a module included or stored in the electronic device.

[0166] In one embodiment of the present disclosure, a method performed by an electronic device may include a step of migrating a cell context for a target cell included in at least one of a radio link control (RLC) layer, a medium access control (MAC) layer, or a physical (PHY) layer of a first distributed unit (DU) to at least one of an RLC layer, a MAC layer, or a PHY layer of a second DU. In one embodiment of the present disclosure, the method may include a step of configuring a connection between an RLC layer of the first DU and a MAC layer of the second DU for the target cell, and identifying that a communication state of the target cell is a communication-capable state. In one embodiment of the present disclosure, the method may include a step of migrating a UE context for at least one target UE among a plurality of UE contexts for the target cell included in an RLC layer of the first DU, to an RLC layer of the second DU. In one embodiment of the present disclosure, the method may include switching an F1-U interface for the one or more target UEs from a first DU to a second DU, and establishing a connection between an RLC layer and a MAC layer of the second DU for the one or more target UEs.

[0167] According to one embodiment of the present disclosure, since communication with the target cell continues in the first DU, there may be no time constraints on transferring the cell context for the target cell, and the communication service may not be interrupted, and the target cell may be set in the second DU. According to one embodiment of the present disclosure, by transferring the UE context and F1-U path of the RLC layer on a per-UE basis, operation stability can be secured and system reliability can be improved.

[0168] In one embodiment of the present disclosure, the method may include a step of switching a fronthaul interface for the target cell from a first DU to a second DU based on the transfer of a cell context for the target cell. According to one embodiment of the present disclosure, since two MAC schedulers do not share Air Resources (or radio resources) for one RU (or cell) and only one MAC is valid at a time, the complexity of the MAC scheduling operation may be reduced. According to one embodiment of the present disclosure, the fronthaul interface may be prevented from communicating with two H-PHY layers. That is, the fronthaul interface is switched between two H-PHY layers and does not operate, and after the fronthaul interface is switched from the first DU to the second DU for a specific period of time, the fronthaul interface may only process communication for the second DU. This may prevent a situation in which the fronthaul interface is connected to two H-PHY layers at the same time, and may prevent additional use of resources for packet distribution.

[0169] In one embodiment of the present disclosure, the method may include a step of transferring UE contexts for the plurality of UEs included in at least one of the MAC layer or PHY layer of the first DU to at least one of the MAC layer or PHY layer of the second DU, based on the transfer of cell contexts for the target cell.

[0170] In one embodiment of the present disclosure, the method may include a step of removing a cell context for the target cell and a UE context for the plurality of UEs from at least one of a MAC layer or a PHY layer of the first DU based on identifying that the communication state of the target cell is a communication-capable state.

[0171] In one embodiment of the present disclosure, the method may further include a step of selecting one or more target UEs from among the plurality of UEs.

[0172] In one embodiment of the present disclosure, the method may further include the step of removing a UE context for the one or more target UEs from the RLC of the first DU based on the transfer of the UE context for the one or more target UEs.

[0173] In one embodiment of the present disclosure, the method may further include a step of removing a cell context for the target cell from the RLC of the first DU based on completion of transfer of the UE context for the plurality of UEs to the RLC of the second DU.

[0174] In one embodiment of the present disclosure, the method may further include a step of identifying a scaling-out decision for the first DU.

[0175] In one embodiment of the present disclosure, based on the scaling out decision for the first DU, the second DU may be generated, and a midhaul interface between a centralized unit (CU) for the first DU and the second DU may be established.

[0176] In one embodiment of the present disclosure, the method may further include a step of identifying a scaling-in decision for the first DU.

[0177] In one embodiment of the present disclosure, a program for performing the method on a computer can be recorded on a computer-readable recording medium.

[0178] In one embodiment of the present disclosure, an electronic device may include a memory that stores one or more instructions and at least one processor that executes the one or more instructions stored in the memory. In one embodiment of the present disclosure, the at least one processor may migrate a cell context for a target cell included in at least one of an RLC (radio link control) layer, a MAC (medium access control) layer, or a PHY (physical) layer of a first distributed unit (DU) to at least one of an RLC layer, a MAC layer, or a PHY layer of a second DU by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor may configure a connection between an RLC layer of the first DU and a MAC layer of the second DU for the target cell, and identify that a communication state of the target cell is a communication-capable state by executing the one or more instructions. In one embodiment of the present disclosure, the at least one processor can transfer a UE context for one or more target UEs among a plurality of UE contexts for user equipment (UEs) associated with the target cell, included in an RLC layer of the first DU, to an RLC layer of the second DU by executing the one or more commands. In one embodiment of the present disclosure, the at least one processor can switch an F1-U interface for the one or more target UEs from the first DU to the second DU, and establish a connection between an RLC layer and a MAC layer of the second DU for the one or more target UEs by executing the one or more commands.

[0179] In one embodiment of the present disclosure, the at least one processor can switch a fronthaul interface for the target cell from a first DU to a second DU based on a transfer of a cell context for the target cell.

[0180] In one embodiment of the present disclosure, the at least one processor can transfer UE contexts for the plurality of UEs included in at least one of the MAC layer or PHY layer of the first DU to at least one of the MAC layer or PHY layer of the second DU based on the transfer of cell contexts for the target cell.

[0181] In one embodiment of the present disclosure, the at least one processor can remove a cell context for the target cell and a UE context for the plurality of UEs from at least one of a MAC layer or a PHY layer of the first DU based on identifying that the communication state of the target cell is a communication-capable state.

[0182] In one embodiment of the present disclosure, the at least one processor may select one or more target UEs from among the plurality of UEs.

[0183] In one embodiment of the present disclosure, the at least one processor may remove a UE context for the one or more target UEs from the RLC of the first DU based on a transfer of the UE context for the one or more target UEs.

[0184] In one embodiment of the present disclosure, the at least one processor may remove a cell context for the target cell from the RLC of the first DU based on completion of transfer of the UE context for the plurality of UEs to the RLC of the second DU.

[0185] In one embodiment of the present disclosure, the at least one processor may identify a scaling-out decision for the first DU. In one embodiment of the present disclosure, based on the scaling-out decision for the first DU, the second DU may be generated, and a midhaul interface between a centralized unit (CU) for the first DU and the second DU may be established.

[0186] In one embodiment of the present disclosure, a scaling-in decision for the first DU can be identified.

[0187] 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.

[0188] 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 a method performed by an electronic device, A step of migrating a cell context for a target cell included in at least one of an RLC (radio link control) layer, a MAC (medium access control) layer or a PHY (physical) layer of a first DU (distributed unit) to at least one of the RLC layer, the MAC layer or the PHY layer of a second DU; A step of configuring a connection between the RLC layer of the first DU and the MAC layer of the second DU for the target cell, and identifying that the communication status of the target cell is a communication-capable state; A step of transferring a UE context for at least one target UE among a plurality of UE (user equipment) contexts associated with the target cell included in the RLC layer of the first DU to the RLC layer of the second DU; and A method comprising the steps of switching an F1-U interface for said one or more target UEs from a first DU to a second DU and establishing a connection between an RLC layer and a MAC layer of the second DU for said one or more target UEs.

2. In paragraph 1, A method further comprising the step of switching a fronthaul interface for the target cell from a first DU to a second DU based on the transfer of a cell context for the target cell.

3. In paragraph 1 or 2, A method further comprising the step of transferring UE contexts for the plurality of UEs included in at least one of the MAC layer or the PHY layer of the first DU to at least one of the MAC layer or the PHY layer of the second DU, based on the transfer of cell contexts for the target cell.

4. In any one of paragraphs 1 to 3, A method further comprising the step of removing a cell context for the target cell and a UE context for the plurality of UEs from at least one of a MAC layer or a PHY layer of the first DU based on identifying that the communication status of the target cell is a communication-capable state.

5. In any one of paragraphs 1 to 4, A method further comprising the step of selecting one or more target UEs from among the plurality of UEs.

6. In any one of paragraphs 1 to 5, A method further comprising the step of removing a UE context for the one or more target UEs from an RLC of the first DU based on the transfer of the UE context for the one or more target UEs.

7. In any one of paragraphs 1 to 6, A method further comprising the step of removing a cell context for the target cell from the RLC of the first DU based on completion of transfer of the UE context for the plurality of UEs to the RLC of the second DU.

8. In any one of paragraphs 1 to 7, A method further comprising the step of identifying a scaling-out decision for said first DU.

9. In any one of paragraphs 1 to 8, A method wherein, based on a scaling out decision for the first DU, the second DU is generated, and a midhaul interface between a centralized unit (CU) for the first DU and the second DU is established.

10. In any one of paragraphs 1 to 7, A method further comprising the step of identifying a scaling-in decision for said first DU.

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 (1100), A memory (1120) storing one or more instructions; and At least one processor (1110) for executing one or more instructions stored in the memory (1120), The at least one processor (1110) executes the one or more instructions, Migrate a cell context for a target cell included in at least one of the RLC (radio link control) layer, MAC (medium access control) layer or PHY (physical) layer of the first DU (distributed unit) to at least one of the RLC layer, MAC layer or PHY layer of the second DU, Establish a connection between the RLC layer of the first DU and the MAC layer of the second DU for the target cell, and identify that the communication status of the target cell is a communication-capable state; Transferring a UE context for at least one target UE among a plurality of UE (user equipment) contexts associated with the target cell included in the RLC layer of the first DU to the RLC layer of the second DU, An electronic device that switches an F1-U interface for one or more target UEs from a first DU to a second DU and establishes a connection between an RLC layer and a MAC layer of the second DU for the one or more target UEs.

13. In paragraph 12, At least one processor (1110) above, An electronic device that switches a fronthaul interface for the target cell from a first DU to a second DU based on a transfer of a cell context for the target cell.

14. In paragraph 12 or 13, At least one processor (1110) above, An electronic device that transfers UE contexts for the plurality of UEs included in at least one of the MAC layer or the PHY layer of the first DU to at least one of the MAC layer or the PHY layer of the second DU based on the transfer of cell contexts for the target cell.

15. In any one of paragraphs 12 to 14, At least one processor (1110) above, An electronic device that removes a cell context for the target cell and a UE context for the plurality of UEs from at least one of a MAC layer or a PHY layer of the first DU based on identifying that the communication status of the target cell is a communication-capable state.

Images