KR20230090963A - Network operating distributed unit scaling and method for operating thereof - Google Patents

Abstract

According to various embodiments, a communication method of a wireless access network device including a distributed unit (DU) comprises the steps of: obtaining information about resource usage of a first DU running through a first server by a scaling controller; selecting a second DU based on the information about resource usage of the first DU by the scaling controller; selecting a second RU to be migrated to the second DU from among first remote units (RUs) processing a service of the first DU by the scaling controller; and transmitting information about the second RU to the second DU by the first DU. According to the method, among the first RUs, remaining RUs excluding the second RU process the service of the first DU. In addition, various other embodiments are possible. Therefore, server resources required by an entire DU can be used efficiently.

Description

A network performing distributed unit scaling and its operating method

Various embodiments relate to a method for scaling a distribution unit that is a separate function of a radio access network and allocation of radio resources.

In an existing base station, a distributed unit (DU) and a radio unit (or remote unit, RU) of the base station are installed in a cell site. However, this all-in-one implementation has physical limitations. For example, in accordance with an increase in service subscribers or traffic, an operator must newly build a base station in a cell site. To overcome this, a centralized radio access network (C-RAN) or cloud RAN (C-RAN) structure has been implemented. The C-RAN may have a structure in which DUs are placed in one physical location and RUs are placed in a cell site that transmits and receives radio signals with an actual user equipment (UE). DU and RU may be connected by optical cable or coaxial cable. As the RU and DU are separated, an interface standard for communication between them is required, and a standard such as CPRI (Common Public Radio Interface) is used between the RU and the DU. The base station structure is being standardized in the 3rd Generation Partnership Project (3GPP), and discussions on an open radio access network (O-RAN), which is an open network standard that can be applied to 5G systems, are underway.

O-RAN replaces existing 3GPP NEs, RU, DU, CU-CP (central unit-control plane), and CU-UP (central unit-user plane), respectively, with O-RU, O-DU, O-CU-CP, It is newly defined as O-CU-UP (which can be collectively referred to as O-RAN base station), and additionally proposes RIC (RAN Intelligent Controller) and NRT-RIC (non-real-time RAN Intelligent Controller) .

In a next-generation communication system, a new radio access network (RAN) structure is a radio access including centralized units (CUs), distributed units (DUs), and remote units (RUs). The network structure is being considered. Radio protocol stacks or functions for communication may be split into CUs, DUs, and RUs in various ways. In the specification, this is called function split. By separating the RAN function, various types of operation are possible according to the environment of each mobile operator. Overall operating cost can be reduced by installing only RU equipment in the cell site, distributing CU and DU in the central office or cloud data center, and connecting them through fronthaul. There may be at least one or more DUs under one CU. Radio protocol stacks or functions for communication can be divided between CUs and DUs in various ways. For example, PDCP layer/functions can be located in CU and RLC/MAC/PHY functions/layers can be located in DU. In another option, PDCP/RLC layers/functions may be located in the CU and MAC/PHY layers/functions may be located in the DU. Similarly, there may be other options to separate functions between CUs, DUs and RUs. In a radio access network architecture, due to user equipment (UE) mobility, a UE can move from one DU to another DU in the same CU, or a UE can move from one DU to another DU in a different CU. Alternatively, the UE may detect a radio link failure (RLF) on the source DU, and then switch to a target DU in the same CU or a different CU. Evolved from the existing H/W-based CU and DU operating method to implementing software and operating CU and DU in a cloud environment based on virtual machine (VM) or container technology. are doing

With the introduction of the cloud environment, internal resources can be used efficiently in developing applications or providing services, and container-based services that can deploy and manage agile applications in seconds can emerge. However, container-based microservices had a problem in responding to the explosively increasing user traffic. Existing services cannot move services between container platforms, and it is difficult to flexibly expand resources. Accordingly, a scaling-out/in method for balanced use of resources within a container in a cloud environment has attracted attention.

If server resources are dynamically allocated to DUs only enough to process RU data, the total amount of server resources required can be reduced. can't make a suggestion about it.

Server resources are allocated to DUs as much as the capacity needed to process the average data of RUs, and when the data capacity of RUs increases, additional DUs are executed on other servers, and some of the multiple RUs covered by the previous DUs are newly deployed. Traffic can be shifted to be handled by a dedicated DU. Dynamically allocating server resources to DUs can reduce overall resource (CPU, Memory, Accelerator, etc.) usage. There is a data flow between existing (source) DU-RU-UEs (terminals), and a method of seamlessly transferring the data flow to a new (target) DU-RU-UE is required.

Various embodiments describe a method of scaling a DU in a state in which communication of a terminal is not disconnected.

According to various embodiments, a radio access network apparatus including a distribution unit (DU), which controls a scaling process according to resource conditions of a first DU communicating with at least one first remote unit (RU) and a first server. A scaling controller and a second DU selected by the scaling controller based on resource usage information of the first DU, wherein the scaling controller is processing the service of the first DU The first RU selects a 2nd RU to be migrated to the 2nd DU from among the 2nd DU, and the 1st DU transmits information on the 2nd RU to be migrated to the 2nd DU; An apparatus for processing the service of the first DU in the remaining RUs except for the second RU is proposed.

According to various embodiments, a communication method of a wireless access network device including a distribution unit (DU), the method comprising information on resource usage of a first DU executed through a first server by a scaling controller Obtaining, selecting a second DU based on the information on the resource usage of the first DU by the scaling controller, and a first remote mode that is processing the service of the first DU by the scaling controller Selecting a second RU to be migrated to the second DU from among units (RUs), and transmitting information about the second RU to the second DU by the first DU; A method of processing the service of the first DU in the remaining RUs other than the second RU among the first RUs is proposed.

According to various embodiments, server resources required by all DUs can be efficiently used by enabling dynamic scaling of softwareized virtual DUs in a RAN that supports user terminals to connect and communicate.

According to various embodiments, instead of allocating dedicated DUs to RUs, the server resource pooling effect of the cloud platform is used to allocate server resources to DUs by the required amount according to the amount of traffic in the RU, thereby reducing the required server resources and reducing the number of servers Through this, power consumption can also be reduced.

According to various embodiments, a scheduler in charge of radio resource allocation within a DU may seamlessly control a radio bearer from a resource source DU allocated to a UE to a target DU.

1A shows a block diagram for illustrating a RAN and a core network (CN) in accordance with various embodiments.
Figure 1b shows a block diagram for explaining the hardware configuration of a RAN device according to various embodiments.
2A illustrates cell sites and central offices in a RAN system, according to various embodiments.
2B illustrates servers and resource pools in a cloud environment, according to various embodiments.
3A is a block diagram including network components, in accordance with various embodiments.
3B is a block diagram of a network including a plurality of DUs, in accordance with various embodiments.
3C shows the data flow of a DU and the migration of the data flow.
4 illustrates an operation by a scaling controller, according to various embodiments.
5A illustrates a process of scaling out by a scaling controller in a cloud environment according to resource usage of DUs.
5B illustrates a process of scaling in by a scaling controller in a cloud environment according to resource usage of DUs.

1A shows a block diagram for illustrating a RAN and a core network (CN) in accordance with various embodiments.

According to various embodiments, the RAN 150 includes at least one distributed unit (DU) 151, at least one central unit-control plane (CU-CP) 152, or at least one central unit CU-UP. -user plane) (153). Although the RAN 150 is shown as being connected to at least one RU (remote unit, or radio unit) 161, this is exemplary and at least one RU 161 is connected to the RAN 150, or or included in the RAN 150 . The RAN 150 may be an O-RAN, in this case, the DU 151 may be an O-DU, the CU-CP 152 may be an O-CU-CP, and the CU-UP 153 ) may be O-CU-UP, and RU 161 may be O-RU.

According to various embodiments, the RU 161 may communicate with a user equipment (UE) 160 . RU 161 may be a logical node that provides lower physical layer (low-PHY) functions and RF processing. The DU 151 may be a logical node providing RLC, MAC, and high-PHY functions, and may be connected to the RU 161, for example. The CUs 152 and 153 may be logical nodes that provide functions of radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) protocols. CU-CP 152 may be a logical node providing functions of the control plane portion of RRC and PDCP. CU-UP 153 may be a logical node providing the functionality of the user plane part of SDAP and PDCP.

According to various embodiments, the core network (eg, 5GC 5th generation core) 154 may include an access and mobility management function (AMF) 155, a user plane function (UPF) 156, or a session management function (SMF). ) (157). The AMF 155 may provide a function for managing access and mobility of each UE 160 . SMF 156 may provide session management functions. The UPF 156 may forward downlink data received from the data network to the UE 160 or uplink data received from the UE 160 to the data network. For example, the CU-CP 152 may be connected to the AMF 155 through an N2 interface (or NGAP interface). The AMF 155 may be connected to the SMF 157 through an N11 interface. The CU-UP 153 may be connected to the UPF 153 through an N3 interface.

1B is a block diagram illustrating a hardware configuration of a network device according to various embodiments.

According to various embodiments, the RAN device may include at least one of the processor 120, the storage device 130, or the communication module 190.

According to various embodiments, the processor 120, for example, the RIC 101 connected to the processor 120 by executing software (eg, a program) (or an electronic device configured to perform functions of the RIC 101). ), and can control at least one other component (eg, a hardware or software component) and perform various data processing or calculations. The software may include, for example, xAPP, but is not limited thereto. According to one embodiment, as at least part of data processing or operation, the processor 120 stores instructions or data received from other components in the storage device 130, and stores the instructions or data stored in the storage device 130. It can be processed, and the resulting data can be stored in the storage device 130 . According to one embodiment, the processor 120 may include at least some of a central processing unit, an application processor, a neural processing unit (NPU), or a communication processor, but the type of the processor 120 is limited. there is no The neural network processing device may include a hardware structure specialized for processing an artificial intelligence model. The artificial intelligence model may include machine learning (eg, reinforcement learning, supervised learning, unsupervised learning, or semi-supervised learning), but is limited to the above examples. An artificial intelligence model may include a plurality of artificial neural network layers, such as a deep neural network (DNN), a convolutional neural network (CNN), a recurrent neural network (RNN), and a restricted boltzmann (RBM) machine), deep belief network (DBN), bidirectional recurrent deep neural network (BRDNN), deep Q-networks, or a combination of two or more of the above, but is not limited to the above examples. The intelligence model may include, in addition to or alternatively, a software structure in addition to a hardware structure It will be understood by those skilled in the art that the storage device 130 is not limited to any device capable of storing data such as a disk (eg, HDD). will be.

According to various embodiments, the storage device 130 may store various data used by the processor 120 or the communication module 190 . Data may include, for example, input data or output data for software and related commands.

According to various embodiments, the communication module 190 may support establishment of a direct (eg, wired) communication channel or wireless communication channel between a RAN device and an external electronic device, and communication through the established communication channel. The communication module 190, for example, as long as it can support the E2 interface, the type is not limited. Meanwhile, when the RAN 150 is implemented as a single device, the communication module 190 may mean an interface for both entities.

A new radio access network (RAN) architecture in a communication system is a radio access network that includes centralized units (CUs), distributed units (DUs) and remote units (RUs). structure is being considered. Radio protocol stacks or functions for communication may be split between CUs and DUs in various ways. In the specification, this is called function split. By separating the RAN function, various types of operation are possible according to the environment of each mobile operator. Overall operating cost can be reduced by installing only RU equipment in the cell site, distributing CU and DU in the central office or cloud data center, and connecting them through fronthaul. There can be one or more DUs under one CU. Radio protocol stacks or functions for communication can be divided between CUs and DUs in various ways. For example, in one option, PDCP layer/functions may be located in CU and RLC/MAC/PHY functions/layers may be located in DU. In another option, PDCP/RLC layers/functions may be located in the CU and MAC/PHY layers/functions may be located in the DU. Similarly, there may be other options to separate functions between CUs and DUs. In a radio access network architecture, due to user equipment (UE) mobility, a UE can move from one DU to another DU in the same CU, or a UE can move from one DU to another DU in a different CU. Or, the UE may detect a radio link failure (RLF) on a serving DU and then switch to a target DU in the same CU or a different CU.

2A illustrates a cell site and a central office in a RAN system, according to various embodiments.

By separating the RAN function in the next-generation communication system, various types of operation are possible according to the environment of each mobile operator. For example, only at least one RU (211) equipment is installed in the cell site (210), and the CU (222) (or virtual CU) and at least one DU (221) (or virtual DU) are central office (220) or deployed in a cloud environment (eg, a cloud data center) and connected to the fronthaul (FH) 223, the overall operating cost can be reduced. One or more DUs 221 may correspond to (or be connected to) one CU 222 . In contrast to the existing H/W-based CU and DU operation method, the CU and/or DU may be implemented as software. For example, the CU and/or DU may be operated in a cloud environment based on virtual machine (VM) or container technology.

2B illustrates servers and resource pools in a cloud environment, according to various embodiments.

Referring to the embodiment shown on the left side of FIG. 2B , at least one DU 231 may be connected to each of the at least one cell site 210 . For example, one or more RUs 211 may correspond to (or be connected to) one cell site 210 . According to the embodiment shown on the left, for example, one DU 231 may be fixedly corresponded to (or connected to) one cell site 210 . This is because a dedicated DU for the cell site 210 (or an entity constituting the cell site 210 (eg, one or more RUs 211) may be set, and accordingly, the DU 231 It can be exemplarily named as a dedicated DU. That a dedicated DU is set for one cell site 210 means that a dedicated DU for one or more RUs 211 constituting one cell site 210 For the execution of each dedicated DU, the network device must allocate (or execute) a server (eg, a VM or container) for each dedicated DU, and the size specified for the execution of the server Resources greater than or equal to a specified size may be allocated in advance or may be flexible. On the other hand, referring to the left side of FIG. 2B, each of at least one DU (320a, 320b) has a bar-shaped indicator ( 231a) is displayed Each indicator 231a may indicate a ratio of a resource currently being used in each of the at least one DU 231 to a maximum resource available in the at least one DU 231. The maximum available resource may be, for example, the maximum available resource allocated to a server (eg, a VM or a container) for executing a dedicated DU As shown in the left embodiment of FIG. 2B, for a cell site When dedicated DUs correspond (or are connected), all available resources in one DU (eg, DU 231) may not be used, and thus idle resources may occur, which may cause For example, available resources may be determined by assuming a case in which the maximum number of UEs are connected to one or more RUs 211, and accordingly, UEs smaller than the maximum number are connected to the RU 211. In the case of connection, idle resources may occur, but since fixed resources are allocated to one or more RUs 211, the idle resources are unavailable.

Referring to the embodiment on the right side of FIG. 2B , a resource pooling function may be utilized by placing a server pool 232 in a cloud environment instead of allocating a dedicated DU 231 to the RU 211 . In contrast to the embodiment on the left side of FIG. 2B, rather than a dedicated DU for one cell site being allocated, one server (eg, server 232b) corresponds to RUs included in a plurality of cell sites. function can be performed. For example, the server 232b may perform a function corresponding to an RU included in another cell site while performing a function corresponding to an RU included in one cell site. The network device may determine a server to perform a corresponding function in units of RUs (or in units of UEs included in RUs). Accordingly, as shown in the right-side embodiment of FIG. 2B, one server (eg, server 232a) is a resource for performing a function corresponding to an RU included in the first cell site 210a. Resources 233b for performing functions corresponding to RUs included in 233a and the second cell site 210b may be allocated. Accordingly, the server 232a uses the remaining idle resources after allocating the resource 233a for processing of the first cell site 210a as a resource for processing of at least one RU included in the second cell site 210b. 233b, idle resources can be minimized. A server 232c to which resources are not allocated may not be used.

Referring to FIG. 2B, a portion of at least one server 232b and a server 232c indicated by a dotted line may mean surplus servers that are not allocated to perform the function of the DU, in other words, resources of unallocated servers, , Resource waste can be prevented by not running redundant servers or allocating resources to the network device.

Referring to FIG. 2B, one or more RUs 211 constituting one cell site 210 are allocated to each dedicated DU 231, but when the server pool 232 is used, the RU 211 ) may allocate resources of an arbitrary server in the server pool 232 as much as the amount of traffic required. Accordingly, in the central office 220, the number of servers driven to perform the functions of the DU 221 through the server pool 232 may be reduced.

3A is a block diagram including network components, in accordance with various embodiments.

According to various embodiments, radio protocol stacks or functions for communication may be divided between the CU 310 and the DU 311 in various ways. For example, packet data convergence protocol (PDCP) 311 / RRC 312 / SDAP 313 layers / functions are located in CU 310 and RLC 325 / MAC 327 / PHY 239 functions /Layers can be located in DU (311). In another option, PDCP 311/RRC 312/SDAP 313 layers/functions are located in CU 310 and RLC 325/MAC 327 layers/functions are located in DU 320. It can be. Similarly, there may be other options to separate functionality between CU 310 and DU 311. In a radio access network structure, due to user equipment (UE) mobility, a UE 340 can move between RUs 330a, 330b, and 330c within the same DU 320 or can move to the RU connected to the DU of Alternatively, the UE 340 may detect a radio link failure (RLF) on the same DU 320, and then switch to a DU other than the DU 320 in the same CU 310 or a different CU can do.

According to various embodiments, the three-tiered structure of the CU 310, DU 320, and RU 330 constituting the RAN is a 5G structure for building a 5G RAN flexibly for various 5G applications (eMBB, URLLC, mMTC, etc.) A base station (gNB) can be configured.

Referring to FIG. 3A, the base station is divided into a three-tiered structure, and RRC, SDAP, and PDCP can be classified as CU, RLC, MAC, and high PHY as DU, and low PHY as RU. Specifically, midhaul channels may be located between the CU (310) and the DU (311), and fronthaul channels may be located between the DU (311) and the RU (331). Separation points of function are not limited to those shown in the drawings.

3B is a block diagram of a network including a plurality of DUs, in accordance with various embodiments.

According to various embodiments, the network device includes a CU 310, at least one or more DUs (eg, a source DU 320a and a target DU 320b in FIG. 3B), a scaling controller 312, and a CU 310. F1 splitter 311 decoupling at least one or more DUs 320a, 320b, scaling controller 312 controlling scaling process, F1 handlers 321a, 321b included in at least one or more DUs, scale agent (322a, 322b). RLC (325a, 325b), MAC (327a, 327b), PHY-H (329a, 329b), scheduler (324a, 324b), fronthaul handler (323a, 323b), at least one or more DUs (320a, 320b) and at least one A fronthaul splitter 331 decoupling the RUs 330a, 330b, and 330c and at least one UE 340 corresponding to each of the at least one or more RUs 330a, 330b, and 330c.

According to various embodiments, the CU 310 may transmit downlink data to the UE 340 or transmit uplink data received from the UE 340 to the network in the UE's data flow on the U-plane. . A description of the CU 310 may apply mutatis mutandis to that of FIGS. 1A to 3A.

According to various embodiments, referring to the 3GPP F1 interface standard, the F1 splitter 311 provides a decoupling function between the CU 310 and the DUs 320a and 320b. The CU 310 may provide a function for recognizing the source DU 320a and the target DU 320b as one DU. A data flow path (IP address translation) between the CU 310, the source DU 320a, and the target DU 320b can be controlled. The F1 splitter 311 may be a standalone component or a component included in the CU 310 .

According to various embodiments, the scaling controller 312 may control overall scaling. Referring to FIG. 3B, the scaling controller 312 may communicate with a source DU 320a, a target DU 320b, an F1 splitter 311, and a fronthaul splitter 331. According to various embodiments, the scaling controller 312 may receive a report on resource usage from the source DU 320a in order to determine whether scaling out is necessary in the source DU 320a. When it is determined that scaling out is necessary, the scaling controller 312 may request a cloud platform such as Kubernetes to create a new target DU 320b. The scaling controller 312 may transmit information on the target DU 320b to the F1 splitter 311 and the fronthaul splitter 331 to register the target DU 320b to the F1 splitter 311 and the fronthaul splitter 331. there is. Alternatively, the scaling controller 312 transmits information on the target DU 320b to the F1 splitter 311 and the fronthaul splitter 331 to register the target DU 320b to the F1 splitter 311 and the fronthaul splitter 331 It may instruct the scale agents 322a and 322b.

According to various embodiments, the descriptions of FIGS. 1A to 3A may be applied to DUs 320a and 320b. Referring to Figure 3b, the source DU (320a) is F1 handler (321a), scale agent (322a), fronthaul handler (323a), scheduler (324a), RLC (325a), MAC (327a), PHY-H (329a) ) may be included. According to various embodiments, the source DU 320a may report resource usage to the scaling controller 312 through the scale agent 322a regularly or under certain conditions. According to various embodiments, the target DU (320b) that receives traffic processing from the source DU (320a) is a F1 handler (321b), scale agent (322b), fronthaul handler (323b), scheduler (324b) ), RLC 325b, MAC 327b, and PHY-H 329b. The scale agent 322b of the target DU 320b may receive information for context synchronization from the scale agent 322a of the source DU 320a.

According to various embodiments, the F1 handlers 321a and 321b are configured to communicate with the CU 310 within the DUs 320a and 320b and may conform to the 3GPP F1 interface standard.

According to various embodiments, the fronthaul handlers 323a and 323b are parts that communicate with the RU 330 within the DU 320 and may comply with the ORAN Fronthaul standard (7.2x) or the Small Cell Forum's nFAPI.

According to various embodiments, according to the ORAN Fronthaul standard, the fronthaul (FH) splitter 331 may provide a decoupling function between DUs 320a and 320b and RUs 330a, 330b and 330c. The RUs 330a, 330b, and 330c may provide a function of recognizing the source DU 320a and the target DU 320b as one DU. A data flow path (MAC Address Translation) between the RUs 330a, 330b, and 330c, the source DU 320a, and the target DU 320b can be controlled. According to various embodiments, the fronthaul splitter 331 may be a standalone component or a component included in the RU 330.

According to various embodiments, the RU 330 may communicate with the UE 340. RU 330 may be a logical node providing lower physical layer (PHY-low) functions and RF processing. The RU 330 may be connected to or included in the RAN. A description of the RU 330 may apply mutatis mutandis to that of FIGS. 1A to 3A. 3C shows the data flow of a DU and the migration of the data flow.

According to various embodiments, due to the mobility of a user equipment (UE) in a radio access network structure, the UE 340 is one DU in the same CU 310 (eg, the source DU of FIG. 3B). (320a)) to another DU (eg, target DU (320b) of FIG. 3B). Alternatively, the UE 340 may move from one DU (eg, source DU 320a in FIG. 3B) to another DU (eg, target DU 320b in FIG. 3B) in a different CU. For example, the UE 340 may detect a radio link failure (RLF) on one DU (eg, the source DU 320a of FIG. 3B), and then the same CU 310 Alternatively, it may be switched to another DU (eg, target DU 320b of FIG. 3B) in a different CU.

Referring to FIG. 3c, the target DU (320b) may be a DU generated (301) by the scaling controller (312) for scaling out, or in the process of generating the target DU (320b), the previously generated DU is scaled out Those skilled in the art will understand that it may be replaced by what is designated for. The scaling controller 312 transmits information on the target DU 320b to the F1 splitter 311 so that the F1 splitter 311 can register a new DU (302). For example, at least one event for scaling out may be detected in the source DU 320a, and a target DU 320b for scaling out may be generated (or designated) in response to the detected event. Here, the event is, for example, that the source DU 320a (or a server for driving the source DU 320a) is available This may mean that the ratio of the size of the resource currently being used to the total available resources is greater than or equal to the critical ratio, but this is an example, and the resource being used in the source DU (320a) is relatively excessive and scaling out is required. A person skilled in the art will understand that this is not the case. The scaling controller 312 may transmit information on the new DU to the fronthaul splitter 331 to register 303 information on the new DU. The current source DU (320a) may transmit the context to the target DU (320b) in order to synchronize (304) the context with the target DU (320b). For example, the context may include system information (synchronization, system information block, random access, reference signal), scheduling context (can include channel status, power management, HARQ, DRX), control information (MAC- CE and paging information may be included.), frequency resource (carrier aggregation, BWP, and SUL information may be included), and spatial resource (beam management, MINO information may be included.) It may include at least one of UE context (which may include information on RNTI, SRB, DRB, and RAT) or RU context. Here, the context may be associated with a RU (or at least one UE connected to the corresponding RU) for which migration is requested among at least one RU 330 corresponding to (or connected to) the source DU 320a. can, but there is no limit. The target DU 320b may receive the above-described context, and accordingly may check information on an RU to be migrated (or at least one UE connected to the corresponding RU). The F1 splitter 311 may prepare data to be transmitted or data to be received 305 according to downlink/uplink resource allocation information for the target DU 320b. The fronthaul splitter 311 may receive transmission data prepared according to downlink/uplink resource information allocated to the target DU 320b or transmit it to the target DU 320b (306). For the aforementioned operations 301 to 306 of FIG. 3c, the data flow is transferred to the target DU 320b for at least one UE connected to the RU (eg, 330c) in charge of the target DU 320b through a data radio bearer The above operations may be repeated 307 for each UE. Accordingly, information on at least one UE connected to the RU 330c to be scaled out may be provided to the target DU 320b, and transmission of downlink data and/or uplink data associated with the at least one UE and/or Alternatively, the reception procedure may be managed.

4 illustrates an operation by a scaling controller, according to various embodiments.

According to various embodiments, in the wireless access network apparatus, information on the resource usage of a first source DU (320a in FIG. 3B) executed through the first server by the operation of the scaling controller (312 in FIG. 3B) It may be acquired (401) from the first DU (320a). A second DU (target DU, 320b in FIG. 3B) may be selected (403) based on the information on the resource usage of the first DU 320a by the scaling controller 312 of FIG. 3B. The scaling controller 312 transfers the service of the first DU 320a to the second DU (eg, 320b of FIG. 3B) among the first RUs (eg, 330a, 330b, and 330c of FIG. 3B) that are processing the service. The second RU (eg, 330c of FIG. 3B) may be selected (405). A communication session is established with the first DU 320a so that information on the second RU (eg, 330c in FIG. 3B) is transmitted from the first DU 320a to the second DU 320b by the scaling controller 312 You may request 407 to do so. A specific operation of the scaling controller will be described below.

5A and 5B illustrate scale-out and scale-in processes by a scaling controller in a cloud environment according to resource usage of DUs.

According to various embodiments, when applications or workloads running in the cloud are running in virtual machines (VMs) or logical partitions that cause memory shortage problems or performance degradation, container-based scaling out or scaling in can do

Referring to FIG. 5A, a source DU (320a) may report a resource status to a scaling controller (312) (501). Based on the reported resource status, the scaling controller 312 may determine whether to scale out (503). The scaling controller 312 may generate a target DU 320b to be scaled out. The scaling controller 312 may register information about the target DU 320b to the F1 splitter and fronthaul splitter (505). The scaling controller 312 selects a previous target RU (eg, 330a, 330b, and 330c of FIG. 3b) to be migrated to a target DU (320b) among RUs (eg, 330a, 330b, and 330c in FIG. 3b) that are processing the service of the source DU (320a). 330c of 3b) may be selected (507). The scaling controller 312 may select (509) a server for scaling out (eg, 232b or 232c of FIG. 2B). The scaling controller 312 switches the data flow from the source DU 320a to the target DU 320b for the UE 340, which is the previous target connected to the RU (eg, 330c in FIG. 3B), which is the previous target RU (511) can do. The previous switching operation may be repeated (513) for each UE until all UEs 340 connected to the previous target RU (eg, 330c in FIG. 3B) are transferred to the target DU 320b. .

Referring to FIG. 5B, the target DU 320b may report the resource status to the scaling controller 312 (521). Based on the reported resource status, the scaling controller 312 determines whether to scale in, and the scaling controller 312 can select a target DU 320b to scale in (523). The scaling controller 312 selects a previous target RU (eg, 330a, 330b, and 330c in FIG. 3B) to be migrated to the source DU 320a among RUs (eg, 330a, 330b, and 330c in FIG. 3B) that are processing the service of the target DU 320b. 330c of 3b) may be selected (525). The scaling controller 312 may select (527) a server for scaling in (eg, 232b of FIG. 2B). The scaling controller 312 switches the data flow from the target DU 320b to the source DU 320a for the previous target UE 340 connected to the previous target RU (eg, 330c in FIG. 3B) (529 ) can do. The previous switching operation may be repeated (531) for each UE until all UEs 340 connected to the RU (eg, 330c in FIG. 3B) are transferred to the source DU 320a. .

The specific process may be as follows.

1) scaling out process

a) The scaling agent 322 periodically monitors resource status such as CPU usage, memory usage, network throughput, power consumption, and accelerator usage (FPGA/GPU/Smart NIC, etc.) of the DU (320) server by scaling controller ( 312) can be reported. According to various embodiments, the scaling agent 322 may report when a resource usage condition previously set by the scaling controller 312 is satisfied instead of reporting periodically.

b) The scaling controller 312 selects the DU 320 to be scaled out based on the resource usage information of the DU 320 (scaling decision), The RU 330 to be moved to the server and processed may be selected. According to various embodiments, selection of a source DU (320a) to be scaled can be selected according to various policies. For example, if the server resources allocated to the source DU (320a) are allocated to process 30% of the peak throughput and 3 RUs per RU, the total throughput is 60% (30% x 2) or more of the peak When it is done, scaling out of the corresponding DU can be started. Alternatively, the optimal DU to be scaled can be selected through artificial intelligence/machine learning technology. According to various embodiments, the scaling controller 312 may generate a target DU 320b, which is a new DU to be scaled out, and register the target DU 320b to the F1 splitter 311. The scaling controller 312 may register the target DU 320b to the fronthaul splitter. According to various embodiments, selection of the RU 330 is selectable by various policies. For example, among the RUs 330 processing the service of the source DU 320a in the current server (eg, 232a in FIG. 2B), an RU having a throughput smaller than the average is selected and transferred to another server (eg, FIG. 2B). The service of the target DU 320b may be executed in 232b of 2b) and moved to be processed by the RU corresponding to the target DU 320b. Alternatively, an RU having the highest throughput may be selected, the target DU 320b may be executed on a server having capacity capable of processing the peak rate, and the RU corresponding to the target DU 320b may be processed.

c) The scaling controller 312 selects a server (eg, 232b in FIG. 2b) having processing capacity in the target DU 320b for a new service (scale out server selection) and executes the service in the server. . According to various embodiments, selection of a server for executing the target DU 320b service can be selected according to various policies. For example, a server capable of processing the maximum amount of data for one RU 330 or a server capable of processing average data may be selected. Server selection for scaling out is related to a policy for selecting an RU 330 to be scaled out. If the RU (330) targeted for scaling out, that is, the RU whose processing is transferred to the target DU (320b) service needs to process the peak rate, the service of the target DU (320b) has the resource capacity to handle the corresponding traffic. It can run on the server. Making the target DU (320b) service run on a server having necessary resources can generally be performed through a cloud platform such as Kubernetes. The scaling controller 312 may provide necessary resource information so that the cloud platform can select a server to execute a DU service.

d) The scaling controller 312 can register the service of the target DU 320b to the F1 splitter 311. For example, the F1 splitter 311 prepares to transmit (switch) data transmitted to the source DU 320a to the target DU 320b using the registered information. If necessary, the F1 splitter 311 may newly create a stream control transmission protocol (SCTP) communication session with the target DU 320b. (transport network layer connection)

e) The scaling controller 312 may allow the service of the target DU 320b to be registered in the FH splitter 331. (including transport network layer connection)

For example, the FH splitter 331 may prepare to transmit (switch) data transmitted to the source DU 320a to the target DU 320b using the registered information.

f) The scaling controller 312 may instruct creation of a communication session for context synchronization between the scale agents 322 in the source DU 320a and the target DU 320b.

g) The scale agent (322a) of the source DU (320a) starts transmitting the context for the RU (330) that is the migration target to the scale agent (322b) of the target DU (320b), and the changed part of the context continues you can update it. Transmitted context may be information on UE context, channel state, radio resource scheduling information, and system information.

h) The scale agent 322a may select a UE to be processed in the target DU 320b from among UEs connected to the RU 330 to be migrated. According to various embodiments, UE selection is possible through various policies. For example, it is possible to move from a UE in an inactive state and sequentially select a UE in a connected state in an order from a UE having a small data transmission rate to a large number of UEs. The reverse order is also possible. Alternatively, the DRB QoS values of the UEs may be compared and selected in the order of lowest priority.

i) The scale agent 322a of the source DU 320a may transmit information about a UE to be migrated to the scale agent 322b of the target DU 320b. For example, the transmitted information about the UE may include a signaling radio bearer (SRB) list, a data radio bearer (DRB) list, and the like.

j) The scale agent 322a of the source DU 320a may request the F1 splitter 311 to transmit data toward the UE, which is a migration target, to the target DU 320b. According to various embodiments, the F1 splitter 312 transmits all data going to the UE to be migrated to the target DU 320b (switching the data path from the source DU 320a to the target DU 320b) can do.

k) The scale agent 322a of the source DU 320a may request the scheduler of the source DU 320a to stop allocating uplink/downlink resources to the UE as a migration target.

l) The scale agent 322a of the source DU 320a may transmit currently remaining uplink/downlink data to the scale agent 322b of the target DU 320b.

m) The target DU (320b) resets the buffer with the data received from the source DU (320a) and the F1 splitter (311), and may prepare to transmit and receive data to and from the UE.

n) The scale agent 322b of the target DU 320b may notify the scale agent 322a of the source DU 320a of completion of preparation for data transmission and reception with respect to the UE.

o) The scale agent 322a of the source DU 320a may request the scheduler to re-allocate uplink/downlink resources for a migration target UE.

p) The scale agent 322a of the source DU 320a may deliver Uplink/Downlink resource allocation information for the UE of a migration target to the scale agent 322b of the target DU 320b to the scheduler. According to various embodiments, scheduling information may be continuously transmitted until migration of the RU 330 is completed.

q) The scale agent 322a of the source DU 320a may transmit source DU address and/or target DU address information to the FH splitter 331.

r) The target DU may prepare transmission data according to Uplink/Downlink resource allocation information and transmit to or receive from the FH splitter 331.

s) When the FH splitter (331) receives a C-Plane Message (ORAN Fronthaul 7.2x standard) from the target DU (320b), it can process it as follows. According to various embodiments, since the RU 330 cannot know the new target DU 320b, the FH splitter 331 can change the MAC address of the source DU 320a and transmit it to the RU 330. At least one of FrameID, SubframeID, SlotID, SymbolID, and SectionID of the C-Plane Packet may be stored. For example, in the case of uplink, when receiving a packet having the MAC address of the source DU (320a) as the destination address from the RU (330), at least one of FrameID, SubframeID, SlotID, SymbolID, and SectionID is checked, and if it matches the stored one, the target The destination address can be changed to the MAC address of the DU (320b). For example, in the case of downlink, when receiving a U-Plane packet from the target DU (320b), the RU (330) does not know the changed target DU (320b), so it changes to the MAC address of the source DU (320a) and returns to the RU (330). can transmit

t) In the process of h to s, the control agent 322a of the source DU 320a selects a UE to be processed by the target DU 320b among UEs connected to the RU 330 to be migrated All UEs connected to the target RU perform a series of processes from the process to the process in which the FH splitter 331 receives the C-plane message from the target DU and transmits the MAC address of the source DU 320a to the target RU. It can be performed repeatedly until it is migrated to the target DU (320b).

u) The scale agent 322a of the source DU 320a may request the scale agent 322b of the target DU 320b to process scheduling of the migration RU.

v) The scale agent 322a of the source DU 320a may notify the scaling controller 312 of the completion of migration to the migration RU and may remove information about the migration RU. According to various embodiments, the scale agent 322a of the source DU 320a maintains information about RUs for which migration has been completed, receives information about RUs from the scale agent 322b of target DUs 320b, and performs synchronization. can proceed.

w) The scaling controller 312 may notify the F1 splitter 311 and the FH splitter 331 of completion of migration of the RU 330. For example, the F1 splitter 311 may perform IP address-based Network Address Translation (NAT) to switch data to the RU 330 where the transfer is completed. The FH splitter 331 may perform medium access control (MAC) address-based network address translation (NAT) for data switching from the RU 330 on which the transfer is completed to the target DU 320b.

2) scaling in process

a) The scaling agent (322a) of the source DU (320a) periodically monitors the resource status such as CPU utilization, memory utilization, network throughput, power consumption, and accelerator usage (FPGA/GPU/Smart NIC, etc.) of the DU server. It can be reported to the scaling controller 312. According to various embodiments, instead of periodically reporting to the scaling controller 312, the scaling agent 322a may report when the scaling controller 312 satisfies a previously set resource usage condition.

b) The scaling controller 312 selects a DU (target DU) to be scaled in based on the resource usage information of the DU 320 (scaling decision), and the first server (eg, 232c of FIG. 2B) selects the target DU Among the RUs 330 that are processing services, an RU (eg, 330c) to be processed by moving the service to another server (eg, 232b in FIG. 2B) may be selected. According to various embodiments, selection of a DU (target DU 320b) to be scaled in can be performed with various policies. As an example, the resources allocated to the target DU (320a) are allocated to process three RUs (eg, 330a, 330b, and 330c in FIG. 3B) based on 30% of the peak throughput of the RU. , today If one RU (eg, 330a in FIG. 3B) is connected and uses 20% of the capacity that can be processed (total 90%), scaling in can be started. Alternatively, the scaling controller 312 may select an optimal DU to be scaled through artificial intelligence/machine learning technology. The scaling controller 312 can select the RU 330 according to various policies. For example, among the RUs (eg, 330a, 330b, and 330c of FIG. 3B) processing the service of the target DU 320b in the server (eg, 232c of FIG. 2B), RUs having a throughput smaller than the average ( For example, by selecting 330c of FIG. 3b), the target DU (320b) service can be executed in another server (eg, 232b of FIG. 2b) and moved to be processed by the corresponding RU (330c). Alternatively, the scaling controller 312 may select an RU having the largest throughput and process the RU, which is a transfer target, as the source DU 320a capable of handling the corresponding capacity.

c) The scaling controller 312 selects a server (eg, 232b of FIG. 2b) having processing capacity for the target DU 320b service (scaling in server selection) and executes the service on the corresponding server. According to various embodiments, selection of a server for executing the service of the target DU 320b can be selected according to various policies. For example, the scaling controller 312 may select a server capable of processing a peak data rate or a server capable of processing an average rate among several RUs. The selection of a server to be a target for scaling in may be related to a policy for selecting an RU to be a target for scaling in. If the scaling controller 312 has a throughput of 20% of the peak of the RU targeted for scaling in (the RU to which processing is transferred to the target DU service), 20% of the target DU 320b than the scaling out reference value A corresponding RU may be moved to a DU (eg, source DU 320a) using the following resources. According to various embodiments, retrieving resources used by a DU (eg, target DU 320b) service from a server may be generally performed through a cloud environment such as Kubernetes. A server whose resources are recovered (eg, 232c of FIG. 2B ) may be removed from the cloud environment. Alternatively, the target DU 320b may be removed by moving the corresponding RU from the target DU 320b using less resources to the source DU 320a. The scaling controller 312 may provide information for deleting a DU (eg, target DU 320b) service in a cloud environment.

d) The scaling controller 312 modifies the information registered to the F1 splitter 311 of the target DU 320b to be scaled in (when the target DU 320b scales in to a server different from the source DU 320a), or It can be deleted (when the target DU (320b) scales in to the same server as the source DU (320a)).

e) The scaling controller 312 modifies the information registered in the fronthaul splitter 331 of the target DU 320b to be scaled in (when the target DU 320b scales in to a server different from the source DU 320a), or It can be deleted (when the target DU (320b) scales in to the same server as the source DU (320a)).

f) The scaling controller 312 may instruct creation of a communication session for context synchronization between the scale agents 321a and 321b in the source DU 320a and the target DU 320b.

g) The scale agent 322b of the target DU 320b may start transmitting the context for the RU (eg, 330c) that is the migration target to the scale agent 322a of the source DU 320a, and the context The changed part of can be continuously updated. According to various embodiments, context may include at least one or more of UE Context, Channel State, Radio Resource Scheduling Information, and System Information.

h) The scaling agent 322b of the target DU 320b selects a UE to be processed by the source DU 320a from among at least one UE connected to the previous target RU (eg, 330c in FIG. 3B). there is. According to various embodiments, the scaling agent 322b may select an RU (eg, 330c of FIG. 3B ) as a transfer target according to various policies. For example, UEs in an inactive state may be moved, and among UEs in an RRC connected state, UEs with small data transmission may be sequentially selected in the order of many UEs. Alternatively, the DRB QoS values of the UEs may be compared and selected in the order of lowest priority.

i) The scale agent 322b of the target DU 320b may transmit information about the UE as a transfer target to the scale agent 322a of the source DU 320a. According to various embodiments, the scale agent 322b of the target DU 320b may transmit information about the RU to the scale agent 322a of the source DU 320a before transmitting information about the UE. According to various embodiments, the information on the UE may include a Signaling Radio Bearer (SRB) List and a Data Radio Bearer (DRB) List.

j) The scale agent 322b of the target DU 320b may request the F1 splitter 311 to send data directed to the previous target UE to the source DU 320b. According to various embodiments, the F1 splitter 311 may transmit all data going to the previous target UE as the source DU 320a. That is, the data flow can be switched from the target DU 320b to the source DU 320a.

k) The scale agent 322b of the target DU 320b may request the scheduler 324b to stop allocating uplink/downlink resources to the UE, which is the transfer target.

l) The scale agent 322b of the target DU 320b may transmit currently remaining uplink/downlink data to the scale agent 322a of the source DU 320a.

m) The source DU (320a) resets the buffer with the data received from the target DU (320b) and the F1 splitter (311), and can prepare for UE data transmission and reception.

n) The scale agent 322a of the source DU 320a may notify the scale agent 322b of the target DU 320b of completion of preparation for data transmission and reception with respect to the UE.

o) The scale agent 322b of the target DU 320b may request the scheduler 324b to re-allocate uplink/downlink resources for the UE that is the previous target.

p) The scale agent 322b of the target DU 320b may deliver uplink/downlink resource allocation information to the UE as a transfer target of the scheduler 324b to the scale agent 322a of the source DU 320a. According to various embodiments, the scale agent 322b of the target DU 320b may continue to deliver scheduling information until the transfer of the target RU is completed.

q) The scale agent 322b of the target DU 320b may transmit source DU Address and target DU Address information to the FH Splitter 331.

r) The source DU (320a) may prepare transmission data according to the uplink/downlink resource allocation information and transmit it to the fronthaul splitter (331) or receive it from the fronthaul splitter (331).

s) When the fronthaul splitter (331) receives a C-Plane message (ORAN Fronthaul 7.2x standard) from the source DU (320a), it changes to the MAC address of the target DU (320b) and transmits it to the RU, and the FrameID of the C-Plane packet , SubframeID, SlotID, SymbolID, and SectionID may store at least one or more. According to various embodiments, in the case of uplink transmission, when the fronthaul splitter 331 receives a packet having the MAC address of the target DU 320b as a destination address from the RU 330, FrameID, SubframeID, SlotID, After checking at least one of SymbolID and SectionID, if it matches the stored one, the destination address can be changed to the MAC address of the source DU (320a). According to various embodiments, in the case of downlink transmission, when the fronthaul splitter 331 receives a U-Plane packet from the target DU 320b, it can be changed to the MAC address of the source DU 320a and then the changed address can be transmitted to the RU. .

t) Processes h to s may be repeatedly performed for each UE until all UEs connected to the RU to be transferred are transferred to the source DU 320a.

u) The scale agent 322b of the target DU 320b may request the scale agent 322a of the source DU 320a to process scheduling of an RU (eg, 330c) as a transfer target.

v) The scale agent 322b of the target DU 320b notifies the scaling controller 312 of the transfer completion of the transfer target RU (eg, 330c in FIG. 330c) may be removed.

w) The scaling controller 312 may notify the F1 splitter 311 and/or the fronthaul splitter 331 of transfer completion of the RU (eg, 330c).

x) The scaling controller 312 may delete an instance of the target DU 320b when there is no RU 330 processed by the target DU 320b.

According to various embodiments according to the present disclosure, in a 5G RAN system composed of CUs, DUs, and RUs, an F1 splitter decoupling CUs and DUs, a fronthaul splitter decoupling DUs and RUs, and a scaling process according to server resource conditions. We propose a software and device consisting of a scaling controller that controls and a scaling agent that communicates with the scaling controller to control data flow required for scaling within a DU and handles context synchronization between DUs.

According to various embodiments, when a resource allocated to a terminal is moved from a source DU to a target DU using a scheduler in charge of resource allocation within a DU, a radio bearer can be seamlessly controlled.

According to various embodiments, RU and target DU based on Frame ID, Subframe ID, Slot ID, Symbol ID, and Section ID information for conversion (switching) from a data flow between source DU and terminal to data flow between target DU and terminal It can be changed to the data flow for .

According to various embodiments, instead of allocating dedicated DUs to the RU 330, server resources may be allocated to the DU 320 by a required amount according to the amount of traffic of the RU through server resource pooling of the cloud platform. As a result, server resources may be secured and the number of servers may be reduced, and thus power consumption may also be reduced.

According to various embodiments, a resource pool may refer to a state in which resources such as at least one server or storage are secured and provided according to a user's request, and may be implemented in a virtual space. In a cloud environment, resources can be provided immediately or upon request by a user through a minimal process through a resource pool secured in advance.

Electronic devices according to various embodiments disclosed in this document may be devices of various types. The electronic device may include, for example, a communication company base station system and a private network device (Private 5G system). An electronic device according to an embodiment of the present document is not limited to the aforementioned devices.

Various embodiments of this document and terms used therein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various modifications, equivalents, or substitutes of the embodiments. In connection with the description of the drawings, like reference numbers may be used for like or related elements. The singular form of a noun corresponding to an item may include one item or a plurality of items, unless the relevant context clearly dictates otherwise. In this document, "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "A Each of the phrases such as "at least one of , B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first", "second", or "first" or "secondary" may simply be used to distinguish a given component from other corresponding components, and may be used to refer to a given component in another aspect (eg, importance or order) is not limited. A (e.g., first) component is said to be "coupled" or "connected" to another (e.g., second) component, with or without the terms "functionally" or "communicatively." When mentioned, it means that the certain component may be connected to the other component directly (eg by wire), wirelessly, or through a third component.

The term "module" used in various embodiments of this document may include a unit implemented in hardware, software, or firmware, and is interchangeable with terms such as, for example, logic, logical blocks, parts, or circuits. can be used as A module may be an integrally constructed component or a minimal unit of components or a portion thereof that performs one or more functions. For example, according to one embodiment, the module may be implemented in the form of an application-specific integrated circuit (ASIC).

Various embodiments of this document provide one or more instructions stored in a storage medium (eg, internal memory 136 or external memory 138) readable by a machine (eg, electronic device 101). It may be implemented as software (eg, the program 140) including them. For example, a processor (eg, the processor 120 ) of a device (eg, the electronic device 101 ) may call at least one command among one or more instructions stored from a storage medium and execute it. This enables the device to be operated to perform at least one function according to the at least one command invoked. The one or more instructions may include code generated by a compiler or code executable by an interpreter. The device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-temporary' only means that the storage medium is a tangible device and does not contain a signal (e.g. electromagnetic wave), and this term refers to the case where data is stored semi-permanently in the storage medium. It does not discriminate when it is temporarily stored.

According to one embodiment, the method according to various embodiments disclosed in this document may be included and provided in a computer program product. Computer program products may be traded between sellers and buyers as commodities. The computer program product is distributed in the form of a device-readable storage medium (e.g. compact disc read only memory (CD-ROM)), or through an application store (e.g. Play StoreTM) or distribution system of a mobile operator. , it can be distributed (e.g., downloaded or uploaded) online. In the case of online distribution, at least part of the computer program product may be temporarily stored or temporarily created in a device-readable storage medium such as a manufacturer's server, an application store server, or a relay server's memory.

According to various embodiments, each component (eg, module or program) of the above-described components may include a single object or a plurality of entities, and some of the plurality of entities may be separately disposed in other components. there is. According to various embodiments, one or more components or operations among the aforementioned corresponding components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (eg modules or programs) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by a corresponding component of the plurality of components prior to the integration. . According to various embodiments, the actions performed by a module, program, or other component are executed sequentially, in parallel, iteratively, or heuristically, or one or more of the actions are executed in a different order, or omitted. or one or more other actions may be added.

Claims (20)

A radio access network device comprising a distributed unit (DU), comprising:
a first DU communicating with at least one or more first remote units (RUs);
a scaling controller controlling a scaling process according to resource conditions of the first server; and
A second DU selected by the scaling controller based on the resource usage information of the first DU;
The scaling controller selects a second RU to be migrated to the second DU from among the first RUs processing the service of the first DU;
The first DU transmits information about the second RU, which is a transfer target, to the second DU;
And the remaining RUs other than the second RU among the first RUs process the service of the first DU.
According to claim 1,
wherein the scaling controller is configured to select a second server having capacity to execute the service of the second DU.
According to claim 1,
The selected second DU provides at least a part of the service of the first DU to a second server different from the first server, based on the resource usage of the first DU satisfying a condition related to the available resources of the first server. The device selected as the second DU to be processed using
According to claim 1,
The information on the second RU includes a signaling radio bearer (SRB) list and a data radio bearer (DRB) list for the UE to be transferred.
According to claim 1,
The information on the second RU includes at least one of information about a UE related to the second RU, information about a channel state, radio resource scheduling information, and system information. in device.
According to claim 1,
The device configured to create a communication session for the first DU to synchronize information on a second RU, which is a transfer target, to the second DU.
According to claim 1,
The second DU is configured to select a UE to be processed by the second DU from among UEs connected to the second RU.
According to claim 1,
The first DU is configured to transmit information about a UE that is a transfer target to the second DU, and the UE that is the transfer target processes a service for the second DU.
According to claim 1,
The radio access network device further includes an F1 splitter connecting the first DU and the second DU to a central unit (CU), wherein the F1 splitter switches data flow from the first DU to the second DU. A device configured to transmit.
According to claim 1,
The radio access network device includes an F1 splitter connecting a distribution unit (DU) and a central unit (CU); and
Further comprising a fronthaul (FH) splitter connecting the distribution unit (DU) and the remote unit (RU),
The scaling controller is configured to register information about the service of the second DU to the F1 splitter and the FH splitter, respectively.
A communication method of a radio access network device comprising a distribution unit (DU), the method comprising:
obtaining information on resource usage of a first DU executed through a first server by a scaling controller;
selecting a second DU based on the information on resource usage of the first DU by the scaling controller;
selecting, by the scaling controller, a second RU to be migrated to the second DU from among first remote units (RUs) processing a service of the first DU; and
Transmitting information on the second RU to the second DU by the first DU;
And processing the service of the first DU in remaining RUs other than the second RU among the first RUs.
According to claim 11,
The method further comprising selecting, by the scaling controller, a second server having capacity to execute the service of the second DU.
According to claim 11,
In the process of selecting the second DU, at least part of the service of the first DU is different from that of the first server, based on the resource usage of the first DU satisfying a condition related to the available resources of the first server. and selecting the second DU to be processed using a second server.
According to claim 11,
Wherein the information on the second RU includes a signaling radio bearer (SRB) list and a data radio bearer (DRB) list for the UE to be transferred.
According to claim 11,
The information on the second RU includes at least one of information about a UE related to the second RU, information about a channel state, radio resource scheduling information, and system information. way of being.
According to claim 11,
The scaling controller further comprises instructing the first DU to create a communication session for synchronizing information on a second RU as a transfer target to the second DU.
According to claim 11,
The second DU further comprises selecting a UE to be processed by the second DU from among UEs connected to the second RU.
According to claim 11,
The method of claim 1 , wherein the first DU further comprises transmitting information about a UE to be transferred to the second DU, and the UE to be transferred processes a service for the second DU.
According to claim 11,
The radio access network apparatus further includes an F1 splitter connecting the first DU and the second DU to a central unit (CU), wherein the first DU switches a data flow to the F1 splitter from the first DU to The method further comprising requesting to be transmitted in 2 DUs.
According to claim 11,
The radio access network device includes an F1 splitter connecting a distribution unit (DU) and a central unit (CU); and
Further comprising a fronthaul (FH) splitter connecting the distribution unit (DU) and the remote unit (RU),
and registering, by the scaling controller, service information of the second DU in the F1 splitter and the FH splitter, respectively.

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