Device, method, and storage medium for communication between distributed units in wireless communication system

Abstract

A device of a first distributed unit (DU) may comprise at least one processor, and a memory for storing instructions. The instructions, when executed individually or collectively by the at least one processor, may cause the device to: acquire information about a buffer status report (BSR) of a UE on a primary cell related to the first DU; and transmit a split BSR management message for uplink scheduling of a second DU to the second DU related to a secondary cell of carrier aggregation (CA) configured for the UE via an interface between the first DU and the second DU. The split BSR management message may include the identifier (ID) of the UE, an index of the primary cell, information about a time at which the BSR is received, logical channel group (LCG) ID information about the BSR, and split buffer occupancy (BO) to be used by the second DU.

Description

Device, method, and storage medium for communication between distributed units in a wireless communication system

[0001] The following descriptions relate to wireless communication systems, and more specifically to devices, methods, and storage media for communication between distributed units in a wireless communication system.

[0002] As transmission capacity increases in wireless communication systems, functional splitting, which functionally separates base stations, is being implemented. Through functional splitting, base stations can be divided into distributed units (DUs) and radio units (RUs). A fronthaul interface is defined for communication between DUs and RUs.

[0003] Spectrum aggregation refers to a wireless communication technology that uses a certain frequency interval in the frequency domain and another frequency interval together with the frequency interval.

[0004] A device of a first distributed unit (DU) may include at least one processor including a processing circuit. The device may include a memory storing instructions and including one or more storage media. The instructions, when individually or collectively executed by the at least one processor, may cause the device to obtain information about a buffer status report (BSR) of a UE on a primary cell associated with the first DU. The instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit, to a second DU associated with a secondary cell of a carrier aggregation (CA) configured for the UE, a split BSR management message for uplink scheduling of the second DU through an interface between the first DU and the second DU. The above distribution BSR management message may include an ID (identifier) ​​of the UE, an index (index) of the primary cell, information on the time at which the BSR was received, LCG (logical channel group) ID information of the BSR, and a distribution BO (split buffer occupancy) to be used by the second DU.

[0005] A method performed by a first distributed unit (DU) may include obtaining information about a buffer status report (BSR) of a UE on a primary cell associated with the first DU. The method may include transmitting, to a second DU associated with a secondary cell of a carrier aggregation (CA) configured for the UE, a split BSR management message for uplink scheduling of the second DU through an interface between the first DU and the second DU. The split BSR management message may include an identifier (ID) of the UE, an index of the primary cell, time information at which the BSR was received, logical channel group (LCG) ID information of the BSR, and a split buffer occupancy (BO) to be used by the second DU.

[0006] A non-transitory computer-readable storage medium may store one or more programs comprising instructions that, when individually or collectively executed by at least one processor including a processing circuit of a first distributed unit (DU), cause the first DU to obtain information about a buffer status report (BSR) of a UE on a primary cell associated with the first DU. The non-transitory computer-readable storage medium may store one or more programs comprising instructions that, when individually or collectively executed by the at least one processor, cause the first DU to transmit, to a second DU associated with a secondary cell of a carrier aggregation (CA) configured for the UE, a split BSR management message for uplink scheduling of the second DU through an interface between the first DU and the second DU. The above distribution BSR management message may include an ID (identifier) ​​of the UE, an index (index) of the primary cell, information on the time at which the BSR was received, LCG (logical channel group) ID information of the BSR, and a distribution BO (split buffer occupancy) to be used by the second DU.

[0007] Figures 1a and 1b illustrate examples of wireless communication systems.

[0008] Figures 2a to 2c illustrate examples of spectrum aggregation environments.

[0009] Figure 3 illustrates an example of a resource structure in the time domain and frequency domain.

[0010] Figure 4a illustrates an example of a protocol stack in the control plane.

[0011] Figure 4b illustrates an example of a protocol stack in the user plane.

[0012] Figure 5 illustrates an example of a functional configuration of an electronic device.

[0013] Figure 6a illustrates an example of carrier aggregation (CA) between distributed units (DUs).

[0014] Figure 6b illustrates an example of a protocol stack for CA between DUs.

[0015] Figures 7a and 7b illustrate examples of a SCell (secondary cell) status management procedure for CA between DUs.

[0016] Figures 8a and 8b illustrate examples of buffer status report (BSR) management procedures for CA between DUs.

[0017] Figures 9a to 9c illustrate examples of split BSR management procedures for CA between DUs.

[0018] Figures 10a and 10b illustrate examples of power headroom report (PHR) management procedures for CA between DUs.

[0019] Figures 11a to 11c illustrate examples of split PHR management procedures for CA between DUs.

[0020] Figures 12a and 12b illustrate examples of a physical uplink shared channel (PUSCH) resource allocation procedure for CA between DUs.

[0021] Figures 13a and 13b illustrate examples of SCell TA (timing advance) management procedures for CA between DUs.

[0022] FIG. 14a and FIG. 14b illustrate examples of signal flows for a method of performing uplink resource allocation for a terminal in CA between DUs.

[0023] Figure 15 illustrates an example of an operational flow for how a first DU transmits a distributed BSR management message for uplink scheduling of a second DU.

[0024] The terms used in this disclosure are used only to describe specific embodiments and may not be intended to limit the scope of other embodiments. The singular expression may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by those of ordinary skill in the art described in this disclosure. Terms defined in general dictionaries among the terms used in this disclosure may be interpreted as having the same or similar meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this disclosure. In some cases, even if a term is defined in this disclosure, it cannot be interpreted to exclude embodiments of the present disclosure.

[0025] The various embodiments of the present disclosure described below illustrate a hardware-based approach as an example. However, since the various embodiments of the present disclosure include techniques utilizing both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.

[0026] In the following description, terms referring to signals (e.g., packet, message, signal, information, signaling), terms referring to resources (e.g., section, symbol, slot, subframe, radio frame, subcarrier, RE (resource element), RB (resource block), BWP (bandwidth part), occasion), terms for operational states (e.g., step, operation, procedure), terms referring to data (e.g., packet, message, user stream, information, bit, symbol, codeword), terms referring to channels, terms referring to network entities (distributed unit (DU), radio unit (RU), central unit (CU), CU-CP (control plane), CU-UP (user plane), O-DU (O-RAN (open radio access network) DU), O-RU (O-RAN RU), O-CU (O-RAN Terms such as CU), O-CU-UP (O-RAN CU-CP), O-CU-CP (O-RAN CU-CP)), and components of the device are provided for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used. In addition, terms such as '...part', '...machine', '...object', and '...body' used below may mean at least one shape structure or a unit that processes a function.

[0027] In addition, in the present disclosure, expressions such as "more than" or "less than" may be used to determine whether a specific condition is satisfied or fulfilled, but this is merely a description for expressing an example and does not exclude descriptions such as "more than" or "less than." A condition described as "more than" may be replaced with "more than," a condition described as "less than" may be replaced with "less than," and a condition described as "more than and less than" may be replaced with "more than and less than." In addition, hereinafter, "A" to "B" mean at least one of elements from A (including A) to B (including B). hereinafter, "C" and / or "D" mean at least one of "C" or "D," that is, including {"C", "D", "C" and "D"}.

[0028] Although this disclosure describes embodiments using terminology used in certain communication standards (e.g., 3rd Generation Partnership Project (3GPP)), this is merely an example for illustrative purposes. Embodiments of this disclosure can also be applied to other communication and broadcasting systems.

[0029] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0030] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0031] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0032] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0033] While a 5G environment is described below as an example, this description does not limit the scope of the communication environment of the embodiments of the present disclosure. The technical principles according to the embodiments of the present disclosure can also be applied to 4G, 6G, and post-6G communication technologies and network environments.

[0034] Figures 1a and 1b illustrate examples of wireless communication systems.

[0035] Referring to FIG. 1A, FIG. 1A illustrates a base station (110) and a terminal (120) as some of the nodes utilizing a wireless channel in a wireless communication system. Although FIG. 1A illustrates only one base station, the wireless communication system may further include other base stations identical or similar to the base station (110).

[0036] The base station (110) is a network infrastructure that provides wireless access to the terminal (120). The base station (110) has coverage defined based on the distance at which a signal can be transmitted. In addition to the base station, the base station (110) may be referred to as an 'access point (AP)', 'eNodeB (eNB)', '5th generation node', 'next generation nodeB (gNB)', 'wireless point', 'transmission / reception point (TRP)', or other terms having equivalent technical meanings.

[0037] The terminal (120) is a device used by a user and communicates with the base station (110) via a wireless channel. The link from the base station (110) to the terminal (120) is referred to as a downlink (DL), and the link from the terminal (120) to the base station (110) is referred to as an uplink (UL). In addition, although not shown in FIG. 1A, the terminal (120) and another terminal may communicate with each other via a wireless channel. In this case, the link between the terminal (120) and another terminal (device-to-device link, D2D) is referred to as a sidelink, and the sidelink may be used interchangeably with the PC5 interface. In some other embodiments, the terminal (120) may be operated without the involvement of a user. In one embodiment, the terminal (120) is a device that performs machine type communication (MTC) and may not be carried by the user. Additionally, according to one embodiment, the terminal (120) may be an NB (narrowband)-IoT (internet of things) device.

[0038] The terminal (120) may be referred to as a terminal, or other terms such as 'user equipment (UE),' 'customer premises equipment (CPE),' 'mobile station,' 'subscriber station,' 'remote terminal,' 'wireless terminal,' 'electronic device,' or 'user device,' or other terms having equivalent technical meanings.

[0039] The base station (110) and the terminal (120) can perform beamforming. The base station (110) and the terminal (120) can transmit and receive wireless signals in a relatively low frequency band (e.g., FR 1 (frequency range 1) of NR). In addition, the base station (110) and the terminal (120) can transmit and receive wireless signals in a relatively high frequency band (e.g., FR 2 (or, FR 2-1, FR 2-2, FR 2-3), FR 3 of NR), millimeter wave (mmWave) band (e.g., 28 GHz, 30 GHz, 38 GHz, 60 GHz)). To improve channel gain, the base station (110) and the terminal (120) can perform beamforming. Here, the beamforming can include transmission beamforming and reception beamforming. The base station (110) and the terminal (120) can impart directionality to the transmitted or received signal. To this end, the base station (110) and the terminal (120) can select serving beams through a beam search or beam management procedure. After the serving beams are selected, subsequent communication can be performed through resources that have a QCL relationship with the resource that transmitted the serving beams.

[0040] The terminal (120) may be configured with cells of the base station (110) and carrier aggregation (CA). CA technology is a technology that increases the frequency usage efficiency of the terminal (120) and the base station (110) by connecting the terminal to a group of homogeneous wireless communication cells having a common radio resource control entity, and simultaneously using frequency resources on component carriers of each cell located in different frequency bands for signal transmission and reception. The cells configured for CA may include one PCell (primary cell) and one or more SCells (secondary cells).

[0041] Referring to FIG. 1B, a terminal (120) may be configured in dual connectivity (DC) using a first base station (110-1) and a second base station (110-2). DC technology is a technology that increases frequency utilization efficiency by simultaneously connecting a terminal to two independent heterogeneous or homogeneous wireless communication cell groups having separate radio resource control entities, and utilizing frequency resources on component carriers of cells within each cell group located in different frequency bands for signal transmission and reception. For example, a terminal (120) may be connected to two different radio resource entities (e.g., a first base station (110-1) and a second base station (110-2)) and utilize radio resources allocated by each radio resource entity. In MR-DC (multi-radio DC), a UE (e.g., terminal 120) in a radio resource control (RRC) connected state (i.e., RRC_CONNECTED) may be configured to utilize radio resources provided by two independent schedulers. Each scheduler may be located in an NG-RAN node (e.g., a first base station (110-1) or a second base station (110-2)). Here, one node is a master node (MN) and the other node is a secondary node (SN). The MN and SN are connected via a network interface, and the MN may be connected to a core network. The SN may or may not be connected to the core network.

[0042] The MN may provide a master cell group (MCG). The MN, in addition to the MN, may be referred to as an M-NODE or an M-NG-RAN node. The MCG may include one or more cells. The MCG may include a PCell (primary cell). The MCG may include multiple aggregated cells. The MCG may include a PCell and one or more secondary cells (SCells). The SN may provide a secondary cell group (SCG). The SN, in addition to the SN, may be referred to as an S-NODE or an S-NG-RAN node. The SCG may include one or more cells. The SCG may include multiple aggregated cells. Like the MCG, the SCG may include a PCell and / or an SCell. A cell functioning as a PCell within the SCG may be referred to as a PSCell (primary secondary cell). The secondary cell group may include a PSCell and one or more SCells. Hereinafter, the term "SpCell" (special cell) may be used to encompass PCell and PSCell. "SpCell" refers to the primary cell of an MCG or SCG. In other words, an MCG SpCell refers to a PCell, and an SCG SpCell refers to an SCell.

[0043] The possible types of DC can be defined as follows:

[0044] 1) EN-DC: Dual connectivity in which the eNB is connected to the evolved packet core (EPC), and the UE is connected to the eNB acting as an MN and the gNB acting as an SN. Here, the gNB may be referred to as an en-gNB, and the en-gNB may or may not be connected to the EPC.

[0045] 2) NGEN-DC: Dual connectivity in which the eNB is connected to the 5GC (5G core), and the terminal is connected to the eNB operating as an MN and the gNB operating as an SN. Here, the eNB may be referred to as ng-eNB.

[0046] 3) NE-DC: Dual connectivity in which the gNB is connected to the 5GC, and the terminal is connected to the gNB operating as an MN and the eNB operating as an SN. Here, the eNB may be referred to as ng-eNB.

[0047] 4) NR-DC: Dual connectivity where gNBs are connected to 5GC, and the UE is connected to a gNB that acts as an MN and a gNB that acts as an SN. NR-DC can also be used when a UE is connected to a single gNB that acts as both an MN and SN and configures both an MCG and an SCG.

[0048] The terminal (120) can support MR-DC. The terminal (120) can be connected to a first base station (110-1) and a second base station (110-2). The first base station (110-1) is an MN, and the second base station (110-2) is an SN, and can be connected to the terminal. With the CA provided by each base station, the DC technology can provide higher data rates. The first base station (110-1) and the second base station (110-2), as MN and SN, respectively, can transmit downlink traffic to the terminal (120) or receive uplink traffic from the terminal (120).

[0049] Figures 2a to 2c illustrate examples of spectrum aggregation environments.

[0050] The above spectrum aggregation refers to a wireless communication technology that uses a certain frequency interval in the frequency domain and another frequency interval together with the frequency interval. The frequency intervals may correspond to at least one of a resource block (RB), a bandwidth part (BWP), a bandwidth, a cell, a cell group, a frequency band, and / or a frequency range, depending on the technology used. For example, spectrum aggregation may include CA. The bandwidth of a PCell (primary cell) and a SCell (secondary cell) may be used together for data communication. For example, spectrum aggregation may include DC. The frequency range occupied by a cell of an MN's MCG and the frequency range occupied by a cell of an SN's SCG may be used together for communication. For example, spectrum aggregation may include CoMP (coordinated multi-point operation). Base stations with different frequency spectrums can be used for data communications. For example, spectrum aggregation may include multi-transmission reception points (M-TRPs). Resources allocated in different frequency ranges can be used for data transmission.

[0051] A cell can refer to an area (or coverage) that can be covered by one base station (e.g., gNB) (or one DU (distributed unit) (or DU (digital unit))). A cell can indicate not only a geographical area but also an area that occupies a specific spectrum in the frequency domain. A DU (distributed unit) can cover one cell or multiple cells. Here, the multiple cells can be distinguished by the frequency they support and the area of ​​the sector they cover. A serving cell is a cell that provides a terminal and upper layer signaling (e.g., RRC (radio resource control) signaling), and can refer to one cell or multiple cells. If the terminal (120) is not configured to support CA (carrier aggregation) and DC (dual connectivity), the serving cell can be one cell corresponding to a PCell. When the terminal (120) is set to support CA or DC, the serving cell may be a set of cells including a PCell and one or more SCells.

[0052] In the present disclosure, a base station (e.g., a base station (110), a first base station (110-1), a second base station (110-2)) may be implemented in a distributed deployment according to a central unit (CU) (or a control unit (CU)) configured to perform functions of upper layers of an access network and a distributed unit (DU) configured to perform functions of lower layers. The CU and the DU may represent independent network entities (or may be referred to as network nodes, network equipment, or network devices) for an access network. The CU may be connected to one or more DUs and may be responsible for functions of a higher layer than the DU (e.g., a packet data convergence protocol (PDCP) protocol, a radio resource control (RRC) protocol). The DU may be responsible for functions of lower layers (e.g., a radio link control (RLC) layer, a medium access control (MAC) layer, and a physical (PHY) layer). Hereinafter, unless otherwise defined, the operations of the CU and the DU are described, but the implementation method according to the embodiments of the present disclosure is not limited thereto. As a non-limiting example, the DU is connected to the RU (radio unit), the DU performs some functions (high PHY) of the RLC (radio link control), MAC (media access control), and PHY (physical) layers, and the RU may be responsible for the remaining functions (low PHY) of the PHY layer.

[0053] Referring to FIG. 2A, a base station (e.g., a base station (110), a first base station (110-1), and a second base station (110-2)) may be divided into a central unit (CU) and a DU. The CU and the DU may be connected via an F1 interface. A DU may support one or more cells, and a cell may be supported by only one DU. The first base station (110-1) may include CU #1 (205-1) and DU #1 (210-1). DU #1 (210-1) may provide one or more cells. The second base station (110-2) may include CU #2 (205-2) and DU #2 (210-2). DU #2 (210-2) may provide one or more cells. For example, for DC operation, MgNB-DU may represent a gNB-DU (e.g., DU #1 (210-1)) of an en-gNB or gNB acting as a master node, and SgNB-DU may represent a gNB-DU (e.g., DU #2 (210-2)) of an en-gNB or gNB acting as a secondary node. From the perspective of the terminal (120), CU #1 (205-1) may operate as a logical node (e.g., gNB) corresponding to one base station, and CU #2 (205-2) may operate as a logical node (e.g., gNB) corresponding to another base station, DU #2 (232). According to one embodiment, the terminal (120) may access the network through a cell provided by DU #1 (231) and a cell provided by DU #2 (232).

[0054] Referring to FIG. 2B, a base station (e.g., base station (110), first base station (110-1), second base station (110-2)) can be divided into CUs and DUs. Unlike multiple independent base stations (e.g., first base station (110-1), second base station (110-2)) that serve a terminal (120), one CU and multiple DUs can serve a terminal (120). For example, CU #1 (215) can be connected to DU #1 (231) and DU #2 (232). CU #1 (215) can be connected to each of DU #1 (231) and DU #2 (232) via an F1 interface. DU #1 (231) can provide one or more cells. DU #2 (232) can provide one or more cells. For example, for CA operation, DU #1 (231) may provide a cell corresponding to PCell. DU #2 (232) may provide a cell corresponding to SCell. From the perspective of the terminal (120), CU #1 (215) may operate as a logical node (e.g., gNB) corresponding to one base station, and CU #1 (215) may operate as a logical node (e.g., gNB) corresponding to another base station, DU #2 (232). According to one embodiment, the terminal (120) may access the network through CA (carrier aggregation) using a cell (e.g., PCell) provided by DU #1 (231) and a cell (e.g., SCell) provided by DU #2 (232). Two cells for CA may be configured for the terminal (120).

[0055] Referring to Fig. 2c, the base station can be divided into CU and DU. In addition to the distributed arrangement separated into CU and DU, a node (242) for a small cell can be additionally deployed. For example, CU #1 (215) can be connected to DU #1 (231) via the F1 interface. Node (242) can communicate with CU #1 (215) as an independent entity. DU #1 (231) can provide one or more cells. Node (242) can provide one or more small cells. For example, for CA operation, DU #1 (231) can provide a cell corresponding to PCell. Node (242) can provide a cell corresponding to SCell. From the perspective of the terminal (120), CU #1 (215) and DU #1 (231) may operate as logical nodes (e.g., gNB) corresponding to one base station, and CU #1 (215) and node (242) may operate as logical nodes (e.g., gNB) corresponding to another base station. According to one embodiment, the terminal (120) may access the network through CA using a cell (e.g., PCell) provided by DU #1 (231) and a cell (e.g., SCell) provided by DU #2 (232). Two cells for CA may be configured for the terminal (120).

[0056] The vendors of DUs (or the nodes providing DUs and small cells) may be different. The frequency bands used by multiple vendors may not be compatible with each other. For example, the vendors of the first DU and the second DU may purchase different frequency bands. The frequency range occupied by the cell provided by the first DU may be different from the frequency range occupied by the cell provided by the second DU. Since the second DU does not have accurate information about the cell of the first DU, it may be difficult to configure CA between the two cells. If CA is configured between the two cells, signaling via the CU or a higher-level entity is required because there is no interface between the first DU and the second DU. However, the increase in signaling causes delay, making effective resource management difficult.

[0057] Hereinafter, embodiments of the present disclosure describe interfaces between DUs (e.g., referred to as X1 interfaces) for spectrum aggregation, such as the CA or DC described above, and procedures and messages for configuring the interface. First, resources at the physical layer are described through FIG. 3.

[0058] Figure 3 illustrates an example of a resource structure in the time domain and frequency domain.

[0059] Figure 3 illustrates the basic structure of the time-frequency domain, which is a radio resource region in which data or control channels are transmitted in the downlink or uplink.

[0060] Referring to Figure 3, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM (orthogonal frequency division multiplexing) symbol, N symbOFDM symbols (302) are grouped to form one slot (306). The length of a subframe is defined as 1.0 ms, and the length of a radio frame (314) is defined as 10 ms. The minimum transmission unit in the frequency domain is a subcarrier, and the carrier bandwidth constituting the resource grid is N DL RB Dog (downlink) or N UL RB It consists of subcarriers (304) of the dog (uplink).

[0061] The basic unit of resources in the time-frequency domain is a resource element (RE) (312), which can be represented by an OFDM symbol index and a subcarrier index. A resource block may include multiple resource elements. In the LTE system, a resource block (RB) (or physical resource block (PRB)) is N in the time domain. symb N consecutive OFDM symbols and frequency domain SC RB are defined as N consecutive subcarriers. In the NR system, a resource block (RB) (308) is defined as N in the frequency domain. SC RB can be defined as a series of consecutive subcarriers (310). One RB (308) is N on the frequency axis. SC RB It contains REs (312). In general, the minimum transmission unit of data is RB and the number of subcarriers is N. SC RB=12. The frequency domain may include common resource blocks (CRBs). Physical resource blocks (PRBs) may be defined in the bandwidth part (BWP) of the frequency domain. The CRB and PRB numbers may be determined based on the subcarrier spacing. The data rate may increase in proportion to the number of RBs scheduled to the terminal.

[0062] In the NR system, in the case of a frequency division duplex (FDD) system that operates the downlink and uplink by frequency division, the downlink transmission bandwidth and the uplink transmission bandwidth may be different. The channel bandwidth represents the radio frequency (RF) bandwidth corresponding to the system transmission bandwidth. [Table 1] shows part of the correspondence between the system transmission bandwidth, subcarrier spacing (SCS), and channel bandwidth defined in the NR system in a frequency band lower than x GHz (e.g., frequency range (FR) 1 (310 MHz to 7125 MHz)). And [Table 2] shows part of the correspondence between the transmission bandwidth, subcarrier spacing, and channel bandwidth defined in the NR system in a frequency band higher than y GHz (e.g., FR2 (24250 MHz - 52600 MHz) or FR2-2 (52600 MHz to 71000 MHz)). For example, an NR system with a 100 MHz channel bandwidth and a 30 kHz subcarrier spacing has a transmission bandwidth of 273 RBs. In [Table 1] and [Table 2], N / A may be a bandwidth-subcarrier combination not supported by the NR system.

[0063] Channel bandwidth [MHz] SCS 5 10 20 50 80 100 Transmission bandwidth configuration N RB15kHz2552106207N / AN / A30kHz11245113321727360kHzN / A112465107135

[0064] Channel bandwidth [MHz] SCS50100200400 Transmission bandwidth configuration N RB 60kHz66132264N / A120kHz3266132264

[0065] Figure 4a illustrates an example of a protocol stack in the control plane.

[0066] Referring to FIG. 4A, in an NR communication system, a wireless protocol of a control plane of a terminal (120) (e.g., UE) may include PHY (411), MAC (412), RLC (413), PDCP (414), and RRC (415). In an NR communication system, a wireless protocol of a control plane of a base station (110) (e.g., gNB) may include PHY (421), MAC (422), RLC (423), PDCP (424), and RRC (425).

[0067] The main functions of RRC (415, 425) may include some of the following functions.

[0068] - Broadcast of system information related to AS (Access Stratum) and NAS (Non Access Stratum)

[0069] - Paging initiated by 5GC or NG-RAN

[0070] - Establishment, maintenance and release of RRC connection between UE and NG-RAN including:

[0071] 1) Adding, modifying, and releasing carrier aggregation

[0072] 2) Add, modify and remove Dual Connectivity within NR or between E-UTRA and NR.

[0073] - Security functions including key management

[0074] - Setup, configuration, maintenance, and release of SRB (Signaling Radio Bearer) and DRB (Data Radio Bearer).

[0075] - Mobility features including:

[0076] 1) Handover and context transfer

[0077] 2) UE cell selection and reselection and control of cell selection and reselection

[0078] 3) Inter-RAT mobility

[0079] - QoS (Quality of Service) management function

[0080] - UE measurement reporting and reporting control;

[0081] - Detection of and recovery from radio link failure

[0082] - Transmitting NAS messages from / to the UE to / from the NAS.

[0083] The main functions of PDCP (414, 424) may include some of the following functions:

[0084] - Header compression and decompression (ROHC only)

[0085] - User data transfer function

[0086] - In-sequence delivery of upper layer PDUs

[0087] - Out-of-sequence delivery of upper layer PDUs

[0088] - PDCP PDU reordering for reception

[0089] - Duplicate detection of lower layer SDUs

[0090] - Retransmission function (Retransmission of PDCP SDUs)

[0091] - Encryption and decryption functions (Ciphering and deciphering)

[0092] - Timer-based SDU discard in uplink.

[0093] In the above, the reordering function of the PDCP layer may refer to the function of reordering PDCP PDUs received from the lower layer in order based on the PDCP SN (sequence number). The reordering function of the PDCP layer may include the function of transmitting data to the upper layer in the reordered order, the function of transmitting data directly without considering the order, the function of recording lost PDCP PDUs by reordering the order, the function of reporting the status of lost PDCP PDUs to the transmitting side, and the function of requesting retransmission of lost PDCP PDUs.

[0094] The main functions of RLC (413, 423) may include some of the following functions:

[0095] - Data transfer function (Transfer of upper layer PDUs)

[0096] - In-sequence delivery of upper layer PDUs

[0097] - Out-of-sequence delivery of upper layer PDUs

[0098] - ARQ function (Error Correction through ARQ)

[0099] - Concatenation, segmentation and reassembly of RLC SDUs

[0100] - Re-segmentation of RLC data PDUs

[0101] - Reordering of RLC data PDUs

[0102] - Duplicate detection function

[0103] - Protocol error detection

[0104] - RLC SDU discard function

[0105] - RLC re-establishment function

[0106] In the above, the in-sequence delivery function of the RLC layer may refer to the function of sequentially delivering RLC SDUs received from lower layers to upper layers. If a single RLC SDU is originally received divided into multiple RLC SDUs, the in-sequence delivery function of the RLC layer may include the function of reassembling and delivering them.

[0107] The in-sequence delivery function of the RLC layer may include a function to reorder received RLC PDUs based on the RLC SN (sequence number) or PDCP SN (sequence number), a function to record lost RLC PDUs by reordering them, a function to report status of lost RLC PDUs to the transmitter, and a function to request retransmission of lost RLC PDUs.

[0108] The in-sequence delivery function of the RLC layer may include a function to sequentially deliver to the upper layer only the RLC SDUs up to the lost RLC SDU when there is a lost RLC SDU. In addition, the in-sequence delivery function of the RLC layer may include a function to sequentially deliver to the upper layer all RLC SDUs received before the timer starts if a predetermined timer has expired even if there is a lost RLC SDU. In addition, the in-sequence delivery function of the RLC layer may include a function to sequentially deliver to the upper layer all RLC SDUs received up to the present if a predetermined timer has expired even if there is a lost RLC SDU.

[0109] The RLC layer can process RLC PDUs in the order they are received (out-of-sequence delivery) and deliver them to the PDCP (405, 440) device, regardless of the order of the sequence number.

[0110] When the RLC layer receives a segment, it can receive segments that are stored in a buffer or will be received later, reconstruct them into a complete RLC PDU, and then transmit them to the PDCP device.

[0111] The RLC layer may not include concatenation functionality, and the function may be performed by the MAC layer or replaced by the multiplexing functionality of the MAC layer.

[0112] In the above, the out-of-sequence delivery function of the RLC layer may refer to the function of directly delivering RLC SDUs received from a lower layer to an upper layer regardless of the order. The out-of-sequence delivery function of the RLC layer may include the function of reassembling and delivering multiple RLC SDUs when an original RLC SDU is received fragmented into multiple RLC SDUs. The out-of-sequence delivery function of the RLC layer may include the function of storing and arranging the RLC SN or PDCP SN of the received RLC PDUs to record any lost RLC PDUs.

[0113] MAC (412, 422) can be connected to multiple RLC layer layers configured in one terminal, and the main functions of MAC can include some of the following functions.

[0114] - Mapping function (Mapping between logical channels and transport channels)

[0115] - Multiplexing / demultiplexing of MAC SDUs

[0116] - Scheduling information reporting function

[0117] - HARQ function (Error correction through HARQ)

[0118] - Priority handling between logical channels of one UE

[0119] - Priority handling between UEs by means of dynamic scheduling

[0120] - MBMS service identification function

[0121] - Transport format selection function

[0122] - Padding function

[0123] The PHY layer (411, 421) can perform operations such as channel coding and modulating upper layer data, converting it into OFDM symbols and transmitting it through a wireless channel, or demodulating and channel decoding OFDM symbols received through a wireless channel and transmitting them to a higher layer.

[0124] Figure 4b illustrates an example of a protocol stack in the user plane.

[0125] Referring to FIG. 4b, the wireless protocol of the user plane of the terminal (120) (e.g., UE) may include PHY (461), MAC (462), RLC (463), PDCP (464), and SDAP (465). In an NR communication system, the wireless protocol of the user plane of the base station (110) (e.g., gNB) may include PHY (471), MAC (472), RLC (473), PDCP (474), and SDAP (475).

[0126] The main functions of SDAP (465, 475) may include some of the following functions:

[0127] - Transfer of user plane data

[0128] - Mapping function between QoS flow and data bearer for both DL and UL

[0129] - QoS flow ID marking function for uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0130] - Ability to map relective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0131] For the SDAP layer, the terminal (120) can be configured by a Radio Resource Control (RRC) message for each PDCP layer, each bearer, or each logical channel to use the header of the SDAP layer or to use the function of the SDAP layer. When the SDAP header is configured, the terminal (120) can instruct the terminal (120) to update or reset the mapping information for the QoS flow and data bearer of the uplink and downlink using a 1-bit indicator (NAS reflective QoS) for reflecting the Non-Access Stratum (NAS) Quality of Service (QoS) of the SDAP header and a 1-bit indicator (AS reflective QoS) for reflecting the Access Stratum (AS) QoS. The SDAP header can include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority, scheduling information, etc. to support a smooth service.

[0132] For PDCP (464, 474) in the user plane, reference may be made to the description of PDCP (414, 424) in the control plane. For RLC (463, 473) in the user plane, reference may be made to the description of RLC (413, 423) in the control plane. For MAC (462, 472) in the user plane, reference may be made to the description of MAC (412, 422) in the control plane. For PHY (461, 471) in the user plane, reference may be made to the description of PHY (411, 421) in the control plane.

[0133] Although the wireless protocol of the NR communication system in the radio access network is described as an example, the embodiments of the present disclosure are not limited thereto. For example, even in the LTE communication system, a DU may be defined (e.g., eNB-DU), in which case the SDAP (465, 475) may be omitted. The embodiments of the present disclosure provide procedures for an interface between DUs or an interface between a DU and a base station (e.g., eNB / gNB) for spectrum aggregation that can be applied in 4G, 5G, and / or 6G systems, and various types of layers or protocols may be used in addition to the communication protocol of FIG. 4b.

[0134] Figure 5 illustrates an example of a functional configuration of an electronic device.

[0135] The configuration of the electronic device (500) illustrated in FIG. 5 can be understood as a configuration of a base station (110), a terminal (120), and a DU (e.g., DU #1 (210-1) and DU #2 (210-2) of FIG. 2a, DU #1 (231) of FIG. 2b or FIG. 2c, DU #1 (621), DU #2 (622), and DU #n (623) of FIG. 6a). Terms such as '... unit', '... device', etc. used hereinafter mean a unit that processes at least one function or operation, and this can be implemented by hardware, software, or a combination of hardware and software.

[0136] Referring to FIG. 5, the electronic device (500) may include a transceiver (510), a memory (520), and a processor (530). However, the present disclosure is not limited thereto. For example, the electronic device (500) may not include at least some of the components illustrated in FIG. 5, or may further include components not illustrated in FIG. 5.

[0137] The transceiver (510) can perform functions for transmitting and receiving signals in a wired communication environment. The transceiver (510) can include a wired interface for controlling direct connections between devices via a transmission medium (e.g., copper wire, optical fiber). For example, the transceiver (510) can transmit electrical signals to other devices via copper wire, or perform conversion between electrical signals and optical signals.

[0138] The transceiver (510) may perform functions for transmitting and receiving signals in a wireless communication environment. For example, the transceiver (510) may perform a conversion function between baseband signals and bit streams according to the physical layer specifications of the system. For example, when transmitting data, the transceiver (510) encodes and modulates the transmitted bit stream to generate complex-valued symbols. Furthermore, when receiving data, the transceiver (510) demodulates and decodes the baseband signal to restore the received bit stream. Furthermore, the transceiver (510) may include multiple transmission and reception paths.

[0139] The transceiver (510) transmits and receives signals as described above. Accordingly, all or part of the transceiver (510) may be referred to as a "communication unit," a "transmitter," a "receiver," or a "transmitting and receiving unit." Furthermore, in the following description, transmission and reception performed via a wireless channel are used to mean that the transceiver (510) performs the processing described above.

[0140] Although not illustrated in FIG. 5, the transceiver (510) may further include a backhaul transceiver for connection to the core network or other base stations. The backhaul transceiver provides an interface for communicating with other nodes within the network. That is, the backhaul transceiver converts a bit stream transmitted from the base station to other nodes, such as other access nodes, other base stations, upper nodes, the core network, etc., into a physical signal, and converts a physical signal received from other nodes into a bit stream.

[0141] The memory (520) stores data such as basic programs, application programs, and setting information for the operation of the electronic device (500). The memory (520) may be referred to as a storage unit. The memory (520) may be composed of volatile memory, nonvolatile memory, or a combination of volatile memory and nonvolatile memory. In addition, the memory (520) provides stored data upon request from the processor (530).

[0142] For example, the processor (530) may include various processing circuits and / or multiple processors. For example, the term "processor" as used herein, including in the claims, may include various processing circuits including at least one processor, one or more of which may be configured to individually and / or collectively perform the various functions described below in a distributed manner. As used herein, when "processor," "at least one processor," and "one or more processors" are described as being configured to perform various functions, these terms encompass, for example, and without limitation, situations where one processor performs some of the recited functions and other processor(s) perform other parts of the recited functions, and also situations where one processor may perform all of the recited functions. Additionally, the at least one processor may include a combination of processors that perform the various functions enumerated / disclosed, for example, in a distributed manner. At least one processor may execute program instructions to achieve or perform the various functions.

[0143] The processor (530) controls the overall operations of the electronic device (500). The processor (580) may be referred to as a control unit. For example, the processor (530) transmits and receives signals via the transceiver (510) (or via the backhaul communication unit). In addition, the processor (530) records and reads data from the memory (520). In addition, the processor (530) may perform functions of a protocol stack required by a communication standard. Although only the processor (530) is illustrated in FIG. 5 , the electronic device (500) may include two or more processors according to other implementation examples.

[0144] The configuration of the electronic device (500) illustrated in FIG. 5 is merely an example, and examples of electronic devices (500) that perform embodiments of the present disclosure are not limited to the configuration illustrated in FIG. 5. In some embodiments, some configurations may be added, deleted, or changed.

[0145] As communication technology advances, the number of network entities increases, and communication with external nodes (e.g., base stations, other DUs) through CUs causes delays. Therefore, interfaces between DUs or interfaces between DUs and base stations need to be defined. Hereinafter, a new interface and procedures and messages for configuring the interface are proposed for spectrum aggregation, such as the CA described above. Although procedures and messages related to the interface between DUs are described below, it should be understood that the descriptions can be applied in the same or similar manner to the interface between a DU and an independent base station (e.g., a base station of a small cell). In the present disclosure, when describing the interface between DUs, the DUs may be from the same vendor or different vendors. That is, information can be exchanged between DUs from different vendors through the interfaces and messages described below.

[0146] Figure 6a illustrates an example of carrier aggregation (CA) between distributed units (DUs). Figure 6b illustrates an example of a protocol stack for CA between DUs.

[0147] Figure 6a illustrates examples (601, 602) of a communication network providing CA between DUs (621, 622, 623). Example (601) illustrates an example in which a CA in which cells of each of DUs (621, 622, 623) are aggregated is configured for a terminal. Example (602) illustrates an example in which a CA in which cells of DUs (621, 622, 623) are aggregated is configured for a terminal.

[0148] Referring to FIG. 6A, the communication network may include a radio access network and a core network. A node (e.g., a base station (110)) providing the radio access network may provide a communication service to a user device (e.g., a terminal (120)) through one or more cells. The core network may include various entities so that the communication service can be smoothly performed. For example, the core network may include an entity responsible for an access management function (AMF). For example, the core network may include an entity responsible for a user plane function (UPF). However, the present disclosure is not limited thereto. The core network may be implemented through the radio access network and an NG interface. The NG interface may include an NG-C interface for a control plane and an NG-U interface for a user plane. The NG-C interface may be defined between the node providing the radio access network and the AMF. The above NG-U interface can be defined between a node providing the wireless access network and the UPF.

[0149] For example, a node providing the wireless access network may be implemented in a distributed deployment according to a central unit (CU) (or control unit (CU)) (610) configured to perform functions of upper layers (e.g., PDCP, RRC) of the access network and a distributed unit (DU) configured to perform functions of lower layers (e.g., RLC, MAC, PHY). An interface between the CU (610) and the DU may be referred to as an F1 interface. The F1 interface may include an F1-C interface for a control plane and an F1-U interface for a user plane. The CU (610) may be connected to one or more DUs (621, 622, 623). For example, the CU (610) may be connected to DU #1 (621), DU #2 (622), ..., DU #n (623). Each DU can provide one or more cells. For example, DU #1 (621) can provide cell #1 (621-1), cell #2 (621-2), ..., cell #m (621-3). For example, DU #2 (622) can provide cell #1 (622-1), cell #2 (622-2), ..., cell #m (622-3). For example, DU #n (623) can provide cell #1 (623-1), cell #2 (623-2), ..., cell #m (623-3). Although FIG. 6A illustrates an example in which the same number (m) of cells are provided by one DU, the present disclosure is not limited thereto. For example, DUs (621, 622, 623) can provide different numbers of cells. Additionally, one or more cells provided by each of the DUs (621, 622, 623) may correspond to (or be associated with) one or more radio units (RUs). For example, an RU may be utilized to provide one or more cells.

[0150] CA (Carrier Aggregation) can aggregate two or more cells. A cell can have a component carrier (CC). A UE can simultaneously receive or transmit signals through one or more CCs, depending on its capabilities. During RRC connection establishment / reestablishment / handover, one serving cell can provide NAS mobility information, and during RRC connection reestablishment / handover, one serving cell can provide security input. The serving cell can be referred to as a PCell (Primary Cell). Depending on the UE capability of the UE, a SCell (Secondary Cell) can be configured to form a serving cell set together with the PCell. The serving cell set configured for the UE can always consist of one PCell and one or more SCells. Reconfiguration, addition, and removal of SCells can be performed by RRC. During intra-NR handover and during connection resumption in RRC_INACTIVE, the network can also add, remove, maintain, or reconfigure SCells to be used together with the target PCell. When adding a new SCell, dedicated RRC signaling can be used to transmit all essential system information of the SCell.

[0151] Referring to example (601), cells (621-1, 621-2, 621-3) of DU #1 (621) can be aggregated for terminal (625-1). For example, among cells (621-1, 621-2, 621-3), cell #1 (621-1) can be configured as a serving cell (or PCell) for terminal (625-1). Among cells (621-1, 621-2, 621-3), cell #2 (621-2) and cell #m (621-3) can be configured as SCells for terminal (625-1). Cells (622-1, 622-2, 622-3) of DU #2 (622) can be aggregated for terminal (625-2). For example, among cells (622-1, 622-2, 622-3), cell #2 (622-2) may be configured as a serving cell for terminal (625-3). Among cells (622-1, 622-2, 622-3), cell #1 (622-1) and cell #m (622-3) may be configured as SCells for terminal (625-2). Cells (623-1, 623-2, 623-3) of DU #n (623) may be aggregated for terminal (625-3). For example, among cells (623-1, 623-2, 623-3), cell #n (623-3) may be configured as a serving cell for terminal (625-3). Among the cells (623-1, 623-2, 623-3), cell #1 (623-1) and cell #2 (623-2) can be configured as SCells for the terminal (625-3).

[0152] In embodiments of the present disclosure, a CA for a terminal (120) can be configured through multiple DUs. Depending on the network environment and carrier availability, the operator can establish DUs across multiple sites or for multiple vendors. Inter-DU CA can be supported even if the DUs are not from the same vendor or are not in the same region.

[0153] Referring to example (602), cell #1 (621-1) of DU #1 (621), cell #1 (622-1) of DU #2 (622), and cell #2 (623-2) of DU #n (623) can be aggregated for terminal (625-1). For example, cell #1 (621-1) of DU #1 (621) among cells (621-1, 622-1, 623-2) can be configured as a serving cell (or PCell) for terminal (625-1). For example, cell #1 (622-1) of DU #2 (622) and cell #2 (623-2) of DU #n among cells (621-1, 622-1, 623-2) can be configured as SCells for terminal (625-1). Cell #m (621-3) of DU #1 (621) and cell #2 (622-2) of DU #2 (622) can be aggregated for terminal (625-2). For example, among cells (621-3, 622-2), cell #m (621-3) of DU #1 (621) can be configured as a serving cell (or PCell) for terminal (625-2). For example, among cells (621-3, 622-2), cell #2 (622-2) of DU #2 (622) can be configured as a SCell for terminal (625-2). Cell #2 (621-2) of DU #1 (621), cell #1 (623-1) of DU #n (623), and cell #m (623-3) of DU #n (623) can be aggregated for terminal (625-3). For example, among cells (621-2, 623-1, 623-3), cell #1 (623-1) of DU #n (623) can be configured as a serving cell (or PCell) for terminal (625-3). For example, among cells (621-2, 623-1, 623-3), cell #2 (621-2) of DU #1 (621) and cell #m (623-3) of DU #n (623) can be configured as SCells for terminal (625-3).

[0154] FIG. 6B illustrates an example (630) of the protocol stack and interface of DUs (621, 622) of FIG. 6A. Referring to example (630), the protocol stack of DU #1 (621) may include a call processing block (631) (or RRC processing module), RLC (632) (or RLC processing module), and MAC (633) (or MAC processing module). For example, RLC (632) may include RLC-H (high) and RLC-L (low). The protocol stack of DU #2 (622) may include a call processing block (641) (or RRC processing module), RLC (642) (or RLC processing module), and MAC (643) (or MAC processing module). For example, RLC (642) may include RLC-H (high) and RLC-L (low). For example, call processing blocks (631, 641) may be configured to process RRC messages (or RRC configuration information). For example, the RRC messages may be provided from a CU (e.g., CU (610) of FIG. 6A). For example, RLCs (632, 642) may be configured to process functions of RLC (423) and RLC (473). For example, MACs (633, 643) may be configured to process functions of MAC (422) and MAC (472).

[0155] Referring to example (630), in order to support CA between DUs (621, 622), an interface (645) between DUs (621, 622) may be defined. For example, the interface (645) may be defined for MACs (633, 643). However, the present disclosure is not limited thereto. Hereinafter, the interface (645) between DUs is referred to as an X1 interface, but the interface (645) may instead be referred to as another term having the same technical meaning (e.g., D2, M1, F3, MV, XD). In the control plane, the interface (645) between DUs (621, 622) may be referred to as an X1-C interface. In the user plane, the interface (645) between DUs (621, 622) may be referred to as an X1-U interface. The X1-C interface can be used to share call control information between DUs (621, 622) and for setup procedures. The X1-U interface can be used to transfer CA bearers between DUs (621, 622) and for signaling and information sharing between MAC layers.

[0156] For convenience of explanation, DU #1 (621) may be referred to as a DU that provides a primary cell (PCell) among the CAs configured for a terminal (e.g., terminal (120) of FIGS. 1A and 1B). For example, DU #1 (621) may be referred to as a pDU or first DU. DU #2 (622) may be referred to as a DU that provides a secondary cell (SCell) among the CAs configured for a terminal (e.g., terminal (120) of FIGS. 1A and 1B). For example, DU #2 (622) may be referred to as an sDU or second DU.

[0157] To configure inter-DU CA according to embodiments of the present disclosure, various parameters may be provided through an interface between DUs (e.g., interface (645) of FIG. 6b ). At least some of the parameters may be received from a CU (e.g., CU (610) of FIG. 6a ) or generated within the DU.

[0158] A terminal configured with inter-DU CA (e.g., terminal 120 of FIGS. 1A and 1B or terminal 625-1 of FIG. 6A) can perform uplink transmission. For example, the uplink transmission may include PUSCH (physical uplink channel) transmission. For example, the terminal can perform uplink transmission to DUs providing the inter-DU CA. At this time, various parameters can be provided through the interface between DUs for scheduling the uplink transmission of the terminal. For example, DUs can exchange uplink information through the interface between MACs. Examples of the various parameters described above can be referenced in the table below.

[0159] ParameterDescriptionUE IDUnique ID information for a UESCell activation statusSCell activation status information for the UEDRX statusDRX information for the UEBeam statusbeam report / determined beam information for the UEBSR informationBSR information transmitted from the UEDistributed BSR informationBuffer information to be used by the UE for a specific DUPHR informationPHR information transmitted from the UEDistributed PHR informationPower information that the UE can transmit for a specific DUPUSCH resource allocation informationPUSCH resource allocation information for the UETA informationtiming advance information for the UE

[0160] According to embodiments, identification information (UE ID) of the terminal configured with the CA may be provided through an interface between DUs. For example, the identification information of the terminal may be used as a unique factor for information exchange between MACs of DUs. Since there is a plurality of pieces of information exchanged between MACs that are set (or defined) for each terminal, the identification information for identifying the terminal between DUs may be required. The identification information for identifying the terminal may be generated based on a cell identifier (ID), a DU ID, a gNB ID, and an index of the terminal. For example, the cell ID, the DU ID, and the gNB ID may represent unique information of a base station. For example, the index of the terminal may include an identifier for identifying the terminal within a cell. For example, the index of the terminal may include a cell-radio network temporary identifier (C-RNTI). However, the present disclosure is not limited thereto. For example, the identification information of the terminal may include the mobile subscriber identity (MSI) of the terminal. For example, the identification information of the terminal may be negotiated between a DU (pDU) providing a PCell and a DU (sDU) providing an SCell within a call procedure of inter-DU CA. For example, when the PCell and the SCell are provided by different DUs, the pDU and the sDU may mutually verify the identification information of the terminal while performing a procedure for setting up CA based on cells (PCell, SCell). Verifying the identification information of the terminal may include matching (or mapping, corresponding) the identification information of the terminal in the pDU and the identification information of the terminal in the sDU.

[0161] According to embodiments, SCell activation status may be provided for the terminal via an interface between DUs. In order to operate inter-DU CA for the terminal, adding and releasing CA may be required. For example, an operation for activating and deactivating SCell may be required in the MAC between DUs. For example, the activation information may indicate information indicating whether the SCell of the DU is activated or deactivated for the terminal. The activation information may be used to determine whether to start or stop CA operation for the terminal in the PCell and SCell.

[0162] According to embodiments, BSR (buffer status report) information received from the terminal may be provided through an interface between DUs. For example, the BSR information may include information about a BSR received from the terminal. For example, the terminal may provide information about the BSR to a DU providing a PCell or a DU providing a SCell. In order to schedule uplink traffic (or resources), DUs may share information about the BSR. For example, the scheduling may include resource allocation.

[0163] According to embodiments, split BSR information for the terminal may be provided via an interface between DUs. For example, the split BSR information may be used to determine the traffic to be scheduled by each DU for the CA among the total amount of uplink traffic required by the terminal. For example, the split BSR information may be determined (or generated, identified) by a DU providing a PCell or a DU providing an SCell.

[0164] According to embodiments, power headroom report (PHR) information received from the terminal may be provided through an interface between DUs. For example, the PHR information may include information about a PHR received from the terminal. For example, the terminal may provide information about the PHR to a DU providing a PCell or a DU providing a SCell. The PHR information may include a maximum power that the terminal can transmit in each carrier (or component carrier (CC), cells) and a power (or power level) currently used for transmission. In order to perform uplink scheduling such that the transmission power for the uplink of the terminal does not exceed the maximum power, DUs may share information about the PHR.

[0165] According to embodiments, split PHR information for the terminal may be provided via an interface between DUs. For example, the split PHR information may be used to determine the uplink transmission power to be scheduled by each of the DUs for the CA, so as to schedule the terminal so as not to exceed the maximum transmittable power. For example, the split PHR information may be determined (or generated, identified) by a DU providing a PCell or a DU providing an SCell.

[0166] According to embodiments, PUSCH resource allocation information for the terminal may be provided through an interface between DUs. For example, the information may include information on uplink resources scheduled for the terminal in each of the DUs for inter-DU CA. For example, the PUSCH resource allocation information may be used to confirm information on scheduled uplink resources between DUs. The PUSCH resource allocation information may be used to identify and schedule uplink control information (UCI), whether to transmit PUSCH, or the amount of resources required by the terminal. For example, the PUSCH resource allocation information may include a modulation and coding scheme (MCS), a waveform, a rank, and a transport block size (TBS) of the terminal.

[0167] According to embodiments, timing advance (TA) information between the terminal and the SCell may be provided via the interface between DUs. For example, the TA information may be used to determine the time difference in uplink synchronization between the terminal and the SCell. For example, if the time difference is greater than a reference time, scheduling of the SCell may be restricted.

[0168] According to embodiments, discontinuous reception (DRX) information of the terminal may be provided through an interface between DUs. For example, the DRX information may be used to perform uplink scheduling in PCell and SCell considering the DRX status of the terminal. For example, the DRX information may be exchanged between a DU providing the PCell and a DU providing the SCell.

[0169] According to embodiments, beam information of the terminal may be provided through an interface between DUs. For example, the beam information may include beam reports and determined beam information received from the terminal for the PCell or SCell. For example, the PCell and the SCell may have independent beam information (or beam status) set. Through the exchange of beam information, the DU providing the PCell and the DU providing the SCell may perform scheduling.

[0170] The above parameters for CA between DUs according to embodiments of the present disclosure are exemplary, and the above table is not intended to be used to limit the interpretation of embodiments of the present disclosure. For example, some of the above parameters may not be used in the interface between DUs. For example, some of the above parameters may be set internally within the DU. For example, some of the above parameters may have fixed values.

[0171] Figures 7a and 7b illustrate examples of a SCell (secondary cell) status management procedure for CA between DUs.

[0172] The pDU (621) of FIGS. 7A and 7B may be an example of DU #1 (621) of FIG. 6A. The sDU (622) of FIGS. 7A and 7B may be an example of DU #2 (622) of FIG. 6A. For example, the pDU (621) and the sDU (622) may provide inter-DU CA for a terminal (e.g., the terminal (120) of FIGS. 1A and 1B or the terminal (625-1) of FIG. 6A). For example, the pDU (621) may provide a PCell of the inter-DU CA for the terminal. The pDU (621) may be referred to as a PCell gNB-DU or a first DU. For example, the sDU (622) may provide an SCell of the inter-DU CA for the terminal. The sDU (622) may be referred to as an SCell gNB-DU or a second DU. Each of the pDU (621) and the sDU (622) may include at least some of the components of the electronic device (500) of FIG. 5.

[0173] Example (700) of FIG. 7a may represent an example of the SCell state management procedure by the PCell. For example, the SCell state management procedure may be used to activate or deactivate the SCell.

[0174] Referring to example (700), in operation (705), pDU (621) may transmit a SCell status update message to sDU (622). For example, pDU (621) may transmit the SCell status update message to sDU (622) through an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the SCell status update message may include information (or IE (information element)) indicating the status of the SCell. Examples of information included in the SCell status update message may be referenced in the table below.

[0175] IE / Group NamePresenceRangeIE type and referenceSemantics descriptionCriticalityAssigned CriticalityUE listM> UE IDM> Serving cell listM>> Serving cell indexM>> SCell stateMENUMERATED (DEACTIVATED, ACTIVATED, PREEMPTION OVERHEAT)>> ReservedM

[0176] Referring to the above table, 'M' in the table may indicate mandatory information. However, the embodiments of the present disclosure are not limited thereto. For example, in the above table, IEs set to 'M' are merely exemplary. For example, IEs set to mandatory information ('M') may also be set to optional information ('O'). For example, the UE list may include one or more terminals for which inter-DU CA (hereinafter, CA) is set (or to be set). For example, the UE ID may include identification information of the terminal for distinguishing the terminal among DUs (621, 622) for the CA. For example, the Serving cell list may include one or more SCells for which the status is to be updated. For example, the Serving cell index may include the index of the SCell of the CA of the terminal indicated by the UE ID.

[0177] For example, the SCell state may include a state of the SCell indicated by the index of the SCell. For example, the state may include a deactivated state, an activated state, or a PREEMPTION OVERHEAT state. For example, if the SCell state indicates "deactivated," the state may be the deactivated state. For example, if the SCell state indicates "activated," the state may be the activated state. For example, if the SCell state indicates "PREEMPTION OVERHEAT," the state may be the PREEMPTION OVERHEAT state. The PREEMPTION OVERHEAT state may be included in the deactivated state. For example, the PREEMPTION OVERHEAT state may include a state in which the SCell is deactivated due to abnormal operation of the terminal (e.g., abnormal operation due to heat generation).

[0178] For example, the Reserved field may represent reserved information to provide designated information between DUs. In the table above, the Reserved field is exemplified as mandatory information ('M') included in the SCell status update message, but the present disclosure is not limited thereto. For example, the Reserved field may be optional information ('O').

[0179] In operation (710), the pDU (621) may receive a SCell status update response message from the sDU (622). For example, the pDU (621) may receive the SCell status update response message from the sDU (622) through an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the SCell status update response message may be transmitted in response to the SCell status update message. For example, the SCell status update response message may include information (or IE (information element)) indicating completion of an update on the status of the SCell. Examples of information included in the SCell status update response message may be referenced in the table below.

[0180] IE / Group NamePresenceRangeIE type and referenceSemantics descriptionCriticalityAssigned CriticalityUE listM> UE IDM> Serving cell listM>> Serving cell indexM>> ReservedM

[0181] Referring to the above table, 'M' in the table may indicate mandatory information. However, the embodiments of the present disclosure are not limited thereto. For example, in the above table, IEs set to 'M' are merely exemplary. For example, IEs set to mandatory information ('M') may also be set to optional information ('O'). For example, the UE list may include one or more terminals for which inter-DU CA (hereinafter, CA) is set (or to be set). For example, the UE ID may include identification information of the terminal for distinguishing the terminal among DUs (621, 622) for the CA. For example, the Serving cell list may include one or more SCells for which status update has been completed. For example, the Serving cell index may include the index of the SCell of the CA of the terminal indicated by the UE ID. For example, the Reserved field may represent reserved information to provide designated information between DUs. In the table above, the Reserved field is exemplified as mandatory information ('M') included in the SCell status update message, but the present disclosure is not limited thereto. For example, the Reserved field may be optional information ('O').

[0182] Referring to the above, the pDU (621) can check the updated status of the SCell by receiving the SCell status update response message.

[0183] Example (750) of FIG. 7b may illustrate an example of a SCell deactivation status management procedure by the SCell. For example, the SCell deactivation status management procedure may be used to deactivate the SCell upon a request for the SCell by the SDU (622).

[0184] Referring to example (750), in operation (755), pDU (621) may receive a SCell deactivation request message. For example, pDU (621) may receive the SCell deactivation request message transmitted from sDU (622) through an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, sDU (622) may determine (or judge) to deactivate the status of the SCell among one or more cells of sDU (622) and transmit the SCell deactivation request message to pDU (621). The SCell deactivation request message may include information (or IE (information element)) for requesting deactivation of the SCell. An example of information included in the SCell deactivation request message may be referred to in the table below.

[0185] IE / Group NamePresenceRangeIE type and referenceSemantics descriptionCriticalityAssigned CriticalityUE listM> UE IDM> Serving cell listM>> Serving cell indexM>> ReservedM

[0186] Referring to the above table, 'M' in the table may indicate mandatory information. However, the embodiments of the present disclosure are not limited thereto. For example, in the above table, IEs set to 'M' are merely exemplary. For example, IEs set to mandatory information ('M') may also be set to optional information ('O'). For example, the UE list may include one or more terminals for which inter-DU CA (hereinafter, CA) is set (or to be set). For example, the UE ID may include identification information of the terminal for distinguishing the terminal among DUs (621, 622) for the CA. For example, the Serving cell list may include one or more SCells for which deactivation is requested. For example, the Serving cell index may include an index of the SCell of the CA of the terminal indicated by the UE ID. For example, the Reserved field may represent reserved information to provide designated information between DUs. In the table above, the Reserved field is exemplified as mandatory information ('M') included in the SCell status update message, but the present disclosure is not limited thereto. For example, the Reserved field may be optional information ('O').

[0187] In operation (760), the pDU (621) may transmit a SCell status update message to the sDU (622). For example, the pDU (621) may transmit the SCell status update message to the sDU (622) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the SCell status update message may include information (or information element (IE)) indicating the status of the SCell. Examples of information included in the SCell status update message may be referred to in Table 4 described above. For example, the SCell status update message transmitted from the pDU (621) to the sDU (622) in operation (760) may include information for indicating deactivation of the SCell indicated by the SCell deactivation request message received in operation (755). For example, the Serving cell index exemplified in Table 4 may indicate the index of the SCell indicated by the SCell deactivation request message, and the SCell state may indicate a 'deactivated' value.

[0188] In operation (765), the pDU (621) may receive a SCell status update response message from the sDU (622). For example, the pDU (621) may receive the SCell status update response message from the sDU (622) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the SCell status update response message may be transmitted in response to the SCell status update message. For example, the SCell status update response message may include information (or IE (information element)) indicating completion of an update on the status of the SCell. Examples of information included in the SCell status update response message may be referred to Table 5 described above. For example, the SCell status update response message transmitted from the sDU (622) to the pDU (621) in operation (765) may indicate that the status of the SCell is changed to an inactive state. Accordingly, the pDU (621) can confirm that the SCell has been changed to an inactive state.

[0189] The names of the messages illustrated in FIGS. 7A and 7B are merely for convenience of explanation and are not intended to limit the present disclosure. For example, the names of the information exchanged between DUs to provide inter-DU CA and the names of the messages containing such information may be changed. Furthermore, for example, some of the information (or IE) included in the message may be omitted or other configurations may be added.

[0190] Figures 8a and 8b illustrate examples of buffer status report (BSR) management procedures for CA between DUs.

[0191] The pDU (621) of FIGS. 8A and 8B may be an example of DU #1 (621) of FIG. 6A. The sDU (622) of FIGS. 8A and 8B may be an example of DU #2 (622) of FIG. 6A. For example, the pDU (621) and the sDU (622) may provide inter-DU CA for a terminal (e.g., the terminal (120) of FIGS. 1A and 1B or the terminal (625-1) of FIG. 6A). For example, the pDU (621) may provide a PCell of the inter-DU CA for the terminal. The pDU (621) may be referred to as a PCell gNB-DU or a first DU. For example, the sDU (622) may provide an SCell of the inter-DU CA for the terminal. The sDU (622) may be referred to as an SCell gNB-DU or a second DU. Each of the pDU (621) and the sDU (622) may include at least some of the components of the electronic device (500) of FIG. 5.

[0192] Example (800) of FIG. 8A may represent an example of the BSR management procedure. For example, the BSR management procedure may be used to recognize the amount of data buffered in the terminal (or terminal side (UE side)) in the pDU (621) and sDU (622).

[0193] Referring to example (800), in operation (805), pDU (621) may receive a BSR management message. For example, pDU (621) may receive the BSR management message from sDU (622) through an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, sDU (622) may obtain information about BSR from the terminal. For example, sDU (622) may receive information about BSR from the terminal through uplink transmission (e.g., PUSCH transmission) on the SCell provided by sDU (622). For example, sDU (622) may generate the BSR management message based on the received information about BSR and transmit the generated BSR management message to pDU (621).

[0194] For example, the information about the BSR may include information about a buffer of the terminal. For example, the BSR may be included in a medium access control (MAC) control element (CE). For example, the MAC CE may include a MAC header having an index. For example, the MAC CE may have a value of a logical channel (LC) ID according to the index of the MAC header. The LC ID value may indicate the type of the MAC CE. For example, the type may indicate a BSR. Specific details about the information about the BSR (or the BSR) transmitted from the terminal may refer to the contents of TS 38.321 or TS 36.321 standards.

[0195] For example, the BSR management message may include information (or IE (information element)) about the BSR. Examples of information included in the BSR management message may be referenced in the table below.

[0196] IE / Group NamePresenceRangeIE type and referenceSemantics descriptionCriticalityAssigned CriticalityUE listM> UE IDM> Serving cell listM>> Serving cell indexM>> BSR Tx System TimeM>> BSR TypeMENUMERATED (SHORT, SHORTTRUNCATED, LONG, LONG TRUNCATED)>> LCG ID bitmapM>> LongBSRM>>> LCG ID listM>>>> LCG IDM>>>> BSRM>> ShortBSRM>>> BSRM

[0197] Referring to the above table, 'M' in the table may indicate mandatory information. However, the embodiments of the present disclosure are not limited thereto. For example, in the above table, IEs set to 'M' are merely exemplary. For example, IEs set to mandatory information ('M') may also be set to optional information ('O'). For example, the UE list may include one or more terminals for which inter-DU CA (hereinafter, CA) is set (or to be set). For example, the UE ID may include identification information of the terminal for distinguishing the terminal among DUs (621, 622) for the CA. For example, the Serving cell list may include one or more SCells that provide information on the BSR of the terminal indicated by the UE ID. For example, the Serving cell index may include an index of an SCell of a CA configured for the terminal indicated by the UE ID.

[0198] For example, the BSR Tx system Time may indicate the time at which the BSR was received from the terminal indicated by the UE ID. For example, the time at which the BSR was received may indicate time information at which the BSR was received by the SCell (or sDU (622)). For example, the BSR Type may indicate the type of the BSR. For example, the type of the BSR may include 'SHORT', 'SHORTTRUNCATED', 'LONG', and 'LONGTRUNCATED'. For example, when the type indicates 'SHORT', the BSR may be a Short BSR. For example, when the type indicates 'SHORTTRUNCATED', the BSR may be a Short truncated BSR. For example, when the type indicates 'LONG', the BSR may be a Long BSR. For example, if the above type indicates 'LONGTRUNCATED', the BSR may be a Long truncated BSR.

[0199] For example, the LCG ID bitmap may represent a bitmap for indicating an LCG (logical channel group) ID within the BSR. For example, depending on the value of the bitmap, an LCG ID included in the BSR may be indicated.

[0200] For example, the LongBSR may indicate information for indicating a buffer size for each LCG ID when the BSR Type indicates 'LONG' or 'LONGTRUNCATED'. For example, the LCG ID list, which is a lower IE of the LongBSR, may indicate one or more LCG IDs within the BSR, which is a Long BSR. For example, the LCG ID, which is a lower IE of the LongBSR, may indicate one LCG ID among the one or more LCG IDs of the LGC ID list. For example, the BSR, which is a lower IE of the LongBSR, may indicate a buffer size corresponding to the LCG ID.

[0201] For example, the ShortBSR may indicate information for indicating the buffer size of the BSR, which is a Short BSR, when the BSR Type indicates 'SHORT' or 'SHORTTRUNCATED'. For example, the BSR, which is a lower IE of the ShortBSR, may indicate the buffer size of the Short BSR corresponding to the LCG ID bitmap.

[0202] For example, pDU (621) can recognize the amount of data buffered in the terminal based on the BSR management message received from sDU (622). In example (800) of FIG. 8A, an example is illustrated in which sDU (622) shares information about the BSR with pDU (621) as the terminal provides information about the BSR to sDU (622), but the present disclosure is not limited thereto.

[0203] Example (850) of FIG. 8b may represent an example of the BSR management procedure. For example, the BSR management procedure may be used to recognize the amount of data buffered in the terminal (or terminal side (UE side)) in the pDU (621) and sDU (622).

[0204] Referring to example (850), in operation (855), pDU (621) can transmit a BSR management message. For example, pDU (621) can transmit the BSR management message to sDU (622) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, pDU (621) can obtain information about BSR from the terminal. For example, pDU (621) can obtain information about BSR of the terminal from a radio unit (RU) associated with a PCell of a CA configured for the terminal. For example, the RU can receive information about BSR from the terminal via uplink transmission (e.g., PUSCH transmission) on the PCell provided by pDU (621). For example, pDU (621) can generate the BSR management message based on the information about the received BSR and transmit the generated BSR management message to sDU (622).

[0205] For example, the information about the BSR may include information about the buffer of the terminal. For example, the BSR may be included in a medium access control (MAC) control element (CE). For example, the MAC CE may include a MAC header having an index. For example, the MAC CE may have a value of a logical channel (LC) ID according to the index of the MAC header. The LC ID value may indicate the type of the MAC CE. For example, the type may indicate a BSR.

[0206] For example, the BSR management message may include information (or IE (information element)) about the BSR. For an example of information included in the BSR management message, reference may be made to Table 7 above. For example, the Serving cell list included in the BSR management message transmitted from pDU (621) to sDU (622) may include one or more PCells that provide information about the BSR of the terminal indicated by the UE ID. For example, the Serving cell index may include the index of the PCell of the CA configured for the terminal indicated by the UE ID. For specific details about the IE included in the BSR management message transmitted from pDU (621) to sDU (622), reference may be made to Table 7 of FIG. 8A.

[0207] For example, sDU (622) can recognize the amount of data buffered in the terminal based on the BSR management message received from pDU (621).

[0208] Referring to FIGS. 8A and 8B , the terminal can transmit information about the BSR of the terminal to the pDU (621) or the sDU (622). At this time, the pDU (621) or the sDU (622) that has obtained the information about the BSR can recognize (or share, exchange) the amount of buffered data of the terminal through a BSR management message. In FIGS. 8A and 8B , a CA between DUs formed by a pDU (621) and one sDU (622) is exemplified, but the present disclosure is not limited thereto. For example, a CA between DUs may be formed by a pDU (621) and a plurality of sDUs. For example, the sDU (622) of FIG. 8A may transmit the BSR management message to an sDU other than the pDU (621). Additionally, for example, the pDU (621) of FIG. 8b may transmit the BSR management message to an sDU other than the sDU (622).

[0209] Referring to FIGS. 8A and 8B, if the pDU (621) among the DUs for providing inter-DU CA is a DU (or a split entity) that distributes the buffer, the sDU (622) (or gNB-DU of SCell) may transmit a BSR management message to the pDU (621) (or gNB-DU of PCell). At this time, the operation of the pDU (621) (or gNB-DU of PCell)) transmitting the BSR management message to the sDU (622) (or gNB-DU of SCell) may be selectively performed. In addition, the operation of the sDU (622) (or gNB-DU of SCell) transmitting the BSR management message to another sDU (or gNB-DU of SCell) may be selectively performed.

[0210] The names of the messages illustrated in FIGS. 8A and 8B are merely for convenience of explanation and are not intended to limit the present disclosure. For example, the names of the information exchanged between DUs to provide inter-DU CA and the names of the messages containing such information may be changed. Furthermore, for example, some of the information (or IE) included in the message may be omitted or other configurations may be added.

[0211] Figures 9a to 9c illustrate examples of split BSR management procedures for CA between DUs.

[0212] The pDU (621) of FIGS. 9A, 9B, and 9C may be an example of DU #1 (621) of FIG. 6A. The sDU (622) of FIGS. 9A, 9B, and 9C may be an example of DU #2 (622) of FIG. 6A. The sDU (623) of FIG. 9C may be an example of DU #n (623) of FIG. 6A. For example, the pDU (621), the sDU (622), and the sDU (623) may provide inter-DU CA for a terminal (e.g., the terminal (120) of FIGS. 1A and 1B or the terminal (625-1) of FIG. 6A). For example, the pDU (621) may provide a PCell of the inter-DU CA for the terminal. The pDU (621) may be referred to as a PCell gNB-DU or a first DU. For example, the sDU (622) may provide an SCell for inter-DU CA for the terminal. For example, the sDU (623) may provide an SCell for inter-DU CA for the terminal. The sDU (622) (or sDU (623)) may be referred to as a SCell gNB-DU or a second DU. Each of the pDU (621), the sDU (622), and the sDU (623) may include at least some of the components of the electronic device (500) of FIG. 5 .

[0213] Example (900) of Fig. 9a may represent an example of the distributed BSR management procedure. For example, the distributed BSR management procedure may be used to split (or distribute, segment) a buffer based on the BSR of the terminal in inter-DU CA, and to provide the distributed BSR information to DUs for providing inter-DU CA. Example (900) of Fig. 9a exemplifies a case where, among the DUs for providing inter-DU CA, pDU (621) is a DU (or split entity) that distributes the buffer. However, the present disclosure is not limited thereto.

[0214] Referring to example (900), in operation (905), pDU (621) may transmit a distributed BSR management message. For example, pDU (621) may transmit the distributed BSR management message to sDU (622) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the distributed BSR management message may be used for uplink scheduling of the terminal of sDU (622).

[0215] For example, the pDU (621) can determine the SCell uplink scheduling based on the acquired information about the BSR of the terminal. For example, the pDU (621) can divide the buffer available to the terminal according to the amount of data to be scheduled in the SCell based on the information about the BSR. For example, the pDU (621) can determine the distributed buffer occupancy (BO) to be used by the sDU (622). For example, the information about the BSR can be acquired directly from the terminal or by a BSR management message received from the sDU (622).

[0216] For example, the distributed BSR management message may include information (or IE (information element)) about the buffer distributed for the terminal. Examples of information included in the distributed BSR management message may be referenced in the table below.

[0217] IE / Group NamePresenceRangeIE type and referenceSemantics descriptionCriticalityAssigned CriticalityUE listM> UE IDM> Serving cell listM>> Serving cell indexM>> BSR Tx System TimeM>>> LCG ID listM>>>> LCG IDM>>>> Split BOM>> SCell schedule allowO

[0218] Referring to the above table, 'M' in the table may represent mandatory information, and 'O' may represent optional information. However, the embodiments of the present disclosure are not limited thereto. For example, in the above table, IEs set to 'M' and 'O' are merely exemplary. For example, an IE set to mandatory information ('M') may also be set to optional information ('O'). For example, the UE list may include one or more terminals for which inter-DU CA (hereinafter, CA) has been set (or will be set). For example, the UE ID may include identification information of the terminal for distinguishing the terminal between DUs (621, 622) for the CA. For example, the Serving cell list may include one or more PCells that provide information on the distributed buffer. For example, the Serving cell index may include an index of the PCell of the CA configured for the terminal indicated by the UE ID.

[0219] For example, the BSR Tx system Time may indicate the time at which the BSR was received from the terminal indicated by the UE ID. For example, the LCG ID list may indicate one or more LCG IDs in the BSR received from the terminal. For example, the Split BO may indicate the amount of BO distributed for the LCG ID. In the example (900), the Split BO may include information on a buffer to be scheduled (or serviced) by the sDU (622). However, the present disclosure is not limited thereto. For example, the Split BO may include information on a buffer to be scheduled (or serviced) by the pDU (621). Or, for example, the Split BO may include information on a buffer to be scheduled (or serviced) by the sDU (622) and information on a buffer to be scheduled (or serviced) by the pDU (621).

[0220] For example, the SCell schedule allow may indicate whether scheduling is permitted in the SCell. For example, if the SCell schedule allow indicates able, the sDU (622) may be able to perform uplink scheduling for the terminal. Conversely, if the SCell schedule allow indicates disable, the sDU (622) may be unable to perform uplink scheduling for the terminal. For example, the inability to perform the uplink scheduling may be understood as refraining from (or omitting) the uplink scheduling. In example (900), the SCell schedule allow included in the distributed BSR management message that the pDU (621) transmits to the sDU (622) may be included in the distributed BSR management message when the pDU (621) detects whether scheduling for the SCell of the sDU (622) is possible. In other words, the pDU (621) can determine the scheduling capability of the sDU (622), and the value of the SCell schedule allow can be determined accordingly. However, the present disclosure is not limited thereto.

[0221] In the example (900) of FIG. 9a, the distribution entity, pDU (621), can transmit the distribution BSR management message to sDU (622) for providing inter-DU CA. Thereafter, sDU (622) can perform uplink scheduling for the terminal using the distribution BSR management message. The terminal can transmit uplink transmission (e.g., PUSCH) to sDU (622) according to the scheduled resource. At this time, the terminal can perform uplink transmission to pDU (621) according to inter-DU CA.

[0222] Example (930) of Fig. 9b may represent an example of the distributed BSR management procedure. For example, the distributed BSR management procedure may be used to split (or distribute, segment) a buffer based on the BSR of the terminal in inter-DU CA, and to provide the distributed BSR information to DUs for providing inter-DU CA. Example (930) of Fig. 9b exemplifies a case where, among the DUs for providing inter-DU CA, sDU (622) is a DU (or split entity) that distributes the buffer. However, the present disclosure is not limited thereto.

[0223] Referring to example (930), in operation (935), pDU (621) may receive a distributed BSR management message. For example, sDU (622) may transmit the distributed BSR management message to pDU (621) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the distributed BSR management message may be used for uplink scheduling of the terminal of pDU (621).

[0224] For example, sDU (622) can determine PCell uplink scheduling based on the acquired information about the BSR of the terminal. For example, pDU (621) can divide the buffer available to the terminal according to the amount of data to be scheduled in the PCell based on the information about the BSR. For example, sDU (622) can determine the distributed buffer occupancy (BO) to be used by pDU (621). For example, the information about the BSR can be acquired directly from the terminal or by a BSR management message received from pDU (621).

[0225] For example, the distributed BSR management message may include information (or IE (information element)) about the buffer distributed for the terminal. An example of information included in the distributed BSR management message may be referred to Table 8. For example, the Serving cell list included in the distributed BSR management message transmitted from sDU (622) to pDU (621) may include one or more SCells that provide information about the distributed buffer. For example, the Serving cell index in the distributed BSR management message transmitted from sDU (622) to pDU (621) may include the index of the SCell of the CA configured for the terminal indicated by the UE ID. For example, the Split BO included in the distributed BSR management message transmitted from sDU (622) to pDU (621) may indicate the amount of BO distributed for the LCG ID. In example (930), the Split BO may include information on a buffer to be scheduled (or serviced) by the pDU (621). However, the present disclosure is not limited thereto. For example, the Split BO may include information on a buffer to be scheduled (or serviced) by the sDU (622). Alternatively, for example, the Split BO may include information on a buffer to be scheduled (or serviced) by the sDU (622) and information on a buffer to be scheduled (or serviced) by the pDU (621).

[0226] For example, the SCell schedule allow included in the distributed BSR management message transmitted from sDU (622) to pDU (621) may indicate whether scheduling is permitted in the SCell. For example, if the SCell schedule allow indicates able, the sDU (622) may be able to perform uplink scheduling for the terminal. Conversely, if the SCell schedule allow indicates disable, the sDU (622) may not be able to perform uplink scheduling for the terminal. In example (930), the SCell schedule allow included in the distributed BSR management message transmitted from sDU (622) to pDU (621) may be included in the distributed BSR management message when sDU (622) detects whether scheduling for the SCell is possible. In other words, the sDU (622) may directly determine the scheduling capability for the SCell, and the value of the SCell schedule allow may be determined accordingly.

[0227] In example (930) of FIG. 9b, the distribution entity sDU (622) can transmit the distribution BSR management message to pDU (621) for providing inter-DU CA. Thereafter, pDU (621) can perform uplink scheduling for the terminal using the distribution BSR management message. The terminal can transmit uplink transmission (e.g., PUSCH) to pDU (621) according to the scheduled resource. At this time, the terminal can perform uplink transmission to sDU (622) according to inter-DU CA.

[0228] Example (960) of Fig. 9c may represent an example of the distributed BSR management procedure. For example, the distributed BSR management procedure may be used to split (or distribute, segment) a buffer based on the BSR of the terminal in inter-DU CA, and to provide the distributed BSR information to DUs for providing inter-DU CA. Example (960) of Fig. 9c exemplifies a case where, among the DUs for providing inter-DU CA, sDU (622) is the DU (or split entity) that distributes the buffer. In this case, the DUs may further include pDU (621) and sDU (623).

[0229] Referring to example (960), in operation (965), pDU (621) may receive a distributed BSR management message. For example, sDU (622) (e.g., sDU #1) may transmit the distributed BSR management message to pDU (621) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the distributed BSR management message may be used for uplink scheduling of the terminal of pDU (621). In addition, in operation (970), sDU (623) (e.g., sDU #2) may receive a distributed BSR management message. For example, sDU (622) may transmit the distributed BSR management message to sDU (623) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the distributed BSR management message may be used for uplink scheduling for the terminal of sDU (623). For specific details on the distributed BSR management message transmitted from sDU (622) to each of pDU (621) and sDU (623), reference may be made to Table 8 above.

[0230] In the example (960) of FIG. 9c, the sDU (622), which is the distribution entity, can transmit a distribution BSR management message to each of the pDU (621) and the sDU (623) for providing inter-DU CA. Thereafter, the pDU (621) and the sDU (623) can perform uplink scheduling for the terminal using the distribution BSR management message. In FIG. 9c, an example in which the sDU (622) is the distribution entity is illustrated, but the present disclosure is not limited thereto. For example, the pDU (621) can be the distribution entity, and the pDU (621) can transmit a distribution BSR management message to each of the sDUs (622, 623) for providing inter-DU CA.

[0231] Referring to FIGS. 9A to 9C, if the pDU (621) among the DUs for providing inter-DU CA is a DU (or a split entity) that distributes the buffer, the pDU (621) (or gNB-DU of PCell) may transmit a distributed BSR management message to the sDU (622) (or gNB-DU of SCell). At this time, the operation of the sDU (622) (or gNB-DU of SCell) transmitting the distributed BSR management message to the pDU (621) (or gNB-DU of PCell) may be selectively performed. In addition, the operation of the sDU (622) (or gNB-DU of SCell) transmitting the distributed BSR management message to another sDU (or gNB-DU of SCell) may be selectively performed.

[0232] The names of the messages illustrated in Figures 9a through 9c are merely for convenience of explanation and are not intended to limit the present disclosure. For example, the names of the information exchanged between DUs to provide inter-DU CA and the names of the messages containing such information may be changed. Furthermore, for example, some of the information (or IE) included in the message may be omitted or other components may be added.

[0233] Figures 10a and 10b illustrate examples of power headroom report (PHR) management procedures for CA between DUs.

[0234] The pDU (621) of FIGS. 10A and 10B may be an example of DU #1 (621) of FIG. 6A. The sDU (622) of FIGS. 10A and 10B may be an example of DU #2 (622) of FIG. 6A. For example, the pDU (621) and the sDU (622) may provide inter-DU CA for a terminal (e.g., the terminal (120) of FIGS. 1A and 1B or the terminal (625-1) of FIG. 6A). For example, the pDU (621) may provide a PCell of the inter-DU CA for the terminal. The pDU (621) may be referred to as a PCell gNB-DU or a first DU. For example, the sDU (622) may provide a SCell of the inter-DU CA for the terminal. The sDU (622) may be referred to as an SCell gNB-DU or a second DU. Each of the pDU (621) and the sDU (622) may include at least some of the components of the electronic device (500) of FIG. 5.

[0235] Example (1000) of FIG. 10A may represent an example of the PHR management procedure. For example, the PHR management procedure may be used to recognize the amount of power available to the terminal (or terminal side (UE side)) in the pDU (621) and sDU (622).

[0236] Referring to example (1000), in operation (1005), pDU (621) may receive a PHR management message. For example, pDU (621) may receive the PHR management message from sDU (622) through an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, sDU (622) may obtain information on PHR from the terminal. For example, sDU (622) may receive information on PHR from the terminal through uplink transmission (e.g., PUSCH transmission) on the SCell provided by sDU (622). For example, sDU (622) may generate the PHR management message based on the received information on PHR and transmit the generated PHR management message to pDU (621).

[0237] For example, the information about the PHR may include information about the transmission power that can be used for uplink transmission from the terminal. For example, the PHR may be included in a medium access control (MAC) control element (CE). For example, the MAC CE may include a MAC header having an index. For specific details about the information about the PHR (or the PHR) transmitted from the terminal, reference may be made to the contents of TS 38.321 or TS 36.321 standards.

[0238] For example, the PHR management message may include information (or IE (information element)) about the PHR. Examples of information included in the PHR management message may be referenced in the table below.

[0239] IE / Group NamePresenceRangeIE type and referenceSemantics descriptionCriticalityAssigned CriticalityUE listM> UE IDM> Serving cell listM>> Serving cell indexM>> PHR Tx System TimeM>> PHR TypeMENUMERATED (SINGLE, MULTIPLE)>> PHR MAC CE SIZEM>> PHR MAC CEM

[0240] Referring to the above table, 'M' in the table may indicate mandatory information. However, the embodiments of the present disclosure are not limited thereto. For example, in the above table, IEs set to 'M' are merely exemplary. For example, IEs set to mandatory information ('M') may also be set to optional information ('O'). For example, the UE list may include one or more terminals for which inter-DU CA (hereinafter, CA) is set (or to be set). For example, the UE ID may include identification information of the terminal for distinguishing the terminal among DUs (621, 622) for the CA. For example, the Serving cell list may include one or more SCells that provide information on the PHR of the terminal indicated by the UE ID. For example, the Serving cell index may include an index of the SCell of the CA configured for the terminal indicated by the UE ID.

[0241] For example, the PHR Tx system Time may indicate the time at which the PHR was received from the terminal indicated by the UE ID. For example, the time at which the PHR was received may indicate time information at which the PHR was received by the SCell (or sDU (622)). For example, the PHR Type may indicate the type of the PHR. For example, the type of the PHR may include 'SINGLE' and 'MULTIPLE'. For example, when the type indicates 'SINGLE', the PHR may be a single entry PHR MAC CE. For example, when the type indicates 'MULTIPLE', the PHR may be a multiple entry PHR MAC CE.

[0242] For example, the PHR MAC CE SIZE may indicate the size of the PHR. For example, the PHR, which is a single-entry PHR MAC CE, may have a fixed size. For example, the PHR, which is a multiple-entry PHR MAC CE, may have a variable size.

[0243] For example, the PHR MAC CE may include the PH (power headroom) level and maximum power (e.g., P) included in the PHR. CMAX,f,c) may include. For example, in the case of the PHR being a single entry PHR MAC CE, the PHR MAC CE may have one PH level and a maximum power corresponding to the PH level. For example, in the case of the PHR being a multiple entry PHR MAC CE, the PHR MAC CE may have a plurality of PH levels and maximum powers corresponding to the plurality of PH levels. In addition, in the case of the PHR being a multiple entry PHR MAC CE, the PHR MAC CE may include a field (C) for indicating the presence of a PH field for a serving cell. i ), may further include a field (V) for indicating whether the PH level is a value based on real transmission or reference format, and a field (P) for indicating whether power backoff is applied.

[0244] For example, the pDU (621) can recognize the power (or maximum power) used (or usable) for uplink transmission to the terminal based on the PHR management message received from the sDU (622). In the example (1000) of FIG. 10A, an example is illustrated in which the sDU (622) shares information about the PHR with the pDU (621) as the terminal provides information about the PHR to the sDU (622), but the present disclosure is not limited thereto.

[0245] Example (1050) of FIG. 10b may illustrate an example of the PHR management procedure. For example, the PHR management procedure may be used to recognize the amount of power available to the terminal (or terminal side (UE side)) in the pDU (621) and sDU (622).

[0246] Referring to example (1050), in operation (1055), pDU (621) may transmit a PHR management message. For example, pDU (621) may transmit the PHR management message to sDU (622) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, pDU (621) may obtain information about PHR from the terminal. For example, pDU (621) may obtain information about PHR of the terminal from a radio unit (RU) associated with a PCell of a CA configured for the terminal. For example, the RU may receive information about PHR from the terminal via uplink transmission (e.g., PUSCH transmission) on the PCell provided by pDU (621). For example, pDU (621) can generate the PHR management message based on the information about the received PHR and transmit the generated PHR management message to sDU (622).

[0247] For example, the information about the PHR may include information about the transmission power available for uplink transmission from the terminal. For example, the PHR may be included in a medium access control (MAC) control element (CE). For example, the MAC CE may include a MAC header having an index.

[0248] For example, the PHR management message may include information (or IE (information element)) about the PHR. For an example of information included in the PHR management message, reference may be made to Table 9 above. For example, the Serving cell list included in the PHR management message transmitted from pDU (621) to sDU (622) may include one or more PCells that provide information about the PHR of the terminal indicated by the UE ID. For example, the Serving cell index may include the index of the PCell of the CA configured for the terminal indicated by the UE ID. For specific details about the IE included in the PHR management message transmitted from pDU (621) to sDU (622), reference may be made to Table 9 of FIG. 10A above.

[0249] For example, sDU (622) can recognize the power (or maximum power) available for uplink transmission in the terminal based on the PHR management message received from pDU (621).

[0250] Referring to FIGS. 10A and 10B , the terminal can transmit information about the PHR of the terminal to the pDU (621) or the sDU (622). At this time, the pDU (621) or the sDU (622) that has obtained the information about the PHR can recognize (or share, exchange) the transmission power of the terminal through a PHR management message. In FIGS. 10A and 10B , a CA between DUs formed by a pDU (621) and one sDU (622) is exemplified, but the present disclosure is not limited thereto. For example, a CA between DUs may be formed by a pDU (621) and a plurality of sDUs. For example, the sDU (622) of FIG. 10A may transmit the PHR management message to an sDU other than the pDU (621). Additionally, for example, the pDU (621) of FIG. 10b may transmit the PHR management message to an sDU other than the sDU (622).

[0251] Referring to FIGS. 10A and 10B, if the pDU (621) among the DUs for providing inter-DU CA is a DU (or a distribution entity (split entity)) that distributes the power, the sDU (622) (or gNB-DU of SCell) may transmit a PHR management message to the pDU (621) (or gNB-DU of PCell). At this time, the operation of the pDU (621) (or gNB-DU of PCell)) transmitting the PHR management message to the sDU (622) (or gNB-DU of SCell) may be selectively performed. In addition, the operation of the sDU (622) (or gNB-DU of SCell) transmitting the PHR management message to another sDU (or gNB-DU of SCell) may be selectively performed.

[0252] The names of the messages illustrated in FIGS. 10A and 10B are merely for convenience of explanation and are not intended to limit the present disclosure. For example, the names of the information exchanged between DUs to provide inter-DU CA and the names of the messages containing such information may be changed. Furthermore, for example, some of the information (or IE) included in the message may be omitted or other configurations may be added.

[0253] Figures 11a to 11c illustrate examples of split PHR management procedures for CA between DUs.

[0254] The pDU (621) of FIGS. 11A, 11B, and 11C may be an example of DU #1 (621) of FIG. 6A. The sDU (622) of FIGS. 11A, 11B, and 11C may be an example of DU #2 (622) of FIG. 6A. The sDU (623) of FIG. 11C may be an example of DU #n (623) of FIG. 6A. For example, the pDU (621), the sDU (622), and the sDU (623) may provide inter-DU CA for a terminal (e.g., the terminal (120) of FIGS. 1A and 1B or the terminal (625-1) of FIG. 6A). For example, the pDU (621) may provide a PCell of the inter-DU CA for the terminal. The pDU (621) may be referred to as a PCell gNB-DU or a first DU. For example, the sDU (622) may provide an SCell for inter-DU CA for the terminal. For example, the sDU (623) may provide an SCell for inter-DU CA for the terminal. The sDU (622) (or sDU (623)) may be referred to as a SCell gNB-DU or a second DU. Each of the pDU (621), the sDU (622), and the sDU (623) may include at least some of the components of the electronic device (500) of FIG. 5 .

[0255] Example (1100) of Fig. 11a may represent an example of the distributed PHR management procedure. For example, the distributed PHR management procedure may be used to split (or distribute, segment) power (or transmission power) based on the PHR of the terminal in inter-DU CA, and to provide the distributed PHR information to DUs for providing inter-DU CA. Example (1100) of Fig. 11a exemplifies a case where among the DUs for providing inter-DU CA, pDU (621) is a DU (or distribution entity) that distributes the power. However, the present disclosure is not limited thereto.

[0256] Referring to example (1100), in operation (1105), pDU (621) may transmit a distributed PHR management message. For example, pDU (621) may transmit the distributed PHR management message to sDU (622) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the distributed PHR management message may be used for uplink scheduling of the terminal of sDU (622).

[0257] For example, the pDU (621) can determine the SCell uplink scheduling based on the acquired information about the PHR of the terminal. For example, the pDU (621) can divide the power (or transmission power) to be used by the terminal to transmit data to be scheduled in the SCell based on the information about the PHR. For example, the pDU (621) can determine the maximum number of RBs that can be allocated by the sDU (622). For example, the information about the PHR can be acquired directly from the terminal or by a PHR management message received from the sDU (622).

[0258] For example, the distributed PHR management message may include information (or IE (information element)) regarding the distributed power (or transmission power) for the terminal. Examples of information included in the distributed PHR management message may be referenced in the table below.

[0259] IE / Group NamePresenceRangeIE type and referenceSemantics descriptionCriticalityAssigned CriticalityUE listM> UE IDM> Serving cell listM>> Serving cell indexM>> PHR Tx System TimeM>> PHR indexM>> PcmaxM>> PHR Tx RBM>> Available Max number of RBM>> SCell schedule allowO

[0260] Referring to the above table, 'M' in the table may represent mandatory information, and 'O' may represent optional information. However, the embodiments of the present disclosure are not limited thereto. For example, in the above table, IEs set to 'M' and 'O' are merely exemplary. For example, an IE set to mandatory information ('M') may also be set to optional information ('O'). For example, the UE list may include one or more terminals for which inter-DU CA (hereinafter, CA) has been set (or will be set). For example, the UE ID may include identification information of the terminal for distinguishing the terminal between DUs (621, 622) for the CA. For example, the Serving cell list may include one or more PCells that provide information on distributed power.

[0261] For example, the Serving cell index may include an index of a PCell of a CA configured for the terminal indicated by the UE ID. For example, the PHR Tx system Time may indicate a time at which a PHR is received from the terminal indicated by the UE ID. For example, the PHR index may indicate an index of a PHR indicating distributed power. For example, the PHR index may indicate an index of a PHR for a specific carrier. For example, the PHR index may have an index converted from an index indicating a PHR MAC CE of the PHR transmitted by the terminal. For example, the converted index may be updated by the pDU (621) to indicate the PHR indicating the distributed power. For example, the Pcmax may indicate a maximum transmit power available in the SCell of the sDU (622). For example, the PHR Tx RB may indicate the number of allocated RBs when the PHR is transmitted by the terminal. For example, the Available Max number of RBs may indicate the maximum number of RBs that can be allocated in the SCell based on the distributed power. In example (1100), the Available Max number of RBs may include information on power that the sDU (622) will schedule (or service). For example, the power may be changed (or calculated) depending on the number of allocated RBs. However, the present disclosure is not limited thereto. For example, the Available Max number of RBs may indicate the maximum number of RBs that can be allocated in the PCell based on the distributed power.Alternatively, for example, the Available Max number of RBs may indicate the maximum number of RBs that can be allocated in the PCell and the maximum number of RBs that can be allocated in the SCell based on the distributed power.

[0262] For example, the SCell schedule allow may indicate whether scheduling is allowed in the SCell. For example, if the SCell schedule allow indicates able, the sDU (622) may be able to perform uplink scheduling for the terminal. Conversely, if the SCell schedule allow indicates disable, the sDU (622) may be unable to perform uplink scheduling for the terminal. For example, the inability to perform the uplink scheduling may be understood as refraining from (or omitting) the uplink scheduling. In example (900), the SCell schedule allow included in the distributed PHR management message that the pDU (621) transmits to the sDU (622) may be included in the distributed PHR management message when the pDU (621) detects whether scheduling for the SCell of the sDU (622) is possible. In other words, the pDU (621) can determine the scheduling capability of the sDU (622), and the value of the SCell schedule allow can be determined accordingly. However, the present disclosure is not limited thereto.

[0263] In the example (1100) of FIG. 11a, the distribution entity, pDU (621), can transmit the distribution PHR management message to sDU (622) for providing inter-DU CA. Thereafter, sDU (622) can perform uplink scheduling for the terminal using the distribution PHR management message. The terminal can transmit uplink transmission (e.g., PUSCH) to sDU (622) according to the scheduled resource. At this time, the terminal can perform uplink transmission to pDU (621) according to inter-DU CA.

[0264] Example (1130) of Fig. 11b may represent an example of the distributed PHR management procedure. For example, the distributed PHR management procedure may be used to split (or distribute, segment) power (or transmission power) based on the PHR of the terminal in inter-DU CA, and to provide the distributed PHR information to DUs for providing inter-DU CA. Example (1130) of Fig. 11b exemplifies a case where among the DUs for providing inter-DU CA, sDU (622) is a DU (or distribution entity) that distributes the power. However, the present disclosure is not limited thereto.

[0265] Referring to example (1130), in operation (1135), pDU (621) may receive a distributed PHR management message. For example, sDU (622) may transmit the distributed PHR management message to pDU (621) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the distributed PHR management message may be used for uplink scheduling of the terminal of pDU (621).

[0266] For example, sDU (622) can determine PCell uplink scheduling based on the acquired information about the PHR of the terminal. For example, pDU (621) can divide the power (or transmission power) to be used by the terminal to transmit data to be scheduled in the PCell based on the information about the PHR. For example, sDU (622) can determine the maximum number of RBs that can be allocated by pDU (621). For example, the information about the PHR can be acquired directly from the terminal or by a PHR management message received from pDU (621).

[0267] For example, the distributed PHR management message may include information (or IE (information element)) about the power (or transmission power) distributed for the terminal. An example of the information included in the distributed PHR management message may be referred to Table 10. For example, the Serving cell list included in the distributed PHR management message transmitted from sDU (622) to pDU (621) may include one or more SCells that provide information about the distributed power. For example, the Serving cell index in the distributed PHR management message transmitted from sDU (622) to pDU (621) may include an index of an SCell of a CA configured for the terminal indicated by the UE ID. For example, the Available Max number of RBs included in the distributed PHR management message transmitted from sDU (622) to pDU (621) may indicate the maximum number of RBs that can be allocated in PCell based on the distributed power. In example (1130), the Available Max number of RBs may include information on power that pDU (621) will schedule (or service). For example, the power may be changed (or calculated) according to the number of allocated RBs. However, the present disclosure is not limited thereto. For example, the Available Max number of RBs may indicate the maximum number of RBs that can be allocated in PCell based on the distributed power. Alternatively, for example, the Available Max number of RBs may indicate the maximum number of RBs that can be allocated in PCell and the maximum number of RBs that can be allocated in SCell based on the distributed power.

[0268] For example, the SCell schedule allow included in the distributed PHR management message transmitted from sDU (622) to pDU (621) may indicate whether scheduling is permitted in the SCell. For example, if the SCell schedule allow indicates able, the sDU (622) may be able to perform uplink scheduling for the terminal. Conversely, if the SCell schedule allow indicates disable, the sDU (622) may not be able to perform uplink scheduling for the terminal. In example (1130), the SCell schedule allow included in the distributed PHR management message transmitted from sDU (622) to pDU (621) may be included in the distributed PHR management message when sDU (622) detects whether scheduling for the SCell is possible. In other words, the sDU (622) may directly determine the scheduling capability for the SCell, and the value of the SCell schedule allow may be determined accordingly.

[0269] In example (1130) of FIG. 11b, the distribution entity sDU (622) can transmit the distribution PHR management message to pDU (621) for providing inter-DU CA. Thereafter, pDU (621) can perform uplink scheduling for the terminal using the distribution PHR management message. The terminal can transmit uplink transmission (e.g., PUSCH) to pDU (621) according to the scheduled resource. At this time, the terminal can perform uplink transmission to sDU (622) according to inter-DU CA.

[0270] Example (1160) of Fig. 11c may represent an example of the distributed PHR management procedure. For example, the distributed PHR management procedure may be used to split (or distribute, segment) power (or transmission power) based on the PHR of the terminal in inter-DU CA, and to provide the distributed PHR information to DUs for providing inter-DU CA. Example (1160) of Fig. 11c exemplifies a case where among the DUs for providing inter-DU CA, sDU (622) is a DU (or distribution entity) that distributes the power. In this case, the DUs may further include pDU (621) and sDU (623).

[0271] Referring to example (1160), in operation (1165), pDU (621) may receive a distributed PHR management message. For example, sDU (622) (e.g., sDU #1) may transmit the distributed PHR management message to pDU (621) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the distributed PHR management message may be used for uplink scheduling of the terminal of pDU (621). In addition, in operation (1170), sDU (623) (e.g., sDU #2) may receive a distributed PHR management message. For example, sDU (622) may transmit the distributed PHR management message to sDU (623) via an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the above-described distributed PHR management message may be used for uplink scheduling for the terminal of sDU (623). For specific details regarding the above-described distributed PHR management message transmitted from sDU (622) to each of pDU (621) and sDU (623), reference may be made to Table 10 above.

[0272] In example (1160) of FIG. 11c, the sDU (622), which is a distribution entity, can transmit a distribution PHR management message to each of the pDU (621) and the sDU (623) for providing inter-DU CA. Thereafter, the pDU (621) and the sDU (623) can perform uplink scheduling for the terminal using the distribution PHR management message. In FIG. 11c, an example in which the sDU (622) is a distribution entity is illustrated, but the present disclosure is not limited thereto. For example, the pDU (621) can be a distribution entity, and the pDU (621) can transmit a distribution PHR management message to each of the sDUs (622, 623) for providing inter-DU CA.

[0273] Referring to FIGS. 11A to 11C, if the pDU (621) among the DUs for providing inter-DU CA is a DU (or a split entity) that distributes the power, the pDU (621) (or gNB-DU of PCell) may transmit a distributed PHR management message to the sDU (622) (or gNB-DU of SCell). At this time, the operation of the sDU (622) (or gNB-DU of SCell) transmitting the distributed PHR management message to the pDU (621) (or gNB-DU of PCell) may be selectively performed. In addition, the operation of the sDU (622) (or gNB-DU of SCell) transmitting the distributed PHR management message to another sDU (or gNB-DU of SCell) may be selectively performed.

[0274] The names of the messages illustrated in Figures 11a to 11c are merely for convenience of explanation and are not intended to limit the present disclosure. For example, the names of the information exchanged between DUs to provide inter-DU CA and the names of the messages containing such information may be changed. Furthermore, for example, some of the information (or IE) included in the message may be omitted or other components may be added.

[0275] Figures 12a and 12b illustrate examples of a physical uplink shared channel (PUSCH) resource allocation procedure for CA between DUs.

[0276] The pDU (621) of FIG. 12A may be an example of DU #1 (621) of FIG. 6A. The sDU (622) of FIG. 12A may be an example of DU #2 (622) of FIG. 6A. For example, the pDU (621) and the sDU (622) may provide inter-DU CA for a terminal (e.g., the terminal (120) of FIG. 1A and FIG. 1B or the terminal (625-1) of FIG. 6A). For example, the pDU (621) may provide a PCell of the inter-DU CA for the terminal. The pDU (621) may be referred to as a PCell gNB-DU or a first DU. For example, the sDU (622) may provide a SCell of the inter-DU CA for the terminal. The sDU (622) may be referred to as an SCell gNB-DU or a second DU. Each of the pDU (621) and the sDU (622) may include at least some of the components of the electronic device (500) of FIG. 5.

[0277] Example (1200) of FIG. 12A may represent an example of the PUSCH resource allocation procedure. For example, the PUSCH resource allocation procedure may be used to provide other cells with information about the resources allocated to the UE (or UE side) by each of the pDU (621) and sDU (622). For example, the information about the resources allocated to the PUSCH may be used for HARQ-ACK (hybrid automatic repeat request-acknowledgement) decoding or estimation of channel conditions.

[0278] Referring to example (1200), in operation (1205), pDU (621) may receive a PUSCH resource allocation message. For example, pDU (621) may receive the PUSCH resource allocation message from sDU (622) via an inter-DU interface (e.g., interface (645) of FIG. 6A). Hereinafter, for convenience of explanation, the PUSCH resource allocation message received by pDU (621) from sDU (622) may be referred to as a first PUSCH resource allocation message.

[0279] For example, in operation (1210), pDU (621) may transmit a PUSCH resource allocation message. For example, pDU (621) may transmit the PUSCH resource allocation message to sDU (622) via an inter-DU interface (e.g., interface (645) of FIG. 6A). Hereinafter, for convenience of explanation, the PUSCH resource allocation message transmitted by pDU (621) to sDU (622) may be referred to as a second PUSCH resource allocation message.

[0280] In example (1200) of FIG. 12A, pDU (621) is illustrated as first receiving the first PUSCH resource allocation message from sDU (622) and then transmitting the second PUSCH resource allocation message, but the present disclosure is not limited thereto. For example, pDU (621) may transmit the second PUSCH resource allocation message before or simultaneously with receiving the first PUSCH resource allocation message from sDU (622).

[0281] For example, the PUSCH resource allocation message may include information (or IE (information element)) about the allocated uplink resources. Examples of information included in the PUSCH resource allocation message may be referenced in the table below.

[0282] IE / Group NamePresenceRangeIE type and referenceSemantics descriptionCriticalityAssigned CriticalityUE listM> UE IDM> Serving cell indexM> PUSCH Air TimeM> Service TypeM> MCS levelM> TBS SizeM> Number of allocated RBM> Number of layerM> Retx TypeM> WaveformM

[0283] Referring to the above table, 'M' in the table may indicate mandatory information. However, the embodiments of the present disclosure are not limited thereto. For example, in the above table, IEs set to 'M' are merely exemplary. For example, IEs set to mandatory information ('M') may also be set to optional information ('O'). For example, the UE list may include one or more terminals for which inter-DU CA (hereinafter, CA) is set (or to be set). For example, the UE ID may include identification information of the terminal for distinguishing the terminal among DUs (621, 622) for the CA. For example, the Serving cell index may include the index of the PCell or SCell of the CA configured for the terminal indicated by the UE ID. For example, the first PUSCH resource allocation message including the resource allocation result of the sDU (622) may include the index of the SCell. For example, the second PUSCH resource allocation message including the resource allocation result of pDU (621) may include the index of PCell.

[0284] For example, the PUSCH Air Time may indicate the time at which the terminal indicated by the UE ID performs PUSCH transmission. For example, the Service Type may indicate the type of service provided by the PUSCH transmission. For example, the service type may include SR (scheduling request), QoS (quality of service), VoNR (enhanced voice new radio), and ViNR (enhanced video new radio). However, the present disclosure is not limited thereto.

[0285] For example, the MCS level may indicate the MCS level for the PUSCH. For example, the TBS Size may indicate the size of the TBS for the PUSCH. For example, the Number of allocated RBs may indicate the number of RBs allocated for the PUSCH. For example, the Number of layers may indicate the number of transmission layers for transmission of the PUSCH. For example, the Retx Type may indicate whether transmission of the PUSCH is a retransmission. For example, the Waveform may indicate the waveform of the PUSCH. For example, the waveform may include CP-OFDM (cyclic prefix-orthogonal frequency division multiplexing) or DFT-s OFDM (discrete Fourier transform spread-OFDM). However, the present disclosure is not limited thereto.

[0286] For example, each of pDU (621) and sDU (622) can recognize the scheduling result (or resource allocation result) for the terminal through the PUSCH resource allocation message. By sharing the result, pDU (621) and sDU (622) can more accurately allocate uplink resources or perform distribution of BSR and / or PHR. In the example of Fig. 12a, a PUSCH resource allocation procedure between pDU (621) and one sDU (622) is illustrated, but the present disclosure is not limited thereto. For example, a PUSCH resource allocation procedure between pDU (621) and multiple sDUs can be referred to Fig. 12b.

[0287] Fig. 12b illustrates an example (1250) of a PUSCH resource allocation procedure between a pDU (621) and sDUs (622, 623). The pDU (621) of Fig. 12b may be an example of DU #1 (621) of Fig. 6a. The sDU (622) of Fig. 12b (e.g., sDU #1) may be an example of DU #2 (622) of Fig. 6a. The sDU (623) of Fig. 12b (e.g., sDU #2) may be an example of DU #n (623) of Fig. 6a. For example, pDU (621), sDU (622), and sDU (623) can provide inter DU CA for a terminal (e.g., terminal 120 of FIGS. 1A and 1B or terminal 625-1 of FIG. 6A). For example, pDU (621) can provide a PCell of inter DU CA for the terminal. pDU (621) can be referred to as PCell gNB-DU or first DU. For example, sDU (622) can provide a SCell of inter DU CA for the terminal. For example, sDU (623) can provide a SCell of inter DU CA for the terminal. sDU (622) (or sDU (623)) can be referred to as SCell gNB-DU or second DU. Each of the pDU (621), sDU (622), and sDU (623) may include at least some of the components of the electronic device (500) of FIG. 5.

[0288] Referring to example (1250), in operations (1260) and (1265), pDU (621) may transmit a PUSCH resource allocation message. For example, pDU (621) may transmit a PUSCH resource allocation message indicating the PUSCH resource allocation result of pDU (621) to sDU (622). In addition, pDU (621) may transmit a PUSCH resource allocation message indicating the PUSCH resource allocation result of pDU (621) to sDU (623).

[0289] For example, in operations (1270) and (1275), the sDU (622) may transmit a PUSCH resource allocation message. For example, the sDU (622) may transmit a PUSCH resource allocation message indicating the PUSCH resource allocation result of the sDU (622) to the pDU (621). In addition, the sDU (622) may transmit a PUSCH resource allocation message indicating the PUSCH resource allocation result of the sDU (622) to the sDU (623).

[0290] For example, in operations (1280) and (1285), the sDU (623) may transmit a PUSCH resource allocation message. For example, the sDU (623) may transmit a PUSCH resource allocation message indicating the PUSCH resource allocation result of the sDU (623) to the pDU (621). In addition, the sDU (623) may transmit a PUSCH resource allocation message indicating the PUSCH resource allocation result of the sDU (623) to the sDU (622).

[0291] Specific details regarding the PUSCH resource allocation messages transmitted by pDU (621), sDU (622), and sDU (623) may be referenced in Table 11 above. Referring to FIG. 12b, through signaling between pDU (621) and multiple sDUs (622, 623), DUs providing inter-DU CA can recognize (or share) the results of uplink resource allocation of each DU. Accordingly, each DU can perform more accurate uplink resource allocation and PHR distribution and BSR distribution.

[0292] In one example, the PUSCH resource allocation messages of FIGS. 12A and 12B may be periodically transmitted and received according to a transmission time interval (TTI). For example, the BSR management message of FIGS. 8A and 8B may be periodically transmitted and received according to a first time interval that is longer than the period according to the TTA. For example, the first time interval may indicate a time interval at which a BSR (or information about a BSR) related to the BSR management message is received. For example, the PHR management message of FIGS. 10A and 10B may be periodically transmitted and received according to a second time interval that is longer than the first time interval. For example, the second time interval may indicate a time interval at which a PHR (or information about a PHR) related to the PHR management message is received.

[0293] Referring to FIGS. 8A and 8B, if the pDU (621) among the DUs for providing inter-DU CA is a DU (or a split entity) that distributes the buffer and / or the power, the sDU (622) (or gNB-DU of SCell) may transmit a PUSCH resource allocation message to the pDU (621) (or gNB-DU of PCell). At this time, the pDU (621) (or gNB-DU of PCell)) may transmit the PUSCH resource allocation message to the sDU (622) (or gNB-DU of SCell). Alternatively, the operation of the sDU (622) (or gNB-DU of SCell) transmitting the PUSCH resource allocation message to another sDU (or gNB-DU of SCell) may be selectively performed.

[0294] The names of the messages illustrated in FIGS. 12A and 12B are merely for convenience of explanation and are not intended to limit the present disclosure. For example, the names of the information exchanged between DUs to provide inter-DU CA and the names of the messages containing such information may be changed. Furthermore, for example, some of the information (or IE) included in the message may be omitted or other configurations may be added.

[0295] Figures 13a and 13b illustrate examples of SCell TA (timing advance) management procedures for CA between DUs.

[0296] The pDU (621) of FIGS. 13A and 13B may be an example of DU #1 (621) of FIG. 6A. The sDU (622) of FIGS. 13A and 13B may be an example of DU #2 (622) of FIG. 6A. The sDU (623) of FIG. 13B may be an example of DU #n (623) of FIG. 6A. For example, the pDU (621), the sDU (622), and the sDU (623) may provide inter-DU CA for a terminal (e.g., the terminal (120) of FIGS. 1A and 1B or the terminal (625-1) of FIG. 6A). For example, the pDU (621) may provide a PCell of the inter-DU CA for the terminal. The pDU (621) may be referred to as a PCell gNB-DU or a first DU. For example, the sDU (622) may provide an SCell for inter-DU CA for the terminal. For example, the sDU (623) may provide an SCell for inter-DU CA for the terminal. The sDU (622) (or sDU (623)) may be referred to as a SCell gNB-DU or a second DU. Each of the pDU (621), the sDU (622), and the sDU (623) may include at least some of the components of the electronic device (500) of FIG. 5 .

[0297] Example (1300) of FIG. 13a may represent an example of the SCell TA management procedure. For example, the SCell TA management procedure may be used to determine whether uplink transmission to the SCell is possible based on a timing mismatch between the SCell of the SDU (622) and the terminal.

[0298] For example, the timing for the uplink of the PCell may be aligned based on the timing for the downlink of the PCell. Furthermore, the timing for the uplink of the SCell may be aligned based on the timing for the downlink of the SCell. For example, unlike the PCell, which can achieve timing matching according to a random access procedure, the SCell does not have a method for aligning the SCell uplink timing with the UE, and therefore, the SCell TA management procedure may be required.

[0299] For example, if the terminal is a terminal (or a single TAG terminal) that supports a single timing advance group (TAG), the SCell TA management procedure may be required. For example, timing synchronization between DUs (621, 622) may be performed via a global positioning system (GPS). Even if the timing synchronization between DUs (621, 622) is performed, the timing of the cells of the DUs (621, 622) (e.g., the PCell of the pDU (621) and the SCell of the sDU (622)) may not match. For example, the timing between the cells may differ by 10 TAs (timing advance) or more. However, since the single TAG terminal cannot support different TA values ​​for each cell, it is necessary to determine whether to perform CA between DUs using SCells according to the SCell TA management procedure. In contrast, if the terminal is a terminal that supports multiple TAGs (or a multiple TAG terminal), the SCell TA management procedure may be optionally used.

[0300] Referring to example (1300), in operation (1305), pDU (621) may receive an SCell TA management message. For example, pDU (621) may receive the SCell TA management message from sDU (622) through an inter-DU interface (e.g., interface (645) of FIG. 6A).

[0301] For example, the SCell TA management message may include information (or IE (information element)) regarding the difference in time offset (or timing offset) between the SCell and the terminal measured by sDU (622). Examples of information included in the SCell TA management message may be referenced in the table below.

[0302] IE / Group NamePresenceRangeIE type and referenceSemantics descriptionCriticalityAssigned CriticalityUE listM> UE IDM> Serving cell indexM> Time offset differenceM

[0303] Referring to the above table, 'M' in the table may indicate mandatory information. However, the embodiments of the present disclosure are not limited thereto. For example, in the above table, IEs set to 'M' are merely exemplary. For example, IEs set to mandatory information ('M') may also be set to optional information ('O'). For example, the UE list may include one or more terminals for which inter-DU CA (hereinafter, CA) is set (or to be set). For example, the UE ID may include terminal identification information for distinguishing the terminal between DUs (621, 622) for the CA. For example, the Serving cell index may include the index of the SCell having the time offset difference measured by the sDU (622) for the terminal identified by the UE ID. For example, the Time offset difference may indicate a time offset difference between the terminal indicated by the UE ID and the SCell indicated by the Serving cell index.

[0304] Referring to the above, when the pDU (621) is a DU that distributes BSR and / or PHR, the SCell TA management message can be used to determine whether the sDU (622) uses the SCell TA management message. For example, the pDU (621) can determine not to use the SCell if the time offset difference of the SCell TA management message is greater than or equal to a reference difference. For example, the pDU (621) can determine to use the SCell if the time offset difference of the SCell TA management message is less than or equal to the reference difference. In the example (1300) of FIG. 13a, an example of the pDU (621) determining whether to use the SCell is described, but the present disclosure is not limited thereto. For example, if the DU that distributes BSR and / or PHR is sDU (622), sDU (622) can determine whether to use the SCell of sDU (622) based on the measured time offset difference. For example, if sDU (622) decides not to use the SCell, it can transmit a message (e.g., a distribution BSR management message or a distribution PHR management message) including an SCell schedule allow indicating 'disable' to DU (621). Accordingly, pDU (621) can update the status of the SCell of sDU (622) to a disabled state, or sDU (622) can perform a deactivation request of the SCell.

[0305] Although the example (1300) of FIG. 13a illustrates the SCell TA management procedure including signaling between a pDU (621) and one sDU (622), the present disclosure is not limited thereto. For example, the SCell TA management procedure may include signaling between a pDU (621) and multiple sDUs. For a specific example related thereto, reference may be made to example (1350) of FIG. 13b below.

[0306] Referring to example (1350), in operation (1355), sDU (622) may transmit a SCell TA management message to pDU (621). Further, in operation (1360), sDU (622) may transmit a SCell TA management message to sDU (623). For example, the Time offset difference of the SCell TA management message transmitted to pDU (621) may indicate a time offset difference between the SCell of sDU (622) and the terminal. Further, for example, the Time offset difference of the SCell TA management message transmitted to sDU (623) may indicate a time offset difference between the SCell of sDU (622) and the terminal. In other words, SCell TA management messages transmitted from sDU (622) may include the same information.

[0307] In example (1350) of FIG. 13b, an example is illustrated in which sDU (622) simultaneously transmits the SCell TA management message to pDU (621) and sDU (623), but the present disclosure is not limited thereto. For example, sDU (622) may transmit the SCell TA management message to sDU (623) after transmitting the SCell TA management message to pDU (621), or may transmit the SCell TA management message to sDU (623) after transmitting the SCell TA management message to pDU (621).

[0308] Referring to FIGS. 13a and 13b, if among the DUs for providing inter-DU CA, the pDU (621) is a DU (or a split entity) that distributes the buffer and / or the power, and the terminal is a single TAG terminal, the sDU (622) (or gNB-DU of SCell) may transmit an SCell TA management message to the pDU (621) (or gNB-DU of PCell). If the terminal is a multi-TAG terminal, the operation of the sDU (622) (or gNB-DU of SCell) transmitting an SCell TA management message to the pDU (621) (or gNB-DU of PCell)) may be selectively performed. Additionally, regardless of the terminal (or, if the terminal is a single TAG terminal or multiple TAG terminals), the operation of transmitting a PUSCH resource allocation message from an sDU (622) (or a gNB-DU of SCell) to another sDU (or a gNB-DU of SCell) can be selectively performed.

[0309] The names of the messages illustrated in FIGS. 13A and 13B are merely for convenience of explanation and are not intended to limit the present disclosure. For example, the names of the information exchanged between DUs to provide inter-DU CA and the names of the messages containing such information may be changed. Furthermore, for example, some of the information (or IE) included in the message may be omitted or other configurations may be added.

[0310] FIG. 14a and FIG. 14b illustrate examples of signal flows for a method of performing uplink resource allocation for a terminal in CA between DUs.

[0311] The pDU (621) of FIGS. 14A and 14B may be an example of DU #1 (621) of FIG. 6A. The sDU (622) of FIGS. 14A and 14B may be an example of DU #2 (622) of FIG. 6A. The terminal (625) of FIGS. 14A and 14B may be an example of the terminal (625-1) of FIG. 6A. For example, the pDU (621) and the sDU (622) may provide inter-DU CA for the terminal (625). For example, the pDU (621) may provide a PCell of the inter-DU CA for the terminal (625). The pDU (621) may be referred to as a PCell gNB-DU or a first DU. For example, the sDU (622) may provide an SCell of inter-DU CA for the terminal (625). The sDU (622) may be referred to as an SCell gNB-DU or a second DU. Each of the pDU (621) and the sDU (622) may include at least some of the components of the electronic device (500) of FIG. 5.

[0312] FIGS. 14A and 14B illustrate signal flow examples (1400, 1450) for a method of performing uplink resource allocation in inter DU CA for a terminal (625). The example (1450) of FIG. 14B may represent an example of a signal flow that is continuous with respect to the example (1400) of FIG. 14A. The signal flow between the terminal (625) and the DUs (621, 622) illustrated in the example (1400) of FIG. 14A and the example (1450) of FIG. 14B is merely exemplary for convenience of explanation and the present disclosure is not limited thereto. In the examples (1400, 1450) of FIGS. 14a and 14b, the case where the pDU (621) is a DU that is the distribution subject of uplink scheduling in the DU-to-DU CA is exemplified, but the present disclosure is not limited thereto.

[0313] Referring to example (1400) of FIG. 14A, in operation (1401), the pDU (621) may determine the activation of an SCell. For example, the pDU (621) may determine the addition and activation of an sDU (622) to provide inter-DU CA for the terminal (625).

[0314] For example, in operation (1403), the pDU (621) may transmit a MAC CE for SCell activation to the terminal (625). For example, the pDU (621) may transmit the MAC CE indicating the activation of the SCell to the terminal (625) based on determining the activation. Accordingly, the terminal (625) may recognize that the SCell for inter-DU CA will be activated based on receiving the MAC CE. For example, the MAC CE may be transmitted to the terminal (625) via a physical downlink shared channel (PDSCH).

[0315] For example, in operation (1405), the terminal (625) may transmit a HARQ-ACK to the pDU (621). For example, the HARQ-ACK may be a response to the MAC CE for activating the SCell.

[0316] For example, in operation (1407), pDU (621) may transmit a SCell status update message to sDU (622). For example, pDU (621) may transmit the SCell status update message to sDU (622) to activate the SCell of sDU (622). For example, in operation (1409), sDU (622) may transmit a SCell status update response message to pDU (621). For example, specific details regarding the SCell status update message and the SCell status update response message may be referred to FIG. 7A. According to operation (1407) and operation (1409), the SCell of sDU (622) may be changed to an activated state.

[0317] For example, in operation (1411), the terminal (625) may transmit a PHR and a BSR to the pDU (621). For example, the PHR and the BSR may be transmitted to the pDU (621) via a PUSCH transmission of the terminal (625). In operation (1411), the PHR and the BSR may be transmitted together via the PUSCH transmission.

[0318] For example, in operation (1413), the pDU (621) may determine the uplink scheduling of the SCell using the received PHR and BSR. For example, the pDU (621) may determine the amount and power of the buffer to be scheduled for the terminal (625) and the amount and power of the buffer to be scheduled for the terminal (625) by the sDU (622) based on the PHR and BSR received from the terminal (625). Accordingly, the pDU (621) may generate distributed PHR information and distributed BSR information.

[0319] For example, in operation (1415), pDU (621) may transmit a distribution PHR management message including the distributed PHR information to sDU (622). For specific details about the distribution PHR management message, reference may be made to the contents of FIG. 11A. In addition, for example, in operation (1417), pDU (621) may transmit a distribution BSR management message including the distributed BSR information to sDU (622). For specific details about the distribution BSR management message, reference may be made to the contents of FIG. 9A.

[0320] For example, in operation (1419), sDU (622) may perform uplink scheduling for the SCell using the received distributed PHR management message and distributed BSR management message. For example, sDU (622) may perform uplink scheduling for the SCell for terminal (625) based on the transmission power indicated by the distributed PHR management message and the amount of buffer indicated by the distributed BSR management message. Although not shown in FIG. 14A, sDU (622) may transmit configuration information according to the uplink scheduling to terminal (625). Thereafter, terminal (625) may perform uplink transmission (e.g., PUSCH transmission) according to the configuration information.

[0321] For example, in operation (1421), the terminal (625) may transmit a PHR to the sDU (622). For example, the PHR may be transmitted in an uplink transmission scheduled according to operation (1419).

[0322] For example, in operation (1423), sDU (622) may transmit a PHR management message including information about the PHR received from terminal (625) to pDU (621). For example, the PHR management message may be used to share information about the PHR received by sDU (622) with pDU (621). For specific details about the PHR management message, reference may be made to the contents of FIG. 10A.

[0323] For example, in operation (1425), the pDU (621) may determine the uplink scheduling of the SCell using the received PHR management message. For example, the pDU (621) may determine the power to be scheduled for the terminal (625) using the information about the PHR of the PHR management message received from the sDU (622), and the sDU (622) may determine the power to be scheduled for the terminal (625). Accordingly, the pDU (621) may generate distributed PHR information.

[0324] For example, in operation (1427), pDU (621) may transmit a distributed PHR management message including the distributed PHR information to sDU (622). For specific details regarding the distributed PHR management message, reference may be made to the contents of FIG. 11A.

[0325] For example, in operation (1429), sDU (622) may perform uplink scheduling for the SCell using the received distributed PHR management message. For example, sDU (622) may perform uplink scheduling for the SCell for terminal (625) based on the transmission power indicated by the distributed PHR management message. Although not illustrated in FIG. 14A, sDU (622) may transmit configuration information according to the uplink scheduling to terminal (625). Thereafter, terminal (625) may perform uplink transmission (e.g., PUSCH transmission) according to the configuration information.

[0326] For example, in operation (1431), the terminal (625) may transmit a PHR to the pDU (621). For example, the PHR may be transmitted in an uplink transmission scheduled according to operation (1429).

[0327] For example, in operation (1433), the pDU (621) may determine the uplink scheduling of the SCell using the received PHR management message. For example, the pDU (621) may determine the power to be scheduled for the terminal (625) using the information about the PHR of the PHR management message received from the terminal (625), and the sDU (622) may determine the power to be scheduled for the terminal (625). Accordingly, the pDU (621) may generate distributed PHR information.

[0328] Although not illustrated in the example (1400) of FIG. 14a, the pDU (621) may transmit a PHR management message including information about the PHR received from the terminal (625) to the sDU (622). For example, the PHR management message may be used to share information about the PHR received by the pDU (621) (or an RU associated with the PCell of the pDU (621)) with the sDU (622). For specific details about the PHR management message, reference may be made to the contents of FIG. 10b.

[0329] For example, in operation (1435), pDU (621) may transmit a distributed PHR management message including the distributed PHR information to sDU (622). For specific details regarding the distributed PHR management message, reference may be made to the contents of FIG. 11A.

[0330] For example, in operation (1437), sDU (622) may perform uplink scheduling for the SCell using the received distributed PHR management message. For example, sDU (622) may perform uplink scheduling for the SCell for terminal (625) based on the transmission power indicated by the distributed PHR management message. Although not illustrated in FIG. 14A, sDU (622) may transmit configuration information according to the uplink scheduling to terminal (625). Thereafter, terminal (625) may perform uplink transmission (e.g., PUSCH transmission) according to the configuration information.

[0331] Referring to example (1450), for example, in operation (1451), the terminal (625) may transmit a BSR to the pDU (621). For example, the BSR may be transmitted in an uplink transmission scheduled according to operation (1437).

[0332] For example, in operation (1453), the pDU (621) may determine the uplink scheduling of the SCell using the received BSR management message. For example, the pDU (621) may determine the amount of buffer to be scheduled for the terminal (625) using information about the BSR of the BSR management message received from the terminal (625), and the sDU (622) may determine the amount of buffer to be scheduled for the terminal (625). Accordingly, the pDU (621) may generate distributed BSR information.

[0333] Although not illustrated in the example (1450) of FIG. 14b, the pDU (621) may transmit a BSR management message including information about the BSR received from the terminal (625) to the sDU (622). For example, the BSR management message may be used to share information about the BSR received by the pDU (621) (or an RU associated with the PCell of the pDU (621)) with the sDU (622). For specific details about the BSR management message, reference may be made to the contents of FIG. 8b.

[0334] For example, in operation (1455), pDU (621) may transmit a distributed BSR management message including the distributed BSR information to sDU (622). For specific details on the distributed BSR management message, reference may be made to the contents of FIG. 9A.

[0335] For example, in operation (1457), sDU (622) may perform uplink scheduling for the SCell using the received distributed BSR management message. For example, sDU (622) may perform uplink scheduling for the SCell for terminal (625) based on the amount of buffer indicated by the distributed BSR management message. Although not illustrated in FIG. 14b, sDU (622) may transmit configuration information according to the uplink scheduling to terminal (625). Thereafter, terminal (625) may perform uplink transmission (e.g., PUSCH transmission) according to the configuration information.

[0336] For example, in operation (1459), the terminal (625) may transmit a BSR to the sDU (622). For example, the BSR may be transmitted in an uplink transmission scheduled according to operation (1457).

[0337] For example, in operation (1461), sDU (622) may transmit a BSR management message including information about the BSR received from terminal (625) to pDU (621). For example, the BSR management message may be used to share information about the BSR received by sDU (622) with pDU (621). For specific details about the BSR management message, reference may be made to the contents of FIG. 8A.

[0338] For example, in operation (1463), the pDU (621) may determine the uplink scheduling of the SCell using the received BSR management message. For example, the pDU (621) may determine the amount of buffer to be scheduled for the terminal (625) using the information about the BSR of the BSR management message received from the sDU (622), and the sDU (622) may determine the amount of buffer to be scheduled for the terminal (625). Accordingly, the pDU (621) may generate distributed BSR information.

[0339] For example, in operation (1465), pDU (621) may transmit a distributed BSR management message including the distributed BSR information to sDU (622). For specific details regarding the distributed BSR management message, reference may be made to the contents of FIG. 9A.

[0340] For example, in operation (1467), sDU (622) may perform uplink scheduling for the SCell using the received distributed BSR management message. For example, sDU (622) may perform uplink scheduling for the SCell for terminal (625) based on the amount of buffer indicated by the distributed BSR management message. Although not illustrated in FIG. 14b, sDU (622) may transmit configuration information according to the uplink scheduling to terminal (625). Thereafter, terminal (625) may perform uplink transmission (e.g., PUSCH transmission) according to the configuration information.

[0341] In FIGS. 14A and 14B , the case where the pDU (621) is a distribution entity performing scheduling for inter-DU CA is illustrated, but the present disclosure is not limited thereto. For example, the present disclosure can also be applied to a case where the sDU (622) for inter-DU CA is a distribution entity. In addition, in FIGS. 14A and 14B , the DUs (621, 622) for inter-DU CA include one sDU (622), but the present disclosure is not limited thereto. For example, the present disclosure may include multiple sDUs for inter-DU CA.

[0342] Figure 15 illustrates an example of an operational flow for how a first DU transmits a distributed BSR management message for uplink scheduling of a second DU.

[0343] At least some of the above methods of FIG. 15 may be performed by DU #1 (621) (or pDU (621)) (hereinafter, first DU) of FIG. 6A. For example, at least some of the above methods may be controlled by a processor (530) of an electronic device (or device, apparatus, node, entity) (500) of the first DU. In the following embodiments, each operation may be performed sequentially, but is not necessarily performed sequentially. For example, the order of each operation may be changed, and at least two operations may be performed in parallel.

[0344] According to one embodiment, in operation (1510), the electronic device (500) may obtain information about a BSR of a terminal (UE) (e.g., terminal (625-1) of FIG. 6A) on a primary cell (PCell) associated with the first DU.

[0345] For example, the electronic device (500) can receive a BSR management message. For example, the electronic device (500) can receive the BSR management message from another electronic device of the second DU (e.g., DU #2 (622) (or sDU)) through an inter-DU interface (e.g., interface (645) of FIG. 6A). For example, the other electronic device can obtain information about the BSR from the terminal. For example, the other electronic device can receive information about the BSR from the terminal through uplink transmission (e.g., PUSCH transmission) on a secondary cell (SCell) provided by the sDU (622). For example, the other electronic device can generate the BSR management message based on the received information about the BSR and transmit the generated BSR management message to the electronic device (500).

[0346] Alternatively, for example, the electronic device (500) may obtain information about the BSR from the terminal. For example, the electronic device (500) may obtain information about the BSR of the terminal from a radio unit (RU) associated with the PCell of a CA configured for the terminal. For example, the RU may receive information about the BSR from the terminal through uplink transmission (e.g., PUSCH transmission) on the PCell provided by a pDU (621). For example, the electronic device (500) may generate the BSR management message based on the received information about the BSR and transmit the generated BSR management message to the other electronic device.

[0347] Although not illustrated in FIG. 15, prior to performing operation (1510), the electronic device (500) may perform addition and activation of the second DU through signaling with the other electronic device. For specific details related thereto, reference may be made to the SCell status update management procedure of FIG. 7a and the example (1400) of FIG. 14a.

[0348] According to one embodiment, in operation (1520), the electronic device (500) may transmit a distributed BSR management message for uplink scheduling of the second DU through an interface between the first DU and the second DU. For example, the electronic device (500) may transmit the distributed BSR management message to the second DU (or the other electronic device) associated with the SCell of a CA (e.g., an inter-DU CA) configured for the terminal. For example, the interface may include an inter-DU interface (e.g., interface (645) of FIG. 6A).

[0349] For example, the electronic device (500) may determine SCell uplink scheduling based on the acquired information about the BSR of the terminal. For example, the electronic device (500) may divide the buffer available to the terminal according to the amount of data to be scheduled in the SCell based on the information about the BSR. For example, the electronic device (500) may determine the distributed buffer occupancy (BO) to be used by the other electronic device. For example, the information about the BSR may be acquired directly from the terminal or through a BSR management message received from the other electronic device.

[0350] For example, the distributed BSR management message may include information (or IE (information element)) about the buffer distributed for the terminal. Examples of information included in the distributed BSR management message may be referenced to the contents of FIG. 9A and Table 8.

[0351] For example, the other electronic device may perform uplink scheduling for the terminal using the distributed BSR management message. The terminal may transmit uplink transmission (e.g., PUSCH) to the other electronic device according to the scheduled resources. At this time, the terminal may perform uplink transmission to the electronic device (500) according to the CA between DUs.

[0352] In the example of FIG. 15, an example is described of a method in which an electronic device (500) performs uplink scheduling for an SCell of another electronic device by obtaining information about a BSR and generating and transmitting a distributed BSR management message accordingly, but the present disclosure is not limited thereto.

[0353] For example, the electronic device (500) may receive a deactivation request message for the SCell from the other electronic device and perform deactivation of the SCell. For specific details related thereto, reference may be made to FIG. 7b and Table 6.

[0354] Additionally, for example, when the electronic device (500) acquires information about a BSR through an RU associated with the PCell, it may transmit the acquired information about the BSR to another electronic device. For specific details related thereto, reference may be made to FIG. 8b and Table 7.

[0355] In addition, for example, the electronic device (500) may receive a PHR management message including information about a PHR from the other electronic device. The information about the PHR may be used to perform uplink scheduling considering the power (or transmission power) of the terminal. For specific details related thereto, reference may be made to FIG. 10a and Table 9. Alternatively, when the electronic device (500) obtains information about a PHR through an RU associated with the PCell, the electronic device (500) may transmit the obtained information about the PHR to the other electronic device. For specific details related thereto, reference may be made to FIG. 10b and Table 9. For example, the electronic device (500) may generate distributed PHR information using the information about the PHR and transmit the distributed PHR information to the other electronic device. For example, the distributed PHR information may be included in a distributed PHR management message. For specific details related thereto, reference may be made to FIG. 11a and Table 10.

[0356] Additionally, for example, the electronic device (500) may share PUSCH resource allocation information with another electronic device. For example, the electronic device (500) may transmit a PUSCH resource allocation message to the other electronic device and receive a PUSCH resource allocation message from the other electronic device. For specific details related thereto, reference may be made to FIG. 12A and Table 11.

[0357] Additionally, for example, the electronic device (500) may receive information about the time offset difference of the SCell to determine whether the SCell of the other electronic device is available. For example, the electronic device (500) may receive an SCell TA management message including information about the time offset difference. For specific details related thereto, reference may be made to FIG. 13A and Table 12.

[0358] Referring to FIGS. 1A to 15, the device, method, and storage medium according to embodiments of the present disclosure can provide CA using cells of different DUs as well as CA performed in cells within the same DU. The device, method, and storage medium according to embodiments of the present disclosure can provide flexible network operation by providing CA using cells of DUs of different operators (or vendors). In other words, the device, method, and storage medium according to embodiments of the present disclosure can resolve restrictions on CA operations between DUs of different operators. Accordingly, the device, method, and storage medium according to embodiments of the present disclosure can provide services using a more expanded capacity.

[0359] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0360] A device of a first distributed unit (DU) as described above may include at least one processor including a processing circuit. The device may include a memory storing instructions and including one or more storage media. The instructions, when individually or collectively executed by the at least one processor, may cause the device to obtain information about a buffer status report (BSR) of a UE on a primary cell associated with the first DU. The instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit, to a second DU associated with a secondary cell of a carrier aggregation (CA) configured for the UE, a split BSR management message for uplink scheduling of the second DU through an interface between the first DU and the second DU. The above distribution BSR management message may include an ID (identifier) ​​of the UE, an index (index) of the primary cell, information on the time at which the BSR was received, LCG (logical channel group) ID information of the BSR, and a distribution BO (split buffer occupancy) to be used by the second DU.

[0361] According to one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to receive, from the second DU through the interface, a BSR management message including information about the BSR of the UE. The BSR management message may include the ID of the UE, an index of the secondary cell, time information at which the BSR was received by the second DU, a type of the BSR, LCG ID information of the BSR, and buffer size information according to the type of the BSR.

[0362] According to one embodiment, the type of the BSR may indicate one of a Short BSR, a Short truncated BSR, a Long BSR, and a Long truncated BSR. When the type indicates the Short BSR or the Short truncated BSR, the buffer size information may include a buffer size of the Short BSR or the Short truncated BSR. When the type indicates the Long BSR or the Long truncated BSR, the buffer size information may include at least one LCG ID and at least one buffer size of the Long BSR or the Long truncated BSR corresponding to the at least one LCG ID.

[0363] According to one embodiment, the distributed BSR management message may further include information for indicating whether uplink scheduling of the second DU is permitted.

[0364] According to one embodiment, the information about the BSR can be obtained through a radio unit (RU) for the primary cell associated with the first DU.

[0365] According to one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to obtain information about a power headroom report (PHR) of the UE. The instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit, to the second DU, a distributed PHR management message for uplink scheduling of the second DU through the interface. The distributed PHR management message may include the index of the primary cell, information about a time at which the PHR was received, an index of the PHR, maximum power information of the secondary cell of the second DU, a number of RBs used when the PHR was received, and a maximum number of RBs usable by the second DU.

[0366] According to one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to receive, from the second DU through the interface, a PHR management message including information about the PHR of the UE. The PHR management message may include the ID of the UE, an index of the secondary cell, time information at which the PHR was received by the second DU, a type of the PHR, a size of the PHR, and power information according to the type of the PHR.

[0367] According to one embodiment, the type of the PHR may indicate one of a single PHR and multiple PHRs. If the type of the PHR indicates the single PHR, the power information may include a power headroom (PH) level and a maximum transmit power for the PH level. If the type of the PHR indicates the multiple PHRs, the power information may include a first PH level, a first maximum transmit power for the first PH level, a second PH level, and a second maximum transmit power for the second PH level.

[0368] According to one embodiment, the information about the PHR can be obtained through a radio unit (RU) for the primary cell associated with the first DU.

[0369] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit, to the second DU, via the interface, a first uplink resource allocation message comprising first physical uplink shared channel (PUSCH) resource allocation information for the UE of the first DU. The instructions, when individually or collectively executed by the at least one processor, may cause the device to receive, from the second DU, via the interface, a second uplink resource allocation message comprising second PUSCH resource allocation information for the UE of the second DU.

[0370] According to one embodiment, the first PUSCH resource allocation information may include the ID of the UE, the index of the primary cell, a transmission time of the first PUSCH, a service type related to the first PUSCH, a modulation and coding scheme (MCS) for the first PUSCH, a transport block size (TBS) for the first PUSCH, a number of RBs allocated for the first PUSCH, a number of layers for the first PUSCH, information indicating retransmission of the first PUSCH, and a waveform of a signal of the first PUSCH. The second PUSCH resource allocation information may include the ID of the UE, the index of the secondary cell, the transmission time of the second PUSCH, the service type related to the second PUSCH, the MCS for the second PUSCH, the TBS for the second PUSCH, the number of RBs allocated for the second PUSCH, the number of layers for the second PUSCH, information indicating retransmission of the second PUSCH, and a waveform for the second PUSCH.

[0371] According to one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to receive, from the second DU, a timing advance (TA) management message for time synchronization between the second DU and the UE. The TA management message may include the ID of the UE, an index of the secondary cell, and a time offset difference between the second DU and the UE.

[0372] According to one embodiment, the UE may include a UE having one timing advance group (TAG) configured.

[0373] According to one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit, to the second DU, a status update message of the secondary cell via the interface. The instructions, when individually or collectively executed by the at least one processor, may cause the device to receive, from the second DU, a status update response message via the interface. The status update message may include the ID of the UE, an index of the secondary cell, and status information of the secondary cell. The status update response message may include the ID of the UE and the index of the secondary cell. The status information of the secondary cell may include an activation state and a deactivation state of the secondary cell.

[0374] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to receive, from the second DU via the interface, a deactivation request message of the secondary cell. The instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit, to the second DU via the interface, a status update message of the secondary cell in response to the deactivation request message. The deactivation request message may include the ID of the UE and the index of the secondary cell. The status update message may include the ID of the UE, the index of the secondary cell, and status information of the secondary cell indicating a deactivation state.

[0375] The method performed by the first distributed unit (DU) as described above may include an operation of obtaining information about a buffer status report (BSR) of a UE on a primary cell associated with the first DU. The method may include an operation of transmitting, to a second DU associated with a secondary cell of a carrier aggregation (CA) configured for the UE, a split BSR management message for uplink scheduling of the second DU through an interface between the first DU and the second DU. The split BSR management message may include an identifier (ID) of the UE, an index of the primary cell, time information at which the BSR was received, logical channel group (LCG) ID information of the BSR, and a split buffer occupancy (BO) to be used by the second DU.

[0376] According to one embodiment, the method may include receiving, from the second DU, a BSR management message including information about the BSR of the UE through the interface. The BSR management message may include the ID of the UE, an index of the secondary cell, information about the time at which the BSR was received by the second DU, a type of the BSR, LCG ID information of the BSR, and buffer size information according to the type of the BSR.

[0377] According to one embodiment, the method may include an operation of obtaining information about a power headroom report (PHR) of the UE. The method may include an operation of transmitting, to the second DU, a distributed PHR management message for uplink scheduling of the second DU through the interface. The distributed PHR management message may include an index of the primary cell, information on a time at which the PHR was received, an index of the PHR, maximum power information of the secondary cell of the second DU, a number of RBs used when the PHR was received, and a maximum number of RBs available to the second DU.

[0378] According to one embodiment, the method may include receiving, from the second DU, a PHR management message including information about the PHR of the UE through the interface. The PHR management message may include the ID of the UE, an index of the secondary cell, time information at which the PHR was received by the second DU, a type of the PHR, a size of the PHR, and power information according to the type of the PHR.

[0379] The non-transitory computer-readable storage medium as described above may store one or more programs including instructions that, when individually or collectively executed by at least one processor including a processing circuit of a first distributed unit (DU), cause the processor to obtain information about a buffer status report (BSR) of a UE on a primary cell associated with the first DU. The non-transitory computer-readable storage medium may store one or more programs including instructions that, when individually or collectively executed by the at least one processor, cause the processor to transmit, to a second DU associated with a secondary cell of a carrier aggregation (CA) configured for the UE, a split BSR management message for uplink scheduling of the second DU through an interface between the first DU and the second DU. The above distribution BSR management message may include an ID (identifier) ​​of the UE, an index (index) of the primary cell, information on the time at which the BSR was received, LCG (logical channel group) ID information of the BSR, and a distribution BO (split buffer occupancy) to be used by the second DU.

[0380] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0381] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure. The one or more programs may be provided as a computer program product. The computer program product may be traded between a seller and a buyer as a commodity. 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) via an application store (e.g., Play Store™) or directly between two user devices (e.g., smart phones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily created in a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0382] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc-ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in memories formed by a combination of some or all of these. In addition, each configuration memory may include multiple copies.

[0383] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present disclosure.

[0384] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0385] According to embodiments, one or more of the components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0386] Meanwhile, although the detailed description of the present disclosure has described specific embodiments, it is obvious that various modifications are possible within the scope of the present disclosure.

Claims

1. In the device of the first DU (distributed unit), At least one processor comprising a processing circuit; and A memory storing instructions and including one or more storage media, The above instructions, when individually or collectively executed by the at least one processor, cause the device to: Obtain information about the BSR (buffer status report) of the UE on the primary cell related to the first DU, and Causing a second DU associated with a secondary cell of a carrier aggregation (CA) configured for the UE to transmit a split BSR management message for uplink scheduling of the second DU through an interface between the first DU and the second DU, The above distribution BSR management message includes an ID (identifier) ​​of the UE, an index (index) of the primary cell, information on the time at which the BSR was received, LCG (logical channel group) ID information of the BSR, and a distribution BO (split buffer occupancy) to be used by the second DU. device.

2. In claim 1, The above instructions, when individually or collectively executed by the at least one processor, cause the device to: Causing the UE to receive a BSR management message including information about the BSR of the UE through the interface from the second DU, The BSR management message includes the ID of the UE, the index of the secondary cell, the time information at which the BSR was received by the second DU, the type of the BSR, the LCG ID information of the BSR, and buffer size information according to the type of the BSR. device.

3. In claim 2, The above type of the above BSR indicates one of Short BSR, Short truncated BSR, Long BSR, and Long truncated BSR, If the type indicates the Short BSR or the Short truncated BSR, the buffer size information includes the buffer size of the Short BSR or the Short truncated BSR, and If the type indicates the Long BSR or the Long truncated BSR, the buffer size information includes at least one LCG ID and at least one buffer size of the Long BSR or the Long truncated BSR corresponding to the at least one LCG ID. device.

4. In claim 1, The above distribution BSR management message further includes information for indicating whether uplink scheduling of the second DU is permitted. device.

5. In claim 1, The information about the above BSR is obtained through the RU (radio unit) for the primary cell associated with the first DU. device.

6. In claim 1, The above instructions, when individually or collectively executed by the at least one processor, cause the device to: Obtain information about the PHR (power headroom report) of the above UE, and Causing the second DU to transmit a distribution PHR management message for uplink scheduling of the second DU through the interface, The above distribution PHR management message includes the index of the primary cell, information on the time at which the PHR was received, the index of the PHR, maximum power information of the secondary cell of the second DU, the number of RBs used when the PHR was received, and the maximum number of RBs available to the second DU. device.

7. In claim 6, The above instructions, when individually or collectively executed by the at least one processor, cause the device to: Causing the second DU to receive a PHR management message including information about the PHR of the UE through the interface, The PHR management message includes the ID of the UE, the index of the secondary cell, the time information at which the PHR was received by the second DU, the type of the PHR, the size of the PHR, and power information according to the type of the PHR. device.

8. In claim 7, The above type of the above PHR indicates one of a single PHR and multiple PHR, If the type of the PHR indicates the single PHR, the power information includes a PH (power headroom) level and a maximum transmit power for the PH level, and If the type of the PHR indicates the plurality of PHRs, the power information includes a first PH level, a first maximum transmission power for the first PH level, a second PH level, and a second maximum transmission power for the second PH level. device.

9. In claim 1, The above instructions, when individually or collectively executed by the at least one processor, cause the device to: Transmitting a first uplink resource allocation message including first PUSCH (physical uplink shared channel) resource allocation information for the UE of the first DU to the second DU through the interface, and Causing to receive, from the second DU through the interface, a second uplink resource allocation message including second PUSCH resource allocation information for the UE of the second DU. device.

10. In claim 9, The first PUSCH resource allocation information includes the ID of the UE, the index of the primary cell, a transmission time of the first PUSCH, a service type related to the first PUSCH, a modulation and coding scheme (MCS) for the first PUSCH, a transport block size (TBS) for the first PUSCH, a number of RBs allocated for the first PUSCH, a number of layers for the first PUSCH, information indicating retransmission of the first PUSCH, and a waveform of a signal of the first PUSCH, and The second PUSCH resource allocation information includes the ID of the UE, the index of the secondary cell, the transmission time of the second PUSCH, the service type related to the second PUSCH, the MCS for the second PUSCH, the TBS for the second PUSCH, the number of RBs allocated for the second PUSCH, the number of layers for the second PUSCH, information indicating retransmission of the second PUSCH, and a waveform for the second PUSCH. device.

11. In claim 1, The above instructions, when individually or collectively executed by the at least one processor, cause the device to: Causes to receive a TA (timing advance) management message for time synchronization between the second DU and the UE from the second DU, The TA management message includes the ID of the UE, the index of the secondary cell, and the time offset difference between the second DU and the UE. device.

12. In claim 1, The above instructions, when individually or collectively executed by the at least one processor, cause the device to: Transmitting a status update message of the secondary cell to the second DU through the interface, and Causing to receive a status update response message from the second DU through the interface, The above status update message includes the ID of the UE, the index of the secondary cell, and status information of the secondary cell, The above status update response message includes the ID of the UE and the index of the secondary cell, and The state information of the secondary cell includes an activation state and a deactivation state of the secondary cell. device.

13. In claim 1, The above instructions, when individually or collectively executed by the at least one processor, cause the device to: Receive a deactivation request message of the secondary cell from the second DU through the interface, and Causing the second DU to transmit a status update message of the secondary cell in response to the deactivation request message through the interface, The above deactivation request message includes the ID of the UE and the index of the secondary cell, and The above status update message includes the ID of the UE, the index of the secondary cell, and status information of the secondary cell indicating a deactivation state. device.

14. In a method performed by the first DU (distributed unit), An operation for obtaining information about a BSR (buffer status report) of a UE on a primary cell related to the first DU, and An operation of transmitting a split BSR management message for uplink scheduling of the second DU to the second DU associated with a secondary cell of a carrier aggregation (CA) configured for the UE through an interface between the first DU and the second DU, The above distribution BSR management message includes an ID (identifier) ​​of the UE, an index (index) of the primary cell, information on the time at which the BSR was received, LCG (logical channel group) ID information of the BSR, and a distribution BO (split buffer occupancy) to be used by the second DU. method.

15. A non-transitory computer-readable storage medium, when individually or collectively executed by at least one processor including a processing circuit of a first DU (distributed unit), wherein the first DU: Obtain information about the BSR (buffer status report) of the UE on the primary cell related to the first DU, and Store one or more programs including instructions causing a second DU associated with a secondary cell of a carrier aggregation (CA) configured for the UE to transmit a split BSR management message for uplink scheduling of the second DU through an interface between the first DU and the second DU, The above distribution BSR management message includes an ID (identifier) ​​of the UE, an index (index) of the primary cell, information on the time at which the BSR was received, LCG (logical channel group) ID information of the BSR, and a distribution BO (split buffer occupancy) to be used by the second DU. A non-transitory computer-readable storage medium.

Images