Apparatus and method for distributing traffic of split bearer in wireless communication system, and storage medium

Abstract

A base station having a packet data convergence protocol (PDCP) for a split bearer may comprise at least one processor and a memory for storing instructions. The instructions may cause, when executed individually or collectively by the at least one processor, the base station to: identify first traffic of a first communication scheme according to the number of downlink packets provided through a first path for the split bearer; identify second traffic of a second communication scheme according to the number of downlink packets provided through a second path for the split bearer; on the basis of the first traffic and the second traffic, determine a reference number indicating the number of consecutive packets to be transmitted to the terminal; transmit consecutive first downlink packets corresponding to the reference number to the terminal through the first path; and transmit consecutive second downlink packets corresponding to the reference number to the terminal through the second path.

Description

Device, method, and storage medium for distributing traffic of a split bearer in a wireless communication system

[0001] The following descriptions relate to a wireless communication system, and more specifically, to a device, method, and storage medium for distributing traffic of a split bearer in a wireless communication system.

[0002] In wireless communication systems, a split bearer may be utilized for dual connectivity. For example, the split bearer may be applied to a radio bearer. For example, the radio bearer may include a bearer between a base station and a terminal.

[0003] The above information may be provided as background art to aid in understanding the present disclosure. No claim or determination is made as to whether any of the above-described matters constitute prior art related to the present disclosure.

[0004] A base station having packet data convergence protocol (PDCP) for a split bearer may include at least one processor including a processing circuit. The base station may include a memory including one or more storage media storing instructions. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to identify first traffic of a first communication scheme according to a number of downlink packets provided through a first path for the split bearer. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to identify second traffic of a second communication scheme according to a number of downlink packets provided through a second path for the split bearer. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to determine a reference number indicating a number of consecutive packets to be transmitted to a terminal based on the first traffic and the second traffic. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to transmit consecutive first downlink packets corresponding to the reference number to the terminal via the first path and to transmit consecutive second downlink packets corresponding to the reference number to the terminal via the second path.

[0005] A method performed by a base station having a packet data convergence protocol (PDCP) for a split bearer may include an operation of identifying first traffic of a first communication method according to a number of downlink packets provided through a first path for the split bearer. The method may include an operation of identifying second traffic of a second communication method according to a number of downlink packets provided through a second path for the split bearer. The method may include an operation of determining a reference number indicating a number of consecutive packets to be delivered to a terminal based on the first traffic and the second traffic. The method may include an operation of transmitting consecutive first downlink packets corresponding to the reference number to the terminal through the first path, and transmitting consecutive second downlink packets corresponding to the reference number to the terminal through the second path.

[0006] A non-transitory computer-readable storage medium may store one or more programs including instructions that, when individually or collectively executed by at least one processor of a base station having a packet data convergence protocol (PDCP) for a split bearer, cause the base station to identify first traffic of a first communication scheme according to a number of downlink packets provided through a first path for the split bearer. 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 base station to identify second traffic of a second communication scheme according to a number of downlink packets provided through a second path for the split bearer. 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 at least one processor to determine a reference number indicating the number of consecutive packets to be transmitted to the terminal based on the first traffic and the second traffic. 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 at least one processor to transmit consecutive first downlink packets corresponding to the reference number to the terminal via the first path, and to transmit consecutive second downlink packets corresponding to the reference number to the terminal via the second path.

[0007] A device of a central unit (CU) having a packet data convergence protocol (PDCP) for a split bearer may include at least one processor including a processing circuit. The device may include a memory including one or more storage media storing instructions. The instructions, when individually or collectively executed by the at least one processor, may cause the device to identify first traffic of a first communication scheme according to a number of downlink packets provided through a first path for the split bearer. The instructions, when individually or collectively executed by the at least one processor, may cause the device to identify second traffic of a second communication scheme according to a number of downlink packets provided through a second path for the split bearer. The instructions, when individually or collectively executed by the at least one processor, may cause the device to determine a reference number indicating a number of consecutive downlink packets to be delivered to a terminal based on the first traffic and the second traffic. The instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit consecutive first downlink packets corresponding to the reference number to the terminal via the first path, and to transmit consecutive second downlink packets corresponding to the reference number to the terminal via the second path.

[0008] A method performed by a central unit (CU) having a packet data convergence protocol (PDCP) for a split bearer may include an operation of identifying first traffic of a first communication method according to a number of downlink packets provided through a first path for the split bearer. The method may include an operation of identifying second traffic of a second communication method according to a number of downlink packets provided through a second path for the split bearer. The method may include an operation of determining a reference number indicating a number of consecutive downlink packets to be delivered to a terminal based on the first traffic and the second traffic. The method may include an operation of transmitting consecutive first downlink packets corresponding to the reference number to the terminal through the first path, and transmitting consecutive second downlink packets corresponding to the reference number to the terminal through the second path.

[0009] A non-transitory computer-readable storage medium may store one or more programs including instructions that, when individually or collectively executed by at least one processor of a central unit (CU) having a packet data convergence protocol (PDCP) for a split bearer, cause the processor to identify first traffic of a first communication scheme according to a number of downlink packets provided through a first path for the split bearer. The non-transitory computer-readable storage medium may store one or more programs including instructions that, when individually or collectively executed by the processor, cause the processor to identify second traffic of a second communication scheme according to a number of downlink packets provided through a second path for the split bearer. 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 at least one processor to determine a reference number indicating the number of consecutive downlink packets to be transmitted to the terminal based on the first traffic and the second traffic. 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 at least one processor to transmit consecutive first downlink packets corresponding to the reference number to the terminal via the first path, and to transmit consecutive second downlink packets corresponding to the reference number to the terminal via the second path.

[0010] Figure 1 illustrates an example of a wireless communication system.

[0011] Figure 2a illustrates an example of a protocol stack in the control plane.

[0012] Figure 2b illustrates an example of a protocol stack in the user plane.

[0013] Figures 3a and 3b illustrate examples of dual connectivity in a wireless communication system.

[0014] Figure 4 illustrates an example of a functional configuration of an electronic device.

[0015] Figures 5a and 5b illustrate examples of how a base station transmits a downlink packet received from an entity of a core network to a terminal using a split bearer.

[0016] FIG. 6a illustrates an example of an operational flow for a method of determining a reference number indicating the number of consecutive downlink packets to be transmitted over a path for a split bearer based on traffic of a communication mode.

[0017] FIG. 6b illustrates an example of an operational flow for a method of identifying resource usage per path using log information indicating the number of downlink packets.

[0018] Figure 6c illustrates an example of an operational flow for a method of managing record information.

[0019] FIG. 7 illustrates an example of an operational flow for a method of determining a reference number indicating the number of consecutive downlink packets to be transmitted over a path for a split bearer based on mapping information.

[0020] Figures 8a to 8c illustrate examples of graphs of resource usage and average throughput of a base station according to changes in the number of references.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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"}.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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).

[0029] 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.

[0030] 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.

[0031] Figure 1 illustrates an example of a wireless communication system.

[0032] Referring to FIG. 1, FIG. 1 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. 1 illustrates only one base station, the wireless communication system may further include other base stations identical or similar to the base station (110).

[0033] 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.

[0034] 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. 1, 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.

[0035] 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.

[0036] 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.

[0037] 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).

[0038] Figure 2a illustrates an example of a protocol stack in the control plane.

[0039] Referring to FIG. 2A, in an NR communication system, a wireless protocol of a control plane of a terminal (120) (e.g., UE) may include PHY (211), MAC (212), RLC (213), PDCP (214), and RRC (215). In an NR communication system, a wireless protocol of a control plane of a base station (110) (e.g., gNB) may include PHY (221), MAC (222), RLC (223), PDCP (224), and RRC (225).

[0040] The main functions of RRC (215, 225) may include some of the following functions.

[0041] - Broadcast of system information related to AS (Access Stratum) and NAS (Non Access Stratum)

[0042] - Paging initiated by 5GC or NG-RAN

[0043] - Establishment, maintenance and release of RRC connection between UE and NG-RAN including:

[0044] 1) Adding, modifying, and releasing carrier aggregation

[0045] 2) Add, modify and remove Dual Connectivity within NR or between E-UTRA and NR.

[0046] - Security functions including key management

[0047] - Setup, configuration, maintenance, and release of SRB (Signaling Radio Bearer) and DRB (Data Radio Bearer).

[0048] - Mobility features including:

[0049] 1) Handover and context transfer

[0050] 2) UE cell selection and reselection and control of cell selection and reselection

[0051] 3) Inter-RAT mobility

[0052] - QoS (Quality of Service) management function

[0053] - UE measurement reporting and reporting control;

[0054] - Detection of and recovery from radio link failure

[0055] - Transmitting NAS messages from / to the UE to / from the NAS.

[0056] The main functions of PDCP (214, 224) may include some of the following functions:

[0057] - Header compression and decompression (ROHC only)

[0058] - User data transfer function

[0059] - In-sequence delivery of upper layer PDUs

[0060] - Out-of-sequence delivery of upper layer PDUs

[0061] - PDCP PDU reordering for reception

[0062] - Duplicate detection of lower layer SDUs

[0063] - Retransmission function (Retransmission of PDCP SDUs)

[0064] - Encryption and decryption functions (Ciphering and deciphering)

[0065] - Timer-based SDU discard in uplink.

[0066] 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.

[0067] The main functions of RLC (213, 223) may include some of the following functions:

[0068] - Data transfer function (Transfer of upper layer PDUs)

[0069] - In-sequence delivery of upper layer PDUs

[0070] - Out-of-sequence delivery of upper layer PDUs

[0071] - ARQ function (Error Correction through ARQ)

[0072] - Concatenation, segmentation and reassembly of RLC SDUs

[0073] - Re-segmentation of RLC data PDUs

[0074] - Reordering of RLC data PDUs

[0075] - Duplicate detection function

[0076] - Protocol error detection

[0077] - RLC SDU discard function

[0078] - RLC re-establishment function

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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 received RLC PDUs to record any lost RLC PDUs.

[0086] MAC (212, 222) 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.

[0087] - Mapping function (Mapping between logical channels and transport channels)

[0088] - Multiplexing / demultiplexing of MAC SDUs

[0089] - Scheduling information reporting function

[0090] - HARQ function (Error correction through HARQ)

[0091] - Priority handling between logical channels of one UE

[0092] - Priority handling between UEs by means of dynamic scheduling

[0093] - MBMS service identification function

[0094] - Transport format selection function

[0095] - Padding function

[0096] The PHY layer (211, 221) can perform operations of 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.

[0097] Figure 2b illustrates an example of a protocol stack in the user plane.

[0098] Referring to FIG. 2b, the wireless protocol of the user plane of the terminal (120) (e.g., UE) may include PHY (261), MAC (262), RLC (263), PDCP (264), and SDAP (265). In an NR communication system, the wireless protocol of the user plane of the base station (110) (e.g., gNB) may include PHY (271), MAC (272), RLC (273), PDCP (274), and SDAP (275).

[0099] The main functions of SDAP (265, 275) may include some of the following functions:

[0100] - Transfer of user plane data

[0101] - Mapping function between QoS flow and data bearer for both DL and UL

[0102] - QoS flow ID marking function for uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0103] - Ability to map reflective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0104] 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.

[0105] For PDCP (264, 274) in the user plane, reference may be made to the description of PDCP (214, 224) in the control plane. For RLC (263, 273) in the user plane, reference may be made to the description of RLC (213, 223) in the control plane. For MAC (262, 272) in the user plane, reference may be made to the description of MAC (212, 222) in the control plane. For PHY (261, 271) in the user plane, reference may be made to the description of PHY (211, 221) in the control plane.

[0106] Referring to FIGS. 2A and 2B , a wireless protocol of an NR communication system in a radio access network is described as an example; however, embodiments of the present disclosure are not limited thereto. For example, the descriptions of FIGS. 2A and 2B can be applied to other communication systems (e.g., an LTE communication system or a 6G communication system).

[0107] In FIGS. 2A and 2B, protocol stacks of the base station (110) are illustrated, but the present disclosure is not limited thereto. For example, the base station (110) may be implemented with a central unit (CU) (or a control unit (CU)) and a distributed unit (DU). For example, the CU may include an upper layer, and the DU may include a lower layer. For example, the upper layer of the CU may include RRC and PDCP in the control plane, and SDAP and PDCP in the user plane. For example, the lower layer of the DU may include RLC, MAC, and an upper PHY. The above examples are merely examples for convenience of description, and the present disclosure is not limited thereto.

[0108] Figures 3a and 3b illustrate examples of dual connectivity in a wireless communication system.

[0109] FIG. 3A illustrates an example (300) of dual connectivity (DC) between a terminal (120) and multiple base stations (110-1, 110-2). Referring to example (300), the terminal (120) can be configured in dual connectivity 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 allowing a terminal to simultaneously connect to two independent heterogeneous or homogeneous wireless communication cell groups having separate radio resource control entities, and to use 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), a second base station (110-2)) and may 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), 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 the 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.

[0110] 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.

[0111] The possible types of DC can be defined as follows:

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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. 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).

[0117] FIG. 3B illustrates an example (350) of dual connectivity between a terminal (120), multiple DUs (371, 372), and a CU (360). Referring to example (350), a base station (e.g., base station (110), a first base station (110-1), a second base station (110-2)) may be divided into CUs and DUs. Unlike multiple independent base stations (e.g., the first base station (110-1), the second base station (110-2)) that serve the terminal (120), one CU and multiple DUs may serve the terminal (120). For example, the CU (360) may be connected to DU #1 (371) and DU #2 (372). The CU (360) may be connected to each of DU #1 (371) and DU #2 (372) via an F1 interface. DU #1 (371) can provide one or more cells. For example, the one or more cells provided by DU #1 (371) can be referred to as MCG (or SCG). DU #2 (372) can provide one or more cells. For example, the one or more cells provided by DU #2 (372) can be referred to as SCG (or MCG). From the terminal (120) side, CU (360) and DU #1 (371) can operate as logical nodes (e.g., gNB) corresponding to one base station, and DU #2 (372) can operate as logical nodes (e.g., gNB) corresponding to another base station.

[0118] 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 represent 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, 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 terminals and upper layer signaling (e.g., RRC (radio resource control) signaling), and can refer to one cell or multiple cells.

[0119] 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, 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 may perform 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.

[0120] Figure 4 illustrates an example of a functional configuration of an electronic device.

[0121] The configuration of the electronic device (400) illustrated in FIG. 4 can be understood as the configuration of the base station (110) of FIG. 1, the terminal (120) of FIG. 1, the base station (110-1 or 110-2) of FIG. 3A, the CU (360) of FIG. 3B, or the DU (371 or 372) of FIG. 3B. Terms such as "...unit" and "...unit" 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.

[0122] Referring to FIG. 4, the electronic device (400) may include a transceiver (410), a memory (420), and a processor (430). However, the present disclosure is not limited thereto. For example, the electronic device (400) may not include at least some of the components illustrated in FIG. 4, or may further include components not illustrated in FIG. 4.

[0123] The transceiver (410) can perform functions for transmitting and receiving signals in a wired communication environment. The transceiver (410) 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 (410) can transmit electrical signals to other devices via copper wire, or perform conversion between electrical signals and optical signals.

[0124] The transceiver (410) may perform functions for transmitting and receiving signals in a wireless communication environment. For example, the transceiver (410) 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 (410) encodes and modulates the transmitted bit stream to generate complex-valued symbols. Furthermore, when receiving data, the transceiver (410) demodulates and decodes the baseband signal to restore the received bit stream. Furthermore, the transceiver (410) may include multiple transmission and reception paths.

[0125] The transceiver (410) transmits and receives signals as described above. Accordingly, all or part of the transceiver (410) may be referred to as a "communication unit," a "transmitter," a "receiver," or a "transmitter-receiver unit." Furthermore, in the following description, transmission and reception performed via a wireless channel are used to mean that the transceiver (410) performs the processing described above.

[0126] Although not shown in FIG. 4, the transceiver (410) 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. For example, the backhaul transceiver may be used for communicating with entities (or nodes) of the core network. That is, the backhaul transceiver converts a bit stream transmitted from the base station to another node, such as another access node, another base station, an upper node, the core network, etc., into a physical signal, and converts a physical signal received from another node into a bit stream.

[0127] The memory (420) stores data such as basic programs, application programs, and setting information for the operation of the electronic device (400). The memory (420) may be referred to as a storage unit. The memory (420) may be composed of volatile memory, nonvolatile memory, or a combination of volatile memory and nonvolatile memory. In addition, the memory (420) provides stored data upon request from the processor (430).

[0128] For example, the processor (430) 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.

[0129] The processor (430) controls the overall operations of the electronic device (400). The processor (480) may be referred to as a control unit. For example, the processor (430) transmits and receives signals via the transceiver (410) (or via a backhaul communication unit). In addition, the processor (430) records and reads data from the memory (420). In addition, the processor (430) may perform functions of a protocol stack required by a communication standard. Although only the processor (430) is illustrated in FIG. 4, the electronic device (400) may include two or more processors according to other implementation examples.

[0130] The configuration of the electronic device (400) illustrated in FIG. 4 is merely an example, and examples of electronic devices (400) that perform embodiments of the present disclosure are not limited to the configuration illustrated in FIG. 4. In some embodiments, some configurations may be added, deleted, or changed.

[0131] In a wireless communication system, a split bearer may be used for DC. For example, the split bearer may be applied to a radio bearer in the user plane. For example, the radio bearer may be referred to as an E-UTRAN radio access bearer (E-RAB), a data radio bearer, or an access network resource. For example, the data stream segmentation (or routing) for the split bearer may be performed in the PDCP layer (e.g., PDCP (274) in FIG. 2b). For example, the PDCP layer may be connected to the RLC layers (e.g., RLC (273) in FIG. 2b) of multiple nodes (e.g., base station (110-1) and base station (110-2), or DU #1 (371) and DU #2 (372)). The data path (or paths) of the split bearer may include layers of a protocol stack. For specific details on the path along which downlink packets are provided, reference may be made to the examples of FIGS. 5a and 5b below.

[0132] Figures 5a and 5b illustrate examples of how a base station transmits a downlink packet received from an entity of a core network to a terminal using a split bearer.

[0133] FIG. 5A illustrates an example (500) of a base station (510) connected to an evolved packet core (EPC). Referring to example (500), the base station (510) and a node (520) may be configured to provide DC (e.g., EN-DC) to a terminal (540). In example (500), the base station (510) may be a gNB, and the node (520) may be an eNB. However, the present disclosure is not limited thereto. For example, the base station (510) may be implemented as a CU and a DU. The base station (510) may be connected to a serving-gateway (S-GW) (530), which is an entity of the EPC. For example, the S-GW (530) may be an entity (or node) that provides packets (or data) to the base station (510) in the user plane. The base station (510) (or CU) of FIG. 5a may be included in the electronic device (400) of FIG. 4.

[0134] For example, the base station (510) may include NR PDCP (or PDCP, PDCP layer) (511), NR RLC (or RLC, RLC layer) (512), and NR MAC (or MAC, MAC layer). In the example (500), the base station (510) is illustrated as including NR PDCP (511), NR RLC (512), and NR MAC, but this is merely an example for convenience of description, and the present disclosure is not limited thereto. For example, the base station (510) may further include at least one of NR PHY, NR SDAP, or NR RRC. For specific details regarding the NR PDCP (511), reference may be made to the description of PDCP (274) in FIG. 2B. For specific details regarding the NR RLC (512), reference may be made to the description of RLC (273) in FIG. 2B. For specific details on NR MAC, reference may be made to the description of MAC (272) in FIG. 2b.

[0135] For example, node (520) may include EUTRA RLC (or RLC, RLC layer) (522) and EUTRA MAC (or MAC, MAC layer). In example (500), node (520) is illustrated as including EUTRA RLC (522) and EUTRA MAC, but this is merely an example for convenience of description, and the present disclosure is not limited thereto. For example, node (520) may further include at least one of EUTRA PHY, EUTRA PDCP, EUTRA SDAP, or EUTRA RRC. For specific details regarding EUTRA RLC (522), reference may be made to the description of RLC (273) in FIG. 2B. For specific details regarding EUTRA MAC, reference may be made to the description of MAC (272) in FIG. 2B.

[0136] Referring to example (500), in order to support split bearer, NR PDCP (511) of base station (510) can be connected to NR RLC (512) of base station (510) and EUTRA RLC (522) of node (520). Base station (510) can perform packet distribution for split bearer using DDDS (downlink data delivery status) obtained from each of NR RLC (512) and EUTRA RLC (522). For example, NR PDCP (511) of base station (510) can obtain first DDDS from corresponding node NR RLC (512). For example, NR PDCP (511) of base station (510) can obtain second DDDS from corresponding node EUTRA RLC (522). For example, the DDDS may include a DBS (desired buffer size for the data radio bearer) indicating the size of the data. For example, the DDDS may be transmitted from the RLC to the PDCP via the uplink path (502). For example, the DBS may indicate a buffer size for the radio bearer. For example, the DBS may indicate the number of packets according to the buffer size. For example, the base station (510) (or NR PDCP (511)) may perform distribution for downlink packets received from the S-GW (530) based on the first DBS of the first DDDS and the second DBS of the second DDDS. At this time, the distribution for the downlink packets may include selection of a path.

[0137] For example, the path may be referred to as a downlink path (501). For example, the downlink path (501) may include paths (501-1, 501-2) for a split bearer. For example, each of the paths (501-1, 501-2) for a split bearer may be used to transmit (or forward) downlink packets. For example, the first path (501-1) may include NR-PDCP (511), NR RLC (512), NR MAC of the base station (510), NR MAC of the terminal (540), NR RLC of the terminal (540), and NR PDCP (541). For example, the second path (501-2) may include NR-PDCP (511), EUTRA RLC (522), EUTRA MAC of node (520), EUTRA MAC of terminal (540), EUTRA RLC of terminal (540), and NR PDCP (541). In other words, terminal (540) may include EUTRA MAC, EUTRA RLC, NR MAC, NR RLC, and NR PDCP (541) to support split bearer.

[0138] For example, the first path (501-1) may be associated with a group of cells provided by the base station (510). For example, if the base station (510) is composed of a CU and a DU, the first path (501-1) may be associated with a group of cells provided by the DU. For example, the group of cells associated with the first path (501-1) may include an SCG. For example, the second path (501-2) may be associated with a group of cells provided by the node (520). For example, the group of cells associated with the second path (501-2) may include an MCG.

[0139] For example, when using a split bearer, the base station (510) (or NR PDCP (511)) can provide a downlink packet to an RLC (NR RLC (512) or EUTRA RLC (522)). At this time, the downlink packet provided from the NR PDCP (511) to the NR RLC (512) (or EUTRA RLC (522)) can include a PDCP data PDU (protocol data unit). At this time, the header of the PDCP data PDU can include a PDCP SN (sequence number). The terminal (540) (or NR PDCP (541)) can reorder the downlink packet provided through the paths (501-1, 501-2) for the split bearer. For example, the terminal (540) (or NR PDCP (541)) can sort the order of downlink packets using the PDCP SN included in the received downlink packet.

[0140] In FIG. 5A, an example (500) of a user plane of a base station (510), a node (520), and a terminal (540) is illustrated, but the present disclosure is not limited thereto. For example, the base station (510), the node (520), and the terminal (540) may establish a connection in the control plane for DC. For example, an upper layer (e.g., RRC) of the node (520) may be connected to an entity of the EPC.

[0141] Also, in FIG. 5A, an example (500) is illustrated in which a single base station (510) includes multiple layers (NR PDCP (511), NR RLC (512), and NR MAC), but the present disclosure is not limited thereto. For example, the base station (510) may be composed of a CU (or gNB-CU) and a DU (or gNB-DU). For example, the CU may include NR PDCP (511). For example, the DU may include NR RLC (512) and NR MAC. For example, a DC (e.g., EN-DC) using the split bearer may be provided between the base station (510) having NR PDCP (511) and a node (520) which is an eNB. Alternatively, for example, a DC (e.g., EN-DC) using the split bearer may be provided between a node (520) that is a DU and an eNB connected to a CU having NR PDCP (511).

[0142] FIG. 5B illustrates an example (550) of a base station (560) connected to a 5th generation core (5GC). Referring to example (550), the base station (560) and the node (570) may be configured to provide DC (e.g., NR-DC) to the terminal (590). In example (550), the base station (560) may be a gNB, and the node (570) may be a gNB. However, the present disclosure is not limited thereto. For example, the base station (560) and / or the node (570) may be implemented as a CU and a DU. The base station (560) may be connected to a user plane function (UPF) (580), which is an entity of the 5GC. For example, the UPF (580) may be an entity (or node) that provides packets (or data) to the base station (560) in the user plane. The base station (560) (or CU) of FIG. 5b may be included in the electronic device (400) of FIG. 4.

[0143] For example, the base station (560) may include NR PDCP (or PDCP, PDCP layer) (561), NR RLC (or RLC, RLC layer) (562), and NR MAC (or MAC, MAC layer). In the example (550), the base station (560) is illustrated as including NR PDCP (561), NR RLC (562), and NR MAC, but this is merely an example for convenience of description, and the present disclosure is not limited thereto. For example, the base station (560) may further include at least one of NR PHY, NR SDAP, or NR RRC. For specific details regarding the NR PDCP (561), reference may be made to the description of PDCP (274) in FIG. 2B. For specific details regarding the NR RLC (562), reference may be made to the description of RLC (273) in FIG. 2B. For specific details on NR MAC, reference may be made to the description of MAC (272) in FIG. 2b.

[0144] For example, the node (570) may include an NR RLC (or RLC, RLC layer) (572) and an NR MAC (or MAC, MAC layer). In the example (550), the node (570) is illustrated as including an NR PDCP (561), an NR RLC (562), and an NR MAC, but this is merely an example for convenience of description, and the present disclosure is not limited thereto. For example, the node (570) may further include at least one of an NR PDCP, an NR PHY, an NR SDAP, or an NR RRC. For specific details regarding the NR RLC (572), reference may be made to the description of the RLC (273) in FIG. 2B. For specific details regarding the NR MAC, reference may be made to the description of the MAC (272) in FIG. 2B.

[0145] Referring to example (550), in order to support split bearer, NR PDCP (561) of base station (560) can be connected to NR RLC (562) of base station (560) and NR RLC (572) of node (570). Base station (560) can perform packet distribution for split bearer using DDDS (downlink data delivery status) obtained from each of NR RLC (562) and NR RLC (572). For example, NR PDCP (561) of base station (560) can obtain first DDDS from corresponding node NR RLC (572). For example, NR PDCP (561) of base station (560) can obtain second DDDS from corresponding node NR RLC (572). For example, the DDDS may include a DBS (desired buffer size for the data radio bearer) indicating the size of the data. For example, the DDDS may be transmitted from the RLC to the PDCP via the uplink path (552). For example, the DBS may indicate a buffer size for the radio bearer. For example, the DBS may indicate the number of packets according to the buffer size. For example, the base station (560) (or NR PDCP (561)) may perform distribution for downlink packets received from the UPF (580) based on the first DBS of the first DDDS and the second DBS of the second DDDS. At this time, the distribution for the downlink packets may include selection of a path.

[0146] For example, the path may be referred to as a downlink path (551). For example, the downlink path (551) may include paths (551-1, 551-2) for a split bearer. For example, each of the paths (551-1, 551-2) for a split bearer may be used to transmit (or forward) downlink packets. For example, the first path (551-1) may include NR-PDCP (561), NR RLC (562), NR MAC of the base station (560), NR MAC of the terminal (590), NR RLC of the terminal (590), and NR PDCP (591). For example, the second path (551-2) may include NR-PDCP (561), NR RLC (572), NR MAC of node (570), NR MAC of terminal (590), NR RLC of terminal (590), and NR PDCP (591). In other words, terminal (590) may include multiple NR MACs, multiple NR RLCs, and NR PDCP (591) to support split bearer.

[0147] For example, the first path (551-1) may be associated with a group of cells provided by the base station (560). For example, if the base station (560) is composed of a CU and a DU, the first path (551-1) may be associated with a group of cells provided by the DU. For example, the group of cells associated with the first path (551-1) may include an SCG. For example, the second path (551-2) may be associated with a group of cells provided by the node (570). For example, if the node (570) is composed of a CU and a DU, the second path (551-2) may be associated with a group of cells provided by the DU. For example, the group of cells associated with the second path (551-2) may include an MCG.

[0148] For example, when using a split bearer, the base station (560) (or NR PDCP (561)) can provide a downlink packet to the RLC (NR RLC (562) or NR RLC (572)). At this time, the downlink packet provided from the NR PDCP (561) to the NR RLC (562) (or NR RLC (572)) can include a PDCP data PDU (protocol data unit). At this time, the header of the PDCP data PDU can include a PDCP SN (sequence number). The terminal (590) (or NR PDCP (591)) can reorder the downlink packet provided through the paths (551-1, 551-2) for the split bearer. For example, the terminal (590) (or NR PDCP (591)) can sort the order of downlink packets using the PDCP SN included in the received downlink packet.

[0149] In FIG. 5B, an example (550) of a user plane of a base station (560), a node (570), and a terminal (590) is illustrated, but the present disclosure is not limited thereto. For example, a connection can be established in the control plane for the DC between the base station (560), the node (570), and the terminal (590). For example, a higher layer (e.g., RRC) of the node (570) can be connected to an entity of the 5GC.

[0150] Also, in FIG. 5B, an example (550) is illustrated where a base station (560) includes multiple layers (NR PDCP (561), NR RLC (562), and NR MAC), but the present disclosure is not limited thereto. For example, the base station (560) may be composed of a CU (or gNB-CU) and a DU (or gNB-DU). For example, the CU may include NR PDCP (561). For example, the DU may include NR RLC (562) and NR MAC. In example (550), a node (570) that is a gNB is described, but the present disclosure is not limited thereto. For example, DC (e.g., NR-DC) using the split bearer may be provided between a base station (560) having NR PDCP (561) and a node (570) that is a gNB. Alternatively, for example, a DC (e.g., NR-DC) using the split bearer may be provided between a DU connected to a CU having NR PDCP (561) and another DU, a node (570). However, the present disclosure is not limited thereto. For example, the other DU, a node (570) connected to a CU having NR PDCP (561), may further include another CU.

[0151] As described above, when a split bearer is used for DC, downlink packets (or PDCP data PDUs) sequentially transmitted (or delivered, provided) from PDCP (e.g., NR PDCP (511) of FIG. 5A and NR PDCP (561) of FIG. 5B) of a base station (e.g., base station (510) of FIG. 5A or base station (560) of FIG. 5B) may be provided through different paths (e.g., first path (501-1) or second path (501-2) of FIG. 5A, first path (551-1) or second path (551-2) of FIG. 5B). Downlink packets provided through different paths may be received by terminals (e.g., terminals (540) of FIG. 5A and terminals (590) of FIG. 5B). For example, the base station may utilize the acquired DBS values ​​to select a path for transmitting downlink packets among the paths for the split bearer and to distribute the packets. Accordingly, the base station may not consider the priorities between cell groups (or communication methods) when selecting a path. In other words, the base station needs to manage the load of cell groups according to the operator's site environment by performing offloading between the communication methods of the paths.

[0152] Hereinafter, the device, method, and storage medium according to the present disclosure propose a traffic distribution technique in DC using a split bearer. For example, the traffic distribution technique may be referred to as a packet distribution technique. For example, the device, method, and storage medium according to the present disclosure can continuously transmit downlink packets corresponding to a specified number through a path selected from among paths for a split bearer. At this time, by determining (or changing) the specified number, traffic distribution can be performed considering priorities between communication methods. In other words, the base station can control offloading between communication methods (or between cell groups) without ignoring the acquired DBS.

[0153] FIG. 6a illustrates an example of an operational flow for a method of determining a reference number indicating the number of consecutive downlink packets to be transmitted over a path for a split bearer based on traffic of a communication mode.

[0154] At least some of the methods of FIG. 6A may be performed by the electronic device (400) of FIG. 4. For example, at least some of the methods may be controlled by the processor (430) of the electronic device (400). 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. For example, the electronic device (400) may have a PDCP for a split bearer. For example, the electronic device (400) may include the base station (510) of FIG. 5A (or the base station (560) of FIG. 5B) having a PDCP for the split bearer. For example, the electronic device (400) may include a CU having a PDCP for the split bearer.

[0155] In operation (600), the electronic device (400) may identify first traffic of a first communication method. For example, the electronic device (400) may identify the first traffic of the first communication method based on the number of downlink packets provided through the first path for the split bearer. For example, the first traffic may be referred to as downlink traffic of the first communication method. For example, the first path may include an RLC of the electronic device (400) connected to the PDCP for the split bearer. For example, the first path may be related to a cell group (e.g., SCG) provided by the electronic device (400).

[0156] In operation (605), the electronic device (400) may identify second traffic of the second communication method. For example, the electronic device (400) may identify the second traffic of the second communication method based on the number of downlink packets provided through the second path for the split bearer. For example, the second traffic may be referred to as downlink traffic of the second communication method. For example, the second path may include an RLC of a node connected to the PDCP for the split bearer. For example, the node may be connected to the electronic device (400) to provide DC through the split bearer. For example, the second path may be related to a cell group (e.g., MCG) provided by the node.

[0157] According to one embodiment, the first communication method and the second communication method may be different radio access technologies (RATs). For example, the first communication method may be NR, and the second communication method may be EUTRA. Alternatively, the first communication method and the second communication method may be the same RAT servicing different frequency bands. The first communication method may be NR of a first frequency band (hereinafter, NR#1), and the second communication method may be NR of a second frequency band (hereinafter, NR#2). For example, the first frequency band of the first communication method may be A6 (above 6 GHz). For example, the second frequency band of the second communication method may be B6 (below 6 GHz). However, the present disclosure is not limited thereto.

[0158] According to one embodiment, the electronic device (400) may receive downlink packets from an entity of the core network. For example, the core network may include an EPC or a 5GC. For example, the entity may include an entity for providing data in the user plane. For example, the entity may be an S-GW when the core network is an EPC. For example, the entity may be an UPF when the core network is a 5GC.

[0159] According to one embodiment, traffic of a communication method provided through a path may be identified based on resource usage of the electronic device (400). For example, the first traffic may be identified based on a first resource usage amount for downlink packets provided according to the first communication method among the total resource usage amount used to provide downlink packets received from the core network. For example, the second traffic may be identified based on a second resource usage amount for downlink packets provided according to the second communication method among the total resource usage amount used to provide downlink packets received from the core network. Specific details related to an operation of identifying traffic based on resource usage are described below with reference to FIGS. 6B and 6C.

[0160] In FIG. 6A, operation (605) is depicted as being performed after operation (600), but the present disclosure is not limited thereto. For example, operation (605) may be performed before operation (600) or may be performed together with operation (600).

[0161] In operation (610), the electronic device (400) may determine a reference number indicating the number of consecutive downlink packets based on the first traffic and the second traffic. For example, the reference number (N) may indicate the number of consecutive downlink packets to be delivered to the terminal via a specific path. For example, the terminal may include a terminal supporting the split bearer.

[0162] According to one embodiment, the reference number may be related to resource usage between communication methods. For example, when the reference number decreases, the first resource usage for the first communication method may increase, and the second resource usage for the second communication method may decrease. Conversely, when the reference number increases, the first resource usage for the first communication method may decrease, and the second resource usage for the second communication method may increase. Examples of resource usage of the electronic device (400) (e.g., base station) according to a change (or adjustment) of the reference number may be referenced to FIGS. 8A to 8C . Referring to the above, the electronic device (400) may perform offloading between communication methods (or between cell groups (e.g., SCG and MCG)) by changing (or adjusting) the reference number.

[0163] In operation (615), the electronic device (400) may transmit the consecutive first downlink packets corresponding to the reference number through the first path. For example, the electronic device (400) may transmit the consecutive first downlink packets corresponding to the reference number through the first path selected based on a comparison of DBSs among the first path and the second path.

[0164] For example, the electronic device (400) may select a path based on DBS when there is no previously selected path (or when selecting the first path). For example, the electronic device (400) may select a path to be used for transmitting a downlink packet based on the first DBS of the first path and the second DBS of the second path. A path selection method based on DBS may be referred to as a path selection algorithm. For example, the electronic device (400) may select the first path among the first path and the second path for the split bearer based on the first DBS being greater than the second DBS. In this case, when the ratios of the remaining DBSs of the second DBS and the first DBS are the same, a path may be selected based on a comparison of the sizes of the DBSs.

[0165] For example, the electronic device (400) may transmit the first consecutive downlink packets corresponding to the reference number among the downlink packets sequentially received from the entity of the core network to the terminal through the first path.

[0166] In operation (620), the electronic device (400) may transmit the consecutive second downlink packets corresponding to the reference number through the second path. For example, the electronic device (400) may transmit the consecutive second downlink packets corresponding to the reference number through the second path selected based on the path selection algorithm after transmitting the first downlink packets through the first path.

[0167] For example, when the electronic device (400) transmits the first downlink packets corresponding to the reference number through the first path, the electronic device (400) may select a path for transmitting downlink packets after the last packet among the first downlink packets based on the path selection algorithm. For example, the electronic device (400) may select a path according to a ratio between the remaining DBS and DBS of each path. For example, the electronic device (400) may identify a first ratio between the DBS of the first path and the remaining DBS, and may identify a second ratio between the DBS of the second path and the remaining DBS. For example, the electronic device (400) may select a path corresponding to a ratio having a larger value among the first ratio and the second ratio as a path for transmitting downlink packets. In the example of operation (620), a case in which the second path is selected based on a comparison of ratios is exemplified, but the present disclosure is not limited thereto. For example, even after transmitting through the first path in operation (615), if the first ratio has a larger value among the first ratio for the first path and the second ratio for the second path, the first path may be selected again.

[0168] For example, the electronic device (400) may transmit the consecutive second downlink packets corresponding to the reference number, after the first downlink packets, among the downlink packets sequentially received from the entity of the core network, to the terminal through the second path.

[0169] Referring to operations (615) and (620), the electronic device (400) can continuously transmit downlink packets corresponding to the reference number (N) through a specific path. Thereafter, the electronic device (400) can continuously transmit another downlink packet corresponding to the reference number (N) for a path selected based on the path selection algorithm. At this time, the selected path may be the same as or different from the specific path.

[0170] For example, assume that the first DBS indicates 500 packets and the second DBS indicates 100 packets. For example, the electronic device (400) may obtain the first DBS and the second DBS in operation (600). If there is no path previously used for transmission (or if the first path is selected), the electronic device (400) may select a path based on the path selection algorithm. For example, the electronic device (400) may select the first path among the first path and the second path for the split bearer based on the first DBS being larger than the second DBS. In this case, if the ratios of the remaining DBSs of the second DBS and the first DBS are the same, a path may be selected based on a comparison of the sizes of the DBSs. For example, the first ratio (e.g., 500 / 500) of the first DBS and the second ratio (100 / 100) of the second DBS may be the same.

[0171] For example, the electronic device (400) may transmit the received first downlink packet to the terminal through the first path. In addition, the electronic device (400) may identify the remaining DBS and the number of continuously transmitted packets. For example, the electronic device (400) may change (or decrease) the value of the first DBS from 500 to 499. For example, the remaining DBS of the first DBS may be identified as 499. For example, the electronic device (400) may change (or increase) the number of packets continuously transmitted through the first path from 0 to 1. For example, the number of packets continuously transmitted may be identified as 1.

[0172] For example, the electronic device (400) may receive a second downlink packet. For example, the electronic device (400) may determine whether the remaining DBS of the first path, which is a previous path, exceeds a reference value (e.g., 0). The electronic device (400) may determine that the remaining DBS (e.g., 499) of the first path exceeds the reference value. Based on the remaining DBS of the first path exceeding the reference value, the electronic device (400) may reselect the path for transmitting the second downlink packet as the first path. For example, the electronic device (400) may transmit the second downlink packet to the terminal through the first path. In addition, the electronic device (400) may identify the remaining DBS and the number of packets transmitted continuously. For example, the electronic device (400) can change (or decrease) the value of the first DBS from 499 to 498. For example, the remaining DBS of the first DBS can be identified as 498. For example, the electronic device (400) can change (or increase) the number of packets continuously transmitted through the first path from 1 to 2. For example, the number of packets continuously transmitted can be identified as 2.

[0173] By repeatedly performing the operations described above, the electronic device (400) can transmit consecutive downlink packets corresponding to a reference number (e.g., N=5) to the terminal through the first path. When the consecutive downlink packets corresponding to the reference number are transmitted, the remaining DBS of the first DBS can be identified as 495, and the number of consecutively transmitted packets can be identified as 5.

[0174] Thereafter, the electronic device (400) may receive a third downlink packet. For example, the electronic device (400) may determine whether the number of continuously transmitted packets (e.g., 5) is less than the reference number based on determining that the remaining DBS (e.g., 495) of the first path exceeds the reference value. The electronic device (400) may set the number of continuously transmitted packets to an initial value (e.g., 0) based on determining that the number of continuously transmitted packets (e.g., 5) is greater than or equal to the reference number (or equal to the reference number). The electronic device (400) may select a path on which to transmit the third downlink packet based on the path selection algorithm. In the above example, the electronic device (400) may select a path based on the remaining DBS (e.g., 495) of the first path and the DBS (e.g., 100) of the second path (or the remaining DBS (e.g., 100) of the second path). At this time, the electronic device (400) may select a path according to the ratio between the remaining DBS and the DBS of each path. For example, the first ratio for the first path may be 495 / 500. For example, the second ratio for the second path may be 100 / 100. For example, the electronic device (400) may select the second path corresponding to the second ratio having a larger value among the first ratio and the second ratio as the path for transmitting the third downlink packet.

[0175] For example, the electronic device (400) can transmit the third downlink packet to the terminal through the second path. In addition, the electronic device (400) can identify the remaining DBS and the number of continuously transmitted packets. For example, the electronic device (400) can change (or decrease) the value of the second DBS from 100 to 99. For example, the remaining DBS of the second DBS can be identified as 99. For example, the electronic device (400) can change (or increase) the number of packets continuously transmitted through the second path from 0 to 1. For example, the number of packets continuously transmitted can be identified as 1.

[0176] For example, the electronic device (400) may receive a fourth downlink packet. For example, the electronic device (400) may determine whether the remaining DBS of the second path, which is a previous path, exceeds a reference value (e.g., 0). The electronic device (400) may determine that the remaining DBS (e.g., 99) of the second path exceeds the reference value. Based on the fact that the remaining DBS of the second path exceeds the reference value, the electronic device (400) may reselect the second path as the path for transmitting the fourth downlink packet. For example, the electronic device (400) may transmit the fourth downlink packet to the terminal through the second path. In addition, the electronic device (400) may identify the remaining DBS and the number of packets transmitted continuously. For example, the electronic device (400) can change (or decrease) the value of the second DBS from 99 to 98. For example, the remaining DBS of the second DBS can be identified as 98. For example, the electronic device (400) can change (or increase) the number of packets continuously transmitted through the second path from 1 to 2. For example, the number of packets continuously transmitted can be identified as 2.

[0177] By repeatedly performing the operations described above, the electronic device (400) can transmit consecutive downlink packets corresponding to a reference number (e.g., N=5) to the terminal through the second path. When the consecutive downlink packets corresponding to the reference number are transmitted, the remaining DBS of the second DBS can be identified as 95, and the number of consecutively transmitted packets can be identified as 5.

[0178] Thereafter, the electronic device (400) may receive a fifth downlink packet. For example, the electronic device (400) may determine whether the number of continuously transmitted packets (e.g., 5) is less than the reference number based on determining that the remaining DBS (e.g., 95) of the second path exceeds the reference value. The electronic device (400) may set the number of continuously transmitted packets to an initial value (e.g., 0) based on determining that the number of continuously transmitted packets (e.g., 5) is greater than or equal to the reference number (or equal to the reference number). The electronic device (400) may select a path on which to transmit the fifth downlink packet based on the path selection algorithm. In the example, the electronic device (400) may select a path based on the remaining DBS (e.g., 495) of the first path and the remaining DBS (e.g., 95) of the DBS of the second path. At this time, the electronic device (400) may select a path based on the ratio between the remaining DBSs of each path. For example, the first ratio for the first path may be 495 / 500. For example, the second ratio for the second path may be 95 / 100. For example, the electronic device (400) may select the first path corresponding to the first ratio having a larger value between the first ratio and the second ratio as the path for transmitting the fifth downlink packet.

[0179] Referring to the above, the electronic device (400) can transmit consecutive downlink packets corresponding to a reference number determined based on traffic through a selected path. A specific example of a method for determining the reference number based on the traffic is described below in FIGS. 6b and 6c.

[0180] FIG. 6b illustrates an example of an operational flow for a method of identifying resource usage per path using log information indicating the number of downlink packets.

[0181] At least some of the methods of FIG. 6B may be performed by the electronic device (400) of FIG. 4. For example, at least some of the methods may be controlled by the processor (430) of the electronic device (400). 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. For example, the electronic device (400) may have a PDCP for a split bearer. For example, the electronic device (400) may include the base station (510) of FIG. 5A (or the base station (560) of FIG. 5B) having a PDCP for the split bearer. For example, the electronic device (400) may include a CU having a PDCP for the split bearer.

[0182] At least a portion of the method of FIG. 6B may include specific examples of operations (600, 605) of FIG. 6A. For example, at least a portion of the method of FIG. 6B may be performed before operations (600, 605) or while operations (600, 605) are being performed.

[0183] Referring to FIG. 6B, in operation (650), the electronic device (400) may store record information indicating the number of downlink packets provided through a path during a time interval. For example, the electronic device (400) may store record information indicating the number of downlink packets provided through a selected path among the paths for the split bearer during the time interval. For example, the electronic device (400) may store first record information indicating the number of downlink packets provided through a first path during the time interval. For example, the electronic device (400) may store second record information indicating the number of downlink packets provided through a second path during the time interval. For example, the first record information and the second record information may be associated with a specific radio bearer (e.g., the split bearer).

[0184] For example, the first record information and the second record information may be stored in a buffer of the electronic device (400). For example, the first record information may be stored in the buffer for the first path, and the second record information may be stored in the buffer for the second path. For example, the buffer may be included in a PDCP (e.g., NR PDCP (511) of FIG. 5A and NR PDCP (561) of FIG. 5B).

[0185] For example, the length of the time interval may be shorter than the reference time. For example, the reference time may represent a period (or reference time interval) during which the electronic device (400) acquires the DDDS. In other words, the electronic device (400) may store the number of downlink packets provided for each path during the time interval within the period during which the DDDS is acquired as record information.

[0186] In operation (655), the electronic device (400) may identify resource usage for downlink packets provided through a path. For example, the electronic device (400) may identify resource usage for downlink packets provided through each of the paths for the split bearer. For example, the electronic device (400) may identify a first resource usage for downlink packets provided according to a first communication method from the first record information using the first record information. For example, the electronic device (400) may identify a second resource usage for downlink packets provided according to a second communication method from the second record information using the second record information. For example, the first resource usage may indicate an amount of data for an SCG associated with the first path. For example, the second resource usage may indicate an amount of data for an MCG associated with the second path. For example, each of the first resource usage and the second resource usage may indicate the amount of data during the time interval. For example, the first resource usage may be identified using a set of record information for each of a plurality of radio bearers associated with the SCG, including the first record information. For example, the second resource usage may be identified using a set of record information for each of a plurality of radio bearers associated with the MCG, including the second record information. In the example (500) of FIG. 5A, the first resource usage may represent the resource usage of the base station (510) for the first communication mode, and the second resource usage may represent the resource usage of the node (520) for the second communication mode. When the base station (510) is implemented with a CU and a DU, the first resource usage may represent the resource usage of the DU for the first communication mode.Additionally, in the example (550) of FIG. 5b, the first resource usage may represent the resource usage of the base station (560) for the first communication method, and the second resource usage may represent the resource usage of the node (570) for the second communication method. When the base station (560) is implemented as a CU and a DU, the first resource usage may represent the resource usage of the DU for the first communication method. When the node (570) is implemented as a DU (or a CU and a DU), the second resource usage may represent the resource usage of the DU for the second communication method.

[0187] According to one embodiment, the electronic device (400) can identify traffic of each path based on resource usage. For example, the electronic device (400) can identify total resource usage for downlink packets received from an entity of the core network during the time interval. For example, the electronic device (400) can identify the first traffic according to the first resource usage for the first path among the total resource usage. The electronic device (400) can identify the second traffic according to the second resource usage for the second path among the total resource usage. For example, each of the first traffic and the second traffic can be indicated as a relative value or an absolute value.

[0188] Figure 6c illustrates an example of an operational flow for a method of managing record information.

[0189] At least some of the methods of FIG. 6C may be performed by the electronic device (400) of FIG. 4. For example, at least some of the methods may be controlled by the processor (430) of the electronic device (400). 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. For example, the electronic device (400) may have a PDCP for a split bearer. For example, the electronic device (400) may include the base station (510) of FIG. 5A (or the base station (560) of FIG. 5B) having a PDCP for the split bearer. For example, the electronic device (400) may include a CU having a PDCP for the split bearer.

[0190] At least part of the method of FIG. 6c illustrates an example of how to manage the recorded information stored in operation (650) of FIG. 6b.

[0191] Referring to FIG. 6C, in operation (670), the electronic device (400) may determine whether the length of a time interval exceeds a reference time. For example, the electronic device (400) may determine whether the length of the time interval, which represents the time at which record information indicating the number of downlink packets is stored, exceeds the reference time. For example, the reference time may represent a cycle (or reference time interval) at which DDDS is acquired.

[0192] For example, in operation (670), the electronic device (400) may perform operation (675) if the length of the time interval exceeds the reference time. Alternatively, in operation (670), the electronic device (400) may perform operation (680) if the length of the time interval is less than or equal to the reference time.

[0193] In one example, the electronic device (400) may identify whether a DDDS has been acquired, instead of performing a comparison between the length of the time interval of the recorded information and the reference time. For example, if the DDDS according to the period has been acquired, the electronic device (400) may perform operation (675). Alternatively, if the DDDS according to the period has not been acquired (or before the DDDS has been acquired), the electronic device (400) may perform operation (680).

[0194] In operation (675), the electronic device (400) may reset the recorded information to an initial value. For example, the electronic device (400) may reset (or change, set) the number of downlink packets included in the recorded information to the initial value. For example, the initial value may be 0. At this time, the electronic device (400) may also initialize the time interval (or the length of the time interval) of the recorded information to an initial value (e.g., 0).

[0195] In operation (680), the electronic device (400) may update the record information. For example, the electronic device (400) may update (or change, set) the number of downlink packets included in the record information from a first value to a second value. At this time, the electronic device (400) may also update the time interval (or the length of the time interval) of the record information.

[0196] Referring to FIGS. 6A to 6C , the electronic device (400) can identify resource usage for each communication method based on the number of packets transmitted through each path among downlink packets received from an entity of the core network, and can identify traffic according to the identified resource usage. For example, the traffic can be defined for each communication method. In other words, the electronic device (400) can identify traffic using information about past traffic (e.g., history information), thereby determining (or changing) a reference number to satisfy the resource usage for each communication method requested by each operator. FIG. 7 illustrates an example of a method for determining the reference number using mapping information indicating the reference number according to the communication method requested by each operator.

[0197] FIG. 7 illustrates an example of an operational flow for a method of determining a reference number indicating the number of consecutive downlink packets to be transmitted over a path for a split bearer based on mapping information.

[0198] At least some of the methods of FIG. 7 may be performed by the electronic device (400) of FIG. 4. For example, at least some of the methods may be controlled by the processor (430) of the electronic device (400). 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. For example, the electronic device (400) may have a PDCP for a split bearer. For example, the electronic device (400) may include the base station (510) of FIG. 5A (or the base station (560) of FIG. 5B) having a PDCP for the split bearer. For example, the electronic device (400) may include a CU having a PDCP for the split bearer.

[0199] In operation (700), the electronic device (400) may store mapping information indicating a reference number according to communication methods. For example, the electronic device (400) may store the mapping information indicating a reference number according to a combination of communication methods for the split bearer. For example, the mapping information may include the reference number having a first value for EUTRA associated with MCG and NR associated with SCG in the split bearer for EN-DC. For example, the mapping information may include the reference number having a second value for NR supporting B6 band associated with MCG and NR supporting A6 band associated with SCG in the split bearer for NR-DC. However, the present disclosure is not limited thereto. For example, the first value and the second value of the reference number may be specified by a user (or a service provider) of the electronic device (400).

[0200] In operation (705), the electronic device (400) may identify mapping information. For example, the electronic device (400) may identify the stored mapping information according to the communication methods to be used based on the identification of the use (or configuration) of the split bearer. For example, identifying the mapping information may be understood as loading (or calling) the stored mapping information.

[0201] In operation (710), the electronic device (400) may determine the reference number based on the communication methods and the mapping information. For example, the electronic device (400) may determine the reference number based on the first communication method, the second communication method, and the mapping information. For example, the electronic device (400) may identify the first communication method and the second communication method included in the communication methods to be used in the split bearer. For example, the electronic device (400) may obtain a value (e.g., the first value or the second value) in the mapping information for the first communication method and the second communication method. The electronic device (400) may determine the reference number for consecutive downlink packets to be transmitted through the paths of the split bearer as the value.

[0202] The above example illustrates a method for determining the value of the reference number using mapping information, but the present disclosure is not limited thereto. For example, the electronic device (400) may obtain the value of the reference number based on input from a user (or operator) according to a communication method, and determine the reference number as the value.

[0203] Figures 8a to 8c illustrate examples of graphs of resource usage and average throughput of a base station according to changes in the number of references.

[0204] Figure 8a illustrates a graph (810) of the total resource usage of a base station according to changes in the number of references and the average throughput according to the total resource usage. The horizontal axis of the graph (810) represents time (unit: day), the vertical axis on the left represents the total resource usage (unit: MB (megabyte)), and the vertical axis on the right represents the average throughput (unit: Mbps (mega bit per second)).

[0205] In the graph (810), the portion before time (815) may represent a case where the reference number is a first value. In contrast, the portion after time (815) of the graph (810) may represent a case where the reference number is a second value greater than the first value. Referring to the graph (810), regardless of a change in the reference number, the total resource usage and the average throughput may have generally similar values. In other words, even if the reference number changes, the total resource usage and the average throughput may each be maintained. This may indicate that the total resource usage of a base station (e.g., electronic device (400)) having PDCP for a split bearer is not related to a change in the reference number.

[0206] Figure 8b illustrates a graph (820) of the LTE resource usage of a base station according to a change in the reference number and the average throughput according to the LTE resource usage. Figure 8c illustrates a graph (830) of the NR resource usage of a base station according to a change in the reference number and the average throughput according to the NR resource usage. The horizontal axes of the graphs (820) and (830) represent time (unit: day), the vertical axis on the left represents total resource usage (unit: MB (megabyte)), and the vertical axis on the right represents average throughput (unit: Mbps (mega bit per second)).

[0207] In the graph (820), the portion before time (825) may represent a case where the reference number is a first value. In contrast, the portion after time (825) of the graph (820) may represent a case where the reference number is a second value greater than the first value. In the graph (830), the portion before time (835) may represent a case where the reference number is a first value. In contrast, the portion after time (835) of the graph (830) may represent a case where the reference number is a second value greater than the first value.

[0208] Referring to graph (820), as the reference number changes (or increases), LTE resource usage and average throughput may increase. Conversely, referring to graph (830), as the reference number changes (or decreases), NR resource usage and average throughput may decrease. In other words, when the reference number changes, the resource usage (and average throughput) for each communication method may change. The resource usage for each communication method may be referred to as the resource usage of the path for each communication method.

[0209] While FIGS. 8A to 8C illustrate cases where the reference number increases, the present disclosure is not limited thereto. For example, the present disclosure can also be applied to cases where the reference number decreases.

[0210] The device, method, and storage medium according to the present disclosure propose a traffic distribution technique in a DC using a split bearer. For example, the traffic distribution technique may be referred to as a packet distribution technique. For example, the device, method, and storage medium according to the present disclosure can continuously transmit downlink packets corresponding to a specified number through a path selected from among paths for a split bearer. At this time, the device, method, and storage medium according to the present disclosure can perform offloading between communication methods by changing the reference number based on traffic of the communication method (or traffic of the path for the split bearer) or mapping information according to the communication method.

[0211] 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.

[0212] A base station having a packet data convergence protocol (PDCP) for a split bearer as described above may include at least one processor including a processing circuit. The base station may include a memory including one or more storage media storing instructions. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to identify first traffic of a first communication scheme according to a number of downlink packets provided over a first path for the split bearer. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to identify second traffic of a second communication scheme according to a number of downlink packets provided over a second path for the split bearer. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to determine a reference number indicating a number of consecutive packets to be transmitted to a terminal based on the first traffic and the second traffic. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to transmit consecutive first downlink packets corresponding to the reference number to the terminal via the first path and to transmit consecutive second downlink packets corresponding to the reference number to the terminal via the second path.

[0213] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the base station to receive downlink packets from an entity of a core network connected to the base station. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to identify a first resource usage amount for downlink packets provided according to the first communication method and a second resource usage amount for downlink packets provided according to the second communication method. The first traffic may be identified based on the first resource usage amount among the total resource usage used to provide the received downlink packets. The second traffic may be identified based on the second resource usage amount among the total resource usage used to provide the received downlink packets.

[0214] In one embodiment, the first resource usage may indicate an amount of data for a secondary cell group (SCG) associated with the first path for the split bearer. The second resource usage may indicate an amount of data for a master cell group (MCG) associated with the second path for the split bearer.

[0215] According to one embodiment, the entity of the core network may include a user plane function (UPF) or a serving-gateway (S-GW).

[0216] According to one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the base station to store first record information indicating the number of downlink packets provided via the first path during a time interval and second record information indicating the number of downlink packets provided via the second path during the time interval. The first resource usage may be identified using the first record information. The second resource usage may be identified using the second record information.

[0217] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the base station to determine whether the length of the time interval exceeds a reference time. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to reset each of the first record information and the second record information to an initial value if the length of the time interval exceeds the reference time. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to update each of the first record information and the second record information if the length of the time interval is less than or equal to the reference time. The reference time may include a period at which a downlink data delivery status (DDDS) is acquired.

[0218] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the base station to identify mapping information indicating the reference number according to the communication methods to be used. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to further determine the reference number based on the first communication method, the second communication method, and the mapping information.

[0219] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the base station to obtain a first DBS (desired buffer size for the data radio bearer) of the first path for the split bearer and a second DBS of the second path for the split bearer. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to transmit, to the terminal, the consecutive first downlink packets corresponding to the reference number through the first path selected based on the first DBS and the second DBS. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to transmit, to the terminal, the consecutive second downlink packets corresponding to the reference number through the second path selected based on the remaining DBS of the first DBS and the second DBS among the first path and the second path, after transmitting the consecutive first downlink packets.

[0220] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the base station to receive a first downlink packet of the consecutive first downlink packets from an entity of a core network connected to the base station. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to transmit the first downlink packet of the consecutive first downlink packets to the terminal via the first path. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to identify the remaining DBS of the first DBS by decreasing a value of the first DBS as the base station transmits the first downlink packet, and to identify a number of packets continuously transmitted via the first path.

[0221] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the base station to determine, based on receiving a second downlink packet following the first downlink packet from the entity, whether the number of the continuously transmitted packets is less than the reference number. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to select the first path along which the second downlink packet included in the continuously transmitted first downlink packets is to be transmitted, if the number of the continuously transmitted packets is less than the reference number. The instructions, when individually or collectively executed by the at least one processor, may cause the base station to set the number of the continuously transmitted packets to an initial value when the number of the continuously transmitted packets is greater than or equal to the reference number, and to select the second path along which the second downlink packet included in the second downlink packets is to be transmitted based on the remaining DBS of the first DBS and the second DBS.

[0222] A method performed by a base station having a packet data convergence protocol (PDCP) for a split bearer as described above may include an operation of identifying first traffic of a first communication method according to a number of downlink packets provided through a first path for the split bearer. The method may include an operation of identifying second traffic of a second communication method according to a number of downlink packets provided through a second path for the split bearer. The method may include an operation of determining a reference number indicating a number of consecutive packets to be delivered to a terminal based on the first traffic and the second traffic. The method may include an operation of transmitting consecutive first downlink packets corresponding to the reference number to the terminal through the first path, and transmitting consecutive second downlink packets corresponding to the reference number to the terminal through the second path.

[0223] The non-transitory computer-readable storage medium as described above can store one or more programs including instructions that, when individually or collectively executed by at least one processor of a base station having a packet data convergence protocol (PDCP) for a split bearer, cause to identify first traffic of a first communication scheme according to the number of downlink packets provided through a first path for the split bearer. The non-transitory computer-readable storage medium can store one or more programs including instructions that, when individually or collectively executed by the at least one processor, cause to identify second traffic of a second communication scheme according to the number of downlink packets provided through a second path for the split bearer. 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 at least one processor to determine a reference number indicating the number of consecutive packets to be transmitted to the terminal based on the first traffic and the second traffic. 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 at least one processor to transmit consecutive first downlink packets corresponding to the reference number to the terminal via the first path, and to transmit consecutive second downlink packets corresponding to the reference number to the terminal via the second path.

[0224] A device of a central unit (CU) having a packet data convergence protocol (PDCP) for a split bearer as described above may include at least one processor including a processing circuit. The device may include a memory including one or more storage media storing instructions. The instructions, when individually or collectively executed by the at least one processor, may cause the device to identify first traffic of a first communication method according to a number of downlink packets provided through a first path for the split bearer. The instructions, when individually or collectively executed by the at least one processor, may cause the device to identify second traffic of a second communication method according to a number of downlink packets provided through a second path for the split bearer. The instructions, when individually or collectively executed by the at least one processor, may cause the device to determine a reference number indicating a number of consecutive downlink packets to be delivered to a terminal based on the first traffic and the second traffic. The instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit consecutive first downlink packets corresponding to the reference number to the terminal via the first path, and to transmit consecutive second downlink packets corresponding to the reference number to the terminal via the second path.

[0225] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to receive downlink packets from an entity of a core network connected to the CU. The instructions, when individually or collectively executed by the at least one processor, may cause the device to identify a first resource usage amount for downlink packets provided according to the first communication method and a second resource usage amount for downlink packets provided according to the second communication method. The first traffic may be identified based on the first resource usage amount among the total resource usage used to provide the received downlink packets. The second traffic may be identified based on the second resource usage amount among the total resource usage used to provide the received downlink packets.

[0226] In one embodiment, the first resource usage may indicate the amount of data for a secondary cell group (SCG) associated with a distributed unit (DU) connected to the CU. The second resource usage may indicate the amount of data for a master cell group (MCG) associated with a node connected to the CU.

[0227] According to one embodiment, the entity of the core network may include a user plane function (UPF) or a serving-gateway (S-GW).

[0228] According to one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to store first record information indicating a number of downlink packets provided via the first path during a time interval and second record information indicating a number of downlink packets provided via the second path during the time interval. The first resource usage may be identified using the first record information. The second resource usage may be identified using the second record information.

[0229] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to determine whether the length of the time interval exceeds a reference time. The instructions, when individually or collectively executed by the at least one processor, may cause the device to reset each of the first record information and the second record information if the length of the time interval exceeds the reference time. The instructions, when individually or collectively executed by the at least one processor, may cause the device to update each of the first record information and the second record information if the length of the time interval is less than or equal to the reference time. The reference time may include a period at which a downlink data delivery status (DDDS) is acquired.

[0230] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to identify mapping information indicating the reference number according to the communication methods to be used. The instructions, when individually or collectively executed by the at least one processor, may cause the device to further determine the reference number based on the first communication method, the second communication method, and the mapping information.

[0231] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to receive a first DBS (desired buffer size for the data radio bearer) of the first path for the split bearer from a distributed unit (DU) connected to the CU. The instructions, when individually or collectively executed by the at least one processor, may cause the device to receive a second DBS of a second path for the split bearer from a node connected to the CU. The instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit, to the terminal, the consecutive first downlink packets corresponding to the reference number through the first path selected based on the first DBS and the second DBS. The instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit, to the terminal, the consecutive second downlink packets corresponding to the reference number through the second path selected based on the remaining DBS of the first DBS and the second DBS among the first path and the second path, after transmitting the consecutive first downlink packets.

[0232] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to receive a first downlink packet of the consecutive first downlink packets from an entity of a core network connected to the CU. The instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit the first downlink packet of the consecutive first downlink packets to the terminal via the first path. The instructions, when individually or collectively executed by the at least one processor, may cause the device to identify the remaining DBS of the first DBS by decreasing a value of the first DBS as the device transmits the first downlink packet, and to identify a number of packets continuously transmitted via the first path.

[0233] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the device to determine, based on receiving a second downlink packet following the first downlink packet from the entity, whether the number of the continuously transmitted packets is less than the reference number. The instructions, when individually or collectively executed by the at least one processor, may cause the device to select the first path along which the second downlink packet included in the continuously transmitted first downlink packets is to be transmitted, if the number of the continuously transmitted packets is less than the reference number. The instructions, when individually or collectively executed by the at least one processor, may cause the device to set the number of the continuously transmitted packets to an initial value when the number of the continuously transmitted packets is greater than or equal to the reference number, and to select the second path along which the second downlink packet included in the second downlink packets is to be transmitted based on the remaining DBS of the first DBS and the second DBS.

[0234] A method performed by a central unit (CU) having a packet data convergence protocol (PDCP) for a split bearer as described above may include an operation of identifying first traffic of a first communication method according to a number of downlink packets provided through a first path for the split bearer. The method may include an operation of identifying second traffic of a second communication method according to a number of downlink packets provided through a second path for the split bearer. The method may include an operation of determining a reference number indicating a number of consecutive downlink packets to be delivered to a terminal based on the first traffic and the second traffic. The method may include an operation of transmitting consecutive first downlink packets corresponding to the reference number to the terminal through the first path, and transmitting consecutive second downlink packets corresponding to the reference number to the terminal through the second path.

[0235] The non-transitory computer-readable storage medium as described above can store one or more programs including instructions that, when individually or collectively executed by at least one processor of a central unit (CU) having a packet data convergence protocol (PDCP) for a split bearer, cause to identify first traffic of a first communication scheme according to a number of downlink packets provided through a first path for the split bearer. The non-transitory computer-readable storage medium can store one or more programs including instructions that, when individually or collectively executed by the at least one processor, cause to identify second traffic of a second communication scheme according to a number of downlink packets provided through a second path for the split bearer. 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 at least one processor to determine a reference number indicating the number of consecutive downlink packets to be transmitted to the terminal based on the first traffic and the second traffic. 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 at least one processor to transmit consecutive first downlink packets corresponding to the reference number to the terminal via the first path, and to transmit consecutive second downlink packets corresponding to the reference number to the terminal via the second path.

[0236] 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.

[0237] 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 for execution 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 specifications of the present disclosure. The one or more programs may be provided as included in a computer program product. The computer program product may be traded between sellers and buyers as a product. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read only memory (CD-ROM)) or an application store (e.g., Play Store). ™ ) or directly between two user devices (e.g., smart phones), online distribution (e.g., downloading or uploading). In the case of online distribution, at least a portion of the computer program product may be at least temporarily stored or temporarily created in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0238] 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.

[0239] 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.

[0240] 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.

[0241] 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.

[0242] 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 a base station having PDCP (packet data convergence protocol) for split bearer, At least one processor comprising a processing circuit; and A memory comprising one or more storage media for storing instructions, The above instructions, when individually or collectively executed by the at least one processor, cause the base station to: Identifying the first traffic of the first communication method according to the number of downlink packets provided through the first path for the above split bearer, Identifying the second traffic of the second communication method according to the number of downlink packets provided through the second path for the above split bearer, Based on the first traffic and the second traffic, a reference number indicating the number of consecutive packets to be transmitted to the terminal is determined, and Causing to transmit consecutive first downlink packets corresponding to the above reference number to the terminal through the first path, and to transmit consecutive second downlink packets corresponding to the above reference number to the terminal through the second path. Base station.

2. In claim 1, The above instructions, when individually or collectively executed by the at least one processor, cause the base station to: Receive downlink packets from an entity of a core network connected to the base station, and To cause a first resource usage amount for downlink packets provided according to the first communication method and a second resource usage amount for downlink packets provided according to the second communication method to be identified, The first traffic is identified based on the first resource usage among the total resource usage used to provide the received downlink packets, and The second traffic is identified based on the second resource usage among the total resource usage used to provide the received downlink packets. Base station.

3. In claim 2, The above first resource usage indicates the amount of data for the secondary cell group (SCG) associated with the first path for the split bearer, and The above second resource usage indicates the amount of data for the MCG (master cell group) associated with the second path for the split bearer. Base station.

4. In claim 2, The above entity of the core network includes a user plane function (UPF) or a serving-gateway (S-GW). Base station.

5. In claim 2, The above instructions, when individually or collectively executed by the at least one processor, cause the base station to: Causes to store first record information indicating the number of downlink packets provided through the first path during the time interval and second record information indicating the number of downlink packets provided through the second path during the time interval, The above first resource usage is identified using the above first record information, and The above second resource usage is identified using the above second record information, Base station.

6. In claim 5, The above instructions, when individually or collectively executed by the at least one processor, cause the base station to: Determine whether the length of the above time interval exceeds the reference time, If the length of the above time interval exceeds the above reference time, each of the first record information and the second record information is reset to an initial value, and If the length of the above time interval is less than or equal to the reference time, each of the first record information and the second record information is caused to be updated, The above reference time includes the cycle in which DDDS (downlink data delivery status) is obtained. Base station.

7. In claim 1, The above instructions, when individually or collectively executed by the at least one processor, cause the base station to: Identify mapping information indicating the above reference number according to the communication methods to be used, and Causing the reference number to be further determined based on the first communication method, the second communication method, and the mapping information. Base station.

8. In claim 1, The above instructions, when individually or collectively executed by the at least one processor, cause the base station to: Obtaining a first DBS (desired buffer size for the data radio bearer) of the first path for the split bearer and a second DBS of the second path for the split bearer, Transmitting the first consecutive downlink packets corresponding to the reference number to the terminal through the first path selected based on the first DBS and the second DBS, and After transmitting the above-mentioned consecutive first downlink packets, causing the terminal to transmit the above-mentioned consecutive second downlink packets corresponding to the reference number through the second path selected based on the remaining DBS of the first DBS and the second DBS among the first path and the second path. Base station.

9. In claim 8, The above instructions, when individually or collectively executed by the at least one processor, cause the base station to: Receive a first downlink packet among the consecutive first downlink packets from an entity of a core network connected to the base station, Transmitting the first downlink packet among the consecutive first downlink packets to the terminal through the first path, and As the first downlink packet is transmitted: Identifying the residual DBS of the first DBS by decreasing the value of the first DBS, and causing the number of packets transmitted continuously through the first path to be identified, Base station.

10. In claim 9, The above instructions, when individually or collectively executed by the at least one processor, cause the base station to: Based on receiving a second downlink packet following the first downlink packet from the entity, determining whether the number of continuously transmitted packets is less than the reference number, If the number of the continuously transmitted packets is less than the reference number, the first path along which the second downlink packet included in the continuous first downlink packets is to be transmitted is selected, and If the number of packets transmitted continuously is greater than or equal to the above standard number: The number of packets transmitted continuously is set as an initial value, and Based on the residual DBS of the first DBS and the second DBS, causing the second path to be selected to be transmitted for the second downlink packets included in the second downlink packets. Base station.

11. A method performed by a base station having PDCP (packet data convergence protocol) for split bearer, An operation for identifying first traffic of a first communication method according to the number of downlink packets provided through the first path for the above split bearer; An operation for identifying second traffic of a second communication method according to the number of downlink packets provided through a second path for the split bearer; An operation of determining a reference number indicating the number of consecutive packets to be transmitted to a terminal based on the first traffic and the second traffic, and An operation including transmitting consecutive first downlink packets corresponding to the above reference number to the terminal through the first path, and transmitting consecutive second downlink packets corresponding to the above reference number to the terminal through the second path. method.

12. In claim 11, The above method is: An operation of receiving downlink packets from an entity of a core network connected to the base station, and Including an operation of identifying a first resource usage amount for downlink packets provided according to the first communication method and a second resource usage amount for downlink packets provided according to the second communication method, The first traffic is identified based on the first resource usage among the total resource usage used to provide the received downlink packets, and The second traffic is identified based on the second resource usage among the total resource usage used to provide the received downlink packets. method.

13. In claim 12, The above first resource usage indicates the amount of data for the secondary cell group (SCG) associated with the first path for the split bearer, and The above second resource usage indicates the amount of data for the MCG (master cell group) associated with the second path for the split bearer. method.

14. In claim 12, The above entity of the core network includes a user plane function (UPF) or a serving-gateway (S-GW). method.

15. In a non-transitory computer-readable storage medium, when individually or collectively executed by at least one processor of a base station having a packet data convergence protocol (PDCP) for a split bearer, the base station: Identifying the first traffic of the first communication method according to the number of downlink packets provided through the first path for the above split bearer, Identifying the second traffic of the second communication method according to the number of downlink packets provided through the second path for the above split bearer, Based on the first traffic and the second traffic, a reference number indicating the number of consecutive packets to be transmitted to the terminal is determined, and Storing one or more programs including instructions that cause the terminal to transmit consecutive first downlink packets corresponding to the reference number to the terminal through the first path and to transmit consecutive second downlink packets corresponding to the reference number to the terminal through the second path. Non-transitory computer-readable storage medium.

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