Electronic device and method for transmitting user plane messages over fronthaul interface

Abstract

There is provided a method performed by a distributed unit (DU), comprising a step of sending a management message to a radio unit (RU) via a fronthaul interface, the management message comprising information indicating a representative extended antenna carrier (eAxC) port. The method may include the step of sending a control plane message to the RU via a fronthaul interface, the control plane message including segment information and segment extension information for resource allocation. The segment extension information may be used to combine a plurality of user plane (U-plane) messages into one of the DU or the RU. A representative eAxC port of the fronthaul interface may be used to transmit or receive the combined one U-plane message.

Description

Technical Field

[0001] The present disclosure relates to a fronthaul interface. More specifically, the present disclosure relates to an electronic device and method for sending a user plane (U-plane) message in a fronthaul interface. Background Art

[0002] As the transmission capacity in wireless communication systems increases, functional partitioning that functionally separates base stations is being applied. According to this functional partitioning, a base station can be divided into a distributed unit (DU) and a radio unit (RU). A fronthaul interface is defined for communication between the DU and the RU.

[0003] The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above may be applicable as prior art with respect to the present disclosure. Summary of the invention

[0004] Technical Solutions

[0005] According to an embodiment of the present disclosure, a method performed by a distributed unit (DU) is provided. The method includes sending a management message to a radio unit (RU) via a fronthaul interface, the management message including information for indicating a representative extended antenna carrier (eAxC) port. The method includes sending a control plane message to the RU via a fronthaul interface, the control plane message including segment information and segment extension information for resource allocation. The segment extension information can be used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU. The representative eAxC port of the fronthaul interface can be used to send or receive a combined U-plane message.

[0006] According to an embodiment of the present disclosure, a method performed by a radio unit (RU) is provided. The method includes receiving a management message from a distributed unit (DU) through a fronthaul interface, the management message including information for indicating a representative extended antenna carrier (eAxC) port. The method includes: receiving a control plane (C-plane) message from the DU through the fronthaul interface, the control plane message including segment information and segment extension information for resource allocation. The segment extension information can be used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU. The representative eAxC port of the fronthaul interface can be used to send or receive a combined U-plane message.

[0007] According to an embodiment of the present disclosure, an electronic device of a distributed unit (DU) is provided. The electronic device includes at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor is configured to control the at least one transceiver to send a management message to a radio unit (RU) through a fronthaul interface, and the management message includes information for indicating a representative extended antenna carrier (eAxC) port. The at least one processor is configured to control the at least one transceiver to send a control plane message to the RU through the fronthaul interface, and the control plane message includes segment information and segment extension information for resource allocation. The segment extension information can be used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU. The representative eAxC port of the fronthaul interface can be used to send or receive a combined U-plane message.

[0008] According to an embodiment of the present disclosure, an electronic device of a radio unit (RU) includes at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor is configured to control the at least one transceiver to receive a management message from a distributed unit (DU) through a fronthaul interface, and the management message includes information for indicating a representative extended antenna carrier (eAxC) port. The at least one processor is configured to control the at least one transceiver to receive a control plane message from the DU through the fronthaul interface, and the control plane message includes segment information and segment extension information for resource allocation. The segment extension information can be used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU. The representative eAxC port of the fronthaul interface can be used to send or receive a combined U-plane message. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0010] Figure 1 A wireless communication system according to an embodiment of the present disclosure is shown;

[0011] Figure 2a A fronthaul interface according to an embodiment of the present disclosure is shown;

[0012] Figure 2b A fronthaul interface of an open radio access network (O-RAN) according to an embodiment of the present disclosure is shown;

[0013] Figure 3a shows a functional configuration of a distributed unit (DU) according to an embodiment of the present disclosure;

[0014] Figure 3bshows a functional configuration of a radio unit (RU) according to an embodiment of the present disclosure;

[0015] Figure 4 shows the functional division between DU and RU according to an embodiment of the present disclosure;

[0016] Figure 5 shows a user plane (U-plane) message according to an embodiment of the present disclosure;

[0017] Figure 6 shows a combination of user plane messages according to an embodiment of the present disclosure;

[0018] Figure 7 shows signaling between DU and RU for combining user plane messages according to an embodiment of the present disclosure;

[0019] Figure 8 illustrates transmission of user plane messages using representative ports according to an embodiment of the present disclosure;

[0020] Fig. 9 A control plane message for combining user plane messages according to an embodiment of the present disclosure is shown; and

[0021] Fig.10 User plane messages using representative ports according to an embodiment of the present disclosure are shown.

[0022] The same reference numerals are used throughout the drawings to denote the same elements. DETAILED DESCRIPTION

[0023] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in understanding, but these details should be considered as merely exemplary. Therefore, it will be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the various embodiments described herein without departing from the scope of the present disclosure. In addition, descriptions of well-known functions and structures may be omitted for clarity and conciseness.

[0024] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustrative purposes only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

[0025] It should be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

[0026] In various examples of the present invention described below, a hardware method will be described as an example. However, since various embodiments of the present disclosure may include techniques utilizing both hardware-based methods and software-based methods, they are not intended to exclude software-based methods.

[0027] As used herein, terms related to merging (e.g., merging, grouping, combining, aggregating, uniting, integrating, unifying), terms related to signals (e.g., packets, messages, signals, information, signaling), terms related to resources (e.g., segments, symbols, time slots, subframes, radio frames, subcarriers, resource elements (REs), resource blocks (RBs), bandwidth parts (BWPs), opportunities), terms used to refer to any operating state (e.g., steps, operations, procedures), terms related to data (e.g., packets, messages, user flows, information, bits, symbols, codewords), terms related to channels, terms related to network entities Distributed Unit (DU), Radio Unit (RU), Central Unit (CU), Control Plane (CU-CP), User Plane (CU-UP), O-DU-Open Radio Access Network (O-RAN) DU), O-RU (O-RAN RU), O-CU (O-RAN CU), O-CU-UP (O-RAN CU-CP), O-CU-CP (O-RANCU-CP)), terms related to components of devices or equipment, etc. are shown in this disclosure only for the convenience of description. Therefore, the present disclosure is not limited to those terms described below, and other terms with the same or equivalent technical meanings may be used. In addition, as used herein, terms such as "module", "unit", "component", "main body", etc. may refer to at least one shape of a structure or unit for processing a specific function.

[0028] In addition, throughout the disclosure, expressions such as, for example, "higher than" or "lower than" can be used to determine whether a specific condition is met or achieved, but it is merely a description for expressing an example, and is not intended to exclude the meaning of "greater than or equal to" or "less than or equal to". Respectively, a condition described as "greater than or equal to" can be replaced with an expression such as "higher than", a condition described as "less than or equal to" can be replaced with an expression such as "lower than", and a condition described as "greater than or equal to and lower than" can be replaced with "higher than and less than or equal to". In addition, hereinafter, "A" to "B" means at least one of the elements from A (including A) to B (including B). hereinafter, "C" and / or "D" means including at least one of "C" or "D", that is, {"C", "D", or "C" and "D"}.

[0029] The present disclosure uses terms used in some communication standards (e.g., 3rd Generation Partnership Project (3GPP), extensible radio access network (xRAN), open radio access network (O-RAN), etc.) to describe various embodiments, but it is only an example for explanation, and the various embodiments of the present disclosure can be easily modified and applied to other communication systems even in other communication systems.

[0030] The present disclosure provides an electronic device and method for combining multiple user plane (U-plane) messages into one user plane over a fronthaul interface.

[0031] In addition, the present disclosure provides an apparatus and method for transmitting one user plane message by merging user plane data of each layer on a fronthaul interface.

[0032] In addition, the present disclosure provides an apparatus and method for merging segments of different layers into one segment on a fronthaul interface.

[0033] Furthermore, the present disclosure provides an apparatus and method for reducing the number of packets on a fronthaul interface between a distributed unit (DU) and a radio unit (RU).

[0034] The electronic device and method according to the embodiments of the present disclosure make it possible to reduce the operation burden of a distributed unit (DU) and a radio unit (RU) by transmitting one user plane message via a combination of user plane (U-plane) messages.

[0035] Effects that can be obtained from the present disclosure are not limited to the above-mentioned effects, and any other effects not mentioned herein will be clearly understood by a person of ordinary skill in the art to which the present disclosure pertains from the following description.

[0036] Figure 1 A wireless communication system according to an embodiment of the present disclosure is shown.

[0037] refer to Figure 1 , which shows a base station 110 and a terminal 120 as a part of a node using a wireless channel in a wireless communication system. Figure 1 Only one base station is shown, but the wireless communication system may also include another base station that is the same as or similar to the base station 110 .

[0038] The base station 110 is a network infrastructure that provides wireless access to the terminal 120. The base station 110 may have coverage defined based on the distance at which a signal can be transmitted. In addition to the term "base station", the base station 110 may be referred to as an "access point (AP), "eNode B (eNB)", "fifth generation node", "next generation node B (gNB)", "wireless point", "transmission / reception" or other terms having the same or equivalent meanings.

[0039] The terminal 120, which is a device used by a user, performs communication with the base station 110 through a wireless channel. A link from the base station 110 to the terminal 120 is called a downlink (DL), and a link from the terminal 120 to the base station 110 is called an uplink (UL). Figure 1 Not shown, but the terminal 120 and other terminals can communicate with each other through a wireless channel. In this context, the link between the terminal 120 and another terminal (device-to-device link, D2D) is called a side link, and the side link can be mixed with the PC5 interface. In some other embodiments of the present disclosure, the terminal 120 can be operated without any user participation. According to an embodiment of the present disclosure, the terminal 120 is a device that performs machine type communication (MTC) and can not be carried by the user. In addition, according to an embodiment of the present disclosure, the terminal 120 can be a narrowband (NB)-Internet of Things (IoT) device.

[0040] Terminal 120 may be referred to as “user equipment (UE), “customer premises equipment (CPE),” “mobile station,” “subscriber station,” “remote terminal,” “wireless terminal,” “electronic device,” “user device,” or any other term having the same or equivalent technical meaning.

[0041] The base station 110 may perform beamforming with the terminal 120. The base station 110 and the terminal 120 may transmit and receive radio signals in a relatively low frequency band, for example, FR 1 (frequency range 1) of NR. In addition, the base station 110 and the terminal 120 may transmit and receive radio signals in a relatively high frequency band, for example, FR 2 (or FR 2-1, FR 2-2, FR 2-3), FR 3 or millimeter wave (mmWave) band (for example, 28 GHz, 30 GHz, 38 GHz, 60 GHz) of NR. In order to improve channel gain, the base station 110 and the terminal 120 may perform beamforming. In this context, beamforming may include transmit beamforming and receive beamforming. The base station 110 and the terminal 120 may assign directivity to a transmit signal or a receive signal. To this end, the base station 110 and the terminal 120 may select a service beam through a beam search or beam management process. After selecting a serving beam, subsequent communication may be performed through a resource having a QCL relationship with a resource that has transmitted the serving beam.

[0042] The first antenna port and the second antenna port may be evaluated as being in such a QCL relationship if a wide-scale characteristic of a channel carrying symbols on a first antenna port can be estimated from a channel carrying symbols on a second antenna port. For example, the wide-scale characteristic may include at least one of delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial receiver parameters.

[0043] Despite Figure 1 In the embodiment, both the base station 110 and the terminal 120 are described as performing beamforming, but the embodiments of the present disclosure are not necessarily limited thereto. In some embodiments of the present disclosure, the terminal may or may not perform beamforming. Similarly, the base station may or may not perform beamforming. That is, only either the base station or the terminal may perform beamforming, or both the base station and the terminal may not perform beamforming.

[0044] In the present disclosure, a beam means a spatial stream of a signal in a radio channel, and may be formed by one or more antennas (or antenna elements), and the formation process thereof may be referred to as beamforming. Beamforming may include at least one of analog beamforming and digital beamforming (e.g., precoding). Reference signals transmitted based on beamforming may include, for example, a demodulation reference signal (DM-RS), a channel state information reference signal (CSI-RS), a synchronization signal / physical broadcast channel (SS / PBCH), or a sounding reference signal (SRS). In addition, for the configuration of each reference signal, IEs such as CSI-RS resources, SRS resources, etc. may be used, and the configuration may include information associated with the beam. The beam-associated information may refer to whether the corresponding configuration (e.g., CSI-RS resource) uses the same spatial domain filter as other configurations (e.g., another CSI-RS resource within the same CSI-RS resource set) or uses a different spatial domain filter, or with which reference signal is quasi-co-located (QCL), or if it is QCL, it refers to what type it has (e.g., QCL type A, B, C, or D).

[0045] According to the related art, in a communication system in which the cell radius of a base station is relatively large, each base station is installed so that each base station includes the functions of a digital processing unit (or distributed unit (DU)) and a radio frequency (RF) processing unit (or radio unit (RU)). However, with the use of high frequency bands in the fourth generation (4G) system and / or its subsequent communication systems (e.g., the fifth generation (5G)), and the reduction in cell coverage of base stations, the number of base stations covering a specific area increases. As a result, the burden of the initial installation cost of installing more base stations by the communication provider increases. In order to minimize the installation cost of the base station, a structure has been proposed in which the DU and RU of the base station are separated so that one or more RUs are connected to one DU via a wired network, and one or more RUs distributed geographically are arranged to cover a specific area. In the following, reference will be made to Figure 2a to Figure 2b Describe the deployment structure and extension examples of base stations according to various embodiments of the present disclosure.

[0046] Figure 2a 1 shows a fronthaul interface according to an embodiment of the present disclosure. Fronthaul refers to the entity between the wireless LAN and the base station, as opposed to the backhaul between the base station and the core network. Figure 2a An example of a forward transport structure between a DU 210 and one RU 220 is shown, but this is only for ease of description, and the present disclosure is not limited thereto. In other words, the embodiments of the present disclosure may also be applied to a forward transport structure between a DU and multiple RUs. For example, the embodiments of the present disclosure may be applied to a forward transport structure between a DU and two RUs. In addition, the embodiments of the present disclosure may also be applied to a forward transport structure between a DU and three RUs.

[0047] Reference Figure 2a , the base station 110 may include a DU 210 and a RU 220. The fronthaul 215 between the DU 210 and the RU 220 may be operated through an Fx interface. For the operation of the fronthaul 215, an interface such as an enhanced common public radio interface (eCPRI) or a radio over Ethernet (ROE) may be used.

[0048] With the development of communication technology, mobile data services have greatly increased, and therefore, the bandwidth requirements required for fronthaul between digital units (DUs) and radio units (RUs) have increased significantly. In deployments such as centralized / cloud radio access networks (C-RANs), DUs may be implemented to perform functions for packet data convergence protocol (PDCP), radio link control (RLC), media access control (MAC), and physical (PHY), and RUs may be implemented to perform functions for the PHY layer in addition to radio frequency (RF) functions.

[0049] DU 210 may be used as an upper layer of a wireless network. For example, DU 210 may perform the functions of a MAC layer and a portion of a PHY layer. Here, this portion of the PHY layer is performed at a higher level among the functions of the PHY layer, and may include, for example, channel coding (or channel decoding), scrambling (or descrambling), modulation (or demodulation), or layer mapping (or layer demapping). According to an embodiment of the present disclosure, when DU 210 complies with the O-RAN standard, it may be referred to as an O-DU (O-RAN DU). As circumstances require, in an embodiment of the present disclosure, DU 210 may be represented as being replaced by a first network entity for a base station (e.g., a gNB).

[0050] The RU 220 may be responsible for lower layer functions of the wireless network. For example, the RU 220 may perform a portion of the PHY layer and the RF function. Here, a portion of the PHY layer is performed at a relatively lower level than the DU 210 in the function of the PHY layer, and may include, for example, iFFT transformation (or FFT transformation), CP insertion (CP removal), and digital beamforming. Figure 4 An example of this specific functional split is further described in detail. RU 220 may be referred to as an "access unit (AU)", "access point (AP)", "transmit / receive point (TRP)", "remote radio head (RRH)", "radio unit (RU)" or any other term having a technical meaning equivalent thereto. According to an embodiment of the present disclosure, when RU 220 complies with the O-RAN standard, it may be referred to as an O-RU (O-RANRU). In an embodiment of the present disclosure, as the situation requires, RU 220 may be represented as being replaced by a second network entity for a base station (e.g., a gNB).

[0051] although Figure 2a The base station 110 is described as including the DU 210 and the RU 220, but the embodiments of the present disclosure are not limited thereto. The base station according to the embodiments of the present disclosure may be implemented by using a distributed deployment of a centralized unit (CU) configured to perform functions of an upper layer (e.g., Packet Data Convergence Protocol (PDCP), Radio Resource Control (RRC)) of an access network and a distributed unit (DU) configured to perform functions of a lower layer. In this case, the distributed unit (DU) may include Figure 1 The digital unit (DU) and radio unit (RU) of the 5G network. Between the core (e.g., 5G core (5GC) or next generation core (NGC)) network and the radio network (RAN), the deployment of base stations can be achieved in the order of CU, DU, and RU. The interface between the CU and the distributed unit (DU) can be called the F1 interface.

[0052] A centralized unit (CU) may be connected to one or more DUs to act as a higher layer than the DU. For example, the CU may be responsible for the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers, and the DU and RU may be responsible for the functions of the lower layers. The DU may perform some functions of the radio link control (RLC), media access control (MAC), and physical (PHY) layers (high PHY), and the RU may be responsible for the remaining functions of the PHY layer (low PHY). In addition, as an example, according to the implementation of the distributed arrangement of the base station, the digital unit (DU) may be included in the distributed unit (DU). In the following, unless otherwise defined, the operation of the digital unit (DU) and the RU will be described, but it should be noted that the various embodiments of the present disclosure may be applied to a base station deployment including a CU or a deployment in which the DU is directly connected to the core network (i.e., incorporated into a base station (e.g., an NG-RAN node) in which the CU and DU are one entity).

[0053] Figure 2b A fronthaul interface of an O(Open)-RAN (Radio Access Network) according to an embodiment of the present disclosure is shown. According to a distributed deployment, an eNB or a gNB is shown as a base station 110.

[0054] refer to Figure 2b , the base station 110 may include an O-DU 251 and O-RUs (253-1, ..., 253-n). Hereinafter, for ease of explanation, the operation and function of the O-RU 253-1 may be understood by explaining each other O-RU (e.g., O-RU 253-n).

[0055] DU 251 is a logical node that includes Figure 4The O-DU 251 may control the operation of the O-RUs (253-1, ..., 253-n). The O-DU 251 may be referred to as a lower layer segmentation (LLS) central unit (CU). The O-RU 253-1 is a block diagram including a base station (e.g., eNB, gNB) and a plurality of base stations (e.g., eNB, gNB) and a plurality of base stations (e.g., eNB, gNB). The O-DU 251 may control the operation of the O-RUs (253-1, ..., 253-n). The O-DU 251 may be referred to as a lower layer segmentation (LLS) central unit (CU). The O-RU 253-1 is a block diagram including a base station (e.g., eNB, gNB) and a plurality of base stations ... Figure 4 A logical node that is a subset of the functionality of a base station (e.g., eNB, gNB). Real-time aspects of control plane (C-plane) communication and user plane (U-plane) communication with the O-RU 253-1 can be controlled by the O-DU 251.

[0056] DU 251 can perform communication with O-RU 253-1 through an LLS interface. The LLS interface corresponds to a fronthaul interface. The LLS interface refers to a logical interface between O-DU 251 and O-RU 253-1 using lower layer functional splitting (i.e., based on functional splitting within PHY). LLS-C between O-DU 251 and O-RU 253-1 provides a C-plane through an LLS interface. LLS-U between O-DU 251 and O-RU 253-1 provides a U-plane through an LLS interface.

[0057] exist Figure 2b In the present invention, the entities of the base station 110 are described by referring to the O-DU and the O-RU to explain the O-RAN. However, this designation should not be interpreted as limiting the embodiments of the present disclosure thereto. Figure 3a , 3b In the embodiments described in 4 to 10, the operations of DU 210 can of course be performed by O-DU 251. The description of DU 210 can also be applied to O-DU 251. Similarly, in reference Figure 3a , Figure 3b and Figures 4 to 10 In the described embodiment, the operations of RU 220 may of course be performed by O-RU 253-1. The description of RU 220 may also be applied to O-DU 253-1.

[0058] Figure 3a A functional configuration of a distributed unit (DU) according to an embodiment of the present disclosure is shown. Figure 3a The configuration shown in FIG. 1 can be understood as a part of a base station. Figure 2a DU 210 (or Figure 2b As used herein, the term "module", "unit" or "part" means a unit for processing at least one function or operation, which can be implemented by hardware, software or a combination of hardware and software.

[0059] refer to Figure 3a , the DU 210 includes a transceiver 310 , a memory 320 , and a processor 330 .

[0060] The transceiver 310 may perform functions for sending and / or receiving signals in a wired communication environment. The transceiver 310 may include a wired interface for controlling a direct connection between a device and another device through a transmission medium (e.g., copper wire, optical fiber, etc.). For example, the transceiver 310 may send an electrical signal to another device through a copper wire, or perform conversion between an electrical signal and an optical signal. The DU 210 may communicate with a radio unit (RU) via the transceiver 310. The DU 210 may be connected to a core network or a distributed CU via the transceiver 310.

[0061] The transceiver 310 can perform functions for sending and receiving signals in a wireless communication environment. For example, the transceiver 310 can perform functions for conversion between baseband signals and bit strings according to the physical layer standard of the system. For example, during data transmission, the transceiver 310 generates complex symbols by encoding and modulating the transmitted bit string. In addition, during data reception, the transceiver 310 recovers the received bit string by demodulating and decoding the baseband signal. In addition, the transceiver 310 may include multiple transmit / receive paths. In addition, according to an embodiment of the present disclosure, the transceiver 310 may be connected to a core network or to other nodes (e.g., integrated access backhaul (IAB)).

[0062] The transceiver 310 is configured to send and receive signals. For example, the transceiver 310 may send a management plane (M-plane) message. For example, the transceiver 310 may send a synchronization plane (S-plane) message. For example, the transceiver 310 may send a control plane (C-plane) message. For example, the transceiver 310 may send a user plane (U-plane) message. For example, the transceiver 310 may receive a user plane message. Figure 3a Only the transceiver 310 is shown in FIG. 2 , but according to another embodiment, the DU 210 may include two or more transceivers.

[0063] The transceiver 310 transmits and receives signals as described above. Therefore, all or at least a portion of the transceiver 310 may also be referred to as a communication unit, a transmission unit, a reception unit, or a transmission / reception unit. In addition, throughout the description, it should be noted that transmission and reception performed via a wireless channel are intended to include the above-mentioned processing performed by the transceiver 310.

[0064] although Figure 3aAlthough not shown in the figure, the transceiver 310 may also include a backhaul transceiver for connecting to the core network or another base station. The backhaul transceiver provides an interface for performing communication with other nodes in the network. In other words, the backhaul transceiver converts a bit string sent from the base station to another node (e.g., another access node, another base station, a higher node, a core network, etc.) into a physical signal, and converts a physical signal received from other nodes into a bit string.

[0065] The memory 320 stores data such as basic programs, application programs, and setting information for the overall operation of the DU 210. The memory 320 may be referred to as a storage unit. The memory 320 may be configured as a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. In addition, the memory 320 provides stored data according to a request of the processor 330.

[0066] The processor 330 controls the overall operation of the DU 210. The processor 380 may be referred to as a controller. For example, the processor 330 sends and receives signals through the transceiver 310 (or via a backhaul communication unit). In addition, the processor 330 records data to and reads data from the memory 320. In addition, the processor 330 may perform the functions of the protocol stack required by the communication standard. Although in Figure 3a Only the processor 330 is shown in FIG. 2 , but according to another example of an embodiment, the DU 210 may include two or more processors.

[0067] Figure 3a The configuration of the DU 210 shown in FIG. 1 is only an example, and the configuration of the DU to perform the embodiments of the present disclosure is not limited to Figure 3a In some embodiments of the present disclosure, some configurations may be added, deleted or changed.

[0068] Figure 3b A functional configuration of a radio unit (RU) according to an embodiment of the present disclosure is shown. Figure 3b The configuration shown in can be understood as Figure 2b RU 220 or Figure 2b The configuration of the O-RU 253-1 is as a part of the base station. As used herein, terms such as "module", "unit" or "part" mean a unit for processing at least one function or operation, which can be implemented by hardware, software, or a combination of hardware and software.

[0069] refer to Figure 3b , RU 220 includes an RF transceiver 360 , a fronthaul transceiver 365 , a memory 370 , and a processor 380 .

[0070] The RF transceiver 360 performs functions for transmitting and receiving signals through a wireless channel. For example, the RF transceiver 360 up-converts a baseband signal into an RF band signal to transmit the RF band signal through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF transceiver 360 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

[0071] The RF transceiver 360 may include multiple transmit / receive paths. In addition, the RF transceiver 360 may include an antenna unit. The RF transceiver 360 may include at least one antenna array configured with multiple antenna elements. In terms of hardware, the RF transceiver 360 may be configured with digital circuits and analog circuits (e.g., radio frequency integrated circuits (RFIC)). Here, the digital circuits and the analog circuits may be implemented in a single package. In addition, the RF transceiver 360 may include multiple RF chains. The RF transceiver 360 may perform beamforming. The RF transceiver 360 may apply beamforming weights to signals to be transmitted / received to allocate directivity according to the settings of the processor 380. According to an embodiment of the present disclosure, the RF transceiver 360 may include a radio frequency (RF) block (or RF component).

[0072] According to an embodiment of the present disclosure, the RF transceiver 360 can send and receive signals through a radio access network. For example, the RF transceiver 360 can send a downlink signal. The downlink signal may include a synchronization signal (SS), a reference signal (RS) (e.g., a cell-specific reference signal (CRS), DM (demodulation)-RS), system information (e.g., MIB, SIB, RMSI (remaining system information), OSI (other information)), a configuration message, control information, or downlink data. In addition, for example, the RF transceiver 360 can receive an uplink signal. The uplink signal may include a random access-related signal (e.g., a random access preamble (RAP) (or Msg1 (message 1), Msg3 (message 3)), a reference signal (e.g., a sounding reference signal (SRS), DM-RS), a power headroom report (PHR), etc. Although in Figure 3b Only the RF transceiver 360 is shown in FIG. 2 , but according to another implementation example, the RU 220 may include two or more RF transceivers.

[0073] According to an embodiment of the present disclosure, the RF transceiver 460 may transmit a RIM-RS. The RF transceiver 460 may transmit a first type of RIM-RS (e.g., RIM-RS type 1 of 3GPP) for notifying detection of far-field interference. The RF transceiver 460 may transmit a second type of RIM-RS (e.g., RIM-RS type 2 of 3GPP) for notifying the presence or absence of far-field interference.

[0074] The fronthaul transceiver 365 can send and receive signals. According to an embodiment of the present disclosure, the fronthaul transceiver 365 can send and receive signals on the fronthaul interface. For example, the fronthaul transceiver 365 can receive a management plane (M-plane) message. For example, the fronthaul transceiver 365 can receive a synchronization plane (S-plane) message. For example, the fronthaul transceiver 365 can receive a control plane (C-plane) message. For example, the fronthaul transceiver 365 can send a user plane (U-plane) message. For example, the fronthaul transceiver 365 can receive a user plane message. Although in Figure 3b Only the fronthaul transceiver 365 is shown in FIG. 2 , but according to another implementation example, the RU 220 may include two or more fronthaul transceivers.

[0075] The RF transceiver 360 and the fronthaul transceiver 365 transmit and receive signals as described above. Therefore, all or at least a portion of the RF transceiver 360 and the fronthaul transceiver 365 may be referred to as a communication unit, a transmission unit, a reception unit, or a transmission / reception unit. In addition, throughout the following disclosure, transmission and reception performed through a radio channel are used to indicate that the above-mentioned processing is performed by the RF transceiver 360.

[0076] The memory 370 stores data such as basic programs, application programs, and setting information for the overall operation of the RU 220. The memory 370 may be referred to as a storage unit. The memory 370 may be configured with a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. In addition, the memory 370 provides stored data according to a request of the processor 380. According to an embodiment of the present disclosure, the memory 370 may include a memory for storing conditions, instructions, or setting values ​​related to the SRS transmission scheme.

[0077] The processor 380 controls the overall operation of the RU 220. The processor 380 may be referred to as a controller. For example, the processor 380 sends and receives signals through the RF transceiver 360 or the fronthaul transceiver 365. In addition, the processor 380 writes and reads data to and from the memory 370. The processor 380 may then perform the functions of the protocol stack required by the communication standard. Figure 3b Only the processor 380 is shown in the figure, but according to another implementation example, the RU 220 may include two or more processors. The processor 380 may include a storage space for storing instructions / codes that are at least temporarily resident in the processor 380, because the instructions / codes are instruction sets or codes stored in the memory 370. The processor 380 may also include various communication modules for performing communication. The processor 380 may control the RU 220 to perform operations according to the following embodiments of the present disclosure.

[0078] Figure 3b The configuration of the RU (220) shown in FIG. 1 is only an example, and examples of the RU for performing the embodiments of the present disclosure are not limited to Figure 3b The configuration shown in . In some configurations, some configurations may be added, deleted or changed.

[0079] Figure 4 The functional split between the DU and the RU according to an embodiment of the present disclosure is shown. With the further development of wireless communication technology (for example, with the introduction of the 5G communication system (or NR (New Radio) communication system), the frequency bands used have increased even more. As the cell radius of the base station becomes very small, the number of RUs that need to be installed further increases. In addition, in the 5G communication system, the amount of data transmission has greatly increased by 10 times or more, and therefore, the transmission capacity of the wired network used for transmission to the fronthaul has also increased significantly. Therefore, due to the above factors, the installation cost of the wired network in the 5G communication system may increase very significantly. Thus, in order to reduce the transmission capacity of the wired network and reduce the installation cost of the wired network, this "functional split" can be used to reduce the transmission capacity of the fronthaul by transferring some functions of the DU's modem to the RU.

[0080] In order to reduce the burden on the DU, the role of the RU, which is only responsible for the existing RF functions, can be extended to certain functions of the physical layer. As the RU performs higher-layer functions, the throughput of the RU increases, resulting in an increase in the transmission bandwidth at the fronthaul and at the same time reducing the latency requirement constraints due to response processing. At the same time, as the RU performs higher-layer functions, the virtualization gain decreases, and the size, weight, and cost of the RU increase. Therefore, it is necessary to achieve the optimal functional split based on the trade-offs of the above advantages and disadvantages.

[0081] refer to Figure 4 , showing the functional division in the physical layer below the MAC layer. In the case of a downlink (DL) sending a signal to a terminal through a wireless network, the base station can sequentially perform channel coding / scrambling, modulation, layer mapping, antenna mapping, RE mapping, digital beamforming (e.g., precoding), iFFT transform / CP insertion, and RF conversion. In the case of an uplink (UL) receiving a signal from a terminal through a wireless network, the base station can sequentially perform RF conversion, FFT transform / CP removal, digital beamforming (e.g., precombination), RE demapping, channel estimation, layer demapping, demodulation, decoding / descrambling. Based on the above trade-offs, the separation of uplink functions and downlink functions can be defined in various types according to needs between vendors, discussions on standards, etc.

[0082] In the first functional partition 405, the RU performs RF functions and the DU performs PHY functions. In the first functional partition, the PHY functions in the RU are basically not implemented, and it can be referred to as, for example, option 8. In the second functional partition 410, the RU performs iFFT transform / CP insertion in the DL of the PHY function and performs FFT transform / CP removal in the UL, and the DU performs the remaining PHY functions. For example, the second functional partition 410 can be referred to as option 7-1. In the third functional partition 420a, the RU performs iFFT transform / CP insertion in the DL of the PHY function and performs FFT transform / CP removal in the UL, and the DU performs the remaining PHY functions. For example, the third functional partition 420a can be referred to as option 7-2x category A. In the fourth functional partition 420b, the RU performs digital beamforming in both DL and UL, and the DU performs upper layer PHY functions after digital beamforming. For example, the fourth functional partition 420b can be referred to as option 7-2x category B. In the fifth functional partition 425, the RU performs RE mapping (or RE demapping) in both DL and UL, and the DU performs upper layer PHY functions after RE mapping (or RE demapping). For example, the fifth functional partition 425 can be referred to as option 7-2. In the sixth functional partition 430, the RU performs up to modulation (or demodulation) in both DL and UL, and the DU performs upper layer PHY functions after modulation (or demodulation). For example, the sixth functional partition 430 can be referred to as option 7-3. In the seventh functional partition 440, the RU performs up to encoding / scrambling (or decoding / descrambling) in both DL and UL, and the DU performs higher PHY functions after modulation (or demodulation). For example, the seventh functional partition 440 can be referred to as option 6.

[0083] According to an embodiment of the present disclosure, when a large amount of signal processing is expected (such as FR 1MMU), functional splitting at a relatively high level (e.g., the fourth functional splitting 420b) may be required to reduce the fronthaul capacity. In addition, since multiple PHY processing blocks are included in the RU, functional splitting at an excessively high level (e.g., the sixth functional splitting 430) may result in a more complex control interface and impose a great burden on the implementation of the RU, and therefore, appropriate functional splitting may be required depending on the deployment and implementation scheme of the DU and the RU.

[0084] According to an embodiment of the present disclosure, in the case where it is impossible to process precoding of data received from the DU (i.e., when the precoding capability of the RU is limited), the third functional partition 420a or a lower functional partition thereof (e.g., such as the second functional partition 410) may be applied. Conversely, when it is possible to process precoding of data received from the DU, the fourth functional partition 420b or a higher functional partition thereof (e.g., such as the sixth functional partition 430) may be applied.

[0085] Hereinafter, in the present disclosure, unless otherwise limited, embodiments are described based on the third functional partition 420a (referred to as Category A or CAT-A) or the fourth functional partition 420b (referred to as Category B or CAT-B) for performing beamforming processing in the RU. The O-RAN specification distinguishes the types of O-RUs according to whether the precoding function is located on the O-DU interface or on the O-RU interface. An O-RU in which precoding is not performed (i.e., with low complexity) may be referred to as a CAT-A O-RU. An O-RU in which precoding is performed may be referred to as a CAT-B O-RU.

[0086] Hereinafter, the upper layer PHY may refer to the physical layer processing performed in the DU of the fronthaul interface. For example, the upper layer PHY may include FEC encoding / decoding, scrambling, and modulation / demodulation. Hereinafter, the lower layer PHY may refer to the physical layer processing performed in the RU of the fronthaul interface. For example, the sub-PHY may include FFT / iFFT, digital beamforming, or physical random access channel (PRACH) extraction and filtering. However, the above standards do not exclude embodiments implemented by other functional splitting. The following will be described Figures 5 to 10 The functional configuration, signaling, or operation may be applied not only to the third functional partition 420a or the fourth functional partition 420b but also to other functional partitions.

[0087] The embodiments of the present disclosure show that when a DU (e.g., Figure 2a DU 210) and RU (e.g. Figure 2a When sending messages between RU 220 in the fronthaul interface, the specifications of eCPRI and O-RAN as the fronthaul interface are followed. The Ethernet payload of the message may include an eCPRI header, an O-RAN header, and additional fields. In the following, the standard terms of eCPRI or O-RAN will be used to describe various embodiments of the present disclosure, but other expressions having the same or equivalent meaning to each term may be used to replace the various embodiments of the present disclosure.

[0088] For the fronthaul transport protocol, Ethernet and eCPRI, which are easy to share with the network, can be used. The eCPRI header and O-RAN header can be included in the Ethernet payload. The eCPRI header can be located at the front end of the Ethernet payload. The content of the eCPRI header is as follows.

[0089] 1) ecpriVersion (4 bits): This parameter indicates the eCPRI protocol version.

[0090] 2) ecpriReserved (3 bits): This parameter is reserved for further use of eCPRI.

[0091] 3) ecpriConcation (1 bit): This parameter indicates when eCPRI cascading is used.

[0092] 4) ecpriMessage (1 byte): This parameter indicates the type of service carried by the message type. For example, the parameter indicates an IQ data message, a real-time control data message, or a transport network delay measurement message.

[0093] 5) ecpriPayload (2 bytes): This parameter indicates the byte size of the payload portion of the eCPRI message.

[0094] 6) ecpriRtcid / ecpriPcid (2 bytes): This parameter is the eAxC (Extended Antenna Carrier) Identifier (eAxCID) which identifies the specific data stream associated with each C-plane (ecpriRtcid) or U-plane (ecpriPcid) message.

[0095] 7) ecpriSeqid (2 bytes): This parameter provides unique message identification and ordering at two levels. The first octet of this parameter is the sequence ID used to identify the order of messages within the eAxC message stream, and the sequence ID is used to verify that all messages have been received and to reorder out-of-order messages. The second octet of this parameter is the subsequence ID. The subsequence ID is used to verify the order and enable reordering when radio transmission level segmentation (eCPRI or IEEE-1914.3) occurs.

[0096] The eAxC identifier (ID) includes a band and sector identifier ('BandSector_ID'), a component carrier identifier ('CC_ID'), a spatial stream identifier ('RU_Port_ID'), and a distributed unit identifier ('DU_Port_ID'). The bit allocation of the eAxC ID may be categorized as follows.

[0097] 1) DU_port ID: This ID is used to distinguish the processing units in the O-DU (e.g., other baseband cards). It is expected that the O-DU will allocate bits for the DU_port ID, and the O-RU will append the same value to the UL U-plane message to carry the same sectionId data.

[0098] 2) BandSector_ID: This ID is the aggregated cell identifier (band and sector classification supported by the O-RU).

[0099] 3) CC_ID: This ID distinguishes the carrier component supported by the O-RU.

[0100] 4) RU_port ID: This ID specifies a logical stream, such as a data layer or a spatial stream, and a logical stream, such as a signal channel that requires a special antenna allocation, such as a separate parameter set (eg, PRACH) or SRS.

[0101] The application protocol of the fronthaul may include a control plane (C-plane), a user plane (U-plane), a synchronization plane (S-plane), and a management plane (M-plane).

[0102] The control plane can be configured to provide scheduling information and beamforming information through control messages. The control plane means real-time control between DU and RU. The user plane may include IQ sampling data sent between DU and RU. The user plane may include the user's downlink data (IQ data or SSB / RS), uplink data (IQ data or SRS / RS) or PRACH data. The weight vector of the above beamforming information can be multiplied by the user's data. The synchronization plane generally means the service between DU and RU to the synchronization controller (e.g., IEEE master clock). The synchronization plane may be related to timing and synchronization. The management plane means non-real-time control between DU and RU. The management plane may be related to initial setup, non-real-time reset or reset or non-real-time reporting.

[0103] The control plane messages (i.e., C-plane messages) can be encapsulated based on a two-layer header approach scheme. The first layer may include an eCPRI common header or an IEEE 1914.3 common header, which includes fields for indicating the message type. The second layer is an application layer including fields required for control and synchronization. The sections in the application layer define the characteristics of the U-plane data sent or received in a beam with a mode ID. The section types supported in the C-plane are as follows.

[0104] The segment type may indicate the usage of the control message sent in the control plane. For example, the specific usage of the segment type is as follows.

[0105] 1) sectionType = 0: This is used to indicate a resource block or symbol that is not used in DL or UL.

[0106] 2) sectionType = 1: This is used for most DL / UL radio channels. Here, the term "most" refers to channels that do not require time or frequency offsets, as required for hybrid neuron channels.

[0107] 3)sectionType=2: This is reserved for further use.

[0108] 4) sectionType = 3: PRACH and mixed parameter set channels. Channels that require time or frequency offset or different from the nominal SCS value.

[0109] 5)sectionType=4: This is reserved for further use

[0110] 6) sectionType = 5: UE scheduling information, which transmits UE scheduling information so that the RU can perform real-time BF (beamforming) weight calculation (O-RAN optional BF solution).

[0111] 7) sectionType = 6: UE-specific channel information transmission, which periodically delivers UE channel information so that the RU can perform real-time BF weight calculation (O-RAN optional BF solution).

[0112] 8)sectionType=7: This is used to support LAA

[0113] 9)sectionType=8: This is used for ACK / NACK feedback.

[0114] Figure 5 User plane (U-plane) messages according to an embodiment of the present disclosure are shown.

[0115] The current FH (fronthaul) standard of the O-RAN Working Group (WG) 4 does not allow the sending and receiving of U-plane payloads of ORAN with different eAxC IDs through one packet (e.g., Ethernet-based eCPRI packet). For example, a CAT-A O-RU with four transmit / receive antennas is assigned a different eAxC ID for each antenna. When downlink RB resources are allocated, the CAT-A O-RU can receive one U-plane packet for each transmission in each symbol. In other words, the CAT-A O-RU can receive a total of four U-plane packets. When uplink RB resources are allocated, the CAT-A O-RU can send a U-plane packet for each reception to the O-DU in each symbol. For example, the CAT-A O-RU can send a total of four U-plane packets to the O-DU. In the following, reference is made to Figure 5 , an example of U-plane grouping between DU and RU in the case of allocating uplink RB resources will be described.

[0116] refer to Figure 5 , an RU with four receive antennas can send an uplink signal received by each receive antenna to the DU through a fronthaul interface. The physical resource block (PRB) index (idx) refers to the index of the PRB in the frequency domain. A PRB can include 12 resource elements (REs). Regardless of the parameter set, the number of REs included in the PRB is the same. Here, the uplink signal refers to the data received per unit time by the receive antenna.

[0117] exist Figure 5 In the RU, the RU may receive an uplink signal through each receiving antenna. The uplink signal may include a physical uplink shared channel (PUSCH) (or a physical uplink control channel (PUCCH)). For example, the subcarrier spacing (SCS) of the PUSCH may be 15kHz (kilohertz). The uplink signal may include a physical random access channel (PRACH) in band A. For example, the SCS of the PRACH in band A may be 1.25kHz. The uplink signal may include PRACH in band A and another band B at the same time. For example, the SCS of the PRACH in band B may also be 1.25kHz. The uplink signal may include a narrowband physical uplink shared channel (NPUSCH) of an intra-band type using resource blocks of a frequency band (e.g., an LTE band). For example, the SCS of the intra-band type of the NPUSCH may be 15kHz. The uplink signal may include a narrowband physical uplink shared channel (NPUSCH) of a guard band type using unused resource blocks in a guard band of a frequency band (e.g., an LTE band). For example, the SCS of the guard band type of NPUSCH may be 3.75kHz. The uplink signal may include a narrowband physical random access channel (NPRACH). The NPRACH may be distinguished according to the coverage extension (CE) level. The uplink signal may include an NPRACH with a CE level of 0, an NPRACH with a CE level of 1, and an NPRACH with a CE level of 2. For example, the SCS of each NPRACH may be 3.75kHz.

[0118] The RU may send information corresponding to the four uplink signals to the DU. The RU may generate one or more U-plane messages based on the four uplink signals. The RU may send information corresponding to the four uplink signals to the DU via one or more U-plane messages. In order to send information corresponding to the four uplink signals to the DU, the RU may use a fronthaul interface.

[0119] The eAxC ID can be assigned for fronthaul transmission between DU and RU. In an actual operating cell, an eAxC ID can be assigned for each antenna, each layer, or each channel type. The transmission corresponding to one OFDM symbol requires sending and receiving multiple packets. In NB (narrowband)-IoT (Internet of Everything) or multi-band PRACH operating cells, each band, NPUSCH (narrowband physical uplink shared channel) and NPRACH (narrowband PRACH) are distinguished by eAxC ID. Figure 5 In , each block represents a segment with a different eAxC ID. Therefore, a total of eight channels are operated for each receive antenna. Figure 5 The number of packets required to transmit the uplink signal to the DU is shown to be 32.

[0120] The increase in the number of packets sent and received per unit time significantly affects the processing load. If the load of packet processing in a DU or RU increases, a large amount of hardware resources is required, so the cost of the corresponding product increases. In a virtualized DU, the number of cells that can be processed in a given hardware resource is reduced.

[0121] Figure 6 FIG. 4 shows a combined user plane message according to an embodiment of the present disclosure. Figure 6 , describes the Figure 5 The method of combining uplink signals into less than 32 packets is shown in FIG. Figure 6 In the embodiment, packet transmission using jumbo frames is described as an example. The RU can generate Ethernet packets so that the size of the maximum transmission unit (MTU) does not exceed 9000 bytes. However, jumbo frames are only examples for describing embodiments of the present disclosure and are not to be construed as limiting the embodiments of the present disclosure thereto.

[0122] refer to Figure 6 , since the transmit / receive window is different for each SCS, merging can be performed based on the same SCS. Specifically, the number of slots in a subframe and the SCS vary according to the parameter set, and therefore, the number of slots (e.g., slotId) (or SCS) used for one U-plane message is generally defined. Therefore, uplink packets (i.e., U-plane messages) sent through the fronthaul interface can be distinguished according to the SCS.

[0123] exist Figure 5 In the example shown, the number of packets required according to 15kHz is 8. In addition, the number of packets required according to 1.25kHz is 8. In addition, the number of packets required according to 3.75kHz is 16. In the current 3GPP standard, for example, the maximum transmittable capacity per unit time (e.g., per OFDM symbol) of PUSCH (or PUCCH) is 2,858 bytes. In the frequency domain with 1.25kHz SCS, the maximum transmittable capacity per unit time of PRACH is 2,046 bytes. In addition, the maximum transmittable capacity per unit time of NPUSCH of the guard band type with 3.75kHz SCS is 170 bytes. In addition, the maximum transmittable capacity per unit time of NPUSCH of the in-band type with 15kHz SCS is 86 bytes.

[0124] The RU can divide the uplink data of each SCS based on 9000 bytes so that the size of the MTU does not exceed the 9000 bytes. For example, the total size of the data corresponding to 3.75kHz of the SCS is 2720 (= 16 × 170) bytes. The data corresponding to the SCS of 3.75kHz can be carried by a packet with a size of 9000 bytes. For example, the total size of the data corresponding to 15kHz of the SCS is 11776 (= 4x86 + 4x2858) bytes. The data corresponding to the SCS of 3.75kHz can be carried by two packets. One packet can provide a maximum size of 9000 bytes. For example, data corresponding to 5888 (= 2×86 + 2×2858) bytes can be carried for each packet. For example, the total size of the data corresponding to the SCS of 1.25kHz is 16368 (= 8x2046) bytes. The data corresponding to the SCS of 1.25kHz can be carried by two packets. One packet can provide a maximum size of 9000 bytes. For example, data corresponding to 8184 (=4*2046) bytes may be carried for each packet.

[0125] Compare Figure 5 and Figure 6 , although the same size of information is sent, the number of Ethernet packets sent over the fronthaul interface is reduced from 32 to 5. Instead of sending data with different eAxC IDs in separate U-plane messages, resources of the fronthaul interface can be saved by merging U-plane packets, such as Figure 6 shown.

[0126] As described above, in order to reduce the load on message processing (hereinafter, referred to as "message processing load") and ensure sufficient resources for the fronthaul interface, an embodiment of the present disclosure proposes a method for merging U-plane data with different eAxC IDs into one packet. By merging U-plane data with different eAxC IDs into a single packet, the number of packets in the fronthaul interface can be reduced. At the same time, in order to reduce the number of C-plane packets, a scheme for merging C-plane segments with different eAxC IDs into a single segment has been proposed through the segment confirmation information in the O-RAN WG 4 standard (e.g., segment extension type = 10). Therefore, in the present disclosure, segment extension information for merging U-plane packets, as well as DU operations and RU operations related to the segment extension information will be described, which are different from the existing segment extension information for merging C-plane packets.

[0127] Figure 7 FIG. 4 shows signaling between DU and RU for combining user plane (U-plane) messages according to an embodiment of the present disclosure. Figure 2aAccording to an embodiment of the present disclosure, the DU 210 may include an O-DU 251. Figure 2a According to an embodiment of the present disclosure, the RU 220 may include an O-RU 253.

[0128] refer to Figure 7 In operation S701, the DU may perform group configuration. The fronthaul interface between the DU and the RU may include multiple ports. For example, each port may correspond to a layer or a Tx / Rx path. According to an embodiment of the present disclosure, each port may correspond to an eAxC ID. The group configuration may include a grouping operation of the eAxC ports. The group configuration may include specifying a representative port of a group of eAxC ports. The group configuration may include specifying a member port of a group of eAxC ports.

[0129] In operation S703, the DU may send a management plane (M-plane) message to the RU. The DU may generate the M-plane message based on the group configuration in operation S701. The M-plane message may include the result of the group configuration in operation S701. The RU may receive the M-plane message from the DU. The RU may identify the group configuration based on the M-plane message.

[0130] According to an embodiment of the present disclosure, an M-plane message may include port group information for transmission. The port group information for transmission may indicate a representative port of the group. The M-plane message may include information for indicating a representative port of the group. For example, the M-plane message may include information for indicating a representative eAxC port. The port group information for transmission may indicate one or more member ports of the group. The M-plane message may include information for indicating one or more member ports of the group. For example, the M-plane message may include information for indicating a member eAxC port.

[0131] According to an embodiment of the present disclosure, the M-plane message may include port group information for receiving. The port group information for receiving may indicate a representative port of the group. The M-plane message may include information for indicating a representative port of the group. For example, the M-plane message may include information for indicating a representative eAxC port. The port group information for receiving may indicate one or more member ports of the group. The M-plane message may include information for indicating one or more member ports of the group. For example, the M-plane message may include information for indicating a member eAxC port.

[0132] According to an embodiment of the present disclosure, the M-plane message may include capability information related to the group. According to an embodiment of the present disclosure, the M-plane message may include information for indicating the maximum number of groups for transmission. According to an embodiment of the present disclosure, the M-plane message may include information for indicating the maximum number of ports per group for transmission. According to an embodiment of the present disclosure, the M-plane message may include information for indicating the maximum number of groups for reception. According to an embodiment of the present disclosure, the M-plane message may include information for indicating the maximum number of ports per group for reception.

[0133] For example, the M-plane message may be configured as shown in Table 1 below.

[0134] [Table 1]

[0135]

[0136] 'rw max-num-tx-exac-id-groups? ' indicates the maximum number of groups for transmission. 'rw max-num-tx-exac-ids-per-groups? ' indicates the maximum number of ports per group for transmission. 'rw max-num-rx-exac-id-groups? ' indicates the maximum number of groups for reception. 'rw max-num-rx-exac-ids-per-groups? ' indicates the maximum number of ports per group for reception. 'rwtx-exac-id group*[representative-tx-eaxc-id]' indicates the port group information for transmission. 'rw presentative-tx-exac-id unit16' indicates the eAxC ID pointing to the representative port of the port group for transmission. 'rw member-tx-exac-id*unit 16' indicates the eAxC ID pointing to the member port of the port group for transmission. 'rwrx-exac-id group*[representative-rx-eaxc-id]' indicates the port group information for reception. 'rw presentative-rx-exac-id unit16' indicates the eAxC ID pointing to the representative port of the port group for reception. 'rw member-rx-exac-id*unit16' indicates the eAxC ID pointing to the member port of the port group for reception. The M-plane message may include at least some of the components set forth in Table 1. In operation S705, the DU may send a C-plane message for merging user plane (U-plane) segments of multiple ports. The C-plane message may include segment information. The segment information, which is layer-specific information, may include information about resources allocated in a time slot (e.g., 14 symbols). In the C-plane and U-plane, the term "segment" may refer to an area to which resources are allocated. For example, in a resource grid represented as time-frequency resources, one segment may indicate a resource allocation region for N RBs in the frequency domain (e.g., N is 1 to 273 according to the current NR standard) and M symbols in the time domain (e.g., M is 1 to 14 according to the current NR standard). In other words, the segment information may include resource allocation information for communication between the RU and the terminal.

[0137] In some embodiments of the present disclosure, the C-plane message may include beam information. Beam information, which is beam information for each segment and / or each layer, may indicate a beam pattern to be applied to U-plane data. Beam information related to a scheme for pointing a beam may include parameters directly pointing to a weight vector (or a weight matrix according to an embodiment) applied to form a beam, a predefined weight vector, or an indicator (e.g., beam ID, precoding indicator) indicating the resource to which a particular beam is applied. Beamforming may include digital beamforming, analog beamforming, or hybrid beamforming (i.e., digital beamforming and analog beamforming).

[0138] According to an embodiment of the present disclosure, a C-plane message can be used to merge user plane (U-plane) segments of multiple ports. In addition to segment information related to resource allocation, the C-plane message may also include information indicating that the U-plane message is combined according to resource allocation. Depending on the C-plane message, in order to reduce the number of U-plane packets sent or received, U-plane segments with different eAxC IDs can be merged into one U-plane segment. For example, except for the beam ID or UE ID, the segment information about multiple ports (ie, layers or Tx / Rx paths) can be the same. When two or more ports share common segment information in an RU, the U-plane segments to be sent through each port can be merged into the U-plane segments through the specified port.

[0139] According to an embodiment of the present disclosure, the segment extension information of the C-plane message may indicate a combination of U-plane messages. In order to send U-plane segments with different eAxC IDs through one packet, the segment extension information may be added to the segment protocol of the C-plane message including the scheduling of one packet. The segment extension information may include type information, length information, and beam group type information, such as an extension field for merging C-plane segments. The type information may indicate the merging of U-plane segments with different eAxC IDs. The length information indicates the length of the segment extension information. The beam group type information indicates a scheduling scheme of beam IDs in the C-plane.

[0140] According to an embodiment of the present disclosure, the number of segment extension information of the C-plane message may be determined based on the segment extension type (SET) 10 of the current O-RAN standard. For example, in order to load U-plane segments with different eAxC IDs into a single packet, a set 74 may be added to the segment protocol of the C-plane message. The type information may be configured with 7 bits. A bit string '100 101 0' in which only one bit is changed in a bit string '000101 0' corresponding to an existing set 10 may be used to merge U-plane segments.

[0141] According to an embodiment of the present disclosure, the processing operation of set 10 in the RU may be the same as the processing operation of set 74 in the RU. In other words, except for the type information, the segment extension information according to set 74 may be the same as the segment extension information according to set 10. A change of one bit may provide a small amount of overhead without violating the O-RAN standard in terms of implementation. A change of one bit may provide backward compatibility in terms of standards, and the RU may perform user plane merging with minimal operations. Although set 74 has been described as an example of segment extension information of a similar type with minimal bits, other examples may be used. As another example, the type information of the segment extension information for merging U-plane segments may indicate 42 corresponding to '010 1010'. As another example, the type information of the segment extension information for merging U-plane segments may indicate 26 corresponding to '001 1010'. A change of one bit indicates the merging of U-plane segments instead of the merging of C-plane segments. However, the numbering of the segment extension information is an additional embodiment of the present disclosure, and it goes without saying that a different numbering (e.g., set 22) may be simply used.

[0142] In operation S707, the RU may perform user plane merging. The RU may perform an operation for merging a plurality of U-plane segments into one U-plane segment. The RU may generate one U-plane message by combining U-plane messages. The one U-plane message may be referred to as an integrated U-plane message, a combined U-plane message, a combined U-plane message, or any term having a technical meaning equivalent thereto. Reference will be made to the description to be made later. Figure 8 User plane merging of RUs is described in more detail.

[0143] exist Figure 7 In the embodiment of the present disclosure, the user plane merging in the uplink is mainly described as an example, but the embodiments of the present disclosure are not limited thereto. The user plane merging according to the embodiments of the present disclosure can also be applied to downlink packets. According to the embodiments of the present disclosure, the DU can send multiple IQ sampling data to the RU through one U-plane message. Each of the multiple IQ sampling data can correspond to one port, that is, eAxC ID.

[0144] although Figure 7 It is shown that the DU performs group configuration, but the embodiments of the present disclosure are not limited thereto. According to an embodiment of the present disclosure, the group configuration of the DU may be manually set by an operator or obtained from another node.

[0145] exist Figure 7In, the M-plane message for group configuration has been described. According to an embodiment of the present disclosure, the group configuration through the M-plane message can be used for the merging of C-plane segments and the merging mode of U-plane segments. That is, for the user plane merging in operation S707, no additional configuration may be defined in the M-plane. The RU may perform the merging of U-plane segments based on the group configuration for merging C-plane segments. The RU may perform the merging of U-plane segments according to set 74 based on the group configuration of the eAxC ID according to set 10. For example, the M-plane message may be referenced in Table 1. According to another embodiment of the present disclosure, the M-plane message may independently include a group configuration for multiple ports in the C-plane and a group configuration for multiple ports in the U-plane.

[0146] Figure 8 FIG. 2 shows the transmission of U-plane messages using representative ports according to an embodiment of the present disclosure. Figure 8 The conditions for sending a U-plane message combined with an uplink signal from the RU to the DU are described.

[0147] refer to Figure 8 , RU 220 may acquire uplink signals corresponding to multiple eAxCs. If user plane merging according to an embodiment of the present disclosure is not performed, RU 220 may send a U-plane message for each eAxC ID to DU 210. A processing unit of RU 220 (e.g., a CPU of a C-plane) may send a U-plane message to DU 210 through an eAxC corresponding to each layer. RU 220 may send a total of N U-plane messages to DU 210. For example, a U-plane message corresponding to eAxC#1 may include IQ sample data #1. The U-plane message corresponding to eAxC#1 may be sent from RU 220 to DU 210 through segment layer #1 810-1. For example, a U-plane message corresponding to eAxC#2 may include IQ sample data #2. The U-plane message corresponding to eAxC#2 may be sent from RU 220 to DU 210 through segment layer #2 810-2. For example, a U-plane message corresponding to eAxC#3 may include IQ sample data #3. The U-plane message corresponding to eAxC#3 may be sent from RU 220 to DU 210 through segment layer #3 810-3. For example, a U-plane message corresponding to eAxC#N may include IQ sample data #N. The U-plane message corresponding to eAxC#N may be sent from RU 220 to DU 210 through segment layer #N 810-N.

[0148] At least some of the U-plane messages sent through each layer may include the same payload. According to an embodiment of the present disclosure, U-plane messages sent in the same segment (e.g., RB) may include the same segment information. According to an embodiment of the present disclosure, U-plane messages with the same parameter set may include the same segment information. Therefore, if information sharing is possible for multiple eAxCs, the reception of the same information by RU 220 may act as an overhead due to its duplication. According to an embodiment of the present disclosure, RU 220 may perform user plane merging. RU 220 may combine N U-plane messages of a total of N layers. RU 220 may generate one U-plane message by combining N U-plane messages. RU 220 may identify layer 820 for sending one U-plane message. DU 210 may receive one U-plane message through layer 820.

[0149] exist Figure 8 In the above, it has been described that the RU sends one integrated U-plane message to the DU by combining U-plane messages in the uplink, but the embodiments of the present disclosure are not limited to this. In the downlink, the DU can combine downlink services corresponding to the eAxC ID. The DU can generate one U-plane message including IQ sample data corresponding to each eAxC ID. The DU can send one U-plane message to the RU.

[0150] Fig. 9 An example 900 of a control plane (C-plane) message for combining a user plane (U-plane) message according to an embodiment of the present disclosure is shown. For example, the segment type of the segment provided by the C-plane message can be 1, 3, or 5. The selected type of C-plane message (e.g., segment type 1, 3, and 5) can carry a data segment description that conveys information applicable to the data segment included in the U-plane message.

[0151] refer to Fig. 9 , the C-plane message may include transport header (e.g., eCPRI header or IEEE 1914.3) information, common header information 910, section information 920, and section extension information 930. As described above, the transport header may include "eCPRI Version (ecpriVersion)", "eCPRI Reserved (ecpriReserved)", "eCPRI Concatenation (ecpriConcatenation)", "eCPRI Message (ecpriMessage)", "eCPRI Payload (ecpriPayload)", "eCPRI RTCID / ecpriPcid" and "ecpriSeqid".

[0152] The common header information 910 may include "dataDirection" indicating the data transmission direction of the base station (e.g., gNB), "payloadVersion" indicating the effective payload protocol version of the IE in the application layer, and "filterindex" meaning the index of the channel filter between the IQ data and the air interface.

[0153] The common header information 910 may include information for indicating the location of the time resource to which the message applies. The location of the time resource may be indicated by a frame, a subframe, a time slot, or a symbol. The common header information 910 may include a "frameId" indicating a frame number, a "subframeId" indicating a subframe number, a "slotId" indicating a time slot number, and a "startSymblId" indicating a symbol number. The frame is determined based on a 256 modulo operation. The subframe has a unit of 1 ms included in a 10 ms frame. The time slot number is numbered within the subframe, and its maximum size may be 1, 2, 4, 8, or 16 depending on the parameter set.

[0154] The common header information 910 may include a "numberOfsections" indicating the number of data sections included in the C-plane message. The common header information 910 may include a "section type (sectionType)" for determining the characteristics of the U-plane data. The common header information 910 may include a "timeoffset" defining an offset from the start of a time slot to the start of a cyclic prefix (CP) as the number of samples (e.g., Ts=1 / 30.72MHz (megahertz)), a "frameStructure" for indicating a frame structure defining an FFT (Fast Fourier Transform) size and an SCS, and a "cpLength" defining the length of the CP as the number of samples (e.g., Ts=1 / 30.72MHz (megahertz)). According to an embodiment of the present disclosure, the "sectionType" of the common header information 910 may indicate 1, 3, or 5. However, the section types indicating 1, 3, or 5 are merely examples, and this does not mean that the section extension type information 930 according to an embodiment of the present disclosure cannot be applied to other section types (e.g., 2, 4, 6, 7, ...).

[0155] The segment information 920 as layer-specific information may include information about resources allocated in one time slot (e.g., 14 symbols). In the C-plane and the U-plane, the term "segment" may mean an area to which resources are allocated. For example, in a resource grid represented as time-frequency resources, one segment may indicate a resource allocation area for N RBs in the frequency domain (e.g., N is 1 to 273 according to the current NR standard) and M symbols in the time domain (e.g., M is 1 to 14 according to the current NR standard).

[0156] The segment information 920 may include a "sectionld" which means a segment identifier. When the C-plane and U-plane coupling via "sectionld" is used, the "sectionld" identifies the individual data segment described by the data segment description within the C-plane message. The "sectionld" is intended to map the U-plane data segment to the corresponding C-plane message (and segment type) associated with the data. The segment information 920 may include an "rb" indicating whether to use each RB or every other RB, a "symInc" indicating a symbol number increment command, a "startPrbc" indicating the starting PRB number of the data segment description, a "numPrbc" indicating the number of consecutive PRBs for each data segment description, a "reMask" defining the RE mask in the PRB, a "numSymbol" defining the number of physical random access channel (PRACH) repetitions or the number of symbols to which segment control is applied, an "ef" indicating an extension flag, and a "beamld" defining the beam pattern to be applied to the U-plane data.

[0157] The section extension information 930 may include an 'extType' indicating the type of extension providing additional parameters. The section extension information 930 may include an 'ef' indicating whether there is another extension or whether the current extension field is the last extension. The section extension information 930 may include an 'extLen' providing the length of the section extension in units of 32-bit (or 4-byte) words.

[0158] According to an embodiment of the present disclosure, "extType" may indicate user plane merging. For example, "extType" may indicate a bit string "100 1010". The bit string "100 1010" may indicate 74 (= 0x4A). As another example, "extType" may indicate a bit string '010 1010'. As yet another example, "extType" may indicate a bit string "001 1010".

[0159] According to an embodiment of the present disclosure, the section extension information 930 may also include control information for combining layers of U-plane messages. For example, the section extension information 930 may be defined as shown in Table 2 below.

[0160] [Table 2]

[0161]

[0162] According to an embodiment of the present disclosure, the 'beamGroupType' field may be added as a payload in an extension field. For example, a 'beamGroupType' field having 2 bits may be configured to indicate a scheduling scheme of a beamId (beam ID) in a C-plane message. The 'beamGroupType' field may refer to 00b or 01b. The 'numPortc' field may indicate the number of eAxC ports (or the number of layers or the number of transmit / receive paths) indicated by the extension field. According to the standard, the 'numPortc' field may indicate the number of eAxC ports up to 64 ports. The 'reserved' field indicates a reserved bit. Although not specified in the standard, the 'reserved' field indicates a reserved bit. Fig. 9 However, according to another embodiment of the present disclosure, the segment extension information 930 may also include control information for each layer. For example, the segment extension information 930 may be defined as shown in Table 3 below.

[0163] [Table 3]

[0164]

[0165]

[0166] The 'xth port beam ID' field indicates the beam information of a separate layer. The 'beam ID' of the first port may be included in the O-RAN header in the C-plane message. The 'beamGroupType' field having 2 bits may be configured to indicate the beamforming scheme applied to each layer in the integrated U-plane message. For example, the 'beamGroupType' field may be configured as shown in Table 4 below. The 'beamGroupType' field may indicate 11b.

[0167] [Table 4]

[0168]

[0169] Meanwhile, the extended fields and respective structures of Tables 2 to 4 are exemplary, and it is apparent that any modifications may be made in a manner apparent to those skilled in the art. The transmission path (or reception path) of each layer may correspond to the eAxC in the eCPRI. The eAxC may refer to a data stream for each antenna of each carrier in a sector. For example, an eAxC may be a unit of a spatially distinguishable signal stream. The RU may identify a representative eAxC for integrated U-plane message transmission. A representative eAxC of N eAxCs (N is an integer of 1 or greater) may be set. According to an embodiment of the present disclosure, the eAxC may be configured according to the embodiment of the present disclosure. Figure 7The representative eAxC is set by using an M-plane message of the service non-real-time OAM domain (ORAN M-plane) interface. The representative eAxC can be pre-assigned to the DU and RU through the service non-real-time OAM domain (ORAN M-plane) interface, and when sending multiple layers, the DU can identify the eAxC specified when sending the control message. According to another embodiment of the present disclosure, the representative eAxC can be set according to a predetermined rule (e.g., the first eAxC). The RU according to an embodiment of the present disclosure can generate a U-plane message to be sent through an identified path (e.g., a representative eAxC). The U-plane message can be an integrated message including IQ sampling data for each layer of the N layers. By configuring the U-plane message to include segment header information for multiple layers instead of including segment header information for a single layer, the overhead within the fronthaul interface can be reduced.

[0170] According to an embodiment of the present disclosure, the RU capability can be used to perform Fig. 9 C-plane messages and related operations for user plane merging. In case the RU capabilities indicate that the RU supports segment extensions for user plane merging, the DU may send a C-plane message including segment extensions for user plane merging to the RU. The DU and RU may be used in conjunction with 'Representative eAxC' ID (M-plane configuration) to reduce the overhead of having several U-plane messages to the overhead of sending a single U-plane message. For example, in the uplink case, the DU receives a single U-plane message from the RU, but it may perform operations as if it had received four U-plane messages.

[0171] Fig.10 FIG. 4 shows a user plane (U-plane) message using a representative port according to an embodiment of the present disclosure. By including segment extension information (e.g., Fig. 9 The RU may load the IQ sample data of the data segment into a U-plane packet by sending a C-plane message of the Segment Extension Information 930 in ...

[0172] refer to Fig.10 , the U-plane message 1000 merged according to the user plane may include a transport header, an application layer header and a segment header information 1010, and individual PRB information 1020, 1021, 1022 and 1023. Fig. 9 Refer to the description of the transport header and the description of the application layer header.

[0173] The segment header information 1010 may include "sectionId" representing a segment identifier, "rb" indicating whether each RB or every other RB is used, "symInc" indicating a symbol number increment command, "startPrbu" indicating the starting PRB number of the U-plane segment, and "numPrbu" indicating the number of consecutive PRBs for each data segment. The values ​​of the parameters (e.g., rb, startPrbu, and numPrbu) of the segment header information 1010 ensure that data segments never overlap. For a given eAxC, only a single PRB may exist within a data segment. In order to describe a segment in a C-plane message, multiple U-plane data segments associated with the segment are required to define the PRBs to which the IQ data included therein can be applied. Typically, a data segment within a U-plane may include a PRB corresponding to a segment description of a C-plane message.

[0174] The segment header information 1010 may include a 'udCompHdr' indicating a compression scheme and an IQ bit width for user data of the data segment. The compression scheme may include no compression, block floating point (BFP), block scaling, μ-law, modulation compression, 'BFP and selective RE transmission', or 'modulation compression and selective RE transmission'. The segment header information 1010 may include a 'udCompLen' that specifies the total number of octets including padding in the PRB field until the end of the current segment. The compression scheme may be set by the M-plane or may be specified in the 'udCompHdr' of the data segment including the PRB. The segment header information 1010 may contain a 'reserved' field, which is a bit reserved for further use.

[0175] The RU may identify a representative eAxC ID and one or more member eAxC IDs based on a group configuration of multiple ports. For example, Fig.10 The group configuration in can be shown in Table 5. Fig.10 Four eAxC ports are shown in FIG. 1 , but the number of ports used for user plane merging may depend on the parameters of the C-plane message (e.g., Fig. 9 The port number varies depending on the port number of the controller.

[0176] [Table 5]

[0177]

[0178] The U-plane message may include PRB information. The PRB information may include IQ sampling data of the eAxC. For example, for the IQ sampling data of four eAxCs, the RU may generate four U-plane messages. The U-plane message for the first eAxC may include segment header information 1010 and first PRB information 1020. The U-plane message for the second eAxC may include segment header information 1010 and second PRB information 1021. The U-plane message for the third eAxC may include segment header information 1010 and third PRB information 1022. The U-plane message for the fourth eAxC may include segment header information 1010 and fourth PRB information 1023. However, sending the same segment header information 1010 three additional times may result in a waste of resources of the fronthaul interface. According to an embodiment of the present disclosure, in response to receiving a segment extension information (e.g., Fig. 9 The RU may perform user plane merging by sending a C-plane message of the segment extension information 930 of the representative eAxC ID. The RU may merge the IQ sample data of the segments with different eAxC IDs. According to an embodiment of the present disclosure, if the header information of the segment of the representative eAxC ID set by the M-plane is the same as the header information of the segment of the member eAxC ID, the RU may subsequently append the IQ sample data corresponding to the member eAxC ID to the IQ sample data corresponding to the representative eAxC ID.

[0179] The RU may add IQ sample data up to 'numPortc' times to facilitate the IQ sample data and PRB information of the representative eAxC ID of the segment header information 1010. The added IQ sample data may include iSample and qSample for each member eAxC ID. The RU may generate an integrated U-plane message in which each PRB information is then sequentially added to the PRB information of the representative eAxC port in order to reduce resource waste in the aforementioned fronthaul interface.

[0180] The first PRB information 1020 may include "udCompParam" to indicate the parameters of the compression scheme used in the PRB corresponding to the representative eAxC port. The first PRB information 1020 may include iSample (in-phase sampling) and qSample (quadrature sampling) of each RE of the PRB corresponding to the representative eAxC port. The second PRB information 1021 may include "udCompParam" to indicate the parameters of the compression scheme used in the PRB corresponding to the first member eAxC port (e.g., eAxC ID#1). The second PRB information 1021 may include iSample (in-phase sampling) and qSample (quadrature sampling) of each RE of the PRB corresponding to the first member eAxC port. The third PRB information 1022 may include "udCompParam" to indicate the parameters of the compression scheme used in the PRB corresponding to the second member eAxC port (e.g., eAxC ID#2). The third PRB information 1022 may include iSample (in-phase sampling) and qSample (quadrature sampling) of each RE of the PRB corresponding to the second member eAxC port. The fourth PRB information 1023 may include "udCompParam" to indicate the parameters of the compression scheme used in the PRB corresponding to the third member eAxC port (e.g., eAxC ID#3). The fourth PRB information 1023 may include iSample (in-phase sampling) and qSample (quadrature sampling) of each RE of the PRB corresponding to the third member eAxC port.

[0181] According to an embodiment of the present disclosure, an M-plane message may be used to set an eAxC ID port for a user plane combination. The group configuration of the M-plane message may include a representative eAxC ID for a user plane combination and one or more member eAxCIDs. According to an embodiment of the present disclosure, the group configuration of the M-plane message may be used for both the combination of C-plane messages and the combination of U-plane messages. In other words, a group configuration of multiple ports for combining C-plane messages may be shared for merging U-plane messages. Using a single group configuration, the combination of C-plane messages and the combination of U-plane messages may be performed. According to another embodiment of the present disclosure, a group configuration of multiple ports for combining U-plane messages may be set independently of the group configuration of multiple ports for combining U-plane messages. For example, the representative eAxC ID for combining U-plane messages and the representative eAxC ID for combining C-plane messages may be different from each other.

[0182] According to an embodiment of the present disclosure, the C-plane message may include segment extension information for indicating the combination of the U-plane message. The segment extension type indicator (eg, Fig. 9 "extType" in the segment extension information) may indicate a combination of U-plane messages. According to an embodiment of the present disclosure, the segment extension information may indicate a combination of U-plane messages separately from a combination of C-plane messages. The RU may recognize a combination of U-plane messages (for example, in the case of DL), or may perform a combination of U-plane messages (for example, in the case of UL). In this context, the combination of C-plane messages may be configured by separate segment extension information (for example, set = 10). Alternatively, in this case, the C-plane messages may be sent from the DU to the RU separately without combining the C-plane messages.

[0183] According to another embodiment of the present disclosure, segment extension information may indicate a combination of U-plane messages and a combination of C-plane messages. One segment extension information may be used to set both a combination of C-plane messages and a combination of U-plane messages of the RU. Based on one segment extension information, the RU may receive a C-plane message combined with a C-plane segment, and send a U-plane message combined with a U-plane segment to the DU. Parameters of the segment extension information, such as "extLen", "numPortc", and "beamGroupType", may be shared between a combination of C-plane messages (hereinafter referred to as "control plane merging") and a combination of U-plane messages (hereinafter referred to as "user plane merging").

[0184] According to another embodiment of the present disclosure, the segment extension information may indicate the combination of the U-plane message through some reserved bits of the segment extension information used to combine the C-plane message. For example, the segment type of the C-plane message may indicate '000 1010', and at least some of the 'reserved' bits (e.g., see Table 2 or Table 3) may indicate the combination of the U-plane message. For example, the value of the 'reserved' bit at a specified position (e.g., the 'reserved' bit of octet N+3) may indicate whether the U-plane message is combined. For another example, the value of the 'reserved' bit included in the octet of the beam ID of each eAxC ID may indicate whether it is used for the user plane combination of the corresponding eAxC ID.

[0185] When a large number of C-plane messages and U-plane messages are required due to a large number of eAxC ID branches, such as in the operation of CAT-ALTE NB-IOT cells, the problem that the amount of message processing load is not reduced enough to cope with many cells may occur. In particular, in the case of C-plane messages with a set = 10 defined in the current standard, only the number of C-plane sections is reduced, and therefore, the amount of message processing load is still high. Therefore, the user plane merging according to an embodiment of the present disclosure has proposed a method for reducing the number of U-plane messages.

[0186] The user plane merging according to the embodiment of the present disclosure makes it possible to reduce the load of message processing by merging U-plane messages between different eAxC ports within the size limit of the C-plane message of the scheduling data segment. Specifically, it makes it possible to merge NB-IoT cells or segment resources to improve the resource efficiency of the fronthaul interface, thereby ensuring the processing resources required to expand the number of cells or perform other functions in DU and RU.

[0187] In addition to using a combination of C-plane messages of the related art, a combination of corresponding U-plane messages is also used, which can significantly and quickly reduce the load of message processing in the DU and RU. In actual O-RAN cell operation, the effect of the reduced message processing load according to an embodiment of the present disclosure can be maximized in an environment with many segments of eAxC IDs, segments, and messages (e.g., NB-IoT, enhanced machine type communication (eMTC), or hybrid parameter sets).

[0188] According to an embodiment of the present disclosure, a method performed by a distributed unit (DU) includes: sending a management message to a radio unit (RU) through a fronthaul interface, the management message including information for indicating a representative extended antenna carrier (eAxC) port. The method includes sending a control plane message to the RU through the fronthaul interface, the control plane message including segment information and segment extension information for resource allocation. The segment extension information can be used to combine multiple user plane (U-plane) messages into one U-plane message in the DU or RU. The representative eAxC port of the fronthaul interface can be used to send or receive the combined one U-plane message.

[0189] According to an embodiment of the present disclosure, the segment extension information includes type information for indicating the merging of user plane data, beam group type information for indicating the type of beam grouping, and port information for indicating the total number of one or more eAxC ports. One U-plane message includes downlink (DL) data or uplink (UL) data corresponding to the eAxC port and each of the one or more eAxC ports.

[0190] According to an embodiment of the present disclosure, for each of the multiple eAxC ports for combination, one U-plane message includes a user data compression parameter for indicating a compression scheme in a physical resource block (PRB), an in-phase sample (isample) value of each resource element (RE) of the PRB, and an orthogonal sample (qsample) value of each resource element (RE) of the PRB.

[0191] According to an embodiment of the present disclosure, the method further includes receiving a U-plane message from the RU through a representative eAxC port of the fronthaul interface.

[0192] According to an embodiment of the present disclosure, the segment extension information and other segment extension information can be used to combine multiple control plane (C-plane) messages into one C-plane message. The one C-plane message can be sent to the RU through the representative eAxC port of the fronthaul interface.

[0193] According to an embodiment of the present disclosure, a method performed by a radio unit (RU) includes: receiving a management message from a distributed unit (DU) through a fronthaul interface, the management message including information for indicating a representative extended antenna carrier (eAxC) port. The method includes: receiving a control plane (C-plane) message from the DU through the fronthaul interface, the control plane message including segment information and segment extension information for resource allocation. The segment extension information can be used to combine multiple user plane (U-plane) messages into one U-plane message in the DU or RU. The representative eAxC port of the fronthaul interface can be used to send or receive the combined one U-plane message.

[0194] According to an embodiment of the present disclosure, the segment extension information includes type information for indicating the merging of user plane data, beam group type information for indicating the type of beam grouping, and port information for indicating the total number of one or more eAxC ports. One U-plane message includes downlink (DL) data or uplink (UL) data corresponding to the eAxC port and each of the one or more eAxC ports.

[0195] According to an embodiment of the present disclosure, for each of the multiple eAxC ports for combination, one U-plane message includes a user data compression parameter for indicating a compression scheme in a physical resource block (PRB), an in-phase sample (isample) value of each resource element (RE) of the PRB, and an orthogonal sample (qsample) value of each resource element (RE) of the PRB.

[0196] According to an embodiment of the present disclosure, the method further includes sending a U-plane message to the DU through a representative eAxC port of the fronthaul interface.

[0197] According to an embodiment of the present disclosure, the segment extension information and other segment extension information may be used to combine multiple control plane (C-plane) messages into one C-plane message. One C-plane message may be received from the DU via a representative eAxC port of the fronthaul interface.

[0198] According to an embodiment of the present disclosure, an electronic device of a distributed unit (DU) includes at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor is configured to control the at least one transceiver to send a management message to a radio unit (RU) through a fronthaul interface, and the management message includes information for indicating a representative extended antenna carrier (eAxC) port. The at least one processor is configured to control the at least one transceiver to send a control plane message to the RU through the fronthaul interface, and the control plane message includes segment information and segment extension information for resource allocation. The segment extension information can be used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU. The representative eAxC port of the fronthaul interface can be used to send or receive a combined U-plane message.

[0199] According to an embodiment of the present disclosure, the segment extension information includes type information for indicating the merging of user plane data, beam group type information for indicating the type of beam grouping, and port information for indicating the total number of one or more eAxC ports. One U-plane message includes downlink (DL) data or uplink (UL) data corresponding to the eAxC port and each of the one or more eAxC ports.

[0200] According to an embodiment of the present disclosure, for each of the multiple eAxC ports for combination, one U-plane message includes a user data compression parameter for indicating a compression scheme in a physical resource block (PRB), an in-phase sample (isample) value of each resource element (RE) of the PRB, and an orthogonal sample (qsample) value of each resource element (RE) of the PRB.

[0201] According to an embodiment of the present disclosure, at least one processor is further configured to control at least one transceiver to receive a U-plane message from the RU through a representative eAxC port of the fronthaul interface.

[0202] According to an embodiment of the present disclosure, the segment extension information and other segment extension information can be used to combine multiple control plane (C-plane) messages into one C-plane message. The one C-plane message can be sent to the RU through the representative eAxC port of the fronthaul interface.

[0203] According to an embodiment of the present disclosure, an electronic device of a radio unit (RU) includes at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor is configured to control the at least one transceiver to receive a management message from a distributed unit (DU) through a fronthaul interface, and the management message includes information for indicating a representative extended antenna carrier (eAxC) port. The at least one processor is configured to control the at least one transceiver to receive a control plane message from the DU through the fronthaul interface, and the control plane message includes segment information and segment extension information for resource allocation. The segment extension information can be used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU. The representative eAxC port of the fronthaul interface can be used to send or receive a combined U-plane message.

[0204] According to an embodiment of the present disclosure, the segment extension information includes type information for indicating the merging of user plane data, beam group type information for indicating the type of beam grouping, and port information for indicating the total number of one or more eAxC ports. One U-plane message includes downlink (DL) data or uplink (UL) data corresponding to the eAxC port and each of the one or more eAxC ports.

[0205] According to an embodiment of the present disclosure, for each of the multiple eAxC ports for combination, one U-plane message includes a user data compression parameter for indicating a compression scheme in a physical resource block (PRB), an in-phase sample (isample) value of each resource element (RE) of the PRB, and an orthogonal sample (qsample) value of each resource element (RE) of the PRB.

[0206] According to an embodiment of the present disclosure, the at least one processor is further configured to control the at least one transceiver to send the one U-plane message to the DU through a representative eAxC port of the fronthaul interface.

[0207] According to an embodiment of the present disclosure, the segment extension information and other segment extension information may be used to combine multiple control plane (C-plane) messages into one C-plane message. One C-plane message may be received from the DU via a representative eAxC port of the fronthaul interface.

[0208] According to an embodiment of the present disclosure, at least one non-transitory computer-readable recording medium is provided. The at least one non-transitory computer-readable recording medium includes instructions that cause at least one processor to send a management message to a radio unit (RU) through a fronthaul interface, the management message including information for indicating a representative extended antenna carrier (eAxC) port, and to send a control plane message to the RU through the fronthaul interface, the control plane message including segment information and segment extension information for resource allocation. The segment extension information is used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU. The representative eAxC port of the fronthaul interface is used to send or receive a combined U-plane message.

[0209] According to an embodiment of the present disclosure, at least one non-transitory computer-readable recording medium is provided. The at least one non-transitory computer-readable recording medium includes instructions that cause at least one processor to receive a management message from a distributed unit (DU) through a fronthaul interface, the management message including information for indicating a representative extended antenna carrier (eAxC) port, and receive a control plane message from the DU through the fronthaul interface, the control plane message including segment information and segment extension information for resource allocation. The segment extension information is used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU. The representative eAxC port of the fronthaul interface is used to send or receive a combined U-plane message.

[0210] The methods according to various embodiments described in the claims and / or the specification of the present disclosure may be implemented in hardware, software, or a combination of hardware and software.

[0211] When implemented by software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in such a computer-readable storage medium are configured to be executed by one or more processors in an electronic device. One or more programs include instructions that cause the electronic device to perform the method according to the embodiments described in the claims or description of the present disclosure.

[0212] Such a program (e.g., software module, software) may be stored in a random access memory, a non-volatile memory including flash memory, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic disk storage device, a compact disk-ROM (CD-ROM), a digital versatile disk (DVD), other types of optical storage devices, or a magnetic tape cassette. Alternatively, it may be stored in a memory configured with a combination of some or all of the above. In addition, the corresponding component memories may be provided in multiple quantities.

[0213] In addition, the program may be stored in an attachable storage device that can be accessed via a communication network (such as, for example, the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a communication network configured using a combination thereof). Such a storage device can access the apparatus for executing the embodiments of the present disclosure through an external port. In addition, a separate storage device on a communication network can access the apparatus for executing the embodiments of the present disclosure.

[0214] In the above-mentioned specific embodiments of the present disclosure, the components included therein may be expressed in singular or plural form, depending on the specific embodiments proposed. However, for ease of description, such singular or plural expressions may be appropriately selected for the context presented, and the present disclosure is not limited to singular or plural elements. Therefore, an element expressed in plural form may be formed by a singular element, or an element expressed in a singular form may be formed by a plural element.

[0215] While specific embodiments have been described in the detailed description of the present disclosure, it goes without saying that various modifications are possible without departing from the scope of the present disclosure.

Claims

1. A method performed by a distributed unit (DU), the method comprising: sending a management message to a radio unit (RU) via a fronthaul interface, the management message including information indicating a representative extended antenna carrier (eAxC) port; as well as Sending a control plane message to the RU via the fronthaul interface, wherein the control plane message includes segment information and segment extension information for resource allocation, wherein the segment extension information is used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU, and The representative eAxC port of the fronthaul interface is used to send or receive a combined U-plane message.

2. The method according to claim 1, The section extension information includes: Type information for indicating the merging of user plane data; Beam group type information for indicating the type of beam grouping; as well as port information indicating the total number of one or more eAxC ports, and The one U-plane message includes downlink (DL) data or uplink (UL) data corresponding to the eAxC port and each of the one or more eAxC ports.

3. The method of claim 1 , wherein for each eAxC port in the plurality of eAxC ports for the combination, the one U-plane message comprises: User data compression parameter, used to indicate the compression scheme in a physical resource block (PRB); The in-phase sample (isample) value of each resource element (RE) of the PRB; as well as Orthogonal sampling (qsample) values ​​for each resource element (RE) of a PRB.

4. The method according to claim 1, further comprising: The one U-plane message is received from the RU through the representative eAxC port of the fronthaul interface.

5. The method according to claim 1, in, The section extension information and other section extension information are used to combine multiple control plane (C-plane) messages into one C-plane message, and The one C-plane message is sent to the RU through the representative eAxC port of the fronthaul interface.

6. A method performed by a radio unit (RU), the method comprising: receiving a management message from a distributed unit (DU) via a fronthaul interface, the management message including information indicating a representative extended antenna carrier (eAxC) port; as well as receiving a control plane (C-plane) message including segment information and segment extension information for resource allocation from the DU through the fronthaul interface, wherein the segment extension information is used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU, and The representative eAxC port of the fronthaul interface is used to send or receive a combined U-plane message.

7. The method according to claim 6, The section extension information includes: Type information for indicating the merging of user plane data; Beam group type information for indicating the type of beam grouping; as well as port information indicating the total number of one or more eAxC ports, and The one U-plane message includes downlink (DL) data or uplink (UL) data corresponding to the eAxC port and each of the one or more eAxC ports.

8. The method of claim 6, wherein for each eAxC port in the combined plurality of eAxC ports, the one U-plane message comprises: User data compression parameter, used to indicate the compression scheme in a physical resource block (PRB); The in-phase sample (isample) value of each resource element (RE) of the PRB; as well as Orthogonal sampling (qsample) values ​​for each resource element (RE) of a PRB.

9. The method according to claim 6, further comprising: The one U-plane message is sent to the DU through the representative eAxC port of the fronthaul interface.

10. The method according to claim 6, wherein the segment extension information and other segment extension information are used to combine multiple control plane (C-plane) messages into one C-plane message, and The one C-plane message is received from the DU via the representative eAxC port of the fronthaul interface.

11. An electronic device of a distributed unit (DU), the electronic device comprising: at least one transceiver; and at least one processor coupled to the at least one transceiver, wherein the at least one processor is configured to: controlling the at least one transceiver to send a management message to a radio unit (RU) through a fronthaul interface, the management message including information for indicating a representative extended antenna carrier (eAxC) port, and controlling the at least one transceiver to send a control plane message to the RU through the fronthaul interface, wherein the control plane message includes segment information and segment extension information for resource allocation, wherein the segment extension information is used to combine multiple user plane (U-plane) messages into one U-plane message in a DU or RU, and The representative eAxC port of the fronthaul interface is used to send or receive a combined U-plane message.

12. The electronic device according to claim 11, The section extension information includes: Type information for indicating the merging of user plane data; Beam group type information for indicating the type of beam grouping; as well as port information indicating the total number of one or more eAxC ports, and The one U-plane message includes downlink (DL) data or uplink (UL) data corresponding to the eAxC port and each of the one or more eAxC ports.

13. The electronic device of claim 11, wherein for each eAxC port in the plurality of eAxC ports for the combination, the one U-plane message comprises: User data compression parameter, used to indicate the compression scheme in a physical resource block (PRB); The in-phase sample (isample) value of each resource element (RE) of the PRB; as well as Orthogonal sampling (qsample) values ​​for each resource element (RE) of a PRB.

14. The electronic device of claim 11, wherein the at least one processor is further configured to control the at least one transceiver to receive the one U-plane message from the RU through the representative eAxC port of the fronthaul interface.

15. The electronic device according to claim 11, wherein the segment extension information and other segment extension information are used to combine multiple control plane (C-plane) messages into one C-plane message, and The one C-plane message is sent to the RU through the representative eAxC port of the fronthaul interface.

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