Coupling method for O-RAN shared cell configuration

Abstract

The present invention discloses a method for operating a node device in an O-RAN (Open Radio Access Network), the method including the steps of receiving a message related to a user plane from at least one south-node device, and determining, based on the message, a timing of an operation to combine messages on an extended antenna carrier (eAxC) basis.

Description

[Technical Field]

[0001] The present invention relates to wireless communication including a combining method for a shared cell configuration of an O-RAN (Open Radio Access Network). [Background technology]

[0002] The O-RAN Alliance has released specifications that define the architecture for implementing next-generation RAN (Radio Access Network) infrastructure. 'O-RAN' stands for Open RAN, and the O-RAN architecture uses 'O-DU (O-RAN Distributed Unit)' and 'O-RU (O-RAN Remote Unit)'. Each O-DU implements Layer 2 and upper Layer 1 functions for the air interface used when communicating wirelessly with user equipment, and each O-RU implements lower Layer 1 functions for the air interface. Each O-DU and O-RU are communicatively connected via a fronthaul link.

[0003] The O-RAN Alliance has published specifications that define an open fronthaul interface for communication between the O-DU and O-RU via the fronthaul. For example, the O-RAN Fronthaul Working Group 4 provides the "Control, User and Synchronization Plane Specification," which specifies the functional split used between the functions implemented in the O-DU and O-RU.

[0004] Early versions of the O-RAN specifications only specified a point-to-point configuration in which each O-DU is paired with one O-RU to serve one physical cell, and individual O-RAN fronthaul interfaces for each O-DU and O-RU pair. However, more recently, O-RAN specifications have been developed that define further configurations that can be used to implement a "shared cell," in which one O-DU is paired with multiple O-RUs to serve one physical cell.

[0005] The recently published O-RAN specifications provide examples of shared cells, including a topology in which one O-DU communicates with multiple O-RUs via a fronthaul including a fronthaul multiplexer (FHM), a topology in which one O-DU communicates with multiple cascaded O-RUs, and a combination of these topologies.

[0006] In a shared cell, the O-RU cascaded with the FHM copies and transmits messages in the downlink direction and combines and transmits messages in the uplink direction. This copying and combining process increases the number of O-RUs that make up the shared cell and the number of carriers supported by the O-RU, and the more complex the FHM-O-RU connection structure becomes, the greater the network congestion of the O-RAN, a package-based network. This is particularly problematic in the uplink direction, where message combining must be performed within limited time resources, causing serious physical constraints when implementing fronthaul.

[0007] Therefore, there is a need for an effective uplink message combining scheme for shared cells. Summary of the Invention [Problem to be solved by the invention]

[0008] The technical problem to be solved by the present invention is to provide a coupling scheme for a shared cell configuration of O-RAN that can effectively use limited time resources.

[0009] The technical problems that the technical idea of ​​the present invention aims to solve are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is disclosed a method for operating a node device in an O-RAN (Open Radio Access Network), the method including the steps of receiving a message related to a user plane from at least one south-node device, and determining, based on the message, a timing of an operation to combine the messages on an extended antenna carrier (eAxC) basis.

[0011] According to an exemplary embodiment, the determining step includes determining whether a final message for the eAxC unit is received from at least one port, and if it is determined that the final message has been received, generating a first combining trigger for the eAxC unit that indicates the timing of an operation to combine the messages.

[0012] According to an exemplary embodiment, the determining step determines whether the eAxC unit messages are continuously received from the at least one port.

[0013] According to an exemplary embodiment, the determining step includes determining whether a first message for the eAxC unit is received from at least one port, and if it is determined that the first message has been received, generating a second combining trigger for the eAxC unit that indicates the timing of an operation to combine the messages.

[0014] According to an exemplary embodiment, the step of generating the second combined trigger includes delaying the timing at which the first message is received by a predetermined time, and then generating the second combined trigger.

[0015] According to an exemplary embodiment, the at least one south node device includes a plurality of south node devices, and the determining step uses a message received from a south node device among the plurality of south node devices that has the longest transmission delay for the node device.

[0016] According to an exemplary embodiment, among the messages, messages of the same eAxC unit are received consecutively.

[0017] According to an exemplary embodiment, the at least one south node device includes a plurality of south node devices, and messages received from each of the plurality of south node devices are received in the same order based on the eAxC unit.

[0018] According to an exemplary embodiment, the method further includes combining the messages in units of eAxCs according to the determined timing, and transmitting the combined messages to a north node device in a combination order.

[0019] According to another aspect of the technical idea of ​​the present invention, there is disclosed an O-RAN node device including at least one processor, wherein the at least one processor is configured to determine, based on user plane related messages received from at least one south node device, a timing of an operation to combine the messages on an eAxC basis.

[0020] According to an exemplary embodiment, the at least one processor is further configured to determine whether a final message for the eAxC unit is received from at least one port, and if it is determined that the final message has been received, to generate a first combine trigger in the eAxC unit that indicates the timing of an operation to combine the messages.

[0021] According to an exemplary embodiment, the at least one processor is further configured to determine whether a final message of the eAxC unit is received based on whether messages of the eAxC unit are received consecutively from the at least one port.

[0022] According to an exemplary embodiment, the at least one processor is further configured to determine whether a first message for the eAxC unit is received from at least one port, and if it is determined that the first message has been received, generate a second combine trigger in the eAxC unit that indicates the timing of an operation to combine the messages.

[0023] According to an exemplary embodiment, the at least one processor is further configured to delay the timing of receipt of the first message by a predetermined time to generate the second combined trigger.

[0024] According to an exemplary embodiment, the at least one south node device includes a plurality of south node devices, and the at least one processor is further configured to determine, in the eAxC unit, a timing of an operation of combining the messages received from a south node device having the longest transmission delay for the node device among the plurality of south node devices.

[0025] According to an exemplary embodiment, among the messages, messages of the same eAxC unit are received consecutively.

[0026] According to an exemplary embodiment, the at least one south node device includes a plurality of south node devices, and messages received from each of the plurality of south node devices are received in the same order based on the eAxC unit.

[0027] According to an exemplary embodiment, the at least one processor may be further configured to combine the messages on an eAxC basis according to the determined timing, and to control transmission of the combined messages to a north node device according to a combining procedure. [Effects of the Invention]

[0028] According to an exemplary embodiment of the present invention, by controlling the combining timing and combining operation of user plane related messages on an extended antenna carrier (eAxC) basis, it is possible to effectively configure and operate a shared cell even under limited fronthaul time resources.

[0029] The effects obtained by the present invention are not limited to those mentioned above, and other effects not mentioned above will be clearly understood by those skilled in the art from the following description. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a conceptual diagram for explaining a shared cell configuration of O-RAN. [Figure 2] 10 is a diagram illustrating a user plane message combining method in a node device constituting a shared cell according to an exemplary embodiment of the present invention; [Figure 3] 1 is a diagram illustrating a frame format of a user-plane message applied to a combining method according to an exemplary embodiment of the present invention; [Figure 4] 1 is a diagram illustrating a node device supporting a bonding scheme and an operation method thereof according to an exemplary embodiment of the present invention; [Figure 5] 1 is a diagram illustrating a node device supporting a bonding scheme and an operation method thereof according to an exemplary embodiment of the present invention; [Figure 6] 1 is a diagram illustrating a node device supporting a bonding scheme and an operation method thereof according to an exemplary embodiment of the present invention; [Figure 7] 1 is a diagram illustrating a node device supporting a bonding scheme and an operation method thereof according to an exemplary embodiment of the present invention; [Figure 8] 1 is a diagram illustrating a node device supporting a bonding scheme and an operation method thereof according to an exemplary embodiment of the present invention; [Figure 9] 1 is a diagram illustrating a node device supporting a bonding scheme and an operation method thereof according to an exemplary embodiment of the present invention; [Figure 10] 1 is a diagram illustrating a node device supporting a bonding scheme and an operation method thereof according to an exemplary embodiment of the present invention; [Figure 11] 1 is a diagram illustrating a node device supporting a bonding scheme and an operation method thereof according to an exemplary embodiment of the present invention; [Figure 12] 10 is a flowchart illustrating an operation method of a node device supporting a bonding scheme according to an exemplary embodiment of the present invention. [Figure 13] 10 is a flowchart illustrating an operation method of a node device supporting a bonding scheme according to an exemplary embodiment of the present invention. [Figure 14] 10 is a flowchart illustrating an operation method of a node device supporting a bonding scheme according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] The terms used in the present invention are merely used to describe specific embodiments and are not intended to limit the scope of other embodiments. A singular expression includes a plural expression unless the context clearly dictates otherwise. Terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those skilled in the art. Terms used in the present invention that are defined in a general dictionary should be interpreted in the same or similar meaning as they have in the context of the related art, and should not be interpreted in an ideal or overly formal sense unless clearly defined in the present invention. In some cases, even terms defined in the present invention should not be interpreted to exclude embodiments of the present invention.

[0032] In the various embodiments of the present invention described below, a hardware approach will be mainly described as an example, but since the various embodiments of the present invention include techniques using both hardware and software, the various embodiments of the present invention do not exclude software-based approaches.

[0033] The various illustrative logic blocks / sections, modules, and circuits, processors described in connection with the present invention may be embodied or implemented by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions disclosed herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be embodied as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other configuration.

[0034] In the following description, terms referring to signals (e.g., message, information, preamble, signal, signaling, sequence, stream), terms referring to resources (e.g., symbol, slot, subframe, radio frame, subcarrier, resource element (RE), resource block (RB), bandwidth part (BWP), occasion), terms for operation states (e.g., step, operation, procedure), terms referring to data (e.g., package, user stream, information, bit, symbol, codeword), terms referring to channels, terms referring to control information (e.g., downlink control information (DCI), medium access control element (MACCE), radio resource control (RRC) signal), terms referring to network entities, terms referring to device components, etc. are provided as examples for convenience of explanation. Therefore, the present invention is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

[0035] Furthermore, in the present invention, expressions such as "more than" or "less than" may be used to determine whether a particular condition is satisfied or fulfilled, but this is merely a description to express one example and does not exclude descriptions such as "more than" or "less than." A condition described as "more than" may be replaced with "more than," a condition described as "less than," and a condition described as "more than and less than" may be replaced with "more than and less than."

[0036] Furthermore, although the present invention will be described in various embodiments using terminology used in some communication standards (e.g., 3GPP (3rd Generation Partnership Project), xRAN (extensible radio access network), and O-RAN (open-radio access network), this is for illustrative purposes only. The various embodiments of the present invention can be easily modified and applied to other communication systems.

[0037] Hereinafter, various embodiments according to the technical concept of the present invention will be described in detail.

[0038] FIG. 1 is a conceptual diagram for explaining a shared cell configuration of O-RAN.

[0039] First, a first shared cell configuration will be described with reference to (a) of FIG. 1. In the first shared cell configuration, an O-DU 10 is paired with a plurality of O-RUs 30 (e.g., O-RU#1 to O-RU#n), and the O-DUs 10 and O-RUs 30 communicate with each other via a fronthaul including an FHM 20. Here, the FHM 20 refers to a node device that is modeled after an O-RU with copy and combine functions in addition to a lower layer split (LLS) fronthaul support function like a general O-RU, but does not have radio transmission and reception functions. The first shared cell configuration is referred to as an FHM mode.

[0040] In the downlink (e.g., the path from the north node to the south node), the O-DU 10 transmits a duplicated version of each control-plane and user-plane message to the FHM 20, which duplicates each control-plane and user-plane message and transmits each duplicated version to each of the multiple O-RUs 20.

[0041] In the uplink (e.g., the path from the south node to the north node), each O-RU 30 transmits a user plane message to the FHM 20, which combines the resource elements (REs) received from the O-RUs 30 and then transmits a single user plane message including the combined REs to the O-DU 10.

[0042] A second shared cell configuration will be described with reference to (b) of FIG. 1. In the second shared cell configuration, an O-DU 10 is paired with multiple O-RUs 30 (e.g., O-RU #1 to O-RU #n), and a cascade topology is applied to implement a fronthaul for intercommunication between the O-DU 10 and the O-RUs 30. The O-DU 10 directly communicates with the first O-RU (e.g., O-RU #1) in the cascade, and each O-RU directly communicates with the previous and subsequent O-RUs in the cascade. The second shared cell configuration is referred to as a cascade mode.

[0043] In the downlink, the O-DU 10 transmits a duplicated version of each control plane and user plane message to the first O-RU (e.g., O-RU #1) of the cascaded O-RUs 30, and each O-RU in the cascade transmits a duplicated version to the next O-RU in the cascade using each message transmitted to it from the previous O-RU.

[0044] In the uplink, the last O-RU (e.g., O-RU #n) of the cascaded O-RUs 30 transmits a user plane message including an RE generated from the received RF signal to the previous O-RU, and each O-RU in the cascade combines the RE included in the user plane message received from the immediately succeeding O-RU with the RE generated from its own received RF signal and transmits it to the previous O-RU in a single user plane message.

[0045] 1(c), the third shared cell configuration is a hybrid configuration of the first and second shared cell configurations, in which the O-DU 10 communicates with multiple O-RUs (O-RU#1 to O-RU#n) via a fronthaul including FHM#1 of the cascaded FHMs 20, and communicates with multiple O-RUs (O-RU#1 to O-RU#m) via a fronthaul including FHM#2 of the cascaded FHMs 20. The third shared cell configuration is referred to as a cascaded FHM mode, and the intercommunication between the O-DU 10, FHMs 20, and O-RUs 30 in the downlink and uplink is substantially the same as that described above with reference to FIGS. 1(a) and 1(b), and therefore detailed description thereof will be omitted.

[0046] As mentioned above, in the first to third shared cell configurations, message duplication and merging are required in the FHM and cascaded O-RU, which are nodes that make up the fronthaul. As a result, as the number of shared cell nodes increases, the interconnection structure between nodes becomes more complex, and as the number of carriers to be supported increases, network congestion in the O-RAN, which is a package-based network, increases significantly, making operation control more difficult and imposing serious physical constraints on network implementation.

[0047] This is particularly problematic in the uplink direction. In conventional combining methods, due to differences in transmission delays caused by the physical and logical locations of nodes, the arrival times of symbol-based messages to be combined at the FHM and cascaded O-RU are not constant, and each node transmits messages related to various resource elements in an arbitrary order, making it difficult to control the combining timing and operation. Furthermore, due to limitations on the allowable fronthaul delay, each node is unable to provide sufficient waiting time and processing time for the symbol-based messages to be combined, making it difficult to handle error situations.

[0048] The technical idea of ​​the present invention is to solve the above-mentioned problems, and proposes a method of using an extended antenna-carrier (eAxC) as a message combining unit related to the user plane in a shared cell configuration, and controlling the timing and operation of message combining in units of the eAxC.

[0049] 2 is a diagram illustrating a user plane message combining method in a node device configuring a shared cell according to an exemplary embodiment of the present invention, and FIG. 3 is a diagram illustrating a frame format of a user plane message applied to the combining method according to an exemplary embodiment of the present invention. For convenience of explanation, FIG. 2 illustrates an example in which the shared cell configuration is implemented in FHM mode, and the FHM 20 receives and combines user plane messages for one antenna port each from the O-RU.

[0050] Referring to FIG. 2, a shared cell configuration according to an exemplary embodiment of the present invention includes an FHM 20, an O-RU#1 30-1, and an O-RU#2 30-2.

[0051] First, O-RU#1 30-1 and O-RU#2 30-2 each include an interface section 31 and a Low-PHY section 33. Although not shown, O-RU#1 30-1 and O-RU#2 30-2 each further include at least one antenna port (and / or antenna) for transmitting and receiving radio signals to and from user equipment (UE) devices, and an RF section (or RF transceiver) for digital conversion of the radio signals. Meanwhile, the terms "...section" and "...device" used below refer to a unit that processes at least one function or operation, and are embodied in hardware, software, or a combination of hardware and software. At least some of the operations or actions of any one section may be performed in another section, or any one section itself may be integrated into another section.

[0052] The Low-PHY section 33 generates IQ data based on a radio signal received via at least one antenna port (antenna) and digitally converted via the RF section.

[0053] The Low-PHY section 33 generates a user plane message according to a fronthaul transport protocol based on the generated IQ data. The transport protocol uses Ethernet and eCPRI, which are easily shared with networks, and the frame format 300 of the message has a structure as shown in FIG.

[0054] 3, the message frame format 300 includes an eCPRI header 310 and an eCPRI payload 330. The eCPRI header 310 includes a message source and destination identifier ecpriPcid, and the O-RAN fronthaul specification defines the eAxC (eAxC ID) 311 by the message source and destination identifier ecpriPcid. The eAxC 311 includes an O-DU port identifier (DU_Port_ID) 3111, a band sector identifier (BandSector_ID) 3113, a component carrier identifier (CC_ID) 3115, and an O-RU port identifier (RU_Port_ID) 3117.

[0055] The Low-PHY section 33 is configured to group IQ data having the same eAxC among the IQ data for each antenna port to generate a message in eAxC units. The eAxC unit message is a single message, but is not limited to this, and may be fragmented into multiple messages.

[0056] The interface section 31 transmits the eAxC-based messages to the FHM 20 via the fronthaul link.

[0057] The interface section 31 continuously transmits messages having the same eAxC among the eAxC-based messages to the FHM 20 .

[0058] Furthermore, the interface section 31 transmits the eAxC messages to the FHM 20 in a predetermined transmission order. Specifically, a transmission order is predetermined for each eAxC, and the interface section 31 transmits the eAxC messages in accordance with the transmission order.

[0059] For example, as shown in Fig. 2, the interface section 31 transmits the eAxC-based messages for a specific antenna port to the FHM 20 in ascending order of eAxC ID numbers (eAxC ID-1, eAxC ID-2, ...). However, without being limited thereto, the interface section 31 may transmit the eAxC-based messages for a specific antenna port to the FHM 20 in descending order of eAxC ID numbers or in a certain pattern order of eAxC ID numbers.

[0060] The transmission order is determined by the O-DU 10 (see FIG. 1) and updated according to the network operation environment / condition, the service provider's request, etc. The transmission order may be updated in real time, but is not limited to this. In addition, the transmission order may be set and updated remotely, but is not limited to this.

[0061] In this way, O-RU#1 30-1 and O-RU# 30-2 each generate eAxC unit messages for at least one antenna port and transmit the eAxC unit messages for the antenna ports to FHM 20 in an equal eAxC unit-based transmission order.

[0062] The FHM 20 includes an interface section 21 , a coupling section 23 and a triggering section 25 .

[0063] First, the triggering section 25 determines the timing of an operation to combine messages in eAxC units (hereinafter, "combining operation timing") based on messages received from at least one of the south nodes, i.e., O-RU#1 30-1 and O-RU#2 30-2. Here, the term "determine" as used above includes various actions. For example, "determine" includes calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, database, or other data structure), and confirming. Also, "determine" includes receiving (e.g., receiving information) and accessing (e.g., accessing data in a memory). Also, "determine" includes resolving, selecting, choosing, establishing, etc.

[0064] In one embodiment, the triggering section 25 determines whether the final message is received for each eAxC unit among the received messages, and determines the timing of the combining operation based on the determination result.

[0065] In another embodiment, the triggering section 25 determines whether the first message is received for each eAxC unit among the received messages, and determines the timing of the combining operation based on the determination result.

[0066] In yet another embodiment, the triggering section 25 determines the timing of the combining operation using the result of the determination of whether the last message or the first message has been received in the eAxC unit, as well as waiting time-related information calculated based on the frame structure applied to the message in the eAxC unit and the timing of the control plane message applied to the eAxC unit.

[0067] On the other hand, when performing the above example, the triggering section 25 can determine the timing of the combining operation without using either the messages received from O-RU#1 30-1 or O-RU#2 30-2, but only using the message received from O-RU#2 30-2, which has the largest transmission delay for FHM 20.

[0068] In FHM 20, since the concept of triggering a combining operation is based on whether a message is received last or first, a message from a south node with the largest transmission delay among multiple south nodes is likely to arrive later than messages from other south nodes, triggering can be controlled based on a specific path in order to prevent further delays by controlling the timing of the combining operation and simplifying the process. Here, a specific south node is used as an example of a comparison target for transmission delay values, but the comparison target is not limited to this, and it goes without saying that a specific antenna port, etc., can be selected as a comparison target.

[0069] The triggering section 25 is described in more detail below with reference to Figures 4 to 11.

[0070] The combining section 23 combines messages on an eAxC basis according to the combining operation timing determined by the triggering section 25. For example, as shown in Fig. 2, messages relating to each antenna port (e.g., port a of O-RU#1, port b of O-RU#2) can be combined in units of eAxC ID-1 and eAxC ID-2. The message combining on an eAxC basis in the combining section 23 refers to combining IQ data samples of corresponding eAxC-based messages as defined in the O-RAN fronthaul specifications, and is a concept that includes compression processing after combining.

[0071] Meanwhile, the combining section 23 generates a message related to the user plane according to the fronthaul transmission protocol based on the IQ data generated by the combining operation. For convenience of explanation, it has been described that the message generation function is performed in the combining section 23, but the message generation function may be implemented by a separate section.

[0072] The interface section 21 transmits the message generated by combining the messages on an eAxC basis to the north node (for example, the O-DU 10 (see FIG. 1)).

[0073] The interface section 21 may transmit the messages to the north node in the order in which the messages were generated, i.e., in the order in which the messages were generated as a result of executing the combining operation. However, this is not limiting. Depending on the embodiment, the interface section 21 may also transmit the messages generated as a result of executing the combining operation based on a specific parameter (e.g., Ta3_min, FHM, or the minimum value of the latest time that a cascaded O-RU can transmit a user plane message to an O-DU or the north node based on the reception timing at the O-RU antenna) in consideration of the O-RU delay profile.

[0074] As such, according to the combining scheme of the exemplary embodiment of the present invention, the combining operation can be triggered on an eAxC basis more quickly than the existing combining scheme in which the FHM or cascaded O-RU waits until all symbols to be combined are received before combining, thereby enabling more effective utilization of time resources under limited fronthaul delay.

[0075] In addition, the combining operation triggering per eAxC and the combining operation triggering specified in the existing O-RAN fronthaul specifications can be used in a mutually complementary manner, preventing errors caused by message loss (or drops).

[0076] In addition, by simplifying the trigger procedure for the combining operation on an eAxC basis in consideration of transmission delays, it is possible to prevent further delays based on the combining operation on an eAxC basis, which is performed more frequently than before.

[0077] 4 to 11 are diagrams illustrating a node device supporting a combining scheme according to an exemplary embodiment of the present invention and an operation method thereof. In describing FIG. 4 to 11, the embodiment of the present invention shown in FIG. 2 will also be referred to. For ease of explanation, the triggering section in FIG. 4 and FIG. 8 and the subsection in FIG. 6 and FIG. 10 are each shown as a single structure, but the sections may be configured in multiple locations according to the number of symbols.

[0078] FIG. 4 illustrates one embodiment of the triggering section of an FHM or cascaded O-RU in a shared cell configuration.

[0079] Referring to FIG. 4, the triggering section 43 includes a first combined trigger generator 431, logic 433, and first to j-th end flag generators 435-1 to 435-j.

[0080] The first to jth end flag generators 435-1 to 435-j each determine whether the final message is received for each eAxC unit for a corresponding antenna port among user plane messages transmitted from a plurality of south node devices, and can generate an end flag if it is determined that the final message has been received.

[0081] In one embodiment, the first to j-th end flag generators 435-1 to 435-j determine whether the last message has been received in a particular eAxC unit based on whether messages are continuously received in that eAxC unit.

[0082] The consecutive reception of the messages may be determined based on whether the messages received sequentially within a predetermined time period have the same eAxC, for example, by searching a predetermined parameter (e.g., filter index).

[0083] Alternatively, whether the messages are continuously received can be determined by using a W timer based on whether a message is received within a predetermined time after any one eAxC unit message is received. This is to prevent delays due to waiting when the reception interval between messages is long, and if a message does not arrive within the predetermined time, the previously received eAxC unit message is determined to be the last message.

[0084] In another embodiment, the first through j-th end flag generators 435-1 through 435-j may determine whether the final message has been received for a particular eAxC unit based on predetermined information included in the message. The message transmitted from the south node may include a predetermined field (e.g., subseq-ID) indicating whether it is the final message for the eAxC unit, and the first through j-th end flag generators 435-1 through 435-j may determine whether the final message has been received based on the field.

[0085] The logic 433 performs a logical operation on the per-port end flags generated by the first to j-th end flag generators 435-1 to 435-j, for example, the logic 433 performs an AND operation.

[0086] The first combining trigger generator 431 generates a first combining trigger (hereinafter referred to as an AR (arrival)-trigger) that indicates the timing of the combining operation based on the calculation result of the logic 433.

[0087] The first combining trigger generator 431 determines whether an end flag is generated for the message stream of a specific eAxC unit at all ports based on the AND operation result of the logic 433. If an end flag is generated at all ports, the eAxC unit determines that the final message has arrived from all ports and generates an AR-trigger that triggers the combining operation of the messages of the eAxC unit.

[0088] Meanwhile, according to an embodiment, the triggering section 43 generates the AR-trigger using only a user plane message transmitted from a south node device with the longest transmission delay among a plurality of south node devices. Since a message from the south node device with the longest transmission delay is likely to arrive the latest, the AR-trigger can be generated based only on that message.

[0089] FIG. 5 is a diagram illustrating an operation of determining the timing of an operation of combining messages related to the user plane in eAxC units by the triggering section 43 of FIG.

[0090] FIG. 5(a) illustrates an operation of generating an AR-trigger based on a message per eAxC for one antenna port.

[0091] 5(a), the end flag generator corresponding to antenna port a of south node #1 can generate an end flag for eAxC ID-1 because messages for eAxC ID-1 are continuously received and another message for eAxC ID-2 is received, and in the case of eAxC ID-2, no subsequent message is received within the time specified by the W-timer, so an end flag for eAxC ID-2 can be generated. The first combined trigger generator 431 can generate AR-triggers for eAxC ID-1 and 2 at the timing of generating each end flag.

[0092] FIG. 5(b) illustrates an operation of generating an AR-trigger based on eAxC-based messages for two antenna ports.

[0093] 5(b), the end flag generators corresponding to antenna port a of south node #1 and antenna port b of south node #2 can generate end flags for eAxC ID-1 and eAxC ID-2, respectively, as shown in FIG. 5(a). Logic 433 can perform an AND operation on the generated end flags, and first combined trigger generator 431 can generate an AR-trigger for eAxC ID-1 and 2, respectively, when the end flags are both generated at each port according to the AND operation result of logic 433.

[0094] FIG. 5(c) illustrates an operation of generating an AR-trigger for messages in eAxC units related to two antenna ports, taking into consideration only the message from South node #2, which has the larger transmission delay among the transmission delays of South nodes #1 and #2.

[0095] 5(c), only the end flag generator corresponding to antenna port b of south node #2, which has a relatively larger transmission delay, can generate end flags for eAxC ID-1 and eAxC ID-2, as shown in FIG. 5(a). The first combined trigger generator 431 can generate AR-triggers for eAxC ID-1 and 2 at the timing of generating each end flag.

[0096] Figure 6 shows another embodiment of the triggering section of an FHM or cascaded O-RU in a shared cell configuration. The triggering section 63 in Figure 6 is a modification of the triggering section 43 in Figure 4, and is an embodiment in which the timing of message combining operations is determined by using an AR-trigger and a TW (Timing Window)-trigger based on timing-related information in a complementary manner. In describing Figures 6 and 7, reference will be made to Figures 4 and 5, but overlapping descriptions will be omitted.

[0097] Referring to FIG. 6, the triggering section 63 includes a first subsection 63-1 for generating an AR-trigger, a second subsection 63-2 and a selector 641 for generating and selecting a TW-trigger, and logic 62 for selecting an AR-trigger and / or a TW-trigger.

[0098] The first subsection 63-1 generates an AR-trigger substantially identical to the triggering section 43 of Figure 4. The first subsection 63-1 outputs the generated AR-trigger to the logic 62.

[0099] The second subsection 63-2 includes a TWN-trigger generator 643 and a TWC-trigger generator 645.

[0100] The triggers generated by the TWN-trigger generator 643 and the TWC-trigger generator 645 are based on the contents specified in the O-RAN fronthaul standard specifications and can be calculated from the frame structure and control plane timing applied to the eAxC unit, respectively.

[0101] For example, the TWN-trigger generator 643 can determine a waiting time by applying an offset to a normal frame structure (e.g., determined by SCS (Sub-Carrier Spacing) and N_TA_Offset, etc.) applied to an eAxC unit of a PUSCH / PUCCH, and then generate a TWN-trigger that triggers a combining operation at the end of the waiting time.

[0102] For example, the TWC-trigger generator 645 can determine the waiting time from the eAxC unit of the PRACH and its control plane timing, and then generate a TWC-trigger that triggers the combining operation at the end of the waiting time.

[0103] The reference time of the TWN-trigger is the starting point of the symbol including the CP (Cyclic Prefix), and the reference time of the TWC-trigger is the starting point of the sequence duration excluding the PRACHCP, which can be calculated using the time offset and the CP length.

[0104] The TWN-trigger and TWC-trigger can be calculated based on their respective reference times as (Ta3-Prime_max)-(T_Combine_Net)-(Txwindow), where Ta3_Prime_max refers to the maximum value of the latest time that the FHM or cascaded O-RU can transmit a user plane message to the O-DU or north node based on the reception timing at the O-RU antenna, T_Combine_net refers to the maximum processing delay of the FHM or cascaded O-RU between the start time of combining IQ samples in the received message and the start time of transmitting the message to the O-DU or north node through the fronthaul interface, and Txwindow refers to the time that the FHM or cascaded O-RU must wait for an uplink user plane message transmitted from the south node ORU.

[0105] The TWN-trigger and TWC-trigger generated by the second subsection 63-2 can be used selectively or simultaneously since they apply different eAxC units.

[0106] The selector 641 selects at least one of the generated TWN-trigger and TWC-trigger and outputs it to the logic 62 .

[0107] The logic 62 performs a logical operation on the generated AR-trigger, TWN-trigger, and TWC-trigger, for example, the logic 62 performs an OR operation.

[0108] The logic 62 can output at least one of an AR-trigger, a TWN-trigger, and a TWC-trigger, and the trigger output from the logic 62 triggers the combining operation of messages on an eAxC basis.

[0109] 7, the triggering section 63 can selectively use the AR-trigger generated for each eAxC ID-1, 2, 8, the TWN-trigger calculated based on the reception waiting time, and the TWC-trigger generated for each eAxC ID-8 when the end flag is generated at each port to trigger the message combining operation for each eAxC.

[0110] In this way, when controlling the message combining operation of each eAxC based on the final reception of a message stream of a specific eAxC, even if an error such as a missing message occurs, the combining operation can be further performed on an eAxC basis for the missing message using the TWN-trigger or TWC-trigger, thereby minimizing errors during message combining and effectively dealing with error situations.

[0111] FIG. 8 shows yet another embodiment of the triggering section of an FHM or cascaded O-RU in a shared cell configuration.

[0112] Referring to FIG. 8, the triggering section 83 includes a second combined trigger generator 831, logic 833, and first to j-th start flag generators 835-1 to 835-j.

[0113] The first to jth start flag generators 835-1 to 835-j each determine whether a first message is received for each eAxC unit for a message of a corresponding antenna port among user plane messages transmitted from a plurality of south node devices, and can generate a start flag if it is determined that the first message is received.

[0114] The logic 833 performs a logical operation on the per-port start flags generated by the first to j-th start flag generators 835-1 to 835-j, for example, the logic 833 performs an AND operation.

[0115] Based on the calculation result of the logic 833, the second combining trigger generator 831 generates a second combining trigger (hereinafter referred to as an ST (start)-trigger) that indicates the timing of the combining operation.

[0116] The second combining trigger generator 831 determines whether a start flag is generated for the message stream of a specific eAxC unit at all ports based on the AND operation result of the logic 833, and if a start flag is generated at all ports, the eAxC unit determines that the first message has arrived and generates an ST-trigger that triggers the combining operation of the messages of the eAxC unit.

[0117] When start flags are generated at all ports, the second combined trigger generator 831 generates the ST-trigger at a point where the generation of the last start flag is delayed by a predetermined time (e.g., eAxC message duration) using an S timer.

[0118] Meanwhile, according to an embodiment, the triggering section 83 generates the ST-trigger using only a user plane message transmitted from a south node device with the longest transmission delay among a plurality of south node devices. Since the message from the south node device with the longest transmission delay is likely to arrive the latest, the ST-trigger can be generated based only on that message.

[0119] FIG. 9 is a diagram illustrating an operation of determining the timing of an operation of combining messages related to the user plane in eAxC units by the triggering section 83 of FIG.

[0120] FIG. 9(a) illustrates an example of an operation for generating an ST-trigger based on a message per eAxC for one antenna port.

[0121] 9(a), the start flag generator corresponding to antenna port a of south node #1 receives a message for eAxC ID-1 and a message for eAxC ID-2, and thus generates a start flag for each of them. The second combined trigger generator 831 generates an ST-trigger for eAxC ID-1 and ID-2 at a time point delayed by a predetermined time (e.g., a time set by an S timer) from the time point when each start flag is generated.

[0122] FIG. 9(b) illustrates an operation of generating an ST-trigger based on eAxC-based messages for two antenna ports.

[0123] 9(b), start flag generators corresponding to antenna port a of south node #1 and antenna port b of south node #2 can generate start flags for eAxC ID-1 and eAxC ID-2, respectively, as shown in FIG. 9(a). Logic 833 can perform an AND operation on the generated start flags, and second combined trigger generator 831 can delay the point at which all start flags are generated at each port by a predetermined time according to the result of the AND operation by logic 833, and generate ST-triggers for eAxC ID-1 and eAxC ID-2, respectively.

[0124] FIG. 9(c) illustrates an example of an operation for generating an ST-trigger for messages in eAxC units related to two antenna ports, taking into consideration only the message from south node #2, which has a larger transmission delay than the messages from south nodes #1 and #2.

[0125] 9(c), only the start flag generator corresponding to antenna port b of south node #2, which has a relatively larger transmission delay, can generate start flags for eAxC ID-1 and eAxC ID-2, as shown in FIG. 9(a). The second combined trigger generator 831 delays the generation time of each generated start flag by a predetermined time, and generates ST-triggers for eAxC ID-1 and ID-2.

[0126] Figure 10 shows another embodiment of the triggering section of an FHM or cascaded O-RU in a shared cell configuration. Triggering section 103 in Figure 10 is a modification of triggering section 83 in Figure 8, and is an embodiment in which the timing of message combining operations is determined by using an ST-trigger and a TW-trigger based on timing-related information in a complementary manner. When describing Figures 10 and 11, reference will be made to Figures 6 to 9, but overlapping descriptions will be omitted.

[0127] Referring to FIG. 10, the triggering section 103 includes a first subsection 103-1 for generating an AR-trigger, a second subsection 103-2 and a selector 1041 for generating and selecting a TW-trigger, and logic 102 for selecting between an ST-trigger and a TW-trigger.

[0128] The first subsection 103-1 generates an ST-trigger substantially equivalent to the triggering section 83 of Figure 8. The first subsection 103-1 outputs the generated ST-trigger to the logic 102.

[0129] The second subsection 103-2 includes a TWN-trigger generator 1043 and a TWC-trigger generator 1045, and generates a TWN-trigger and a TWC-trigger, substantially similar to the second subsection 63-2 in Figure 6. The selector 1041 selects at least one of the generated TWN-trigger and TWC-trigger and outputs it to the logic 102.

[0130] The logic 102 performs a logical operation on the generated ST-trigger, TWN-trigger, and TWC-trigger, for example, the logic 102 performs an OR operation.

[0131] The logic 102 can output at least one of an ST-trigger, a TWN-trigger, and a TWC-trigger, and the trigger output from the logic 102 triggers a message combining operation on an eAxC basis.

[0132] Referring further to FIG. 11, the triggering section 103 can delay the timing when all start flags are generated at each port by a predetermined time, and selectively use the ST-trigger generated for each of eAxC ID-1, 2, and 8, the TWN-trigger calculated based on the reception waiting time, and the TWC-trigger to trigger the message combining operation for each eAxC.

[0133] In this way, when controlling the message combining operation of each eAxC based on whether a message stream of a specific eAxC unit is initially received, even if an error such as a missing message occurs, the combining operation can be further performed on the missing message unit by the TWN-trigger or TWC-trigger, thereby minimizing errors during message combining and effectively dealing with error situations.

[0134] 12 to 14 are flowcharts illustrating an operation method of a node device supporting a combining scheme according to an exemplary embodiment of the present invention. Figures 12 to 14 are flowcharts illustrating a combining operation process performed in an FHM or cascaded O-RU in a shared cell configuration. The following description focuses on an embodiment in which the process is performed in the FHM 20 of FIG. 2.

[0135] In step S1201, the FHM 20 receives user plane messages from at least one south node device. The messages are for each antenna port of the south node device, and the messages for each antenna port are consecutive in the same eAxC unit. The eAxC unit messages received from each south node device have the same eAxC unit sequence order.

[0136] In step S1203, the FHM 20 determines the timing of the message combining operation in eAxC units based on the received messages.

[0137] The FHM 20 determines the timing of the combining operation based on the determination result of whether the message was received first or last, or alternatively, the FHM 20 determines the timing of the combining operation using the determination result of whether the message was received first or last, as well as wait time-related information calculated based on the frame structure applied to the eAxC unit message and the timing of the control plane message applied to the eAxC unit.

[0138] The process for determining the timing of the coupling operation of the FHM 20 will be described in more detail with reference to FIGS.

[0139] First, referring to FIG. 13, in step S1301, the FHM 20 determines whether the last message in eAxC unit has been received.

[0140] In some embodiments, the FHM 20 determines whether a message stream for a particular eAxC unit has been finally received from all antenna ports. The FHM 20 determines this based on the continuity of messages for the eAxC unit, information indicating the last message, etc.

[0141] In another embodiment, the FHM 20 uses only the message received from the south node device with the largest transmission delay value for the FHM 20 to determine whether the message stream for a particular eAxC unit has finally been received.

[0142] In step S1303, if it is determined that the final message of the eAxC unit has been received, the FHM 20 generates an AT-trigger.

[0143] In step S1305, the FHM 20 calculates the waiting time from the frame structure and control plane timing applied to the eAxC-based message, and in step S1307, generates a TW-trigger based on the calculation result.

[0144] In step S1309, the FHM 20 outputs the generated AT-trigger and / or TW-trigger.

[0145] Next, referring to FIG. 14, in step S1401, the FHM 20 determines whether the first message in eAxC unit has been received.

[0146] In some embodiments, the FHM 20 determines whether the message stream for a particular eAxC unit has been received from all antenna ports first.

[0147] In another embodiment, the FHM 20 uses only the message received from the south node device with the largest transmission delay value for the FHM 20 to determine whether or not the first message in the message stream for a particular eAxC unit has been received.

[0148] In step S1403, the FHM 20 generates an ST-trigger if it determines that the first message of the eAxC unit has been received.

[0149] In step S1405, the FHM 20 calculates the waiting time from the frame structure and control plane timing applied to the eAxC-based message, and in step S1407, generates a TW-trigger based on the calculation result.

[0150] In step S1409, the FHM 20 outputs the generated ST-trigger and / or TW-trigger.

[0151] Referring back to FIG. 12, in step S1205, the FHM 20 combines messages from each port in eAxC units according to the determined timing.

[0152] In step S1207, the FHM 20 transmits the combined messages to the north node device in the combining order.

[0153] 12-14 include one or more steps or actions for achieving the method described above. At least some of the steps and / or actions for achieving the method may be interchanged with one another or omitted without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0154] Additionally, the various operations of the methods described above may be performed by any suitable means capable of performing the corresponding functions, including, but not limited to, various hardware and / or software components and / or modules, such as an application specific integrated circuit (ASIC), or a processor. Generally, where there are corresponding operations in the figures, such operations may also have corresponding relative means and functional components with the same numbers.

[0155] The above-described methods may be embodied in the form of program instructions executed by various computer means and recorded on a computer-readable medium. Computer-readable media may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the computer-readable medium may be specially designed and constructed for the present invention, or may be known and available to those skilled in the art of computer software. Examples of computer-readable media include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include not only machine code, such as produced by a compiler, but also high-level language code that can be executed by a computer using an interpreter, etc. The above-described hardware devices may be configured to operate with at least one software module to perform the operations of the present invention, or vice versa.

[0156] Those skilled in the art will appreciate that various modifications and variations may be made without departing from the essential characteristics of the technical idea of ​​the present invention.

[0157] Therefore, the embodiments exemplified in the present invention are intended to explain rather than limit the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by these embodiments.

[0158] The scope of protection of the technical idea of ​​the present invention should be interpreted by the following claims, and all technical ideas within the equivalent range should be interpreted as being included in the technical imaginary scope of the present invention.

Claims

1. A method for operating a node device in an O-RAN (Open Radio Access Network), comprising: receiving a user-plane related message from at least one south-node device; determining a timing of an operation of combining the messages on an extended antenna-carrier (eAxC) basis based on the messages; The determining step includes: determining whether a final message for the eAxC unit is received from at least one port; generating a first combining trigger instructing timing of an operation of combining the messages in units of the eAxC when it is determined that the final message has been received; A method comprising:

2. The determining step includes:

2. The method of claim 1, wherein the determination is based on whether the eAxC unit messages are received consecutively from the at least one port.

3. A method for operating a node device in an O-RAN (Open Radio Access Network), comprising: receiving a user-plane related message from at least one south-node device; determining a timing of an operation of combining the messages on an extended antenna-carrier (eAxC) basis based on the messages; The determining step includes: determining whether a first message for the eAxC unit is received from at least one port; generating a second combining trigger instructing timing of an operation of combining the messages in units of the eAxC when it is determined that the first message has been received; A method comprising:

4. The step of generating the second combined trigger comprises:

4. The method of claim 3, wherein the second combined trigger is generated by delaying the timing at which the first message is received by a predetermined time.

5. the at least one south node device includes a plurality of south node devices; The method according to claim 1 , wherein the determining step uses a message received from a south node device having the longest transmission delay for the node device among the plurality of south node devices.

6. The method according to claim 1 , wherein the messages of the same eAxC unit are received consecutively.

7. the at least one south node device includes a plurality of south node devices; The method according to claim 6, wherein messages received from the plurality of south node devices are received in the same order based on the eAxC unit.

8. combining the messages in units of the eAxCs according to the determined timing; transmitting the combined messages to a north node device in combination order; 5. The method of claim 1, comprising:

9. A node device of an O-RAN, at least one processor; The at least one processor: and configured to determine, on an eAxC basis, a timing of an operation of combining the messages based on messages related to a user plane received from at least one south node device; The at least one processor: determining whether a final message for the eAxC unit is received from at least one port; The node device is further configured to, when it is determined that the final message has been received, generate a first combining trigger indicative of timing of an operation to combine the messages in units of the eAxC.

10. The at least one processor:

10. The node device according to claim 9, further configured to determine whether a final message of the eAxC unit is received based on whether messages of the eAxC unit are received consecutively from the at least one port.

11. A node device of an O-RAN, at least one processor; The at least one processor: and configured to determine, on an eAxC basis, a timing of an operation of combining the messages based on messages related to a user plane received from at least one south node device; The at least one processor: determining whether a first message of the eAxC unit is received from at least one port; The node device is further configured to, if it is determined that the first message has been received, generate, on an eAxC basis, a second combining trigger that indicates timing of an operation to combine the messages.

12. The at least one processor: The node apparatus according to claim 11, further configured to delay the timing at which the first message is received by a predetermined time, and then generate the second combined trigger.

13. the at least one south node device includes a plurality of south node devices; The at least one processor:

13. The node apparatus according to claim 9, further configured to determine, for each eAxC, a timing of an operation of combining the messages, using a message received from a south node apparatus having the longest transmission delay for the node apparatus among the plurality of south node apparatuses.

14. The node device according to claim 9 , wherein messages of the same eAxC unit among the messages are received consecutively.

15. the at least one south node device includes a plurality of south node devices; The node device according to claim 14, wherein messages received from each of the plurality of south node devices are received in the same order based on the eAxC unit.

16. The at least one processor: combining the messages in units of the eAxCs according to the determined timing; 13. A node device according to any one of claims 9 to 12, further configured to control transmission of the combined message to a north node device according to a combining procedure.

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