Method and apparatus for robust messaging over a fronthaul network

Abstract

A method and apparatus are provided for processing an acknowledgement (ACK) of a C-plane message in a wireless communication system. The method in a transmitting device includes an act of generating a section extension for an ACK / NACK request including an ackNackReqId field and an extLen field. The ackNackReqId field indicates an ACK / NACK request ID of the section description, and the extLen field indicates a size of the section extension. The method includes an act of transmitting a C-plane message including the section extension of the ACK / NACK request to a receiving device. The method includes an act of receiving an ACK message corresponding to the C-plane message from the receiving device.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to communication systems, and more particularly to robust messaging over fronthaul networks. [Background technology]

[0002] Fifth-generation (5G) or New Radio (NR) mobile communications has recently gained increasing momentum with global technical activities on various candidate technologies from industry and academia. Current Open Radio Access Network (O-RAN) fronthaul networks require robustness of the underlying network, providing several methods for message senders to detect failures in message transmission over the fronthaul network and failures in message decoding at receivers. Summary of the Invention [Problem to be solved by the invention]

[0003] The present disclosure relates to communication systems, and more particularly to robust messaging over fronthaul networks. [Means for solving the problem]

[0004] According to one embodiment, a base station transmitting device for processing an acknowledgement (ACK) of a control plane (C-plane) message in a wireless communication system is provided. A DU includes a processor configured to generate a section extension for requesting an acknowledgement / negative acknowledgment (ACK / NACK), the section extension including an ACK / NACK request identifier (ackNackReqId) field and a length (extLen) field, where the ackNackReqId field includes the ACK / NACK request identifier (ID) of a section description, and the extLen field indicates a size of the section extension. The transmitting device further includes a transceiver operatively connected to the processor, the transceiver configured to transmit the C-plane message including the section extension for the ACK / NACK request to a receiving device and to receive an ACK message corresponding to the C-plane message from a RU.

[0005] According to another embodiment, a receiving device for processing an acknowledgement (ACK) of a C-plane message in a wireless communication system is provided. The receiving device includes a transceiver configured to receive a C-plane message including a section extension for requesting an ACK / NACK from a transmitting device. The receiving device further includes a processor operatively coupled to the transceiver, the processor configured to identify a section extension included in the C-plane message for requesting an ACK / NACK, the section extension including an ackNackReqId field and an extLen field, where the ackNackReqId field indicates an ACK / NACK request ID of a section description and the extLen field indicates a size of the section extension. The transceiver of the receiving device is further configured to transmit an ACK message corresponding to the C-plane message to the transmitting device.

[0006] According to yet another embodiment, there is provided a method for a base station transmitting device in a wireless communication system for processing an acknowledgement (ACK) of a C-plane message, the method including: generating a section extension for requesting an ACK / NACK including an ackNackReqId field and an extLen field, where the ackNackReqId field indicates an ACK / NACK request ID of a section description and the extLen field indicates a size of the section extension; transmitting a C-plane message including the section extension for the ACK / NACK request to a receiving device; and receiving an ACK message corresponding to the C-plane message from the receiving device.

[0007] According to an embodiment, there is provided a method performed by an open-radio access network (O-RAN) distributed unit (O-DU). The method includes transmitting one or more control plane (C-plane) messages to an O-RAN Radio Unit (O-RU) via a fronthaul interface. The method also includes receiving, from the O-RU via the fronthaul interface, an acknowledgement (ACK) / non-acknowledgement (NACK) feedback message for the one or more C-plane messages. Each C-plane message of the one or more C-plane messages includes section extension information for requesting an ACK / NACK. The section extension information includes a request identifier (ID) used to identify a section description for which ACK / NACK feedback is requested. The ACK / NACK feedback message includes at least one of ACK information for indicating the request ID of a correctly decoded section description or NACK information for indicating the request ID of an incorrectly decoded section description.

[0008] According to an embodiment, a method performed by an open-radio access network (O-RAN) radio unit (O-RU) is provided. The method includes receiving one or more control plane (C-plane) messages from an O-RAN distributed unit (O-DU) via a fronthaul interface. The method may include transmitting, to the O-RU via the fronthaul interface, an acknowledgement (ACK) / non-acknowledgement (NACK) feedback message for the one or more C-plane messages. Each C-plane message of the one or more C-plane messages includes section extension information for requesting an ACK / NACK. The section extension information includes a request identifier (ID) used to identify a section description for which ACK / NACK feedback is requested. The ACK / NACK feedback message includes at least one of ACK information for indicating the request ID of a correctly decoded section description or NACK information for indicating the request ID of an incorrectly decoded section description.

[0009] According to an embodiment, an Open-Radio Access Network (O-RAN) distributed unit (O-DU) apparatus 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 transmit one or more control plane (C-plane) messages to an O-RAN radio unit (O-RU) via a fronthaul interface. The at least one processor is configured to control the at least one transceiver to receive, from the O-RU via the fronthaul interface, acknowledgement (ACK) / non-acknowledgement (NACK) feedback messages for the one or more C-plane messages. Each C-plane message of the one or more C-plane messages includes section extension information for requesting an ACK / NACK. The section extension information includes a request identifier (ID) used to identify a section description for which ACK / NACK feedback is requested. The ACK / NACK feedback message includes at least one of ACK information for indicating the request IDs of correctly decoded section descriptions or NACK information for indicating the request IDs of erroneously decoded section descriptions.

[0010] According to an embodiment, an Open-Radio Access Network (O-RAN) radio unit (O-RU) apparatus 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 one or more control plane (C-plane) messages from an O-RAN distributed unit (O-DU) via a fronthaul interface. The at least one processor is configured to control the at least one transceiver to transmit, to the O-RU via the fronthaul interface, acknowledgement (ACK) / non-acknowledgement (NACK) feedback messages for the one or more C-plane messages. Each C-plane message of the one or more C-plane messages includes section extension information for requesting an ACK / NACK. The section extension information includes a request identifier (ID) used to identify a section description for which ACK / NACK feedback is requested. The ACK / NACK feedback message includes at least one of ACK information for indicating the request IDs of correctly decoded section descriptions or NACK information for indicating the request IDs of erroneously decoded section descriptions.

[0011] Other technical features may be readily apparent to those skilled in the art from the following drawings, descriptions, and claims.

[0012] Before proceeding with the detailed description below, it may be desirable to explain definitions of certain words and phrases used throughout this disclosure. "Couple" and its derivatives refer to direct or indirect communication between two or more elements, regardless of whether the corresponding elements are in physical contact with one another. The terms "transmit," "receive," and "communicate," and their derivatives, are inclusive of all direct and indirect communication. The terms "include" and "comprise," and their derivatives, mean inclusion without limitation. The term "or" is inclusive, meaning "and / or." The phrase "associated with" and its derivatives means "include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be in communication with, cooperate with, interleave, juxtapose, be adjacent to, be bound to / with, have, have an attribute of, be associated with, etc." The term "controller" refers to any device, system, or portion thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller may be centralized or distributed, whether local or remote. When used with a list of items, the phrase "at least one" means that other combinations of one or more of the listed items can be used, and only one item from the list is required. For example, the phrase "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A, B, and C.

[0013] Furthermore, various functions described below may be implemented or supported by one or more computer programs, each of which may be formed from computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, associated data, or portions thereof, adapted for implementation in suitable computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes all types of media accessible by a computer, such as, for example, read-only memory (ROM), random access memory (RAM), hard disk drives, compact discs (CDs), digital video discs (DVDs), and other memory. "Non-transitory" computer-readable medium excludes wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable media include media that can permanently store data and media that can store data and later be overwritten, such as rewritable optical disks or erasable memory devices.

[0014] Definitions of other specific words and phrases are provided throughout this patent document, and those of ordinary skill in the art should understand that in many, if not most, cases, these definitions apply not only to the prior use of those defined words and phrases, but also to future uses.

[0015] For a more complete understanding of the present disclosure and its advantages, please refer to the following description and to the accompanying drawings, in which like reference numerals represent like elements and in which: [Brief explanation of the drawings]

[0016] [Figure 1] 1 illustrates an example of a communication system according to an embodiment of the present disclosure. [Figure 2] 1 illustrates an example of a network entity according to an embodiment of the present disclosure. [Figure 3] 1 illustrates an example of a client device according to an embodiment of the present disclosure. [Figure 4] 1 illustrates an example of a base station according to an embodiment of the present disclosure. [Figure 5] 1 illustrates an example of a high-level message flow according to an embodiment of the present disclosure. [Figure 6] 1 illustrates an example message flow for robust messaging according to an embodiment of the present disclosure. [Figure 7] 10 illustrates another example of a message flow for robust messaging according to an embodiment of the present disclosure. [Figure 8] 1 illustrates an example of a message format according to an embodiment of the present disclosure. [Figure 9] 10 illustrates another example of a message format according to an embodiment of the present disclosure. [Figure 10] 1 illustrates a flowchart of a method for robust messaging over a fronthaul network, according to an embodiment of the present disclosure. [Figure 11] 1 illustrates a flowchart of a method for robust messaging over a fronthaul network, according to an embodiment of the present disclosure. [Figure 12] 1 illustrates an example of a fronthaul interface according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0017] 1-12 described below, and the various embodiments used to illustrate the principles of the present disclosure in this patent document, are exemplary only and should not be construed as limiting the scope of the present disclosure in any way. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any suitably arranged device or system.

[0018] Figure 1 illustrates an example of a communication system 100 according to the present disclosure. The embodiment of communication system 100 illustrated in Figure 1 is for illustrative purposes only. Other embodiments of communication system 100 may be used without departing from the scope of the present disclosure.

[0019] 1, system 100 includes a network 102 that facilitates communication between various components within system 100. For example, network 102 may communicate Internet Protocol (IP) packets, frame relay frames, asynchronous transfer mode (ATM) cells, or other information between network addresses. Network 102 may include one or more local area networks (LANs), metropolitan area networks (MANs), wide area networks (WANs), all or part of a global network such as the Internet, or other communication systems at one or more locations.

[0020] The network 102 facilitates communication between at least one server 104 and various client devices 106-114, such as user equipment (UE), terminals, or any device that includes communications capabilities. Each server 104 includes any suitable computing or processing device capable of providing computing services to one or more client devices. Each server 104 may include, for example, one or more processing devices, one or more memories for storing instructions and data, and one or more network interfaces that facilitate communication over the network 102.

[0021] Each client device 106-114 represents any suitable communication or processing device that interacts with at least one server or other communication device via network 102. In this case, client devices 106-114 include a desktop computer 106, a mobile phone or smartphone 108, a personal digital assistant (PDA) 110, a laptop computer 112, and a tablet computer 114. However, any other or additional client devices may be used in communication system 100.

[0022] In this example, some client devices 108-114 communicate indirectly with network 102. For example, client devices 108-110 communicate through one or more base stations 116, such as cellular base stations or eNodeBs. Additionally, client devices 112-114 communicate through one or more wireless access points 118, such as IEEE 802.11 wireless access points. It should be noted that these are examples only, and each client device can communicate directly or indirectly with network 102 through any suitable intermediate device or network.

[0023] Although Figure 1 illustrates an example of a communications system 100, various modifications may be made to Figure 1. For example, system 100 may include any number of components in any suitable arrangement. In general, computing and communications systems may be configured in a wide variety of ways, and Figure 1 does not limit the scope of the present disclosure to any particular configuration. While Figure 1 illustrates one operating environment in which various features disclosed in this patent document may be used, these features may also be used in any other suitable system.

[0024] 2 and 3 illustrate example devices in a communication system according to the present disclosure. In particular, FIG. 2 illustrates an example server 200, and FIG. 3 illustrates an example client device 300. Server 200 may represent server 104 of FIG. 1, and client device 300 may represent one or more of client devices 106-114 of FIG. 1.

[0025] As shown in FIG. 2, server 200 includes a bus system 205 that supports communication between at least one processor 210, at least one storage device 215, at least one communication circuit 220, and at least one input / output (I / O) circuit 225.

[0026] Processor 210 executes instructions that may be loaded into memory 230. Processor 210 may include any suitable number and type of processors or other devices in any suitable arrangement. Examples of processor 210 include microprocessors, microcontrollers, digital signal processors, field programmable gate arrays, application-specific integrated circuits, and discrete circuits. Additionally, processor 210 may execute other processes and programs resident in memory 230, such as processes for robust message transmission and reception over a fronthaul network in a wireless communication system.

[0027] Memory 230 and permanent storage 235 are examples of storage 215, which refers to any structure in which information (such as data, program code, and / or other suitable information) can be temporarily or permanently stored and easily retrieved. Memory 230 can refer to random access memory or any other suitable volatile or non-volatile storage device. Permanent storage 235 can include one or more components or devices that support long-term storage of data, such as read-only memory, a hard drive, flash memory, or an optical disk.

[0028] Communications circuitry 220 supports communications with other systems or devices. For example, communications circuitry 220 may include a network interface card or a wireless transceiver that facilitates communications over network 102. Communications circuitry 220 may support communications over any suitable physical or wireless communications link.

[0029] The input / output circuitry 225 allows for the input and output of data. For example, the input / output circuitry 225 may provide a connection for user input through a keyboard, mouse, keypad, touch screen, or other suitable input device. The input / output circuitry 225 may also transmit output to a display, printer, or other suitable output device.

[0030] Processor 210 is also coupled to display 240. Display 240 may be, for example, a liquid crystal display or other display capable of rendering text and / or at least limited graphics from a website.

[0031] 2 is described as showing server 104 of FIG. 1, it should be noted that the same or similar structure may be used in one or more of client devices 106-114. For example, a notebook or desktop computer may have the same or similar structure as that shown in FIG.

[0032] Figure 3 illustrates an example of a client device 116 according to an embodiment of the present disclosure. The embodiment of client device 116 illustrated in Figure 3 is merely exemplary and may have the same or similar configuration as client devices 106-114 in Figure 1. However, client devices may have a wide variety of configurations, and Figure 3 does not limit the scope of the present disclosure to any particular implementation of a client device.

[0033] 3, client devices 106-114 may include an antenna 305, an RF transceiver 310, TX processing circuitry 315, a microphone 320, and RX processing circuitry 325. Client devices 104-116 may include a speaker 330, a processor 340, an input / output interface (IF) 345, a touchscreen 350, a display 355, and memory 360. Memory 360 includes an operating system 361 and one or more applications 362.

[0034] The RF transceiver 310 receives incoming RF signals transmitted by network entities (e.g., gNBs, BSs, eNBs) of the network 100 from the antenna 305. The RF transceiver 310 downconverts the incoming RF signals to generate intermediate frequency (IF) or baseband signals. The IF or baseband signals are communicated to the RX processing circuitry 325, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The RX processing circuitry 325 transmits the processed baseband signals to a speaker 330 (e.g., for voice data) or to a processor 340 for additional processing (e.g., for web browsing data).

[0035] TX processing circuitry 315 receives analog or digital voice data from microphone 320 or other outgoing baseband data (e.g., web data, email, interactive video game data, etc.) from processor 340. TX processing circuitry 315 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate processed baseband or IF signals. RF transceiver 310 receives the outgoing processed baseband or IF signals from TX processing circuitry 315 and upconverts the baseband or IF signals to RF signals that are transmitted via antenna 305.

[0036] Processor 340 may include one or more processors or other processing devices and may execute operating system 361 stored in memory 360 to control the overall operation of client devices 106-114. For example, processor 340 may control the reception of DL channel signals and the transmission of UL channel signals by RF transceiver 310, RX processing circuitry 325, and TX processing circuitry 315 in accordance with known principles. In some embodiments, processor 340 includes at least one microprocessor or microcontroller.

[0037] The processor 340 may also execute other processes and programs resident in the memory 360, such as processes for robust messaging over a fronthaul network in a wireless communication system. The processor 340 may move data in and out of the memory 360 as needed depending on the execution of the processes. In some embodiments, the processor 340 is configured to execute applications 362 based on an operating system 361 or in response to signals received from a base station or operator. The processor 340 is also coupled to an I / O interface 345, which provides the client devices 106-114 with the ability to connect to other devices, such as notebook computers, handheld computers, etc. The I / O interface 345 is a communication path between such accessories and the processor 340.

[0038] Processor 340 is also coupled to touchscreen 350 and display 355. An operator of a client device 106-114 can use touchscreen 350 to input data into client device 106-114. Display 355 may be a liquid crystal display, a light emitting diode display, or other display capable of rendering, for example, text and / or at least limited graphics from a website.

[0039] Memory 360 is coupled to processor 340. A portion of memory 360 may include random access memory (RAM), and another portion of memory 360 may include flash memory or other read-only memory (ROM).

[0040] While FIG. 3 illustrates an example of client devices 106-114, various modifications may be made to FIG. 3. For example, various components in FIG. 3 may be combined, further divided, or omitted, and additional components may be added as desired. As a specific example, processor 340 may be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphic processing units (GPUs). Furthermore, while FIG. 3 illustrates a client device configured as a mobile phone or smartphone, the UE may be configured to operate as other types of mobile or fixed devices.

[0041] Figure 4 illustrates an example of a base station (e.g., 116 and 118) according to an embodiment of the present disclosure. The embodiment of base station 400 illustrated in Figure 4 is for illustrative purposes only and may have the same or similar configuration as base stations 116, 118 of Figure 1. However, base stations have a variety of configurations, and Figure 2 does not limit the scope of the present disclosure to any particular implementation of a base station.

[0042] 2, the base station 400 includes multiple antennas 405a-405n, multiple RF transceivers 410a-410n, transmit (TX) processing circuitry 415 and receive (RX) processing circuitry 420. The base station 400 also includes a controller / processor 425, a memory 430, and a backhaul or network interface 435.

[0043] The RF transceivers 410a-410n receive incoming RF signals, such as signals transmitted by client devices, such as UEs, in the network 100, from the antennas 405a-405n. The RF transceivers 410a-410n downconvert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are communicated to the RX processing circuitry 420, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The RX processing circuitry 420 sends the processed baseband signals to the controller / processor 425 for further processing.

[0044] The TX processing circuitry 415 receives analog or digital data (such as voice data, web data, email, or interactive video game data) from the controller / processor 425. The TX processing circuitry 415 generates processed baseband or IF signals by encoding, multiplexing, and / or digitizing outgoing baseband data. The RF transceivers 410a-410n receive the outgoing processed baseband or IF signals from the transmit processing circuitry 415 and upconvert the baseband or IF signals to RF signals that are transmitted via the antennas 405a-405n.

[0045] The controller / processor 425 may include one or more processors or other processing devices that control the overall operation of the base station 400. For example, the controller / processor 425 may control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceivers 410a-410n, the RX processing circuitry 420, and the TX processing circuitry 415 in accordance with known principles. The controller / processor 425 may also support additional functionality, such as more advanced wireless communication functions. For example, the controller / processor 425 may support beamforming or directional routing operations that differentially weight outgoing / incoming signals from or to multiple antennas 405a-405n to effectively steer the outgoing signals in a desired direction. The controller / processor 425 may support any of a wide variety of other functions in the base station 400.

[0046] The controller / processor 225 may also execute programs and other processes, such as an operating system, that reside in the memory 430. The controller / processor 425 may move data in or out of the memory 430 as required by the executing processes.

[0047] The controller / processor 425 is also coupled to a backhaul or network interface 435. The backhaul or network interface 435 enables the base station 400 to communicate with other devices or systems over a backhaul connection or over a network. The interface 435 may support communication over any suitable wired or wireless connection. For example, if the base station 400 is implemented as part of a cellular communication system (e.g., supporting 5G / NR, LTE, or LTE-A), the interface 435 may enable the base station 400 to communicate with other base stations over a wired or wireless backhaul connection. If the base station 400 is implemented as an access point, the interface 435 may enable the base station 400 to communicate to a larger network (e.g., the Internet) over a wired / wireless short-range network or wired / wireless connection. The interface 435 includes any suitable structure supporting communication over a wired or wireless connection, such as an Ethernet or RF transceiver.

[0048] The memory 430 is coupled to the controller / processor 425. A portion of the memory 430 may include RAM, and another portion of the memory 430 may include flash memory or other ROM.

[0049] While FIG. 4 illustrates an example base station 400, various modifications may be made to FIG. 4 . For example, the base station 400 may include any number of each component shown in FIG. 4 . As a specific example, an access point may include multiple interfaces 435, and the controller / processor 425 may support robust message transmission and reception over a fronthaul network. As another specific example, while shown including a single instance of the TX processing circuitry 415 and a single instance of the RX processing circuitry 420, the base station 400 may include multiple instances of each (e.g., one per RF transceiver). Furthermore, various components in FIG. 4 may be combined, further divided, or omitted, and additional components may be added as needed.

[0050] While FIGS. 2, 3, and 5 depict exemplary devices in a communication system, various modifications may be made to FIGS. 2, 3, and 4. For example, various components may be combined, further divided, or omitted in FIGS. 2, 3, and 4, and additional components may be added as needed. As a specific example, main processor 340 may be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Furthermore, while FIG. 3 depicts client device 300 configured as a mobile phone or smartphone, client devices may be configured to operate as other forms of mobile or stationary devices. Furthermore, like computing and communication networks, client devices and servers may be implemented in a wide variety of configurations, and FIGS. 2, 3, and 4 do not limit the present disclosure to any particular client device or server.

[0051] Current O-RAN fronthaul protocol standards assume the robustness of the underlying network, and the sender has no way to detect failure to send a message over the fronthaul network or failure to decode the message at the receiver.

[0052] As an example, an open distributed unit (O-DU) (e.g., a baseband unit (BBU)) sends control plane messages to an open-radio unit (O-RU) that describe how to transmit user plane data over the air in the downlink direction, or how to receive on-air data and send it to the O-DU in the uplink.

[0053] In one example, if a control plane packet is lost in the fronthaul network or is not correctly decoded by the O-RU, the O-RU cannot transmit data on the DL or receive data on the UL.

[0054] In one example, this information that user data is not being transmitted over the air is not available to the O-DU to take further action for a very long period of time (i.e., until 3GPP (3rd Generation Partnership Project) HARQ (hybrid automatic repeat and request) or ARQ feedback is received from the UE).

[0055] The sender of an O-RAN message over the fronthaul interface has no way of understanding whether the message was received by the receiver, and if so, whether it was correctly decoded by the receiver. In some cases, the lack of this information can cause failures in mobile network transmission and reception.

[0056] Embodiments of the present disclosure provide a method for signaling the intention of a transmitter (e.g., O-DU) to receive feedback from a receiver (e.g., O-RU) regarding the reception and decoding status of a message transmitted by the transmitter. In this disclosure, the term "O-DU" can be replaced with the term "DU" in the overall description. Furthermore, the term "O-RU" can be replaced with the term "DU" in the overall description.

[0057] In one embodiment, a new section extension is provided for this purpose, which can be attached to existing O-RAN control plane messages.

[0058] In one example, upon receiving a message with a section extension indicating a request for feedback, the receiver of the message (e.g., O-RU) transmits the status of the message decoding to the transmitter (e.g., O-DU). This disclosure provides for the creation of a new control plane message type (Section Type 8) in the O-RAN standard for this purpose.

[0059] In one example, a new section extension to C-plane messages is provided that requests confirmation of the receipt and decoding status of the C-plane messages (eg, acknowledgement / negative acknowledgement (ACK / NACK)).

[0060] In one example, the O-DU attaches the provided new section extension to a C-plane message to request ACK / NACK feedback.

[0061] In one example, a new message from the O-RU to the O-DU is provided that indicates the ACK / NACK status of the section description in the C-plane message.

[0062] FIG. 5 illustrates an example of a high-level message flow 500 according to an embodiment of the present disclosure. The high-level message flow 500 may be performed by a network entity (e.g., the networks 102, 200 illustrated in FIG. 2) and / or a client device (e.g., 106-114 illustrated in FIG. 1). For example, the O-DU 520 may be realized in one of the network entities in 102, the server 104, and / or the base stations 116, 118. Specifically, the base stations 116, 118 may be implemented in a gNB that includes logical nodes hosting the radio link control (RLC), medium access control (MAC), and higher physical (PHY) layers based on lower layer functional split. For example, the O-RU 530 may be implemented in the base stations 116, 118. Specifically, the base stations 116, 118 may be implemented with a transmission and reception point (TRP) or remote radio head (RRH) that includes logical nodes hosting the low PHY layer and RF processing based on lower layer functional separation.

[0063] The embodiment of high-level message flow 500 shown in Figure 5 is for illustrative purposes only. One or more of the components shown in Figure 5 may be implemented with specialized circuitry configured to perform the functions described above, or one or more components may be implemented by one or more processors executing instructions to perform the functions described above.

[0064] As shown in FIG. 5, in step 502, the O-DU 520 transmits a C-plane message #1 with an ACK / NACK section extension to the O-RU 530. However, this transmission is dropped and not correctly transmitted to the O-RU 530. In step 504, the O-RU 530 transmits a C-plane message #2 with an ACK / NACK section extension to the O-RU 530, and this message is successfully transmitted to the O-RU. In step 506, the O-RU 530 transmits a C-plane message #3 with an ACK / NACK section extension to the O-RU 530, and this message is successfully transmitted to the O-RU 530. However, the O-RU 530 cannot correctly decode this message #3. In step 508, the O-RU 530 transmits U-plane data #1 for the C-plane message #1, but when the O-RU 530 receives it, the U-plane data #1 is dropped. In step 510, the O-RU 530 transmits U-plane data #2 for C-plane message #2. In step 512, the O-RU 530 transmits ACK / NACK messages as (1) C-plane #1=ACK and (2) C-plane #3=NACK.

[0065] FIG. 6 illustrates an example message flow 600 for robust messaging according to an embodiment of the present disclosure. Message flow 600 may be performed by a network entity (e.g., networks 102, 200 illustrated in FIG. 2) and / or a client device (e.g., 106-114 illustrated in FIG. 1). The embodiment of message flow 600 illustrated in FIG. 5 is for illustrative purposes only. One or more components illustrated in FIG. 5 may be implemented with specialized circuitry configured to perform the functions described above, or one or more components may be implemented by one or more processors executing instructions to perform the functions described above.

[0066] For example, the O-DU 620 may be implemented in one of the network entities 102, the server 104, and / or the base stations 116, 118. Specifically, the base stations 116, 118 may be implemented in a gNB including a logical node hosting the RLC / MAC / high PHY layers based on lower layer function separation. For example, the O-RU 630 may be implemented in the base stations 116, 118. Specifically, the base stations 116, 118 may be implemented in an RRH or TRP including a logical node hosting the low PHY layer and RF processing based on lower layer function separation.

[0067] As shown in FIG. 6, in step 602, the O-DU 620 transmits a C-plane message to the O-RU 630. During transmission, after Ext=xx is decoded in slot #n, the C-plane message (Ext=xx, ackReqSeqId=S13) is dropped. For example, in this instance, "xx" can be set to "22." In step 604, the O-RU 630 transmits an ACK message (numberofACKs=2, ackSeqId=SI1, SI2, numberofNACKs=1, nackSeqId=SI3) to the O-DU 630. Based on the nackSeqId set as SI3, the O-DU knows SI3 transmitted in Slot #n, and in step 604, it is dropped after Ext=xx is decoded. In step 606, the C-plane message (Ext=xx, ackReqSeqId=SI1) is lost or dropped before Ext=xx is decoded. In step 608, the O-DU 620 sends a C-plane message retransmission (Ext=xx, ackReqSeqId=SI3) to the O-RU 630. At the end of Slot #n+2, the O-DU recognizes that SI1, sent in Slot #n+1 in step 606, was lost or dropped before Ext=xx was decoded. In step 610, the O-RU 630 sends an ACK message (numberofACKs=1, ackSeqId=SI3). In step 612, the O-DU 620 sends a C-plane message retransmission (Ext=xx, ackReqSeqId=SI1) in slot #n+3.

[0068] FIG. 7 illustrates another example of a message flow 700 for robust messaging according to an embodiment of the present disclosure. Message flow 700 may be performed by a network entity (e.g., networks 102, 200 illustrated in FIG. 2) and / or a client device (e.g., 106-114 illustrated in FIG. 1). The embodiment of message flow 700 illustrated in FIG. 7 is for illustrative purposes only. One or more components illustrated in FIG. 7 may be implemented with specialized circuitry configured to perform the functions described above, or one or more components may be implemented by one or more processors executing instructions to perform the functions described above.

[0069] For example, the O-DU 720 may be implemented in one of the network entities in 102, the server 104, and / or the base stations 116, 118. Specifically, the base stations 116, 118 may be implemented in a gNB including a logical node hosting the RLC / MAC / high PHY layers based on lower layer function separation. For example, the O-RU 730 may be implemented in the base stations 116, 118. Specifically, the base stations 116, 118 may be implemented in an RRH or TRP including a logical node hosting the low PHY layer and RF processing based on lower layer function separation.

[0070] As shown in Figure 7, in step 702, the O-DU 720 transmits a C-plane message to the O-RU 730. During transmission, the C-plane message (Ext=xx, ackReqSeqId=Sl2) for symbol M is lost or dropped before "Ext=xx" is decoded. In step 702, the C-plane message (Ext=xx, ackReqSeqId=Sl3) for symbol M is dropped after Ext=xx is decoded. In step 702, the C-plane message (Ext=xx, ackReqSeqId=Sl1) for symbol M is received and correctly decoded. In step 704, the O-RU 730 transmits an ACK / NACK message (numberofACKs=1, ackSeqId=SI1, numberofNACKs=1, nackSeqId=SI3) after the time over-the-air of symbol M, i.e., at the start of the UL C-plane transmission window, where Tax_min_cp_ack can be 0 or a negative value. In step 702, the O-DU receives an ACK / NACK message (numberofACKs=1, ackSeqId=SI1, numberofNACKs=1, nackSeqId=SI3) between the start of the UL U-plane reception window and the end of the UL U-plane reception window. The O-DU recognizes that SI2 is dropped before decoding Ext=xx and that SI3 is dropped after decoding Ext=xx. The O-DU can decide to retransmit the dropped section descriptions.

[0071] 8 illustrates an example of a message format 800 according to an embodiment of the present disclosure. The embodiment of the message format 800 illustrated in FIG. 8 is for illustrative purposes only.

[0072] In one embodiment, an AckNackRequest section extension format is provided as shown in FIG.

[0073] Table 1 shows the description of the newly provided fields for the AckNackRequest section extension format, as shown in FIG.

[0074] [Table 1]

[0075] Table 2 shows a description of the Type #8 message format.

[0076] [Table 2]

[0077] 9 illustrates another example of a message format 900 according to an embodiment of the present disclosure. The embodiment of the message format 900 illustrated in FIG. 9 is for illustrative purposes only.

[0078] As shown in FIG. 9, the message format 900 includes the following fields:

[0079] Transport Header Fields: These fields indicate basic data routing capabilities, including a description of the data flow type, send and receive port identifiers, the ability to support the concatenation of multiple application messages in a single Ethernet packet, and sequence numbering.

[0080] Reserved Field: This field is reserved for future use.

[0081] Payload version field: This field indicates the payload protocol version.

[0082] FrameId field: This field indicates the frame identification and counter of the 10 ms frame.

[0083] subframeID field: This field indicates the subframe identification and counter of the 1 ms subframe.

[0084] SlotId field: This field indicates the slot number within the 1 ms subframe.

[0085] SymbolId field: This field indicates the symbol number.

[0086] SectionType field: This field indicates the characteristics of the U-plane date.

[0087] numberOfAcks field: This field indicates multiple ACKs.

[0088] numberOfNacks field: This field indicates the number of NACKs.

[0089] ackId field: This field indicates the identification of the Ack.

[0090] nackId field: This field indicates the identification of the Nack.

[0091] Padding field: This field is used to align to a 32-bit boundary.

[0092] FIG. 10 illustrates a flowchart of a method 1000 for robust message transmission and reception over a fronthaul network according to an embodiment of the present disclosure. The method 1000 may be performed by an O-DU (e.g., a transmitting device), such as a network entity shown in FIG. 2 (e.g., networks 102, 104, 116, 118, 200 shown in FIG. 1) and / or a client device (e.g., 106-114 shown in FIG. 1). The embodiment of the method 1000 shown in FIG. 10 is for illustrative purposes only. One or more components shown in FIG. 10 may be implemented with specialized circuitry configured to perform the functions described above, or one or more components may be implemented by one or more processors executing instructions to perform the functions described above.

[0093] As shown in FIG. 10, the method 1000 may be performed by an O-DU. The O-DU may be implemented in a base station and may communicate with an O-RU (e.g., a receiving device). The O-RU may be implemented in an RRH or TRP. A fronthaul link between the O-DU and O-RU is established to support robust message transmission between the O-DU and O-RU. The O-DU may include an RLC protocol layer, a MAC protocol layer, and a PHY protocol layer. The O-RU may include a lower PHY layer and an RF layer.

[0094] In one embodiment, a protocol stack including an RLC protocol layer, a MAC protocol layer, a PHY protocol layer, and an RF layer may be flexibly implemented regardless of the type of specific hardware or device, i.e., this protocol stack for fulfilling the roles of the O-DU and O-RU mentioned in this disclosure may be freely implemented in any kind of electronic device.

[0095] As shown in FIG. 10, in step 1002, a DU (e.g., O-DU) of a base station generates a section extension for an ACK / NACK request including an ackNackReqId field and an extLen field, where the ackNackReqId field indicates the ACK / NACK request ID of the section description and the extLen field indicates the size of the section extension.

[0096] Thereafter, in step 1004, the DU sends a C-plane message including a section extension to request an ACK / NACK to the RU.

[0097] Finally, in step 1006, the DU receives an ACK message corresponding to the C-plane message from the RU.

[0098] In one embodiment, the ACK message includes a numberOfAcks field indicating the number of ACKs included in the ACK message and an ackId field indicating that the section description included in the C-plane message was correctly received and decoded by the RU, and the ackId field corresponds to the ackNackReqId of the section description.

[0099] In one embodiment, the ACK message indicates a numberOfNacks field indicating the number of NACKs contained in the ACK message and a nackId field indicating that the section description contained in the C-plane message was not correctly received by the RU, and the nackId field corresponds to the ackNackReqId of the section description.

[0100] In one embodiment, the DU transmits a set of C-plane messages, each of which includes a section extension.

[0101] In one embodiment, the DU identifies an ACK reception window including a minimum window value (ta3_min_ack) and a maximum window value (ta3_max_ack) of symbol M for receiving an ACK message including at least one of ackId or nackId, where symbol M is the value of startSymbolId in the C-plane message conveying the section extension. The DU determines whether the ACK message or NACK message is received within the ACK reception window. The DU further retransmits another section description based on a determination that the ACK message or NACK message was not received within the ACK reception window. In this embodiment, the other section description is the same as the section description or a new section description updated from the section description, or the DU omits retransmission of the section description based on a determination that the ACK message was not received within the ACK reception window. In this embodiment, the ta3_min_ack and ta3_max_ack are measured from reception at the RU antenna to reception at the RU port.

[0102] In one embodiment, the DU checks an ACK reception window of symbol M for receiving an ACK message including ackId and nackId, where symbol M is the value of startSymbolId in a C-plane message conveying a section extension, and the DU determines whether the ACK message is received within the ACK reception window and includes nackId, and the DU further retransmits the section description to the RU based on the nackId.

[0103] In one embodiment, the DU determines whether the ACK message includes a NACK ID (nackId), and if an ACK message is received before sending the C-plane message, omits sending a U-plane message corresponding to the C-plane message including a section description corresponding to the NackId to the RU.

[0104] FIG. 11 illustrates a flowchart of a method 1100 for robust message transmission and reception over a fronthaul network according to an embodiment of the present disclosure. The method 1100 may be performed by an O-RU (e.g., a receiving device), such as a network (e.g., network entities 102, 104, 116, 118, 200 shown in FIG. 2) and / or a client device (e.g., 106-114 shown in FIG. 1). The embodiment of the method 1100 illustrated in FIG. 11 is for illustrative purposes only. One or more components illustrated in FIG. 11 may be implemented with specialized circuitry configured to perform the functions described above, or one or more components may be implemented by one or more processors executing instructions to perform the functions described above.

[0105] 11, the method 1100 may be performed by an O-RU. The O-RU may be implemented in a base station and in communication with an O-DU (e.g., a transmitting device). The O-RU may be implemented in an RRH, a TRP, or a UE. A fronthaul link between the O-DU and the O-RU is established to support robust message transmission between the O-DU and the O-RU.

[0106] 11, the method 1100 begins in step 1102. In step 1102, the RU receives a C-plane message including a section extension for requesting an ACK / NACK from the DU.

[0107] Next, in step 1104, the RU identifies the section extension included in the C-plane message for the ACK / NACK request, which includes an ackNackReqId field and an extLen field. In one example, the ackNackReqId field indicates the ACK / NACK request ID of the section description, and the extLen field indicates the size of the section extension.

[0108] Finally, in step 1106, the RU sends an ACK message corresponding to the C-plane message to the DU.

[0109] In one embodiment, the ACK message includes a numberOfAcks field indicating the number of ACKs included in the ACK message and an ackId field indicating that the section description included in the C-plane message was correctly received by the RU, and the ackId field corresponds to the ackNackReqId of the section description.

[0110] In one embodiment, the ACK message includes a numberOfNacks field indicating the number of NACKs included in the ACK message and a nackId field indicating that the section description included in the C-plane message was not received correctly by the RU, and the nackId field corresponds to the ackNackReqId of the section description.

[0111] In one embodiment, an RU receives a set of C-plane messages, each of which includes a section extension.

[0112] In one embodiment, the RU receives a retransmission of the section description based on determining that an ACK message was not received within an ACK receive window that includes ta3_min_ack and ta3_max_ack, where the retransmitted section description is the same as the previously received section description or a new section description updated from the previously received section description. The ACK receive window is identified to receive an ACK message with symbol M including at least one of ackId or nackId, where symbol M is the value of startSymbolId in the C-plane message conveying the section extension, and ta3_min_ack and ta3_max_ack are measured from reception at the RU antenna to reception at the RU port.

[0113] In one embodiment, the RU receives a retransmission of the section description to the RU based on nackId, and an ACK reception window is identified such that a symbol M receives an ACK message including ackId and nackId, where the symbol M is the value of startSymbolId in the C-plane message conveying the section extension.

[0114] In one embodiment, if the RU receives an ACK message before transmitting a C-plane message, it omits receiving a C-plane message including a section description corresponding to the nackId from the DU.

[0115] Figure 12 illustrates an example of a fronthaul interface 1200 according to an embodiment of the present disclosure. The embodiment of the fronthaul interface 1200 illustrated in Figure 12 is for illustrative purposes only.

[0116] As shown in FIG. 12, the network architecture 1200 includes a user equipment (UE) 1202 (e.g., 106-114 as shown in FIG. 1), a base station (BS) 1212 (e.g., 104, 116, 118 as shown in FIG. 1), and a core network 1210. The base station 1212 further includes an antenna 1204, a radio interface 1206, and a baseband 1208. The UE 1202 and the base station 1212 are connected via an air interface. The base station 1212 and the core network 1210 are connected via a backhaul interface. The antenna 1204 and the radio interface 1206 are connected via an RF interface, and the radio interface 1206 and the baseband 1208 are connected via a fronthaul interface.

[0117] DL / UL control messages may be transmitted and received between the air interface 1206 and the baseband 1208. To transmit and receive DL / UL control messages, a transmitter and a receiver may be implemented in the air interface 1206 and / or the baseband 1208.

[0118] The current xRAN / O-RAN standard uses five candidate compression techniques to address efficient fronthaul bandwidth (BW) utilization. Among these candidates, block floating is a good candidate from the perspective of simple implementation. From the perspective of BW efficiency, modulation compression is highly recommended for DL. The motivation for modulation compression shows a perfect picture that enables efficient fronthaul BW with ideal compression performance without compromising system performance. However, when considering modulation compression, there are some operational flaws that need to be resolved in the current specification. Namely, after RE mapping, several different data coexist within the PRB. Furthermore, per-channel power offset information is needed for clarification.

[0119] According to an embodiment, there is provided a transmitting device of a base station for processing an acknowledgement (ACK) of a control plane (C-plane) message in a wireless communication system. The transmitting device includes a processor that generates a section extension for requesting an acknowledgement / negative acknowledgement (ACK / NACK), the section extension including an ACK / NACK request identifier (ackNackReqId) field and a length (extLen) field. The ackNackReqId field indicates an ACK / NACK request identifier (ID) of a section description, and the extLen field indicates a size of the section extension. The transmitting device includes a transceiver operatively coupled to the processor. The transceiver is configured to transmit the C-plane message including the section extension for the ACK / NACK request to a receiving device and to receive an ACK message corresponding to the C-plane message from the receiving device.

[0120] In some embodiments In some embodiments, the ACK message includes a numberOfNacks field indicating the number of NACKs included in the ACK message, and a NACK ID (nackId) field indicating that a section description included in the C-plane message was not correctly received by the receiving device, where the nackId field corresponds to the ackNackReqId of the section description.

[0121] In some embodiments, the transceiver is further configured to transmit a set of C-plane messages, each C-plane message including a section extension.

[0122] In some embodiments, the processor is further configured to identify an ACK reception window of symbol M, including a minimum window value (ta3_min_ack) and a maximum window value (ta3_max_ack), for receiving an ACK message including at least one of an ACK ID (ackId) or a NACK ID (nackId). The symbol M is a value of a start symbol ID (startSymbolId) in a C-plane message conveying a section extension. ta3_min_ack and ta3_max_ack are measured from reception at a receiver antenna to reception at a receiver port. The processor is further configured to determine whether an ACK message is received within the ACK reception window. The transceiver is further configured to retransmit another section description based on determining that the ACK message or NACK message is not received within the ACK reception window. The other section description is the same as the section description or a new section description updated from the section description, or omit retransmission of the section description based on determining that the ACK message or the NACK message was not received within the ACK reception window.

[0123] In some embodiments, the processor is further configured to identify an ACK reception window relative to a symbol M for receiving an ACK message including an ACK ID (ackId) and a NACK ID (nackId), where the symbol M is a value of a start symbol ID (startSymbolId) in a C-plane message conveying a section extension. The processor is further configured to determine whether an ACK message received within the ACK reception window includes a nackId. The transceiver is further configured to retransmit a section description to a receiving device based on the nackId.

[0124] In some embodiments, the processor is further configured to determine whether the ACK message includes a NACK ID (nackId), and to omit sending to the receiving device a user plane (U-plane) message corresponding to a C-plane message that includes a section description corresponding to the nackId in the ACK message.

[0125] According to an embodiment, a receiving device for transmitting an acknowledgement (ACK) of a control plane (C-plane) message in a wireless communication system is provided. The receiving device includes a transceiver configured to receive, from a transmitting device, a C-plane message including a section extension for requesting an acknowledgement / negative acknowledgement (ACK / NACK). The receiving device includes a processor operatively coupled to the transceiver, the processor configured to identify the section extension included in a C-plane message for the ACK / NACK request, the C-plane message including an ACK / NACK request identifier (ackNackReqId) field and a length (extLen) field. The ackNackReqId field indicates the ACK / NACK request identifier (ID) of a section description, and the extLen field indicates the size of the section extension. The transceiver is further configured to transmit an ACK message corresponding to the C-plane message to the transmitting device.

[0126] In some embodiments, the ACK message includes a numberOfAcks field indicating the number of ACKs included in the ACK message, and an ACK ID (ackId) field indicating that the section description included in the C-plane message was correctly received by the receiving device, the ackId field corresponding to the ackNackReqId of the section description.

[0127] In some embodiments, the ACK message includes a numberOfNacks field indicating the number of NACKs included in the ACK message, and a NACK ID (nackId) field indicating that a section description included in the C-plane message was not correctly received by the receiving device, the nackId field corresponding to the ackNackReqId of the section description.

[0128] In some embodiments, the transceiver is further configured to receive a set of C-plane messages, each C-plane message including a respective section extension.

[0129] In some embodiments, the transceiver is further configured to receive a retransmission of the section description to a receiving device based on the NackId, where an ACK reception window of symbol M is identified for receiving an ACK message including an ACK ID (ackId) and a NACK ID (nackId), the symbol M being a start symbol ID (startSymbolId) value of a C-plane message conveying a section extension.

[0130] In some embodiments, the processor is further configured to skip receiving from a transmitting device the C-Plane message including a section description corresponding to a nackId when an ACK message is received before transmitting the C-Plane message.

[0131] According to an embodiment, a method for a base station transmitting device for processing acknowledgements (ACKs) of control plane (C-plane) messages in a wireless communication system is provided, the method including operations of generating a section extension for an acknowledgement / negative acknowledgement (ACK / NACK) request including an ACK / NACK request identifier (ackNackReqId) field and a length (extLen) field, where the ackNackReqId field indicates an ACK / NACK request identifier (ID) of a section description, and the extLen field indicates a size of the section extension.

[0132] The method includes an operation of transmitting a C-plane message including a section extension for requesting an ACK / NACK to a receiving device, and an operation of receiving an ACK message corresponding to the C-plane message from the receiving device.

[0133] In some embodiments, the ACK message includes a numberOfAcks field indicating the number of ACKs included in the ACK message, and an ACK ID (ackId) field indicating that the section description included in the C-plane message was correctly received by the receiving device, the ackId field corresponding to the ackNackReqId of the section description.

[0134] In some embodiments, the ACK message includes a numberOfNacks field indicating the number of NACKs included in the ACK message, and a NACK ID (nackId) field indicating that a section description included in the C-plane message was not correctly received by the receiving device, the nackId field corresponding to the ackNackReqId of the section description.

[0135] In some embodiments, the method further includes an act of transmitting a set of C-plane messages, each C-plane message including a section extension.

[0136] In some embodiments, the method further includes an operation of identifying an ACK receive window including a minimum window value (ta3_min_ack) and a maximum window value (ta3_max_ack) for receiving an ACK message, where symbol M includes at least one of an ACK ID (ackId) or a NACK ID (nackId). The symbol M is a value of a start symbol ID (startSymbolId) in a C-plane message conveying a section extension. The operation of determining whether an ACK message was received within the ACK receive window includes determining whether ta3_min_ack and ta3_max_ack are measured from reception at a receiver antenna to reception at a receiver port. The method further includes an operation of performing one of the following operations based on a determination that the ACK message or NACK message was not received within the ACK receive window: retransmitting another section description (the other section description is the same as the section description or a new section description updated from the section description), or skipping retransmission of the section description based on a determination that the ACK message or NACK message was not received within the ACK receive window.

[0137] In some embodiments, the method further includes an operation of identifying an ACK reception window for receiving an ACK message, where symbol M includes an ACK ID (ackId) and a NACK ID (nackId). The symbol M is a value of a start symbol ID (startSymbolId) of a C-plane message conveying a section extension. The method further includes an operation of determining whether an ACK message received within the ACK reception window includes a nackId. The method further includes an operation of retransmitting the section description to the receiving device based on the NackId.

[0138] According to an embodiment, a method is provided that is performed by an Open Radio Access Network (O-RAN) distributed unit (O-DU). The method includes transmitting one or more control plane (C-plane) messages to an O-RAN radio unit (O-RU) via a fronthaul interface. The method also includes receiving, from the O-RU via the fronthaul interface, an acknowledgement (ACK) / non-acknowledgement (NACK) feedback message for one or more C-plane messages. Each C-plane message of the one or more C-plane messages includes section extension information for an ACK / NACK request. The section extension information includes a request identifier (ID) used to identify a section description for which ACK / NACK feedback is requested. The ACK / NACK feedback message includes one or more of ACK information indicating the request ID of a correctly decoded section description or NACK information indicating the request ID of an incorrectly decoded section description.

[0139] For example, the incorrectly decoded section description is dropped after the section extension information associated with the incorrectly decoded section description is decoded.

[0140] For example, the section extension information includes an extension type for an ACK / NACK request and an extension length, which is one word equivalent to 4 bytes and indicates the size of the section extension information. The extension type is indicated by 7 bits of section extension information. The extension length is indicated by 8 bits of section extension information. The request identifier (ID) is indicated by 16 bits of section extension information.

[0141] For example, the method further includes an operation of identifying that a section description in one or more C-plane messages is dropped before section extension information corresponding to the dropped section description is decoded based on identifying that the ACK / NACK status of the section description in the one or more C-plane messages is not received by the end of the receive window.

[0142] For example, the ACK / NACK feedback message is associated with a C-plane message and includes a transport header and an application header. The application header includes a frame identifier, a subframe identifier, a slot identifier, a start symbol identifier, a section number, and a section type indicating section type 8 for transmitting ACK / NACKs from an O-RU to an O-DU. The ACK / NACK feedback message includes information indicating the number of ACKs included in the ACK / NACK feedback message and information indicating the number of NACKs included in the ACK / NACK feedback message. The number of ACKs is indicated by 8 bits in the ACK / NACK feedback message. The number of NACKs is indicated by 8 bits in the ACK / NACK feedback message.

[0143] According to an embodiment, a method is provided that is performed by an open radio access network (O-RAN) radio unit (O-RU). The method includes receiving one or more control plane (C-plane) messages from an O-RAN distributed unit (O-DU) via a fronthaul interface. The method also includes transmitting, via the fronthaul interface, an acknowledgement (ACK) / non-acknowledgement (NACK) feedback message for one or more C-plane messages to the O-RU. Each C-plane message of the one or more C-plane messages includes section extension information for requesting an ACK / NACK. The section extension information includes a request identifier (ID) used to identify a section description for which ACK / NACK feedback is requested. The ACK / NACK feedback message includes one or more of ACK information indicating the request ID of a correctly decoded section description or NACK information indicating the request ID of an incorrectly decoded section description.

[0144] For example, the incorrectly decoded section description is dropped after the section extension information associated with the incorrectly decoded section description is decoded.

[0145] For example, the section extension information includes an extension type for an ACK / NACK request and an extension length, which is one word equivalent to 4 bytes and indicates the size of the section extension information. The extension type is indicated by 7 bits of section extension information. The extension length is indicated by 8 bits of section extension information. The request identifier (ID) is indicated by 16 bits of section extension information.

[0146] For example, the ACK / NACK feedback message is transmitted within the ACK transmission window.

[0147] For example, the ACK / NACK feedback message is associated with a C-plane message and includes a transport header and an application header. The application header includes a frame identifier, a subframe identifier, a slot identifier, a start symbol identifier, a section number, and a section type indicating section type 8 for transmitting ACK / NACKs from an O-RU to an O-DU. The ACK / NACK feedback message includes information indicating the number of ACKs included in the ACK / NACK feedback message and information indicating the number of NACKs included in the ACK / NACK feedback message. The number of ACKs is indicated by an 8-bit ACK / NACK feedback message. The number of NACKs is indicated by an 8-bit ACK / NACK feedback message.

[0148] According to an embodiment, an open radio access network (O-RAN) distributed unit (O-DU) apparatus 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 transmit one or more control plane (C-plane) messages to an O-RAN radio unit (O-RU) via a fronthaul interface. The at least one processor is configured to control the at least one transceiver to receive, from the O-RU via the fronthaul interface, acknowledgement (ACK) / non-acknowledgement (NACK) feedback messages for one or more C-plane messages. Each C-plane message of the one or more C-plane messages includes section extension information for requesting an ACK / NACK. The section extension information includes a request identifier (ID) used to identify a section description for which ACK / NACK feedback is requested. The ACK / NACK feedback message includes one or more of ACK information indicating a request ID of a correctly decoded section description or NACK information indicating a request ID of an incorrectly decoded section description.

[0149] For example, the incorrectly decoded section description is dropped after the section extension information associated with the incorrectly decoded section description is decoded.

[0150] For example, the section extension information includes an extension type for an ACK / NACK request and an extension length, which is one word equivalent to 4 bytes and indicates the size of the section extension information. The extension type is indicated by 7 bits of section extension information. The extension length is indicated by 8 bits of section extension information. The request identifier (ID) is indicated by 16 bits of section extension information.

[0151] For example, the at least one processor is further configured to identify that a section description is dropped before section extension information corresponding to the dropped section description is decoded based on identifying that an ACK / NACK status for the section description from one or more C-plane messages is not received by the end of the receive window.

[0152] For example, the ACK / NACK feedback message is associated with a C-plane message and includes a transport header and an application header. The application header includes a frame identifier, a subframe identifier, a slot identifier, a start symbol identifier, the number of sections, and a section type indicating section type 8 for transmitting ACK / NACKs from an O-RU to an O-DU. The ACK / NACK feedback message includes information indicating the number of ACKs included in the ACK / NACK feedback message and information indicating the number of NACKs included in the ACK / NACK feedback message. The number of ACKs is indicated by an 8-bit ACK / NACK feedback message. The number of NACKs is indicated by an 8-bit ACK / NACK feedback message.

[0153] According to an embodiment, a method is provided in an apparatus for an Open Radio Access Network (O-RAN) Radio Unit (O-RU). The method 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 one or more control plane (C-plane) messages from an O-RAN distributed unit (O-DU) via a fronthaul interface. The at least one processor is configured to control the at least one transceiver to transmit acknowledgement (ACK) / negative acknowledgment (NACK) feedback messages for the one or more C-plane messages to the O-RU via the fronthaul interface. Each C-plane message of the one or more C-plane messages includes section extension information for requesting an ACK / NACK. The section extension information includes a request identifier (ID) used to identify a section description for which ACK / NACK feedback is requested. The ACK / NACK feedback message includes at least one of ACK information indicating a request ID of a correctly decoded section description or NACK information indicating a request ID of an incorrectly decoded section description.

[0154] For example, the incorrectly decoded section description is dropped after the section extension information associated with the incorrectly decoded section description is decoded.

[0155] For example, the section extension information includes an extension type for an ACK / NACK request and an extension length, which is one word equivalent to 4 bytes and indicates the size of the section extension information. The extension type is indicated by 7 bits of section extension information. The extension length is indicated by 8 bits of section extension information. The request identifier (ID) is indicated by 16 bits of section extension information.

[0156] For example, the ACK / NACK feedback message is transmitted within an ACK transmission window.

[0157] For example, the ACK / NACK feedback message is associated with a C-plane message and includes a transport header and an application header. The application header includes a frame identifier, a subframe identifier, a slot identifier, a start symbol identifier, a section number, and a section type indicating section type 8 for transmitting ACK / NACKs from an O-RU to an O-DU. The ACK / NACK feedback message includes information indicating the number of ACKs included in the ACK / NACK feedback message and information indicating the number of NACKs included in the ACK / NACK feedback message. The number of ACKs is indicated by an 8-bit ACK / NACK feedback message. The number of NACKs is indicated by an 8-bit ACK / NACK feedback message.

[0158] While the flowcharts illustrate exemplary methods that can be implemented in accordance with the principles of the present disclosure, various modifications may be made to the methods illustrated in the flowcharts of the present disclosure. For example, although shown as a series of steps, various steps in each figure may be overlapped, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0159] Although the present disclosure has been described in exemplary embodiments, those skilled in the art may suggest various modifications and variations. The present disclosure is intended to cover all such modifications and variations that fall within the scope of the appended claims. Nothing in this application should be construed as suggesting that a particular element, step, or function is an essential element that must be included in the scope of the claims. The scope of patented subject matter is defined by the claims that follow. [Explanation of symbols]

[0160] 100 Communication Systems 102 Network 104 Server 106~114 Client device 116 Base Station 118 Wireless Access Points 200 servers 205 Bus System 210 processors 215 Storage device 220 Communication Circuit 225 Input / Output (I / O) Circuit 225 processor 230 memory 235 Permanent Storage 240 display 300 Client Device 305 Antenna 310 RF Transceiver 315 TX processing circuit 320 microphone 325 RX processing circuit 330 Speaker 340 Main Processor 345 I / O interface 350 Touchscreen 355 Display 360 memory 361 Operating Systems 362 Applications 400 base stations 405 Antenna 410 RF Transceiver 415 Transmit (TX) Processing Circuit 420 Receive (RX) Processing Circuit 425 processor 430 memory 435 Network Interface 500 High-Level Message Flow 520 DU 530RU 600 Message Flow 620 DU 630RU 700 Message Flow 720 DU 730RU 800 Message Format 900 Message Format 1200 Fronthaul Interface 1200 Network Architecture 1202 User Equipment (UE) 1204 Antenna 1206 Wireless Interface 1208 Baseband 1210 Core Network 1212 Base Station (BS)

Claims

1. 1. A method performed by an Open Radio Access Network (O-RAN) Distribution Unit (O-DU), comprising: transmitting one or more control plane (C-plane) messages to an O-RAN radio unit (O-RU) via a fronthaul interface; and receiving an acknowledgement (ACK) / negative-acknowledgement (NACK) feedback message for the one or more C-plane messages from an O-RU via the fronthaul interface; Each C-plane message of the one or more C-plane messages includes a section description and section extension information for requesting ACK / NACK; The section extension information includes a request identifier (ID) used to identify the section description for which ACK / NACK feedback is requested; and The method, wherein the ACK / NACK feedback message includes at least one of ACK information indicating request IDs of correctly decoded section descriptions or NACK information indicating request IDs of erroneously decoded section descriptions.

2. The method of claim 1 , wherein the erroneously decoded section description is dropped after section extension information associated with the erroneously decoded section description is decoded.

3. the section extension information includes an extension type for the ACK / NACK request and an extension length indicating the size of the section extension information as one word corresponding to 4 bytes; The extension type is indicated by 7 bits of the section extension information, The extension length is indicated by 8 bits of the section extension information, The method of claim 1 , wherein the request ID is indicated by 16 bits of the section extension information.

4. 2. The method of claim 1, further comprising: based on identifying that an ACK / NACK status of the section description in the one or more C-plane messages is not received until an end of a receive window, recognizing that a C-plane message including the section description has been lost or that the section description is dropped before section extension information corresponding to the section description is decoded.

5. the ACK / NACK feedback message is associated with a C-Plane message and includes a transport header and an application header; The application header includes a frame identifier, a subframe identifier, a slot identifier, and a section type indicating section type 8 for transmitting ACK / NACK from the O-RU to the O-DU; the ACK / NACK feedback message includes information indicating the number of ACKs included in the ACK / NACK feedback message and information indicating the number of NACKs included in the ACK / NACK feedback message; The number of ACKs is indicated by 8 bits of an ACK / NACK feedback message; and The method of claim 1 , wherein the number of NACKs is indicated by 8 bits of an ACK / NACK feedback message.

6. 1. A method performed by an Open Radio Access Network (O-RAN) Radio Unit (O-RU), comprising: receiving one or more control plane (C-plane) messages from an O-RAN distributed unit (O-DU) via a fronthaul interface; and transmitting an acknowledgement (ACK) / negative-acknowledgement (NACK) feedback message for the one or more C-plane messages to the O-RU via the fronthaul interface; Each C-plane message of the one or more C-plane messages includes a section description and section extension information for requesting ACK / NACK; The section extension information includes a request identifier (ID) used to identify the section description for which ACK / NACK feedback is requested; and The method, wherein the ACK / NACK feedback message includes at least one of ACK information indicating request IDs of correctly decoded section descriptions or NACK information indicating request IDs of erroneously decoded section descriptions.

7. The method of claim 6 , wherein the erroneously decoded section description is dropped after section extension information associated with the erroneously decoded section description is decoded.

8. the section extension information includes an extension type for an ACK / NACK request and an extension length indicating the size of the section extension information as one word corresponding to 4 bytes; The extension type is indicated by 7 bits of the section extension information, The extension length is indicated by 8 bits of the section extension information, The method of claim 6 , wherein the request ID is indicated by 16 bits of the section extension information.

9. The method of claim 6 , wherein the ACK / NACK feedback message is transmitted within an ACK transmission window.

10. the ACK / NACK feedback message is associated with a C-Plane message and includes a transport header and an application header; The application header includes a frame identifier, a subframe identifier, a slot identifier, and a section type indicating section type 8 for transmitting ACK / NACK from an O-RU to an O-DU; the ACK / NACK feedback message includes information indicating the number of ACKs included in the ACK / NACK feedback message and information indicating the number of NACKs included in the ACK / NACK feedback message; The number of ACKs is indicated by 8 bits of an ACK / NACK feedback message; and The method of claim 6 , wherein the number of NACKs is indicated by 8 bits of an ACK / NACK feedback message.

11. 1. An apparatus for an Open Radio Access Network (O-RAN) Distributed Unit (O-DU), comprising: at least one transceiver; and at least one processor coupled to the at least one transceiver; The at least one processor controls the at least one transceiver to: Sending one or more control plane (C-plane) messages to an O-RAN Radio Unit (O-RU) via a fronthaul interface; and configured to receive, via the fronthaul interface, from an O-RU, an acknowledgement (ACK) / negative-acknowledgement (NACK) feedback message for the one or more C-plane messages; Each C-plane message of the one or more C-plane messages includes a section description and section extension information for requesting ACK / NACK; The section extension information includes a request identifier (ID) used to identify the section description for which ACK / NACK feedback is requested; and The ACK / NACK feedback message includes at least one of ACK information indicating request IDs of correctly decoded section descriptions or NACK information indicating request IDs of erroneously decoded section descriptions.

12. the section extension information includes an extension type for the ACK / NACK request and an extension length indicating the size of the section extension information as one word corresponding to 4 bytes; The extension type is indicated by 7 bits of the section extension information, The extension length is indicated by 8 bits of the section extension information, The request ID is indicated by 16 bits of the section extension information, the ACK / NACK feedback message is associated with a C-Plane message and includes a transport header and an application header; The application header includes a frame identifier, a subframe identifier, a slot identifier, and a section type indicating section type 8 for transmitting ACK / NACK from an O-RU to an O-DU; the ACK / NACK feedback message includes information indicating the number of ACKs included in the ACK / NACK feedback message and information indicating the number of NACKs included in the ACK / NACK feedback message; The number of ACKs is indicated by 8 bits of an ACK / NACK feedback message; and The apparatus of claim 11 , wherein the number of NACKs is indicated by 8 bits of an ACK / NACK feedback message.

13. 1. An apparatus for an open radio access network (O-RAN) radio unit (O-RU), comprising: at least one transceiver; and at least one processor coupled to the at least one transceiver; The at least one processor controls the at least one transceiver to: receiving one or more control plane (C-plane) messages from an O-RAN distributed unit (O-DU) via a fronthaul interface; and sending an acknowledgement (ACK) / negative-acknowledgement (NACK) feedback message for the one or more C-plane messages to an O-RU via the fronthaul interface; Each C-plane message of the one or more C-plane messages includes a section description and section extension information for requesting ACK / NACK; The section extension information includes a request identifier (ID) used to identify the section description for which ACK / NACK feedback is requested; and The ACK / NACK feedback message includes at least one of ACK information indicating request IDs of correctly decoded section descriptions or NACK information indicating request IDs of erroneously decoded section descriptions.

14. the section extension information includes an extension type for an ACK / NACK request and an extension length indicating the size of the section extension information as one word corresponding to 4 bytes; The extension type is indicated by 7 bits of the section extension information, The extension length is indicated by 8 bits of the section extension information, The request ID is indicated by 16 bits of the section extension information, the ACK / NACK feedback message is associated with a C-Plane message and includes a transport header and an application header; The application header includes a frame identifier, a subframe identifier, a slot identifier, and a section type indicating section type 8 for transmitting ACK / NACK from an O-RU to an O-DU; the ACK / NACK feedback message includes information indicating the number of ACKs included in the ACK / NACK feedback message and information indicating the number of NACKs included in the ACK / NACK feedback message; The number of ACKs is indicated by 8 bits of an ACK / NACK feedback message; and The apparatus of claim 13 , wherein the number of NACKs is indicated by 8 bits of an ACK / NACK feedback message.

15. A non-transitory computer-readable medium storing instructions that, when executed by an apparatus of an Open Radio Access Network (O-RAN) Distributed Unit (O-DU), cause the apparatus to perform a method according to any one of claims 1 to 5.

16. A non-transitory computer-readable medium storing instructions that, when executed by an apparatus of an open radio access network (O-RAN) radio unit (O-RU), cause the apparatus to perform a method according to any one of claims 6 to 10.

Images