Method and apparatus for providing broadcast service in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a base station in a wireless communication system includes identifying a second temporary mobile group identity (TMGI) different from a first TMGI for a broadcast service, and transmitting information about the second TMGI to an access and mobility function (AMF), and receiving, from the AMF, information about a broadcast session allocated by a multicast / broadcast-session management function (MB-SMF) based on the information about the second TMGI, and receiving, from the MB-UPF, broadcast data for broadcasting to a user equipment (UE).

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system, and to a method and apparatus for providing a broadcast service. Background Art

[0002] 5G mobile communication technology defines a wide frequency band, making high transmission rates and new services possible, and can be implemented not only in "below 6 GHz" frequency bands such as 3.5 GHz, but also in "above 6 GHz" frequency bands called mmWave including 28 GHz and 39 GHz. In addition, 6G mobile communication technology (called super 5G system) has been considered to be implemented in terahertz (THz) frequency bands (e.g., 95 GHz to 3 THz frequency bands) to achieve a transmission rate 50 times faster than 5G mobile communication technology and an ultra-low latency of one tenth of 5G mobile communication technology.

[0003] In the early stage of the development of 5G mobile communication technology, in order to support services and meet performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC) and massive machine type communication (mMTC), beamforming and massive MIMO for alleviating radio wave path loss and increasing radio wave transmission distance in mmWave, dynamic operation of parameter sets (e.g., operating multiple subcarrier spacings) and time slot formats supporting efficient utilization of mmWave resources, initial access technology for supporting multi-beam transmission and broadband, definition and operation of bandwidth parts (BWPs), new channel coding and decoding methods (such as low-density parity-check (LDPC) codes for large amounts of data transmission and polar codes for highly reliable control information transmission), L2 preprocessing, and standardization of network slicing for providing dedicated networks dedicated to specific services have been underway.

[0004] Currently, discussions are ongoing on improvements and performance enhancements of initial 5G mobile communication technologies in consideration of the services that 5G mobile communication technologies will support, and there is already physical layer standardization on technologies such as Vehicle-to-Everything (V2X) for assisting driving determination of autonomous vehicles based on information about the location and status of the vehicle sent by the vehicle and for enhancing user convenience, NR-U (New Radio Unlicensed) designed to allow system operation to comply with various regulatory-related requirements in unlicensed bands, NR UE power saving, a non-terrestrial network (NTN) as UE-satellite direct communication for providing coverage in areas where communication with terrestrial networks is unavailable, and positioning.

[0005] In addition, standardization is being conducted in air interface architecture / protocols on technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and integration with other industries, Integrated Access and Backhaul (IAB) for providing nodes for network service area expansion by supporting wireless backhaul links and access links in an integrated manner, mobility enhancement including conditional handover and dual active protocol stack (DAPS) handover, and two-step random access (2-step RACH for NR) for simplifying the random access procedure. Standardization is also being conducted in system architecture / services on 5G baseline architecture (e.g., service-based architecture or service-based interface) for combining network function virtualization (NFV) and software defined network (SDN) technologies, and mobile edge computing (MEC) for receiving services based on UE location.

[0006] As 5G mobile communication systems are commercialized, an exponentially increasing number of connected devices will be connected to the communication network, and therefore, it is expected that enhanced functions and performance of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is planned in relation to efficiently supporting extended reality (XR) such as augmented reality (AR), virtual reality (VR), mixed reality (MR), etc., 5G performance improvement and complexity reduction by utilizing artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a foundation for developing not only new waveforms for providing coverage in the terahertz band for 6G mobile communication technology, multi-antenna transmission technologies (such as full-dimensional MIMO (FD-MIMO), array antennas, and large antennas), metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional spatial multiplexing technologies using orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS), but also full-duplex technologies for improving the frequency efficiency of 6G mobile communication technology and improving system networks, AI-based communication technologies for implementing system optimization by utilizing satellites and artificial intelligence (AI) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technologies for implementing services with a complexity level that exceeds the limits of UE operating capabilities by utilizing ultra-high performance communication and computing resources.

[0008] As described above and according to the development of wireless communication systems, various services can be provided, and thus a method for seamlessly providing these services is required. In particular, a technology for providing a broadcast service in a wireless communication system is required.

[0009] The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above may be applicable as prior art with respect to the present disclosure. Summary of the invention

[0010] Solution to the problem

[0011] The present disclosure relates to a wireless communication network, and more particularly to a terminal and a communication method thereof in a wireless communication system.

[0012] According to one aspect of the present disclosure, a method performed by a base station in a wireless communication system may include: receiving information about a broadcast service associated with a first primary temporary mobile group identity (TMGI) from an application function (AF), identifying whether an update to a second primary TMGI is required, the second primary TMGI being different from the first primary TMGI, and when an update to the second primary TMGI is required, sending a first message associated with the second primary TMGI to an access and mobility management function (AMF), and receiving a second message associated with the second primary TMGI from the AMF as a response to the first message, wherein the base station is shared between a first operator and a second operator to provide services.

[0013] Advantageous Effects of the Invention

[0014] Aspects of the present disclosure are to address at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below. Therefore, one aspect of the present disclosure is to provide an efficient communication method in a wireless communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0016] Figure 1 An example of the structure of a 5G system in a wireless communication system according to an embodiment of the present disclosure is shown;

[0017] Figure 2 An example of a configuration of a base station in a wireless communication system according to an embodiment of the present disclosure is shown;

[0018] Figure 3 An example of a configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure is shown;

[0019] Figure 4 An example of configuration of a network entity in a wireless communication system according to an embodiment of the present disclosure is shown;

[0020] Figure 5 An example of a case where a service operator is changed in a case of RAN sharing in a wireless communication system according to an embodiment of the present disclosure is shown;

[0021] Figure 6An example of a process of generating a broadcast session for a broadcast service through a shared base station in a wireless communication system according to an embodiment of the present disclosure is shown;

[0022] Figure 7 An example of a method for updating a primary TMGI when a RAN is shared in a wireless communication system according to an embodiment of the present disclosure is shown;

[0023] Figure 8 Another example of a method for updating a primary TMGI when a RAN is shared in a wireless communication system according to an embodiment of the present disclosure is shown;

[0024] Fig. 9 An example of a method of updating a primary TMGI when an operator serving the primary TMGI does not provide a service in a wireless communication system according to an embodiment of the present disclosure is shown; and

[0025] Fig.10 Another example of a method of updating a primary TMGI when an operator serving the primary TMGI does not provide a service in a wireless communication system according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0026] Aspects of the present disclosure are to address at least the above-mentioned problems and / or disadvantages and provide at least the advantages described below. Therefore, one aspect of the present disclosure is to provide a terminal in a wireless communication system and a communication method thereof.

[0027] Various embodiments of the present disclosure provide an apparatus and method for efficiently providing a service in a wireless communication system.

[0028] According to an embodiment of the present disclosure, a method performed by a base station in a wireless communication system may include: receiving information about a broadcast service related to a first primary temporary mobile group identifier (TMGI) from an application function (AF), identifying whether an update to a second primary TMGI is required, the second primary TMGI is different from the first primary TMGI, when an update to the second primary TMGI is required, sending a first message related to the second primary TMGI to an access and mobility management function (AMF), and receiving a second message related to the second primary TMGI from the AMF as a response to the first message, wherein the base station is shared between a first operator and a second operator to provide services.

[0029] According to an embodiment of the present disclosure, a method performed by an application function (AF) in a wireless communication system may include: sending information about a broadcast service related to a first primary temporary mobile group identifier (TMGI) to a base station, receiving a first message from a network exposure function (NEF), the first message including information indicating that a broadcast session for the first primary TMGI has been released, and sending a second message including information about a second primary TMGI to the NEF, the second primary TMGI being different from the first primary TMGI, wherein the base station is shared between a first operator and a second operator to provide services.

[0030] According to an embodiment of the present disclosure, a method performed by a base station in a wireless communication system may include: receiving information about a broadcast service associated with a first primary temporary mobile group identifier (TMGI) from an application function (AF), receiving a first message from an access and mobility management function (AMF), the first message including information for deleting the broadcast service associated with the first primary TMGI, identifying whether an update to a second primary TMGI is required, the second primary TMGI being different from the first primary TMGI, and sending information about the second primary TMGI, wherein the base station is shared between a first operator and a second operator to provide services.

[0031] According to an embodiment of the present disclosure, a method performed by an application function (AF) in a wireless communication system may include: sending information about a broadcast service associated with a first primary temporary mobile group identifier (TMGI) to a base station, identifying whether an update to a second primary TMGI is required, the second primary TMGI being different from the first primary TMGI, and sending a first message including information for deleting the broadcast service associated with the first primary TMGI to a session management function (SMF) through a network exposure function (NEF), wherein the first message includes information about the second primary TMGI, and the base station is shared between the first operator and the second operator to provide services.

[0032] Various embodiments of the present disclosure provide an apparatus and method for efficiently providing a service in a wireless communication system.

[0033] Effects obtainable from the present disclosure are not limited to the above-mentioned effects, and other effects that are not mentioned can be clearly understood by those skilled in the art in the art of the present disclosure through the following description.

[0034] Before proceeding to the following detailed description, it may be helpful to set forth definitions of certain words and phrases used throughout this patent document: the terms "include" and "comprising," and their derivatives, mean inclusion without limitation; the term "or" is inclusive, meaning and / or; the phrases "associated with" and "associated with," and their derivatives may mean including, included, interconnected with, containing, contained within, connected to or connected with, coupled to or coupled with, capable of, cooperating with, interleaved, juxtaposed, proximate, combined with or combined with, having, having characteristics, and the like; and the term "controller" refers to any device, system, or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware, or software, or some combination of at least the two. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether local or remote.

[0035] In addition, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed by a computer-readable program code and contained in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data or a part thereof suitable for implementation with a 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 any type of medium that can be accessed by a computer, such as a read-only memory (ROM), a random access memory (RAM), a hard drive, a compact disk (CD), a digital video disc (DVD) or any other type of memory. "Non-transitory" computer-readable media does not include wired, wireless, optical or other communication links that transmit temporary electrical signals or other signals. Non-transitory computer-readable media include media that can permanently store data and media that can store data and rewrite it later, such as rewritable optical disks or erasable memory devices.

[0036] Definitions for certain words and phrases are provided in this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

[0037] Embodiments of the present invention

[0038] Discussed below Figures 1 to 10 The various embodiments used to describe the principles of the present disclosure in this patent document are exemplary only and should not be interpreted in any way as limiting the scope of the present disclosure. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any appropriately arranged system or device.

[0039] Hereinafter, the operating principle of the present disclosure will be described in detail with reference to the accompanying drawings. When describing the present disclosure below, when it is determined that a detailed description of a known function or configuration incorporated herein may make the subject matter of the present disclosure unnecessarily unclear, the description will be omitted. The terms to be described below are terms defined in consideration of the functions in the present disclosure, and may differ depending on the user, the user's intention or custom. Therefore, the definition of the terms should be based on the content in the entire specification.

[0040] For the same reason, in the accompanying drawings, some elements may be enlarged, omitted or schematically shown. In addition, the size of each element does not fully reflect the actual size. In the accompanying drawings, the same or corresponding elements have the same reference numerals.

[0041] By referring to the embodiments described in detail below in conjunction with the accompanying drawings, the advantages and features of the present disclosure and the ways to achieve them will be clear. However, the present disclosure is not limited to the embodiments set forth below, but can be implemented in various different forms. The following embodiments are provided only to fully disclose the present disclosure and inform those skilled in the art of the scope of the present disclosure, and the present disclosure is limited only by the scope of the attached claims. Throughout the specification, the same or similar reference numerals represent the same or similar elements.

[0042] Here, it should be understood that each box of the flowchart diagram and the combination of boxes in the flowchart diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create a component for implementing the function specified in one or more flowchart boxes. These computer program instructions can also be stored in a computer-usable or computer-readable memory, which can instruct the computer or other programmable data processing device to act in a specific way, so that the instructions stored in the computer-usable or computer-readable memory produce an article of instruction components including the functions specified in one or more flowchart boxes. The computer program instructions can also be loaded on a computer or other programmable data processing device so that a series of operating steps are performed on a computer or other programmable device to produce a computer-implemented process, so that the instructions executed on a computer or other programmable device provide steps for implementing the functions specified in one or more flowchart boxes.

[0043] In addition, each box of the flowchart diagram may represent a module, fragment or part of a code, which includes one or more executable instructions for implementing the specified one or more logical functions. It should also be noted that in some alternative implementations, the functions mentioned in the box may not occur in order. For example, two boxes shown in succession can actually be executed substantially simultaneously, or these boxes can sometimes be executed in reverse order, depending on the functions involved.

[0044] As used herein, "unit" refers to a software element or hardware element that performs a predetermined function, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, "unit" does not always have a meaning limited to software or hardware. "Unit" can be constructed to be stored in an addressable storage medium or to execute one or more processors. Therefore, "unit" includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, processes, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays and parameters. The elements and functions provided by "unit" can be combined into a smaller number of elements or "units", or divided into a larger number of elements or "units". In addition, elements and "units" can be implemented as one or more CPUs in a reproduction device or a secure multimedia card. In addition, "unit" in an embodiment can include one or more processors.

[0045] In the following description of the present disclosure, when it is determined that a detailed description of a known function or configuration incorporated herein may make the subject matter of the present disclosure unnecessarily unclear, the description will be omitted.

[0046] In the following description, for the convenience of description, terms for identifying access nodes, terms referring to network entities (NEs), terms referring to messages, terms referring to interfaces between NEs, terms referring to various identification information, etc. are illustratively used. Therefore, the present disclosure is not limited to the terms used below, and other terms referring to subjects having equivalent technical meanings may be used.

[0047] The terms used in the present disclosure are only used to describe specific embodiments and are not intended to limit the present disclosure. Singular expressions may include plural expressions unless they are clearly different in context. Unless otherwise defined, all terms used herein (including technical terms and scientific terms) have the same meaning as the meanings generally understood by those skilled in the art to which the present disclosure belongs. Those terms as defined in commonly used dictionaries may be interpreted as having the same meaning as the contextual meanings in the relevant art, and should not be interpreted as having ideal or overly formal meanings, unless clearly defined in the present disclosure. In some cases, even the terms defined in the present disclosure should not be interpreted as excluding embodiments of the present disclosure.

[0048] Hereinafter, various embodiments of the present disclosure will be described based on a hardware method. However, various embodiments of the present disclosure include technologies using both hardware and software, and therefore various embodiments of the present disclosure may not exclude the software aspect.

[0049] In the following description of the present disclosure, for ease of description, the terms and names defined in the LTE and NR standards are used, and the LTE and NR standards are the latest standards specified by the Third Generation Partnership Project (3GPP) group in the existing communication standards. However, the present disclosure is not limited to these terms and names, and can be applied to systems that comply with other standards in the same manner. In particular, the present disclosure can be applied to 3GPP NR (5th generation mobile communication standard). In addition, based on the determination of those skilled in the art, without significantly departing from the scope of the present disclosure, the embodiments of the present disclosure can also be applied to other communication systems with similar technical backgrounds or channel types with some modifications.

[0050] Hereinafter, the present disclosure relates to a wireless communication system, and provides a method and apparatus for efficiently performing broadcast data transmission. Specifically, the present disclosure provides a method for updating a session for a broadcast service in a shared base station. When multiple operators share an NG-RAN in a wireless communication system supporting broadcast services (i.e., when the NG-RAN is shared in a multi-operator core network (MOCN) solution), and when each of the operators provides the same service from the same broadcast service provider, the NG-RAN can provide services through a single temporary mobile group identifier (TMGI) (e.g., a primary TMGI). A technique for performing an update of a primary TMGI while saving and using resources by reducing overlapping broadcast data transmissions when the NG-RAN provides services through a single TMGI is described.

[0051] In the description, for the convenience of description, the terms used to identify access nodes, the terms referring to network entities, the terms referring to messages, the terms referring to interfaces between network entities, the terms referring to various identification information, etc. have been illustratively used. Therefore, the present disclosure is not limited by the terms used below, and other terms referring to themes with equivalent technical meanings may be used. For example, in the following description, for the convenience of description, the terms referring to signals (e.g., messages, information, preambles, signals, signaling, sequences, and flows), the terms for operating states (e.g., steps, operations, and processes), the terms referring to data (e.g., packets, user flows, information, bits, symbols, and codewords), the terms referring to channels, the terms referring to control information (e.g., downlink control information (DCI), media access control control elements (MAC CE), and radio resource control (RRC) signaling), the terms referring to network entities, the terms referring to interfaces between network entities (e.g., N1, N2, and N3), the terms referring to device elements, etc. are illustratively used. Therefore, the present disclosure is not limited by the terms used below, and other terms referring to subjects having equivalent technical meanings may be used.

[0052] In the present disclosure, various embodiments will be described using terms adopted in some communication standards (eg, the 3rd Generation Partnership Project (3GPP)), but they are for illustrative purposes only. The embodiments of the present disclosure can also be easily applied to other communication systems by modification.

[0053] In order to provide broadcast services, the 5G system (5GS) may receive broadcast service data from an application function (AF) or a content provider. The 5GC may transmit the broadcast service data to a new generation radio access network (NG-RAN) to send the broadcast service data to a terminal at a desired location. According to an embodiment of the present disclosure, the NG-RAN may include a base station. In the 5G core network, the broadcast data may be transmitted to the NG-RAN corresponding to the base station of the 5G network through shared delivery. That is, when the NG-RAN has a multicast / broadcast service (MBS) capability, the broadcast service data may be sent to the NG-RAN from a user plane function (multicast / broadcast user plane function (MB-UPF)) for providing broadcast services through a tunnel for shared delivery. For ease of description, the 5G network is described as an example, but a limited interpretation that the embodiments of the present disclosure are only applied to the 5G core network or the 5G network should not be made.

[0054] In the case of using NG-RAN as MOCN between multiple operators through RAN sharing, when a content provider provides the same broadcast service to each operator, NG-RAN can perform broadcast based on the primary temporary mobile group identity (TMGI). In this case, the update of the primary TMGI may be required due to the situation of NG-RAN, the change of the operator network through which the primary TMGI is served, etc.

[0055] Hereinafter, when an operator provides the same broadcast service in an NG-RAN used by an operator through RAN sharing in a 5G system (5GS) and the broadcast service is provided while reducing the use of overlapping resources through a primary TMGI, the apparatus and method according to an embodiment of the present disclosure may perform an update of the primary TMGI. Therefore, the apparatus and method according to an embodiment of the present disclosure may continuously provide the broadcast service through the update of the primary TMGI.

[0056] Based on the above discussion, the present disclosure relates to a wireless communication system, wherein when multiple operators share an NG-RAN in a wireless communication system supporting broadcast services (i.e., when the NG-RAN is shared in a multi-operator core network (MOCN) solution), and when each of the operators provides the same service from the same broadcast service provider, the NG-RAN can provide the broadcast service through a primary TMGI. The present disclosure provides a method and apparatus for updating the primary TMGI when reducing the use of overlapping resources while the NG-RAN provides the broadcast service.

[0057] In addition, the present disclosure provides a method and apparatus for an operation of a terminal to continuously receive broadcast data when a primary TMGI is updated in a RAN-sharing NG-RAN for providing broadcast service data in a wireless communication system.

[0058] Advantageous effects obtainable from the present disclosure may not be limited to the above-mentioned effects, and other effects that are not mentioned may be clearly understood by those skilled in the art to which the present disclosure pertains through the following description.

[0059] In addition, in the following description, for the convenience of description, the terms and names defined in the %G system standard are used. However, the present disclosure is not limited to these terms and names, and can be applied to systems conforming to other standards in the same manner.

[0060] Figure 1 An example of the structure of a 5G system (5GS) in a wireless communication system according to an embodiment of the present disclosure is shown. Figure 1 The 5G system (5GS) 100 is an example for convenience of description, but it should not be assumed that the embodiments of the present disclosure are only applicable to Figure 1 Explanation of the structure of the 5GS100.

[0061] refer to Figure 1 , 5GS100 may include a user equipment (UE) 101, a NG-RAN 102 corresponding to a base station, an access and mobility management function (AMF) 103, a multicast / broadcast user plane function (MB-UPF) 105, a multicast / broadcast-session management function (MB-SMF) 107, a policy control function (PCF) 109, a session management function (SMF) 111, a network exposure function (NEF) 113, a multicast / broadcast service function (MBSF) 1115, a multicast / broadcast service traffic function (MBSTF) 117, an application function (AF) device or content provider, a unified data management (UDM) 121, a user plane function (UPF) 123, an authentication server function (AUSF) 125, and a NF repository function (NRF) 127. The network entities included in 5GS100 are not limited to the above examples, and 5GS100 may include more than Figure 1 The configurations shown may be more or less configurations.Herein, each device may be referred to as a network entity, a network function, or a network function means.

[0062] refer to Figure 1 , each network function (NF) of 5GS100 itself is described as a "network entity" or "network function". However, it is clear to those skilled in the art that the NF and / or NF device can be implemented in one server or two or more servers, and two or more NFs performing the same operation can be implemented in a single server.

[0063] In addition, according to an embodiment of the present disclosure, one NF or two or more NFs may be implemented as one network slice. Network slices may be generated based on specific purposes. For example, network slices may be configured for a subscriber group to provide the same type of service (e.g., maximum transmission rate and data usage, guaranteed minimum transmission rate, etc.) to a specific subscriber group. In addition, network slices may be implemented according to various purposes.

[0064] refer to Figure 1 , Figure 1The interfaces between the various nodes of the 5GS 100 are shown. For example, a Uu interface may be used between the UE 101 and the NG-RAN 102. An N2 interface may be used between the NG-RAN 102 and the AMF 103. An N3 interface may be used between the NG-RAN 102 and the UPF 123. An N3mb interface may be used between the NG-RAN 102 and the MB-UPF 105. In addition, an N4mb interface may be used between the MB-UPF 105 and the MB-SMF 107. An N19mb interface may be used between the MB-UPF 105 and the UPF 123. An N4 interface may be used between the SMF 111 and the UPF 123. An N6 interface may be used between the UPF 123 and the AF 119. An Nmb2 interface may be used between the MBSF 115 and the MBSTF 117. In addition, an Nm9 interface may be used between the MB-UPF 105 and the MBSTF 117. The Mmb8 / xMB-U / MB2 interfaces may be used between the AF 119 and the MBSTF 117. These interfaces are defined in detail in the NR standard, and thus a detailed description of these interfaces is omitted.

[0065] In general, to support broadcast services in 5GS100, a cellular system for broadcast services may be configured based on the following network function (NF) devices and services.

[0066] According to an embodiment of the present disclosure, AF 119 may provide various services. For example, AF 119 may be a V2X application server, a cellular Internet of Things (CIoT), an application server, a mission-critical push-to-talk (MCPTT) application, a content provider, a TV or audio service provider, a streaming video service provider, etc.

[0067] In addition, the AF 119 may request MBS service provision to the MBSF 115 corresponding to the NF for controlling session management and traffic of the MBS service to provide the MBS service. The MBSF 115 may be an NF for receiving a request for the MBS service from the AF 119 in order to manage the MBS service session and control the MBS service traffic. In addition, the MBSTF 117 may be an NF for receiving media from a content provider based on the control of the MBSF 115, an application server (AS) for providing MBS, or an AF for providing MBS in order to process media traffic. That is, the MBSTF 117 may operate as an MBS service anchor in the 5GS 100.

[0068] In the 5G core network (5GC), the MBS system may be configured and operated without including the MBSF 115 and the MBSTF 117. When the MBSF 115 and the MBSTF 117 are not included, the AF 119 may request the MB-SMF 107 for MBS service provision directly, or request the MB-SMF 107 for MBS service provision through the NEF 113. In this case, the MBS data may be provided to the 5G network from an application server (AS) for providing MBS or from a content provider through the MB-UPF 105.

[0069] In the present disclosure, AF 119 may be an application server (AS) for providing a specific broadcast application service. Therefore, the AS hereinafter may be understood to be the same as AF 119, or to exist together with AF 119. In order to provide MBS services to UE 101, AF 119 may send a request for MBS service provision to MBSF 115. MBSF 115 may control MBSTF 117 corresponding to the MBS service media anchor in 5GS 100, which sends MBS service traffic to UE 101. Therefore, MBSF 115 may provide MBS services to UE 101. In this case, MBS services may refer to data received from a specific content provider according to a multicast / broadcast service.

[0070] According to an embodiment, MBSF 115 and MBSTF 117 may be configured to be integrated into one entity or one NF. In addition, MBSF 115 may be configured to be integrated with NEF 113 or another NF. In addition, in 5GS 100, AF 119 may directly request MBS services from MB-SMF 107 without MBSF 115 and MBSTF 117, and MB-UPF 105 may receive media from a content provider corresponding to AS or AF 119 and forward traffic.

[0071] According to an embodiment, MBS services may be managed, and service traffic may be generated through MBSF 115 and MBSTF 117. Here, when service traffic is transmitted to UE 101 via broadcast, MBSF 115 may manage MBS services, MB-SMF 107 may allocate MBS sessions, and MBSTF 117 may operate as a media anchor point for corresponding MBS traffic. That is, MBSF 115 may correspond to a control plane for managing MBS services, and MBSTF 117 may correspond to a user plane for managing MBS traffic.

[0072] Hereinafter, in the present disclosure, the term "Multimedia Broadcast-Multicast Service Gateway-Control Plane (MBMS-GW-C)" may be used to collectively refer to a control function or service for generating an MBS context for an MBS PDU session, managing the MBS session, and transmitting traffic of the MBS session to the NG-RAN 102 corresponding to a base station via IP multicast.

[0073] The MBMS-GW-C service may be integrated with the existing SMF 111 for managing unicast PDU sessions and configured as the SMF 111 having the MBS session control function, or may be configured as a separate NF. Hereinafter, in the present disclosure, the NF that supports the MBMS-GW-C service and also has the function of the existing SMF is referred to as MF-SMF 107.

[0074] In addition, in the present disclosure, a service for transmitting traffic received from the MB-UPF 105 according to the MBS context of the MBS PDU session via IP multicast to the NG-RAN 102 for performing multicast / broadcast according to the MBMS-GW-C service is referred to as a Multimedia Broadcast-Multicast Service Gateway-User Plane (MBMS-GW-U) service.

[0075] The MBMS-GW-U service may be integrated with an existing UPF for handling unicast PDU sessions and configured as a UPF with the functionality to deliver MBS traffic to the appropriate NG-RAN 102 via IP multicast, or may be configured as Figure 1 Therefore, hereinafter, in the present disclosure, a NF that supports the MBMS-GW-U service and also has the function of the existing UPF is referred to as MB-UPF 105.

[0076] As mentioned above, the MBMS-GW-C service can use the N4mb interface to control the MBMS-GW-U service.

[0077] When describing the embodiments of the present disclosure, for the convenience of description, the MBMS-GW-C and the MBMS-GW-U may be referred to as the MB-STF 107 and the MB-UPF 105, respectively.

[0078] MBS traffic may be delivered from the MBMS-GW-U (or MB-UPF 105) to the NG-RAN 102. For example, the MBS traffic may be delivered to the NG-RAN 102 by using IP multicast, or may be delivered to the NG-RAN 102 by using a unicast tunnel. In this case, the tunnel between the MBMS-GW-U (or MB-UPF 105) and the NG-RAN 102 may be referred to as a shared delivery tunnel. Hereinafter, for ease of description, the tunnel between the MBMS-GW-U and the NG-RAN 102 may be referred to as a shared delivery tunnel or a shared tunnel.

[0079] To configure the shared delivery tunnel, MBMS-GW-C (or MB-SMF 107) may send a control message to NG-RAN 102 via AMF 103.

[0080] Figure 2 An example of a configuration of a base station in a wireless communication system according to an embodiment of the present disclosure is shown. Figure 2 The configuration of the base station 102 shown in FIG. 1 can be understood as Figure 1 Configuration of the NG-RAN 102. The terms "... unit", "... device" and the like used hereinafter refer to a unit for processing at least one function or operation and may be implemented as hardware, software, or a combination of hardware and software.

[0081] refer to Figure 2 , the base station 102 may include a wireless communication circuit 210 , a backhaul communication circuit 220 , a storage device 230 , and a controller 240 .

[0082] The wireless communication circuit 210 performs a function for transmitting or receiving a signal via a wireless channel. For example, the wireless communication circuit 210 performs a function of converting between a baseband signal and a bit stream according to the physical layer specification of the system. For example, during data transmission, the wireless communication circuit 210 generates complex symbols by encoding and modulating the transmission bit stream. When receiving data, the wireless communication circuit 210 recovers the received bit stream by demodulating and decoding the baseband signal.

[0083] In addition, the wireless communication circuit 210 up-converts the baseband signal into a radio frequency (RF) band signal, then transmits the up-converted RF band signal via the antenna, and down-converts the RF band signal received via the antenna into a baseband signal. To this end, the wireless communication circuit 210 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. In addition, the wireless communication circuit 210 may include multiple transmit / receive paths. In addition, the wireless communication circuit 210 may include at least one antenna array including multiple antenna elements.

[0084] In terms of hardware, the wireless communication circuit 210 may include a digital unit and an analog unit, wherein the analog unit includes a plurality of subunits according to operating power, operating frequency, etc. The digital unit may be implemented as at least one processor (eg, a digital signal processor (DSP)).

[0085] The wireless communication circuit 210 transmits and receives signals as described above. Therefore, all or part of the wireless communication circuit 210 may be referred to as a "transmitter," "receiver," or "transceiver." In addition, in the following description, transmission and reception performed via a wireless channel are used as meanings including that the above-mentioned processing is performed by the wireless communication circuit 210.

[0086] The backhaul communication circuit 220 provides an interface for performing communication with other nodes within the network. That is, the backhaul communication circuit 220 converts a bit stream sent from a base station to another node (e.g., another access node, another base station, a higher node, a core network, etc.) into a physical signal, and converts a physical signal received from another node into a bit stream.

[0087] The storage device 230 stores data used for the operation of the base station, such as basic programs, application programs, configuration information, etc. The storage device 230 may include a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The storage device 230 provides the stored data according to a request of the controller 240.

[0088] The controller 240 controls the overall operation of the base station. For example, the controller 240 sends and receives signals via the wireless communication circuit 210 or the backhaul communication circuit 220. In addition, the controller 240 records data in the storage device 230 and reads data from the storage device 230. In addition, the controller 240 can perform the functions of the protocol stack required by the communication standard. According to another implementation example, the protocol stack can be included in the wireless communication circuit 210. To this end, the controller 240 may include at least one processor. According to various embodiments, the controller 240 may perform control to perform synchronization using a wireless communication network. For example, the controller 240 may control the base station to perform operations according to the various embodiments described below.

[0089] Figure 3 An example of a configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure is shown. Figure 3 The configuration of the terminal 101 shown in FIG. 1 can be understood as Figure 1 The terms "... unit", "... device" and the like used hereinafter refer to a unit for processing at least one function or operation and may be implemented as hardware, software, or a combination of hardware and software.

[0090] refer to Figure 3 , the terminal 101 may include a communication circuit 310 , a storage device 320 and a controller 330 .

[0091] The communication circuit 310 performs a function for transmitting or receiving a signal via a wireless channel. For example, the communication circuit 310 performs a function of converting between a baseband signal and a bit stream according to the physical layer specification of the system. For example, during data transmission, the communication circuit 310 generates complex symbols by encoding and modulating the transmitted bit stream. When receiving data, the communication circuit 310 recovers the received bit stream by demodulating and decoding the baseband signal. In addition, the communication circuit 310 up-converts the baseband signal to an RF band signal, then transmits the up-converted RF band signal via an antenna, and down-converts the RF band signal received via the antenna to a baseband signal. For example, the communication circuit 310 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

[0092] In addition, the communication circuit 310 may include multiple transmit / receive paths. In addition, the communication circuit 310 may include at least one antenna array including multiple antenna elements. In terms of hardware, the communication circuit 310 may include digital circuits and analog circuits (e.g., radio frequency integrated circuits (RFIC)). The digital circuits and analog circuits may be implemented in a single package. In addition, the communication circuit 310 may include multiple RF chains. In addition, the communication circuit 310 may perform beamforming.

[0093] The communication circuit 310 transmits and receives signals as described above. Therefore, all or part of the communication circuit 310 may be referred to as a "transmitter," "receiver," or "transceiver." In addition, in the following description, transmission and reception performed via a wireless channel are used as meanings including that the above-mentioned processing is performed by the communication circuit 310.

[0094] The storage device 320 stores data used for the operation of the terminal, such as basic programs, application programs, configuration information, etc. The storage device 320 may include a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The storage device 320 provides the stored data according to a request of the controller 330.

[0095] The controller 330 controls the overall operation of the terminal. For example, the controller 330 sends and receives signals via the communication circuit 310. In addition, the controller 330 records data in the storage device 320 and reads data from the storage device 320. The controller 330 can perform the functions of the protocol stack required by the communication standard. To this end, the controller 330 may include at least one processor or microprocessor, or may be a part of a processor. In addition, a part of the communication circuit 310 and the controller 330 may be referred to as a communication processor (CP). According to various embodiments, the controller 330 may perform control to perform synchronization using a wireless communication network. For example, the controller 330 may control the terminal to perform operations according to the various embodiments described below.

[0096] Figure 4 An example of the configuration of a network entity in a wireless communication system according to an embodiment of the present disclosure is shown. Figure 4 The network entity 400 shown may be understood as having Figure 1 The present invention relates to a configuration of a device for performing at least one function of AMF 103, MB-UPF 105, MB-SMF 107, PCF 109, SMF 111, NEF 113, MBSF 115, MBSTF 117, AF 119, UDM 121, UPF 123, AUSF 125 and NRF 127. The terms "... unit", "... device" and the like used hereinafter refer to a unit for processing at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

[0097] refer to Figure 4 , the network entity 400 may include a communication circuit 410 , a storage device 420 , and a controller 430 .

[0098] The communication circuit 410 provides an interface for performing communication with other devices within the network. That is, the communication circuit 410 converts a bit stream sent from a network entity to another device into a physical signal, and converts a physical signal received from another device into a bit stream. In other words, the communication circuit 410 can send and receive signals. Therefore, the communication circuit 410 can be referred to as a modem, a transmitter, a receiver, or a transceiver. In this case, the communication circuit 410 enables the network entity to communicate with other devices or systems via a network or backhaul connection (e.g., a wired backhaul or a wireless backhaul).

[0099] The storage device 420 stores data used for the operation of the network entity, such as basic programs, applications, and configuration information. The storage device 420 may include a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The storage device 420 provides the stored data according to the request of the controller 430.

[0100] The controller 430 controls the overall operation of the core network entity. For example, the controller 430 sends and receives signals via the communication circuit 410. In addition, the controller 430 records data in the storage device 420 and reads data from the storage device 420. To this end, the controller 430 may include at least one processor. According to various embodiments, the controller 430 may perform control to perform synchronization using a wireless communication network. For example, the controller 430 may control the network entity to perform operations according to various embodiments to be described below.

[0101] Figure 5 An example of a case where a service operator is changed in a case of RAN sharing in a wireless communication system according to an embodiment of the present disclosure is shown. Figure 5 In situation 500, an example is shown of a situation in which an operator providing a service in NG-RAN or 5GC is changed while providing the same broadcast service through RAN sharing NR-RAN in a wireless communication system.

[0102] refer to Figure 5 , a broadcast service may be performed through an MBS system by operator A, and the same broadcast service may be performed through an MBS system by operator B. In this case, operator A and operator B may share a specific NG-RAN. In the case of the RAN sharing NG-RAN 510, data actually broadcasted may be overlapped and broadcasted by operator A and operator B. In this case, the RAN sharing NG-RAN 510 may provide a broadcast service by configuring the TMGI of operator A as the primary TMGI. The broadcast data transmitted from the MB-UPF to the NG-RAN through the network of operator B is the same as the broadcast data transmitted through the network of operator A, so the shared tunnel from the MB-UPF of the network of operator B to the NG-RAN may be deleted.

[0103] Regarding case #1, the NG-RAN 510 may no longer support the network of operator A. Therefore, when the primary TMGI needs to be updated, the broadcast service needs to be continuously provided. Alternatively, regarding case #2, the network of operator A may no longer support the broadcast service. Therefore, when the primary TMGI needs to be updated, the broadcast service needs to be continuously provided. As described above, the present disclosure provides a method for continuously providing a broadcast service even when the primary TMGI is updated.

[0104] Figure 6 An example of a process of generating a broadcast session for a broadcast service through a shared base station in a wireless communication system according to an embodiment of the present disclosure is shown. Figure 6The UE, NG-RAN, AMF, MB-SMF, MB-UPF, NEF / MBSF and AF (content provider) described in Figure 1 The network entities included in the 5GS100 are the same. In addition, Figure 6 The MB-PCF can be understood as Figure 1 The PCF 109 is basically the same. For example, Figure 6 MB-PCF can be referred to as being able to provide Figure 1 The PCF 109 is a PCF for MBS related services.

[0105] According to an embodiment, in operation 600, the AF may receive allocation of a temporary mobile group identity (TMGI) from the MB-SMF through the NEF to generate a broadcast session (MBS session) for a broadcast service.

[0106] In operation 605, the AF may identify that the same broadcast service is provided in another operator's network before requesting an MBS session to the MB-SMF for the TMIG. In addition, the AF may identify the TMGI value used by each operator. That is, the AF may identify a list of one or more TMGIs for providing broadcast services. Here, the TMGI may include information of the operator providing the broadcast service. For example, the TMGI may include a public land mobile network (PLMN) ID. The TMGI may be information indicating the operator through which the broadcast service is provided. According to an embodiment, the AF may define a broadcast service ID value separately from the TMGI value indicating the broadcast service of each network of the operator, and the broadcast service ID value is used to indicate a broadcast service that is not related to the operator's network. In other words, the AF may identify that a broadcast service is provided for each operator based on the TMGI value. In addition, the AF may identify that a broadcast service is provided for each service based on the broadcast service ID.

[0107] In operation 610, the AF may send a message for requesting MBS session generation for the TMGI to the NEF. For example, the message for requesting MBS session generation may be a Nnef_MBSSsession_Create request message. In operation 615, the NEF having received the message for requesting MBS session generation may send an MBS session generation request message to the MB-SMF. For example, the message sent by the NEF to the MB-SMF may be a Nmbsmf_MBSSession_Create request message. In other words, in operations 610 and 615, the AF may request MBS session generation for the TMGI from the MB-SMF through the NEF in a specific operator network. That is, the AF may request an MBS session for the TMGI through an MBS session generation request message (e.g., a Nnef_MBSSession_Create request and a Nmbsmf_MBSSession_Create request message). The MBS session generation request message may include at least one of a TMGI, a broadcast service ID, or a list of one or more TMGIs for providing the same broadcast service in another network. The TMGI list may include or may not include the TMGI of the operator network. Here, when operating a NG-RAN shared between operators through RAN sharing, the broadcast service ID and the TMGI list may be included in the MBS session generation request message. That is, the broadcast service ID and the TMGI list may be used as information for identifying a case where the same broadcast service data is transmitted in the RAN sharing NG-RAN (or MOCN NG-RAN).

[0108] In operation 620, the MB-SMF may generate an N4mb session. In operation 625a, the MB-SMF may send a response to operation 610 to the NEF. In operation 630a, the NEF may send a response to operation 615 to the AF. Alternatively, as shown in operations 625b and 630b, after generating a broadcast session (MBS session) in the MBS network, a response to the AF may be sent to the AF.

[0109] In operation 635, the MB-SMF having received the MBS session generation request for the broadcast service may send a broadcast session context generation request message (Namf_Broadcast_ContextCreate_request) to the AMF. In this case, the broadcast session context generation request message may include a TMGI to select the NG-RAN corresponding to the MBS service area. In addition, when the MB-UPF sends data to the NG-RAN via multicast, the broadcast session context generation request message may include a low-layer source-specific IP multicast address. The broadcast session context generation request message may include the MBS service area. The broadcast session context generation request message may include the received broadcast service ID or a list of one or more TMGIs for providing the same broadcast service.

[0110] In operation 640, the AMF may send an N2 message request to the NG-RAN by using the message received from the MB-SMF. The N2 message request may include a TMGI. In addition, when the MB-UPF sends data to the NG-RAN via multicast, the N2 message request may include a lower layer source specific IP multicast address (LL SSM). The N2 message request may include an MBS service area and may include a service type set to a broadcast service. The N2 message request may include a received broadcast service ID or a list of one or more TMGIs for providing the same broadcast service. According to an embodiment, only when the NG-RAN corresponds to a RAN shared NG-RAN (or MOCN NG-RAN), the N2 message request in operation 640 may include a received broadcast service ID or a list of one or more TMGIs for providing the same broadcast service. However, the present disclosure is not limited thereto, and even when the NG-RAN does not correspond to a RAN shared NG-RAN, the N2 message request may include a broadcast service ID or a list of one or more TMGIs for providing the same broadcast service.

[0111] In operation 645, the NG-RAN may generate an MBS session context for a broadcast service. When the NG-RAN corresponds to a RAN shared NG-RAN (or MOCN NG-RAN), a primary TMGI to be used when the NG-RAN sends broadcast data may be selected, and the selected primary TMGI may be included in the MBS session context. The RAN shared NG-RAN (or MOCN NG-RAN) may select a TMGI for a broadcast service provided by an operator that owns the NG-RAN as the primary TMGI. Alternatively, the RAN shared NG-RAN (or MOCN NG-RAN) may select a TMGI for a broadcast service provided by an operator determined as an operator for providing services to more UEs in an MBS service area among the operators sharing the NG-RAN as the primary TMGI. Alternatively, the RAN shared NG-RAN (or MOCN NG-RAN) may select a TMGI for a broadcast service provided by an operator having the highest importance or the highest facility contribution among the operators sharing the NG-RAN and providing the same broadcast service as the primary TMGI.

[0112] When LL SSM information is received from MB-SMF through operations 635 and 640, NG-RAN may also request to join to receive broadcast service data from MB-UPF via multicast. However, when the TMGI of the operator network is different from the primary TMGI, RAN shared NG-RAN (or MOCN NG-RAN) may not request to join.

[0113] In operations 650 and 655, the NG-RAN may send a response (e.g., an N2 message response and a Namf_MBSBroadcast_ContextCreate response) to operations 635 and 640 to the MB-SMF through the AMF. Through operations 650 and 655, TMGI information and N3mb DL tunnel information for data reception that may be sent to the NG-RAN. Thus, a tunnel for transmitting broadcast service data may be generated between the NG-RAN and the MB-UPF. When the NG-RAN corresponds to a RAN shared NG-RAN (or a MOCN NG-RAN), the message sent in operations 650 and 655 may include at least one of a broadcast service ID, primary TMGI information, or NG-RAN location information. Alternatively, when the NG-RAN corresponds to a RAN shared NG-RAN (or a MOCN NG-RAN), the message sent in operations 650 and 655 may include a broadcast service ID, primary TMGI information, and NG-RAN location information. For example, the NG-RAN location information may include an ID of the NG-RAN, a cell ID, geographic location information, or geographic address information.

[0114] In operations 660 and 665, the MB-SMF may perform an MBS SM policy update procedure with the MB-PCF or PCF. In the case where the RAN shares the NG-RAN (or MOCN NG-RAN), the MB-SMF may perform an MBS SM policy update procedure to identify whether the MB-SMF is allowed to provide services using the primary TMGI. In addition to the TMGI, the MBS SM policy update message may include part or all of the broadcast service ID, primary TMGI information, and NG-RAN location information.

[0115] When the MB-SMF has received a response that the RAN shared NG-RAN can provide services using the primary TMGI, in operation 670, the MB-SMF may generate a tunnel for transmitting broadcast service data between the NG-RAN and the MB-UPF. In operations 625b and 630b, the MB-SMF may transmit the response to operations 610 and 615 to the AF. The messages in operations 625b and 630b may include part or all of the broadcast service ID, the primary TMGI information, or the NG-RAN location information. For example, the NG-RAN location information may include the ID of the NG-RAN, the cell ID, the geographic location information, or the geographic address information.

[0116] In operation 670, when the primary TMGI is different from the TMGI, the MB-SMF may not send downlink tunnel information to the NG-RAN to prevent data from being sent through the tunnel between the NG-RAN and the MB-UPF. Alternatively, the MB-SMF may transmit an indicator instructing the MB-UPF not to send broadcast data corresponding to the TMGI. Alternatively, when the primary TMGI is different from the TMGI, operation 670 may not be performed.

[0117] In operation 675 , the RAN shared NG-RAN (or MOCN NG-RAN) may perform broadcasting to transmit broadcast service data through the primary TMGI determined in operation 645 instead of the TMGI.

[0118] In operation 680, in order to provide a broadcast service through RAN sharing NG-RAN (or MOCN NG-RAN), the AF may notify the terminal of updated information through MBS service announcement to notify the use of the primary TMGI instead of the TMGI. In addition to the TMGI information, the MBS service announcement may include a broadcast service ID, primary TMGI information, NG-RAN location information, MBS frequency selection area ID, or part or all of the session description protocol. For example, the NG-RAN location information may include at least one of the ID of the NG-RAN, the cell ID, the geographic location information, or the geographic address information.

[0119] In operation 690, even if the broadcast service data is received using the TMGI through operation 685, the RAN shared NG-RAN (or MOCN NG-RAN) may transmit only traffic of the broadcast service data received using the primary TMGI.

[0120] In operation 695, when located in the RAN shared NG-RAN (or MOCN NG-RAN), the terminal, which has received the information on the use of the primary TMGI through operation 680, may receive broadcast service data through the primary TMGI.

[0121] Figure 7 An example of a method for updating a primary temporary mobile group identity (TMGI) when a RAN is shared in a wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Figure 7 An example of a method of updating a primary TMGI by a NG-RAN when the primary TMGI is invalid in a RAN shared NG-RAN in a wireless communication system is shown.

[0122] Figure 7 The UE, NG-RAN, AMF, MB-SMF, MB-UPF, NEF / MBSF and AF (content provider) described in Figure 1 The network entities included in the 5GS100 are the same. In addition, Figure 7 The MB-PCF can be understood as Figure 1 The PCF 109 is basically the same. For example, Figure 7 MB-PCF can be referred to as being able to provide Figure 1 The PCF 109 is a PCF for MBS related services.

[0123] In operation 700, the AF (or content provider) may transmit broadcast service data to the RAN shared NG-RAN. In operation 705, the NG-RAN may broadcast the broadcast service data to the terminal through the primary TMGI.

[0124] In operation 710, when the NG-RAN may no longer provide broadcast service data through the primary TMGI, the NG-RAN may select a TMGI of an operator providing the same broadcast service other than the primary TMGI as a new primary TMGI, and recognize that an update is required. For example, the case where the broadcast service can no longer be provided through the primary TMGI may be a case where the contract for RAN sharing for the NG-RAN is terminated for the operator providing services through the TMGI used as the primary TMGI, a case where it is determined that the broadcast service cannot be performed normally according to the policy of the operator providing services through the TMGI used as the primary TMGI, or a case where resources allocated to the operator providing services through the TMGI used as the primary TMGI cannot be used due to a failure in the NG-RAN. In this case, the NG-RAN may need to select a new primary TMGI and perform an update.

[0125] The NG-RAN, which has selected a new primary TMGI, may release the broadcast session that has been served by the existing primary TMGI. In operation 715, the NG-RAN may send a broadcast session release request message for the existing primary TMGI to the AMF. The AMF may perform a broadcast session release with the NG-RAN and notify the MB-SMF that the broadcast session has been released. The MB-SMF may perform an N4mb session update to delete the downlink tunnel between the MB-UPF and the NG-RAN. That is, in the broadcast session release request process, the 3GPP Ts 23.247 may be used to release the broadcast session. Figure 7 .3.6-1 Release the broadcast session of the existing primary TMGI.

[0126] The RAN shared base station may be updated with a new master TMGI of an operator serving a TMGI in addition to an existing master TMGI for providing the same broadcast service.

[0127] In operation 720, for TMGIs other than the existing primary TMGI, the RAN shared NG-RAN may send an MBS broadcast context update request message to the AMF. The NG-RAN may send a request message (e.g., MBSBroadcastConextupdate request) to notify the 5GC of the change of the primary TMGI and update the broadcast session context. The request message may include the new primary TMGI and may include RAN location information or NG-RAN ID to indicate the base station. The request message may include a broadcast service ID to identify that the service is the same broadcast service. In addition, the request message may also include information about the tunnel used to send broadcast downlink data (e.g., N3mb DL tunnel information).

[0128] In operation 725, the AMF may send a Nmbsmf_MBSSession_ContextUpdate request message to the MB-SMF. In this case, in operation 720, the AMF may forward the message received from the NG-RAN, or may send a Namf_MBSBroadcast_ContextStatus notification message to the MB-SMF. The Namf_MBSBroadcast_ContextStatus notification message may include part or all of the new primary TMGI, RAN location information, NG-RAN ID, broadcast service ID, or N3mb DL tunnel information. Therefore, the AMF may notify the MB-SMF whether the primary TMGI has changed.

[0129] In operation 730, the MB-SMF may perform an SM policy update with the MB-PCF. In operation 735, the MB-SMF may send an N4mb session update message including a new primary TMGI and N3mb DL tunnel information to the MB-UPF. The N4mb session update message may include information about a tunnel for sending broadcast downlink data. In this case, when the corresponding TMGI is not the primary TMGI, a deactivation indicator may be included to prevent overlapping broadcast data from being sent to the NG-RAN. Therefore, the MB-UPF that has received the deactivation indicator or has recognized that the TMGI is different from the primary TMGI may not forward the broadcast service data transmitted to the corresponding TMGI to the NG-RAN.

[0130] In operation 740, the MB-SMF may send an MBS broadcast context update response message to the NG-RAN through the AMF. The MB-SMF may send a processing result of the broadcast session context update request to the NG-RAN. In operation 735, the NG-RAN may broadcast broadcast data to the terminal through the newly allocated primary TMGI.

[0131] In operation 745, the MB-SMF may send information about the primary TMGI to the MBSF through a Nmbsmf_MBSSession_StatusNotify message. In operation 750, the NEF may send a Nnef_MBSSession_StatusNotify message to the AF based on the message received from the MB-SMF. The Nmbsmf_MBSSession_StatusNotify and Nnef_MBSSession_StatusNotify messages may include a new primary TMGI, a broadcast service ID, base station location information, and a NG-RAN ID.

[0132] In operation 760, the AF may replace the primary TMGI. Therefore, in operation 765, the AF may send a service announcement message to the terminal. For example, the AF may send information for receiving a broadcast service from the MOCN base station to the terminal. In operations 770 and 775, the NG-RAN may broadcast broadcast service data to the terminal by using the new primary TMGI.

[0133] Figure 8 Another example of a method for updating a primary temporary mobile group identity (TMGI) when a RAN is shared in a wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Figure 8 An example of a method of updating a primary TMGI by an AF when the primary TMGI is invalid in a RAN shared NG-RAN in a wireless communication system is shown.

[0134] Figure 8 The UE, NG-RAN, AMF, MB-SMF, MB-UPF, NEF / MBSF and AF (content provider) described in Figure 1 The network entities included in the 5GS100 are the same. In addition, Figure 8 The MB-PCF can be understood as Figure 1 The PCF 109 is basically the same. For example, Figure 8 MB-PCF can be referred to as being able to provide Figure 1 The PCF 109 is a PCF for MBS related services.

[0135] In operation 800, the AF (or content provider) may transmit broadcast service data to the RAN shared NG-RAN. In operation 804, the NG-RAN may broadcast the broadcast service data to the terminals in the NG-RAN through the primary TMGI.

[0136] In operation 808, when the NG-RAN may no longer provide broadcast service data through the primary TMGI, the NG-RAN may select a TMGI of an operator providing the same broadcast service other than the primary TMGI as a new primary TMGI, and recognize that an update is required. For example, the case where the broadcast service can no longer be provided through the primary TMGI may be a case where the contract for RAN sharing for the NG-RAN is terminated for the operator providing services through the TMGI used as the primary TMGI, a case where it is determined that the broadcast service cannot be performed normally according to the policy of the operator providing services through the TMGI used as the primary TMGI, or a case where resources allocated to the operator providing services through the TMGI used as the primary TMGI cannot be used due to a failure in the NG-RAN. In this case, the NG-RAN may need to select a new primary TMGI and perform an update.

[0137] The NG-RAN, which has selected a new primary TMGI, may release the broadcast session that has been served by the existing primary TMGI. In operation 812, the NG-RAN may send a broadcast session release request message for the existing primary TMGI to the AMF. The AMF may perform a broadcast session release with the NG-RAN and notify the MB-SMF that the broadcast session has been released. The MB-SMF may perform an N4mb session update to delete the downlink tunnel between the MB-UPF and the NG-RAN. That is, in the broadcast session release request process, the 3GPP Ts 23.247 may be used to release the broadcast session. Figure 7 .3.6-1 Release the broadcast session of the existing primary TMGI.

[0138] In operation 816, the MB-SMF may send a Nmbsmf_MBSSession_StatusNotify message to the NEF to notify that the broadcast session through the existing primary TMGI has been released from the NG-RAN. In operation 820, the NEF, which has received the message for notifying that the broadcast session through the existing primary TMGI has been released, may notify the AF through the Nnef_MBSSession_StatusNotify message that the broadcast session through the existing primary TMGI has been released. Here, the message sent by the MB-SMF to the NEF and the message sent by the NEF to the AF (e.g., Nmbsmf_MBSSession_StatusNotify and Nnef_MBSSession_StatusNotify) may include information (indication) indicating that the corresponding TMGI can no longer provide services in the NG-RAN. The messages (e.g., Nmbsmf_MBSSession_StatusNotify and Nnef_MBSSession_StatusNotify) may include NG-RAN location information or NG-RAN ID. In addition, the messages (eg, Nmbsmf_MBSSession_StatusNotify and Nnef_MBSSession_StatusNotify) may include a broadcast service ID. In other words, the MB-SMF may notify the AF of information about the overlapping broadcast services through the broadcast service ID.

[0139] In operation 824, the AF may newly allocate a primary TMGI and update the primary TMGI. The update may be performed for an operator serving a TMGI other than the existing primary TMGI. The process of the AF newly allocating a primary TMGI and updating the primary TMGI may be performed through operations 828 to 884. The process in operations 828 to 884 corresponds to a process for updating the primary TMGI based on the AF, and when initially allocating the primary TMGI, a creation message may be used instead of an update message used in operations 828 to 884. That is, in order to Figure 8 The description in is convincing, describing the process of updating the master TMGI, but the same description applies to the case of initial allocation and generation of the master TMGI.

[0140] In operation 828, for a TMGI other than the existing TMGI, the AF may send a Nnef_MBSSession_Update request message to the NEF. In operation 832, the NEF may send a Nmbsmf_MBSSession_Update request message to the MB-SMF. Thus, the AF may notify the MB-SMF of the newly selected primary TMGI. The request message (e.g., the Nnef_MBSSession_Update request message and the Nmbsmf_MBSSession_Update request message) may include the newly selected primary TMGI other than the TMGI of the corresponding operator. In addition, the request message (e.g., the Nnef_MBSSession_Update request message and the Nmbsmf_MBSSession_Update request message) may include a broadcast service ID for indicating a broadcast service.

[0141] In operation 836, the MB-SMF may configure a broadcast service data path with the MB-UPF. In operations 840a and 844a, the MB-SMF may send a response message to operations 828 and 832 to the AF based on the configured path. That is, in operation 840a, the MB-SMF may send a response message (e.g., Nmbsmf_MBSSession_Update response) to operation 832 to the NEF, and in operation 844a, the NEF may send a response message (e.g., Nnef_MBSSession_Update response) to operation 828 to the AF. Alternatively, the response message may also be sent to the AF through operations 840b and 844b after the completion of the configuration to the NG-RAN.

[0142] In operation 848, the MB-SMF may send a Namf_MBSBroadcast_ContextUpdate request message to the AMF to notify the NG-RAN of the new primary TMGI. The request message (e.g., Namf_MBSBroadcast_ContextUpdate request) may include the new primary TMGI in addition to the TMGI of the corresponding operator, and may also include the broadcast service ID. In operation 852, the AMF may forward the received request message to the NG-RAN in the broadcast service area, or may send a request message corresponding to the received request message to the NG-RAN. The AMF may notify the new primary TMGI and the broadcast service ID in addition to the TMGI of the corresponding operator through a message sent to the NG-RAN. In operation 856, the RAN shared NG-RAN may update the MBS session context and update the primary TMGI. Thereafter, in operation 880, the RAN shared NG-RAN may provide broadcast services to the terminal through the primary TMGI instead of using the TMGI for the corresponding broadcast service.

[0143] In operation 860, the NG-RAN may send information to the AMF on a tunnel for sending downlink broadcast traffic as a response to the message received in operation 852. In addition, in operation 864, the AMF may send a Namf_MBSBroadcast_ContextUpdate response message to the MB-SMF as a response to the message received in operation 848. The Namf_MBSBroadcast_ContextUpdate response message may include tunnel information for sending downlink broadcast traffic, RAN shared NG-RAN location information, ID, etc. For example, the NG-RAN location information may include an ID of the NG-RAN, a cell ID, geographic location information, or geographic address information.

[0144] In operations 868 and 872, the MB-SMF may perform an SM policy update with the MB-PCF. In operation 876, the MB-SMF may perform an N4bmb session update with the MB-UPF. To avoid overlapping transmissions to the NG-RAN when the N4mb session update is performed and the TMGI is different from the new primary TMGI, tunnel information for sending downlink broadcast traffic may not be sent, or an N4mb session update including an indication of deactivation of the downlink tunnel may be sent to the MB-UPF.

[0145] In operation 840b, the MB-SMF may send the result of the primary TMGI update to the NEF. In operation 844b, the NEF may send the result of the primary TMBI update to the AF. In this case, the message including information about the result of the primary TMGI update may include location information or ID of the RAN shared NG-RAN, etc. In addition, the message may also include the broadcast service ID and the newly updated primary TMGI value.

[0146] In operation 884, the AF may send an MBS service announcement message to the terminal. In operations 888 and 892, the RAN shared NG-RAN may broadcast broadcast service data to the terminal by using the newly updated primary TMGI. In operation 896, the terminal may receive the broadcast service. In this case, the terminal may be located in a RAN shared NG-RAN area (e.g., a service area).

[0147] According to an embodiment, in Figure 8 In the master TMGI update method of the present invention, in the case of a network of an operator of a TMGI other than a new master TMGI, the processing of operations 864 to 844b in operations 828 to 884 for master TMGI update may be omitted.

[0148] Fig. 9 An example of a method for updating a primary TMGI when an operator serving the primary TMGI does not provide service in a wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Fig. 9 An example of a method for updating a primary TMGI by an NG-RAN in a wireless communication system when an operator providing services using the primary TMGI no longer provides services is shown.

[0149] Fig. 9 The UE, NG-RAN, AMF, MB-SMF, MB-UPF, NEF / MBSF and AF (content provider) described in Figure 1 The network entities included in the 5GS100 are the same. In addition, Fig. 9 The MB-PCF can be understood as Figure 1 The PCF 109 is basically the same. For example, Fig. 9 MB-PCF can be referred to as being able to provide Figure 1 The PCF 109 is a PCF for MBS related services.

[0150] In operation 905, the AF (or content provider) may transmit broadcast service data to the RAN shared NG-RAN. Fig. 9 As shown in the figure, however, NG-RAN can broadcast broadcast service data to the terminal through the primary TMGI.

[0151] In operation 910, when the broadcast service is no longer provided in the network of the operator of the TMGI corresponding to the primary TMGI, the TMGI may need to be released. In operation 915, the AF may send an Nmbsmf_MBSSession_Delete request regarding the TMGI to the MB-SMF through the NEF. Therefore, the AF may request to delete the MBS session for the broadcast service corresponding to the TMGI.

[0152] In operation 920, the MB-SMF may perform a Namf_MBSBroadcast_ContextRelease request for the TMGI. For example, for the TMGI, the MB-SMF may send a Namf_MBSBroadcast_ContextRelease request message to the AMF. In operation 925, the AMF may perform an MB session resource release request. For example, the AMF may send an MB session resource release request message to the NG-RAN. The MB session resource release request message may include information for deleting the broadcast service corresponding to the TMGI.

[0153] In operation 930, the RAN shared NG-RAN that has provided a broadcast service for the TMGI as the primary TMGI may recognize that the service for the TMGI can no longer be provided. When continuing the same broadcast service as the broadcast service of the operator other than the TMGI, the RAN shared NG-RAN may select a new primary TMGI instead of the existing primary TMGI. Thereafter, in operation 935, the NG-RAN may broadcast the new primary TMGI.

[0154] In operation 940, the NG-RAN may perform a process of releasing a service for a TMGI through which the service can no longer be provided. For example, the NG-RAN may send an MB session resource release response message to the AMF. In operation 945, the AMF may send a Namf_MBSBroadcast_ContextRelease response message to the MB-SMF. In addition, in operation 950, the MB-SMF may send an Nmbsmf_MBSSession_Delete response message in response to the MB session delete request. In this case, the Nmbsmf_MBSSession_Delete response message may include information about the TMGI, and the TMGI is the old primary TMGI.

[0155] In operation 955, since a new primary TMGI is configured, the NG-RAN may perform a process of updating the new primary TMGI for TMGIs other than the existing primary TMGI. Here, the process of updating the primary TMGI may refer to Figure 7 The same process as in operations 720 to 775 in FIG. Fig. 9 The detailed process of updating the master TMGI is omitted.

[0156] Fig.10 Another example of a method for updating a primary temporary mobile group identity (TMGI) in a wireless communication system when an operator serving the primary temporary mobile group identity (TMGI) does not provide service according to an embodiment of the present disclosure is shown. Specifically, Fig.10 The process of a method for updating a primary TMGI by an AMF in a wireless communication system when an operator serving the primary TMGI no longer provides service is shown.

[0157] Fig.10 The UE, NG-RAN, AMF, MB-SMF, MB-UPF, NEF / MBSF and AF (content provider) described in Figure 1 The network entities included in the 5GS100 are the same. In addition, Fig.10 The MB-PCF can be understood as Figure 1 The PCF 109 is basically the same. For example, Fig.10 MB-PCF can be referred to as being able to provide Figure 1 The PCF 109 is a PCF for MBS related services.

[0158] In operation 1005, the AF (or content provider) may transmit broadcast service data to the RAN shared NG-RAN. Fig.10 As shown in the figure, however, NG-RAN can broadcast broadcast service data to the terminal through the primary TMGI.

[0159] When broadcast services are no longer provided in the network of the operator of the TMGI corresponding to the primary TMGI, the TMGI may need to be released in operation 1010. In operation 1010, the AF may recognize that the TMGI that has been used as the primary TMGI can no longer be used to provide services and select a new primary TMGI.

[0160] In operation 1015, the AF may send a Nmbsmf_MBSSession_Delete request regarding the TMGI (old primary TMGI) to the MB-SMF through the NEF. Thus, the AF may request to delete the MBS session for the broadcast service corresponding to the TMGI. In operation 1020, for the TMGI, the MB-SMF may perform a Namf_MBSBroadcast_ContextRelease request to the AMF. For example, for the TMGI, the MB-SMF may send a Namf_MBSBroadcast_ContextRelease request message to the AMF. In operation 1025, the AMF may perform an MB session resource release request. For example, the AMF may send an MB session resource release request message to the NG-RAN. Here, the MB session resource release request message may include information for deleting the broadcast service corresponding to the TMGI.

[0161] In the process of requesting to delete the service for the TMGI in operations 1015 to 1025, the request message may include the newly selected primary TMGI (new primary TMGI). For example, through operations 1015 to 1025, the AF may send the new primary TMGI to the NG-RAN through a message for deleting the service for the existing TMGI. In operation 1030, the RAN shared NG-RAN may update the primary TMGI with the new primary TMGI. Thereafter, in operation 1035, the NG-RAN may broadcast the new primary TMGI.

[0162] In operation 1040, the NG-RAN may perform a process of releasing services for a TMGI (old primary TMGI) through which services can no longer be provided. For example, the NG-RAN may send an MB session resource release response message to the AMF. In operation 1045, the AMF may send a Namf_MBSBroadcast_ContextRelease response message to the MB-SMF. In addition, in operation 1050, the MB-SMF may send a Nmbsmf_MBSSession_Delete response message in response to the MBS session delete request. In this case, the Nmbsmf_MBSSession_Delete response message may include information about the TMGI, and the TMGI may be the old primary TMGI.

[0163] In operation 1055, when a new primary TMGI is configured, the NG-RAN may perform a process of updating the new primary TMGI for TMGIs other than the existing primary TMGI. Here, the process of updating the primary TMGI may refer to Figure 8 The same process as in operations 828 to 896 in FIG. Fig.10The detailed process of updating the master TMGI is omitted.

[0164] As described above, according to an embodiment of the present disclosure, a method performed by a base station in a wireless communication system may include: receiving information about a broadcast service associated with a first primary temporary mobile group identifier (TMGI) from an application function (AF), identifying whether an update to a second primary TMGI is required, the second primary TMGI being different from the first primary TMGI, and when an update to the second primary TMGI is required, sending a first message associated with the second primary TMGI to an access and mobility management function (AMF), and receiving a second message associated with the second primary TMGI from the AMF as a response to the first message, wherein the base station is shared between a first operator and a second operator to provide services.

[0165] In an embodiment, the first operator may provide a broadcast service based on the first primary TMGI and the second primary TMGI.

[0166] In an embodiment, the method may further include sending a message to the AMF for releasing the broadcast session for the first primary TMGI.

[0167] In an embodiment, the first message may include location information of the base station, an ID of the broadcast service, and tunnel information related to the broadcast service.

[0168] In an embodiment, the location information of the base station may include at least one of an ID of the base station, a cell ID, geographical location information, or geographical address information.

[0169] As described above, according to an embodiment of the present disclosure, a method performed by an application function (AF) in a wireless communication system may include: sending information about a broadcast service related to a first primary temporary mobile group identifier (TMGI) to a base station, receiving a first message from a network exposure function (NEF), the first message including information indicating that a broadcast session for the first primary TMGI has been released, and sending a second message including information about a second primary TMGI to the NEF, the second primary TMGI being different from the first primary TMGI, wherein the base station is shared between a first operator and a second operator to provide services.

[0170] In an embodiment, the first operator may provide a broadcast service based on the first primary TMGI and the second primary TMGI.

[0171] In an embodiment, the method may further include receiving a response message to the second message from the NEF.

[0172] In an embodiment, the response message may include location information of the base station, an ID of the broadcast service, and tunnel information related to the broadcast service.

[0173] In an embodiment, the location information of the base station may include at least one of an ID of the base station, a cell ID, geographical location information, or geographical address information.

[0174] As described above, according to an embodiment of the present disclosure, a method performed by a base station in a wireless communication system may include: receiving information about a broadcast service associated with a first primary temporary mobile group identifier (TMGI) from an application function (AF), receiving a first message from an access and mobility management function (AMF), the first message including information for deleting the broadcast service associated with the first primary TMGI, identifying whether an update to a second primary TMGI is required, the second primary TMGI being different from the first primary TMGI, and sending information about the second primary TMGI, wherein the base station is shared between a first operator and a second operator to provide services.

[0175] In an embodiment, the first operator may provide a broadcast service based on the first primary TMGI and the second primary TMGI.

[0176] In an embodiment, the method may further include sending a message to the AMF for releasing the broadcast session for the first primary TMGI.

[0177] In an embodiment, the method may further include: when an update to the second primary TMGI is required, sending a third message related to the second primary TMGI to the AMF, wherein the third message may include location information of the base station, an ID of the broadcast service, and tunnel information related to the broadcast service.

[0178] In an embodiment, the location information of the base station may include at least one of an ID of the base station, a cell ID, geographical location information, or geographical address information.

[0179] As described above, according to an embodiment of the present disclosure, a method performed by an application function (AF) in a wireless communication system may include: sending information about a broadcast service associated with a first primary temporary mobile group identifier (TMGI) to a base station, identifying whether an update to a second primary TMGI is required, the second primary TMGI being different from the first primary TMGI, and sending a first message including information for deleting the broadcast service associated with the first primary TMGI to a session management function (SMF) through a network exposure function (NEF), wherein the first message includes information about the second primary TMGI, and the base station is shared between the first operator and the second operator to provide services.

[0180] In an embodiment, the first operator may provide a broadcast service based on the first primary TMGI and the second primary TMGI.

[0181] In an embodiment, the method may further include: receiving a response message to the first message from the NEF, wherein the response message includes information about the first primary TMGI.

[0182] In an embodiment, the method may further include: sending a second message including information about a second primary TMGI to the NEF, and receiving a response message to the second message, wherein the response message to the second message may include location information of the base station, an ID of the broadcast service, and tunnel information related to the broadcast service.

[0183] In an embodiment, the location information of the base station may include at least one of an ID of the base station, a cell ID, geographical location information, or geographical address information.

[0184] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in software, hardware, or a combination of hardware and software.

[0185] As for software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium may be configured to be executed by one or more processors of an electronic device. One or more programs may include instructions for controlling an electronic device to perform a method according to an embodiment described in a claim or specification of the present disclosure.

[0186] Such a program (software module, software) can be stored in a random access memory, a non-volatile memory including flash memory, a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), a magnetic disk storage device, a compact disk (CD)-ROM, a digital versatile disk (DVD) or other optical storage device, and a magnetic tape cassette. Alternatively, it can be stored in a memory combining part or all of these recording media. Multiple memories can be included.

[0187] In addition, the program can be stored in an attachable storage device that can be accessed via a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WLAN), or a storage area network (SAN), or a communication network that combines these networks. Such a storage device can access the device that performs the embodiments of the present disclosure through an external port. In addition, a separate storage device on the communication network can access the device that performs the embodiments of the present disclosure.

[0188] In the specific embodiments of the present disclosure, the components included in the present disclosure are expressed in singular or plural form. However, for ease of explanation, singular or plural expression is appropriately selected according to the situation proposed, the present disclosure is not limited to a single component or multiple components, a component expressed in plural form can be configured as a single component, and a component expressed in singular form can be configured as multiple components.

[0189] Meanwhile, although specific embodiments have been described in the explanation of the present disclosure, it should be noted that various changes may be made therein without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure is not limited or defined by the described embodiments, and is limited not only by the scope of the appended claims, but also by their equivalents.

[0190] The embodiments of the present disclosure described and shown in the specification and the drawings are merely specific examples presented to easily explain the technical content of the present disclosure and to help understand the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is clear to those skilled in the art that other variations based on the technical concept of the present disclosure can be implemented. In addition, as needed, the above-mentioned various embodiments can be used in combination. For example, a part of an embodiment of the present disclosure can be combined with a part of another embodiment to operate a base station and a terminal. As an example, a part of embodiment 1 of the present disclosure can be combined with a part of embodiment 2 to operate a base station and a terminal. In addition, although the above-mentioned embodiments have been presented based on an FDD LTE system, other variations based on the technical concept of the above-mentioned embodiments can also be implemented in other systems such as TDD LTE, 5G or NR systems.

[0191] In the drawings describing the methods of the present disclosure, the order of description does not always correspond to the order of performing the steps of each method, and the sequential relationship between the steps may be changed or the steps may be performed in parallel.

[0192] Alternatively, in the drawings describing the method of the present disclosure, some elements may be omitted and only some elements may be included therein without departing from the basic spirit and scope of the present disclosure.

[0193] Furthermore, in the method of the present disclosure, some or all of the contents of each embodiment may be implemented in combination without departing from the basic spirit and scope of the present disclosure.

[0194] Various embodiments of the present disclosure have been described above. The above description of the present disclosure is for illustrative purposes only, and the embodiments of the present disclosure are not limited to the embodiments set forth herein. Those skilled in the art will appreciate that the present disclosure can be easily modified and changed into other specific forms without departing from the technical concept or basic features of the present disclosure. Therefore, the scope of the present disclosure should not be determined by the above-mentioned specific embodiments, but by the attached claims, and all modifications and changes derived from the meaning and scope of the claims and their equivalents should be interpreted as falling within the scope of the present disclosure.

[0195] Although the present disclosure has been described with various embodiments, various changes and modifications may be suggested to one skilled in the art. The present disclosure is intended to encompass such changes and modifications as fall within the scope of the appended claims.

Claims

1. A method performed by a base station in a wireless communication system, the method comprising: identifying that a broadcast multicast and broadcast service (MBS) service of the first MBS session is unavailable; identifying a second broadcast MBS session of the MBS service different from the first broadcast MBS session; sending information about the second broadcast MBS session to an access and mobility management function (AMF) entity; receiving, from the AMF entity, information about a broadcast MBS session allocated based on the information about the second broadcast MBS session; as well as receiving MBS data for an MBS service from a Multicast / Broadcast User Plane Function (MB-UPF) entity, wherein information about the second broadcast MBS session is sent to the MB-UPF via a multicast / broadcast-session management function (MB-SMF) entity, and The base station is a shared base station for MBS service.

2. The method according to claim 1, wherein: In a case where the first broadcast MBS session is released or in a case where reception of MBS data via the first broadcast MBS session fails, a second broadcast MBS session is identified.

3. The method according to claim 1, wherein: The information about the second broadcast MBS session includes an identifier of the second broadcast MBS session and information about a downlink tunnel associated with the second broadcast MBS session.

4. The method according to claim 3, wherein: The MBS data is received by unicast transmission via a downlink tunnel.

5. A method performed by a multicast and broadcast-session management function (MB-SMF) entity in a wireless communication system, the method comprising: In a case where the MBS service of the first broadcast multicast and broadcast service (MBS) session is unavailable, receiving information about a second MBS session of the MBS service different from the first broadcast MBS session from an access and mobility management function (AMF) entity; allocating a broadcast MBS session based on the information about the second broadcast MBS session; as well as Send information about the broadcast MBS session to the MB-User Plane Function (UPF) entity, wherein the MBS data of the MBS service is sent based on information about a broadcast MBS session, and The base station is a shared base station for MBS service.

6. The method according to claim 5, wherein: In a case where the first broadcast MBS session is released or in a case where reception of MBS data via the first broadcast MBS session fails, a second broadcast MBS session is identified.

7. The method according to claim 5, wherein: The information about the second broadcast MBS session includes an identifier of the second broadcast MBS session and information about a downlink tunnel associated with the second broadcast MBS session.

8. The method according to claim 7, wherein: The MBS data is sent by unicast transmission via a downlink tunnel.

9. A base station in a wireless communication system, the base station comprising: Transceiver; as well as At least one processor coupled to the transceiver and configured to: identifying that a broadcast multicast and broadcast service (MBS) service of the first MBS session is unavailable, identifying a second broadcast MBS session of the MBS service different from the first broadcast MBS session, sending information about the second broadcast MBS session to an access and mobility management function (AMF) entity, receiving, from the AMF entity, information about a broadcast MBS session allocated based on the information about the second broadcast MBS session, and receiving MBS data for an MBS service from a Multicast / Broadcast User Plane Function (MB-UPF) entity, wherein information about the second broadcast MBS session is sent to the MB-UPF via a multicast / broadcast-session management function (MB-SMF) entity, and The base station is a shared base station for MBS service.

10. The base station according to claim 9, wherein: In a case where the first broadcast MBS session is released or in a case where reception of MBS data via the first broadcast MBS session fails, a second broadcast MBS session is identified.

11. The base station according to claim 9, wherein: The information about the second broadcast MBS session includes an identifier of the second broadcast MBS session and information about a downlink tunnel associated with the second broadcast MBS session.

12. The base station according to claim 11, wherein: The MBS data is received by unicast transmission via a downlink tunnel.

13. A multicast / broadcast-session management function (MB-SMF) entity in a wireless communication system, the MB-SMF entity comprising: Transceiver; as well as At least one processor coupled to the transceiver and configured to: In a case where the MBS service of the first broadcast multicast and broadcast service (MBS) session is unavailable, receiving information about a second MBS session of the MBS service different from the first broadcast MBS session from an access and mobility management function (AMF) entity; allocating a broadcast MBS session based on the information about the second broadcast MBS session; as well as Send information about the broadcast MBS session to the MB-User Plane Function (UPF) entity, wherein the MBS data of the MBS service is sent based on information about a broadcast MBS session, and The base station is a shared base station for MBS service.

14. The MB-SMF entity according to claim 13, wherein: In a case where the first broadcast MBS session is released or in a case where reception of MBS data via the first broadcast MBS session fails, a second broadcast MBS session is identified.

15. The MB-SMF entity according to claim 13, wherein: The information about the second broadcast MBS session includes an identifier of the second broadcast MBS session and information about a downlink tunnel associated with the second broadcast MBS session.

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