Method and device for providing IMS communication service

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates beyond a 4G communication system such as LTE. According to an embodiment of the present disclosure, a method performed by an IP multimedia core network subsystem (IMS) application server (AS) in a wireless communication system may be provided. The method may comprise the steps of: receiving, from an originating network, a session initiation protocol (SIP) INVITE request message that includes a session description protocol (SDP) offer; determining whether a terminating user equipment (UE) supporting an IMS data channel is allowed to use the IMS data channel; and transmitting a session event control notification message to a data channel signaling function (DCSF) when the terminating UE supporting the IMS data channel is allowed to use the IMS data channel.

Description

Method and device for providing IMS communication services

[0001] The present disclosure relates to a method and apparatus for providing a service in IMS (Internet Protocol Multimedia Subsystem) communication.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] To meet the growing demand for wireless data traffic following the commercialization of 4G communication systems, efforts are being made to develop improved 5G or pre-5G communication systems. For this reason, 5G or pre-5G communication systems are also referred to as "Beyond 4G Network" or "Post-LTE" systems. The 5G communication system specified by 3GPP is called the New Radio (NR) system.

[0009] To achieve high data rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (e.g., the 60 GHz band). To mitigate radio path loss and increase the transmission range of radio waves in ultra-high frequency bands, beamforming, massive MIMO (massive MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antenna technologies have been discussed and applied to NR systems in 5G communication systems.

[0010] Additionally, to improve the network of the system, technologies such as evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, moving networks, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation are being developed in 5G communication systems.

[0011] In addition, advanced coding modulation (ACM) methods such as FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), as well as advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (non-orthogonal multiple access), and SCMA (sparse code multiple access) are being developed in 5G systems.

[0012] Meanwhile, the Internet is evolving from a human-centric network where humans create and consume information to an Internet of Things (IoT) network where information is exchanged and processed between distributed components, such as objects. The Internet of Everything (IoE) is also emerging, combining IoT technologies with big data processing technologies, such as those connected to cloud servers. To implement the IoT, technological elements such as sensing technologies, wireless and wired communication and network infrastructure, service interface technologies, and security technologies are required. Recently, research is being conducted on technologies such as sensor networks, Machine-to-Machine (M2M), and Machine-Type Communication (MTC) for connecting objects. In the IoT environment, intelligent IT (Internet Technology) services can be provided that collect and analyze data generated from connected objects to create new value for human life. IoT can be applied to areas such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart appliances, and advanced medical services through the convergence and integration of existing IT (Information Technology) technologies with various industries.

[0013] Accordingly, various attempts are being made to apply 5G communication systems to IoT networks. For example, 5G communication such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC) are being implemented using techniques such as beamforming, MIMO, and array antennas. The application of cloud radio access networks (cloud RAN), a big data processing technology described above, can also be considered an example of the convergence of 5G and IoT technologies.

[0014] According to an embodiment of the present disclosure, a method performed by an IP Multimedia Core Network Subsystem (IMS) Application Server (AS) in a wireless communication system may be provided. The method may include receiving a Session Initiation Protocol (SIP) INVITE request message including a Session Description Protocol (SDP) offer from an originating network. The SDP offer may not include media information regarding an IMS data channel (DC). The method may include determining whether a terminating user equipment (UE) supporting the IMS data channel is permitted to use the IMS data channel. If the terminating UE supporting the IMS data channel is permitted to use the IMS data channel, the method may include transmitting a session event control notification message to a Data Channel Signaling Function (DCSF).

[0015] According to an embodiment of the present disclosure, an IP Multimedia Core Network Subsystem (IMS) Application Server (AS) may be provided in a wireless communication system. The IMS AS may include at least one transceiver, at least one processor communicatively connected to the at least one transceiver, and at least one memory communicatively connected to the at least one processor and storing instructions executable by the at least one processor, either individually or in combination. When the instructions are executed by the at least one processor, individually or in combination, the IMS AS may receive a Session Initiation Protocol (SIP) INVITE request message including a Session Description Protocol (SDP) offer from an originating network. The SDP offer may not include media information regarding an IMS data channel (DC). When the instructions are executed by the at least one processor, individually or in combination, the IMS AS may determine whether a terminating user equipment (UE) supporting the IMS data channel is permitted to use the IMS data channel. The IMS AS may transmit a Session Event Control Notification message to the Data Channel Signaling Function (DCSF) when the IMS data channel is allowed to be used by a called UE supporting the IMS data channel, by executing the command individually or in combination with at least one processor.

[0016] FIG. 1 is a diagram illustrating a 5G system structure related to an embodiment of the present disclosure.

[0017] FIG. 2 is a diagram illustrating an IMS network structure according to various embodiments of the present disclosure.

[0018] FIG. 3 illustrates a method and procedure for providing an IMS DC service in a communication system according to various embodiments of the present disclosure.

[0019] FIG. 4 illustrates a method and procedure for providing an IMS DC service in a communication system according to various embodiments of the present disclosure.

[0020] FIG. 5 illustrates a method and procedure for providing an IMS DC service in a communication system according to various embodiments of the present disclosure.

[0021] FIG. 6 illustrates a method and procedure for providing an IMS DC service in a communication system according to various embodiments of the present disclosure.

[0022] FIG. 7 is a diagram showing the configuration of a network function according to an embodiment of the present disclosure.

[0023] FIG. 8 is a block diagram schematically illustrating the configuration of a terminal according to one embodiment of the present disclosure.

[0024] The operating principle of the present disclosure is described in detail with reference to the attached drawings below.

[0025] In describing the embodiments, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to ensure that the gist of the present disclosure is conveyed more clearly without obscuring it by omitting unnecessary explanations.

[0026] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0027] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0028] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0029] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0030] Here, the term '~ unit' used in this embodiment means a software or hardware component such as an FPGA or ASIC, and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to regenerate one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, the components and '~ units' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Additionally, in the embodiment, '~bu' may include one or more processors.

[0031] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, and terms referring to various identification information are provided for convenience of explanation. Therefore, the present invention is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0032] For convenience of explanation, this disclosure uses terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP) LTE (3rd Generation Partnership Project Long Term Evolution) standard and the 3GPP 5G standard. However, the present invention is not limited to these terms and names and can be equally applied to systems conforming to other standards.

[0033] As described above, it should be noted that the blocks and combinations of flowcharts described in the present disclosure may be implemented by one or more computer programs containing instructions. One or more computer programs may be stored entirely in a single memory device, or one or more computer programs may be divided and stored in different portions across multiple memory devices.

[0034] Additionally, any / any function or operation described in the present disclosure may be processed by a single processor or a combination of processors. The single processor or the combination of processors may include circuitry that performs processing, such as an application processor (AP, e.g., a central processing unit (CPU)), a communication processor (CP, e.g., a modem), a graphics processing unit (GPU), a neural processing unit (NPU) (e.g., an artificial intelligence (AI) chip), a Wi-Fi chip, a Bluetooth® chip, a global positioning system (GPS) chip, a near-field communication (NFC) chip, a connectivity chip, a sensor controller, a touch controller, a fingerprint sensor controller, a display driver integrated circuit (IC), an audio codec (CODEC) chip, a universal serial bus (USB) controller, a camera controller, an image processing IC, a microprocessor unit (MPU), a system on a chip (SoC), an IC, or similar circuitry.

[0035] It should also be noted that the various embodiments in the claims and description of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0036] Such software may be stored on a non-transitory computer-readable storage medium. The non-transitory computer-readable storage medium stores one or more computer programs (software modules), wherein the one or more computer programs include computer-executable instructions that, when executed alone or collectively by one or more processors of an electronic device, cause the electronic device to perform a method according to the present disclosure.

[0037] The software may be stored in a temporary or non-transitory storage device, for example, in the form of a read-only memory (ROM) (whether erasable or rewritable), a random access memory (RAM), a memory chip, a device, or an integrated circuit (IC). The software may also be stored in an optically or magnetically readable medium, for example, a compact disc (CD), a digital versatile disc (DVD), a magnetic disk, or a magnetic tape. It should be understood that the storage device and the storage medium are examples of non-transitory machine-readable storage media suitable for storing a program for implementing various embodiments of the present disclosure. Accordingly, various embodiments of the present disclosure may provide a program comprising code for implementing a device or method according to any one of the claims of the present specification, and a non-transitory machine-readable storage medium storing such a program.

[0038] In the present disclosure, determining the priority between A and B may be referred to in various ways, such as selecting a higher priority according to a predetermined priority rule and performing an action corresponding to it, or omitting or dropping an action for a lower priority.

[0039] Hereinafter, 'A or B' described in the present disclosure may be understood as 'A and / or B', which may be understood to include 'A', or 'B', or 'A and B'.

[0040] Additionally, 'at least one of A, B, and C' described in the present disclosure may be understood to include 'A', or 'B', or 'C', or 'any combination of A, B, and C'.

[0041] Additionally, 'at least one of A, B, or C' described in the present disclosure may be understood to include 'A', or 'B', or 'C', or 'any combination of A, B, and C'.

[0042] Additionally, 'A / B' described in the present disclosure may be understood as 'A and / or B', which may be understood to include 'A', or 'B', or 'A and B'.

[0043] Additionally, 'A, B' described in the present disclosure may be understood as 'A and / or B', which may be understood to include 'A', or 'B', or 'A and B'.

[0044] Additionally, 'A and B' described in the present disclosure may be understood as 'A and / or B', which may be understood to include 'A', or 'B', or 'A and B'.

[0045] In addition, it can be understood that the 'case where conditions A and B are satisfied' described in the present disclosure is not necessarily limited to the case where both conditions A and B are satisfied, but may include the case where each of conditions A or B is satisfied, the case where both conditions A and B are satisfied, or the case where one or more additional conditions are satisfied together.

[0046] Additionally, throughout this specification, ordinal terms such as "first," "second," "third," and the like (and modifiers thereof) are used solely to distinguish between various instances, occurrences, configurations, messages, stages, or aspects of elements, operations, or information, as described below. Unless the context clearly requires otherwise, the use of such ordinal terms does not require that the elements, operations, or information distinguished by them be structurally, numerically, or inherently different. For example, "a first signal" and "a second signal" may represent instances of the same signal transmitted at different times, may represent signals containing the same core information albeit with some modifications, or may represent signals having different content or characteristics depending on the specific context. Similarly, "a first value" and "a second value" may represent measurements or applications of the same magnitude in different circumstances, or may represent different magnitudes. Such interpretation should be determined by the specific technical context, functions and relationships described in the relevant portions of the specification and claims.

[0047] In addition, the expressions "if" and "in case that" described in the present disclosure or claims may be interpreted to mean "when or upon," "in response to," or "based on," or "according to," depending on the context, and these expressions may be used interchangeably. In addition, in addition to these expressions, other expressions having substantially the same meaning may be used interchangeably, within the scope that does not impair the technical features of the present disclosure.

[0048] Additionally, the term "not perform" as used in this disclosure or claims may be understood to mean omitting or skipping a step, depending on the context. Such terms may be replaced with other terms having the same or substantially similar meaning.

[0049] Additionally, "transmitting a message including A and B" as described herein may be interpreted to include both (i) cases where A and B are transmitted in a single message, as well as (ii) cases where A and B are transmitted individually via multiple messages (e.g., transmitting a first message including A and a second message including B). This interpretation may also apply when a message including two or more items, such as A, B, and C, is transmitted together or individually.

[0050] Additionally, 'sending a message containing A and sending a message containing B' can also be interpreted as sending a single message containing A and B.

[0051] In the specific embodiments of the present disclosure described below, terms or components included in the disclosure will be expressed in the singular or plural, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural may be composed of singular elements, or components expressed in the singular may be composed of plural elements.

[0052] Hereinafter, the base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (base station), a radio access unit, a base station controller, or a node on a network. In addition, the base station of the present disclosure may include a structure that is split into a central unit (CU) and a distributed unit (DU). In this structure, the CU is responsible for the upper layers of the control and user planes, and the DU is responsible for radio resource processing of the lower layers. The embodiments of the present disclosure can be equally applied to a 5G base station structure in which functions are separated into the CU and DU.

[0053] The terminal may include a UE (user equipment), MS (mobile station), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions.

[0054] In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station or a network to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station or a network. In addition, although LTE (Long Term Evolution), LTE-A (LTE-Advanced), 5G (5th-generation) system 5G-A (5G-advanced) system, or 6G (6th-generation) system may be described below as an example, embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types.

[0055] For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included in a system to which the embodiments of the present disclosure may be applied, and the 5G or 6G of the present disclosure may be a concept that includes existing LTE, LTE-A, 5G-A, and other similar services. In addition, the present disclosure may be applied to other communication systems through some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as determined by a person having skilled technical knowledge. In this case, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams may be performed by computer program instructions.

[0056] These computer program instructions may be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, so that the instructions, when executed by the processor of the computer or other programmable data processing apparatus, create means for performing the functions described in the flowchart block(s). These computer program instructions may also be stored in a computer-available or computer-readable memory that can direct the computer or other programmable data processing apparatus to perform the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce an article of manufacture that includes instruction means for performing the functions described in the flowchart block(s).

[0057] Since the computer program instructions can also be installed on a computer or other programmable data processing device, a series of operations or steps are performed on the computer or other programmable data processing device to create a computer-executable process, so that the instructions that cause the computer or other programmable data processing device to perform the operations or steps can also provide operations or steps for performing the functions described in the flowchart block(s).

[0058] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order depending on the corresponding function. In this case, the term '~unit' used in the present embodiment means software or a hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the '~unit' may perform certain roles. However, the '~unit' is not limited to software or hardware. The '~unit' may be configured to be on an addressable storage medium and may be configured to execute one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, the components and '~ units' may be implemented to reproduce one or more CPUs within a device or a secure multimedia card. Also, in an embodiment, the '~ unit' may include one or more processors.

[0059] All functions or operations described in this document may be performed by a single processor or a combination of processors. A single processor or a combination of processors is a circuitry that performs processing, and may include circuitry such as an Application Processor (AP), a Communication Processor (CP), a Graphical Processing Unit (GPU), a Neural Processing Unit (NPU), a Microprocessor Unit (MPU), a System on Chip (SoC), an Integrated Chip (IC), or an AI accelerator.

[0060] The expression “configured to” used in the present disclosure can be used interchangeably with, for example, “suitable for”, “having the capacity to”, “designed to”, “adapted to”, “made to”, or “capable of”, depending on the context.

[0061] The term "configured (or set up) to" may not necessarily mean "specifically designed to" hardware. Instead, in some contexts, the phrase "a system configured to" may mean that the system, in conjunction with other devices or components, is "capable of" doing something.

[0062] For example, the phrase "a processor configured (or set) to perform A, B, and C" may include a dedicated processor (e.g., an embedded processor) for performing those operations, or a generic-purpose processor (e.g., a CPU or application processor) that enables the device to perform those operations by executing one or more program codes, instructions, or software stored in memory.

[0063] Singular expressions may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art described herein.

[0064] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the attached drawings. It should be noted that, where possible, identical components are represented by identical reference numerals throughout the attached drawings. Furthermore, the attached drawings of the present disclosure are provided to aid understanding of the present disclosure, and it should be noted that the present invention is not limited to the forms or arrangements illustrated in the drawings.

[0065] In this case, even if any wording is mentioned in different embodiments, if the concepts correspond, they may be used interchangeably, combined, or substituted. For example, for identical or corresponding concepts, even if one embodiment uses the expression "A" and another embodiment uses the expression "B," these may be understood interchangeably, substituted, or combined.

[0066] In the following description, terms used to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc. are examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used. In addition, the terms may be replaced with terms defined in the 3rd generation partnership project (3GPP) Technical Specifications (TS), if appropriate.

[0067] Hereinafter, the expression that information can be configured from a base station in the present disclosure or claims may mean that a terminal receives the information from the base station through physical layer signaling or upper layer signaling, depending on the context, and such expression may be replaced with other terms having the same or substantially similar meaning.

[0068] The operating principle of the present disclosure is described in detail with reference to the attached drawings below.

[0069] An IMS DC session can be set up only when both the calling and called parties' respective terminals and networks support the IMS DC function and the user of each terminal has subscribed to the IMS DC service. However, there are various types of IMS DC sessions, as follows. IMS DC sessions can include IMS DC sessions between terminals and their respective networks, IMS DC sessions between a terminal and the network of the other terminal, and IMS DC sessions between a terminal and the other terminal. Among these, there may be cases where a terminal requests an IMS DC session between the other terminal and the other network. For example, when a service center representative acts as a terminal and the service subscriber acts as the other terminal, if the service center representative determines that it is necessary to provide the service subscriber with additional information residing on an external server through IMS DC during a voice call, the service subscriber can request an IMS DC session to download the additional information from the external server through its own IMS operator network. In this case, whether the service center agent's terminal or the IMS operator network to which the service center agent's terminal is connected supports IMS DC has no bearing on whether the service subscriber's terminal and the IMS operator network to which the service subscriber's terminal is connected establish an IMS DC session. However, despite this fact, the current IMS session structure has a limitation in that the service center agent's terminal and the IMS network to which it is connected must also support IMS DC and be subscribed to the IMS DC service in order to request a local IMS DC session setup from the other network.The present disclosure proposes a method for requesting an IMS DC session even if the calling terminal and the calling network do not support IMS DC or the user of the calling terminal has not subscribed to the IMS DC service, only when requesting the setup of a local IMS DC session in the calling network, i.e., an IMS DC session between the calling network and the calling terminal.

[0070] FIG. 1 is a diagram illustrating a 5G system structure related to an embodiment of the present disclosure.

[0071] Referring to FIG. 1, the 5G system architecture may include various components (i.e., network functions (NFs)). FIG. 1 illustrates some of them, including an authentication server function (AUSF) device (110), an access and mobility management function (AMF) device (103), a session management function (SMF) device (104), a policy control function (PCF) device (107), an application function (AF) device (108), a unified data management (UDM) device (106), a data network (DN) (112), a user plane function (UPF) device (105), a (radio) access network (R)AN) (102), and a terminal, i.e., a user equipment (UE) (101). In addition, in FIG. 1, a Network Slice Selection Function (NSSF) device (109) and a Network Slice Specific Authentication and Authorization Function (NSSAAF) device (111) are exemplarily illustrated.

[0072] Each of the devices illustrated in FIG. 1 may be implemented as a single server or device, or as a network slice instance. When implemented as a network slice instance, two or more identical or different network slice instances may be implemented within a single server or device, or a single network slice instance may be implemented across two or more servers or devices.

[0073] Each NF can support the following functions:

[0074] AUSF (110) can process and store data for UE authentication.

[0075] AMF (103) can provide functions for access and mobility management per UE, and one UE can be connected to one AMF by default. Specifically, the AMF (103) provides signaling between core network (CN) nodes for mobility between 3GPP access networks, termination of a radio access network (RAN) CP interface (i.e., N2 interface), termination of NAS signaling (N1), NAS signaling security (NAS ciphering and integrity protection), AS security control, registration management (registration area management), connection management, idle mode UE reachability (including control and performance of paging retransmission), mobility management control (subscription and policy), intra-system mobility and inter-system mobility support, support for network slicing, SMF selection, lawful intercept (for AMF events and interfaces to the LI system), provision of forwarding of session management (SM) messages between UE and SMF, transparent proxy for SM message routing, access authentication, and roaming authorization check. It may support functions such as access authorization, provision of SMS message transmission between UE and Short Message Service Function (SMSF), security anchor function (SAF), and / or security context management (SCM). Some or all of these functions of AMF (103) may be supported within a single AMF instance operating as one AMF.

[0076] DN (112) may mean, for example, an operator service, Internet access, or a third-party service. DN (112) may transmit a downlink protocol data unit (PDU) to UPF (105) or receive a PDU transmitted from UE (101) through UPF (105).

[0077] PCF (107) can receive information about packet flow from an application server and provide a function to determine policies such as mobility management and session management. Specifically, PCF (107) can support functions such as supporting a unified policy framework for controlling network operations, providing policy rules so that control plane function(s) (e.g., AMF, SMF, etc.) can enforce the policy rules, and implementing a front end for accessing related subscription information for policy determination within a user data repository (UDR).

[0078] The SMF (104) provides session management functions, and when a UE has multiple sessions, each session can be managed by a different SMF. Specifically, the SMF (104) can support functions such as session management (e.g., session establishment, modification, and termination, including tunnel maintenance between the UPF and the AN node), UE IP address allocation and management (optionally including authentication), selection and control of UP functions, traffic steering configuration for routing traffic from the UPF to the appropriate destination, termination of interfaces toward policy control functions, enforcement of the control portion of policies and QoS (quality of service), lawful intercept (for SM events and interfaces to the LI system), termination of the SM portion of NAS messages, downlink data notification, initiator of AN-specific SM information (delivered to the AN via N2 via the AMF), determination of the SSC mode of the session, and roaming functions. As described above, some or all of the functions of SMF (104) may be supported within a single SMF instance that operates as one SMF.

[0079] The UDM (106) can store user subscription data, policy data, etc. The UDM (106) can include two parts, namely, an application front end (FE) (not shown) and a user data repository (UDR) (not shown).

[0080] The FE may include a UDM FE, which is responsible for location management, subscription management, and credential processing, and a PCF-FE, which is responsible for policy control. The UDR may store data required for the functions provided by the UDM-FE and policy profiles required by the PCF. Data stored in the UDR may include user subscription data and policy data, including subscription identifiers, security credentials, access and mobility-related subscription data, and session-related subscription data. The UDM-FE may access subscription information stored in the UDR and support functions such as authentication credential processing, user identification handling, access authentication, registration / mobility management, subscription management, and SMS management.

[0081] UPF (105) can transmit a downlink PDU received from DN (112) to UE (101) via (R)AN (102), and can transmit an uplink PDU received from UE (101) via (R)AN (102) to DN (112). Specifically, the UPF (105) may support an anchor point for intra / inter RAT mobility, an external PDU session point for interconnection to a Data Network, a user plane portion of packet routing and forwarding, packet inspection and policy rule enforcement, an uplink classifier to support lawful intercept, traffic usage reporting, routing of traffic flows to the Data Network, a branching point to support multi-homed PDU sessions, QoS handling for the user plane (e.g., packet filtering, gating, uplink / downlink rate enforcement), uplink traffic validation (service data flow (SDF) mapping between SDFs and QoS flows), transport level packet marking in uplink and downlink, downlink packet buffering and downlink data notification triggering functions, etc. Some or all of these functions of UPF (105) may be supported within a single UPF instance operating as a single UPF.

[0082] The AF (108) can interact with the 3GPP core network to provide services (e.g., support functions such as application impact on traffic routing, access to network capability exposure, and interaction with policy frameworks for policy control).

[0083] (R)AN(102) may be a general term for a new radio access network that supports both evolved E-UTRA, an evolved version of 4G radio access technology, and new radio (NR) (e.g., gNB).

[0084] The gNB provides functions for radio resource management (i.e., radio bearer control, radio admission control, connection mobility control, dynamic allocation of resources to the UE in uplink / downlink (i.e., scheduling), IP (internet protocol) header compression, encryption and integrity protection of user data streams, selection of an AMF (103) upon attachment of the UE (101) if routing to the AMF (103) is not determined from information provided to the UE (101), routing of user plane data to the UPF (105)(s), routing of control plane information to the AMF (103), connection setup and teardown, scheduling and transmission of paging messages (originating from the AMF), scheduling and transmission of system broadcast information (originating from the AMF or operating and maintenance (O&M)), measurement and measurement reporting configuration for mobility and scheduling, It can support functions such as transport level packet marking in uplink, session management, support for network slicing, QoS flow management and mapping to data radio bearers, support for UEs in inactive mode, NAS message distribution, NAS node selection, radio access network sharing, dual connectivity, and tight interworking between NR and E-UTRA.

[0085] UE (101) may refer to a user equipment. The user equipment may be referred to by terms such as terminal, mobile equipment (ME), or mobile station (MS). Furthermore, the user equipment may be a portable device such as a laptop, mobile phone, personal digital assistant (PDA), smartphone, or multimedia device, or may be a non-portable device such as a personal computer (PC) or vehicle-mounted device. Hereinafter, the user equipment (UE) or terminal will be referred to as such.

[0086] For clarity of explanation, the network exposure function (NEF) device and the NF repository function (NRF) device are not illustrated in FIG. 1, but all NFs illustrated in FIGS. 2 to 5 described below can interact with the NEF and NRF as needed.

[0087] Let's take a look at NRF. NRF (not shown in Figure 1) can support service discovery functionality. When receiving a second NF discovery request from a first NF instance, it can perform a second NF discovery operation and provide information about the discovered second NF instance to the first NF instance. It can also maintain a list of available NF instances and the services they support.

[0088] Meanwhile, for convenience of explanation, FIG. 1 illustrates a reference model for a case where a UE accesses one DN using one PDU session, but the present disclosure is not limited thereto.

[0089] A UE (101) can access two (i.e., a local data network and a central data network) simultaneously using multiple PDU sessions. At this time, two SMFs can be selected for different PDU sessions. However, each SMF can have the ability to control both the local UPF and the central UPF within the PDU session.

[0090] Additionally, the UE (101) may simultaneously access two (i.e., a local data network and a central data network) provided within a single PDU session.

[0091] The control plane components of 5GC can be considered as virtualized network functions (VNFs), and communication between these VNFs can be considered as RESTful-based API exchange, where one VNF provides services to other VNFs. This API-based communication interface between VNFs is called a Service Based Interface (SBI).

[0092] In the 3GPP system, a conceptual link connecting NFs within a 5G system is defined as a reference point. The following illustrates a reference point included in the 5G system architecture depicted in Figure 1.

[0093] - N1: Reference point between UE and AMF

[0094] - N2: Reference point between (R)AN and AMF

[0095] - N3: Reference point between (R)AN and UPF

[0096] - N4: Reference point between SMF and UPF

[0097] - N5: Reference point between PCF and AF

[0098] - N6: Reference point between UPF and data network

[0099] - N7: Reference point between SMF and PCF

[0100] - N8: Reference point between UDM and AMF

[0101] - N9: Reference point between two core UPFs

[0102] - N10: Reference point between UDM and SMF

[0103] - N11: Reference point between AMF and SMF

[0104] - N12: Reference point between AMF and AUSF

[0105] - N13: Reference point between UDM and authentication server function (AUSF)

[0106] - N14: Reference point between two AMFs

[0107] - N15: Reference point between PCF and AMF for non-roaming scenarios, reference point between PCF and AMF in visited network for roaming scenarios.

[0108] In the following description, the term "terminal" may refer to UE (101), and the terms "UE" and "terminal" may be used interchangeably. In this case, unless specifically defined additionally, the term "terminal" should be understood as "UE (101).

[0109] A terminal establishes a session by connecting to a data network (e.g., a network providing Internet services) through a 5G system, and can distinguish each data network using an identifier called a Data Network Name (DNN). The DNN can be used to determine NFs, inter-NF interfaces, and operator policies related to the user plane when the terminal connects to a network system and a session. The DNN can be used, for example, to select SMFs and UPF(s) for a PDU session, and to select interface(s) (e.g., N6 interface) between a data network and UPF for a PDU session. In addition, the DNN can be used to determine a mobile communication operator's policy to be applied to a PDU session.

[0110] FIG. 2 is a diagram illustrating an IMS network structure according to various embodiments of the present disclosure.

[0111] Refer to the contents of Figure 1, and duplicate explanations are omitted.

[0112] Referring to FIG. 2, a UE (User Equipment) (101) can communicate with other UEs (not shown) located in a remote IMS network (260) and IM CN subsystem components through an IM CN (IP Multimedia Core Network) subsystem. The IM CN subsystem can include a P-CSCF (210), an I / S-CSCF (220), an IMS AS (230), an IMS HSS (240), an IMS AGW (250), and / or an MRF (270), and the components can perform the following functions.

[0113] - P-CSCF (Proxy Call Session Control Function)(210): P-CSCF can perform the function of the first contact point for UE to access IMS.

[0114] - I / S-CSCF (Interrogating / Serving CSCF)(220): The I-CSCF can perform the function of a contact point for subscribers of a network operator or roaming users currently located in the service area of ​​the network operator. The S-CSCF can handle the actual user session state of the network.

[0115] - IMS AS (Application Server) (230): The IMS AS can provide and execute IM (Internet Multimedia) value-added services. Additionally, the IMS AS can influence SIP (Session Initiation Protocol) sessions by acting on behalf of services supported by the operator network.

[0116] - IMS HSS (Home Subscriber Server)(240): IMS HSS can act as a database that stores information about users.

[0117] - IMS-AGW (Access Gateway)(250): IMS-AGW is located in the media transmission path and can manage network addresses associated with inbound and outbound media streams.

[0118] - MRF (Media Resource Function)(270): MRF can perform various processing tasks related to media streams. MRF can be divided into MRFC (Multimedia Resource Function Controller), which is in charge of control, and MRFP (Multimedia Resource Function Processor), which is in charge of media processing.

[0119] Referring to Fig. 2, the interfaces between the above components can be expressed by the following reference points.

[0120] - Gm: Reference point Gm can support communication between the UE and the IM CN subsystem. For example, the UE can request network registration and session control through the Gm reference point. SIP, described below, can be used for the Gm reference point.

[0121] - Mw: Reference point Mw can support the exchange and transmission of signaling messages between CSCFs.

[0122] - ISC: Reference Point ISC can support the exchange of information required for services provided by the service platform (e.g., IMS AS) between the S-CSCF and the service platform.

[0123] - Sh: Reference point Sh can support the exchange of information required for the service provided by the service platform between the HSS and the service platform (e.g., IMS AS).

[0124] - Cx: Reference point Cx can support information transfer between HSS and CSCF.

[0125] - Mr' / Cr: Reference point Mr' can support interaction for session control between IMS AS and MRFC, and reference point Cr can support interaction for media control between IMS AS and MRFC.

[0126] - Iq: Reference point Iq can support the exchange of information required for allocation and release of transport addresses between P-CSCF and IMS AGW.

[0127] - Mb: Reference point Mb can support IMS media transfer between IMS components.

[0128] Referring to Fig. 2, a P-CSCF (210) supporting a Service Based Interface (SBI) can communicate with a Policy Control Function (PCF) (107), which can be represented by reference point N5. The PCF (107) can support policy establishment and distribution for managing network operations, and the P-CSCF (210) supporting the SBI can be considered an application function (AF: Application Function) that uses a service that the PCF (107) provides to other VNFs.

[0129] An HSS (240) supporting SBI can communicate with an I / S-CSCF (220) supporting SBI through reference point N70, and can communicate with an IMS AS (230) supporting SBI through reference point N71. Similarly, the I / S-CSCF (220) supporting SBI and the IMS AS (230) supporting SBI can be regarded as AFs that use services provided by the HSS (240) supporting SBI, and the functions provided by reference points N70 and N71 can be equivalent to the functions provided by reference points Cx and Sh, respectively.

[0130] The above SIP is an application-layer signaling protocol that specifies the procedures for intelligent terminals wishing to communicate on the Internet to identify each other, locate each other, and create, delete, or modify multimedia communication sessions between them. SIP is a request / response structure that controls the creation, modification, and termination of multimedia service sessions such as Internet-based conferences, telephones, voicemail, event notifications, and instant messaging. It can be used on both TCP and UDP, and by using SIP URLs, similar to email addresses, to distinguish each user, services are provided independent of IP addresses. SIP is text-based and was developed using many parts of HTTP and SMTP, making it easy to implement. It also offers the flexibility and extensibility to create various services by combining it with many other protocols used on the Internet. SIP is a simpler protocol corresponding to ITU-T's H.323. It was proposed as RFC 2543 by the IETF MMUSIC (Multiparty Multimedia Session Control) Working Group in 1999, and later revised by the separate ITEF SIP Working Group, and the RFC3261 standard was established in July 2002.

[0131] In order to provide a service (e.g., a real-time interaction service) in a communication system according to various embodiments of the present disclosure, there must be an agreement on the media session that constitutes the service between user UEs participating in the service. The communication system according to various embodiments of the present disclosure can perform an agreement on the media session through Session Description Protocol (SDP) negotiation to provide the service (e.g., a real-time interaction service).

[0132] The above SDP can be included in a SIP message. The SDP is an ASCII-based protocol for describing multimedia sessions and related scheduling information. SDP conveys information about the media streams of a multimedia session so that a session can be joined. A multimedia session is defined as a set of media streams for a duration, and the duration of the session does not need to be continuous. A multicast-based session on the Internet basically has two purposes: to notify the existence and duration of the session and to convey session joining information. In a unicast environment, the latter purpose is the purpose. The SDP information content can include the session name and purpose, session duration, session composition media, and media reception information.

[0133] Below, various embodiments of the present disclosure are described assuming that the service provided in the communication system is a real-time interaction service, but are not limited thereto.

[0134] FIG. 3 is a diagram illustrating an example of a network structure including a data channel server in a communication system according to various embodiments of the present disclosure.

[0135] Refer to the contents of Figures 1 and 2, and duplicate descriptions are omitted.

[0136] In a communication system according to various embodiments of the present disclosure, a web application for providing a service (e.g., a real-time interaction service) may be provided from a Data Channel Application Server (DCAS). The Data Channel Application Server may be located in an IMS operator network or a third-party network. In the present disclosure, the web application provided by the Data Channel Application Server may be referred to as a Data Channel Application (DCA). A terminal participating in a service (e.g., a real-time interaction service) provided by the Data Channel Application may exchange data required by the service directly or through an intermediate node with another terminal participating in the same service using a Data Channel (DC), and may communicate with the Data Channel Application Server using a Bootstrap Data Channel (BDC).

[0137] Referring to FIG. 3, a communication system may include a UE (101) and an IM CN subsystem. The UE (101) may communicate with other UEs located in a remote IMS network (260) and components of the IM CN subsystem via the IM CN subsystem. The IM CN subsystem may include a P-CSCF (210), an I / S-CSCF (220), an IMS AS (230), an IMS HSS (240), an IMS AGW (250), a data channel signaling function (310), a media function (321), an NEF (330), a data channel application server (340), and / or a data channel application repository (350).

[0138] The above data channel signaling function (310) can perform the following functions:

[0139] - Management and control of data channels, including bootstrap data channels.

[0140] - Data channel management and event generation / reception through communication with IMS AS

[0141] - Management and distribution control of data channel applications

[0142] - Communication with 5G network functions (NF) for providing data channel application services.

[0143] - Proxy role for resource distribution of data channel application server (340)

[0144] The above data application storage (350) can store and manage data channel applications and can be located inside or outside the data channel server (340).

[0145] The above media function (321) and MRF (270) can perform the following functions:

[0146] - Management and control of media resources to be transmitted over data channels, including bootstrap data channels.

[0147] - Acts as a proxy for data exchange with the endpoint of the data channel connected to the terminal and other endpoints.

[0148] The above media function (321) and MRF (270) provide equivalent functions with different interfaces, and the operator may include only one of the media function (321) and the MRF (270) in the data channel server (340), or may include both, taking into consideration compatibility with other network equipment and user terminals.

[0149] FIG. 3 illustrates a method and procedure for providing an IMS DC service in a communication system according to various embodiments of the present disclosure.

[0150] FIG. 3 is a description of an example of a method for establishing a local DC session between a terminating network and a terminating UE (UE#2) when the terminating network supports IMS DC and the terminating UE (UE#2) supports IMS DC and is subscribed to the IMS DC service, regardless of whether the originating network supports IMS DC or whether the originating UE (UE#1) is subscribed to the IMS DC service.

[0151] 0. The Originating S-CSCF, the Originating HSS / UDM, the Originating IMS AS, and / or the Originating DCSF may be provided with information from the OAM, the DCAS, the AF, and / or the NEF that the user may be permitted to establish a local DC session in the terminating network even if the user has not subscribed to the IMS DC service. Additionally, the Originating S-CSCF, the Originating HSS / UDM, the Originating IMS AS, and / or the Originating DCSF may be provided with user ID(s) corresponding to the permitted target from the OAM, the DCAS, the AF, and / or the NEF. (The specific signaling flow may correspond to the description in FIG. 6.)

[0152] 1. UE#1 can inform the Originating S-CSCF whether the UE supports IMS DC. This information can be included in the REGISTER message.

[0153] 2. The originating S-CSCF can inform the originating HSS / UDM that it is the S-CSCF where the user is registered. This information can be conveyed via Cx-put and / or Cx-pull messages.

[0154] 3. The HSS / UDM may register with the S-CSCF and provide information about the user to the S-CSCF. The information about the user may include one or more name / address information that may be used when the user accesses the platform(s) used for service control while registered with the S-CSCF. Additionally, the information about the user may include security information that may be used within the S-CSCF. The information about the user may include at least one of information about whether the user is subscribed to the MMTEL service, whether the user is subscribed to the DC service, and whether the user is allowed to establish a local DC session in the terminating network while not subscribed to the DC service. The information about the user may be conveyed from the HSS / UDM to the CSCF via Cx-put response and / or Cx-pull response messages.

[0155] 4. If the Originating S-CSCF receives information from the UE in step 1 that the UE supports IMS DC, the Originating S-CSCF can determine whether the Originating network supports IMS DC.

[0156] 5. The Originating S-CSCF may decide, based on the information received in step 0 and / or step 3, whether to provide the UE with information that the Originating network supports IMS DC, if the Originating network supports IMS DC. For example, if the user is not subscribed to the IMS DC service and it is allowed to establish a local DC session in the terminating network without the user being subscribed to the DC service, the Originating S-CSCF may decide to provide the UE with information that the Originating network supports IMS DC.

[0157] 6. Based on the decision in Step 4 and / or Step 5, the Originating S-CSCF may provide UE#1 with information indicating that the Originating network supports IMS DC and / or that the Terminating Network allows the user to establish a local DC session without being subscribed to the DC service. This information may be included in the 200 OK response message to the REGISTER request in Step 1.

[0158] 7. Based on the information received in step 6, UE#1 can determine whether to establish a local DC session in the terminating network when the user is not subscribed to the DC service. For example, even if UE#1 is denied connection to a type of DC session other than establishing a local DC session in the terminating network (e.g., a local DC session in the originating network, a DC session with the terminating network) after step 6, UE#1 can determine that a local DC session in the terminating network can be requested based on the information received in step 6 indicating that establishing a local DC session in the terminating network when the user is not subscribed to the DC service is allowed.

[0159] 8. Based on the decision in step 7, UE#1 may send a message to the network requesting establishment of a local DC session in the terminating network. This request may be delivered to the IMS AS via the P-CSCF and / or S-CSCF. This request may be delivered via an INVITE message. This message may include information indicating whether the UE supports IMS DC and / or an SDP Offer. This SDP Offer may include information requesting a bootstrap DC session. The information requesting a bootstrap DC session may include information indicating that the source of the content is a remote network and / or a remote user. For example, a stream ID value may be specified indicating that the source of the content is a remote network and / or a remote UE. For example, a stream-id value of 100 may indicate a remote network provider as the content source, and a stream-id value of 110 may indicate a remote user. Additionally, if the 3gpp-bdc-used-by value is sender, along with the stream id, it may mean that the terminating network, the terminating user, is the content source from the perspective of the sender of this message (here, the originating network, UE#1). (TS 26.114 v18.7.0, Table 6.2.10.1-2, clause 6.2.12) The SDP Offer may additionally include information requesting an IMS session for at least one media among Audio, Video, Text, and Message.

[0160] 9. The Originating IMS AS may request subscriber data from the Originating HSS / UDM. This request may be to verify whether the user who sent the request in step 8 is subscribed to the IMS DC service, and / or to verify whether establishing a local DC session in the terminating network is permitted even if the user is not subscribed to the IMS DC service.

[0161] 10. The originating HSS / UDM may provide subscriber data to the originating IMS AS. This response may include the user's MMTel service subscription information, IMS DC service subscription information, and / or information regarding whether the terminating network is permitted to establish a local DC session even if the user is not subscribed to the IMS DC service.

[0162] 11. The Originating IMS AS may determine whether to notify the DCSF of the occurrence of an event related to an IMS DC session based on the information received in steps 0, 8, and / or 10. For example, if the Originating IMS AS receives an SDP offer containing information requesting a bootstrap DC session from the UE in step 8, and if the information received in step 10 indicates that the user is not subscribed to the IMS DC service and that establishing a local DC session in the terminating network without subscribing to the DC service is permitted, the Originating IMS AS may determine to notify the DCSF of the occurrence of an event related to an IMS DC session. Alternatively, if the Originating IMS AS receives an SDP offer containing information requesting a bootstrap DC session from the UE in step 8, and if the information received in step 10 indicates that the user is not subscribed to the IMS DC service and that establishing a local DC session in the terminating network without subscribing to the DC service is permitted, and if the Originating Network determines that no action such as media resource allocation for the DC is required, the Originating IMS AS may decide not to notify the DCSF. In this case, steps 12 to 14 may be omitted and steps 15 and later may be performed.

[0163] 12. Based on the decision made in step 11, the Originating IMS AS may notify the Originating DCSF that an event related to the IMS DC session has occurred. This notification message may include information related to the IMS DC session. For example, it may include information included in the SDP offer for the Bootstrap DC session request received in step 10. This notification message may be a Nimsas_SessionEventControl_Notify message.

[0164] 13. The Originating DCSF can determine a DC control policy. For example, if the Originating DCSF determines that the Bootstrap session request received in Step 0 and / or Step 12 corresponds to establishing a local DC session in the Terminating Network, the Originating DCSF can determine a DC control policy that does not require operations such as media resource allocation for the DC in the originating network. The Originating DCSF can provide the Originating IMS AS with the information necessary for operations such as media resource allocation based on the determined DC control policy, so that the IMS AS can request the MF and / or MRF to instruct operations such as media resource allocation. The MF and / or MRF can provide the results of operations such as media resource allocation to the Originating IMS AS, and the Originating IMS AS can forward them to the Originating DCSF. The Originating DCSF and the Originating IMS AS can use, for example, the Nimsas_MediaControl_MediaInstruction request / response message. (However, this is not limited to this message.) If the Originating DCSF has determined a DC control policy that does not require tasks such as media resource allocation for the DC in the originating network, tasks such as DC media resource allocation for the MF and / or MRF through the IMS AS can be omitted and step 14 can be performed.

[0165] 14. The Originating DCSF may respond to the Originating IMS AS in step 12. This response may include information that allows the Terminating Network to determine whether the request to establish a local DC session was accepted or not.

[0166] 15. The Originating IMS AS can send a message requesting establishment of a local DC session to the Originating S-CSCF so that the message requesting establishment of a local DC session in the Terminating Network of UE#1 received in step 8 can be sent to the Terminating Network.

[0167] 16. The Originating S-CSCF can send a message requesting establishment of a local DC session in the Terminating Network of UE#1 received in step 15 to the Terminating S-CSCF through the Originating P-CSCF and the Terminating P-CSCF.

[0168] FIG. 4 illustrates a method and procedure for providing an IMS DC service in a communication system according to various embodiments of the present disclosure.

[0169] FIG. 4 is a description of an example of a method for establishing a local DC session between a terminating network and a terminating UE (UE#2) when the terminating network supports IMS DC and the terminating UE (UE#2) supports IMS DC and is subscribed to the IMS DC service, regardless of whether the originating network supports IMS DC or whether the originating UE (UE#1) is subscribed to the IMS DC service.

[0170] 0. The Originating S-CSCF, the Originating HSS / UDM, the Originating IMS AS, and / or the Originating DCSF may be provided with information from the OAM, the DCAS, the AF, and / or the NEF that the user may be permitted to establish a local DC session in the terminating network even if the user has not subscribed to the IMS DC service. Additionally, the Originating S-CSCF, the Originating HSS / UDM, the Originating IMS AS, and / or the Originating DCSF may be provided with user ID(s) corresponding to the permitted target from the OAM, the DCAS, the AF, and / or the NEF. (The specific signaling flow may correspond to the description in FIG. 6.)

[0171] 1. UE#1 can inform the Originating S-CSCF whether the UE supports IMS DC. This information can be included in the REGISTER message.

[0172] 2. The originating S-CSCF can inform the originating HSS / UDM that it is the S-CSCF where the user is registered. This information can be conveyed via Cx-put and / or Cx-pull messages.

[0173] 3. The HSS / UDM may register with the S-CSCF and provide information about the user to the S-CSCF. The information about the user may include one or more name / address information that may be used when the user accesses the platform(s) used for service control while registered with the S-CSCF. In addition, the information about the user may include additional security information that may be used within the S-CSCF. The information about the user may include at least one of information about whether the user is subscribed to the MMTEL service, whether the user is subscribed to the DC service, and whether the user is allowed to establish a local DC session in the terminating network while not subscribed to the DC service. The information about the user may be conveyed via a Cx-put response and / or a Cx-pull response message.

[0174] 4. If the Originating S-CSCF receives information from the UE in step 1 indicating that the UE supports IMS DC, it can determine whether the Originating network supports IMS DC.

[0175] 5. The Originating S-CSCF may determine, based on the information received in Step 0 and / or Step 3, whether to provide the UE with information that the Originating network supports IMS DC, if the Originating network supports IMS DC. For example, if the user is not subscribed to the IMS DC service and it is allowed to establish a local DC session in the terminating network without the user being subscribed to the DC service, the Originating network may decide not to provide the UE with information that it supports IMS DC, and not to reject an IMS DC-related request from the UE. This may correspond to a method of operation in a network configured such that the IMS AS can make an appropriate judgment even if the UE makes a different type of IMS DC session request than the one for establishing a local DC session in the terminating network.

[0176] 6. The Originating S-CSCF may not provide UE#1 with information that the Originating network supports IMS DC based on the decision in Step 4 and / or Step 5. If the Originating network supports MMTEL, the Originating S-CSCF may provide UE#1 with information that it supports MMTEL. Reasons for the Originating S-CSCF's decision not to provide UE#1 with information that the Originating network supports IMS DC may include that the Originating network does not support IMS DC and / or that the user of UE#1 is not subscribed to the IMS DC service. The Originating S-CSCF may provide UE#1 with reasons for its decision not to provide UE#1 with information that the Originating network supports IMS DC.

[0177] 7. Based on the information received in step 6, UE#1 can decide whether to establish a local DC session in the terminating network even if the user is not subscribed to the DC service. For example, even if the network does not support IMS DC in step 6, UE#1 can decide to attempt to request a local DC session in the terminating network.

[0178] 8. Based on the decision in step 7, UE#1 may send a message to the network requesting establishment of a local DC session in the terminating network. This request may be delivered to the S-CSCF via the P-CSCF. This request may be delivered via an INVITE message. This message may include information indicating whether the UE supports IMS DC and / or an SDP Offer. This SDP Offer may include information requesting a bootstrap DC session. The information requesting a bootstrap DC session may include information indicating that the source of the content is a remote network and / or a remote user. For example, a stream ID value may be specified indicating that the source of the content is a remote network and / or a remote UE. For example, a stream-id value of 100 may indicate a remote network provider as the content source, and a stream-id value of 110 may indicate a remote user. Additionally, if the 3gpp-bdc-used-by value is sender, along with the stream id, it may mean that the terminating network, the terminating user, is the content source from the perspective of the sender of this message (here, the originating network, UE#1). (TS 26.114 v18.7.0, Table 6.2.10.1-2, clause 6.2.12) The SDP Offer may additionally include information requesting an IMS session for at least one media among Audio, Video, Text, and Message.

[0179] 9. If the UE sends a message including a request related to IMS DC in step 8 even though the Originating Network did not provide information to UE#1 that the Originating Network supports IMS DC in steps 5 and 6, the Originating S-CSCF may not reject the request from UE#1 based on the decision in steps 4 and / or 5. For example, even if UE#1 includes a media feature tag related to IMS DC in the SIP header, if the user is not subscribed to the IMS DC service and it is allowed to establish a local DC session in the terminating network when the user is not subscribed to the DC service, the Originating S-CSCF may not reject the SIP INVITE message from UE#1 and proceed to step 10.

[0180] 10. The Originating S-CSCF may forward the message to the Originating IMS AS requesting the establishment of a local DC session in the terminating network received in step 8. This request message may be the INVITE message received in step 8. 11. The Originating IMS AS may request subscriber data from the Originating HSS / UDM. This request may be to check whether the user who sent the request in step 10 is subscribed to the IMS DC service and / or to check whether it is allowed to establish a local DC session in the terminating network even if the user is not subscribed to the IMS DC service.

[0181] 12. The originating HSS / UDM may provide subscriber data to the originating IMS AS. This response may include the user's MMTel service subscription information, IMS DC service subscription information, and / or information regarding whether the terminating network is permitted to establish a local DC session even if the user is not subscribed to the IMS DC service.

[0182] 13. The Originating IMS AS may decide whether to notify the DCSF that an event related to an IMS DC session has occurred based on the information received in step 0, step 10 and / or step 12. For example, if the Originating IMS AS receives an SDP offer from the UE in step 10 that includes information requesting a bootstrap DC session, and if the Originating IMS AS determines based on the information received in step 12 that the user is not subscribed to the IMS DC service and that it is allowed to establish a local DC session in the terminating network without the user being subscribed to the DC service, the Originating IMS AS may decide to notify the DCSF that an event related to an IMS DC session has occurred. As another example, if the Originating IMS AS receives an SDP offer containing information requesting a bootstrap DC session from the UE in step 8, and if the Originating IMS AS determines based on the information received in step 12 that the user is not subscribed to the IMS DC service and that establishing a local DC session in the terminating network is allowed while the user is not subscribed to the DC service, and if the Originating IMS AS determines that no work such as media resource allocation for the DC is necessary, the Originating IMS AS may decide not to notify the DCSF. In this case, steps 14 to 16 may be omitted, and steps may be performed from step 17.

[0183] 14. Based on the decision made in step 13, the Originating IMS AS may notify the Originating DCSF that an event related to the IMS DC session has occurred. This notification message may include information related to the IMS DC session. For example, it may include information included in the SDP offer for the Bootstrap DC session request received in step 10. This notification message may be a Nimsas_SessionEventControl_Notify message.

[0184] 15. The Originating DCSF can determine a DC control policy. For example, if the Originating DCSF determines that the Bootstrap session request received in Step 0 and / or Step 14 corresponds to establishing a local DC session in the Terminating Network, the Originating DCSF can determine a DC control policy that does not require operations such as media resource allocation for the DC in the originating network. The Originating DCSF can provide the Originating IMS AS with the information necessary for operations such as media resource allocation based on the determined DC control policy, so that the IMS AS can request the MF and / or MRF to instruct operations such as media resource allocation. The MF and / or MRF can provide the results of operations such as media resource allocation to the Originating IMS AS, and the Originating IMS AS can forward them to the Originating DCSF. The Originating DCSF and the Originating IMS AS can use, for example, the Nimsas_MediaControl_MediaInstruction request / response message. (However, this is not limited to this message.) If the Originating DCSF has determined a DC control policy that does not require tasks such as media resource allocation for the DC in the originating network, tasks such as DC media resource allocation for the MF and / or MRF through the IMS AS can be omitted and step 16 can be performed.

[0185] 16. The Originating DCSF may respond to the Originating IMS AS in step 12. This response may include information that allows the Originating DCSF to determine whether the request to establish a local DC session in the Terminating Network was accepted or not rejected.

[0186] 17. The Originating IMS AS can send a message requesting establishment of a local DC session to the Originating S-CSCF so that the Originating S-CSCF can send the message requesting establishment of a local DC session in the Terminating Network of UE#1 received in Step 10 to the Terminating Network.

[0187] 18. The Originating S-CSCF can send a message requesting establishment of a local DC session in the Terminating Network of UE#1 received in step 17 to the Terminating S-CSCF through the Originating P-CSCF and the Terminating P-CSCF.

[0188] FIG. 5 illustrates a method and procedure for providing an IMS DC service in a communication system according to various embodiments of the present disclosure.

[0189] FIG. 5 is a description of an example of a method for establishing a local DC session between a terminating network and a terminating UE (UE#2) when the terminating network supports IMS DC and the terminating UE (UE#2) supports IMS DC and is subscribed to the IMS DC service, regardless of whether the originating network supports IMS DC or whether the originating UE (UE#1) is subscribed to the IMS DC service.

[0190] 0. The terminating S-CSCF, the terminating HSS / UDM, the terminating IMS AS, and / or the terminating DCSF may be provided with information from the OAM, the DCAS, the AF, and / or the NEF that the terminating network may be allowed to establish a local DC session even if the originating network and / or the originating UE did not request a session related to the IMS DC. Additionally, the terminating S-CSCF, the terminating HSS / UDM, the terminating IMS AS, and / or the terminating DCSF may be provided with user ID(s) corresponding to the allowed target from the OAM, the DCAS, the AF, and / or the NEF. (A detailed signaling flow is described in FIG. 6)

[0191] 1. The terminating S-CSCF can receive information requesting an IMS session from the originating side. This request can be conveyed via an INVITE message. This request message can include an SDP Offer and information requesting an IMS session for at least one media type, including audio, video, text, and message. This request message may not include information requesting a session related to an IMS DC. The terminating S-CSCF can forward this request message to the terminating IMS AS.

[0192] 2. The terminating IMS AS may request subscriber data from the terminating HSS / UDM. This request may be to check whether the user receiving the request in step 1 is subscribed to the IMS DC service, and / or to check whether the terminating network is allowed to establish a local DC session even if the user who sent the request in step 1 is not subscribed to the IMS DC service. In determining whether 'the terminating network is allowed to establish a local DC session even if the user who sent the request in step 1 is not subscribed to the IMS DC service', the terminating network may not be able to determine whether the user who sent the request in step 1 is subscribed to the IMS DC service or not. Therefore, the terminating network may be replaced by checking whether 'the terminating network is allowed to establish a local DC session even if the request in step 1 does not include information requesting a session related to the IMS DC'. In other words, the terminating IMS AS may request subscriber data from the terminating HSS / UDM, which may be to check whether the user receiving the request in step 1 is subscribed to the IMS DC service, and / or to check whether the terminating network is allowed to establish a local DC session even if the request in step 1 does not contain information requesting a session with an IMS DC.

[0193] 3. The terminating HSS / UDM may provide subscriber data to the terminating IMS AS. This response may include information about the user's MMTel service subscription, IMS DC service subscription, and / or whether establishing a local DC session in the terminating network is permitted even if the user is not subscribed to the IMS DC service. Here, 'whether establishing a local DC session in the terminating network is permitted even if the user is not subscribed to the IMS DC service' may mean 'whether establishing a local DC session in the terminating network is permitted even if information requesting a session related to the IMS DC is not received' as described in step 2.

[0194] 4. The terminating IMS AS may determine, based on the information received in step 0, step 1, and / or step 3, whether to notify the DCSF that an event related to an IMS DC session has occurred, even if the terminating IMS AS did not receive a session request related to an IMS DC from the originating network in step 1. For example, if the terminating IMS AS did not receive an SDP offer for an IMS DC and / or an SDP offer containing an IMS DC media description in step 1, and if the information received in step 3 indicates that the receiving user is subscribed to the IMS DC service and that the terminating network is allowed to establish a local DC session even if it did not receive information requesting a session related to an IMS DC, the terminating IMS AS may decide to notify the DCSF that an event related to an IMS DC session has occurred.

[0195] 5. The terminating IMS AS may generate information regarding a session request related to the IMS DC based on the decision made in step 4. For example, it may generate a media description including information requesting a Bootstrap DC session. The information requesting this Bootstrap DC session may include information indicating that the source of the content is a remote network and / or a remote user. For example, a stream ID value may be specified that indicates that the source of the content is a remote network and / or a remote UE. For example, a stream-id value of 100 may indicate that the content source is a remote network provider, and a stream-id value of 110 may indicate a remote user. Additionally, if information indicating that the 3gpp-bdc-used-by value is sender is provided together with the stream id, this may indicate that the source of the content is the terminating network and the terminating user (UE#2) from the perspective of the sender of this message (the originating network, UE#1 in this case). Alternatively, if the stream-id value is 0 for the local network provider or 10 for the local user, and additionally the 3gpp-bdc-used-by value is receiver, it may mean that the terminating network or terminating user (UE#2 in this case) receiving this message is the content source. (TS 26.114 v18.7.0, Table 6.2.10.1-2, clause 6.2.12)

[0196] 6. Based on the decision made in step 5, the terminating IMS AS may notify the terminating DCSF that an event related to the IMS DC session has occurred. This notification message may contain information related to the IMS DC session. For example, it may contain media description information that requests the Bootstrap DC session created in step 5. This notification message may be a Nimsas_SessionEventControl_Notify message.

[0197] 7. The terminating DCSF can determine a DC control policy. For example, if the terminating DCSF determines, based on information about the Bootstrap session request received in Step 0 and / or Step 6, that the request is for establishing a local DC session in the terminating network, it can determine a DC control policy that prevents the originating network from allocating media resources to the DC.

[0198] 8. Terminating DCSF, Terminating IMS AS, and Terminating MF can allocate the media resources required to set up a local DC session between the terminating network and UE#2.

[0199] 9. The terminating DCSF may respond to the terminating IMS AS for step 10. This response may include at least one of the following: information that can determine whether the request to establish a local DC session in the terminating network was accepted or not rejected; and media resource information required to establish a local DC session between UE#2 and the terminating network (which may correspond to the information specified in step 8).

[0200] 10. The terminating IMS AS may add information about the session request associated with the IMS DC created in step 5 to the IMS session request information sent by the Originating side received in step 1. This information about the session request associated with the IMS DC may be information requesting the establishment of a local DC session in the terminating network. For example, an SDP offer including the media description created in step 5 may be added to the INVITE message received in step 1.

[0201] 11. The Originating IMS AS may send to UE#2 an IMS Session Request message containing the information modified in step 10, i.e. requesting establishment of a local DC session in the Terminating Network.

[0202] 12. UE#2 may send a message to the terminating IMS AS in response to the received IMS session request message. This message may include SDP answer information for at least one of the media requested in the message received in step 11 (e.g., Audio, Video, Text, Message, Bootstrap DC). For example, it may include an SDP answer for a local DC session setup between the terminating network and UE#2. This response may be an 18X and / or 200 OK message.

[0203] 13. If UE#2 responds in step 12 to accept the Local DC session setup, the Terminating DCSF, Terminating IMS AS, and Terminating MF may allocate and / or update the media resources required to set up the Local DC session between the terminating network and UE#2.

[0204] 14. The terminating IMS AS can forward the contents of the response message from UE#2 received in step 12 to the originating side through the terminating S-CSCF, excluding the response to the contents added by the terminating IMS AS in step 10. For example, if E#2 responded in step 12 accepting the local DC session setup, only the remaining contents except the SDP answer for the local DC session setup can be forwarded to the terminating S-CSCF. This may correspond to excluding the SDP offer for the local DC session setup because it was not sent by the originating side but was created and added by the terminating IMS AS in steps 5 and 10.

[0205] FIG. 6 illustrates a method and procedure for providing an IMS DC service in a communication system according to various embodiments of the present disclosure.

[0206] FIG. 6 is an example of how, in step 0 of FIGS. 3, 4, and 5, the S-CSCF, HSS / UDM, IMS AS, and / or DCSF are provided with information from the OAM, DCAS, AF, and / or NEF that the user may be allowed to establish a local DC session in the Terminating Network even if the user has not subscribed to the IMS DC service.

[0207] Type #1: Directly from OAM, DCAS, AF, and / or NEF

[0208] The method in which HSS / UDM directly receives and manages OAM, DCAS, AF, and / or NEF corresponds to steps 1 and 2.

[0209] The method by which S-CSCF directly receives and manages information from OAM, DCAS, AF, and / or NEF corresponds to step 11.

[0210] The method by which IMS AS directly receives and manages OAM, DCAS, AF, and / or NEF corresponds to step 12.

[0211] The method by which DCSF receives and manages directly from OAM, DCAS, AF, and / or NEF corresponds to step 13.

[0212] 1. The HSS / UDM may be informed by the OAM, DCAS, AF, and / or NEF that the user may be permitted to establish a local DC session in the terminating network even if the user has not subscribed to the IMS DC service. Additionally, the HSS / UDM may be provided with the user ID(s) corresponding to the permitted target.

[0213] 2. The HSS / UDM may store the received information in the user subscriber information or local configuration. For example, if the HSS / UDM receives user ID(s) corresponding to the allowed target, the HSS / UDM may store in the subscriber information of the user(s) that the user(s) are allowed to establish a local DC session in the terminating network even if they have not subscribed to the IMS DC service. The HSS / UDM may also store in the local configuration of the HSS / UDM that the user(s) are allowed to establish a local DC session in the terminating network even if they have not subscribed to the IMS DC service, for all users it manages, not just for the user(s). If the entity that sent Step 1 is OAM or if the user ID(s) corresponding to the allowed target are not provided in the message of Step 1, the HSS / UDM may store in the local configuration. If the entity that sent Step 1 is DCAS, AF, or NEF, the HSS / UDM may store in the subscriber information.

[0214] 11, 12, 13: The S-CSCF, IMS AS, and DCSF may be provided with information from the OAM, DCAS, AF, and / or NEF that a user may be permitted to establish a local DC session in the terminating network even if the user has not subscribed to the IMS DC service. Additionally, the S-CSCF, IMS AS, and DCSF may be provided with user ID(s) corresponding to the permitted target. The S-CSCF, IMS AS, and DCSF may store the received information in the user context information, local configuration, or subscriber information. For example, if the S-CSCF, IMS AS, and DCSF receive user ID(s) corresponding to the permitted target, the S-CSCF, IMS AS, and DCSF may store in the context information of the user(s) that the user(s) may be permitted to establish a local DC session in the terminating network even if the user(s) has not subscribed to the IMS DC service. S-CSCF, IMS AS, DCSF may store in local configuration that it is allowed to establish local DC sessions in the terminating network even if it has not subscribed to the IMS DC service for all users or IMS DC sessions it serves, not specific to the user. If the entity sending steps 11, 12, 13 is OAM, or if the user ID(s) corresponding to the allowed target are not provided in the messages of steps 11, 12, 13, S-CSCF, IMS AS, DCSF may store in local configuration that it is allowed. If the entity sending steps 11, 12, 13 is DCAS, AF, NEF, S-CSCF, IMS AS, DCSF may store in subscriber information.

[0215] Type #2: Provided via HSS / UDM

[0216] The method by which S-CSCF receives and manages information from OAM, DCAS, AF, and / or NEF via HSS / UDM corresponds to steps 1, 2, 9, and 10.

[0217] The method by which IMS AS receives and manages information from OAM, DCAS, AF, and / or NEF via HSS / UDM corresponds to steps 1, 2, 3, and 4.

[0218] The method by which DCSF receives and manages information from OAM, DCAS, AF, and / or NEF via HSS / UDM corresponds to steps 1, 2, 5, and 6.

[0219] 3, 5, 9: IMS AS, DCSF, S-CSCF may request subscriber information from HSS / UDM or request subscription to events related to IMS sessions and / or IMS DC sessions.

[0220] 4, 6, 10: If the HSS / UDM determines that the IMS AS, DCSF, S-CSCF has requested subscriber information, or has requested a subscription for an event related to an IMS session / IMS DC session and a related event has occurred, or that the HSS / UDM needs to notify the user targeted by the content of step 1 or the IMS AS, DCSF, S-CSCF in charge of the IMS session / IMS DC session of the event of step 1, it may forward the content received in step 1 and / or stored in step 2 to the IMS AS, DCSF, S-CSCF.

[0221] Type #3: How DCSF is provided through IMS AS in Type #2

[0222] The method by which DCSF receives and manages information from OAM, DCAS, AF, and / or NEF through IMS AS and HSS / UDM corresponds to steps 1, 2, 7, and 8.

[0223] 7: DCSF can make subscription requests to IMS AS for events related to IMS sessions and / or IMS DC sessions, and IMS AS can make subscription requests to HSS / UDM for related events.

[0224] 8. If the HSS / UDM determines that a relevant event has occurred or that the user targeted by the content of step 1 or the IMS AS responsible for the IMS session / IMS DC session needs to be notified of the event of step 1, it may forward the content received in step 1 and / or stored in step 2 to the IMS AS. If the IMS AS determines that the received content corresponds to an event subscribed to by the DCSF in step 7, it may forward it to the DCSF.

[0225] Steps 7 and 8 above include a method for the IMS AS to receive subscription requests for events from the HSS / UDM and to notify the DCSF of the same and provide information thereto. In addition to this method, the IMS AS may, based on the information received in steps 1, 2, 3, and 4, and / or the information received in step 12, determine that an event related to the IMS DC session to which the DCSF requested a subscription in step 7 has occurred, and may then forward this information to the DCSF in step 8.

[0226] FIG. 7 is a diagram showing the configuration of a network function according to an embodiment of the present disclosure.

[0227] The network function (700) may include at least one of an Access and Mobility Management Function (AMF), a Session Management Function (SMF), a Network Repository Function (NRF), a Network Data Analytics Function (NWDAF), a Policy Control Function (PCF), a Unified Data Management (UDM), a Network Slice Selection Function (NSSF), an Authentication Server Function (AUSF), a Unified Data Repository (UDR), an Application Function (AF), a Data Network (DN), a Proxy Call Session Control Function (P-CSCF), an Interrogating / Serving CSCF (I / S-CSCF), an Application Server (IMS AS), a Home Subscriber Server (HSS), an Access Gateway (IMS AGW), a Media Resource Function (MRF), a Data Channel Signaling Function, a Media Function, a Network Efficiency Function (NEF), a Data Channel Application Server, and / or a Data Channel Application Repository. The network function (700) of the present disclosure may correspond to the network functions of FIGS. 1 to 6 described above.

[0228] Referring to FIG. 7, the network function (700) of the present disclosure may include a transceiver (710), a memory (720), and a processor (730). The processor (730), the transceiver (710), and the memory (720) of the network function (700) may operate according to the operating method of the network function (700) described above. However, the components of the network function (700) are not limited to the examples described above. The network function (700) may include more or fewer components than the components described above.

[0229] In addition, at least one of the processor (730), the transceiver (710) and the memory (720) may be implemented in the form of a single chip.

[0230] The transceiver (710) is a general term for the network function receiver (700) and the network function transmitter (700), and can transmit and receive signals with a UE, a base station, or other network functions. At this time, the transmitted and received signals may include control information and data. To this end, the transceiver (710) may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-downconverts the received signal. However, this is only one embodiment of the transceiver (710), and the components of the transceiver (710) are not limited to the RF transmitter and RF receiver. The transceiver (710) may include wired and wireless transceivers, and may include various configurations for transmitting and receiving signals.

[0231] Additionally, the transceiver (710) can receive a signal through a communication channel (e.g., a wireless channel) and output the signal to the processor (730), and transmit the signal output from the processor (730) through the communication channel.

[0232] Additionally, the transceiver (710) can receive a communication signal and output it to the processor (730), and transmit the signal output from the processor (730) to the UE or other network function through a wired or wireless network.

[0233] The transceiver (710) enables information to be exchanged between the processor (730) and the memory (720) and an external device, and may further include at least one of PCIe, DMA, RDMA, and Ethernet.

[0234] The transceiver (710) may be a communication circuit for transmitting and receiving signals with a user equipment (UE), a base station, or other network entity. In this case, the communication circuit may include both a communication circuit for wireless communication and a communication circuit for wired communication. For example, the transceiver (710) may include circuits, logic, hardware, etc. configured to exchange control plane messages or user plane messages with the UE, the base station, or other core network entities through wireless communication or wired communication. The transceiver (710) may operate using various protocols (e.g., Non-Access Stratum (NAS) protocol). The transceiver (710) may also be referred to as a network interface, a communication circuitry, a network interface circuitry, or a communication interface circuitry, depending on the convenience of description and technical implementation.

[0235] The memory (720) can store programs and data required for the operation of the network function (700). In addition, the memory (720) can store control information or data included in a signal obtained from the network function (700). The memory (720) can be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD.

[0236] The processor (730) may control a series of processes so that the network entity (700) can operate according to the embodiments of the present disclosure described above. The processor (730) may include at least one processor. The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0237] FIG. 8 is a block diagram schematically illustrating the configuration of a terminal according to one embodiment of the present disclosure.

[0238] Referring to FIG. 8, the terminal (800) may be composed of a transceiver (810), a processor (830), and a memory (820). Depending on the communication method of the terminal (800) described above, the transceiver (810), the processor (830), and the memory (820) of the terminal (800) may operate. However, the components of the terminal (800) are not limited to the examples described above.

[0239] For example, the terminal (800) may include more or fewer components than the aforementioned components. In one embodiment, the transceiver (810), processor (830), and memory (820) may be implemented in the form of a single chip. Additionally, the processor (830) may include one or more processors.

[0240] The transceiver (810) refers to the receiver and transmitter of the terminal (800), and can transmit and receive signals with at least one of another terminal, a base station, or a network function. The signals transmitted and received with the terminal or network entity may include control information and data. To this end, the transceiver (810) may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts a received signal. However, this is only one embodiment of the transceiver (810), and the components of the transceiver (810) are not limited to the RF transmitter and RF receiver.

[0241] Additionally, the transceiver (810) can perform functions for transmitting and receiving signals via a wireless channel. For example, the transceiver (810) can receive a signal via a wireless channel, output it to the processor (830), and transmit the signal output from the processor (830) via the wireless channel.

[0242] The memory (820) can store programs and data required for the operation of the terminal (800). In addition, the memory (820) can store control information or data included in a signal acquired from the base station. The memory (820) can be configured as a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, a DVD, or a combination of storage media. In addition, the memory (820) may not exist separately but may be included in the processor (830). The memory (820) can be configured as a volatile memory, a nonvolatile memory, or a combination of volatile and nonvolatile memories. In addition, the memory (820) can provide stored data upon request of the processor (830).

[0243] The processor (830) may control a series of processes so that the terminal (800) can operate according to the above-described embodiment of the present disclosure. For example, the processor (830) may receive control signals and data signals through the transceiver (810) and process the received control signals and data signals. The processor (830) may transmit the processed control signals and data signals through the transceiver (810). In addition, the processor (830) may write or read data to or from the memory (820). The processor (830) may perform functions of a protocol stack required by a communication standard. For this purpose, the processor (830) may include at least one processor or microprocessor. In one embodiment, a portion of the transceiver (810) or the processor (830) may be referred to as a communication processor (CP).

[0244] The processor (830) may be composed of one or more processors. In this case, one or more processors may be a general-purpose processor, such as a CPU, AP, or DSP (Digital Signal Processor), a graphics-only processor, such as a GPU or VPU (Vision Processing Unit), or an artificial intelligence-only processor, such as an NPU. For example, if one or more processors are artificial intelligence-only processors, the artificial intelligence-only processor may be designed with a hardware structure specialized for processing a specific artificial intelligence model.

[0245] The methods according to the embodiments described in the claims or specification of the present invention may be implemented in the form of hardware, software, or a combination of hardware and software.

[0246] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present invention.

[0247] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0248] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present invention via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present invention.

[0249] In the specific embodiments of the present invention described above, components included in the invention are expressed in the singular or plural form depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present invention is not limited to singular or plural components. Even components expressed in the plural form may be composed of singular elements, or even components expressed in the singular form may be composed of plural elements.

[0250] While the detailed description of the present invention has described specific embodiments, it is clear that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims but also by equivalents thereof.

[0251] A specific example for explaining an embodiment according to the present disclosure is only one combination of each criterion, method, detailed method, operation, and step, and through a combination of at least two or more techniques among the various techniques described, a terminal, a base station, or a network function can perform operations in a communication system. In addition, at this time, it can be performed according to a method determined through one or a combination of at least two or more of the above-described techniques. For example, it may be possible to perform some of the steps disclosed in the description of the drawings in combination with some of the steps of an embodiment disclosed in the description of another drawing. It may also be possible to perform by omitting some of the steps disclosed in the description of the drawings.

[0252] A device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, the term "non-transitory storage medium" simply means a tangible device that does not contain signals (e.g., electromagnetic waves). This term does not distinguish between cases where data is permanently stored in the storage medium and cases where data is temporarily stored. For example, a "non-transitory storage medium" may include a buffer in which data is temporarily stored.

[0253] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0254] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples to easily explain the technical contents of the present disclosure and to help the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art that other modified examples based on the technical idea of ​​the present disclosure are possible. In addition, each of the above embodiments can be combined and operated with each other as needed. For example, parts of one embodiment of the present disclosure and another embodiment can be combined with each other to operate a base station and a terminal. In addition, other modified examples based on the technical idea of ​​the above embodiments can be implemented in various systems such as an FDD LTE system, a TDD LTE system, a 5G or NR system, etc.

[0255] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In a method performed by an IMS (IP Multimedia Core Network Subsystem) AS (Application Server) in a wireless communication system, A step of receiving a Session Initiation Protocol (SIP) INVITE request message including a Session Description Protocol (SDP) offer from an originating network, wherein the SDP offer does not include media information regarding an IMS data channel (DC); A step of determining whether a terminating user equipment (UE) supporting the IMS data channel is permitted to use the IMS data channel; and A method comprising the step of transmitting a session event control notification message to a Data Channel Signaling Function (DCSF) when the use of the IMS data channel is permitted in a called UE supporting the IMS data channel.

2. In paragraph 1, A step for generating a bootstrap data channel media description; and A method further comprising the step of obtaining a modified SDP offer by adding the bootstrap data channel media description to the SDP offer.

3. In paragraph 2, A method further comprising the step of transmitting the modified SDP offer to the called UE supporting the IMS data channel.

4. A method according to claim 2, wherein the stream ID of the bootstrap data channel media description indicates at least one of 0 or 10.

5. In paragraph 1, A step of receiving a response message including an SDP response including media information regarding the IMS data channel from the incoming UE; and A method further comprising the step of performing a procedure for updating a media resource.

6. In the fifth paragraph, the step of performing a procedure for updating the media resource is: A method comprising the step of removing a bootstrap data channel media description of the above SDP response.

7. In paragraph 5, A method wherein the above response message includes an 18x message or a 2xxx message.

8. In the IMS (IP Multimedia Core Network Subsystem) AS (Application Server) in a wireless communication system, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and At least one memory communicatively connected to said at least one processor and storing instructions executable by said at least one processor individually or in combination, The IMS AS, by executing the above command by at least one processor individually or in combination, Receive a Session Initiation Protocol (SIP) INVITE request message containing a Session Description Protocol (SDP) offer from an originating network, wherein the SDP offer does not contain media information regarding an IMS data channel (DC, data channel), Determine whether a terminating user equipment (UE) supporting the IMS data channel is permitted to use the IMS data channel, When the IMS data channel is allowed to be used by the called UE supporting the IMS data channel, the IMS AS transmits a session event control notification message to the Data Channel Signaling Function (DCSF).

9. In the 8th paragraph, the IMS AS is configured such that the command is executed by at least one processor individually or in combination. Create a bootstrap data channel media description, An IMS AS obtains a modified SDP offer by adding the above bootstrap data channel media description to the above SDP offer.

10. In the 9th paragraph, the IMS AS is configured such that the command is executed by at least one processor individually or in combination. An IMS AS that transmits the modified SDP offer to the called UE supporting the IMS data channel.

11. In the 9th paragraph, the stream ID of the bootstrap data channel media description indicates at least one of 0 or 10, IMS AS.

12. In the 8th paragraph, the IMS AS is configured such that the command is executed by at least one processor individually or in combination. Receive a response message including an SDP answer including media information about the IMS data channel from the incoming UE, IMS AS, which performs procedures to update media resources.

13. In the 12th paragraph, the IMS AS performs a procedure for updating the media resource by executing the command by at least one processor individually or in combination. IMS AS, removing the bootstrap data channel media description of the above SDP response.

14. In paragraph 12, The above response message is an IMS AS containing an 18x message or a 2xxx message.

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