Method and apparatus for controlling session in consideration of independent IMS DC service characteristics

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transfer rates. According to an embodiment of the present disclosure, a method performed by a second terminal in a wireless communication system comprises the steps of: obtaining a session description protocol (SDP) offer for a bootstrap data channel related to a first terminal and an SDP offer for an application data channel, wherein the SDP offer includes application binding information related to a data channel application; identifying, on the basis of the application binding information, whether the data channel application is available in the second terminal; if the data channel application is not available in the second terminal, establishing a connection of a bootstrap data channel session between the second terminal and a media function (MF); and downloading the data channel application on the basis of the connection of the bootstrap data channel session.

Description

Session control method and device considering independent IMS DC service characteristics

[0001] The present disclosure relates to the operation of a terminal and an IMS AS entity in a wireless communication system. More specifically, the present disclosure relates to a method and device for controlling a bootstrap data channel session or an application data channel session, for which a terminal requests a connection through a data channel server to support an independent IMS DC service.

[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] The IMS system (IP(internet protocol) multimedia subsystem) is a system for transmitting IP-based multimedia, and various services such as VoLTE and VoNR are provided through the existing IMS network linked to LTE or 5G networks. The purpose of the IMS data channel service is to provide various additional services such as user location information transmission and screen sharing using separate applications in addition to existing voice or video-based services such as voice, video, and text services based on existing RTP (real-time transport protocol) by using the data channel service linked to the IMS. The data channel service linked to the IMS can be an IMS-DC (IP(internet protocol) multimedia subsystem-data channel) service.

[0009] In order to use an additional service or a standalone IMS data channel service utilizing a data channel within an IMS data network, the terminal can transmit a signaling message containing a request for a data channel application and related configuration information for a data channel-based service to the network through a bootstrap data channel setup signaling process. The IMS data channel network that receives the signaling message can transmit application or application list information to the terminal based on the user or service provider's configuration and request information received from the terminal, thereby enabling the terminal to download an application for the data channel service.

[0010] The terminal may select an appropriate data channel application based on the terminal's performance and user selection based on the application or application list information received from the network and request the data channel application. In addition, the network may allocate a separate media function entity within the network during the bootstrap data channel setup process to support the download of a specific application requested by the terminal. The media function entity may receive data channel application-related information (a replacement HTTP URL representing the application list offered via the MDC1 interface) that can be converted into data channel application information through the operation of a media resource management service during the bootstrap data channel setup process.

[0011] Afterwards, the media function entity receives specific data channel application information selected and requested by the terminal through the Mb interface, and then converts the data channel application download request information into HTTP URL information recognizable by the IMS data channel network (e.g. DSCF) to perform application download support operations for the terminal.

[0012] The terminal can receive each data channel application through a bootstrap connection process, and can receive data channel application-related information simultaneously with the reception of the data channel application. Thereafter, the terminal can perform an application data channel setup signaling operation to request a data channel connection of the received data channel application. The application data channel setup signaling message can also transmit application binding information including configuration information for supporting a specific application. Based on the above information received from the terminal, the network can perform at least one of three types of application data channel connection operations: terminal-to-terminal (P2P (peer to peer) application data channel setup), terminal-to-application (P2A (peer to application) application data channel setup), or terminal-to-terminal connection via an application server (P2A2P (peer to application to peer) application data channel setup).

[0013] When connecting to the above IMS DC service, a bootstrap or application data channel connection operation for a standalone IMS data channel service connection, rather than an IMS data channel service in the form of a supplementary service based on existing IMS sessions (e.g. audio / video / messaging), may be requested and performed. In addition, when using a standalone IMS data channel service, a bootstrap data channel session connection must be performed first, and when using the IMS data channel service, the bootstrap data channel session may not always be open. For example, a terminal may request an application data channel connection to the network using a data channel application (e.g. native application) pre-configured by service providers. In this case, the terminal may not proceed with the process of downloading the data channel application and related configuration information through a separate bootstrap data channel session connection.

[0014] The present disclosure, through various embodiments, provides an information management method and device for supporting bootstrap or application data channel connection operations for a standalone IMS data channel service connection. Furthermore, the present disclosure provides an information management method and device for supporting application data channel session connections using native applications on a terminal.

[0015] According to one embodiment of the present disclosure, a method of a terminating-side IMS application server (AS) entity includes the steps of: receiving a data channel session connection request message including data channel-related session description protocol SDP (session description protocol) offer information that does not include separate audio, video, and messaging-related session description protocol information transmitted from an originating-side network through a serving-call session control function (S-CSCF); updating the session connection request message by adding audio, video, and messaging-related session description protocol information when transmission of additional data channel-related session description protocol information is required in addition to the audio, video, and messaging-related session description protocol information based on capability information of a terminal and a network set when registering a terminal in the terminating-side network, or when the terminal only supports audio, video, and messaging-related session description protocol information; transmitting the updated application data channel session connection request message to the terminal by considering capability information of the network and the terminal; and receiving and transmitting response information of the application data channel session connection request transmitted by the terminal.

[0016] According to one embodiment of the present disclosure, a method performed by a second terminal in a wireless communication system includes the steps of: obtaining an SDP (session description protocol) offer for a bootstrap data channel associated with a first terminal and an SDP offer for an application data channel, the SDP offer including application binding information associated with a data channel application; identifying whether the data channel application is available within the second terminal based on the application binding information; establishing a connection of a bootstrap data channel session between the second terminal and a media function (MF) if the data channel application is not available within the second terminal; and downloading the data channel application based on the connection of the bootstrap data channel session.

[0017] According to one embodiment of the present disclosure, a method performed by a first terminal in a wireless communication system comprises the steps of transmitting an SDP (session description protocol) offer for a bootstrap data channel associated with the first terminal and an SDP offer for an application data channel to an IMS (internet protocol (IP) multimedia service) AS (application server), the SDP offer including application binding information associated with a data channel application; and receiving a 200 OK response message from the second terminal, wherein the application binding information is used by the second terminal to identify whether the data channel application is available within the second terminal.

[0018] According to one embodiment of the present disclosure, in a wireless communication system, a second terminal includes a transceiver; and a processing unit, wherein the processing unit obtains an SDP (session description protocol) offer for a bootstrap data channel related to a first terminal and an SDP offer for an application data channel, wherein the SDP offer includes application binding information related to a data channel application, and is configured to identify whether the data channel application is available within the second terminal based on the application binding information, and if the data channel application is not available within the second terminal, establish a connection of a bootstrap data channel session between the second terminal and a media function (MF), and download the data channel application based on the connection of the bootstrap data channel session.

[0019] According to one embodiment of the present disclosure, in a wireless communication system, a first terminal includes a transceiver; and a processing unit, wherein the processing unit transmits an SDP (session description protocol) offer for a bootstrap data channel associated with the first terminal and an SDP offer for an application data channel to an IMS (internet protocol (IP) multimedia service) AS (application server), wherein the SDP offer includes application binding information associated with a data channel application, and is configured to receive a 200 OK response message from the second terminal, wherein the application binding information is used by the second terminal to identify whether the data channel application is available within the second terminal.

[0020] A method and device according to one embodiment of the present disclosure can perform a standalone IMS data channel connection process without connecting an existing IMS session (video / audio / messaging) in a terminal. During the standalone IMS data channel connection process, a method and operation for connecting an IMS data channel according to the capability of the terminal in an IMS AS can be provided. During the standalone IMS data channel connection process, when performing an application data channel connection operation without a bootstrap data channel connection process in the terminal, a method and operation for connecting an IMS data channel in the terminal according to data channel application-related information in an application data channel connection request message can be provided.

[0021] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0022] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure with reference to the accompanying drawings.

[0023] FIG. 1 is a diagram illustrating a network structure and interface of a 5G system according to one embodiment of the present disclosure.

[0024] FIG. 2 is an example of an IMS-DC (IP (internet protocol) multimedia subsystem data channel) structure that provides a data channel service based on an IMS (IP (internet protocol) multimedia subsystem) service according to one embodiment of the present disclosure.

[0025] FIG. 3 is an example of a terminal and network operation structure according to an independent IMS data channel service connection request according to an embodiment of the present disclosure.

[0026] FIG. 4 is an example of a structure for performing a standalone application data channel session connection operation without a separate bootstrap data channel session connection according to one embodiment of the present disclosure.

[0027] FIG. 5 is a flowchart of operations related to selection and registration of an IMS AS that supports a terminal's service based on the terminal's capability information, etc. during an IMS registration procedure of the terminal according to one embodiment of the present disclosure.

[0028] FIG. 6A is a flowchart illustrating an operation process for processing a session connection request message in an existing terminal and network based on a session connection request message including a session description protocol that includes only data channel related information according to one embodiment of the present disclosure.

[0029] FIG. 6B is a flowchart illustrating an operation process for processing a session connection request message in an existing terminal and network based on a session connection request message including a session description protocol that includes only data channel related information according to one embodiment of the present disclosure.

[0030] FIG. 7A is a flowchart illustrating operations for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0031] FIG. 7B is a flowchart illustrating operations for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0032] FIG. 8A is a flowchart illustrating the operation of a terminating side terminal for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0033] FIG. 8B is a flowchart illustrating the operation of a terminating side terminal for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0034] FIG. 8C is a flowchart illustrating the operation of a terminating side terminal for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0035] FIG. 9 is a flowchart illustrating operations based on the ability to support the requested data channel application and related information, in relation to a process for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0036] FIG. 10 is a flowchart illustrating an operation based on a case where the requested data channel application and related information cannot be supported, in relation to a process for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0037] FIG. 11 is a block diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

[0038] FIG. 12 is a block diagram illustrating the structure of an IMS AS entity according to one embodiment of the present disclosure.

[0039] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the attached drawings.

[0040] In describing this disclosure, descriptions of technical details that are well-known in the technical field to which this disclosure pertains and are not directly related to this disclosure will be omitted. This is to avoid obscuring the gist of this disclosure by omitting unnecessary explanations and to convey it more clearly. Furthermore, the terms described below are defined based on their functions in this disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the contents of this specification as a whole.

[0041] 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.

[0042] Hereinafter, a base station (BS) 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 (or an xNode B (where x is an alphabet including g or e)), a wireless access unit, a base station controller, a satellite, an airborn, or a node on a network. A user equipment (UE) may include a mobile station (MS), a vehicle, a satellite, an airborn, a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, a downlink (DL) is a wireless transmission path of a signal transmitted from a base station to a terminal, and an uplink (UL) is a wireless transmission path of a signal transmitted from a terminal to an air station. Additionally, a sidelink (SL) may exist, which means a wireless transmission path of a signal transmitted from a terminal to another terminal.

[0043] In addition, although LTE, LTE-A, or 5G systems may be described below as examples, embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, this may include 5G-Advance or NR-Advance, or 6th generation mobile communication technology (6G) developed after 5G mobile communication technology (or new radio, NR), and the 5G described below may also include existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications within a range that does not significantly deviate from the scope of the present disclosure, as determined by a person having skilled technical knowledge.

[0044] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings 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 flowchart 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 flowchart 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).

[0045] 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.

[0046] Here, the term '~ part' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Therefore, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, 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 '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0047] 3GPP, responsible for cellular mobile communications standards, is standardizing a new core network architecture called 5G Core (5GC) to facilitate the evolution of 4G LTE systems to 5G systems. Compared to the Evolved Packet Core (EPC), the network core for 4G, 5GC supports the following differentiated features:

[0048] 5GC introduces the Network Slice feature. As a requirement of 5G, 5GC must support a variety of terminal types and services, such as enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine Type Communications (mMTC). These terminals and services each have different requirements for the core network. For example, eMBB services may require high data rates, while URLLC services may require high reliability and low latency. To meet these diverse service requirements, Network Slice technology has been proposed.

[0049] Network slicing can refer to a method of virtualizing a single physical network to create multiple logical networks (e.g., network slices). An activated network slice can be called a network slice instance, and each network slice instance (NSI) can have different characteristics. By configuring a network function (NF) for each NSI according to its characteristics, mobile carriers can satisfy various service requirements according to terminals / services. For example, mobile carriers can efficiently support various 5G services (e.g., eMBB, URLLC, or mMTC) by allocating an NSI that matches the characteristics of the service required for each terminal.

[0050] 5GC can easily support the network virtualization paradigm by separating mobility management functions from session management functions. In 4G LTE, all terminals can receive services from the network through signaling exchanges with a single core entity called the mobility management entity (MME), which is responsible for registration, authentication, mobility management, and session management. In 5G, the number of terminals (including MTC terminals) will explode, and the mobility and traffic / session characteristics that must be supported depending on the terminal type will become more specialized. Therefore, supporting all functions from a single entity (such as the MME) will inevitably reduce scalability by adding entities for each required function. Therefore, various functions are being developed based on a structure that separates mobility management and session management functions to improve scalability in terms of functional / implementation complexity and signaling load of the core entity responsible for the control plane.

[0051] FIG. 1 is a diagram illustrating a network structure and interface of a 5G system according to one embodiment of the present disclosure.

[0052] A network entity included in the network structure of the 5G system of Fig. 1 may include a network function (NF) depending on the system implementation.

[0053] Referring to FIG. 1, the network structure of a 5G system may include various network entities. For example, the 5G system may include an authentication server function (AUSF) entity (108), an access and mobility management function (AMF) entity (103), a session management function (SMF) entity (105), a policy control function (PCF) entity (106), an application function (AF) entity (107), a unified data management (UDM) entity (109), a data network (DN) (110), a network exposure function (NEF) entity (111), a network slicing selection function (NSSF) entity (114), a network repository function (NRF) entity (115), a network data analytics function (NWDAF), and an edge application service domain repository (EDS). It may include a domain repository (EDR), an edge application server (EAS), an EAS discovery function (EASDF), a user plane function (UPF) entity (104), a (radio) access network ((R)AN) (102), and a terminal, for example, a user equipment (UE) (101).

[0054] Each NF entity of the 5G system (100) supports the following functions.

[0055] AUSF (108) processes and stores data for authentication of UE (101).

[0056] AMF (103) provides 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 CN nodes for mobility between 3GPP access networks, termination of a radio access network (RAN) CP interface (i.e., N2 interface), termination of non-access stratum (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, access authorization including roaming authorization check. It supports functions such as authorization, provision of SMS message transmission between UE and SMSF, security anchor function (SAF) and / or security context management (SCM). Some or all of the functions of an AMF entity (103) may be supported within a single instance of an AMF entity.

[0057] DN (110) refers to, for example, an operator service, Internet access, or a third-party service. DN (110) transmits a downlink protocol data unit (PDU) to the UPF entity (104) or receives a PDU transmitted from the UE (101) from the UPF entity (104).

[0058] The PCF entity (106) receives information about packet flows from the application server and provides a function to determine policies such as mobility management and session management. Specifically, the PCF entity (106) supports functions such as supporting a unified policy framework for controlling network operations, providing policy rules so that control plane function entity(ies) (e.g., AMF entity, SMF entity, 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).

[0059] The SMF entity (105) provides a session management function, and when the UE (101) has multiple sessions, each session can be managed by a different SMF entity. Specifically, the SMF entity (105) is responsible for session management (e.g., session establishment, modification, and termination, including tunnel maintenance between the UPF entity (104) and the (R)AN (102) node), UE IP address allocation and management (optionally including authentication), selection and control of UP functions, setting up traffic steering to route traffic from the UPF entity (104) to the appropriate destination, termination of the interface to policy control functions, enforcement of the control portion of policy and quality of service (QoS), lawful intercept (for SM events and interfaces to the LI system), termination of the session management (SM) portion of NAS messages, downlink data notification, initiation of AN (access network) specific SM information (delivered to the (R)AN (102) via N2 via the AMF entity (103)), determination of the session and service continuity (SSC) mode of the session, and roaming. Supports functions such as functions, etc. Some or all functions of an SMF entity (105) can be supported within a single instance of an SMF entity.

[0060] The UDM entity (109) stores user subscription data, policy data, etc. The UDM entity (109) includes two parts: an application front end (FE) and a user data repository (UDR).

[0061] The FE (front end) includes the UDM FE, which is responsible for location management, subscription management, and credential processing, and the PCF entity, which is responsible for policy control. The UDR stores the data required for the functions provided by the UDM-FE and the policy profiles required by the PCF entity. The data stored in the UDR includes 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 accesses the subscription information stored in the UDR and supports functions such as authentication credential processing, user identification handling, access authentication, registration / mobility management, subscription management, and SMS management.

[0062] The UPF entity (104) forwards the downlink PDU received from the DN (110) to the UE (101) via the (R)AN (102), and forwards the uplink PDU received from the UE (101) via the (R)AN (102) to the DN (110). Specifically, the UPF entity (104) supports functions such as an anchor point for intra / inter RAT mobility, an external PDU session point for interconnection to the Data Network, a user plane part 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) to QoS flow mapping), transport level packet marking in uplink and downlink, downlink packet buffering and downlink data notification triggering. Some or all of the functions of a UPF entity (104) may be supported within a single instance of a UPF.

[0063] The AF entity (107) interacts with the 3GPP core network to provide services (e.g., supporting functions such as application impact on traffic routing, access to network capability exposure, and interaction with the policy framework for policy control).

[0064] (R)AN(102) is 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).

[0065] 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 upon attachment of the UE if routing to the AMF is not determined from the information provided to the UE, routing of user plane data to UPF(s), routing of control plane information to the AMF, 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 setup for mobility and scheduling, transport level packet marking in uplink, session management, support for network slicing, and QoS flows. It supports features such as mapping to management and data radio bearers, support for UEs in inactive mode, distribution of NAS messages, NAS node selection, radio access network sharing, dual connectivity, and tight interworking between NR and E-UTRA.

[0066] UE (User Equipment, 101) refers to a user device. A user device may be referred to by terms such as terminal, mobile equipment (ME), or mobile station (MS). Furthermore, a user device may be a portable device, such as a laptop, mobile phone, personal digital assistant (PDA), smartphone, or multimedia device, or a non-portable device, such as a personal computer (PC) or vehicle-mounted device.

[0067] The NEF (111) provides a means to securely expose services and capabilities provided by 3GPP network functions, for example, for third parties, internal exposure / re-exposure, application functions, and edge computing. The NEF (111) receives information from other NF (s) (based on the exposed capability(s) of other NF (s)). The NEF (111) can store the received information as structured data using a standardized interface to a data storage network function. The stored information can be re-exposed to other NF entity(s) and AF entity(s) by the NEF entity (111) and used for other purposes, such as analysis.

[0068] EASDF is an NF that can add an ECS (EDNS (extension mechanisms for DNS) client subnet) option that can be expressed as the address of a DNS server to which a DNS (domain name system) request of a terminal is forwarded, and an IP subnet address to be added when forwarding a DNS request of a terminal, for each FQDN (fully qualified domain name). EASDF receives EAS (exchange active sync) domain configuration information from EDR, and processes a DNS request message received from a terminal according to the received information. In addition, EASDF is an NF that receives a terminal IP address, location information of the terminal within 3GPP, DNS message processing rules, and DNS message reporting rules from an SMF (105), processes a DNS Query message received from a terminal, a DNS response message received from a DNS server, and transmits information in a DNS message and statistical information processed therefrom to the SMF (105) according to the DNS message reporting rules.

[0069] NRF (115) supports service discovery. It receives NF discovery requests from NF instances and provides information about discovered NF instances to the NF instances. It also maintains available NF instances and the services they support.

[0070] Meanwhile, for convenience of explanation, FIG. 1 illustrates a reference model for a case where a UE (101) accesses one DN (110) using one PDU session, but the present disclosure is not limited thereto.

[0071] A UE (101) can access two (i.e., local and central) data networks simultaneously using multiple PDU sessions. In this case, 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.

[0072] Additionally, the UE (101) may simultaneously access two (i.e., local and central) data networks provided within a single PDU session.

[0073] In the 3GPP system, a conceptual link connecting NFs within a 5G system is defined as a reference point. For example, the reference point(s) included in the 5G system (100) of FIG. 1 are as follows.

[0074] - N1: Reference point between UE (101) and AMF (103)

[0075] - N2: Reference point between (R)AN(102) and AMF(103)

[0076] - N3: Reference point between (R)AN(102) and UPF(104)

[0077] - N4: Reference point between SMF (105) and UPF (104)

[0078] - N5: Reference point between PCF (106) and AF (107)

[0079] - N6: Reference point between UPF (104) and DN (110)

[0080] - N7: Reference point between SMF (105) and PCF (106)

[0081] - N8: Reference point between UDM (109) and AMF (103)

[0082] - N10: Reference point between UDM (109) and SMF (105)

[0083] - N11: Reference point between AMF (103) and SMF (105)

[0084] - N12: Reference point between AMF (103) and AUSF (108)

[0085] - N13: Reference point between UDM (109) and AUSF (108)

[0086] - N14: Reference point between two AMFs (103)

[0087] - N15: Reference point between PCF and AMF in non-roaming scenario, reference point between PCF and AMF in visited network in roaming scenario.

[0088] - Nx: Reference point between SMF(105) and EASDF

[0089] - Ny: Reference point between NEF (EDF) (111) and EASDF

[0090] FIG. 2 is an example of an IMS-DC (IP (internet protocol) multimedia subsystem data channel) structure that provides a data channel service based on an IMS (IP (internet protocol) multimedia subsystem) service according to one embodiment of the present disclosure.

[0091] In the above structure, the terminal can transmit a SIP (session initiation protocol) INVITE message to an existing CSCF, such as a P-CSCF (proxy - call session control function) and an S-SCSF (serving - call session control function), to request a call session connection. The SIP INVITE message can include SDP (Session Description Protocol) information, and media-related parameters and multiplexing-related requirement information can be included in the SDP information and transmitted to the network. In addition, the terminal can transmit an SDP offer including bootstrap information together with an SDP offer for connecting an existing video or audio session, etc., in the SIP INVITE message in order to use an IMS data channel service.

[0092] The S-CSCF (serving-call session control function) that receives the SIP INVITE including the above SDP information can forward the contents of the bootstrap data channel SDP offer for a data channel service connection request to the IMS AS if the SIP INVITE includes a bootstrap data channel SDP offer. At this time, the S-CSCF can check whether the terminal or network supports IMS-DC based on the contents of the received bootstrap-related SDP offer, and if both sides support the data channel, it can decide to forward the information for the bootstrap data channel connection for the data channel connection to the IMS AS. The IMS AS that receives the bootstrap-related SDP offer message from the S-CSCF can first check with the HSS (home subscriber server) whether the corresponding UE or subscriber can use the corresponding data channel service. If it is determined based on the user profile of the corresponding user that the corresponding user cannot use the data channel, the MMTel (multimedia telephony) session setup operation can be performed without connecting the data channel through a general IMS process. Additionally, if the user cannot use a data channel-based service, the IMS AS can update the SIP INVITE message received from the S-CSCF by deleting the DC (data channel)-related media information in the SIP INVITE message, and then forward the updated SIP INVITE message to the S-CSCF.

[0093] If the service user can use the service based on the IMS data channel, data channel bootstrapping can be performed through a data channel call request with the Data Channel Signaling Function (DCSF). The IMS AS can select a DCSF by performing discovery and selection of a DCSF instance from the NRF based on the local configuration of the network operator or information transmitted from the UE. The IMS AS can transmit a Session Event Control Notification (SessionEventControl_Notify) message containing information such as SessionEstablishmentRequestEvent, Session ID, CallingID, CalledID, SessionCase, Event initiator, MediaInfoList, and DC Stream ID to the DCSF selected through the above process.

[0094] Upon receiving a DC control request from an IMS AS, the DCSF can make policy decisions regarding how to create a bootstrap data channel based on the relevant parameters within the DC control request message. Furthermore, the DCSF can determine MDC1 media information to enable the UE to download applications via the media function (MF) or multimedia resource function (MRF).

[0095] Based on the above decision information, DCSF can forward a MediaControl_MediaInstruction message containing information such as SessionID and MediaInstructionSet to the IMS AS. DCSF can also forward the MediaInstructionSet to the IMS AS, including the MDC1 media endpoint address, DC stream ID, and alternative information for the URL of the application list transmitted on the MDC1 interface. Based on this, DCSF can provide the IMS AS with a policy regarding how to create a bootstrap data channel using MF on the originating and terminating sides.

[0096] IMS AS can select MF through a process of searching and selecting MF instance or enhanced MRF supporting local configuration or DC media capabilities using NRF.

[0097] The IMS AS can forward a list of Media Termination Descriptors to the MF selected in the above process via the Nmf_MRM_Create message. The IMS AS can request the creation of two different Media Terminations. One Media Termination information can be local bootstrap media-related information, and the other Media Termination information can indicate remote bootstrap media-related information to be provided to a remote UE. Each Media Termination information can include resource allocation request information for the Mb and MDC1 interfaces. The MF can forward the negotiation result of the corresponding data channel media resource information to the IMS AS.

[0098] An IMS AS may send a response to a MediaInstruction request from the DCSF. The response message may include information regarding the result of the above operation and information related to the negotiation of MDC1 data channel media resource information.

[0099] DCSF can store media resource information in a response message to a MediaInstruction request received from an IMS AS and forward a response message related to a data channel connection notification (SessionEventControl_Notify) request from the IMS AS to the IMS AS.

[0100] The IMS AS can forward a SIP INVITE message containing an updated SDP offer with media information from the MF or enhanced MRF to the S-CSCF. The S-CSCF can forward the SIP INVITE message containing the received updated SDP offer to the remote network and UE#2.

[0101] UE#2 and the terminating network can forward the SDP response related to the bootstrap data channel to the originating network in an 18X response message. Based on the received SDP response message, the MF or enhanced MRF can update the data channel media resource information of UE#2. Afterwards, UE#2 and the terminating network can send a 200 OK response message indicating the successful completion of the request.

[0102] The IMS AS can notify the DCSF of successful session connection-related event information by sending a SessionEventControl Notify message containing SessionEstablishmentSuccessEvent, SessionID, and MediaInfoList. After receiving a response message for the successful session connection event notification from the DCSF, the IMS AS can send a 200 OK message to UE#1, indicating that the bootstrap data channel has been connected. This allows the bootstrap data channel to be established between UE#1, UE#2, and the originating MF or enhanced MRF. Afterwards, UE#1 and UE#2 can request data channel applications by sending an application request message to the MF or enhanced MRF. If multi-DC applications are supported, UE#1 and UE#2 can request an application list from the MF or enhanced MRF. The MF or MRF can replace the root URL with application-related URL information based on the replacement URL information received from the DCSF. Afterwards, the MF can forward the application request message received from the UE to the DCSF. DCSF can provide a list of applications or appropriate data applications to UE#1 and UE#2, depending on the UE's data channel processing capabilities and selection. Depending on the MF's location, if terminating MF or MRF is used, the UE can perform the above process through terminating DCSF and download the appropriate data channel application.

[0103] After the IMS session and bootstrap data channel connection and data channel application are downloaded to UE#1 and UE#2, UE#1 can send a SIP reINVITE message containing the updated SDP to the IMS AS. The updated SDP may include not only bootstrap data channel information, but also application data channel request information and related DC application binding information.

[0104] An IMS AS can determine whether to notify DCSF of a media change request event based on user subscription data information. If the IMS AS decides to notify DCSF of an event, it can forward a SessionEventControl_Notify message containing the MediaChangeRequest Event, Session ID, Event Direction, Event Initiator, and Media Info List to DCSF.

[0105] After receiving the session event notification message, the DCSF can determine the policy on how to handle the application data channel connection request based on the relevant parameters conveyed in the notification message and the network operator's policy. If UE#2 is the target endpoint and does not require an anchor of the local MF or enhanced MRF, the DCSF can decide to add the application data channel media descriptor to the SDP offer. If the MF or enhanced MRF is required as the anchor of the application data channel, the DCSF can forward the Nimsas_MediaControl message to the IMS AS to instruct the IMS AS to perform data channel media resource allocation of the MF or enhanced MRF.

[0106] DCSF can forward a response to the Session Event Notification message to the IMS AS. The IMS AS can then forward a SIP reINVITE message to the originating S-CSCF, which can then forward it to the terminating network and UE#2.

[0107] The 200 OK response can be included in the SDP response related to the application data channel from UE#2 and the terminating network and forwarded to the originating network. Afterwards, the IMS AS, which receives the SDP offer response message including the 200 OK response from the terminating network, can notify the DCSF of information related to the successful data channel change. The DCSF can send a response to the notification to the IMS AS, and the IMS AS can then forward the 200 OK response to UE#1 through the originating S-CSCF and P-CSCF. At this time, the P-CSCF of the originating network can perform the QoS procedure of the application data channel media based on the SDP response information including the 200 OK response. UE#1 can send an ACK to the terminating network. Through the above process, the application data channel connection operation between UE#1 and UE#2 can be performed.

[0108] FIG. 3 is an example of a terminal and network operation structure according to an independent IMS data channel service connection request according to an embodiment of the present disclosure.

[0109] In one embodiment of the present invention, a terminal supporting an independent IMS data channel service can determine whether the network supports the independent IMS data channel service when registering with an IMS network. If the network supports the independent IMS data channel service, the terminal can determine, based on information received when registering with the IMS network, whether to request an additional IMS data channel service for an existing IMS session when requesting an IMS data channel connection, or to request a standalone IMS data channel service without connecting to the existing IMS session.

[0110] In one embodiment of the present invention, when a terminal requests a standalone IMS data channel service connection, as in the embodiment of FIG. 5, the S-CSCF performs a third-party registration (3) with a data channel service-dedicated application server (e.g., DAS, Data Channel Application Server) for processing a standalone IMS data channel service. rd The party registration process can be performed.

[0111] In one embodiment of the present invention, when a terminal requests an additional IMS data channel service connection to an existing IMS session, as in the embodiment of FIG. 5, the S-CSCF performs a third-party registration (3) with a data channel service-dedicated application server (e.g., TAS, telephony application server) for processing the additional IMS data channel service. rd The party registration process can be performed.

[0112] If a terminal (UE #1) requests a standalone IMS data channel session connection using a local (originating) network-side data channel server, the session description protocol (SDP, session description protocol) that constitutes the session connection request message (e.g., SIP INVITE) generated by the terminal may include only data channel application-related information excluding audio, video, and message-related multimedia session parameter information, and the terminal may transmit the IMS data session connection request message to the network. The terminal may transmit the IMS data channel session connection request message to the network through a bootstrap data channel connection process. The S-CSCF, which has received the IMS data channel session connection request message including only data channel application-related information, may transmit it to the DAS connected to the terminal during the IMS registration process. The DAS, which has received the standalone IMS data channel session connection request, may receive IMS data channel-related application information, and may transmit the data channel application-related information in the session description protocol received from the terminal to the DCSF in order to request the application-related information. The DSCF, which has received data channel application-related information from the DAS, can determine a policy for creating media resources to transmit appropriate data channel applications and related information based on the service information and related media information requested by the terminal (UE#1). The DCSF can request the IMS AS (DAS) to allocate media resources in the MF created based on the above policy, and based on the result, can change the session description protocol information in the session connection request message and then transmit the session request message for IMS data channel session connection to the remote (terminating) network and terminal (UE#2).

[0113] The Remote Network, which has received a session connection request message including changed session description protocol information from the Local Network, can process the service connection request by first forwarding the session connection request message to the relevant IMS AS (e.g., terminating-side TAS) based on the information of the terminal (UE#2) registered in the Network. The Terminating-side IMS AS, which has received a session connection request for an exclusive IMS data channel connection from the Remote Network-side S-CSCF (S-CSCF #2), can perform a service operation to process the connection request.

[0114] For example, if UE #2 registers information to the IMS network about whether it supports a separate standalone service connection request, the terminating-side S-CSCF can perform an action to support the relevant service by forwarding the session connection request message delivered from the originating side to the DAS.

[0115] However, if UE#2 has not registered with the network whether it supports a separate IMS DC function or is a terminal that supports additional IMS data channel services among existing IMS session connections based on video, audio, and messaging, the terminating-side S-CSCF can perform actions to support related services by forwarding the session connection request message transmitted from the originating side to the TAS.

[0116] In one embodiment of the present invention, the S-CSCF may forward a relevant session connection request message to the IMS AS for service control based on a session connection request message transmitted from the originating network and terminal to the terminating network. At this time, if the terminal and network cannot process a single IMS data channel connection based on capability information of the terminating network and / or terminal, the session connection request message may be forwarded to the IMS AS to request an update or change of the session description protocol information in the session connection request message.

[0117] In one embodiment of the present invention, if the session connection request message transmitted from UE #1 to the terminating-side S-CSCF only includes session description protocol information related to IMS data channel, the S-CSCF may transmit the session connection request message to the terminating-side IMS AS (T-IMS AS) to request an update of the session description protocol information to support an existing IMS session. Through the above process, a modified session connection request message based on session description protocol information for supporting an existing IMS session connection including video, audio, or messages, based on terminal information registered in the network, may be transmitted to the terminating terminal (UE #2) through the terminating-side S-CSCF. UE #2, which has received the modified IMS session connection request message, may transmit a 200 OK message including a session description protocol response message based on an existing IMS session connection including video, audio, or messages, to the originating network.

[0118] In an embodiment of the present invention, the Originating IMS AS, which receives a 200 OK message including a session description protocol response message based on an existing IMS session connection from a terminating network and a terminal, may forward the 200 OK message to the DCSF. If, based on the capability information of the terminal registered in the Originating network, the terminal requests information for supporting a standalone IMS service function and additional IMS data channel service functions based on existing video, audio, and messaging when registering in the IMS network, the Originating S-CSCF may, based on the response message transmitted from the terminating network and the terminal, change the application server connected to the existing DAS to the application server connected to the TAS.

[0119] In one embodiment of the present invention, even in a TAS that supports additional IMS data channel services based on existing video, audio, and messaging, depending on the network operator's settings, if processing of session description protocol information for a standalone IMS data channel session connection is supported, the response message of UE #2 can be processed based on additionally updated session description protocol information without changing a separate application server connection.

[0120] DCSF, which receives an existing video-based service connection request response message from UE #2, can complete the setup for a bootstrap data channel connection to use the related IMS data channel service by setting the media resources in the terminating-side MF to the existing video call-based service and setting the media resources in the MF of UE #1 to a single IMS data channel session-based service.

[0121] FIG. 4 is an example of a structure for performing a standalone application data channel session connection operation without a separate bootstrap data channel session connection according to one embodiment of the present disclosure.

[0122] In one embodiment of the present invention, in the case of a native application provided by a network or service provider, a data channel-based service can be provided by utilizing an application (e.g., video call) that provides additional services in a main application (e.g., voice call application) without downloading a separate application.

[0123] In one embodiment of the present invention, without downloading a separate data channel application and data channel application-related setting information through a bootstrap data channel session connection process, when requesting an application data channel connection based on preset information, session description protocol (SDP) information including a data channel application ID and data channel application-related setting information (application binding information, bootstrap ID, DC stream ID, etc.) can be included in a service connection request (SIP INVITE) message.

[0124] Based on the session description protocol information requested by the terminal, the terminal can transmit the session description protocol information for the application data channel session connection request to the S-CSCF and IMS AS, and the IMS AS can transmit this to the Originating DCSF to perform data channel policy determination for the application data channel connection and media resource allocation operations within the MF. After the media resource allocation from the MF is completed, the DCSF can transmit a service connection request message including the updated session description protocol information based on the terminating-side media resource information to the terminating network.

[0125] A terminating network (e.g. S-CSCF) that receives a service connection request message containing only application data channel session-related session description protocol proposal information without separate bootstrap data channel-related session description protocol proposal information can forward the related service connection request message to the terminating UE (UE #2).

[0126] UE #2, which has received a service connection request message including a data channel application ID and data channel application-related configuration information (application binding information, bootstrap ID, DC stream ID, etc.), can determine whether the data channel with the corresponding data channel application ID is supported and whether UE #2 supports the related configuration information.

[0127] If UE #2 cannot support the related data channel application or configuration information based on the application data channel related information, UE #2 may decide to perform a bootstrap data channel connection request operation to request the download of a separate data channel application or configuration information. UE #2 may include at least one piece of information, such as a bootstrap ID, DC stream ID, or application ID, received through the information received through the service connection request message in the service connection request message requesting the bootstrap data channel connection.

[0128] Through the above bootstrap data channel connection process, UE #2 can newly download or update data channel application or data channel application-related configuration information based on the data channel application information requested from UE #1. UE #2 can transmit a response message (200 OK) message accepting the application data channel connection if the data channel application or data channel application-related configuration information received through the bootstrap data channel connection process is included in the data channel connection request message received from UE #1.

[0129] If the data channel application or related information updated through the bootstrap data channel connection operation in UE#2 does not satisfy the information to support the data channel service in the data channel request message received from UE#1, a session connection failure message (e.g., 606 Not Acceptable) including specific connection failure cause information of the session connection request may be transmitted to the originating network.

[0130] FIG. 5 is a flowchart of operations related to selection and registration of an IMS AS that supports a terminal's service based on the terminal's capability information, etc. during an IMS registration procedure of the terminal according to one embodiment of the present disclosure.

[0131] In step 501, the terminal may transmit a registration request (SIP REGISTER) message to the P-CSCF for registration in the IMS network. The terminal may use a media feature tag in the registration request message header to convey capability information related to the service requested by the terminal or the service supported by the terminal.

[0132] In step 502, the P-CSCF may forward the registration request message requested by the terminal to the I-CSCF.

[0133] In step 503, the I-CSCF can determine which S-CSCF can process the registration request message based on the HSS data information and forward it to the appropriate S-CSCF.

[0134] In steps 504 and 505, the S-CSCF transmits a 401 response message including nonce information for performing authentication operations with the terminal to the terminal through the P-CSCF, and the terminal transmits related information, such as shared secret data, to the S-CSCF through a registration request message to perform an IMS network registration procedure for the terminal in order to perform an authentication procedure, and transmits the related result to the terminal to complete the registration procedure.

[0135] In step 506, the S-CSCF performs third-party registration (3-party registration) with the IMS AS based on the initial filter criteria information in the user profile received from the HSS and the service-related information in the registration request message received from the terminal. rd The IMS AS can determine the operation of the IMS Service Registration (SSR) and generate a new registration request message to perform the registration procedure in the IMS AS based on the IMS AS information supporting each service determined through the IFC (Initial Filter Criteria) operation process. The IFC information can include priority, trigger point, and application server-related information.

[0136] In steps 507 to 509, the S-CSCF can obtain information on an IMS AS (TAS) related to a service that supports an additional IMS data channel based on an existing IMS session based on the media capability tag information in the registration request message header of the terminal. Thereafter, the S-CSCF can transmit a registration request message to the IMS AS for a service that supports an additional IMS data channel service based on an existing IMS session and perform a related authentication procedure with the HSS to complete the registration procedure with the IMS AS that supports the additional IMS data channel service.

[0137] From step 510 to step 512, the S-CSCF can obtain information on an IMS AS (DAS) supporting a standalone IMS data channel service connection through an IFC (initial filter criteria) operation if the header of the registration request message of the terminal includes media capability tag information related to a service supporting a standalone IMS data channel service without an existing IMS session. Afterwards, the S-CSCF transmits a registration request message for a three-party registration to the IMS AS supporting a service supporting the standalone IMS data channel service, and the IMS AS receiving the registration request message can perform a related authentication procedure with the HSS to complete the registration procedure with the IMS AS supporting the standalone IMS data channel service.

[0138] FIG. 6 is a flowchart illustrating an operation process for processing a session connection request message in an existing terminal and network based on a session connection request message including a session description protocol that includes only data channel related information according to one embodiment of the present disclosure.

[0139] In one embodiment of the present invention, the IMS AS may be assumed to be an IMS application server that processes and supports video, audio, and messaging-related session description protocols or video, audio, and messaging-related session description protocols and application-related session description protocols for data channels or application-related session description protocols for data channels. In the case of video, audio, and messaging-related session description protocols and application-related session description protocols for data channels or application-related session description protocols for data channels, a separate event-related service subscription procedure between the IMS AS and the DCSF may be required for data channel connection.

[0140] In step 601, the terminal (UE#1) may decide to use a data channel-only service without connecting separate video, audio, and messaging-related IMS sessions, depending on the policy of the service provider or network operator. Whether the IMS network supports the data channel-only service can be communicated to the network through a related media capability tag (e.g., "g.3gpp.IMSDC.Standalone") in the message header when the terminal requests registration. Based on the media capability tag information, the network can communicate to the terminal whether it supports the service requested by the terminal through a registration request response message. Through this, the terminal can know the types of services that the network and the terminal can support based on the media capability information available to the terminal when registering with the network.

[0141] In step 602, UE #1 may forward an application or bootstrap data channel session connection request message containing a session description protocol containing only data channel related information to the S-CSCF via the P-CSCF.

[0142] At step 603, the S-CSCF may perform a service management action to forward the session connection request message, which contains only data channel related information, to an appropriate IMS AS for processing, based on information in the session description protocol delivered during registration with the IMS network.

[0143] In step 604, the S-CSCF may forward an application or bootstrap data channel session connection request message containing a session description protocol that includes only data channel-related information to the IMS AS. The IMS AS receiving the application or bootstrap data channel session connection request message may be an IMS AS that cannot process existing video, audio, and messaging-related media information and can process session description protocol information that only includes IMS data channel-related request information.

[0144] In step 605, the IMS AS may transmit information for a bootstrap data channel session connection or an application data channel session connection to the DCSF for a data channel-related media resource allocation request. When transmitting information for a bootstrap data channel session connection, the IMS AS may complete the configuration for the bootstrap data channel connection, such as allocating a data channel application list and alternative URL information related to data channel applications within the MF to support downloading of service-related data channel applications requested by the terminal, and setting up a media data channel interface connection to support downloading of applications between the DCSF and the MF, and then transmit a data channel session connection request message (SIP INVITE) to the IMS AS.

[0145] At step 606, the IMS AS may forward a SIP INVITE message containing an SDP offer with updated data channel related information based on the information received from the DCSF to the S-CSCF.

[0146] At step 607, the Originating S-CSCF (S-CSCF #1) may forward a data channel session connection request message to the Terminating side S-CSCF (S-CSCF #2).

[0147] In step 608, if the terminal or network cannot process a SIP INVITE message composed only of a data channel-related application session description protocol based on the terminal information stored in the network when registering in the terminating-side network, or if the terminal does not support data channel-related services and only supports existing voice, video, and messaging-based services, S-CSCF #2 can forward the SIP INVITE message received from the originating-side network to the terminating-side IMS AS (ISM-AS-T).

[0148] In step 609, the IMS AS may determine whether to change the SDP offer information in the SIP INVITE message if the data channel-only service is not supported by determining the capability of the terminal registered in the network or the network's supportable services.

[0149] In steps 610 and 611, if the network or terminal provides a data channel service in addition to the existing voice, video, and messaging-based IMS service, the audio or video or messaging-related session description protocol information may be added to the SDP offer included in the SIP INVITE message and transmitted to the terminating UE (UE#2). However, if the network or terminal only supports the existing voice, video, and messaging-based IMS service, the data-related session description protocol information in the SIP INVITE message may be set to INACTIVE and audio or video or messaging-related session description protocol information may be added and transmitted to the terminating UE (UE#2).

[0150] In step 612, UE #2 can forward a 200 OK response message including only audio, video, and messaging-related session description protocol information if it only supports existing voice, video, and messaging-based IMS services, and can forward a response message including audio, video, and messaging-related session description protocol information and data channel-related session description protocol information to S-CSCF #1 if it supports data channel services in addition to voice, video, and messaging-based services.

[0151] In step 613, S-CSCF #1 may forward the response information received from UE #2 to the IMS AS if the IMS AS can process the relevant service based on the session description protocol information related to audio, video, and messaging. However, if the IMS AS is an IMS AS that can only process data channel services based on the session description protocol information related to data channels (e.g., DAS in FIG. 3), the S-CSCF #1 may decide to change to an IMS AS that can process session description protocol information related to audio, video, messaging, and data channels (e.g., TAS in FIG. 3) based on the information about IMS ASs obtained during terminal registration.

[0152] Afterwards, S-CSCF #1 can decide to change IMS AS from DAS to TAS and complete the data channel session connection operation by forwarding the 200 OK response message received from UE #2 to the changed IMS AS (TAS). At this time, the information forwarded to TAS can include at least one or more data channel session information among the session ID, calling ID, called ID, and DC stream ID generated during connection in step 605 at the request of UE #1. The data channel session information can be received from DAS or through information in the data channel-related SDP answer received by UE #2.

[0153] In step 614, the IMS AS may forward the received UE #2-related information to the DCSF to complete the media resource allocation of the terminating-side MF. The DCSF may then notify the IMS AS that the setup for supporting data channel-related services has been successfully completed.

[0154] At step 615, the IMS AS may, based on the information received from the DCSF, forward a modified 200 OK response message to UE #1 based on the information of the Originating side MF, to notify that the data channel connection request operation requested by UE #1 has been successfully performed.

[0155] FIG. 7 is a flowchart illustrating an operation for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0156] At step 700, UE #1 may determine a data channel service connection request using a native data channel application.

[0157] In step 701, UE #1 may transmit an application data channel exclusive session connection request to the IMS AS via a SIP INVITE message based on an SDP offer including application-related information such as a native application-related application ID and bootstrap ID, application binding information, etc.

[0158] At step 702, the IMS AS can determine the location of the appropriate DCSF (e.g. Local DCSF or Remote DCSF) through the Bootstrap ID, etc.

[0159] In step 703, the IMS AS may request execution of a data channel session connection request event by sending a Nimsas_SessionEventControl_Notify message to the DCSF, which includes information such as SessionEstablishmentRequestEvent, SessionID, MediaInfoList, EventInitiator, Application ID, Bootstrap ID, and application binding information (e.g., version ID).

[0160] In steps 704 and 705, the DCSF may determine a data channel policy based on information received from the terminal and generate Originating and Terminating side media resource information within the MF.

[0161] In step 706, the DCSF generates a media instruction set based on media resource allocation information within the MF and then transmits it to the IMS AS to perform a related media resource handling request. Based on the media instruction information received from the DSCF, the IMS AS can receive information on an appropriate MF supporting the media instructions via the NRF and then decide to transmit the media instruction set information to the selected MF.

[0162] In step 707, the IMS AS selects an appropriate MF that supports the media information received from the DCSF and then forwards the relevant media instruction set information to the MF to allocate media resources on the originating and terminating sides to support the data channel service. The MF may then forward the results of the media resource allocation to the IMS AS, and may additionally forward relevant information to support additional interfaces connected to the MF, such as MDC1 and MDC2.

[0163] In step 708, the IMS AS can transmit the MF-related media resource allocation information and media resource allocation result information received from the MF to the DCSF.

[0164] In step 709, the DCSF may forward the results of the data channel session connection request event requested from the IMS AS in step 703 to the IMS AS.

[0165] In steps 710 and 711, the IMS AS may forward a SIP INVITE message containing a modified SDP offer based on the terminating side media resource information in the MF to the terminating network and terminal.

[0166] At step 712, UE #2 determines whether to accept the relevant data channel session connection request from UE #2 based on the information in the SIP INVITE message transmitted from the originating network. Specifically, UE #2 can determine whether the native application is supported by UE #2 based on application-related information such as the native application ID, bootstrap ID, and application binding information transmitted from UE #1.

[0167] In step 713, UE #2 may determine an operation to download a new data channel application or update application-related configuration information through a bootstrap data channel connection if the native application is not supported or the configuration information such as the version is incorrect based on the application-related information such as the application ID and bootstrap ID related to the native application received from UE #1 in the above step.

[0168] FIG. 8 is a flowchart illustrating the operation of a terminating side terminal for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0169] In step 800, UE #2 may determine a new data channel application download operation or an application-related configuration information update operation through a bootstrap data channel connection based on application-related information including the native application-related application ID and bootstrap ID, application binding information, etc., received from UE #1, if the native application is not supported or the configuration information including the version is incorrect.

[0170] In step 801, UE #2 can forward a SIP INVITE message for bootstrap data channel session connection to the Originating Side S-CSCF based on the SDP offer including the application ID, bootstrap ID, and application binding information received from UE #1.

[0171] In step 802, the S-CSCF, which has received the bootstrap data channel session connection request message from UE #2, may forward it to the IMS AS.

[0172] In step 803, the IMS AS may request the DCSF to perform a session connection request event to transfer data channel application download or application-related configuration information to UE #2. At this time, the bootstrap data channel connection between UE #2, DCSF, and MF may be a channel connection requested using a separate session ID to terminate the bootstrap data channel connection after downloading the relevant data channel application or updating the application-related configuration.

[0173] In steps 804 and 805, DCSF may determine a data channel policy based on the application-related information received from UE #2 and generate terminating-side media resource information within the MF.

[0174] In step 806, the DCSF may generate a media instruction set based on media resource allocation information within the MF and forward it to the IMS AS to perform a related media resource handling request. The IMS AS may determine to forward the media instruction set information to the selected MF after receiving information about the appropriate MF supporting the media instructions via the NRF based on the media instruction information received from the DSCF. The media instruction information may include information such as replacement URL information related to native applications.

[0175] In step 807, the IMS AS selects an appropriate MF that supports the media information received from the DCSF and then forwards the relevant media instruction set information to the MF to allocate terminating-side media resources to support the data channel service. The MF may then forward the results of the media resource allocation to the IMS AS, and may additionally forward relevant media resource information to support the MDC1 interface between the MF and the DCSF.

[0176] In step 808, the IMS AS may transmit MF-related media resource allocation information and media resource allocation result information received from the MF to the DCSF.

[0177] In step 809, the DCSF may forward the results of the bootstrap data channel session connection request event requested from the IMS AS in step 803 to the IMS AS.

[0178] In steps 810 and 811, the IMS AS may forward an SDP answer containing the terminating side media resource information and the native application or native application list within the MF to the terminating network and terminal.

[0179] At step 812, UE #2 can check whether the information of the received native data channel application matches the information received from UE #1 based on the received native data channel application or native data channel application list.

[0180] In steps 813 and 814, if the data channel session connection request response message (SDP answer) received from steps 810 and 811 does not include a native application or a native application list, after the bootstrap data channel session connection, UE#2 may request a native application or a native application list from DCSF via MF.

[0181] If the data channel session connection request response message (SDP answer) received from steps 810 and 811 does not include a native application or a native application list, step 812 of comparing the application information received from UE #1 with the native application information received by UE #2 from DCSF may be performed after step 814.

[0182] If UE #2 supports the application received from UE #1 based on the data channel application list received from the Originating DCSF in step 812, UE #2 may perform a bootstrap data channel connection operation between UE #2 and DCSF. Thereafter, UE #2 may perform an operation to download a specific data channel application and application-related information from DCSF through MF based on the selected application information. After UE #2 performs the operation to download the native data channel application and application-related information, UE #2 may transmit a SIP re-INVITE message to DCSF to release the bootstrap data channel session connection according to the settings of the network operator or service provider, and DCSF, which has received the request information, may perform an operation to delete data channel-related lease allocation information in MF and terminate the data channel session.

[0183] FIG. 9 is a flowchart illustrating operations based on the ability to support the requested data channel application and related information, in relation to a process for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0184] In step 901, UE #2 may transmit a response message (200 OK) including an SDP answer for acceptance of the application data channel connection request to the Originating-side S-CSCF if UE #2 can support the data channel application and application-related information requested by UE #1 through step 712 of FIG. 7 or has downloaded the data channel application and application-related information requested by UE #1 through a separate bootstrap data channel session connection process of FIG. 8. The response message may include media resource information of UE #2 related to media resources on the Terminating-side within the MF.

[0185] At step 902, the S-CSCF may forward a response message to the application data channel connection request received from UE #2 to the IMS AS.

[0186] At step 903, the IMS AS may notify the DCSF that the application data channel setup is complete based on the SDP answer information received from UE #2.

[0187] At step 904, DCSF may finally communicate to the IMS AS that the application data channel connection is complete via a 200 OK message.

[0188] At step 905, the IMS AS may communicate the completion of the application data channel session connection to the P-CSCF via a 200 OK message through the S-CSCF.

[0189] At step 906, the P-CSCF may perform QoS resource allocation operations based on the application data channel session related information contained in the 200 OK message.

[0190] At step 907, when the QoS resource allocation operation is completed in the P-CSCF, information that the application data channel session connection using the native data channel application is finally completed can be transmitted to UE #1 via a 200 OK message.

[0191] FIG. 10 is a flowchart illustrating an operation based on a case where the requested data channel application and related information cannot be supported, in relation to a process for performing an application data channel single session connection request without a separate bootstrap data channel connection according to one embodiment of the present disclosure.

[0192] In step 1001, if UE #2 cannot support the data channel application and application-related information requested by UE #1 through step 712 of FIG. 7 or cannot download the data channel application and application-related information requested by UE #1 through a separate bootstrap data channel session connection process of FIG. 8, UE #2 may reject the application data channel connection request based on the data channel application transmitted by UE #1 by sending a message (606 Not Acceptable) to the originating network (S-CSCF).

[0193] At step 1002, the S-CSCF may forward the 606 message received from UE #2 to the IMS AS.

[0194] At step 1003, the IMS AS may notify the DCSF of the failure of the application data channel session connection and may forward the SessionEstablishmentFailureEvent information to the DCSF via the Nimsas_SessionEventControl_Notify message to request deletion of the relevant data channel policy and media resources within the MF.

[0195] At step 1004, DCSF may forward the application data channel related media deletion result to IMS AS via Nimsas_SessionEventControl_Notify Response.

[0196] In steps 1005 and 1006, the IMS AS may convey the result information about the application data channel session connection failure to UE #1 using message 606.

[0197] At step 1007, UE #1 may decide to perform a bootstrap data channel session connection request operation to download appropriate data channel applications and application-related configuration information for UE #1 and UE #2 to use in the data channel service.

[0198] In steps 1008 and 1009, UE #1 transmits appropriate data channel application information to be used in the data channel service to UE #1 and UE #2 through a bootstrap data channel session connection operation, and each UE can download appropriate data channel application and application-related configuration information considering the capabilities of each UE.

[0199] FIG. 11 is a block diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

[0200] Referring to FIG. 11, a terminal according to an embodiment of the present disclosure may include a terminal receiving unit (1100), a terminal transmitting unit (1104), and a terminal processing unit (1102). The terminal receiving unit (1100) and the terminal transmitting unit (1104) may be collectively referred to as a transceiver in the present disclosure. The transceiver unit may transmit and receive signals with a base station. The signals may include control information and data. To this end, the transceiver unit 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. In addition, the transceiver unit may receive a signal through a wireless channel and output it to the terminal processing unit (1102), and transmit the signal output from the terminal processing unit (1102) through the wireless channel. The terminal processing unit (1102) may control a series of processes so that the terminal may operate according to the above-described embodiment.

[0201] FIG. 12 is a block diagram illustrating the structure of an IMS AS entity according to one embodiment of the present disclosure.

[0202] Referring to FIG. 12, an IMS AS entity according to an embodiment of the present disclosure may include at least one of an IMS AS entity receiving unit (1201), an IMS AS entity transmitting unit (1205), and an IMS AS entity processing unit (1203). The IMS AS entity receiving unit (1201) and the IMS AS entity transmitting unit (1205) may be collectively referred to as a transmitting / receiving unit in the present disclosure. The transmitting / receiving unit may transmit and receive signals with a terminal. The signals may include control information and data. To this end, the transmitting / receiving unit may be configured with a SIP server that generates or modifies a new SIP message based on additional information for supporting a service based on a transmitted / received SIP message. In addition, the transceiver can receive a signal through a wired / wireless channel and output it to the IMS AS entity processing unit (1203), and transmit the signal output from the IMS AS entity processing unit (1103) through the wired / wireless channel. The IMS AS entity processing unit (1203) can control a series of processes so that the IMS AS entity can operate according to one embodiment of the present disclosure described above.

[0203] Meanwhile, the order of description in the drawings illustrating the method proposed in this disclosure does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel. Alternatively, the drawings illustrating the method proposed in this disclosure may omit some components and include only some components, as long as it does not detract from the essence of this disclosure.

[0204] 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.

[0205] 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 embodiments described in the claims or specification of the present disclosure.

[0206] These programs (software modules, software) may be stored in a non-volatile memory including random access memory, flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc ROMs (CD-ROMs), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or 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.

[0207] Additionally, the program may be stored on 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 disclosure 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 disclosure.

[0208] In the specific embodiments of the present disclosure described above, components included in the present disclosure are expressed singularly or plurally, 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 plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0209] 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. A method performed by a second terminal in a wireless communication system, A step of obtaining an SDP (session description protocol) offer for a bootstrap data channel associated with a first terminal and an SDP offer for an application data channel, wherein the SDP offer includes application binding information associated with a data channel application; A step of identifying whether the data channel application is available within the second terminal based on the application binding information; A step of establishing a connection of a bootstrap data channel session between the second terminal and an MF (media function) when the data channel application is not available within the second terminal; and A method comprising the step of downloading the data channel application based on a connection to the above bootstrap data channel session.

2. In paragraph 1, The above application binding information corresponds to the application identifier (ID).

3. In paragraph 1, The second terminal transmits an application request message to the MF for downloading the data channel application or the data channel application list; and A method further comprising the step of downloading the data channel application based on the application request message.

4. A method in accordance with claim 1, wherein the SDP proposal for the bootstrap data channel and the SDP proposal for the application data channel are included in a service connection request message for a standalone IMS (IP (internet protocol) multimedia service) data channel session.

5. In paragraph 1, A method further comprising the step of transmitting a 200 OK response message to the first terminal when the data channel application is available within the second terminal or when the second terminal has downloaded the data channel application.

6. In paragraph 1, The steps to download the above data channel application are: If the above data channel application is not available, download the above data channel application via a bootstrap data channel connection, or A method further comprising the step of updating configuration information related to the data channel application through the bootstrap data channel connection when the configuration information of the data channel application is different.

7. A method performed by a first terminal in a wireless communication system, A step of transmitting an SDP (session description protocol) offer for a bootstrap data channel related to the first terminal and an SDP offer for an application data channel to an IMS (internet protocol (IP) multimedia service) AS (application server), wherein the SDP offer includes application binding information related to a data channel application; and A step of receiving a 200 OK response message from the second terminal, The above application binding information is used by the second terminal to identify whether the data channel application is available within the second terminal.

8. In paragraph 7, The step of receiving a 200 OK response message from the second terminal is: Further comprising the step of receiving a 200 OK response message from the second terminal when the data channel application is available within the second terminal or when the second terminal has downloaded the data channel application; The binding information related to the above data channel application corresponds to the application ID (identifier), and A method in which the SDP proposal for the above bootstrap data channel and the SDP proposal for the above application data channel are included in a service connection request message for a standalone IMS (IP (internet protocol) multimedia service) data channel session.

9. In a second terminal in a wireless communication system, Transmitter and receiver; and Including a processing unit, The processing unit obtains an SDP (session description protocol) offer for a bootstrap data channel related to the first terminal and an SDP offer for an application data channel, the SDP offer including application binding information related to the data channel application, and identifies whether the data channel application is available within the second terminal based on the application binding information, and if the data channel application is not available within the second terminal, establishes a connection of a bootstrap data channel session between the second terminal and an MF (media function), and downloads the data channel application based on the connection of the bootstrap data channel session. A second terminal.

10. In paragraph 9, The above application binding information is a second terminal corresponding to the application identifier (ID).

11. In paragraph 9, The above processing unit is a second terminal further configured to transmit an application request message for downloading the data channel application or the data channel application list to the MF, and to download the data channel application based on the application request message.

12. In the 9th paragraph, the SDP proposal for the bootstrap data channel and the SDP proposal for the application data channel are included in a service connection request message for a standalone IMS (IP (internet protocol) multimedia service) data channel session.

13. In paragraph 9, The second terminal, wherein the processing unit is further configured to transmit a 200 OK response message to the first terminal when the data channel application is available within the second terminal or when the second terminal has downloaded the data channel application.

14. In paragraph 9, The above processing unit, in downloading the data channel application, If the above data channel application is not available, download the above data channel application via a bootstrap data channel connection, or A second terminal further configured to update configuration information related to the data channel application through the bootstrap data channel connection when the configuration information of the data channel application is different.

15. In a wireless communication system, at the first terminal, Transmitter and receiver; and Including a processing unit, The above processing unit is configured to transmit an SDP (session description protocol) offer for a bootstrap data channel related to the first terminal and an SDP offer for an application data channel to an IMS (IP (internet protocol) multimedia service) AS (application server), the SDP offer including application binding information related to a data channel application, and receive a 200 OK response message from the second terminal. The above application binding information is used by the first terminal to identify whether the data channel application is available within the second terminal.

Images