How to improve the functionality of NWDAF to make SMF more effective at duplicate transmission

Abstract

One aspect of the present disclosure may provide a method for operating a Session Management Function (SMF) node that manages a Protocol Data Unit (PDU) session. The method may include acquiring analysis information from a Network Data Analytics Function (NWDAF) node. The acquired analysis information may include empirical analysis information regarding duplicate transmission. The method may include determining, based on the analysis information, that the PDU session is to be duplicated and transmitted through two tunnels during a procedure related to the PDU session.

Description

[Technical field]

[0001] This specification relates to mobile communications. [Background technology]

[0002] FIG. 1 is a structural diagram of an evolved mobile communication network.

[0003] The EPC (Evolved Packet Core) may include various components, and FIG. 1 shows some of them, including an S-GW (Serving Gateway) 52, a PDNGW (Packet Data Network Gateway) 53, an MME (Mobility Management Entity) 51, an SGSN (Serving General Packet Radio Service (GPRS) Supporting Node), and an ePDG (enhanced Packet Data Gateway).

[0004] The S-GW 52 is an element that operates as a boundary point between a radio access network (RAN) and a core network, and functions to maintain a data path between the eNodeB 22 and the PDNGW 53. In addition, when a terminal (or User Equipment: UE) moves across an area served by the eNodeB 22, the S-GW 52 serves as a local mobility anchor point. That is, packets are routed through the S-GW 52 for mobility within the E-UTRAN (Evolved-UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access Network defined in 3GPP <registered trademark: the same hereinafter> Release-8 and later). The S-GW 52 can also function as an anchor point for mobility with other 3GPP networks (RANs defined before 3GPP Release-8, for example, UTRAN or GERAN (GSM (Global System for Mobile Communication) / EDGE (Enhanced Datarates for Global Evolution) Radio Access Network).

[0005] The PDNGW (or P-GW) 53 corresponds to the termination point of the data interface toward the packet data network. The PDNGW 53 can support policy enforcement features, packet filtering, charging support, etc. It can also act as an anchor point for mobility management between 3GPP networks and non-3GPP networks (e.g., untrusted networks such as I-WLAN (Interworking Wireless local area network), and trusted networks such as CDMA (Code Division Multiple Access) networks).

[0006] In the example network structure of FIG. 1, S-GW 52 and PDNGW 53 are shown configured as separate gateways, but the two gateways are implemented according to the Single Gateway Configuration Option.

[0007] The MME 51 is an element that performs signaling and control functions to support UE access to network connections, network resource allocation, tracking, paging, roaming, handover, etc. The MME 51 controls control plane functions related to subscriber and session management. The MME 51 manages a number of eNodeBs 22 and performs signaling for selection of a conventional gateway for handover to another 2G / 3G network. The MME 51 also performs functions such as security procedures, terminal-to-network session handling, and idle terminal location management.

[0008] The SGSN handles all packet data such as user mobility management and authentication to other connected 3GPP networks (eg GPRS networks, UTRAN / GERAN).

[0009] The ePDG acts as a security node for untrusted non-3GPP networks (eg, I-WLAN, WiFi hotspots, etc.).

[0010] As described with reference to FIG. 1, a terminal (or UE) having IP capabilities can access an IP service network (e.g., IMS) provided by a carrier (i.e., operator) via various elements in the EPC, both on a 3GPP access basis as well as on a non-3GPP access basis.

[0011] Also shown in FIG. 1 are various reference points (eg, S1-U, S1-MME, etc.). In the 3GPP system, a reference point is defined as a conceptual link between two functions that exist in different functional entities of E-UTRAN and EPC. Table 1 below summarizes the reference points shown in Figure 1. In addition to the examples in Table 1, various reference points exist according to the network structure.

[0012] [Table 1] JPEG0007601909000002.jpg22161

[0013] Among the reference points shown in Figure 1, S2a and S2b correspond to non-3GPP interfaces. S2a is a reference point that provides related control and mobility support between trusted non-3GPP access and PDNGW to the user plane. S2b is a reference point that provides related control and mobility support between ePDG and PDNGW to the user plane.

[0014] <Next-generation mobile communication network>

[0015] Buoyed by the success of LTE (long term evolution) / LTE-Advanced (LTE-A) for fourth-generation mobile communications, interest in the next generation, or fifth generation (so-called 5G) mobile communications is also growing, and research into it is progressing at a rapid pace.

[0016] The 5th generation mobile communications defined by the International Telecommunications Union (ITU) provides a maximum data transmission speed of 20Gbps and a minimum perceived transmission speed of 100Mbps anywhere. Its official name is "IMT-2020."

[0017] 5G mobile communication supports multiple numerologies or subcarrier spacing (SCS) to support various services. For example, if the SCS is 15kHz, it supports wide areas in traditional cellular bands, if the SCS is 30kHz / 60kHz, it supports dense-urban, lower latency and wider carrier bandwidth, and if the SCS is 60kHz or higher, it supports bandwidths larger than 24.25GHz to overcome phase noise.

[0018] The NR frequency band is defined as two types of frequency ranges (FR1, FR2): FR1 is 410MHz-7125MHz, and FR2 is 24250MHz-52600MHz, which can mean millimeter wave (mmW).

[0019] For ease of explanation, among the frequency ranges used in NR systems, FR1 means the “sub 6 GHz range” and FR2 means the “above 6 GHz range”, which can be called millimeter wave (mmW).

[0020] [Table 2]

[0021] As mentioned above, the frequency range values ​​for NR systems can be changed. For example, FR1 is as shown in the table below. 3FR1 can include the band from 410 MHz to 7125 MHz, as in FR1. That is, FR1 can include frequency bands of 6 GHz (or 5850, 5900, 5925 MHz, etc.) and above. For example, the frequency bands of 6 GHz (or 5850, 5900, 5925 MHz, etc.) and above included in FR1 can include unlicensed bands. Unlicensed bands are used for various purposes, for example, for communication for vehicles (e.g., autonomous driving).

[0022] [Table 3]

[0023] The ITU has proposed three usage scenarios, for example, enhanced Mobile BroadBand (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliable and Low Latency Communications (URLLC).

[0024] First, URLLC is related to usage scenarios that require high reliability and low latency. For example, services such as autonomous driving, factory automation, and augmented reality require high reliability and low latency (e.g., latency of 1 ms or less). Currently, the latency of 4G (LTE) is statistically 21-43 ms (best 10%) and 33-75 ms (median). This is insufficient to support services that require latency of 1 ms or less.

[0025] Next, eMBB usage scenarios relate to usage scenarios that require ultra-wideband on the move.

[0026] Such ultra-wideband, high-speed services are unlikely to be accommodated by the existing core networks designed for LTE / LTE-A.

[0027] Therefore, there is a strong demand for redesigning the core network in the so-called fifth generation mobile communications.

[0028] Figure 2 is a diagram of the next-generation mobile communication network structure.

[0029] 5GC (5G Core) can include various components, as shown in Figure 2 These include some of these functions: AMF (Access and Mobility Management Function) 41, SMF (Session Management Function) 42, PCF (Policy Control Function) 43, UPF (User Plane Function) 44, AF (Application Function) 45, UDM (Unified Data Management) 46, and N3IWF (Non-3GPP Inter Working Function) 49.

[0030] The UE 10 is connected to a data network via a Next Generation Radio Access Network (NG-RAN), i.e., a gNB or base station, via a UPF 44.

[0031] The UE 10 is also provided with data services via an untrusted non-3GPP (non-3rd Generation Partnership Project) access, for example, a WLAN (Wireless local area network). An N3IWF 49 is arranged to connect the non-3GPP access to a core network.

[0032] FIG. 3 is an exemplary diagram showing a predicted structure of next-generation mobile communications from the node perspective.

[0033] As can be seen with reference to FIG. 3, the UE is connected to a data network (DN) via a next generation Radio Access Network (RAN).

[0034] The illustrated Control Plane Function (CPF) node performs all or part of the functions of a Mobility Management Entity (MME) for 4G mobile communications, and all or part of the control plane functions of a Serving Gateway (S-GW) and a PDN Gateway (P-GW). The CPF node includes an Access and Mobility Management Function (AMF) and a Session Management Function (SMF).

[0035] The illustrated User Plane Function (UPF) node is a type of gateway through which user data is transmitted and received. The UPF node can perform all or part of the user plane functions of the S-GW and P-GW of 4G mobile communications.

[0036] The illustrated PCF (Policy Control Function) is a node that controls the operator's policy.

[0037] The illustrated Application Function (AF) is a server for providing multiple services to the UE.

[0038] The Unified Data Management (UDM) shown in the figure is a type of server that manages subscriber information, such as the Home Subscriber Server (HSS) of 4G mobile communications. The UDM stores and manages the subscriber information in a Unified Data Repository (UDR).

[0039] The Authentication Server Function (AUSF) shown authenticates and manages the UE.

[0040] The Network Slice Selection Function (NSSF) shown is a node for network slicing, as described below.

[0041] figure 3 In LTE, a UE can connect to two data networks simultaneously using multiple Protocol Data Unit (PDU) sessions.

[0042] FIG. 4 is an exemplary diagram showing an architecture for supporting simultaneous access to two data networks.

[0043] In FIG. 4, an architecture for a UE to simultaneously access two data networks using one PDU session is shown.

[0044] The reference points shown in Figures 3 and 4 are as follows:

[0045] N1 indicates a reference point between the UE and the AMF.

[0046] N2 indicates the reference point between the (R)AN and the AMF.

[0047] N3 represents the reference point between the (R)AN and the UPF.

[0048] N4 represents the reference point between the SMF and the UPF.

[0049] N5 represents a reference point between PCF and AF.

[0050] N6 represents the reference point between the UPF and the DN.

[0051] N7 represents the reference point between the SMF and the PCF.

[0052] N8 represents the reference point between UDM and AMF.

[0053] N9 indicates a reference point between the UPFs.

[0054] N10 represents the reference point between the UDM and the SMF.

[0055] N11 represents the reference point between the AMF and the SMF.

[0056] N12 represents a reference point between the AMF and AUSF.

[0057] N13 marks the reference point between the UDM and AUSF.

[0058] N14 indicates a reference point between the AMFs.

[0059] N15 represents the reference point between the PCF and the AMF.

[0060] N16 represents a reference point between the SMFs.

[0061] N22 represents the reference point between the AMF and the NSSF.

[0062] FIG. 5 is another exemplary diagram showing the structure of a radio interface protocol between a UE and a gNB.

[0063] The radio interface protocol is based on the 3GPP radio access network standard, and is horizontally composed of a physical layer, a data link layer, and a network layer, and vertically divided into a user plane for transmitting data information and a control plane for transmitting signaling.

[0064] The protocol layers are divided into L1 (layer 1), L2 (layer 2), and L3 (layer 3) based on the lower three layers of the Open System Interconnection (OSI) standard model, which is widely known in communication systems.

[0065] In the following, each layer of the wireless protocol is described.

[0066] The first layer, the physical layer, provides an information transfer service using a physical channel. The physical layer is connected to the higher level medium access control layer via a transport channel, and data is transferred between the medium access control layer and the physical layer via the transport channel. Data is also transferred between other physical layers, i.e., between the physical layers of the transmitting side and the receiving side, via the physical channel.

[0067] Layer 2 includes the Medium Access Control (MAC) layer, the Radio Link Control (RLC) layer, and the Packet Data Convergence Protocol (PDCP) layer.

[0068] Layer 3 includes Radio Resource Control (RRC). The RRC layer is defined only in the control plane and is responsible for controlling logical channels, transmission channels, and physical channels in relation to the establishment, re-establishment, and release of Radio Bearers (RBs). Here, RBs refer to the services provided by Layer 2 for data transfer between UE and E-UTRAN.

[0069] The NAS (Non-Access Stratum) layer performs functions such as session management and mobility management.

[0070] The NAS layer is divided into a NAS entity for Mobility Management (MM) and a NAS entity for session management (SM).

[0071] 1) A NAS entity for MM typically provides the following functions:

[0072] NAS procedures related to AMF include:

[0073] Registration management and connection management procedures. AMF supports the following functions:

[0074] - Secure NAS signal connection between UE and AMF (security protection, encryption)

[0075] 2) The NAS entity for SM performs session management between the UE and the SMF.

[0076] SM signaling messages are processed, i.e. generated and processed, in the NAS-SM layer of the UE and the SMF. The content of SM signaling messages is not interpreted by the AMF.

[0077] - For SM signaling transmission,

[0078] The NAS entity for MM generates a NAS-MM message that guides the method and location of forwarding the SM signaling message via a security header indicating the NAS transmission of the SM signaling and additional information for the receiving NAS-MM.

[0079] Upon receiving SM signaling, the NAS entity for SM performs a safety check on the NAS-MM message and interprets additional information to guide how and where to derive the SM signaling message.

[0080] On the other hand, Fig. 5 In the LTE network, the RRC layer, RLC layer, MAC layer, and PHY layer located below the NAS layer can be collectively called the Access Stratum (AS).

[0081] A network system (i.e., 5GC) for next-generation mobile communications (i.e., 5G) also supports non-3GPP access. A representative example of the non-3GPP access is WLAN access. The WLAN access may include both trusted WLAN and untrusted WLAN.

[0082] In the 5G system, the AMF performs registration management (RM) and connection management (CM) for not only 3GPP access but also non-3GPP access.

[0083] In the next generation (i.e., 5th generation) mobile communications, it is considered to provide local services (or geographical area specific services). Such local services are considered to be called LADN in the next generation mobile communications.

[0084] Meanwhile, among network nodes, the Network Data Analytics Function (NWDAF) can collect UE mobility-related information and generate UE mobility statistics or predictions through data analysis.

[0085] Also, in next generation (ie, 5th generation) mobile communications, duplicate transmission is being discussed for URLCC.

[0086] However, research into expanding the functionality of NWDAF to accommodate overlapping transmissions is necessary, but this is an issue that has not been actively pursued to date. Summary of the Invention [Problem to be solved by the invention]

[0087] Therefore, one aspect of the disclosure herein is to provide a method for solving the above-mentioned problems. [Means for solving the problem]

[0088] In order to solve the above-mentioned problems, one disclosure of the present specification may provide a method for operating a Session Management Function (SMF) node that manages a Protocol Data Unit (PDU) session. The method may include a step of acquiring analysis information from a Network Data Analytics Function (NWDAF) node. The acquired analysis information may include empirical analysis information for duplicate transmission. The method may include a step of determining (comprising; configuring; establishing; configuring; including; containing; including) that the PDU session is duplicated and transmitted through two tunnels during a procedure related to the PDU session based on the analysis information.

[0089] In order to solve the above-mentioned problems, one disclosure of the present specification may provide a chipset mounted in a Session Management Function (SMF) node. The chipset may include at least one processor; and at least one memory storing instructions and operably electrically connectable to the at least one processor. Operations performed based on the instructions being executed by the at least one processor may include: acquiring analysis information from a Network Data Analytics Function (NWDAF) node. The acquired analysis information may include empirical analysis information for duplicate transmission. The operations may include determining, based on the analysis information, that a Protocol Data Unit (PDU) session is duplicated and transmitted through two tunnels during a procedure related to the PDU session.

[0090] In order to solve the above-mentioned problems, one disclosure of the present specification may provide an apparatus for a Session Management Function (SMF) node. The apparatus may include a transceiver; at least one processor; and at least one memory storing instructions and operably electrically connectable to the at least one processor. Operations performed based on the instructions being executed by the at least one processor may include: acquiring analysis information from a Network Data Analytics Function (NWDAF) node. The acquired analysis information may include empirical analysis information for duplicate transmission. The operations may include determining, based on the analysis information, that a Protocol Data Unit (PDU) session is duplicated and transmitted through two tunnels during a procedure related to the PDU session.

[0091] In order to solve the above-mentioned problems, one disclosure of the present specification provides a non-volatile computer-readable storage medium having instructions recorded thereon. The storage medium may include instructions. The instructions, when executed by one or more processors attached to a Session Management Function (SMF) node, may cause the one or more processors to perform an operation. The operation may include: acquiring analysis information from a Network Data Analytics Function (NWDAF) node. The acquired analysis information may include empirical analysis information for duplicate transmission. The operation may include: determining, based on the analysis information, that a Protocol Data Unit (PDU) session is duplicated and transmitted through two tunnels during a procedure related to the PDU session. Effect of the Invention

[0092] According to the disclosure of this specification, the problems of the conventional technology can be solved. [Brief description of the drawings]

[0093] [Figure 1] FIG. 1 is a structural diagram of an evolved mobile communication network. [Diagram 2] 1 is a structural diagram of a next-generation mobile communication network. [Diagram 3] 1 is an illustrative diagram showing a predicted structure of next-generation mobile communications from a node perspective. [Figure 4] FIG. 1 is an exemplary diagram showing an architecture for supporting simultaneous access to two data networks. [Diagram 5] FIG. 2 is another illustrative diagram showing the structure of a radio interface protocol between a UE and a gNB. [Figure 6a] FIG. 1 is an illustrative diagram showing an example of an architecture for implementing the concept of network slicing. [Figure 6b]FIG. 13 is an illustrative diagram showing another example of an architecture for implementing the concept of network slicing. [Figure 7a-7b] FIG. 4 is a signal flow diagram illustrating an exemplary registration procedure. [Figure 8a-8b] A signal flow diagram showing an example PDU session establishment procedure. [Figure 9a-9b] The procedure for modifying a PDU session is shown. [Figure 10a-10b] FIG. 10a shows an example of an architecture for duplicate transmission, and FIG. 10b shows another example of an architecture for duplicate transmission. [Figure 11] FIG. 13 is an exemplary diagram showing a signal flow for the operation of NWDAF. [Figure 12] FIG. 13 is a signal flow diagram showing an example of providing analysis results to the NF. [Figure 13] An illustrative diagram showing the procedure of Xn-based inter NG-RAN handover without user plane reassignment. [Figure 14a-14b] An illustrative diagram showing the procedure of Xn-based inter NG-RAN handover when an intermediate UPF exists. [Figure 15] An illustrative diagram showing a procedure for Xn-based inter NG-RAN handover when an intermediate UPF is reassigned. [Figure 16a-16b] An illustrative diagram showing an inter NG-RAN node N2 based handover procedure in an environment without an Xn interface. [Figures 17a-17c] An illustrative diagram showing an inter NG-RAN node N2 based handover procedure in an environment without an Xn interface. [Figure 18] 1 shows a block diagram of a processor in which the disclosure of this specification is implemented. [Figure 19] 1 illustrates a wireless communication system according to an embodiment. [Figure 20] FIG. 2 is a block diagram of a network node according to an embodiment. [Figure 21] 1 is a block diagram showing a configuration of a UE 100 according to an embodiment. [Figure 22] 20 is a detailed block diagram of the transceiver unit of the first device shown in FIG. 19 or the transceiver unit of the device shown in FIG. 17. [Figure 23] 1 illustrates a communication system (1) to which the disclosure of this specification is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0094] It should be noted that the technical terms used in this specification are used only to describe a specific embodiment and are not intended to limit the contents of this specification. In addition, unless otherwise defined in this specification, the technical terms used in this specification should be interpreted as the meaning generally understood by a person having ordinary skill in the art to which the disclosure of this specification belongs, and should not be interpreted as an excessively comprehensive meaning or an excessively narrow meaning. In addition, when the technical terms used in this specification are incorrect technical terms that cannot accurately express the contents and ideas of this specification, they should be understood by replacing them with technical terms that can be correctly understood by a person skilled in the art. In addition, the general terms used in this specification should be interpreted according to what has been previously defined or according to the context, and should not be interpreted as an excessively narrow meaning.

[0095] In addition, singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "comprise" or "have" should not be interpreted as including all of the multiple components or multiple steps described in the specification, but should be interpreted as including some of the components or some of the steps, or including further components or steps.

[0096] In addition, terms including ordinal numbers such as "first" and "second" used in this specification may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component, without departing from the scope of the invention.

[0097] When a component is referred to as being connected or being connected to another component, it may be directly connected or connected to the other component, but there may be other components in between, whereas when a component is referred to as being directly connected or being connected to another component, it should be understood that there are no other components in between.

[0098] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings, and the same or similar components will be given the same reference numerals regardless of the drawing reference numerals, and the duplicated description thereof will be omitted. In addition, in describing the contents of this specification, if it is determined that a detailed description of related known technology may obscure the gist of this specification, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are provided to facilitate easy understanding of the contents and ideas of this specification, and the contents and ideas of this specification should not be construed as being limited by the accompanying drawings. The contents and ideas of this specification should be construed as extending to all modifications, equivalents, and alternatives other than the accompanying drawings.

[0099] As used herein, "A or B" may mean "only A," "only B," or "both A and B." Also, as used herein, "A or B" may be interpreted as "A and / or B." For example, as used herein, "A, B or C" may mean "only A," "only B," "only C," or "any combination of A, B and C."

[0100] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Thus, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0101] In this specification, "at least one of A and B" can mean "only A", "only B", or "both A and B". In addition, in this specification, the expressions "at least one of A or B" and "at least one of A and / or B" can be interpreted as "at least one of A and B".

[0102] In addition, in this specification, "at least one of A, B and C" can mean "only A," "only B," "only C," or "any combination of A, B and C." In addition, "at least one of A, B or C" or "at least one of A, B and / or C" can mean "at least one of A, B and C."

[0103] In addition, parentheses used in this specification may mean "for example." Specifically, when "control information (PDCCH)" is used, "PDCCH" is proposed as an example of "control information." In addition, "control information" in this specification is not limited to "PDCCH" but may be "PD C Also, when "control information (i.e., PDCCH)" is displayed, "PDCCH" is also proposed as an example of "control information".

[0104] In this specification, technical features individually described in one drawing may be embodied individually or simultaneously.

[0105] In the accompanying drawings, UE (User Equipment) is illustrated as an example, and the illustrated UE may be referred to as a UE 100 (Terminal), ME (Mobile Equipment), etc. Also, the UE may be a portable device such as a notebook computer, a mobile phone, a PDA, a smartphone, a multimedia device, etc., or a non-portable device such as a PC or a vehicle-mounted device.

[0106] <Network Slice>

[0107] Below, we explain network slicing that will be introduced in next-generation mobile communications.

[0108] Next-generation mobile communications introduces the concept of network slices to provide various services through one network. Here, a network slice is a combination of network nodes that have the necessary functions to provide a specific service. The network nodes that make up a slice instance are either hardware-independent nodes or logically independent nodes.

[0109] Each slice instance consists of a combination of all the nodes required to form the entire network. In this case, one slice instance can serve a UE alone.

[0110] In contrast, a slice instance is composed of a combination of some of the nodes that make up a network. In this case, the slice instance does not provide a service to the UE alone, but can provide a service to the UE in cooperation with other existing network nodes. In addition, multiple slice instances can provide a service to the UE in cooperation with each other.

[0111] A slice instance differs from a dedicated core network in that the entire network nodes, including the core network (CN) node and the RAN, can be separated. A slice instance also differs from a dedicated core network in that the network nodes are simply logically separated.

[0112] FIG. 6a is an illustrative diagram showing an example of an architecture for implementing the concept of network slicing.

[0113] As can be seen with reference to Figure 6a, a core network (CN) is divided into a number of slice instances, each of which may include one or more CP function nodes and UP function nodes.

[0114] Each UE can use a network slice instance that suits its service via the RAN.

[0115] Unlike the example shown in FIG 6a, each slice instance may share one or more of the CP function node and the UP function node with other slice instances, which will be described with reference to FIG 6b as follows.

[0116] FIG. 6b is an illustrative diagram showing another example of an architecture for implementing the concept of network slicing.

[0117] Referring to FIG. 6b, a plurality of UP function nodes are clustered, and similarly a plurality of CP function nodes are clustered.

[0118] 6b, slice instance #1 (or instance #1) in the core network includes a first cluster of UP function nodes, and slice instance #1 shares a cluster of CP function nodes with slice #2 (or instance #2), which includes a second cluster of UP function nodes.

[0119] The indicated NSSF selects a slice (or instance) that can accommodate the UE's service.

[0120] The UE shown can use service #1 via slice instance #1 selected by the NSSF, and can also use service #2 via slice instance #2 selected by N.

[0121] <Registration Procedure>

[0122] The UE needs to obtain authorization to enable mobility tracking, enable data reception, and receive services. For this, the UE needs to register with the network. The registration procedure is performed when the UE needs to make an initial registration to the 5G system. The registration procedure is also performed when the UE performs a periodic registration update, when the UE moves to a new tracking area (TA) in idle mode, and when the UE needs to perform a periodic registration update.

[0123] During the initial registration procedure, the UE identity is obtained from the UE. The AMF can forward the PEI (IMEISV) to the UDM, SMF and PCF.

[0124] 7a and 7b are signal flow diagrams illustrating an exemplary registration procedure.

[0125] 1) The UE may send an AN message to the RAN. The AN message may include AN parameters and a registration request message. The registration request message may include information such as a registration type, a subscriber's permanent ID or temporary user ID, security parameters, NSSAI (Network Slice Selection Assistance Information), UE's 5G capabilities, and PDU (Protocol Data Unit) session state.

[0126] In the case of a 5G RAN, the AN parameters may include a Subscription Permanent Identifier (SUPI) or temporary user ID, a selected network, and an NSSAI.

[0127] The registration type may indicate whether it is an "initial registration" (i.e., the UE is in an unregistered state), a "mobility registration update" (i.e., the UE is in a registered state and initiates a registration procedure for mobility), or a "periodic registration update" (i.e., the UE is in a registered state and initiates a registration procedure due to expiration of a periodic update timer). If a temporary user ID is included, the temporary user ID indicates the last serving AMF. If the UE has already registered via non-3GPP access in the PLMN (Public Land Mobile Network) of the 3GPP access and in another PLMN, the UE may not provide a temporary ID of the UE assigned by the AMF during the registration procedure via non-3GPP access.

[0128] The security parameters are used for authentication and security purposes.

[0129] The PDU session status may indicate available (previously configured) PDU sessions in the UE.

[0130] 2) If the SUPI is included or the temporary user ID does not indicate a valid AMF, the RAN may select an AMF based on the (R)AT and NSSAI.

[0131] If the (R)AN cannot select a suitable AMF, it selects an arbitrary AMF according to a local policy and forwards the registration request to the selected AMF. If the selected AMF cannot serve the UE, the selected AMF selects another AMF that is more suitable for the UE.

[0132] 3) The RAN sends an N2 message to the new AMF. The N2 message includes N2 parameters, a registration request. The registration request may include a registration type, a subscriber's permanent or temporary user ID, security parameters, NSSAI, and MICO mode preferences.

[0133] When 5G-RAN is used, the N2 parameters include location information related to the cell on which the UE is camped, a cell identifier, and a RAT type.

[0134] If the registration type indicated by the UE is periodic registration update, processes 4 to 17 described below are not executed.

[0135] 4) The newly selected AMF may send an information request message to the previous AMF.

[0136] If the UE's temporary user ID is included in the registration request message and the serving AMF has changed since the last registration, the new AMF may send an information request message including complete registration request information to the previous AMF to request the UE's SUPI and MM context.

[0137] 5) The previous AMF sends an information response message to the newly selected AMF. The information response message may include SUPI, MM context, and SMF information.

[0138] Specifically, the previous AMF sends an information response message including the UE's SUPI and MM context.

[0139] -If the previous AMF has information on an active PDU session, the previous AMF can include SMF information including an SMF ID and a PDU session ID in the information response message.

[0140] 6) If the SUPI is not provided by the UE or has not been previously retrieved from an AMF, the new AMF sends an Identity Request message to the UE.

[0141] 7) The UE sends an Identity Response message including the SUPI to the new AMF.

[0142] 8) The AMF may decide to trigger an AUSF. In this case, the AMF may select the AUSF based on the SUPI.

[0143] 9) The AUSF may initiate authentication of the UE and NAS security functions.

[0144] 10) The new AMF may send an information response message to the previous AMF.

[0145] If the AMF is changed, the new AMF may send the information response message to confirm the transfer of the UEMM context.

[0146] -If the authentication / security procedures fail, the registration is rejected and the new AMF may send a rejection message to the previous AMF.

[0147] 11) The new AMF may send an Identity Request message to the UE.

[0148] If the PEI has not been provided by the UE or has not been previously retrieved from the AMF, an Identity Request message is sent for the AMF to retrieve the PEI.

[0149] 12) The new AMF checks the ME identifier.

[0150] 13) If process 14 described below is executed, the new AMF selects a UDM based on the SUPI.

[0151] 14) If the AMF has changed since the last registration, or there is no valid subscription context for the UE in the AMF, or the UE provides a SUPI that does not refer to a valid context in the AMF, the new AMF initiates an Update Location procedure. It is also initiated when the UDM initiates a Cancel Location procedure for the previous AMF. The previous AMF discards the MM context and notifies all possible SMF(s), and the new AMF obtains AMF-related subscription data from the UDM and then creates an MM context for the UE.

[0152] When network slicing is used, the AMF obtains the allowed NSSAI based on the requested NSSAI, the UE subscription and local policies. If the AMF is not suitable to support the allowed NSSAI, it reroutes the registration request.

[0153] 15) The new AMF can select a PCF based on the SUPI.

[0154] 16) The new AMF sends a UE Context Establishment Request message to the PCF. The AMF may request an operator policy for the UE from the PCF.

[0155] 17) The PCF sends a UE Context Establishment Acknowledged message to the new AMF.

[0156] 18) The new AMF sends an N11 request message to the SMF.

[0157] Specifically, if the AMF changes, the new AMF informs each SMF of the new AMF serving the UE. The AMF verifies the PDU session status from the UE as the available SMF information. If the AMF changes, the available SMF information is received from the previous AMF. The new AMF can request the SMF to release network resources related to PDU sessions that are not activated in the UE.

[0158] 19) The new AMF sends an N11 response message to the SMF.

[0159] 20) The previous AMF sends a UE Context Termination Request message to the PCF.

[0160] If the previous AMF previously requested that a UE context be established in the PCF, the previous AMF may delete the UE context in the PCF.

[0161] 21) The PCF may send a UE Context Termination Request message to the previous AMF.

[0162] 22) The new AMF sends a registration accept message to the UE. The registration accept message may include a temporary user identity, a registration area, a mobility restriction, a PDU session state, an NSSAI, a periodic registration update timer, and an allowed MICO mode.

[0163] The registration accept message may include information on the allowed NSSAI and the mapped NSSAI. The allowed NSSAI information for the UE's access type is included in an N2 message that includes a registration accept message. The mapped NSSAI information is information that maps each S-NSSAI of the allowed NSSAI to an S-NASSI of an NSSAI configured for the HPLMN.

[0164] When the AMF assigns a new temporary user ID, the temporary user ID is further included in the registration acceptance message. When a mobility restriction is applied to the UE, information indicating the mobility restriction is additionally included in the registration acceptance message. The AMF can include information indicating the PDU session state for the UE in the registration acceptance message. The UE can remove any internal resources associated with PDU sessions that are not displayed as active in the received PDU session state. If PDU session state information is in the Registration Request message, the AMF can include information indicating the PDU session state for the UE in the registration acceptance message.

[0165] 23) The UE sends a registration completion message to the new AMF.

[0166] <PDU Session Establishment Procedure>

[0167] There are two types of PDU (Protocol Data Unit) session establishment procedures as follows.

[0168] - PDU session establishment procedure disclosed by the UE

[0169] - PDU session establishment procedure disclosed by the network. For this, the network can send a device trigger message to the UE's application(s).

[0170] Figures 8a and 8b are signal flow diagrams showing exemplary PDU session establishment procedures.

[0171] The procedures shown in Figures 8a and 8b assume that the UE is already registered on the AMF according to the registration procedure shown in Figure 7. Therefore, it is assumed that the AMF has already obtained user subscription data from the UDM.

[0172] 1) The UE sends a NAS message to the AMF. The message may include S-NSSAI (Session Network Slice Selection Assistance Information), DNN, PDU session ID, request type, N1 SM information, etc.

[0173] Specifically, the UE includes an S-NSSAI from the allowed NSSAI of the current access type. If information on the mapped NSSAI is provided to the UE, the UE can provide both an S-NSSAI based on the allowed NSSAI and a corresponding S-NSSAI based on the information on the mapped NSSAI. Here, the information on the mapped NSSAI is information that maps each S-NSSAI of the allowed NSSAI to an S-NASSI of the NSSAI configured for the HPLMN.

[0174] More specifically, the UE extracts and stores information on the permitted S-NSSAI and the mapped S-NSSAI included in the registration accept message received from the network (i.e., AMF) in the registration procedure of Figure 5. Therefore, the UE can transmit the PDU session establishment request message including all of the S-NSSAI based on the permitted NSSAI and the corresponding S-NSSAI based on the information on the mapped NSSAI.

[0175] To establish a new PDU session, the UE may generate a new PDU session ID.

[0176] The UE may initiate a PDU session establishment procedure initiated by the UE by sending a NAS message including a PDU session establishment request message in N1 SM information. The PDU session establishment request message may include a request type, an SSC mode, and a protocol configuration option.

[0177] If the PDU session establishment is for setting up a new PDU session, the request type indicates "initial request". However, if an existing PDU session between a 3GPP access and a non-3GPP access exists, the request type may indicate "existing PDU session".

[0178] The NAS message sent by the UE is encapsulated by the AN in an N2 message, which is sent to the AMF and may include user location information and access technology type information.

[0179] -N1 SM information may include an SM PDU DN request container containing information for PDU session authentication by an external DN.

[0180] 2) The AMF may determine that the message corresponds to a request for a new PDU session if the request type indicates "initial request" and if the PDU session ID was not used for an existing PDU session of the UE.

[0181] If the NAS message does not include the S-NSSAI, the AMF may determine a default S-NSSAI for the requested PDU session according to the UE subscription. The AMF may associate and store the PDU session ID and the SMF ID.

[0182] The AMF may be selected as an SMF.

[0183] 3) The AMF may send a Nsmf_PDUSession_CreateSMContextRequest message or a Nsmf_PDUSession_UpdateSMContextRequest message to the selected SMF.

[0184] The Nsmf_PDUSession_CreateSMContextRequest message may include SUPI, DNN, S-NSSAI(s), PDU Session ID, AMF ID, Request Type, PCF ID, Priority Access, N1 SM container, User location information, Access Type, PEI, GPSI, UE presence in LADN service area, Subscription For PDU Session Status Notification, DNN Selection Mode, and Trace Requirements. The SM container may include a PDU Session Establishment Request message.

[0185] The Nsmf_PDUSession_UpdateSMContextRequest message may include SUPI, DNN, S-NSSAI(s), SM Context ID, AMF ID, Request Type, N1 SM container, User location information, Access Type, RAT type, and PEI. The N1 SM container may include a PDU Session Establishment Request message.

[0186] The AMF ID is used to identify the AMF serving the UE. The N1 SM information may include a PDU session establishment request message received from the UE.

[0187] 4) The SMF sends a subscriber data request message to the UDM. The subscriber data request message can include the subscriber permanent ID, DNN. The UDM can send a subscription data response message to the SMF.

[0188] If the request type indicates "existing PDU session" in process 3 above, the SMF determines that the request is due to a handover between 3GPP access and non-3GPP access. The SMF can identify the existing PDU session based on the PDU session ID.

[0189] If the SMF has not yet retrieved SM-related subscription data for the UE associated with the DNN, the SMF may request the subscription data.

[0190] The subscription data includes information for the authenticated request type, the authenticated SSC mode, and the basic QoS profile.

[0191] The SMF can check whether the UE request complies with the user subscription and local policies, or it can reject the UE request via NASSM signaling forwarded by the AMF (including the associated SM rejection cause) and the SMF informs the AMF that the PDU session ID should be considered released.

[0192] 5) The SMF sends a Nsmf_PDUSession_CreateSMContextResponse message or a Nsmf_PDUSession_UpdateSMContextResponse message to the AMF.

[0193] The Nsmf_PDUSession_CreateSMContextResponse message may include Cause, SM Context ID, or N1 SM container, which may include PDU Session Reject.

[0194] In the above process 3, when the SMF receives the Nsmf_PDUSession_CreateSMContextRequest message, if the SMF can process the PDU Session establishment request message, it creates the SMF SM context and transfers the SM context ID to the AMF.

[0195] 6) Secondary authentication / authorization is optionally performed.

[0196] 7a) If an operating PCC is used for the PDU session, the SMF selects the PCF.

[0197] 7b) The SMF performs an SM policy association establishment procedure to establish an SM policy association with the PCF.

[0198] 8) If the request type of process 3 indicates "initial request", the SMF selects the SSC mode for the PDU session. If process 5 is not performed, the SMF can also select the UPF. If the request type is IPv4 or IPv6, the SMF can allocate an IP address / prefix for the PDU session.

[0199] 9) The SMF performs the SM policy association modification procedure to provide information for the policy control request trigger conditions.

[0200] 10) If the request type indicates "initial request" the SMF may initiate an N4 session establishment procedure with the selected UPF, otherwise an N4 session modification procedure may be initiated with the selected UPF.

[0201] 10a) The SMF sends an N4 Session Establishment / Modification Request message to the UPF, and the SMF can provide packet detection, trial and reporting rules to be installed in the UPF for the PDU session. If the SMF is assigned CN tunnel information, the CN tunnel information is provided to the UPF.

[0202] 10b) The UPF may respond by sending an N4 Session Establishment / Modification Response message. If the CN tunnel information is allocated by the UPF, the CN tunnel information is provided to the SMF.

[0203] 11) The SMF sends a Namf_Communication_N1N2MessageTransfer message to the AMF. The Namf_Communication_N1N2MessageTransfer message may include a PDU Session ID, N2 SM information, and an N1 SM container.

[0204] The N2 SM information may include PDU Session ID, QFI (QoS Flow ID), QoS Profile(s), CN Tunnel Info, S-NSSAI from the Allowed NSSAI, Session-AMBR, PDU Session Type, User Plane Security Enforcement information, and UE Integrity Protection Maximum Data Rate.

[0205] The N1 SM container may include a PDU session establishment accept message.

[0206] The PDU session establishment accept message may include allowed QoS rules, SSC mode, S-NSSAI, and assigned IPv4 address.

[0207] 12) The AMF sends an N2 PDU session request message to the RAN, where the message may include N2 SM information and a NAS message, where the NAS message may include a PDU session ID and a PDU session establishment accept message.

[0208] The AMF may send a NAS message including a PDU session ID and a PDU session establishment accept message. The AMF also includes the N2 SM information received from the SMF in an N2 PDU session request message and sends it to the RAN.

[0209] 13) The RAN may perform specific signaling exchanges with the UE related to the information received from the SMF.

[0210] The RAN also allocates RAN N3 tunnel information for the PDU session.

[0211] The RAN forwards the NAS message provided in process 10 to the UE. The NAS message may include a PDU session ID and N1 SM information. The N1 SM information may include a PDU session establishment accept message.

[0212] The RAN sends a NAS message to the UE only if the required RAN resources are configured and the allocation of RAN tunnel information is successful.

[0213] 14) The RAN sends an N2 PDU Session Response message to the AMF. The message may include a PDU Session ID, a cause, and N2 SM information. The N2 SM information may include a PDU Session ID, (AN) tunnel information, and an accepted / rejected QoS profile list.

[0214] -RAN tunnel information corresponds to the access network address of the N3 tunnel corresponding to the PDU session.

[0215] 15) The AMF may send a Nsmf_PDUSession_UpdateSMContextRequest message to the SMF. The Nsmf_PDUSession_UpdateSMContextRequest message may include N2 SM information, where the AMF is to forward the N2 SM information received in the RAN to the SMF.

[0216] 16a) If an N4 session for the PDU session is not already established, the SMF may initiate an N4 session establishment procedure together with the UPF. Otherwise, the SMF may initiate an N4 session modification procedure with the UPF. The SMF may provide AN tunnel information and CN tunnel information. The CN tunnel information may only need to be provided if the SMF selected the CN tunnel information in process 8.

[0217] 16b) The UPF may send an N4 session modification response message to the SMF.

[0218] 17) The SMF sends a Nsmf_PDUSession_UpdateSMContextResponse message to the AMF.

[0219] Once this process is complete, the AMF can forward the relevant events to the SMF.

[0220] 18) The SMF sends an Nsmf_PDUSession_SMContextStatusNotify message.

[0221] 19) The SMF sends information to the UE via the UPF. Specifically, in the case of PDUType IPv6, the SMF can generate an IPv6 Router Advertisement and send it to the UE via N4 and the UPF.

[0222] 20) If the PDU session establishment is not successful during the procedure, the SMF informs the AMF.

[0223] 9a and 9b show the procedure for modifying a PDU session.

[0224] MA PDU sessions are established / managed based on the PDU session modification procedures.

[0225] The PDU session modification procedure may be UE initiated or network initiated.

[0226] 1a) When the UE initiates, the UE may initiate a PDU session modification procedure by sending a NAS message. The NAS message may include an N1 SM container. The N1 SM container may include a PDU session modification request message, a PDU session ID, and information on the UE's integrity protection maximum data rate. The PDU session modification request message may include a PDU session ID, a packet filter, information on the requested QoS, 5G SM core network capability, and the number of packet filters. The UE's integrity protection maximum data rate indicates the maximum data rate at which the UE can support UP integrity protection. The number of packet filters indicates the number of packet filters supported for a QoS rule.

[0227] The NAS message is forwarded to an appropriate AMF according to the location information of the UE via the RAN. If so, the AMF sends an Nsmf_PDUSession_UpdateSMContext message to the SMF. The message may include a session management (SM) context ID and an N1 SM container. The N1 SM container may include a PDU session modification request message.

[0228] 1b) In a network node, if exposed by a PCF, the PCF can inform the SMF of the policy change by initiating an SM Policy Association Modification procedure.

[0229] 1c) In a network node, if initiated by a UDM, the UDM may update the subscription data of the SMF by sending a Nudm_SDM_Notification message, which in turn may update session management subscriber data and forward an ACK message to the UDM.

[0230] 1d) In a network node, if disclosed by the SMF, the SMF may trigger a QoS update.

[0231] If triggered according to 1a to 1d above, the SMF may perform PDU session modification procedures.

[0232] 1e) In the network node, if initiated by the AN, the AN may inform the SMF when the AN resource to which the QoS flow is mapped is released. The AN may send an N2 message to the AMF. The N2 message may include a PDU session ID and N2 SM information. The N2 SM information may include a QFI (QoS Flow ID), user location information, and an indication that the QoS flow has been released. The AMF may send an Nsmf_PDUSession_UpdateSMContext message. The message may include an SM context ID and N2 SM information.

[0233] 2) The SMF can send a report for the joining event by executing the SM Policy Association Modification procedure. If the PDU Session Modification procedure is triggered by 1b or 1d, this step can be skipped. If no dynamic PCC is deployed in the network, the SMF can apply its internal policies to determine the change in the QoS profile.

[0234] Processes 3 to 7 described below are not executed if the PDU session modification requires only UPF operations.

[0235] 3a) In case of UE or AN initiation, the SMF may respond to the AMF by sending a Nsmf_PDUSession_UpdateSMContext message. The message may include N2 SM information, an N2 SM container. The N2 SM information may include a PDU Session ID, a QFI, a QoS profile, and a Session-AMBR. The N1 SM container may include a PDU Session Modification Command. The PDU Session Modification Command may include a PDU Session ID, a QoS rule, a QuS rule operation, a QoS flow level QoS parameter, and a Session-AMBR.

[0236] The N2 SM information may include information that the AMF needs to transmit to the AN. The N2 SM information may include a QFI and a QoS profile to notify the AN that one or more QoS flows have been added or modified. If a PDU session modification is requested by a UE for which user plane resources are not configured, the N2 SM information transmitted to the AN may include information for establishing user plane resources.

[0237] The N1 SM container may include a PDU session modification command for the AMF to transmit to the UE. The PDU session modification command may include a QoS rule, a QoS flow level QoS parameter.

[0238] 3b) If initiated by the SMF, the SMF may send a Namf_Communication_N1N2MessageTransfer message. The message may include N2 SM information, an N1 SM container. The N2 SM information may include a PDU Session ID, a QFI, a QoS profile, and a Session-AMBR. The N1 SM container may include a PDU Session Modification Command. The PDU Session Modification Command may include a PDU Session ID, a QoS rule, and a QoS flow level QoS parameter.

[0239] If the UE is in a CM-IDLE state and ATC is activated, the AMF updates and stores the UE context based on the Namf_Communication_N1N2MessageTransfer message, and then skips steps 3 to 7. If the UE is in a reachable state, i.e., the UE enters a CM-CONNECTED state, the AMF may send an N1 message to synchronize the UE and UE context.

[0240] 4) The AMF may send an N2 PDU session request message to the AN. The N2 PDU session request message may include N2 SM information received from the SMF and a NAS message. The NAS message may include a PDU session ID and an N1 SM container. The N1 SM container may include a PDU session modification command.

[0241] 5) The AN performs an AN signaling exchange with the UE related to the information received from the SMF. For example, in the case of an NG-RAN (i.e., a gNB or base station), an RRC Connection Reconfiguration procedure is performed with the UE to modify the required AN resources related to the PDU session.

[0242] 6) The AN sends an N2 PDU Session ACK message in response to the received N2 PDU Session Request. The N2 PDU Session ACK message may include N2 SM information and user location information. The N2 SM information may include a list of accepted / rejected QFIs, AN tunnel information, and PDU session IDs.

[0243] 7) The AMF forwards the N2 SM information and user location information received from the AN to the SMF via the Nsmf_PDUSession_UpdateSMContext message. If so, the SMF forwards the Nsmf_PDUSession_UpdateSMContext message to the AMF.

[0244] 8) The SMF sends an N4 session modification request message to the UPF to update the N4 session of the UPF included in the PDU session modification.

[0245] When a new QoS flow is created, the SMF updates the UL packet detection rules of the new QoS flow together with the UPF.

[0246] 9) In response to receiving the PDU session modification command, the UE sends a NAS message, where the NAS message may include a PDU session ID and an N1 SM container, where the N1 SM container may include a PDU session modification command ACK.

[0247] 10) The AN sends the NAS message to the AMF.

[0248] 11) The AMF may forward the N1 SM container and user location information received from the AN to the SMF via a Nsmf_PDUSession_UpdateSMContext message. The N1 SM container may include a PDU session modification command ACK. The SMF may forward a Nsmf_PDUSession_UpdateSMContext response message to the AMF.

[0249] 12) The SMF sends an N4 session modification request message to the UPF to update the N4 session of the UPF included in the PDU session modification, where the message may include an N4 session ID.

[0250] 13) If an SMF interacts with a PCF in process 1b or process 2 above, the SMF may inform the PCF via the SM Policy Association Modification procedure whether the PCC decision can be implemented.

[0251] The SMF may notify the requested entity of user location information related to the PDU session change.

[0252] <Duplicate transmission>

[0253] On the other hand, duplicate transmission is being discussed for URLCC in next generation (ie, 5th generation) mobile communications.

[0254] FIG. 10a illustrates one example of an architecture for duplicate transmission, and FIG. 10b illustrates another example of an architecture for duplicate transmission.

[0255] As can be seen in Fig. 10a, two N3 tunnels are created between the NG-RAN and the UPF. Accordingly, data is redundantly forwarded through the two tunnels. The NG-RAN node and the UPF can support packet copying and dropping.

[0256] As can be seen in Figure 10b, two intermediate UPFs can support duplicate transmission between the UPF and the NG-RAN based on two N3 and N9 tunnels between the NG-RAN node and the UPF. The NG-RAN node and the UPF can perform packet copy and removal functions.

[0257] During or after the URLLC QoS flow establishment, there are two N3 and N9 tunnels between the NG-RAN and the UPF for the URLCC QoS flows of the PDU sessions established for duplicate transmission. For downlink traffic, the UPF can duplicate the downlink packets of the QoS flow from the DN and assign the same GTP-U sequence number to the downlink packets. Such duplicated packets are sent to I-UPF1 and I-UPF2 in N9 tunnel 1 and N9 tunnel 2, respectively. Each I-UPF can forward the packets (with the same GTP-U sequence number) received from the UPF to the NG-RAN via N3 tunnel 1 and N3 tunnel 2. The NG-RAN can remove the duplicated packets based on the GTP-U sequence number. For uplink traffic, the NG-RAN can duplicate the packets of the QoS flow from the UE and assign the same GTP-U sequence number. Such duplicated packets are sent to N3 tunnel 1 and N3 tunnel 2 by I-UPF1 and I-UPF2. Each I-UPF can forward packets (with similar GTP-U sequence numbers) received from NG-RAN to the UPF via N9 Tunnel 1 and N9 Tunnel 2. The UPF can remove duplicate packets based on the GTP-U sequence numbers.

[0258] <NWDAF(Network Data Analytics Function)>

[0259] The NWDAF supporting UE mobility statistics or analysis can collect UE mobility-related information from NF (Network Function) and OAM (Operations, Administration and Maintenance) and generate UE mobility statistics or predictions through data analysis.

[0260] The services provided by the NWDAF are used by multiple NFs, for example, the AMF.

[0261] FIG. 11 is an exemplary diagram showing a signal flow for the operation of the NWDAF.

[0262] The NWDAF can provide UE mobility related analytics in the form of statistics or predictions. 11 In this figure, an AF (Application Function) is an NF that receives services from an NWDAF. The AF can request analysis via an NEF, and the NEF can provide the request to the NWDAF.

[0263] 1) The NF can forward a request message to the NWDAF for analysis for a specific UE or group of UEs. The message can be, for example, a message based on the Nnwdaf_AnalyticsInfo or Nnwdaf_AnalyticsSubscription service. The NF can provide statistics or predictions. The type of information to be analyzed is UE mobility information. The NF can provide a UE id or an internal group ID in the target of the analysis report.

[0264] 2) If the request is granted, and to provide the requested analysis, the NWDAF may subscribe to notify all serving AMFs of events for UE location changes. If the NWDAF has already completed the analysis, this step is not performed.

[0265] The NWDAF subscribes to the AF to receive service data. For this purpose, the Naf_EventExposure_Subscribe or Nnef_EventExposure_Subscribe service-based messages are used.

[0266] The NWDAF collects UE mobility information from the OAM.

[0267] The NWDAF selects the AMF that is responsible for a UE or a group of UEs.

[0268] 3) The NWDAF will carry out the requested analysis.

[0269] 4) The NWDAF provides the requested UE mobility analysis to the NF. For this purpose, a response message to Nnwdaf_AnalyticsInfo_Request or a Nnwdaf_AnalyticsSubscription_Notify message is used.

[0270] 5-6) If the NF has completed subscription to receive notification messages for UE mobility analysis, the NWDAF may generate analysis results and provide them to the NF.

[0271] The present disclosure provides a method for solving the aforementioned problems.

[0272] <Problems that the present disclosure aims to solve>

[0273] Research is underway to utilize the information analysis and prediction capabilities of NWDAF to implement network automation, and efforts are underway to effectively provide MEC (Mobile Edge Computing) services, especially research into UP route optimization.

[0274] In the case of 5G services, more UEs will utilize more network resources to receive real-time services compared to 4G, making decisions on information analysis / resource management important.

[0275] I. Overview of the Disclosure

[0276] I-1. Functions of the First Network Node (e.g., NWDAF)

[0277] According to the disclosure herein, a first network node (e.g., an NWDAF) may obtain information of an NG-RAN serving a UE from a network node.

[0278] From a first network node (eg, NWDAF), information regarding QoS and data efficiency for redundant transmission paths is obtained.

[0279] Additionally, the first network node (e.g., NWDAF) may analyze statistics / predictions for the efficiency of redundant transmission path usage.

[0280] Additionally, the first network node (eg, NWDAF) may send the analyzed statistics and forecasts to a network node, in particular, the SMF.

[0281] I-2. Functions of the second network node (e.g., SMF)

[0282] The second network node (e.g., SMF) can use the acquired information to decide whether to establish and manage a PDU session that applies duplicate transmission.

[0283] If it is decided to establish a PDU session in which duplicate transmission is supported, the second network node (e.g., SMF) informs the PSA (PDU session anchor) UPF and NG-RAN of the execution of duplicate transmission (for reference, messages forwarded to the UE are routed via the AMF).

[0284] The second network node (eg, SMF) may obtain information from the NWDAF that is used to determine whether to efficiently support duplicate transmissions for the URLCC service.

[0285] The second network node (eg, the SMF) may determine whether duplicate transmission should be performed.

[0286] The second network node (eg, SMF) may decide whether to discontinue duplicate transmission if duplicate transmission is activated.

[0287] II. Implementation Example

[0288] II-1.NWDAF support for UP (User Plane) optimization

[0289] UP optimization is supported for edge computing. In edge computing environments, efficient UP resource usage, especially for URLLC services, is supported through empirical analysis of duplicated transmissions.

[0290] The SMF may determine that duplicate transmission is to be performed based on the allowed 5QI (5G QoS Identifier), NG-RAN node capabilities and / or operator settings, and the SMF may inform the PSA UPF and NG-RAN to perform duplicate transmission over the N4 interface and forward the N2 information.

[0291] The NWDAF can send empirical analysis on duplicate transmissions to the SMF, which may influence the operator's policies configured in the SMF that are used to decide whether to perform duplicate transmissions or to abort duplicate transmissions in order to support efficient duplicate transmissions for URLCC services.

[0292] As described below, the NWDAF supports empirical analysis of overlapping transmissions in various environments, such as when the UPF transmits monitoring data to the SMF or when data can be collected directly from the RAN.

[0293] i) UE mobility related information can be collected from NF (e.g., AMF or AF) and OAM.

[0294] Specifically, as the UE moves, the NG-RAN to which it connects may differ, and the NG-RANs have different capabilities related to overlapping transmissions, so the UE movement-related information is collected for use in verifying / predicting validity.

[0295] ii) Information regarding packet drop and / or packet delay measurement can be collected from the NF (e.g., UPF or SMF) and OAM (additionally, from the NG-RAN).

[0296] The information is collected for the purpose of understanding the status of the backhaul network.

[0297] iii) Efficiency information for overlapping transmissions can be collected from the NF (e.g., UPF) and OAM (additionally, from the NG-RAN).

[0298] The information is used to check whether the duplicated paths are actually being used effectively. That is, if sufficient QoS is guaranteed for packets arriving on path 1, packets arriving on path 2 are unnecessary. For example, which path's data is used, which path's data is treated as a duplicate packet and dropped, and the success rate of each path to see if data of each path is actually used are measured.

[0299] iv) Information related to PDU sessions established for overlapping transmissions can be collected from NFs (e.g., SMFs) and OAMs.

[0300] The information may include the number of PDU sessions or the performance of the PDU sessions, etc. The information is used to confirm / predict the effectiveness of the PDU sessions applying duplicate transmission.

[0301] Data analysis can be performed to provide empirical statistics or predictions for duplicate transmissions.

[0302] Analytical services from the NWDAF are provided to NFs (e.g., SMFs).

[0303] An NF receiving such an analytical service (e.g., SMF) may include in the request:

[0304] -Analysis ID="Redundant Transmission Experience"

[0305] The target of the analysis report is a single UE, any UE, or a group of UEs.

[0306] The analysis filter information may selectively include the following information:

[0307] A. Area of ​​interest;

[0308] bS-NSSAI;

[0309] c.DNN.

[0310] Analysis target interval: indicates the time interval for which statistics or predictions are required.

[0311] II-1. Input Data

[0312] The NWDAF, which supports data analysis in relation to experience with overlapping transmissions, can collect UE mobility information from OAM, 5GC and AF, and collect service data from the AF.

[0313] Further, information regarding established PDU sessions related to duplicate transmissions may be collected from the NF (e.g., SMF).

[0314] The following table shows UE mobility information:

[0315] [Table 4]

[0316] The following table shows the service data from the AF related to UE mobility.

[0317] [Table 5]

[0318] Additionally, packet drop and / or packet delay measurements are input per different levels of granularity, i.e. per QoS flow, per UE, per GTP-U path.

[0319] The table below shows packet drop and / or packet delay measurements.

[0320] [Table 6]

[0321] The table below shows the efficiency measures for duplicate transmissions.

[0322] [Table 7]

[0323] The following table shows information for an established PDU session in relation to overlapping transmissions.

[0324] [Table 8]

[0325] II-2. Output of analysis results

[0326] An NWDAF that supports data analysis for experience related to duplicate transmissions may send duplicate transmission experience analysis to an NF (e.g., SMF).

[0327] The following table provides some empirical statistics related to duplicate submissions.

[0328] [Table 9]

[0329] The table below shows empirical predictions related to duplicate transmissions.

[0330] [Table 10]

[0331] II-3. Procedure

[0332] II-3-1.Analysis Procedure

[0333] The NWDAF may provide its analysis in the form of statistics or forecast information.

[0334] FIG. 12 is a signal flow diagram showing an example of providing the analysis results to the NF.

[0335] 1) The NF may forward a request message to the NWDAF for analysis for a specific UE or group of UEs. The message may be, for example, a message based on the Nnwdaf_AnalyticsInfo or Nnwdaf_AnalyticsSubscription service. The NF may provide statistics or predictions. The type of information analyzed is experience related to duplicate transmissions. The NF may provide a UEid or an internal group ID in the target of the analysis report. The analysis filter information may optionally include a DNN, an S-NSAI, and an area of ​​interest.

[0336] 2) If the request is granted, and to provide the requested analysis, the NWDAF may subscribe to notify all serving AMFs of events related to UE location changes and all SMFs serving PDU sessions on the URLCC service of duplicate transmission related information. It may be requested to subscribe to notify.

[0337] The NWDAF can subscribe to the AF to obtain service data using the Naf_EventExposure_Subscribe service or Nnef_EventExposure_Subscribe.

[0338] The NWDAF may collect UE mobility information, packet measurement information, and / or information related to duplicate transmission from the OAM.

[0339] If the NWDAF already has the requested analysis, this step is not performed and can be skipped.

[0340] 3) The NWDAF will perform the analysis for said requested analysis.

[0341] 4) The NWDAF can provide the requested analysis results to the NF. For this purpose, a Nnwdaf_AnalyticsInfo_Request response message or a Nnwdaf_AnalyticsSubscription_Notify message is used.

[0342] 5-7) In process 1, if the NF requests an analysis of the experience related to duplicate transmission, upon receiving an event notification message from the AMF, AF and OAM, the NWDAF can perform the analysis and provide the analysis result to the NF.

[0343] If the SMF intends to use the analysis results, the empirical analysis related to duplicate transmission is used to determine how to handle the PDU session, for example, the empirical analysis related to duplicate transmission is used to determine whether duplicate transmission should be performed or aborted for a PDU session for a URLCC service.

[0344] II-3-2.Improvement of network node functions

[0345] The SMF will be enhanced to obtain information from the NWDAF to make decisions to efficiently support duplicate transmissions for URLCC services.

[0346] Based on the acquired information, the SMF

[0347] It may be determined that duplicate transmission should be performed.

[0348] Or if activated, it may decide that duplicate transmissions need to be stopped.

[0349] NWDAF will be improved as follows:

[0350] The NWDAF can provide empirical statistics and predictions related to overlapping transmissions.

[0351] For the Nnwdaf service operation used in the above procedure in this specification, "Redundant Transmission Experience" can be added to the analysis information provided by NWDAF as follows.

[0352] II-3-3. Standard changes to Nnwdaf service operations

[0353] The table below shows the services provided by the NWDAF.

[0354] [Table 11]

[0355] The table below shows analytical information provided by the NWDAF.

[0356] [Table 12] JPEG0007601909000014.jpg30154

[0357] An example in which the analysis results are utilized will be described below.

[0358] III. Examples of how analysis results are used

[0359] III-1. Support for duplicate transmissions on N3 / N9 interfaces

[0360] During or after the URLLC QoS flow establishment process, if the SMF determines that duplicate transmission is to be performed based on the allowed 5QI, NG-RAN node capability, and / or operator configuration, the SMF may inform the UPF and NG-RAN to perform duplicate transmission via the N4 interface and forward the N2 information. In this case, the NG-RAN may provide other routing information within the tunnel information (e.g., other IP addresses). Such routing information is mapped to be branched to the transmission layer path according to the network configuration.

[0361] In the case of the deployment option using NWDAF for URLCC service, the SMF may determine that duplicate transmission is to be performed based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings as well as empirical analysis for duplicate transmission.

[0362] When duplicate transmissions are performed on the N3 and N9 interfaces, for each download packet of a QoS flow received by the UPF from the DN, the UPF may copy the packet and assign the same GTP-U sequence number to the duplicate transmissions.

[0363] The NG-RAN removes duplicate packets based on the GTP-U sequence number and forwards the PDU to the UE.

[0364] For each uplink packet of a QoS flow that NG-RAN receives from a UE, NG-RAN copies the packet and assigns a similar GTP-U sequence number. Such packets are sent to the UPF through two N3 tunnels. The UPF can remove duplicate packets based on the GTP-U sequence number.

[0365] The UPF and NG-RAN transmit packets through one or two tunnels for each QoS flow based on the SMF instruction.

[0366] III-2. Standard changes to the PDU session establishment procedure required by UE

[0367] The PDU session establishment procedure has already been described with reference to Figures 8a and 8b. The following description will focus on the differences.

[0368] In process 4, the SMF can decide whether the PDU session requires duplication or not.

[0369] When using the NWDAF for URLCC services, based on the allowed 5QI, NG-RAN node capabilities and / or operator configuration as well as empirical analysis for overlapping transmissions, the SMF can determine whether the PDU session requires overlapping, i.e., whether overlapping transmission should be performed or not. If the UE request is not valid, the SMF can decide not to accept the establishment of the PDU session.

[0370] In process 10a, if the SMF decides to perform duplicate transmission for a PDU session, the SMF can inform the UPF that one CN tunnel information is to be used as the duplicate tunnel for the PDU session. do.

[0371] When using NWDAF for URLCC services, Based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis for overlapping transmissions, the SMF can determine whether overlapping transmissions should be performed.

[0372] If the SMF determines that two I-UPFs are used between the UPF and the NG-RAN for overlap transmission, the SMF may request and provide corresponding CN tunnel information to the I-UPF and the UPF. When using the NWDAF for the URLLC service, the SMF may determine whether overlap transmission should be performed or not based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings as well as empirical analysis for overlap transmission. The SMF may inform the UPF to remove overlap packets for QoS flows in the uplink direction. The SMF may inform the UPF that the CN tunnel information is used for overlap tunnels of the PDU session.

[0373] In process 11, the CN tunnel information may correspond to a core network address of an N3 tunnel corresponding to a PDU session. When two CN tunnel information are included for a PDU session for duplicate transmission, the SMF may inform the NG-RAN of one of the CN tunnel information to be used as the duplicate tunnel for the PDU session.

[0374] If the RAN receives two CN tunnel information for a PDU session for overlapping transmission in process 12, the RAN can allocate two AN tunnel information in process 13 and inform the SMF that one of the AN tunnel information is used for the overlapping tunnel of the PDU session.

[0375] Process 16a. If the SMF decides to perform duplicate transmission for one or more QoS flows, the SMF can inform the UPF to perform packet copy of the QoS flow in the downlink direction. If duplicate transmission is performed through two I-UPFs for one or more QoS flows, the SMF can provide AN tunnel information to the two I-UPFs and inform the UPF to perform packet copy.

[0376] The SMF can provide the UPF's UL tunnel information and DL tunnel information to two I-UPFs.

[0377] When using the NWDAF for URLLC services, the SMF may determine whether or not duplicate transmission should be performed based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis for duplicate transmission.

[0378] III-3. Standard changes to PDU session modification procedures

[0379] The PDU session modification procedure has already been described with reference to Figures 9a and 9b. The following description will focus on the differences.

[0380] In step 2a, if duplicate transmission is not activated for the PDU session, the SMF determines to perform duplicate transmission for the QoS flow, and the SMF can instruct the UPF to perform packet copying and removal for the QoS flow.

[0381] When using the NWDAF for URLLC services, the SMF can determine whether or not duplicate transmission should be performed based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis for duplicate transmission.

[0382] When duplicate transmission for a PDU session is activated, if the SMF decides to stop duplicate transmission, the SMF can release the CN tunnel information used as the duplicate tunnel for the PDU session and instruct the UPF to stop packet copying and remove the corresponding QoS flow.

[0383] For NWDAFs using URLCC services, the SMF may decide whether to abort duplicate transmissions based on allowed 5QI, NG-RAN node capabilities, and / or operator configuration, as well as empirical analysis of duplicate transmissions.

[0384] If duplicate transmission is not activated for the PDU session, and if the SMF determines to perform duplicate transmission for the QoS flow using two I-UPFs between the UPF and the NG-RAN, the SMF may send an N4 session establishment request message to the I-UPF, which may include a request to allocate ULCN tunnel information and CN tunnel information of the UPF.

[0385] When using NWDAF using URLLC service, the SMF can decide whether to perform or abort the duplicate transmission based on the allowed 5QI, NG-RAN node capabilities and / or operator settings as well as empirical analysis of duplicate transmission.

[0386] When using the NWDAF for URLLC services, the SMF may decide to discontinue duplicate transmissions based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis of duplicate transmissions.

[0387] In process 3a, if the SMF decides to activate duplicate transmission, the SMF may further include CN tunnel information in the N2 SM information.

[0388] If duplicate transmission is activated for a PDU session and the SMF decides to stop duplicate transmission, the SMF may release the AN tunnel and request the UPF to stop packet copying and remove associated duplicate tunnels for the PDU session.

[0389] When using the NWDAF for URLLC services, the SMF may decide to discontinue duplicate transmissions based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis of duplicate transmissions.

[0390] In process 3b, if duplicate transmission is activated for the PDU session and the SMF decides to stop duplicate transmission, the SMF may request the RAN to release the AN tunnel, stop packet copying and remove the duplicate tunnel for the PDU session.

[0391] In the case of NWDAF using URLLC service, the SMF may decide to discontinue duplicate transmissions based on the allowed 5QI, NG-RAN node capabilities and / or operator settings as well as empirical analysis of duplicate transmissions.

[0392] In process 8, if additional AN tunnel information is returned by the RAN, the SMF can inform the UPF of the AN tunnel information for overlapping transmission. In the case of overlapping transmission using two I-UPFs, the SMF can forward the AN tunnel information to the two I-UPFs. If the CN tunnel information of the two I-UPFs is allocated by the UPF, the SMF can provide two DLCN tunnel information to the UPF.

[0393] III-4.Standard Changes for Xn-based Inter NG-RAN Handover Procedures

[0394] FIG. 13 is an illustrative diagram showing a procedure for Xn-based inter NG-RAN handover without user plane reassignment.

[0395] In the following, only the steps shown in FIG. 13 that relate to duplicate transmission will be described.

[0396] In step 4, if the NWDAF is used for the URLCC service, the SMF may decide to perform duplicate transmission based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings as well as empirical analysis for duplicate transmission.

[0397] In step 6, if overlapping transmission is performed for one or more QoS flows of the PDU session, two CN tunnel information is sent, and the SMF can inform the target NG-RAN that one of the two CN tunnels is used for the overlapping tunnel of the PDU session.

[0398] When the NWDAF is used for the URLCC service, the SMF may decide to perform duplicate transmission based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis for duplicate transmission.

[0399] 14a and 14b are illustrative diagrams showing procedures for Xn-based inter NG-RAN handover when an intermediate UPF exists.

[0400] If duplicate transmission is performed for one or more QoS flows of a PDU session switching to the target NG-RAN, the SMF may select two intermediate UPFs (i.e., I-UPFs) and set up two N3 and N9 tunnels between the target NG-RAN and the UPFs via the two I-UPFs.

[0401] When the NWDAF is used for the URLCC service, the SMF may decide to perform duplicate transmission based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis for duplicate transmission.

[0402] In the following, not all steps shown in FIG. 14 will be described, but only the contents related to duplicate transmission will be described.

[0403] In step 3b, the UPF can send an N4 session establishment response message to the SMF. The UPF can provide the SMF with CN tunnel information. If overlap transmission is performed for one or more QoS flows of the PDU session, the UPF can provide two CN tunnel information to the SMF and inform the SMF that one of the CN tunnel information is used for the overlap tunnel of the PDU session. The UPF can coordinate the CN tunnel information with the UL packet detection provided by the SMF.

[0404] When the NWDAF is used for the URLCC service, the SMF may decide to perform duplicate transmission based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis for duplicate transmission.

[0405] In step 4b, the I-UPF can send an N4 session establishment response message to the SMF. The UL and DLCN tunnel information of the I-UPF is sent to the SMF.

[0406] If the SMF selects two intermediate UPFs (i.e., I-UPFs) to perform overlap transmission of the PDU session, process 4a and process 4b are performed between the SMF and each I-UPF. If the NWDAF is used for the URLCC service, the SMF can decide to perform overlap transmission based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings as well as empirical analysis for overlap transmission.

[0407] In step 5, if duplicate transmission is performed for one or more QoS flows of the PDU session, the SMF may provide two DLCN tunnel information to the UPF and may inform the UPF that one of the DLCN tunnel information is used for the duplicate tunnel of the PDU session. If the NWDAF is used for the URLCC service, the SMF may decide to perform duplicate transmission based on the allowed 5QI, NG-RAN node capability, and / or operator configuration as well as empirical analysis for duplicate transmission.

[0408] FIG. 15 is an illustrative diagram showing a procedure for Xn-based inter NG-RAN handover when an intermediate UPF is reassigned.

[0409] In the following, not all steps shown in FIG. 15 will be described, but only the contents related to duplicate transmission will be described.

[0410] The SMF explains by sending an N4 Session Modification Request message to the PDU session anchor. The DLCN tunnel information of the target UPF is included in this message. If overlap transmission is performed for one or more QoS flows of the PDU session, the SMF can provide two DLCN tunnel information to the UPF and inform the UPF which one of the DLCN tunnel information is used for the overlap tunnel of the PDU session.

[0411] When the NWDAF is used for the URLCC service, the SMF may decide to perform duplicate transmission based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis for duplicate transmission.

[0412] III-5. Standard changes for Inter NG-RAN Node N2 based handover procedures

[0413] 16a and 16b are illustrative diagrams showing an inter NG-RAN node N2 based handover procedure in an environment without an Xn interface.

[0414] In the following, not all steps shown in FIG. 16a and FIG. 16b will be described, but only the contents related to duplicate transmission will be described.

[0415] In step 5, if duplicate transmission is performed for one or more QoS flows of the PDU session, the SMF may select two intermediate UPFs to support duplicate transmission based on two N3 and N9 tunnels between the T-RAN and the UPF.

[0416] If duplicate transmission is performed for one or more QoS flows of the PDU session in step 6a, and if another CN tunnel information needs to be used, the SMF can provide two CN tunnel information to the UPF if the CN tunnel information is allocated by the SMF, and the SMF can inform the UPF that any one of the CN tunnel information is used for the duplicate tunnel of the PDU session.

[0417] When the NWDAF is used for the URLCC service, the SMF may decide to perform duplicate transmission based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis for duplicate transmission.

[0418] In step 6b, if duplicate transmission is performed for one or more QoS flows of the PDU session, the UPF can provide two CN tunnel information of the UPF to the SMF and inform the SMF that one of the CN tunnel information is used for the duplicate tunnel of the PDU session. The UPF can coordinate the CN tunnel information with the UL packet detection rule provided by the SMF.

[0419] When the NWDAF is used for the URLCC service, the SMF may decide to perform duplicate transmission based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis for duplicate transmission.

[0420] In step 7, if overlap transmission is performed for one or more QoS flows of the PDU session, two ULCN tunnel information are included in the N2 SM information. If the NWDAF is used for the URLCC service, the SMF can decide to perform overlap transmission based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings as well as empirical analysis for overlap transmission.

[0421] If overlapping transmission is performed for one or more QoS flows of the PDU session in step 10, the T-RAN may include two AN tunnel information for the PDU session in the N2 SM information.

[0422] 17a to 17c are illustrative diagrams showing an inter NG-RAN node N2 based handover procedure in an environment without an Xn interface.

[0423] In the following, not all steps shown in Figs. 17a to 17c will be described, but only the contents related to duplicate transmission will be described.

[0424] When overlapping transmission is performed for one or more QoS flows of a PDU session, two N3 AN tunnel information of the T-RAN or two DLCN tunnel information of the two T-UPFs are provided, and the SMF can inform the UPF that any one of the AN / CN tunnel information is used for the overlapping tunnel of the PDU session.

[0425] When the NWDAF is used for the URLCC service, the SMF may decide to perform duplicate transmission based on the allowed 5QI, NG-RAN node capabilities, and / or operator settings, as well as empirical analysis for duplicate transmission.

[0426] IV. Summary of the Disclosure

[0427] According to the disclosure herein, a first network control node (eg, NWDAF) can collect and analyze information regarding overlapping transmission paths.

[0428] A second network control node (e.g., SMF) can obtain the analyzed information and determine whether to establish a PDU session with duplicate transmission and how to manage UP resources.

[0429] FIG. 18 shows a configuration block diagram of a processor in which the disclosure of this specification is implemented.

[0430] As can be seen with reference to Figure 18, a processor 1020 in which the disclosure herein may be implemented may include multiple circuits to implement the proposed functions, procedures and / or methods described herein. For example, the processor 1020 may include a first circuit (1020-1), a second circuit (1020-2) and a third circuit (1020-3). Although not shown, the processor 1020 may include more circuits. Each circuit may include multiple transistors.

[0431] The processor 1020 is called an application-specific integrated circuit (ASIC) or application processor (AP), and may include at least one of a digital signal processor (DSP), a central processing unit (CPU), and a graphics processing unit (GPU).

[0432] The processor may be included in a UE, a base station, an AMF or an SMF.

[0433] The case where the processor is included in the SMF will be described.

[0434] The first circuit (1020-1) of the processor included in the SMF may acquire analysis information from a Network Data Analytics Function (NWDAF) node. The acquired analysis information may include experience analysis information for duplicate transmission.

[0435] A second circuit (1020-2) of a processor included in the SMF can determine, based on the analysis information, that the PDU session is to be duplicated and transmitted through two tunnels during a procedure related to the PDU session.

[0436] The procedures related to the PDU session may include one or more of: a PDU session establishment procedure, a PDU session modification procedure, and a handover procedure.

[0437] The second circuit (1020-2) of the processor included in the SMF may take into account the permitted 5QI (5G QoS Identifier), NG-RAN node capabilities, and / or operator settings for the determination.

[0438] The empirical analysis information for overlapping transmissions may include information on the percentage of the UE, any UE or group of UEs that efficiently uses PDU sessions associated with overlapping transmissions; DNN (Data Network Name); observed statistics; and the percentage of the UE, any UE or group of UEs that efficiently uses PDU sessions associated with overlapping transmissions.

[0439] The analysis information is derived by a Network Data Analytics Function (NWDAF) node based on one or more of: UL (Uplink) / DL (Downlink) packet drop ratio, UL / DL packet drop rate and / or number of packets due to duplicate transmission, and normal UL / DL transmission rate and / or number of packets.

[0440] A third circuit (1020-3) of a processor included in the SMF enables the SMF node to select two intermediate UPFs (User Plane Functions) when duplicate transmission is performed for one or more QoS flows of a PDU session to be switched to a target NG-RAN.

[0441] A fourth circuit (not shown) of the processor included in the SMF may be configured such that if the SMF node determines to perform duplicate transmission for one or more QoS flows, the SMF node can inform the UPF to perform packet copying of the QoS flow in the downlink direction.

[0442] A fifth circuit (not shown) of the processor included in the SMF may, if duplicate transmission is activated for a PDU session and if the SMF decides to stop duplicate transmission, the SMF may release the AN tunnel and request the UPF to stop packet copying and associated with and remove the duplicate tunnel for the PDU session.

[0443] FIG. 19 shows a wireless communication system according to an embodiment.

[0444] Referring to FIG. 19, a wireless communication system may include a first device 100a and a second device 100b.

[0445] The first device 100a is a UE described in the disclosure of this specification. Alternatively, the first device 100a is a base station, a network node, a transmitting UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, a robot, an AR (Augmented Reality) device, a VR (Virtual Reality) device, an MR (Mixed Reality) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environment device, a device related to 5G services, or another device related to the fourth industrial revolution field.

[0446] The second device 100b is a network node (e.g., AMF or MME) described in the disclosure of this specification. Alternatively, the second device 100b is a base station, a network node, a transmitting UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, a robot, an AR (Augmented Reality) device, a VR (Virtual Reality) device, an MR (Mixed Reality) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environment device, a device related to 5G services, or another device related to the fourth industrial revolution field.

[0447] For example, the UE 100 may include a mobile phone, a smart phone, a laptop computer, a UE device for digital broadcasting, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a slate PC, a tablet PC, an ultra book, a wearable device (e.g., a smart watch, a smart glass, a head mounted display (HMD)), etc. For example, an HMD is a display device worn on the head. For example, an HMD is used to implement VR, AR, or MR.

[0448] For example, a drone is an aircraft that flies by a wireless control signal without a person on board. For example, a VR device may include a device that implements a virtual world object or background. For example, an AR device may include a device that implements a virtual world object or background by connecting it to a real world object or background. For example, an MR device may include a device that implements a real world object or background by fusing it with a virtual world object or background. For example, a hologram device may include a device that implements a 360-degree stereoscopic image by recording and reproducing stereoscopic information using the interference of light generated by the meeting of two laser beams, called holography. For example, a public safety device may include a video relay device or a video device that can be worn on the user's body. For example, an MTC device and an IoT device are devices that do not require direct human intervention or operation. For example, an MTC device and an IoT device may include a smart meter, a vending machine, a thermometer, a smart light bulb, a door lock, or various sensors. For example, a medical device is a device used for the purpose of diagnosing, treating, mitigating, treating, or preventing a disease. For example, a medical device is a device used for the purpose of diagnosing, treating, mitigating, or correcting an injury or disability. For example, a medical device is a device used for the purpose of inspecting, replacing or modifying a structure or function. For example, a medical device is a device used for the purpose of regulating pregnancy. For example, a medical device may include a diagnostic device, a surgical device, an (in vitro) diagnostic device, a hearing aid or a treatment device. For example, a security device is a device installed to prevent possible dangers and maintain safety. For example, a security device may be a camera, a CCTV, a recorder or a black box. For example, a financial technology device is a device that can provide financial services such as mobile payment. For example, a financial technology device may be a payment device or a POS (Point of Sales), etc. For example, a climate / environment device may be a device that monitors or predicts the climate / environment.

[0449] The first device 100a may include at least one or more processors, such as processor 1020a, at least one or more memories, such as memory 1010a, and at least one or more transceivers, such as transceiver 1031a. The processor 1020a may perform the functions, procedures, and / or methods described above. The processor 1020a may perform one or more protocols. For example, the processor 1020a may perform one or more layers of an air interface protocol. The memory 1010a is coupled to the processor 1020a and may store various forms of information and / or instructions. The transceiver 1031a is coupled to the processor 1020a and is controlled to transmit and receive wireless signals.

[0450] The second device 100b may include at least one processor, such as processor 1020b, at least one memory device, such as memory 1010b, and at least one transceiver, such as transceiver 1031b. The processor 1020b may perform the functions, procedures, and / or methods described above. The processor 1020b may implement one or more protocols. For example, the processor 1020b may implement one or more layers of an air interface protocol. The memory 1010b is coupled to the processor 1020b and may store various forms of information and / or instructions. The transceiver 1031b is coupled to the processor 1020b and is controlled to transmit and receive wireless signals.

[0451] The memory 1010a and / or the memory 1010b may be internal or external to the processor 1020a and / or the processor 1020b, respectively, and may be connected to other processors via various techniques, such as wired or wireless connections.

[0452] The first device 100a and / or the second device 100b may have one or more antennas, for example, antenna 1036a and / or antenna 1036b configured to transmit and receive wireless signals.

[0453] FIG. 20 is a block diagram of a network node according to an embodiment.

[0454] In particular, FIG. 20 is a detailed diagram illustrating a case where a base station is divided into a central unit (CU) and distributed units (DU).

[0455] 20, base stations W20 and W30 are connected to a core network W10, and base station W30 is connected to a neighboring base station W20. For example, the interface between base stations W20 and W30 and the core network W10 can be referred to as NG, and the interface between base station W30 and the neighboring base station W20 can be referred to as XN.

[0456] The base station W30 is divided into a CUW32 and DUWs 34 and W36. That is, the base station W30 is hierarchically separated and operated. The CUW32 is connected to one or more DUWs 34 and W36, and for example, the interface between the CUW32 and the DUWs 34 and W36 can be referred to as F1. The CUW32 can perform the functions of the upper layers of the base station, and the DUWs 34 and W36 can perform the functions of the lower layers of the base station. For example, the CUW32 is a logical node that hosts the radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) layers of the base station (e.g., gNB), and the DUWs 34 and W36 are logical nodes that host the radio link control (RLC), media access control (MAC), and physical (PHY) layers of the base station. Alternatively, the CUW 32 is a logical node that hosts the RRC and PDCP layers of a base station (e.g., en-gNB).

[0457] The operation of the DUW 34, W36 is partially controlled by the CUW 32. One DUW 34, W36 can support one or more cells. One cell is supported by only one DUW 34, W36. One DUW 34, W36 is connected to one CUW 32, and with appropriate implementation one DUW 34, W36 may be connected to multiple CUs.

[0458] FIG. 21 is a block diagram showing a configuration of a UE 100 according to an embodiment.

[0459] In particular, the UE 100 shown in FIG. 21 is a diagram illustrating the first device of FIG. 19 above in more detail.

[0460] The UE 100 includes a memory 1010, a processor 1020, a transceiver 1031, a power management module 1091, a battery 1092, a display 1041, an input 1053, a speaker 1042 and a microphone 1052, a subscriber identification module (SIM) card, and one or more antennas.

[0461] The processor 1020 is configured to implement the proposed functions, procedures and / or methods described herein. A layer of a wireless interface protocol is implemented in the processor 1020. The processor 1020 may include an application-specific integrated circuit (ASIC), other chipset, logic circuit and / or data processing device. The processor 1020 is an application processor (AP). The processor 1020 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). Examples of the processor 1020 are a SNAP DRAGON TM series processor manufactured by Qualcomm®, an EXYNOS TM series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO TM series processor manufactured by Media Tek®, an ATOMT M series processor manufactured by INTEL®, or a corresponding next generation processor.

[0462] A power management module 1091 manages power to the processor 1020 and / or the transceiver 1031. A battery 1092 provides power to the power management module 1091. A display 1041 outputs results processed by the processor 1020. An input 1053 receives inputs used by the processor 1020. The inputs 1053 are displayed on the display 1041. A SIM card is an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and associated keys used to identify and authenticate a subscriber in mobile telephone devices such as mobile phones and computers. Many SIM cards can also store contact information.

[0463] The memory 1010 is operatively coupled to the processor 1020 and stores various information for operating the processor 1020. The memory 1010 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage devices. When an embodiment is implemented in software, the techniques described herein are implemented into modules (e.g., procedures, functions, etc.) that perform the functions described herein. The modules are stored in the memory 1010 and executed by the processor 1020. The memory 1010 may be implemented within the processor 1020. Alternatively, the memory 1010 may be implemented external to the processor 1020 and communicatively connected to the processor 1020 via various means as known in the art.

[0464] The transceiver 1031 is operatively coupled to the processor 1020 to transmit and / or receive radio signals. The transceiver 1031 includes a transmitter and a receiver. The transceiver 1031 may include baseband circuitry for processing radio frequency signals. The transceiver controls one or more antennas to transmit and / or receive radio signals. The processor 1020 transfers instruction information to the transceiver 1031 to transmit radio signals, e.g., constituting voice communication data, to initiate communication. The antenna functions to transmit and receive radio signals. When receiving a radio signal, the transceiver 1031 may convert the signal to baseband, forwarding the signal for processing by the processor 1020. The processed signal is converted to audible or readable information that is output via the speaker 1042.

[0465] The speaker 1042 outputs sound-related results processed by the processor 1020. The microphone 1052 receives sound-related input for use by the processor 1020.

[0466] A user inputs command information such as a telephone number, for example, by pressing (or touching) a button on input unit 1053 or by voice activation using microphone 1052. Processor 1020 receives such command information and processes it to perform an appropriate function, such as dialing the telephone number. Operational data can be retrieved from the SIM card or memory 1010. Processor 1020 can also display the command information or operation information on display 1041 for the user's recognition and convenience.

[0467] FIG. 22 is a detailed block diagram of the transceiver unit of the first device shown in FIG. 19 or the transceiver unit of the device shown in FIG.

[0468] 22, the transceiver unit 1031 includes a transmitter 1031-1 and a receiver 1031-2. The transmitter 1031-1 includes a DFT (Discrete Fourier Transform) unit 1031-11, a subcarrier mapper 1031-12, an IFFT unit 1031-13, a CP insertion unit 1031-14, and a radio transmission unit 1031-15. The transmitter 1031-1 may further include a modulator. In addition, the transmitter 1031-1 may further include, for example, a scramble unit (not shown), a modulation mapper, a layer mapper, and a layer permutator, which are disposed prior to the DFT unit 1031-11. That is, to prevent an increase in the peak-to-average power ratio (PAPR), the transmitter 1031-1 passes information through a DFT 1031-11 before mapping the signal to a subcarrier. The signal that has been spread (or precoded) by the DFT unit 1031-11 is subcarrier mapped through a subcarrier mapper 1031-12, and then converted to a signal on the time axis through an Inverse Fast Fourier Transform (IFFT) unit 1031-13.

[0469] The DFT unit 1031-11 performs DFT on the input symbols and outputs complex-valued symbols. For example, if Ntx symbols are input (where Ntx is a natural number), the DFT size is Ntx. The DFT unit 1031-11 can be called a transform precoder. The subcarrier mapper 1031-12 maps the complex symbols to each subcarrier in the frequency domain. The complex symbols are mapped to resource elements corresponding to resource blocks allocated for data transmission. The subcarrier mapper 1031-12 can be called a resource element mapper. The IFFT unit 1031-13 performs IFFT on the input symbols and outputs a baseband signal for data, which is a time domain signal. The CP insertion unit 1031-14 copies a part of the latter half of the baseband signal for data and inserts it in front of the baseband signal for data. Through CP insertion, Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI) are prevented and orthogonality is maintained even in multipath channels.

[0470] On the other hand, the receiver 1031-2 includes a radio receiving unit 1031-21, a CP removing unit 1031-22, an FFT unit 1031-23, and an equalization unit 1031-24. The radio receiving unit 1031-21, the CP removing unit 1031-22, and the FFT unit 1031-23 of the receiver 1031-2 perform the inverse functions of the radio transmitting unit 1031-15, the CP inserting unit 1031-14, and the IFF unit 1031-13 in the transmitting end 1031-1. The receiver 1031-2 may further include a demodulator.

[0471] <Scenarios where the disclosure of this specification can be applied>

[0472] Without being limited thereto, the various descriptions, functions, procedures, suggestions, methods and / or operational flow diagrams disclosed herein may be applied to a variety of fields requiring wireless communication / connection between devices (e.g., 5G).

[0473] Hereinafter, the present invention will be described in more detail with reference to the drawings. In the following drawings / description, unless otherwise stated, similar reference numerals may represent the same or corresponding hardware blocks, software blocks, or function blocks.

[0474] FIG. 23 illustrates a communication system (1) to which the disclosure of this specification is applied.

[0475] Referring to FIG. 23, the communication system (1) applied to the disclosure of this specification includes a wireless device, a base station, and a network. Here, the wireless device means a device that performs communication using a wireless connection technology (e.g., 5G NR (New RAT), LTE (Long term evolution)), and is referred to as a communication / wireless / 5G device. The wireless device may include, but is not limited to, a robot 100a, a vehicle 100b-1, 100b-2, an XR (eXtended Reality) device 100c, a handheld device (Hand-held device) 100d, a home appliance 100e, an IoT (Internet of Things) device 100), and an AI device / server 400. For example, the vehicle may include a vehicle with a wireless communication function, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, and the like. Here, the vehicle may include a UAV (Unmanned Aerial Vehicle) (e.g., a drone). XR devices include Augmented Reality (AR) / Virtual Reality (VR) / Mixed Reality (MR) devices, and are implemented in the form of Head-Mounted Devices (HMDs), Head-Up Displays (HUDs) attached to vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Portable devices can include smartphones, smart pads, wearable devices (e.g., smart watches, smart glasses), computers (e.g., laptops, etc.), etc. Home appliances can include TVs, refrigerators, washing machines, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented in wireless devices, and a specific wireless device 200a can be operated by a base station / network node to other wireless devices.

[0476] The wireless devices 100a to 100f are connected to a network 300 via a base station 200. AI (Artificial Intelligence) technology is applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f are connected to an AI server 400 via the network 300. The network 300 is configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices 100a to 100f can communicate with each other via the base station 200 / network 300, but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, the vehicles 100b-1 and 100b-2 can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). In addition, an IoT device (e.g., a sensor) can directly communicate with another IoT device (e.g., a sensor) or another wireless device 100a to 100f.

[0477] Wireless communications / connections 150a, 150b, and 150c are established between the wireless devices 100a to 100f and the base station 200, and between the base stations 200 and 200. Here, the wireless communication / connection is performed via various wireless connection technologies (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication 150b (or D2D communication), and communication between base stations 150c (e.g., e.g., relay, IAB (Integrated Access Backhaul)). Through the wireless communication / connections 150a, 150b, and 150c, the wireless device and the base station / wireless device, and the base station and the base station can transmit / receive wireless signals to each other. For example, the wireless communication / connections 150a, 150b, and 150c can transmit / receive signals via various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), resource allocation processes, etc. are performed based on various proposals disclosed in this specification.

[0478] Although the above describes preferred embodiments, the disclosure of this specification is not limited to such specific embodiments, and may be modified, changed, or improved in various ways within the spirit and scope of this specification and the claims.

[0479] In the exemplary systems described above, the methods are described based on flow diagrams as a series of steps or blocks, but are not limited to the order of steps described, and certain steps may occur in other orders or simultaneously with other steps as described above. Additionally, those skilled in the art will appreciate that the steps shown in the flow diagrams are not exclusive, and other steps may be included or one or more steps of the flow diagrams may be omitted without affecting the scope of the invention.

[0480] The claims described herein may be combined in various ways, for example, technical features of the method claims herein may be combined and implemented in an apparatus, technical features of the device claims herein may be combined and implemented in a method, technical features of the method claims herein and the device claims herein may be combined and implemented in an apparatus, and technical features of the method claims herein and the device claims herein may be combined and implemented in a method.

Claims

1. A method executed by a Session Management Function (SMF), comprising: Establishing a Protocol Data Unit (PDU) session; Obtaining RTE (Redundant Transmission Experience) analysis from NWDAF (Network Data Analytics Function); and Based on the RTE analysis, i) whether to perform Redundant Transmission (RT) for the PDU session, or ii) determining whether to discontinue an activated RT for the PDU session; The RTE analysis includes: DNN (Data Network Name), Information related to the expected RTE within the analysis target interval; and A percentage of time slots associated with the PDU session and RT from among the predicted time slots.

2. During the PDU Session Modification procedure, i) whether to execute the RT, or ii) determining whether to discontinue the RT or not.

3. Based on the RTE analysis, as well as the permitted 5QIs (5G QoS Identifiers), NG-RAN node capabilities, and / or operator settings, The method according to claim 1 or 2, further comprising deciding i) whether to perform the RT or not, or ii) whether to abort the RT or not.

4. The RTE analysis includes: UL (Uplink) / DL (Downlink) packet drop ratio, UL / DL packet drop rate and / or number of packets due to duplicate transmissions, and The method according to any one of claims 1 to 3, derived by the NWDAF based on one or more of: a normal UL / DL transmission rate and / or a number of packets.

5. Based on the fact that the RT is performed for one or more QoS flows of a PDU session to be switched to a target Next Generation Radio Access Network (NG-RAN), The method according to any one of claims 1 to 4, further comprising the step of: selecting two intermediate User Plane Functions (I-UPFs).

6. Based on the decision to execute the RT, The method according to any one of claims 1 to 5, further comprising the step of: notifying the UPF to perform copying and removal of packets for the QoS flow.

7. Based on the decision to discontinue the RT, Notifying the UPF to release CN (Core Network) tunnel information used as a duplicate tunnel for the PDU session; and The method of any one of claims 1 to 6, further comprising the step of: notifying the UPF to stop copying and removing packets for a QoS flow.

8. A session management function (SMF), at least one transceiver; at least one processor; at least one memory storing instructions and operably electrically connected to said at least one processor; the instructions, when executed by the at least one processor, perform an action; The operation includes: Establishing a Protocol Data Unit (PDU) session; Obtaining RTE (Redundant Transmission Experience) analysis from NWDAF (Network Data Analytics Function); and Based on the RTE analysis, i) determining whether to perform Redundant Transmission (RT) for the PDU session, or ii) determining whether to discontinue an activated RT for the PDU session; The RTE analysis includes: DNN (Data Network Name), Information related to the expected RTE within the analysis target interval; and An SMF including a percentage of time slots associated with the PDU session and RT from among the predicted time slots.

9. During the PDU Session Modification procedure, i) whether to execute the RT, or ii) determining whether to discontinue the RT or not.

10. Based on the RTE analysis, as well as the permitted 5QI (5G QoS Identifier), NG-RAN node capabilities, and / or operator settings, 10. The SMF of claim 8 or 9, which decides i) whether to perform the RT or not, or ii) whether to abort the RT or not.

11. Based on the decision to execute the RT, The SMF according to any one of claims 8 to 10, wherein the operation further comprises: notifying a UPF to perform copying and removal of packets for a QoS flow.

12. Based on the decision to discontinue the RT, The operation includes: Notifying the UPF to release CN (Core Network) tunnel information used as a duplicate tunnel for the PDU session; and The SMF of any one of claims 8 to 11, further comprising the step of: notifying the UPF to stop copying and removing packets for a QoS flow.

13. A method performed by a terminal (User Equipment: UE), comprising: Establishing a Protocol Data Unit (PDU) session; sending a Non-Access Stratum (NAS) message; and The NAS message includes a PDU session modification request and the PDU session ID (Identifier), The NAS message is forwarded by the RAN (Radio Access Network) to the AMF (Access and Mobility Management Function), The PDU session modification request is forwarded by the AMF to the SMF (Session Management Function), Based on a Redundant Transmission Experience (RTE) analysis, determining to perform Redundant Transmission (RT) for the PDU session; receiving, from the RAN, an Access Network (AN) specific signal from the RAN related to the information received from the SMF; The AN-specific signal includes an N1 SM container including a PDU session modification command; The RTE analysis includes: DNN (Data Network Name), Information related to the expected RTE within the analysis target interval; and A percentage of time slots associated with the PDU session and RT from among the predicted time slots.

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