Method and apparatus for handling always-on pdu session of network slice by considering service area in wireless communication system

Abstract

One disclosure of the specification provides a method of operating in a wireless communication system by a terminal. The method can include transmitting a protocol data unit (PDU) session request message associated with a first network slice selection assistance information (NSSAI), and receiving a PDU session reject message in response to the transmitted PDU session request message. The received PDU session reject message is used to establish an always-on PDU session associated with a second NSSAI, and the first NSSAI and the second NSSAI can be different partial allowed NSSAIs from each other.

Description

Technical Field

[0001] This manual relates to 3GPP wireless communication systems. Background Technology

[0002] Driven by the success of fourth-generation (4G) mobile communication technologies such as LTE and LTE-Advanced (LTE-A), there is growing interest in the next generation, namely fifth-generation (5G) mobile communication, and related research is actively underway.

[0003] As defined by the International Telecommunication Union (ITU), 5G mobile communication refers to providing data transmission rates of up to 20Gbps anywhere and user experience transmission rates of at least 100Mbps, and is officially called "IMT-2020".

[0004] 5G mobile communication supports multiple parameter sets or subcarrier spacing (SCS) to support a variety of services. For example, when the SCS is 15kHz, the SCS supports wide-area coverage in traditional cellular bands; when the SCS is 30kHz / 60kHz, the SCS supports dense urban environments, lower latency, and wider carrier bandwidth; and when the SCS is 60kHz or higher, the SCS supports bandwidths greater than 24.25GHz to overcome phase noise.

[0005] The NR band is defined by two types of frequency ranges (FR1 and FR2). FR1 ranges from 410MHz to 7125MHz, and FR2 ranges from 24250MHz to 52600MHz, which can refer to millimeter waves (mmW).

[0006] For ease of description, in the frequency range used in NR systems, FR1 can refer to "below 6 GHz" and FR2 can refer to "above 6 GHz", which can be referred to as millimeter wave (mmW).

[0007] [Table 1]

[0008] The frequency range in an NR system can be varied. For example, FR1 may include a frequency band from 410 MHz to 7125 MHz as shown in Table 1. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher. For example, the 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher frequency band included in FR1 may include unlicensed frequency bands. Unlicensed frequency bands can be used for various purposes, such as for vehicle communications (e.g., autonomous driving). Figure 1 This is a view showing a wireless communication system.

[0009] The 5G core (5GC) network can include various components, and Figure 1 This includes some of the components, such as Access and Mobility Management Function (AMF)41, Session Management Function (SMF)42, Policy Control Function (PCF)43, User Plane Function (UPF)44, Application Function (AF)45, Unified Data Management (UDM)46, and Non-3GPP Interoperability Function (N3IWF)49.

[0010] User equipment (UE) 10 is connected to the data network (DN) via the next-generation radio access network (NG-RAN) and UPF 44.

[0011] UE 10 can also receive data services via untrusted non-3GPP access, such as wireless local area networks (WLANs). To connect non-3GPP access to the core network, N3IWF 49 can be configured.

[0012] Figure 2 This is an exemplary view showing the structure of a wireless communication system from the perspective of a node.

[0013] By reference Figure 2 It can be seen that the UE connects to the DN through the Radio Access Network (RAN).

[0014] The Control Plane Function (CPF) nodes shown perform some or all of the functions of the Mobility Management Entity (MME) for 4G mobile communications, as well as some or all of the CPF functions of the Serving Gateway (S-GW) and PDN Gateway (P-GW). CPF nodes include the AMF and SMF.

[0015] The UPF node shown is a gateway through which user data is sent and received. A UPF node can perform part or all of the functions of an S-GW and P-GW in 4G mobile communications.

[0016] The PCF shown is the node that controls the operator's policies.

[0017] The AF shown is a server used to provide various services to the UE.

[0018] The UDM shown is a server that manages subscriber information, such as the Home Subscriber Server (HSS) in 4G mobile communications. The UDM stores and manages subscriber information in a Uniform Data Repository (UDR).

[0019] The Authentication Server Function (AUSF) shown authenticates and manages the UE.

[0020] The Network Slice Selection Function (NSSF) shown is used for nodes in the network slices described below.

[0021] A UE can access two data networks simultaneously using multiple Protocol Data Unit (PDU) or Packet Data Unit (PDU) sessions.

[0022] Figure 3 This is another exemplary view showing the structure of a wireless communication system from the perspective of a node.

[0023] Figure 3 An architecture for a UE to access two data networks simultaneously using a single PDU session is shown.

[0024] Figure 2 and Figure 3 The items related to the reference point shown are as follows.

[0025] N1 represents the reference point between the UE and the AMF.

[0026] N2 represents the reference point between (R)AN and AMF.

[0027] N3 represents the reference point between (R)AN and UPF.

[0028] N4 represents the reference point between the SMF and UPF.

[0029] N5 represents the reference point between PCF and AF.

[0030] N6 represents the reference point between UPF and DN.

[0031] N7 represents the reference point between the SMF and PCF.

[0032] N8 represents the reference point between UDM and AMF.

[0033] N9 represents the reference point between UPF nodes.

[0034] N10 represents the reference point between UDM and SMF.

[0035] N11 represents the reference point between AMF and SMF.

[0036] N12 represents the reference point between AMF and AUSF.

[0037] N13 represents the reference point between UDM and AUSF.

[0038] N14 represents the reference point between AMF nodes.

[0039] N15 represents the reference point between the PCF and AMF.

[0040] N16 represents the reference point between SMF nodes.

[0041] N22 represents the reference point between AMF and NSSF.

[0042] N33 represents the reference point between Network Open Function (NEF) and AF.

[0043] Figure 4 This is an exemplary view showing the structure of the radio interface protocol between a terminal and a network.

[0044] The radio interface protocol is based on the 3GPP radio access network standard. Horizontally, the radio interface protocol consists of the physical layer, data link layer, and network layer; vertically, it is classified into the user plane for data transmission and the control plane for signaling transmission.

[0045] Protocol layers can be classified as Layer 1 (L1), Layer 2 (L2), and Layer 3 (L3) based on the three layers of the Open Systems Interconnection (OSI) reference model, which is widely known in communication systems.

[0046] The following text will describe each layer of the wireless interface protocol.

[0047] The physical layer (i.e., layer 1) provides information transmission services using physical channels. The physical layer connects to the upper Media Access Control (MAC) layer via transport channels, and data between the MAC layer and the physical layer is transmitted via transport channels. Additionally, data is transmitted between different physical layers (i.e., between the physical layers on the sending and receiving sides) via physical channels.

[0048] The second layer includes the MAC layer, the Radio Link Control (RLC) layer, and the Packet Data Convergence Protocol (PDCP) layer.

[0049] The third layer includes the Radio Resource Control (RRC) layer. The RRC layer is defined only in the control plane and is responsible for controlling the logical, transport, and physical channels related to the configuration, reconfiguration, and release of radio bearers (RBs). In this context, RB refers to the service provided by the second layer for data transmission between the terminal and the RAN.

[0050] The Non-Access Stratum (NAS) layer performs functions such as Session Management (SM) and Mobility Management (MM).

[0051] The NAS layer is classified into NAS entities for MM and NAS entities for SM.

[0052] 1) The NAS entity used for MM provides the following general functions.

[0053] As a NAS process related to AMF, the following is provided: - Registration and access management processes. AMF supports the following functions.

[0054] - Establish a secure NAS signaling connection (integrity protection and encryption) between the UE and AMF.

[0055] 2) The NAS entity used for SM performs SM between the UE and the SMF.

[0056] SM signaling messages are processed at the NAS-SM layer between the UE and SMF, i.e., generated and processed. The content of SM signaling messages is not interpreted by the AMF.

[0057] - In the case of SM signaling transmission - The NAS entity for MM generates a NAS-MM message, which includes a security header indicating the NAS transmission of SM signaling and additional information for receiving the NAS-MM. The NAS-MM message guides how and where to send SM signaling messages.

[0058] - Upon receiving SM signaling, the NAS entity used for SM performs an integrity check on the NAS-MM message and interprets additional information to guide how and where to derive the SM signaling message.

[0059] also, Figure 4 The RRC, RLC, MAC, and PHY layers located below the NAS layer are sometimes collectively referred to as the Access Layer (AS).

[0060] Network systems used for 5G (i.e., 5GC) also support non-3GPP access. A representative example of non-3GPP access is WLAN access. WLAN access can include both trusted and untrusted WLANs.

[0061] In systems used for 5G, the AMF performs registration management (RM) and connection management (CM) not only for 3GPP access, but also for non-3GPP access. Summary of the Invention

[0062] Technical issues

[0063] The disclosure of this specification is intended to provide methods and apparatus for processing protocol data unit (PDU) sessions of network slices in a wireless communication system.

[0064] Specifically, one embodiment of this specification aims to provide a method and apparatus for processing PDU sessions, taking into account the feature of Network Slice Selection Assistance Information (NSSAI) used to distinguish PDU sessions in a network slice, where NSSAI is partially enabled.

[0065] Additionally, one embodiment of this specification aims to provide a method and apparatus for processing PDU sessions when the PDU session is an always-on PDU session in the case where NSSAI is partially permitted.

[0066] Technical solution

[0067] One embodiment of this specification provides a method for operating a terminal in a wireless communication system. The method may include the following steps: establishing an always-on Protocol Data Unit (PDU) session associated with a first Network Slice Selection Assistance Information (NSSAI); sending a PDU session request message associated with the first NSSAI; and receiving a PDU session rejection message in response to the sent PDU session request message. When the first NSSAI is a partially allowed NSSAI, the PDU session rejection message may be a PDU session rejection message associated with a partial Tracking Area (TA) within the current Registration Area (RA), and when the PDU session associated with the first NSSAI is an always-on PDU session, the PDU session rejection message may be used to establish a PDU session associated with a second NSSAI, which is a partially allowed NSSAI different from the first NSSAI.

[0068] Additionally, one embodiment of this specification provides a communication apparatus in a wireless communication system. The communication apparatus may include a transceiver, at least one processor, and at least one memory configured to store instructions and operatively electrically connected to the at least one processor. Operations performed based on instructions executed by the at least one processor may include: establishing an always-on Protocol Data Unit (PDU) session associated with a first Network Slice Selection Assistance Information (NSSAI), sending a PDU session request message associated with the first NSSAI, and receiving a PDU session rejection message in response to the sent PDU session request message. When the first NSSAI is a partially allowed NSSAI, the PDU session rejection message may be a PDU session rejection message associated with a partial Tracking Area (TA) within the current Registered Area (RA), and when the PDU session associated with the first NSSAI is an always-on PDU session, the PDU session rejection message may be used to establish a PDU session associated with a second NSSAI, which is a partially allowed NSSAI different from the first NSSAI.

[0069] When the PDU session associated with the first NSSAI is not an always-on PDU session, the first NSSAI can be maintained and the establishment of the PDU session associated with the second NSSAI can be postponed based on the PDU session rejection message.

[0070] In addition, the operation may also include: when the PDU session associated with the first NSSAI is an always-on PDU session, after receiving the PDU session rejection message, sending a PDU session establishment request message associated with the second NSSAI even if there is no uplink transmission data.

[0071] PDU session request messages can be either PDU session establishment request messages or PDU session modification request messages. Similarly, PDU session rejection messages can be either PDU session establishment rejection messages or PDU session modification rejection messages.

[0072] The received PDU session establishment rejection message and / or PDU session modification rejection message may include a BO timer value and reason information, and based on the BO timer value, the transmission of the PDU session establishment request message and / or PDU session modification request message associated with the first NSSAI may be backed off.

[0073] Beneficial effects

[0074] According to the disclosure in this specification, before the accurate update / synchronization process of partially permitted NSSAI (and / or NS-AoS) between the terminal and the network is completed, when the terminal executes the always-on PDU session establishment request process and / or PDU session modification request process, low-latency service connectivity degradation, signaling overhead, and resource waste may occur due to inefficient operations. Therefore, the network can quickly stop the NAS process for the terminal regarding unavailable or modified (updated) partially permitted NSSAI, and can also quickly execute always-on PDU session processing, reduce unnecessary signaling overhead, minimize power consumption and resource waste for both the terminal and the network, and continuously provide low-latency service.

[0075] Additionally, in one embodiment of this specification, in the case of a rejection of a PDU session request that partially allows NSSAI, considering that the rejection is associated with a portion of the TA within the current RA, it is possible to efficiently select and apply whether to maintain the session considering the terminal's mobility or to re-establish the session based on another NSSAI.

[0076] In addition, in one embodiment of this specification, when the problematic PDU session is an always-on PDU session, even in the case of partial NSSAI denial as described above, an updated PDU session can be established immediately regardless of whether the terminal has data to transmit, thereby ensuring the performance of latency-sensitive always-on PDU sessions. Attached Figure Description

[0077] Figure 1 This is a view showing a wireless communication system.

[0078] Figure 2 This is an exemplary view showing the structure of a wireless communication system from the perspective of a node.

[0079] Figure 3 This is another exemplary view showing the structure of a wireless communication system from the perspective of a node.

[0080] Figure 4 This is an exemplary view showing the structure of the radio interface protocol between a terminal and a network.

[0081] Figure 5a and Figure 5b This is a signal flow diagram illustrating an exemplary PDU session establishment process.

[0082] Figure 6a and Figure 6b This is a signal flow diagram illustrating an exemplary PDU session modification process.

[0083] Figure 7 This is an exemplary view used to describe the concept of network slicing.

[0084] Figure 8 This specification illustrates a method of operating a terminal according to one embodiment.

[0085] Figure 9 A block diagram showing the configuration of a processor that implements the disclosure of this specification is provided.

[0086] Figure 10 An apparatus according to one embodiment of this specification is shown.

[0087] Figure 11 A block diagram of a network node configuration according to one embodiment of this specification is shown.

[0088] Figure 12 This is a block diagram of the configuration of a terminal according to one embodiment of this specification.

[0089] Figure 13 It is shown in detail Figure 10 The transceiver of the first device shown Figure 12 Block diagram of the transceiver of the device shown.

[0090] Figure 14 Another wireless communication system that can be applied to the disclosure in this specification is shown. Detailed Implementation

[0091] It should be noted that the technical terms used herein are for describing specific embodiments only and are not intended to limit the scope of this specification. Furthermore, unless specifically defined elsewhere in this specification, the technical terms used herein should be interpreted in the sense commonly understood by one of ordinary skill in the art, and not in an overly comprehensive or overly narrow sense. Additionally, when technical terms used herein are incorrect and fail to accurately express the content and concepts of this specification, they should be replaced with terms that would be correctly understood by one of ordinary skill in the art. It should be understood that general terms used herein should be interpreted according to their dictionary definitions or in context, and not in an overly restrictive manner.

[0092] Furthermore, unless the context otherwise requires, singular expressions used herein include plural expressions. In this application, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components or operations described in the specification, but should be construed as excluding some components or operations or including additional components or operations.

[0093] Additionally, terms including ordinal numbers such as "first" and "second" may be used to describe various components, but these components should not be limited by these terms. These terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of this disclosure, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

[0094] When a component is described as being connected to or linked to another component, it can be directly connected to or linked to the other component, or there can be an intermediate component. On the other hand, when a component is described as being directly connected to or linked to another component, there is no intermediate component.

[0095] In the following description, various embodiments will be described in detail with reference to the accompanying drawings, in which identical or similar components are indicated by the same reference numerals regardless of the reference numerals used, and repeated descriptions thereof will be omitted. Furthermore, in describing this specification, detailed descriptions of related known technologies will be omitted where it is determined that such detailed descriptions may unnecessarily obscure the spirit of this specification. It should be noted that the accompanying drawings are provided to facilitate understanding of this specification, and the content and spirit of this specification are not limited by the drawings. The content and spirit of this specification should be interpreted to extend to all modifications, equivalents, and substitutions other than those shown in the accompanying drawings.

[0096] In this specification, "A or B" may mean "A only", "B only", or "both A and B". That is, in this specification, "A or B" can be interpreted as "A and / or B". For example, in this specification, "A, B or C" may mean "A only", "B only", "C only", or "any combination of A, B and C".

[0097] The forward slash ( / ) or comma used in this specification may mean "and / or". For example, "A / B" may mean "A and / or B". Therefore, "A / B" may mean "A only", "B only", or "both A and B". For example, "A, B, C" may mean "A, B, or C".

[0098] In this specification, "at least one of A and B" may mean "A only", "B only" or "both A and B". Additionally, in this specification, "at least one of A or B" or "at least one of A and / or B" may be interpreted as "at least one of A and B".

[0099] Additionally, in this specification, "at least one of A, B, and C" may mean "A only", "B only", "C only", or any combination of A, B, and C. Furthermore, "at least one of A, B, or C" or "at least one of A, B, and / or C" may be interpreted as "at least one of A, B, and C".

[0100] Additionally, the parentheses used in this specification may mean "for example". Specifically, when referred to as "Control Information (PDCCH)", PDCCH may be provided as an example of control information. That is, "Control Information" in this specification is not limited to PDCCH, and PDCCH may be an example of "Control Information". Similarly, even when referred to as "Control Information (i.e., PDCCH)", PDCCH may be an example of control information.

[0101] The technical features described in the individual figures of this specification may be implemented individually or simultaneously.

[0102] In the accompanying drawings, the user equipment (UE) is shown as an example, but the UE shown may also be referred to as UE 100, UE, mobile device (ME), etc. Additionally, the UE can be a portable device such as a laptop computer, mobile phone, personal digital assistant (PDA), smartphone, or multimedia device, or a non-portable device such as a personal computer (PC) or in-vehicle equipment.

[0103] <Protocol Data Unit (PDU) Session Establishment Process>

[0104] There can be two types of PDU session establishment processes.

[0105] - PDU session establishment process initiated by UE

[0106] - The PDU session establishment process initiated by the network. For this purpose, the network can send device trigger messages to the UE's applications.

[0107] Figure 5a and Figure 5b This is a signal flow diagram illustrating an exemplary PDU session establishment process.

[0108] Figure 5a and Figure 5b The process shown assumes that the UE has already registered with the Access and Mobility Management Function (AMF) according to the registration process. Therefore, it is assumed that the AMF has obtained the user subscription data from the Unified Data Management (UDM).

[0109] 1) The UE sends a Non-Access Stratum (NAS) message to the AMF. This message may include Single Network Slice Selection Assistance Information (S-NSSAI), Data Network Name (DNN), PDU Session ID, Request Type, N1 Session Management (SM) information, etc.

[0110] Specifically, the UE includes S-NSSAIs from the allowed NSSAIs of the current access type. When providing the UE with information about mapped NSSAIs, the UE can provide both the S-NSSAIs based on the allowed NSSAIs and the corresponding S-NSSAIs based on the mapped NSSAI information. Here, the information about mapped NSSAIs is the information that maps each S-NSSAI with allowed NSSAIs to the S-NSSAIs configured for the Home Public Land Mobile Network (HPLMN).

[0111] More specifically, the UE can extract and store information about permitted S-NSSAI and mapped S-NSSAI included in the registration acceptance message received from the network (i.e., AMF) during the registration process. Therefore, the UE can include and send both the permitted S-NSSAI and the corresponding mapped S-NSSAI in the PDU session establishment request message.

[0112] To establish a new PDU session, the UE can generate a new PDU session ID.

[0113] The UE can initiate a UE-initiated PDU session establishment process by sending a NAS message. This NAS message includes a PDU session establishment request message within the N1 SM information. The aforementioned PDU session establishment request message may include the request type, session and service continuity (SSC) mode, and protocol configuration options.

[0114] When a PDU session is established with the aim of establishing a new PDU session, the request type indicates "Initial Request". However, when an existing PDU session exists between 3GPP access and non-3GPP access, the request type can indicate "Existing PDU Session".

[0115] The NAS message sent by the UE is encapsulated within an N2 message by the access network (AN). The N2 message is sent to the AMF and may include user location information and access technology type information.

[0116] - N1 SM information may include an SM PDU data network (DN) request container, which contains information about PDU session authentication performed by an external DN.

[0117] 2) When the request type indicates “Initial Request” and the PDU session ID has not yet been used in the UE’s existing PDU session, the AMF can determine that the message corresponds to a request for a new PDU session.

[0118] When the NAS message does not include S-NSSAI, the AMF can determine the default configuration S-NSSAI for the requested PDU session based on the UE subscription. The AMF can store the PDU session ID associated with the Session Management Function (SMF) ID.

[0119] AMF can be selected from SMF.

[0120] 3) The AMF can send an Nsmf_PDUSession_CreateSMContext request message or an Nsmf_PDUSession_UpdateSMContext request message to the selected SMF.

[0121] The Nsmf_PDUSession_CreateSMContext request message may include the Subscription Permanent Identifier (SUPI), DNN, S-NSSAI, PDU Session ID, AMF ID, Request Type, Policy Control Function (PCF) ID, Priority Access, N1 SM Container, User Location Information, Access Type, Permanent Device Identifier (PEI), General Public Subscription Identifier (GPSI), UE Presence in the LADN Service Area, Subscription to PDU Session State Notifications, DNN Selection Mode, and Tracking Request. The SM Container may include the PDU Session Establishment Request message.

[0122] The Nsmf_PDUSession_UpdateSMContext request message may include SUPI, DNN, S-NSSAI, 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 PDU session establishment request messages.

[0123] The AMF ID is used to identify the AMF of the serving UE. The N1 SM information may include a PDU session establishment request message received from the UE.

[0124] 4) The SMF sends a Subscriber Data Request message to the UDM. The Subscriber Data Request message may include the subscriber's permanent ID and DNN. The UDM can then send a Subscriber Data Response message to the SMF.

[0125] In step 3), when the request type indicates "existing PDU session", 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.

[0126] When the SMF has not yet retrieved the SM-related subscription data for the UE associated with the DNN, the SMF can request the subscription data.

[0127] Subscription data can include information about the authentication request type, authentication SSC mode, and default QoS profile.

[0128] The SMF can determine whether a UE request complies with user subscriptions and local policies. Alternatively, the SMF may reject a UE request via NAS SM signaling sent by the AMF (including the relevant SM rejection reason), and the SMF may notify the AMF that the PDU session ID needs to be considered for release.

[0129] 5) The SMF sends an Nsmf_PDUSession_CreateSMContext response message or an Nsmf_PDUSession_UpdateSMContext response message to the AMF.

[0130] The Nsmf_PDUSession_CreateSMContext response message may include a reason, the SM context ID, or the N1 SM container. The N1 SM container may include PDU session rejection.

[0131] In step 3), when the SMF receives the Nsmf_PDUSession_CreateSMContext request message and the SMF can handle the PDU session establishment request message, the SMF generates an SM context and sends the SM context ID to the AMF.

[0132] 6) Optionally perform secondary authentication / authorization.

[0133] 7a) When Dynamic Policy and Charging Control (PCC) is used in a PDU session, the SMF selects the PCF.

[0134] 7b) The SMF performs the SM policy association establishment process to establish an SM policy association with the PCF.

[0135] 8) When the request type in step 3) indicates "Initial Request", the SMF selects the SSC mode for the PDU session. If step 5) is not performed, the SMF can also select UPF. For request types IPv4 or IPv6, the SMF can assign an IP address / prefix to the PDU session.

[0136] 9) SMF performs the SM policy association modification process to provide information about the status of policy control request triggering.

[0137] 10) When the request type indicates “Initial Request”, the SMF initiates the N4 session establishment procedure using the selected UPF; otherwise, the SMF may initiate the N4 session modification procedure using the selected UPF.

[0138] 10a) The SMF sends an N4 session establishment / modification request message to the UPF. The SMF can also provide packet inspection, enforcement, and reporting rules to be installed in the UPF for the PDU session. When core network (CN) tunneling information is assigned to the SMF, CN tunneling information can be provided to the UPF.

[0139] 10b) The UPF can respond by sending an N4 session establishment / modification response message. When CN tunneling information is assigned by the UPF, it can be provided to the SMF.

[0140] 11) The SMF sends a Namf_Communication_N1N2MessageTransfer message to the AMF. The Namf_Communication_N1N2MessageTransfer message may include the PDU session ID, N2 SM information, and N1 SM container.

[0141] N2 SM information may include PDU session ID, QoS flow ID (QFI), QoS profile, CN tunnel information, S-NSSAI from NSSAI-enabled, Session-AMBR maximum bit rate, PDU session type, user plane security enforcement information, and UE integrity protection maximum data rate.

[0142] The N1 SM container can include PDU session establishment and acceptance messages.

[0143] The PDU session establishment accept message may include authorized QoS rules, SSC mode, S-NSSAI, and the assigned IPv4 address.

[0144] 12) The AMF sends an N2 PDU session request message to the RAN. This message may include N2 SM information and a NAS message. The NAS message may include the PDU session ID and a PDU session establishment acceptance message.

[0145] The AMF can send a NAS message that includes the PDU session ID and the PDU session establishment accept message. Additionally, the AMF includes the N2 SM information received from the SMF within an N2 PDU session request message, and then sends the N2 PDU session request message to the RAN.

[0146] 13) The RAN can perform specific signaling exchanges with the UE related to information received from the SMF.

[0147] The RAN also assigns RAN N3 tunnel information to the PDU session.

[0148] The RAN sends the NAS message provided in step 10) to the UE. The NAS message may include the PDU session ID and N1 SM information. The N1 SM information may include a PDU session establishment accept message.

[0149] The RAN sends a NAS message to the UE only when the necessary RAN resources are established and the RAN tunnel information is successfully assigned.

[0150] 14) The RAN sends an N2 PDU session response message to the AMF. This message may include the PDU session ID, reason, and N2 SM information. The N2 SM information may include the PDU session ID, (AN) tunnel information, and a list of allowed / denied QoS profiles.

[0151] - RAN tunnel information can correspond to the access network address of the N3 tunnel corresponding to the PDU session.

[0152] 15) The AMF can send an Nsmf_PDUSession_UpdateSMContext request message to the SMF. The Nsmf_PDUSession_UpdateSMContext request message can include N2 SM information. Here, the AMF can send the N2 SM information received from the RAN to the SMF.

[0153] 16a) When the N4 session for the PDU session has not been established, the SMF can initiate the N4 session establishment procedure together with the UPF. Otherwise, the SMF can use the UPF to initiate the N4 session modification procedure. The SMF can provide AN tunnel information and CN tunnel information. The CN tunnel information can be provided only if the SMF selects the CN tunnel information in step 8).

[0154] 16b) The UPF can send an N4 session modification response message to the SMF.

[0155] 17) The SMF sends an Nsmf_PDUSession_UpdateSMContext response message to the AMF.

[0156] When this procedure is completed, the AMF can send relevant events to the SMF.

[0157] 18) The SMF sends an Nsmf_PDUSession_SMContextStatusNotify message.

[0158] 19) The SMF sends information to the UE via the UPF. Specifically, in the case of PDU type IPv6, the SMF can generate an IPv6 router advertisement and send the IPv6 router advertisement to the UE via N4 and the UPF.

[0159] 20) When the PDU session establishment is unsuccessful during the procedure, the SMF notifies the AMF.

[0160] <PDU Session Modification Procedure>

[0161] There can be the following two types of PDU session establishment procedures.

[0162] - The PDU session establishment procedure initiated by the UE

[0163] - The PDU session establishment procedure initiated by the network. For this, the network can send a device trigger message to the UE's application.

[0164] Figure 6a and Figure 6b are signal flow diagrams showing exemplary PDU session modification procedures.

[0165] The PDU session can be established / managed based on the PDU session modification procedure.

[0166] The PDU session modification procedure can be initiated by the UE or by the network.

[0167] 1a) When initiated by the UE, the UE can 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, the PDU session ID, and information about the UE's maximum data rate for integrity protection. The PDU session modification request message may include the PDU session ID, packet filters, information about the requested QoS, 5G Session Management (5GSM) core network capabilities, and the number of packet filters. The UE's maximum data rate for integrity protection indicates the maximum data rate that the UE can support for UP integrity protection. The number of packet filters indicates the number of packet filters supported by the QoS rules.

[0168] The NAS message is sent to the appropriate AMF via the RAN based on the UE's location information. The AMF then sends an Nsmf_PDUSession_UpdateSMContext message to the SMF. This message may include the SM context ID and the N1 SM container. The N1 SM container may include a PDU session modification request message.

[0169] 1b) When initiated by a PCF in a network node, the PCF can notify the SMF of the policy change by initiating an SM policy association modification process.

[0170] 1c) When initiated by a UDM within a network node, the UDM can update the SMF's subscription data by sending a Nudm_SDM_Notification message. The SMF can then update the session management subscription data and send an ACK message to the UDM.

[0171] 1d) When initiated by an SMF in a network node, the SMF can trigger a QoS update.

[0172] When triggered according to steps 1a) to 1d), the SMF can execute the PDU session modification process.

[0173] 1e) When initiated by the AN within a network node, the AN can notify the SMF when the AN resource to which the QoS flow was mapped is released. The AN can send an N2 message to the AMF. The N2 message may include the PDU session ID and N2 SM information. The N2 SM information may include the QoS flow ID (QFI), user location information, and an indication that the QoS flow has been released. The AMF can send an Nsmf_PDUSession_UpdateSMContext message. This message may include the SM context ID and N2 SM information.

[0174] 2) The SMF can send reports about subscription events by executing the SM policy association modification process. This step can be skipped when the PDU session modification process is triggered by step 1b) or 1d). When dynamic PCC is not configured in the network, the SMF can apply internal policies to determine changes to the QoS profile.

[0175] When the PDU session modification only requires UPF operations, steps 3 to 7 described below may not be performed.

[0176] 3a) When initiated by the UE or AN, the SMF can respond to the AMF by sending the Nsmf_PDUSession_UpdateSMContext message. This message may include N2 SM information and an N2 SM container. The N2 SM information may include the PDU session ID, QFI, QoS profile, and session-AMBR. The N1 SM container may include PDU session modification commands. The PDU session modification commands may include the PDU session ID, QoS rules, QoS rule actions, QoS flow-level QoS parameters, and session-AMBR.

[0177] The N2 SM information may include information that the AMF needs to send to the AN. The N2 SM information may include QFI and QoS profiles to notify the AN that one or more QoS flows have been added or modified. When a PDU session modification is requested by a UE that has not yet established user plane resources, the aforementioned N2 SM information to be sent to the AN may include information about the establishment of user plane resources.

[0178] The N1 SM container can include PDU session modification commands sent by the AMF to the UE. These PDU session modification commands can include QoS rules and QoS flow-level QoS parameters.

[0179] 3b) When initiated by the SMF, the SMF may send a Namf_Communication_N1N2MessageTransfer message. This message may include N2 SM information and an N1 SM container. The N2 SM information may include the PDU session ID, QFI, QoS profile, and session-AMBR. The N1 SM container may include PDU session modification commands. The PDU session modification commands may include the PDU session ID, QoS rules, and QoS flow-level QoS parameters.

[0180] When the UE is in CM-IDLE state and Asynchronous Type Communication (ATC) is activated, the AMF can update and store the UE context based on the Namf_Communication_N1N2MessageTransfer message, and steps 3) to 7) described below can be skipped. When the UE enters a reachable state (i.e., when the UE enters the CM-CONNECTED state), the AMF can send an N1 message to synchronize the UE and the UE context.

[0181] 4) The AMF can 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 the PDU session ID and an N1 SM container. The N1 SM container may include a PDU session modification command.

[0182] 5) The AN performs AN signaling exchanges with the UE associated with information received from the SMF. For example, in the case of NG-RAN, a UE and RRC connection reconfiguration procedure can be performed to modify the necessary AN resources associated with the PDU session.

[0183] 6) The AN responds to the received N2 PDU session request by sending an N2 PDU session ACK message. 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 ID, etc.

[0184] 7) The AMF sends the N2 SM information and user location information received from the AN to the SMF via the Nsmf_PDUSession_UpdateSMContext message. Then, the SMF sends the Nsmf_PDUSession_UpdateSMContext message to the AMF.

[0185] 8) The SMF sends an N4 session update request message to the UPF to update the N4 session of the UPF included in the PDU session update.

[0186] When a new QoS flow is generated, the SMF and UPF update the uplink packet detection rules for the new QoS flow together.

[0187] 9) The UE sends a NAS message in response to receiving a PDU session modification command. The NAS message may include the PDU session ID and the N1 SM container. The N1 SM container may include the PDU session modification command ACK.

[0188] 10) AN sends a NAS message to AMF.

[0189] 11) The AMF can send the N1 SM container and user location information received from the AN to the SMF via the Nsmf_PDUSession_UpdateSMContext message. The N1 SM container may include the PDU session modification command ACK. The SMF can send an Nsmf_PDUSession_UpdateSMContext response message to the AMF.

[0190] 12) The SMF sends an N4 session modification request message to the UPF to update the UPF's N4 session included in the PDU session modification. This message may include the N4 session ID.

[0191] 13) When the SMF interacts with the PCF in step 1b) or 2), the SMF can notify the PCF whether the PCC decision can be executed through the SM policy association modification process.

[0192] SMF can notify entities that request user location information associated with a PDU session change.

[0193] A. Coordination between 5GSM using the N26 interface and EPS Session Management (ESM)

[0194] a) The PDU session type of a PDU session is mapped to the PDN type carried by the default Evolved Packet System (EPS) as follows.

[0195] a-1) When the PDU session type is "unstructured", the PDN type is set to "non-IP".

[0196] a-2) When the PDU session type is “IPv4”, the PDN type is set to “IPv4”.

[0197] a-3) When the PDU session type is “IPv6”, the PDN type is set to “IPv6”.

[0198] a-4) When the PDU session type is “IPv4v6”, the PDN type is set to “IPv4v6”.

[0199] a-5) When the PDU session type is “Ethernet” and neither the UE nor the network supports the Ethernet PDN type in S1 mode, or when neither the UE nor the network supports the Ethernet PDN type in S1 mode, the PDN type is set to “Non-IP”.

[0200] a-6) When the PDU session type is “Ethernet” and both the UE and the network support the Ethernet PDN type in S1 mode, the PDN type is set to “Ethernet”.

[0201] b) The PDU address of the PDU session is mapped to the PDN address of the default EPS bearer as follows.

[0202] b-1) When the PDU session type is “IPv4”, “IPv6” or “IPv4v6”, the default PDN address of the EPS bearer context is set to the PDU address of the PDU session.

[0203] b-2) When the PDU session type is “Ethernet” or “Unstructured”, the PDN address of the default EPS bearer context is set to 0 (zero).

[0204] B. PDU Session Type

[0205] The following PDU session types are supported.

[0206] IPv4; IPv6; IPv4v6; Ethernet (the Ethernet type defined in IEEE Std 802.3 [31A]); and Unstructured.

[0207] C. IP address assignment via NAS signaling

[0208] When a UE requests an IP connection, the UE can set the PDU session type in the PDU session modification request message as follows, based on its IP stack capabilities.

[0209] a) UE can: 1) When both IPv6 and IPv4 are available, the PDU session type is set to IPv4, IPv6, or IPv4v6 according to the UE configuration or the received policy.

[0210] 2) When only IPv6 is available, set the PDU session type to IPv6.

[0211] 3) When only IPv4 is available, set the PDU session type to IPv4.

[0212] b) When the IP version capability within the UE is unknown (in cases where the mobile terminal (MT) and terminal equipment (TE) are separate and the capability of the TE is unknown to the MT), the UE can set the PDU session type to IPv4v6.

[0213] When a UE intends to use DHCPv4 for IPv4 address assignment, the UE can notify the network by using the Extended Protocol Configuration Options Information Element (IE) in the PDU Session Modification Request message.

[0214] When a PDU session modification request message is sent by a UE, the network can assign an IP address by considering the PDU session type, network operator policy, and the UE's subscription information.

[0215] a) When the network sets the selected PDU session type IE to IPv4, the network may include the IPv4 address in the PDU address IE.

[0216] b) When the network sets the selected PDU session type IE to IPv6, the network may include an interface identifier for the IPv6 link-local address in the PDU address IE.

[0217] c) When the network sets the selected PDU session type IE to IPv4v6, the network may include both the IPv4 address and the interface identifier for the IPv6 link-local address in the PDU address IE.

[0218] D. PDU session modification procedure requested by UE

[0219] D-1. Initiation of the PDU session modification procedure requested by the UE

[0220] To enable a UE to request PDU session modification, the UE-requested PDU session modification procedure can be used.

[0221] In order for the UE to initiate the PDU session modification process, the UE generates a PDU session modification request message.

[0222] When a UE requests to establish a new emergency PDU session, the UE includes the PDU session type IE in the PDU session modification request message and sets the IP version capability.

[0223] When the UE supports reflection QoS, the UE can set the RQoS bit in the 5GSM capability IE of the PDU session modification request message to "Support reflection QoS".

[0224] a) The UE may request a new PDU session to modify the “IPv4”, “IPv6”, “IPv4v6” or “Ethernet” PDU session type.

[0225] b) When the UE requests to send an existing PDN connection of type "IPv4", "IPv6", "IPv4v6" or "Ethernet" PDN within the EPS, or an existing PDN connection of type "non-IP" PDN within the EPS mapped to an "Ethernet" PDU session type, to the 5GS, or

[0226] c) When a request is sent to 5GS to an existing PDN connection within an untrusted non-3GPP access to an EPC of type "IPv4", "IPv6", or "IPv4v6" PDN, Regarding PDU connections established in S1 mode, after a system change from S1 mode to N1 mode, when the UE operates in single-registration mode in a network supporting the N26 interface, when the UE supports receiving DNS server addresses in the protocol configuration options, and when the UE has not previously successfully executed a PDU session modification procedure requested by the UE to support this function, the UE may include the following in the extended protocol configuration option IE in the PDU session modification request message.

[0227] a) When the PDU session is of type “IPv4” or “IPv4v6”, the UE may include a request for the IPv4 address of the DNS server.

[0228] b) When the PDU session is of type “IPv6” or “IPv4v6”, the UE may include a request for the IPv6 address of the DNS server.

[0229] D-2. When the PDU session modification procedure requested by the UE is accepted by the network.

[0230] When a PDU session modification procedure requested by the UE is accepted by the network, the SMF initiates a PDU session modification procedure requested by the network. To this end, the SMF generates a PDU session modification request message.

[0231] SMF sets the selected PDU session type IE in the PDU session modification request message to the selected PDU session type, that is, the PDU session type of the PDU session.

[0232] D-3. When the PDU session modification procedure requested by the UE is not accepted by the network.

[0233] When the requested DN connection is rejected by the network, the SMF generates a PDU session modification rejection message.

[0234] To indicate the reason for rejecting PDU session modification, SMF can set the 5GSM reason IE in the PDU session modification rejection message.

[0235] The 5GSM cause IE can represent one of the following SM cause values.

[0236] #8: Prohibitions determined by the operator; #26 Insufficient resources; #27 DNN missing or unknown; #28 Unknown PDU session type; #29 User authentication or authorization failed; #31 Request denied (unspecified); #32 Service option is not supported; #33 The requested service option is not subscribed to; #35 The Process Transaction Identifier (PTI) is already in use; #38 Network failure; #39 Requesting reactivation; #50 Only PDU session type IPv4 is allowed; #51 Only PDU session type IPv6 is allowed; #54 PDU session does not exist; #57: Only PDU session type IPv4v6 is allowed; #58: Only allow untrusted PDU session types; #61: Only Ethernet PDU session types are allowed; #67: Insufficient resources for specific slices and DNNs; #68: SSC mode is not supported; #69: Insufficient resources for a specific slice.

[0237] When a PDU session modification request message includes a PDU session type IE set to IPv6, and the subscriber information or SMF settings, or both the subscriber information and SMF settings, are restricted to IPv4 only for the requested DNN, the SMF may include the 5GSM reason value #50 "IPv4 only allowed" in the 5GSM reason IE of the PDU session modification rejection message.

[0238] When a PDU session modification request message includes a PDU session type IE set to IPv6, and the subscriber information or SMF settings, or both the subscriber information and SMF settings, are restricted to not supporting “IPv4” PDU session types and “IPv6” PDU session types for the requested DNN, the SMF may include the 5GSM reason value #28 “Unknown PDU session type” in the 5GSM reason IE of the PDU session modification rejection message.

[0239] When a PDU session modification request message includes a PDU session type IE set to "IPv4", and the subscriber information or SMF settings, or both the subscriber information and SMF settings, are restricted to allow only IPv6 for the requested DNN, the SMF may include the 5GSM reason value #51 "Allow only PDU session type IPv6" in the 5GSM reason IE of the PDU session modification rejection message.

[0240] When a PDU session modification request message includes a PDU session type IE set to "IPv4", and the subscriber information or SMF settings, or both the subscriber information and SMF settings, do not support both the "IPv4" session type and the "IPv6" PDU session type for the requested DNN, the SMF may include the 5GSM reason value #28 "Unknown PDU session type" in the 5GSM reason IE of the PDU session modification rejection message.

[0241] When a PDU session modification request message includes a PDU session type IE set to "IPv4v6", and the subscriber information or SMF setting, or both the subscriber information and SMF setting, do not support the "IPv4v6" PDU session type, "IPv4" session type, and "IPv6" PDU session type for the requested DNN, the SMF may include the 5GSM reason value #28 "Unknown PDU session type" in the 5GSM reason IE of the PDU session modification rejection message.

[0242] When a PDU session modification request message includes a PDU session type IE set to "unstructured" or "Ethernet", and the subscriber information or SMF settings, or both the subscriber information and SMF settings, do not support the PDU session type for the requested DNN, the SMF may include the 5GSM reason value #28 "Unknown PDU session type" in the 5GSM reason IE of the PDU session modification rejection message.

[0243] When a PDU session modification request message is intended to establish an MA PDU session, and when the PDU session modification request message includes a PDU session type IE that is set to "unstructured", and when the SMF is set to not support the PDU session type, the SMF may include the 5GSM reason value #28 "unknown PDU session type" in the 5GSM reason IE of the PDU session modification rejection message.

[0244] The network can modify the rejection message in the PDU session to include the backoff timer value IE.

[0245] When the 5GSM reason value is #50 "Only allow PDU session type IPv4", #51 "Only allow PDU session type IPv6", #57 "Only allow PDU session type IPv4v6", #58 "Only allow unstructured PDU session type", or #61 "Only allow Ethernet PDU session type", the network may include a retry indicator without a backoff timer value to indicate whether the UE is allowed to attempt the PDU session modification process in the equivalent PLMN in N1 mode using the same PDU session type for the same DNN and the same S-NSSAI.

[0246] SMF can send a PDU session modification rejection message.

[0247] When the UE receives a PDU session modification rejection message and PDU session ID through the NAS transmission process, the UE can stop timer T3580, release the assigned PTI value, and consider that the PDU session has not yet been established.

[0248] When the 5GSM reason value is #28 "Unknown PDU session type" and the PDU session modification request message includes a PDU session IE indicating the PDU session type, the UE can ignore the backoff timer value IE and retry indicator provided by the network. The UE can send another PDU session modification request message to establish a new PDU session using a PDU session type IE indicating a different PDU session type.

[0249] When the 5GSM reason value is #50 "Only allow PDU session type IPv4", #51 "Only allow PDU session type IPv6", #57 "Only allow PDU session type IPv4v6", #58 "Only allow unstructured PDU session type", or #61 "Only allow Ethernet PDU session type", the UE can ignore the backoff timer value IE provided by the network. The UE can evaluate the available USRP rules. The UE may not immediately send different PDU session modification request messages for the same DNN and the same HPLMN S-NSSAI to obtain a PDU session type different from the PDU session type allowed by the network, until one of the following conditions is met.

[0250] a) When a UE registers to a new PLMN that is not in the equivalent PLMN list upon receiving a PDU session modification rejection message; b) When a UE registers to a new PLMN in the equivalent PLMN list upon receiving a PDU session modification rejection message, when the network does not include a retry indicator in the PDU session modification rejection message, or when the network does not include a retry indicator in the message indicating that retry is allowed in the equivalent PLMN; c) When the UE is turned off; or d) When the USIM is removed, or when the UE does not support access to the SNPN and the entry in the "Subscriber Data List" of the current SNPN is updated, or when the UE supports access to the SNPN but the entry in the "Subscriber Data List" is updated.

[0251] For 5GSM cause values ​​#50 "Only allow PDU session type IPv4", #51 "Only allow PDU session type IPv6", #57 "Only allow PDU session type IPv4v6", #58 "Only allow unstructured PDU session type", and #61 "Only allow Ethernet PDU session type", the UE can ignore the value of the Radio Access Technology Change (RATC) bit in the retry indicator IE provided by the network.

[0252] Network Slicing

[0253] Figure 7 This is an exemplary view used to describe the concept of network slicing.

[0254] Network slicing refers to dividing a single physical network into multiple virtual networks. Each segmented network can operate in a customized and optimized manner for specific application services or subscriber types. Based on cloud computing and virtualization technologies, shared physical network resources can be dynamically and efficiently scheduled to logical network slices to meet ever-changing user needs.

[0255] A 5G network slice consists of a set of network functions and configurations for a specific use case or business model. Referring to Figure 5, an example of a 5G network slice is shown, where network slice 1 uses enhanced mobile broadband (eMBB), network slice 2 uses vehicle-to-everything (V2X), and network slice 3 uses massive IoT (MIoT).

[0256] A single network slice can span multiple domains, including radio access networks operating on distributed cloud infrastructure and transport networks, as well as the core network. The fundamental principle of 5G network slicing design is to provide only the customized capabilities required to handle specific use cases. Network slices have the ability to adapt to changing needs along with the necessary customization capabilities.

[0257] Furthermore, according to the definition of Next Generation Mobile Networks (NGMN), network slicing consists of three layers: the service instance layer, the network slice instance layer, and the resource layer. The service instance layer represents end-user services, with each service represented by a service instance. The network slice service instance layer includes the provided network slice instances and, as network slice instances, provides the network characteristics required to serve those instances. The resource layer provides all the virtual or physical resources and network functions needed to generate network slice instances.

[0258] In the current 3GPP 5G mobile networks developed by the Internet Engineering Task Force (IETF) Deterministic Networking (DetNet) working group, network slicing operates based on the Network Coverage Instance (CN), but is essentially based on network slice instance information. A network slice instance refers to information about a set of resources and network function instances required to form a network slice. A single network slice can be used throughout the Public Land Mobile Network (PLMN) or across one or more Tracking Areas (TAs). A single network slice instance can be associated with one or more S-NSSAIs, and conversely, a single S-NSSAI can be associated with one or more network slice instances.

[0259] In 3GPP 5G mobile networks, a single network slice is identified by a single S-NSSAI. The S-NSSAI consists of a Slice / Service Type (SST) and a Slice Distinguisser (SD), and the SST must be included in the S-NSSAI, but the SD can be optionally included or omitted. Currently, as shown in Table 2, a total of six SST types and values ​​are defined as standards in the 3GPP technical specifications.

[0260] [Table 2]

[0261] Furthermore, a collection of one or more S-NSSAIs is referred to as an NSSAI. During the registration process of a 5G mobile communication network, the terminal uses NSSAIs to request network slice connections from the CN, and the CN is responsible for authenticating and authorizing such network slice connection requests from the terminal. The terminal can be configured with or can store various types of NSSAIs provided from the 5G core network. A configuration NSSAI is an NSSAI configured by receiving NSSAIs from the serving PLMN; a default configuration NSSAI is an NSSAI configured by receiving NSSAIs from the home PLMN; and a request NSSAI is an NSSAI used when the terminal requests to connect to a specific network slice of the CN. An allow NSSAI is an NSSAI that instructs the CN to allow the terminal to connect to a specific network slice. Additionally, a subscription S-NSSAI refers to the S-NSSAI included in the subscriber information. The terminal's default configuration NSSAI can be configured by being pre-configured and stored, provided by the CN, or updated. Each S-NSSAI in the default configuration NSSAI corresponds to an S-NSSAI in the subscriber NSSAI. The S-NSSAI in the terminal's requested NSSAI refers to the S-NSSAI in the NSSAI pre-configured or permitted in the network. Ultimately, the NSSAI or S-NSSAI typically used by the terminal refers to the NSSAI or S-NSSAI pre-configured or permitted in the network.

[0262] Furthermore, terminals and 5G mobile networks essentially receive or use NSSAIs during the registration process to support and manage network slice connections. First, terminals typically have a pre-configured and stored configuration NSSAI, as well as an allowed NSSAI pre-permitted by the network. An allowed NSSAI may not exist if no pre-permitted NSSAI is available. To request a connection to a specific network slice, the terminal sends a registration request message to the network during the registration process, including a requested NSSAI. In this case, the requested NSSAI refers to the use of the default configuration NSSAI when neither the configuration NSSAI nor the allowed NSSAI is stored in the terminal (i.e., when no available NSSAI is available). When the allowed NSSAI is not stored and the available configuration NSSAI is stored, the configuration NSSAI is used as the requested NSSAI. Finally, when the available allowed NSSAI is stored, the allowed NSSAI is used as the requested NSSAI. After checking the requested NSSAI included in the registration request message sent by the terminal, the CN responds to the terminal by including the configuration NSSAI, allowed NSSAI, and rejected NSSAI in the registration acceptance message. The terminal stores the configuration NSSAI, allow NSSAI, and deny NSSAI provided in the registration acceptance message sent via the network, and uses these NSSAIs when subsequently requesting network slice connections. However, since deny NSSAIs are NSSAIs that have been rejected by the network, the terminal generally does not use deny NSSAIs. Through the registration request process, the terminal and the network mutually provide NSSAIs for supporting and managing network slice connections, thereby managing the configuration.

[0263] When a terminal sends a PDU session establishment request message to the network for data transmission, the terminal includes the S-NSSAI corresponding to the network slice that the application intends to connect to in relation to the data transmission from the stored allowed NSSAIs, and sends the message to the network. The network checks the S-NSSAI included in the PDU session establishment request message sent by the terminal, and if no problem is found, the network responds by accepting.

[0264] Additionally, when network slicing information, including NSSAI, changes due to subscriber information or mobile network policies, the network can notify the terminal of the changed NSSAI. In this case, the network can provide the terminal with the changed NSSAI through the general terminal configuration update procedure. For this purpose, the AMF sends a configuration update command message to the terminal, including configuring NSSAI, allowing NSSAI, and denying NSSAI. The terminal then updates and stores the received configuration, allow, and deny NSSAI information. Subsequently, the terminal uses the changed NSSAI to execute a network slicing connection request.

[0265] Furthermore, the recent 3GPP Release 18 specification defines an alternative S-NSSAI, which refers to an S-NSSAI (e.g., S-NSSAI #2) that is compatible with or can replace the S-NSSAI (e.g., S-NSSAI #1) when the S-NSSAI (e.g., S-NSSAI #1) becomes unavailable or congested. When the S-NSSAI (e.g., S-NSSAI #1) becomes unavailable or congested in the network, a compatible or alternative S-NSSAI (i.e., the alternative S-NSSAI) is provided to the terminal for updating. In this case, the terminal can be updated by providing the alternative S-NSSAI using the general UE configuration update procedure.

[0266] On the other hand, 3GPP Release 18 defines partially allowed NSSAI, and the existing allowed NSSAI refers to an NSSAI where the network (AMF and / or SMF) informs that the network slice service associated with the NSSAI requested by the terminal is permitted in the registered area where the terminal is registered. In this case, the allowed NSSAI is applied to the PLMN or all TA lists within the terminal's registered area. Conversely, partially allowed NSSAI is applied to the PLMN or some TA lists within the terminal's registered area. Therefore, in some TAs within the registered area, the network slice service associated with the partially allowed NSSAI (e.g., partially allowed NSSAI #1—actually a specific S-NSSAI #1) is permitted, while in other TAs, the network slice service associated with the partially allowed NSSAI (e.g., partially allowed NSSAI #1—actually a specific S-NSSAI #1) is not permitted. This partially allowed NSSAI is provided and updated through the registration process or the general UE configuration update process.

[0267] In addition, to support low-latency services in 5G systems, always-on PDU sessions for fast data transmission and reception are supported. For always-on PDU sessions, terminals can configure access category information differently for each session to support unified access control from general PDU sessions. Furthermore, when a terminal configures a PDU session for time synchronization or time-sensitive communication (TSC) to support low-latency services in 5G systems, the terminal configures the PDU session as an always-on PDU session and manages it. When an application of a terminal receiving low-latency services requests PDU session establishment from the network to send and receive data, the terminal sends a PDU session establishment request NAS message to the network. This message includes "Request Always-On PDU Session" information indicating a request for an always-on PDU session. The network supporting always-on PDU sessions responds by sending a PDU session establishment acceptance NAS message to the terminal. This message includes "Always-On PDU Session Required" information indicating the establishment of the always-on PDU session. Subsequently, the terminal and network maintain and manage the user plane resources and context information of the corresponding PDU session until the terminal switches to idle mode or releases the configured PDU session. Additionally, always-on PDU session modification requests are applied in the same way to PDU session modification requests. Furthermore, when the terminal does not support always-on PDU session establishment requests, the network may reject the terminal's always-on PDU session establishment request. When a terminal application requests PDU session establishment from the network to send and receive data, if the terminal sends a PDU session establishment request NAS message to the network including information indicating a always-on PDU session request, the network that does not support always-on PDU sessions responds by sending a PDU session establishment acceptance NAS message to the terminal including information indicating that always-on PDU sessions are not allowed.

[0268] <PDU Session Handling Using Modified NSSAI>

[0269] When network slice information changes as described above, the timing of the network's execution of the general UE configuration update process is not clearly defined in the current 3GPP standard specifications. Specifically, when a partial NSSAI is generated or modified in a 3GPP network according to operator policy or network configuration, the corresponding partial NSSAI is provided to the terminal and updated. These updates are performed through a registration process or a general UE configuration update process. However, because the timing of the network-executed general UE configuration update process is not clearly defined in the 3GPP technical specifications, the following problematic scenarios may occur.

[0270] 1) Both the terminal and the network are configured to support partial NSSAI, and a Network Slice Service Area (NoS) is deployed based on this.

[0271] 2) When both the terminal and the network are configured to support partial NSSAI, the partial NSSAI permission within the network is modified.

[0272] 3) Since the terminal has not yet been updated with the changed information, it is unaware of the changes and moves to a TA / cell that does not support the (newly changed) NoS, and performs PDU session establishment / modification. (A partial NSSAI mismatch occurs between the terminal and the network.)

[0273] 4) Although NSSAI has been partially changed, 3GPP does not describe a clear handling method for how the network should respond to a terminal's request when the terminal is unaware of this change and moves to a TA / cell area that does not support the (newly changed) NoS and performs a PDU session establishment / modification.

[0274] Specifically, always-on PDU sessions are critical PDU sessions that, once configured, need to remain active until the session is released to provide URLLC services (such as TSC and TSN). The 3GPP technical specifications do not clearly define how to handle always-on PDU sessions in the aforementioned technical context.

[0275] Therefore, prior to allowing NSSAI updates using changes provided by the network, there is no processing mechanism specified in the current 3GPP specification when a terminal performs a PDU session establishment request procedure and / or PDU session modification request procedure associated with an always-on PDU session based on a previously problematic NSSAI (i.e., an S-NSSAI set associated with an area that does not support NoS).

[0276] When the network rejects the terminal's PDU session establishment request and / or PDU session modification request procedures, URLLC-related services may not be available due to the characteristics of always-on PDU sessions. Furthermore, according to the current behavior defined in the 3GPP specification, the terminal cannot determine whether the rejection is due to the network's lack of support for always-on PDU sessions or due to a problem with partially enabled NSSAI information. Therefore, the terminal may repeatedly and inefficiently attempt to perform the PDU session establishment request and / or PDU session modification request procedures with the network.

[0277] In summary, when a terminal executes the PDU session establishment request process and / or PDU session modification request process associated with the always-on PDU session before completing the partial NSSAI accurate update (synchronization) process between the terminal and the network, problems such as URLLC service connectivity degradation due to inefficient operation, increased signaling overhead, and resource waste may occur. Therefore, this specification proposes an efficient and clear solution to the above problems.

[0278] First Public Content

[0279] 1) Partial allowable NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) accordingly receives the newly changed / updated partial allowable NSSAI (e.g., partial allowable NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (i.e., S-NSSAI#3 and NS-AoS#3 information)) from NSSF.

[0280] 2) If the terminal has not yet received a partially allowed NSSAI (and / or NS-AoS) from the network (that is, it is unaware that a partially allowed NSSAI is unavailable or has been changed (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)), the terminal sends a PDU session establishment request message associated with an always-on PDU session to the network based on the partially allowed NSSAI (e.g., partially allowed NSSAI#1). In this case, the terminal sends a PDU session establishment request message to the network that includes the information "requesting an always-on PDU session".

[0281] 3) The network identifies that the PDU session establishment request sent by the terminal is a PDU session establishment request associated with an unavailable or modified partially allowed NSSAI (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)) and that execution is not possible. Therefore, the network responds to the terminal with a PDU session establishment rejection message. In this case, a PDU session establishment rejection message may be sent including information such as "BO timer with partially allowed NSSAI#1 and / or (new / updated) partially allowed NSSAI (e.g., partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) and / or 5GSM reason value (new #wx "partial NSSAI not allowed" or "network slice service area not allowed")".

[0282] 4) When a BO timer with "partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)" is received, the terminal that has received a PDU session establishment rejection message from the network activates the corresponding BO timer. In this case, the terminal does not execute a PDU session establishment request based on partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information) before the BO timer expires. When a (new / updated) partially allowed NSSAI (e.g., partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) is provided, the terminal replaces / updates the existing partially allowed NSSAI#1 with partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information). Subsequently, the terminal performs a new PDU session establishment request procedure with the network based on the replaced / updated partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information). In this scenario, the terminal sends a PDU session establishment request message to the network, including the information "Request Always-On PDU Session," to establish an always-on PDU session. Finally, the network, which supports always-on PDU sessions, accepts the PDU session establishment request sent by the terminal based on partially enabled NSSAI#2, including the "Request Always-On PDU Session" information, and responds to the terminal with a PDU session establishment acceptance message including an indication that "Always-On PDU Session Required." Thus, a service based on always-on PDU sessions is provided.

[0283] Second public disclosure

[0284] 1) Partial allowable NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) accordingly receives the newly changed / updated partial allowable NSSAI (e.g., partial allowable NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (i.e., S-NSSAI#3 and NS-AoS#3 information)) from NSSF.

[0285] 2) If the terminal has not yet received a partially allowed NSSAI (and / or NS-AoS) from the network (that is, if an unavailable or modified partially allowed NSSAI is not identified (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)), the terminal sends a PDU session establishment request message associated with the partially allowed NSSAI (e.g., partially allowed NSSAI#1) to the network. In this case, the terminal sends a PDU session establishment request message to the network that includes the information "Request always-on PDU session".

[0286] 3) The network identifies that the PDU session establishment request sent by the terminal is a PDU session establishment request associated with an unavailable or modified partially allowed NSSAI (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)) and that execution is not possible. Therefore, the network responds to the terminal with a PDU session establishment rejection message. In this case, a PDU session establishment rejection message may be sent including information about "BO timer with partially allowed NSSAI#1 and / or 5GSM reason value (new #wx "partial NSSAI not allowed" or "network slice service area not allowed")".

[0287] 4) The network already has newly modified / updated partially permitted NSSAI (e.g., partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partially tracked area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (i.e., S-NSSAI#3 and NS-AoS#3 information)), and as described above in 3), it identifies that the PDU session establishment request sent by the terminal is associated with an unavailable or modified partially permitted NSSAI (e.g., partially permitted NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)). Therefore, the network can determine that the terminal is attempting to perform the PDU session establishment request procedure based on incorrect information (e.g., partially permitted NSSAI#1). Therefore, after sending a PDU session establishment rejection message to the terminal as described above in 3), the network immediately sends a configuration update command (i.e., general UE configuration update procedure) message to the terminal. In this case, the network sends new changes / updates to the partially permitted NSSAI (e.g., partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partially tracked area identifier list #2 information)).

[0288] 5) When a BO timer with "partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)" is received, the terminal that has received a PDU session establishment rejection message from the network activates the corresponding BO timer. In this case, the terminal does not perform a PDU session establishment request based on partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information) before the BO timer expires. When a configuration update command (i.e., a general UE configuration update procedure message) is received from the network, when the terminal receives a newly changed / updated partially allowed NSSAI (e.g., partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)), the terminal replaces / updates the existing partially allowed NSSAI#1 with partially allowed NSSAI#2. Then, the terminal performs a new PDU session establishment request procedure with the network based on the replaced / updated partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information). In this scenario, the terminal sends a PDU session establishment request message to the network, including the information "Request Always-On PDU Session," to establish an always-on PDU session. Finally, the network, which supports always-on PDU sessions, accepts the PDU session establishment request sent by the terminal based on partially enabled NSSAI#2, including the "Request Always-On PDU Session" information, and responds to the terminal with a PDU session establishment acceptance message including an indication that "Always-On PDU Session Required." Thus, a service based on always-on PDU sessions is provided.

[0289] Third Public Content

[0290] 1) The partial allowable NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) accordingly receives the newly changed / updated partial allowable NSSAI (e.g., partial allowable NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (i.e., S-NSSAI#3 and NS-AoS#3 information)) from the NSSF. Additionally, the terminal configures and maintains an always-on PDU session based on the unavailable or changed partial allowable NSSAI (e.g., partial allowable NSSAI#1). (The UE has an existing always-on PDU session associated with partial allowable NSSAI#1.)

[0291] 2) If the terminal has not yet received a partially allowed NSSAI (and / or NS-AoS) from the network (that is, if an unavailable or modified partially allowed NSSAI is not identified (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)), the terminal sends a PDU session modification request message associated with the partially allowed NSSAI (e.g., partially allowed NSSAI#1) to the network. In this case, the terminal sends a PDU session modification request message to the network that includes the information "requesting an always-online PDU session".

[0292] 3) The network identifies that the PDU session modification request sent by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)) and that execution is not possible. Therefore, the network responds to the terminal with a PDU session modification rejection message. In this case, a PDU session modification rejection message may be sent including information such as "BO timer with partially allowed NSSAI#1 and / or (new / updated) partially allowed NSSAI (e.g., partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) and / or 5GSM reason value (new #wx "partial NSSAI not allowed" or "network slice service area not allowed")".

[0293] 4) The network already has newly changed / updated partially permitted NSSAI (e.g., partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partially tracked area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (i.e., S-NSSAI#3 and NS-AoS#3 information)), and as described above in 3), it identifies that the PDU session modification request sent by the terminal is associated with an unavailable or changed partially permitted NSSAI (e.g., partially permitted NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)). Therefore, the network can determine that the terminal is attempting to perform the PDU session modification request process based on incorrect information (e.g., partially permitted NSSAI#1).

[0294] 5) When a terminal that has received a PDU session modification rejection message from the network activates the corresponding BO timer after receiving a "BO timer with partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)", the terminal will not execute a PDU session establishment request based on partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information) before the BO timer expires.

[0295] Subsequently, when the terminal receives a newly changed / updated partially permitted NSSAI (e.g., partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) via a PDU session modification rejection message from the network, the terminal replaces / updates the existing partially permitted NSSAI#1 with the partially permitted NSSAI#2, and can then perform a new PDU session establishment request procedure with the network based on the replaced / updated partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information). (Always-on PDU session reactivation using an alternative S-NSSAI for always-on PDU sessions) In this case, the terminal sends a PDU session establishment request message to the network including "request PDU session" information to establish an always-on PDU session. Finally, the network supporting always-on PDU sessions accepts the PDU session establishment request sent by the terminal based on partially permitted NSSAI#2, including "request always-on PDU session" information, and responds to the terminal with a PDU session establishment acceptance message including an indication that "always-on PDU session required". Therefore, a service based on always-on PDU sessions is provided.

[0296] Fourth public content

[0297] 1) The partial allowable NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) accordingly receives the newly changed / updated partial allowable NSSAI (e.g., partial allowable NSSAI#2 (in practice, S-NSSAI#2 and partial tracking area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (in practice, S-NSSAI#3 and NS-AoS#3 information)) from the NSSF. Additionally, the terminal configures and maintains an always-on PDU session based on the unavailable or changed partial allowable NSSAI (e.g., partial allowable NSSAI#1). (The UE has an existing always-on PDU session associated with partial allowable NSSAI#1.)

[0298] 2) If the terminal has not yet received a partially allowed NSSAI (and / or NS-AoS) from the network (that is, if an unavailable or modified partially allowed NSSAI is not identified (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)), the terminal sends a PDU session modification request message associated with the partially allowed NSSAI (e.g., partially allowed NSSAI#1) to the network. In this case, the terminal sends a PDU session modification request message to the network that includes the information "requesting an always-online PDU session".

[0299] 3) The network identifies that the PDU session modification request sent by the terminal is related to a partially allowed NSSAI (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information) that is unavailable or changed, and that execution is not possible. Therefore, the network responds to the terminal with a PDU session modification rejection message. In this case, a PDU session modification rejection message may be sent including information about "BO timer with partially allowed NSSAI#1 and / or 5GSM reason value (new #wx "partial NSSAI not allowed" or "network slice service area not allowed")".

[0300] 4) The network already has newly modified / updated partially permitted NSSAI (e.g., partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partially tracked area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (i.e., S-NSSAI#3 and NS-AoS#3 information)), and as described above in 3), it identifies that the PDU session modification request sent by the terminal is associated with an unavailable or modified partially permitted NSSAI (e.g., partially permitted NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)). Therefore, the network can determine that the terminal is attempting to perform the PDU session modification request procedure based on incorrect information (e.g., partially permitted NSSAI#1). Therefore, after sending a PDU session modification rejection message to the terminal as described above in 3), the network immediately sends a PDU session modification command (i.e., a network-requested PDU session modification procedure message) to the terminal. In this case, the network sends new changes / updates to the partially permitted NSSAI (e.g., partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partially tracked area identifier list #2 information)).

[0301] 5) When a "BO timer with partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)" is received, the terminal that has received the PDU session modification request message from the network activates the corresponding BO timer. In this case, the terminal does not execute the PDU session modification request based on partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information) before the BO timer expires.

[0302] Subsequently, when the terminal receives a newly changed / updated partially permitted NSSAI (e.g., partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) via a PDU session modification command message from the network, the terminal replaces / updates the existing partially permitted NSSAI#1 with the partially permitted NSSAI#2, and can then perform a new PDU session establishment request procedure with the network based on the replaced / updated partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information). (This is a reactivation of the always-on PDU session using the alternative S-NSSAI for always-on PDU sessions.) In this case, the terminal sends a PDU session establishment request message to the network including "request PDU session" information to establish an always-on PDU session. Finally, the network supporting always-on PDU sessions accepts the PDU session establishment request sent by the terminal based on partially permitted NSSAI#2, including "request always-on PDU session" information, and responds to the terminal with a PDU session establishment acceptance message including an indication that "always-on PDU session is required." Therefore, a service based on always-on PDU sessions is provided.

[0303] Fifth public content

[0304] 1) The partial allowable NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) accordingly receives the newly changed / updated partial allowable NSSAI (e.g., partial allowable NSSAI#2 (in practice, S-NSSAI#2 and partial tracking area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (in practice, S-NSSAI#3 and NS-AoS#3 information)) from the NSSF. Additionally, the terminal configures and maintains an always-on PDU session based on the unavailable or changed partial allowable NSSAI (e.g., partial allowable NSSAI#1). (The UE has an existing always-on PDU session associated with partial allowable NSSAI#1.)

[0305] 2) If the terminal has not yet received a partially allowed NSSAI (and / or NS-AoS) from the network (that is, if an unavailable or changed partially allowed NSSAI is not identified (e.g., partially allowed NSSAI#1 (in practice, S-NSSAI#1 and partially tracked area identifier list #1 information)), the UE sends a PDU session modification request message associated with the partially allowed NSSAI (e.g., partially allowed NSSAI#1) to the network. In this case, the terminal sends a PDU session modification request message to the network that includes the information "requesting an always-on PDU session".

[0306] 3) The network identifies that the PDU session modification request sent by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)) and that execution is not possible. Therefore, the network responds to the terminal with a PDU session modification rejection message. In this case, a PDU session modification rejection message may be sent including information such as "BO timer with partially allowed NSSAI#1 and / or (new / updated) partially allowed NSSAI (e.g., partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) and / or 5GSM reason value (new #wx "partial NSSAI not allowed" or "network slice service area not allowed")".

[0307] 4) The network already has newly changed / updated partially permitted NSSAI (e.g., partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partially tracked area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (i.e., S-NSSAI#3 and NS-AoS#3 information)), and as described above in 3), it identifies that the PDU session modification request sent by the terminal is associated with an unavailable or changed partially permitted NSSAI (e.g., partially permitted NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)). Therefore, the network can determine that the terminal is attempting to perform the PDU session modification request process based on incorrect information (e.g., partially permitted NSSAI#1).

[0308] 5) When a BO timer with "partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)" is received, the terminal that has received the PDU session modification request message from the network activates the corresponding BO timer. In this case, the terminal does not perform the PDU session modification request based on partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information) before the BO timer expires. In this case, the terminal maintains the existing always-on PDU session (for partially allowed NSSAI#1) as is. That is, the terminal does not additionally perform the PDU session establishment request procedure and / or PDU session modification request procedure based on the newly changed / updated partially allowed NSSAI (e.g., partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)).

[0309] Subsequently, when the existing always-on PDU session (for partially allowed NSSAI#1) is released, when the terminal receives a newly changed / updated partially allowed NSSAI (e.g., partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) via a PDU session modification rejection message from the network, the terminal replaces / updates the existing partially allowed NSSAI#1 with the partially allowed NSSAI#2, and can then perform a new PDU session establishment request procedure with the network for the always-on PDU session based on the replaced / updated partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information).

[0310] Sixth public content

[0311] 1) Partially permitted NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) accordingly receives the newly changed / updated partially permitted NSSAI (e.g., permitted NSSAI#2 (in practice, S-NSSAI#2 and partially permitted Tracking Area Identifier List #2 information)) and NS-AoS (e.g., NS-AoS#3 (in practice, S-NSSAI#3 and NS-AoS#3 information)) from the NSSF. Additionally, the terminal configures and maintains an always-on PDU session based on the unavailable or changed partially permitted NSSAI (e.g., partially permitted NSSAI#1). (The UE has an existing always-on PDU session associated with partially permitted NSSAI#1.)

[0312] 2) If the terminal has not yet received a partially allowed NSSAI (and / or NS-AoS) from the network (that is, if an unavailable or modified partially allowed NSSAI is not identified (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)), the terminal sends a PDU session modification request message associated with the partially allowed NSSAI (e.g., partially allowed NSSAI#1) to the network. In this case, the terminal sends a PDU session modification request message to the network that includes the information "requesting an always-online PDU session".

[0313] 3) The network identifies that the PDU session modification request sent by the terminal is related to a partially allowed NSSAI that is unavailable or changed (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)) and that execution is not possible. Therefore, the network responds to the terminal with a PDU session modification rejection message. In this case, a PDU session modification rejection message may be sent including information such as "BO timer with partially allowed NSSAI#1 and / or (new / updated) partially allowed NSSAI (e.g., allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) and / or 5GSM reason value (new #wx "partial NSSAI not allowed" or "network slice service area not allowed")".

[0314] 4) The network already has newly changed / updated partially permitted NSSAIs (e.g., partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partially tracked area identifier list #2 information)) and NS-AoSs (e.g., NS-AoS#3 (i.e., S-NSSAI#3 and NS-AoS#3 information)), and as described above in 3), it identifies that the PDU session modification request sent by the terminal is associated with an unavailable or changed partially permitted NSSAI (e.g., partially permitted NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)). Therefore, the network can determine that the terminal is attempting to perform the PDU session modification request procedure based on incorrect information (e.g., partially permitted NSSAI#1). Therefore, after sending a PDU session modification rejection message to the terminal as described above in 3), the network immediately sends a configuration update command (i.e., general UE configuration update procedure) message to the terminal. In this case, the network sends new changes / updates to the partially permitted NSSAI (e.g., partially permitted NSSAI#2 (i.e., S-NSSAI#2 and partially tracked area identifier list #2 information)).

[0315] 5) When a BO timer with "partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)" is received, the terminal that has received a PDU session modification rejection message from the network activates the corresponding BO timer. In this case, the terminal does not perform a PDU session modification request based on partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information) before the BO timer expires. In this case, the terminal maintains the existing always-on PDU session (for partially allowed NSSAI#1) as is. That is, the terminal does not additionally perform the PDU session establishment request procedure and / or PDU session modification request procedure based on the newly changed / updated partially allowed NSSAI (e.g., partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)).

[0316] Subsequently, when the existing always-on PDU session (for partially allowed NSSAI#1) is released, when the terminal receives a newly changed / updated partially allowed NSSAI (e.g., partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) via a configuration update command message from the network, the terminal replaces / updates the existing partially allowed NSSAI#1 with partially allowed NSSAI#2, and can then perform a new PDU session establishment request procedure with the network for the always-on PDU session based on the replaced / updated partially allowed NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information).

[0317] Seventh public content

[0318] 1) Partial allowable NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) accordingly receives the newly changed / updated partial allowable NSSAI (e.g., partial allowable NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (i.e., S-NSSAI#3 and NS-AoS#3 information)) from NSSF.

[0319] 2) If the terminal has not yet received a partially allowed NSSAI (and / or NS-AoS) from the network (that is, if an unavailable or modified partially allowed NSSAI is not identified (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information)), the terminal sends a PDU session establishment request message associated with the partially allowed NSSAI (e.g., partially allowed NSSAI#1) to the network.

[0320] 3) The network identifies that the PDU session establishment request sent by the terminal is a PDU session establishment request associated with an unavailable or modified partially permitted NSSAI (e.g., partially permitted NSSAI #1 (i.e., S-NSSAI #1 and partial tracking area identifier list #1 information)) and that execution is impossible. Therefore, the network responds to the terminal with a PDU session establishment rejection message. In this case, unlike a general PDU session establishment rejection message, the PDU session establishment rejection message may be a PDU session rejection message associated with a partial TA within the current RA. In this case, separately and / or additionally, the PDU session rejection message may also include one or more of the location availability information or validity time information of the first partially permitted NSSAI (e.g., partially permitted NSSAI #1) or the first NSSAI. Additionally, the PDU session rejection message may also include a modified second partially permitted NSSAI (e.g., partial tracking area identifier list #2 information).

[0321] 4) When a PDU session establishment rejection message is received from the network, the terminal can determine whether to maintain the first NSSAI or to perform one or more of the PDU session establishment associated with the second NSSAI based on the PDU session rejection message.

[0322] 5) For example, the terminal may determine whether to maintain the first NSSAI or execute the PDU session configuration associated with the second NSSAI based on one or more of the location availability information of the first NSSAI, the validity period information of the first NSSAI, or the QoS information of the PDU session associated with the first NSSAI. Specifically, although a rejection message is received for a PDU session request using the first NSSAI, the terminal may re-enter a TA that can use the first NSSAI based on the location availability information of the first NSSAI. Based on the validity period information of the first NSSAI, even with such a delay, the validity period of the first NSSAI is sufficient, and based on the QoS information of the PDU session associated with the first NSSAI, such a delay will not cause problems in QoS support. In this case, the terminal may maintain the first NSSAI and postpone the execution of the PDU session configuration associated with the second NSSAI.

[0323] 6) However, when such a delay as described above affects the QoS of the corresponding PDU session, preferably, the terminal immediately performs PDU session establishment based on the second NSSAI. To this end, as described above, the PDU session rejection message may include the second NSSAI, and in this case, after receiving the PDU session rejection message, the terminal may immediately send a PDU session establishment request message associated with the second NSSAI.

[0324] Eighth Public Content

[0325] 1) First, assume that the terminal and the network have established an always-on PDU session.

[0326] Assume that the always-on PDU session is associated with a partially allowed NSSAI (first NSSAI).

[0327] 2) The partial allowable NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) accordingly receives the newly changed / updated partial allowable NSSAI (e.g., partial allowable NSSAI#2 (i.e., S-NSSAI#2 and partial tracking area identifier list #2 information)) and NS-AoS (e.g., NS-AoS#3 (i.e., S-NSSAI#3 and NS-AoS#3 information)) from NSSF.

[0328] 3) If the terminal has not yet received a partially allowed NSSAI (and / or NS-AoS) from the network (that is, if an unavailable or modified partially allowed NSSAI is not identified (e.g., partially allowed NSSAI#1 (i.e., S-NSSAI#1 and partially tracked area identifier list #1 information))), the terminal sends a PDU session establishment request message associated with the partially allowed NSSAI (e.g., partially allowed NSSAI#1) to the network.

[0329] 4) The network identifies that the PDU session establishment request sent by the terminal is a PDU session establishment request associated with an unavailable or modified partially permitted NSSAI (e.g., partially permitted NSSAI#1 (i.e., S-NSSAI#1 and partial tracking area identifier list #1 information)) and that execution is impossible. Therefore, the network responds to the terminal with a PDU session establishment rejection message. In this case, unlike a general PDU session establishment rejection message, the PDU session establishment rejection message can be a PDU session rejection message associated with a partial TA within the current RA, as described above in the seventh disclosure. In this case, the PDU session rejection message can include the information described in the seventh disclosure.

[0330] 5) When a PDU session establishment rejection message is received from the network, the terminal can determine whether to maintain the first NSSAI or to perform one or more of the PDU session establishment associated with the second NSSAI based on the PDU session rejection message.

[0331] 6) However, based on the fact that the corresponding PDU session is an always-on PDU session, preferably, the terminal immediately performs PDU session establishment associated with the second NSSAI, which is a part of the NSSAI that is different from the first NSSAI. Normally, a terminal's PDU session establishment request can be requested when there is data being transmitted by the terminal, but in the case of an always-on PDU session, regardless of whether the terminal has data, the terminal can immediately send a PDU session establishment request message based on the second NSSAI after receiving a PDU session rejection message.

[0332] <Summary of the implementation methods in this specification>

[0333] Figure 8 This specification illustrates a method of operating a terminal according to one embodiment.

[0334] Reference Figure 8 The terminal sends a PDU session request message associated with the first NSSAI (Network Slice Selection Auxiliary Information) (S801). Subsequently, it receives a PDU session rejection message in response to the sent PDU session request message (S802). Here, the received PDU session rejection message can be used to establish an always-on PDU session associated with the second NSSAI, and the first NSSAI and the second NSSAI can be different parts of the NSSAI.

[0335] PDU session request messages can be either PDU session establishment request messages or PDU session modification request messages. Similarly, PDU session rejection messages can be either PDU session establishment rejection messages or PDU session modification rejection messages.

[0336] The received PDU session establishment rejection message and / or PDU session modification rejection message may include a BO timer value and reason information, and based on the BO timer value, the transmission of the PDU session establishment request message and / or PDU session modification request message associated with the first NSSAI may be backed off.

[0337] Figure 9 A block diagram showing the configuration of a processor that implements the disclosure of this specification is provided.

[0338] Reference Figure 9 As can be seen, the processor 1020 implemented in the disclosure of this specification may include multiple circuits to implement the functions, processes, 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. Additionally, although not shown, the processor 1020 may include further circuits. Each circuit may include multiple transistors.

[0339] The processor 1020 may be referred to as an application-specific integrated circuit (ASIC) or an 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).

[0340] The processor can be installed on the UE.

[0341] Figure 10 An apparatus according to one embodiment of this specification is shown.

[0342] Reference Figure 10 The wireless communication system may include a first device 100a and a second device 100b.

[0343] The first device 100a may be the UE described in the disclosure of this specification. Alternatively, the first device 100a may be a base station, a network node, a transmitting UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle with autonomous driving capabilities, a connected car, a drone (unmanned aerial vehicle (UAV)), an artificial intelligence (AI) module, a robot, an augmented reality (AR) device, a virtual reality (VR) device, a mixed reality (MR) device, a holographic device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or financial device), a security device, a climate / environment device, a device related to 5G services, or any other device related to the Fourth Industrial Revolution.

[0344] The second device 100b may be a network node (e.g., an AMF or MME) as disclosed in this specification. Alternatively, the second device 100b may be a base station, a network node, a transmitting UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle with autonomous driving capabilities, a connected car, a drone (UAV), an AI module, a robot, an AR device, a VR device, a MR device, a holographic device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or financial device), a security device, a climate / environment device, a device related to 5G services, or any other device related to the Fourth Industrial Revolution.

[0345] For example, UE 100 may include mobile phones, smartphones, laptop computers, digital broadcast UEs, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation devices, tablet PCs, tablet computers, ultrabooks, wearable devices (e.g., smartwatch-type UEs, smart glasses-type UEs, head-mounted displays (HMDs)), etc. For example, an HMD can be a display device worn on the head. For example, an HMD can be used to implement VR, AR, or MR.

[0346] For example, a drone can be an aircraft that flies without human passengers via wireless control signals. For example, a VR device can include a device for realizing objects or backgrounds in a virtual world. For example, an AR device can include a device for realizing objects or backgrounds in a virtual world by connecting them to objects or backgrounds in the real world. For example, a MR device can include a device for fusing objects or backgrounds in a virtual world with objects or backgrounds in the real world. For example, a holographic device can include a device that uses the light interference phenomenon that occurs when two laser beams meet, known as holography, to record and reproduce stereoscopic information, thereby creating a 360-degree stereoscopic image. For example, a public safety device can include a video relay device or video device that can be worn by a user. For example, MTC devices and IoT devices can be devices that do not require direct human intervention or operation. For example, MTC devices and IoT devices can include smart meters, vending machines, thermometers, smart light bulbs, door locks, or various sensors. For example, a medical device can be a device used for the purpose of diagnosing, treating, alleviating, managing, or preventing disease. For example, a medical device can be a device used for the purpose of diagnosing, treating, alleviating, managing, or correcting injury or disability. For example, a medical device can be 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 controlling pregnancy. For example, a medical device can include medical devices, surgical devices, (in vitro) diagnostic devices, hearing aids, etc. For example, a security device can be a device installed to prevent potential risks and maintain security. For example, a security device can be a camera, CCTV, recorder, black box, etc. For example, a fintech device can be a device capable of providing financial services such as mobile payments. For example, a fintech device can include payment devices or point-of-sale (POS) devices. For example, a climate / environment device can include devices used to monitor or predict climate / environment.

[0347] The first device 100a may include at least one processor, such as processor 1020a, at least one memory, such as memory 1010a, and at least one transceiver, such as transceiver 1031a. Processor 1020a may perform the functions, processes, and / or methods described above. Processor 1020a may execute one or more protocols. For example, processor 1020a may execute one or more layers of a wireless interface protocol. Memory 1010a may be connected to processor 1020a and may store information and / or instructions of various forms. Transceiver 1031a may be connected to processor 1020a and controlled to transmit and receive wireless signals.

[0348] The second device 100b may include at least one processor, such as processor 1020b, at least one storage device, such as memory 1010b, and at least one transceiver, such as transceiver 1031b. Processor 1020b may perform the functions, processes, and / or methods described above. Processor 1020b may implement one or more protocols. For example, processor 1020b may implement one or more layers of a wireless interface protocol. Memory 1010b may be connected to processor 1020b and may store information and / or instructions of various forms. Transceiver 1031b may be connected to processor 1020b and controlled to transmit and receive wireless signals.

[0349] Memory 1010a and / or memory 1010b can be internally or externally connected to processor 1020a and / or processor 1020b, respectively, and can be connected to other processors via various technologies such as wired or wireless connections.

[0350] The first device 100a and / or the second device 100b may have one or more antennas. For example, antenna 1036a and / or antenna 1036b may be configured to transmit and receive wireless signals.

[0351] Figure 11 A block configuration diagram of a network node according to one embodiment of this specification is shown.

[0352] Specifically, Figure 11 The diagram shows in detail the division of the base station into a central unit (CU) and a distributed unit (DU).

[0353] Reference Figure 11 Base stations W20 and W30 can connect to the core network W10, and base station W30 can connect to its 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 its neighboring base station W20 can be referred to as Xn.

[0354] Base station W30 can be divided into CU W32 and DU W34 and W36. That is, base station W30 can operate in a hierarchical manner. CU W32 can connect to one or more DU W34 and W36, and for example, the interface between CU W32 and DU W34 and W36 can be referred to as F1. CU W32 can perform the upper-layer functions of the base station, and DU W34 and W36 can perform the lower-layer functions of the base station. For example, CU W32 can be a logical node for the RRC, Serving Data Adaptation Protocol (SDAP), and PDCP layers of a managed base station (e.g., gNB), and DU W34 and W36 can be logical nodes for the RLC, MAC, and physical (PHY) layers of the managed base station. Alternatively, CU W32 can be a logical node for the RRC and PDCP layers of a managed base station (e.g., en-gNB).

[0355] The operation of DU W34 and W36 can be partially controlled by CU W32. A single DU W34 or W36 can support one or more cells. A single cell can be supported by only one DU W34 or W36. A single DU W34 or W36 can be connected to one CU W32, and with proper implementation, a single DU W34 or W36 can be connected to multiple CUs.

[0356] Figure 12 This is a block diagram of the configuration of a UE according to one embodiment of this specification.

[0357] Specifically, Figure 12 The terminal shown (i.e., UE 100) is illustrated in more detail. Figure 10 A view of the first device.

[0358] 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 unit 1053, a speaker 1042, a microphone 1052, a SIM card, and one or more antennas.

[0359] Processor 1020 can be configured to implement the functions, processes, and / or methods described in this specification. The layers of the wireless interface protocol can be implemented in processor 1020. Processor 1020 may include an ASIC, other chipsets, logic circuits, and / or data processing devices. Processor 1020 may be an access point (AP). Processor 1020 may include at least one of a DSP, CPU, GPU, and modem. Examples of processor 1020 may be SNAPDRAGON™ series processors manufactured by Qualcomm®, EXYNOS™ series processors manufactured by Samsung®, A-series processors manufactured by Apple®, HELIO™ series processors manufactured by MediaTek®, ATOM™ series processors manufactured by Intel®, or corresponding next-generation processors.

[0360] Power management module 1091 manages the power of processor 1020 and / or transceiver 1031. Battery 1092 supplies power to power management module 1091. Display 1041 outputs the results processed by processor 1020. Input unit 1053 receives inputs to be used by processor 1020. Input unit 1053 can be displayed on display 1041. A SIM card is an integrated circuit used to securely store the International Mobile Subscriber Identity (IMSI) and associated keys used to identify and authenticate subscribers in mobile devices such as mobile phones and computers. Contact information can also be stored on multiple SIM cards.

[0361] Memory 1010 is operatively coupled to processor 1020 and stores various information for operating processor 1020. Memory 1010 may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium, and / or other storage devices. When the implementation is software-based, the techniques described herein can be implemented as modules (e.g., processes, functions) performing the functions described herein. Modules can be stored in memory 1010 and executed by processor 1020. Memory 1010 may be implemented internally to processor 1020. Alternatively, memory 1010 may be implemented externally to processor 1020 and communicatively connected to processor 1020 by various means known in the art.

[0362] Transceiver 1031 is operatively coupled to processor 1020 and transmits and / or receives wireless signals. Transceiver 1031 includes a transmitter and a receiver. Transceiver 1031 may include baseband circuitry for processing wireless frequency signals. The transceiver controls one or more antennas to transmit and / or receive wireless signals. Processor 1020 sends command information to transceiver 1031 to transmit wireless signals, such as voice communication data, to initiate communication. The antennas function to transmit and receive wireless signals. When an antenna receives a wireless signal, transceiver 1031 can transmit a signal to be processed by processor 1020 and convert the signal to baseband. The processed signal can be converted into audible or readable information output through speaker 1042.

[0363] Speaker 1042 outputs sound-related results processed by processor 1020. Microphone 1052 receives sound-related inputs to be used by processor 1020.

[0364] Users input command information, such as phone numbers, for example, by pressing (or touching) a button on input unit 1053 or by voice activation using microphone 1052. Processor 1020 receives and processes the command information to perform appropriate functions, such as dialing the phone number. Operational data can be retrieved from SIM card or memory 1010. Additionally, processor 1020 can display command information or driving information on display 1041 for user attention and convenience.

[0365] Figure 13 It is shown in detail Figure 10 The transceiver of the first device shown Figure 12 Block diagram of the transceiver of the device shown.

[0366] Reference Figure 13The transceiver 1031 includes a transmitter 1031-1 and a receiver 1031-2. The transmitter 1031-1 includes a Discrete Fourier Transform (DFT) unit 1031-11, a subcarrier mapper 1031-12, an Inverse Fast Fourier Transform (IFFT) unit 1031-13, a CP insertion unit 1031-14, and a wireless transmitter 1031-15. The transmitter 1031-1 may also include a modulator. Additionally, for example, it may include a scrambling unit (not shown), a modulation mapper (not shown), a layer mapper (not shown), and a layer permuter (not shown), which may be positioned before the DFT unit 1031-11. That is, to prevent an increase in the peak-to-average power ratio (PAPR), the transmitter 1031-1 first passes the information through the DFT 1031-11 before mapping the signal to the subcarriers. The signal spread by DFT units 1031-11 (or precoded in the same sense) is mapped to a subcarrier by subcarrier mapper 1031-12, and then converted into a time-domain signal by IFFT unit 1031-13.

[0367] DFT unit 1031-11 performs a DFT on the input symbols to output complex-valued symbols. For example, when Ntx symbols are input (where Ntx is a natural number), the DFT size is Ntx. DFT unit 1031-11 can be referred to as a transform precoder. Subcarrier mapper 1031-12 maps complex-valued symbols to each subcarrier in the frequency domain. Complex-valued symbols can be mapped to resource elements corresponding to resource blocks allocated for data transmission. Subcarrier mapper 1031-12 can be referred to as a resource element mapper. IFFT unit 1031-13 performs an IFFT on the input symbols and outputs a baseband signal for data as a time-domain signal. CP insertion unit 1031-14 copies a portion of the latter part of the baseband signal for data and inserts the copied portion into the former part of the baseband signal for data. CP insertion prevents inter-symbol interference (ISI) and inter-carrier interference (ICI), thus maintaining orthogonality even in multipath channels.

[0368] On the other hand, receiver 1031-2 includes a wireless receiver 1031-21, a CP removal unit 1031-22, an FFT unit 1031-23, and an equalization unit 1031-24, etc. The wireless receiver 1031-21, CP removal unit 1031-22, and FFT unit 1031-23 of receiver 1031-2 perform the inverse functions of the wireless transmitter 1031-15, CP insertion unit 1031-14, and IFFT unit 1031-13 of transmitter 1031-1. Receiver 1031-2 may also include a demodulator.

[0369] Figure 14 Another wireless communication system that can be applied to the disclosure in this specification is shown.

[0370] The various descriptions, functions, processes, proposals, methods, and / or flowcharts disclosed in this specification can be applied to various fields requiring wireless communication / connectivity between devices (e.g., 5G).

[0371] Reference Figure 14 The communication system 1 used in the disclosure of this specification includes wireless devices, base stations, and networks. Here, a wireless device refers to a device that establishes communication using wireless access technologies (e.g., 5G New RAT (NR), LTE), and may be referred to as a communication / wireless / 5G device. Although not limited thereto, wireless devices may include robots 100a, vehicles 100b-1 and 100b-2, extended reality (XR) devices 100c, handheld devices 100d, home appliances 100e, IoT devices 100f, and AI devices / servers 400. For example, vehicles may include vehicles equipped with wireless communication capabilities, autonomous vehicles, vehicles capable of performing vehicle-to-vehicle communication, etc. Here, vehicles may include UAVs (e.g., drones). XR devices may include AR, VR, and MR devices, and may be implemented as HMDs, HUDs installed in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Mobile devices may include smartphones, smart tablets, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops), 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 be implemented as wireless devices, and a specific wireless device 200a can be used as a base station / network node for other wireless devices.

[0372] Wireless devices 100a to 100f can connect to network 300 via base station 200. Wireless devices 100a to 100f can employ AI technology and can connect to AI server 400 via the network. Network 300 can be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Wireless devices 100a to 100f can communicate with each other via base station 200 / network 300, but can also communicate directly (e.g., sidelink communication) without going through a base station / network. For example, vehicles 100b-1 and 100b-2 can communicate directly with each other (e.g., vehicle-to-vehicle (V2V) / V2X communication). Additionally, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or wireless devices 100a to 100f.

[0373] Wireless communication / connections 150a, 150b, and 150c can be established between wireless devices 100a to 100f and base station 200, as well as between base stations 200. Here, wireless communication / connections can be implemented through various wireless access technologies (e.g., 5G NR), such as uplink / downlink communication 150a, sidelink communication 150b (or D2D communication), and inter-base station communication 150c (e.g., relay, Integrated Access Backhaul (IAB)). Through wireless communication / connections 150a, 150b, and 150c, wireless devices and base stations / wireless devices and base stations can send / receive wireless signals to / from each other. For example, wireless communication / connections 150a, 150b, and 150c can send / receive signals through various physical channels. Therefore, based on the various proposals disclosed in this disclosure, at least some of the following can be performed: various configuration information setting processes for sending and receiving wireless signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes.

[0374] While exemplary embodiments have been described above, the disclosure of this specification is not limited to these specific embodiments, and therefore modifications, alterations or improvements can be made in various forms within the spirit of this specification and the scope of the appended claims.

[0375] In the exemplary system described above, the method has been described as a series of steps or blocks based on the flowchart. However, the method is not limited to the order of the described steps, and some steps may occur in a different order or may occur simultaneously. Furthermore, those skilled in the art will understand that the steps shown in the flowchart are not exclusive, and other steps may be included, or one or more steps in the flowchart may be omitted, without affecting the scope of this specification.

[0376] The claims described in this specification can be combined in various ways. For example, the technical features of the method claims of this specification can be combined to implement a device, and the technical features of the device claims of this specification can be combined to implement a method. Furthermore, the technical features of the method claims and the device claims of this specification can be combined to implement a device, or they can be combined to implement a method.

[0377] Industrial applicability

[0378] The methods and devices for handling always-on PDU sessions of network slices in the aforementioned wireless communication systems, taking into account service areas, can be applied to various mobile communication systems based on 3GPP standards.

Claims

1. A method for operating a terminal in a wireless communication system, the method comprising the following steps: Establish an Always-On Protocol Data Unit (PDU) session associated with the first network slice selection assistance information (NSSAI); Send a PDU session request message associated with the first NSSAI; as well as Receive a PDU session rejection message in response to the sent PDU session request message. Wherein, when the first NSSAI is partially allowed NSSAI, the PDU session rejection message is a PDU session rejection message associated with a partial tracking area TA within the currently registered area RA, and When the PDU session associated with the first NSSAI is the always-on PDU session, the PDU session rejection message is used to establish a PDU session associated with the second NSSAI, which is a partially allowed NSSAI different from the first NSSAI.

2. The method of claim 1, wherein, When the PDU session associated with the first NSSAI is not the always-on PDU session, the first NSSAI is maintained according to the PDU session rejection message, and the establishment of the PDU session associated with the second NSSAI is postponed.

3. The method of claim 1, further comprising the step of: When the PDU session associated with the first NSSAI is the always-on PDU session, after receiving the PDU session rejection message, a PDU session establishment request message associated with the second NSSAI is sent even if there is no uplink data transmission.

4. The method of claim 1, wherein, The PDU session request message is either a PDU session establishment request message or a PDU session modification request message.

5. The method according to claim 4, wherein, The PDU session rejection message is either a PDU session establishment rejection message or a PDU session modification rejection message.

6. The method according to claim 5, wherein, The PDU session establishment rejection message or the PDU session modification rejection message, either or one of them, includes a backoff timer value and reason information.

7. The method according to claim 6, wherein, Based on the backoff timer value, the transmission of the PDU session establishment request message or the PDU session modification request message associated with the first NSSAI is backoffed.

8. A communication device in a wireless communication system, the communication device comprising: transceiver; At least one processor; as well as At least one memory, configured to store instructions and electrically connected in operation to the at least one processor. The operations performed based on the instructions being executed by the at least one processor include: Establish an Always-On Protocol Data Unit (PDU) session associated with the first network slice selection assistance information (NSSAI); Send a PDU session request message associated with the first NSSAI; and Receive a PDU session rejection message in response to the sent PDU session request message. Wherein, when the first NSSAI is partially allowed NSSAI, the PDU session rejection message is a PDU session rejection message associated with a partial tracking area TA within the currently registered area RA, and When the PDU session associated with the first NSSAI is the always-on PDU session, the processor is configured to use the PDU session rejection message to establish a PDU session associated with a second NSSAI, the second NSSAI being a partially allowed NSSAI different from the first NSSAI.

9. The communication device according to claim 8, wherein, When the PDU session associated with the first NSSAI is not the always-on PDU session, the processor is configured to maintain the first NSSAI and postpone the establishment of the PDU session associated with the second NSSAI, based on the PDU session rejection message.

10. The communication device according to claim 8, wherein, When the PDU session associated with the first NSSAI is the always-on PDU session, the operation further includes: After receiving the PDU session rejection message, even if there is no uplink data transmission, a PDU session establishment request message associated with the second NSSAI is sent.

11. The communication device according to claim 8, wherein, The PDU session request message is either a PDU session establishment request message or a PDU session modification request message.

12. The communication device according to claim 11, wherein, The PDU session rejection message is either a PDU session establishment rejection message or a PDU session modification rejection message.

13. The communication device according to claim 12, wherein, The PDU session establishment rejection message or the PDU session modification rejection message, either or one of them, includes a backoff timer value and reason information.

14. The communication device according to claim 13, wherein, Based on the backoff timer value, one or more of the transmissions of the PDU session establishment request message or the PDU session modification request message associated with the first NSSAI are backed off.

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