Method and apparatus for processing always-on PDU session of network slicing by considering service area in wireless communication system

Abstract

One disclosure of the present specification provides a method by which a terminal operates in a wireless communication system. The method may comprise the steps of: transmitting a protocol data unit (PDU) session request message associated with 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 for establishment of an always-on PDU session associated with second NSSAI, and the first NSSAI and the second NSSAI can be partially allowed pieces of NSSAI that differ from each other.

Description

Method and device for always-on PDU session processing for network slicing considering service area in wireless communication system

[0001] This specification relates to a 3GPP wireless communication system.

[0002] Following the success of LTE (long term evolution) / LTE-Advanced (LTE-A) for 4th generation mobile communications, interest in the next generation, or 5th generation (so-called 5G) mobile communications is growing, and research is also progressing rapidly.

[0003] The 5th generation mobile communication, as defined by the International Telecommunication Union (ITU), provides data transmission speeds of up to 20 Gbps and a perceived transmission speed of at least 100 Mbps anywhere, and is officially referred to as 'IMT-2020'.

[0004] 5G mobile communications support multiple numerologies, or subcarrier spacing (SCS), to support diverse services. For example, a 15 kHz SCS supports wide areas in traditional cellular bands. A 30 kHz / 60 kHz SCS supports dense urban environments, lower latency, and wider carrier bandwidth. An SCS of 60 kHz or higher supports bandwidths greater than 24.25 GHz to overcome phase noise.

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

[0006] For convenience of explanation, among the frequency ranges used in NR systems, FR1 may mean "sub 6GHz range", FR2 may mean "above 6GHz range" and may be called millimeter wave (mmW).

[0007] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0008] The numerical value of the frequency range of the NR system can be changed. For example, FR1 can include a band from 410 MHz to 7125 MHz as shown in Table 1 above. That is, FR1 can include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher. For example, the frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher included in FR1 can include an unlicensed band. The unlicensed band can be used for various purposes, such as communication for vehicles (e.g., autonomous driving). Fig. 1 is a diagram illustrating a wireless communication system.

[0009] The 5GC (5G Core) network may include various components, and in FIG. 1, some of them include AMF (Access and Mobility Management Function) (41), SMF (Session Management Function) (42), PCF (Policy Control Function) (43), UPF (User Plane Function) (44), AF (Application Function) (45), UDM (Unified Data Management) (46), and N3IWF (Non-3GPP InterWorking Function) (49).

[0010] The UE (User Equipment) (10) is connected to the data network via the UPF (44) through the NG-RAN (Next Generation Radio Access Network).

[0011] The UE (10) can also receive data services via untrusted non-3GPP (non-3rd Generation Partnership Project) access, such as a Wireless Local Area Network (WLAN). To connect the non-3GPP access to the core network, an N3IWF (49) may be deployed.

[0012] Figure 2 is an example diagram showing the structure of a wireless communication system from a node perspective.

[0013] As can be seen from FIG. 2, the UE is connected to a data network (DN) via a radio access network (RAN).

[0014] The illustrated Control Plane Function (CPF) node performs all or part of the functions of the Mobility Management Entity (MME) of 4th generation mobile communication, and all or part of the control plane functions of the Serving Gateway (S-GW) and the PDN Gateway (P-GW). The CPF node includes the Access and Mobility Management Function (AMF) and the Session Management Function (SMF).

[0015] The illustrated User Plane Function (UPF) node is a type of gateway through which user data is transmitted and received. The UPF node can perform all or part of the user plane functions of the S-GW and P-GW of 4G mobile communications.

[0016] The illustrated PCF (Policy Control Function) is a node that controls the business operator's policy.

[0017] The illustrated application function (AF) is a server for providing various services to the UE.

[0018] The Unified Data Management (UDM) depicted is a type of server that manages subscriber information, similar to the Home Subscriber Server (HSS) of 4G mobile communications. The UDM stores and manages the subscriber information in a Unified Data Repository (UDR).

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

[0020] The illustrated Network Slice Selection Function (NSSF) is a node for network slicing, as described below.

[0021] A UE can connect to two data networks simultaneously using multiple PDU (protocol data unit or packet data unit) sessions.

[0022] Figure 3 is another example diagram showing the structure of a wireless communication system from a node perspective.

[0023] Figure 3 shows an architecture for a UE to access two data networks simultaneously using one PDU session.

[0024] Matters related to the reference points shown in FIGS. 2 and 3 are as follows.

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

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

[0033] N9 represents a reference point between UPFs.

[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 a reference point between AMFs.

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

[0040] N16 represents a reference point between SMFs.

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

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

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

[0044] The above wireless interface protocol is based on the 3GPP wireless access network standard. The above wireless interface protocol is horizontally divided into the physical layer, data link layer, and network layer, and vertically divided into the user plane for data information transmission and the control plane for control signal transmission.

[0045] The above protocol layers can be divided into L1 (first layer), L2 (second layer), and L3 (third layer) based on the three lower layers of the Open System Interconnection (OSI) reference model, which is widely known in communication systems.

[0046] Below, each layer of the wireless interface protocol is described.

[0047] The first layer, the Physical layer, provides information transfer services using physical channels. The Physical layer is connected to the upper layer, the Medium Access Control (MAC) layer, via a Transport Channel, through which data is transferred between the MAC layer and the Physical layer. Furthermore, data is transferred between different Physical layers, i.e., between the physical layers of the transmitter and receiver, via the Physical Channel.

[0048] Layer 2 includes the Medium Access Control (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 solely in the control plane and is responsible for controlling logical, transport, and physical channels, related to the configuration, reconfiguration, and release of radio bearers (RBs). Here, RBs represent the services provided by the second layer for data transmission between the terminal and the RAN.

[0050] The above NAS (Non-Access Stratum) layer performs functions such as session management and mobility management.

[0051] The NAS layer is divided into NAS entities for MM (Mobility Management) and NAS entities for SM (Session Management).

[0052] 1) NAS entities for MM provide the following general functions:

[0053] As NAS procedures related to AMF, including:

[0054] Registration management and access management procedures. AMF supports the following functions:

[0055] - Secure NAS signal connection between UE and AMF (integrity protection, encryption)

[0056] 2) The NAS entity for SM performs session management between the UE and SMF.

[0057] SM signaling messages are processed, i.e., generated and processed, at the NAS-SM layer of the UE and SMF. The content of SM signaling messages is not interpreted by the AMF.

[0058] - In case of SM signaling transmission,

[0059] - The NAS entity for MM generates a NAS-MM message that induces how and where to deliver the SM signaling message, with a security header indicating the NAS transmission of the SM signaling, and additional information for the receiving NAS-MM.

[0060] - Upon receiving SM signaling, the NAS entity for SM performs an integrity check of the NAS-MM message and interprets additional information to derive how and where to derive the SM signaling message.

[0061] Meanwhile, the RRC layer, RLC layer, MAC layer, and PHY layer located below the NAS layer in FIG. 4 are collectively called the Access Stratum (AS).

[0062] The network system for 5G (i.e., 5GC) also supports non-3GPP access. A representative example of non-3GPP access is WLAN access. This WLAN access may include both trusted and untrusted WLANs.

[0063] In a system for 5G, AMF performs registration management (RM) and connection management (CM) for 3GPP access as well as non-3GPP access.

[0064] The disclosure of the present specification is intended to provide a method and device for processing a PDU (protocol data unit) session of network slicing in a wireless communication system.

[0065] In particular, one embodiment of the present specification seeks to provide a method and device for processing a PDU session that takes into account the characteristics of a case where the NSSAI (network slice selection assistance information) used for PDU session differentiation of network slicing is a partially allowed NSSAI.

[0066] In addition, in one embodiment of the present specification, a method and device for processing a PDU session when a partially allowed NSSAI as described above is used and the PDU session is an always-on PDU (protocol data unit) session are provided.

[0067] One embodiment of the present disclosure provides a method for a terminal to operate in a wireless communication system. The method may include establishing an always-on protocol data unit (PDU) session associated with a first network slice selection assistance information (NSSAI); transmitting a PDU session request message associated with the first NSSAI; and receiving a PDU session reject message in response to the transmitted PDU session request message. If the first NSSAI is a partially allowed NSSAI, the PDU session reject message may be a PDU session reject message associated with a partial TA (Tracking Area) within a current RA (Registration Area), and if the PDU session associated with the first NSSAI is the always-on PDU session, the PDU session reject message is proposed to be used for PDU session establishment associated with a second NSSAI, which is a different partially allowed NSSAI from the first NSSAI.

[0068] In addition, one embodiment of the present specification provides a communication device in a wireless communication system. The communication device may include a transceiver, at least one processor, and at least one memory storing instructions and being operably electrically connected to the at least one processor. Based on the instructions being executed by the at least one processor, the operations performed may include: establishing an always-on protocol data unit (PDU) session associated with a first network slice selection assistance information (NSSAI), transmitting a PDU session request message associated with the first NSSAI, and receiving a PDU session reject message in response to the transmitted PDU session request message. If the first NSSAI is a partially allowed NSSAI, the PDU session reject message may be a PDU session reject message associated with a partial TA (Tracking Area) within a current RA (Registration Area), and if the PDU session associated with the first NSSAI is the always-on PDU session, the processor is configured to use the PDU session reject message for PDU session establishment associated with a second NSSAI, which is a different partially allowed NSSAI from the first NSSAI.

[0069] If the PDU session associated with the first NSSAI is not the always-on PDU session, the first NSSAI may be maintained and establishment of a PDU session associated with the second NSSAI may be postponed according to the PDU session rejection message.

[0070] Meanwhile, if the PDU session associated with the first NSSAI is the always-on PDU session, the method may further include transmitting a PDU session establishment request message associated with the second NSSAI even when there is no uplink transmission data after receiving the PDU session rejection message.

[0071] The above PDU session request message may be a PDU session establishment request message or a PDU session modification request message. In addition, the PDU session rejection message may be a PDU session establishment reject message or a PDU session modification reject message.

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

[0073] According to the disclosure of the present specification, if an Always-on PDU session establishment request procedure and / or a PDU session modification request procedure of a terminal is performed before an accurate update / synchronization procedure of a partially allowed NSSAI (and / or NS-AoS) between a terminal and a network is completed, an ultra-low latency service connection problem, signaling overhead, and resource waste may occur due to inefficient operations. Accordingly, the network can quickly stop the NAS procedure for an unavailable or changed (updated) partially allowed NSSAI to the terminal, and also quickly perform Always-on PDU session processing, reduce the overhead of unnecessary signaling, minimize power consumption and resource waste of the terminal and the network, and continuously provide an ultra-low latency service.

[0074] Additionally, in one embodiment of the present specification, in case of rejection of a PDU session request for a partially allowed NSSAI, considering that the rejection is related to a partial TA within the current RA, a session reset based on a different NSSAI or a maintenance considering the movement of the terminal can be efficiently selected and applied.

[0075] In addition, in one embodiment of the present specification, if the PDU session in question is an always-on PDU session, even in the case of rejection for a partially accepted NSSAI as described above, the performance of the delay-sensitive always-on PDU session can be guaranteed by performing establishment of an updated PDU session immediately regardless of whether the terminal has transmission data.

[0076] Figure 1 is a diagram illustrating a wireless communication system.

[0077] Figure 2 is an example diagram showing the structure of a wireless communication system from a node perspective.

[0078] Figure 3 is another example diagram showing the structure of a wireless communication system from a node perspective.

[0079] Figure 4 is an example diagram showing the structure of a radio interface protocol between a terminal and a network.

[0080] Figures 5a and 5b are signal flow diagrams illustrating an exemplary PDU session establishment procedure.

[0081] Figures 6a and 6b are signal flow diagrams illustrating a modification procedure of an exemplary PDU session.

[0082] Figure 7 is an example diagram to explain the concept of network slicing.

[0083] Figure 8 illustrates an operation method of a terminal according to one embodiment of the present specification.

[0084] Figure 9 shows a block diagram of a processor in which the disclosure of this specification is implemented.

[0085] Figure 10 illustrates a device according to one embodiment of the present specification.

[0086] FIG. 11 illustrates a block diagram of a network node according to one embodiment of the present specification.

[0087] Fig. 12 is a block diagram showing the configuration of a terminal according to one embodiment of the present specification.

[0088] FIG. 13 is a block diagram showing in detail the transmitter / receiver of the first device illustrated in FIG. 10 or the transmitter / receiver unit of the device illustrated in FIG. 12.

[0089] FIG. 14 illustrates another wireless communication system applicable to the disclosure of this specification.

[0090] It should be noted that the technical terms used in this specification are used merely to describe specific embodiments and are not intended to limit the contents of this specification. In addition, unless specifically defined otherwise herein, the technical terms used in this specification should be interpreted as having a meaning generally understood by those skilled in the art to which this specification pertains, and should not be interpreted in an excessively broad or narrow sense. In addition, if a technical term used in this specification is an incorrect technical term that does not accurately express the contents and ideas of this specification, it should be replaced with a technical term that can be correctly understood by a person skilled in the art. In addition, general terms used in this specification should be interpreted according to their dictionary definitions or according to the preceding and following context, and should not be interpreted in an excessively narrow sense.

[0091] Additionally, the singular expressions used herein include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consist of" or "have" should not be construed to necessarily include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0092] Additionally, terms including ordinal numbers, such as "first," "second," etc., used herein may be used to describe various components, but these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a second component, and similarly, a second component could also be referred to as a first component.

[0093] When a component is referred to as being connected or connected to another component, it may be directly connected or connected to that other component, but there may also be other components intervening. Conversely, when a component is referred to as being directly connected or connected to another component, it should be understood that there are no other components intervening.

[0094] Hereinafter, embodiments will be described in detail with reference to the attached drawings. Regardless of the drawing reference numerals, identical or similar components will be given the same reference numerals, and redundant descriptions thereof will be omitted. In addition, when describing the contents of this specification, if a detailed description of a related known technology is judged to obscure the gist of this specification, the detailed description thereof will be omitted. In addition, it should be noted that the attached drawings are only intended to make the contents and ideas of this specification easily understandable, and should not be construed as limiting the contents and ideas of this specification by the attached drawings. The contents and ideas of this specification should be construed to extend to all changes, equivalents, and substitutes other than the attached drawings.

[0095] In this specification, “A or B” can mean “only A,” “only B,” or “both A and B.” In other words, “A or B” in this specification can be interpreted as “A and / or B.” For example, “A, B or C” in this specification can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0096] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0097] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”

[0098] Additionally, in this specification, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0099] Additionally, parentheses used in this specification may mean “for example.” Specifically, when “control information (PDCCH)” is indicated, “PDCCH” may be suggested as an example of “control information.” In other words, “control information” in this specification is not limited to “PDCCH,” and “PDDCH” may be suggested as an example of “control information.” Furthermore, even when indicated as “control information (i.e., PDCCH),” “PDCCH” may be suggested as an example of “control information.”

[0100] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0101] Although the attached drawing illustrates a UE (User Equipment) as an example, the illustrated UE may also be referred to as a UE (100) (Terminal), ME (Mobile Equipment), etc. In addition, the UE may be a portable device such as a laptop, a mobile phone, a PDA, a smart phone, a multimedia device, etc., or a non-portable device such as a PC or a vehicle-mounted device.

[0102] <PDU 세션 수립 절차>

[0103] There can be two types of PDU (Protocol Data Unit) session establishment procedures as follows.

[0104] - UE-initiated PDU session establishment procedure

[0105] - A network-initiated PDU session establishment procedure. For this purpose, the network may send a device trigger message to the UE's application(s).

[0106] Figures 5a and 5b are signal flow diagrams illustrating an exemplary PDU session establishment procedure.

[0107] The procedures illustrated in Figures 5a and 5b assume that the UE has already registered with the AMF according to the registration procedure. Therefore, the AMF is assumed to have already obtained user subscription data from the UDM.

[0108] 1) The UE transmits an NAS message to the AMF. The message may include S-NSSAI (Single Network Slice Selection Assistance Information), DNN (Data Network Name), PDU session ID, request type, N1 SM (Session Management) information, etc.

[0109] Specifically, the UE includes an S-NSSAI from the allowed NSSAI of the current access type. If information about the mapped NSSAI is provided to the UE, the UE can provide both an S-NSSAI based on the allowed NSSAI and a corresponding S-NSSAI based on the information of the mapped NSSAI. Here, the information about the mapped NSSAI is information that maps each S-NSSAI of the allowed NSSAI to an S-NSSAI of the NSSAI configured for the Home Public Land Mobile Network (HPLMN).

[0110] More specifically, the UE may extract and store information on the allowed S-NSSAI and the mapped S-NSSAI included in the registration acceptance message received from the network (i.e., AMF) in the registration procedure. Accordingly, the UE may transmit a PDU session establishment request message including both the S-NSSAI based on the allowed NSSAI and the corresponding S-NSSAI based on the information on the mapped NSSAI.

[0111] To establish a new PDU session, the UE may generate a new PDU session ID.

[0112] A UE can initiate a PDU session establishment procedure initiated by the UE by transmitting an NAS message including a PDU session establishment request message within N1 SM information. The PDU session establishment request message can include a request type, a Session and Service Continuity (SSC) mode, and protocol configuration options.

[0113] If the PDU session establishment is for establishing a new PDU session, the request type indicates "Initial Request." However, if an existing PDU session exists between a 3GPP access and a non-3GPP access, the request type may indicate "Existing PDU Session."

[0114] The NAS message transmitted by the UE is encapsulated within an N2 message by the AN. The N2 message is transmitted to the AMF and may include user location information and access technology type information.

[0115] - N1 SM information may include an SM PDU DN request container containing information about PDU session authentication by external DN.

[0116] 2) AMF may determine that the message corresponds to a request for a new PDU session if the request type indicates "Initial Request" and the PDU Session ID was not used for an existing PDU session of the UE.

[0117] If the NAS message does not contain an S-NSSAI, the AMF may determine a default configured S-NSSAI for the requested PDU session based on the UE subscription. The AMF may associate and store the PDU session ID with the SMF ID.

[0118] The above AMF can select SMF.

[0119] 3) AMF can send an Nsmf_PDUSession_CreateSMContext request message or an Nsmf_PDUSession_UpdateSMContext request message to the selected SMF.

[0120] The above Nsmf_PDUSession_CreateSMContext request message may include a Subscription Permanent Identifier (SUPI), a DNN, S-NSSAI(s), a PDU Session ID, an AMF ID, a Request Type, a PCF ID, Priority Access, an N1 SM container, user location information, an Access Type, a Permanent Equipment Identifier (PEI), a Generic Public Subscription Identifier (GPSI), UE presence in a Local Area Data Network (LADN) service area, a Subscription For PDU Session Status Notification, a DNN Selection Mode, and Trace Requirements. The SM container may include a PDU Session Establishment Request message.

[0121] The above Nsmf_PDUSession_UpdateSMContext request message may include SUPI, DNN, S-NSSAI(s), SM Context ID, AMF ID, Request Type, N1 SM container, User location information, Access Type, RAT type, and PEI. The N1 SM container may include a PDU Session Establishment Request message.

[0122] The AMF ID is used to identify the AMF serving the UE. The N1 SM information may include a PDU session establishment request message received from the UE.

[0123] 4) The SMF transmits a subscriber data request message to the UDM. The subscriber data request message may include the subscriber's permanent ID and DNN. The UDM may transmit a subscription data response message to the SMF.

[0124] If the request type in step 3 above indicates "Existing PDU Session," the SMF determines that the request is due to a handover between a 3GPP access and a non-3GPP access. The SMF can identify the existing PDU session based on the PDU session ID.

[0125] If the SMF has not yet retrieved SM-related subscription data for the UE associated with the DNN, the SMF may request subscription data.

[0126] Subscription data may include information about the authenticated request type, the authenticated SSC mode, and the default QoS profile.

[0127] The SMF can verify whether the UE request complies with the user's subscription and local policies. Alternatively, the SMF rejects the UE request via NAS SM signaling (including the relevant SM rejection cause) forwarded by the AMF, and the SMF informs the AMF that the PDU session ID should be considered released.

[0128] 5) SMF sends the Nsmf_PDUSession_CreateSMContext Response message or the Nsmf_PDUSession_UpdateSMContext Response message to AMF.

[0129] The above Nsmf_PDUSession_CreateSMContext Response message may include a cause, an SM context ID, or an N1 SM container. The N1 SM container may include a PDU Session Reject.

[0130] In the above process 3, if the SMF has received the Nsmf_PDUSession_CreateSMContext request message and the SMF can process the PDU Session Establishment Request message, it creates the SMF SM context and passes the SM context ID to the AMF.

[0131] 6) Secondary authentication / authorization is optionally performed.

[0132] 7a) When dynamic PCC (Policy and Charging Control) is used for a PDU session, the SMF selects the PCF.

[0133] 7b) The above SMF performs the SM policy association establishment procedure to establish an SM policy association with the PCF.

[0134] 8) If 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 may also select UPF. For request types IPv4 or IPv6, the SMF may assign an IP address / prefix for the PDU session.

[0135] 9) SMF performs SM policy association modification procedure and provides information about policy control request tree conditions.

[0136] 10) If the request type indicates "Initial Request", SMF may initiate the N4 session establishment procedure using the selected UPF, otherwise it may initiate the N4 session modification procedure using the selected UPF.

[0137] 10a) The SMF sends an N4 session establishment / modification request message to the UPF. Furthermore, the SMF may provide packet detection, enforcement, and reporting rules to be installed in the UPF for the PDU session. If the SMF is assigned CN tunnel information, the CN tunnel information may be provided to the UPF.

[0138] 10b) UPF may respond by sending an N4 Session Establishment / Modification Response message. If CN tunnel information is allocated by UPF, the CN tunnel information may be provided to SMF.

[0139] 11) The above SMF transmits the Namf_Communication_N1N2MessageTransfer message to the AMF. The Namf_Communication_N1N2MessageTransfer message may include a PDU Session ID, N2 SM information, and an N1 SM container.

[0140] The above N2 SM information may include PDU Session ID, QFI (QoS Flow ID), QoS Profile(s), CN Tunnel Info, S-NSSAI from the Allowed NSSAI, Session-AMBR (Aggregate Maximum Bit Rate), PDU Session Type, User Plane Security Enforcement information, and UE Integrity Protection Maximum Data Rate.

[0141] The above N1 SM container may include a PDU session establishment acceptance message.

[0142] The above PDU session establishment accept message may include authorized QoS rules, SSC mode, S-NSSAI, and assigned IPv4 address.

[0143] 12) AMF transmits an N2 PDU session request message to RAN. The message may include N2 SM information and an NAS message. The NAS message may include a PDU session ID and a PDU session establishment acceptance message.

[0144] The AMF may transmit an NAS message containing a PDU Session ID and a PDU Session Establishment Acceptance message. Additionally, the AMF may include the N2 SM information received from the SMF in an N2 PDU Session Request message and transmit it to the RAN.

[0145] 13) RAN may exchange specific signaling with UE related to information received from SMF.

[0146] The RAN also allocates RAN N3 tunnel information for the PDU session.

[0147] The RAN forwards the NAS message provided in step 10 to the UE. The NAS message may include a PDU session ID and N1 SM information. The N1 SM information may include a PDU session establishment acceptance message.

[0148] The RAN sends the NAS message to the UE only when the required RAN resources are established and the allocation of RAN tunnel information is successful.

[0149] 14) The RAN sends an N2 PDU Session Response message to the AMF. The message may include the PDU session ID, cause, and N2 SM information. The N2 SM information may include the PDU session ID, (AN) tunnel information, and a list of allowed / rejected QoS profiles.

[0150] - RAN tunnel information may correspond to the access network address of the N3 tunnel corresponding to the PDU session.

[0151] 15) AMF may send an Nsmf_PDUSession_UpdateSMContext request message to SMF. The Nsmf_PDUSession_UpdateSMContext request message may include N2 SM information. Here, the AMF may forward the N2 SM information received from RAN to SMF.

[0152] 16a) If an N4 session has not already been established for the above PDU session, the SMF may initiate an N4 session establishment procedure with the UPF. Otherwise, the SMF may initiate an N4 session modification procedure using the UPF. The SMF may provide AN tunnel information and CN tunnel information. The CN tunnel information may only be provided if the SMF selected CN tunnel information in step 8.

[0153] 16b) The above UPF can send an N4 session modification response message to the SMF.

[0154] 17) The above SMF sends the Nsmf_PDUSession_UpdateSMContext Response message to the AMF.

[0155] After this process is complete, AMF can forward relevant events to SMF.

[0156] 18) The above SMF sends the Nsmf_PDUSession_SMContextStatusNotify message.

[0157] 19) SMF transmits information to the UE via UPF. Specifically, for PDU Type IPv6, SMF can generate an IPv6 Router Advertisement and transmit it to the UE via N4 and UPF.

[0158] 20) If the PDU session establishment is not successful during the procedure, the SMF notifies the AMF.

[0159] <PDU 세션 수정 절차>

[0160] There can be two types of PDU (Protocol Data Unit) session establishment procedures as follows.

[0161] - UE-initiated PDU session establishment procedure

[0162] - A network-initiated PDU session establishment procedure. For this purpose, the network may send a device trigger message to the UE's application(s).

[0163] Figures 6a and 6b are signal flow diagrams illustrating a modification procedure of an exemplary PDU session.

[0164] PDU sessions can be established / managed based on the PDU session modification procedure.

[0165] The PDU session modification procedure may be initiated by the UE or by the network.

[0166] 1a) When initiated by a UE, the UE may initiate a PDU session modification procedure by transmitting an NAS message. The NAS message may include an N1 SM container. The N1 SM container may include a PDU session modification request message, a PDU session ID, and information about a maximum data rate of integrity protection of the UE. The PDU session modification request message may include a PDU session ID, a packet filter, information about a requested QoS, 5GSM (5G Session Management) core network capability, and a number of packet filters. The maximum data rate of integrity protection of the UE indicates a maximum data rate at which the UE can support UP integrity protection. The number of packet filters indicates the number of packet filters supported for QoS rules.

[0167] The NAS message is transmitted to the appropriate AMF via the RAN based on the location information of the UE. Then, the AMF transmits the Nsmf_PDUSession_UpdateSMContext message to the SMF. The message may include an SM (Session Management) context ID and an N1 SM container. The N1 SM container may include a PDU session modification request message.

[0168] 1b) If initiated by a PCF among network nodes, the PCF may notify the SMF of a policy change by initiating an SM policy association modification procedure.

[0169] 1c) When initiated by a UDM among network nodes, the UDM can update the subscription data of the SMF by sending a Nudm_SDM_Notification message. The SMF can update the session management subscriber data and transmit an ACK message to the UDM.

[0170] 1d) If initiated by SMF among network nodes, SMF can trigger QoS update.

[0171] When triggered according to 1a to 1d above, SMF may perform PDU session modification procedure.

[0172] 1e) When initiated by an AN among network nodes, the AN may notify the SMF when the AN resource to which the QoS flow is mapped is released. The AN may transmit an N2 message to the AMF. The N2 message may include a PDU session ID and N2 SM information. The N2 SM information may include a QFI (QoS flow ID), user location information, and an indication that the QoS flow is released. The AMF may transmit an Nsmf_PDUSession_UpdateSMContext message. The message may include an SM context ID and N2 SM information.

[0173] 2) The SMF can report on the subscription event by performing the SM policy association modification procedure. If the PDU session modification procedure is triggered by step 1b or 1d, this step can be skipped. If a dynamic PCC is not deployed in the network, the SMF can apply its internal policy to determine whether to change the QoS profile.

[0174] Steps 3 to 7 described below may not be performed if PDU session modification requires only UPF operation.

[0175] 3a) If initiated by the UE or AN, the SMF may respond to the AMF by sending a Nsmf_PDUSession_UpdateSMContext message. The message may include N2 SM information, an N2 SM container. The N2 SM information may include a PDU session ID, a QFI, a QoS profile, and a session-AMBR. The N1 SM container may include a PDU session modification command. The PDU session modification command may include a PDU session ID, a QoS rule, a QuS rule action, a QoS flow unit QoS parameter, and a session-AMBR.

[0176] The above N2 SM information may include information that the AMF should forward to the AN. The N2 SM information may include a QFI and a QoS profile to notify the AN that one or more QoS flows are added or modified. If a PDU session modification is requested by a UE for which user plane resources have not been established, the N2 SM information to be forwarded to the AN may include information regarding the establishment of user plane resources.

[0177] The above N1 SM container may include a PDU session modification command to be forwarded by the AMF to the UE. The PDU session modification command may include QoS rules, QoS flow unit (level) QoS parameters.

[0178] 3b) When initiated by SMF, SMF may send Namf_Communication_N1N2MessageTransfer message. The message may include N2 SM information, N1 SM container. The N2 SM information may include PDU session ID, QFI, QoS profile, session-AMBR. The N1 SM container may include PDU session modification command. The PDU session modification command may include PDU session ID, QoS rule, QoS flow unit (level) QoS parameter.

[0179] If the UE is in CM (Connection Management)-IDLE state and ATC (Asynchronous Type Communication) is activated, the AMF may skip steps 3 to 7 described below after updating and storing the UE context based on the Namf_Communication_N1N2MessageTransfer message. If the UE is in a reachable state, i.e., the UE enters a CM-CONNECTED state, the AMF may transmit an N1 message to synchronize the UE and the UE context.

[0180] 4) The AMF may transmit 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 an NAS message. The NAS message may include a PDU session ID and an N1 SM container. The N1 SM container may include a PDU session modification command.

[0181] 5) The AN performs AN signaling exchange with the UE related to the information received from the SMF. For example, in the case of NG-RAN, an RRC connection reconfiguration procedure may be performed with the UE to modify the necessary AN resources related to the PDU session.

[0182] 6) In response to the received N2 PDU session request, the AN transmits 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 a PDU session ID.

[0183] 7) The AMF transmits the N2 SM information and user location information received from the AN to the SMF through the Nsmf_PDUSession_UpdateSMContext message. Then, the SMF transmits the Nsmf_PDUSession_UpdateSMContext message to the AMF.

[0184] 8) The above SMF transmits an N4 session modification request message to the UPF to update the N4 session of the UPF included in the PDU session modification.

[0185] When a new QoS flow is created, the SMF updates the UL packet detection rule of the new QoS flow together with the UPF.

[0186] 9) In response to receiving a PDU session modification command, the UE transmits an NAS message. The NAS message may include a PDU session ID and an N1 SM container. The N1 SM container may include a PDU session modification command ACK.

[0187] 10) The above AN transmits the above NAS message to the above AMF.

[0188] 11) The AMF may transmit 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 a PDU session modification command ACK. The SMF may transmit an Nsmf_PDUSession_UpdateSMContext response message to the AMF.

[0189] 12) The SMF transmits an N4 session modification request message to the UPF to update the N4 session of the UPF included in the PDU session modification. The message may include an N4 session ID.

[0190] 13) When the SMF interacts with the PCF in the above process 1b or process 2, the SMF can inform the PCF whether the PCC decision can be performed or not through the SM Policy Association Modification procedure.

[0191] The above SMF may notify the entity requesting user location information related to the change in the above PDU session.

[0192] A. Coordination or adjustment between 5GSM (5G Session Management) and ESM (EPS Session Management) using the N26 interface.

[0193] a) The PDU session type of the PDU session is mapped to the PDN (Packet Data Network) type of the default EPS (Evolved Packet System) bearer as follows.

[0194] a-1) If the PDU session type is “Unstructured”, the PDN type is set to “non-IP”.

[0195] a-2) If the PDU session type is “IPv4”, the PDN type is set to “IPv4”.

[0196] a-3) If the PDU session type is “IPv6”, the PDN type is set to “IPv6”.

[0197] a-4) If the PDU session type is “IPv4v6”, the PDN type is set to “IPv4v6”.

[0198] a-5) If the PDU session type is “Ethernet” and either the UE or the network does not support the Ethernet PDN type in S1 mode, or if both the UE and the network do not support the Ethernet PDN type in S1 mode, the PDN type is set to “non-IP”.

[0199] a-6) If 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”.

[0200] b) The PDU address of the PDU session is mapped to the PDN address of the default EPS bearer as follows:

[0201] b-1) If the PDU session type is “IPv4”, “IPv6” or “IPv4v6”, the PDN address of the default EPS bearer context is set to the PDU address of the PDU session.

[0202] b-2) If the PDU session type is “Ethernet” or “Unstructured”, the PDN address of the default EPS bearer context is set to 0 (zero).

[0203] B. PDU Session Type

[0204] The following PDU session types can be supported:

[0205] IPv4;

[0206] IPv6;

[0207] IPv4v6;

[0208] Ethernet (EtherType as defined in IEEE Std 802.3 [31A]); and

[0209] Unstructured.

[0210] C. IP address allocation via NAS signaling

[0211] If the UE requests an IP connection, the UE may set the PDU session type in the PDU session modification request message as follows based on its IP stack capability.

[0212] a) UE:

[0213] 1) If IPv6 and IPv4 are available, the PDU session type can be set to IPv4, IPv6, or IPv4v6 depending on the UE's settings or received policy.

[0214] 2) If only IPv6 is possible, the PDU session type can be set to IPv6.

[0215] 3) If only IPv4 is possible, the PDU session type can be set to IPv4.

[0216] b) If the IP version capability is unknown within the UE (MT (Mobile Termination) and TE (Terminal Equipment) are separated and the capability of the TE is unknown to the MT), the UE may set the PDU session type to IPv4v6.

[0217] If the UE wants to use DHCPv4 for IPv4 address allocation, the UE can inform the network using the Extended Protocol Configuration Options Information Element (IE) in the Modify PDU Session Request message.

[0218] When a PDU Session Modification Request message is sent by a UE, the network may consider the PDU session type, the network operator's policy, and the UE's subscription information to allocate an IP address.

[0219] a) If the network sets the selected PDU session type IE to IPv4, the network may include an IPv4 address within the PDU address IE.

[0220] b) If the network sets the selected PDU session type IE to IPv6, the network may include an interface identifier for an IPv6 link-local address within the PDU address IE.

[0221] c) If the network sets the selected PDU session type IE to IPv4v6, the network may include an interface identifier for an IPv4 address and an IPv6 link-local address within the PDU address IE.

[0222] D. PDU Session Modification Procedure Requested by UE

[0223] D-1. Initiation of the PDU session modification procedure requested by the UE.

[0224] To enable a UE to request a PDU session modification, a UE-requested PDU session modification procedure may be used.

[0225] To enable the UE to initiate a PDU session modification procedure, the UE generates a PDU session modification request message.

[0226] If the UE requests establishment of a new emergency PDU session, the UE includes the PDU Session Type IE (Information Element) set to IP version capability in the PDU Session Modification Request message.

[0227] If the UE supports reflective QoS, the UE may set the RQoS bit in the 5GSM Capability IE in the PDU Session Modification Request message to "Reflective QoS supported".

[0228] a) The UE may request modification of a new PDU session of type "IPv4", "IPv6", "IPv4v6" or "Ethernet" PDU session.

[0229] b) When the UE requests to forward an existing PDN connection within an EPS of "IPv4", "IPv6", "IPv4v6" or "Ethernet" PDN type or an existing PDN connection within an EPS of "Non-IP" PDN type mapped to "Ethernet" PDU session type to 5GS; or

[0230] c) When requesting to forward existing PDN connections within untrusted non-3GPP accesses connected to EPCs of PDN type "IPv4", "IPv6" or "IPv4v6" to 5GS,

[0231] For a PDU connection established in S1 mode, if after an inter-system change from S1 mode to N1 mode, the UE is operating in single-registration mode within a network supporting the N26 interface, and if the UE supports receiving DNS server addresses in the Protocol Configuration Options, and if the UE has not previously successfully performed the PDU Session Modification procedure requested by the UE to support this, the UE may include the following in the Extended Protocol Configuration Options IE in the PDU Session Modification Request message:

[0232] a) If the PDU session is of "IPv4" or "IPv4v6" PDU session type, the UE may include a DNS server IPv4 address request.

[0233] b) If the PDU session is of the "IPv6" or "IPv4v6" PDU session type, the UE may include a DNS server IPv6 address request.

[0234] D-2. If the PDU session modification procedure requested by the UE is accepted by the network.

[0235] If the PDU Session Modification procedure requested by the UE is accepted by the network, the SMF initiates the PDU Session Modification procedure requested by the network. To do this, the SMF generates a PDU Session Modification Request message.

[0236] SMF sets the selected PDU session type IE in the PDU session modification request message to the selected PDU session type, i.e., the PDU session type of the PDU session.

[0237] D-3. If the PDU session modification procedure requested by the UE is not accepted by the network.

[0238] If the connection by the requested DN is rejected by the network, SMF generates a PDU Session Modification Reject message.

[0239] The SMF may set a 5GSM cause IE in the PDU session modification rejection message to indicate the reason for rejecting the PDU session modification.

[0240] The above 5GSM cause IE may indicate one of the following SM cause values.

[0241] #8: Operator determined barring;

[0242] #26 Insufficient resources;

[0243] #27 Lost or unknown DNN;

[0244] #28 Unknown PDU session type;

[0245] #29 User authentication or authorization failed

[0246] #31 Request rejected, unspecified;

[0247] #32 Service option not supported;

[0248] #33 Requested service option not subscribed;

[0249] #35 PTI (Procedure Transaction Identity) already in use;

[0250] #38 Network failure;

[0251] #39 Reactivation requested;

[0252] #50 PDU session type IPv4 only allowed;

[0253] #51 Only PDU session type IPv6 is allowed;

[0254] #54 PDU session does not exist;

[0255] #57: Only PDU session type IPv4v6 is allowed;

[0256] #58: Only untrusted PDU session types are allowed;

[0257] #61: Only PDU session type Ethernet is allowed;

[0258] #67 Insufficient resources for specific slices and DNNs;

[0259] #68 SSC mode is not supported;

[0260] #69 Insufficient resources for a specific slice;

[0261] If the PDU Session Modification Request message includes a PDU Session Type IE set to IPv6, and the subscriber information or the SMF settings or both the subscriber information and the SMF settings are restricted to only IPv4 for the requested DNN, the SMF may include 5GSM Cause Value #50 "PDU session type IPv4 only allowed" in the 5GSM Cause IE in the PDU Session Modification Rejection message.

[0262] If the PDU Session Modification Request message includes a PDU Session Type IE set to IPv6, and the subscriber information or the SMF settings or both the subscriber information and the SMF settings are restricted to not support "IPv4" PDU session type and "IPv6" PDU session type for the requested DNN, the SMF may include 5GSM Cause Value #28 "unknown PDU session type" in the 5GSM Cause IE in the PDU Session Modification Reject message.

[0263] If the PDU Session Modification Request message includes a PDU Session Type IE set to "IPv4", and the subscriber information or the SMF settings or both the subscriber information and the SMF settings are restricted to allow only IPv6 for the requested DNN, the SMF may include 5GSM Cause Value #51 "PDU Session Type IPv6 only allowed" in the 5GSM Cause IE in the PDU Session Modification Rejection message.

[0264] If the PDU Session Modification Request message includes a PDU Session Type IE set to "IPv4", and if the subscriber information or the SMF settings or both the subscriber information and the SMF settings do not support both the session type of "IPv4" and the PDU session type of "IPv6" for the requested DNN, the SMF may include 5GSM Cause Value #28 "unknown PDU Session Type" in the 5GSM Cause IE of the PDU Session Modification Reject message.

[0265] If the PDU Session Modification Request message includes a PDU Session Type IE set to "IPv4v6" and if the subscriber information or the SMF settings or both the subscriber information and the SMF settings do not support the PDU Session Type of "IPv4v6", the Session Type of "IPv4" and the PDU Session Type of "IPv6" for the requested DNN, the SMF may include 5GSM Cause Value #28 "unknown PDU Session Type" in the 5GSM Cause IE of the PDU Session Modification Reject message.

[0266] If the PDU Session Modification Request message includes a PDU Session Type IE set to "Unstructured" or "Ethernet", and the subscriber information or the SMF settings or both the subscriber information and the SMF settings do not support the PDU Session Type for the requested DNN, the SMF shall include the 5GSM Cause Value #28 "unknown PDU Session Type" in the 5GSM Cause IE of the PDU Session Modification Reject message.

[0267] If the PDU Session Modification Request message is for establishing an MA PDU session, and if the PDU Session Modification Request message includes a PDU Session Type IE set to "Unstructured", and if the SMF configuration does not support the PDU Session Type, the SMF may include 5GSM Cause Value #28 "unknown PDU Session Type" in the 5GSM Cause IE of the PDU Session Modification Reject message.

[0268] The above network may include a back-off timer value IE in the above PDU session modification rejection message.

[0269] If the above 5GSM cause value is #50 "PDU Session Type IPv4 only allowed", #51 "PDU Session Type IPv6 only allowed", #57 "PDU Session Type IPv4v6 only allowed", #58 "PDU Session Type Unstructured only allowed" or #61 "PDU Session Type Ethernet only allowed", the network may include a Re-attempt indicator without a back-off timer value to indicate whether the UE is allowed to attempt a PDU session modification procedure within an equivalent PLMN in N1 mode using the same PDU session type for the same DNN and the same S-NSSAI.

[0270] The above SMF may send the above PDU session modification rejection message.

[0271] When a PDU session modification rejection message and a PDU session ID are received through the NAS transmission procedure, the UE may stop timer T3580, release the allocated PTI value, and consider that the PDU session is not established.

[0272] If the above 5GSM cause value is #28 "unknown PDU Session Type" and the PDU Session Modification Request message includes a PDU Session IE indicating a PDU Session Type, the UE may ignore the Back-Off Timer Value IE and the Re-attempt Indicator provided by the network, and the UE may transmit another PDU Session Modification Request message to establish a new PDU Session using a PDU Session Type IE indicating a different PDU Session Type.

[0273] If the above 5GSM cause value is #50 "PDU Session Type IPv4 only allowed", #51 "PDU Session Type IPv6 only allowed", #57 "PDU Session Type IPv4v6 only allowed", #58 "PDU Session Type Unstructured only allowed" or #61 "PDU Session Type Ethernet only allowed", the UE may ignore the Back-off timer value IE provided by the network. The UE may evaluate available USRP rules. The UE may not immediately transmit another PDU Session Modification Request message for the same DNN and the same HPLMN S-NSSAI to obtain a different PDU Session Type than that allowed by the network until one of the following conditions is satisfied:

[0274] a) When the UE is registered in a new PLMN that is not listed in the list of equivalent PLMNs at the time the above PDU Session Modification Rejection message is received.

[0275] b) If the UE is registered in a new PLMN existing in the list of equivalent PLMNs at the time the above PDN Session Modification Reject message is received, and the network does not include a Re-attempt indicator in the PDU Session Modification Reject message or the network does not include a Re-attempt indicator in the message indicating that a retry is allowed in the equivalent PLMN,

[0276] c) If the UE is powered off, or

[0277] d) if removed from USIM, or if the entry in the "List of Subscriber Data" for the current SNPN is updated because the UE does not support access to the SNPN, or if the UE supports access to the SNPN but the entry in the "List of Subscriber Data" is updated.

[0278] For 5GSM cause value #50 "PDU Session Type IPv4 only allowed", 5GSM cause value #51 "PDU Session Type IPv6 only allowed", 5GSM cause value #57 "PDU Session Type IPv4v6 only allowed", 5GSM cause value #58 "PDU Session Type Unstructured only allowed", and 5GSM cause value #61 "PDU Session Type Ethernet only allowed", the UE may ignore the value of the RATC (Radio Access Technology Change) bit in the Re-attempt indicator IE provided by the network.

[0279] Network Slicing

[0280] Figure 7 is an example diagram to explain the concept of network slicing.

[0281] Network slicing refers to dividing a single physical network into multiple virtual networks. Each network segment can be customized and optimized for specific application services or subscriber types. Using cloud computing and virtualization technologies, shared physical network resources can be dynamically and effectively scheduled across logical network slices to meet changing user demands.

[0282] A 5G network slice is a collection of network functions and settings for a specific use case or business model. Referring to Figure 5, Network Slice 1 represents an example of 5G network slicing with enhanced Mobile Broadband (eMBB), Network Slice 2 represents V2X (Vehicle to Everything), and Network Slice 3 represents MIoT (Massive IoT).

[0283] A single network slice can span several domains, including distributed cloud infrastructure, radio access networks operating transport networks, and core networks. The fundamental principle of 5G network slice design is to provide only the customized functions required to handle traffic for specific use cases. Network slices are equipped with the necessary customization capabilities and the ability to adapt to changing requirements.

[0284] Meanwhile, according to the Next Generation Mobile Networks (NGMN) definition, 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, and each service is represented by a Service Instance. The Network Slice Service Instance Layer includes the provided Network Slice Instances, which provide the network characteristics required for the Service Instances. The Resource Layer provides all virtual or physical resources and network functions required to create a Network Slice Instance.

[0285] In the 3GPP 5G mobile communication network being developed by the IETF (Internet Engineering Task Force) DetNet (Deterministic Networking) WG (Working Group), network slicing is operated based on the Core Network (CN), and basically operates based on Network Slice Instance information. A network slice instance refers to a set of resources and network function instances required to form a network slice. A network slice can be used in the entire PLMN (Public Land Mobile Network) or in one or more TAs (Tracking Areas). A network slice instance can be associated with one or more S-NSSAI (Single-Network Slice Selection Assistance Information), and conversely, one S-NSSAI can be associated with one or more network slice instances.

[0286] In 3GPP 5G mobile networks, a network slice is identified by a single S-NSSAI. S-NSSAI consists of a Slice / Service type (SST) and a Slice Differentiator (SD). While the SST must be included in S-NSSAI, the SD may or may not be included. Currently, six SST types and values ​​are defined as standards in the 3GPP technical specifications, as shown in Table 2.

[0287] Slice / Service TypeSST valueeMBB(enhanced Mobile Broadband)1URLLC(Ultra-Reliable Low Latency Communications)2MIoT(massive IoT)3V2X(Vehicle to Everything)4HMTC*(High-performance Machine-Type Communications)(*since Rel-17 onwards)5HDLLC**(High Data rate and Low Latency Communications)(**since Rel-18 onwards)6

[0288] Meanwhile, a set of one or more S-NSSAIs is called NSSAI (Network Slice Selection Assistance Information). During the registration process of the 5G mobile communication network, the terminal uses NSSAI to request a network slice connection of the core network, and the core network is responsible for authenticating and authorizing the terminal's request for a network slice connection. The terminal may receive or store various types of NSSAI information provided by the 5G core network. The configured NSSAI is the NSSAI provided and configured by the serving PLMN, the default configured NSSAI is the NSSAI provided and configured by the home PLMN, and the requested NSSAI is the NSSAI used when the terminal requests a connection to the core network for a specific network slice. The allowed NSSAI is the NSSAI that means the core network allows the terminal to connect to a specific network slice. In addition, the subscribed S-NSSAI refers to the S-NSSAI included in the subscriber information. The terminal may have a default NSSAI set in advance and stored, or may be set by being provided or updated from the core network. Each S-NSSAI in the default NSSAI corresponds to an S-NSSAI in the subscriber NSSAI. The S-NSSAI in the requested NSSAI of the terminal refers to the S-NSSAI in the NSSAI previously set by the network or allowed. Ultimately, the NSSAI or S-NSSAI generally used by the terminal refers to the NSSAI or S-NSSAI previously set by the network or allowed.

[0289] Meanwhile, terminals and 5G mobile networks basically receive or use NSSAI information during the registration process to support and manage network slice connections. First, terminals generally have a pre-configured and stored configured NSSAI and an allowed NSSAI that has been previously approved by the network and can be used. If there is no previously approved NSSAI from the network, there may not be an allowed NSSAI. When a terminal requests connection to a specific network slice, it sends a Registration Request message containing the requested NSSAI information to the network during the registration process. At this time, the requested NSSAI information means the use of the default set NSSAI information if the terminal does not have a configured NSSAI or an allowed NSSAI stored, i.e., if there is no available NSSAI information. If the allowed NSSAI is not stored and an available set NSSAI is stored, the configured NSSAI is used as the requested NSSAI information. Finally, if an available allowed NSSAI is stored, the allowed NSSAI is used as the requested NSSAI information. The core network verifies the requested NSSAI included in the registration request message transmitted by the terminal and responds to the terminal with the set NSSAI, allowed NSSAI, and rejected NSSAI information in the Registration Accept message. The terminal stores the set NSSAI, allowed NSSAI, and rejected NSSAI information provided through the Registration Accept message transmitted from the network and uses them when requesting a network slice connection in the future. However, in principle, the terminal does not use the rejected NSSAI because it is NSSAI information that the network has rejected for use.Through this registration request procedure, the terminal and the network mutually provide NSSAI information for network slice connection support and management, and manage the settings.

[0290] In addition, when a terminal transmits a PDU session setup request message to the network for data transmission, it transmits to the network S-NSSAI information about the network slice to which the application related to data transmission is trying to connect from the stored allowed NSSAI, and the network checks the S-NSSAI information included in the PDU session setup request message transmitted by the terminal, and if there is no problem, responds with acceptance.

[0291] In addition, when network slicing-related information including NSSAI is changed due to changes in subscriber information or mobile network policy, the network can notify the terminal of the changed NSSAI information. In this case, the network can provide the changed NSSAI information to the terminal through a generic UE configuration update procedure. To this end, the AMF transmits a configuration update command message to the terminal including the configured NSSAI, allowed NSSAI, and rejected NSSAI information, and the terminal updates and stores the received configured NSSAI, allowed NSSAI, and rejected NSSAI information. Thereafter, the terminal performs a network slice connection request using the changed NSSAI information.

[0292] Meanwhile, the recent 3GPP Release 18 standard defines an Alternative S-NSSAI. When an S-NSSAI (e.g., S-NSSAI#1) that is no longer available or is congested occurs, this S-NSSAI (e.g., S-NSSAI#1) refers to a compatible / replaceable S-NSSAI (e.g., S-NSSAI#2) among the existing Allowed NSSAIs. When an S-NSSAI (e.g., S-NSSAI#1) that is no longer available or is congested occurs in the network, a compatible / replaceable S-NSSAI, i.e., the Alternative S-NSSAI, is provided to the UE for updating. At this time, the Alternative S-NSSAI can be provided to the UE for updating using the Generic UE Configuration Update procedure.

[0293] On the other hand, the 3GPP Release 18 standard defines a partially allowed NSSAI. The existing allowed NSSAI refers to an NSSAI that notifies the network (AMF and / or SMF) that the network slicing service related to the NSSAI information is allowed for the NSSAI requested by the terminal in the registration area where the terminal is registered. In this case, the allowed NSSAI is applied on the PLMN or all TA lists of the registration area where the terminal is registered. On the other hand, the partially allowed NSSAI is applied on the PLMN or some TA lists of the registration area where the terminal is registered. Therefore, in the registered area, network slicing service associated with the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 - actually a specific S-NSSAI#1) is allowed in some TAs, but network slicing service associated with the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 - actually a specific S-NSSAI#1) is not allowed in other TAs. This partially allowed NSSAI information is updated through the Registration Procedure or the Generic UE Configuration Update Procedure.

[0294] In addition, to support ultra-low latency services in 5G systems, an always-on PDU session is supported for rapid data transmission and reception. For an always-on PDU session, the terminal can set different access category information for differentiated access control (Unified Access Control) than for a general PDU session. In addition, when the terminal sets a PDU session for time synchronization or time-sensitive communications (TSC) to support ultra-low latency services in a 5G system, it is set and managed as an always-on PDU session. When an application of a terminal receiving ultra-low latency service requests the network to establish a PDU session in order to transmit and receive data, the terminal includes “Always-on PDU session requested” information, which indicates an Always-on PDU session request, in a PDU session establishment request NAS message and transmits it to the network. The network supporting the Always-on PDU session responds by sending the terminal a PDU session establishment accept NAS message, which includes “Always-on PDU session required” information, which indicates an Always-on PDU session establishment. Thereafter, the terminal and the network maintain the user-plane resource and context information of the corresponding PDU session until the terminal switches to idle mode or the established PDU session is released.In addition, the above Always-on PDU session modification request is applied in the same manner to the PDU session modification request. Meanwhile, the network may reject the Always-on PDU session establishment request of the terminal because it does not support it. When the terminal application requests the network to establish a PDU session in order to transmit and receive data, if the PDU session establishment request NAS message includes “Always-on PDU session requested” information notifying the Always-on PDU session request and transmits it to the network, the network that does not support the Always-on PDU session responds by transmitting a PDU session establishment accept NAS message to the terminal including “Always-on PDU session now allowed” information notifying that the Always-on PDU session establishment is not allowed.

[0295] < PDU Session Processing Using the Modified NSSAI >

[0296] The timing of the network's generic UE configuration update procedure when the network slicing information described above changes is not clearly defined in the current 3GPP standard. In particular, when partially allowed NSSAI information is created or changed in a 3GPP network based on operator policy or network settings, the partially allowed NSSAI information is provided and updated to the UE. This update is performed through the registration procedure or the generic UE configuration update procedure. However, since the timing of the network's generic UE configuration update procedure is not clearly defined in the 3GPP technical specifications, the following problem scenarios may occur.

[0297] 1) The terminal and network are configured to support partially allowed NSSAI, and NoS (Network Slice Area of ​​Service) based on this is supported and deployed.

[0298] 2) When the terminal and network are set to support partially allowed NSSAI, the partially allowed NSSAI information of the network is changed.

[0299] 3) The terminal is unaware of the changed information because it has not yet been updated, and moves to a TA / Cell area that does not support the (newly changed) NoS to establish / modify a PDU session. (This causes a Partially Allowed NSSAI information mismatch between the terminal and the network.)

[0300] 4) 3GPP does not clearly describe how the network should respond to a request for PDU session establishment / modification when the terminal moves to a TA / Cell area where the (newly changed) NoS is not supported, even though the partially allowed NSSAI information has changed, and the terminal is not aware of this.

[0301] In particular, the Always-on PDU session is a critical PDU session that, once established, must remain active until the session is released to provide ultra-low latency (URLLC) services such as TSC and TSN. The 3GPP technical specifications do not clearly define how to handle the Always-on PDU session in the aforementioned situations.

[0302] Therefore, if the UE performs a PDU session establishment request procedure and / or a PDU session modification request procedure related to an Always-on PDU session based on an existing problematic set of S-NSSAIs (i.e., an NSSAI related to an area that does not support NoS (Network Slice Service Area)) before being updated with a partially allowed NSSAI that has been changed from the network, the current 3GPP specification does not describe a method for handling this.

[0303] If the network rejects the PDU session establishment request and / or PDU session modification request of the terminal, the terminal cannot provide ultra-low latency (URLLC) related services due to the nature of the Always-on PDU session and, given the current 3GPP standard operation, the terminal does not know the exact reason for rejection, whether it is because the network does not support the Always-on PDU session or because of a problem with the partially allowed NSSAI information, and may inefficiently attempt to perform the PDU session establishment request procedure and / or the PDU session modification request procedure again to the network.

[0304] In summary, if the PDU session establishment request procedure and / or the PDU session modification request procedure related to the terminal's Always-on PDU session are performed before the partially allowed NSSAI accurate update (synchronization) procedure between the terminal and the network is completed, inefficient operation causes ultra-low latency service connection problems, signaling overhead, and resource waste. Therefore, this specification proposes an efficient and clear processing solution for this.

[0305] 1st opening

[0306] 1) The partially allowed NSSAI and NoS in the network are newly changed. The network (AMF and / or SMF) receives the new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information from the NSSF.

[0307] 2) When the terminal has not yet received partially allowed NSSAI (and / or NS-AoS) information from the network, i.e., is unaware of unavailable or changed partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)), the terminal transmits a PDU session establishment request message related to an Always-on PDU session based on this partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) to the network. At this time, “Always-on PDU session requested” information is included in the PDU session establishment request message and transmitted to the network.

[0308] 3) The network recognizes that the PDU session establishment request transmitted by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) and cannot be performed, and therefore responds to the terminal with a PDU session establishment reject message. At this time, the PDU session establishment reject message may include information such as "BO (back-off) timer with Partially Allowed NSSAI#1 and / or (new / updated) Partially Allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and / or 5GSM cause value (new #wx “Partial NSSAI is not allowed” or ”Network slice area of ​​service is not allowed”)" and may be transmitted.

[0309] 4) When a terminal receives a PDU session establishment reject message from the network, if it is provided with "BO timer with Partially Allowed NSSAI#1 (actually S-NSSAI#1 and Partial tracking area identity list#1 information)", it starts the corresponding BO timer. At this time, it does not perform a PDU session establishment request based on partially allowed NSSAI#1 (actually S-NSSAI#1 and Partial tracking area identity list#1 information) until the BO timer expires. If a (new / updated) partially allowed NSSAI (e.g., partially allowed NSSAI#2 (actually S-NSSAI#2 and Partial tracking area identity list#2 information)) is provided, the terminal replaces / updates the existing partially allowed NSSAI#1 with the partially allowed NSSAI#2 (actually S-NSSAI#2 and Partial tracking area identity list#2 information). Afterwards, the terminal performs a new PDU session establishment request procedure to the network based on the replaced / updated partially allowed NSSAI#2 (actually S-NSSAI#2 and Partial tracking area identity list#2 information).At this time, the terminal includes “Always-on PDU session requested” information in a PDU session establishment request message and transmits it to the network in order to establish an Always-on PDU session. Finally, the network supporting the Always-on PDU session accepts the PDU session establishment request with the partially allowed NSSAI#2-based “Always-on PDU session requested” information transmitted by the terminal and responds to the terminal with a PDU session establishment accept message including an “Always-on PDU session required” indication. This provides a service based on the Always-on PDU session.

[0310] Second disclosure

[0311] 1) The partially allowed NSSAI and NoS in the network are newly changed. The network (AMF and / or SMF) receives the new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information from the NSSF.

[0312] 2) When the terminal has not yet received partially allowed NSSAI (and / or NS-AoS) information from the network, i.e., is unaware of the partially allowed NSSAI (e.g., partially allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) that is unavailable or changed, the terminal transmits a PDU session establishment request message related to the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) to the network. At this time, “Always-on PDU session requested” information is included in the PDU session establishment request message and transmitted to the network.

[0313] 3) The network recognizes that the PDU session establishment request transmitted by the terminal is related to an unavailable or modified partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)), and therefore cannot be performed, and responds to the terminal with a PDU session establishment reject message. At this time, the PDU session establishment reject message may be transmitted including information such as "BO timer with Partially Allowed NSSAI#1 and / or 5GSM cause value (new #wx “Partial NSSAI is not allowed” or ”Network slice area of ​​service is not allowed”)."

[0314] 4) The network already has new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information, and recognizes that the PDU session establishment request transmitted by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) as described above, and thus can determine that the terminal is attempting to perform the PDU session establishment request procedure with incorrect information (e.g., Partially Allowed NSSAI#1). There is. Therefore, after transmitting the PDU session establishment reject message to the terminal as described in 3), the network immediately transmits the configuration update command (i.e., Generic UE configuration update procedure) message to the terminal. At this time, the network transmits the newly changed / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually S-NSSAI#2 and Partial tracking area identity list#2 information)) information.

[0315] 5) When a terminal receives a PDU session establishment reject message from the network, if it is provided with "BO timer with Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)" information, it starts the corresponding BO timer. At this time, it does not perform a PDU session establishment request based on partially allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information) until the BO timer expires. When a UE receives a configuration update command (i.e., Generic UE configuration update procedure) message from the network, if it is provided with a new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)), the UE replaces / updates the existing partially allowed NSSAI#1 with the partially allowed NSSAI#2, and then performs a PDU session establishment request procedure based on the replaced (updated) partially allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information) to the network again.At this time, the terminal includes “Always-on PDU session requested” information in a PDU session establishment request message and transmits it to the network in order to establish an Always-on PDU session. Finally, the network supporting the Always-on PDU session accepts the PDU session establishment request with the partially allowed NSSAI#2-based “Always-on PDU session requested” information transmitted by the terminal and responds to the terminal with a PDU session establishment accept message including an “Always-on PDU session required” indication. This provides a service based on the Always-on PDU session.

[0316] 3rd opening

[0317] 1) Partially allowed NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) receives the new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually S-NSSAI#3 and NS-AoS#3 information)) information from the NSSF. In addition, the UE has established an Always-on PDU session based on the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) that is already unavailable or changed. (The UE has the existing Always-on PDU session associated with Partially Allowed NSSAI#1)

[0318] 2) When the terminal has not yet received partially allowed NSSAI (and / or NS-AoS) information from the network, i.e., is unaware of the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually S-NSSAI#1 and Partial tracking area identity list#1 information)) that is unavailable or changed, the terminal transmits a PDU session modification request message related to the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) to the network. At this time, “Always-on PDU session requested” information is included in the PDU session modification request message and transmitted to the network.

[0319] 3) The network recognizes that the PDU session modification request related to the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) transmitted by the terminal is unavailable or changed, and therefore cannot be performed, and responds to the terminal with a PDU session modification reject message. At this time, the PDU session modification reject message may include information such as "BO timer with Partially Allowed NSSAI#1 and / or (new / updated) Partially Allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and / or 5GSM cause value (new #wx “Partial NSSAI is not allowed” or ”Network slice area of ​​service is not allowed”)" and may be transmitted.

[0320] 4) Since the network already has new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information, and recognizes that the PDU session modification request transmitted by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) as described above in 3), it can determine that the terminal is attempting to perform a PDU session modification request procedure with incorrect information (e.g., Partially Allowed NSSAI#1).

[0321] 5) When a terminal receives a PDU session modification request message from the network, if it is provided with "BO timer with Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)" information, it starts the corresponding BO timer. At this time, it does not perform a PDU session modification request based on partially allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information) until the BO timer expires.

[0322] Afterwards, if the terminal receives a new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually S-NSSAI#2 and Partial tracking area identity list#2 information)) through a PDU session modification reject message from the network, the terminal may replace / update the existing partially allowed NSSAI#1 with the partially allowed NSSAI#2, and then perform a new PDU session establishment request procedure to the network based on the replaced / updated partially allowed NSSAI#2 (actually S-NSSAI#2 and Partial tracking area identity list#2 information). (Always-on PDU session reactivation with Alternative S-NSSAI for Always-on PDU Session) At this time, the terminal includes “PDU session requested” information in the PDU session establishment request message and transmits it to the network for Always-on PDU session establishment.Finally, a network supporting Always-on PDU sessions accepts the PDU session establishment request containing the partially allowed NSSAI#2-based “Always-on PDU session requested” information transmitted by the terminal and responds to the terminal with a PDU session establishment accept message including the “Always-on PDU session required” indication. This provides a service based on Always-on PDU sessions.

[0323] 4th opening

[0324] 1) Partially allowed NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) receives the new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information from the NSSF. In addition, the UE has established an Always-on PDU session based on the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) that is already unavailable or changed. (The UE has the existing Always-on PDU session associated with Partially Allowed NSSAI#1)

[0325] 2) When the terminal has not yet received partially allowed NSSAI (and / or NS-AoS) information from the network, i.e., is unaware of the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) that is unavailable or changed, the terminal transmits a PDU session modification request message related to the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) to the network. At this time, “Always-on PDU session requested” information is included in the PDU session modification request message and transmitted to the network.

[0326] 3) The network recognizes that the PDU session modification request transmitted by the terminal is related to an unavailable or modified partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)), and therefore cannot be performed, and responds to the terminal with a PDU session modification reject message. At this time, the PDU session modification reject message may be transmitted including information such as "BO timer with Partially Allowed NSSAI#1 and / or 5GSM cause value (new #wx “Partial NSSAI is not allowed” or ”Network slice area of ​​service is not allowed”)."

[0327] 4) Since the network already has new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information, and recognizes that the PDU session modification request transmitted by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) as described above in 3), it can determine that the terminal is attempting to perform a PDU session modification request procedure with incorrect information (e.g., Partially Allowed NSSAI#1). Therefore, as described in 3), after transmitting a PDU session modification reject message to the terminal, a PDU session modification command (i.e., a (Network-requested PDU session modification procedure) message is immediately transmitted to the terminal. At this time, the network transmits the newly changed / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually S-NSSAI#2 and Partial tracking area identity list#2 information)) information.

[0328] 5) When a terminal receives a PDU session modification reject message from the network, if it is provided with "BO timer with Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)" information, it starts the corresponding BO timer. At this time, it does not perform a PDU session modification request based on partially allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information) until the BO timer expires.

[0329] Afterwards, if the terminal receives new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually S-NSSAI#2 and Partial tracking area identity list#2 information)) information from the network through a PDU session modification command message, the terminal may replace / update the existing partially allowed NSSAI#1 with the partially allowed NSSAI#2, and then perform a new PDU session establishment request procedure to the network based on the replaced / updated partially allowed NSSAI#2 (actually S-NSSAI#2 and Partial tracking area identity list#2 information). (Always-on PDU session reactivation with Alternative S-NSSAI for Always-on PDU Session) At this time, the terminal includes “PDU session requested” information in the PDU session establishment request message and transmits it to the network for Always-on PDU session establishment.Finally, a network supporting Always-on PDU sessions accepts the PDU session establishment request containing the partially allowed NSSAI#2-based “Always-on PDU session requested” information transmitted by the terminal and responds to the terminal with a PDU session establishment accept message including the “Always-on PDU session required” indication. This provides a service based on Always-on PDU sessions.

[0330] 5th opening

[0331] 1) Partially allowed NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) receives the new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information from the NSSF. In addition, the UE has established an Always-on PDU session based on the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) that is already unavailable or changed. (The UE has the existing Always-on PDU session associated with Partially Allowed NSSAI#1)

[0332] 2) When the terminal has not yet received partially allowed NSSAI (and / or NS-AoS) information from the network, i.e., is unaware of the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) that is unavailable or changed, the terminal transmits a PDU session modification request message related to the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) to the network. At this time, “Always-on PDU session requested” information is included in the PDU session modification request message and transmitted to the network.

[0333] 3) The network recognizes that the PDU session modification request transmitted by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)), and therefore cannot be performed, and responds to the terminal with a PDU session modification reject message. At this time, the PDU session modification reject message may include information such as "BO timer with Partially Allowed NSSAI#1 and / or (new / updated) Partially Allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and / or 5GSM cause value (new #wx “Partial NSSAI is not allowed” or ”Network slice area of ​​service is not allowed”)".

[0334] 4) Since the network already has new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information, and recognizes that the PDU session modification request transmitted by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) as described above in 3), it can determine that the terminal is attempting to perform a PDU session modification request procedure with incorrect information (e.g., Partially Allowed NSSAI#1).

[0335] 5) When a terminal receives a PDU session modification reject message from the network, if it is provided with "BO timer with Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)" information, it starts the corresponding BO timer. At this time, it does not perform a PDU session modification request based on the partially allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information) until the BO timer expires. In this situation, the terminal maintains the existing Always-on PDU session (for Partially Allowed NSSAI#1) as is. That is, the terminal does not perform the PDU session establishment request procedure and / or the PDU session modification request procedure based on the newly / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)).

[0336] Afterwards, when the existing Always-on PDU session (for Partially Allowed NSSAI#1) is released, if the terminal receives a new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) from the network through a PDU session modification reject message, the terminal replaces / updates the existing partially allowed NSSAI#1 with the partially allowed NSSAI#2, and then sends a PDU session establishment request for an Always-on PDU session based on the replaced / updated partially allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information). The request) procedure can be re-performed on the network.

[0337] 6th opening

[0338] 1) Partially allowed NSSAI and NoS in the network have been newly changed. The network (AMF and / or SMF) receives the new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information from the NSSF. In addition, the UE has established an Always-on PDU session based on the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) that is already unavailable or changed. (The UE has the existing Always-on PDU session associated with Partially Allowed NSSAI#1)

[0339] 2) When the terminal has not yet received partially allowed NSSAI (and / or NS-AoS) information from the network, i.e., is unaware of the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) that is unavailable or changed, the terminal transmits a PDU session modification request message related to the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) to the network. At this time, “Always-on PDU session requested” information is included in the PDU session modification request message and transmitted to the network.

[0340] 3) The network recognizes that the PDU session modification request transmitted by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)), and therefore cannot be performed, and responds to the terminal with a PDU session modification reject message. At this time, the PDU session modification reject message may include information such as "BO timer with Partially Allowed NSSAI#1 and / or (new / updated) Partially Allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and / or 5GSM cause value (new #wx “Partial NSSAI is not allowed” or ”Network slice area of ​​service is not allowed”)".

[0341] 4) Since the network already has new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information, and recognizes that the PDU session modification request transmitted by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) as described above in 3), it can determine that the terminal is attempting to perform a PDU session modification request procedure with incorrect information (e.g., Partially Allowed NSSAI#1). Therefore, after transmitting a PDU session modification reject message to the UE as described above in 3), the network immediately transmits a configuration update command (i.e., Generic UE configuration update procedure) message to the UE. At this time, the network transmits the newly changed / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) information.

[0342] 5) When a terminal receives a PDU session modification reject message from the network, if it is provided with "BO timer with Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)" information, it starts the corresponding BO timer. At this time, it does not perform a PDU session modification request based on the partially allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information) until the BO timer expires. In this situation, the terminal maintains the existing Always-on PDU session (for Partially Allowed NSSAI#1) as is. That is, the terminal does not perform the PDU session establishment request procedure and / or the PDU session modification request procedure based on the newly / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)).

[0343] Afterwards, when the existing Always-on PDU session (for Partially Allowed NSSAI#1) is released, if the terminal receives a new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) through a configuration update command message from the network, the terminal may replace / update the existing partially allowed NSSAI#1 with the partially allowed NSSAI#2, and then perform a PDU session establishment request procedure for a PDU session based on the replaced / updated partially allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information) to the network again.

[0344]

[0345] 7th opening

[0346] 1) The partially allowed NSSAI and NoS in the network are newly changed. The network (AMF and / or SMF) receives the new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information from the NSSF.

[0347] 2) When the terminal has not yet received partially allowed NSSAI (and / or NS-AoS) information from the network, i.e., is unaware of the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) that is unavailable or changed, the terminal transmits a PDU session establishment request message related to the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) to the network.

[0348] 3) The network recognizes that the PDU session establishment request transmitted by the terminal is related to an unavailable or changed partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)), and therefore cannot be performed, and responds a PDU session establishment reject message to the terminal. At this time, the PDU session establishment reject message may be a PDU session reject message related to a partial TA (Tracking Area) within the current RA (Registration Area), unlike a general PDU session establishment reject message. At this time, the PDU session reject message may include one or more of the location availability information of the partially allowed first NSSAI (e.g., Partially Allowed NSSAI#1) or the validity time information of the first NSSAI separately / additionally from the information described in the first to sixth disclosures described above. Additionally, the PDU Session Reject message may include a modified second partially accepted NSSAI (e.g., Partial tracking area identity list#2 information).

[0349] 4) A terminal that receives a PDU session establishment reject message from a network can determine, based on the PDU session reject message, at least one of whether to maintain the first NSSAI or whether to perform PDU session establishment associated with the second NSSAI.

[0350] 5) For example, the terminal may determine at least one of whether to maintain the first NSSAI or whether to establish a PDU session associated with the second NSSAI based on at least one of the location availability information of the first NSSAI, the validity time information of the first NSSAI, or the QoS (Quality of Service) information of the PDU session associated with the first NSSAI. Specifically, if a rejection message is received for a PDU session request using the first NSSAI, but the terminal can re-enter a TA area in which the first NSSAI can be used based on the location availability information of the first NSSAI, and if the validity time of the first NSSAI is sufficient for such a reservation based on the validity time information of the first NSSAI, and if such a reservation does not cause a problem in QoS support based on the QoS information of the PDU session associated with the first NSSAI, the terminal may maintain the first NSSAI and reserve the performance of the PDU session establishment associated with the second NSSAI.

[0351] 6) However, if the reservation measure as described above affects the QoS of the corresponding PDU session, it is desirable for the terminal to immediately perform PDU session establishment based on the second NSSAI. To this end, as described above, the PDU session rejection message may include the second NSSAI information, and in this case, the terminal may immediately transmit a PDU session establishment request message associated with the second NSSAI after receiving the PDU session rejection message.

[0352]

[0353] 8th opening

[0354] 1) First, the terminal and the network establish the always-on PDU session described above.

[0355] Assume that the always-on PDU session is associated with a partially allowed NSSAI (the first NSSAI).

[0356] 2) The partially allowed NSSAI and NoS in the network are newly changed. The network (AMF and / or SMF) receives the new / updated partially allowed NSSAI (e.g., Partially Allowed NSSAI#2 (actually, S-NSSAI#2 and Partial tracking area identity list#2 information)) and NS-AoS (e.g., NS-AoS#3 (actually, S-NSSAI#3 and NS-AoS#3 information)) information from the NSSF.

[0357] 3) The terminal transmits a PDU session establishment request message related to the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1) to the network while not yet receiving partially allowed NSSAI (and / or NS-AoS) information from the network, i.e., without being aware of the partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)) that is unavailable or changed.

[0358] 4) The network recognizes that the PDU session establishment request transmitted by the terminal is related to an unavailable or modified partially allowed NSSAI (e.g., Partially Allowed NSSAI#1 (actually, S-NSSAI#1 and Partial tracking area identity list#1 information)), and therefore cannot be performed, and responds a PDU session establishment reject message to the terminal. At this time, the PDU session establishment reject message may be a PDU session reject message related to a partial TA within the current RA, unlike the general PDU session establishment reject message as described in the 7th disclosure. At this time, the PDU session reject message may also include the information described in the 7th disclosure.

[0359] 5) A terminal that receives a PDU session establishment reject message from a network can determine, based on the PDU session reject message, at least one of whether to maintain the first NSSAI or whether to perform PDU session establishment associated with the second NSSAI.

[0360] 6) However, based on the fact that the PDU session is an always-on PDU session, it is preferable that the terminal immediately performs PDU session establishment associated with a second NSSAI, which is a partially allowed NSSAI different from the first NSSAI. In general, a PDU session establishment request from the terminal can be requested when the terminal has transmission data, but in the case of an always-on PDU session, a PDU session establishment message based on the second NSSAI can be transmitted immediately after receiving the PDU session rejection message, regardless of whether the terminal has data.

[0361]

[0362] <Summary of the embodiments of this specification>

[0363] Figure 8 illustrates an operation method of a terminal according to one embodiment of the present specification.

[0364] Referring to FIG. 8, the terminal transmits a PDU (protocol data unit) session request message associated with a first NSSAI (network slice selection assistance information) (S801). Thereafter, in response to the transmitted PDU session request message, a PDU session reject message is received (S802). Here, the received PDU session reject message is used for establishing an always-on PDU session associated with a second NSSAI, and the first NSSAI and the second NSSAI may be different partially allowed NSSAIs.

[0365] The above PDU session request message may be a PDU session establishment request message or a PDU session modification request message. In addition, the PDU session rejection message may be a PDU session establishment reject message or a PDU session modification reject message.

[0366] The received PDU session establishment rejection message and / or PDU session modification rejection message may include a back-off timer value and cause information, and based on the back-off timer value, transmission of the PDU session establishment request message and / or the PDU session modification request message associated with the first NSSAI may be backed off.

[0367] Figure 9 shows a block diagram of a processor in which the disclosure of this specification is implemented.

[0368] As can be seen from FIG. 9, the processor (1020) implementing the disclosure of the present specification may include multiple circuits to implement the proposed functions, procedures, and / or methods described herein. For example, the processor (1020) may include a first circuit (1020-1), a second circuit (1020-2), and a third circuit (1020-3). Furthermore, although not shown, the processor (1020) may include more circuits. Each circuit may include multiple transistors.

[0369] The above processor (1020) may be called an ASIC (application-specific integrated circuit) or AP (application processor) and may include at least one of a DSP (digital signal processor), a CPU (central processing unit), and a GPU (graphics processing unit).

[0370] The above processor can be mounted on a UE.

[0371] Figure 10 illustrates a device according to one embodiment of the present specification.

[0372] Referring to FIG. 10, a wireless communication system may include a first device (100a) and a second device (100b).

[0373] The first device (100a) may be a 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 equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, a robot, an AR (Augmented Reality) device, a VR (Virtual Reality) device, an MR (Mixed Reality) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or any other device related to the field of the 4th Industrial Revolution.

[0374] The second device (100b) may be a network node (e.g., AMF or MME) described in the disclosure of 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 equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, a robot, an AR (Augmented Reality) device, a VR (Virtual Reality) device, an MR (Mixed Reality) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or any other device related to the field of the 4th Industrial Revolution.

[0375] For example, the UE (100) may include a mobile phone, a smart phone, a laptop computer, a digital broadcasting UE, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, a slate PC, a tablet PC, an ultrabook, a wearable device (e.g., a smartwatch, a smart glass, a head mounted display (HMD)), etc. For example, the HMD may be a display device worn on the head. For example, the HMD may be used to implement VR, AR, or MR.

[0376] For example, a drone may be an unmanned aircraft that flies by wireless control signals. For example, a VR device may include a device that implements virtual world objects or backgrounds. For example, an AR device may include a device that implements virtual world objects or backgrounds by connecting them to real world objects or backgrounds. For example, an MR device may include a device that implements virtual world objects or backgrounds by merging them with real world objects or backgrounds. For example, a holographic device may include a device that utilizes holography, a light interference phenomenon that occurs when two laser beams meet, to record and reproduce three-dimensional information to implement a 360-degree stereoscopic image. For example, a public safety device may include a video relay device or a wearable imaging device on the user's body. For example, MTC devices and IoT devices may be devices that do not require direct human intervention or operation. For example, MTC devices and IoT devices may include smart meters, bending machines, thermometers, smart light bulbs, door locks, or various sensors. For example, a medical device may be a device used for the purpose of diagnosing, treating, alleviating, managing, or preventing a disease. For example, a medical device may be a device used for the purpose of diagnosing, treating, alleviating, or correcting an injury or disability. For example, a medical device may be a device used for the purpose of examining, replacing, or modifying a structure or function. For example, a medical device may be a device used for the purpose of regulating pregnancy. For example, a medical device may include a diagnostic device, a surgical device, an (in vitro) diagnostic device, a hearing aid, or a device for a procedure. For example, a security device may be a device installed to prevent potential risks and maintain safety. For example, a security device may be a camera, CCTV, a recorder, or a black box.For example, a fintech device may be a device capable of providing financial services, such as mobile payments. For example, a fintech device may include a payment device or a point of sale (POS). For example, a climate / environmental device may include a device that monitors or predicts the climate / environment.

[0377] The first device (100a) may include at least one processor, such as a processor (1020a), at least one memory, such as a memory (1010a), and at least one transceiver, such as a transceiver (1031a). The processor (1020a) may perform the functions, procedures, and / or methods described above. The processor (1020a) may perform one or more protocols. For example, the processor (1020a) may perform one or more layers of a wireless interface protocol. The memory (1010a) may be connected to the processor (1020a) and may store various types of information and / or commands. The transceiver (1031a) may be connected to the processor (1020a) and may be controlled to transmit and receive wireless signals.

[0378] The second device (100b) may include at least one processor, such as a processor (1020b), at least one memory device, such as a memory (1010b), and at least one transceiver, such as a transceiver (1031b). The processor (1020b) may perform the functions, procedures, and / or methods described above. The processor (1020b) may implement one or more protocols. For example, the processor (1020b) may implement one or more layers of a wireless interface protocol. The memory (1010b) may be connected to the processor (1020b) and may store various types of information and / or commands. The transceiver (1031b) may be connected to the processor (1020b) and may be controlled to transmit and receive wireless signals.

[0379] The memory (1010a) and / or the memory (1010b) may be connected internally or externally to the processor (1020a) and / or the processor (1020b), or may be connected to another processor via various technologies such as a wired or wireless connection.

[0380] The first device (100a) and / or the second device (100b) may have one or more antennas. For example, the antenna (1036a) and / or the antenna (1036b) may be configured to transmit and receive wireless signals.

[0381] FIG. 11 illustrates a block diagram of a network node according to one embodiment of the present specification.

[0382] In particular, FIG. 11 is a drawing that illustrates in detail a case where a base station is divided into a central unit (CU) and a distributed unit (DU).

[0383] Referring to FIG. 11, the base stations (W20, W30) may be connected to the core network (W10), and the base station (W30) may be connected to the neighboring base station (W20). For example, the interface between the base stations (W20, W30) and the core network (W10) may be referred to as NG, and the interface between the base station (W30) and the neighboring base station (W20) may be referred to as Xn.

[0384] The base station (W30) can be divided into a CU (W32) and DUs (W34, W36). That is, the base station (W30) can be operated hierarchically separated. The CU (W32) can be connected to one or more DUs (W34, W36), and for example, the interface between the CU (W32) and the DUs (W34, W36) can be referred to as F1. The CU (W32) can perform functions of upper layers of the base station, and the DUs (W34, W36) can perform functions of lower layers of the base station. For example, the CU (W32) may be a logical node hosting radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) layers of a base station (e.g., gNB), and the DUs (W34, W36) may be logical nodes hosting radio link control (RLC), media access control (MAC), and physical (PHY) layers of the base station. Alternatively, the CU (W32) may be a logical node hosting RRC and PDCP layers of a base station (e.g., en-gNB).

[0385] The operation of DU (W34, W36) can be partially controlled by CU (W32). One DU (W34, W36) can support more than one cell. One cell can be supported by only one DU (W34, W36). One DU (W34, W36) can be connected to one CU (W32), and by suitable implementation, one DU (W34, W36) can also be connected to multiple CUs.

[0386] Fig. 12 is a block diagram showing the configuration of a terminal according to one embodiment of the present specification.

[0387] In particular, the terminal, i.e., UE (100) illustrated in FIG. 12 is a drawing that exemplifies the first device of FIG. 10 in more detail.

[0388] 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 subscriber identification module (SIM) card, and one or more antennas.

[0389] The processor (1020) may be configured to implement the proposed functions, procedures and / or methods described herein. Layers of a wireless interface protocol may be implemented in the processor (1020). The processor (1020) may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. The processor (1020) may be an application processor (AP). The processor (1020) may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). Examples of the processor (1020) may be a SNAPDRAGON™ series processor manufactured by Qualcomm®, an EXYNOSTM series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO™ series processor manufactured by MediaTek®, an ATOM™ series processor manufactured by INTEL®, or a corresponding next-generation processor.

[0390] The power management module (1091) manages power to the processor (1020) and / or the transceiver (1031). The battery (1092) supplies power to the power management module (1091). The display (1041) outputs the results processed by the processor (1020). The input unit (1053) receives input to be used by the processor (1020). The input unit (1053) can be displayed on the display (1041). A SIM card is an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and its associated keys, which are used to identify and authenticate subscribers in mobile devices such as mobile phones and computers. Contact information can also be stored on many SIM cards.

[0391] The memory (1010) is operably coupled to the processor (1020) and stores various information for operating the processor (610). The memory (1010) may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices. When the embodiment is implemented in software, the techniques described herein may be implemented as modules (e.g., procedures, functions, etc.) that perform the functions described herein. The modules may be stored in the memory (1010) and executed by the processor (1020). The memory (1010) may be implemented within the processor (1020). Alternatively, the memory (1010) may be implemented external to the processor (1020) and communicatively connected to the processor (1020) via various means known in the art.

[0392] The transceiver (1031) is operably coupled to the processor (1020) and transmits and / or receives a radio signal. The transceiver (1031) includes a transmitter and a receiver. The transceiver (1031) may include a baseband circuit for processing a radio frequency signal. The transceiver controls one or more antennas to transmit and / or receive a radio signal. The processor (1020) transmits command information to the transceiver (1031) to initiate communication, for example, to transmit a radio signal constituting voice communication data. The antenna functions to transmit and receive radio signals. Upon receiving a radio signal, the transceiver (1031) may transmit the signal for processing by the processor (1020) and convert the signal to baseband. The processed signal may be converted into audible or readable information output through the speaker (1042).

[0393] The speaker (1042) outputs sound-related results processed by the processor (1020). The microphone (1052) receives sound-related input to be used by the processor (1020).

[0394] A user inputs command information, such as a phone number, for example, by pressing (or touching) a button on an input unit (1053) or by voice activation using a microphone (1052). The processor (1020) receives this command information and processes it to perform an appropriate function, such as dialing a phone number. Operational data can be extracted from a SIM card or memory (1010). In addition, the processor (1020) can display command information or operation information on a display (1041) for the user's recognition and convenience.

[0395] FIG. 13 is a block diagram showing in detail the transmitter / receiver of the first device illustrated in FIG. 10 or the transmitter / receiver unit of the device illustrated in FIG. 12.

[0396] Referring to FIG. 13, the transceiver unit (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 IFFT unit (1031-13), a CP insertion unit (1031-14), and a wireless transmitter unit (1031-15). The transmitter (1031-1) may further include a modulator. In addition, for example, the transmitter may further include a scramble unit (not shown), a modulation mapper (not shown), a layer mapper (not shown), and a layer permutator (not shown), which may be arranged before the DFT unit (1031-11). That is, in order to prevent an increase in PAPR (peak-to-average power ratio), the transmitter (1031-1) first passes the information through a DFT (1031-11) before mapping the signal to a subcarrier. The signal spread (or precoded in the same sense) by the DFT unit (1031-11) is mapped to a subcarrier through a subcarrier mapper (1031-12) and then passes through an IFFT (Inverse Fast Fourier Transform) unit (1031-13) to be converted into a signal on the time axis.

[0397] The DFT unit (1031-11) performs DFT on the input symbols and outputs complex-valued symbols. For example, if Ntx symbols are input (where Ntx is a natural number), the DFT size is Ntx. The DFT unit (1031-11) may be called a transform precoder. The subcarrier mapper (1031-12) maps the complex symbols to each subcarrier in the frequency domain. The complex symbols may be mapped to resource elements corresponding to resource blocks allocated for data transmission. The subcarrier mapper (1031-12) may be called a resource element mapper. The IFFT unit (1031-13) performs IFFT on the input symbols and outputs a baseband signal for data, which is a time-domain signal. The CP insertion unit (1031-14) copies a portion of the rear portion of the baseband signal for data and inserts it into the front portion of the baseband signal for data. CP insertion prevents ISI (Inter-Symbol Interference) and ICI (Inter-Carrier Interference), thereby maintaining orthogonality even in multipath channels.

[0398] On the other hand, the receiver (1031-2) includes a wireless reception unit (1031-21), a CP removal unit (1031-22), an FFT unit (1031-23), and an equalization unit (1031-24). The wireless reception unit (1031-21), the CP removal unit (1031-22), and the FFT unit (1031-23) of the receiver (1031-2) perform the inverse functions of the wireless transmission unit (1031-15), the CP insertion unit (1031-14), and the IFF unit (1031-13) of the transmitter (1031-1). The receiver (1031-2) may further include a demodulator.

[0399] FIG. 14 illustrates another wireless communication system applicable to the disclosure of this specification.

[0400] The various descriptions, functions, procedures, proposals, methods and / or operational flowcharts of the disclosure of this specification can be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0401] Referring to FIG. 14, a communication system (1) applicable to the disclosure of the present specification includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0402] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0403] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and base station-to-base station communication (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the disclosure of the present specification.

[0404] Although the preferred embodiments have been described above by way of example, the disclosure of this specification is not limited to such specific embodiments, and may be modified, changed, or improved in various forms within the scope described in the spirit and claims of this specification.

[0405] In the exemplary system described above, the methods are described based on a flowchart as a series of steps or blocks. However, the order of the steps described is not limited, and some steps may occur in a different order or simultaneously with other steps described above. Furthermore, those skilled in the art will understand that the steps depicted in the flowchart are not exclusive, and other steps may be included, or one or more steps in the flowchart may be deleted without affecting the scope of the invention.

[0406] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method.

[0407] The method and device for processing an always-on PDU session for network slicing considering a service area in the above-described wireless communication system can be utilized in various mobile communication systems based on 3GPP.

Claims

1. In a method for operating a terminal in a wireless communication system, Establish an always-on PDU (protocol data unit) session associated with the first NSSAI (network slice selection assistance information); Transmitting a PDU session request message associated with the first NSSAI; and In response to the above transmitted PDU session request message, including receiving a PDU session reject message, If the above first NSSAI is a partially allowed NSSAI, the PDU session rejection message is a PDU session rejection message related to a partial TA (Tracking Area) within the current RA (Registration Area), A method of operating a terminal, wherein, when the PDU session associated with the first NSSAI is the always-on PDU session, the PDU session rejection message is used for establishing a PDU session associated with a second NSSAI, which is a partially allowed NSSAI different from the first NSSAI.

2. In paragraph 1, A method of operating a terminal, wherein, if the PDU session associated with the first NSSAI is not the always-on PDU session, the first NSSAI is maintained and establishment of a PDU session associated with the second NSSAI is reserved according to the PDU session rejection message.

3. In paragraph 1, A method of operating a terminal, further comprising transmitting a PDU session establishment request message associated with the second NSSAI, even when there is no uplink transmission data after receiving the PDU session rejection message, if the PDU session associated with the first NSSAI is the always-on PDU session.

4. In paragraph 1, A terminal operation method, wherein the above PDU session request message is a PDU session establishment request message or a PDU session modification request message.

5. In paragraph 4, A terminal operation method, wherein the above PDU session reject message is a PDU session establishment reject message or a PDU session modification reject message.

6. In paragraph 5, A method of operating a terminal, wherein at least one of the above PDU session establishment rejection message or PDU session modification rejection message includes a back-off timer value and cause information.

7. In paragraph 6, A method of operating a terminal, wherein transmission of the PDU session establishment request message or the PDU session modification request message associated with the first NSSAI is backed off based on the back-off timer value.

8. In a communication device in a wireless communication system, Transmitter and receiver; at least one processor; and At least one memory storing instructions and being operably electrically connected to at least one processor, Based on the above instruction being executed by the at least one processor, the operations performed are: Establish an always-on PDU (protocol data unit) session associated with the first NSSAI (network slice selection assistance information), Transmits a PDU session request message associated with the first NSSAI, and In response to the above transmitted PDU session request message, including receiving a PDU session reject message, If the above first NSSAI is a partially allowed NSSAI, the PDU session rejection message is a PDU session rejection message related to a partial TA (Tracking Area) within the current RA (Registration Area), A communications device, wherein, if the PDU session associated with the first NSSAI is the always-on PDU session, the processor is configured to use the PDU session reject message for the establishment of a PDU session associated with a second NSSAI, which is a partially allowed NSSAI different from the first NSSAI.

9. In paragraph 8, A communication device, wherein if 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 reserve establishment of the PDU session associated with the second NSSAI, in accordance with the PDU session rejection message.

10. In paragraph 8, If the PDU session associated with the above first NSSAI is the always-on PDU session, the above operation is: A communication device further comprising transmitting a PDU session establishment request message associated with the second NSSAI even when there is no uplink transmission data after receiving the PDU session rejection message.

11. In paragraph 8, A communication device, wherein the above PDU session request message is a PDU session establishment request message or a PDU session modification request message.

12. In paragraph 11, A communication device in which the above PDU session reject message is a PDU session establishment reject message or a PDU session modification reject message.

13. In paragraph 12, A communication device, wherein at least one of the above PDU session establishment rejection message or PDU session modification rejection message includes a back-off timer value and cause information.

14. In paragraph 13, A communication device, wherein transmission of one or more of the PDU session establishment request message or the PDU session modification request message associated with the first NSSAI is backed off based on the back-off timer value.

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