Efficient congestion control scheme for industrial traffic in 3GPP (3rd generation partnership project) 5G system

Abstract

One disclosure of the present specification provides an operation method at a terminal. The method may include driving a mobility management (MM) back-off timer or a session management (SM) back-off timer, and driving the MM back-off timer or the session management (SM) back-off timer, the MM back-off timer, the SM back-off timer, the SM back-off timer, the SM back-off timer, and the SM back-off timer. And when industrial traffic needs to be transmitted, terminating or ignoring the MM backoff timer or the SM timer and sending an SM signaling or an MM signaling. The SM signaling or MM signaling may include information that displays a neglect or exception of congestion control.

Description

Technical Field

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

[0002] Based on the success of the fourth generation of mobile communications, long term evolution (LTE) / LTE-Advanced (LTE-A), interest in the next generation, the fifth generation (so-called 5G) mobile communications is increasing, and research work is progressing.

[0003] The fifth generation of mobile communications defined by the International Telecommunication Union (ITU) is to provide data transmission speeds of up to 20Gbps and experience transmission speeds of at least 100Mbps anywhere. The official name is "IMT-2020" and the goal is to achieve commercialization worldwide in 2020.

[0004] The fifth generation of mobile communications supports multiple numerologies or subcarrier spacing (SCS) to support various services. For example, if the SCS is 15kHz, it supports wide area of ​​traditional cellular bands, if the SCS is 30kHz / 60kHz, it supports dense-urban, lower latency and wider carrier bandwidth, and when the SCS is above 60kHz, it supports bandwidth greater than 24.25GHz in order to overcome phase noise.

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

[0006] For the sake of convenience, in the frequency range used in the NR system, FR1 can represent "range below 6 GHz", FR2 can represent "range above 6 GHz", and can be called millimeter wave (millimeter wave, mmW).

[0007] [Table 1]

[0008]

[0009]

[0010] As described above, the value of the frequency range of the NR system can be changed. For example, FR1 may include a frequency band from 410 MHz to 7125 MHz, as shown in Table A7 below. That is, FR1 may include frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included in FR1 may include unlicensed bands. Unlicensed bands can be used for a variety of purposes, for example, for vehicle communications (e.g., autonomous driving).

[0011] [Table 2]

[0012] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 410MHz–7125MHz 15, 30, 60kHz FR2 24250MHz–52600MHz 60, 120, 240kHz

[0013] The ITU suggests three major usage scenarios: for example, eMBB (enhanced Mobile BroadBand), mMTC (massive Machine Type Communication) and URLLC (Ultra Reliable and Low Latency Communications).

[0014] First, URLLC involves usage scenarios that require high reliability and low latency. For example, services such as autonomous driving, factory automation, and augmented reality require high reliability and low latency (e.g., latency below 1ms). The current 4G (LTE) latency is statistically 21-43ms (best 10%) and 33-75ms (middle). This is not enough to support services that require latency below 1ms.

[0015] Next, eMBB use cases involve use cases that require mobile ultra-wideband.

[0016] This ultra-wideband high-speed service seems difficult to be accommodated by the existing LTE / LTE-A designed core network.

[0017] Therefore, in the so-called fifth generation of mobile communications, there is an urgent need to redesign the core network.

[0018] Figure 1 is a diagram showing the structure of a next generation mobile communication network.

[0019] 5GC (5G Core) can include various components. Figure 1Including the Access and Mobility Management Function (AMF) 41, Session Management Function (SMF) 42, Policy Control Function (PCF) 43, User Plane Function (UPF) 44, Application Function (AF) 45, Unified Data Management (UDM) 46, and Non-3GPP InterWorking Function (Non-3GPP InterWorking Function) 49, which are part of it.

[0020] The UE 10 is connected to a data network through the Next Generation Radio Access Network (NG-RAN) via the UPF 44 .

[0021] The UE 10 may also receive data services via an untrusted non-3rd Generation Partnership Project (non-3GPP) access such as a Wireless Local Area Network (WLAN). In order to access the non-3GPP core network, a N3IWF 49 may be provided.

[0022] Figure 2 is an example showing the expected structure of the next generation mobile communication from the perspective of nodes.

[0023] refer to Figure 2 It can be seen that the UE is connected to the data network (DN) through the next generation Radio Access Network (RAN).

[0024] The control plane function (CPF) node shown performs all or part of the mobility management entity (MME) functions of the fourth generation mobile communication, as well as all or part of the control plane functions of the serving gateway (S-GW) and the PDN gateway (P-GW). The CPF node includes an access and mobility management function (AMF) and a session management function (SMF).

[0025] The user plane function (UPF) node shown is a type of gateway for sending and receiving user data. The UF node can perform all or part of the user plane functions of the S-GW and P-GW of the fourth generation mobile communication.

[0026] The Policy Control Function (PCF) shown is a node that controls operator policies.

[0027] The application function (AF) shown is a server that provides various services to UE.

[0028] The Unified Data Management (UDM) shown is a server that manages subscriber information, such as the Home Subscriber Server (HSS) of the fourth generation mobile communication. The UDM stores the subscriber information in a Unified Data Repository (UDR) and manages it.

[0029] The Authentication Server Function (AUSF) shown authenticates and manages the UE.

[0030] The Network Slice Selection Function (NSSF) shown is a node for network slicing as described later.

[0031] exist Figure 2In the present invention, the UE uses multiple protocol data units or packet data units (PDU) sessions to access two data networks simultaneously.

[0032] Figure 3 is a diagram showing an example of an architecture that supports simultaneous access to two data networks.

[0033] exist Figure 3 It shows the architecture where the UE uses one PDU session to access two data networks simultaneously.

[0034] Figure 2 and Figure 3 The reference points shown are as follows.

[0035] N1 represents the reference point between UE and AMF.

[0036] N2 represents the reference point between (R)AN and AMF.

[0037] N3 represents the reference point between (R)AN and UPF.

[0038] N4 represents the reference point between SMF and UPF.

[0039] N5 represents the reference point between PCF and AF.

[0040] N6 represents the reference point between UPF and DN.

[0041] N7 represents the reference point between SMF and PCF.

[0042] N8 represents the reference point between UDM and AMF.

[0043] N9 represents the reference point between UPFs.

[0044] N10 represents the reference point between UDM and SMF.

[0045] N11 represents the reference point between AMF and SMF.

[0046] N12 represents the reference point between AMF and AUSF.

[0047] N13 represents the reference point between UDM and AUSF.

[0048] N14 represents the reference point between AMFs.

[0049] N15 represents the reference point between PCF and AMF.

[0050] N16 represents the reference point between SMFs.

[0051] N22 represents the reference point between AMF and NSSF.

[0052] Figure 4 is another example diagram showing the structure of the Radio Interface Protocol between UE and gNB.

[0053] The wireless interface protocol is based on the 3GPP wireless access network standard. The wireless interface protocol consists of the physical layer, data link layer and network layer horizontally, and is divided into the user plane (User Plane) for data information transmission and the control plane (Control Plane) for control signal transmission vertically.

[0054] The protocol layer is based on the lower three layers of the Open System Interconnection (OSI) standard model which is widely known in communication systems, and can be divided into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3).

[0055] Each layer of the wireless protocol is described below.

[0056] The first layer, the physical layer, uses a physical channel to provide information transfer services. The physical layer is connected to the upper media access control layer through a transport channel, and data between the media access control layer and the physical layer is transferred through the transport channel. In addition, data is transmitted between different physical layers, that is, between the physical layers on the sending side and the receiving side, through the physical channel.

[0057] The second layer includes a medium access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer.

[0058] The third layer includes Radio Resource Control (RRC). The RRC layer is defined only in the control plane and is related to the establishment (setting), reset (Resetting) and release (Release) of Radio Bearers (RBs), and is responsible for the control of logical channels, transport channels, and physical channels. At this time, RB means the service provided by the second layer for data transmission between the terminal and E-UTRAN.

[0059] The Non-Access Stratum (NAS) layer performs functions such as connection management (session management) and mobility management.

[0060] The NAS layer is divided into a NAS entity for mobility management (MM) and a NAS entity for session management (SM).

[0061] 1) The NAS entity for MM generally provides the following functions.

[0062] As NAS processes related to AMF, they include:

[0063] -Registration management and access management process, AMF supports the following functions:

[0064] -Secure NAS signaling connection between UE and AMF (integrity protection, encryption)

[0065] 2) The NAS entity for SM performs session management between the UE and SMF.

[0066] The session management signaling message is processed at the NAS-SM layer of the UE and SMF, i.e. created and processed. The content of the session management signaling message is not interpreted by the AMF.

[0067] -When sending session management signaling,

[0068] - The NAS entity for MM creates a NAS-MM message indicating the security header for NAS transport of session management signalling, and derives the method and location of delivering the session management signalling message from the received additional information for NAS-MM.

[0069] - When receiving session management signalling, the NAS entity for SM performs an integrity check of the NAS-MM message and interprets the additional information to deduce the method and location of deriving the session management signalling message.

[0070] At the same time, Figure 4 In the wireless communication network, the RRC layer, RLC layer, MAC layer and PHY layer located below the NAS layer are collectively referred to as the access stratum (AS).

[0071] The network system (ie, 5GC) for the next generation mobile communication (ie, 5G) also supports non-3GPP access. A representative example of non-3GPP access is WLAN access. WLAN access can include trusted WLAN and untrusted WLAN.

[0072] In the system used for 5G, AMF not only performs 3GPP access, but also performs registration management (RM) and connection management (CM) for non-3GPP access.

[0073] At the same time, in the future ultra-connected intelligent information society of the Fourth Industrial Revolution and 5G mobile communications, ultra-low latency (Ultra Reliable Low Latency Communications, URLLC) network technology, which is used to organically connect and exchange and process information between people and objects, online and offline, is becoming a necessary technology based on network infrastructure.

[0074] As part of URLLC network technologies such as Time Sensitive Networking (TSN) are being introduced for industrial use.

[0075] On the other hand, the explosive growth of user data usage may cause congestion in mobile communication networks. Currently, in 3GPP 5GS (5G system), when network congestion occurs in the core network (CN), the network rejects the request of the UE (i.e., terminal) and provides a backoff timer to the UE (i.e., terminal), so that no further request is allowed until the backoff timer expires.

[0076] However, in the case of industrial traffic (e.g., TSN or DetNet, TSC, URLLC, IIoT), the QoS requirements for latency are very strict, so in the case of specific industrial traffic (e.g., TSN or DetNet, TSC, URLLC, IIoT), it must be transmitted directly and very quickly.

[0077] Therefore, even in congested conditions, it may be possible to transmit industrial (e.g., TSN or DetNet, TSC, URLLC, IIoT) traffic directly and quickly, but this is currently not possible. Summary of the invention

[0078] Technical issues

[0079] Therefore, the purpose of the present specification is to propose a method for solving the above problems.

[0080] Technical Solution

[0081] In order to solve the above problem, a disclosure of this specification provides an operation method in a terminal. The method may include: driving a mobility management (MM) backoff timer or a session management (SM) backoff timer; and when industrial traffic needs to be transmitted, terminating or ignoring the MM backoff timer or the SM timer and sending SM signaling or MM signaling. The SM signaling or MM signaling may include information indicating the ignore or exception of congestion control.

[0082] In order to solve the above problems, a disclosure of the present specification provides a chipset installed in a terminal. The chipset includes: at least one processor; and at least one memory storing instructions and operably electrically connected to the at least one processor. Based on the instructions, the at least one processor executes the operations performed, which may include: driving a mobility management (MM) backoff timer or a session management (SM) backoff timer; and when industrial traffic needs to be transmitted, terminating or ignoring the MM backoff timer or the SM timer and sending SM signaling or MM signaling, wherein the SM signaling or MM signaling includes information showing the ignore or exception of congestion control.

[0083] In order to solve the above problems, a disclosure of this specification provides a device for a terminal. The device may include: a transceiver unit; at least one processor; and at least one memory storing instructions and operably electrically connected to the at least one processor. Based on the instructions executed by the at least one processor, the operations performed may include: driving a mobility management (Mobility Management, MM) backoff timer or a session management (Session Management, SM) backoff timer; and when industrial traffic needs to be transmitted, terminating or ignoring the MM backoff timer or the SM timer and sending SM signaling or MM signaling, wherein the SM signaling or MM signaling includes information showing the ignore or exception of congestion control.

[0084] The industrial traffic may be traffic for time-sensitive networks (TSN), time-sensitive communications (TSC), deterministic networks (DetNet), ultra-reliable and low-latency communications (URLLC), or industrial Internet of Things (IIoT).

[0085] Beneficial Effects

[0086] The disclosure of this specification is that even if the SM backoff timer or the MM backoff timer operates according to network congestion conditions, urgent or important industrial traffic (for example, TSN traffic, TSC traffic, DetNet traffic, URLLC traffic, or IIoT traffic) can be transmitted normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 is a diagram showing the structure of a next generation mobile communication network.

[0088] Figure 2 is an example showing the expected structure of the next generation mobile communication from the perspective of nodes.

[0089] Figure 3 is a diagram showing an example of an architecture that supports simultaneous access to two data networks.

[0090] Figure 4 is another example diagram showing the structure of the Radio Interface Protocol between UE and gNB.

[0091] FIG5 is a flow chart illustrating an exemplary registration process.

[0092] Figure 6a and Figure 6b is a signal flow diagram illustrating an exemplary PDU session establishment process.

[0093] Figure 7a and Figure 7b It shows the modification process of the PDU session.

[0094] Figure 8a and Figure 8b This is a process of rejecting MM operation or SM operation of UE in case of network congestion or overload. Figure 8c is an example showing that the RRC connection is rejected.

[0095] Fig. 9 is a diagram showing an example of a network architecture that interoperates with a TSN network.

[0096] Fig.10 is an example diagram illustrating an architecture that supports time-sensitive communications and time synchronization services.

[0097] Fig.11 This is a diagram showing an example of one disclosure of this specification.

[0098] Fig.12 is a block diagram showing the configuration of a processor that implements the disclosure of this specification.

[0099] Fig.13 FIG. 2 is a diagram showing a wireless communication system according to an embodiment.

[0100] Fig.14 is a block diagram illustrating a network node according to an embodiment.

[0101] Fig.15 is a block diagram showing the configuration of UE 100 according to an embodiment.

[0102] Fig.16 It is shown in Fig.13 The transceiver unit of the first device shown in FIG. Fig.15 A block diagram of the transceiver unit of the device shown.

[0103] Fig.17 1 is a diagram showing a communication system 1 applicable to the disclosure of this specification. DETAILED DESCRIPTION

[0104] It should be noted that the technical terms used in this specification are only used to describe specific embodiments and are not intended to limit the contents of this specification. In addition, unless specifically defined in different ways in this specification, the technical terms used in this specification should be interpreted as the meanings commonly understood by technicians in the technical field to which the disclosure of this specification belongs, and should not be interpreted as over-generalized meanings or over-reduced meanings. In addition, if the technical terms used in this specification are incorrect technical terms that cannot accurately express the contents and ideas of this specification, they should be replaced with technical terms that can be correctly understood by those skilled in the art. In addition, the general terms used in this specification should be interpreted as defined in the dictionary or according to the context, and should not be interpreted as over-reduced meanings.

[0105] In addition, singular expressions as used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "consisting of" or "having" should not be interpreted as necessarily including all the various constituent elements or steps described in the specification, and may not include some constituent elements or steps, or should be interpreted as also including additional constituent elements or steps.

[0106] In addition, the terms including ordinal numbers such as first, second, etc. used in this specification can be used to describe various constituent elements, but the constituent elements should not be limited by the terms. The terms are only used to distinguish one constituent element from another constituent element. For example, without departing from the scope of the rights, the first constituent element can be named as the second constituent element, and similarly, the second constituent element can also be named as the first constituent element.

[0107] When a component is mentioned as being connected or accessed to another component, it can be directly connected or accessed to another component, but other components may also exist in between. On the other hand, when it is mentioned that a component is directly connected or directly accessed to another component, it should be understood that there are no other components in between.

[0108] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings, but the same or similar constituent elements will be given the same figure marks regardless of the drawing symbols, and repeated descriptions thereof will be omitted. In addition, when interpreting the contents of this specification, if it is determined that the detailed description of the relevant known technology may obscure the gist of this specification, its detailed description will be omitted. In addition, it should be noted that the drawings are only for the purpose of facilitating the understanding of the contents and ideas of this specification, and should not be understood as limiting the contents and ideas of this specification by the drawings. The contents and ideas of this specification should be interpreted as extending to all changes, equivalents or substitutes other than the drawings.

[0109] In the present specification, "A or B" may mean "only A", "only B", or "both A and B". In other words, in the present specification, "A or B" may be interpreted as "A and / or B". For example, in the present specification, "A, B or C" may mean "only A", "only B", "only C", or "any combination of A, B and C".

[0110] A slash ( / ) or a comma used in this specification may mean "and / or". For example, "A / B" may mean "A and / or B". Thus, "A / B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B, or C".

[0111] In the present specification, "at least one of A and B" may mean "only A", "only B", or "both A and B". In addition, the expression "at least one of A or B" or "at least one of A and / or B" in the present specification may be interpreted the same as "at least one of A and B".

[0112] In addition, in the present specification, "at least one of A, B, and C" may mean "only A", "only B", "only C", or "any combination of A, B, and C". In addition, "at least one of A, B, or C" or "at least one of A, B and / or C" may mean "at least one of A, B, and C".

[0113] In addition, brackets used in this specification may indicate "for example". Specifically, when expressed as "control information (PDCCH)", "PDCCH" is suggested as an example of "control information". In other words, the "control information" of this specification is not limited to "PDCCH", and "PDDCH" may be suggested as an example of "control information". In addition, when expressed as "control information (ie, PDCCH)", "PDCCH" may also be suggested as an example of "control information".

[0114] The technical features described separately in one drawing of the present specification may be implemented separately or simultaneously.

[0115] In the drawings, a user equipment (UE) is shown by way of example, but the UE shown may also be referred to by terms such as UE 100 (terminal), mobile equipment, etc. In addition, the UE may be a portable device such as a laptop computer, a mobile phone, a PDA, a smart phone, or a multimedia device, or may be a non-portable device such as a PC or a vehicle-mounted device.

[0116] <Registration Process>

[0117] It is necessary for the UE to obtain authorization in order to enable mobility tracking and receive data and services. To this end, the UE needs to register with the network. The registration process is performed when it is necessary for the UE to initially register with the 5G system. In addition, the registration process is performed when the UE performs a periodic registration update, moves to a new tracking area (TA) in idle mode, and when the UE needs to perform a periodic registration update.

[0118] During the initial registration process, the UE ID can be obtained from the UE. The AMF can forward the PEI (IMEISV) to the UDM, SMF and PCF.

[0119] Figure 5a and 5b A signal flow diagram showing an exemplary registration process.

[0120] 1) The UE may send an AN message to the RAN. The AN message may include AN parameters and a registration request message. The registration request message may include information such as registration type, joiner permanent ID or temporary user ID, security parameters, NSSAI, UE's 5G capabilities, and PDU session status.

[0121] In case of 5G RAN, the AN parameters may include SUPI or Temporary User ID, Selected Network, and NSSAI.

[0122] The Registration Type may show whether the UE is "Initial Registration" (i.e., the UE is in an unregistered state), "Mobility Registration Update" (i.e., the UE is in a registered state and the registration procedure is initiated due to mobility) or "Periodic Registration Update" (i.e., the UE is in a registered state and the registration procedure is initiated due to expiration of the periodic update timer). If a Temporary User ID is included, the Temporary User ID shows the last serving AMF. If the UE has registered in a PLMN different from the PLMN of the 3GPP access through non-3GPP access, the UE may not provide a UE Temporary ID allocated by the AMF during the registration procedure through non-3GPP access.

[0123] Security parameters can be used for authentication and integrity protection.

[0124] The PDU Session Status displays the (previously set up) PDU Sessions available in the UE.

[0125] 2) If the included SUPI or Temporary User ID does not indicate a valid AMF, the RAN may select an AMF based on the (R)AT and NSSAI.

[0126] If the (R)AN cannot select a suitable AMF, it selects a random AMF according to the local policy and forwards the registration request to the selected AMF. If the selected AMF cannot serve the UE, the selected AMF selects another more suitable AMF for the UE.

[0127] 3) RAN sends an N2 message to the new AMF. The N2 message includes N2 parameters and a registration request. The registration request may include the registration type, the permanent identifier of the subscriber or the temporary user ID, security parameters, NSSAI and basic settings of MICO mode, etc.

[0128] When using 5G-RAN, the N2 parameters include location information related to the cell where the UE is located, the cell identifier and the RAT type.

[0129] If the registration type indicated by the UE is periodic registration update, processes 4 to 17 described later may not be performed.

[0130] 4) The newly selected AMF may send an information request message, such as Namf_Communication_UEContextTransfer, to the previous AMF.

[0131] The Registration Request message contains the temporary user ID of the UE and if the serving AMF has changed since the last registration, the new AMF may send an Information Request message containing the complete Registration Request information for requesting the SUPI and MM context of the UE to the previous AMF.

[0132] 5) The previous AMF sends an information response message, such as Namf_Communication_UEContextTransfer response, to the newly selected AMF. The information response message may include SUPI, MM context and SMF information.

[0133] Specifically, the AMF previously sends an information response message including the SUPI and MM context of the UE.

[0134] -If there is information on activating a PDU session in the previous AMF, the previous AMF may include SMF information including the ID of the SMF and the PDU session ID in the information response message.

[0135] 6) If the SUPI is not provided by the UE or not retrieved from the previous AMF, the new AMF sends an IdentityRequest message to the UE.

[0136] 7) The UE sends an Identity Request message including the SUPI to the new AMF.

[0137] 8) AMF may determine to trigger AUSF. In this case, AMF may select AUSF based on SUPI.

[0138] 9)AUSF can initiate verification of UE and NAS security functions.

[0139] 10) The new AMF may send a Namf_Communication_RegistrationCompleteNotify message to the previous AMF.

[0140] 11) The new AMF may send an Identity Request message to the UE.

[0141] If the PEI is not provided by the UE or not previously retrieved from the AMF, the AMF may send an Identity Request message in order to retrieve the PEI.

[0142] 12) New AMF check identifier.

[0143] 13) If procedure 14 described later is performed, the new AMF selects the UDM based on the SUPI.

[0144] 14) The new AMF performs the registration process in the UDM.

[0145] 15) The new AMF may select the PCF based on the SUPI.

[0146] 16) A new AMF is established to implement the PCF strategy association.

[0147] 17) The new AMF sends a PDU session update SM context message or a PDU session release SM context message to the SMF.

[0148] 18-19) The new SMF sends an AMF mobility request message to N3IWF and receives a mobility response message from AMF.

[0149] 20) Previously, AMF sent a UE context termination request message to PCF.

[0150] If the AMF has previously requested to set up the UE context in the PCF, the AMF may delete the UE context in the PCF.

[0151] 21) The new AMF sends a registration accept message to the UE. The registration accept message may include temporary user ID, registration area, mobility restriction, PDU session status, NSSAI, periodic registration update timer and allowed MICO mode.

[0152] When the AMF allocates a new temporary user ID, the temporary user ID may also be included in the registration accept message. When mobility restrictions apply to the UE, information indicating the mobility restrictions may additionally be included in the registration accept message. The AMF may include information indicating the PDU session status for the UE in the registration accept message. The UE may delete any internal resources related to the PDU session that is not marked as activated in the received PDU session status. If the PDU session status information is in the registration request, the AMF may include information displaying the PDU session status to the UE in the registration accept message.

[0153] 22) The UE sends a registration complete message to the new AMF.

[0154] <PDU Session Establishment Procedure>

[0155] The Protocol Data Unit (PDU) session establishment procedure can have the following two types of PDU session establishment procedures.

[0156] - PDU session establishment procedure initiated by the UE

[0157] - PDU session establishment procedure initiated by the network. For this purpose, the network can trigger a message to the application sending device of the UE.

[0158] Figure 6a and 6b are signal flow diagrams showing exemplary PDU session establishment procedures.

[0159] Figure 6a and Figure 6b The procedures shown are based on the registration procedure shown in Figure 5, assuming that the UE has already registered with the AMF. Therefore, it is assumed that the AMF has obtained the user subscription data from the UDM.

[0160] 1) The UE sends a NAS message to the AMF. The message packet can include Single Network Slice Selection Assistance Information (S-NSSAI), data network name (DNN), PDU session ID, request type, and N1 SM information, etc.

[0161] Specifically, the NSSAI allowed for the current access type of the UE includes the S-NSSAI. If the information about the mapped NSSAI has been provided to the UE, the UE can provide all the corresponding S-NSSAIs based on the allowed NSSAI and the S-NSSAI of the information based on the mapped NSSAI. Among them, the mapped NSSAI information is the information that maps each S-NSSAI in the allowed NSSAI to the S-NSSAI of the NSSAI set for the Home Public Land Mobile Network (HPLMN).

[0162] More specifically, the UE may extract and store the information of the S-NSSAI and the mapped S-NSSAI in the registration process of FIG. 5 including the registration acceptance message received from the network (ie, AMF). Therefore, the UE includes the S-NSSAI based on the allowed NSSAI and the corresponding S-NSSAI based on the information of the mapped NSSAI in the PDU session establishment request message and sends it.

[0163] To establish a new PDU session, the UE may create a new PDU session ID.

[0164] The UE may send a NAS message including a PDU Session Establishment Request message in the N1 SM information, thereby initiating a UE-initiated PDU Session Establishment procedure. The PDU Session Establishment Request message may include a request type, an SSC mode, and a protocol configuration option.

[0165] If the PDU session establishment is for setting up a new PDU session, the request type indicates "initial request". However, if there is an existing PDU session between the 3GPP access and the non-3GPP access, the request type may indicate "existing PDU session".

[0166] The NAS message sent by the UE is encapsulated in 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.

[0167] -N1 SM information may include a SMPDUDN request container, which contains information for PDU session authentication by an external DN.

[0168] 2) If the message indicates that the request type is "initial request" and the PDU Session ID does not have an existing PDU Session for the UE, the AMF may determine that it is a request for a new PDU Session.

[0169] If the NAS message does not contain S-NSSAI, the AMF may determine the requested default S-NSSAI for the PDU session based on the UE joining. The AMF may correlate the PDU session ID and the SMF ID and store them.

[0170] AMF can select SMF.

[0171] 3)AMF may send a Nsmf_PDUSession_CreateSMContext request message or a Nsmf_PDUSession_UpdateSMContext request message to the selected SMF.

[0172] The Nsmf_PDUSession_CreateSMContext request message may include SUPI, DNN, S-NSSAI(s), PDU session ID, AMF ID, request type, PCF ID, priority access, N1 SM container, user location information, access type, PEI, GPSI, UE presence in LADN service area, join PDU session state notification, DNN selection mode and tracking requirements. The SM container may include the PDU session establishment request message.

[0173] The Nsmf_PDUSession_UpdateSMContext request message may include SUPI, DNN, S-NSSAI, SMContext ID, AMFID, 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.

[0174] 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.

[0175] 4) SMF sends a user data request message to UDM. The joiner data request message may include the joiner permanent ID and DNN. UDM may send a join data response message to SMF.

[0176] In the above process 3, if the request type indicates "existing PDU session", the SMF determines that the request is caused by the handover between 3GPP access and non-3GPP access. The SMF can identify the existing PDU session according to the PDU session ID.

[0177] If the SMF has not retrieved the SM-related joining data for the UE related to the DNN, the SMF can request the joining data.

[0178] The joining data may include information about the authenticated request type, authenticated SSC mode, and basic QoS profile.

[0179] SMF can confirm whether the UE request complies with the user joining and local policies. Alternatively, SMF rejects the UE request through NAS session management signaling sent by AMF (including the relevant SM rejection reason), and SMF notifies AMF that the PDU session ID should be considered to be released.

[0180] 5)SMF sends Nsmf_PDUSession_CreateSMContextResponse message or Nsmf_PDUSession_UpdateSMContextResponse message to AMF.

[0181] The Nsmf_PDUSession_CreateSMContextResponse message may include Cause, SM ContextID or N1 SM container. The N1 SM container may include PDU Session Reject.

[0182] In the above process 3, SMF receives the Nsmf_PDUSession_CreateSMContext request message. If SMF can process the PDU session establishment request message, it creates the SMF SM Context and passes the SM Context ID to AMF.

[0183] 6) Optionally perform secondary authentication / authorization.

[0184] 7a) If operating PCC is used for the PDU session, the SMF selects PCF.

[0185] 7b) In order to establish an SM policy association with the PCF, the SMF executes the SM policy association establishment process.

[0186] 8) If the request type in process 3 indicates "initial request", the SMF selects the SSC mode for the PDU session. If process 5 is not performed, the SMF may also select the UPF. For request type IPv4 or IPv6, the SMF may allocate an IP address / prefix for the PDU session.

[0187] 9)SMF executes the SM policy association modification program and provides information on the triggering conditions for the policy control request.

[0188] 10) The request type indicates "initial request" and the SMF uses the selected UPF to initiate the N4 session establishment process. If not, the SMF can use the selected UPF to initiate the N4 session modification process.

[0189] 10a) SMF sends N4 Session Establishment / Modification Request message to UPF. Also, SMF can provide packet detection, enforcement and reporting rules to be installed in UPF for PDU session. When SMF allocates CN tunnel information, CN tunnel information can be provided to UPF.

[0190] 10b) UPF sends N4 Session Establishment / Modification Response message so that it can respond. If CN tunnel information is allocated by UPF, CN tunnel information can be provided to SMF.

[0191] 11)SMF sends Namf_Communication_N1N2MessageTransfer message to AMF. The Namf_Communication_N1N2MessageTransfer message may include PDU session ID, N2SM information and N1 SM container.

[0192] The N2 SM information may include PDU session ID, QFI (QoS flow ID), QoS profile, CN tunnel information, S-NSSAI from allowed NSSAI, session AMBR, PDU session type, user plane security enforcement information, UE integrity protection maximum data rate.

[0193] The N1 SM container may include a PDU Session Establishment Accept message.

[0194] The PDU Session Establishment Accept message may include allowed QoS rules, SSC mode, S-NSSAI, and allocated IPv4 address.

[0195] 12)AMF sends an N2 PDU Session Request message to RAN. The message may include N2 SM information and NAS message. The NAS message may include PDU Session ID and PDU Session Establishment Accept message.

[0196] AMF may send a NAS message including PDU Session ID and PDU Session Establishment Accept message. In addition, AMF includes the received N2 SM information from SMF in the N2 PDU Session Request message and sends it to RAN.

[0197] 13) The RAN may perform specific signaling exchanges with the UE related to the information received from the SMF.

[0198] The RAN also allocates RAN N3 tunnel information for the PDU session.

[0199] The RAN delivers the NAS message provided in process 10 to the UE. The NAS message may include the PDU session ID and N1 SM information. The N1 SM information may include a PDU session establishment accept message.

[0200] The RAN sends a NAS message to the UE only when the necessary RAN resources are set up and the allocation of the RAN tunnel information is successful.

[0201] 14) RAN sends an N2 PDU Session Response message to AMF. The message may include PDU Session ID, cause and N2 SM information. N2 SM information may include PDU Session ID, (AN) tunnel information and a list of allowed / rejected QoS profiles.

[0202] - The RAN tunnel information can belong to the access network address of the N3 tunnel corresponding to the PDU session.

[0203] 15) The AMF can send an Nsmf_PDUSession_UpdateSMContext request message to the SMF. The Nsmf_PDUSession_UpdateSMContext request message can include N2 SM information. Among them, the AMF can send the N2 SM information received from the RAN to the SMF.

[0204] 16a) If the N4 session for the PDU session has not been established, the SMF can initiate an N4 session establishment process together with the UPF. Otherwise, the SMF can use the UPF to initiate an N4 session modification process. The SMF can provide AN tunnel information and CN tunnel information. The CN tunnel information needs to be provided only when the SMF selects the CN tunnel information in process 8.

[0205] 16b) The UPF can send an N4 session modification response message to the SMF.

[0206] 17) The SMF sends an Nsmf_PDUSession_UpdateSMContextResponse message to the AMF.

[0207] After this process is completed, the AMF can pass relevant events to the SMF.

[0208] 18) The SMF sends an Nsmf_PDUSession_SMContextStatusNotify message.

[0209] 19) The SMF sends information to the UE through the UPF. Specifically, for the PDU type IPv6, the SMF can create an IPv6 router advertisement and transmit it to the UE through N4 and the UPF.

[0210] 20) If the PDU session establishment is not successful during this process, the SMF notifies the AMF.

[0211] <PDU session modification process>

[0212] Figure 7a and Figure 7b shows the modification process of the PDU session.

[0213] The PDU session is established / managed based on the PDU session modification process.

[0214] The PDU session modification process can be initiated by the UE or can be initiated by the network.

[0215] 1a) If initiated by the UE: The UE may initiate the PDU session modification procedure by sending a NAS message. The NAS message may include an N1 SM container. The N1 SM container may include a PDU session modification request message, a PDU session ID, and information about the UE's integrity protection (Integrity Protection) maximum data rate. The PDU session modification request message may include a PDU session ID, a packet filter, for the requested QoS, a 5GSM core network function, and the number of packet filters. The UE's integrity protection maximum data rate shows the maximum data rate that the UE can support for UP integrity protection. The number of packet filters indicates the number of packet filters supported for QoS rules.

[0216] The NAS message is sent to the appropriate AMF via the RAN based on the UE's location information. The AMF then sends the Nsmf_PDUSession_UpdateSMContext message to the SMF. The message may include a session management (SM) Context ID and an N1 SM container. The N1 SM container may include a PDU session modification request message.

[0217] 1b) When initiated by PCF in the network node, PCF initiates the SM policy association modification process, thereby notifying the SMF of the policy change.

[0218] 1c) When initiated by UDM between network nodes, UDM updates SMF's joining data by sending Nudm_SDM_Notification message. SMF can update session management joiner data and send ACK message to UDM.

[0219] 1d) When initiated by SMF in a network node, SMF can trigger QoS update.

[0220] When 1a to 1d above are triggered, SMF can perform the PDU session modification process.

[0221] 1e) When the AN resource to which the QoS flow is mapped is released when it is initiated by the AN in the network node, the AN may notify the SMF. The AN may send an N2 message to the AMF. The N2 message may include a PDU session ID and N2 SM information. The N2 SM information may include QFI (QoS flow ID), user location information, and an indication that the QoS flow is released. The AMF may send an Nsmf_PDUSession_UpdateSMContext message. The message may include an SM Context ID and N2 SM information.

[0222] 2) The above SMF sends a report on the join event by executing the SM Policy Partnership Modification process. If the PDU Session Modification process is triggered by 1b or 1d, this step can be skipped. If dynamic PCC is not configured to the network, the SMF applies internal policies to determine the changes to the QoS profile.

[0223] Processes 3 to 7 described later may not be performed when the PDU session modification only requires the operation of the UPF.

[0224] 3a) When 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 and N2 SM container. N2 SM information may include PDU session ID, QFI, QoS profile and session-AMBR. N1 SM container may include PDU session modification command. PDU session modification command may include PDU session ID, QoS rule, QuS rule operation, QoS flow unit QoS parameters and session-AMBR.

[0225] The N2 SM information may include information to be sent by the AMF to the AN. The N2 SM information may include a QFI and a QoS profile to inform the AN that one or more QoS flows are added or modified. If a PDU session modification is requested by a UE that is not configured with user plane resources, the N2 SM information to be delivered to the AN may include information for the establishment of user plane resources.

[0226] The N1 SM container may include a PDU session modification command to be delivered by the AMF through the UE. The PDU session modification command may include QoS rules and QoS flow unit (level) QoS parameters.

[0227] 3b) When initiated by SMF, SMF may send Namf_Communication_N1N2MessageTransfer message. The message may include N2 SM information and N1 SM container. N2 SM information may include PDU session ID, QFI, QoS profile, session-AMBR. N1 SM container may include PDU session modification command. PDU session modification command may include PDU session ID, QoS rules and QoS flow unit (level) QoS parameters.

[0228] If the UE is in the CM-IDLE state and ATC is activated, after the AMF updates and stores the UE context based on the Namf_Communication_N1N2MessageTransfer message, processes 3 to 7 described later can be skipped. When the UE enters a reachable state, that is, when the UE enters the CM-CONNECTED state, the AMF can send an N1 message to synchronize the UE and the UE context.

[0229] 4) AMF may send an N2 PDU Session Request message to AN. The N2 PDU Session Request message may include the N2 SM information and NAS message received from SMF. The NAS message may include the PDU Session ID and N1 SM container. The N1 SM container may include a PDU Session Modification Command.

[0230] 5) AN performs AN signaling exchanges with the UE related to the information received from the SMF. For example, in the case of NG-RAN, in order to modify the required AN resources related to the PDU session, an RRC connection reconfiguration procedure (ConnectionReconfiguration) can be performed with the UE.

[0231] 6) The AN sends an N2 PDU Session ACK message in response to the received N2 PDU Session Request. The N2 PDU Session ACK message may include N2 SM information and user location information. The N2 SM information may include a list of accepted / rejected QFIs, AN tunnel information, and PDU Session ID.

[0232] 7)AMF sends the N2 SM information and user location information received from AN to SMF via Nsmf_PDUSession_UpdateSMContext message. Then, SMF sends Nsmf_PDUSession_UpdateSMContext message to AMF.

[0233] 8) SMF sends an N4 session modification request message to UPF to update the N4 session of UPF included in the PDU session modification.

[0234] When a new QoS flow is created, the SMF works with the UPF to update the UL packet detection rules for the new QoS flow.

[0235] 9) The UE sends a NAS message in response to the received PDU session modification command. 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.

[0236] 10) AN sends the NAS message to AMF.

[0237] 11)AMF may send the N1 SM container and user location information received from AN to SMF via Nsmf_PDUSession_UpdateSMContext message. N1 SM container may include PDU session modification command ACK. SMF may send Nsmf_PDUSession_UpdateSMContext response message to AMF.

[0238] 12) In order to update the N4 session of the UPF included in the PDU session modification, the SMF sends an N4 session modification request message to the UPF. The message may include the N4 session ID.

[0239] 13) When the SMF interacts with the PCF in the above process 1b or 2, the SMF can inform the PCF whether to execute the PCC decision through the SM policy association modification process.

[0240] The SMF may notify the requesting entity of user location information associated with the PDU session change.

[0241] <Unified access control>

[0242] Methods for controlling access to the network

[0243] A large number of user equipment (UE) can access the communication system, and various services can exist in the UE. If a large number of UEs and a large number of services have data communication requests, but the network cannot accept data communication requests from all UEs and services, it is necessary for the network to increase the stability of the system by controlling the access requests from the UE. Otherwise, there may be a problem that communication access requests such as emergency calls cannot be properly processed.

[0244] This access control method is generally called access control, and 5G uses the "unified access control" technology.

[0245] Hereinafter, unified access control will be described in detail.

[0246] Depending on operator policy, deployment scenarios, joiner profiles, and available services, different criteria are used to determine which access attempts are allowed or restricted when congestion occurs in the 5G system. The different criteria for access control are associated with access identifiers and access categories. The 5G system provides operators with a single unified access control that controls access based on these two aspects.

[0247] In unified access control, each access attempt is classified into one or more access identifiers and access categories. The UE tests whether the actual access attempt can be performed based on the access control information applicable to the access identifier and access category associated / matched with the access attempt.

[0248] Unified access control supports extensibility to allow additional standardized access identifiers and access categories, and supports flexibility to allow operator-defined access identifiers and access categories, leveraging the operator's own standards (access identifiers, joining information, access categories, such as network slicing, applications and application servers).

[0249] Additionally, the use of legacy Access Classes 11-15 is expanded while potentially allowing success of access attempts that might otherwise be restricted based on user type.

[0250] According to the operator policy, the 5G system must be able to restrict UE access to the network using barring parameters based on access identifiers and access categories. As shown in Table 1 below, the access identifier is set on the UE. The access category is defined by combining the conditions of the UE and the access attempt type listed in Table 2 below. Select more than one access identifier and one access category and test the access attempt.

[0251] The 5G network may send barring control information (i.e., a list of barring parameters associated with an access identifier and access category) in more than one zone in the RAN.

[0252] The UE may determine whether a new specific access attempt may be allowed based on the barring parameters received from the barring control information and the UE's settings.

[0253] In the case of multiple core networks sharing the same RAN, the RAN may apply access control individually to different core networks.

[0254] The unified access control framework can be applied to UEs using E-UTRA to access the 5G core network (CN) and all UEs using new radio (NR) to access the 5G CN.

[0255] When initiating a new access attempt (ie, a new session request), the unified access control framework may be applicable to UEs in RRC Idle, RRC Inactive, or RRC Connected states.

[0256] The 5G system supports operator-defined access categories that can be defined mutually exclusively by operators.

[0257] The unified access control framework may be applicable to roamers entering the PLMN.The serving PLMN may provide the UE with the definition of operator-defined access categories.

[0258] The following Table 3 shows the access identifier.

[0259] [Table 3]

[0260] Access Identifier UE Settings 0 The UE does not set any parameters in this table. 1 The UE is configured for multimedia priority service (MPS). 2 The UE is set to an essential (mission critical) service (MCS: mission critical service). 3 Suitable for disaster conditions 4-10 Reservation for frequency of use 11 Access category 11 is set in the UE. 12 Access category 12 is set in the UE. 13 Access category 13 is set in the UE. 14 Access category 14 is set in the UE. 15 Access category 15 is set in the UE.

[0261] Access identifiers may be restricted at any time.

[0262] [Table 4]

[0263]

[0264] The 5G network may broadcast barring control information in one or more areas of the RAN. The barring control information may be, for example, a list of barring parameters associated with an access ID and an access category. The UE may determine whether to allow a specific new access attempt based on the barring parameters (which the UE receives from the broadcast barring control information) and the UE's settings.

[0265] In the case of multiple core networks sharing the same RAN, the RAN may apply access control to other core networks individually.

[0266] The unified access control framework can be applied to both UEs using E-UTRA to access the 5G core network (CN) and UEs using NR to access the 5G CN.

[0267] When a UE initiates a new access attempt (eg, a new session request), the unified access control framework may be applicable to UEs in Radio Resource Control (RRC) Idle state, RRC Inactive state, and RRC Connected state.

[0268] For reference, "new session request" in the RRC connected state may mean an event. For example, an event may be a new MMTEL voice session, an MMTEL video session, sending SMS (SMS over IP or SMS over NAS), a new PDU session establishment, an existing PDU session modification, and a service request for re-establishing the user plane of an existing PDU session.

[0269] The 5G system may support a means for operators to define operator-defined access categories as mutually exclusive. For example, standard examples of operator-defined access categories may be network slices, applications, and application servers.

[0270] A unified access control framework may be applicable to inbound roamers of a PLMN.

[0271] The serving PLMN may provide the UE with the definition of the operator-defined access class.

[0272] If the UE needs to access the 5G system, the UE may first perform an access control check to determine whether access is allowed. The access control check may be performed on access attempts defined by the following event list.

[0273] a) When the UE is in 5GS Mobility Management (5GMM)-IDLE mode via 3GPP access and an event occurs that requires transition to 5GMM-CONNECTED mode; and

[0274] b) When the UE is in 5G MM-CONNECTED mode via 3GPP access, or in 5G MM-CONNECTED mode with RRC inactivity indication, and one of the following events occurs:

[0275] b-1) When the NAS layer (e.g., 5GMM) of the terminal receives MO-MMTEL-voice-call-started information / indication, MO-MMTEL-video-call-started information / indication, or MO-SMSoIP-attempt-started information / indication from an upper layer (e.g., application layer);

[0276] b-2) when a request originating from the NAS layer (e.g., 5GMM) of a mobile transmitting terminal is received from an upper layer (e.g., application layer) through NAS, and the request does not trigger a service request to transition the UE from 5GMM-IDLE mode to 5GMM-CONNECTED mode;

[0277] b-3) the NAS layer (e.g., 5GMM) of the terminal receives a request from an upper layer (e.g., application layer) to send a ULNASTRANASPORT message for the purpose of PDU session establishment, and the request does not trigger a service request to transition the UE from 5GMM-IDLE mode to 5GMM-CONNECTED mode;

[0278] b-4) the NAS layer (e.g. 5GMM) of the terminal receives a request from an upper layer (e.g. application layer) to send a ULNASTRANASPORT message for the purpose of PDU session modification, and the request does not trigger a service request to transition the UE from 5GMM-IDLE mode to 5GMM-CONNECTED mode;

[0279] b-5) when the NAS layer (e.g., 5GMM) of the terminal receives a request to re-establish user-plane resources for an existing PDU session; and

[0280] b-6) When the NAS layer (e.g. 5GMM) of the terminal is notified to send uplink user data packets for a PDU session with user-plane resources.

[0281] If the NAS layer of the terminal detects one of the above events, the NAS layer of the terminal may perform an operation of mapping the request kind to more than one access ID and access category. In addition, the lower layer (e.g., RRC layer) of the terminal may perform an access barring check on the request based on the determined access ID and access category. For reference, the NAS layer of the terminal may identify the above events through information / indication provided from the upper layer and / or when determining that a normal NAS operation needs to be initiated.

[0282] In order to determine the requested access ID and access category, the NAS layer of the terminal may check the access reason for the set of access IDs and the set of access categories, the requested service type, and the user profile of the UE including the UE settings. Examples of the set of access IDs and the set of access categories are as follows:

[0283] - A set of standardized access IDs;

[0284] - a set of standardized access categories; and

[0285] - Where feasible, the operator-defines a set of access categories.

[0286] When a terminal (e.g., UE) needs to initiate an access attempt for one of the events such as the examples a) to b-6) above, the terminal determines one or more access IDs associated with the access attempt from a set of standardized access IDs, and can determine an access category associated with the access attempt from a set of standardized access categories and a set of operator-defined access categories.

[0287] For example, the set of access IDs applicable for a request related to an access attempt may be determined by a terminal (e.g., UE) as follows:

[0288] i) In the example of Table 3, for each of access IDs 1, 2, 11, 12, 13, 14 and 15, when selecting a new PLMN, the UE may check whether the access ID is available in the selected PLMN. Alternatively, the UE may check whether the access ID is applicable to the RPLMN or an equivalent PLMN; and

[0289] ii) If there is no available access ID among access IDs 1, 2, 11, 12, 13, 14, and 15, access ID0 may be used.

[0290] To determine the available access categories for the access attempt, the NAS layer of the terminal may check rules such as the example in Table 5 below, and use the matching access category for a barring check.

[0291] Table 5 below is an example of rules used by the NAS layer of the terminal when determining an available access category for an access attempt.

[0292] [Table 5]

[0293]

[0294]

[0295] If the access attempt matches more than one rule, the access class with the lowest rule number among the more than one rule may be selected. If the access attempt matches more than one operator-defined access class definition, the UE may select the operator-defined access class definition with the lowest precedence value. The situation where an access attempt matches more than one rule may include the situation where multiple events trigger an access attempt simultaneously.

[0296] <Due to network congestion control>

[0297] When congestion occurs, nodes in the core network (e.g., AMF) perform congestion control at the NAS level to avoid or control signaling congestion and DNN congestion.

[0298] Generally, when the core network performs congestion control in the NAS step, it will send a NAS reject message to the UE in idle mode or connected mode with a back-off timer value, but the UE will not send a request message to the network until the back-off timer expires. The request message may include a registration request message, a service request message, a PDU session establishment request message, and a PDU session modification request message.

[0299] These back-off timers can be divided into mobility management (MM) back-off timers and session management (SM) back-off timers.

[0300] On the other hand, the gNB (i.e., base station) can also perform congestion control. In the case of RAN or core network congestion, the UE receives a rejection response from the gNB (i.e., base station) when performing the RRC connection establishment procedure with the wait timer. In this case, the UE cannot initiate the RRC connection establishment procedure until the wait timer received from the gNB (i.e., base station) expires.

[0301] Figure 8a and Figure 8b This is a process of rejecting MM operation or SM operation of UE in case of network congestion or overload.

[0302] Reference Figure 8a It can be seen that in the case of network congestion or overload, if UE 100 sends a registration request message, a service request message, a PDU session establishment request message or a PDU session modification request message through gNB 200, the node in the network (e.g., AMF or SMF) sends a reject message for the message according to the network conditions (e.g., operator policy), etc.

[0303] In addition, the AMF or SMF may include a back-off timer in the rejection message when sending the rejection message, thereby preventing the UE 100 from retrying access before the time period expires.

[0304] Or, if Figure 8b As shown, when the network is congested or overloaded, a node in the network (e.g., AMF or SMF) may communicate a back-off timer to the UE (100) through the gNB 200 according to the network conditions (e.g., operator policy, etc.). When the AMF or SMF sends a message to the UE 100, the back-off timer may be included.

[0305] At the same time, gNB 200 can also perform congestion control. For example, for an RRC connection request, gNB 200 can Figure 8c The operations shown are used to perform congestion control.

[0306] Figure 8c is an example showing that the RRC connection is rejected.

[0307] Figure 8c It can be seen that when the UE 100 in the idle state wishes to establish an RRC connection in order to attempt data transmission, it sends an RRC Setup request message to the gNB 200.

[0308] At this time, if the gNB 200 is in an overload state, the gNB 200 sends an RRC Reject message to the UE 100. The RRC Reject message may include a wait timer. Then, the UE 100 cannot send an RRC Establishment Request message again until the wait timer expires.

[0309] <Contents of relevant standard documents>

[0310] A. NAS-level congestion control

[0311] NAS-level congestion control may be applicable generally (ie, for all NAS messages), per DNN, per S-NSSAI, per DNN and S-NSSAI, or to a specific UE group.

[0312] NAS-level congestion control is achieved by providing backoff times to the UE. To prevent a large number of UEs from opening requests (almost) simultaneously, the 5GC must select each backoff time value so that a large number of requests are not transmitted simultaneously. Once the UE receives the backoff time, the UE shall not transmit any NAS signaling for applicable congestion control until the backoff timer expires, or until the UE receives a mobile terminated request from the network, or until the UE initiates signaling transmission for emergency services or high priority access.

[0313] AMF and SMF can apply NAS-level congestion control, but NAS-level congestion control cannot be applied to processes that are not the subject of congestion control.

[0314] A-1. Conventional NAS-level congestion control

[0315] The following description applies to NAS Mobility Management congestion control.

[0316] Under normal overload conditions, the AMF may reject NAS messages for UEs using 5G-AN. When a NAS request is rejected, a mobility management backoff time may be sent to the UE by the AMF. During the operation of the Mobility Management (MM) backoff timer, the UE cannot initiate NAS requests except for the deregistration procedure and procedures that are not congestion control objects (e.g., high priority access, emergency services) and are not mobile terminated (MT) service objects. The backoff timer may continue to run even after the deregistration procedure. During the operation of the Mobility Management MM backoff timer, if the UE is already in the CM-CONNECTED state, the UE may perform a mobility registration update. During the operation of the Mobility Management MM backoff timer, when the UE receives a paging request or a NAS notification message from the AMF, the UE terminates the Mobility Management MM and starts a Service Request procedure or a Mobility Registration Update procedure through an available 3GPP access or non-3GPP access. When the back-off timer expires, if the UE is in the CM-IDLE state on the non-3GPP access, the UE may immediately initiate the UE-triggered service request procedure after converting to the CM-CONNECTED state again.

[0317] In order for the UE to report the PS data off state change in the PDU session modification request message, the UE may perform the following operations while the NAS MM backoff timer is running in the UE.

[0318] - If the UE is in CM-IDLE state and has not moved outside the registration area, the UE may send a Service Request message with an indication that the message is exempt from NAS congestion control. When the UE is in CM-IDLE mode and moves outside the registration area, the UE may send a Mobility Registration Update Request message with a subsequent request. The Mobility Registration Update Request message may include an indication that it is exempt from NAS congestion control.

[0319] - When the UE is in CM-CONNECTED state, the UE sends a PDU Session Modification Request including a PS Data Off state change within an UL NAS transport message with an indication of exemption from NAS congestion control.

[0320] When NAS MM congestion control is activated in the AMF, if the UE indicates that the NAS MM message is exempt from NAS congestion control, the AMF does not reject the NAS MM message and sends the NAS SM message to the SMF together with an indication showing that the NAS SM message is excluded from NAS congestion control. The SMF then ensures that the NAS SM message does not become the subject of congestion control. However, if there is no indication, the SMF may reject the message. In addition, if the received PDU Session Modification Request message is not for a data closed status report, the SMF may reject the PDU Session Modification Request message.

[0321] The Mobility Management Back-off Timer may not affect Cell / RAT / Access Type and PLMN changes. A Cell / RAT / TA / Access Type change shall not cause the Mobility Management MM Back-off Timer to expire. The Mobility Management MM Back-off Timer shall not be a trigger for PLMN reselection. The Back-off Timer may expire when accessing a new PLMN that is not an equivalent PLMN.

[0322] To avoid a large number of UEs sending requests at the same time, the AMF selects the MM backoff timer value to prevent a large number of requests from being sent at the same time.

[0323] If the NAS MM congestion control timer is running and MM signaling cannot be initiated, the UE needs to report a change in the 5GSM core network capability (Capability) or display an indication of always (Always-on) requesting a PDU session, then the UE knows that the MM congestion control is completed, delays the related MM signaling, and can only report after the corresponding timer expires.

[0324] For a UE in scheduled communication mode, the AMF may take the UE's communication mode into consideration during the selection of the value of the MM backoff timer in order that the UE does not miss its only scheduled communication window.

[0325] The AMF shall not reject the Registration Request message for a Mobility Registration Update performed when the UE is already in CM-CONNECTED state.

[0326] When the UE is already in the CM-CONNECTED state, the AMF may transmit the MM backoff time while rejecting the service request message and the UL NAS transfer message. If the UE receives a DL NAS Transfer message from the AMF during the execution of the MM backoff timer, the UE may terminate the backoff timer.

[0327] In case of CM-IDLE state mobility, the AMF may send a Registration Reject message including the MM Backoff Time value in order to reject the Registration Request message for mobility registration update.

[0328] If the UE is registered in the same PLMN for 3GPP access and non-3GPP access and receives the MM backoff time from the AMF, the backoff time (and the corresponding initiation and termination) may be applied equally to both 3GPP access and non-3GPP access. Conversely, when the UE is registered in different PLMNs for 3GPP access and non-3GPP access and receives the MM backoff time, the backoff time may only be applied to the PLMN that provided the time to the UE.

[0329] When the AMF rejects the Registration Request message or Service Request and is about to send an MM backoff time that is greater than the sum of the periodic Registration Update timer and the implicit Registration Release timer, the AMF adjusts the Mobility Arrival Possible timer and / or the Implicit Registration Release timer so that the AMF does not implicitly register and release the UE during the Mobility Management Backoff Timer.

[0330] A-2. DNN-based congestion control

[0331] DNN-based congestion control is designed to be independent of the presence or absence of S-NSSAI, using backoff timers related to or not related to DNN, thereby alleviating NAS SM signaling congestion to the UE. Both UE and 5GC must support DNN-based congestion control.

[0332] Except for the message sent for the purpose of reporting the 3GPP PS Data Off state change of a specific DNN with a running backoff timer, the SMF rejects the PDU Session Establishment Request message or the PDU Session Modification Request message, so that DNN-based congestion control can be applied at the UE. The SMF together with the DNN backoff timer can send a PDU Session Release Command message to the UE, so that the PDU session belonging to the congested DNN can be released. If the DNN backoff time is set in the PDU Session Release Command message, the reason value of "Reactivation Request" can be not set.

[0333] If NWDAF is configured, the SMF may use the session management congestion control empirical analysis provided to the NWDAF to determine the back-off timer provided to the UE.

[0334] If DNN-based congestion control is activated in the AMF, for example, by OAM settings, the AMF may respond to the NAS transport message including the SM message with a NAT transport error message. The NAS transport error message may include a DNN backoff timer.

[0335] The UE may link the received backoff time with the DNN contained in the uplink NAS MM message including the corresponding NAS SM request message (ie, no DNN, only DNN).

[0336] If the DNN associated with the backoff timer is not the LADN DNN, the UE may associate the received backoff time with the DNN of the PLMN.

[0337] When the backoff timer is running, the UE operates as follows:

[0338] -If a DNN is associated with a backoff timer, the UE may not initiate a session management procedure for a congested DNN. Instead, the UE may initiate a session management procedure for other DNNs. When the UE moves to the EPS of a 4G network, the UE may not initiate a session management procedure for the corresponding APN. Instead, when the UE moves to the EPS of a 4G network, the UE may initiate a session management procedure for other APNs.

[0339] - If there is no connected DNN with back-off timer, the UE can only initiate session management request for all PDU session types for a specific DNN.

[0340] - In case of cell / TA / PLMN / RAT change, untrusted non-3GPP access network change or access type change, the UE may not terminate the back-off timer.

[0341] - The UE may initiate session management procedures for high priority access and emergency services.

[0342] - To report the data off state change to the network, the UE may initiate a session management procedure.

[0343] -If the UE receives a network initiated session management message other than a PDU session release command for a congested DNN associated with a running backoff timer, the UE may terminate the backoff timer and respond to the 5GC.

[0344] -When the UE receives a PDU Session Release Command message to a congested DNN, the backoff timer may be terminated unless a new backoff time is received from the SMF.

[0345] - The UE may be allowed to initiate a PDU session release procedure (ie send a PDU session release request message). When the related PDU session is released, the UE may not terminate the backoff timer.

[0346] When the UE initiates one of the session management procedures that is exempt from NAS congestion control, the UE indicates that the NAS SM message included in the UL NAS transport message is exempt from NAS congestion control. If DNN-based congestion control is activated in the AMF, and the UE indicates that the NAS SM message included in the UL NAS transport message is exempt from NAS congestion control, the AMF does not apply DNN-based congestion control to the UL NAS transport message and executes the next step. The NAS SM message is received together with the indication that it is exempt, and the AMF sends a corresponding message to the SMF. The SMF determines whether the NAS SM message is allowed to be exempt from DNN-based congestion control. If exemption from NAS congestion control is not allowed, the SMF rejects the above message. If it is not for data closing status reporting, the SMF may reject the received PDU session modification.

[0347] The UE may maintain a separate backoff timer for each DNN that the UE may use.

[0348] To prevent a large number of UEs from sending requests at the same time, 5GC can select a backoff timer value so that requests are not sent simultaneously.

[0349] In the case that the UE cannot initiate SM signaling during the execution of DNN-based congestion control, if the UE needs to report changes in 5GSM core network capabilities or Always-on PDU session request indications, the UE postpones the sending of related SM signaling until the DNN-based congestion control timer expires, and can only send SM signaling after the timer expires.

[0350] DNN-based SM congestion control may be applicable to NAS SM signaling initiated from the UE in the control plane.Session management congestion control does not prevent the UE from sending or receiving data or initiating a service request procedure for activating a user plane connection to the DNN under session management congestion control.

[0351] A-3. Congestion Control Based on S-NSSAI

[0352] S-NSSAI based congestion control is designed to be independent of the presence or absence of DNN and use backoff timers related or unrelated to S-NSSAI, thereby alleviating NAS signaling congestion to the UE.

[0353] The UE links the received backoff time to the S-NSSAI and DNN included in the uplink NAS MM message including the corresponding NAS SM request message to the PLMN (i.e., no S-NSSAI and DNN, no S-NSSAI, only S-NSSAI, S-NSSAI and DNN).

[0354] The operation of S-NSSAI-based congestion control is as follows:

[0355] - If it is determined that the S-NSSAI is congested, the SMF may apply S-NSSAI based congestion control for the UE at the SM request, except for sending a 3GPP PS data off state change for a specific S-NSSAI for reporting purposes. For this purpose, the SMF may provide a backoff time and HPLMN congestion indication.

[0356] - If the UE receives an S-NSSAI based backoff time without an indication of HPLMN congestion, the UE may apply the S-NSSAI backoff timer only in the PLMN of the received backoff time. If the UE receives an indication of HPLMN congestion and an S-NSSAI based backoff time, the UE may apply the S-NSSAI based backoff timer in the PLMN of the received backoff time and in other PLMNs.

[0357] -SMF sends a PDU Session Release Request message containing a back-off timer associated with only S-NSSAI (i.e., without a specific DNN) or a combination of S-NSSAI and a specific DNN to the UE so that the SMF can release the PDU session belonging to the congested S-NSSAI. If NWDAF is not configured, the SMF may use the session management congestion control empirical analysis provided by NWDAF to determine the back-off timer provided to the UE.

[0358] -When S-NSSAI-based congestion control is activated by AMF, such as by OAM setting, and S-NSSAI is determined to be congested, AMF may initiate a session management request to the UE to apply S-NSSAI-based congestion control. In this case, AMF may send a NAS transport error message in response to a NAS transport message including an SM message. A backoff timer may be included in the NAS transport error message. If NWDAF is configured, AMF may determine S-NSSAI congestion based on network slice load level analysis.

[0359] -When the back-off timer is running, the UE can perform the following operations in the PLMN where S-NSSAI based congestion control is applied.

[0360] - If the back-off timer is associated only with the S-NSSAI (ie, not associated with the S-NSSAI and the DNN), the UE may not initiate a session management procedure for the congested S-NSSAI.

[0361] -If the back-off timer is associated with S-NSSAI and DNN, the UE may not initiate the session management procedure for the corresponding combination of S-NSSAI and DNN.

[0362] - If the UE receives a network initiated session management message other than a PDU Session Release Command for a congested S-NSSAI, the UE may terminate this backoff timer and respond to the 5GC.

[0363] - When the UE receives a PDU Session Release Command message for a congested S-NSSAI, it terminates the backoff timer unless a new backoff time is received from the SMF.

[0364] - In case of cell / TA / PLMN / RAT change, untrusted non-3GPP access network change or access type change, the UE may not terminate the backoff timer for S-NSSAI or the combination of S-NSSAI and DNN.

[0365] -The UE may initiate a session management procedure for high priority access to the S-NSSAI and emergency services.

[0366] - The UE may initiate a session management procedure for reporting a PS data off state change for the S-NSSAI or a combination of S-NSSAI and DNN.

[0367] - If the back-off timer is not associated with an S-NSSAI, the UE may initiate session management procedures only for a specific S-NSSAI.

[0368] -If the back-off timer is not associated with an S-NSSAI and a DNN, the UE may initiate the session management procedure only for a specific S-NSSAI and DNN.

[0369] - The UE is allowed to initiate a PDU Session Release procedure (eg, send a PDU Session Release Request message). When releasing the associated PDU Session, the UE may not terminate the backoff timer.

[0370] The UE may maintain a separate backoff timer for each S-NSSAI and each combination of S-NSSAI and DNN that the UE may use. When the UE initiates one of the session management procedures that is exempt from NAS congestion control, the UE indicates that the NAS SM message included in the UL NAS transport message is exempt from NAS congestion control. When S-NSSAI-based congestion control is activated in the AMF, if the UE indicates that the NAS SM message in the UL NAS Transport message is exempt from NAS congestion control, the AMF does not apply S-NSSAI-based congestion control for the UL NAS transport message. The AMF may send the indication and NAS SM message received together with the exemption indication to the corresponding SMF. The SMF determines whether the NAS SM message is allowed to be exempt from S-NSSAI-based congestion control. If exemption of the NAS SM message is not allowed for S-NSSAI-based congestion control, the SMF may reject the message. If it is not for a data closing status report, the SMF may reject the received PDU session modification.

[0371] The back-off timer associated with S-NSSAI or the combination of S-NSSAI and DNN applies only to congestion control for session management procedures when the UE is in 5GS.

[0372] To avoid a large number of UEs sending requests at the same time, 5GC selects a backoff timer value for S-NSSAI based congestion control to prevent a large number of requests from being sent at the same time.

[0373] S-NSSAI based congestion control may allow the UE to send or receive data or initiate a service request procedure to activate a user plane connection for a PDU session associated with the S-NSSAI under congestion control.

[0374] A-4. Group-specific NAS-level congestion control

[0375] Group-specific NAS-level congestion control may be applicable to a specific UE group. Group-specific NAS-level congestion control is performed only in the 5GC and may be transparent to the UE. AMF or SMF or both may apply NAS-level congestion control to UEs associated with an internal group identifier.

[0376] <Excerpt from 3GPP TS24.501v17.6.1>

[0377] B. Handling of NAS-level mobility management congestion control

[0378] The AMF can detect 5GMM signaling congestion and perform general NAS-level congestion control. In the case of 5GMM signaling congestion, the AMF can reject the 5GMM signaling request from the UE. The AMF shall not reject the following:

[0379] a) Requests for emergency services;

[0380] b) Requests for emergency service fallback;

[0381] c) a request from the UE set by a high priority access in the selected PLMN;

[0382] d) DEREGISTRATION REQUEST message;

[0383] e) Request for MT service triggered by a paging procedure or a notification procedure; and

[0384] f) Emergency services are used for initial registration or mobility registration request or periodic registration update request when indicated by the lower layer.

[0385] If general NAS-level congestion control is activated, the AMF may include the value of the MM backoff timer T3346 in the reject message. The UE initiates timer T3346 by the value received in the 5GMM reject message. In order to prevent a large number of UEs from sending requests at the same time, the AMF may determine the value of timer T3346 for the UE.

[0386] If the UE is registered to the same PLMN through 3GPP access and non-3GPP access and the UE receives timer T3346 from the AMF, timer T3346 may be applicable to both 3GPP access and non-3GPP access.

[0387] While timer T3346 is running, the UE receives a paging message or a NOTIFICATION message, and the UE is registered to the same PLMN through 3GPP access and non-3GPP access, then the UE terminates timer T3346 for both accesses and may send a response message to the paging message or the NOTIFICATION message.

[0388] When the UE enters the 5GMM-DEREGISTERED state, timer T3346 is running and if the UE remains turned on and the UE's USIM is maintained identically, timer T3346 may continue to run until expiration or termination.

[0389] If the UE enters a new PLMN while timer T3346 is running, and the new PLMN is different from the PLMN in which the UE initiated timer T3346, the UE may terminate timer T3346 when initiating a 5GMM procedure in the new PLMN.

[0390] After the registration area is changed, timer T3346 is running and the 5GS update status is 5U1UPDATED, the UE may set the 5GS update status to 5U2 NOT UPDATED and enter the 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state.

[0391] When timer T3346 is running or is not activated, the UE is a UE configured for high priority access in the selected PLMN, or the UE needs to initiate signaling for emergency services or emergency service backup, the UE may initiate the 5GMM procedure.

[0392] B-1. DNN-based congestion control processing

[0393] When one or more DNN congestion criteria are met, the AMF may detect and initiate execution of DNN-based congestion control. If the UE does not provide a DNN for non-emergency PDU sessions, the AMF may use the selected DNN or a DNN associated with a PDU session corresponding to the 5GSM procedure.

[0394] B-2. Congestion control processing based on S-NSSAI

[0395] When one or more S-NSSAI congestion criteria are met, the AMF may detect and initiate the execution of S-NSSAI based congestion control. If the UE does not provide a DNN for a non-emergency PDU session, the AMF may use the selected DNN or a DNN associated with a PDU session corresponding to a 5GSM procedure. If the UE does not provide an S-NSSAI for a non-emergency PDU session, the AMF may use the selected S-NSSAI or an S-NSSAI associated with a PDU session corresponding to a 5GSM procedure.

[0396] B-3. ​​DNN-based congestion control processing

[0397] When one or more DNN congestion criteria are met, the network can detect and initiate execution of DNN-based congestion control. If the UE does not provide a DNN for non-emergency PDU sessions, the network can use the selected DNN.

[0398] When the 5GS session management timer T3396 for DNN-based congestion control in the UE is a PLMN, except for LADNN, it can be initiated and terminated in DNN units. In the case of LADN DNN, the 5GS session management timer T3396 for DNN-based congestion control can be applicable to the registered PLMN and the PLMN corresponding thereto.

[0399] The DNN associated with T3396 may be the DNN provided by the UE during PDU session establishment. If the DNN is not provided in the PDU SESSION ESTABLISHMENT REQUEST sent by the UE, T3396 may not be associated with the DNN. To do this, the UE needs to store the DNN provided to the network during PDU session establishment. Timer T3396 associated with the DNN is not initiated due to 5GSM procedures related to emergency PDU sessions. If timer T3396 associated with the DNN is running, it may not affect the UE's ability to request an emergency PDU session.

[0400] If T3396 is running or not activated, the UE cannot initiate:

[0401] a)PDU session establishment process

[0402] b) PDU Session Modification Procedure; or

[0403] c) NAS transport procedures for transmitting CIoT user data;

[0404] B-4. Congestion control processing based on S-NSSAI

[0405] When one or more S-NSSAI congestion criteria are met, the network may detect and initiate the execution of S-NSSAI based congestion control. If the UE does not provide a DNN for a non-emergency PDU session, the network may use the selected DNN. If the UE does not provide an S-NSSAI for a non-emergency PDU session, the network may use the selected S-NSSAI.

[0406] For PLMN, the 5GS session management timer T3584 used for S-NSSAI-based congestion control in the UE can be initiated and terminated in S-NSSAI, DNN and PLMN units. If the 5GSM congestion retry indicator IE with the ABO bit set to "backoff timer applies to all PLMNs" is included in the 5GSM message together with the 5GSM cause value #67 "Insufficient resources for specific slices and DNNs", the UE can apply timer T3584 for all PLMNs. Otherwise, the UE can apply timer T3584 to the registered PLMN. If timer T3584 is applicable to all PLMNs, timer T3584 can be initiated when the UE registers with the VPLMN and the S-NSSAI is provided by the UE during PDU session establishment. At this time, timer T3584 can be related to the combination of [mapped S-NSSAI, DNN] PDU session.

[0407] For PLMNs, the 5GS session management timer T3584 used for S-NSSAI-based congestion control in the UE can be initiated and terminated in S-NSSAI and PLMN units. If the 5GSM Congestion Retry Indicator IE with the ABO bit set to "Backoff timer applies to all PLMNs" is included in the 5GSM message together with the 5GSM cause value #67 "Insufficient resources for a specific slice", the UE can apply timer T3584 for all PLMNs. Otherwise, the UE can apply timer T3584 to the registered PLMN. If timer T3584 is applicable to all PLMNs, timer T3584 can be initiated when the UE registers with the VPLMN and the S-NSSAI is provided by the UE during PDU session establishment. Timer T3584 can be linked to the mapped S-NSSAI. In addition, if the 5GSM congestion retry indicator IE with the CATBO bit set to "backoff timer applies to the current access type" is included in the 5GSM message together with the 5GSM cause value #69 "Insufficient resources for a specific slice", the UE may apply the timer T3585 for the current access type. Otherwise, the UE may apply the timer T3585 to all 3GPP access types and non-3GPP access types.

[0408] If timer T3584 or timer T3585 is provided during the PDU session establishment procedure, the S-NSSAI associated with T3584 or T3585 may be an S-NSSAI that does not include the S-NSSAI provided by the UE during the PDU session establishment.

[0409] If timer T3584 is provided during the PDU session modification or PDU session release process, the UE may operate as follows. The DNN associated with T3584 may be the DNN provided by the UE during PDU session establishment. If the UE does not provide an S-NSSAI but only provides a DNN through the PDU SESSION ESTABLISHMENT REQUEST message, T3584 may be associated with the DNN provided to the network during PDU session establishment and may not be associated with the S-NSSAI. If the PDN connection is established in S1 mode, T3584 may not be associated with the S-NSSAI. If the UE does not provide a DNN but provides an S-NSSAI through the PDU SESSION ESTABLISHMENT REQUEST message, T3584 may be associated with the DNN of the PDU session but may not be associated with the S-NSSAI. If DNN and S-NSSAI are not provided in the PDU SESSION ESTABLISHMENT REQUEST message sent by the UE, T3584 may not be associated with DNN and S-NSSAI. To this end, the UE may store the DNN and S-NSSAI provided to the network during PDU session establishment. Due to 5GSM procedures related to emergency PDU sessions, timer T3584 associated with DNN and S-NSSAI may not be initiated. If timer T3584 associated only with S-NSSAI and not DNN is running, this will not affect the UE's ability to request an emergency PDU session.

[0410] If timer T3585 is provided during the PDU Session Modification or PDU Session Release procedure, the UE may operate as follows. If S-NSSAI is not provided in the PDU SESSION ESTABLISHMENT REQUEST message sent by the UE, T3585 may not be associated with S-NSSAI. If the PDN connection is established in S1 mode, T3585 may not be associated with S-NSSAI.

[0411] If T3584 is running or not activated, the UE cannot initiate:

[0412] a)PDU session establishment process

[0413] b) PDU Session Modification Procedure; or

[0414] c) NAS transport procedures for transmitting CIoT user data;

[0415] If timer T3584 is running or is not activated for all PLMNs and is connected to another S-NSSAI that is not S-NSSAI, then

[0416] a) A UE registered in the HPLMN may not be allowed to initiate:

[0417] a-1) PDU session establishment process;

[0418] a-2) PDU session modification process; or

[0419] a-3) NAS transmission process for transmitting CIoT user data;

[0420] b) A UE registered in a VPLMN may not be allowed to initiate:

[0421] b-1) PDU session establishment process;

[0422] b-2) PDU session modification process; or

[0423] b-3) NAS transmission process for transmitting CIoT user data;

[0424] If timer T3584 is running or is not activated for all PLMNs and is connected with the combination of [no S-NSSAI, no DNN] or [no S-NSSAI, DNN], the UE may not be allowed to initiate:

[0425] a)PDU session establishment process

[0426] b) PDU Session Modification Procedure; or

[0427] c) NAS transport procedures for transmitting CIoT user data;

[0428] If timer T3585 is running or is not activated for all PLMNs and is connected to another S-NSSAI that is not S-NSSAI, then

[0429] a) A UE registered in the HPLMN may not be allowed to initiate:

[0430] a-1) PDU session establishment process;

[0431] a-2) PDU session modification process; or

[0432] a-3) NAS transmission process for transmitting CIoT user data;

[0433] b) A UE registered in a VPLMN may not be allowed to initiate:

[0434] b-1) PDU session establishment process;

[0435] b-2) PDU session modification process; or

[0436] b-3) NAS transmission process for transmitting CIoT user data;

[0437] If timer T3585 is running or is not activated for all PLMNs and is associated with no S-NSSAI, the UE is not allowed to initiate:

[0438] a)PDU session establishment process

[0439] b) PDU Session Modification Procedure; or

[0440] c) NAS transport procedures for transmitting CIoT user data;

[0441] If timer T3585 is running or is not activated for all PLMNs and there is no S-NSSAI, the UE may not be able to initiate:

[0442] a)PDU session establishment process

[0443] b) PDU Session Modification Procedure; or

[0444] c) NAS transport procedures for transmitting CIoT user data.

[0445] <Time-Sensitive Networking (TSN)>

[0446] On the other hand, the time-sensitive network TSN will be described.

[0447] In the future ultra-connected intelligent information society of the fourth industrial revolution and 5G mobile communications, ultra-low latency (URLLC; Ultra Reliable Low Latency Communications) network technology, which is used to organically connect people and objects, online and offline, etc. to exchange and process information, is becoming a necessary technology based on network infrastructure. As a result, 3GPP is also actively accommodating the challenging requirements of vertical industry fields, and is developing research on the Industrial Internet of Things (IioT) centered on automation to maximize the productivity and profitability of industry through changes in communication infrastructure. In particular, task-oriented industries such as smart factories, smart grids, and smart traffic systems require ultra-reliable and low-latency communication performance at the wired infrastructure level, so new technologies to support them are reflected in the standards.

[0448] IEEE TSN technology has emerged to realize the industrial Internet of Things (IIoT) of multiple devices and systems to be connected by networks in these industrial sites. IEEE TSN technology is considered to be the next-generation industrial network standard that can accommodate most network application examples of Ethernet by combining multiple existing IEEE standards into one packet technology. In 3GPP, 5G-TSN technology is vigorously promoted for standardization after Rel-16 for the vertical field diffusion of 5G technology. 5G-TSN technology is a technology that basically integrates IEEE TSN technology into 5G system (5GS; 5G system), and is a time-sensitive communication technology (Time-Sensitive Communications, TSC) that defines and supports various IIoT service requirements. In TSC, 5GS and TSN basically go through the time synchronization process. After that, TSC QoS Flow based on TSC assistance information is supported.

[0449] Fig. 9 is a diagram showing an example of a network architecture that interoperates with a TSN network.

[0450] Reference Fig. 9 , the 5G system can communicate with the TSN bridge through the external network. The logical TSN bridge may include TSN translation functionality for the user plane and control plane to interoperate between the 5GS system and the TSN system. The 5GS TSN translation function may include a device-side TSN translator (DS-TT) and a network-side TSN translator (NW-TT). TSNAF is part of 5GC and can provide control plane translation functions that integrate 5GS and TSN. In 5GC and RAN, processes, wireless communication links, etc. that are characteristics of the 5G system may not be visible in the TSN network. 5GS provides TSN input (ingress) ports and output (egress) ports through DS-TT and NW-TT.

[0451] In order to discover the Ethernet device connected to the DS-TT, the DS-TT may support the link layer connection retrieval and reporting. In order to discover the Ethernet device connected to the NW-TT, the NW-TT may also support the link layer connection retrieval and reporting. If the DS-TT does not support the link layer connection retrieval and reporting, the NW-TT performs the link layer connection retrieval and reporting instead of the DS-TT, so that the Ethernet device connected to the DS-TT can be retrieved.

[0452] Fig.10 is an example diagram illustrating an architecture that supports time-sensitive communications and time synchronization services.

[0453] Reference Fig.10 , in order to support time synchronization services for Ethernet or IP type sessions, DS-TT, NW-TT and Time Sensitive Communication and Time Synchronization Function (TSCTSF) are shown. NEF provides 5GS capability information to support time synchronization services. TSCTSF controls DS-TT and NW-TT.

[0454] UPF / NW-TT transmits (g)PTP messages.

[0455] When the UPF supports more than one NW-TT, there can be a one-to-one association between the NW-TT and the network instance or a one-to-one association between the NW-TT and the network instance together with the DNN / S-NSSAI in the UPF. When there are multiple network instances in the UPF, each network instance can be considered to be logically separated.

[0456] <Deterministic Networking (Det Net)

[0457] The deterministic network DetNet technology being developed by the IETF DetNet WG is a technology that expands the application scope of Ethernet TSN technology (Layer 2 technology) and integrates with IP and MPLS basic networks (Layer 3 technology). Ultimately, DetNet technology refers to the technology that supports the extension of Ethernet TSN technology (Layer 2 technology) to IP technology (Layer 3 technology). In 3GPP, in order to support IETF DetNet technology from Rel-18 to 5GS, the TSC framework extension technology is reflected in the standard.

[0458] <Problems to be Solved by the Disclosure of This Specification>

[0459] On the other hand, the explosive growth in users' data usage may lead to congestion problems in mobile communication networks.

[0460] At present, in 3GPP 5GS (5G system), when network congestion occurs in the core network (CN), NAS-level congestion control can generally be performed. According to NAS-level congestion control, the network rejects requests such as session establishment modification for data transmission of UE (i.e., terminal) or requests for registration or registration update, and provides a backoff timer to the UE (i.e., terminal). The UE (i.e., terminal) that receives the backoff timer together with the rejection message from the network operates the backoff timer. The UE (i.e., terminal) cannot perform any signaling request until the backoff timer expires.

[0461] These mechanisms are NAS level congestion control and are basically divided into Mobility Management (MM) congestion control and Session Management (SM) congestion control operations.

[0462] In the case of performing NAS-level congestion control, in the case of a deregistration request process performed from the network or in response to a paging message, as an exception, even if the backoff timer of the UE (i.e., terminal) is running, the UE (i.e., terminal) can perform a MM or SM signaling request to the network. In addition, even if the backoff timer of the UE (i.e., terminal) is running, if the UE (i.e., terminal) requests an emergency service or is set to high priority access, as an exception, the UE (i.e., terminal) can send an MM or SM signaling request to the network. At this time, the MM signaling request refers to a registration request message, a service request message, a deregistration request message, a UL NAS transmission message, and a NAS message, and the SM signaling request refers to a NAS message such as a PDU session establishment request, a PDU session modification request message, and a PDU session release request message.

[0463] On the one hand, industrial traffic has very strict QoS requirements for latency. In particular, specific industrial traffic (for example, TSN traffic, TSC traffic, DetNet traffic, URLLC traffic, or IIoT traffic) that needs to transmit urgent or important information needs to be transmitted directly and very quickly.

[0464] General traffic and other industrial traffic may refer to time-sensitive / deterministic or ultra-reliable low latency communication (URLLC) or Industrial IoT (Internet of Things), IIoT or time-sensitive communication (TSC) traffic or traffic of related sessions.

[0465] Therefore, even in congested conditions, when transmitting urgent or important TSN (or DetNet, TSC, DetNet, URLLC, IIoT) information (important / special information), it is necessary to transmit it quickly, but the current 3GPP specifications do not have these control transmission schemes.

[0466] Therefore, for the signaling of these urgent or important TSN (or DetNet, TSC, DetNet, URLLC, IIoT) information flows, a control method is required that allows the terminal to transmit the network even under congestion conditions.

[0467] <Disclosure of this specification>

[0468] Therefore, the purpose of the present specification is to propose a method for solving the above-mentioned problems.

[0469] I. First disclosure of this specification

[0470] Fig.11 This is a diagram showing an example of one disclosure of this specification.

[0471] Below, refer to Fig.11 Give a description.

[0472] 1) When a UE (or, terminal) supporting (available for) TSN (or DetNet, TSC, URLLC, IIoT) sends NAS MM (Mobility Management) or SM (Session Management) signaling to transmit industrial information / traffic, setting information / indication including displaying TSN (or DetNet, TSC, URLLC, IIoT) (e.g., NAS configured for TSN (or DetNet, TSC, URLLC, IIoT)) is set in a NAS MM signaling (e.g., a registration request message, a service request message, a deregistration request message, a UL NAS transmission message) message or a NAS SM signaling (e.g., a PDU session establishment request message, a PDU session modification request message, and a PDU session release request) message and sent to the network.

[0473] General traffic and other industrial traffic may refer to time-sensitive / deterministic or ultra-reliable low latency communication (URLLC) or Industrial IoT (Internet of Things), IIoT or time-sensitive communication (TSC) traffic or traffic of related sessions.

[0474] On the one hand, based on the above information / indications, the network (e.g., SMF or AMF) can distinguish whether the corresponding MM signaling or SM signaling is used for TSN (or DetNet, TSC, URLLC, IIoT) traffic, and perform relevant QoS and session establishment processes.

[0475] 2) However, if congestion occurs in the network, the network (eg, AMF or SMF) rejects the NAS MM signaling or SM signaling request of the UE (or terminal) and sends a rejection message.

[0476] If it is MM signaling, the rejection message may be a registration request rejection message (or registration rejection message), a service request rejection message (or service rejection message), or a deregistration request rejection message (or deregistration rejection message).

[0477] If it is SM signaling, the rejection message can be a PDU session establishment request rejection message (or PDU session establishment rejection message), a PDU session modification request rejection message (or PDU session modification rejection message), or a PDU session release request rejection message (or PDU session release rejection message).

[0478] The rejection message may include a rejection reason value and a backoff timer. Specifically, if it is MM signaling, the rejection message may include an MM backoff timer (e.g., T_abcd) together with a rejection cause value (reject cause value) for the MM signaling request (e.g., #xy:congestionfor TSN (or DetNet, TSC, URLLC, IIoT)). If it is SM signaling, the rejection message may include an SM backoff timer (e.g., T_efgh) together with a rejection reason (e.g., #wz:insufficient resourcesfor TSN (or DetNet, TSC, URLLC, IIoT)) for SM signaling.

[0479] At this time, the rejection reason value can reuse the first value (e.g., #22: congestion) among the rejection reason values ​​for the existing MM signaling request. In addition, the rejection reason value can reuse one of the first value (e.g., #26: insufficient resources), the second value (#67: insufficient resources for specific slice and DNN), and the third value (e.g., #69: insufficient resources for specific slice) among the rejection reason values ​​for the existing SM signaling request. In addition, the MM backoff timer can use the first timer (e.g., T3346) in the existing timer. In addition, the SM backoff timer can reuse one of the first timer (e.g., T3396 for specific DNN and PLMN), the second timer (e.g., T3584 for specific DNN and S-NSSAI), and the third timer (e.g., T3585 for specific S-NSSAI and PLMN) in the existing timer.

[0480] 3) The UE (or terminal) receiving the rejection message from the network interrupts the MM signaling request or SM signaling request process and runs the received back-off timer.

[0481] Thereafter, until the backoff timer for MM signaling expires, the UE does not send any MM signaling request to the network.

[0482] Alternatively, until the backoff timer for SM signaling expires, the UE does not send any SM signaling request to the network.

[0483] 4) However, if urgent or important data occurs in the TSN (or DetNet, TSC, URLLC, IIoT) related application layer of the UE (or terminal), the application layer of the UE (or terminal) informs the NAS layer of this.

[0484] 5) Then, the NAS layer of the UE (or terminal) may selectively terminate or ignore the timer in progress.

[0485] 6) And the NAS layer of the UE (or terminal) may send an SM signaling request or an MM signaling request to the network. The SM signaling request may be, for example, a PDU session establishment request message, a PDU session modification request message, or a PDU session release request message. The MM signaling request may be a registration request message, a service request message, a deregistration request message, or a UL NAS transmission message.

[0486] On the one hand, if the NAS layer does not terminate the running timer in process 5, in order to send urgent or important data, the running timer is ignored and an SM signaling request or an MM signaling request can be sent to the network.

[0487] The SM signaling request or the MM signaling request may include an indication / information (eg, overriding indication / information) indicating overriding or exception congestion control.

[0488] The network does not reject when receiving SM signaling containing instructions / information from the UE (or terminal) during the period of controlling the execution of congestion, and sends an acceptance message for acceptance, thereby allowing the UE (or terminal) to transmit urgent or important data.

[0489] Process 6 is described in more detail as follows.

[0490] If the NAS layer of the UE (or terminal) is in the 5GMM IDLE state, it needs to switch to the 5GMM Connected state in order to send data. For this purpose, only a Service Request message must be sent to the network.

[0491] Therefore, the NAS layer of the UE (or terminal) ignores even if the MM backoff timer (e.g., T3346) is not terminated and runs in process 5, and sends a service request message to the network. At this time, the service request message may include an indication / information (e.g., overriding indication / information) showing the ignore or exception congestion control. Then, the network accepts the service request message without rejecting it.

[0492] When the NAS layer of the UE (or terminal) receives an acceptance message for the service request message, it switches to the 5GMMConnected state, and then sends an SM signaling request (e.g., a PDU session establishment request message, a PDU session modification request message, a PDU session release request message) to the network. When the UE (or terminal) receives an acceptance message for the SM signaling request, it can send urgent or important data.

[0493] To explain again, in order to transmit urgent or important data, the NAS layer of the UE (or terminal) sends MM signaling (for example, a registration request message, a service request message, a registration request message, or a UL NAS transmission message) before sending SM signaling (for example, a PDU session establishment request message, a PDU session modification request message, or a PDU session release request message) to the network. At this time, even if the MM backoff timer (for example, T3346) is running, it is ignored, and the NAS layer of the UE (or terminal) can include an indication / information showing the ignored or exceptional congestion control in the MM signaling (for example, overriding Then, upon receiving an acceptance message for the MM signaling from the network, the NAS layer of the UE (or terminal) may send SM signaling (e.g., a PDU session establishment request message, a PDU session modification request message, or a PDU session release request message) to the network. However, even in this case, if the SM backoff timer is running, the NAS layer of the UE (or terminal) ignores the SM backoff timer and includes an indication / information (e.g., overriding indication / information) showing the ignoring or exceptional congestion control in the SM signaling and sends it.

[0494] Even if the network is controlling the congestion condition, when receiving MM signaling and SM signaling including an indication / information (eg, overriding indication / information) showing ignoring or exception congestion control from the UE (or terminal), accept instead of rejecting.

[0495] However, if an indication / information showing the override or exception congestion control (eg, overriding indication / information) is not included and is transmitted, the network recognizes that it is not NAS signaling for transmitting urgent or important data and rejects it.

[0496] In the above description, other processes may be performed regardless of the execution of process 1 or process 3. That is, in process 1, even if the NAS MM signaling or SM signaling request message sent by the UE does not include setting information / indication for displaying TSN (or DetNet, TSC, URLLC, IIoT) (e.g., NAS configured for TSN (or DetNet, TSC, URLLC, IIoT)), other processes may be performed without any problems. In addition, even if the timer is not terminated in process 5, the timer is ignored in process 6 and MM signaling or SM signaling may be sent.

[0497] II. Second disclosure of this specification

[0498] The above first disclosed content may be operated in conjunction with the access control of the RRC layer of the UE (or terminal).

[0499] The UE (or terminal) performs the above-mentioned first disclosed operation in order to send urgent or important data. At this time, the NAS layer of the UE (or terminal) sends to the RRC layer setting information / indication showing TSN (or DetNet, TSC, URLLC, IIoT) and / or indication / information (e.g., overriding indication / information) showing the neglect or exception of congestion control.

[0500] Then, based on the setting information / indication showing TSN (or DetNet, TSC, URLLC, IIoT), the RRC layer can skip the check for access control (i.e., unified access control). To this end, the NAS layer of the UE (or terminal) can provide the RRC layer with an indication / information showing skipping access control (e.g., Access Control skip indication / information or UAC skip indication / information). In this case, based on the indication / information, the RRC layer does not perform a check for access control, thereby sending an RRC message including a NAS message.

[0501] III. Brief Summary of the Disclosure of This Specification

[0502] A disclosure of the present specification provides an operation method in a terminal. The method may include: driving a mobility management (MM) backoff timer or a session management (SM) backoff timer; and when industrial traffic needs to be transmitted, terminating or ignoring the MM backoff timer or the SM timer and sending SM signaling or MM signaling. The SM signaling or MM signaling may include information indicating the ignore or exception of congestion control.

[0503] The industrial traffic may be traffic for time-sensitive networks (TSN), time-sensitive communications (TSC), deterministic networks (DetNet), ultra-reliable and low-latency communications (URLLC), or industrial Internet of Things (IIoT).

[0504] The industrial traffic may be urgent or important industrial traffic.

[0505] The SM signaling may include: a protocol data unit (PDU) session establishment request (Session Establishment Request) message, a PDU session modification request (Session Modification Request) message, a PDU session release request (Session Release Request) message, or at least one of a non-access stratum (Non-Access Stratum, NAS) message.

[0506] The MM signaling may include at least one of a registration request (Registration Request) message, a service request (ServiceRequest) message, a deregistration request (Deregistration Request) message or an uplink (UP) non-access stratum (NAS) transmission message.

[0507] The method may further include the step of receiving a NAS reject message including a value for the MM backoff timer or a value for the SM backoff timer.

[0508] The NAS reject message may include at least one of a PDU session establishment reject message, a PDU session modification reject message, or a PDU session release reject message.

[0509] The NAS reject message may include at least one of a registration reject message, a service reject message, or a deregistration reject message.

[0510] The terminal may include an application layer, a non-access stratum (NAS) and a radio resource control (RRC) layer.

[0511] In order to send the session management signaling or the mobility management signaling, the NAS sends the information showing the industrial traffic or the information showing the neglect or exception of the congestion control to the RRC layer. Then, the RRC layer skips the check for access control and sends the RRC message to the base station based on the information showing the industrial traffic or the information showing the neglect or exception of the congestion control.

[0512] A disclosure of the present specification provides a chipset installed in a terminal. The chipset includes: at least one processor; and at least one memory storing instructions and operably electrically connected to the at least one processor. Based on the instructions executed by the at least one processor, the operations performed may include: the step of driving a mobility management (MM) backoff timer or a session management (SM) backoff timer; and the step of terminating or ignoring the MM backoff timer or the SM timer and sending SM signaling or MM signaling when industrial traffic needs to be transmitted. The SM signaling or MM signaling may include information showing the ignore or exception of congestion control.

[0513] A disclosure of the present specification provides a device for a terminal. The device may include: a transceiver unit; at least one processor; and at least one memory storing instructions and operably electrically connected to the at least one processor. Based on the instructions executed by the at least one processor, the operations performed may include: a step of driving a mobility management (MM) backoff timer or a session management (SM) backoff timer; and a step of terminating or ignoring the MM backoff timer or the SM timer and sending SM signaling or MM signaling when industrial traffic needs to be transmitted. The SM signaling or MM signaling may include information showing the ignore or exception of congestion control.

[0514] Hereinafter, a device disclosed as described above to which the present specification can be applied will be described.

[0515] Fig.12 is a block diagram showing the configuration of a processor that implements the disclosure of this specification.

[0516] refer to Fig.12 It can be seen that the processor 1020 implementing the disclosure of this specification may include multiple circuits to implement the functions, processes and / or methods described and proposed in this specification. For example, the processor 1020 may include a first circuit 1020-1, a second circuit 1020-2, and a third circuit 1020-3. In addition, although not shown, the processor 1020 may also include more circuits. Each circuit may include multiple transistors.

[0517] The processor 1020 may be referred to as an application-specific integrated circuit (ASIC) or an application processor (AP) and may include at least one of a digital signal processor (DSP), a central processing unit (CPU), and a graphics processing unit (GPU).

[0518] The processor may be installed in the UE.

[0519] Fig.13 FIG. 2 is a diagram showing a wireless communication system according to an embodiment.

[0520] Reference Fig.13 , a wireless communication system may include a first device 100a and a second device 100b.

[0521] 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 sending UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, an unmanned aerial vehicle (UAV), an artificial intelligence (AI) module, a robot, an augmented reality (AR) device, a virtual reality (VR) device, a mixed reality (MR) device, a holographic device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or other devices related to the field of the fourth industrial revolution.

[0522] 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 sending UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, an unmanned aerial vehicle (UAV), an artificial intelligence (AI) module, a robot, an augmented reality (AR) device, a virtual reality (VR) device, a mixed reality (MR) device, a holographic device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or other devices related to the field of the fourth industrial revolution.

[0523] For example, UE 100 may be a mobile phone, a smart phone, a laptop computer, a digital broadcast UE device, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation, a slate PC, a tablet PC, an ultrabook, a wearable device (e.g., a watch-type UE device (smartwatch), a glasses-type UE device (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.

[0524] For example, a drone may be a flying object that flies by radio control signals without human piloting. For example, a VR device may include a device that realizes an object or background in a virtual world, etc. For example, an AR device may include a device that connects an object or background in a virtual world to an object or background in a real world, etc. and realizes it. For example, an MR device may include a device that merges an object or background in a virtual world into an object or background in a real world, etc. and realizes it. For example, a holographic device may include a device that uses holography, which is an interference phenomenon of light that occurs when two lasers meet, to record and reproduce three-dimensional information to realize a 360-degree stereoscopic image. For example, a public safety device may include a live video device or a video device that can be worn on a user, etc. For example, an MTC device and an IoT device may be a device that does not require direct human intervention or manipulation. For example, an MTC device and an IoT device may include a smart meter, a bending machine, a thermometer, a smart light bulb, a door lock, or various sensors, etc. For example, a medical device may be a device that is intended to diagnose, treat, alleviate, treat, or prevent a disease. For example, a medical device may be a device that is intended to diagnose, treat, alleviate, or correct an injury or disability. For example, a medical device may be a device that is intended to inspect, replace, or deform a structure or function. For example, a medical device may be a device intended to regulate pregnancy. For example, a medical device may include a diagnostic device, a surgical device, an (in vitro) diagnostic device, a hearing aid or a surgical device. For example, a security device may be a device installed to prevent possible 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 that can provide financial services such as mobile payments. For example, a fintech device may include a payment device or a point of sales (POS). For example, a climate / environmental device may include a device that monitors or predicts the climate / environment.

[0525] The first device 100a may include at least one processor (such as processor 1020a), at least one memory (such as memory 1010a) and at least one transceiver (such as transceiver 1031a). Processor 1020a can perform the above functions, processes and / or methods. Processor 1020a can execute one or more protocols. For example, processor 1020a can execute one or more layers of a wireless interface protocol. Memory 1010a is connected to processor 1020a and can store various types of information and / or commands. Transceiver 1031a is connected to processor 1020a and can be controlled to send and receive wireless signals.

[0526] The second device 100b may include at least one processor (such as processor 1020b), at least one memory device (such as memory 1010b) and at least one transceiver (such as transceiver 1031b). Processor 1020b can perform the above functions, processes and / or methods. Processor 1020b can implement one or more protocols. For example, processor 1020b can implement one or more layers of a wireless interface protocol. Memory 1010b is connected to processor 1020b and can store various types of information and / or commands. Transceiver 1031b is connected to processor 1020b and can be controlled to send and receive wireless signals.

[0527] The memory 1010a and / or the memory 1010b may be connected to each other inside or outside the processor 1020a and / or the processor 1020b, and may also be connected to other processors through various technologies such as a wired or wireless connection.

[0528] 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.

[0529] Fig.14 is a block diagram illustrating a network node according to an embodiment.

[0530] Specifically, Fig.14 The diagram shows in detail a case where a base station is divided into a central unit (CU) and a distributed unit (DU).

[0531] Reference Fig.14 , base stations W20, W30 can be connected to the core network W10, and base station W30 can be connected to the adjacent base station W20. For example, the interface between base stations W20, W30 and the core network W10 can be called NG, and the interface between base station W30 and the adjacent base station W20 can be called Xn.

[0532] The base station W30 can be divided into CU W32 and DU W34, W36. That is, the base station W30 can be separated and operated by layers. CUW32 can be connected to one or more DU W34, W36, for example, the interface between CU W32 and DU W34, W36 can be called F1. CU W32 can perform the functions of the upper layers of the base station, and DU W34, W36 can perform the functions of the lower layers of the base station. For example, CU W32 can be a logical node of the radio resource control (RRC), service data adaptation protocol (SDAP) and packet data convergence protocol (PDCP) layers of the hosting base station (e.g., gNB), and DU W34, W36 can be a logical node of the radio link control (RLC), media access control (MAC) and physical (PHY) layers of the hosting base station. Alternatively, CU W32 may be a logical node for the RRC and PDCP layers of a hosting base station (e.g., en-gNB).

[0533] The operation of DU W34, W36 can be partially controlled by CU W32. One DU W34, W36 can support one or more cells. One cell can only be supported by one DU W34, W36. One DU W34, W36 can be connected to one CU W32, and with proper implementation one DU W34, W36 can be connected to multiple CUs.

[0534] Fig.15 is a block diagram showing the configuration of UE 100 according to an embodiment.

[0535] especially, Fig.15 The UE 100 shown in FIG. 1 is a more detailed view of the above Fig.14 Figure 1 of the first device.

[0536] UE 100 includes a memory 1010, a processor 1020, a transceiver unit 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.

[0537] The processor 1020 may be configured to implement the functions, processes and / or methods described and suggested in this specification. The layers of the 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, Modem). An example of the processor 1020 may be a processor composed of MANUFACTURED BY SNAPDRAGON TM Series processors, EXYNOSTM series processors manufactured by A series processors manufactured by Made by HELIO TM Series processors, ATOM manufactured TM series processors or corresponding next-generation processors.

[0538] The power management module 1091 manages the power of the processor 1020 and / or the transceiver unit 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. The SIM card is an integrated circuit for identifying the international mobile subscriber identity (IMSI) and securely storing the keys associated with it in mobile devices such as mobile phones and computers to identify subscribers and perform authentication. Contact information can also be stored in multiple SIM cards.

[0539] The memory 1010 is operably coupled to the processor 1020 and stores various information for operating the processor 610. The memory 1010 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage devices. When the embodiment is implemented by software, the technology described in this specification may be implemented by a module (e.g., a process, a function, etc.) that performs the functions described in this specification. The module 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 outside the processor 1020 and may be communicatively connected to the processor 1020 by various means known in the art.

[0540] The transceiver unit 1031 is operably coupled to the processor 1020 and sends and / or receives wireless signals. The transceiver unit 1031 includes a transmitter and a receiver. The transceiver unit 1031 may include a baseband circuit for processing wireless frequency signals. The transceiver unit controls one or more antennas to send and / or receive wireless signals. The processor 1020 communicates command information to the transceiver unit 1031 in order to initiate communication, for example, to send a wireless signal constituting voice communication data. The function of the antenna is to send and receive wireless signals. When receiving a wireless signal, the transceiver unit 1031 can transmit the signal and convert the signal to baseband in order to be processed by the processor 1020. The processed signal can be converted into audible or readable information output through the speaker 1042.

[0541] Speaker 1042 outputs sound related results processed by processor 1020. Microphone 1052 receives sound related input to be used by processor 1020.

[0542] The user inputs command information such as a phone number by, for example, pressing (or touching) a button of the input unit 1053 or voice activation using the microphone 1052. The processor 1020 receives the command information and processes it to perform appropriate functions, such as dialing a phone number. Operational data may be extracted from the SIM card or the memory 1010. In addition, the processor 1020 may display command information or operation information on the display 1041 for user recognition and convenience.

[0543] Fig.16 It is shown in Fig.13 The transceiver unit of the first device shown in FIG. Fig.15 A block diagram of the transceiver unit of the device shown.

[0544] Reference Fig.16 , 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 transmission unit 1031-15. The transmitter 1031-1 may also include a modulator. In addition, for example, a scramble unit (scramble unit, not shown), a modulation mapper (modulation mapper, not shown), a layer mapper (layer mapper, not shown), and a layer permutator (layer permutator, not shown) may also be included, which may be arranged before the DFT unit 1031-11. That is, in order to prevent the increase of the peak-to-average power ratio (PAPR), the transmitter 1031-1 first passes the signal through the DFT 1031-11 before mapping the signal to the subcarrier. The signal spread (or precoded in the same sense) by the DFT unit 1031-11 is mapped to subcarriers by the subcarrier mapper 1031-12, and then passes through the Inverse Fast Fourier Transform (IFFT) unit 1031-13 again to create a signal on the time axis.

[0545] The DFT unit 1031-11 performs DFT on the input symbol and outputs a complex-valued symbol. For example, if Ntx symbols (where Ntx is a natural number) are input, the DFT size is Ntx. The DFT unit 1031-11 may be referred to as a transform precoder. The subcarrier mapper 1031-12 maps the complex-valued symbols to each subcarrier in the frequency domain. The complex-valued symbols may be mapped to resource elements corresponding to resource blocks allocated for data transmission. The subcarrier mapper 1031-12 may be referred to as a resource element mapper. The IFFT unit 1031-13 performs IFFT on the input symbol and outputs a baseband signal of the data as 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. By inserting CP, inter-symbol interference (ISI) and inter-carrier interference (ICI) can be prevented, thereby maintaining orthogonality even in a multipath channel.

[0546] On the other hand, the receiver 1031-2 includes a wireless receiving unit 1031-21, a CP removal unit 1031-22, an FFT unit 1031-23, an equalization unit 1031-24, etc. The wireless receiving 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 transmitting unit 1031-15, the CP insertion unit 1031-14, and the IFF unit 1031-13 in the transmitting end 1031-1. The receiver 1031-2 may also include a demodulator.

[0547] <Scenarios to which this specification is applicable>

[0548] Although not limited to this, the various descriptions, functions, processes, suggestions, methods and / or operational flowcharts disclosed in this specification disclosed herein may be applicable to a variety of fields requiring wireless communication / connection (e.g., 5G) between devices.

[0549] In the following, more detailed examples will be provided with reference to the accompanying drawings. In the following drawings / descriptions, unless otherwise specified, the same reference numerals represent the same or corresponding hardware blocks, software blocks or functional blocks.

[0550] Fig.17 1 is a diagram showing a communication system 1 applicable to the disclosure of this specification.

[0551] Reference Fig.17 , the disclosed communication system 1 applicable to the present specification includes a wireless device, a base station and a network. Among them, the wireless device refers to a device that performs communication using a wireless access technology (such as 5GNR (new RAT), Long Term Evolution (Long Term Evolution, LTE)), and is referred to as a communication / wireless / 5G device. Although not limited to this, the wireless device may include a robot 100a, a vehicle 100b-1, 100b-2, an extended reality (eXtended Reality, XR) device 100c, a handheld device (Hand-held device) 100d, a home appliance 100e, an Internet of Things (Internet of Things, IoT) device 100f and an AI device / server 400. For example, a vehicle may include a vehicle equipped with a wireless communication function, an autonomous driving vehicle, a vehicle capable of inter-vehicle communication, etc. Among them, the vehicle may include an unmanned aerial vehicle (Unmanned Aerial Vehicle, UAV) (for example, a drone). XR devices include augmented reality (AR) / virtual reality (VR) / mixed reality (MR) devices, and can be embodied in the form of head-mounted devices (HMD), head-up displays (HUD) equipped in vehicles, televisions, smart phones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Mobile devices may include smart phones, smart pads, wearable devices (e.g., smart watches, smart glasses), computers (e.g., laptops, etc.), etc. Home appliances may include televisions, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, base stations and networks may also be implemented through wireless devices. A specific wireless device 200a may operate as a base station / network node for other wireless devices.

[0552] The wireless devices 100a to 100f may be connected to the network 300 through the base station 200. Artificial Intelligence (AI) technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI ​​server 400 through the network 300. The network 300 may be formed using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network, etc. The wireless devices 100a to 100f may communicate with each other through the base station 200 / network 300, but may also communicate directly (e.g., sidelink communication) without passing through the base station / network. For example, vehicles 100b-1, 100b-2 may communicate directly (e.g., vehicle to vehicle (V2V) / vehicle to everything (V2X) communication). In addition, an IoT device (e.g., a sensor) may communicate directly with other IoT devices (e.g., a sensor) or other wireless devices 100a to 100f.

[0553] Wireless communication / connection 150a, 150b, 150c can be established between wireless devices 100a~100f / base station 200, and base station 200 / base station 200. Among them, wireless communication / connection can be established through various wireless access technologies (for example, 5GNR) such as uplink / downlink communication 150a and side link communication 150b (or, D2D communication), communication between base stations 150c (for example, relay, Integrated Access Backhaul (IAB)), etc. Through wireless communication / connection 150a, 150b, 150c, wireless devices and base stations / wireless devices, and base stations and base stations can send / receive wireless signals to each other. For example, wireless communication / connection 150a, 150b, 150c can send / receive signals through various physical channels. To this end, based on the various suggestions disclosed in this specification, at least a part of various configuration information setting processes for sending / receiving wireless signals, various signal processing processes (for example, channel coding / decoding, modulation / demodulation, resource mapping / demapping, etc.) and resource allocation processes can be performed.

[0554] The above is an exemplary description through preferred embodiments, but the disclosure of this specification is not limited to such specific embodiments. Therefore, it can be modified, changed or improved in various forms within the scope of the concept of this specification and the scope of the claims.

[0555] In the above exemplary system, the method is described as a series of steps or boxes based on the flowchart, but the order of the steps described is not limited, and as mentioned above, some steps can occur in other orders or at the same time as other steps. In addition, those skilled in the art will understand that the steps shown in the flowchart are not exclusive, and other steps may be included or one or more steps in the flowchart may be deleted without affecting the scope of the rights.

[0556] The claims described in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined to implement an apparatus, and the technical features of the device claims of this specification may be combined to implement a method. In addition, the technical features of the method claims of this specification and the technical features of the device claims may be combined to implement an apparatus, and the technical features of the method claims of this specification and the technical features of the device claims may be combined to implement a method.

Claims

1. A method for operating a terminal, wherein: The operation method comprises: The step of driving a mobility management back-off timer or a session management back-off timer; and When industrial traffic needs to be transmitted, the step of terminating or ignoring the mobility management backoff timer or the session management timer and sending session management signaling or mobility management signaling, The session management signaling or mobility management signaling includes information indicating the ignore or exception of congestion control.

2. The operating method according to claim 1, wherein: The industrial traffic is traffic used for time-sensitive networking, time-sensitive communication, deterministic networking, ultra-reliable and low-latency communication, or industrial Internet of Things.

3. The operating method according to claim 1, wherein: The industrial traffic is urgent or important industrial traffic.

4. The operating method according to claim 1, wherein: The session management signaling includes at least one of a protocol data unit session establishment request message, a protocol data unit session modification request message, a protocol data unit session release request message, or a non-access layer message.

5. The operating method according to claim 1, wherein: The mobility management signaling includes at least one of a registration request message, a service request message, a deregistration request message, or an uplink non-access layer transmission message.

6. The operating method according to claim 1, further comprising: The step of receiving a non-access stratum reject message including a value for said mobility management back-off timer or a value for said session management back-off timer.

7. The operating method according to claim 6, wherein: The non-access layer rejection message includes at least one of a protocol data unit session establishment rejection message, a protocol data unit session modification rejection message or a protocol data unit session release rejection message.

8. The operating method according to claim 6, wherein: The non-access stratum reject message includes at least one of a registration reject message, a service reject message or a deregistration reject message.

9. The operating method according to claim 1, wherein: The terminal includes an application layer, a non-access layer and a radio resource control layer, and In order to send the session management signaling or the mobility management signaling, the following is performed: A process in which the non-access layer sends information indicating the industrial traffic or information indicating the ignore or exception of the congestion control to the radio resource control layer; and The radio resource control layer skips a check for access control and transmits a radio resource control message to a base station based on the information indicating the industrial traffic volume or the information indicating the ignore or exception of the congestion control.

10. A chipset installed in a terminal, the chipset comprising: at least one processor; as well as At least one memory stores instructions and is operably electrically connected to the at least one processor, and is executed by the at least one processor based on the instructions, and the operations performed include: The step of driving a mobility management back-off timer or a session management back-off timer; and When industrial traffic needs to be transmitted, the step of terminating or ignoring the mobility management backoff timer or the session management timer and sending session management signaling or mobility management signaling, The session management signaling or mobility management signaling includes information indicating the ignore or exception of congestion control.

11. The chipset according to claim 10, wherein: The industrial traffic is traffic used for time-sensitive networking, time-sensitive communication, deterministic networking, ultra-reliable and low-latency communication, or industrial Internet of Things.

12. The chipset according to claim 10, wherein: The industrial traffic is urgent or important industrial traffic.

13. The chipset according to claim 10, wherein: The session management signaling includes at least one of a protocol data unit session establishment request message, a protocol data unit session modification request message, a protocol data unit session release request message, or a non-access layer message.

14. The chipset according to claim 10, wherein: The mobility management signaling includes at least one of a registration request message, a service request message, a deregistration request message, or an uplink non-access layer transmission message.

15. The chipset according to claim 10, wherein: The operations also include: The step of receiving a non-access stratum reject message including a value for said mobility management back-off timer or a value for said session management back-off timer.

16. The chipset according to claim 10, wherein: The processor includes an application layer, a non-access layer, and a radio resource control layer, and In order to send the session management signaling or the mobility management signaling, The non-access layer sends information indicating the industrial traffic or information indicating the ignore or exception of the congestion control to the radio resource control layer, and The radio resource control layer skips the check for access control and transmits a radio resource control message to the base station based on the information indicating the industrial traffic volume or the information indicating the ignore or exception of the congestion control.

17. A device for a terminal, the device comprising: Transceiver unit; at least one processor; as well as at least one memory storing instructions and being operably electrically connected to the at least one processor, and Based on the instruction being executed by the at least one processor, the operations performed include: The step of driving a mobility management back-off timer or a session management back-off timer; When industrial traffic needs to be transmitted, the step of terminating or ignoring the mobility management backoff timer or the session management timer and sending session management signaling or mobility management signaling, The session management signaling or mobility management signaling includes information indicating the ignore or exception of congestion control.

18. The device according to claim 17, wherein: The industrial traffic is traffic used for time-sensitive networking, time-sensitive communication, deterministic networking, ultra-reliable and low-latency communication, or industrial Internet of Things.

19. The device according to claim 17, wherein: The industrial traffic is urgent or important industrial traffic.

20. The device according to claim 17, wherein: The processor includes an application layer, a non-access layer, and a radio resource control layer, and In order to send the session management signaling or the mobility management signaling, The non-access layer sends information indicating the industrial traffic or information indicating the ignore or exception of the congestion control to the radio resource control layer, and The radio resource control layer skips the check for access control and transmits a radio resource control message to the base station based on the information indicating the industrial traffic volume or the information indicating the ignore or exception of the congestion control.

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