WO2021025431A1 - Ims signaling - Google Patents

Abstract

One disclosure of the present specification provides a method for a terminal to perform communication related to an IMS. The above method may comprise: a step in which an IMS layer determines that IMS signaling for non-service attempts is required; and a step in which the IMS layer transmits a first request message, including information about a first access category related to an IMS service, to a NAS layer.

Description

IMS signaling

The present specification relates to mobile communication.

Thanks to the success of LTE (long term evolution)/LTE-Advanced (LTE-A) for 4G mobile communication, interest in the next generation, that is, 5G (so-called 5G) mobile communication, is also increasing, and research is continuing. .

For the fifth generation (so-called 5G) mobile communication, a new radio access technology (New RAT or NR) has been studied.

　5th generation mobile communication defined by the International Telecommunication Union (ITU) refers to providing a maximum 　20Gbps data transmission speed and a sensible transmission speed of at least 　100Mbps　 or more anywhere. Its official name is'IMT-2020' and it aims to be commercialized globally in 2020.

A terminal using a 3rd Generation Partnership Project (3GPP) system including LTE and 5G provides IP Multimedia Subsystem (IMS) services such as voice call, video call, and SMS (Short Messge Service) (e.g. SMS over IP (Internet Protocol)). Can be provided.

When the IMS layer of such a terminal needs to deliver IMS signaling for non-service attempts (e.g., IMS signaling for the purpose of initial registration, re-registration, and subscription refresh) to the IMS network rather than the actual attempt related to the IMS service. There may be. In this case, the IMS layer of the terminal transmits the IMS signaling for non-service attempts to the RRC layer of the terminal through the NAS layer of the terminal, and the RRC layer of the terminal can transmit it to the network.

If access control is being applied to the network and/or the terminal due to a network congestion situation, etc., the RRC layer of the terminal performs an access control check on IMS signaling for non-service attempts based on the access category. IMS signaling for non-service attempts does not define a separate access category for this and uses an access category for general transmission data (e.g., access category 7 for Mobile Originating (MO) data), which is applicable to other access categories. Compared to this, the priority is low, so it is highly likely to be blocked by the RRC layer.

In this way, when IMS signaling for non-service attempts is blocked, the terminal cannot register in the IMS network, and thus the terminal cannot receive the IMS service. Conventionally, a method for increasing the possibility that IMS signaling for non-service attempts is not blocked by access control has not been discussed.

Accordingly, one disclosure of the present specification aims to provide a solution to the above-described problem.

In order to solve the above-described problem, one disclosure of the present specification provides a method for a terminal to perform communication related to IMS. The method includes the steps of determining, by the IMS layer, that IMS signaling for non-service attempts is required; And transmitting, by the IMS layer, a first request message including information on a first access category related to the IMS service to the NAS layer.

In order to solve the above-described problem, one disclosure of the present specification provides a wireless communication device. A wireless communication device includes at least one processor; And at least one memory that stores an instruction and is operably electrically connected to the at least one processor. Operations performed based on the instruction being executed by the at least one processor include: determining, by the IMS layer, that IMS signaling for a non-service attempt is required; And transmitting, by the IMS layer, a first request message including information on a first access category related to the IMS service to the NAS layer.

In order to solve the above-described problem, one disclosure of the present specification provides an apparatus in mobile communication. The apparatus includes at least one processor; And at least one memory that stores an instruction and is operably electrically connected to the at least one processor. Operations performed based on the instruction being executed by the at least one processor include: determining that IMS signaling for a non-service attempt is required; And generating a first request message including information on a first access category related to the IMS service.

In order to solve the above-described problem, one disclosure of the present specification provides a non-volatile computer-readable storage medium for recording instructions. The instructions, when executed by one or more processors, cause the one or more processors to: determine that IMS signaling for a non-service attempt is required; And generating a first request message including information on a first access category related to the IMS service.

According to the disclosure of the present specification, problems of the prior art can be solved.

The effects that can be obtained through a specific example of the present specification are not limited to the effects listed above. For example, there may be various technical effects that a person having ordinary skill in the related art can understand or derive from the present specification. Accordingly, the specific effects of the present specification are not limited to those explicitly described in the present specification, and may include various effects that can be understood or derived from the technical features of the present specification.

1 is an example of a structural diagram of a next-generation mobile communication network.

2 is an exemplary diagram showing an expected structure of next-generation mobile communication from a node perspective.

3 is an exemplary diagram showing an architecture for supporting simultaneous access to two data networks.

4 is another exemplary diagram showing the structure of a radio interface protocol between a UE and a gNB.

5A and 5B are signal flow diagrams illustrating an exemplary registration procedure.

6A and 6B are signal flow diagrams illustrating an exemplary PDU session establishment procedure.

7 shows an example of a problem to be solved by the disclosure of the present specification.

8 is an exemplary signal flow diagram illustrating the disclosure of the present specification.

9 is an exemplary signal flow diagram illustrating operations according to case 1 of FIG. 8.

10 is an exemplary signal flow diagram illustrating operations according to a first example of the disclosure of the present specification.

11 is an exemplary signal flow diagram illustrating a second example of the disclosure of the present specification.

12 illustrates a communication system 1 applied to the disclosure of this specification.

13 illustrates a wireless device applicable to the disclosure of the present specification.

14 illustrates a signal processing circuit for a transmission signal.

15 shows another example of a wireless device applied to the disclosure of the present specification.

16 shows an example of a vehicle or an autonomous vehicle that is applied to the disclosure of the present specification.

17 illustrates an AI device applied to the disclosure of the present specification.

It should be noted that the technical terms used in the present specification are only used to describe specific embodiments and are not intended to limit the content of the present specification. In addition, the technical terms used in the present specification should be interpreted in the meaning generally understood by those of ordinary skill in the technical field to which the disclosure of the present specification belongs, unless otherwise defined in the specification. It should not be construed in a comprehensive or excessively reduced sense. In addition, when a technical term used in the present specification is an incorrect technical term that does not accurately express the contents and spirit of the present specification, a technical term that can be correctly understood by those skilled in the art should be replaced and understood. In addition, general terms used in the present specification should be interpreted as defined in the dictionary or according to the context before and after, and should not be interpreted as an excessively reduced meaning.

In addition, the singular expression used in the present specification includes a plurality of expressions unless the context clearly indicates otherwise. In the present application, terms such as constitute or have should not be construed as necessarily including all of the various components or steps described in the specification, and some components or some steps may not be included, and Or, it should be interpreted that it may further include additional components or steps.

In addition, terms including ordinal numbers such as first and second used in the present specification may be used to describe various elements, but the elements should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another component. For example, without departing from the scope of the rights, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

When a component is connected to or is said to be connected to another component, it may be directly connected or connected to the other component, but other components may exist in the middle. On the other hand, when a component is directly connected to or directly connected to another component, it should be understood that there is no other component in the middle.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings, but identical or similar elements are denoted by the same reference numerals regardless of reference numerals, and redundant descriptions thereof will be omitted. In addition, in describing the contents of the present specification, if it is determined that a detailed description of a related known technology may obscure the subject matter of the present specification, a detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are for easy understanding of the content and spirit of the present specification, and should not be construed as limiting the content and spirit of the present specification by the accompanying drawings. The content and spirit of this specification should be construed as extending to all changes, equivalents, or substitutes other than the accompanying drawings.

In the present specification, “A or B (A or B)” may mean “only A”, “only B” or “both A and B”. In other words, in the present specification, “A or B (A or B)” may be interpreted as “A and/or B (A and/or B)”. For example, in the present specification, “A, B or C (A, B or C)” refers to “only A”, “only B”, “only C”, or “A, B, and any combination of C ( It can mean any combination of A, B and C)”.

A forward slash (/) or comma used in the present specification may mean "and/or". For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B or C”.

In the present specification, “at least one of A and B” may mean “only A”, “only B”, or “both A and B”. In addition, in this specification, the expression “at least one of A or B” or “at least one of A and/or B” means “at least one It can be interpreted the same as "at least one of A and B".

In addition, in the present specification, “at least one of A, B and C” means “only A”, “only B”, “only C”, or “A, B and C Can mean 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" means It can mean “at least one of A, B and C”.

In addition, parentheses used in the present specification may mean "for example". Specifically, when displayed as “control information (PDCCH)”, “PDCCH” may be proposed as an example of “control information”. In other words, “control information” of the present specification is not limited to “PDCCH”, and “PDDCH” may be suggested as an example of “control information”. In addition, even when indicated as “control information (ie, PDCCH)”, “PDCCH” may be proposed as an example of “control information”.

In the present specification, technical features that are individually described in one drawing may be implemented individually or simultaneously.

In the accompanying drawings, a user equipment (UE) is illustrated by way of example, but the illustrated UE may be referred to in terms of terminal, mobile equipment (ME), and the like. In addition, the UE may be a portable device such as a notebook 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.

Hereinafter, the UE is used as an example of a wireless communication device (or a wireless device, or a wireless device) capable of wireless communication. The operation performed by the UE may be performed by a wireless communication device. The wireless communication device may also be referred to as a wireless device, a wireless device, or the like. Hereinafter, AMF may refer to an AMF node, SMF may refer to an SMF node, and UPF may refer to a UPF node.

A base station, which is a term used below, generally refers to a fixed station that communicates with a wireless device, eNodeB (evolved-NodeB), eNB (evolved-NodeB), BTS (Base Transceiver System), access point ( Access Point), gNB (Next generation NodeB), and other terms.

I. Technologies and procedures applicable to the disclosure of this specification

1 is an example of a structural diagram of a next-generation mobile communication network.

5GC (5G Core) may include various components, and in FIG. 1, AMF (Access and Mobility Management Function) 41 and SMF (session management function: Session Management) corresponding to some of them Function)(42), PCF(Policy Control Function)(43), UPF(User Plane Function)(44), AF(Application Function)(45), UDM(Integrated Data) Management: Includes Unified Data Management (46) and Non-3GPP InterWorking Function (N3IWF) (49).

The UE 100 is connected to a data network through the UPF 44 through a Next Generation Radio Access Network (NG-RAN) including the gNB 200.

The UE 100 may receive a data service even through untrusted non-3GPP access, for example, a wireless local area network (WLAN). In order to connect the non-3GPP access to the core network, an N3IWF 49 may be deployed.

The illustrated N3IWF 49 performs a function of managing non-3GPP access and interworking between 5G systems. When the UE 100 is connected to non-3GPP access (e.g., WiFi referred to as IEEE 801.11), the UE 100 may be connected to the 5G system through the N3IWF 49. The N3IWF 49 performs control signaling with the AMF 41 and is connected to the UPF 44 through an N3 interface for data transmission.

The illustrated AMF 41 can manage access and mobility in a 5G system. The AMF 41 may perform a function of managing NAS (Non-Access Stratum) security. The AMF 41 may perform a function of handling mobility in an idle state.

The illustrated UPF 44 is a type of gateway through which user data is transmitted and received. The UPF node 44 may perform all or part of a user plane function of a serving gateway (S-GW) and a packet data network gateway (P-GW) of 4G mobile communication.

The UPF 44 operates as a boundary point between a next generation RAN (NG-RAN) and a core network, and is an element that maintains a data path between the gNB 200 and the SMF 42. In addition, when the UE 100 moves over an area served by the gNB 200, the UPF 44 serves as a mobility anchor point. The UPF 44 may perform a function of handling a PDU. Packets may be routed in the UPF for mobility within the NG-RAN (Next Generation-Radio Access Network defined after 3GPP Release-15). In addition, the UPF 44 is another 3GPP network (RAN defined before 3GPP Release-15, for example, UTRAN, E-UTRAN (Evolved-UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access Network)) or GERAN (GSM ( It may also function as an anchor point for mobility with Global System for Mobile Communication)/EDGE (Enhanced Data rates for Global Evolution) Radio Access Network). The UPF 44 may correspond to a termination point of a data interface toward a data network.

The illustrated PCF 43 is a node that controls the operator's policy.

The illustrated AF 45 is a server for providing various services to the UE 100.

The illustrated UDM 46 is a kind of server that manages subscriber information, such as a 4G mobile communication HSS (Home Subscriber Server). The UDM 46 stores and manages the subscriber information in a Unified Data Repository (UDR).

The illustrated SMF 42 may perform a function of allocating an Internet Protocol (IP) address of the UE. In addition, the SMF 42 may control a protocol data unit (PDU) session.

For reference, in the following AMF (41), SMF (42), PCF (43), UPF (44), AF (45), UDM (46), N3IWF (49), gNB (200), or UE (100) Reference numerals for may be omitted.

5G mobile communication supports a number of numerology or subcarrier spacing (SCS) to support various 5G services. For example, when the SCS is 15 kHz, it supports a wide area in traditional cellular bands, and when the SCS is 30 kHz/60 kHz, it is dense-urban, lower latency. And a wider carrier bandwidth (wider carrier bandwidth) is supported, and when the SCS is 60 kHz or higher, a bandwidth greater than 24.25 GHz is supported to overcome phase noise.

The NR frequency band may be defined as a frequency range of two types (FR1, FR2). The numerical value of the frequency range may be changed, for example, the frequency range of the two types (FR1, FR2) may be as shown in Table 1 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 may mean “sub 6GHz range”, and FR2 may mean “above 6GHz range” and may be called millimeter wave (mmW). .

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing
FR1	450MHz-6000MHz	15, 30, 60 kHz
FR2	24250MHz-52600MHz	60, 120, 240 kHz

As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band of 410MHz to 7125MHz as shown in Table 2 below. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher included in FR1 may include an unlicensed band. The unlicensed band can be used for a variety of purposes, and can be used, for example, for communication for vehicles (eg, autonomous driving).

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing
FR1	410MHz-7125MHz	15, 30, 60 kHz
FR2	24250MHz-52600MHz	60, 120, 240 kHz

2 is an exemplary diagram showing an expected structure of next-generation mobile communication from a node perspective. As can be seen with reference to FIG. 2, the UE is connected to a data network (DN) through a next-generation radio access network (RAN).

The illustrated control plane function (CPF) node is all or part of the functions of a mobility management entity (MME) of 4G mobile communication, and a control plane function of a serving gateway (S-GW) and a PDN gateway (P-GW). Do all or part of. The CPF node includes an Access and Mobility Management Function (AMF) and a Session Management Function (SMF).

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

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

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

The illustrated Unified Data Management (UDM) is a kind of server that manages subscriber information, such as a 4G mobile communication HSS (Home Subscriber Server). The UDM stores and manages the subscriber information in a Unified Data Repository (UDR).

The illustrated authentication server function (AUSF) authenticates and manages the UE.

The illustrated network slice selection function (NSSF) is a node for network slicing as described below.

The illustrated network exposure function (NEF) is a node for providing a mechanism to securely disclose services and functions of the 5G core. For example, NEF discloses functions and events, securely provides information from external applications to the 3GPP network, translates internal/external information, provides control plane parameters, and provides packet flow description (PFD). ) Can be managed.

In FIG. 3, a UE may simultaneously access two data networks using multiple protocol data unit or packet data unit (PDU) sessions.

3 is an exemplary diagram showing an architecture for supporting simultaneous access to two data networks.

In FIG. 3, an architecture for a UE to access two data networks simultaneously using one PDU session is shown.

Reference points shown in FIGS. 2 and 3 are as follows.

N1 represents a reference point between the UE and the AMF.

N2 represents a reference point between (R)AN and AMF.

N3 represents a reference point between (R)AN and UPF.

N4 represents a reference point between SMF and UPF.

N5 represents the reference point between PCF and AF.

N6 represents a reference point between UPF and DN.

N7 represents a reference point between the SMF and PCF.

N8 represents a reference point between UDM and AMF.

N9 represents a reference point between UPFs.

N10 represents a reference point between UDM and SMF.

N11 represents a reference point between AMF and SMF.

N12 represents a reference point between AMF and AUSF.

N13 represents a reference point between UDM and AUSF.

N14 represents a reference point between AMFs.

N15 denotes a reference point between the PCF and the AMF in a non-roaming scenario, and a reference point between the AMF and the PCF of a visited network in a roaming scenario.

N16 represents a reference point between SMFs.

N22 represents a reference point between AMF and NSSF.

N30 represents a reference point between PCF and NEF.

N33 represents a reference fit between AF and NEF.

For reference, in FIGS. 2 and 3, AF by a third party other than an operator may be connected to 5GC through NEF.

4 is another exemplary diagram showing the structure of a radio interface protocol between a UE and a gNB.

The air interface protocol is based on the 3GPP radio access network standard. The radio interface protocol is horizontally composed of a physical layer (Physical layer), a data link layer (Data Link layer), and a network layer (Network layer), and vertically, a user plane for data information transmission and control It is divided into a control plane for signal transmission.

The protocol layers are L1 (layer 1), L2 (layer 2), and L3 (layer 3) based on the lower 3 layers of the Open System Interconnection (OSI) reference model widely known in communication systems. ) Can be separated.

In the following, each layer of the radio protocol will be described.

The first layer, the physical layer, provides an information transfer service using a physical channel. The physical layer is connected to an upper medium access control layer through a transport channel, and data between the medium access control layer and the physical layer is transmitted through the transport channel. In addition, data is transmitted between different physical layers, that is, between the physical layers of the transmitting side and the receiving side through a physical channel.

The second layer includes a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, and a Packet Data Convergence Protocol (PDCP) layer.

The third layer includes Radio Resource Control (hereinafter abbreviated as RRC). The RRC layer is defined only in the control plane, and is related to setting (setting), resetting (Re-setting) and release (Release) of radio bearers (Radio Bearer; RB). In charge of control. In this case, RB means a service provided by the second layer for data transmission between the UE and the E-UTRAN.

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

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

1) NAS entity for MM provides the following functions in general.

NAS procedures related to AMF, including the following.

-Registration management and access management procedures. AMF supports the following functions.

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

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

The SM signaling message is processed, that is, generated and processed at the NAS-SM layer of the UE and SMF. The contents of the SM signaling message are not interpreted by the AMF.

-In the case of SM signaling transmission,

-The NAS entity for the MM generates a NAS-MM message that derives how and where to deliver the SM signaling message through the security header representing the NAS transmission of SM signaling, and additional information about the receiving NAS-MM.

-Upon receiving the SM signaling, the NAS entity for the SM performs an integrity check of the NAS-MM message, analyzes the additional information, and derives a method and place to derive the SM signaling message.

Meanwhile, in FIG. 4, an RRC layer, an RLC layer, a MAC layer, and a PHY layer located below the NAS layer are collectively referred to as an Access Stratum (AS).

The network system (ie, 5GC) for next-generation mobile communication (ie, 5G) also supports non-3GPP access. An example of the non-3GPP access is typically WLAN access. The WLAN access may include both a trusted WLAN and an untrusted WLAN.

In a system for 5G, AMF performs registration management (RM: Registration Management) and connection management (CM: Connection Management) for non-3GPP access as well as 3GPP access.

A multi-access (MA) PDU session using both 3GPP access and non-3GPP access may be used.

The MA PDU session is a PDU session capable of simultaneously serving 3GPP access and non-3GPP access using one PDU session.

<Registration Procedure>

The UE needs to obtain authorization in order to enable mobility tracking, enable data reception, and receive services. For this, the UE must register with the network. The registration procedure is performed when the UE needs to do initial registration for the 5G system. In addition, the registration procedure is performed when the UE performs periodic registration update, when moving from an idle mode to a new tracking area (TA), and when the UE needs to perform periodic registration update.

During the initial registration procedure, the ID of the UE can be obtained from the UE. AMF can deliver PEI (IMEISV) to UDM, SMF and PCF.

5A and 5B are signal flow diagrams illustrating an exemplary registration procedure.

1) The UE can transmit an AN message to the RAN. The AN message may include an AN parameter and a registration request message. The registration request message may include information such as registration type, subscriber permanent ID or temporary user ID, security parameters, Network Slice Selection Assistance Information (NSSAI), 5G capability of the UE, and protocol data unit (PDU) session state.

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

The registration type is "initial registration" (ie, the UE is in a non-registered state), "mobility registration update" (ie, the UE is in a registered state and starts the registration process due to mobility) or "regular registration update" ( That is, it may indicate whether the UE is in a registered state and starts a registration procedure due to periodic update timer expiration). When the temporary user ID is included, the temporary user ID indicates the last serving AMF. If the UE has already been registered through non-3GPP access in a PLMN different from the PLMN of 3GPP access, the UE may not provide the temporary ID of the UE allocated by the AMF during the registration procedure through the non-3GPP access.

Security parameters can be used for authentication and integrity protection.

The PDU session state may indicate a (previously established) PDU session available in the UE.

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

If the (R)AN cannot select an appropriate AMF, it selects a random AMF according to local policy, and transmits a registration request to the selected AMF. If the selected AMF cannot serve the UE, the selected AMF selects another AMF more appropriate for the UE.

3) The RAN transmits an N2 message to a new AMF. The N2 message includes an N2 parameter and a registration request. The registration request may include a registration type, a subscriber permanent identifier or a temporary user ID, a security parameter, and a default setting for NSSAI and MICO modes.

When 5G-RAN is used, the N2 parameter includes location information related to a cell in which the UE is camping, a cell identifier, and a RAT type.

If the registration type indicated by the UE is a periodic registration update, steps 4 to 17 described below may not be performed.

4) The newly selected AMF may transmit an information request message to the previous AMF.

If the temporary user ID of the UE is included in the registration request message and the serving AMF has changed since the last registration, the new AMF can send an information request message containing complete registration request information to the previous AMF to request the SUPI and MM context of the UE. have.

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

Specifically, the previous AMF transmits an information response message including the SUPI and MM context of the UE.

-When there is information on an active PDU session in the previous AMF, SMF information including the ID of the SMF and the PDU session ID may be included in the information response message in the previous AMF.

6) The new AMF transmits an Identity Request message to the UE if SUPI is not provided by the UE or is not retrieved from the previous AMF.

7) The UE transmits an Identity Response message including the SUPI to the new AMF.

8) AMF may decide to trigger AUSF. In this case, AMF may select AUSF based on SUPI.

9) AUSF can initiate authentication of UE and NAS security functions.

10) The new AMF may transmit an information response message to the previous AMF.

If the AMF is changed, the new AMF may transmit the information response message to confirm delivery of the UE MM context.

-If the authentication/security procedure fails, registration is rejected and the new AMF can transmit a rejection message to the previous AMF.

11) The new AMF may transmit an Identity Request message to the UE.

If the PEI has not been provided by the UE or has not been retrieved from the previous AMF, an Identity Request message may be sent for the AMF to retrieve the PEI.

12) The new AMF checks the ME identifier.

13) If step 14 described later is performed, the new AMF selects UDM based on SUPI.

14) After the final registration, if the AMF is changed, there is no valid subscription context for the UE in the AMF, or the UE provides a SUPI that does not refer to a valid context in the AMF, the new AMF starts the update location procedure. . Alternatively, it may be initiated even when the UDM initiates a cancel location for the previous AMF. The old AMF discards the MM context and notifies all possible SMF(s), and the new AMF creates an MM context for the UE after obtaining the AMF-related subscription data from the UDM.

When network slicing is used, the AMF obtains the allowed NSSAI based on the requested NSSAI, UE subscription and local policy. If AMF is not suitable to support the allowed NSSAI, it will reroute the registration request.

15) The new AMF can select a PCF based on SUPI.

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

17) The PCF transmits a UE Context Establishment Acknowledged message to the new AMF.

18) The new AMF transmits an N11 request message to the SMF.

Specifically, when the AMF is changed, the new AMF notifies each SMF of the new AMF serving the UE. The AMF verifies the PDU session state from the UE with available SMF information. When the AMF is changed, usable SMF information may be received from the previous AMF. The new AMF may request the SMF to release network resources related to a PDU session that is not active in the UE.

19) The new AMF transmits an N11 response message to the SMF.

20) The previous AMF transmits a UE Context Termination Request message to the PCF.

If the previous AMF has previously requested that the UE context be set in the PCF, the previous AMF may delete the UE context from the PCF.

21) The PCF may transmit a UE Context Termination Request message to the previous AMF.

22) The new AMF transmits a registration acceptance message to the UE. The registration acceptance message may include a temporary user ID, a registration area, mobility restriction, PDU session state, NSSAI, a regular registration update timer, and an allowed MICO mode.

The registration acceptance message may include the allowed NSSAI and information of the mapped NSSAI. The allowed NSSAI information on the access type of the UE may be included in an N2 message including a registration acceptance message. The mapped NSSAI information is information obtained by mapping each S-NSSAI of the allowed NSSAI to the S-NASSI of the NSSAI set for HPLMN.

When the AMF allocates a new temporary user ID, a temporary user ID may be further included in the registration acceptance message. When mobility limitation is applied to the UE, information indicating mobility limitation may be additionally included in the registration acceptance message. The AMF may include information indicating the PDU session state for the UE in the registration acceptance message. The UE may remove any internal resources related to a PDU session that is not marked as active in the received PDU session state. If the PDU session state information is in the Registration Request, the AMF may include information indicating the PDU session state to the UE in the registration acceptance message.

23) The UE transmits a registration completion message to the new AMF.

<PDU session establishment procedure>

As for the protocol data unit (PDU) session establishment procedure, there may be two types of PDU session establishment procedures as follows.

-PDU session establishment procedure initiated by the UE

-PDU session establishment procedure initiated by the network. To this end, the network may transmit a device trigger message to the application(s) of the UE.

6A and 6B are signal flow diagrams illustrating an exemplary PDU session establishment procedure.

The procedures shown in FIGS. 6A and 6B assume that the UE has already registered on the AMF according to the registration procedure shown in FIGS. 5A and 5B. Therefore, it is assumed that the AMF has already obtained user subscription data from UDM.

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

Specifically, the UE includes the S-NSSAI from the allowed NSSAI of the current access type. If information on the mapped NSSAI is provided to the UE, the UE may provide both the S-NSSAI based on the allowed NSSAI and the corresponding S-NSSAI based on the information of the mapped NSSAI. Here, the mapped NSSAI information is information obtained by mapping each S-NSSAI of the allowed NSSAI to the S-NASSI of the NSSAI set for HPLMN.

More specifically, the UE extracts and stores information of the allowed S-NSSAI and the mapped S-NSSAI included in the registration acceptance message received from the network (ie, AMF) in the registration procedure of FIGS. 7A and 7B Can be doing. Accordingly, the UE may include and transmit both the S-NSSAI based on the allowed NSSAI and the corresponding S-NSSAI based on information of the mapped NSSAI in the PDU session establishment request message.

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

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

When the PDU session establishment is to establish a new PDU session, the request type indicates "initial request". However, when there is an existing PDU session between 3GPP access and non-3GPP access, the request type may indicate "existing PDU session".

The NAS message transmitted by the UE is encapsulated in the N2 message by the AN. The N2 message is transmitted through AMF, and may include user location information and access technology type information.

-The N1 SM information may include an SM PDU DN request container that includes information on PDU session authentication by an external DN.

2) The AMF may determine that the message corresponds to a request for a new PDU session when the request type indicates "initial request" and when the PDU session ID is not used for the existing PDU session of the UE.

If the NAS message does not include the S-NSSAI, the AMF may determine the default S-NSSAI for the requested PDU session according to the UE subscription. The AMF may store the PDU session ID and the SMF ID in association with each other.

3) AMF sends an SM request message to the SMF. The SM request message may include a subscriber permanent ID, DNN, S-NSSAI, PDU session ID, AMF ID, N1 SM information, user location information, and access technology type. The N1 SM information may include a PDU session ID and a PDU session establishment request message.

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.

4a) SMF transmits a subscriber data request message to UDM. The subscriber data request message may include a subscriber permanent ID and DNN.

In step 3 above, if the request type indicates "existing PDU session", the SMF determines that the request is due to handover between 3GPP access and non-3GPP access. The SMF can identify an existing PDU session based on the PDU session ID.

If the SMF has not yet retrieved the SM-related subscription data for the DNN-related UE, the SMF may request subscription data.

4b) UDM may transmit a subscription data response message to the SMF.

The subscription data may include information on an authenticated request type, an authenticated SSC mode, and a basic QoS profile.

The SMF can check whether the UE request complies with the user subscription and local policy. Alternatively, the SMF rejects the UE request through NAS SM signaling (including the related SM rejection cause) delivered by the AMF, and the SMF informs the AMF that the PDU session ID should be considered released.

5) SMF sends a message to DN through UPF.

Specifically, when the SMF needs to approve/authenticate PDU session establishment, the SMF selects the UPF and triggers the PDU.

If PDU session establishment authentication/authorization fails, the SMF terminates the PDU session establishment procedure and notifies the UE of rejection.

6a) When dynamic PCC (Policy and Charging Control) is deployed, SMF selects PCF.

6b) The SMF may initiate PDU-CAN session establishment towards the PCF to obtain basic PCC rules for the PDU session. If the request type in step 3 indicates "existing PDU session", the PCF may start modifying the PDU-CAN session instead.

7) If the request type of step 3 indicates "initial request", the SMF selects the SSC mode for the PDU session. If step 5 is not performed, the SMF may also select UPF. In case of request type IPv4 or IPv6, SMF may allocate an IP address/prefix for a PDU session.

8) If a dynamic PCC is deployed and PDU-CAN session establishment has not yet been completed, the SMF can start the PDU-CAN session.

9) If the request type indicates "initial request" and step 5 is not performed, the SMF starts the N4 session establishment procedure using the selected UPF, otherwise the N4 session modification procedure can start using the selected UPF.

9a) SMF transmits an N4 session establishment/modification request message to the UPF. In addition, the SMF may provide a packet detection, enforcement and reporting rule to be installed in the UPF for the PDU session. When the SMF is allocated CN tunnel information, CN tunnel information may be provided to the UPF.

9b) UPF can respond by transmitting an N4 session establishment/modification response message. When CN tunnel information is allocated by UPF, CN tunnel information may be provided to the SMF.

10) The SMF transmits an SM response message to the AMF. The message may include cause, N2 SM information, and N1 SM information. The N2 SM information may include PDU session ID, QoS profile, and CN tunnel information. The N1 SM information may include a PDU session establishment acceptance message. The PDU session establishment acceptance message may include a permitted QoS rule, an SSC mode, an S-NSSAI, and an assigned IPv4 address.

The N2 SM information is information that the AMF must deliver to the RAN and may include the following.

-CN tunnel information: This corresponds to the core network address of the N3 tunnel corresponding to the PDU session.

-QoS Profile: This is used to provide a mapping between QoS parameters and QoS flow identifiers to the RAN.

-PDU Session ID: This may be used to indicate to the UE the association between the PDU session and AN resources for the UE by AN signaling for the UE.

Meanwhile, the N1 SM information includes a PDU session acceptance message that the AMF must provide to the UE.

Multiple QoS rules may be included in the N1 SM information and the N2 SM information in the PDU session establishment acceptance message.

-The SM response message also contains information that allows the PDU session ID and AMF to determine which target UE as well as which access should be used for the UE.

11) AMF transmits an N2 PDU session request message to the RAN. The message may include N2 SM information and NAS message. The NAS message may include a PDU session ID and a PDU session establishment acceptance message.

The AMF may transmit a NAS message including a PDU session ID and a PDU session establishment acceptance message. Also, the AMF includes received N2 SM information from the SMF in the N2 PDU session request message and transmits it to the RAN.

12) The RAN may exchange specific signaling with the UE related to information received from the SMF.

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

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

The RAN transmits a NAS message to the UE only when necessary RAN resources are set and allocation of RAN tunnel information is successful.

13) The RAN transmits an N2 PDU session response message to the AMF. The message may include PDU session ID, cause, and N2 SM information. The N2 SM information may include a PDU session ID, (AN) tunnel information, and a list of allowed/rejected QoS profiles.

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

14) The AMF may transmit an SM request message to the SMF. The SM request message may include N2 SM information. Here, the AMF may be to transmit the N2 SM information received from the RAN to the SMF.

15a) If the N4 session for the PDU session has not already been established, the SMF may start the N4 session establishment procedure together with the UPF. Otherwise, the SMF can start the N4 session modification procedure using UPF. SMF may provide AN tunnel information and CN tunnel information. CN tunnel information may be provided only when the SMF selects CN tunnel information in step 8.

15b) The UPF may transmit an N4 session establishment/modification response message to the SMF.

16) The SMF may transmit an SM response message to the AMF. When this process is over, the AMF can deliver the related event to the SMF. Occurs at handover when RAN tunnel information is changed or AMF is relocated.

17) SMF transmits information to the UE through UPF. Specifically, in the case of PDU Type IPv6, the SMF may generate an IPv6 Router Advertisement and transmit it to the UE through N4 and UPF.

18) When the PDU session establishment request is due to a handover between 3GPP access and non-3GPP access, that is, when the request type is set to “existing PDU session”, the SMF is Release the plane.

19) If the ID of the SMF is not included in process 4b by the UDM of the DNN subscription context, the SMF may call "UDM_Register UE serving NF service" including the SMF address and DNN. UDM can store SMF's ID, address, and related DNN.

During the procedure, if the PDU session establishment is not successful, the SMF notifies the AMF.

<unified access control>

When congestion occurs in the 5G system, any access attempt according to operator policies, deployment scenarios, subscriber profiles, and available services Other criteria can be used to determine whether a is allowed or blocked. These other criteria for access control relate to Access Identities and Access Categories. The 5G system can provide a single unified access control for operators to control access based on access ID and access category.

In unified access control, each access attempt may be categorized into one or more access IDs and one access category. Based on the access ID corresponding to the access attempt and the access control information available for the access category corresponding to the access attempt, the terminal (eg, the UE) may test whether an actual access attempt can be made.

Unified access control supports extensibility to include additional standardized access IDs and additional standardized access categories. In addition, the integrated access control supports the flexibility of the operator to define an access category using the operator's own criterion.

Based on the provider's policy, the 5G system may prevent a terminal (eg, a UE) from accessing the network by using an access ID and a related barring parameter that varies according to an access category.

Here, the access ID may be set in the UE as shown in Table 3 below. The access category may be defined as a combination of a condition related to the UE and a type of access attempt, as shown in Table 4 below. One or more access IDs and one access category can be selected and tested for an access attempt.

Table 3 below shows an example of an access ID that can be set in the UE.

Access Identity number	UE configuration
0	UE is not configured with any parameters from this table.
1 (NOTE 1)	UE is configured for Multimedia Priority Service (MPS).(UE is configured for MPS)
2 (NOTE 2)	UE is configured for Mission Critical Service (MCS).(UE is configured for MCS)
3-10	Reserved for future use
11 (NOTE 3)	Access Class 11 is configured in the UE.
12 (NOTE 3)	Access Class 12 is configured in the UE.
13 (NOTE 3)	Access Class 13 is configured in the UE.
14 (NOTE 3)	Access Class 14 is configured in the UE.
15 (NOTE 3)	Access Class 15 is configured in the UE.
NOTE 1: Access ID 1 can be used by UEs configured for MPS in PLMNs whose configuration is valid. PLMNs for which the configuration is valid may be HPLMNs, PLMNs equivalent to HPLMNs, and visted PLMNs of a home country. Access ID 1 may also be valid when the UE is explicitly authenticated based on the PLMN set inside and outside the local station. NOTE 2: Access ID 2 may be used by the UE configured for the MCS in PLMNs for which the configuration is valid. have. PLMNs for which the configuration is valid may be HPLMNs, PLMNs equivalent to HPLMNs, and visted PLMNs of a home country. Access ID 2 may also be valid when the UE is explicitly authenticated based on the PLMN set inside and outside the local station. NOTE 3: Access IDs 11 and 15 are Home when the EHPLMN (Equivalent HPLMN) list does not exist. It can be valid in PLMN, or it can be valid in any EHPLMN. Access IDs 12, 13, and 14 may be valid only in Home PLMNs and visited PLMNs of the host country. To this end, a mother station may be defined as a country of a mobile country code (MCC) part of an international mobile subscriber identity (IMSI).

Table 4 below shows an example of an access category that can be defined as a combination of a condition related to a UE and a type of an access attempt.

Access Category number	Conditions related to UE	Type of access attempt
0	All	MO signaling resulting from paging (Mobile Originating (MO) signaling due to paging)
1 (NOTE 1)	The UE is set for a delay tolerant service, and may be an object of access control for access category 1 (an object of access control determined according to the relationship between the HPLMN of the UE and the selected PLMN).	All except for Emergency
2	All	Emergency
3	All except conditions of access category 1	NAS level MO signaling due to results other than paging
4	All except conditions of access category 1	MMTEL(multimedia telephony) voice (NOTE 3)
5	All except conditions of access category 1	MMTEL video
6	All except conditions of access category 1	SMS
7	All except conditions of access category 1	MO data not belonging to any other access category (NOTE 4)
8	All except conditions of access category 1	RRC level MO signaling due to results other than paging
9-31		Reserved standardized Access Categories
32-63 (NOTE 2)	All	Can be set based on business classification
NOTE 1: The barring parameter for access category 1 may be accompanied by information defining whether or not to apply to one of the following categories: a) UEs configured for delay allowable service; b) delay UEs set for allowed service and not in PLMN equivalent to HPLMN or HPLMN; c) “most preferred PLMN of countries set for delay allowed service and roaming within the operator-defined PLMN selector list of SIM/USIM "Listed in PLMN or UEs that are configured for delay tolerant service and are neither in the PLMN listed as most preferred PLMN of the country where the UE is roaming in the operator -defined PLMN selector list on the SIM/USIM, nor in their HPLMN nor in a PLMN that is equivalent to their HPLMN.) When the UE is set for EAB (Extended Access Barring), the UE can also be set for delay-tolerant service. have. When the UE is configured for both EAB and EAB override, if a higher layer (eg, application layer) indicates to override access category 1, access category 1 is not applicable. (When a UE is configured for EAB, the UE is also configured for delay tolerant service.In case a UE is configured both for EAB and for EAB override, when upper layer indicates to override Access Category 1, then Access Category 1 is not applicable .) NOTE 2: If there are both an access category based on the operator classification in which the access attempt can be classified and an access category based on the standardized access category, and the standardized access category is not 0 or 2, the UE is based on the operator classification. To apply the access category. If both the access category based on the operator classification and the standardized access category in which the access attempt can be classified exist, and the standardized access category is 0 or 2, the UE applies the standardized access category. NOTE 3 :Including Real-Time Text (RTT) NOTE 4: Including IMS Messaging.

The 5G network may broadcast barring control information in one or more areas of the RAN. The blocking control information may be, for example, a list of blocking parameters related to an access ID and an access category.

The UE may determine whether a particular new access attempt is allowed based on the blocking parameter (the UE receives from the broadcasted blocking control information) and the UE's settings.

In the case of a plurality of core networks sharing the same RAN, the RAN may individually apply access control to different core networks.

The unified access control framework may be applicable to both a UE accessing a 5G Core Network (CN) using E-UTRA and a UE accessing 5G CN using NR.

The integrated access control framework may be applicable to a UE in a Radio Resource Control (RRC) Idle state, an RRC Inactive (inactive) state, and an RRC Connected state when the UE starts a new access attempt (eg, a new session request).

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

The 5G system may support a means by which an operator can define an operator-defined access category as mutually exclusive. For example, examples of the criteria for the operator-defined access category may be network slicing, applications, and application servers.

The unified access control framework may be applicable to inbound roamers to the PLMN.

The serving PLMN may provide the definition of the operator-defined access category to the UE.

If the UE needs to access a 5G system (5GS), the UE may first perform an access control check to determine whether access is allowed. Access control checks can be performed on access attempts defined by a list of events such as:

a) When the UE is in 5GMM (5GS Mobility Management)-IDLE mode through 3GPP access, and an event requiring a transition to the 5GMM-CONNECTED mode occurs; And

b) When the UE is in 5GMM-CONNECTED mode through 3GPP access, or in 5GMM-CONNECTED mode with RRC inactivity indication, and one of the following events occurs:

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

b-2) The NAS layer of the terminal (e.g. 5GMM) receives a request to transmit mobile originated SMS over NAS from a higher layer (e.g., application layer), and the request sends the UE in 5GMM-IDLE mode When not triggering a service request to switch to 5GMM-CONNECTED mode;

b-3) The NAS layer (e.g., 5GMM) of the terminal receives a request to transmit a UL NAS TRANASPORT message for the purpose of establishing a PDU session from an upper layer (e.g., application layer), and the request is 5GMM- When not triggering a service request to switch from IDLE mode to 5GMM-CONNECTED mode;

b-4) The NAS layer (e.g., 5GMM) of the terminal receives a request to transmit a UL NAS TRANASPORT message for the purpose of PDU session modification from a higher layer (e.g., application layer), and the request is 5GMM- When not triggering a service request to switch from IDLE mode to 5GMM-CONNECTED mode;

b-5) When the NAS layer (eg, 5GMM) of the terminal receives a request to re-establish a user-plane resource for an existing PDU session; And

b-6) When notified that an uplink user data packet will be transmitted for a PDU session with a UE's NAS layer (eg, 5GMM) suspended user-plane resource.

When the NAS layer of the terminal detects one of the aforementioned events, the NAS layer of the terminal may perform an operation of mapping one or more access IDs and a kind of request to an access category. Further, a lower layer of the terminal (eg, an RRC layer) 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 recognize the above-described events through information/indication provided from an upper layer and/or when determining that normal NAS operation needs to be started.

In order to determine the access ID and access category of the request, the NAS layer of the terminal includes a set of access IDs and a reason for access to the set of access categories, the type of the requested service, and the UE's configuration. You can check the profile. Here, an example of the set of the access ID and the set of the access category is as follows:

-A set of standardized access IDs;

-A set of standardized access categories; And

-If possible, a set of operator-defined access categories.

When the terminal (e.g., UE) needs to initiate an access attempt to one of the events as examples of a) to b-6) above, the terminal is one related to the access attempt in a set of standardized access IDs. The above access ID may be determined, and one access category related to the access attempt may be determined from a set of standardized access categories and a set of operator-defined access categories.

For example, the set of access IDs available for a request related to an access attempt may be determined by the terminal (eg, UE) in the following manner:

i) In the example of Table 3, for each of the access IDs 1, 2, 11, 12, 13, 14 and 15, the UE will check whether the access ID is available in the selected PLMN when a new PLMN is selected. I can. Or the UE may check whether the access ID is applicable to the RPLMN or equivalent PLMN; And

ii) If there is no available access ID among the access IDs 1, 2, 11, 12, 13, 14, and 15, access ID 0 can be used.

In order to determine an available access category for an access attempt, the NAS layer of the terminal may check a rule as shown in Table 5 below, and use a matching access category for a barring check.

Table 5 below is an example of rules used when the NAS layer of the terminal determines an available access category for an access attempt.

Rule #	Type of access attempt	Requirements to be met	Access category
One	Response to notification through paging or non-3GPP access; 5GMM connection management procedure initiated for the purpose of delivering LTE Positioning Protocol (LPP) messages	Access attempt is for MT access	0 (= MT_acc)
2	Emergency	UE attempts to access emergency session (NOTE　1, NOTE　2)	2 (= emergency)
3	Attempts to access operator-defined access categories	The UE is currently storing valid operator-defined access category definitions in the PLMN, and the access attempt matches the criteria of the operator-defined access category definition.	32-63 (= based on operator classification)
4	Access attempt for delay tolerant service	(a) The UE is set for low priority NAS signaling (UE is configured for NAS signaling low priority) or the UE supporting S1 mode is set for EAB (Extended Access Barring) to which "EAB override" is not applied (B) The UE receives one of categories a, b, or c as part of a parameter for integrated access control in broadcast system information (e.g., broadcast barring control information), and the UE Is a member of a broadcast category within the selected PLMN or RPLMN/equivalent PLMN. (the UE received one of the categories a, b or c as part of the parameters for unified access control in the broadcast system information(eg broadcasted barring control information), and the UE is a member of the broadcasted category in the selected PLMN or RPLMN/equivalent PLMN) (NOTE　3, NOTE　5, NOTE　6)	1 (= delay tolerant)
5	MO MMTel voice call	When the access attempt is for MO MMTel voice call or when the access attempt is for NAS signaling connection recovery during an ongoing MO MMTel voice call (NOTE　2)	4 (= MO MMTel voice)
6	MO MMTel video call	When the access attempt is for MO MMTel video call or when the access attempt is for NAS signaling connection recovery during an ongoing MO MMTel video call (NOTE　2)	5 (= MO MMTel video)
7	MO SMS over NAS or MO SMSoIP	When the access attempt is for MO SMS over NAS, or the access attempt is for MO SMS over SMSoIP transfer, or when the access attempt is for NAS signaling connection recovery during ongoing MO SMS or SMSoIP transfer ( NOTE　2)	6 (= MO SMS and SMSoIP)
8	UE NAS initiated 5GMM specific procedures (5GMM specific procedures initiated by the NAS layer of the UE)	When the access attempt is for MO signaling	3 (= MO_sig)
9	UE NAS initiated 5GMM connection management procedure or 5GMM NAS transport procedure (5GMM connection management procedure or 5GMM NAS transport procedure initiated by the NAS layer of the UE)	If the access attempt is for MO data	7 (= MO_data)
10	An uplink user data packet is to be sent for a PDU session with suspended user-plane resources (when an uplink user data packet is transmitted for a PDU session with suspended user-plane resources)	No further requirement is to be met	7 (= MO_data)
NOTE　1: This includes 5GMM specific procedures and request types during the ongoing service (ongoing) required to establish a PDU session with "initial emergency request" or "existing emergency PDU session", or user-plane resources for these PDU sessions. The 5GMM connection management procedure required to re-establish the network may be included. In addition, this may include a service request procedure initiated by a SERVICE REQUEST message in which the service type IE is set to "emergency services fallback". NOTE 　2: Access to the purpose for NAS signaling connection recovery during ongoing service, or access to the purpose for establishing NAS signaling connection after a fallback indication received from a lower layer during ongoing service is the cause of RRC establishment ( RRC establishment cause), may be mapped to the access category of the ongoing service. However, the barring check may be skipped for this access attempt. NOTE3: When the UE selects a new PLMN, the selected PLMN may be used to check membership; Otherwise, the UE may use RPLMN or PLMN equivalent to the RPLMN. NOTE4: This may include a 5GMM connection management procedure triggered by a UE-initiated NAS transport procedure for transmitting MO SMS. NOTE5: Available access categories for access attempts. In case of 1, the UE may further determine a second access category in the range of 3 to 7. If more than one access category matches, the access category with the lowest rule number will be selected. The UE may use the second access category only to detect the reason for establishing the RRC for the access attempt. NOTE 6: The UE is not configured to allow overriding the EAB, or the NAS layer of the UE is a higher layer. In the case of not receiving an indication to override the EAB from (eg, the application layer), if the UE does not have a PDU session established based on the EAB override, “EAB override” may not be applied.

When an access attempt matches one or more rules, an access category having the lowest rule number among the one or more rules may be selected. If the access attempt matches one or more operator-defined access category definitions, the UE may select the operator-defined access category definition having the lowest precedence value. Here, the case where one access attempt matches one or more rules may include a case where a plurality of events simultaneously trigger one access attempt.

When the UE is in the 5GMM-IDLE mode, when the NAS layer of the terminal receives a request for an access attempt from the upper layer of the terminal, the NAS layer of the terminal determines the access attempt according to the examples of Tables 4 and 5 They can be classified by access category. For access control checking, the NAS layer of the terminal may forward a request including an available access ID and an available access category to a lower layer (eg, an RRC layer). The lower layer may perform an access blocking check. The NAS layer of the terminal may provide the cause of RRC establishment in the request for the lower layer. Depending on the implementation option, the NAS layer of the terminal may provide the RRC establishment cause to the lower layer after receiving a notification that the access attempt is allowed from the lower layer.

When the lower layer informs the NAS layer that the access attempt is allowed, the NAS layer may initiate a procedure for transmitting an initial NAS message for the access attempt.

When the lower layer informs the NAS layer that the access attempt is barred, the NAS layer may not initiate a procedure for transmitting the initial NAS message for the access attempt. In addition, the event triggering the access attempt is MO-MMTEL-voice-call-started information/indication, MO-MMTEL-video-call-started information/indication, or MO-SMSoIP-attempt-started information/indication If so, the NAS layer can inform the upper layer (eg, the application layer) that the access attempt has been blocked. In this case, when the NAS layer receives information/indication from a lower layer (eg, RRC layer) that the blocking of the access category related to the access attempt has been relaxed, the NAS layer indicates that the blocking of the access category has been relaxed. You can inform the hierarchy. And, the NAS layer can initiate a procedure for transmitting the initial NAS message if still necessary. For reference, a barring timer for each access category may be run by a lower layer. When the blocking timer expires, the lower layer may notify the NAS layer of the information/indication that the access blocking has been relaxed to the NAS layer for each access category.

When the UE is in a 5GMM-CONNECTED mode or a 5GMM-CONNECTED mode with an RRC deactivation indication, when the upper layer of the terminal detects one of the events of b-1) to b-6), the NAS layer of the terminal A request for an access attempt may be received from an upper layer of the terminal. Then, the NAS layer of the terminal may classify the access attempt into an access ID and an access category according to the examples of Tables 4 and 5 described above. For access control checking, the NAS layer of the terminal may forward a request including an available access ID and an available access category to a lower layer (eg, an RRC layer). The lower layer may perform an access blocking check. The NAS layer of the terminal may provide the cause of RRC establishment in the request for the lower layer. Depending on the implementation option, the NAS layer of the terminal may provide the RRC establishment cause to the lower layer after receiving a notification that the access attempt is allowed from the lower layer.

When the UE builds a registration request (REGISTRATION REQUEST) message or a service request (SERVICE REQUEST) message for an access attempt, when the UE has uplink user data pending for one or more PDU sessions , Regardless of the access category in which the access blocking check is performed, the UE may indicate each PDU session in an uplink data state information element (IE). Even when the blocking timer is running for some of the corresponding access categories, the UE may indicate user data waiting for each PDU session.

When the downlink layer informs the NAS layer that the access attempt is allowed, the NAS layer may perform the following operation according to the event triggering the access attempt:

a) The event triggering the access attempt is MO-MMTEL-voice-call-started information/indication, MO-MMTEL-video-call-started information/indication or MO-SMSoIP-attempt-started information/indication If so, the NAS layer may notify the upper layer (eg, the application layer) that the access attempt has been allowed;

b) If the event triggering the access attempt is a request from a higher layer to transmit a mobile originated SMS over NAS, the NAS layer (e.g., 5GMM layer) transmits the SMS in a UL NAS TRANSPORT message message. To initiate NAS transport procedures;

c) When the event triggering the access attempt is a request from a higher layer to establish a new PDU session, the NAS layer (eg, 5GMM layer) may initiate a NAS transport procedure to transmit a PDU session establishment request message. ;

d) If the event triggering the access attempt is a request from a higher layer to modify an existing PDU session, the NAS layer (e.g., 5GMM layer) performs a NAS transport procedure to transmit a PDU session modification request message. Can initiate;

e) If the event triggering the access attempt is a request for re-establishing a user-plane resource for an existing PDU session, the NAS layer (eg, 5GMM layer) may initiate a service request procedure; And

f) If the event triggering the access attempt is an uplink user data packet to be transmitted for a PDU session with a delayed user-plane resource, the NAS layer (e.g. 5GMM layer) considers that the uplink user data packet can be transmitted. can do.

When the downlink layer notifies the NAS layer that the access attempt has been blocked, the NAS layer may perform the following actions according to the event triggering the access attempt:

a) The event triggering the access attempt is MO-MMTEL-voice-call-started information/indication, MO-MMTEL-video-call-started information/indication or MO-SMSoIP-attempt-started information/indication If so, the NAS layer may notify the upper layer that the access attempt has been blocked. The upper layer may prohibit the initiation of the MMTEL voice session, the MMTEL video session, or the transmission of the SMS over IP. In this case, when the NAS layer receives information/indication from a lower layer (eg, RRC layer) that the blocking of the access category related to the access attempt has been relaxed, the NAS layer indicates that the blocking of the access category has been relaxed. Can inform the hierarchy;

b) If the event triggering the access attempt is a request from a higher layer to transmit a mobile originated SMS over NAS, the NAS layer (e.g., 5GMM layer) is used to transmit the SMS through the UL NAS TRANSPORT message. The NAS transmission procedure may not be initiated. When the NAS layer receives information/indication from a lower layer (e.g., RRC layer) that the blocking of the access category associated with the access attempt has been relaxed, the NAS layer will initiate the NAS transmission procedure if the NAS transmission procedure is still required. Can;

c) If the event triggering the access attempt is a request from a higher layer to establish a new PDU session, the NAS layer (e.g., 5GMM layer) may not initiate a NAS transport procedure to transmit a PDU session establishment request message. have. When the NAS layer receives information/indication from a lower layer (e.g., RRC layer) that the blocking of the access category associated with the access attempt has been relaxed, the NAS layer will initiate the NAS transmission procedure if the NAS transmission procedure is still required. Can;

d) If the event triggering the access attempt is a request from a higher layer to modify an existing PDU session, the NAS layer (e.g., 5GMM layer) performs a NAS transport procedure to transmit a PDU session modification request message. May not be disclosed. When the NAS layer receives information/indication from a lower layer (e.g., RRC layer) that the blocking of the access category associated with the access attempt has been relaxed, the NAS layer will initiate the NAS transmission procedure if the NAS transmission procedure is still required. Can;

e) If the event triggering the access attempt is a request to re-establish a user-plane resource for an existing PDU session, the NAS layer (e.g., 5GMM layer) performs a service request procedure. May not be disclosed. When the NAS layer receives information/indication from a lower layer (e.g., RRC layer) that the blocking of the access category associated with the access attempt has been relaxed, the NAS layer may initiate a service request procedure if the service request procedure is still required. Can; And

f) If the event triggering the access attempt is an uplink user data packet to be transmitted for a PDU session with a delayed user-plane resource, the NAS layer (e.g. 5GMM layer) considers that the uplink user data packet can be transmitted. I can't. When the NAS layer receives information/indication from a lower layer (eg, an RRC layer) indicating that the blocking of the access category associated with the access attempt has been relaxed, the NAS layer may consider that the blocking of the access category is relaxed.

For reference, when the terminal is connected to the IM (IP Multimedia) CN (Core Network) subsystem, a specific example to which the integrated access control is applied is as follows. Here, the IM CN subsystem may mean the core network of the IMS.

The upper layer of the terminal (eg, the application layer) can provide information such as the following example to the NAS layer of the terminal:

-MO-MMTEL-voice-started;

-MO-MMTEL-voice-ended.

-MO-MMTEL-video-started; and

-MO-MMTEL-video-ended;

When the upper layer of the terminal (e.g., application layer) receives a request from the user to establish an originating multimedia telephony (MMTEL) communication session, the upper layer of the terminal (e.g., application layer) of the terminal is as shown in the following example. You can perform the action:

1) If the MMTEL communication session to be established is an emergency session, the following steps may be skipped and a procedure for establishing an MMTEL communication set may be performed;

2) When audio, or real-time text, or both audio and real-time text are provided in the MMTEL communication session, and there is no other outgoing MMTEL communication session providing audio, real-time text, or audio and real-time text, the terminal (e.g., UE ) The application layer may transmit the MO-MMTEL-voice-started indication/information to the NAS layer. And:

2-a) When the barring result is “not-barred”, the upper layer (eg, application layer) of the terminal may continue the session establishment procedure for establishing the MMTEL communication session. For reference, the blocking result may be a blocking result for MO-MMTEL-voice-started indication/information transmitted from the NAS layer.

2-b) When the barring result is “barred”, the upper layer (eg, application layer) of the terminal rejects the establishment of the MMTEL communication session, and may skip the following steps; And

3) When video is provided in the MMTEL communication session, and there is no other outgoing MMTEL communication session providing video, the application layer of the UE may transmit the MO-MMTEL-video-started indication/information to the NAS layer. And:

3-a) When the barring result is "not-barred", the upper layer (eg, application layer) of the terminal may continue the session establishment procedure for establishing the MMTEL communication session.

3-b) When the barring result is “barred”, the upper layer (eg, application layer) of the terminal rejects the establishment of the MMTEL communication session and may skip the following steps.

For reference, while communication based on the MMTEL communication session is being performed, adding or removing media may not be subject to integrated access control.

When an outgoing MMTEL communication session (audio or real-time text or an outgoing MMTEL communication session that was initiated with both audio and real-time text) is terminated (e.g. due to a response to a BYE message or a failure response to an initial INVITE request message), If there is no audio or real-time text or other outgoing MMTEL communication session that provides audio and real-time text, the application layer of the terminal (e.g., UE) transmits the MO-MMTEL-voice-ended indication/information to the NAS layer. I can.

When the outgoing MMTEL communication session (the outgoing MMTEL communication session that was initiated with the video provided) ends (e.g. BYE or the response to the message is due to a failure response to the initial INVITE request message), providing the video (e.g., initial INVITE) If there is no other outgoing MMTEL communication session (in SDP (Session Description Protocol) offer) in the request message, the application layer of the terminal (e.g., UE) transmits MO-MMTEL-video-ended indication/information to the NAS layer. Can be transferred to.

Under the above IMS, an IP-based session can be controlled by a session initiation protocol (SIP). SIP is a protocol for controlling sessions, and SIP specifies a procedure for communicating terminals to identify each other and find their location, to create a multimedia service session between them, or to delete and change the created session. Refers to the signaling protocol. Such SIP uses a SIP Uniform Resource Identifier (URI) similar to an e-mail address to identify each user, so that services can be provided without being subordinated to an IP (Internet Protocol) address. These SIP messages are transmitted between the UE and the IMS network through the control message or the user plane of the 5G core network.

II. Problems to be solved by the disclosure of the present specification

In order for a terminal using the 3GPP system to receive IMS services such as voice call, video call, and SMS (eg, SMS over IP), the terminal must be registered in the IMS network. In addition, the terminal must periodically re-registration in the IMS network.

The signaling between the terminal and the IMS may be performed through SIP signaling (or IMS signaling) between the IMS layer of the terminal and the core IMS. Here, the IMS layer of the terminal may be a layer included in an application layer of the terminal. Here, the IMS layer of the terminal may be an upper layer based on the NAS layer of the terminal. The application layer of the terminal may also be a higher layer based on the NAS layer of the terminal. Depending on the implementation of the terminal, the IMS layer of the terminal and the application layer of the terminal may be implemented separately from each other. Alternatively, the IMS layer of the terminal may be included in the application layer of the terminal. For reference, the operation performed by the IMS layer of the terminal may also be performed by the application layer of the terminal. IMS signaling may mean signaling between the IMS layer of the terminal and the IMS.

This IMS signaling is a user plane or PDN (Packet Data) of a PDU session based on IMS APN (Access Point Name)/DNN (Data Network Name) (when a terminal performs 5GS (5G System)-based communication). Network) connection (when the terminal performs EPS-based communication) may be performed through the user plane.

When an attempt related to the IMS service occurs, the IMS layer of the terminal may transmit related information or indication to the attempt related to the IMS service to the NAS layer of the terminal. Here, the attempt related to the IMS service may mean an attempt related to the IMS service such as multimedia telephony (MMTEL) voice, MMTEL video, and SMS. The NAS layer of the terminal may determine an access category of an attempt related to the IMS service based on the information or indication received from the IMS layer of the terminal. For example, the access category related to the IMS service is 4 (for example, an access category related to MO (Mobile Originated) MMTel voice), 5 (for example, an access category related to MO MMTel video), 6 (for example, MO SMS or SMSoIP ( SMS over IP) related access category). The NAS layer of the terminal may determine the access category according to the information or indication delivered by the IMS layer of the terminal.

The NAS layer of the terminal may deliver the information or indication transmitted by the IMS layer of the terminal and information on the determined access category to the RRC layer of the terminal. The RRC layer of the terminal is based on information on the access category transmitted by the NAS layer of the terminal, system information block (SIB) information broadcast by the base station, and access control information (e.g., unified access control information). Barring check) can be performed. The RRC layer of the terminal may deliver information on whether to barring the access category delivered by the NAS layer to a higher layer (eg, the NAS layer).

When the RRC layer of the terminal transmits information that the access category has been barred to the NAS layer of the terminal, the NAS layer of the terminal may transmit information that the access category is barred to the IMS layer.

IMS signaling (e.g., initial registration, re-registration, subscription refresh, etc.), not actual attempts related to IMS service (e.g., MMTEL (multimedia telephony) voice, MMTEL video, SMS, etc.) IMS signaling according to the purpose) may need to be delivered.

Hereinafter, IMS signaling that is not an actual attempt related to the IMS service will be referred to as IMS signaling for a non-service attempt. In this case, the IMS layer of the terminal is information that user data for a general IMS-related PDU session or IMS-related PDN connection has occurred without an interaction between a separate IMS layer and the NAS layer in general (e.g., MO data information). Can be delivered to the NAS layer of the terminal.

Accordingly, the terminal transmits information that user data has occurred through the user plane to the IMS through the user plane (if the terminal is connected to the IMS) or the terminal performs a connected transition procedure (the terminal is in an idle state for the IMS). Or connected with inactive indication).

The NAS layer of the terminal uses category 7 (MO data) for IMS signaling transmission for non-service attempts. The NAS layer of the terminal may deliver the access category information (category 7) to the RRC layer of the terminal. If access control is being applied to the network and/or terminal due to network congestion, etc., the category for general data transmission (e.g., category 7 (MO data)) is a different access category (e.g., category 4~6, etc.). Since the priority is likely to be low compared to the service related category), it is likely to be barred (blocked) by the RRC layer. For example, when access control is applied to a network and/or a terminal, a policy for priority between a plurality of access categories may be set (or may be preset). When a situation in which access is restricted such as a network congestion situation occurs, a network node (eg, AMF) sets barring information for each access category based on this policy, and informs the UEs. According to this policy, the probability of blocking for each access category may differ, and it is highly likely that the access category with a lower priority is first blocked.

7 is a signal flow diagram illustrating an example of a problem to be solved by the disclosure of the present specification. The following drawings are made to explain an example of a problem to be solved by the disclosure of the present specification. Since the names of specific devices or names of specific signals/messages/fields described in the drawings are provided by way of example, technical features of the present specification are not limited to specific names used in the following drawings.

7 shows an example of a problem to be solved by the disclosure of the present specification.

Referring to FIG. 7, a terminal (eg, UE) may include an IMS layer, a NAS layer, and an RRC layer.

In step S701, the IMS layer may determine that IMS signaling for non-service attempts is required. For example, IMS signaling for non-service attempts may be IMS signaling according to the purpose of initial registration, re-registration, and subscription refresh.

In step S702, the IMS layer may transmit a request message including information related to outgoing data to the NAS layer. Information related to outgoing data may indicate information that user data has occurred. Information related to outgoing data may include information called MO data (corresponding to access category 7).

In step S703, since the NAS layer has received information related to outgoing data (eg, MO data information) from the IMS layer, the NAS layer may use access category 7 for IMS signaling for non-service attempts. The NAS layer may transmit a request message (including information on access category 7) to the RRC layer.

In step S704, the RRC layer may be in a state in which access control is being applied due to a network congestion situation or the like. Since the RRC layer has received information on the access category 7 from the NAS layer, it may perform an access control check based on the access category 7. This category for general data transmission (e.g., access category 7 (MO data)) has a lower priority than other access categories (e.g., categories related to IMS services such as access categories 4-6), so it is barred by the RRC layer. Is likely to be. For example, when access control is applied to the RRC layer, priorities for a plurality of access categories may be set (or may be set in advance), and the network and/or terminal may have a specific access category (eg, category 5). When access control is applied to the network and/or the terminal, the network and/or the terminal may barring access related to a specific access category and an access category 7 having a lower priority than the specific access category.

In step S705, the RRC layer may transmit a response message to the NAS layer. The response message may include information indicating that the request message transmitted by the NAS layer in step S703 is barred.

In step S706, the NAS layer may transmit a response message to the IMS layer. The response message may include information that the request message transmitted by the IMS layer is barred in step S702.

As described above, when IMS signaling for a non-service attempt is blocked, an access attempt related to IMS signaling for a non-service attempt may fail. Since the attempt to access the IMS, such as re-registration, has failed, it may be impossible for the terminal to use the IMS-related service.

Specifically, compared with other data services, in the related art, differentiated access control (eg, congestion control) may be performed on IMS services such as voice, video, and SMS.

However, since differentiated congestion control is not supported for IMS signaling (e.g., IMS registration message such as SIP REGISTER) for non-service attempts that must be preceded in order for the terminal to receive such IMS service, the terminal can register with the IMS. There may be a problem that the terminal is not provided with the IMS service because there is no. In particular, in this case, there may be a problem that the terminal cannot use services that are very important to the user such as voice call.

For reference, in this specification, the SIP signal may be used interchangeably with the IMS signal.

III. Disclosure of this specification

The disclosures described later in this specification may be implemented in one or more combinations. Each of the drawings shows an embodiment of each disclosure, but the embodiments of the drawings may be implemented in combination with each other.

Various measures (eg, the first example, the second example, and the measures described in) of the disclosure of the present specification described below may be implemented in one or more combinations.

The IMS layer of the terminal may need to transmit SIP (Session Initiation Protocol) signaling (or IMS signaling) (that is, the IMS layer of the terminal may need to transmit SIP signaling (or IMS signaling)). Here, the SIP signaling (or IMS signaling) is not a call attempt related to MMTEL voice (eg, SIP INVITE), a call attempt related to MMTEL video (eg, SIP INVITE), or SMS over IP (eg, SIP MESSAGE). In the case of (ie, SIP signaling, not an actual attempt related to the IMS service), the terminal can operate as described below. For reference, in the following, SIP signaling (or IMS signaling) and IMS signaling may have the same meaning.

In the following, SIP signaling (or IMS signaling) for IMS services such as a call attempt related to MMTEL voice (eg, SIP INVITE), a call attempt related to MMTEL video (eg, SIP INVITE), or SMS over IP (eg, SIP MESSAGE) ) Will be referred to as SIP signaling (or IMS signaling) for service attempt. As for SIP signaling (or IMS signaling) for service attempt, an access category related to the corresponding SIP signaling (or IMS signaling) may be defined. For example, an access category of MO MMTEL voice related signaling may be 4, an access category of MO MMTel video related signaling may be 5, and an access category of MO SMS or MO SMSoIP related signaling may be 6.

Here, SIP signaling (or IMS signaling) that is not an actual attempt related to the IMS service may be, for example, a SIP REGISTER for initial registration or re-registration, or a SIP SUBSCRBE for refreshing a subscription. Hereinafter, SIP signaling (or IMS signaling) that is not an actual attempt related to the IMS service will be referred to as SIP signaling (or IMS signaling) for a non-service attempt. That is, SIP signaling (or IMS signaling) for a non-service attempt may be SIP signaling (or IMS signaling) other than SIP signaling (or IMS signaling) for the service attempt. In the following, SIP signaling and IMS signaling may be used interchangeably.

When "SIP signaling for non-service attempts (or IMS signaling)" occurs (eg, when IP REGISTER for re-registration occurs), the IMS layer of the terminal is the NAS layer of the terminal, Information or indication related to one of the access categories (eg, access category 4 (MO MMTel voice), access category 5 (MO MMTel video), or access category 6 (MO SMS and MO SMSoIP)) may be additionally provided.

Optionally, the IMS layer of the terminal may also provide information or indication (hereinafter referred to as information/indication) related to "SIP signaling for non-service attempts (or IMS signaling)" to the NAS layer of the terminal. Information or indication related to "SIP signaling for non-service attempt (or IMS signaling)" may be, for example, information/indication that "SIP signaling for non-service attempt (or IMS signaling)" has occurred. have.

For example, the IMS layer of the terminal may provide "MO-MMTEL-voice-started" information/indication related to access category 4 (MO MMTel voice) to the NAS layer of the terminal. Optionally, the IMS layer of the terminal may also provide information/indication related to "SIP signaling (or IMS signaling) for non-service attempts" to the NAS layer of the terminal. Specifically, the IMS layer of the terminal may transmit a request message including "MO-MMTEL-voice-started" information/indication related to access category 4 (MO MMTel voice) to the NAS layer of the terminal. The request message may optionally further include information/indication related to "SIP signaling (or IMS signaling)" for non-service attempts. Then, the NAS layer of the terminal is "MO-MMTEL-voice-started" information / Based on the indication, the access category of the request message may be determined as an access category 4 corresponding to the MO MMTel voice. The NAS layer of the terminal may transmit information that the access category of the request message is an access category 4 to the RRC layer. Then, the RRC layer of the terminal may perform a barring check on the request message based on access category 4. In this case, having a high priority (eg, access category 4 has a higher priority than access category 7). If yes) If the MMTEL voice attempt request passes, the IMS layer of the terminal may succeed in IMS signaling transmission through a PDU session or PDN connection.

For example, access control for access category 7 is being applied to the network and/or terminal due to network congestion, and access control is not applied to access category 4, which has a higher priority of service than access category 7. If not, the request message including "MO-MMTEL-voice-started" information/indication related to access category 4 (MO MMTel voice) passes the barring check, and the RRC layer of the terminal sends the request message to the PDU session. It can be transmitted to a network (eg IMS-related network) through (eg, IMS PDU session) or PDN connection (eg, IMS PDN connection). That is, when the IMS layer of the terminal transmits a request message including information/indication related to access category 7 to the NAS layer, the request message is barred by an access control check (e.g., barring check), but the IMS layer of the terminal When information/indication related to an access category (eg, access category 4) having a higher priority than access category 7 is transmitted, the request message may pass through the barring check of the RRC layer.

In other words, the IMS layer of the terminal is among a plurality of access categories (e.g., access category 4 (MO MMTel voice), access category 5 (MO MMTel video), or access category 6 (MO SMS and MO SMSoIP)) related to the IMS service attempt. By transmitting a request message including information/indication related to one (optionally, it may also include information/indication related to “SIP signaling (or IMS signaling) for non-service attempts”) to the NAS layer, The terminal may perform a proactive operation (eg, initial registration, re-registration, subscription refresh, etc.) for attempting an IMS service. For example, the IMS layer of the terminal transmits the request message so that the terminal (eg, the UE) in the IMS network can maintain the registered state in the registered IMS network as re-registration is successful. Since the terminal maintains the registration state in the IMS network, when an IMS service attempt such as a voice call is required later, the terminal can perform IMS signaling for an IMS service attempt.

In the above-described example, the IMS layer of the terminal is a request message including "MO-MMTEL-voice-started" information/indication related to access category 4 (MO MMTel voice) (optionally, "SIP for non-service attempts" An example of transmitting information/indication related to "signaling (or IMS signaling)" to the NAS layer of the terminal has been described. However, this is only an example, and in order for the NAS layer of the terminal to receive an access category different from the access category 7 for "SIP signaling (or IMS signaling) for non-service attempts," the IMS layer of the terminal is newly Defined information/indication can also be used. For example, the newly defined information/indication may be "MO-MMTEL-voice related SIP signaling. Therefore, in the disclosure of the present specification, the IMS layer of the terminal" is non- The range of information/indication transmitted for "SIP signaling for service attempt (or IMS signaling)" is the NAS layer of the terminal for "SIP signaling (or IMS signaling) for non-service attempt", access category 7 and Includes all types of information/indications applicable to receive different access categories.

As in the above example, the IMS layer of the terminal includes a request message including "MO-MMTEL-voice-started" information/indication related to access category 4 (MO MMTel voice) (optionally, "non-service attempt In a situation in which information/indication related to "SIP signaling (or IMS signaling) for" is transmitted to the NAS layer of the terminal, there may be a case where access to access category 4 (MMTel voice) is barred. . For example, if the base station (ng-eNB or gNB) notifies the terminal of barring for access category 4 through SIB, the terminal (eg, the RRC layer of the terminal) barring access category 4 ), the access attempt to transmit "SIP signaling for non-service attempt (or IMS signaling)" may be rejected. For example, the request message may be rejected by the RRC layer of the terminal.

In this way, the IMS layer of the terminal includes information/indication related to "SIP signaling (or IMS signaling) for non-service attempt" and information/indication related to one of a plurality of access categories related to IMS service attempt. Although the request message is transmitted to the NAS layer, when the request message is rejected or barred, the first example of disclosure of the present specification described below and/or the second example of disclosure of the present specification may be applied.

An example of the operation of a terminal and a network according to the disclosure of the present specification described above will be described with reference to FIGS. 8 and 9.

The following drawings are prepared to explain a specific example of the present specification. Since the names of specific devices or names of specific signals/messages/fields described in the drawings are provided by way of example, technical features of the present specification are not limited to specific names used in the following drawings.

8 is an exemplary signal flow diagram illustrating the disclosure of the present specification.

Referring to FIG. 8, a terminal (eg, UE) may include an IMS layer, a NAS layer, and an RRC layer.

In step S801, the IMS layer may determine that IMS signaling for non-service attempts is required. For example, IMS signaling for non-service attempts may be IMS signaling according to the purpose of initial registration, re-registration, and subscription refresh.

In step S802, the IMS layer may transmit a request message to the NAS layer. Here, the request message is related to one of a plurality of access categories (e.g., access category 4 (MO MMTel voice), access category 5 (MO MMTel video), or access category 6 (MO SMS and MO SMSoIP)) related to the IMS service attempt. It may include information/indication. Optionally, the request message may further include information/indication related to "SIP signaling (or IMS signaling) for non-service attempts". One of the plurality of access categories related to the IMS service attempt is a first access category ( For example, it may be an access category 4) For example, the information on the first access category (eg, access category 4) in step S802 may be “MO-MMTEL-voice-started” information/indication. .

In step S803, since the NAS layer has received information on the first access category from the IMS layer, the NAS layer may use the first access category for IMS signaling for non-service attempts. The NAS layer may transmit a request message (including information on the first access category (eg, access category 4)) to the RRC layer.

In step S804, the RRC layer may be in a state in which access control is being applied due to a network congestion situation or the like. Since the RRC layer has received information on a first access category (eg, access category 4) from the NAS layer, it may perform an access control check based on the first access category (eg, access category 4).

When access control is not applied for the first access category (e.g., access category 4) (e.g., when the priority of an access category blocked according to access control is lower than access category 4), the RRC layer receives from the NAS layer One request message can be accepted. The RRC layer may transmit information (eg, "not barred" information) indicating that the request message is allowed to the NAS layer. If the request message is accepted, an operation related to case 1 may be performed.

When access control is applied to the first access category (e.g., access category 4) (e.g., when the priority of an access category blocked according to access control is higher than access category 4), the RRC layer receives from the NAS layer. You can block the request message. The RRC layer may transmit information (eg, "barred" information) that the request message has been blocked to the NAS layer. When the request message is blocked, an operation related to case 2 may be performed.

According to the result of the access control check (accept or block) performed by the RRC layer, when the request message is accepted, the operation related to case 1 of FIG. 8 may be performed, and when the request message is blocked, case 2 of FIG. An operation related to can be performed.

For example, when the request message is accepted, an operation related to case 1 may be performed.

In step S805a, the RRC layer may transmit to an upper layer (eg, the NAS layer) that the access request due to the request message (including information on the first access category) has been approved. For example, the RRC layer may transmit a response message including information that the request message has been accepted (eg, information that the access request due to the request message has been approved) to the NAS layer.

The NAS layer may prioritize related NAS operations if necessary. For example, when the terminal is in the IDLE state, the NAS layer may perform a first service request procedure for IMS signaling transmission for non-service attempts. When access is finally granted, for example, if the PDU session related to IMS signaling for non-service attempts is successfully activated by transitioning to the CONNECTED state, in step S806a, the NAS layer accepts a request message to the IMS layer. It is possible to transmit a response message including information indicating that it has been completed.

In step S807a, the IMS layer of the terminal may transmit a request message including information related to IMS signaling for non-service attempts to the IMS network through the packet data convergence protocol (PDCP) layer of the terminal. For example, the IMS layer of the terminal may transmit a request message including information related to IMS signaling for a non-service attempt to the PDCP layer based on the response message received in step S806a. Then, the PDCP layer can transmit the request message to the IMS network through the RAN and UPF through the IMS PDU session.

The IMS layer of the terminal is a request message including information/indication related to one of a plurality of access categories related to an IMS service attempt (optionally, information related to "SIP signaling for non-service attempts (or IMS signaling)"/ By transmitting an indication to the NAS layer (e.g., S802 in Fig. 8), the terminal performs a preliminary operation (e.g., initial registration, re-registration, subscription refresh, etc.) for attempting IMS service. can do. A specific example in which the request message of step S807a is transmitted to the network will be described with reference to FIG. 9.

For example, when the request message is blocked, an operation related to case 2 may be performed.

In step S805b, the RRC layer may transmit a response message (including information that the request message has been blocked) to the NAS layer.

In step S806b, the NAS layer may transmit a response message (including information that the request message has been blocked) to the IMS layer.

For reference, after steps S805b and S806b of case 2, an operation according to the description of the first example and/or the second example of the disclosure of the present specification to be described later may be performed.

Hereinafter, a specific example in which the request message of step S805a is transmitted to the network will be described with reference to FIG. 9.

The following drawings are prepared to explain a specific example of the present specification. Since the names of specific devices or names of specific signals/messages/fields described in the drawings are provided by way of example, technical features of the present specification are not limited to specific names used in the following drawings.

9 is an exemplary signal flow diagram illustrating operations according to case 1 of FIG. 8.

In step S807a, the IMS layer transmits IMS signaling for non-service attempts through the user plane of the corresponding PDU session (eg, a PDU session between the IMS layer of the terminal and the IMS network). For example, the IMS layer may transmit a request message (including information related to IMS signaling for non-service attempts) to the PDCP layer. Then, the PDCP layer may transmit a request message (including information related to IMS signaling for non-service attempts) to the IMS network (eg, P-CSCF (Proxy Call Session Control Function)) through the RAN and UPF.

When the IMS network (e.g., P-CSCF) receives a request message (including information related to IMS signaling for non-service attempts), the terminal and the IMS network perform procedures for initial registration, re-registration, or subscription refresh. Can be done.

In step S808a, the IMS network (eg, P-CSCF) may transmit a response message (eg, initial registration acceptance, re-registration acceptance, subscription refresh acceptance, etc.) to the request message to the IMS layer of the terminal. . The response message is transmitted to the PDCP layer of the terminal through the user plane of the terminal through the UPF and RAN, and the PDCP layer may transmit the response message to the IMS layer. For example, the IMS layer of the terminal transmits a request message for re-registration, so that the terminal (eg, UE) in the IMS network can maintain the registered state in the registered IMS network as re-registration is successful. Since the terminal maintains the registration state in the IMS network, when an IMS service attempt such as a voice call is required later, the terminal can perform IMS signaling for an IMS service attempt.

As in case 2 of FIG. 8 described above, the IMS layer of the terminal includes a request message including information/indication related to one of a plurality of access categories related to an IMS service attempt (optionally, "SIP signaling for non-service attempts (Or may further include information/indication related to “IMS signaling)” is transmitted to the NAS layer, but when the request message is rejected or barred, the first of the disclosure of the present specification described below The example and/or the second example of the disclosure of the present specification may be applied.

1. First example of disclosure of this specification

When "SIP signaling for non-service attempt (or IMS signaling)" occurs, the IMS layer of the terminal includes information/indication related to one of a plurality of access categories (eg, a first access category) related to an IMS service attempt A request message (optionally, it may further include information/indication related to “SIP signaling for non-service attempt (or IMS signaling)”) may be transmitted to the NAS layer. When the request message is rejected or barred, the IMS layer of the terminal may receive a response indicating that the request message has been rejected or blocked from the NAS layer of the terminal. In this case, the IMS layer of the terminal includes a request message including information/indication related to an access category different from the first access category (eg, a second access category) among a plurality of access categories related to an IMS service attempt (optionally, Information/indication related to "SIP signaling for non-service attempts (or IMS signaling)" may be further included) may be transmitted to the NAS layer of the terminal.

For example, when IMS signaling ("SIP signaling for non-service attempts (or IMS signaling)") occurs in the IMS layer of the terminal, MO-MMTEL-voice-started information related to access category 4 (MO MMTel voice) / Can send indication. Thereafter, when the IMS layer of the terminal receives a response from the NAS layer of the terminal that the request message has been blocked, the IMS layer of the terminal is an access category related to an attempted IMS service of a different type than the access category 4 (eg: Transmission of IMS signaling may be retried using access category 5 (MO MMTel video) or access category 6 (MO SMS and MO SMSoIP)).

For example, when a request related to access category 4 (MO MMTel voice) transmitted by the IMS layer of the UE is barred, the IMS layer of the UE is not MMTEL voice, but “MO-MMTEL-video-call” related to access category 5 -started" information/indication can be delivered to the NAS layer of the terminal to retry transmission of IMS signaling. Specifically, the IMS layer of the terminal is "MO-MMTEL-video-call-started" information related to access category 5. Transmission of IMS signaling by transmitting a request message including /indication (optionally, may further include information/indication related to "SIP signaling for non-service attempts (or IMS signaling)") to the NAS layer You can try again. In this case, since the NAS layer of the terminal has received the MMTEL video request related to the access category 5, the NAS layer of the terminal may determine the access category of the request message as the access category 5. For example, the NAS layer of the terminal may allocate access category 5 to the request message. And, the NAS layer of the terminal may request a barring check for the request message from a lower layer (eg, an RRC layer) based on access category 5. If the access request is barred for access category 4 and the access request is allowed (for example, not barred) for access category 5, the IMS layer of the terminal is not blocked from retrying using access category 5. , Transmission of IMS signaling through an IMS-related PDU session or an IMS-related PDN connection of the terminal may be successful.

In the above example (an example of retrying the transmission request of IMS signaling using access category 5 after a failure of the transmission request of IMS signaling using access category 4), when the retry of IMS signaling based on access category 5 fails (i.e., access category If the IMS signaling transmission request using access category 5 fails after the IMS signaling transmission request using 4 fails), the IMS layer of the terminal may selectively transmit the request message to the NAS layer of the terminal again. For example, the IMS layer of the terminal may once again transmit the request message to the NAS layer of the terminal based on "MO-SMSoIP-attempt-started" information/indication related to access category 6. In this case, since the NAS layer of the terminal has received an SMSoIP request related to access category 6, a barring check for the request message is performed to a lower layer (eg, RRC layer) by allocating access category 6 to the request message. Can be requested. When the access request is barred for access category 4 (MMTEL voice) and access category 5 (MMTEL video) and the access request is allowed (eg, not barred) for access category 6, the IMS layer of the terminal The retry using this access category 6 is not blocked and proceeds as it is, so that transmission of IMS signaling through an IMS-related PDU session or IMS PDN connection of the terminal may be successful.

In the above-described example, after the IMS signaling transmission request fails using access category 4, the IMS signaling transmission request retry using the access category 5 and the IMS signaling transmission request retry using the access category 6 may be sequentially performed. In addition, the order in which the access categories are used for retrying the IMS signaling transmission request may be changed according to the implementation of the terminal or operator policy.

For example, information on an access category used for transmission and retransmission of "SIP signaling for non-service attempt (or IMS signaling)" may be set in the terminal. Information on an access category used for transmission and retransmission of "SIP signaling for non-service attempt (or IMS signaling)" may be set equally for each PLMN or for all PLMNs. In addition, these settings may be changed according to the operator policy.

For example, as described above, the IMS layer of the terminal is in the order of access category 4 (MMTEL voice)-access category 5 (MMTEL video)-access category 6 (SMSoIP), in the order of "SIP signaling for non-service attempts (or IMS Signaling)" can be retried to transmit the request message. However, this is only an example, access category 4 (MMTEL voice)-access category 6 (SMSoIP)-access category 5 (MMTEL video), access category 5 (MMTEL video)-access category 6 (SMSoIP)-access category 4 ( MMTEL voice), Access Category 5 (MMTEL video)-Access Category 4 (MMTEL voice)-Access Category 6 (SMSoIP), Access Category 6 (SMSoIP)-Access Category 5 (MMTEL video)-Access Category 4 (MMTEL voice), A plurality of access categories related to IMS service attempts such as access category 6 (SMSoIP)-access category 4 (MMTEL voice)-access category 5 (MMTEL video), etc. are used in the IMS layer for "non-service attempts by SIP signaling (or IMS signaling). The order used for retrying ")" is subject to change.

In order for the IMS layer of the terminal to use a plurality of access categories related to IMS service attempts in retry of "SIP signaling for non-service attempts (or IMS signaling)" in order based on the terminal's configuration and/or operator policy, etc. , The IMS layer of the terminal may store whether or not to barring each of the access categories. For example, the IMS layer of the terminal is voice (MMTEL voice) (access category 4): barred / video (MMTEL video) (access category 5): not barred / SMS (MO SMS and SMSoIP) (access category 6): unknown As such, information on whether to barring a plurality of access categories related to an IMS service attempt may be stored. After the IMS layer of the terminal stores the information, there may be a case where it is necessary to transmit IMS signaling (eg, "SIP signaling for non-service attempts (or IMS signaling)") again. In this case, the IMS layer of the terminal is based on the stored information, a request message including information/indication related to the previously not barred access category (eg video (MMTEL video) (access category 5)) (optional As such, information/indication related to "SIP signaling for non-service attempts (or IMS signaling)" may be further included) to the NAS layer of the terminal.

Information/indication related to the access category (eg, MMTEL voice, MMTEL video, SMS-related access category) related to the IMS service attempt for the IMS layer of the terminal to transmit "SIP signaling (or IMS signaling) for non-service attempts" After transmitting the request message to the NAS layer of the terminal based on the, the corresponding access category is barred by the RRC layer, so that "SIP signaling for non-service attempts (or IMS signaling)" transmission may fail. In this case, the NAS layer of the terminal transmits information indicating that the corresponding access category has been barred to the IMS layer of the terminal, while providing information related to an unbarred access category among a plurality of access categories related to an IMS service attempt.

As an example, when the NAS layer of the terminal transmits the request message to the RRC layer of the terminal, the RRC layer of the terminal performs a barring check on the request message, and information about the result (eg, barred) is transmitted to the NAS layer of the terminal. To deliver. As an example, the NAS layer of the terminal requests information on an unbarred access category from among a plurality of access categories related to an IMS service attempt from the RRC layer, or the RRC layer of the terminal delivers the result of the barring check to the NAS layer of the terminal. In addition, information on an access category that is not barred among a plurality of access categories may be provided. Then, the NAS layer of the terminal may provide information related to an unbarred access category among a plurality of access categories related to an IMS service attempt to the IMS layer of the terminal.

If there are two access categories that are not barred among a plurality of access categories related to an IMS service attempt, the NAS layer of the terminal transmits information on all two access categories that are not barred or information on one of the two access categories. Can be provided to the IMS layer.

For example, the IMS layer of the terminal attempted to transmit "SIP signaling (or IMS signaling) for non-service attempts" based on information/indication related to access category 4 (MMTEL voice), but the RRC layer of the terminal In the case where the access category 4 is barred, transmission of "SIP signaling for non-service attempts (or IMS signaling)" may fail. When the access category 5 is barred in the RRC layer of the terminal and the access category 6 is not barred, the RRC layer of the terminal is not barred by itself or at the request of the NAS layer of the terminal (e.g., access category 6). ) Information can be provided to the NAS layer of the terminal. Then, the NAS layer of the terminal may provide information on the access category 6 and/or SMS (MO SMS and SMSoIP) (ie, IMS service related to the access category 6) to the IMS layer of the terminal. The IMS layer includes information/indications related to access category 6 (eg, SMS) based on the received information when retrying transmission of “SIP signaling for non-service attempts (or IMS signaling)” A request message (optionally, it may further include information/indication related to "SIP signaling (or IMS signaling) for non-service attempts") may be provided to the NAS layer of the terminal.

The following drawings are prepared to explain a specific example of the present specification. Since the names of specific devices or names of specific signals/messages/fields described in the drawings are provided by way of example, technical features of the present specification are not limited to specific names used in the following drawings.

10 is an exemplary signal flow diagram illustrating operations according to a first example of the disclosure of the present specification.

For reference, the operations shown in FIG. 10 are only examples, and the scope of the disclosure of the present specification for operations performed by the IMS layer, the NAS layer, and the RRC layer is not limited by the example of FIG. 10.

Steps S805b and S806b shown in FIG. 10 are the same as steps S805b and S806b of FIG. 8.

In step S1001, the IMS layer may determine to use an access category different from the first access category (eg, a second access category) among a plurality of access categories related to an IMS service attempt. In other words, the IMS layer may retry IMS signaling for non-service attempts using the second access category. For example, when the first access category is the access category 4, the IMS layer may use one of the access category 5 or the access category 6 as the second access category.

In step S1002, the IMS layer may transmit a request message to the NAS layer. Here, the request message may include information on a second access category (eg, access category 5) related to the IMS service. Optionally, the request message may include information related to IMS signaling for non-service attempts. For example, information on the second access category (eg, access category 5) is MO-MMTEL-video-call -started” may be information/indication.

In step S1003, since the NAS layer has received information on the second access category (eg, access category 5) from the IMS layer, the NAS layer receives the second access category (eg, for IMS signaling for non-service attempts). Access category 5) can be used. The NAS layer may transmit a request message (including information on the second access category (eg, access category 5)) to the RRC layer.

In step S1004, the RRC layer may be in a state in which access control is being applied due to a network congestion situation or the like. Since the RRC layer has received information on the second access category (eg, access category 5) from the NAS layer, the access control check may be performed based on the second access category (eg, access category 5).

When access control is not applied to the second access category (e.g., access category 5) (e.g., when the priority of an access category blocked according to access control is lower than access category 5), the RRC layer receives from the NAS layer One request message can be accepted. The RRC layer may transmit information (eg, "not barred" information) indicating that the request message is allowed to the NAS layer. When the request message is accepted, the PDCP layer transmits the request message (including information related to IMS signaling for non-service attempts) to the network in the same manner as the operation related to case 1 of FIGS. 8 and 9 described above. Can be done.

When access control is applied to the second access category (e.g., access category 5) (e.g., when the priority of an access category blocked according to access control is higher than access category 5), the RRC layer receives from the NAS layer. You can block the request message. The RRC layer may transmit information (eg, "barred" information) that the request message has been blocked to the NAS layer. When the request message is blocked, the RRC layer transmits the response message to the IMS layer via the NAS layer in the same manner as the operations related to case 2 of FIGS. 8 and 10 (step S805b and step S806b). The operation can be performed.

In this way, when the retry of IMS signaling based on the second access category fails, the IMS layer of the terminal selectively selects a request message once again (information on the third access category (eg, access category 6) related to the IMS service) ( Example: "MO-SMSoIP-attempt-started" indication/information) included, optionally, including information related to IMS signaling for non-service attempts) may be transmitted to the NAS layer of the UE. Then, the NAS layer transmits a request message (including information on a third access category related to the IMS service (eg, access category 6)) to the RRC layer, and the RRC layer performs an access control check based on the third access category. can do.

In the above-described example, after the IMS signaling transmission request fails using access category 4, the IMS signaling transmission request retry using the access category 5 and the IMS signaling transmission request retry using the access category 6 may be sequentially performed. In addition, the order in which the access categories are used for retrying the IMS signaling transmission request may be changed according to the implementation of the terminal or operator policy.

2. Second example of disclosure of this specification

When "SIP signaling for non-service attempts (or IMS signaling)" occurs, the IMS layer of the terminal includes information/indication related to one of a plurality of access categories (eg, a first access category) related to the "IMS service attempt" Request message (optionally, it may further include information/indication related to “SIP signaling (or IMS signaling) for non-service attempts”) to the NAS layer The request message is rejected or blocked. When (barred), the IMS layer of the terminal may receive a response indicating that the request message has been rejected or blocked from the NAS layer of the terminal. In this case, according to the second example of the disclosure of the present specification, the IMS layer of the terminal The operation described below may be performed.

When a request message including information/indication related to one of a plurality of access categories related to an IMS service attempt fails (barred by the RRC layer), the IMS layer of the terminal is "SIP signaling for non-service attempts ( Or, additional retry for "IMS signaling)" may not be performed.

The IMS layer of the terminal transmits "SIP signaling for non-service attempts (or IMS signaling)" instead of retrying the transmission of the request message for "SIP signaling for non-service attempts (or IMS signaling)" You may remember that this has failed. That is, the IMS layer of the terminal may store information that transmission of "SIP signaling (or IMS signaling) for non-service attempt" has failed.

For example, the IMS layer of the terminal may store information that transmission of "SIP signaling (or IMS signaling) for non-service attempts" has failed in the IMS layer in the form of a flag or the like. For example, if information stored in the form of a flag is set, mark, or indicated as 1, the information is required IMS signaling (eg, "SIP signaling for non-service attempts (or IMS signaling)") fails It can indicate that you did it.

Optionally, the IMS layer of the terminal determines the type of "SIP signaling for non-service attempts (or IMS signaling)" that failed to be transmitted and the type of event used for transmission of the request message "SIP signaling for non-service attempts". (Or IMS signaling)" can be stored together with information that the transmission has failed. For example, the type of "SIP signaling (or IMS signaling) for non-service attempts" in which transmission has failed may mean information on SIP REGISTER for initial registration or re-registration, or SIP SUBSCRBE for subscription refresh. have. For example, the type of event used to transmit the request message is information on one of a plurality of access categories related to the IMS service attempt used by the terminal to transmit the request message (e.g., access category 4 (MO MMTel voice ), access category 5 (= MO MMTel video) or access category 6 (MO SMS and SMSoIP)).

In addition, the IMS layer of the terminal may store the signaling message itself, which has failed to perform, in the queue of the IMS layer. For example, the IMS layer of the terminal includes a request message including information/indication related to one of a plurality of access categories related to an IMS service attempt (optionally, "SIP signaling for a non-service attempt (or IMS signaling)" It may further include information/indication related to) and may store itself in a queue. The storage time limit for storing the failed signaling message may be determined based on the implementation of the terminal, the configuration of the terminal, and/or the operator policy. After the failed signaling message is stored, when a reset event of the terminal occurs, the failed signaling message may be deleted. For example, the reset event of the terminal may include power off, power on, and SIM removal (Universal Subscriber Identity Module (USIM) removal), or deregistration for the 3GPP system. It may include attach, registration, attach, and the like.

Thereafter, when an IMS service attempt occurs (i.e., when SIP signaling (or IMS signaling) for an IMS service attempt is required), the IMS layer of the terminal performs at least one of the operations described below or the operations described below. The operation can be performed. Here, when an IMS service attempt occurs (i.e., when SIP signaling (or IMS signaling) is required for an IMS service attempt), for example, a request related to an IMS service such as a voice call, video call, or SMS may occur. have.

1) Before an IMS service attempt occurs, the IMS layer of the terminal includes a request message including event information/indication for "SIP signaling for non-service attempt (or IMS signaling)" (optionally, "non-service When the request message is barred after transmitting access through "SIP signaling (or IMS signaling) for an attempt", and the request message is barred, the event type in which the IMS layer of the terminal is barred (the Information on one of a plurality of access categories related to an IMS service attempt used to transmit a request message) can be stored.

In this situation, when an IMS service attempt occurs (i.e., when SIP signaling (or IMS signaling) for an IMS service attempt is required), the access category related to the generated IMS service attempt is previously barred. In the case of the same, the IMS layer of the terminal may not transmit a request message for SIP signaling (or IMS signaling) for an IMS service attempt to the NAS layer of the terminal. Conversely, when an IMS service attempt occurs (i.e., when SIP signaling (or IMS signaling) for an IMS service attempt is required), the access category related to the generated IMS service attempt is different from the access category related to the previously barred event type. In this case, the IMS layer of the terminal may transmit a request message for SIP signaling (or IMS signaling) for an IMS service attempt to the NAS layer of the terminal. That is, the IMS layer of the terminal may itself stop a procedure (eg, an access request procedure) before transmitting a request message for SIP signaling (or IMS signaling) for an IMS service attempt to the NAS layer of the terminal. The IMS layer of the terminal is in the IMS layer based on the previously stored barring information (eg, information related to the failure of transmission of “SIP signaling for non-service attempts (or IMS signaling)” such as barred event types). Barring may be preemptively applied to "SIP signaling (or IMS signaling) for IMS service attempt".

2) If the contents described in item 1) above do not apply (e.g., the IMS layer of the terminal does not preemptively apply barring for "SIP signaling for IMS service attempt (or IMS signaling)", or When barring information is not stored), the IMS layer of the terminal may transmit a request message for attempting an IMS service to the NAS layer of the terminal.

3) Before an IMS service attempt occurs, the IMS layer of the terminal provides a request message including event information/indication for "SIP signaling for non-service attempt (or IMS signaling)" (optionally, "non-service The request message is barred after access is transmitted through SIP signaling (or IMS signaling) for an attempt (which may further include information), and the IMS layer of the terminal is "for non-service attempts. Information that transmission of "SIP signaling (or IMS signaling)" has failed may have been stored in the form of a flag.

In this situation, the IMS layer of the terminal first transmits "SIP signaling for non-IMS service attempts (or IMS signaling)" before attempting to access "SIP signaling for service attempts (or IMS signaling)". For example, if the transmission of "SIP signaling (or IMS signaling) for non-service attempts (eg, re-registration)" has failed and cannot be re-registered, the IMS layer of the terminal The layer may transmit a request message including a SIP REGISTER for re-registration.. The IMS layer of the terminal is a request message including information/indication related to the generated IMS service attempt (optionally, "non- -SIP signaling for service attempt (or IMS signaling)" related information/indication may be further included) to the NAS layer of the terminal. For example, a previously barred request message is "non-IMS". Information/indication (eg, SIP REGISTER) related to “SIP signaling (or IMS signaling) for service attempts” and access category 4 (MMTEL voice) related to IMS service attempts were included, and IMS service attempts related to access category 5 ( MMTEL video), the IMS layer of the terminal is a request message including information/indication (eg, SIP REGISTER) related to “SIP signaling (or IMS signaling) for non-IMS service attempts” and “MMTEL video start” Can be transmitted to the NAS layer of the terminal.

This is not for the purpose of barring bypass for transmission of “SIP signaling (or IMS signaling) for non-IMS service attempts”, but for access attempts to use actual IMS services (for IMS service attempts). It can be regarded as transmission of a request message when SIP signaling (or access attempt related to IMS signaling) occurs.

If the access request can be successfully accepted (eg, the request message may not be barred). In this case, before the IMS layer of the terminal transmits a request message related to an actual access attempt (an access attempt related to SIP signaling (or IMS signaling) for an IMS service attempt), the previously failed “SIP signaling for non-service attempts” When information related to "(or IMS signaling)" is stored, the IMS layer of the terminal may retransmit the previously failed "SIP signaling for non-service attempts (or IMS signaling)". Or, in this case, the IMS layer of the terminal determines that a procedure (eg, registration for IMS) related to "SIP signaling (or IMS signaling)" for a non-service attempt should be performed again, and the REGISTER may be attempted again. After the IMS layer of the terminal successfully transmits a request message related to "SIP signaling (or IMS signaling) for non-service attempts", or after the IMS layer of the terminal successfully completes the REGISTER, the IMS layer of the terminal Services related to service attempts can be used.

In the above 1) to 3), when transmission of a request message related to "SIP signaling (or IMS signaling)" for a non-service attempt is successful, the IMS layer of the terminal is set, mark, or indicated "non-service The flag related to transmission failure of "SIP signaling (or IMS signaling) for attempt" may be reset to 0.

The following drawings are prepared to explain a specific example of the present specification. Since the names of specific devices or names of specific signals/messages/fields described in the drawings are provided by way of example, technical features of the present specification are not limited to specific names used in the following drawings.

11 is an exemplary signal flow diagram illustrating a second example of the disclosure of the present specification.

For reference, the operations shown in FIG. 11 are only examples, and the scope of the disclosure of the present specification for operations performed by the IMS layer, the NAS layer, and the RRC layer is not limited by the example of FIG. 11.

Steps S805b and S806b shown in FIG. 11 are the same as steps S805b and S806b of FIG. 8.

In step S1101, the IMS layer may remember that the transmission of "SIP signaling for non-service attempt (or IMS signaling)" has failed. For example, the IMS layer of the terminal may store information that transmission of "SIP signaling (or IMS signaling) for non-service attempt" has failed.

In other words, instead of retrying transmission of the request message for "SIP signaling for non-service attempts (or IMS signaling)", the IMS layer of the terminal is "SIP signaling for non-service attempts (or IMS signaling)" You may remember that the transmission of "has failed.

For example, the IMS layer of the terminal may store information that transmission of "SIP signaling (or IMS signaling) for non-service attempts" has failed in the IMS layer in the form of a flag or the like.

Optionally, the IMS layer of the terminal determines the type of "SIP signaling for non-service attempts (or IMS signaling)" that failed to be transmitted and the type of event used for transmission of the request message "SIP signaling for non-service attempts". (Or IMS signaling)" can be stored together with information that the transmission has failed.

In addition, the IMS layer of the terminal may store the signaling message itself, which has failed to perform, in the queue of the IMS layer.

Thereafter, when an IMS service attempt occurs (i.e., when SIP signaling (or IMS signaling) for an IMS service attempt is required), the IMS layer of the terminal performs at least one of the operations described below or the operations described below. The operation can be performed.

1) The IMS layer of the terminal may have stored the barred event type (information on one of a plurality of access categories (eg, first access category) related to the IMS service attempt used to transmit the request message). When the access category related to the generated IMS service attempt is the same as the access category related to the previously barred event type, the IMS layer of the terminal sends a request message for SIP signaling (or IMS signaling) for the IMS service attempt to the NAS layer of the terminal. May not be transferred. If the access category related to the generated IMS service attempt is different from the access category related to the previously barred event type, the IMS layer of the terminal sends a request message for SIP signaling (or IMS signaling) for the IMS service attempt to the NAS layer of the terminal. Can be transferred to. That is, before the IMS layer of the terminal transmits a request message for SIP signaling (or IMS signaling) for an IMS service attempt to the NAS layer of the terminal, the IMS layer of the terminal stores previous barring information (e.g., barred). SIP signaling (or IMS signaling for IMS service attempt) preemptively within the IMS layer based on information related to the failure of transmission of "SIP signaling for non-service attempts (or IMS signaling)" such as event types )" can be applied to barring.

2) If the contents described in item 1) above do not apply (e.g., the IMS layer of the terminal does not preemptively apply barring for "SIP signaling for IMS service attempt (or IMS signaling)", or When barring information is not stored), the IMS layer of the terminal may transmit a request message for attempting an IMS service to the NAS layer of the terminal.

3) The IMS layer of the terminal may have stored information that transmission of "SIP signaling for non-service attempts (or IMS signaling)" has failed in the form of a flag or the like. In this situation, the IMS layer of the terminal first transmits "SIP signaling for non-IMS service attempts (or IMS signaling)" before attempting to access "SIP signaling for service attempts (or IMS signaling)". The IMS layer of the terminal is a request message including information/indication related to the generated IMS service attempt that has previously failed (optionally, related to "SIP signaling for non-service attempts (or IMS signaling)" Information/indication may be further included) can be transmitted to the NAS layer of the terminal.

According to the disclosure of the present specification described based on various drawings and examples, when it is necessary to transmit IMS signaling for a non-service request in a situation in which access control is being applied due to a network congestion, etc., access control may be bypassed. This enables the user's terminal to continuously provide IMS services such as voice calls, video calls, and SMS that the user wants to use.

For reference, the operation of the UE described in this specification may be implemented by the devices of FIGS. 12 to 17 to be described below. For example, the UE may be the first wireless device 100 or the second wireless device 200 of FIG. 13. For example, the operation of the UE described herein may be processed by one or more processors 102 or 202. The operation of the UE described herein may be stored in one or more memories 104 or 204 in the form of an instruction/program (e.g. instruction, executable code) executable by one or more processors 102 or 202. One or more processors 102 or 202 control one or more memories 104 or 204 and one or more transceivers 106 or 206, and execute instructions/programs stored in one or more memories 104 or 204 to be used herein. It is possible to perform the operation of the UE described in the disclosure.

In addition, instructions for performing the operation of the UE described in the disclosure of the present specification may be stored in a recording nonvolatile computer-readable storage medium. The storage medium may be included in one or more memories 104 or 204. In addition, instructions recorded in the storage medium may be executed by one or more processors 102 or 202 to perform the operation of the UE described in the disclosure of the present specification.

For reference, the operation of a network node (eg, P-CSCF, AMF, etc.) described in this specification may be implemented by the devices of FIGS. 12 to 17 to be described below. For example, the network node may be the first wireless device 100 or the second wireless device 200 of FIG. 13. For example, the operations of the network nodes described herein may be processed by one or more processors 102 or 202. The operations of the network nodes described herein may be stored in one or more memories 104 or 204 in the form of an instruction/program (e.g. instruction, executable code) executable by one or more processors 102 or 202. One or more processors 102 or 202 control one or more memories 104 or 204 and one or more transceivers 106 or 206, and execute instructions/programs stored in one or more memories 104 or 204 to be used herein. The operation of the network node described in the disclosure may be performed.

V. Examples to which the disclosure of the present specification applies

Although not limited thereto, various descriptions, functions, procedures, proposals, methods, and/or operational flow charts of the disclosure of the present specification disclosed in this document are used in various fields requiring wireless communication/connection (eg, 5G) between devices. Can be applied.

Hereinafter, it will be illustrated in more detail with reference to the drawings. In the following drawings/description, the same reference numerals may exemplify the same or corresponding hardware block, software block, or functional block, unless otherwise indicated.

12 illustrates a communication system 1 applied to the disclosure of this specification.

Referring to FIG. 12, a communication system 1 applied to the disclosure of the present specification includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (eg, 5G NR (New RAT), LTE (Long Term Evolution)), and may be referred to as a communication/wireless/5G device. Although not limited thereto, wireless devices include robots 100a, vehicles 100b-1 and 100b-2, eXtended Reality (XR) devices 100c, hand-held devices 100d, and home appliances 100e. ), an Internet of Thing (IoT) device 100f, and an AI device/server 400. For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, and a vehicle capable of performing inter-vehicle communication. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (eg, a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, including HMD (Head-Mounted Device), HUD (Head-Up Display), TV, smartphone, It can be implemented in the form of a computer, wearable device, home appliance, digital signage, vehicle, robot, and the like. Portable devices may include smart phones, smart pads, wearable devices (eg, smart watches, smart glasses), computers (eg, notebook computers, etc.). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors, smart meters, and the like. For example, the base station and the network may be implemented as a wireless device, and the specific wireless device 200a may operate as a base station/network node to another wireless device.

The wireless devices 100a to 100f may be connected to the network 300 through the base station 200. AI (Artificial Intelligence) 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 configured using a 3G network, a 4G (eg, LTE) network, or a 5G (eg, NR) network. The wireless devices 100a to 100f may communicate with each other through the base station 200 / network 300, but may perform direct communication (e.g. sidelink communication) without going through the base station / network. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g. V2V (Vehicle to Vehicle)/V2X (Vehicle to Everything) communication). In addition, the IoT device (eg, sensor) may directly communicate with other IoT devices (eg, sensors) or other wireless devices 100a to 100f.

Wireless communication/ connections 150a, 150b, and 150c may be established between the wireless devices 100a to 100f / base station 200 and the base station 200 / base station 200. Here, the wireless communication/connection includes various wireless access such as uplink/downlink communication 150a, sidelink communication 150b (or D2D communication), base station communication 150c (eg relay, Integrated Access Backhaul). This can be achieved through technology (eg 5G NR) Through wireless communication/ connections 150a, 150b, 150c, the wireless device and the base station/wireless device, and the base station and the base station can transmit/receive radio signals to each other. For example, the wireless communication/ connection 150a, 150b, 150c may transmit/receive signals through various physical channels. To this end, based on various proposals disclosed herein, transmission/reception of radio signals At least some of a process of setting various configuration information for, a process of processing various signals (eg, channel encoding/decoding, modulation/demodulation, resource mapping/demapping, etc.), a resource allocation process, and the like may be performed.

13 illustrates a wireless device applicable to the disclosure of the present specification.

Referring to FIG. 13, the first wireless device 100 and the second wireless device 200 may transmit and receive wireless signals through various wireless access technologies (eg, LTE and NR). Here, {the first wireless device 100, the second wireless device 200} is the {wireless device 100x, the base station 200} and/or {wireless device 100x, wireless device 100x) of FIG. 12 } Can be matched. Alternatively, it may correspond to the first wireless device 100 and the UE, AMF, SMF, or UPF described in the disclosure of the present specification. In addition, the second wireless device 200 may correspond to a UE, AMF, SMF, or UPF that communicates with the first wireless device 100. The first wireless device 100 includes one or more processors 102 and one or more memories. 104, and may further include one or more transceivers 106 and/or one or more antennas 108 in addition. The processor 102 controls the memory 104 and/or the transceiver 106 and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed herein. For example, the processor 102 may process information in the memory 104 to generate first information/signal, and then transmit a radio signal including the first information/signal through the transceiver 106. In addition, the processor 102 may store information obtained from signal processing of the second information/signal in the memory 104 after receiving a radio signal including the second information/signal through the transceiver 106. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may perform some or all of the processes controlled by the processor 102, or instructions for performing the descriptions, functions, procedures, suggestions, methods, and/or operational flow charts disclosed in this document. It can store software code including Here, the processor 102 and the memory 104 may be part of a communication modem/circuit/chip designed to implement wireless communication technology (eg, LTE, NR). The transceiver 106 may be coupled with the processor 102 and may transmit and/or receive radio signals through one or more antennas 108. The transceiver 106 may include a transmitter and/or a receiver. The transceiver 106 may be mixed with an RF (Radio Frequency) unit. In the disclosure of the present specification, a wireless device may mean a communication modem/circuit/chip.

The second wireless device 200 includes one or more processors 202 and one or more memories 204, and may further include one or more transceivers 206 and/or one or more antennas 208. The processor 202 controls the memory 204 and/or the transceiver 206 and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed herein. For example, the processor 202 may process information in the memory 204 to generate third information/signal, and then transmit a wireless signal including the third information/signal through the transceiver 206. In addition, the processor 202 may store information obtained from signal processing of the fourth information/signal in the memory 204 after receiving a radio signal including the fourth information/signal through the transceiver 206. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may perform some or all of the processes controlled by the processor 202, or instructions for performing the descriptions, functions, procedures, suggestions, methods and/or operational flow charts disclosed in this document. It can store software code including Here, the processor 202 and the memory 204 may be part of a communication modem/circuit/chip designed to implement wireless communication technology (eg, LTE, NR). The transceiver 206 may be connected to the processor 202 and may transmit and/or receive radio signals through one or more antennas 208. The transceiver 206 may include a transmitter and/or a receiver. The transceiver 206 may be used interchangeably with an RF unit. In the disclosure of the present specification, a wireless device may mean a communication modem/circuit/chip.

Hereinafter, the hardware elements of the wireless devices 100 and 200 will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (eg, functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors 102, 202 may be configured to generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Units (SDUs) according to the description, functions, procedures, proposals, methods, and/or operational flow charts disclosed in this document. Can be generated. One or more processors 102, 202 may generate messages, control information, data, or information according to the description, function, procedure, suggestion, method, and/or operational flow chart disclosed herein. At least one processor (102, 202) generates a signal (e.g., a baseband signal) including PDU, SDU, message, control information, data or information according to the functions, procedures, proposals and/or methods disclosed herein. , It may be provided to one or more transceivers (106, 206). One or more processors 102, 202 may receive signals (e.g., baseband signals) from one or more transceivers 106, 206, and the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed herein PDUs, SDUs, messages, control information, data, or information may be obtained according to the parameters.

One or more of the processors 102 and 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more of the processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) May be included in one or more processors 102 and 202. The description, functions, procedures, suggestions, methods, and/or operational flow charts disclosed in this document may be implemented using firmware or software, and firmware or software may be implemented to include modules, procedures, functions, and the like. The description, functions, procedures, proposals, methods and/or operational flow charts disclosed in this document are included in one or more processors 102, 202, or stored in one or more memories 104, 204, and are It may be driven by the above processors 102 and 202. The descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and/or a set of instructions.

One or more memories 104 and 204 may be connected to one or more processors 102 and 202 and may store various types of data, signals, messages, information, programs, codes, instructions and/or instructions. One or more memories 104 and 204 may be composed of ROM, RAM, EPROM, flash memory, hard drive, register, cache memory, computer readable storage medium, and/or combinations thereof. One or more memories 104 and 204 may be located inside and/or outside of one or more processors 102 and 202. In addition, one or more memories 104, 204 may be connected to one or more processors 102, 202 through various technologies such as wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, control information, radio signals/channels, and the like mentioned in the methods and/or operation flow charts of this document to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, radio signals/channels, etc. mentioned in the description, functions, procedures, suggestions, methods and/or operation flow charts disclosed in this document from one or more other devices. have. For example, one or more transceivers 106 and 206 may be connected to one or more processors 102 and 202, and may transmit and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to transmit user data, control information, or radio signals to one or more other devices. In addition, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information, or radio signals from one or more other devices. In addition, one or more transceivers (106, 206) may be connected with one or more antennas (108, 208), and one or more transceivers (106, 206) through one or more antennas (108, 208), the description and functionality disclosed in this document. It may be set to transmit and receive user data, control information, radio signals/channels, and the like mentioned in a procedure, a proposal, a method and/or an operation flowchart. In this document, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (eg, antenna ports). One or more transceivers (106, 206) in order to process the received user data, control information, radio signal / channel, etc. using one or more processors (102, 202), the received radio signal / channel, etc. in the RF band signal. It can be converted into a baseband signal. One or more transceivers 106 and 206 may convert user data, control information, radio signals/channels, etc. processed using one or more processors 102 and 202 from a baseband signal to an RF band signal. To this end, one or more of the transceivers 106 and 206 may include (analog) oscillators and/or filters.

14 illustrates a signal processing circuit for a transmission signal.

Referring to FIG. 14, the signal processing circuit 1000 may include a scrambler 1010, a modulator 1020, a layer mapper 1030, a precoder 1040, a resource mapper 1050, and a signal generator 1060. have. Although not limited thereto, the operations/functions of FIG. 14 may be performed in the processors 102 and 202 and/or the transceivers 106 and 206 of FIG. 13. The hardware elements of FIG. 14 may be implemented in the processors 102 and 202 and/or the transceivers 106 and 206 of FIG. 13. For example, blocks 1010 to 1060 may be implemented in the processors 102 and 202 of FIG. 13. Further, blocks 1010 to 1050 may be implemented in the processors 102 and 202 of FIG. 13, and block 1060 may be implemented in the transceivers 106 and 206 of FIG. 13.

The codeword may be converted into a wireless signal through the signal processing circuit 1000 of FIG. 14. Here, the codeword is an encoded bit sequence of an information block. The information block may include a transport block (eg, a UL-SCH transport block, a DL-SCH transport block). The radio signal may be transmitted through various physical channels (eg, PUSCH, PDSCH).

Specifically, the codeword may be converted into a scrambled bit sequence by the scrambler 1010. The scramble sequence used for scramble is generated based on an initialization value, and the initialization value may include ID information of a wireless device. The scrambled bit sequence may be modulated by the modulator 1020 into a modulation symbol sequence. The modulation scheme may include pi/2-Binary Phase Shift Keying (pi/2-BPSK), m-Phase Shift Keying (m-PSK), m-Quadrature Amplitude Modulation (m-QAM), and the like. The complex modulation symbol sequence may be mapped to one or more transport layers by the layer mapper 1030. The modulation symbols of each transport layer may be mapped to the corresponding antenna port(s) by the precoder 1040 (precoding). The output z of the precoder 1040 can be obtained by multiplying the output y of the layer mapper 1030 by the N*M precoding matrix W. Here, N is the number of antenna ports, and M is the number of transmission layers. Here, the precoder 1040 may perform precoding after performing transform precoding (eg, DFT transform) on complex modulation symbols. Also, the precoder 1040 may perform precoding without performing transform precoding.

The resource mapper 1050 may map modulation symbols of each antenna port to a time-frequency resource. The time-frequency resource may include a plurality of symbols (eg, CP-OFDMA symbols, DFT-s-OFDMA symbols) in the time domain, and may include a plurality of subcarriers in the frequency domain. The signal generator 1060 generates a radio signal from the mapped modulation symbols, and the generated radio signal may be transmitted to another device through each antenna. To this end, the signal generator 1060 may include an Inverse Fast Fourier Transform (IFFT) module and a Cyclic Prefix (CP) inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, and the like. .

The signal processing process for the received signal in the wireless device may be configured as the reverse of the signal processing process 1010 to 1060 of FIG. 14. For example, a wireless device (eg, 100 and 200 in FIG. 13) may receive a wireless signal from the outside through an antenna port/transmitter. The received radio signal may be converted into a baseband signal through a signal restorer. To this end, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP canceller, and a Fast Fourier Transform (FFT) module. Thereafter, the baseband signal may be reconstructed into a codeword through a resource de-mapper process, a postcoding process, a demodulation process, and a de-scramble process. The codeword may be restored to an original information block through decoding. Accordingly, a signal processing circuit (not shown) for a received signal may include a signal restorer, a resource demapper, a postcoder, a demodulator, a descrambler, and a decoder.

15 shows another example of a wireless device applied to the disclosure of the present specification.

The wireless device may be implemented in various forms according to use-examples/services (see FIG. 12).

Referring to FIG. 15, the wireless devices 100 and 200 correspond to the wireless devices 100 and 200 of FIG. 13, and various elements, components, units/units, and/or modules ) Can be composed of. For example, the wireless devices 100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130, and an additional element 140. The communication unit may include a communication circuit 112 and a transceiver(s) 114. For example, the communication circuit 112 may include one or more processors 102 and 202 and/or one or more memories 104 and 204 of FIG. 13. For example, transceiver(s) 114 may include one or more transceivers 106,206 and/or one or more antennas 108,208 of FIG. 13. The control unit 120 is electrically connected to the communication unit 110, the memory unit 130, and the additional element 140 and controls all operations of the wireless device. For example, the controller 120 may control the electrical/mechanical operation of the wireless device based on the program/code/command/information stored in the memory unit 130. In addition, the control unit 120 transmits the information stored in the memory unit 130 to an external (eg, other communication device) through the communication unit 110 through a wireless/wired interface, or through the communication unit 110 to the outside (eg, Information received through a wireless/wired interface from another communication device) may be stored in the memory unit 130.

The additional element 140 may be variously configured according to the type of wireless device. For example, the additional element 140 may include at least one of a power unit/battery, an I/O unit, a driving unit, and a computing unit. Although not limited thereto, wireless devices include robots (Figs. 12, 100a), vehicles (Figs. 12, 100b-1, 100b-2), XR devices (Figs. 12, 100c), portable devices (Figs. (Figs.12, 100e), IoT devices (Figs. 12, 100f), digital broadcasting terminals, hologram devices, public safety devices, MTC devices, medical devices, fintech devices (or financial devices), security devices, climate/environment devices, It may be implemented in the form of an AI server/device (FIGS. 12 and 400), a base station (FIGS. 12 and 200), and a network node. The wireless device can be used in a mobile or fixed location depending on the use-example/service.

In FIG. 15, various elements, components, units/units, and/or modules within the wireless devices 100 and 200 may be connected to each other through a wired interface, or at least part of them may be wirelessly connected through the communication unit 110. For example, in the wireless devices 100 and 200, the control unit 120 and the communication unit 110 are connected by wire, and the control unit 120 and the first unit (eg, 130, 140) are connected through the communication unit 110. Can be connected wirelessly. In addition, each element, component, unit/unit, and/or module in the wireless device 100 and 200 may further include one or more elements. For example, the controller 120 may be configured with one or more processor sets. For example, the control unit 120 may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphic processing processor, and a memory control processor. As another example, the memory unit 130 includes random access memory (RAM), dynamic RAM (DRAM), read only memory (ROM), flash memory, volatile memory, and non-volatile memory. volatile memory) and/or a combination thereof.

16 shows an example of a vehicle or an autonomous vehicle that is applied to the disclosure of the present specification.

16 illustrates a vehicle or an autonomous driving vehicle applied to the disclosure of the present specification. The vehicle or autonomous vehicle may be implemented as a mobile robot, a vehicle, a train, an aerial vehicle (AV), or a ship.

Referring to FIG. 16, the vehicle or autonomous vehicle 100 includes an antenna unit 108, a communication unit 110, a control unit 120, a driving unit 140a, a power supply unit 140b, a sensor unit 140c, and autonomous driving. It may include a unit (140d). The antenna unit 108 may be configured as a part of the communication unit 110. Blocks 110/130/140a to 140d correspond to blocks 110/130/140 of FIG. 15, respectively.

The communication unit 110 may transmit and receive signals (eg, data, control signals, etc.) with external devices such as other vehicles, base stations (e.g. base stations, roadside base stations, etc.), and servers. The controller 120 may perform various operations by controlling elements of the vehicle or the autonomous vehicle 100. The control unit 120 may include an Electronic Control Unit (ECU). The driving unit 140a may cause the vehicle or the autonomous vehicle 100 to travel on the ground. The driving unit 140a may include an engine, a motor, a power train, a wheel, a brake, a steering device, and the like. The power supply unit 140b supplies power to the vehicle or the autonomous vehicle 100, and may include a wired/wireless charging circuit, a battery, and the like. The sensor unit 140c may obtain vehicle status, surrounding environment information, user information, and the like. The sensor unit 140c is an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight detection sensor, a heading sensor, a position module, and a vehicle advancement. /Reverse sensor, battery sensor, fuel sensor, tire sensor, steering sensor, temperature sensor, humidity sensor, ultrasonic sensor, illumination sensor, pedal position sensor, etc. may be included. The autonomous driving unit 140d is a technology for maintaining a driving lane, a technology for automatically adjusting the speed such as adaptive cruise control, a technology for automatically driving along a predetermined route, and for driving by automatically setting a route when a destination is set. Technology, etc. can be implemented.

For example, the communication unit 110 may receive map data and traffic information data from an external server. The autonomous driving unit 140d may generate an autonomous driving route and a driving plan based on the acquired data. The controller 120 may control the driving unit 140a so that the vehicle or the autonomous driving vehicle 100 moves along the autonomous driving path according to the driving plan (eg, speed/direction adjustment). During autonomous driving, the communication unit 110 asynchronously/periodically acquires the latest traffic information data from an external server, and may acquire surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit 140c may acquire vehicle state and surrounding environment information. The autonomous driving unit 140d may update the autonomous driving route and the driving plan based on the newly acquired data/information. The communication unit 110 may transmit information about a vehicle location, an autonomous driving route, and a driving plan to an external server. The external server may predict traffic information data in advance using AI technology or the like based on information collected from the vehicle or autonomously driving vehicles, and may provide the predicted traffic information data to the vehicle or autonomously driving vehicles.

17 illustrates an AI device applied to the disclosure of the present specification.

17 illustrates an AI device applied to the disclosure of the present specification. AI devices are fixed devices such as TVs, projectors, smartphones, PCs, notebooks, digital broadcasting terminals, tablet PCs, wearable devices, set-top boxes (STBs), radios, washing machines, refrigerators, digital signage, robots, vehicles, etc. It can be implemented with possible devices.

Referring to FIG. 17, the AI device 100 includes a communication unit 110, a control unit 120, a memory unit 130, an input/output unit 140a/140b, a running processor unit 140c, and a sensor unit 140d. It may include. Blocks 110 to 130/140a to 140d correspond to blocks 110 to 130/140 of FIG. 15, respectively.

The communication unit 110 uses wired/wireless communication technology to provide external devices such as other AI devices (eg, FIGS. 12, 100x, 200, 400) or AI servers (eg, 400 in FIG. 12) and wired/wireless signals (eg, sensor information). , User input, learning model, control signals, etc.). To this end, the communication unit 110 may transmit information in the memory unit 130 to an external device or may transmit a signal received from the external device to the memory unit 130.

The controller 120 may determine at least one executable operation of the AI device 100 based on information determined or generated using a data analysis algorithm or a machine learning algorithm. In addition, the controller 120 may perform a determined operation by controlling the components of the AI device 100. For example, the control unit 120 may request, search, receive, or utilize data from the learning processor unit 140c or the memory unit 130, and may be a predicted or desirable operation among at least one executable operation. Components of the AI device 100 can be controlled to execute the operation. In addition, the control unit 120 collects history information including the operation content or user's feedback on the operation of the AI device 100 and stores it in the memory unit 130 or the running processor unit 140c, or the AI server ( 12 and 400). The collected history information can be used to update the learning model.

The memory unit 130 may store data supporting various functions of the AI device 100. For example, the memory unit 130 may store data obtained from the input unit 140a, data obtained from the communication unit 110, output data from the running processor unit 140c, and data obtained from the sensing unit 140. In addition, the memory unit 130 may store control information and/or software codes necessary for the operation/execution of the controller 120.

The input unit 140a may acquire various types of data from the outside of the AI device 100. For example, the input unit 140a may acquire training data for model training and input data to which the training model is to be applied. The input unit 140a may include a camera, a microphone, and/or a user input unit. The output unit 140b may generate output related to visual, auditory or tactile sense. The output unit 140b may include a display unit, a speaker, and/or a haptic module. The sensing unit 140 may obtain at least one of internal information of the AI device 100, surrounding environment information of the AI device 100, and user information by using various sensors. The sensing unit 140 may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, an optical sensor, a microphone, and/or a radar. have.

The learning processor unit 140c may train a model composed of an artificial neural network using the training data. The running processor unit 140c may perform AI processing together with the running processor unit of the AI server (FIGS. 12 and 400 ). The learning processor unit 140c may process information received from an external device through the communication unit 110 and/or information stored in the memory unit 130. In addition, the output value of the learning processor unit 140c may be transmitted to an external device through the communication unit 110 and/or may be stored in the memory unit 130.

Although preferred embodiments have been exemplarily described above, the disclosure of the present specification is not limited to such specific embodiments, and thus modifications, changes, or modifications in various forms within the scope of the spirit and claims of the present specification It can be improved.

In the exemplary system described above, the methods are described on the basis of a flowchart as a series of steps or blocks, but are not limited to the order of the steps described, and certain steps may occur in a different order or concurrently with the steps described above. have. In addition, those skilled in the art will understand that the steps shown in the flowchart are not exclusive, other steps may be included, or one or more steps in the flowchart may be deleted without affecting the scope of the rights.

The claims set forth herein may be combined in a variety of ways. For example, the technical features of the method claims of the present specification may be combined to be implemented as a device, and the technical features of the device claims of the present specification may be combined to be implemented by a method. In addition, the technical characteristics of the method claim of the present specification and the technical characteristics of the device claim may be combined to be implemented as a device, and the technical characteristics of the method claim of the present specification and the technical characteristics of the device claim may be combined to be implemented by a method.

Claims (17)

1. As a method for a terminal to perform communication related to IMS (Internet Protocol Multimedia Subsystem),

   Determining, by the IMS layer of the terminal, that IMS signaling for a non-service attempt is required,

   IMS signaling for the non-service attempt (attempt) is signaling that does not request IMS service; And

   Transmitting, by the IMS layer of the terminal, a first request message including information on a first access category among a plurality of access categories related to the IMS service to a non-access stratum (NAS) layer of the terminal How to include.
2. The method of claim 1,

   The method further comprising the step of receiving, by the IMS layer of the terminal, a response message indicating that the first request message is barred from the NAS layer of the terminal.
3. The method of claim 2,

   Based on the reception of a response message indicating that the first request message has been blocked, the IMS layer of the terminal sends a second request message including information on a second access category among the plurality of access categories related to the IMS service. The method further comprising transmitting to the NAS layer of the terminal.
4. The method of claim 3,

   The method further comprising the step of receiving, by the IMS layer of the terminal, a response message indicating that the second request message has been barred from the NAS layer of the terminal.
5. The method of claim 4,

   Based on receiving a response message indicating that the second request message has been blocked, the IMS layer of the terminal sends a third request message including information on a third access category among the plurality of access categories related to the IMS service. The method further comprising transmitting to the NAS layer of the terminal.
6. According to claim 2

   Storing, by the IMS layer of the terminal, information indicating that transmission of information related to IMS signaling for the non-service attempt has failed, based on receiving a response message indicating that the first request message has been barred
7. The method of claim 6,

   The storing step is a step of storing information indicating that transmission of information related to IMS signaling for the non-service attempt has failed and information on the first access category.
8. The method of claim 6,

   In order to request the first IMS service, the method further comprising the step of determining that IMS signaling for service attempt is necessary.
9. The method of claim 8,

   When the access category related to the first IMS service is the same as the first access category among a plurality of access categories related to the IMS service, the IMS layer of the terminal requests including information related to the IMS signaling The method further comprising the step of barring the transmission of the message.
10. The method of claim 8,

    The method further comprising transmitting a second request message including information on IMS signaling for the non-service attempt and information on an access category related to the first IMS service.
11. The method of claim 10,

    When the second request message is accepted, transmitting a third request message including information on IMS signaling for the service attempt and information on an access category related to the first IMS service.
12. The method of claim 1,

    The non-service attempt is an attempt for any one of initial registration, re-registration, or subscription refresh.
13. The method of claim 1,

    The IMS service comprises at least one of a multimedia telephony (MMTEL) voice related service, an MMTEL video related service, and a short message service (SMS) related service.
14. In the wireless communication device,

    At least one processor; And

    It includes at least one memory that stores instructions and is operably electrically connected to the at least one processor,

    The operation performed based on the instruction being executed by the at least one processor is:

    Determining that IMS signaling for a non-service attempt is required by an Internet protocol Multimedia Subsystem (IMS) layer of the wireless communication device,

    IMS signaling for the non-service attempt (attempt) is signaling that does not request IMS service; And

    The IMS layer of the wireless communication device sends a first request message including information on a first access category from among a plurality of access categories related to the IMS service, and a Non Access Stratum (NAS) layer of the wireless communication device. Wireless communication device comprising the step of transmitting to.
15. The method of claim 14,

    The wireless communication device is an autonomous driving device that communicates with at least one of a mobile terminal, a network, and an autonomous driving vehicle other than the wireless communication device.
16. As an apparatus in mobile communication,

    At least one processor; And

    It includes at least one memory that stores instructions and is operably electrically connected to the at least one processor,

    The operation performed based on the instruction being executed by the at least one processor is:

    Determining that IMS (Internet protocol Multimedia Subsystem) signaling for non-service attempt is necessary,

    IMS signaling for the non-service attempt (attempt) is signaling that does not request IMS service; And

    And generating a first request message including information on a first access category from among a plurality of access categories related to the IMS service.
17. A non-volatile computer-readable storage medium storing instructions,

    The instructions, when executed by one or more processors, cause the one or more processors to:

    Determining that IMS (Internet protocol Multimedia Subsystem) signaling for non-service attempt is necessary,

    IMS signaling for the non-service attempt (attempt) is signaling that does not request IMS service; And

    A non-volatile computer-readable storage medium configured to perform the step of generating a first request message including information on a first access category among a plurality of access categories related to the IMS service.

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