WO2021029383A1 - Ue and communication control method - Google Patents

Abstract

In one embodiment of the present invention, if an established PDU session was a PDU session for a 5G VN group, if a PLMN change was carried out during start-up of a back-off timer received together with a 5G congestion management cause value and if the PLMN prior to the change was a home PLMN, the communication control method determines in the destination whether or not to permit transmission of an SM request message of a UE on the basis of whether or not there is an information element notified from the network; by making this determination, the method determines whether or not congestion management will also be continued in the destination PLMN if the established PDU session was a PDU session for a 5G VN group, if the PLMN change was carried out during application of congestion management and if the PLMN prior to the change was a home PLMN.

Description

UE and communication control method

This application relates to UE and communication control method. This application claims the benefit of priority to Japanese Patent Application No. 2019-147405, which is a Japanese patent application filed on August 9, 2019, and by referring to it, the content of the application is claimed. All are included in this application.

3GPP (3rd Generation Partnership Project), which is engaged in standardization activities for mobile communication systems in recent years, is studying SAE (System Architecture Evolution), which is the system architecture of LTE (Long Term Evolution). 3GPP is specifying EPS (Evolved Packet System) as a communication system that realizes all IP (Internet Protocol). The core network that makes up EPS is called EPC (Evolved Packet Core).

In recent years, 3GPP has also been studying the next-generation communication technology and system architecture of 5G (5th Generation) mobile communication systems, which are next-generation mobile communication systems. In particular, 5GS (5GS) is a system that realizes 5G mobile communication systems. 5G System) is being specified (see Non-Patent Document 1 and Non-Patent Document 2). 5GS extracts technical issues for connecting a wide variety of terminals to cellular networks and specifies solutions.

For example, in a virtual network (Virtual Network; VN) configured on a 5G mobile communication system, a LAN that realizes private communication in a 5G VN group, which is a group composed of a plurality of terminals (User Equipment; UE). The requirements include optimization and diversification of communication procedures to support type services (5G LAN-type Service), and optimization of system architecture in line with optimization and diversification of communication procedures.

In 5GS, in addition to the mechanism that provides the function equivalent to congestion management, control signal management based on reasons other than congestion management is being studied (Non-Patent Document 1, Non-Patent Document 2 and Non-Patent Document). 3).

However, when congestion management is applied, the UE that established the PDU session for the 5GVN group changes the PLMN, and the PLMN before the change is the home PLMN, the destination PLMN However, it is not clear whether congestion management will be continued.

The present invention has been made in view of such circumstances, and an object of the present invention is to realize a control signal management process based on the reason for congestion management at the time of system change when establishing a PDU session for a 5GVN group. It is to provide the mechanism and communication control method of.

The UE (User Equipment; terminal device) of the present invention includes a control unit and a transmission / reception unit, and the control unit starts a backoff timer associated with a DNN (Data Network Name), and the DNN is 5GVN (5GVN). In the case of a DNN associated with a Virtual Network) group, the backoff timer is applied to the first PLMN (Public Land Mobile Network) and the second PLMN, and the UE is registered in the first PLMN. The second PLMN is an equal PLMN.

The UE (User Equipment; terminal device) communication control method of the present invention includes a step of starting a backoff timer associated with a DNN (Data Network Name), and the DNN corresponds to a 5G VN (Virtual Network) group. In the case of the attached DNN, the backoff timer is applied to the first PLMN (Public Land Mobile Network) and the second PLMN, and the first PLMN is the PLMN in which the UE is registered, and the said The second PLMN is characterized in that it is an equal PLMN.

According to one aspect of the present invention, the terminal device constituting 5GS and the device in the core network perform management processing such as congestion management for each terminal device-driven network slice and / or DNN for different systems. It is characterized by doing.

It is a figure which shows the outline of the mobile communication system. It is a figure which shows an example of the configuration of an access network in a mobile communication system. It is a figure which shows an example such as the configuration of the core network_A in a mobile communication system. It is a figure which shows an example of the configuration of the core network_B in the mobile communication system. It is a figure which shows the device configuration of UE. It is a figure which shows the apparatus configuration of an eNB / NR node. It is a figure which shows the apparatus configuration of MME / AMF. It is a figure which shows the apparatus configuration of SMF / PGW / UPF. It is a figure which shows the initial procedure. It is a figure which shows the registration procedure. It is a figure which shows the PDU session establishment procedure. It is a figure which shows the session management procedure led by a network.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. In this embodiment, as an example, an embodiment of a mobile communication system to which the present invention is applied will be described.

[1. System overview]
The outline of the mobile communication system in this embodiment will be described with reference to FIGS. 1, 2, 3, and 4. FIG. 2 is a diagram showing details of an access network among the mobile communication systems of FIG. FIG. 3 is a diagram showing details of the core network_A90 mainly in the mobile communication system of FIG. FIG. 4 is a diagram showing details of the core network_B190 mainly in the mobile communication system of FIG. As shown in FIG. 1, the mobile communication system 1 in the present embodiment includes a terminal device (also referred to as a user device or mobile terminal device) UE (User Equipment) _A10, an access network (AN; Access Network) _A, and an access network _B. , Core Network (CN) _A90, Core Network _B190, Packet Data Network (PDN) _A6, and Data Network (DN) _A5. The combination of access network_A and core network_A90 may be called EPS (Evolved Packet System; 4G mobile communication system), and the combination of access network_B, core network_B190 and UE_A10 is 5GS (5G System). It may be referred to as (5G mobile communication system), and the configuration of 5GS and EPS is not limited to these. For simplification, core network_A90, core network B, or a combination thereof may also be referred to as a core network, and access network_A, access network_B, or a combination thereof may also be referred to as an access network or a wireless access network. Sometimes DN_A5, PDN_A6 or a combination thereof may also be referred to as DN.

Here, UE_A10 can connect to network services via 3GPP access (also referred to as 3GPP access or 3GPP access network) and / or non-3GPP access (also referred to as non-3GPP access or non-3GPP access network). It may be a device. In addition, UE_A10 may be provided with UICC (Universal Integrated Circuit Card) or eUICC (Embedded UICC). Further, UE_A10 may be a terminal device capable of wireless connection, or may be an ME (Mobile Equipment), MS (Mobile Station), CIoT (Cellular Internet of Things) terminal (CIoT UE), or the like.

Also, UE_A10 can be connected to the access network and / or the core network. UE_A10 can also connect to DN_A and / or PDN_A via the access network and / or core network. UE_A10 sends and receives (communicate) user data with DN_A and / or PDN_A using a PDU (Protocol Data Unit or Packet Data Unit) session and / or PDN (Packet Data Network) connection (also called PDN connection). ). Furthermore, the communication of user data is not limited to IP (Internet Protocol) communication (IPv4 or IPv6), for example, EPS may be non-IP communication, and 5GS may be Ethernet (registered trademark) communication or Unstructured communication. There may be.

Here, IP communication is data communication using IP, and is data communication realized by sending and receiving an IP packet to which an IP header is added. The payload portion constituting the IP packet may include user data sent and received by UE_A10. Further, non-IP communication is data communication that does not use IP, and is data communication that is realized by sending and receiving data to which an IP header is not added. For example, non-IP communication may be data communication realized by sending and receiving application data to which an IP address is not assigned, or UE_A10 may be provided with another header such as a Mac header or an Ethernet (registered trademark) frame header. You may send and receive user data to be sent and received.

A PDU session is a connectivity established between UE_A10 and DN_A5 to provide a PDU connection service. More specifically, the PDU session may be the connectivity established between UE_A10 and the external gateway. Here, the external gateway may be UPF, PGW (Packet Data Network Gateway), or the like. Further, the PDU session may be a communication path established for transmitting / receiving user data between UE_A10 and the core network and / or DN, or may be a communication path for transmitting / receiving PDU. Further, the PDU session may be a session established between UE_A10 and the core network and / or DN, and is a logical configuration consisting of one or more bearers or other transfer paths between each device in the mobile communication system 1. Communication path may be used. More specifically, the PDU session may be a connection established by UE_A10 between the core network_B190 and / or an external gateway, or may be a connection established between UE_A10 and the UPF. The PDU session may also be connectivity and / or connection between UE_A10 and UPF_A235 via NR node_A122. In addition, the PDU session may be identified by a PDU session ID and / or an EPS bearer ID.

Note that UE_A10 can send and receive user data using a device such as an application server located in DN_A5 and a PDU session. In other words, the PDU session can transfer user data transmitted and received between UE_A10 and a device such as an application server arranged in DN_A5. In addition, each device (UE_A10, device in the access network, and / or device in the core network, and / or device in the data network) manages one or more identifications associated with each PDU session. You may. These identification information includes APN (Access Point Name), TFT (Traffic Flow Template), session type, application identification information, DN_A5 identification information, NSI (Network Slice Instance) identification information, and DCN (Dedicated Core Network). ) At least one of the identification information and the access network identification information may be included, and other information may be further included. Further, when a plurality of PDU sessions are established, the identification information associated with the PDU session may have the same content or different contents. Further, the NSI identification information is information that identifies NSI, and may be NSI ID or Slice Instance ID below.

As the access network_A and access network_B, as shown in Fig. 2, UTRAN (Universal Terrestrial Radio Access Network) _A20, E-UTRAN (Evolved Universal Terrestrial Radio Access Network) _A80, NG-RAN (5G-) It may be any of RAN) _A120. Hereinafter, UTRAN_A20 and / or E-UTRAN_A80 and / or NG-RAN_A120 are referred to as 3GPP access or 3GPP access network, and wireless LAN access network and non-3GPP AN are referred to as non-3GPP access or non-3GPP access network. Sometimes referred to. Each radio access network includes a device (for example, a base station device or an access point) to which the UE_A10 actually connects.

For example, E-UTRAN_A80 is an LTE access network and is configured to include one or more eNB_A45. eNB_A45 is a radio base station to which UE_A10 is connected by E-UTRA (Evolved Universal Terrestrial Radio Access). Further, when there are a plurality of eNBs in E-UTRAN_A80, each eNB may be connected to each other.

In addition, NG-RAN_A120 is a 5G access network, which may be (R) AN shown in FIG. 4, and includes one or more NR nodes (New Radio Access Technology node) _A122 and / or ng-eNB. It is composed. Note that NR node_A122 is a radio base station to which UE_A10 is connected by 5G radio access (5G Radio Access), and is also referred to as gNB. The ng-eNB may be an eNB (E-UTRA) that constitutes a 5G access network, may be connected to the core network_B190 via NR node_A, or may be directly connected to the core network_B190. You may be. Further, when there are a plurality of NR node_A122 and / or ng-eNB in NG-RAN_A120, each NR node_A122 and / or ng-eNB may be connected to each other.

Note that NG-RAN_A120 may be an access network composed of E-UTRA and / or 5G Radio Access. In other words, NG-RAN_A120 may contain eNB_A45, NR node_A122, or both. In this case, eNB_A45 and NR node_A122 may be similar devices. Therefore, NR node_A122 can be replaced with eNB_A45.

UTRAN_A20 is an access network for 3G mobile communication systems, and is composed of RNC (Radio Network Controller) _A24 and NB (Node B) _A22. NB_A22 is a radio base station to which UE_A10 is connected by UTRA (Universal Terrestrial Radio Access), and UTRAN_A20 may be configured to include one or more radio base stations. Further, RNC_A24 is a control unit that connects the core network_A90 and NB_A22, and UTRAN_A20 may be configured to include one or more RNCs. Also, RNC_A24 may be connected to one or more NB_A22s.

In this specification, the fact that UE_A10 is connected to each radio access network means that it is connected to a base station device, an access point, or the like included in each radio access network, and data, signals, etc. to be transmitted and received. It also means that it goes through a base station device or an access point. The control message sent and received between UE_A10 and the core network_B190 may be the same control message regardless of the type of access network. Therefore, sending and receiving messages between UE_A10 and core network_B190 via NR node_A122 may be the same as sending and receiving messages between UE_A10 and core network_B190 via eNB_A45.

Furthermore, the access network is a wireless network connected to UE_A10 and / or the core network. The access network may be a 3GPP access network or a non-3GPP access network. The 3GPP access network may be UTRAN_A20, E-UTRAN_A80, NG-RAN (Radio Access Network) _A120, and the non-3GPP access network may be a wireless LAN access point (WLAN AN). In addition, UE_A10 may be connected to the access network in order to connect to the core network, or may be connected to the core network via the access network.

Further, DN_A5 and PDN_A6 are data networks (Data Networks) that provide communication services to UE_A10, and may be configured as a packet data service network or may be configured for each service. Further, DN_A5 may include a connected communication terminal. Therefore, connecting to DN_A5 may be connecting to a communication terminal or server device arranged in DN_A5. Further, sending and receiving user data to and from DN_A5 may be sending and receiving user data to and from a communication terminal or server device arranged in DN_A5. Further, although DN_A5 is outside the core network in FIG. 1, it may be inside the core network.

Further, the core network_A90 and / or the core network_B190 may be configured as devices in one or more core networks. Here, the device in the core network may be a device that executes a part or all of the processing or function of each device included in the core network_A90 and / or the core network_B190. The device in the core network may be referred to as a core network device.

Furthermore, the core network is an IP mobile communication network operated by a mobile network operator (MNO; Mobile Network Operator) connected to an access network and / or DN. The core network may be a core network for a mobile communication operator that operates and manages the mobile communication system 1, or a virtual mobile communication operator such as MVNO (Mobile Virtual Network Operator) or MVNE (Mobile Virtual Network Enabler) or a virtual network operator. It may be a core network for mobile communication service providers. The core network_A90 may be an EPC (Evolved Packet Core) that constitutes an EPS (Evolved Packet System), and the core network_B190 may be a 5GC (5G Core Network) that constitutes a 5GS. Further, the core network_B190 may be the core network of the system that provides the 5G communication service. Conversely, the EPC may be the core network_A90 and the 5GC may be the core network_B190. The core network_A90 and / or the core network_B190 is not limited to this, and may be a network for providing a mobile communication service.

Next, the core network_A90 will be explained. Core network _A90 includes HSS (Home Subscriber Server) _A50, AAA (Authentication Authorization Accounting), PCRF (Policy and Charging Rules Function), PGW_A30, ePDG, SGW_A35, MME (Mobility Management Entity) _A40, SGSN (Serving GPRS Support). Node), SCEF, at least one may be included. And these may be configured as NF (Network Function). NF may refer to a processing function configured in the network. In addition, the core network_A90 can be connected to a plurality of radio access networks (UTRAN_A20, E-UTRAN_A80).

For simplification, FIG. 3 shows only HSS (HSS_A50), PGW (PGW_A30), SGW (SGW_A35) and MME (MME_A40), but other devices and / or NFs. Does not mean that is not included. For simplification, UE_A10 is also referred to as UE, HSS_A50 is referred to as HSS, PGW_A30 is referred to as PGW, SGW_A35 is referred to as SGW, MME_A40 is referred to as MME, and DN_A5 and / or PDN_A6 is also referred to as DN or PDN.

The following is a brief description of each device included in the core network_A90.

PGW_A30 is a relay device that is connected to DN, SGW_A35, ePDG, WLAN ANa70, PCRF, and AAA, and transfers user data as a gateway between DN (DN_A5 and / or PDN_A6) and core network_A90. The PGW_A30 may be a gateway for IP communication and / or non-IP communication. Further, PGW_A30 may have a function of transferring IP communication, and may have a function of converting non-IP communication and IP communication. A plurality of such gateways may be arranged in the core network_A90. Further, the plurality of gateways to be arranged may be a gateway connecting the core network_A90 and a single DN.

Note that the U-Plane (User Plane; UP) may be a communication path for transmitting and receiving user data, and may be composed of a plurality of bearers. Further, the C-Plane (Control Plane; CP) may be a communication path for transmitting and receiving a control message, and may be composed of a plurality of bearers.

Furthermore, PGW_A30 may be connected to SGW and DN and UPF (User plane function) and / or SMF (Session Management Function), or may be connected to UE_A10 via U-Plane. In addition, PGW_A30 may be configured with UPF_A235 and / or SMF_A230.

SGW_A35 is connected to PGW_A30, MME_A40, E-UTRAN_A80, SGSN and UTRAN_A20, and is a relay that transfers user data as a gateway to the core network_A90 and 3GPP access networks (UTRAN_A20, GERAN, E-UTRAN_A80). It is a device.

MME_A40 is a control device that is connected to SGW_A35, an access network, HSS_A50, and SCEF, and performs location information management including mobility management of UE_A10 and access control via the access network. Further, the MME_A40 may include a function as a session management device that manages the sessions established by the UE_A10. Further, a plurality of such control devices may be arranged in the core network_A90, and for example, a position management device different from the MME_A40 may be configured. A location management device different from the MME_A40 may be connected to the SGW_A35, the access network, the SCEF, and the HSS_A50, similar to the MME_A40. Furthermore, MME_A40 may be connected to AMF (Access and Mobility Management Function).

Also, if multiple MMEs are included in the core network_A90, the MMEs may be connected to each other. As a result, the context of UE_A10 may be transmitted and received between MMEs. In this way, the MME_A40 is a management device that transmits and receives control information related to mobility management and session management to and from the UE_A10, in other words, it may be a control plane (Control Plane; C-Plane; CP) control device.

Further, although MME_A40 has been described as an example of being included in core network_A90, MME_A40 may be one or more core networks or a management device composed of DCN or NSI, or one or more core networks or. It may be a management device connected to a DCN or NSI. Here, the plurality of DCNs or NSIs may be operated by a single telecommunications carrier or may be operated by different telecommunications carriers.

Further, MME_A40 may be a relay device that transfers user data as a gateway between the core network_A90 and the access network. The user data transmitted / received using MME_A40 as a gateway may be small data.

Furthermore, MME_A40 may be an NF that plays a role of mobility management such as UE_A10, or an NF that manages one or more NSIs. In addition, MME_A40 may be an NF that plays one or more of these roles. The NF may be one or more devices arranged in the core network_A90, and may also be a CP function for control information and / or a control message (hereinafter, CPF (Control Plane Function) or Control Plane Network Function). It may be a shared CP function shared between multiple network slices.

Here, NF is a processing function configured in the network. That is, the NF may be a functional device such as MME, SGW, PGW, CPF, AMF, SMF, UPF, or function / capability information such as MM (Mobility Management) or SM (Session Management). Further, the NF may be a functional device for realizing a single function, or may be a functional device for realizing a plurality of functions. For example, an NF for realizing the MM function and an NF for realizing the SM function may exist separately, or there is an NF for realizing both the MM function and the SM function. You may.

HSS_A50 is a management node that is connected to MME_A40, AAA, and SCEF and manages subscriber information. The subscriber information of HSS_A50 is referred to when, for example, access control of MME_A40 is performed. Further, the HSS_A50 may be connected to a position management device different from that of the MME_A40. For example, HSS_A50 may be connected to CPF_A140.

Further, HSS_A50 and UDM (Unified Data Management) _A245 may be configured as different devices and / or NFs, or may be configured as the same device and / or NFs.

AAA is connected to PGW30, HSS_A50, PCRF, and WLAN ANa70, and controls access to UE_A10, which is connected via WLAN ANa70.

PCRF is connected to PGW_A30, WLAN ANa75, AAA, DN_A5 and / or PDN_A6, and performs QoS management for data delivery. For example, it manages the QoS of the communication path between UE_A10 and DN_A5 and / or PDN_A6. Further, the PCRF may be a device that creates and / or manages PCC (Policy and Charging Control) rules and / or routing rules that each device uses when transmitting and receiving user data.

The PCRF may also be a PCF that creates and / or manages policies. More specifically, the PCRF may be connected to UPF_A235.

The ePDG is connected to PGW30 and WLAN ANb75, and delivers user data as a gateway between core network _A90 and WLAN ANb75.

The SGSN is connected to UTRAN_A20, GERAN and SGW_A35, and is a control device for position management between the 3G / 2G access network (UTRAN / GERAN) and the LTE (4G) access network (E-UTRAN). Is. In addition, the SGSN has a PGW and SGW selection function, a UE_A10 time zone management function, and an MME_A40 selection function during handover to E-UTRAN.

SCEF is a relay device that is connected to DN_A5 and / or PDN_A6, MME_A40 and HSS_A50, and transfers user data as a gateway connecting DN_A5 and / or PDN_A6 and core network_A90. SCEF may be a gateway for non-IP communication. In addition, SCEF may have the ability to convert between non-IP communication and IP communication. In addition, a plurality of such gateways may be arranged in the core network_A90. In addition, multiple gateways connecting the core network_A90 with a single DN_A5 and / or PDN_A6 and / or DN may also be deployed. The SCEF may be configured outside the core network or inside the core network.

Next, the core network_B190 will be explained. The core network _B190 includes AUFF (Authentication Server Function), AMF (Access and Mobility Management Function) _A240, UDSF (Unstructured Data Storage Function), NEF (Network Exposure Function), NRF (Network Repository Function), PCF (Policy Control). Function), SMF (Session Management Function) _A230, UDM (Unified Data Management), UPF (User Plane Function) _A235, AF (Application Function), N3IWF (Non-3GPP InterWorking Function) may be included. .. And these may be configured as NF (Network Function). NF may refer to a processing function configured in the network.

For simplicity, FIG. 4 shows only AMF (AMF_A240), SMF (SMF_A230), and UPF (UPF_A235), but other than these (devices and / or NF (Network)). It does not mean that Function)) is not included. For simplicity, UE_A10 is also referred to as UE, AMF_A240 is referred to as AMF, SMF_A230 is referred to as SMF, UPF_A235 is referred to as UPF, and DN_A5 is also referred to as DN.

In addition, Fig. 4 shows the N1 interface (hereinafter, also referred to as reference point), N2 interface, N3 interface, N4 interface, N6 interface, N9 interface, and N11 interface. Here, the N1 interface is the interface between the UE and AMF, the N2 interface is the interface between (R) AN (access network) and AMF, and the N3 interface is (R) AN (access network). The interface between UPF, the N4 interface is the interface between SMF and UPF, the N6 interface is the interface between UPF and DN, and the N9 interface is the interface between UPF and UPF. , N11 interface is the interface between AMF and SMF. Communication can be performed between the devices by using these interfaces. Here, (R) AN is also referred to as NG RAN below.

The following is a brief description of each device included in the core network_B190.

First, AMF_A240 is connected to other AMF, SMF (SMF_A230), access network (that is, UTRAN_A20 and E-UTRAN_A80 and NG-RAN_A120), UDM, AUSF, PCF. AMF_A240 is used for registration management (Registration management), connection management (Connection management), reachability management (Reachability management), mobility management such as UE_A10 (Mobility management), and transfer of SM (Session Management) messages between UE and SMF. , Access Authentication, Access Authorization, Security Anchor Function (SEA; Security Anchor Function), Security Context Management (SCM), N2 Interface Support for N3IWF, NAS Signals with UE via N3IWF It may play a role of support of transmission / reception, authentication of UE connected via N3IWF, management of RM state (Registration Management states), management of CM state (Connection Management states), and the like. Further, one or more AMF_A240s may be arranged in the core network_B190. In addition, AMF_A240 may be an NF that manages one or more NSIs (Network Slice Instances). Further, AMF_A240 may be a shared CP function (CCNF; Common CPNF (Control Plane Network Function)) shared among a plurality of NSIs.

In addition, the RM state includes a non-registered state (RM-DEREGISTERED state) and a registered state (RM-REGISTERED state). In the RM-DEREGISTERED state, the UE is not registered in the network, so the UE context in AMF does not have valid location information or routing information for that UE, so AMF cannot reach the UE. is there. Also, in the RM-REGISTERED state, the UE is registered in the network, so the UE can receive services that require registration with the network.

In addition, there are two types of CM states: a non-connected state (CM-IDLE state) and a connected state (CM-CONNECTED state). In the CM-IDLE state, the UE is in the RM-REGISTERED state, but does not have a NAS signaling connection established with the AMF via the N1 interface. Also, in the CM-IDLE state, the UE does not have an N2 interface connection (N2 connection) and an N3 interface connection (N3 connection). On the other hand, in the CM-CONNECTED state, it has a NAS signaling connection established with the AMF via the N1 interface. Further, in the CM-CONNECTED state, the UE may have an N2 interface connection (N2 connection) and / or an N3 interface connection (N3 connection).

In addition, SMF_A230 has session management (Session Management; SM; session management) functions such as PDU sessions, IP address allocation to UEs and its management functions, UPF selection and control functions, and traffic to appropriate destinations. UPF setting function for routing, function to notify that downlink data has arrived (Downlink Data Notification), AN-specific (AN) transmitted to AN via AMF via N2 interface It may have a function of providing SM information (for each session), a function of determining an SSC mode (Session and Service Continuity mode) for a session, a roaming function, and the like. Further, SMF_A230 may be connected to AMF_A240, UPF_A235, UDM, and PCF.

Also, UPF_A235 is connected to DN_A5, SMF_A230, other UPFs, and access networks (that is, UTRAN_A20, E-UTRAN_A80, and NG-RAN_A120). UPF_A235 is an anchor for intra-RAT mobility or inter-RAT mobility, packet routing & forwarding, UL CL (Uplink Classifier) function that supports routing of multiple traffic flows to one DN, Routing point function that supports multi-homed PDU session, QoS processing for userplane, verification of uplink traffic, buffering of downlink packets, downlink data notification (Downlink Data Notification) It may play a role such as a trigger function. Further, UPF_A235 may be a relay device that transfers user data as a gateway between DN_A5 and core network_B190. UPF_A235 may be a gateway for IP communication and / or non-IP communication. Further, UPF_A235 may have a function of transferring IP communication, and may have a function of converting non-IP communication and IP communication. Further, the plurality of gateways to be arranged may be a gateway connecting the core network_B190 and a single DN. The UPF_A235 may have connectivity with other NFs, or may be connected to each device via other NFs.

Note that UPF_C239 (also referred to as branching point or uplink classifier), which is a UPF different from UPF_A235, may exist as a device or NF between UPF_A235 and the access network. If UPF_C239 is present, the PDU session between UE_A10 and DN_A5 will be established via the access network, UPF_C239, UPF_A235.

Also, AUSF is connected to UDM and AMF_A240. AUSF acts as an authentication server.

UDSF provides a function for all NFs to store and retrieve information as unstructured data.

NEF provides a means to safely provide the services and capabilities provided by the 3GPP network. Information received from other NFs is saved as structured data.

When NRF receives an NF discovery request (NF Discovery Request) from an NF instance, it provides information on the discovered NF instance to that NF, and information on available NF instances and services supported by that instance. Or hold.

PCF is connected to SMF (SMF_A230), AF, AMF_A240. Provide policy rules, etc.

UDM is connected to AMF_A240, SMF (SMF_A230), AUSF, PCF. UDM includes UDM FE (application front end) and UDR (User Data Repository). UDM FE processes authentication information (credentials), location management (location management), subscription management (subscription management), and the like. UDR stores the data required to be provided by UDM FE and the policy profiles required by PCF.

AF is connected to PCF. AF influences traffic routing and participates in policy control.

N3IWF establishes an IPsec tunnel with the UE, relays NAS (N1) signaling between the UE and AMF, processes N2 signaling transmitted from SMF and relayed by AMF, and establishes IPsec Security Association (IPsec SA). , Provides functions such as relaying userplane packets between UE and UPF, and AMF selection.

In addition, S1 mode is a UE mode that allows sending and receiving of messages using the S1 interface. The S1 interface may be composed of an S1-MME interface, an S1-U interface, and an X2 interface that connects radio base stations.

The UE in S1 mode can, for example, access the EPC via eNB that provides the E-UTRA function and access the EPC via en-gNB that provides the NR function.

The S1 mode is used for access to the EPC via eNB that provides the E-UTRA function and access to the EPC via en-gNB that provides the NR function, but each may be configured as a different mode. ..

In addition, N1 mode is a UE mode in which the UE can access 5GC via a 5G access network. Further, the N1 mode may be a UE mode capable of transmitting and receiving messages using the N1 interface. The N1 interface may be composed of an N1 interface and an Xn interface that connects radio base stations.

The N1 mode UE can, for example, access 5GC via ng-eNB that provides the E-UTRA function and access 5GC via gNB that provides the NR function.

The access to 5GC via ng-eNB that provides the E-UTRA function and the access to 5GC via gNB that provides the NR function are set to N1 mode, but they may be configured as different modes individually. ..

[1.2. Configuration of each device]
Hereinafter, the configuration of each device will be described. It should be noted that some or all of the following devices and some or all of the functions of each part of each device may operate on physical hardware, or logical hardware virtually configured on general-purpose hardware. It may be the one that operates on the hardware.

[1.2.1. UE Configuration]
First, an example of the device configuration of UE_A10 is shown in FIG. As shown in FIG. 5, UE_A10 is composed of a control unit_A500, a transmission / reception unit_A520, and a storage unit_A540. The transmission / reception unit_A520 and the storage unit_A540 are connected to the control unit_A500 via a bus. An external antenna 410 is connected to the transmitter / receiver _A520.

The control unit_A500 is a functional unit for controlling the entire UE_A10, and realizes various processes of the entire UE_A10 by reading and executing various information and programs stored in the storage unit_A540.

The transmitter / receiver_A520 is a functional unit for UE_A10 to connect to the base stations (UTRAN_A20 and E-UTRAN_A80 and NG-RAN_A120) and / or wireless LAN access point (WLAN AN) in the access network and connect to the access network. is there. In other words, the UE_A10 can be connected to a base station and / or an access point in the access network via an external antenna 410 connected to the transmitter / receiver_A520. Specifically, the UE_A10 transmits / receives user data and / or control information to / from a base station and / or an access point in the access network via an external antenna 410 connected to the transmission / reception unit_A520. Can be done.

The storage unit_A540 is a functional unit that stores programs and data required for each operation of UE_A10, and is composed of, for example, a semiconductor memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), and the like. The storage unit_A540 stores identification information, control information, flags, parameters, rules, policies, and the like included in control messages sent and received in a communication procedure described later.

[1.2.2. eNB / NR node]
Next, a device configuration example of eNB_A45 and NR node_A122 is shown in FIG. As shown in FIG. 6, the eNB_A45 and the NR node_A122 are composed of a control unit_B600, a network connection unit_B620, a transmission / reception unit_B630, and a storage unit_B640. The network connection unit_B620, the transmission / reception unit_B630, and the storage unit_B640 are connected to the control unit_B600 via a bus. An external antenna 510 is connected to the transmitter / receiver _B630.

The control unit_B600 is a functional unit for controlling the entire eNB_A45 and NR node_A122, and by reading and executing various information and programs stored in the storage unit_B640, the entire eNB_A45 and NR node_A122 Realize various processes.

The network connection part_B620 is a functional part for eNB_A45 and NR node_A122 to connect with AMF_A240 and UPF_A235 in the core network. In other words, eNB_A45 and NR node_A122 can be connected to AMF_A240 and UPF_A235 in the core network via the network connection part_B620. Specifically, eNB_A45 and NR node_A122 can send and receive user data and / or control information to and from AMF_A240 and / or UPF_A235 via the network connection unit_B620.

The transmission / reception unit_B630 is a functional unit for eNB_A45 and NR node_A122 to connect to UE_A10. In other words, the eNB_A45 and NR node_A122 can send and receive user data and / or control information to and from the UE_A10 via the transmission / reception unit_B630.

The storage unit_B640 is a functional unit that stores programs and data required for each operation of eNB_A45 and NR node_A122. The storage unit_B640 is composed of, for example, a semiconductor memory, an HDD, an SSD, or the like. The storage unit_B640 stores identification information, control information, flags, parameters, and the like included in the control messages transmitted and received in the communication procedure described later. The storage unit_B640 may store this information as a context for each UE_A10.

[1.2.3. MME / AMF configuration]
Next, an example of the device configuration of MME_A40 or AMF_A240 is shown in FIG. As shown in FIG. 7, the MME_A40 or AMF_A240 is composed of a control unit_C700, a network connection unit_C720, and a storage unit_C740. The network connection unit_C720 and the storage unit_C740 are connected to the control unit_C700 via a bus. In addition, the storage unit_C740 stores the context 642.

The control unit_C700 is a functional unit for controlling the entire MME_A40 or AMF_A240, and realizes various processes of the entire AMF_A240 by reading and executing various information and programs stored in the storage unit_C740. To do.

The network connection part_C720 is MME_A40 or AMF_A240, other MME_A40, AMF_240, SMF_A230, base stations in the access network (UTRAN_A20 and E-UTRAN_A80 and NG-RAN_A120) and / or wireless LAN access point (WLAN AN), UDM. , AUSF, a functional part for connecting to PCF. In other words, the MME_A40 or AMF_A240 sends and receives user data and / or control information to and from the base station and / or access point, UDM, AUSF, PCF in the access network via the network connection_C720. Can be done.

The storage unit_C740 is a functional unit that stores programs and data required for each operation of MME_A40 or AMF_A240. The storage unit_C740 is composed of, for example, a semiconductor memory, an HDD, an SSD, or the like. The storage unit_C740 stores identification information, control information, flags, parameters, and the like included in the control messages transmitted and received in the communication procedure described later. The context 642 stored in the storage unit_C740 may include a context stored for each UE, a context stored for each PDU session, and a context stored for each bearer. The contexts stored for each UE include IMSI, MSISDN, MMState, GUTI, MEIdentity, UERadioAccessCapability, UENetworkCapability, MSNetworkCapability, AccessRestriction, MMEF-TEID, SGWF-TEID, eNBAddress. , MMEUES1APID, eNBUES1APID, NRnodeAddress, NRnodeID, WAGAddress, WAGID may be included. Further, the context stored for each PDU session may include APN in Use, Assigned Session Type, IP Address (es), PGW F-TEID, SCEF ID, and Default bearer. In addition, the contexts stored for each bearer are EPS Bearer ID, TI, TFT, SGW F-TEID, PGW F-TEID, MME F-TEID, eNB Address, NR node Address, WAG Address, eNB ID, NR node. ID and WAG ID may be included.

Also, there may be an N26 interface as an interface between the core networks between MME_A40 in EPC and AMF_A240 in 5GC. Here, the N26 interface is an optional interface for inter-system interworking between 5GS and EPS.

The N26 interface is an interface that enables transmission and reception for exchanging information on the mobility management status such as UE_A10 and the SM (Session Management) status between the UE and SMF between 5GS and EPS. It may be there. In addition, the N26 interface may be the interface required to enable seamless session continuity for inter-system change from N1 mode to S1.

[1.2.4. SMF configuration]
Next, an example of the device configuration of SMF_A230 is shown in FIG. As shown in FIG. 8, the SMF_A230 is composed of a control unit_D800, a network connection unit_D820, and a storage unit_D840, respectively. The network connection unit _D820 and the storage unit _D840 are connected to the control unit _D800 via a bus. In addition, the storage unit_D840 stores the context 742.

The control unit_D800 of SMF_A230 is a functional unit for controlling the entire SMF_A230, and realizes various processes of the entire SMF_A230 by reading and executing various information and programs stored in the storage unit_D840. To do.

Also, the network connection part_D820 of SMF_A230 is a functional part for SMF_A230 to connect with AMF_A240, UPF_A235, UDM, and PCF. In other words, the SMF_A230 can send and receive user data and / or control information to and from the AMF_A240, UPF_A235, UDM, and PCF via the network connection _D820.

In addition, the storage unit_D840 of SMF_A230 is a functional unit that stores programs and data required for each operation of SMF_A230. The storage unit_D840 of the SMF_A230 is composed of, for example, a semiconductor memory, an HDD, an SSD, or the like. The storage unit_D840 of SMF_A230 stores identification information, control information, flags, parameters, etc. included in control messages transmitted and received in the communication procedure described later. The context 742 stored in the storage unit_D840 of SMF_A230 includes a context stored for each UE, a context stored for each APN, a context stored for each PDU session, and a context stored for each bearer. There may be a context. The context stored for each UE may include IMSI, MEIdentity, MSISDN, and RATtype. The context stored for each APN may include APN in use. The context stored for each APN may be stored for each Data Network Identifier. The context stored for each PDU session may include AssignedSessionType, IPAddress (es), SGWF-TEID, PGWF-TEID, DefaultBearer. The context stored for each bearer may include EPS Bearer ID, TFT, SGW F-TEID, and PGW F-TEID.

[1.2.5. PGW / UPF configuration]
Next, an example of the device configuration of PGW_A30 or UPF_A235 is shown in FIG. As shown in FIG. 8, PGW_A30 or UPF_A235 is composed of a control unit_D800, a network connection unit_D820, and a storage unit_D840, respectively. The network connection unit _D820 and the storage unit _D840 are connected to the control unit _D800 via a bus. In addition, the storage unit_D840 stores the context 742.

The control unit_D800 of PGW_A30 or UPF_A235 is a functional unit for controlling the entire PGW_A30 or UPF_A235, and by reading and executing various information and programs stored in the storage unit_D840, PGW_A30 or UPF_A235 Realize various processing as a whole.

In addition, the network connection part_D820 of PGW_A30 or UPF_A235 connects PGW_A30 or UPF_A235 to DN (that is, DN_A5), SMF_A230, other UPF_A235, and access networks (that is, UTRAN_A20 and E-UTRAN_A80 and NG-RAN_A120). It is a functional part to do. In other words, UPF_A235 is between the DN (ie DN_A5), SMF_A230, other UPF_A235, and the access network (ie UTRAN_A20 and E-UTRAN_A80 and NG-RAN_A120) via the network connection_D820. User data and / or control information can be sent and received.

In addition, the storage unit_D840 of UPF_A235 is a functional unit that stores programs, data, etc. required for each operation of UPF_A235. The storage unit_D840 of UPF_A235 is composed of, for example, a semiconductor memory, an HDD, an SSD, or the like. The storage unit_D840 of UPF_A235 stores identification information, control information, flags, parameters, etc. included in control messages transmitted and received in the communication procedure described later. In addition, as the context 742 stored in the storage unit_D840 of UPF_A235, the context stored for each UE, the context stored for each APN, the context stored for each PDU session, and the context stored for each bearer are stored. There may be a context. The context stored for each UE may include IMSI, MEIdentity, MSISDN, and RATtype. The context stored for each APN may include APN in use. The context stored for each APN may be stored for each Data Network Identifier. The context stored for each PDU session may include AssignedSessionType, IPAddress (es), SGWF-TEID, PGWF-TEID, DefaultBearer. The context stored for each bearer may include EPS Bearer ID, TFT, SGW F-TEID, and PGW F-TEID.

[1.2.6. Information stored in the storage unit of each of the above devices]
Next, each information stored in the storage unit of each of the above devices will be described.

IMSI (International Mobile Subscriber Identity) is the permanent identification information of the subscriber (user), and is the identification information assigned to the user who uses the UE. The IMSI stored by UE_A10 and MME_A40 / CPF_A140 / AMF_A2400 and SGW_A35 may be equal to the IMSI stored by HSS_A50.

EMM State / MM State indicates the mobility management state of UE_A10 or MME_A40 / CPF_A140 / AMF_A240. For example, the EMM State / MM State may be an EMM-REGISTERED state (registered state) in which UE_A10 is registered in the network, and / or an EMM-DEREGISTERD state (unregistered state) in which UE_A10 is not registered in the network. Further, the EMM State / MM State may be an ECM-CONNECTED state in which the connection between UE_A10 and the core network is maintained, and / or an ECM-IDLE state in which the connection is released. The EMM State / MM State may be information that can distinguish between the state in which UE_A10 is registered in the EPC and the state in which it is registered in the NGC or 5GC.

GUTI (Globally Unique Temporary Identity) is a temporary identification information of UE_A10. GUTI is composed of MME_A40 / CPF_A140 / AMF_A240 identification information (GUMMEI (Globally Unique MME Identifier)) and UE_A10 identification information (M-TMSI (M-Temporary Mobile Subscriber Identity)) within the specific MME_A40 / CPF_A140 / AMF_A240. Will be done. MEIdentity is UE_A10 or ME ID, and may be, for example, IMEI (International Mobile Equipment Identity) or IMEISV (IMEI Software Version). MSISDN represents the basic telephone number of UE_A10. The MSISDN stored by MME_A40 / CPF_A140 / AMF_A240 may be the information indicated by the storage unit of HSS_A50. The GUTI may include information that identifies CPF_140.

MME F-TEID is information that identifies MME_A40 / CPF_A140 / AMF_A240. The MME F-TEID may include the IP address of MME_A40 / CPF_A140 / AMF_A240, the TEID (Tunnel Endpoint Identifier) of MME_A40 / CPF_A140 / AMF_A240, or both of them. May be good. Further, the IP address of MME_A40 / CPF_A140 / AMF_A240 and the TEID of MME_A40 / CPF_A140 / AMF_A240 may be stored independently. Further, the MME F-TEID may be identification information for user data or identification information for control information.

SGW F-TEID is information that identifies SGW_A35. The SGW F-TEID may include the IP address of SGW_A35, the TEID of SGW_A35, or both of them. Further, the IP address of SGW_A35 and the TEID of SGW_A35 may be stored independently. Further, the SGW F-TEID may be identification information for user data or identification information for control information.

PGW F-TEID is information that identifies PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235. The PGW F-TEID may include the IP address of PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235, the TEID of PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235, or both. Good. Further, the IP address of PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235 and the TEID of PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235 may be stored independently. Further, the PGW F-TEID may be identification information for user data or identification information for control information.

ENB F-TEID is information that identifies eNB_A45. The eNB F-TEID may include the IP address of eNB_A45, the TEID of eNB_A45, or both of them. Further, the IP address of eNB_A45 and the TEID of SGW_A35 may be stored independently. Further, the eNB F-TEID may be identification information for user data or identification information for control information.

In addition, APN may be identification information that identifies the core network and the external network such as DN. Furthermore, the APN can also be used as information for selecting a gateway such as PGW_A30 / UPGW_A130 / UPF_A235 that connects the core network A_90. The APN may be a DNN (Data Network Name). Therefore, APN may be expressed as DNN, and DNN may be expressed as APN.

Note that the APN may be identification information that identifies such a gateway, or identification information that identifies an external network such as a DN. When a plurality of gateways connecting the core network and the DN are arranged, there may be a plurality of gateways that can be selected by the APN. Furthermore, one gateway may be selected from a plurality of these gateways by another method using identification information other than APN.

UERadioAccessCapability is identification information indicating the wireless access capability of UE_A10. UENetworkCapability includes security algorithms and key derivation functions supported by UE_A10. MS Network Capability is information that includes one or more information required for SGSN_A42 for UE_A10 having GERAN_A25 and / or UTRAN_A20 functions. Access Restriction is registration information for access restrictions. eNB Address is the IP address of eNB_A45. The MMEUES1APID is information that identifies UE_A10 in MME_A40 / CPF_A140 / AMF_A240. The eNB UES1AP ID is information that identifies UE_A10 in eNB_A45.

APN in Use is a recently used APN. APN in Use may be a Data Network Identifier. This APN may consist of network identification information and default operator identification information. Further, APN in Use may be information that identifies the DN at which the PDU session is established.

Assigned Session Type is information indicating the type of PDU session. The Assigned Session Type may be the Assigned PDN Type. The type of PDU session can be IP or non-IP. In addition, if the type of PDU session is IP, it may further include information indicating the type of PDN assigned by the network. The AssignedSessionType may be IPv4, IPv6, or IPv4v6.

Unless otherwise specified, IP Address is the IP address assigned to the UE. The IP address may be an IPv4 address, an IPv6 address, an IPv6 prefix, or an interface ID. When AssignedSessionType indicates non-IP, it is not necessary to include the element of IPAddress.

DN ID is identification information that distinguishes the core network_B190 from an external network such as DN. Furthermore, the DN ID can also be used as information for selecting a gateway such as UPGW_A130 or PF_A235 that connects the core network_B190.

Note that the DN ID may be identification information that identifies such a gateway, or identification information that identifies an external network such as a DN. When a plurality of gateways connecting the core network_B190 and the DN are arranged, there may be a plurality of gateways that can be selected by the DN ID. Further, one gateway may be selected from the plurality of gateways by another method using identification information other than DNID.

Furthermore, the DN ID may be information equal to the APN or information different from the APN. If the DN ID and the APN are different information, each device may manage the information indicating the correspondence between the DN ID and the APN, or may carry out the procedure for inquiring the APN using the DN ID. Alternatively, the procedure for inquiring the DN ID using the APN may be carried out.

SCEFID is the IP address of SCEF_A46 used in the PDU session. The Default Bearer is information acquired and / or generated when the PDU session is established, and is EPS bearer identification information for identifying the default bearer associated with the PDU session.

EPS Bearer ID is the identification information of EPS bearer. Further, the EPS Bearer ID may be identification information for identifying SRB (Signalling Radio Bearer) and / or CRB (Control-plane Radio bearer), or may be identification information for identifying DRB (Data Radio Bearer). TI (Transaction Identifier) is identification information that identifies a bidirectional message flow (Transaction). The EPS Bearer ID may be EPS bearer identification information that identifies the dedicated bearer. Therefore, the identification information that identifies the EPS bearer different from the default bearer may be used. TFT shows all packet filters associated with EPS bearers. The TFT is information that identifies a part of the user data to be transmitted / received, and UE_A10 transmits / receives the user data identified by the TFT using the EPS bearer associated with the TFT. In other words, UE_A10 sends and receives user data identified by the TFT using the RB (Radio Bearer) associated with the TFT. Further, the TFT may associate user data such as application data to be transmitted / received with an appropriate transfer path, or may be identification information for identifying application data. In addition, UE_A10 may send and receive user data that cannot be identified by the TFT using the default bearer. UE_A10 may also store the TFT associated with the default bearer in advance.

Default Bearer is EPS bearer identification information that identifies the default bearer associated with the PDU session. The EPS bearer may be a logical communication path established between UE_A10 and PGW_A30 / UPGW_A130 / UPF_A235, or may be a communication path constituting a PDN connection / PDU session. Further, the EPS bearer may be a default bearer or a dedicated bearer. In addition, the EPS bearer may be configured to include an RB established between UE_A10 and a base station and / or access point in the access network. In addition, RBs and EPS bearers may have a one-to-one correspondence. Therefore, the RB identification information may be associated with the EPS bearer identification information on a one-to-one basis, or may be the same identification information. The RB may be SRB and / or CRB, or may be DRB. The Default Bearer may be information acquired by UE_A10 and / or SGW_A35 and / or PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235 from the core network when the PDU session is established. The default bearer is an EPS bearer that is first established in a PDN connection / PDU session, and is an EPS bearer that can be established only once in one PDN connection / PDU session. The default bearer may be an EPS bearer that can be used to communicate user data that is not associated with a TFT. A decadeted bearer is an EPS bearer that is established after the default bearer is established during a PDN connection / PDU session, and is an EPS bearer that can be established multiple times during a single PDN connection / PDU session. is there. A decadeted bearer is an EPS bearer that can be used to communicate user data associated with a TFT.

User Identity is information that identifies the subscriber. User Identity may be IMSI or MSISDN. Further, User Identity may be identification information other than IMSI and MSISDN. Serving Node Information is information that identifies MME_A40 / CPF_A140 / AMF_A240 used in the PDU session, and may be the IP address of MME_A40 / CPF_A140 / AMF_A240.

ENB Address is the IP address of eNB_A45. The eNB ID is information that identifies the UE in eNB_A45. MMEAddress is the IP address of MME_A40 / CPF_A140 / AMF_A240. The MME ID is information that identifies MME_A40 / CPF_A140 / AMF_A240. NR nodeAddress is the IP address of NR node_A122. The NR node ID is information that identifies the NR node_A122. WAGAddress is the IP address of WAG. WAG ID is information that identifies WAG.

Anchor or anchor point is a UPF that has a gateway function for DN and PDU sessions. The UPF serving as an anchor point may be a PDU session anchor or an anchor.

The SSC mode indicates the mode of service session continuity (Session and Service Continuity) supported by the system and / or each device in 5GC. More specifically, it may be a mode indicating the types of service session continuation supported by the PDU session established between UE_A10 and the anchor point). Here, the anchor point may be UPGW or UPF_A235. Note that SSC mode may be a mode indicating the type of service session continuation set for each PDU session. Further, the SSC mode may be composed of three modes, SSC mode 1, SSC mode 2, and SSC mode 3. The SSC mode is associated with the anchor point and cannot be changed while the PDU session is established.

Further, SSC mode 1 in the present embodiment is a service session continuation mode in which the same UPF is maintained as an anchor point regardless of the access technology such as RAT (Radio Access Technology) and cell used when UE_A10 connects to the network. Is. More specifically, SSC mode1 may be a mode that realizes the continuation of the service session without changing the anchor point used by the established PDU session even when the mobility of UE_A10 occurs.

Further, when SSC mode2 in the present embodiment includes an anchor point associated with one SSC mode2 in the PDU session, the service session continuation in which the PDU session is released first and then the PDU session is established continuously. The mode. More specifically, SSC mode2 is a mode in which when an anchor point relocation occurs, the PDU session is deleted once and then a new PDU session is established.

Furthermore, SSC mode2 is a service session continuation mode in which the same UPF is maintained as an anchor point only within the serving area of the UPF. More specifically, SSC mode2 may be a mode that realizes service session continuation without changing the UPF used by the established PDU session as long as UE_A10 is within the serving area of the UPF. Furthermore, SSC mode2 is a mode that realizes service session continuation by changing the UPF used by the established PDU session when the mobility of UE_A10 occurs, such as leaving the serving area of the UPF. Good.

Here, the TUPF serving area may be an area where one UPF can provide the service session continuation function, or a subset of the access network such as RAT and cell used when UE_A10 connects to the network. It may be. Further, the subset of the access network may be a network composed of one or more RATs and / or cells, or may be a TA.

Further, SSC mode 3 in the present embodiment is a service session continuation mode in which a PDU session can be established between a new anchor point and the UE for the same DN without releasing the PDU session between the UE and the anchor point. is there.

In addition, SSCmode3 will have a PDU session established between UE_A10 and the UPF, and / or a new PDU session via the new UPF for the same DN before disconnecting the communication path, and / Alternatively, it is a mode of service session continuation that allows the establishment of a communication path. Further, SSC mode 3 may be a service session continuation mode that allows UE_A10 to be multihoming.

And / or SSC mode 3 may be a mode in which the continuation of the service session using the UPF associated with a plurality of PDU sessions and / or the PDU session is permitted. In other words, in the case of SSC mode 3, each device may realize the service session continuation by using a plurality of PDU sessions, or may realize the service session continuation by using a plurality of TUPFs.

Here, if each device establishes a new PDU session and / or communication path, the selection of the new UPF may be carried out by the network, and the new UPF is the location where UE_A10 is connected to the network. It may be the most suitable UPF. In addition, if the UPF used by multiple PDU sessions and / or PDU sessions is enabled, UE_A10 will immediately address the newly established PDU session for application and / or flow communication. It may be carried out based on the completion of communication.

[1.3. Explanation of initial procedure]
Next, before explaining the detailed procedure of the initial procedure in the present embodiment, in order to avoid duplicate explanation, the terms specific to the present embodiment and the main identification information used for each procedure will be described in advance.

In the present embodiment, the network refers to at least a part of access network_A20 / 80, access network_B80 / 120, core network_A90, core network_B190, DN_A5, and PDN_A6. In addition, one or more devices included in at least a part of access network_A20 / 80, access network_B80 / 120, core network_A90, core network_B190, DN_A5, and PDN_A6 are referred to as a network or network device. You may call it. That is, the fact that the network executes the transmission / reception and / or procedure of the message means that the device (network device) in the network executes the transmission / reception and / or procedure of the message.

The session management (SM; Session Management) message (also referred to as NAS (Non-Access-Stratum) SM message or SM message) in the present embodiment is a procedure for SM (also referred to as session management procedure or SM procedure). It may be a NAS message used in the above, and may be a control message sent and received between UE_A10 and SMF_A230 via AMF_A240. Further, the SM message includes a PDU session establishment request message, a PDU session establishment acceptance message, a PDU session completion message, a PDU session rejection message, a PDU session change request message, a PDU session change acceptance message, a PDU session change rejection message, and the like. You may. In addition, the procedure for SM may include a PDU session establishment procedure, a PDU session change procedure, and the like.

Of the SM messages, the message sent by UE_A10 is expressed as an SM request message. Specifically, the PDU session establishment request message and the PDU session change request message are SM request messages.

The tracking area (also referred to as TA; Tracking Area) in the present embodiment is a range that can be represented by the position information of UE_A10 managed by the core network, and may be composed of, for example, one or more cells. Further, the TA may be a range in which a control message such as a paging message is broadcast, or a range in which UE_A10 can move without performing a handover procedure.

The TA list in this embodiment is a list including one or more TAs assigned to UE_A10 by the network. Note that UE_A10 may be able to move without executing the registration procedure while moving within one or more TAs included in the TA list. In other words, the TA list may be a group of information indicating areas where UE_A10 can move without performing the registration procedure.

In this embodiment, the network slice is a logical network that provides specific network capabilities and network characteristics. Hereinafter, the network slice is also referred to as a NW slice.

The NSI (Network Slice Instance) in this embodiment is an entity of a network slice (Network Slice) composed of one or more in the core network_B190. Further, the NSI in this embodiment may be composed of a virtual NF (Network Function) generated by using NST (Network Slice Template). Here, NST is a logical expression of one or more NFs (Network Functions) associated with a resource request for providing a required communication service or capability. In other words, the NSI may be an aggregate in the core network_B190 composed of a plurality of NFs. In addition, NSI may be a logical network configured to divide user data delivered by services or the like. At least one or more NFs may be configured in the network slice. The NF configured in the network slice may or may not be a device shared with other network slices. UE_A10 and / or devices in the network include NSSAI and / or S-NSSAI and / or UE usage type and / or one or more network slice type IDs and / or one or more NS IDs, etc. It can be assigned to one or more network slices based on registration information and / or APN.

S-NSSAI in this embodiment is an abbreviation for Single Network Slice Selection Assistance information, and is information for identifying a network slice. S-NSSAI may be composed of SST (Slice / Service type) and SD (Slice Differentiator). S-NSSAI may be composed of SST only or both SST and SD. Here, SST is information indicating the operation of the network slice expected in terms of function and service. Further, SD may be information that complements SST when selecting one NSI from a plurality of NSIs represented by SST. S-NSSAI may be information specific to each PLMN (Public Land Mobile Network), standard information shared among PLMNs, or information specific to a telecommunications carrier that differs for each PLMN. There may be.

More specifically, SST and / or SD may be standard information (Standard Value) shared among PLMNs, or information specific to a telecommunications carrier (Non Standard Value) that differs for each PLMN. You may.

In addition, the network may store one or more S-NSSAI in the registration information of UE_A10 as the default S-NSSAI.

NSSAI (Single Network Slice Selection Assistance information) in this embodiment is a collection of S-NSSAI. Each S-NSSAI contained in NSSAI is information that assists the access network or core network in selecting NSI. UE_A10 may store NSSAI permitted from the network for each PLMN. Also, NSSAI may be the information used to select AMF_A240.

The operator A network in this embodiment is a network operated by network operator A (operator A). Here, for example, the operator A may develop a NW slice common to the operator B described later.

The operator B network in this embodiment is a network operated by network operator B (operator B). Here, for example, the operator B may develop a NW slice common to the operator A.

The first NW slice in this embodiment is the NW slice to which the established PDU session belongs when the UE connects to a specific DN. For example, the first NW slice may be a NW slice managed in the operator A network or a NW slice commonly managed in the operator B network.

The second NW slice in the present embodiment is a NW slice to which another PDU session that can connect to the DN to which the PDU session belonging to the first NW slice belongs belongs. The first NW slice and the second NW slice may be operated by the same operator or may be operated by different operators.

The equal PLMN (equivalent PLMN) in the present embodiment is a PLMN that is treated as if it is the same PLMN as any PLMN in the network.

The DCN (Dedicated Core Network) in this embodiment is a core network dedicated to a specific subscriber type, which is composed of one or more in the core network_A90. Specifically, for example, a DCN for a UE registered as a user of an M2M (Machine to Machine) communication function may be configured in the core network_A90. Alternatively, a default DCN may be configured within core network_A90 for UEs that do not have a suitable DCN. In addition, the DCN may be populated with at least one MME_40 or SGSN_A42, and may further be populated with at least one SGW_A35 or PGW_A30 or PCRF_A60. The DCN may be identified by the DCN ID, and the UE may be assigned to one DCN based on information such as the UE usage type and / or the DCN ID.

The back-off timer in the present embodiment is a timer that manages the start of a procedure for session management such as a PDU session establishment procedure and / or the transmission of an SM (Session Management) message such as a PDU session establishment request message, and is a session. It may be information indicating the value of the backoff timer for managing the behavior of management. Hereinafter, the back-off timer and / or the back-off timer may be referred to as a timer. While the backoff timer is running, each device may be prohibited from starting procedures for session management and / or sending and receiving SM messages. The backoff timer may be set in association with at least one of the congestion management unit applied by the NW and / or the congestion management unit identified by the UE. For example, APN / DNN units and / or identification information units indicating one or more NW slices, and / or rejection reason value units in the session management procedure, and / or session units indicated to be rejected in the session management procedure, and / Or it may be set in at least one PTI unit of the session management procedure.

The SM message may be a NAS message used in the procedure for session management, and may be a control message sent and received between UE_A10 and SMF_A230 via AMF_A240. In addition, SM messages include PDU session establishment request message, PDU session establishment acceptance message, PDU session completion message, PDU session rejection message, PDU session change request message, PDU session change acceptance message, PDU session change rejection message, and PDU session release. A request message, a PDU session release acceptance message, a PDU session release refusal message, a PDU session release command message, and the like may be included. Further, the procedure for session management may include a PDU session establishment procedure, a PDU session change procedure, a PDU session opening procedure, and the like. Also, in these procedures, the backoff timer value may be included for each message received by UE_A10. The UE may set the backoff timer received from the NW as the backoff timer, may set the timer value by another method, or may set a random value. Further, when the backoff timer received from the NW is composed of a plurality of backoff timers, the UE may manage a plurality of "backoff timers" corresponding to the plurality of backoff timers, and the policy held by the UE. One timer value may be selected from a plurality of backoff timer values received from the NW, set in the backoff timer, and managed based on the above. For example, when two backoff timer values are received, the UE sets and manages the backoff timer values received from the NW in "backoff timer # 1" and "backoff timer # 2", respectively. Further, based on the policy held by the UE, one value may be selected from a plurality of backoff timer values received from the NW, set in the backoff timer, and managed.

UE_A10 may manage a plurality of "backoff timers" corresponding to a plurality of backoff timers when receiving a plurality of backoff timer values from the NW. Here, in order to distinguish a plurality of "backoff timers" received by UE_A10, the following may be described as, for example, "backoff timer # 1" or "backoff timer # 2". The plurality of backoff timers may be acquired by one session management procedure or by different different session management procedures.

Here, the back-off timer is set for a plurality of related NW slices based on the information for identifying one NW slice as described above, and is a back-off timer for suppressing reconnection, or an APN / DNN. It may be a backoff timer that is set in units of a combination of and one NW slice to prevent reconnection, but it is not limited to this, and it is based on the information for identifying the APN / DNN and one NW slice. It may be a back-off timer that is set in units of a combination of a plurality of related NW slices and suppresses reconnection.

The re-attempt (Re-attempt) information in the present embodiment determines whether or not the rejected PDU session establishment request (S1100) is allowed to be reconnected by using the same DNN information and / or S-NSSAI information. ) Is the information to instruct UE_A10.

At this time, if the UE is executing the PDU session establishment request (S1100) that does not include the DNN in the PDU session establishment request (1100), the fact that the DNN is not included is referred to as the same information. Further, when the UE executes the PDU session establishment request (S1100) that does not include S-NSSAI in the PDU session establishment request (1100), the fact that S-NSSAI is not included is referred to as the same information.

The re-attempt information may be set in units of UTRAN access and / or E-UTRAN access and / or NR access and / or slice information and / or equal PLMN and / or S1 mode and / or NW mode. ..

Furthermore, the re-attempt information specified in the access unit (UTRAN access, E-UTRAN access, NR access) may be information indicating reconnection using the same information to the network on the premise of access change. .. For the re-attempt information specified in slice units, slice information different from the rejected slice is specified, and reconnection using the specified slice information may be permitted.

Furthermore, the re-attempt information specified in units of equal PLMN may be information indicating that reconnection using the same information is permitted if the PLMN of the change destination is equal PLMN when the PLMN is changed. In addition, if the PLMN to be changed is not an equal PLMN, it may be information indicating that reconnection using this procedure is not permitted.

Furthermore, the re-attempt information specified for each mode (S1 mode, N1 mode) indicates that when the mode is changed, if the mode to be changed is the S1 mode, reconnection using the same information is permitted. It may be information. Further, if the mode to be changed is the S1 mode, it may be information indicating that reconnection using the same information is not permitted.

The network slice association rule in the present embodiment is a rule that associates information that identifies a plurality of network slices. The network slice association rule may be received in the PDU session rejection message, or may be set in UE_A10 in advance. In addition, the newest network slice association rule may be applied in UE_A10. Conversely, UE_A10 may behave based on the latest network slice association rules. For example, if UE_A10 has a network slice association rule set in advance and a new network slice association rule is received in the PDU session rejection message, UE_A10 updates the network slice association rule held in UE_A10. May be good.

The priority management rule for the backoff timer in this embodiment is a rule set in UE_A10 in order to collectively manage a plurality of backoff timers that have occurred in a plurality of PDU sessions into one backoff timer. For example, if conflicting or duplicate congestion management is applied and the UE has multiple backoff timers, UE_A10 will have multiple backoff timers based on the backoff timer's preferred management rules. May be managed collectively. Note that the pattern in which conflict or duplicate congestion management occurs is when congestion management based only on DNN and congestion management based on both DNN and slice information are applied at the same time. In this case, congestion based only on DNN. Management is prioritized. The priority management rule for the backoff timer does not have to be limited to this. The backoff timer may be a backoff timer included in the PDU session rejection message.

The LADN (Local Area Data Network) in the present embodiment is a DN to which the UE can connect only in a specific place, and provides connectivity to a specific DNN (that is, LADN DNN).

The LADN information in this embodiment is information related to LADN. The LADN information may be information indicating a specific LADN available to the UE. The LADN information may include LADN DNN and LADN service area information. The LADN DNN may be information indicating LADN, information indicating a DN treated as LADN, or a DNN used when establishing a PDU session for LADN. Further, the LADN service area information may be information indicating the LADN service area. Further, LADN service area information may be provided as a set of tracking areas or as a TAI (Tracking area identity) list. The LADN service area may be an area where a PDU session for LADN can be established, or an area where connection to LADN is possible.

The PDU session for LADN (PDU session for LADN) in the present embodiment is a PDU session associated with the DNN associated with LADN. The PDU session for LADN may be a PDU session established for LADN. In other words, it may be a PDU session established between the UE and LADN, or it may be a PDU session used for user data communication between the UE and LADN. The PDU session for LADN may be a PDU session that can be established only in the LADN service area.

The 5G LAN type service (5G LAN-type service) in the present embodiment is a service that provides private communication by IP type or non-IP type communication via 5GS. Here, the IP type communication may be, for example, either an IPv4 type, an IPv6 type, or an IPv4v6 type, and the non-IP type communication may be, for example, an Ethernet type.

The 5G VN (Virtual Network) in this embodiment is a virtual network (Virtual Network) on 5GS that supports 5G LAN type services.

The 5G VN group (5G Virtual Network (VN) Group) in this embodiment is a group composed of a plurality of UEs used for private communication for a 5G LAN type service.

Information about the 5GVN group may include the 5GVN group ID, 5GVN group membership, and 5GVN group data, and 5GS uses this information to support the management of the 5GVN group. To do. Here, the 5GVN group ID may be an External Group ID and an Internal Group ID used to identify the 5GVN group. As a 5GVN group membership, GPSI (Generic Public Subscription Identifier) may be used to uniquely identify a UE that is a 5GVN group member. The 5GVN group data may include information such as a PDU session type, DNN and S-NSSAI, and an application descriptor.

Here, the 5GVN group may be associated with the DNN on a one-to-one basis. In other words, one 5GVN group may be associated with one DNN, and a specific 5GVN group may be specified by a specific DNN. Further, the DNN associated with the 5GVN group and the 5GVN group may be associated one-to-many or many-to-one. In other words, a plurality of 5GVN groups may be associated with one DNN, or a plurality of DNNs may be associated with one 5GVN group.

The PDU session (PDU session for 5G VN Group) for the 5G VN group in the present embodiment is a PDU session by DNN associated with the 5G VN group. The PDU session for the 5GVN group may be a PDU session in which UE_A10 is established using the DNN associated with the 5GVN group to connect (access or join) the 5GVN group. In other words, UE_A10 connecting to a 5GVN group may mean that UE_A10 establishes a PDU session for the 5GVN group.

In addition, the UE that has established the PDU session for the 5GVN group communicates user data with the UEs of other members accessing the same 5GVN group using the PDU session for the 5GVN group. You may be able to do it.

The PDU session type of the PDU session for the 5GVN group may be an IP type or a non-IP type, and the IP type may be, for example, either an IPv4 type, an IPv6 type, or an IPv4v6 type. The non-IP type may be, for example, an Ethernet type, and one of the modes (SSC mode 1, SSC mode 2, or SSC mode 3) for continuing the session service is set. You may be.

The DNN (Data Network Name) associated with the 5GVN group in this embodiment may be associated with the 5GVN group on a one-to-one basis. In other words, one 5GVN group may be associated with one DNN, and a specific 5GVN group may be specified by a specific DNN.

Since UE_A10 accesses the 5GVN group, the DNN associated with the 5GVN group may be transmitted / provided to the network in the PDU session establishment procedure. More specifically, UE_A10 sends the NAS message for requesting the establishment of a PDU session including the DNN associated with the 5GVN group, and is based on the DNN associated with the 5GVN group from the core network. The PDU session for the 5GVN group may be established by receiving the PDU session establishment acceptance message.

Here, when UE_A10 sends the NAS message for requesting the establishment of the PDU session in the PDU session establishment procedure without including the DNN associated with the 5GVN group, the AMF that received the NAS message requests. PDU for 5GVN group by using DNN associated with 5GVN group selected based on user subscription information, network settings, network policy, etc. for the PDU session You may establish a session.

Note that the DNN used in the PDU session that supports interworking with EPS must be associated with the APN included in the default EPS bearer context of the PDN connection used when the PDU session is moved to EPS. However, the APN associated with the DNN associated with the 5GVN group does not have to exist.

The first state in the present embodiment is a state in which each device has completed the registration procedure and the PDU session establishment procedure. Here, UE_A10 and / or each device may be in a state in which UE_A10 is registered in the network (RM-REGISTERED state) by completing the registration procedure, and when the PDU session establishment procedure is completed, UE_A10 is PDU from the network. It may be in the state of receiving the session establishment acceptance message or the PDU session establishment rejection message.

Congestion management in the present embodiment is composed of one or a plurality of congestion managements from the first congestion management to the fourth congestion management. The control of the UE by the NW is realized by the backoff timer and the congestion management recognized by the UE, and the UE may store the association of these information.

The first congestion management in the present embodiment indicates control signal congestion management for DNN parameters. For example, if the NW detects congestion for DNN # A and the NW recognizes that it is a UE-driven session management request for DNN # A-only parameters, the NW will be the first. Congestion management may be applied. Even if the UE-led session management request does not include the DNN information, the NW may select the default DNN led by the NW and set it as the congestion management target. Alternatively, the NW may apply the first congestion management even if the NW recognizes that it is a UE-driven session management request that includes DNN # A and S-NSSAI # A. If the first congestion management is applied, the UE may suppress UE-led session management requests for DNN # A only.

In other words, the first congestion management in the present embodiment may be control signal congestion management for the DNN, and may be congestion management due to the connectivity to the DNN being in a congestion state. For example, the first congestion management may be congestion management to regulate the connection to DNN # A in all connectivity. Here, the connection to DNN # A in all connectivity may be the connection of DNN # A in connectivity using any S-NSSAI available to the UE, and the network slice to which the UE can connect. It may be a DNN # A connection via. In addition, connectivity to DNN # A via network slices may be included.

Also, DNN # A may be a DNN associated with a 5GVN group. In this case, in addition to the above, the first congestion management based on the DNN associated with the 5GVN group is applied to the PLMN (registered PLMN) in which the UE is registered and the equal PLMN (equivalent PLMN) of the registered PLMN. A backoff timer may be applied to these PLMNs. Hereinafter, the DNN associated with the 5GVN group is also referred to as DNN # A.

The second congestion management in this embodiment indicates control signal congestion management for S-NSSI parameters. For example, when the control signal congestion for S-NSSAI # A is detected in the NW, and the NW recognizes that it is a UE-led session management request targeting only the parameters of S-NSSAI # A. , NW may apply a second congestion management. If a second congestion management is applied, the UE may suppress UE-led session management requests for S-NSSAI # A only. In other words, the second congestion management in the present embodiment is control signal congestion management for S-NSSAI, and is congestion management due to the network slice selected by S-NSSAI being in a congestion state. It may be there. For example, the second congestion management may be congestion management for regulating all connections based on S-NSSAI # A. That is, it may be congestion management to regulate connections to all DNNs via the network slice selected by S-NSSAI # A.

Further, S-NSSAI # A may be S-NSSAI associated with the 5GVN group. In this case, in addition to the above, the second congestion management based on S-NSSAI associated with the 5GVN group is the PLMN (registered PLMN) in which the UE is registered and the equal PLMN (equivalent PLMN) of the registered PLMN. A backoff timer may be applied to these PLMNs. Hereinafter, the S-NSSAI associated with the 5GVN group is also referred to as S-NSSAI # A.

The third congestion management in the present embodiment indicates control signal congestion management for the parameters of DNN and S-NSSAI. For example, when the control signal congestion for DNN # A and the control signal congestion for S-NSSAI # A are detected at the same time in the NW, the NW sets the parameters of DNN # A and S-NSSAI # A. The NW may apply a third congestion management if it recognizes that it is a targeted UE-driven session management request. Even if the UE-led session management request does not include information indicating the DNN, the NW may select the default DNN led by the NW and also make it a congestion management target. If a third congestion management is applied, the UE may suppress UE-led session management requests for DNN # A and S-NSSAI # A parameters.

In other words, the third congestion management in the present embodiment is control signal congestion management for the parameters of DNN and S-NSSAI, and the control signal congestion management to the DNN via the network slice selected based on S-NSSAI is performed. Congestion management may be performed due to the connectivity being in a congested state. For example, the third congestion management may be congestion management for restricting the connection to DNN # A among the connectivity based on S-NSSAI # A.

The fourth congestion management in the present embodiment indicates control signal congestion management for at least one parameter of DNN and / or S-NSSAI. For example, when the control signal congestion for DNN # A and the control signal congestion for S-NSSAI # A are detected at the same time in the NW, the NW is DNN # A and / or S-NSSAI # A. The NW may apply a fourth congestion management if it recognizes that it is a UE-driven session management request for at least one parameter. Even if the UE-led session management request does not include information indicating the DNN, the NW may select the default DNN led by the NW and also make it a congestion management target. If a fourth congestion management is applied, the UE may suppress UE-led session management requests for at least one parameter of DNN # A and / or S-NSSAI # A.

In other words, the fourth congestion management in the present embodiment is control signal congestion management for the parameters of DNN and S-NSSAI, and the network slice selected based on S-NSSAI and the connection to DNN. It may be congestion management due to the fact that the sex is in a congestion state. For example, the fourth congestion management is congestion management for regulating all connections based on S-NSSAI # A, and congestion management for regulating connections to DNN # A in all connectivity. It may be management. In other words, it is congestion management to regulate the connection to all DNNs through the network slice selected by S-NSSAI # A, and to regulate the connection to DNN # A in all connectivity. It may be congestion management. Here, the connection to DNN # A in all connectivity may be the connection of DNN # A in connectivity using any S-NSSAI available to the UE, and the network slice to which the UE can connect. It may be a DNN # A connection via. In addition, connectivity to DNN # A via network slices may be included.

Therefore, the fourth congestion management with DNN # A and S-NSSAI # A as parameters is the first congestion management with DNN # A as parameters and the second congestion management with S-NSSAI # A as parameters. May be congestion management that executes at the same time.

The second behavior in this embodiment is that the UE uses different slice information different from the slice information specified in the first PDU session establishment to make the same APN / DNN as the first PDU session establishment request. This is the behavior of sending a PDU session establishment request for connection. Specifically, the second behavior is that if the UE receives a backoff timer value from the network of zero or invalid, it uses slice information different from the slice information specified in establishing the first PDU session. The behavior may be to send a PDU session establishment request for connecting to the same APN / DNN as the first PDU session establishment request. Also, if the first PDU session is rejected because the wireless access of the specific PLMN to which the specified APN / DNN is connected is not supported, or the first PDU session is rejected for a temporary reason. If so, the UE connects to the same APN / DNN as the APN / DNN included in the first PDU session establishment request, using slice information different from the slice information specified in the first PDU session establishment. It may be the behavior of sending a PDU session establishment request for the purpose.

The third behavior in this embodiment is that when the PDU session establishment request is rejected, the UE does not send a new PDU session establishment request using the same identification information until the backoff timer expires. It is a behavior. Specifically, the third behavior is that if the UE receives a backoff timer value from the network that is neither zero nor invalid, a new PDU session will use the same identification information until the backoff timer expires. The behavior may be such that the establishment request is not transmitted. Here, the same identification information means that the S-NSSAI and / or DNN included in the new PDU session establishment request is the same as the S-NSSAI and / or DNN transmitted in the rejected PDU session establishment request. May mean.

Also, when another PLMN is selected, or when another NW slice is selected, and the reason for refusal regarding the setting failure of network operation is received, it is received when the first PDU session establishment request is rejected. When the backoff timer is activated, the behavior may be such that a new PDU session establishment request using the same identification information is not transmitted until the backoff timer expires.

Specifically, the PDU session that does not send a new PDU session establishment request in the third behavior may be a PDU session to which congestion management associated with the backoff timer is applied. More specifically, in the third behavior, the DNN and / or S-NSSAI that has the connectivity according to the type of congestion management to which the backoff timer is associated and is associated with the congestion management is used. The behavior may be such that a new PDU session establishment request is not transmitted to the used PDU session. The process in which the UE is prohibited by this behavior may be the start of the procedure for session management including the PDU session establishment request and / or the transmission / reception of the SM message.

The fourth behavior in the present embodiment is that when the PDU session establishment request is rejected, the UE makes a new PDU session establishment request that does not carry slice information and DNN / APN information until the backoff timer expires. It is a behavior that does not transmit. Specifically, the fourth behavior is that if the backoff timer received by the UE from the network is neither zero nor invalid, a new PDU session that does not carry slice information or DNN / APN information until the backoff timer expires. The behavior may be such that the establishment request is not transmitted.

The fifth behavior in the present embodiment is the behavior in which the UE does not send a new PDU session establishment request using the same identification information when the PDU session establishment request is rejected. Specifically, the fifth behavior is a new PDU session using the same identification information when the UE is in the uniform PLMN when the PDP types supported by the UE and the network are different. The behavior may be such that the establishment request is not transmitted.

The sixth behavior in the present embodiment is the behavior in which the UE transmits a new PDU session establishment request as an initial procedure using the same identification information when the PDU session establishment request is rejected. Specifically, the sixth behavior is that if the UE rejects the first PDU session establishment request because the target PDN session context does not exist in the handover from non-3GPP access, the same identification information As an initial procedure using, the behavior may be to send a new PDU session establishment request.

The seventh behavior in the present embodiment is that when the UE selects another NW slice in the procedure for selecting PLMN, the backoff timer received when the previous PDU session establishment request is rejected is continued. It is a behavior. Specifically, the seventh behavior is when the UE makes a PLMN selection when the first PDU session establishment request is rejected, and is specified in the first PDU session establishment request in the selected PLMN. If it is possible to specify a NW slice that is common to the NW slice that has been created, the backoff timer received when the first PDU session establishment request is rejected may be continued.

The eighth behavior in the present embodiment is a behavior in which the UE sets a value notified from the network or a value set in the UE in advance as a backoff timer value. Specifically, the eighth behavior may be the behavior in which the UE sets the backoff timer value received in the rejection notification of the first PDU session establishment request as the backoff timer value, or the UE may be set in advance. The behavior may be such that the value to be set or held is set as the backoff timer value. If the timer to be set or held in the UE is set as the backoff timer value in advance, it may be limited to HPLMN or even PLMN in the service area.

The ninth behavior in the present embodiment is that when the PDU session establishment request is rejected, the UE makes a new PDU session establishment request until the terminal power is turned on / off or the USIM (Universal Subscriber Identity Module) is inserted or removed. It is a behavior that does not transmit. Specifically, the ninth behavior is that the UE has an invalid backoff timer received from the network, or the first PDU session rejection reason is a PDP type between the UE and the network. If they are different, do not send a new PDU session establishment request until the terminal power is turned on / off or USIM is inserted / removed. Also, when the first PDU session is rejected because the specified APN / DNN is not supported by the connected PLMN radio, there is no information element of the backoff timer from the network, and the Re-attempt information is displayed. If there is no PDU session reconnection to the equal PLMN, the connected PLMN does not send a new PDU session establishment request until the terminal power is turned on / off or the USIM is inserted / removed. You may. Also, when the first PDU session is rejected because the specified APN / DNN is not supported by the connected PLMN radio, there is no information element of the backoff timer from the network, and the Re-attempt information is displayed. If there is no PDU session reconnection to the equal PLMN, the connected PLMN does not send a new PDU session establishment request until the terminal power is turned on / off or the USIM is inserted / removed. You may. Also, if the first PDU session is rejected because the specified APN / DNN is not supported by the connected PLMN radio, and the backoff timer from the network is neither zero nor disabled, the terminal power is turned on. The behavior may be such that a new PDU session establishment request is not sent until / off or USIM insertion / removal. Also, if the first PDU session is rejected because the specified APN / DNN is not supported by the connected PLMN radio, and the backoff timer from the network is disabled, the terminal power on / off, Alternatively, the behavior may be such that a new PDU session establishment request is not transmitted until the USIM is inserted or removed.

The tenth behavior in the present embodiment is the behavior in which the UE transmits a new PDU session establishment request when the PDU session establishment request is rejected. Specifically, the tenth behavior is that the UE further notifies from the network when the backoff timer received from the network is zero, or when the first PDU session establishment request is rejected for a temporary reason. If there is no backoff timer information element itself, it may behave to send a new PDU session establishment request. Also, if another PLMN is selected, or if another NW slice is selected and the first PDU session establishment request is rejected for a temporary reason, the target APN / DNN in the selected PLMN If the backoff timer is not activated, or if the backoff timer received from the network is invalid, the behavior may be to send a new PDU session establishment request. Also, when the first PDU session establishment request is rejected because the PDP type of the UE and the network are different, when different PLMNs are selected, Re-attempt information is not received or PLMNs that are not on the equal PLMN list. When is selected, when the PDP type is changed, when the terminal power is turned on / off, or when the USIM is inserted / removed, the behavior may be to send a new PDU session establishment request. Also, if the backoff timer notified by the network is zero when the first PDU session is rejected because the specified APN / DNN is not supported by the connected PLMN radio, a new PDU session It may be the behavior of sending an establishment request.

The 16th behavior in this embodiment is the behavior of stopping the backoff timer when the session management procedure led by NW is executed while the UE is activating the backoff timer.

Note that the UE may identify a plurality of congestion managements to be stopped from being applied. Hereinafter, a method of identifying a second congestion management different from the first congestion management will be described, with the congestion management identified by the above-mentioned method as the first congestion management.

For example, the UE may identify the congestion management associated with the same DNN as the DNN associated with the first congestion management as the second congestion management. And / or, the UE may identify the congestion management associated with the same S-NSSAI as the S-NSSAI associated with the first congestion management as the second congestion management. It should be noted that identifying a plurality of congestion managements to be stopped may be set to be executed only when the first congestion management and / or the second congestion management is a specific type of congestion management.

Specifically, when the first congestion management is any of the first congestion management to the fourth congestion management, the UE may identify the second congestion management. And / or, in identifying the second congestion management, the UE identifies the second congestion management when the congestion management to be searched is any of the first congestion management to the fourth congestion management. May be good. It should be noted that in which type the first congestion management and / or the second identification information can identify a plurality of congestion managements may be preset in the core network and / or the UE. It should be noted that the specific types of congestion management that are allowed to be identified need not be specified as one, and may be set in plurality.

The first identification information in the present embodiment may be a reason value indicating the reason for rejecting the request for establishing the PDU session. For example, the first identification information may include the reason value indicated by the second identification information described later. Further, the first identification information may be information indicating that the request for establishing the PDU session is rejected. The request for establishing a PDU session is a request made by UE_A10 and includes DNN and / or S-NSSAI. That is, the first identification information may be a reason indicating that the NW rejects the establishment request for the PDU session corresponding to these DNNs and / or S-NSSAs, or information indicating that the NW rejects the establishment request. Further, the first identification information may be information indicating re-attempt (Re-attempt) information.

The second identification information in the present embodiment may be a reason value indicating the reason for rejecting the request for establishing the PDU session. Specifically, the second identification information may be a value indicating that the resource is insufficient as the reason for rejecting the request to establish the PDU session.

The fifth identification information in the present embodiment may be a back-off timer value, and the start of a procedure for session management such as a PDU session establishment procedure and / or SM (Session Management) such as a PDU session establishment request message. It is a timer that manages the transmission of messages, and may be information indicating the value of the backoff timer for managing the behavior of session management.

Specifically, the fifth identification information is a value indicating that the PDU session establishment request message or the PDU session setting change request message cannot be sent for the period indicated by the backoff timer value when the PLMN is not changed. Good. The fifth identification information is a value indicating that the PDU session establishment request message or the PDU session setting change request message cannot be sent for the period indicated by the backoff timer value even when the PLMN is changed. Good. The fifth identification information is a value indicating that the PDU session establishment request message or the PDU session setting change request message cannot be sent for the period indicated by the backoff timer value regardless of whether or not the PLMN is changed. You can.

The UE that receives the PDU session establishment refusal message containing the fifth identification information sends a PDU session establishment request message or a PDU session setting change request message for the period indicated by the backoff timer value indicated by the fifth identification information. Can't.

The eleventh identification information in the present embodiment may be a reason value indicating a reason for rejecting the setting change of the PDU session. For example, the eleventh identification information may include the reason value indicated by the twelfth identification information described later. Further, the eleventh identification information may be information indicating that the request for changing the setting of the PDU session (PDU session modification) is rejected. The request to change the PDU session is a request made by the UE, and includes DNN and / or S-NSSAI. That is, the eleventh identification information may be information indicating that the NW rejects the change request for the PDU session corresponding to these DNNs and / or S-NSSAs. Further, the eleventh identification information may be information indicating re-attempt (Re-attempt) information.

The twelfth identification information in the present embodiment may be a reason value indicating a reason indicating that the resource is insufficient. Specifically, the twelfth identification information may be a value indicating that the resource is insufficient as the reason for rejecting the setting change of the PDU session.

The fifteenth identification information in the present embodiment may be a backoff timer value, and the start of a procedure for session management such as a PDU session establishment procedure and / or SM (Session Management) such as a PDU session establishment request message. It is a timer that manages the transmission of messages, and may be information indicating the value of the backoff timer for managing the behavior of session management.

Specifically, the fifteenth identification information is a value indicating that the PDU session establishment request message or the PDU session setting change request message cannot be sent for the period indicated by the backoff timer value when the PLMN is not changed. Good. The fifteenth identification information is a value indicating that the PDU session establishment request message or the PDU session setting change request message cannot be sent for the period indicated by the backoff timer value even when the PLMN is changed. Good. The fifteenth identification information is a value indicating that the PDU session establishment request message or the PDU session setting change request message cannot be sent for the period indicated by the backoff timer value regardless of whether or not the PLMN is changed. You can.

Upon receiving the PDU session establishment refusal message containing the 15th identification information, the UE sends a PDU session establishment request message or a PDU session setting change request message for the period indicated by the backoff timer value indicated by the 5th identification information. Can't.

The 21st identification information in the present embodiment may be a reason value indicating the reason for opening the PDU session. For example, the 21st identification information may include the reason value indicated by the 22nd identification information described later. Further, the 21st identification information may be information indicating that the request for PDU session release is rejected. The request for opening the PDU session is a request made by the UE, and includes DNN and / or S-NSSAI. That is, the 21st identification information may be information indicating that the NW rejects the release request for the PDU session corresponding to these DNNs and / or S-NSSAs. Further, the eleventh identification information may be information indicating re-attempt (Re-attempt) information.

The 22nd identification information in this embodiment may be a reason value indicating the reason for opening the PDU session. Specifically, the 22nd identification information may be a value indicating that the reason for releasing the PDU session is insufficient resources.

The 25th identification information in the present embodiment may be a backoff timer value, and is the start of a procedure for session management such as a PDU session establishment procedure and / or SM (Session Management) such as a PDU session establishment request message. It is a timer that manages the transmission of messages, and may be information indicating the value of the backoff timer for managing the behavior of session management.

Specifically, the 25th identification information is a value indicating that the PDU session establishment request message or the PDU session setting change request message cannot be sent for the period indicated by the backoff timer value when the PLMN is not changed. Good. The 25th identification information is a value indicating that the PDU session establishment request message or the PDU session setting change request message cannot be sent during the period indicated by the backoff timer value even when the PLMN is changed. Good. The 25th identification information is a value indicating that the PDU session establishment request message or the PDU session setting change request message cannot be sent for the period indicated by the backoff timer value regardless of whether or not the PLMN is changed. You can.

Upon receiving the PDU session establishment refusal message containing the 25th identification information, the UE sends a PDU session establishment request message or a PDU session setting change request message for the period indicated by the backoff timer value indicated by the 25th identification information. Can't.

Next, the initial procedure in this embodiment will be described with reference to FIG. Hereinafter, the initial procedure is also referred to as this procedure, and this procedure includes a registration procedure (Registration procedure), a UE-led PDU session establishment procedure (PDU session establishment procedure), and a network-led session management procedure. Details of the registration procedure, PDU session establishment procedure, and network-led session management procedure will be described later.

Specifically, when each device executes the registration procedure (S900), UE_A10 transitions to the state registered in the network (RM-REGISTERED state). Next, each device executes the PDU session establishment procedure (S902), so that UE_A10 establishes a PDU session with DN_A5, which provides the PDU connection service, via the core network_B190, and between each device. Transitions to the first state (S904). It is assumed that this PDU session is established via the access network, UPF_A235, but it is not limited to this. That is, there may be a UPF (UPF_C239) different from the UPF_A235 between the UPF_A235 and the access network. At this time, this PDU session will be established via the access network, UPF_C239, UPF_A235. Next, each device in the first state may execute a network-driven session management procedure at any time (S906).

Note that each device may exchange various capability information and / or various request information of each device in the registration procedure and / or the PDU session establishment procedure and / or the network-led session management procedure. In addition, when each device exchanges various information and / or negotiates various requests in the registration procedure, the exchange of various information and / or negotiation of various requests is performed in the PDU session establishment procedure and / or the network-led session management procedure. It may or may not be carried out at. In addition, if each device does not exchange various information and / or negotiate various requests in the registration procedure, exchange various information and / or negotiate various requests in the PDU session establishment procedure and / or network-led session. It may be carried out by the management procedure. In addition, even if each device exchanges various information and / or negotiates various requests in the registration procedure, the exchange of various information and / or negotiation of various requests is performed in the PDU session establishment procedure and / or network-led session management. It may be carried out by the procedure.

Further, each device may execute the PDU session establishment procedure in the registration procedure or after the registration procedure is completed. Also, if the PDU session establishment procedure is performed during the registration procedure, the PDU session establishment request message may be included in the registration request message and sent / received, and the PDU session establishment acceptance message may be included in the registration acceptance message and sent / received. The PDU session establishment completion message may be included in the registration completion message and sent / received, and the PDU session establishment rejection message may be included in the registration rejection message and sent / received. Further, when the PDU session establishment procedure is executed in the registration procedure, each device may establish a PDU session based on the completion of the registration procedure, or the PDU session is established between the devices. You may transition.

In addition, each device involved in this procedure sends and receives one or more identification information included in each control message by transmitting and receiving each control message described in this procedure, and stores each transmitted and received identification information as a context. May be good.

[1.3.1. Outline of registration procedure]
First, the outline of the registration procedure will be described. The registration procedure is a procedure for UE_A10 to take the lead in registering with the network (access network and / or core network_B190 and / or DN_A5). UE_A10 can execute this procedure at any time such as when the power is turned on, as long as it is not registered in the network. In other words, UE_A10 may start this procedure at any time as long as it is in the unregistered state (RM-DEREGISTERED state). Further, each device may transition to the registration state (RM-REGISTERED state) based on the completion of the registration procedure.

In addition, this procedure updates the location registration information of UE_A10 in the network and / or periodically notifies the network of the status of UE_A10 from UE_A10 and / or updates specific parameters regarding UE_A10 in the network. It may be the procedure of.

UE_A10 may start this procedure when it has mobility across TAs. In other words, UE_A10 may start this procedure when it moves to a TA different from the TA shown in the held TA list. In addition, UE_A10 may start this procedure when the running timer expires. In addition, UE_A10 may initiate this procedure when the context of each device needs to be updated due to disconnection or invalidation (also referred to as deactivation) of the PDU session. In addition, UE_A10 may initiate this procedure if there is a change in capability information and / or preferences regarding UE_A10's PDU session establishment. In addition, UE_A10 may initiate this procedure on a regular basis. UE_A10 is not limited to these, and this procedure can be executed at any timing as long as the PDU session is established.

[1.3.1.1. Example of registration procedure]
An example of the procedure for executing the registration procedure will be described with reference to FIG. In this chapter, this procedure refers to the registration procedure. Each step of this procedure will be described below.

First, UE_A10 performs the registration procedure by sending a registration request message to AMF_A240 via NR node (also called gNB) _A122 and / or ng-eNB (S1000) (S1002) (S1004). Start. In addition, UE_A10 sends an SM (Session Management) message (for example, a PDU session establishment request message) in the registration request message, or sends an SM message (for example, a PDU session establishment request message) together with the registration request message. By doing so, the procedure for session management (SM) such as the PDU session establishment procedure may be started during the registration procedure.

Specifically, UE_A10 sends an RRC (Radio Resource Control) message including a registration request message to NR node_A122 and / or ng-eNB (S1000). When NR node_A122 and / or ng-eNB receives the RRC message including the registration request message, it extracts the registration request message from the RRC message and selects AMF_A240 as the NF or shared CP function to which the registration request message is routed. (S1002). Here, NR node_A122 and / or ng-eNB may select AMF_A240 based on the information contained in the RRC message. NR node_A122 and / or ng-eNB sends or forwards a registration request message to the selected AMF_A240 (S1004).

The registration request message is a NAS (Non-Access-Stratum) message sent and received on the N1 interface. The RRC message is a control message sent and received between UE_A10 and NR node_A122 and / or ng-eNB. In addition, NAS messages are processed in the NAS layer, RRC messages are processed in the RRC layer, and the NAS layer is a layer higher than the RRC layer.

In addition, UE_A10 may send a registration request message for each NSI when there are multiple NSIs requesting registration, or may send multiple registration request messages by including them in one or more RRC messages. Good. Further, the above-mentioned plurality of registration request messages may be included in one or more RRC messages and transmitted as one registration request message.

When AMF_A240 receives a registration request message and / or a control message different from the registration request message, it executes the first condition determination. The first conditional determination is for determining whether or not AMF_A240 accepts the request of UE_A10. In the first condition determination, AMF_A240 determines whether the first condition determination is true or false. AMF_A240 initiates procedure (A) during this procedure if the first condition determination is true (ie, if the network accepts the request for UE_A10) and if the first condition determination is false (ie). , If the network does not accept the request of UE_A10), start the procedure (B) during this procedure.

Hereinafter, the steps when the first condition determination is true, that is, each step of the procedure (A) in this procedure will be described. AMF_A240 executes the fourth condition determination and starts the procedure (A) during this procedure. The fourth condition determination is for determining whether or not AMF_A240 sends and receives SM messages to and from SMF_A230. In other words, the fourth condition determination may determine whether or not AMF_A240 is in the process of performing the PDU session establishment procedure. AMF_A240 selects SMF_A230 and sends and receives SM messages to and from the selected SMF_A230 when the fourth condition determination is true (that is, when AMF_A240 sends and receives SM messages to and from SMF_A230). If the fourth condition determination is false (that is, AMF_A240 does not send or receive SM messages to or from SMF_A230), omit them (S1006). When AMF_A240 receives an SM message indicating refusal from SMF_A230, it may cancel the procedure (A) during this procedure and start the procedure (B) during this procedure.

In addition, AMF_A240 sends a Registration Accept message to UE_A10 via NR node_A122 based on the receipt of the registration request message from UE_A10 and / or the completion of sending and receiving SM messages to and from SMF_A230. (S1008). For example, if the fourth condition determination is true, AMF_A240 may send a registration acceptance message based on the receipt of the registration request message from UE_A10. Further, if the fourth condition determination is false, AMF_A240 may send a registration acceptance message based on the completion of transmission / reception of the SM message with SMF_A230. Here, the registration acceptance message may be sent as a response message to the registration request message. The registration acceptance message is a NAS message sent and received on the N1 interface. For example, AMF_A240 sends to NR node_A122 as a control message for N2 interface, and NR node_A122 that receives this is an RRC message to UE_A10. You may include it in and send it.

Further, if the fourth condition determination is true, the AMF_A240 may send the registration acceptance message including the SM message (eg, PDU session establishment acceptance message), or together with the registration acceptance message, the SM message (eg, PDU). A session establishment acceptance message) may be sent. This transmission method may be executed when the SM message (for example, the PDU session establishment request message) is included in the registration request message and the fourth condition determination is true. Further, this transmission method may be executed when the SM message (for example, the PDU session establishment request message) is included together with the registration request message and the fourth condition determination is true. AMF_A240 may indicate that the procedure for SM has been accepted by performing such a transmission method.

UE_A10 receives the registration acceptance message via NR node_A122 (S1008). UE_A10 recognizes the contents of various identification information included in the registration acceptance message by receiving the registration acceptance message.

Next, UE_A10 sends a Registration Complete message to AMF_A240 based on the receipt of the registration acceptance message (S1010). When UE_A10 receives an SM message such as a PDU session establishment acceptance message, it may send the registration completion message including the SM message such as the PDU session establishment completion message, or by including the SM message. , May indicate that the procedure for SM is completed. Here, the registration completion message may be sent as a response message to the registration acceptance message. The registration completion message is a NAS message sent and received on the N1 interface. For example, UE_A10 sends it to NR node_A122 by including it in the RRC message, and NR node_A122 that receives this is sent to AMF_A240 on the N2 interface. It may be sent as a control message.

AMF_A240 receives a registration completion message (S1010). In addition, each device completes the procedure (A) in this procedure based on the transmission / reception of the registration acceptance message and / or the registration completion message.

Next, the steps when the first condition determination is false, that is, each step of the procedure (B) in this procedure will be described. AMF_A240 starts the procedure (B) during this procedure by sending a Registration Reject message to UE_A10 via NR node_A122 (S1012). Here, the registration refusal message may be sent as a response message to the registration request message. The registration refusal message is a NAS message sent and received on the N1 interface. For example, AMF_A240 sends an N2 interface control message to NR node_A122, and NR node_A122 that receives this is an RRC message to UE_A10. You may include it in and send it. Further, the registration refusal message transmitted by AMF_A240 is not limited to this as long as it is a message that rejects the request of UE_A10.

Note that the procedure (B) during this procedure may be started when the procedure (A) during this procedure is cancelled. In the procedure (A), if the fourth condition determination is true, AMF_A240 may send the registration refusal message including the SM message indicating refusal such as the PDU session establishment refusal message, or reject the registration. The inclusion of the meaning SM message may indicate that the procedure for SM has been rejected. In that case, UE_A10 may further receive an SM message indicating rejection such as a PDU session establishment refusal message, or may recognize that the procedure for SM has been rejected.

Furthermore, UE_A10 may recognize that the request of UE_A10 has been rejected by receiving the registration refusal message or by not receiving the registration acceptance message. Each device completes the procedure (B) during this procedure based on the transmission and reception of the registration refusal message.

Each device completes this procedure (registration procedure) based on the completion of procedure (A) or (B) during this procedure. In addition, each device may transition to the state in which UE_A10 is registered in the network (RM_REGISTERED state) based on the completion of the procedure (A) during this procedure, or the procedure (B) during this procedure. UE_A10 may remain unregistered in the network (RM_DEREGISTERED state) based on the completion of. Further, the transition of each device to each state may be performed based on the completion of this procedure, or may be performed based on the establishment of the PDU session.

Furthermore, each device may perform processing based on the identification information transmitted / received in this procedure based on the completion of this procedure.

Further, the first condition determination may be executed based on the identification information and / or the subscriber information included in the registration request message and / or the operator policy. For example, the first condition determination may be true if the network allows the request for UE_A10. Further, the first condition determination may be false if the network does not allow the request of UE_A10. Further, the first condition determination may be true if the network to which UE_A10 is registered and / or the device in the network supports the function required by UE_A10, and false if it does not support it. Good. Further, the first condition determination may be true if the network determines that it is in a congested state, and may be false if it is determined that it is not in a congested state. The condition for determining the truth of the first condition determination does not have to be limited to the above-mentioned condition.

Further, the fourth condition determination may be executed based on whether or not AMF_A240 has received the SM, and may be executed based on whether or not the registration request message includes the SM message. For example, the fourth condition determination may be true if AMF_A240 receives SM and / or if the registration request message contains an SM message, if AMF_A240 does not receive SM, and / Or it may be false if the registration request message does not contain the SM message. The condition for determining the truth of the fourth condition determination does not have to be limited to the above-mentioned condition.

[1.3.2. Outline of PDU session establishment procedure]
Next, the outline of the PDU session establishment procedure performed to establish the PDU session for DN_A5 will be described. Hereinafter, the PDU session establishment procedure is also referred to as this procedure. This procedure is a procedure for each device to establish a PDU session. In addition, each device may execute this procedure in a state where the registration procedure is completed, or may execute this procedure in the registration procedure. Further, each device may start the main procedure in the registered state, or may start the main procedure at an arbitrary timing after the registration procedure. In addition, each device may establish a PDU session based on the completion of the PDU session establishment procedure. Further, each device may establish a plurality of PDU sessions by executing this procedure a plurality of times.

[1.3.2.1. Example of PDU session establishment procedure]
An example of the procedure for executing the PDU session establishment procedure will be described with reference to FIG. Each step of this procedure will be described below. First, UE_A10 starts the PDU session establishment procedure by sending a PDU session establishment request (PDU Session Establishment Request) message to the core network_B via the access network_B (S1100).

Specifically, UE_A10 uses the N1 interface to send a PDU session establishment request message to AMF_A240 in the core network_B190 via NR node_A122 (S1100). AMF_A receives the PDU session establishment request message and executes the third condition determination. The third condition determination is for determining whether or not AMF_A accepts the request of UE_A10. In the third condition determination, AMF_A determines whether the fifth condition determination is true or false. If the third condition determination is true, the core network_B starts processing # 1 in the core network (S1101), and if the third condition determination is false, the procedure (B) in this procedure is performed. Start. The step when the third condition determination is false will be described later. Here, the process # 1 in the core network may be SMF selection by AMF_A in the core network_B190 and / or transmission / reception of a PDU session establishment request message between AMF_A and SMF_A.

Core network_B190 starts processing # 1 in the core network. In process # 1 in the core network, AMF_A240 selects SMF_A230 as the routing destination NF for the PDU session establishment request message, and uses the N11 interface to send or forward the PDU session establishment request message to the selected SMF_A230. May be good. Here, AMF_A240 may select the routing destination SMF_A230 based on the information contained in the PDU session establishment request message. More specifically, the AMF_A240 is an identification information and / or a subscriber information acquired based on the reception of a PDU session establishment request message, and / or a network capability information, and / or an operator policy, and / or a network. The routing destination SMF_A230 may be selected based on the state and / or the context already held by AMF_A240.

The PDU session establishment request message may be a NAS message. Further, the PDU session establishment request message may be any message that requests the establishment of a PDU session, and is not limited to this.

Here, UE_A10 may include the DNN associated with the 5GVN group in the NAS message for requesting the establishment of the PDU session or the PDU session establishment request message, and by including this DNN, UE_A10 may be included. May indicate the request of.

Furthermore, UE_A10 sends the DNN associated with the 5GVN group by including it in the NAS message for requesting the establishment of the PDU session or the PDU session establishment request message, so that the PDU session for the 5GVN group can be sent. It may request establishment, it may indicate the 5GVN group to which the PDU session belongs, as requested by UE_A10, or it may indicate the 5GVN group to which the PDU session will belong.

In addition, UE_A10 indicates whether or not to include the DNN associated with the 5GVN group in the NAS message for requesting the establishment of the PDU session or the PDU session establishment request message, the capability information of UE_A10, and / or the UE policy. Etc., and / or UE_A10 preferences, and / or may be determined based on the application (upper layer). The decision by UE_A10 whether to include the DNN associated with the 5GVN group in the NAS message for requesting the establishment of the PDU session or the PDU session establishment request message is not limited to this.

SMF_A230 in the core network_B190 receives the PDU session establishment request message and executes the third condition determination. The third condition determination is for determining whether or not SMF_A230 accepts the request of UE_A10. In the third condition determination, SMF_A230 determines whether the third condition determination is true or false. SMF_A230 starts the procedure (A) in this procedure when the third condition judgment is true, and starts the procedure (B) in this procedure when the third condition judgment is false. The step when the third condition determination is false will be described later.

Hereinafter, the steps when the third condition determination is true, that is, each step of the procedure (A) in this procedure will be described. SMF_A230 selects UPF_A235 to establish the PDU session and executes the eleventh condition determination.

Here, the eleventh condition determination is for determining whether or not each device executes the process # 2 in the core network. Here, process # 2 in the core network is the start and / or execution of the PDU session establishment authentication procedure by each device, and / or the session establishment request message between SMF_A and UPF_A in the core network_B190. And / or the transmission and reception of a session establishment response message, etc. (S1103). In the eleventh condition determination, SMF_A230 determines whether the eleventh condition determination is true or false. SMF_A230 starts the PDU session establishment authentication approval procedure when the eleventh condition determination is true, and omits the PDU session establishment authentication approval approval procedure when the eleventh condition determination is false. The details of the PDU session establishment authentication approval procedure for process # 2 in the core network will be described later.

Next, SMF_A230 sends a session establishment request message to the selected UPF_A235 based on the completion of the eleventh condition determination and / or the PDU session establishment authentication approval procedure, and starts the procedure (A) during this procedure. To do. In addition, SMF_A230 may start the procedure (B) in this procedure without starting the procedure (A) in this procedure based on the completion of the PDU session establishment authentication approval procedure.

Here, the SMF_A230 is the identification information acquired based on the reception of the PDU session establishment request message, and / or the network capability information and / or the subscriber information, and / or the operator policy, and / or the network status. And / or one or more UPF_A235s may be selected based on the context already held by SMF_A230. When a plurality of UPF_A235s are selected, SMF_A230 may send a session establishment request message to each UPF_A235.

UPF_A235 receives the session establishment request message and creates a context for the PDU session. In addition, UPF_A235 receives a session establishment request message and / or sends a session establishment response message to SMF_A230 based on creating a context for the PDU session. In addition, SMF_A230 receives a session establishment response message. The session establishment request message and the session establishment response message may be control messages sent and received on the N4 interface. Further, the session establishment response message may be a response message to the session establishment request message.

Further, the SMF_A230 may assign an address to be assigned to the UE_A10 based on the reception of the PDU session establishment request message and / or the selection of the UPF_A235 and / or the reception of the session establishment response message. Note that SMF_A230 may assign the address assigned to UE_A10 during the PDU session establishment procedure, or may perform it after the PDU session establishment procedure is completed.

Specifically, when SMF_A230 assigns an IPv4 address without using DHCPv4, the address may be assigned during the PDU session establishment procedure, or the assigned address may be transmitted to UE_A10. Furthermore, when SMF_A230 assigns an IPv4 address and / or an IPv6 address and / or an IPv6 prefix using DHCPv4 or DHCPv6 or SLAAC (Stateless Address Autoconfiguration), the address may be assigned after the PDU session establishment procedure. The assigned address may be sent to UE_A10. The address allocation performed by SMF_A230 is not limited to these.

In addition, SMF_A230 may include the assigned address in the PDU session establishment acceptance message and send it to UE_A10 based on the completion of address assignment of the address assigned to UE_A10, or send it to UE_A10 after the PDU session establishment procedure is completed. You may.

SMF_A230 sends to UE_A10 via AMF_A240 based on the receipt of the PDU session establishment request message and / or the selection of UPF_A235 and / or the reception of the session establishment response message and / or the completion of address assignment of the address assigned to UE_A10. Send a PDU session establishment accept message (S1110).

Specifically, SMF_A230 sends a PDU session establishment acceptance message to AMF_A240 using the N11 interface, and AMF_A240 that receives the PDU session establishment acceptance message sends a PDU session establishment acceptance message to UE_A10 using the N1 interface. ..

Here, the PDU session establishment acceptance message may include the DNN associated with the 5GVN group. Also, if UE_A10 sends a NAS message for requesting PDU session establishment without including the DNN associated with the 5GVN group in the PDU session establishment procedure, the AMF that received the NAS message will establish the establishment. For the requested PDU session, for the 5GVN group by using the DNN associated with the 5GVN group selected based on the user subscription information, network settings, network policy, etc. A PDU session may be established. Further, the DNN associated with the 5GVN group included in the PSU session establishment acceptance message may be the DNN used in the first congestion management.

If the PDU session is a PDN connection, the PDU session establishment acceptance message may be a PDN connectivity accept message. Further, the PDU session establishment acceptance message may be a NAS message sent and received on the N11 interface and the N1 interface. Further, the PDU session establishment acceptance message is not limited to this, and may be any message indicating that the establishment of the PDU session has been accepted.

UE_A10 receives the PDU session establishment acceptance message from SMF_A230. UE_A10 recognizes the contents of various identification information included in the PDU session establishment acceptance message by receiving the PDU session establishment acceptance message.

Next, UE_A10 sends a PDU session establishment complete message to SMF_A230 via AMF_A240 based on the completion of receiving the PDU session establishment acceptance message (S1114). In addition, SMF_A230 receives the PDU session establishment completion message and executes the second condition determination.

Specifically, UE_A10 uses the N1 interface to send a PDU session establishment completion message to AMF_A240, and AMF_A240, which receives the PDU session establishment completion message, sends a PDU session establishment completion message to SMF_A230 using the N11 interface. ..

When the PDU session is a PDN connection, the PDU session establishment completion message may be a PDN connection completion (PDN Connectivity complete) message or a default EPS bearer context activation acceptance (Activate default EPS bearer context accept) message. Further, the PDU session establishment completion message may be a NAS message sent and received on the N1 interface and the N11 interface. Further, the PDU session establishment completion message may be a response message to the PDU session establishment acceptance message, and is not limited to this, and may be a message indicating that the PDU session establishment procedure is completed.

The second condition determination is for SMF_A230 to determine the type of message sent and received on the N4 interface. If the second condition determination is true, processing # 3 in the core network may be started (S1115). Here, the process # 3 in the core network may include transmission / reception of a session modification request (Session Modification request) message and / or transmission / reception of a session modification response (Session Modification response) message. SMF_A230 sends a session change request message to UPF_A235, and further receives a session change acceptance message sent by UPF_A235 that received the session change request message. If the second condition determination is false, SMF_A230 executes process # 2 in the core network. That is, SMF_A sends a session establishment request message to UPF_A235, and further receives a session change acceptance message sent by UPF_A235 that has received the session establishment request message.

Each device is in the process of this procedure based on sending and receiving PDU session establishment completion messages, / or sending and receiving session change response messages, and / or sending and receiving session establishment response messages, and / or sending and receiving RA (Router Advertisement). Complete the procedure of (A).

Next, the steps when the third condition determination is false, that is, each step of the procedure (B) in this procedure will be described. SMF_A230 sends a PDU session establishment reject message to UE_A10 via AMF_A240 (S1122), and starts the procedure (B) during this procedure.

Specifically, SMF_A230 uses the N11 interface to send a PDU session establishment rejection message to AMF_A240, and AMF_A240, which receives the PDU session establishment request message, sends a PDU session establishment rejection message to UE_A10 using the N1 interface. ..

If the PDU session is a PDN connection, the PDU session establishment refusal message may be a PDN connection rejection (PDN connectivity reject) message. Further, the PDU session establishment refusal message may be a NAS message sent and received on the N11 interface and the N1 interface. Further, the PDU session establishment refusal message is not limited to this, and may be any message indicating that the establishment of the PDU session has been rejected.

Here, SMF_A230 may include one or more of the first identification information, the second identification information, and the fifth identification information in the PDU session establishment refusal message, and include these identification information. This may indicate that the request for UE_A10 has been rejected. In addition, two or more identification information of these identification information may be configured as one or more identification information.

In addition, the SMF_A230 will include the first and / or second identification and / or fifth identification in the PDU session establishment refusal message to send the PDU for the 5GVN group. It may indicate that the request to establish a session has been rejected, or it may indicate a 5G VN group that is not allowed to establish a PDU session.

Further, SMF_A230 may make a request combining the above-mentioned matters by transmitting a combination of two or more identification information out of the first identification information, the second identification information, and the fifth identification information. It should be noted that the matters indicated by SMF_A230 by transmitting each identification information are not limited to these.

In addition, SMF_A230 determines which of the first identification information, the second identification information, and the fifth identification information is included in the PDU session establishment refusal message of the received identification information and / or the network. It may be determined based on capability information and / or policies such as operator policies and / or network conditions.

As described above, the core network_B190 notifies the congestion management applied to UE_A10 by sending a PDU session rejection message. It should be noted that this indicates that the core network_B190 applies congestion management to UE_A10 and / or performs congestion management to UE_A10, and / or information that identifies the type of congestion management to be applied. , And / or notify the information that identifies the target of congestion management such as DNN and / or S-NSSAI corresponding to the applied congestion management, and / or the value of the timer associated with the applied congestion management. May be good.

Here, each of the above-mentioned information may be information identified by one or more identification information of the first identification information, the second identification information, and the fifth identification information.

The PDU session establishment refusal message received by UE_A10 from SMF_A230 may include one or more identification information among the first identification information, the second identification information, and the fifth identification information.

Next, UE_A10 performs the fourth process based on the reception of the PDU session establishment refusal message (S1124). In addition, UE_A10 may carry out the fourth process based on the completion of this procedure.

The first example of the fourth process will be described below.

Here, the fourth process may be a process in which UE_A10 recognizes the matter indicated by SMF_A230. Further, the fourth process may be a process in which UE_A10 stores the received identification information as a context, or may be a process of transferring the received identification information to the upper layer and / or the lower layer. .. Further, the fourth process may be a process in which UE_A10 recognizes that the request for this procedure has been rejected.

Further, when UE_A10 receives the first identification information, the second identification information, and the fifth identification information, in the fourth process, UE_A10 sets the value indicated by the fifth identification information as the backoff timer value. It may be a process of starting a back-off timer in which a timer value based on the fifth identification information is set.

Further, the fourth process may be a process in which UE_A10 starts this procedure again after a certain period of time, or a process in which the request of UE_A10 transitions to a limited or restricted state.

Note that UE_A10 may transition to the first state when the fourth process is completed.

Next, the second example of the fourth process will be described.

Here, the fourth process may be a process in which UE_A10 recognizes the matter indicated by SMF_A230. Further, the fourth process may be a process in which UE_A10 stores the received identification information as a context, or may be a process of transferring the received identification information to the upper layer and / or the lower layer. ..

Further, in the fourth process, a process for identifying that congestion management is applied is executed based on one or more of the first identification information, the second identification information, and the fifth identification information. You may.

Further, in the fourth process, the fifth identification information associated with the applied congestion management is based on one or more of the first identification information, the second identification information, and the fifth identification information. The value to be set in the back-off timer indicated by may be identified and set, and the count of the back-off timer may be started. More specifically, this process may be the process described in the third behavior.

Further, in the fourth process, one or more of the third to seventh actions may be executed with the start or completion of any of the above-mentioned processes.

Further, in the fourth process, one or more of the ninth to fifteenth actions may be executed with the start or completion of any of the above-mentioned processes.

Note that UE_A10 may transition to the first state when the fourth process is completed.

So far, the processing contents have been explained using the first example and the second example for the fourth processing, but it is not limited to these processings of the fourth processing. For example, the fourth process is a process in which a part of the plurality of detailed processes described in the first example and a part of the plurality of detailed processes described in the second example are combined. May be good.

Furthermore, UE_A10 may recognize that the request of UE_A10 has been rejected by receiving the PDU session establishment refusal message or by not receiving the PDU session establishment acceptance message. Each device completes the procedure (B) during this procedure based on the transmission / reception of the PDU session establishment refusal message.

Each device completes this procedure based on the completion of procedure (A) or (B) during this procedure. In addition, each device may transition to the state where the PDU session is established based on the completion of the procedure (A) during this procedure, or based on the completion of the procedure (B) during this procedure. , You may recognize that this procedure has been rejected, you may transition to a state where the PDU session has not been established, or you may transition to the first state.

Furthermore, each device may perform processing based on the identification information transmitted / received in this procedure based on the completion of this procedure. In other words, UE_A10 may carry out the fourth process based on the completion of this procedure, or may transition to the first state after the completion of the fourth process.

Further, the third condition determination may be executed based on the identification information and / or the subscriber information included in the PDU session establishment request message and / or the operator policy. For example, the third condition determination may be true if the network allows the request for UE_A10. Further, the third condition determination may be false if the network does not allow the request of UE_A10. Furthermore, the third condition determination may be true if the network to which UE_A10 is connected and / or the devices in the network support the functions required by UE_A10, and false if they do not. Good. Further, the third condition determination may be true if the network determines that it is in a congested state, and may be false if it is determined that it is not in a congested state. The condition for determining the truth of the third condition determination is not limited to the above-mentioned condition.

Further, the second condition determination may be executed based on whether or not a session on the N4 interface for the PDU session has been established. For example, the second condition determination may be true if the session on the N4 interface for the PDU session is established and false if it is not. The condition for determining the truth of the second condition determination does not have to be limited to the above-mentioned condition.

By sending and receiving the PDU session rejection message in the above procedure, the core network_B190 notifies the congestion management to be applied to the UE_A10, and the UE_A10 can apply the congestion management instructed by the core network_B190. The core networks B190 and UE_A10 may apply a plurality of congestion managements by executing the procedures and processes described in this procedure a plurality of times. Note that each applicable congestion management is a different congestion management type and / or congestion management corresponding to a different DNN, and / or a congestion management corresponding to a different S-NNSAI, and / or a combination of DNN and S-NSSAI. Congestion management may be different.

[1.3.3. Outline of session management procedure]
Next, the outline of the UE-led or network-led session management procedure will be described. Hereinafter, the network-led session management procedure is also referred to as this procedure. This procedure is a procedure for session management that is executed by the network for the established PDU session. This procedure may be executed at any time after the above-mentioned registration procedure and / or PDU session establishment procedure is completed and each device transitions to the first state. In addition, each device may send and receive a message containing identification information for stopping or changing congestion management during this procedure, or based on new congestion management instructed by the network based on the completion of this procedure. You may start the behavior.

Also, UE_A10 may stop applying congestion management identified based on the control information sent and received by this procedure. In other words, the core network_B190 stops applying congestion management that can be identified using these control information by leading this procedure and also by sending control messages and control information for this procedure to UE_A10. You can notify UE_A10 to do so.

This procedure may be a UE-led or network-led PDU session modification (PDU session modification) procedure, and / or a network-led PDU session release (PDU session release) procedure, or the like. Network-led session management procedures may be performed. Each device may send and receive a PDU session change message in the network-led PDU session change procedure, and may send and receive a PDU session release message in the network-led PDU session release procedure.

[1.3.3.1. Example of first network-led session management procedure]
An example of a network-driven session management procedure will be described with reference to FIG. In this chapter, this procedure refers to a network-led session management procedure. Each step of this procedure will be described below.

As described above, each device in UE_A10 and core network_B190 that has transitioned to the first state (S1200) based on the completion of the registration procedure and / or the PDU session establishment procedure is network-driven session management at any time. Start the procedure. Here, the device in the core network_B190 that initiates this procedure may be SMF_A and / or AMF_A, and UE_A may send and receive messages in this procedure via AMF_A and / or access network_B. ..

Specifically, the device in the core network_B190 sends a network-driven session management request message to UE_A (S1202). Here, the devices in the core network_B190 include the 11th identification information, the 12th identification information, the 15th identification information, the 21st identification information, the 22nd identification information, and the 22nd identification information in the network-driven session management request message. One or more of the 25 identification information may be included, and by including this identification information, the request of the core network_B190 may be indicated.

Next, UE_A, which receives the network-led session management request message, sends a network-led session management completion message (S1204). Furthermore, UE_A is one of the 11th identification information, the 12th identification information, the 15th identification information, the 21st identification information, the 22nd identification information, and the 25th identification information received from the core network_B190. Based on the above identification information, the fifth process may be executed (S1206) to complete this procedure. Here, the 11th identification information, the 12th identification information, and the 15th identification information may be included in the PDU session change command (PDU SESSION MODIFICATION COMMAND), or the 21st identification information, the 22nd identification information. The identification information and the 25th identification information may be included in the PDU session release command (PDU SESSION RELEASE COMMAND). Further, for example, when this procedure is led by the UE, the 11th identification information, the 12th identification information, and the 15th identification information are transmitted by the NW and received by the UE to reject the PDU session change (PDU SESSION). It may be included in the MODIFICATION REJECT) message. In addition, UE_A10 may carry out the fifth process based on the completion of this procedure.

The fifth processing example will be described below.

Here, the fifth process may be a process in which UE_A10 recognizes the matter indicated by the core network_B190, or may be a process in which the request of the core network_B190 is recognized. Further, the fifth process may be a process in which UE_A10 stores the received identification information as a context, or may be a process of transferring the received identification information to the upper layer and / or the lower layer. ..

Further, the message sent and received in the network-led session management procedure may be a PDU session change command message or a PDU session release command message, and is not limited thereto. Further, the message sent and received in the UE-led session management procedure may be a PDU session change refusal message.

Note that UE_A10 may perform the congestion management identification process applied by UE_A10 based on the received identification information in the fifth process. Here, the congestion management identification process may be the 17th behavior.

Furthermore, when UE_A10 receives the 21st identification information, the 5th process may be the 16th behavior. Specifically, for example, it may be a process of stopping one or a plurality of timers executed based on the above-mentioned fourth process.

In other words, the UE_A10 that received the 21st identification information identifies the congestion management that makes the stop or change instructed by the network by executing the 17th action, and then executes the 16th action. By doing so, the identified congestion management is stopped or changed.

Furthermore, each device may perform processing based on the identification information transmitted / received in this procedure based on the completion of this procedure. In other words, UE_A10 may carry out the fifth process based on the completion of this procedure, or may complete this procedure after the completion of the fifth process.

In the above procedure, the core network_B190 can instruct UE_A10 to stop or change the congestion management that UE_A10 has already applied by sending and receiving a network-led session management request message. In addition, UE_A10 can suspend or change the congestion management applied by UE_A10 based on the network-driven session management request message. Here, when UE_A10 applies one or more congestion management, the congestion management that implements the stop or change is identified based on the reception of the identification information contained in the network-driven session management request message from the core network_B190. You may. Note that each applicable congestion management is a different congestion management type and / or congestion management corresponding to a different DNN, and / or a congestion management corresponding to a different S-NNSAI, and / or a combination of DNN and S-NSSAI. Congestion management may be different.

[1.3.3.2. Example of second network-led session management procedure]
In the first network-driven session management procedure example described in Section 1.3.3.1, the congestion management applied to UE_A10 is regardless of which of the first to fourth congestion managements. An example of stopping congestion management in the procedure was explained.

Not limited to that, the procedure explained in the first network-driven session management procedure example explained in Chapter 1.3.3.1 may be a procedure executed according to congestion management. For example, among one or more congestion managements applied by UE_A10, it is a procedure executed for congestion management classified into the first congestion management, the third congestion management, and the fourth congestion management. Good.

In other words, UE_A10 may stop the first congestion management, the third congestion management, and the congestion management corresponding to the fourth congestion management by the fifth process.

If UE_10 receives a network-driven session management request message for the second congestion management while executing the count of the backoff timer associated with the second congestion management, the UE_A10 will be the second. It is also possible to respond to the core network_B190 without stopping the backoff timer associated with congestion management.

In other words, UE_A10 received a network-driven session management request message for the congested S-NSSAI # A and any DNN while the backoff timer count associated with S-NSSAI # A was running. In some cases, UE_A10 may respond to core network_B190 without stopping the backoff timer associated with S-NSSAI # A.

Thus, for the second congestion management, in receiving the network-driven session management request message, UE_A10 sends the response message to the network-driven session management request message to the core network_B190, but congestion management. May continue. Therefore, the transmission of UE-led session management request messages regulated by the second congestion management may continue to be suppressed.

Here, as described above, the network-driven session management request message in the present embodiment may be a PDU session change command (PDU SESSION MODIFICATION COMMAND) message in the network-driven PDU session change (PDU session modification) procedure. It may be a PDU session release command (PDU SESSION RELEASE COMMAND) message in a network-driven PDU session release procedure.

Further, as described above, the network-led session management completion message that responds to the PDU session change command message in the present embodiment may be a PDU session change completion message (PDU SESSION MODIFICATION COMPLETE), and the PDU in the present embodiment. The network-driven session management completion message that responds to the session release command message may be a PDU session release completion message (PDU SESSION RELEASE COMPLETE). Also, if the network-driven session management request message is a PDU session change command and / or a PDU session release message, UE_A10 and core network_B190 perform more detailed processing described below in addition to the processing described above. May be set to.

For example, when the core network_B190 sends a network-led session management request message including information indicating a reactivation request (Reactivation Required), the process may be executed as follows. The information indicating the reactivation request (Reactivation Required) is the information indicating that the activation is requested, and a specific example is the 5G session management reason value # 39 (5GSM Cause # 39). Good.

The first process and procedure example when the information indicating the reactivation request is received will be described below.

When UE_A10 receives a network-driven session management request message containing information indicating a reactivation request, it re-leads the UE-led PDU session establishment procedure immediately after completing the network-driven session management procedure. Instead, wait for congestion management to be released and re-lead the UE-led PDU session establishment procedure. Here, this UE-driven PDU session establishment procedure is UE-driven for the PDU session type, SSC mode, DNN and S-NSSAI provided in the UE-driven PDU establishment procedure when establishing a modified or released PDU session. PDU session establishment procedure may be used.

Note that waiting for the release of congestion management may be executed after the timer associated with the first congestion management has expired (Expire). In other words, it may be executed after the count of the timer associated with the first congestion management is completed and / or after the timer value associated with the first congestion management becomes zero.

Furthermore, UE_A10 may include the following supplementary information in the network-led session management completion message.

Supplementary information may be information indicating that the timer is waiting to expire and / or information indicating the remaining timer value. Here, the timer may be a timer associated with the first congestion management. Further, waiting for the expiration of the timer may be executed after the timer has expired (Expire). In other words, it may be executed after the count of the timer associated with the first congestion management is completed and / or after the timer value associated with the first congestion management becomes zero.

Note that the core network B_190 may receive a network-led session management completion message containing supplementary information and recognize the value of the remaining timer. Furthermore, it may be recognized that the UE-led PDU session establishment procedure will be led after the time indicated by the remaining timer has elapsed.

Here, the remaining timer recognized by the core network_B190 may be a value indicated by the received supplementary information, or is an offset between the transmission time of UE_A10 and the reception time of the core network_B190 of the network-led session management completion message. May be a value in consideration of the value indicated by the received supplementary information.

In addition, not only the first process and procedure example when the information indicating the reactivation request is received, but also the second process and procedure example when the information indicating the reactivation request is received as shown below. It may be executed.

As described above, for the first congestion management, in receiving the network-driven session management request message, UE_A10 sends the response message to the network-driven session management request message to the core network_B190. , Congestion management may be continued. Therefore, while the transmission of UE-led session management request messages regulated by the first congestion management continues to be suppressed, UE_A10 and / or core network_B190 goes through the UE-led PDU session establishment procedure. It may be set to be acceptable as long as it leads again.

In other words, if UE_A10 receives a network-driven session management request message that contains information indicating a reactivation request, the UE_A10 will have a UE-led PDU session after the network-driven network-driven session management procedure is complete. Lead the establishment procedure again. Here, this UE-driven PDU session establishment procedure is UE-driven for the PDU session type, SSC mode, DNN and S-NSSAI provided in the UE-driven PDU establishment procedure when establishing a modified or released PDU session. PDU session establishment procedure may be used.

For UE_A10, while the application of congestion management continues, UE_A10 and core network B190 may execute and complete the procedures allowed as an exception to this exception, but UE_A10 is suppressed by the first congestion management. Other UE-led session management procedures may be deterred.

In addition, not only the first and second processes and procedure examples when the information indicating the reactivation request is received, but also the third process and the third process when the information indicating the reactivation request is received as follows. A procedure example may be executed.

As explained so far, for the first congestion management, when receiving the network-driven session management request message, UE_A10 sends the response message to the network-driven session management request message to the core network_B190. In addition, UE_A10 may suspend the application of the first congestion management when it receives a network-driven session management request message containing information indicating a reactivation request (Reactivation Required).

In other words, UE_A10 may continue congestion management if the network-driven session management request message does not contain information indicating a reactivation request (Reactivation Required). In this case, the transmission of the UE-led session management request message regulated by the first congestion management may continue to be suppressed.

Therefore, when UE_A10 receives a network-driven session management request message containing information indicating a reactivation request, the UE_A10 establishes a UE-led PDU session after completing the network-driven network-driven session management procedure. Lead the procedure again. Here, this UE-driven PDU session establishment procedure is UE-driven for the PDU session type, SSC mode, DNN and S-NSSAI provided in the UE-driven PDU establishment procedure when establishing a modified or released PDU session. PDU session establishment procedure may be used.

In addition, not limited to the first, second, and third processing and procedure examples when the information indicating the reactivation request is received, the information indicating the reactivation request is transmitted by the core network_B190 as shown below. It may be set not to be done.

More specifically, the core network_B190 should include information indicating a reactivation request (Reactivation Required) when sending a network-driven session management request message to UE_A10 to which congestion management is applied. It may be set to suppress.

Alternatively, the core network_B190 suppresses the inclusion of information indicating a reactivation request (Reactivation Required) when sending a network-driven session management request message to UE_A10 to which the first congestion management is applied. May be set to.

The processing and procedures of UE_A10 and core network B190 have been explained above. More specifically, the processing of core network_B190 described in this chapter is the device in core network_B190, SMF_A230 and /. Alternatively, it may be a process executed by a control device such as AMF_A240. Therefore, when the core network B190 sends and receives control messages, it may mean that control devices such as SMF_A230 and / or AMF_A240, which are devices in the core network_B190, send and receive control messages.

Further, not limited to this chapter, in the expressions used in the description of the present embodiment, when the application to the congestion management is canceled or the congestion management is stopped, the backoff timer associated with the congestion management is stopped. Processing may be included, and continuing the application to congestion management, or continuing congestion management may include continuing counting of the backoff timer associated with congestion management.

In addition, in the first, second, and third processing and procedure examples when the information indicating the reactivation request explained in this chapter is received, the network-driven session management request message and / or the network-led session management procedure Has explained that UE_A10 is for congested S-NSSAI # A and any DNN.

In other words, this congested S-NSSAI # A and any DNN are associated with the network-driven session management request messages in this chapter and / or the PDU session targeted by the network-driven session management procedure. It can be NSSAI # A and any DNN.

Note that UE_A10 and core network_B190 may execute the anchor relocation procedure of SSC mode 2 including the procedure of this chapter, and switch to the anchor of the PDU session or the PDU session with a different anchor to continue the communication. Here, the anchor relocation procedure in SSC mode 2 is a procedure initiated by the core network_B190, and the procedure associated with the transmission of the PDU session release command executed within this procedure is one of the procedures described in this chapter. It may be.

In addition, UE_A10 and core network_B190 may execute the anchor relocation procedure of SSC mode 3 including the procedure of this chapter, and switch to the anchor of the PDU session or the PDU session with a different anchor to continue the communication. Here, the anchor relocation procedure in SSC mode 3 is a procedure initiated by the core network_B190, and the procedure associated with the transmission of the PDU session change command executed within this procedure is one of the procedures described in this chapter. It may be.

Next, the processing when the UE moves with a change in PLMN while congestion management is applied will be described.

Here, the processing when UE_A10 changes PLMN will be described especially in the state where the first congestion management is applied. Here, the first congestion management and the processing regulated when the first congestion management is applied may be as described above.

Repeatedly, the first congestion management may be DNN-based congestion management. For example, in the first congestion management, when the NW receives a UE-led session management request using DNN # A from UE_A10 and the NW detects congestion for a specific DNN, for example, DNN # A. , It may be congestion management applied by NW to UE_A10 based on the message rejecting the UE-led session management request. In this case, in applying the first congestion management, UE_A10 starts counting the backoff timer corresponding to the first congestion management received from the NW, and DNN # A until the backoff timer expires. It may be set not to send UE-led session management requests using. Note that using DNN may mean including DNN information in a UE-led session management request such as a PDU session establishment request message. Here, DNN # A may be a DNN associated with a 5GVN group.

Further, when the destination PLMN is an equal PLMN and the DNN is DNN # A, the transmission of the UE-led session management request using DNN # A is a backoff timer corresponding to the first congestion management. May be allowed regardless of whether or not the count is done. Also, if the destination PLMN is not a uniform PLMN and the DNN is DNN # A, sending a UE-led session management request using DNN # A is a backoff timer that corresponds to the first congestion management. It may be configured not to send UE-led session management requests using DNN # A until it expires.

Furthermore, if the destination PLMN is an even PLMN and the DNN is not DNN # A, sending a UE-led session management request using DNN # A is a backoff timer that corresponds to the first congestion management. It may be configured not to send UE-led session management requests using DNN # A until it expires.

Here, for the sake of explanation, such first congestion management is referred to as "first congestion management for a specific DNN".

Further, in the first congestion management, the NW may select the default DNN led by the NW and set it as the congestion management target even if the UE-led session management request does not include the DNN information. In other words, the first congestion management is UE-driven session management when the NW receives a UE-driven session management request without DNN information from UE_A10 and the NW detects congestion for the default DNN. It may be the congestion management that the NW applies to UE_A10 based on the message rejecting the request. In this case, in applying the first congestion management, UE_A10 starts counting the backoff timer corresponding to the first congestion management received from the NW, and uses the DNN until the backoff timer expires. It may be configured not to send UE-led session management requests. Note that not using DNN may mean that DNN information is not included in the UE-led session management request such as the PDU session establishment request message.

Here, for the sake of explanation, the first congestion management for the default DNN is distinguished from the first congestion management for a specific DNN because it is applied based on the UE-led session management request that does not use the DNN information. Therefore, it is expressed as "congestion management for No DNN". Furthermore, a UE-led session management request such as a PDU session establishment request message that does not use DNN is expressed as a UE-led session management request that uses No DNN. For example, the PDU session establishment request message using No DNN is a PDU session establishment request message not using DNN.

Thus, the first congestion management for a particular DNN may be applied in different PLMNs.

For example, when the DNN is a LADN DNN or a DNN associated with a 5GVN group, the backoff timer for the first congestion management is PLMN (registered PLMN) in which the UE is registered and equal PLMN (equivalent). PLMN) may be associated and applied.

For example, if the DNN is not a LADN DNN and is not a DNN associated with a 5GVN group, the first congestion management backoff timer is associated with and applied to all PLMNs. Good. That is, the UE is not limited to the registered PLMN (registered PLMN) or the equal PLMN (equivalent PLMN).

Here, as the processing associated with the above-mentioned PLMN change, whether the same processing or different processing is performed regardless of whether the first congestion management is for a specific DNN or No DNN is determined in advance in UE_A10. It may be set based on the set information, but it may be determined by whether or not the second PLMN after the change is an equal PLMN with respect to the first PLMN before the change. For example, if the second PLMN after the change is not an equal PLMN with respect to the first PLMN before the change, the same processing may be applied. Further, when the second PLMN after the change is an equal PLMN with respect to the first PLMN before the change, different processing may be executed.

Furthermore, UE_A10 may determine its behavior based on more detailed conditions as well as whether or not it is an equal PLMN. For example, when the second PLMN after the change is an equal PLMN with respect to the first PLMN before the change and the registration area is not changed in the PLMN change, and when the second PLMN after the change is changed. UE_A10 may be set to perform different behaviors depending on whether it is an equal PLMN to the previous first PLMN and the PLMN change involves a change in the registration area.

The behavior of UE_A10 executed in each case may be one of the behaviors at the time of PLMN change described so far.

Next, a third example will be described in which the second PLMN after the change is an equal PLMN with respect to the first PLMN before the change, and the PLMN change involves a change in the registration area. UE_A10 may stop the backoff timer associated with the first congestion management for a particular DNN and / or NoDNN in these PLMN changes. Thereby, UE_A10 may be set so that UE_A10 can send a PDU session establishment request message using a specific DNN and / or a PDU session establishment request message not using a specific DNN in the new PLMN. Further, based on this setting, UE_10 may send a PDU session establishment request message using a specific DNN and / or a PDU session establishment request message not using a specific DNN.

Further, whether the same processing or different processing is performed regardless of whether the first congestion management is for a specific DNN or No DNN may be set based on the information set in UE_A10 in advance. However, as mentioned above, it may be determined by whether or not the second PLMN after the change is an equal PLMN with respect to the first PLMN before the change, but regardless of the first congestion management, the second It may be set to execute different processing also for the fourth congestion management. For example, if the second PLMN after the change is not an equal PLMN with respect to the first PLMN before the change, the same processing may be applied. Further, when the second PLMN after the change is an equal PLMN with respect to the first PLMN before the change, different processing may be executed.

Furthermore, UE_A10 may determine its behavior based on more detailed conditions as well as whether or not it is an equal PLMN. For example, when the second PLMN after the change is an equal PLMN with respect to the first PLMN before the change and the registration area is not changed in the PLMN change, and when the second PLMN after the change is changed. UE_A10 may be set to perform different behaviors depending on whether it is an equal PLMN to the previous first PLMN and the PLMN change involves a change in the registration area.

The behavior of UE_A10 executed in each case may be one of the behaviors at the time of PLMN change described so far.

The processing of UE_A10 and NW due to the change of PLMN described so far has been described for the backoff timer for the first congestion management, but the second congestion management, the third congestion management, and the fourth congestion management have been described. Similar processing may be performed for management. However, the PDU session establishment request message whose transmission is restricted or permitted may be a message according to each type.

In other words, the backoff timer associated with congestion management and / or congestion management may be associated with PLMN regardless of the type of congestion management.

Alternatively, the backoff timer associated with arbitrary congestion management and / or congestion management may be set to be associated with PLMN. Therefore, for the first congestion management, the second congestion management, and the third congestion management, the backoff timer associated with the congestion management and / or the congestion management is set to be associated with the PLMN. Good. Alternatively, for the first congestion management, the second congestion management, and the third congestion management for NoDNN, the backoff timer associated with the congestion management and / or the congestion management can be associated with the PLMN. The first congestion management that is set and for a particular DNN need not be associated with the PLMN.

Note that the processing when each congestion management is made compatible with PLMN and / or the processing related to the backoff timer corresponding to each congestion management is the above-mentioned first congestion management associated with PLMN. The first congestion management in the description of the processing and / or the processing related to the backoff timer corresponding to the first congestion management associated with the PLMN described above is the congestion management of each of the second to fourth types. It may be replaced with.

In addition, the processing when each congestion management is not compatible with PLMN and / or the processing related to the backoff timer corresponding to each congestion management is the first processing not associated with PLMN as described above. The second to fourth types of the first congestion management in the description of the processing for the congestion management and / or the processing related to the backoff timer corresponding to the first congestion management not associated with the PLMN described above. It may be replaced with another congestion management.

However, as described above, the PDU session establishment request message whose transmission is restricted or permitted may be a message according to each type.

Alternatively, the behavior at the time of PLMN change when executing the count of the backoff timer associated with the second congestion management and / or the third congestion management is executed as follows in addition to the above-mentioned processing. You may.

The backoff timer associated with the first congestion management may be a backoff timer for DNN-based congestion management, as described above.

Specifically, the DNN-based backoff timer may be a timer that is associated with a specific DNN and prohibits the transmission of SM request messages using that specific DNN. In other words, UE_A10 may be configured not to send SM request messages with that particular DNN while this timer is counting. Here, the DNN may be a DNN associated with the 5GVN group.

In addition, UE_A10 may be set to allow the new PLMN to send SM request messages that were prohibited by the PLMN before the change, based on certain conditions described below, during the counting of this timer. .. If it is expressed that the SM request message that was prohibited by PLMN before the change is allowed to be sent, the SM request message using the same S-NSSAI as the S-NSSAI associated with the backoff timer will be sent. It may mean that it is acceptable.

Further, the slice-based backoff timer may be a timer associated with noS-NSSAI and prohibiting the transmission of SM request messages using noS-NSSAI. In other words, UE_A10 may be set not to send SM request messages using noSNSSAI during the counting of this timer. In addition, UE_A10 may be set to allow the new PLMN to send SM request messages that were prohibited by the PLMN before the change, based on certain conditions described below, during the counting of this timer. .. In addition, when it is expressed that the transmission of the SM request message prohibited by PLMN before the change is permitted, it may mean that the transmission of the SM request message using no S-NSSAI is permitted.

Further, the back-off timer associated with the third congestion management may be a back-off timer for congestion management for the combination of S-NSSAI and DNN, as described above.

Specifically, a backoff timer for congestion management for a combination of S-NSSAI and DNN is associated with a specific S-NSSA and specific DNN combination, and the specific S-NSSAI and specific DNN are assigned. It may be a timer for prohibiting the transmission of the SM request message used. In other words, UE_A10 may be configured not to send SM request messages with that particular S-NSSAI and a particular DNN while this timer is counting. In addition, UE_A10 may be set to allow the new PLMN to send SM request messages that were prohibited by the PLMN before the change, based on certain conditions described below, during the counting of this timer. .. If it is expressed that the transmission of SM request messages prohibited by PLMN before the change is allowed, it is associated with the same S-NSSAI as the S-NSSAI associated with the backoff timer and the backoff timer. It may mean that the transmission of the SM request message using the same DNN as the DNN is allowed.

In addition, the backoff timer for congestion management for the combination of S-NSSAI and DNN is associated with the combination of noS-NSSA and a specific DNN, and sends an SM request message using noSNSSAI and a specific DNN. It may be a timer for prohibiting. In other words, UE_A10 may be set not to send SM request messages including no S-NSSAI and a specific DNN during the counting of this timer. In addition, UE_A10 may be set to allow the new PLMN to send SM request messages that were prohibited by the PLMN before the change, based on certain conditions described below, during the counting of this timer. .. If it is expressed that the transmission of the SM request message prohibited by the PLMN before the change is permitted, the SM request message using no S-NSSAI and the same DNN as the DNN associated with the backoff timer. May mean that the transmission of is allowed.

In addition, the backoff timer for congestion management for the combination of S-NSSAI and DNN is associated with the combination of specific S-NSSA and noDNN, and the SM request message using the specific S-NSSAI and noDNN It may be a timer for prohibiting transmission. In other words, UE_A10 may be set not to send SM request messages using a particular S-NSSAI and noDNN during this timer count. In addition, UE_A10 may be set to allow the new PLMN to send SM request messages that were prohibited by the PLMN before the change, based on certain conditions described below, during the counting of this timer. .. If it is expressed that the transmission of SM request messages prohibited by PLMN before the change is allowed, SM using the same S-NSSAI as S-NSSAI associated with the backoff timer and no DNN It may mean that the request message is allowed to be sent.

In addition, the back-off timer for congestion management for the combination of S-NSSAI and DNN is associated with the combination of no S-NSSAI and no DNN, and the SM request message is transmitted using no S-NSSAI and no DNN. It may be a timer for prohibiting. In other words, UE_A10 may be set not to send SM request messages using noS-NSSAI and noDNN during the counting of this timer. In addition, UE_A10 may be set to allow the new PLMN to send SM request messages that were prohibited by the PLMN before the change, based on certain conditions described below, during the counting of this timer. .. In addition, when it is expressed that the transmission of SM request message prohibited by PLMN before the change is permitted, it means that the transmission of SM request message using no S-NSSAI and no DNN is permitted. You may.

In the present embodiment, when it is expressed that the SM request message is transmitted using no S-NSSAI, the SM request message may be transmitted without including the specific S-NSSAI. Since the network that received such an SM request message does not include S-NSSAI, it may be recognized as a request for the default S-NSSAI and / or the default network slice. Therefore, no S-NSSAI may be information indicating that the SM request message does not include S-NSSAI and / or information indicating that a default network slice is requested.

Further, in the present embodiment, when it is expressed that the SM request message is transmitted using no DNN, the SM request message may be transmitted without including the specific DNN. The network that receives such an SM request message may be recognized as a request for the default DNN because it does not contain a DNN. Therefore, no DNN may be information indicating that the SM request message does not include S-NSSAI and / or information indicating that a default DNN is requested.

Furthermore, when the PLMN is changed, UE_A10 counts if the backoff timer is being counted in the PLMN before the change and the backoff timer is being counted in the destination PLMN as well. Depending on the back-off timer, the regulation of sending the SM request message described in each example may be continued. In other words, in this case, in the destination PLMN, UE_A10 may be set to prohibit the transmission of the SM request message described in each example according to the counting backoff timer.

In all processing examples, when the PLMN is changed, if the above conditions are not met, the SM request message described in each example will be sent according to the backoff timer being counted in the destination PLMN. May be set to allow transmission of. In other words, in this case, in the destination PLMN, UE_A10 may be set to allow the transmission of the SM request message described in each example according to the counting backoff timer. In other words, in this case, in the destination PLMN, UE_A10 is allowed to send the SM request message described in each example, which was prohibited by the PLMN before the change, depending on the backoff timer being counted. It may be set to.

Further, in the description of the present embodiment, when it is expressed that NW transmits to UE_A10, AMF or SMF may transmit to UE_A10, and when it is expressed that UE_A10 transmits to NW, UE_A10 expresses that it transmits to AMF. Alternatively, it may be transmitted to the SMF. Furthermore, when NW expresses that it receives from UE_A10, AMF or SMF may receive from UE_A10, and when UE_A10 expresses that it receives from NW, UE_A10 may receive from AMF or SMF. It may be there.

[2. Modification example]
The program that operates in the apparatus according to the present invention may be a program that controls the Central Processing Unit (CPU) or the like to operate the computer so as to realize the functions of the embodiments according to the present invention. The program or the information handled by the program is temporarily stored in a volatile memory such as Random Access Memory (RAM), a non-volatile memory such as a flash memory, a Hard Disk Drive (HDD), or another storage device system.

Note that the program for realizing the function of the embodiment according to the present invention may be recorded on a computer-readable recording medium. It may be realized by loading the program recorded on this recording medium into a computer system and executing it. The term "computer system" as used herein is a computer system built into a device, and includes hardware such as an operating system and peripheral devices. The "computer-readable recording medium" is a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a medium that dynamically holds a program for a short time, or another recording medium that can be read by a computer. Is also good.

Further, each functional block or various features of the device used in the above-described embodiment can be implemented or executed in an electric circuit, for example, an integrated circuit or a plurality of integrated circuits. Electrical circuits designed to perform the functions described herein are general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or others. Programmable logic devices, discrete gate or transistor logic, discrete hardware components, or a combination thereof may be included. The general purpose processor may be a microprocessor, a conventional processor, a controller, a microcontroller, or a state machine. The electric circuit described above may be composed of a digital circuit or an analog circuit. In addition, when an integrated circuit technology that replaces the current integrated circuit appears due to advances in semiconductor technology, one or more aspects of the present invention can also use a new integrated circuit according to the technology.

The invention of the present application is not limited to the above-described embodiment. In the embodiment, an example of the device has been described, but the present invention is not limited to this, and the present invention is not limited to this, and a stationary or non-movable electronic device installed indoors or outdoors, for example, an AV device or a kitchen device. , Cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other terminal devices or communication devices such as living equipment.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like within a range not deviating from the gist of the present invention are also included. Further, the present invention can be variously modified within the scope of the claims, and the technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is done. In addition, the elements described in each of the above-described embodiments include a configuration in which elements having the same effect are replaced with each other.

1 Mobile communication system
5 DN_A
6 PDN_A
10 UE_A
20 UTRAN_A
22 NB_A
24 RNC_A
30 PGW_A
35 SGW_A
40 MME_A
45 eNB_A
50 HSS_A
80 E-UTRAN_A
90 Core Network_A
120 NG-RAN_A
122 NR node_A
190 Core network_B
230 SMF_A
235 UPF_A
239 UPF_C
240 AMF_A

Claims (2)

1. UE (User Equipment)
   Equipped with a control unit and a transmitter / receiver
   The control unit starts a backoff timer associated with a DNN (Data Network Name), and then starts a backoff timer.
   When the DNN is a DNN associated with a 5G VN (Virtual Network) group, the backoff timer is applied to the first PLMN (Public Land Mobile Network) and the second PLMN.
   The first PLMN is a PLMN in which the UE is registered.
   The second PLMN is an equal PLMN,
   UE characterized by that.
2. UE (User Equipment) communication control method
   It has a step to start a backoff timer associated with a DNN (Data Network Name).
   When the DNN is a DNN associated with a 5G VN (Virtual Network) group, the backoff timer is applied to the first PLMN (Public Land Mobile Network) and the second PLMN.
   The first PLMN is a PLMN in which the UE is registered.
   The second PLMN is an equal PLMN,
   UE communication control method characterized by that.

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