WO2019139141A1

WO2019139141A1 - User equipment

Info

Publication number: WO2019139141A1
Application number: PCT/JP2019/000756
Authority: WO
Inventors: 強高倉; 靖夫菅原; 真史新本
Original assignee: シャープ株式会社
Priority date: 2018-01-12
Filing date: 2019-01-11
Publication date: 2019-07-18
Also published as: JP2019125843A

Abstract

This user equipment (UE) is connectable to a 5G core network (5GC) via a first access network and/or a second access network using dual connectivity, and connectable thereto via a third access network, and is characterized by being provided with: a control unit that executes a registration procedure in the first access network or the second access network; and a transmission/reception unit that receives a registration refusal message from an access and mobility management function (AMF) in the registration procedure, and, on the basis of information included in the registration refusal message, retrieving and/or selecting a cell in an access network different from the access network in which the registration procedure has been executed.

Description

User equipment

The present invention relates to user equipment. This application claims the benefit of priority over Japanese Patent Application No. 2018-003297, which is a Japanese patent application filed on Jan. 12, 2018, the contents of which are incorporated herein by reference. All are included in the present application.

The 3rd Generation Partnership Project (3GPP) has developed specifications for the second generation (2G), third generation (3G), and fourth generation (4G) communication systems. The 4G communication system is called EPS (Evolved Packet System), the core network that configures EPS is called EPC (Evolved Packet Core), and the access network that configures EPS is E-UTRAN (Evolved Universal Terrestrial Radio Access Network). ) is called.

Further, in 3GPP, examination of the system architecture of 5GS (5G System), which is the next generation, ie, fifth generation (5G) mobile communication system, has been started (see Non-Patent Document 1 and Non-Patent Document 2).

When UE (User Equipment) connectable to 2G or 3G communication system is in 4G communication area (cell) or moved to that cell, it can be connected to EPC (Mobility Management Entity) to connect to EPC. In contrast, a Tracking Area Update Procedure may be initiated by sending a Tracking Area Update Request message. Then, when the MME receiving the tracking area update request message permits the tracking area update request message, the MME transmits a tracking area update accept message to the UE while updating the tracking area. When rejecting a request message, a Tracking Area Update Reject message is sent to the UE. Here, the tracking area update rejection message includes an EMM cause value and an Extended EMM cause. The EMM cause value is set to No. 15, which indicates that the cell is not a suitable cell in the tracking area. Further, as the Extended EMM cause, a value indicating E-UTRAN not allowed or E-UTRAN allowed is set. The UE that has received this tracking area update rejection message is added to the forbidden TA list by adding the tracking area list held by the UE to the forbidden tracking area (also referred to as forbidden Tracking Area or forbidden TA) list. The tracking area update procedure may not be initiated using the tracking area or tracking area list. In this case, the UE may try to connect to the 2G or 3G communication system. Thereafter, for example, when a predetermined time period has elapsed, the tracking area list may be deleted from the forbidden TA list. In this case, the UE can transmit a tracking area update request message using this tracking area list to the MME to connect to the EPC, but from the MME, for the same reason, the tracking area update rejection message May be received. In this way, the connection to the radio access technology (RAT) of the 2G or 3G communication system and the switching of the connection to the RAT of the 4G communication system may be repeated.

In addition, in 5GS system architecture examination, it is considered to extend EPS. Here, as one of the EPS system architectures, the base station provides the UE with the E-UTRA (Evolved Universal Terrestrial Radio Access) function belonging to the E-UTRAN as one of the EPS system architectures, and / or the NR (New Radio) function. A method of connecting to the EPC through a base station provided to the For example, when the UE connected to the EPC through the base station providing the E-UTRA function selects the cell of the base station providing the NR function, the UE performs the tracking area update procedure in that cell. When performing the above, there is a possibility that cell switching may be repeated between the cell of the base station providing the E-UTRA function and the cell of the base station providing the NR function, but the solution to this problem is Not disclosed. Also, the UE connected to the EPC through the base station providing the NR function selects the cell of the base station providing the E-UTRA function, and the UE performs the tracking area update procedure in that cell. Even when performing the above, there is a possibility that cell switching may be repeated between the cell of the base station providing the E-UTRA function and the cell of the base station providing the NR function, but the solution to this problem is Not disclosed.

Furthermore, in 5GS system architecture examination, it is considered not to expand EPS but to construct 5GS which is a new system. Here, as one of the 5GS system architectures, the UE provides the NR function belonging to 5G-AN (5G Access Network) to the UE, and / or the E-UTRA function belonging to 5G-AN to UE A method of connecting to 5 GC via a provided base station is also considered. For example, when the UE connected to the 5GC via the base station providing the E-UTRA function selects the cell of the base station providing the NR function, the UE executes the registration procedure in that cell When there is a possibility that cell switching may be repeated between the cell of the base station providing the E-UTRA function and the cell of the base station providing the NR function, a solution to this problem is disclosed. Not. In addition, the UE connected to the 5GC via the base station providing the NR function selects the cell of the base station providing the E-UTRA function, and the UE executes the registration procedure in that cell. When there is a possibility that cell switching may be repeated between the cell of the base station providing the E-UTRA function and the cell of the base station providing the NR function, a solution to this problem is disclosed. Not.

Moreover, in addition to the above-mentioned situation, when the mode of UE switches from S1 mode to N1 mode or when N1 mode is switched to S1 mode, a solution for not repeating cell switching is also disclosed. It has not been.

A UE according to an embodiment of the present invention is capable of dual connectivity connection to an EPC (Evolved Packet Core) via a first access network and / or a second access network, and via a third access network. Control unit configured to execute a tracking area update procedure in the first access network or the second access network, and an MME (Mobility Management) in the tracking area update procedure. A transmitting / receiving unit for receiving a tracking area update rejection message from Entity), and based on the information included in the tracking area update rejection message, a cell of an access network different from the access network that has executed the tracking area update procedure Search and / or Selecting, characterized in that.

Also, the UE according to an embodiment of the present invention can be connected to an EPC (Evolved Packet Core) via a first access network, and can be connected to a 5GC (5G Core Network) via a fourth access network. A control unit that executes a tracking area update procedure in the first access network, and a MME (User Equipment) that can be connected via a third access network; A transmitting / receiving unit for receiving a tracking area update rejection message from a Mobility Management Entity), and searching and / or selecting a cell of an access network corresponding to dual connectivity based on the information contained in the tracking area update rejection message Or for a stand-alone access network Determining whether to search and / or select the Le, characterized in that.

In addition, the UE according to an embodiment of the present invention is capable of dual connectivity connection to 5GC (5G Core Network) via the first access network and / or the second access network, and a third access network A control unit that executes a registration procedure in the first access network or the second access network, and a UE (User Equipment) connectable via the AMF (Access and Mobility Management) in the registration procedure. And a receiver / receiver for receiving a registration rejection message from Function), and based on the information contained in the registration rejection message, search and / or select a cell of an access network different from the access network that has performed the registration procedure. It is characterized by

Also, the UE according to an embodiment of the present invention can be connected to an EPC (Evolved Packet Core) via a first access network, and can be connected to a 5GC (5G Core Network) via a fourth access network. A UE (User Equipment) connectable via a third access network, and a control unit that executes a registration procedure in the fourth access network, and AMF (Access and Mobility Management) in the registration procedure And transmitting / receiving unit for receiving a registration refusal message from Function), and searching and / or selecting a cell of an access network corresponding to dual connectivity based on the information included in said registration refusal message, or stand-alone Determining whether to search and / or select a corresponding access network cell.

According to one aspect of the present invention, unnecessary cell switching can be prevented from being repeated between the RAT in EPS (E-UTRAN) and the RAT in 5 GS (5G-AN).

FIG. 1 is a diagram showing an outline of a mobile communication system 1; FIG. 2 is a diagram showing a detailed configuration of the mobile communication system 1; FIG. 1 is a diagram showing an outline of a mobile communication system 2; FIG. 2 is a diagram showing a detailed configuration of a mobile communication system 2; It is a figure which shows the apparatus structure of UE. It is a figure which shows the structure of an access network apparatus. It is a figure showing composition of a core network device. It is a figure which shows a tracking area update procedure. It is a figure which shows a tracking area update procedure. It is a figure which shows a registration procedure. It is a figure which shows a registration procedure. FIG. 2 is a schematic view of a mobile communication system 3; It is a figure which shows the data format of rejection reason value. It is a figure which shows the data format of rejection reason value.

The best mode for carrying out the present invention will be described with reference to the drawings.

[1. System Overview]
First, FIG. 1 is a diagram for explaining the outline of the mobile communication system 1, and FIG. 2 is a diagram for explaining the detailed configuration of the mobile communication system 1. FIG. 3 is a diagram for explaining the outline of the mobile communication system 2, and FIG. 4 is a diagram for explaining the detailed configuration of the mobile communication system 2. As shown in FIG. FIG. 12 is a diagram for explaining the outline of the mobile communication system 3.

Further, in FIG. 1, the mobile communication system 1 includes UE (User Equipment) 10, access network A100, access network B110, access network E140, core network A200, core network C220, PDN (Packet Data Network). It is stated that it is constituted including 5). In addition, these may be called UE, access network A, access network B, access network E, core network A, core network C, and PDN, respectively.

Moreover, although FIG. 2 is described about UE, access network A, access network B, core network A, and PDN among FIG. 1, it describes in detail about core network A especially. In FIG. 2, the core network A includes an MME (Mobility Management Entity) 40, an SGW (Serving Gateway) 35, and a PGW (Packet Data Network Gataway) 30, and these devices and functions are mutually connected. Interface is described. The MME 40, SGW 35, and PGW 30 may be referred to as MME, SGW, and PGW, respectively.

Further, FIG. 3 describes that the mobile communication system 2 is configured to include the UE 10, the access network C 120, the access network D 130, the core network B 210, and the DN (Data Network) 6. In addition, these may be called UE, access network C, access network D, core network B, and DN, respectively.

Also, FIG. 4 describes in detail the core network B described in FIG. In FIG. 4, the core network _B is configured to include an Access and Mobility Management Function (AMF) 70, a User Plane Function (UPF) 60, and a Session Management Function (SMF) 65, and these devices / functions Interfaces that connect to each other are described. The AMF 70, UPF 60, and SMF 65 may be referred to as AMF, UPF, and SMF, respectively.

Further, in FIG. 12, the mobile communication system 3 includes the UE 10, access network A, access network D, access network E, core network A, core network B, core network C, PDN, and DN. It is described that it consists of The mobile communication system 3 is configured as a system combining the mobile communication system 1 of FIG. 1 and the mobile communication system 2 of FIG. 2, but the access network B and the access network C may not be included. That is, in mobile communication system 3, access network A is not connected to access network B, core network A is not connected to access network B, and access network D is connected to access network C. The core network B need not be connected to the access network C.

Also, the EPS that is a 4G system is configured to include the UE, the access network _A, the access network _B, and the core network _A, but may further include a PDN. Also, the base station (eNB) of access network A and the base station (en-gNB) of access network B are connected to each other by, for example, an X2 interface.

Also, 5GS, which is a 5G system, is configured to include UE, access network C, access network D, and core network B, but may further include a DN. Also, the base station (ng-eNB) of the access network C and the base station (gNB) of the access network D are mutually connected, for example, by an Xn interface.

In addition, 3G, which is an old system, is configured with Universal Mobile Telecommunications System (UMTS), and includes UMTS Terrestrial Radio Access Network (UTRAN). In addition, 2G which is an old system is configured by GSM (registered trademark) (global system for mobile communications), and includes GERAN (GSM (registered trademark) EDGE Radio Access Network). The radio access provided by the old system of UMTS and GSM (registered trademark) may be referred to as 2G / 3G.

Also, the access network _A corresponds to an E-UTRAN (Evolved Universal Terrestrial Radio Access Network) and / or a wireless LAN access network. One or more base stations (eNB (evolved Node B)) 50 are arranged in E-UTRAN belonging to access network _A. In addition, eNB50 may be called eNB or MeNB (Master eNB). The eNB is a node that provides the E-UTRA user plane and the control plane to the UE, and is a node that connects to the EPC via the S1 interface. In addition, when there are a plurality of eNBs, each eNB is preferably connected by, for example, an X2 interface, but may be connected via another interface. Also, one or more access points are arranged in the wireless LAN access network.

Also, access network B corresponds to E-UTRAN and / or wireless LAN access network. One or more base stations (en-gNB 56) are arranged in E-UTRAN belonging to access network _B. In addition, en-gNB56 may be called en-gNB or SgNB (Secondary gNB). The en-gNB is a node that provides an NR (New Radio) user plane and a control plane to the UE, and is a node connected to the EPC via the S1-U interface. That is, en-gNB is a base station apparatus newly designed for EPC to accommodate NR, and has a function different from that of a base station apparatus (eNB) used in EPS which is a 4G system. Further, in the case where there are a plurality of en-gNBs, it is preferable that the respective en-gNBs are connected to each other, for example, by an X2 interface, but they may be connected via other interfaces.

Also, access network C corresponds to 5G access network (5G-AN). The 5G-AN is configured with an NG Radio Access Network (NG-RAN) and / or a non-3 GPP access network. One or more ng-eNBs 52 are arranged in the NG-RAN belonging to the access network C. In addition, ng-eNB 52 may be called ng-eNB or SN (Secondary Node). The ng-eNB is a node that provides the E-UTRA user plane and control plane to the UE, and is a node connected to the 5GC via an NG-U interface (including an N2 interface or an N3 interface). That is, ng-eNB is a base station apparatus newly designed for 5GS, and has a function different from the base station apparatus (eNB) used by EPS which is 4G system. Also, in the case where there are a plurality of ng-eNBs, each ng-eNB is preferably connected to each other by, for example, an Xn interface, but may be connected via other interfaces. Also, one or more access points are arranged in the wireless LAN access network.

Also, access network D corresponds to 5G access network (5G-AN). The 5G-AN is configured with an NG-RAN and / or a non-3 GPP access network. One or more gNBs (NR Node B) 54 are arranged in the NG-RAN belonging to the access network _D. The gNB 54 may be called gNB or MN (Master Node). gNB is a node that provides an NR user plane and a control plane to the UE, and is a node connected to the 5 GC via an NG interface (including an N2 interface or an N3 interface). That is, gNB is a base station apparatus newly designed for 5GS, and has a function different from that of a base station apparatus (eNB) used in EPS that is a 4G system. Also, in the case where there are a plurality of gNBs, it is preferable that the respective gNBs are connected to each other, for example, by an Xn interface, but may be connected via other interfaces.

Also, the access network _E corresponds to the radio access network of the 2G / 3G system.

Also, core network A corresponds to EPC (Evolved Packet Core). For example, MME, SGW, PGW, Policy and Charging Rules Function (PCRF), Home Subscriber Server (HSS), etc. are arranged in the EPC.

Also, core network B corresponds to 5 GC (5 G Core Network). For example, AMF, UPF, SMF, PCF (Policy Control Function), UDM (Unified Data Management), etc. are arranged in 5 GC.

Also, the core network C corresponds to the core network of the 2G / 3G system.

Also, UEs connect to network services via 3GPP access (also referred to as 3GPP access network, also referred to as 3GPP AN) and / or non-3GPP access (also referred to as non-3GPP access network, also referred to as non-3GPP AN) It is a possible device. The UE may be a terminal device capable of wireless communication such as a mobile phone or a smart phone, and may be a terminal device connectable to both EPS and 5GS. The UE may include a Universal Integrated Circuit Card (UICC) or an Embedded UICC (eUICC). In addition, UE may be expressed as a user apparatus or may be expressed as a terminal apparatus. Also, 3GPP access may refer to E-UTRAN and NG-RAN (NG Radio Access Network). Also, non-3 GPP access may refer to a wireless LAN access network.

Also, PDN and DN may be identical or different. Also, the PDN and the DN may be a network that provides communication services to the UE. The PDN and the DN may be configured as a packet data service network or may be configured for each service. Furthermore, the PDN and DN may include connected communication terminals and server devices. Therefore, connecting with the PDN and / or the DN may be connecting with a communication terminal or a server apparatus arranged in the PDN and / or the DN. Furthermore, transmitting / receiving user data to / from PDN and / or DN may be transmitting / receiving user data to / from a communication terminal or a server apparatus arranged in PDN and / or DN. DN may be expressed as PDN, and PDN may be expressed as DN.

The core network may be an access network and an IP mobile communication network operated by a mobile network operator (MNO (Mobile Network Operator)) connected to a DN, or the mobile communication system is operated and managed. May be a core network for mobile operators, or a core network for virtual mobile operators such as MVNOs (Mobile Virtual Network Operators) and MVNEs (Mobile Virtual Network Enablers) or virtual mobile communications service providers. May be.

Also included in Access Network A, and / or Access Network B, and / or Access Network C, and / or Access Network D, and / or Access Network E, and / or these Access Networks 1 The above devices / functions may be called an access network or an access network device.

That is, the fact that the access network and / or the access network device transmit / receive messages and / or execute the procedure is the access network _A, and / or the access network _B, and / or the access network _C, and And / or access network _D, and / or access network _E, and / or one or more devices / functions included in these access networks mean to send and / or receive messages and / or perform procedures. It is also good.

Also, core network A, and / or core network B, and / or core network C, and / or one or more devices / functions included in these core networks are referred to as core network or core network device. May.

That is, that the core network and / or the core network device transmit / receive messages and / or execute the procedure is the same as the core network _A, and / or the core network _B, and / or the core network _C, and It may mean that one or more devices / functions included in these core networks send and / or receive messages and / or perform procedures.

Also included in Access Network A, and / or Access Network B, and / or Access Network C, and / or Access Network D, and / or Access Network E, and / or these Access Networks 1 One or more devices / functions included in the above devices / functions, and / or core network A, and / or core network B, and / or core network C, and / or core networks thereof, and / or One or more devices / functions included in the PDN and / or PDN and / or one or more devices / functions included in the DN and / or DN may be referred to as a network or a network device.

That is, the fact that the network and / or the network device transmit and receive the message and / or execute the procedure corresponds to the access network _A, and / or the access network _B, and / or the access network _C, and / or Access network D, and / or access network E, and / or one or more devices / functions included in these access networks, and / or core network A, and / or core network B, and / or core Network_C, and / or one or more devices / functions included in these core networks, and / or PDN, and / or one or more devices / functions included in PDN, and / or DNs, and / or DNs One or more of the included devices / functions may mean to send and receive messages and / or perform procedures.

Also, the UE can connect to the access network. Furthermore, the UE can be connected to the core network via an access network. Furthermore, the UE can connect to the PDN and / or the DN via the access network and the core network. That is, the UE can transmit / receive (communicate) user data with the PDN and / or the DN. When transmitting and receiving user data, not only IP (Internet Protocol) communication but also non-IP communication may be used.

Here, IP communication is data communication using IP, and data transmission / reception is performed by IP packets. An IP packet is composed of an IP header and a payload. The payload section may include devices / functions included in the EPS, and data transmitted / received by devices / functions included in the 5GS.

Further, non-IP communication is data communication not using IP, and data transmission / reception is performed in a format different from the structure of the IP packet. For example, non-IP communication may be data communication realized by transmission and reception of application data not having an IP header attached, or the UE may add another header such as a MAC header or Ethernet (registered trademark) frame header. It may be data communication to transmit and receive.

[2. Configuration of each device]
Next, the configuration of each device used in each embodiment will be described using the drawings. Note that each device or at least part (including all) of the functions of each device may be configured as physical hardware, or logically (virtually configured on general-purpose hardware) Hardware) or as software.

Incidentally, each storage unit (storage unit _A340, storage unit _A440, storage unit _A640) in each device / function appearing below is, for example, a semiconductor memory, a solid state drive (SSD), a hard disk drive (HDD) And so on. Also, each storage unit is not only information originally set from the shipping stage, but also devices / functions other than its own device / function (eg, UE, and / or access network device, and / or core network device, // Or, various information transmitted / received to / from PDN and / or DN) can be stored. Each storage unit can store identification information, control information, flags, parameters, and the like included in control messages transmitted and received within various communication procedures described later. Each storage unit may store these pieces of information for each UE. Each storage unit can store control messages and user data transmitted and received in each procedure in each embodiment.

[2.1. Device Configuration of UE]
First, an example of the device configuration of the UE will be described using FIG. The UE includes a control unit A 300, an antenna 310, a transceiver unit A 320, and a storage unit A 340. The control unit A300, the transmission / reception unit A320, and the storage unit A340 are connected via a bus. The transmitting / receiving unit A320 is connected to the antenna 310.

Control unit_A 300 is a functional unit that controls the operation and function of the entire UE. Control unit_A 300 implements various types of processing in the UE by reading out and executing various programs stored in storage unit _A 340 as necessary.

The transmission / reception unit A320 is a functional unit for performing wireless communication with a base station apparatus (eNB or en-gNB or ng-eNB or gNB) in the access network via an antenna. That is, the UE may transmit / receive user data and / or control information to / from the access network device and / or core network device, and / or PDN, and / or DN using the transceiver unit_A 320. it can.

Referring to FIG. 2 and FIG. 4, the UE uses base transceiver station (A) in access network _A and / or a base station device in access network _B by using transmitting / receiving unit _A 320. It can communicate with a base station apparatus (ng-eNB) in the access network C and / or with a base station apparatus (gNB) in the access network D. Also, the UE can transmit / receive an MME (Non-Access-Stratum) message to / from the MME via the S1-MME interface by using the transmission / reception unit A320. Moreover, UE can transmit / receive an AMF and a NAS message via N1 interface by using transmitting / receiving part_A320.

The storage unit_A 340 is a functional unit for storing programs, user data, control information, and the like necessary for each operation of the UE.

[2.2. Device configuration of eNB]
Next, a device configuration example of the base station device (eNB) in the access network_A will be described using FIG. The eNB includes a control unit A 400, an antenna 410, a network connection unit A 420, a transmission / reception unit A 430, and a storage unit A 440. The control unit A 400, the network connection unit A 420, the transmission / reception unit A 430, and the storage unit A 440 are connected via a bus. The transmitting / receiving unit _A 430 is connected to the antenna 410.

Control part_A400 is a function part which controls operation | movement / function of the whole eNB. Control part_A400 implement | achieves the various processes in eNB by reading and running the various programs memorize | stored in memory | storage part_A440 as needed.

The network connection unit _A 420 is a functional unit for the eNB to communicate with the SGW and / or the MME and / or the base station apparatus (en-gNB) in the access network _B. That is, the eNB can transmit / receive user data and / or control information to / from the SGW and / or the MME and / or the en-gNB using the network connection unit A420.

The transceiver unit_A 430 is a functional unit for performing wireless communication with the UE via the antenna 410. That is, the eNB can transmit and receive user data and / or control information to and from the UE using the transceiver unit_A 430.

Referring to FIG. 2, the eNB can communicate with the MME via the S1-MME interface by using the network connection unit A420 and communicates with the SGW via the S1-U interface. And can communicate with en-gNB via the X2 interface. Also, the eNB can communicate with the UE via the LTE-Uu interface by using the transceiver unit_A 430.

The storage unit_A 440 is a functional unit for storing programs, user data, control information, and the like necessary for each operation of the eNB.

[2.3. Device configuration of en-gNB]
Next, a device configuration example of the base station device (en-gNB) in the access network B will be described using FIG. The en-gNB is configured to include a control unit A400, an antenna 410, a network connection unit A420, a transmission / reception unit A430, and a storage unit A440. The control unit A 400, the network connection unit A 420, the transmission / reception unit A 430, and the storage unit A 440 are connected via a bus. The transmitting / receiving unit _A 430 is connected to the antenna 410.

A control unit A 400 is a functional unit that controls the operation and function of the entire en-gNB. The control unit A 400 implements various processes in en-gNB by reading out and executing various programs stored in the storage unit A 440 as necessary.

The network connection unit A420 is a functional unit for the en-gNB to communicate with the base station apparatus (eNB) and / or the SGW in the access network A. That is, the en-gNB can transmit and receive user data and / or control information to and from the eNB and / or the SGW using the network connection unit A420.

The transceiver unit_A 430 is a functional unit for performing wireless communication with the UE via the antenna 410. That is, the en-gNB can transmit / receive user data and / or control information to / from the UE using the transmission / reception unit A430.

Describing with reference to FIG. 2, the en-gNB can communicate with the eNB via the X2 interface by using the network connection unit A420 and communicates with the SGW via the S1-U interface. be able to. Also, the en-gNB can communicate with the UE by using the transceiver unit_A 430.

The storage unit _A 440 is a functional unit for storing programs, user data, control information, and the like necessary for each operation of the en-gNB.

[2.4. Device Configuration of ng-eNB]
Next, a device configuration example of the base station device (ng-eNB) in the access network C will be described using FIG. The ng-eNB includes a control unit A400, an antenna 410, a network connection unit A420, a transmission / reception unit A430, and a storage unit A440. The control unit A 400, the network connection unit A 420, the transmission / reception unit A 430, and the storage unit A 440 are connected via a bus. The transmitting / receiving unit _A 430 is connected to the antenna 410.

Control part_A400 is a function part which controls operation | movement / function of the whole ng-eNB. Control part_A400 implement | achieves the various processes in ng-eNB by reading and running the various programs memorize | stored in memory | storage part A440 as needed.

The network connection unit A420 is a functional unit for the ng-eNB to communicate with the base station apparatus (gNB) and / or the UPF in the access network D. That is, the ng-eNB can transmit / receive user data and / or control information to / from the gNB and / or the UPF using the network connection unit A420.

The transceiver unit_A 430 is a functional unit for performing wireless communication with the UE via the antenna 410. That is, the ng-eNB can transmit and receive user data and / or control information to and from the UE using the transceiver unit_A 430.

Describing with reference to FIG. 2, the ng-eNB can communicate with the gNB via the Xn interface by using the network connection unit _A 420 and can communicate with the UPF via the N3 interface. it can. Moreover, ng-eNB can communicate with UE by using transmission / reception unit A430.

Storage unit_A 440 is a functional unit for storing a program, user data, control information, and the like necessary for each operation of ng-eNB.

[2.5. Configuration of gNB]
Next, an example of device configuration of the base station device (gNB) in the access network D will be described using FIG. gNB includes a control unit A 400, an antenna 410, a network connection unit A 420, a transmission / reception unit A 430, and a storage unit A 440. The control unit A 400, the network connection unit A 420, the transmission / reception unit A 430, and the storage unit A 440 are connected via a bus. The transmitting / receiving unit _A 430 is connected to the antenna 410.

The control unit A 400 is a functional unit that controls the operation and function of the entire gNB. The control unit A 400 implements various processes in the gNB by reading out and executing various programs stored in the storage unit A 440 as necessary.

The network connection unit_A 420 is a functional unit for the gNB to communicate with the UPF and / or the AMF and / or the base station apparatus (ng-eNB) in the access network_C. That is, the gNB can transmit / receive user data and / or control information to / from UPF and / or AMF and / or ng-eNB using network connection unit A420.

The transceiver unit_A 430 is a functional unit for performing wireless communication with the UE via the antenna 410. That is, the gNB can transmit / receive user data and / or control information to / from the UE using the transmission / reception unit A430.

Referring to FIG. 2, the gNB can communicate with the AMF through the N2 interface by using the network connection_A 420 and can communicate with the UPF through the N3 interface. It can communicate with ng-eNB via Xn interface. Moreover, gNB can communicate with UE by using transmission / reception unit A430.

The storage unit _A 440 is a functional unit for storing programs, user data, control information, and the like necessary for each operation of gNB.

[2.6. Device configuration of MME]
Next, an example of the device configuration of the MME will be described using FIG. The MME includes a control unit A 600, a network connection unit A 620, and a storage unit A 640. The control unit A 600, the network connection unit A 620, and the storage unit A 640 are connected via a bus.

Control unit_A 600 is a functional unit that controls the operation and function of the entire MME. Control unit_A 600 implements various types of processing in MME by reading out and executing various programs stored in storage unit _A 640 as necessary.

The network connection unit_A 620 is a functional unit for the MME to connect with the base station apparatus (eNB) and / or the SGW in the access network_A. That is, the MME can transmit and receive user data and / or control information to and from the eNB and / or the SGW using the network connection unit A620.

Referring to FIG. 2, the MME can communicate with the eNB via the S1-MME interface by using the network connection unit A620, and can communicate with the SGW via the S11 interface. it can.

The storage unit_A 640 is a functional unit for storing programs, user data, control information, and the like necessary for each operation of the MME.

Also, the MME is a control apparatus or function that performs location information management including mobility management of the UE, connection state management of the UE, and access control via the access network_A. The MME may include a function as a session management device that manages a session established by the UE.

Also, in location information management including mobility management of UE, an EMM state (EMM state) is managed. The EMM state may be synchronized between the UE and the MME. EMM states include EMM non-registration state (EMM-DEREGISTERED state) and EMM registration state (EMM-REGISTERED state). Here, in the EMM-DEREGISTERED state, the MME can not reach the UE because the UE is not registered in the network and the UE context in the MME does not have valid location information or routing information for the UE. . Also, in the EMM-REGISTERED state, since the UE is registered in the network, the UE can receive services that require registration with the network.

Also, in connection state management of the UE, an EMM mode (EMM mode) is managed. The EMM mode may be synchronized between the UE and the MME. EMM modes include EMM disconnected mode (EMM-IDLE mode) and EMM connected mode (EMM-CONNECTED mode). Here, in the EMM-IDLE mode, the UE is in the EMM-REGISTERED state but does not have a NAS signaling connection (NAS signaling connection) established with the MME. Also, in the EMM-IDLE mode, the UE does not have a LTE-Uu interface connection. On the other hand, in the EMM-CONNECTED mode, it has a NAS signaling connection established with the MME. Also, in the EMM-CONNECTED mode, the UE may have an LTE-Uu interface connection.

Moreover, when several MME is contained in core network_A, MMEs may be connected. Thereby, transmission / reception of UE context can be performed between MMEs. As described above, the MME is a management device that transmits and receives control information related to mobility management and session management with the UE, and in other words, may be a control device of a control plane (also referred to as C-Plane or CP).

Also, the MME may be a relay device that transfers user data as a gateway between the core network A and the access network. The user data transmitted and received by the MME serving as the gateway may be small data.

[2.7. SGW device configuration]
Next, an example of the device configuration of the SGW will be described using FIG. The SGW includes a control unit A 600, a network connection unit A 620, and a storage unit A 640. The control unit A 600, the network connection unit A 620, and the storage unit A 640 are connected via a bus.

Control unit_A 600 is a functional unit that controls the operation and function of the entire SGW. Control unit_A 600 implements various processing in SGW by reading out and executing various programs stored in storage unit _A 640 as necessary.

In the network connection unit A620, the SGW is a base station apparatus (eNB) in the access network A, and / or a base station apparatus (en-gNB) in the access network B, and / or an MME, and / or a PGW. It is a functional unit for connecting to That is, the SGW can transmit and receive user data and / or control information with the eNB and / or the en-gNB and / or the MME and / or the PGW using the network connection unit A620. .

Referring to FIG. 2, the SGW can communicate with the eNB via the S1-U interface by using the network connection unit A620, and the en-gNB and the SGW can be communicated via the S1-U interface. It can communicate, can communicate with the MME via the S11 interface, and can communicate with the PGW via the S5 interface.

The storage unit_A 640 is a functional unit for storing programs, user data, control information, and the like necessary for each operation of the SGW.

The SGW is a relay device that transfers user data as a gateway between the core network A and the access network A.

[2.8. PGW device configuration]
Next, an example of the device configuration of the PGW will be described using FIG. The PGW includes a control unit A 600, a network connection unit A 620, and a storage unit A 640. The control unit A 600, the network connection unit A 620, and the storage unit A 640 are connected via a bus.

Control unit_A 600 is a functional unit that controls the operation and function of the entire PGW. Control unit_A 600 realizes various processing in PGW by reading out and executing various programs stored in storage unit _A 640 as necessary.

The network connection unit_A 620 is a functional unit for the PGW to connect to the SGW and / or the PDN. That is, the PGW can transmit and receive user data and / or control information to and from the SGW and / or PDN using the network connection unit A620.

Referring to FIG. 2, the PGW can communicate with the SGW via the S5 interface by using the network connection unit A620. The PGW can also communicate with the PDN by using the network connection unit A620.

A storage unit_A 640 is a functional unit for storing programs, user data, control information, and the like necessary for each operation of the PGW.

The PGW is a relay apparatus that transfers user data as a gateway between the PDN and the core network A. The PGW may be a gateway for IP communication and / or non-IP communication. Furthermore, the PGW 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_A. Further, the plurality of arranged gateways may be gateways connecting the core network A and a single PDN.

[2.9. AMF device configuration]
Next, an example of the device configuration of the AMF will be described with reference to FIG. The AMF includes a control unit A 600, a network connection unit A 620, and a storage unit A 640. The control unit A 600, the network connection unit A 620, and the storage unit A 640 are connected via a bus.

The control unit_A 600 is a functional unit that controls the operation and function of the entire AMF. The control unit_A 600 implements various processes in the AMF by reading out and executing various programs stored in the storage unit _A 640 as necessary.

The network connection unit A620 is a functional unit for connecting the AMF to a base station (gNB) and / or an SMF in the access network D. That is, the AMF can transmit and receive user data and / or control information to and from the gNB and / or the SMF using the network connection unit _A 620.

Referring to FIG. 2, the AMF can communicate with the gNB via the N2 interface by using the network connection_A 620 and can communicate with the SMF via the N11 interface. In addition, the AMF can transmit and receive a NAS message to and from the UE via the N1 interface by using the network connection unit A620.

The storage unit_A 640 is a functional unit for storing programs, user data, control information, and the like necessary for each operation of the AMF.

In addition, AMF has a function of exchanging control messages with RAN using N2 interface, a function of exchanging NAS messages with UE using N1 interface, a function of performing encryption and integrity protection of NAS messages, registration management (Registration management; RM) function, Connection management (CM) function, Reachability management function, Mobility management function such as UE, SM (Session Management) between UE and SMF The function to transfer messages, Access authentication (Access Authorization) function, Security anchor function (SEA), Security anchor functionality (SEA), Security context management (SCM) function, N2 to N3 IWF (Non-3GPP Interworking Function) Supports interface function, supports sending and receiving of NAS signal with UE via N3 IWF That function, has a function for authenticating the UE connected through N3IWF.

Also, in registration management, RM state (RM state) for each UE is managed. The RM state may be synchronized between the UE and the AMF. The RM state includes a non-registration state (RM-DEREGISTERED state) and a registration state (RM-REGISTERED state). Here, in the RM-DEREGISTERED state, the AMF can not reach the UE because the UE is not registered in the network and the UE context in the AMF does not have valid location information or routing information for the UE. . Also, in the RM-REGISTERED state, since the UE is registered in the network, the UE can receive services that require registration with the network. The RM state may be expressed as 5 GMM state (5 GMM state). In this case, the RM-DEREGISTERED state may be expressed as 5GMM-DEREGISTERED state, and the RM-REGISTERED state may be expressed as 5GMM-REGISTERED state.

In connection management, the CM state (CM state) of each UE is managed. The CM state may be synchronized between the UE and the AMF. The CM states include a disconnected state (CM-IDLE state) and a connected state (CM-CONNECTED state). Here, in the CM-IDLE state, the UE is in the RM-REGISTERED state but does not have a NAS signaling connection (NAS signaling connection) established with the AMF via the N1 interface. Also, in the CM-IDLE state, the UE does not have the connection of the N2 interface (N2 connection) and the connection of the N3 interface (N3 connection). On the other hand, the CM-CONNECTED state has a NAS signaling connection (NAS signaling connection) established with the AMF via the N1 interface. Also, in the CM-CONNECTED state, the UE may have an N2 interface connection (N2 connection) and / or an N3 interface connection (N3 connection).

Furthermore, in connection management, the CM state in 3GPP access and the CM state in non-3GPP access may be separately managed. In this case, as a CM state in 3GPP access, there may be no connection state in 3GPP access (CM-IDLE state over 3GPP access) and a connection state in 3GPP access (CM-CONNECTED state over 3GPP access). Furthermore, as a CM state in non-3GPP access, a connection state in non-3GPP access (CM-IDLE state over non-3GPP access) and a connection state in non-3GPP access (CM-CONNECTED state over non-3GPP access) ) May be.

The CM state may be expressed as 5GMM mode (5GMM mode). In this case, the unconnected state may be expressed as 5GMM unconnected mode (5GMM-IDLE mode), and the connected state may be expressed as 5GMM connected mode (5GMM-CONNECTED mode). Furthermore, the disconnection state in 3GPP access may be expressed as 5 GMM non-connection mode (5 GMM-IDLE mode over 3 GPP access) in 3 GPP access, the connection state in 3 GPP access is 5 GMM connection mode in 3 GPP access (5 GMM- It may be expressed as CONNECTED mode over 3GPP access). Furthermore, the disconnection state in non-3GPP access may be expressed as 5GMM non-connection mode (5 GMM-IDLE mode over non-3GPP access) in non-3GPP access, and the connection state in non-3GPP access is non- -It may be expressed as 5GMM connection mode (non-3GPP access) in 3GPP access.

Also, one or more AMFs may be arranged in the core network _B. Also, the AMF may be an NF that manages one or more NSI (Network Slice Instance). Also, the AMF may be a shared CP function (CCNF; Common CPNF (Control Plane Network Function)) shared among a plurality of NSIs.

N3 IWF is an apparatus and / or function disposed between non-3 GPP access and 5 GC when UE connects to 5 GS via non-3 GPP access.

[2.10. SMF device configuration]
Next, an example of the device configuration of the SMF will be described with reference to FIG. The SMF includes a control unit A 600, a network connection unit A 620, and a storage unit A 640. The control unit A 600, the network connection unit A 620, and the storage unit A 640 are connected via a bus.

The control unit_A 600 is a functional unit that controls the operation and function of the entire SMF. The control unit A 600 implements various processes in the SMF by reading and executing various programs stored in the storage unit A 640 as necessary.

A network connection unit A 620 is a functional unit for the SMF to connect with the AMF and / or the UPF. That is, the SMF can transmit / receive user data and / or control information to / from the AMF and / or the UPF using the network connection unit _A 620.

Referring to FIG. 2, the SMF can communicate with the AMF through the N11 interface by using the network connection_A 620 and can communicate with the UPF through the N4 interface.

A storage unit A 640 is a functional unit for storing programs, user data, control information, and the like necessary for each operation of the SMF.

SMF is a session management function such as establishment / modification / release of PDU session, IP address allocation to the UE (IP address allocation) and its management function, UPF selection and control function, appropriate destination (destination ) UPF setting function for routing traffic, function to send and receive SM part of NAS message, function to notify that downlink data has arrived (Downlink Data Notification), AN via N2 interface via AMF It has the function of providing the AN-specific (per AN) SM information to be sent, the function of determining the SSC mode (Session and Service Continuity mode) for the session, the roaming function, etc.

[2.11. Device configuration of UPF]
Next, an example of the apparatus configuration of the UPF will be described using FIG. The UPF includes a control unit A 600, a network connection unit A 620, and a storage unit A 640. The control unit A 600, the network connection unit A 620, and the storage unit A 640 are connected via a bus.

The control unit_A 600 is a functional unit that controls the operation and function of the entire UPF. Control unit_A 600 implements various types of processing in UPF by reading out and executing various programs stored in storage unit _A 640 as necessary.

The network connection unit A620 is a base station apparatus (gNB) in the access network D, and / or a base station apparatus (ng-eNB) in the access network C, and / or an SMF, and / or a DN. It is a functional unit for connecting to That is, UPF can transmit / receive user data and / or control information to / from gNB and / or ng-eNB, and / or SMF, and / or DN using network connection unit _A 620. .

Referring to FIG. 2, the UPF can communicate with the gNB via the N3 interface by using the network connection unit A620, and can communicate with the ng-eNB via the N3 interface. It can communicate with the SMF via the N4 interface, can communicate with the DN via the N6 interface, and can communicate with other UPFs via the N9 interface.

The storage unit_A 640 is a functional unit for storing programs, user data, control information, and the like necessary for each operation of the UPF.

UPF functions as an anchor point for intra-RAT mobility or inter-RAT mobility, functions as an external PDU session point for interconnecting to DN (that is, a user as a gateway between DN and core network B) Data forwarding function), packet routing and forwarding function, UL Link Classifier (UL CL) function supporting routing of multiple traffic flows for one DN, multi-homed PDU session support It has a Branching point function, a QoS processing function for the user plane, an uplink traffic verification function, buffering of downlink packets, and a function to trigger downlink data notification.

Also, the UPF may be a gateway for IP communication and / or non-IP communication. Also, UPF 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 may be gateways connecting the core network _B and a single DN. Note that the UPF may have connectivity with other NFs, and may be connected to each device via other NFs.

[3. Description of terms and identification information used in each embodiment]
Next, highly specialized terms used in at least one of the embodiments and identification information used in the procedure will be described in advance.

First, dual connectivity may be composed of a master base station and a secondary base station, and may indicate connectivity of user data distribution using either the master base station or the secondary base station, or two user planes. The base station may be in the operation mode of the configured UE. The master base station and the secondary base station are connected by an Xn interface or an X2 interface. Also, the master base station may interface the control plane and the user plane with the core network. Also, in the secondary base station, only the user plane may be interfaced with the core network, and the control plane may be connected with the core network via the master base station.

In other words, dual connectivity is comprised of two types of base stations: a base station providing the NR function to the UE and a base station providing the E-UTRA function to the UE.

In addition, a stand-alone connection configuration (also referred to as a stand-alone) is configured by any one of a base station that provides the NR function to the UE or a base station that provides the E-UTRA function to the UE.

Further, the S1 mode is a UE mode capable of transmitting and receiving messages using the S1 interface. The S1 interface may be configured by the S1-MME interface, the S1-U interface, and the X2 interface that connects between the radio base stations.

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

In addition, although the access to the EPC via the eNB providing the E-UTRA function and the access to the EPC via the en-gNB providing the NR function are set to the S1 mode, they may be respectively configured as different modes. .

In addition, the N1 mode is a UE mode in which the UE can access the 5GC via the 5G access network. Also, the N1 mode may be a UE mode capable of transmitting and receiving messages using the N1 interface. The N1 interface may be configured by an Xn interface connecting between the N1 interface and the radio base stations.

For example, a UE in the N1 mode can access 5GC via ng-eNB providing E-UTRA function, and access 5GC via gNB providing NR function.

In addition, although the access to 5GC via ng-eNB which provides E-UTRA function and the access to 5 GC via gNB which provides NR function are set as N1 mode, they may be respectively configured as different modes. .

Also, equivalent PLMN (Public Land Mobile Network) is a PLMN treated as being the same PLMN as a HPLMN (Home PLMN) in a network and / or a UE.

Also, the first behavior is that, when the tracking area update request (also referred to as a tracking area update request message) for core network A is rejected, the UE searches for an access network different from the located access network and And / or the behavior of choice. The UE performing the first behavior may select a different access network and then attempt to reconnect to core network A via the selected access network. In addition, when the UE performing the first behavior selects a different access network, the UE may stop the connection function to the access network that was in the area (that is, search for the cell of the access network in the area) And / or may not be selected.

Specifically, when the UE transmits a tracking area update request to core network A via access network B, and core network A rejects the tracking area update request (that is, the core network When the tracking area update rejection (also referred to as tracking area update rejection message) is received from _A and the rejection reason value included in the tracking area update rejection indicates the first rejection reason value, the UE is , The function of connecting to access network _B may be stopped, and cells of access network _A may be searched and / or selected.

Also, when the UE transmits a tracking area update request to core network A via access network B, and core network A rejects the tracking area update request (that is, from core network A) When the tracking area update rejection is received) and the rejection reason value included in the tracking area update rejection indicates the second rejection reason value, the UE transmits the request to the access network _A and the access network _B. The connection function may be stopped and 2G / 3G cells (ie, cells of access network _E) may be searched and / or selected.

The second behavior is a behavior in which the UE searches and / or selects an access network different from the located access network when the tracking area update request to the core network_A is rejected. The UE performing the second behavior may select a different access network and then attempt to reconnect to core network A via the selected access network. In addition, when the UE performing the second behavior selects a different access network, the UE may stop the connection function to the existing access network (that is, searches for a cell of the existing access network) And / or may not be selected.

Specifically, when the UE transmits a tracking area update request to core network A via access network A, and core network A rejects the tracking area update request (that is, the core network When the tracking area update rejection is received from _A) and the rejection reason value included in the tracking area update rejection indicates the third rejection reason value, the UE has a function of connecting to the access network _A. , And may search and / or select cells of access network _B.

Also, if the UE transmits a tracking area update request to core network A via access network A, and core network A rejects the tracking area update request (ie, from core network A) When the tracking area update rejection is received) and the rejection reason value included in the tracking area update rejection indicates the second rejection reason value, the UE transmits the request to the access network _A and the access network _B. The connection function may be stopped, and 2G / 3G cells (ie, cells of access network _E) may be searched and / or selected.

Also, the third behavior is that when the registration request (also referred to as a registration request message) for the core network B is rejected, the UE searches and / or selects an access network different from the located access network. It is a behavior. The UE performing the third behavior may select a different access network and then attempt to reconnect to core network B via the selected access network. In addition, when the UE performing the third behavior selects a different access network, the UE may stop the connection function to the existing access network (that is, searches for a cell of the existing access network) And / or may not be selected.

Specifically, when the UE transmits a registration request to the core network _B via the access network _D, and the core network _B rejects the registration request (that is, registration from the core network _B) If a rejection (also referred to as a registration rejection message) is received, and the rejection reason value included in the registration rejection indicates a fourth rejection reason value, the UE performs a connection function to the access network _D. It may stop and search and / or select the cell of access network C.

Furthermore, if the UE sends a registration request to core network _B via access network _D, and core network _B rejects the registration request (ie, receives a registration rejection from core network _B When the rejection reason value included in the registration rejection indicates the fifth rejection reason value, the UE stops the connection function to the access network C and access network D, and 2G / A 3G cell (ie, a cell of access network _E) may be searched and / or selected.

The fourth behavior is a behavior in which the UE searches and / or selects an access network different from the located access network when the registration request for the core network _B is rejected. The UE performing the fourth behavior may select a different access network and then attempt to reconnect to core network B via the selected access network. When the UE performing the fourth behavior selects a different access network, it may stop the connection function to the existing access network (that is, searches for a cell of the existing access network) And / or may not be selected.

Specifically, when the UE transmits a registration request to core network B via access network C, and core network B rejects the registration request (that is, registration from core network B) When the rejection reason value included in the registration rejection indicates the sixth rejection reason value), the UE stops the connection function to the access network C, and the access network D is received. Cells of may be searched and / or selected.

Furthermore, if the UE sends a registration request to core network B via access network C, and core network B rejects the registration request (ie, receives a registration rejection from core network B) When the rejection reason value included in the registration rejection indicates the fifth rejection reason value, the UE stops the connection function to the access network C and access network D, and 2G / A 3G cell (ie, a cell of access network _E) may be searched and / or selected.

The fifth behavior is that the tracking area update request for core network A is rejected and the rejection reason value is received, and when the UE mode is switched from S1 mode to N1 mode, within the same PLMN and equally. In PLMN (equivalent PLMN), it is the behavior of performing access network selection in N1 mode based on the rejection reason value acquired in S1 mode.

In other words, after the UE operating in S1 mode transmits a tracking area update request to core network A and receives a tracking area update rejection including any rejection reason value from core network A, the UE Even if the mode is changed from S1 mode to N1 mode, the UE may search and / or select the access network according to the rejection reason value within the same PLMN and within the equivalent PLMN. .

The sixth behavior is that the registration request for core network B is rejected and the rejection reason value is received, and when the UE mode is switched from the N1 mode to the S1 mode, within the same PLMN and within the equivalent PLMN. If it is, it is a behavior which performs access network selection in S1 mode based on the rejection reason value acquired in N1 mode.

In other words, after the UE operating in the N1 mode transmits a registration request to the core network B and receives a registration rejection including any rejection reason value from the core network B, the UE mode is the N1 mode. Even when the mode is changed to S1 mode, the UE may search and / or select an access network according to the rejection reason value within the same PLMN and within the equivalent PLMN.

The seventh behavior is that the tracking area update request to the core network A is rejected, and the rejection reason value included in the first identification information indicates the applicability of the connection permission information of the wireless access system in dual connectivity. It is a process which performs access network selection based on the information to show.

Specifically, the UE determines the applicability of dual connectivity based on the information indicating the applicability of connection permission information of the wireless access system in dual connectivity, and if applicable, the connection of the wireless access system Perform access network selection with dual connectivity based on the permission information.

The UE performs access network selection in a stand-alone connection configuration based on connection permission information of the wireless access system when dual connectivity is not applicable or when information on dual connectivity application is not included. Also good. For example, when the connection permission of the wireless access system is not connectable in the standalone connection configuration provided by the core network A, the cell selection of the 2G / 3G wireless access system or the wireless access system provided by the core network B is performed Also good. In this case, the UE is either the 2G / 3G radio access system or any one of the radio access systems provided by the core network B based on the user preference and / or operator policy preset in the UE. The cell to be provided may be selected.

The eighth behavior is that the registration request for the core network B is rejected, and the rejection reason value included in the first identification information indicates the applicability of the connection permission information of the wireless access system in dual connectivity. Is a process of selecting an access network based on

The UE performs access network selection in a stand-alone connection configuration based on connection permission information of the wireless access system when dual connectivity is not applicable or when information on dual connectivity application is not included. Also good. For example, when the connection permission of the wireless access system is not connectable in the stand-alone connection configuration provided by the core network B, the cell selection of the wireless access system provided by the core network B may be performed.

Also, the first rejection reason value allows connection to Access Network_A or registration with the core network via Access Network_A, but connection via Access Network_B or via Access Network_B It may indicate that registration to the core network is not permitted.

Also, the second rejection reason value does not permit connection to access network A or registration with the core network via access network A, or connection to access network B or via access network B. It may indicate that registration to the core network is also not permitted.

Also, the third rejection reason value does not permit connection to Access Network A or registration with the core network via Access Network A, but connection via Access Network B or Access Network B Registration to the core network may indicate to allow.

Also, the fourth rejection reason value allows connection to access network C or registration with the core network via access network C, but connection via access network D or access network D It may indicate that registration to the core network is not permitted.

Also, the fifth rejection reason value does not permit connection to access network C or registration with core network via access network C, or connection to access network D or via access network D It may indicate that registration to the core network is also not permitted.

Also, the sixth rejection reason value does not permit connection to access network C or registration with core network via access network C, but via connection to access network D or access network D Registration to the core network may indicate to allow.

The seventh rejection reason value is information indicating whether to permit connection to the access network A or registration with the core network via the access network A. The seventh rejection reason value takes a value of 0 or 1.

Here, when the seventh rejection reason value is 0, it indicates that the connection to the access network A or the registration with the core network via the access network A is permitted.

Also, when the seventh rejection reason value is 1, it indicates that the connection to the access network A or the registration with the core network via the access network A is not permitted.

The meaning when the seventh rejection reason value is 1 and the meaning when it is 0 may be reversed.

The eighth rejection reason value is information indicating whether to permit connection to the access network _B or registration in the core network via the access network _B. The eighth rejection reason value takes a value of 0 or 1.

Here, when the eighth rejection reason value is 0, it indicates that the connection to the access network _B or the registration with the core network via the access network _B is permitted.

Also, when the eighth rejection reason value is 1, it indicates that the connection to the access network _B or the registration in the core network via the access network _B is not permitted.

The meaning when the eighth rejection reason value is 1 and the meaning when it is 0 may be reversed.

The ninth rejection reason value is information indicating whether to permit connection to the access network C or registration in the core network via the access network C. The ninth rejection reason value takes a value of 0 or 1.

Here, when the ninth rejection reason value is 0, it indicates that the connection to the access network_C or the registration with the core network via the access network_C is permitted.

Also, when the ninth rejection reason value is 1, it indicates that the connection to the access network C or the registration in the core network via the access network C is not permitted.

The meaning when the ninth rejection reason value is 1 and the meaning when it is 0 may be reversed.

The tenth rejection reason value is information indicating whether connection to the access network D or registration in the core network via the access network D is permitted. The tenth rejection reason value takes a value of 0 or 1.

Here, when the tenth rejection reason value is 0, it indicates that connection to the access network D or registration with the core network via the access network D is permitted.

Also, when the tenth rejection reason value is 1, it indicates that the connection to the access network D or the registration in the core network via the access network D is not permitted.

The meaning when the tenth rejection reason value is 1 and the meaning when it is 0 may be reversed.

The eleventh rejection reason value is information indicating whether to allow dual connectivity. The eleventh rejection reason value takes a value of 0 or 1.

Here, when the eleventh rejection reason value is 0, it indicates that dual connectivity is permitted.

Further, when the eleventh rejection reason value is 1, it indicates that dual connectivity is not permitted.

The meaning when the eleventh rejection reason value is 1 and the meaning when it is 0 may be reversed.

The first to eleventh rejection reason values are, of course, information.

The first identification information is information indicating that the request of the UE_A 10 is not permitted to the core network A. Furthermore, the first identification information may be reason information (Reject Cause) indicating a reason why the request of the UE_A 10 is rejected.

Specifically, the first identification information may or may not permit the request to the core network A of UE_A 10 via E-UTRA, and / or the request to the core network A of UE A 10 via NR. May be information indicating whether to permit or not, or information indicating that the connection to the core network_A and / or PDN via the access network in which the UE_A 10 is located may have failed.

The first identification information may be information indicating a connection permission pattern in the combination of the radio access system and the core network. For example, it may be information indicating whether or not to allow connection in a combination of core network A and / or core network B for connection via NR. In addition, it may be information indicating whether or not to allow connection by a combination of core network A and / or core network B with respect to connection via E-UTRA.

Further, the first identification information may be information indicating permission of connection of the wireless access system, and may be information indicating availability of connection permission information of the wireless access system in dual connectivity.

Also, the first identification information may be information assisting the determination of whether or not the master base station requests establishment of dual connectivity, or the master base station may be for dual connectivity with the secondary base station. It may be information indicating the necessity and / or permission of connection establishment.

Further, the eleventh identification information in the present embodiment is information indicating that the request of the UE_A 10 is not permitted to the core network B. Furthermore, the eleventh identification information may be reason information (Reject Cause) indicating a reason why the request of the UE_A 10 is rejected.

Specifically, the eleventh identification information may or may not permit the request to the core network _B of UE_A10 via E-UTRA, and / or the request to the core network _B of UE_A10 via NR May be information indicating whether to allow or not, or information indicating that the connection to the core network _B and / or the DN via the access network in which the UE_A 10 is located may be failed.

The eleventh identification information may be information indicating a connection permission pattern in the combination of the wireless access system and the core network. For example, it may be information indicating whether or not to allow connection in a combination of core network A and / or core network B for connection via NR. In addition, it may be information indicating whether or not to allow connection by a combination of core network A and / or core network B with respect to connection via E-UTRA.

The eleventh identification information may be information indicating permission of connection of the wireless access system, and may be information indicating availability of connection permission information of the wireless access system in dual connectivity.

Further, the eleventh identification information may be information assisting the determination of whether or not the master base station requests establishment of dual connectivity, or the master base station may be for dual connectivity with the secondary base station. It may be information indicating the necessity and / or permission of connection establishment.

[4. First Embodiment]
Next, the first embodiment will be described using the drawings. The communication system in the present embodiment is the mobile communication system 1 shown in FIG. 1 and FIG.

First, the UE is operating in the S1 mode, and is in a state of being connected to or located in the core network A via the base station (MeNB (eNB)) disposed in the access network A. That is, the UE is in a state of being position registered in the MME.

Next, when the UE selects a cell configured by a base station (SeNB (en-gNB)) placed in access network B regardless of whether it moves or not, through the access network B The case of performing the tracking area update procedure to connect to the core network A will be described.

[4.1. Tracking area update procedure]
Next, an outline of the tracking area update procedure will be described. Hereinafter, this procedure refers to a tracking area update procedure. This procedure updates the location registration information of the UE in the network (access network and / or core network_A), and / or notifies the status of the UE periodically from the UE to the network, and / or for the UE in the network It is a procedure for updating a specific parameter. The UE may execute this procedure at any timing or may periodically execute this procedure as long as the PDN connection is established.

The tracking area update procedure will be described with reference to FIG. Hereinafter, each step of this procedure will be described. First, the UE transmits a Tracking Area Update Request message to the MME via the SeNB (en-gNB) and the MeNB (eNB) (S1000) (S1001) (S1002), and the tracking area update procedure. To start. Specifically, the UE transmits a tracking area update request message to the SeNB (en-gNB) (S1000), and the SeNB (en-gNB) that has received the tracking area tracking message to the MeNB (eNB) The area update request message is transferred (S1001). MeNB (eNB) which received this transfers a tracking area update request message to MME (S1002).

When the MME receives the tracking area update request message, the MME performs a first condition determination. In the first condition determination, the MME determines whether the first condition is true or false. The MME starts the procedure of (A) in the present procedure if the first condition is true, and starts the procedure of (B) in the procedure if the first condition is false. The steps in the case where the first condition is false will be described later.

Note that the first condition determination is reception of a tracking area update request message, and / or identification information included in the tracking area update request message, and / or subscriber information, and / or operator policy, and / or the other When the network is located, it may be performed based on the location registration authentication result based on the roaming agreement. For example, if the network grants the UE's request, the first condition may be true, and if the network does not grant the UE's request, the first condition may be false. Also, if the network to which the UE is registered and / or the devices within the network support the UE requested function, then the first condition is true and the UE does not support the requested function The first condition may be false. Furthermore, the first condition may be true if the transmitted and received identification information is permitted, and the first condition may be false if the transmitted and received identification information is not permitted. Also, if the UE requests a tracking area update and the network grants the request, the first condition may be true. Also, if the UE requests a tracking area update and the network does not grant the request, the first condition may be false. Furthermore, if the network to which the UE is connected and / or the devices within the network do not support the tracking area update requested by the UE, the first condition may be false. The conditions under which the true / false determination of the first condition determination is determined are not limited to the conditions described above.

First, when it is determined that the first condition is true, the MME transmits a Tracking Area Update Accept message to the UE via the MeNB (eNB) and the SeNB (en-gNB) ( S1006) (S1007) (S1008). Specifically, the MME transmits a tracking area update acceptance message to the MeNB (eNB) (S1006), and the MeNB (eNB) that receives this updates the tracking area to the SeNB (en-gNB) Transfer the acceptance message (S1007). The SeNB (en-gNB) that has received this transmits a tracking area update request message to the UE (S1008).

The tracking area update acceptance message may include an appropriate acceptance reason. Also, the tracking area update acceptance message may be a response message to the tracking area update request message, and is not limited thereto, and may be a message that accepts the request for tracking area update.

Here, the MME may indicate that the request of the UE has been accepted by transmitting a tracking area update acceptance message.

When the UE receives the tracking area update acceptance message, the UE can transmit a tracking area update complete message to the MME via the SeNB (en-gNB) and the MeNB (eNB) (S1010) ) (S1011) (S1012). Specifically, the UE transmits a tracking area update completion message to the SeNB (en-gNB) (S1010), and the SeNB (en-gNB) that has received the message tracks the MeNB (eNB). The area update completion message is transferred (S1011). MeNB (eNB) which received this transfers a tracking area update completion message to MME (S1012).

When transmitting and receiving the tracking area update completion message, each device completes the procedure of (A) in this procedure based on the transmission and reception of the tracking area update completion message. Further, when not transmitting and receiving the tracking area update completion message, each device completes the procedure of (A) in the present procedure based on the transmission and reception of the tracking area update acceptance message.

Next, if the first condition is determined to be false, the MME transmits a Tracking Area Update Reject message to the UE via the MeNB (eNB) and the SeNB (en-gNB) ( S1020) (S1022) (S1023). Specifically, the MME transmits a Tracking Area Update Reject message to the MeNB (eNB) (S1020). The tracking area update rejection message includes the first identification information, and / or the first rejection reason value, and / or the second rejection reason value, and / or the seventh rejection reason value, and / or the eighth. A rejection reason value of may be included. The seventh rejection reason value and the eighth rejection reason value can take values of 0 and 1, respectively. When the seventh rejection reason value is 0, it indicates that the connection to the access network _A or the registration with the core network through the access network _A is permitted, and the seventh rejection reason value is 1 It shows that the connection to the access network A or the registration to the core network via the access network A is not permitted. Further, when the eighth rejection reason value is 0, it indicates that the connection to the access network _B or the registration with the core network via the access network _B is permitted, and the eighth rejection reason value is When it is 1, it indicates that the connection to the access network _B or the registration in the core network via the access network _B is not permitted.

Note that the first rejection reason value is included, for example, in the first bit and the second bit (E-UTRAN and NR allowed) in the information element described in FIG. Can be sent. In addition, the second rejection reason value is included, for example, in the first bit and the second bit (E-UTRAN and NR allowed) in the information element described in FIG. Can be sent.

Also, the seventh rejection reason value can be transmitted, for example, in the first bit (E-UTRAN allowed) in the information element described in FIG. Also, the eighth rejection reason value can be transmitted, for example, in the second bit (NR allowed) in the information element described in FIG.

The MeNB (eNB) that has received the tracking area update rejection message may execute the first process (S1021).

Here, the first process may be to determine whether the master base station (MeNB) requests establishment of dual connectivity, or the master base station may be dual to the secondary base station (SeNB). It may be to determine the need and / or permission of establishing a connection for connectivity.

Next, the MeNB (eNB) transfers the tracking area update rejection message to the SeNB (en-gNB) (S1022), and the SeNB (en-gNB) receiving this transfers the tracking area update rejection message to the UE (S1023).

When the UE receives the tracking area update rejection message, the UE identifies the first identification information and / or the first rejection reason value, and / or the second rejection reason value, and / or the seventh rejection information included therein. The reason value and / or the eighth rejection reason value is extracted and stored, and the first behavior and / or the fifth behavior are determined based on the identification information and the rejection reason value included in the tracking area update rejection message. It may be executed.

Here, the first behavior is a behavior in which the UE searches and / or selects an access network different from the located access network when the tracking area update request for the core network_A is rejected. The UE performing the first behavior may select a different access network and then attempt to reconnect to core network A via the selected access network. In addition, when the UE performing the first behavior selects a different access network, the UE may stop the connection function to the access network that was in the area (that is, search for the cell of the access network in the area) And / or may not be selected.

Specifically, when the tracking area update rejection message including the rejection reason value indicating the first rejection reason value is received, or the seventh rejection reason value included in the tracking area update rejection message is 0, If the eighth rejection cause value is 1, the UE may stop connecting to access network B and search and / or select cells of access network A.

Also, when the tracking area update rejection message including the rejection reason value indicating the second rejection reason value is received, or the seventh rejection reason value included in the tracking area update rejection message is 1, and the eighth If the rejection reason value is 1, the UE stops the connection function to access network _A and access network _B, and searches and / or selects 2G / 3G cells (ie cells of access network _E). May be

Also, if the eighth rejection reason value is 1, the UE stops the connection function to the access network _B and, based on the value of the seventh rejection reason value, the UE determines the cell of the access network _A. It may be determined whether to search and / or select or search and / or select 2G / 3G cells (ie, cells of access network _E). For example, when the seventh rejection reason value is 0, a cell of access network _A may be searched and / or selected, and when the seventh rejection reason value is 1, 2G / 3G cells (ie access) A cell of network _E) may be searched and / or selected.

Also, the fifth behavior is that the mode of the UE is S1 to N1 after receiving the tracking area update rejection message including the rejection reason value indicating the first rejection reason value and / or the second rejection reason value. Even when switching to the mode, within the same PLMN and in the equivalent PLMN, the rejection reason value obtained in S1 mode (ie, the first rejection reason value and / or the second rejection) It is the behavior of searching and / or selecting the cell of the access network in N1 mode based on the reason value).

Also, by receiving the tracking area update rejection message, the UE recognizes that the request of the UE by the tracking area update request message is rejected. Each device completes the procedure of (B) in the present procedure based on transmission and reception of the tracking area update rejection message.

The tracking area update rejection message may be a response message to the tracking area update request message, and is not limited thereto, and may be a message for rejecting the tracking area update request.

Each device completes the procedure based on the completion of the procedure of (A) or (B) in the procedure. Furthermore, each device may perform processing based on the information transmitted and received in this procedure based on the completion of this procedure.

[5. Second embodiment]
Next, a second embodiment will be described using the drawings. The communication system in the present embodiment is the mobile communication system 1 shown in FIG. 1 and FIG.

First, the UE is operating in the S1 mode, and is in a state of being connected to or located in the core network A via the base station (SeNB (en-gNB)) located in the access network B. . That is, the UE is in a state of being position registered in the MME.

Next, when the UE selects a cell configured by a base station (MeNB (eNB)) located in access network A regardless of whether it moves or not, the core via access network A A case of performing a tracking area update procedure to connect to the network _A will be described.

[5.1. Tracking area update procedure]
Next, an outline of the tracking area update procedure will be described. Hereinafter, this procedure refers to a tracking area update procedure. This procedure updates the location registration information of the UE in the network (access network and / or core network_A), and / or notifies the status of the UE periodically from the UE to the network, and / or for the UE in the network It is a procedure for updating a specific parameter. The UE may execute this procedure at any timing or may periodically execute this procedure as long as the PDN connection is established.

The tracking area update procedure will be described with reference to FIG. Hereinafter, each step of this procedure will be described. First, the UE starts a tracking area update procedure by transmitting a Tracking Area Update Request message to the MME via the MeNB (eNB) (S1100).

The authenticity of the first condition may be determined based on the contents described in the first embodiment. The first condition may be the same as or different from the first condition in the first embodiment.

First, when it is determined that the first condition is true, the MME transmits a Tracking Area Update Accept message to the UE via the MeNB (eNB) (S1106).

When the UE receives the tracking area update acceptance message, the UE can transmit a Tracking Area Update Complete message to the MME via the MeNB (eNB) (S1110).

Next, when determining that the first condition is false, the MME transmits a Tracking Area Update Reject message to the UE via the MeNB (eNB) (S1120). The tracking area update rejection message includes the first identification information, and / or the third rejection reason value, and / or the second rejection reason value, and / or the seventh rejection reason value, and / or the eighth. A rejection reason value of may be included. The seventh rejection reason value and the eighth rejection reason value can take values of 0 and 1, respectively. When the seventh rejection reason value is 0, it indicates that the connection to the access network _A or the registration with the core network through the access network _A is permitted, and the seventh rejection reason value is 1 It shows that the connection to the access network A or the registration to the core network via the access network A is not permitted. Further, when the eighth rejection reason value is 0, it indicates that the connection to the access network _B or the registration with the core network via the access network _B is permitted, and the eighth rejection reason value is When it is 1, it indicates that the connection to the access network _B or the registration in the core network via the access network _B is not permitted.

The third rejection reason value is included, for example, in the first bit and the second bit (E-UTRAN and NR allowed) in the information element described in FIG. Can be sent. In addition, the second rejection reason value is included, for example, in the first bit and the second bit (E-UTRAN and NR allowed) in the information element described in FIG. Can be sent.

The MeNB (eNB) that has received the tracking area update rejection message may execute the second process (S1121).

Here, the second process may be to determine whether the master base station (MeNB) requests establishment of dual connectivity, or the master base station may be dual to the secondary base station (SeNB). It may be to determine the need and / or permission of establishing a connection for connectivity.

Next, the MeNB (eNB) transfers a tracking area update rejection message to the UE (S1122).

When the UE receives the tracking area update rejection message, the UE identifies the first identification information and / or the third rejection reason value, and / or the second rejection reason value, and / or the seventh rejection information included therein. The reason value and / or the eighth rejection reason value is extracted and stored, and the second behavior and / or the fifth behavior is determined based on the identification information and the rejection reason value included in the tracking area update rejection message. It may be executed.

Here, the second behavior is a behavior in which the UE searches and / or selects an access network different from the located access network when the tracking area update request for the core network_A is rejected. The UE performing the second behavior may select a different access network and then attempt to reconnect to core network A via the selected access network. In addition, when the UE performing the second behavior selects a different access network, the UE may stop the connection function to the existing access network (that is, searches for a cell of the existing access network) And / or may not be selected.

Specifically, when the tracking area update rejection message including the rejection reason value indicating the third rejection reason value is received, or the seventh rejection reason value included in the tracking area update rejection message is 1, and If the eighth rejection cause value is 0, the UE may stop the connection function to Access Network_A, and may search and / or select a cell of Access Network_B.

Also, if the seventh rejection reason value is 1, the function of connecting to access network A is stopped, and based on the value of the eighth rejection reason value, the UE determines the cell of access network B as well. It may be determined whether to search and / or select or search and / or select 2G / 3G cells (ie, cells of access network _E). For example, when the eighth rejection reason value is 0, a cell of access network _B may be searched and / or selected, and when the eighth rejection reason value is 1, 2G / 3G cells (ie, access) A cell of network _E) may be searched and / or selected.

Also, the fifth behavior is that the mode of the UE is S1 to N1 after receiving the tracking area update rejection message including the third rejection reason value and / or the rejection reason value indicating the second rejection reason value. Even when switching to the mode, within the same PLMN and within the equivalent PLMN, the rejection reason value acquired in S1 mode (ie, the third rejection reason value and / or the second rejection) It is the behavior of searching and / or selecting the cell of the access network in N1 mode based on the reason value).

Each device completes the procedure based on the completion of the procedure of (A) or (B) in the procedure. Furthermore, each device may perform processing based on the identification information transmitted and received in this procedure based on the completion of this procedure.

[6. Third Embodiment]
Next, a third embodiment will be described using the drawings. The communication system in the present embodiment is the mobile communication system 2 described in FIG. 3 and FIG.

First, the UE is operating in the N1 mode, and is in a state of being connected to or located in the core network B via the base station (SN (ng-eNB)) disposed in the access network C. . That is, the UE is in a state of being registered in AMF.

Next, when the UE selects a cell configured by a base station (MN (gNB)) located in access network D regardless of whether it moves or not, the core via access network D is selected. The case where the registration procedure (Registration procedure) is executed to connect to network _B will be described.

[6.1. Registration procedure]
First, the registration procedure will be described with reference to FIG. The registration procedure is a procedure initiated by the UE for registration to the access network D and / or core network B and / or DN. When the UE is not registered in the network, for example, the UE can execute this procedure at an arbitrary timing such as power on. In other words, the UE can start this procedure at any timing in the non-registration state (RM-DEREGISTERED state). Also, each device (especially UE and AMF) can transition to the registration state (RM-REGISTERED state) based on the completion of the registration procedure.

In addition, the registration procedure is for updating location registration information of the UE in the network and / or notifying UE status periodically from the UE to the network and / or updating specific parameters regarding the UE in the network It may be

Also, the UE may start the registration procedure when performing mobility across the TA. In other words, the UE may start the registration procedure when moving to a TA different from the TA indicated in the TA list it holds. Furthermore, the UE may initiate this procedure when the running timer has expired. Furthermore, the UE may initiate the registration procedure when it is necessary to update the context of each device due to disconnection or invalidation of the PDU session. Furthermore, the UE may initiate a registration procedure if there is a change in the capability information and / or preferences regarding the PDU session establishment of the UE. Furthermore, the UE may initiate registration procedures periodically. In addition, UE can perform a registration procedure at arbitrary timing not only in these.

First, the UE starts the registration procedure by transmitting a Registration Request message to the AMF via the MN (gNB) (S1300). Specifically, the UE transmits an RRC message including a registration request message to the MN (gNB) (S1300). The registration request message is a NAS message. Also, the RRC message may be a control message transmitted and received between the UE and the MN (gNB). Also, NAS messages are processed in the NAS layer and RRC messages are processed in the RRC layer. The NAS layer is a layer higher than the RRC layer.

Next, when the MN (gNB) receives the RRC message including the registration request message, it selects an AMF to which the registration request message is transferred (S1302). Note that the MN (gNB) can select an AMF based on the information contained in the registration request message and / or the RRC message. The MN (gNB) extracts a registration request message from the received RRC message, and transfers the registration request message to the selected AMF (S1304).

When the AMF receives the registration request message, it can perform the first condition determination. The first condition determination is to determine whether the network (or AMF) accepts the request of the UE. AMF starts the procedure of FIG. 11A when the first condition is true, whereas it starts the procedure of FIG. 11B when the first condition is false.

The first condition determination is reception of a registration request message, and / or identification information included in a registration request message, and / or subscriber information, and / or operator policy, and / or when the UE is in another network. May be performed based on the location registration authentication result based on the roaming agreement. For example, if the network grants the UE's request, the first condition may be true, and if the network does not grant the UE's request, the first condition may be false. Also, if the network to which the UE is registered and / or the devices within the network support the UE requested function, then the first condition is true and the UE does not support the requested function The first condition may be false. Furthermore, the first condition may be true if the transmitted and received identification information is permitted, and the first condition may be false if the transmitted and received identification information is not permitted. The conditions under which the true / false determination of the first condition determination is determined are not limited to the conditions described above.

First, when it is determined that the first condition is true, the AMF transmits a Registration Accept message to the UE via the MN (gNB) as a response message to the registration request message (S1308). The registration acceptance message is a NAS message transmitted and received on the N1 interface, but is transmitted and received between the UE and the MN (gNB) by being included in the RRC message.

Also, the AMF may transmit a registration acceptance message based on the received identification information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, etc. May indicate that the request of the UE has been accepted.

The UE receives a registration acceptance message via the MN (gNB) (S1308). By receiving the registration acceptance message, the UE can recognize that the request of the UE by the registration request message has been accepted.

Also, the UE can further transmit a Registration Complete message to the AMF via the MN (gNB) as a response message to the registration acceptance message (S1310). Here, although the registration completion message is a NAS message transmitted and received on the N1 interface, the UE and the MN (gNB) are transmitted and received as they are included in the RRC message.

The AMF receives a registration completion message via the MN (gNB) (S1310).

When transmitting and receiving a registration completion message, each device completes the procedure of (A) in the present procedure based on transmission and reception of the registration completion message. Further, when not transmitting and receiving the registration completion message, each device completes the procedure of (A) in the present procedure based on the transmission and reception of the registration acceptance message.

Next, when it is determined that the first condition is false, the AMF transmits a Registration Reject message to the UE via the MN (gNB) as a response message to the registration request message (S1320) (S1322). Specifically, the AMF sends a Registration Reject message to the MN (gNB) (S1320). The registration refusal message includes an eleventh identification information, and / or a fourth rejection reason value, and / or a fifth rejection reason value, and / or a ninth rejection reason value, and / or a tenth rejection. Reason values may be included. The ninth rejection reason value and the tenth rejection reason value can take values of 0 and 1, respectively. When the ninth rejection reason value is 0, it indicates that the connection to the access network C or the registration with the core network via the access network C is permitted, and the ninth rejection reason value is 1. It indicates that the connection to the access network C or the registration to the core network via the access network C is not permitted. Further, when the tenth rejection reason value is 0, it indicates that the connection to the access network D or the registration with the core network via the access network D is permitted, and the tenth rejection reason value is When it is 1, it indicates that connection to the access network D or registration with the core network via the access network D is not permitted.

The fourth rejection reason value is included, for example, in the first bit and the second bit (E-UTRAN and NR allowed) in the information element described in FIG. Can be sent. In addition, the fifth rejection reason value is included, for example, in the first bit and the second bit (E-UTRAN and NR allowed) in the information element described in FIG. Can be sent.

Also, the ninth rejection reason value can be transmitted, for example, in the first bit (E-UTRAN allowed) in the information element shown in FIG. Also, the tenth rejection reason value can be transmitted, for example, in the second bit (NR allowed) of the information element described in FIG.

Here, although the registration rejection message is a NAS message transmitted / received on the N1 interface, the UE and the MN (gNB) are transmitted / received by being included in the RRC message.

The AMF may indicate that the request of the UE by the registration request message has been rejected by transmitting a registration rejection message. Furthermore, the AMF may transmit information indicating the reason for rejection in the registration rejection message, or may indicate the reason for rejection by transmitting the reason for rejection. Furthermore, the UE may recognize the reason for the rejection of the UE request by receiving information indicating the reason for the rejection of the UE request. The reason for the rejection may be information indicating that the content indicated by the identification information received by the AMF is not permitted.

The MN (gNB) that has received the registration rejection message may execute the fourth process (S1321).

Here, the fourth process may be to determine whether the master base station (MN) assists in determining whether to request establishment of dual connectivity, or the master base station may be a secondary. It may be to determine the need and / or permission to establish a connection for dual connectivity with the base station (SN).

Next, the MN (gNB) transfers a registration rejection message to the UE (S1322).

When the UE receives the registration rejection message, the eleventh identification information and / or the fourth rejection reason value, and / or the fifth rejection reason value, and / or the ninth rejection reason value are included therein. And / or the tenth rejection reason value is extracted and stored, and the third behavior and / or the sixth behavior may be executed based on the identification information and the rejection reason value included in the registration rejection message. Good.

Here, the third behavior is a behavior in which the UE searches and / or selects an access network different from the located access network when the registration request message for the core network _B is rejected. The UE performing the third behavior may select a different access network and then attempt to reconnect to core network B via the selected access network. In addition, when the UE performing the third behavior selects a different access network, the UE may stop the connection function to the existing access network (that is, searches for a cell of the existing access network) And / or may not be selected.

Specifically, when the registration rejection message including the rejection reason value indicating the fourth rejection reason value is received, or the ninth rejection reason value included in the registration rejection message is 0, and the tenth rejection is generated. If the reason value is 1, the UE may stop connecting to access network D and search and / or select cells of access network C.

Furthermore, when the registration rejection message including the rejection reason value indicating the fifth rejection reason value is received, or the ninth rejection reason value included in the registration rejection message is 1, and the tenth rejection reason value is When it is 1, the UE may stop the connection function to the access network C and access network D, and may search and / or select 2G / 3G cells (that is, cells of the access network E).

Also, when the tenth rejection reason value is 1, the UE stops the connection function to the access network _D, and based on the value of the ninth rejection reason value, the UE determines the cell of the access network _C. It may be determined whether to search and / or select or search and / or select 2G / 3G cells (ie, cells of access network _E). For example, when the ninth rejection reason value is 0, a cell of the access network C may be searched and / or selected, and when the ninth rejection reason value is 1, 2G / 3G cells (ie access) A cell of network _E) may be searched and / or selected.

Also, the sixth behavior is that the mode of the UE changes from N1 mode to S1 mode after receiving a registration rejection message including a rejection reason value indicating the fourth rejection reason value and / or the fifth rejection reason value. Even if it is switched, within the same PLMN and within the equivalent PLMN, based on the rejection reason value acquired in the N1 mode (ie, the fourth rejection reason value and / or the fifth rejection reason value), This is the behavior of searching and / or selecting cells of the access network in S1 mode.

Also, the UE can recognize that the request of the UE according to the registration request message is rejected by receiving the registration rejection message. Each device completes the procedure of (B) in this procedure based on transmission and reception of the registration refusal message.

Each device completes the registration procedure based on the completion of the procedure of (A) or (B) of FIG. Note that each device may transition to the state where the UE is registered in the network (RM_REGISTERED state) based on the completion of the procedure in FIG. 11A, or the completion of the procedure in FIG. 11B. , The UE may maintain a state (RM_DEREGISTERED state) in which the UE is not registered in the network, or may transition to a state in which the UE is not registered in the network. Also, transition to each state of each device may be performed based on the completion of the registration procedure.

Furthermore, each device may perform processing based on the information transmitted and received in the registration procedure based on the completion of the registration procedure.

7. Fourth Embodiment
Next, a fourth embodiment will be described using the drawings. The communication system in the present embodiment is the mobile communication system 2 described in FIG. 3 and FIG.

First, the UE is operating in the N1 mode and is in a state of being connected to or located in the core network B via the base station (MN (gNB)) disposed in the access network D. That is, the UE is in a state of being registered in AMF.

Next, when the UE selects a cell configured by a base station (SN (ng-eNB)) placed in access network C regardless of whether it moves or not, through the access network C Describes the case of executing a registration procedure in order to connect to the core network _B.

[7.1. Registration procedure]
First, the registration procedure will be described with reference to FIG. The registration procedure is a procedure initiated by the UE to register with the access network C and / or the core network B and / or the DN. When the UE is not registered in the network, for example, the UE can execute this procedure at an arbitrary timing such as power on. In other words, the UE can start this procedure at any timing in the non-registration state (RM-DEREGISTERED state). Also, each device (especially UE and AMF) can transition to the registration state (RM-REGISTERED state) based on the completion of the registration procedure.

First, the UE starts the registration procedure by transmitting a Registration Request message to the AMF via the SN (ng-eNB) and the MN (gNB) (S1200) (S1201) (S1204). Specifically, the UE transmits an RRC message including a registration request message to the SN (ng-eNB) (S1200), and the SN (ng-eNB) that has received it transmits to the MN (gNB) The registration request message is transferred (S1201). The registration request message is a NAS message. Also, the RRC message may be a control message transmitted and received between the UE and the SN (ng-eNB). Also, NAS messages are processed in the NAS layer and RRC messages are processed in the RRC layer. The NAS layer is a layer higher than the RRC layer.

Next, when the MN (gNB) receives the registration request message, it selects an AMF to which the registration request message is transferred (S1202). The MN (gNB) can select the AMF based on the information contained in the registration request message. The MN (gNB) transfers a registration request message to the selected AMF (S1204).

When the AMF receives the registration request message, it can perform the first condition determination. The first condition determination is to determine whether the network (or AMF) accepts the request of the UE. AMF starts the procedure of FIG. 10A if the first condition is true, whereas it starts the procedure of FIG. 10B if the first condition is false. The steps in the case where the first condition is false will be described later.

The authenticity of the first condition may be determined based on the contents described in the third embodiment. The first condition may be the same as or different from the first condition in the third embodiment.

First, if it is determined that the first condition is true, the AMF sends a Registration Accept message to the UE via the MN (gNB) and the SN (ng-eNB) as a response message to the registration request message. Is sent (S1208). Specifically, when the AMF transmits a registration acceptance to the MN (gNB), the MN (gNB) that has received this transmits a registration acceptance message to the SN (ng-eNB). The SN (ng-eNB) that has received this transfers a registration acceptance message to the UE (S1208).

Although the registration acceptance message is a NAS message transmitted and received on the N1 interface, the UE and the SN (ng-eNB) are included in the RRC message and transmitted and received.

Here, the AMF may indicate that the UE's request has been accepted by sending a registration acceptance message.

The UE receives a registration acceptance message (S1208). By receiving the registration acceptance message, the UE can recognize that the request of the UE by the registration request message has been accepted.

Also, the UE can further transmit a Registration Complete message as a response message to the registration acceptance message to the AMF via the SN (ng-eNB) and the MN (gNB) (S1210). Specifically, when the UE transmits a registration completion message to the SN (ng-eNB), the SN (ng-eNB) that has received this transmits the registration completion message to the MN (gNB). The MN (gNB) having received this transfers a registration complete message to the MME (S1210).

Here, although the registration completion message is a NAS message transmitted and received on the N1 interface, the UE and the SN (ng-eNB) are included in the RRC message and transmitted and received.

The AMF receives the registration completion message via the MN (gNB) (S1210).

Next, if it is determined that the first condition is false, the AMF rejects the registration rejection (Registration Reject) to the UE via the MN (gNB) and the SN (ng-eNB) as a response message to the registration request message. A message is transmitted (S1220) (S1222). Specifically, the AMF sends a Registration Reject message to the MN (gNB) (S1220). The registration refusal message includes an eleventh identification information, and / or a sixth rejection reason value, and / or a fifth rejection reason value, and / or a ninth rejection reason value, and / or a tenth rejection. Reason values may be included. The ninth rejection reason value and the tenth rejection reason value can take values of 0 and 1, respectively. When the ninth rejection reason value is 0, it indicates that the connection to the access network C or the registration with the core network via the access network C is permitted, and the ninth rejection reason value is 1. It indicates that the connection to the access network C or the registration to the core network via the access network C is not permitted. Further, when the tenth rejection reason value is 0, it indicates that the connection to the access network D or the registration with the core network via the access network D is permitted, and the tenth rejection reason value is When it is 1, it indicates that connection to the access network D or registration with the core network via the access network D is not permitted.

The sixth rejection reason value is included, for example, in the first bit and the second bit (E-UTRAN and NR allowed) in the information element shown in FIG. Can be sent. In addition, the fifth rejection reason value is included, for example, in the first bit and the second bit (E-UTRAN and NR allowed) in the information element described in FIG. Can be sent.

The MN (gNB) that has received the registration rejection message may execute the third process (S1221).

Here, the third process may be to determine whether the master base station (MN) assists in determining whether to request establishment of dual connectivity, or the master base station may be a secondary. It may be to determine the need and / or permission to establish a connection for dual connectivity with the base station (SN).

Next, the MN (gNB) transfers a registration rejection message to the UE (S1222).

When the UE receives the registration rejection message, the eleventh identification information and / or the sixth rejection reason value, and / or the fifth rejection reason value, and / or the ninth rejection reason value are included therein. And / or the tenth rejection reason value is extracted and stored, and the fourth behavior and / or the sixth behavior is executed based on the identification information and the rejection reason value included in the registration rejection message. Good.

Here, the fourth behavior is a behavior in which the UE searches and / or selects an access network different from the located access network when the registration request message for the core network _B is rejected. The UE performing the fourth behavior may select a different access network and then attempt to reconnect to core network B via the selected access network. When the UE performing the fourth behavior selects a different access network, it may stop the connection function to the existing access network (that is, searches for a cell of the existing access network) And / or may not be selected.

Specifically, when the registration rejection message including the rejection reason value indicating the sixth rejection reason value is received, or the ninth rejection reason value included in the tracking area update rejection message is 1, and the tenth If the rejection reason value of is 0, the UE may stop the connection function to Access Network_C, and may search and / or select a cell of Access Network_D.

Furthermore, when the registration rejection message including the rejection reason value indicating the fifth rejection reason value is received, or the ninth rejection reason value included in the tracking area update rejection message is 1, and the tenth rejection reason When the value is 1, the UE stops the connection function to access network C and access network D, and searches and / or selects 2G / 3G cell (that is, the cell of access network E). Good.

Also, if the ninth rejection reason value is 1, the UE stops the connection function to the access network C, and the UE determines the cell of the access network D based on the value of the tenth rejection reason value. It may be determined whether to search and / or select or search and / or select 2G / 3G cells (ie, cells of access network _E). For example, when the tenth rejection reason value is 0, the cell of the access network _D may be searched and / or selected, and when the tenth rejection reason value is 1, 2G / 3G cell (ie access) A cell of network _E) may be searched and / or selected.

Also, the sixth behavior is that the mode of the UE changes from the N1 mode to the S1 mode after receiving the registration rejection message including the sixth rejection reason value and / or the rejection reason value indicating the fifth rejection reason value. Even if it is switched, within the same PLMN and within the equivalent PLMN, based on the rejection reason value acquired in the N1 mode (ie, the sixth rejection reason value and / or the fifth rejection reason value), This is the behavior of searching and / or selecting cells of the access network in S1 mode.

8. Fifth Embodiment
Next, a fifth embodiment will be described using the drawings. The communication system in the present embodiment is the mobile communication system 3 shown in FIG. Although the first to fourth embodiments mainly describe the case of dual connectivity, this embodiment describes a case of stand alone (also referred to as stand alone connection configuration). That is, the access network A, the access network D, and the access network E in the mobile communication system 3 illustrated in FIG. 12 do not perform connection using dual connectivity.

A case will be described in which the UE performs a tracking area update procedure on the core network A via the base station (eNB) located in the access network A.

[8.1. Tracking area update procedure]
Next, an outline of the tracking area update procedure will be described. Hereinafter, this procedure refers to a tracking area update procedure. This procedure updates the location registration information of the UE in the network (access network and / or core network_A), and / or notifies the status of the UE periodically from the UE to the network, and / or for the UE in the network It is a procedure for updating a specific parameter. The UE may execute this procedure at any timing or may periodically execute this procedure as long as the PDN connection is established.

The tracking area update procedure will be described with reference to FIG. It should be noted that MeNB in FIG. 9 is replaced with eNB to explain the tracking area update procedure in this embodiment.

First, the UE starts a tracking area update procedure by transmitting a Tracking Area Update Request message to the MME via the eNB (S1100).

First, when it is determined that the first condition is true, the MME transmits a Tracking Area Update Accept message to the UE via the eNB (S1106).

When the UE receives the tracking area update acceptance message, the UE may transmit a Tracking Area Update Complete message to the MME via the eNB (S1110).

Next, if it is determined that the first condition is false, the MME transmits a Tracking Area Update Reject message to the UE via the eNB (S1120). The tracking area update rejection message includes the first identification information and / or the seventh rejection reason value, and / or the ninth rejection reason value, and / or the tenth rejection reason value, and / or the eleventh. A rejection reason value of may be included. The seventh rejection reason value indicates 1, indicating that the connection to the access network A or the registration with the core network via the access network A is not permitted. Also, the ninth rejection reason value, the tenth rejection reason value, and the eleventh rejection reason value may take values of 0 and 1, respectively. When the ninth rejection reason value is 0, it indicates that the connection to the access network C or the registration with the core network via the access network C is permitted, and the ninth rejection reason value is 1. It indicates that the connection to the access network C or the registration to the core network via the access network C is not permitted. Further, when the tenth rejection reason value is 0, it indicates that the connection to the access network D or the registration with the core network via the access network D is permitted, and the tenth rejection reason value is When it is 1, it indicates that connection to the access network D or registration with the core network via the access network D is not permitted. Further, when the eleventh rejection reason value is 0, it indicates that dual connectivity is permitted, and when the eleventh rejection reason value is 1, it indicates that dual connectivity is not permitted.

The seventh rejection reason value can be transmitted, for example, in the first bit (E-UTRAN allowed) in the information element described in FIG. Also, the tenth rejection reason value can be transmitted, for example, in the second bit (NR allowed) of the information element described in FIG. Also, the eleventh rejection reason value can be transmitted, for example, in the third bit (Dual connectivity allowed) in the information element shown in FIG. When the ninth rejection reason value is transmitted, for example, it may be transmitted by being included in the 4th bit (spare) in the information element described in FIG. 13 or transmitted as another information. It is also good.

The eNB that has received the tracking area update rejection message may execute the second process (S1121).

Here, the second process may be the same as the process in the second embodiment.

Next, the eNB transfers a tracking area update rejection message to the UE (S1122).

When the UE receives the tracking area update rejection message, the UE identifies the first identification information and / or the seventh rejection reason value, and / or the ninth rejection reason value, and / or the tenth rejection information contained therein. The cause value and / or the eleventh rejection reason value may be extracted and stored, and the seventh behavior may be executed based on the identification information or the rejection reason value included in the tracking area update rejection message.

Here, the seventh behavior is that the tracking area update request to the core network A is rejected, and the rejection reason value included in the first identification information can be applied to the connection permission information of the wireless access system in dual connectivity. Is a process of selecting an access network based on the information indicating.

More specifically, the UE searches for and / or selects a cell of an access network different from the visited access network_A, since the tracking area update rejection message in which the seventh rejection reason value is 1 is received. Try to do.

Here, when the tenth rejection reason value is 1, the UE searches and / or selects 2G / 3G cells (that is, cells of the access network E) regardless of the eleventh rejection reason value. It is also good.

Also, when the tenth rejection reason value is 0, the UE may determine a cell to search and / or select according to the eleventh rejection reason value.

For example, when the tenth rejection reason value is 0 and the eleventh rejection reason value is 1, the UE determines that the cell of access network _D (a cell without dual connectivity, a cell with stand-alone capability) You may search and / or select.

Also, when the tenth rejection reason value is 0 and the eleventh rejection reason value is 0, the UE is an access network capable of dual connectivity, ie, the mobile communication system 2 shown in FIG. 3 or 4. The cell of the access network (Access Network_C and / or Access Network_D) in may be searched and / or selected. At this time, the UE may further use the ninth rejection reason value to determine a cell to search and / or select. For example, when the ninth rejection reason value is 0, the UE may search and / or select a cell of access network C and / or access network D. Also, when the ninth rejection reason value is 1, the UE may search and / or select a cell of the access network _D.

Note that even when the tenth rejection reason value is 0, the UE may search and / or select 2G / 3G cells (ie, cells of access network E).

[9. Sixth Embodiment]
Next, a sixth embodiment will be described using the drawings. The communication system in the present embodiment is the communication system 3 shown in FIG. Although the first to fourth embodiments mainly describe the case of dual connectivity, this embodiment is also stand-alone (also referred to as a stand-alone connection configuration) as in the fifth embodiment. Describe the case of That is, the access network A, the access network D, and the access network E in the mobile communication system 3 illustrated in FIG. 12 do not perform connection using dual connectivity.

A case will be described where the UE performs a registration procedure for core network B via a base station (gNB) located in access network D.

[9.1. Registration procedure]
First, the registration procedure will be described with reference to FIG. It should be noted that MN in FIG. 11 is replaced with gNB to explain the registration procedure in this embodiment.

The registration procedure is a procedure initiated by the UE for registration to the access network D and / or core network B and / or DN. When the UE is not registered in the network, for example, the UE can execute this procedure at an arbitrary timing such as power on. In other words, the UE can start this procedure at any timing in the non-registration state (RM-DEREGISTERED state). Also, each device (especially UE and AMF) can transition to the registration state (RM-REGISTERED state) based on the completion of the registration procedure.

First, the UE starts the registration procedure by transmitting a Registration Request message to the AMF via gNB (S1300). Specifically, the UE transmits an RRC message including a registration request message to the gNB (S1300). The registration request message is a NAS message. Also, the RRC message may be a control message transmitted and received between the UE and the gNB. Also, NAS messages are processed in the NAS layer and RRC messages are processed in the RRC layer. The NAS layer is a layer higher than the RRC layer.

Next, when gNB receives the RRC message including the registration request message, it selects an AMF to which the registration request message is transferred (S1302). Note that gNB can select an AMF based on the information contained in the registration request message and / or the RRC message. The gNB extracts a registration request message from the received RRC message, and transfers the registration request message to the selected AMF (S1304).

First, when it is determined that the first condition is true, the AMF transmits a Registration Accept message to the UE via gNB as a response message to the registration request message (S1308). Although the registration acceptance message is a NAS message transmitted and received on the N1 interface, the UE and the gNB are included in the RRC message and transmitted and received.

The UE receives a registration acceptance message via gNB (S1308). By receiving the registration acceptance message, the UE can recognize that the request of the UE by the registration request message has been accepted.

In addition, the UE can further transmit a Registration Complete message as a response message to the registration acceptance message to the AMF via gNB (S1310). Here, although the registration completion message is a NAS message transmitted and received on the N1 interface, the UE and the gNB are included in the RRC message and transmitted and received.

The AMF receives a registration completion message via gNB (S1310).

Next, if it is determined that the first condition is false, the AMF transmits a Registration Reject message to the UE via gNB as a response message to the registration request message (S1320) (S1322) . Specifically, the AMF sends a Registration Reject message to gNB (S1320). The registration rejection message includes the eleventh identification information, and / or the seventh rejection reason value, and / or the eighth rejection reason value, and / or the tenth rejection reason value, and / or the eleventh rejection. Reason values may be included. The tenth rejection reason value indicates 1, indicating that connection to the access network D or registration with the core network via the access network D is not permitted. Also, the seventh rejection reason value, the eighth rejection reason value, and the eleventh rejection reason value may take values of 0 and 1, respectively. When the seventh rejection reason value is 0, it indicates that the connection to the access network _A or the registration with the core network through the access network _A is permitted, and the seventh rejection reason value is 1 It shows that the connection to the access network A or the registration to the core network via the access network A is not permitted. Further, when the eighth rejection reason value is 0, it indicates that the connection to the access network _B or the registration with the core network via the access network _B is permitted, and the eighth rejection reason value is When it is 1, it indicates that the connection to the access network _B or the registration in the core network via the access network _B is not permitted. Further, when the eleventh rejection reason value is 0, it indicates that dual connectivity is permitted, and when the eleventh rejection reason value is 1, it indicates that dual connectivity is not permitted.

The seventh rejection reason value can be transmitted, for example, in the first bit (E-UTRAN allowed) in the information element described in FIG. Also, the tenth rejection reason value can be transmitted, for example, in the second bit (NR allowed) of the information element described in FIG. Also, the eleventh rejection reason value can be transmitted, for example, in the third bit (Dual connectivity allowed) in the information element shown in FIG. When the eighth rejection reason value is transmitted, for example, it may be transmitted by being included in the fourth bit (spare) in the information element shown in FIG. 13 or transmitted as another information. It is also good.

Here, although the registration rejection message is a NAS message transmitted and received on the N1 interface, the UE and the gNB are included in the RRC message and transmitted and received.

The gNB having received the registration refusal message may execute the fourth process (S1321).

Here, the fourth process may be the same as the process in the third embodiment.

Next, the gNB transfers a registration rejection message to the UE (S1322).

When the UE receives the registration rejection message, the eleventh identification information and / or the seventh rejection reason value, and / or the eighth rejection reason value, and / or the tenth rejection reason value included therein. And / or the eleventh rejection reason value may be extracted and stored, and the eighth behavior may be performed based on the identification information included in the registration rejection message or the rejection reason value.

The eighth behavior is that the registration request message for core network _B is rejected, and the rejection reason value included in the first identification information is the application of the connection permission information of the wireless access system in dual connectivity. It is a process which performs access network selection based on the information which shows propriety.

More specifically, the UE searches and / or selects a cell of an access network different from the visited access network D because the registration rejection message having a tenth rejection reason value of 1 is received. Try.

Here, when the seventh rejection reason value is 1, the UE searches and / or selects 2G / 3G cells (that is, cells of the access network E) regardless of the eleventh rejection reason value. It is also good.

Also, when the seventh rejection reason value is 0, the UE may determine a cell to search and / or select according to the eleventh rejection reason value.

For example, when the seventh rejection reason value is 0 and the 11th rejection reason value is 1, the UE determines that the access network _A cell (dual connectivity non-compliant cell, stand-alone compliant cell) You may search and / or select.

Also, when the seventh rejection reason value is 0 and the 11th rejection reason value is 0, the UE is an access network capable of dual connectivity, ie, the mobile communication system 1 described in FIG. 1 or 2. The cell of the access network (Access Network_A and / or Access Network_B) in may be searched and / or selected. At this time, the UE may further use the eighth rejection reason value to determine a cell to search and / or select. For example, when the eighth rejection reason value is 0, the UE may search and / or select cells of access network _A and / or access network _B. Also, when the eighth rejection cause value is 1, the UE may search and / or select a cell of access network A.

Note that even when the seventh rejection reason value is 0, the UE may search and / or select 2G / 3G cells (that is, cells of access network E).

[10. Modification]
The program that operates in the apparatus according to the present invention may be a program that controls a central processing unit (CPU) or the like to cause a computer to function so as to realize the functions of the embodiments according to the present invention. The program or information handled by the program is temporarily stored in volatile memory such as Random Access Memory (RAM) or nonvolatile memory such as flash memory, Hard Disk Drive (HDD), or other storage system.

A program for realizing the functions of the embodiments according to the present invention may be recorded in a computer readable recording medium. It may be realized by causing a computer system to read and execute the program recorded in this recording medium. The "computer system" referred to here is a computer system built in an apparatus, 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 for dynamically holding a program for a short time, or another computer-readable recording medium. Also good.

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

The present invention is not limited to the above embodiment. Although an example of the device is described in the embodiment, the present invention is not limited thereto, and a stationary or non-movable electronic device installed indoors and outdoors, for example, an AV device, a kitchen device The present invention can be applied to terminal devices or communication devices such as cleaning and washing equipment, air conditioners, office equipment, vending machines, and other household appliances.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within the scope of the present invention are also included. Furthermore, the present invention can be modified in various ways within the scope of the claims, and embodiments obtained by appropriately combining the technical means respectively disclosed in different embodiments are also included in the technical scope of the present invention. Be Moreover, it is an element described in each said embodiment, and the structure which substituted the elements which show the same effect is also contained.

Claims

It is possible to connect to 5GC (5G Core Network) with dual connectivity via the first access network and / or the second access network, and with UE (User Equipment) that can connect via the third access network There,
A control unit that executes a registration procedure in the first access network or the second access network;
A sending / receiving unit that receives a registration rejection message from an Access and Mobility Management Function (AMF) in the registration procedure;
A UE characterized by searching and / or selecting a cell of an access network different from the access network that has performed the registration procedure based on information included in the registration rejection message.
The case where the control unit executes the registration procedure on the second access network,
When the transmission / reception unit receives, from the AMF, the registration rejection message including information indicating that the connection to the second access network or the registration on the core network via the second access network is not permitted. Is
The control unit
Stopping the connection function to the second access network,
The first access is based on information included in the registration rejection message and indicating whether to permit connection to the first access network or registration to the core network via the first access network. Determine whether to search and / or select a cell of the network or search and / or select a cell of the third access network,
The UE according to claim 1, characterized in that:
The control unit
If the information contained in the registration rejection message indicates that the connection to the first access network or the registration in the core network via the first access network is permitted, the first access network Search and / or select a cell,
In the third access network, when the information included in the registration rejection message indicates that connection to the first access network or registration in the core network through the first access network is not permitted. Search and / or select a cell,
The UE according to claim 2, characterized in that:
The control unit executes the registration procedure in the second access network, and when the UE mode is switched from the N1 mode to the S1 mode, within the same PLMN (Public Land Mobile Network) and within the equal PLMN. If within (equivalent PLMN), search and / or select the cell of the access network in S1 mode based on the rejection reason value obtained in N1 mode,
The UE according to claim 2 or 3, characterized in that:
The case where the control unit executes the registration procedure on the first access network,
When the transmission / reception unit receives, from the MME, the registration rejection message including information indicating that the connection to the first access network or the registration on the core network via the first access network is not permitted. Is
The control unit
Stopping the connection function to the first access network,
The second access is based on information included in the registration refusal message indicating whether to permit connection to the second access network or registration to the core network via the second access network. Determine whether to search and / or select a cell of the network or search and / or select a cell of the third access network,
The UE according to claim 1, characterized in that:
The control unit
If the information contained in the registration refusal message indicates that connection to the second access network or registration in the core network via the second access network is permitted, the second access network Search and / or select a cell,
If the information contained in the registration rejection message indicates that connection to the second access network or registration in the core network through the second access network is not permitted, the third access network Search and / or select a cell,
The UE according to claim 4, characterized in that:
The control unit executes the tracking area update procedure in the first access network, and when the UE mode is switched from the N1 mode to the S1 mode, the control unit is in the same PLMN (Public Land Mobile Network) and equally. Within the PLMN (equivalent PLMN), search and / or select the cell of the access network in the S1 mode based on the rejection reason value acquired in the N1 mode
The UE according to claim 5 or 6, characterized in that:
Connectable to EPC (Evolved Packet Core) via the first access network, connectable to 5 GC (5G Core Network) via the fourth access network, connectable via the third access network UE (User Equipment), and
A control unit that executes a registration procedure in the fourth access network;
A sending / receiving unit that receives a registration rejection message from an Access and Mobility Management Function (AMF) in the registration procedure;
Based on the information contained in the registration rejection message, it is determined whether to search and / or select the cell of the access network corresponding to dual connectivity or to search and / or select the cell of the access network corresponding to standalone. Do,
UE characterized by that.