Method and apparatus for providing access control in RAN sharing of next generation mobile communication system when disaster situation occurs

Abstract

The present disclosure relates to a communication technology for fusing IoT technology with a 5G communication system supporting a data transmission rate higher than that of a 4G system, and a system therefor. The present disclosure may be applied to intelligent services (e.g., smart residences, smart buildings, smart cities, smart cars or connected cars, health care, digital education, retail business, security and safety-related services, and the like) based on the 5G communication technology and the IoT-related technology. The invention relates to operation of a terminal and a base station in a mobile communication system. The present disclosure provides a method and apparatus for providing access control in RAN sharing when a disaster situation occurs.

Description

Technical Field

[0001] The present disclosure relates to the operation of a terminal and a base station in a mobile communication system. In particular, the present disclosure relates to a method and apparatus for providing access control in a Radio Access Network (RAN) sharing when a disaster situation occurs. Background Art

[0002] 5G mobile communication technology defines a wide frequency band that enables high transmission rates and new services, and can be implemented not only in "sub-6 GHz" frequency bands such as 3.5 GHz, but also in "above 6 GHz" frequency bands (including 28 GHz and 39 GHz) called millimeter waves. In addition, it has been considered to implement 6G mobile communication technology (called super 5G system) in terahertz frequency bands (such as 95 GHz to 3 THz bands) in order to achieve a transmission rate fifty times faster than 5G mobile communication technology and an ultra-low latency that is one-tenth of 5G mobile communication technology.

[0003] In the initial stage of 5G mobile communication technology, in order to support services and meet performance requirements for enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC) and massive machine-type communication (mMTC), standardization has been ongoing on the following technologies: beamforming and massive MIMO for reducing radio wave path loss and increasing radio wave transmission distance in millimeter waves, parameter sets for dynamic operation of efficient utilization of millimeter wave resources and time slot formats (for example, operating multiple subcarrier spacings), initial access technology for supporting multi-beam transmission and wide frequency bands, definition and operation of bandwidth parts (BWPs), new channel coding methods such as low-density parity-check (LDPC) codes for large-capacity data transmission and polar codes for highly reliable transmission of control information, L2 preprocessing, and network slicing for providing dedicated networks customized for specific services.

[0004] Currently, with respect to services supported by 5G mobile communication technology, discussions are underway on improvements and performance enhancements of initial 5G mobile communication technology, and physical layer standardization has been conducted on technologies such as vehicle-to-everything (V2X) for assisting driving decisions of autonomous vehicles based on information about the location and status of a vehicle sent by the vehicle and for improving user convenience, new radio unlicensed (NR-U) for system operation in compliance with various regulatory-related requirements in unlicensed frequency bands, NR UE energy saving, non-terrestrial network (NTN) for UE satellite direct communication to ensure coverage in areas where communication with terrestrial networks is not possible, and positioning.

[0005] In addition, the air interface architecture / protocols for the following technologies are being standardized, such as the Industrial Internet of Things (IIoT) for supporting new services through interworking and integration with other industries, IAB (Integrated Access and Backhaul) for providing nodes for network service area extension by supporting wireless backhaul links and access links in an integrated manner, mobility enhancement including conditional switching and DAPS (Dual Active Protocol Stack) switching, and two-step random access (2-step RACH for NR) for simplifying the random access process. The system architecture / services for the following technologies are also being standardized: 5G baseline architecture (e.g., service-based architecture or service-based interface) for combining network function virtualization (NFV) and software defined network (SDN) technologies, and mobile edge computing (MEC) for receiving services based on UE location.

[0006] If such a 5G mobile communication system is commercialized, the already exponentially growing number of connected devices will be connected to the communication network, and it is therefore expected that the functions and performance of the 5G mobile communication system and the integrated operation of the connected devices will need to be enhanced. To this end, new research on the following technologies is on the agenda: extended reality (XR) for efficient support of augmented reality (AR), virtual reality (VR), mixed reality (MR), etc.; 5G performance improvement and complexity reduction by utilizing artificial intelligence (AI) and machine learning (ML); AI service support; metaverse service support; and drone communication.

[0007] In addition, such developments in 5G mobile communication systems will serve not only as a basis for developing the following technologies: new waveforms for securing coverage in the terahertz band for 6G mobile communication technology; full-dimensional MIMO (FD-MIMO); multi-antenna transmission technologies such as array antennas and massive antennas; metamaterial-based lenses and antennas for improving coverage of terahertz band signals; high-dimensional spatial multiplexing technology using orbital angular momentum (OAM); and reconfigurable smart surfaces (RIS), but will also serve as a basis for developing the following technologies: full-duplex technology for improving the frequency efficiency of 6G mobile communication technology and improving system networks; AI-based communication technology for achieving system optimization by utilizing satellites and AI (artificial intelligence) from the design stage and internalizing end-to-end AI support functions; and next-generation distributed computing technology for achieving services at a complexity level that exceeds the limits of UE operating capabilities by utilizing ultra-high performance communication and computing resources. Summary of the invention

[0008]

Technical issues

[0009] The present disclosure below describes embodiments for providing access control by efficiently utilizing radio resources in RAN sharing when disaster situations occur.

[0010]

Technical solution

[0011] In order to solve the problem, an embodiment of the present disclosure provides a method performed by a terminal in a wireless communication system. The method may include: receiving a system information block 1 (SIB1) from a base station that shares a radio access network (RAN) with a first public land mobile network (PLMN) and a second PLMN, the SIB1 including prohibition configuration information for at least one terminal that performs roaming access based on the occurrence of a disaster; determining whether the disaster roaming access of the terminal is prohibited based on the prohibition configuration information; receiving a SIB15 including an applicable disaster information list from the base station; and sending a control message for a radio resource control (RRC) connection to the base station when the roaming access of the terminal to the base station is not prohibited, wherein the SIB15 including the applicable disaster information list includes first applicable disaster information for the first PLMN and second applicable disaster information for the second PLMN, wherein the first applicable disaster information is first information indicating that the first PLMN supports disaster roaming of terminals registered in all PLMNs (any PLMN), and wherein the second applicable disaster information is second information about a PLMN associated with disaster roaming supported by the second PLMN, and the second information is different from the first information.

[0012] According to another embodiment of the present disclosure, a method is provided for execution by a base station that shares a radio access network (RAN) with a first public land mobile network (PLMN) and a second PLMN in a wireless communication system. The method may include: sending a system information block 1 (SIB1), the SIB1 including prohibition configuration information for at least one terminal that performs roaming access based on the occurrence of a disaster; sending a SIB15 including an applicable disaster information list; and receiving a control message for a radio resource control (RRC) connection from a terminal when the roaming access of the terminal to the base station is not prohibited, wherein whether to prohibit the disaster roaming access of the terminal to the base station is determined based on the prohibition configuration information, wherein the SIB15 including the applicable disaster information list includes first applicable disaster information for the first PLMN and second applicable disaster information for the second PLMN, wherein the first applicable disaster information is first information indicating that the first PLMN supports disaster roaming of a terminal registered in all PLMNs (any PLMN), and wherein the second applicable disaster information is second information about a PLMN associated with the disaster roaming supported by the second PLMN, and the second information is different from the first information.

[0013] According to another embodiment of the present disclosure, a terminal in a wireless communication system is provided. The terminal may include a transceiver and a processor, wherein the processor is configured to: receive a system information block 1 (SIB1) from a base station that shares a radio access network (RAN) with a first public land mobile network (PLMN) and a second PLMN, wherein the SIB1 includes prohibition configuration information for at least one terminal that performs roaming access based on the occurrence of a disaster; determine whether the disaster roaming access of the terminal is prohibited based on the prohibition configuration information; receive a SIB15 including an applicable disaster information list from the base station; and send a control message for a radio resource control (RRC) connection to the base station if the disaster roaming access of the terminal to the base station is not prohibited, wherein the SIB15 including the applicable disaster information list includes first applicable disaster information for the first PLMN and second applicable disaster information for the second PLMN, wherein the first applicable disaster information is first information indicating that the first PLMN supports disaster roaming of terminals registered in all PLMNs (any PLMN), and wherein the second applicable disaster information is second information about a PLMN associated with disaster roaming supported by the second PLMN, and the second information is different from the first information.

[0014] According to another embodiment of the present disclosure, a base station that shares a radio access network (RAN) with a first public land mobile network (PLMN) and a second PLMN in a wireless communication system is provided. The base station may include a transceiver and a processor, wherein the processor is configured to: send a system information block 1 (SIB1), the SIB1 including prohibition configuration information for at least one terminal that performs roaming access based on the occurrence of a disaster; send an SIB15 including an applicable disaster information list; and receive a control message for a radio resource control (RRC) connection from a terminal when the roaming access of the terminal to the base station is not prohibited, wherein whether to prohibit the disaster roaming access of the terminal to the base station is determined based on the prohibition configuration information, wherein the SIB15 including the applicable disaster information list includes first applicable disaster information for the first PLMN and second applicable disaster information for the second PLMN, wherein the first applicable disaster information is first information indicating that the first PLMN supports disaster roaming of terminals registered in all PLMNs (any PLMN), and wherein the second applicable disaster information is second information about a PLMN associated with disaster roaming supported by the second PLMN, and the second information is different from the first information.

[0015]

Beneficial Effects

[0016] According to the disclosed embodiments, radio resources can be efficiently utilized, and various services can be efficiently provided to users according to priorities. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The structure of the next generation mobile communication system is shown.

[0018] Figure 2 A process of performing UE access control in the present disclosure is shown.

[0019] Figure 3 is a flow chart illustrating a process of performing access control in the present disclosure.

[0020] Figure 4A and Figure 4B The method for configuring access control information in the present disclosure is shown.

[0021] Figure 5 The present disclosure shows that when a disaster occurs, in a RAN shared network, a method of applying a 1-bit indicator is used, especially in considering access control for UEs roaming from a network where the disaster occurs.

[0022] Figure 6 A method for controlling access to a UE in a disaster state in a RAN shared network when a disaster occurs as proposed in the present disclosure is shown.

[0023] Figure 7 A method illustrating a UE operation for performing an access control operation when a disaster situation occurs as an embodiment proposed in the present disclosure.

[0024] Figure 8 The present invention illustrates a method of operating in a network supporting UE roaming in a disaster when a disaster situation occurs as an embodiment proposed in the present disclosure.

[0025] Fig. 9 is a block diagram showing the internal structure of a UE to which the present disclosure is applied.

[0026] Fig.10 is a block diagram showing a configuration of a base station according to the present disclosure. Specific embodiments

[0027] In describing the present disclosure below, a detailed description of well-known functions or configurations incorporated herein will be omitted when it is determined that the description will make the subject matter of the present disclosure unnecessarily unclear. Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0028] Figure 1 The structure of the next generation mobile communication system is shown.

[0029] Reference Figure 1As shown therein, the radio access network of the next generation mobile communication system (new radio, NR) includes a next generation base station (new radio node B, hereinafter referred to as gNB) 1-10 and an access and mobility management function (AMF; new radio core network) 1-05. A user terminal (new radio user equipment, hereinafter referred to as NR UE, UE or NR terminal) 1-15 accesses an external network through the gNB 1-10 and the AMF 1-05.

[0030] exist Figure 1 In the next generation mobile communication system, gNB corresponds to the evolved Node B (eNB) of the conventional LTE system. Compared with the conventional Node B, the gNB can be connected to the NR UE through a radio channel and provide superior services. In the next generation mobile communication system, since all user services are served through a shared channel, a device that collects status information such as the buffer status of the UE, the available transmission power status, and the channel status and performs scheduling accordingly is required, and the gNB 1-10 is used as the device. Generally, one gNB controls multiple cells. In order to achieve ultra-high-speed data transmission beyond the current LTE, the next generation mobile communication system can provide a wider bandwidth than the existing maximum bandwidth, can adopt orthogonal frequency division multiplexing (hereinafter referred to as OFDM) as a radio access technology, and can additionally integrate beamforming technology with it. In addition, the next generation mobile communication system adopts an adaptive modulation and coding (hereinafter referred to as AMC) scheme for determining the modulation scheme and channel coding rate according to the channel status of the UE. AMF 1-05 performs mobility support and access control functions. AMF 1-05 is a device responsible for various control functions and mobility management functions for UEs, and is connected to multiple base stations. In addition, the next generation mobile communication system can interwork with the existing LTE system, and the AMF 1-05 is connected to the MME 1-25 via a network interface. The MME is connected to the eNB 1-30 which is an existing base station. A UE supporting LTE-NR dual connectivity can send / receive data while maintaining connections to the gNB and eNB (1-35).

[0031] Figure 2 A process of performing UE access control in the present disclosure is shown.

[0032] In the present disclosure, a method for efficiently providing access control configuration information based on access identifiers and access categories is described. Access identifiers are defined in 3GPP, i.e., indication information specified in standard documents. Access identifiers are used to indicate specific accesses, as shown in Table 1 below. Mainly, accesses classified as access levels 11 to 15, multimedia services with priority (Multimedia Priority Service (MPS)) and dedicated services (Mission Critical Service (MCS)) are indicated. Access levels 11 to 15 indicate access only for business personnel or for public purposes.

[0033]

Table 1

[0034]

[0035]

[0036] Access categories are divided into two types. One type is a standardized access category. This category is defined at the RAN level, that is, it is a category specified in a standard document. Therefore, the same standardized access category is applied to different service operators. In the present disclosure, the category corresponding to an emergency belongs to a standardized access category. All accesses correspond to at least one of the above-mentioned standardized access categories. The other type is an operator-specific (non-standardized) access category. These categories are defined outside 3GPP and are not specified in standard documents. Therefore, the meaning of an operator-specific access category is different for each operator. This is the same as the category in the existing application-specific congestion control (ACDC) for data communication. Access triggered by UE NAS may not be mapped to an operator-specific access category. The big difference from the existing ACDC is that the category can correspond not only to an application, but also to other elements other than an application, such as a service type, a call type, a UE type, a user group, a signaling type, a slice type, or a combination of the above elements. In other words, it is possible to control whether access to access belonging to other elements is approved. Access categories are used to indicate specific access, as shown in Table 2 below. Access categories 0 to 10 are used to indicate standardized access categories, while access categories 32 to 63 are used to indicate operator specific access categories.

[0037]

Table 2

[0038]

[0039]

[0040]

[0041] The operator server 2-25 provides information (management object (MO)) about operator-specific access category information to the UE NAS through NAS signaling or application-level data transmission. The information indicates the element corresponding to each operator-specific category, such as an application. For example, the access category 32 corresponding to the access corresponding to the Facebook application can be specified in the information. The base station 2-20 provides the UE with the prohibition configuration information corresponding to each category and the category list for providing the prohibition configuration information by using system information. The UE 2-05 includes the logical blocks of the NAS 2-10 and the AS 2-15.

[0042] UE NAS2-10 maps the triggered access to one or more access identifiers and an access category according to a predetermined rule. The mapping operation can be performed in all RRC states, namely, connected mode (RRC_CONNECTED), idle mode (RRC_IDLE) and inactive mode (RRC_INACTIVE). The characteristics of each RRC state are listed below.

[0043] RRC_IDLE:

[0044] -UE-specific DRX can be configured by upper layers;

[0045] - UE controlled mobility based on network configuration;

[0046] UE:

[0047] -Monitor the paging channel;

[0048] -Perform neighbor cell measurements and cell (re)selection;

[0049] -Get system information.

[0050] RRC_INACTIVE:

[0051] -UE-specific DRX can be configured by upper layers or by the RRC layer;

[0052] - UE controlled mobility based on network configuration;

[0053] -UE stores the AS context;

[0054] UE:

[0055] -Monitor the paging channel;

[0056] -Perform neighbor cell measurements and cell (re)selection;

[0057] -Perform RAN-based notification area updates when moving outside of the RAN-based notification area;

[0058] -Get system information.

[0059] RRC_CONNECTED:

[0060] -UE stores the AS context.

[0061] -Transmission of unicast data to / from UE.

[0062] - At lower layers, the UE may be configured with UE-specific DRX;

[0063] -For UEs supporting CA, use one or more SCcells aggregated with SpCell for increased bandwidth;

[0064] -For UEs supporting DC, use one SCG aggregated with the MCG for increased bandwidth;

[0065] - Network controlled mobility, i.e. handover within NR and handover to / from E-UTRAN.

[0066] UE:

[0067] -Monitor the paging channel;

[0068] - monitoring a control channel associated with a shared data channel to determine whether data is scheduled for it;

[0069] -Provide channel quality and feedback information;

[0070] -Perform neighbor cell measurements and measurement reporting;

[0071] -Get system information.

[0072] As another option, in access class mapping, if an access can be mapped to a standardized access class, this access can be additionally mapped to an operator specific access class. The UE NAS transmits the mapped access identity and access class together with the service request to the UE AS (Access Stratum) 2-15.

[0073] In all RRC states, when the UE AS has access identification or access category information and a message received from the UE NAS, the UE AS performs a prohibition check operation to determine whether the radio access caused by the message is allowed before performing radio access. When the radio access is allowed by the prohibition check operation, the UE AS requests the network to establish an RRC connection. For example, the UE NAS in the connected mode or the inactive mode sends the access identification and access category to the UE AS due to the following reasons (indicated by reference numerals 2-30). In the present disclosure, the following reasons are collectively referred to as "new session request".

[0074] - New MMtel voice or video session

[0075] -Send SMS (Send SMS via IP or Send SMS via NAS)

[0076] - New PDU session establishment

[0077] - Modification of existing PDU session

[0078] - Service request to re-establish the user plane for an existing PDU session

[0079] On the other hand, during a service request, the UE NAS in idle mode sends an access identity and access category to the UE AS.

[0080] The UE AS uses the barring configuration information to determine whether to allow access triggered by the UE NAS (barring check).

[0081] The operator may wish to allow only a specific service type in the access corresponding to at least one of the access classes 11 to 15. Therefore, it may be determined whether to allow access belonging to the access classes 11, 12, 13, 14, and 15 indicated by the access identifier according to the attributes distinguished by the access class. To this end, the barring configuration information of the access identifier or the access class is configured, and the barring configuration information of the access class includes uac-barringFactor and uac-barringTime.

[0082] Figure 3 is a flow chart illustrating a process of performing access control in the present disclosure.

[0083] UE 3-05 includes NAS 3-10 and AS 3-15. NAS is responsible for processes not directly related to radio access, i.e., authentication, service request and session management, while AS is responsible for processes related to radio access. The network provides management object information to NAS by using OAM (application level data message) or NAS message (operation 3-25). This information indicates the elements corresponding to each operator-specific access category, such as applications. NAS uses this information to determine the operator-specific category to which the triggered access is mapped. The triggered access corresponds to a new MMTEL service (voice call, video call), SMS transmission, establishment of a new PDU session, and a change to an existing PDU session. When a service is triggered, NAS maps the service to an access identifier and an access category corresponding to the attributes of the service (operation 3-30). A service may not be mapped to any access identifier, or may be mapped to one or more access identifiers. In addition, a service may be mapped to an access category. Under the assumption that a service can be mapped to an access category, it is first identified whether the service is mapped to an operator-specific access category provided by the management object. If the service is not mapped to any operator-specific access category, the service is mapped to one of the standardized access categories that may correspond to the attributes of the service. Under the assumption that a service may be mapped to multiple access categories, a service is mapped to one operator-specific access category and one standardized access category. However, if the service is not mapped to any operator-specific access category, the service is mapped to one of the standardized access categories that may correspond to the attributes of the service. Emergency services may be an exception to the above mapping rules. NAS sends a new session request or a service request together with the mapped access identifier and access category to AS (operation 3-40). NAS sends a new session request in connected mode or inactive mode, and sends a service request in idle mode. AS receives prohibition configuration information from system information broadcast by the network (operation 3-35). An example of the ASN.1 structure of the prohibition configuration information is shown in Table 3 below, and a detailed description thereof will be provided later.

[0084]

Table 3

[0085]

[0086]

[0087] The AS determines whether to allow the service request by using the access identifier and access category information mapped by the NAS and the corresponding barring configuration information received from the network (operation 3-45). In the present disclosure, the operation of determining whether to allow the service request is referred to as a barring check. The UE receives system information including access control configuration information and stores the configuration information. Barring configuration information is provided for each PLMN and each access category. The BarringPerCatList IE is used to provide barring configuration information for access categories belonging to one PLMN. To this end, the PLMN id and barring configuration information for each access category are included in the IE in the form of a list. The barring configuration information for each access category may include an access category id (or index) indicating a specific access category, a uac-BarringForAccessIdentity field, a uac-BarringFactor field, and a uac-BarringTime field. The above-mentioned barring check operation is as follows. First, each bit constituting the uac-BarringForAccessIdentityList corresponds to an access identifier, and when the bit value is indicated as "0", access related to the access identifier can be allowed. For at least one of the mapped access identifiers, when at least one of the corresponding bits in uac-BarringForAccessIdentity is "0", access can be allowed. For at least one of the mapped access identifiers, when none of the corresponding bits in uac-BarringForAccessIdentity is "0", the uac-BarringFactor field can be used to additionally perform the additional barring check described below. The uac-BarringFactor α has a range of 0≤α≤1. The UE AS derives a random value "rand" (0≤rand<1), and if the random value is less than the uac-BarringFactor, the access is considered not to be prohibited. Otherwise, the access is considered to be prohibited. When it is determined that the access is prohibited, the UE AS delays the access attempt for a predetermined time derived using the following equation. The UE AS drives a timer with a time value. In the present disclosure, the timer is referred to as a prohibition timer. "Tbarring" = (0.7+0.6*rand)*uac-BarringTime [Equation 1].

[0088] When access is prohibited, the UE AS notifies the UE NAS of this. In addition, when the derived predetermined time expires, the UE AS notifies the UE NAS that it can request access again (prohibition mitigation). From this point on, the UE NAS can request access from the UE AS again.

[0089] According to a predetermined rule, when the service request is allowed, the AS requests the network to establish an RRC connection (or resume an RRC connection), or sends data related to the new session (operation 3-50).

[0090] Figure 4A and Figure 4B The method for configuring access control information in the present disclosure is shown.

[0091] In the present disclosure, access control information mainly includes UAC-BarringPerPLMN-List4-05 and UAC-BarringInfoSetList 4-60. Basically, barring configuration information consisting of uac-BarringFactor, uac-BarringTime and uac-BarringForAccessIdentity is provided for each access category. In addition, barring configuration information for each access category can be provided differently for each PLMN. UAC-BarringPerPLMN-List includes barring configuration information for the access category of each PLMN. In terms of signaling overhead, it is desirable to provide barring configuration information for each access category that requires barring check. By providing a limited number of barring configuration information lists and indexing the barring configuration information applied to each access category in the list so as to perform signaling more efficiently, signaling overhead can be minimized. The list is UAC-BarringInfoSetList, and the list is configured by UAC-BarringInfoSets 4-65 storing barring configuration information configured to have a specific value. In addition, an index value of uac-barringInfoSetIndex corresponds to a UAC-BarringInfoSet stored in a sequence. The maximum number of UAC-BarringInfoSets that can be stored in the above list is 8. According to the needs of the network, a list including no more than the maximum number of UAC-BarringInfoSets is broadcast.

[0092] The barring configuration information for each PLMN is stored in UAC-BarringPerPLMN4-10. UAC-BarringPerPLMN is mainly configured by plmn-IdentityIndex 4-15, which is the ID information indicating the PLMN, and uac-ACBarringListType4-20, which stores the barring configuration information. The structure for storing the barring configuration information is mainly divided into two types such as uac-ImplicitACBarringList 4-25 and uac-ExplicitACBarringList 4-30. When there is a predetermined number or more of access categories that require barring checks, uac-ImplicitACBarringList is preferred in terms of signaling overhead. Otherwise, uac-ExplicitACBarringList is preferred. The base station selects one of the above structures and broadcasts the barring configuration information, depending on whether the total number of access categories that require barring checks is a specified number or more, or whether there is a specified amount or more of barring configuration information for the access categories. For each signaling structure, in uac-ImplicitACBarringList, the index value uac-BarringInfoSetIndex 4-40 of one of the Uac-BarringInfoSets is stored sequentially according to the access category number for all valid (defined) access categories. On the other hand, uac-ExplicitACBarringList stores UAC-BarringPerCat 4-45, which includes accessCategory 4-50 as an indicator indicating the access category only for access categories that require barring check, and the index value uac-barringInfoSetIndex 4-55 of one of the UAC-BarringInfoSets. One UAC-BarringPerCat corresponds to one access category. For example, a UAC-BarringInfoSetIndex that does not correspond to any UAC-BarringInfoSet can be mapped to UAC-BarringPerCat, and an index value that does not correspond to any UAC-BarringInfoSet is considered to mean no barring.

[0093] Figure 5 The present disclosure illustrates that when a disaster occurs, in a RAN shared network, a method of applying a 1-bit indicator is used, particularly in considering access control for UEs roaming from a network where the disaster occurs.

[0094] UE 5-15 and 5-20 selects a PLMN and a cell according to the subscription information and channel conditions of the UE in a specific area, and accesses and connects to the corresponding PLMN and cell to receive cellular service support. Figure 5 An example is explained in which UE 1 5-15 and UE 2 5-20 are registered in base station 1 (gNB1) 5-05 through PLMN1 and PLMN2, respectively, and are connected to gNB1 5-05. In a specific case, due to a disaster situation occurring at gNB1 5-05 to which they are connected, the corresponding UEs are no longer able to connect to gNB1 5-05, and they need to roam to another network that supports access by UEs roaming from the network when the disaster occurs.

[0095] Base station 2 (gNB2) 5-10 may be a base station existing in the same area as gNB1 5-05, and is a base station serving a PLMN different from the PLMN served by gNB1 5-05. For example, a base station supporting a prohibited PLMN for gNB1 5-05 may be gNB2 5-10. gNB2 5-10 is a base station supporting access by UEs roaming from a network where a disaster has occurred, and broadcasts to the UEs through system information whether the support is available. In particular, in system information 1 (SIB1), a list of PLMNs supporting the corresponding base stations is broadcast, and an access control configuration is broadcast. In particular, prohibition configuration information for access identity 3 (AC 3) is broadcast, and an access control configuration for UEs roaming from a network where a disaster has occurred is transmitted. For reference, the prohibition configuration for access identity 3 is dedicated prohibition configuration information for UEs roaming from a network where a disaster has occurred. In addition, gNB2 5-10 broadcasts system information 15 (SIB15) at the same time as broadcasting SIB1, thereby providing information on whether disaster roaming from UEs registered in a predetermined PLMN is allowed. In particular, SIB15 can explicitly indicate a specific PLMN or indicate a public PLMN so that when a disaster situation occurs at a base station serving the corresponding PLMN, roaming from UEs registered in the corresponding PLMN is allowed. In addition, for all PLMNs or each PLMN, a base station that broadcasts system information through a 1-bit indicator (disasterRoamingFromAnyPLMN) can transmit an indicator that allows disaster roaming from UEs registered in all other PLMNs. This is a signaling optimization method.

[0096] See Table 4 and Table 5 below for relevant signaling.

[0097]

Table 4

[0098]

[0099] -SIB15

[0100] SIB15 contains the configuration of disaster roaming information

[0101]

Table 5

[0102]

[0103]

[0104] like Figure 5 As shown, in the case where gNB2 5-10 supports PLMN3 and PLMN4 (the same RAN, PLMN3 and PLMN4 are used in a network to which RAN sharing is applied) and the corresponding supported PLMN list is broadcast in SIB1, gNB2 5-10 can transmit information about which PLMN allows disaster roaming (i.e., when a failure occurs in the base station serving the specific PLMN, roaming from UEs registered in a specific PLMN is allowed) in SIB15 to each PLMN it supports (i.e., PLMN3, PLMN4). If the PLMN supported by gNB1 allows disaster roaming for UEs belonging to any other PLMN, a 1-bit indicator (disasterRoamingFromAnyPLMN) indicating whether the PLMN supported by gNB1 allows disaster roaming for UEs belonging to any other PLMN can be transmitted. In this case, since gNB2 5-10 is a base station to which RAN sharing is applied, gNB2 can include a 1-bit indicator (disasterRoamingFromAnyPLMN) for both PLMN3 and PLMN4 for SIB15. In other words, even for UEs belonging to any PLMN, PLMN3 and PLMN4 that commonly use gNB25-10 support UE roaming in a disaster. In the later embodiments of the present disclosure, in the above example where RAN sharing is applied, a specific PLMN shares a RAN function, but unlike the base station shared by the UE roaming function during a disaster, if the PLMN excludes the function because it does not want to support the function, a method for supporting the function is proposed. Figure 5 As described, in the current signaling structure, when a PLMN to which RAN sharing is applied supports UE roaming in disaster situations through a 1-bit indicator (disasterRoamingFromAnyPLMN), all PLMNs to which RAN sharing is applied should set and transmit a 1-bit indicator (disasterRoamingFromAnyPLMN) in SIB15.

[0105] Figure 6 A method for controlling access to a UE in a disaster state in a RAN shared network when a disaster occurs as proposed in the present disclosure is shown.

[0106] The UE 6-05 comprises a NAS 6-10 and an AS 6-15. The NAS is responsible for processes not directly related to radio access, ie authentication, service request and session management, while the AS is responsible for processes related to radio access.

[0107] In operation 6-30, the UE registers with the PLMN and performs a connection procedure such as cell selection / reselection. In other words, when powered on, the UE performs a PLMN selection procedure in the NAS 6-10 and determines a selected PLMN. The radio access technology (RAT) associated with the corresponding PLMN is set, and the NAS 6-10 provides a list of equivalent PLMNs that are equivalent to the selected PLMN. Thereafter, the AS 6-15 of the UE performs a cell selection / reselection procedure to camp on a suitable cell 6-21 in the selected PLMN. In the above, camping on a specific cell refers to the operation of the UE receiving system information, selecting a cell that provides valid services, and starting to monitor the PDCCH on the corresponding cell. In addition, the above operation 6-30 includes Figure 3 All operations.

[0108] Through the above process, the UE registers with the selected PLMN, and thus the corresponding PLMN becomes the registered PLMN. In addition, although not separately indicated in the above operation, the UE can identify whether the corresponding cell supports the unified access control (UAC) optimization technology for disaster situations in the specific PLMN considered in the present disclosure through the system information (SIB1, SIB15) broadcasted from the cell where the connection has been performed.

[0109] Thereafter, if a disaster situation occurs in a network including the corresponding PLMN, a network change and connection process (PLMN selection and cell selection / reselection) from the currently registered PLMN to another PLMN should be performed. An indication of the occurrence of a disaster can be provided to the NAS by updating the management object information in the network 6-20 using an application-level data message (OAM) or a NAS message, as shown in operation 6-35. The information indicates the elements corresponding to each operator-specific access category, such as an application. The NAS uses this information to determine the operator-specific category to which the triggered access is mapped. In addition, the message can include an indicator indicating that a disaster situation has occurred. The message can be transmitted from the core network 6-22 to the UE NAS 6-10 and the base station 6-21.

[0110] In operation 6-45, the NAS of the UE checks the PLMN list stored in the buffer to select a PLMN other than the currently registered PLMN. In this operation, the NAS of the UE first identifies whether a disaster has occurred at a base station serving an equivalent PLMN, and if the base station serving all equivalent PLMNs indicates that a disaster has occurred, the NAS of the UE identifies other PLMNs. This operation can be identified by the NAS message in the above operations 6-35 and 6-40, and when a disaster occurs, the UE also identifies whether a disaster has occurred at a base station serving a stored prohibited PLMN. Alternatively, contrary to the above description, when a disaster occurs at a base station serving a currently registered PLMN, there is a high probability that a disaster will occur at a base station serving an equivalent PLMN, and therefore the UE NAS immediately performs a fast PLMN change to a prohibited PLMN and performs an access procedure for the corresponding network. Even in this case, it is necessary to identify whether a disaster has occurred at a prohibited PLMN.

[0111] When it is determined in the above operation whether access to a specific PLMN is possible, the NAS sends a new session request or a service request and the mapped access identity and access category to the AS (operation 6-50). The NAS sends a new session request in a connected mode or an inactive mode, and sends a service request in an idle mode. The AS receives prohibition configuration information from the system information broadcast by the network in a disaster situation (operation 6-40 / 6-55). System information reception can occur at a time point between operations 6-40 and 6-55, and can be received for a specific other PLMN, and affects PLMN selection and cell selection. In particular, with respect to roaming in a disaster situation, refer to the prohibition configuration broadcast in the above-mentioned SIB1 and SIB15. In addition, if there is prohibition information of a cell in the master information block (MIB) broadcast by gNB2 6-26, the UE determines to prohibit the cell before identifying the information broadcast in SIB1 / 15.

[0112] At operation 6-60, the UE AS performs a barring check on the PLMN to be accessed. An example of an ASN.1 structure of barring configuration information is as follows, and a possible method is described separately.

[0113] 1. Disaster Barring Configuration Method: SIB1 provides a barring factor for access identifier 3

[0114] like Figure 3 , Figure 4A and Figure 4BAs described in , the existing UAC-BarringInfoSetList is constructed to provide a barring factor during access in a specific PLMN and access category. Basically, UAC-BarringInfoSetList includes uac-BarringFactor, uac-BarringTime, and uac-BarringForAccessIdentity, and has the following signaling structure. For UE roaming in disaster situations, uac-BarringFactorForAI3-r17 dedicated to access identity 3 is configured as an additional barring factor, as shown in Table 6 below.

[0115]

Table 6

[0116]

[0117] In addition, the base station broadcasts the above SIB1 and SIB15 to transmit UE roaming support information in a disaster from a base station whose corresponding cell serves a specific PLMN. Figure 5 The detailed operation is described. In the corresponding operation, when a 1-bit indicator (disasterRoamingFromAnyPLMN) is used in a RAN shared network, if some of the RAN shared PLMNs do not support disaster roaming of the UE, a signaling method is proposed. 1) Method 1: Signaling that a specific PLMN in the RAN shared PLMN does not have a 1-bit indicator (disasterRoamingFromAnyPLMN) set and does not support disaster roaming (no disaster roaming, i.e., noDisasterRoaming-r17"). In this case, the signaling is described as clearly as shown in Table 7 below.

[0118]

Table 7

[0119]

[0120] 2) Method 2: If there is a PLMN that does not support disaster roaming of the UE in the RAN shared PLMN, additional signaling is introduced to provide a separate PLMN list about the PLMN that does not support disaster roaming of the UE (this can be achieved by directly signaling the shared PLMN identifier (i.e., PLMN-Identity) in SIB1, or by using the identifier indication in the PLMN list provided in SIB1 (i.e., the signaling overhead can be reduced here by not using PLMN-Identity)).

[0121] - Example of signaling (Table 8):

[0122]

Table 8

[0123]

[0124] - Condition: The PLMNs indicated in the excludedPLMN list are signaled only if a 1-bit indicator (disasterRoamingFromAnyPLMN) is signaled, and in this case, the PLMNs included in the list means a list of PLMNs that do not support disaster roaming of the UE in the RAN shared PLMN.

[0125] 3) Method 3: In case of RAN sharing, only the first PLMN from the list of supported PLMNs provided by SIB1 is allowed to indicate a 1-bit indicator (disasterRoamingFromAnyPLMN), while the remaining PLMNs do not signal a 1-bit indicator (disasterRoamingFromAnyPLMN). In this case, other PLMNs should always consistently support roaming of UEs in disasters. In other words, UE roaming control in disasters for each PLMN is not supported.

[0126] 4) Method 4: In terms of network implementation, when a specific PLMN does not support the UE roaming function in a disaster, the corresponding PLMN is excluded from the supported PLMN list in SIB1 broadcast by the corresponding base station (that is, since the corresponding PLMN is subject to RAN sharing and supports other functions while not supporting UE roaming in a disaster, access to the PLMN itself is blocked to prevent access to the PLMN from the network). The corresponding operation is implemented by instructing a system information update operation and updating the system information.

[0127] In fact, in the above process, in the case where the UE AS is connected to the base station serving the prohibited PLMN due to a disaster situation, the UE camps on a specific cell within the corresponding PLMN and then continues the RRC connection establishment process (operation 6-65) (Table 9). When the UE attempts an RRC connection to the prohibited PLMN through the connection process, the UE can select and send "disaster", which is a new value of the establishmentCause value as the RRCSetupRequest message. The value reserved as the existing standby value can be changed by introducing "disaster" as a new cause value.

[0128]

Table 9

[0129]

[0130] The cause value (disatsterLoaming) can be used as a value for the base station to subsequently identify whether the UE requires PLMN fallback for the UE. Alternatively, the cause value (disatsterLoaming) can be used to allow the base station to send an RRCReject (of operation 6-70) for access control in an AS operation for UEs accessed in a disaster state after receiving the corresponding RRCSetupRequest message, so as to enable additional access control for the corresponding UE. In operation 6-70, in response to the RRC connection establishment request from the UE, the base station can accept the connection establishment through RRCSetup, or reject the connection establishment through an RRCReject message.

[0131] Figure 7 The present disclosure provides a method for illustrating UE operation for performing access control operation when a disaster situation occurs as an embodiment proposed in the present disclosure. The present disclosure specifies access-related procedures when a UE registered and connected to a specific PLMN no longer receives service from the currently registered PLMN due to a disaster situation and needs to change to another PLMN, and in particular, is characterized by a method for accessing a specific PLMN via a 1-bit indicator.

[0132] In operation 7-10, the UE NAS receives an indication of a disaster situation in a base station serving the currently registered PLMN, and when the corresponding signaling is to be indicated, the UE is forced to find and change to another PLMN. This is because the PLMN selection operation is performed in the UE NAS, and the above information affects the PLMN reselection. The UE NAS can associate the access identity 3 with the access category and send it to the UE AS to change the PLMN according to the disaster status.

[0133] In operation 7-15, the UE AS receives a request from a higher layer (e.g., UE NAS) for accessing a specific PLMN other than the currently registered PLMN. Here, an indication of a change due to a disaster situation may be included, and an access request to a specific PLMN may be received without a corresponding indication. The UE NAS may select an appropriate PLMN and explicitly send the PLMN information to the UE AS. The most important condition for determining the corresponding PLMN may be a PLMN served by a base station where no disaster has occurred, and under the corresponding condition, the following priority is applied to the PLMN selection.

[0134] 1. Equivalent PLMN

[0135] 2. One of the stored PLMNs (determined by priority in the list)

[0136] 3. The banned PLMN in the stored banned PLMN list (determined according to the priority in the list)

[0137] Alternatively, a fast PLMN check dedicated to disaster situations may be applied, which may be understood to mean that when a disaster situation indicator is transmitted, there is a high probability that a disaster state will occur in a cell of the equivalent PLMN, and therefore other PLMN check procedures are omitted and a banned PLMN is immediately selected.

[0138] If the requested PLMN in operation 7-20 is an equivalent PLMN, the UE AS performs a cell selection / reselection process for a cell belonging to the equivalent PLMN (operation 7-25). In other words, the UE AS attempts to access a cell with good channel performance within the equivalent PLMN. In this operation, the PLMN selected as a result of the PLMN selection process (operation 7-10) of the UE NAS may be indicated, and in this case, the following two methods may be considered.

[0139] 1) Priority-based PLMN check: Determine whether the access of the corresponding PLMN in a disaster situation can be performed in the order of equivalent PLMN → stored PLMN → prohibited PLMN, and transmit it to the UE AS.

[0140] 2) Fast PLMN check dedicated to disaster situations: When a disaster situation indicator is transmitted, there is a high probability that a disaster state will occur in the cell of the equivalent PLMN, so other PLMN check processes are omitted and a banned PLMN is immediately selected.

[0141] If the PLMN requested by the UE NAS in the above operation 7-20 is not an equivalent PLMN, but a different PLMN in the stored PLMN list of the UE (operation 7-30), the UE AS identifies the barring information for the corresponding PLMN and performs access to the corresponding PLMN. The access may be performed in consideration of the barring factor for the barring configuration, and when the PLMN is changed due to a disaster state indication, the new barring factor and process proposed in the present disclosure dedicated to access identity 3 are considered. The detailed operation is described in Figure 6 As shown in . In operation 7-30, when the UE AS receives a disaster state indication (and also receives an indication of access to a prohibited PLMN), the UE performs access to a PLMN in the prohibited PLMN list that supports connection in a disaster state. The above information can be determined using system information broadcast by a specific cell of the prohibited PLMN. The system information can be SIB1 and SIB15, wherein SIB1 contains new prohibition factor configuration information dedicated to access identity 3, and SIB15 contains PLMN information that allows UE access in a disaster from a specific PLMN. Reference Figure 6These details are explained.

[0142] In operation 7-40, the UE AS may perform a barring operation on a specific PLMN belonging to the barred PLMN, and in this case, consider the barring condition in the disaster state. Figure 6 The UE completes the access change of the corresponding PLMN. In particular, when a 1-bit access indicator is used in a RAN shared network as proposed in the present disclosure, the operation includes a method for controlling UE access in the event of a disaster for each PLMN. Figure 6 UE operation for each method proposed in .

[0143] 1. Method 1: In the RAN shared PLMN, the specific PLMN does not set a 1-bit indicator (disasterRoamingFromAnyPLMN) and does not support disaster roaming (no disaster roaming, i.e. noDisasterRoaming-r17).

[0144] -The UE receives information about the PLMNs to which the disaster situation is applied for each PLMN broadcast in SIB15, and applies the received information as is. In other words, the information includes information about how the UE (including the RAN shared PLMN) supports disaster roaming supported in all PLMNs and NPNs that can be supported in the corresponding cells.

[0145] - Even in the case of RAN sharing PLMN, there may be signaling indicating that the PLMN does not support roaming (no disaster roaming, i.e. noDisasterRoaming-r17), and when the UE receives the corresponding indicator, the UE does not perform access to the corresponding PLMN in the disaster situation.

[0146] 2. Method 2: When the RAN shared PLMN does not support roaming for UEs in a disaster, additional signaling is introduced and a separate PLMN list is provided to indicate which PLMNs do not support the roaming (directly signaling the shared PLMN identifier (i.e., PLMN-Identity) in SIB1 or by using an identifier in the PLMN list provided in SIB1).

[0147] -The UE first identifies the 1-bit indicator (disasterRoamingFromAnyPLMN) received for each PLMN in SIB15, and identifies that the corresponding 1-bit indicator (disasterRoamingFromAnyPLMN) exists in common in the RAN shared PLMN. The UE identifies the PLMN list provided separately to the PLMNs that do not support UE roaming in disaster in the RAN shared PLMN in SIB15, and operates to exclude access to these PLMNs.

[0148] 3. Method 3: In case of RAN sharing, only the first PLMN from the supported PLMN list provided by SIB1 is allowed to indicate a 1-bit indicator (disasterRoamingFromAnyPLMN), while the remaining PLMNs do not signal a 1-bit indicator (disasterRoamingFromAnyPLMN). In this case, the other PLMNs should always consistently support roaming of UEs in disasters. In other words, it is not supported to control whether UE roaming in disasters is supported differently for each PLMN.

[0149] -UE identifies the 1-bit indicator (disasterRoamingFromAnyPLMN) in SIB15 broadcasted by the representative PLMN in the RAN shared PLMN and applies it to all RAN shared PLMNs. In other words, the UE can perform access after checking and determining the access operation to all RAN shared PLMNs (the supported PLMN list broadcasted in SIB1).

[0150] 4. Method 4: In terms of network implementation, when a specific PLMN does not support the UE roaming function in a disaster, the corresponding PLMN is excluded from the supported PLMN list in SIB1 broadcast by the corresponding base station (that is, since the corresponding PLMN is subject to RAN sharing and supports other functions while not supporting UE roaming in a disaster, access to the PLMN itself is blocked to prevent access to the PLMN from the network). The corresponding operation is implemented by instructing a system information update operation and updating the system information.

[0151] - This method only affects the implementation operation in the network, and the UE applies the configuration related to disaster access for the RAN shared PLMN according to the received SIB1 / SIB15 system information, as received.

[0152] In operation 7-45, a cell selection / reselection and RRC connection establishment process is performed for a specific suitable cell belonging to the prohibited PLMN. In other words, the UE performs an RRC connection process to a cell belonging to the prohibited PLMN, and the RRCSetupRequest message of the process includes an indicator indicating that the RRC connection establishment is performed due to disaster roaming (roaming in a disaster situation). The purpose of this message is to enable the base station to perform access control for roaming UEs in a disaster state in AS operation (through RRCSetup or RRCReject), or thereafter, when the UE is instructed to resume the network of the previous PLMN, to enable the base station to know the previous information of the UE to perform an operation to migrate the UE back to the previous PLMN.

[0153] In operation 7-50, the UE AS may receive an instruction from the UE NAS to return to the original PLMN after a certain period of time due to the termination of the disaster state. Depending on the implementation of the UE NAS, this operation may be performed or not performed, and when the UE AS receives the instruction, in operation 7-55, the UE AS performs a PLMN selection process to return to the previous PLMN. This operation may be performed by re-executing the existing PLMN selection process or by directly selecting the previous PLMN that has been saved.

[0154] Figure 8 The present invention is a method showing the operation in a network supporting UE roaming in a disaster when a disaster situation occurs according to an embodiment proposed in the present disclosure.

[0155] In operation 8-05, the network provides management object information to the UE NAS by using OAM (application level data message) or NAS message. This information indicates the elements corresponding to each operator specific access category, such as application. NAS uses this information to determine the operator specific category to which the triggered access is mapped. The triggered access corresponds to a new MMTEL service (voice call, video call), SMS transmission, establishment of a new PDU session, and change to an existing PDU session.

[0156] In operation 8-10, the network NAS may transmit the management object information generated in operation 8-05 and information necessary for generating configuration information for AS access control to the network AS. In addition, information related to the barring configuration of the UE in the disaster for access identity 3 may also be included in the management object information and transmitted.

[0157] In operation 8-15, the network AS uses the access identity and access category information mapped by the network NAS and the corresponding prohibition configuration information received from the network to determine whether to allow support for the service, and broadcasts the relevant access configuration via system information. In the present disclosure, when the base station allows disaster roaming for UEs in SIB1 and SIB15 in this operation, a prohibition configuration for access identity 3 (AC 3) UE is included, and a valid PLMN list is provided. Specifically, the present disclosure describes the following detailed method, which involves transmitting a list of PLMNs supporting RAN sharing in SIB1 and signaling in SIB15 which UEs from the PLMN belonging to the disaster network are allowed. A method is described for setting a SIB1 / SIB15 value including a 1-bit indicator (disasterRoamingFromAnyPLMN) by the RAN shared PLMN based on whether the RAN shared PLMN supports the corresponding function. Reference Figure 7 and Figure 7 The detailed operation is described.

[0158] Fig. 9 Shows the structure of UE.

[0159] Reference Fig. 9 , the UE includes a radio frequency (RF) processor 9-10, a baseband processor 9-20, a memory 9-30, and a controller 9-40. The controller 9-40 may also include a multi-connection processor 9-42.

[0160] The RF processor 9-10 may perform functions for sending and receiving signals through a radio channel, such as signal band conversion and amplification. That is, the RF processor 9-10 up-converts the baseband signal provided by the baseband processor 9-20 into an RF band signal and transmits the RF band signal through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 9-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), and an analog-to-digital converter (ADC). Although in Fig. 9 Only a single antenna is shown in the figure, but the UE may include multiple antennas. The RF processor 9-10 may include multiple RF chains. The RF processor 9-10 may perform beamforming. For beamforming, the RF processor 9-10 may adjust the phase and amplitude of the signal transmitted or received by multiple antennas or antenna elements. The RF processor 9-10 may perform MIMO and may receive multiple layers in MIMO operation.

[0161] The baseband processor 9-20 can perform conversion functions between baseband signals and bit streams based on the physical layer specifications of the system. For example, for data transmission, the baseband processor 9-20 generates complex symbols by encoding and modulating the transmission bit stream. For data reception, the baseband processor 9-20 can reconstruct the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 9-10. For example, according to the orthogonal frequency division multiplexing (OFDM) scheme, for data transmission, the baseband processor 9-20 generates complex symbols by encoding and modulating the transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols by performing an inverse fast Fourier transform (IFFT) operation and a cyclic prefix (CP) insertion. For data reception, the baseband processor 9-20 can divide the baseband signal provided from the RF processor 9-10 into OFDM symbol units, reconstruct the signal mapped to the subcarrier by performing a fast Fourier transform (FFT) operation, and then reconstruct the received bit stream by demodulating and decoding the signal.

[0162] The baseband processor 9-20 and the RF processor 9-10 send and receive signals as described above. Therefore, each of the baseband processor 9-20 and the RF processor 9-10 may also be referred to as a transmitter, a receiver, a transceiver or a communicator. At least one of the baseband processor 9-20 or the RF processor 9-10 may include a plurality of communication modules supporting a plurality of different radio access technologies. In addition, at least one of the baseband processor 9-20 and the RF processor 9-10 may include different communication modules to process signals of different frequency bands. For example, different radio access technologies may include wireless LAN (e.g., IEEE802.11), cellular networks (e.g., LTE), etc. In addition, different frequency bands may include ultra-high frequency (SHF) (e.g., 2.NRHz and NRhz) bands and millimeter wave (e.g., 60GHz) bands.

[0163] The memory 9-30 may store data for the operation of the UE, such as basic programs, applications, and configuration information. In particular, the memory 9-30 may store information related to a second access node that performs wireless communication using a second radio access technology. In addition, the memory 9-30 may provide the stored data according to a request of the controller 9-40.

[0164] The controller 9-40 may control the overall operation of the UE. For example, the controller 9-40 may send and receive signals through the baseband processor 9-20 and the RF processor 9-10. In addition, the controller 9-40 may record data on the memory 9-30 and read data from the memory 9-30. To this end, the controller 9-40 may include at least one processor. For example, the controller 9-40 may include a communication processor (CP) for controlling communication and an application processor (AP) for controlling an upper layer such as an application program.

[0165] Fig.10 is a block diagram of a master base station in a wireless communication system according to an embodiment of the present disclosure.

[0166] like Fig.10 As shown, the base station may include an RF processor 10-10, a baseband processor 10-20, a backhaul communicator 10-30, a memory 10-40, and a controller 10-50. However, the controller 10-50 may also include a multi-connection processor 10-52.

[0167] The RF processor 10-10 may perform functions for transmitting and receiving signals through a radio channel, such as signal band conversion and amplification. That is, the RF processor 10-10 up-converts the baseband signal provided from the baseband processor 10-20 into an RF band signal and transmits the RF band signal through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 10-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. Although in Fig.10 Only a single antenna is shown in the figure, but the first access node may include multiple antennas. The RF processor 10-10 may include multiple RF chains. In addition, the RF processor 10-10 may perform beamforming. For beamforming, the RF processor 10-10 may adjust the phase and amplitude of the signal transmitted or received by multiple antennas or antenna elements. The RF processor may perform downlink MIMO operations by sending one or more layers.

[0168] The baseband processor 10-20 performs a conversion function between a baseband signal and a bit stream based on the physical layer specification of the first radio access technology. For example, for data transmission, the baseband processor 10-20 can generate complex symbols by encoding and modulating the transmission bit stream. For data reception, the baseband processor 10-20 reconstructs the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 10-10. For example, according to the OFDM scheme, for data transmission, the baseband processor 10-20 generates complex symbols by encoding and modulating the transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols by performing IFFT operations and CP insertion. For data reception, the baseband processor 10-20 can divide the baseband signal provided from the RF processor 10-10 into OFDM symbol units, reconstruct the signal mapped to the subcarrier by performing an FFT operation, and then reconstruct the received bit stream by demodulating and decoding the signal. The baseband processor 10-20 and the RF processor 10-10 can send and receive signals as described above. Therefore, each of the baseband processor 10 - 20 and the RF processor 10 - 10 may also be referred to as a transmitter, a receiver, a transceiver, a communicator, or a wireless communicator.

[0169] The backhaul communicator 10-30 provides an interface for communicating with other nodes in the network. That is, the backhaul communicator 10-30 converts a bit stream sent from the main base station to another node (eg, auxiliary base station, core network, etc.) into a physical signal, and converts a physical signal received from another node into a bit stream.

[0170] The memory 10-40 may store data for the operation of the above-mentioned master base station, such as basic programs, applications, and configuration information. In particular, the memory 10-40 may store information about the bearer assigned to the accessed UE, the measurement report sent from the accessed UE, etc. In addition, the memory 10-40 may store information used as a criterion for determining whether to provide multiple connections to the UE or to interrupt the UE. The memory 10-40 may provide the stored data according to the request of the controller 10-50.

[0171] The controller 10-50 may control the overall operation of the master base station. For example, the controller 10-50 may send and receive signals through the baseband processor 10-20 and the RF processor 10-10 or through the backhaul communicator 10-30. In addition, the controller 10-50 may record data on the memory 10-40 and read data from the memory 10-40. To this end, the controller 10-50 may include at least one processor.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving a system information block 1 SIB1 from a base station that shares a radio access network RAN ​​with a first public land mobile network PLMN and a second PLMN, the SIB1 including barring configuration information for at least one terminal that performs roaming access based on occurrence of a disaster; Based on the prohibition configuration information, determining whether disaster roaming access of the terminal is prohibited; receiving, from the base station, a SIB15 including a list of applicable disaster information; as well as In a case where the disaster roaming access of the terminal to the base station is not prohibited, sending a control message for a radio resource control RRC connection to the base station, wherein the SIB15 including the applicable disaster information list includes first applicable disaster information for the first PLMN and second applicable disaster information for the second PLMN, The first applicable disaster information is first information indicating that the first PLMN supports disaster roaming of terminals registered in all PLMNs (any PLMN), and The second applicable disaster information is second information about a PLMN associated with the disaster roaming supported by the second PLMN, and the second information is different from the first information.

2. The method according to claim 1, wherein: The second information is one of the following information: information indicating that the disaster roaming is not supported, information indicating that the disaster roaming from a terminal registered in a PLMN configured as a public PLMN is supported, or information indicating that the disaster roaming from a terminal registered in a PLMN configured as a dedicated PLMN is supported.

3. The method according to claim 1, wherein: The first applicable disaster information of the first PLMN sharing the RAN indicates that the disaster roaming of the terminal registered in all PLMNs (any PLMN) is supported, and The second applicable disaster information of the second PLMN used to share the RAN with the first PLMN indicates that the disaster roaming is not supported.

4. The method according to claim 2, wherein: The barring configuration information for at least one terminal performing the roaming access from the network where the disaster occurred is new barring configuration information dedicated to the access identity 3, The information indicating that the disaster roaming is not supported is a noDisasterRoaming parameter. wherein the information indicating the disaster roaming from the terminal registered in the PLMN configured as the public PLMN is a commonPLMN parameter, and The information indicating the disaster roaming from the terminal registered in the PLMN configured as the dedicated PLMN is a dedicatedPLMN parameter.

5. A method performed by a base station in a wireless communication system that shares a radio access network RAN ​​with a first public land mobile network PLMN and a second PLMN, the method comprising: Sending a system information block 1 SIB1, wherein the SIB1 includes prohibition configuration information for at least one terminal that performs roaming access based on the occurrence of a disaster; Sending SIB15 including a list of applicable disaster information; and In a case where the roaming access of the terminal to the base station is not prohibited, receiving a control message for a radio resource control RRC connection from the terminal, Whether to prohibit the terminal from disaster roaming access to the base station is determined based on the prohibition configuration information, wherein the SIB15 including the applicable disaster information list includes first applicable disaster information for the first PLMN and second applicable disaster information for the second PLMN, The first applicable disaster information is first information indicating that the first PLMN supports disaster roaming of terminals registered in all PLMNs (any PLMN), and The second applicable disaster information is second information about a PLMN associated with the disaster roaming supported by the second PLMN, and the second information is different from the first information.

6. The method according to claim 5, wherein: The second information is one of the following information: information indicating that the disaster roaming is not supported, information indicating that the disaster roaming from a terminal registered in a PLMN configured as a public PLMN is supported, or information indicating that the disaster roaming from a terminal registered in a PLMN configured as a dedicated PLMN is supported.

7. The method according to claim 5, wherein: The first applicable disaster information of the first PLMN sharing the RAN indicates that the disaster roaming of the terminal registered in all PLMNs (any PLMN) is supported, and The second applicable disaster information of the second PLMN used to share the RAN with the first PLMN indicates that the disaster roaming is not supported.

8. The method according to claim 6, wherein: The barring configuration information for at least one terminal performing the roaming access from the network where the disaster occurred is new barring configuration information dedicated to the access identity 3, The information indicating that the disaster roaming is not supported is a noDisasterRoaming parameter. wherein the information indicating the disaster roaming from the terminal registered in the PLMN configured as the public PLMN is a commonPLMN parameter, and The information indicating the disaster roaming from the terminal registered in the PLMN configured as the dedicated PLMN is a dedicatedPLMN parameter.

9. A terminal in a wireless communication system, the terminal comprising: Transceiver; as well as processor, Wherein, the processor is configured to: receiving a system information block 1 SIB1 from a base station that shares a radio access network RAN ​​with a first public land mobile network PLMN and a second PLMN, the SIB1 including barring configuration information for at least one terminal that performs roaming access based on occurrence of a disaster; Based on the prohibition configuration information, determining whether disaster roaming access of the terminal is prohibited; receiving, from the base station, a SIB15 including a list of applicable disaster information; and In a case where the disaster roaming access of the terminal to the base station is not prohibited, sending a control message for a radio resource control RRC connection to the base station, wherein the SIB15 including the applicable disaster information list includes first applicable disaster information for the first PLMN and second applicable disaster information for the second PLMN, The first applicable disaster information is first information indicating that the first PLMN supports disaster roaming of terminals registered in all PLMNs (any PLMN), and The second applicable disaster information is second information about a PLMN related to the disaster roaming supported by the second PLMN, and the second information is different from the first information.

10. The terminal according to claim 9, wherein: The second information is one of the following information: information indicating that the disaster roaming is not supported, information indicating that the disaster roaming from a terminal registered in a PLMN configured as a public PLMN is supported, or information indicating that the disaster roaming from a terminal registered in a PLMN configured as a dedicated PLMN is supported.

11. The terminal according to claim 9, wherein: The first applicable disaster information of the first PLMN sharing the RAN indicates that the disaster roaming of the terminal registered in all PLMNs (any PLMN) is supported, and The second applicable disaster information of the second PLMN used to share the RAN with the first PLMN indicates that the disaster roaming is not supported.

12. The terminal according to claim 10, wherein: The barring configuration information for at least one terminal performing roaming access from a network where a disaster occurs is new barring configuration information dedicated to access identity 3, The information indicating that the disaster roaming is not supported is a noDisasterRoaming parameter. wherein the information indicating the disaster roaming from the terminal registered in the PLMN configured as the public PLMN is a commonPLMN parameter, and The information indicating the disaster roaming from the terminal registered in the PLMN configured as the dedicated PLMN is a dedicatedPLMN parameter.

13. A base station in a wireless communication system that shares a radio access network RAN ​​with a first public land mobile network PLMN and a second PLMN, the base station comprising: Transceiver; as well as processor, Wherein, the processor is configured to: Sending a system information block 1 SIB1, wherein the SIB1 includes prohibition configuration information for at least one terminal that performs roaming access based on the occurrence of a disaster; Sending SIB15 including a list of applicable disaster information; and In a case where the roaming access of the terminal to the base station is not prohibited, receiving a control message for a radio resource control RRC connection from the terminal, Whether to prohibit the terminal from disaster roaming access to the base station is determined based on the prohibition configuration information, wherein the SIB15 including the applicable disaster information list includes first applicable disaster information for the first PLMN and second applicable disaster information for the second PLMN, The first applicable disaster information is first information indicating that the first PLMN supports disaster roaming of terminals registered in all PLMNs (any PLMN), and The second applicable disaster information is second information about a PLMN associated with the disaster roaming supported by the second PLMN, and the second information is different from the first information.

14. The base station according to claim 13, wherein: The second information is one of the following information: information indicating that the disaster roaming is not supported, information indicating that the disaster roaming from a terminal registered in a PLMN configured as a public PLMN is supported, or information indicating that the disaster roaming from a terminal registered in a PLMN configured as a dedicated PLMN is supported.

15. The base station according to claim 13, wherein: The first applicable disaster information of the first PLMN sharing the RAN indicates that the disaster roaming of the terminal registered in all PLMNs (any PLMN) is supported, and The second applicable disaster information of the second PLMN used to share the RAN with the first PLMN indicates that the disaster roaming is not supported.

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