CN117083917A - Method and apparatus for transmitting and receiving signal for supporting non-public network (NPN) in wireless communication system - Google Patents

Abstract

Disclosed is a method for transmitting and receiving a signal for supporting a non-public network (NPN) in a wireless communication system, the method comprising: receiving, by an Access Stratum (AS) of a User Equipment (UE), a loading indicator and a Group ID (GID) from at least one independent non-public network (SNPN) base station; the AS of the user equipment may report a loading indicator and GID of each of the at least one SNPN base station to a non-access stratum (NAS) of the user equipment; and if the NAS of the user equipment selects an SNPN base station from the at least one SNPN base station to perform loading access, the AS of the user equipment transmits an RRCSetup request message to the selected SNPN.

Description

Method and apparatus for transmitting and receiving signal for supporting non-public network (NPN) in wireless communication system

Technical Field

The present disclosure relates to a method and apparatus for transmitting and receiving a signal for supporting a non-public network (NPN) in a wireless communication system.

Background

In view of the development of the generation and generation of wireless communication, these technologies have been developed mainly for services targeted for personal purposes, such as voice calls, multimedia services, data services, and the like. With the fifth generation (5 ^th generation, 5G) communication systems, it is expected that the number of connected devices will increase exponentially. These will increasingly be connected to a communication network. Examples of the internet of things may include vehicles, robots, drones, home appliances, displays, smart sensors connected to various infrastructure, construction machinery, factory equipment, and the like. Mobile devices are expected to evolve in a variety of forms such as augmented reality glasses, virtual reality headphones, and holographic devices. There is a continuing effort to develop improved 6G communication systems to provide for improved communication in the sixth generation (6 ^th generation, 6G) era has provided various services by connecting hundreds of billions of devices and things. For these reasons, the 6G communication system is called a super 5G system.

It is expected that a 6G communication system commercialized around 2030 will have a peak data rate of megabits (tera) (1,000 giga) level bps and a radio delay of less than 100 musec, and thus will be 50 times the data rate of a 5G communication system and have a radio delay of 1/10 thereof.

To achieve such high data rates and ultra-low delays, it has been considered to implement 6G communication systems in the terahertz band (e.g., the 95GHz to 3THz band). It is expected that a technology capable of securing a signal transmission distance (i.e., coverage) will become more critical since path loss and atmospheric absorption in the terahertz band are more serious than those in the millimeter wave (mmWave) band introduced in 5G. As a main technique of ensuring coverage, it is necessary to develop a Radio Frequency (RF) element, an antenna, a novel waveform with better coverage than an orthogonal frequency division multiplexing (orthogonal frequency division multiplexing, OFDM), beamforming and massive multiple input multiple output (multiple input multiple output, MIMO), full-dimensional MIMO (full dimensional multiple input multiple output, FD-MIMO), an array antenna, and a multi-antenna transmission technique such as a massive antenna. Furthermore, new technologies to improve terahertz band signal coverage, such as metamaterial-based lenses and antennas, orbital angular momentum (orbital angular momentum, OAM) and reconfigurable smart surfaces (reconfigurable intelligence surface, RIS), are always being discussed.

Furthermore, in order to improve spectral efficiency and overall network performance, the following techniques have been developed for 6G communication systems: full duplex techniques for enabling uplink and downlink transmissions to use the same frequency resources simultaneously; network technologies utilizing satellites, high-altitude platform station, HAPS, etc. in an integrated manner; an improved network structure for supporting mobile base stations and the like and making network operation optimization, automation and the like possible; dynamic spectrum sharing via collision avoidance based on spectrum usage prediction: using artificial intelligence (artificial intelligence, AI) in wireless communications to improve overall network operation by leveraging AI from the design phase of development 6G and internalizing end-to-end AI support functions; and next generation distributed computing technologies that overcome User Equipment (UE) computing capability limitations by ultra-high performance communications and computing resources such as mobile edge computing (mobile edge computing, MEC), cloud, etc. that are available on the network. Further, attempts are being continued to strengthen connectivity between devices, optimize networks, promote the software of network entities, and increase the openness of wireless communications by designing new protocols to be used in 6G communication systems, developing mechanisms for achieving secure use of hardware-based secure environments and data, and developing techniques for maintaining privacy.

Research and development of 6G communication systems including human-to-machine (person to machine, P2M) and machine-to-machine (machine to machine, M2M) hyperlinks would be expected to bring about the next hyperlinking experience. In particular, it is desirable to provide services such as true immersive augmented reality (XR), high fidelity mobile holograms, and digital replicas through 6G communication systems. In addition, services such as teleoperation for enhanced safety and reliability, industrial automation and emergency response will be provided through the 6G communication system, so that the technology can be applied to various fields such as industry, health care, automobiles, home appliances, and the like.

Disclosure of Invention

Technical problem

In embodiments of the present disclosure, a method and apparatus for transmitting and receiving signals for supporting a non-public network (NPN) may be provided.

Technical solution

In accordance with the present disclosure, a method of transmitting and receiving a signal for supporting a non-public network (NPN) in a wireless communication system may include: receiving, by an Access Stratum (AS) of a User Equipment (UE), a loading (onboard) indicator and a group identification (group identification, GID) from at least one stand-alone non-public network (snp) base station, reporting the loading indicator and the GID of each of the at least one SNPN base station from the AS of the UE to a non-access stratum (NAS) of the UE, and transmitting an rrcsetup request message from the AS of the UE to the selected SNPN when the NAS of the UE selects the SNPN base station from the at least one SNPN base station to perform the loading access.

Drawings

Fig. 1A is a diagram illustrating an architecture of a next-generation mobile communication system according to an embodiment of the present disclosure.

Fig. 1B is a diagram for describing a method of providing system information in a next generation mobile communication system according to an embodiment of the present disclosure.

Fig. 1C is a conceptual diagram illustrating a visited independent non-public network (V-SNPN) according to an embodiment of the disclosure.

Fig. 1D shows a flowchart of a process for accessing a V-SNPN supporting cell according to an embodiment of the disclosure.

Fig. 1E is a flowchart of a process for supporting handover in a V-SNPN supporting cell according to an embodiment of the disclosure.

Fig. 1F is a flowchart of a process for collecting and reporting V-SNPN associated information according to an embodiment of the disclosure.

Fig. 1G is a conceptual diagram for describing loading of SNPN (O-SNPN) according to an embodiment of the disclosure.

Fig. 1H is a flowchart of a process for accessing an O-SNPN supporting cell according to an embodiment of the disclosure.

Fig. 1I is a flowchart of a process for supporting handover in an O-SNPN supporting cell according to an embodiment of the disclosure.

Fig. 1J is a flowchart of a process for collecting and reporting O-SNPN associated information according to an embodiment of the disclosure.

Fig. 1K is a block diagram showing an internal configuration of a User Equipment (UE) to which the present disclosure is applied.

Fig. 1L is a block diagram illustrating a configuration of a Base Station (BS) according to the present disclosure.

Detailed Description

According to an embodiment of the present disclosure, a method performed by a User Equipment (UE) for supporting a non-public network (NPN) in a wireless communication system may include: receiving, by an Access Stratum (AS) of the UE, a loading indicator and a Group Identification (GID) from at least one independent non-public network (SNPN) base station; reporting a loading indicator and a GID of each of the at least one SNPN base station from the AS of the UE to a non-access stratum (NAS) of the UE; and transmitting an rrcsetup request message from the AS of the UE to the selected SNPN when the NAS of the UE selects a snp base station from the at least one snp base station to perform the loading access.

According to an embodiment of the present disclosure, a method performed by an independent non-public network (snp) base station for supporting a non-public network (NPN) in a wireless communication system may include: broadcast load indicator (GID); when the loading indicator and the GID are received by an Access Stratum (AS) of a User Equipment (UE) and the SNPN base station is selected by a non-access stratum (NAS) of the UE that has received the loading indicator and the GID from the AS of the UE, an rrcsetup request message is received from the AS of the UE, wherein the AS of the UE reports the loading indicator and the GID of at least one SNPN base station including the SNPN base station to the NAS of the UE.

According to an embodiment of the present disclosure, a User Equipment (UE) for supporting a non-public network (NPN) in a wireless communication system may include: a transceiver; and a processor coupled to the transceiver and configured to receive, by an Access Stratum (AS) of the UE, the loading indicator and the Group Identification (GID) from at least one independent non-public network (snp) base station, report, from the AS of the UE to a non-access stratum (NAS) of the UE, the loading indicator and the GID of each of the at least one snp base station, and send an rrcsetup request message from the AS of the UE to the selected snp when the NAS of the UE selects a snp base station from the at least one snp base station to perform the loading access.

According to an embodiment of the present disclosure, an independent non-public network (SNPN) base station for supporting a non-public network (NPN) in a wireless communication system may include: a transceiver; and a processor coupled with the transceiver and configured to: broadcasting a loading indicator and a Group Identification (GID), and when the loading indicator and the GID are received by an Access Stratum (AS) of a User Equipment (UE) and the SNPN base station is selected by a non-access stratum (NAS) of the UE that has received the loading indicator and the GID from the AS of the UE, receiving an rcsetup request message from the AS of the UE, wherein the AS of the UE reports the loading indicator and the GID of at least one SNPN base station including the SNPN base station to the NAS of the UE.

MODE OF THE INVENTION

In the description of the present disclosure, the detailed description of the related art is omitted when it is considered that the detailed description of the related art may unnecessarily obscure the essence of the present disclosure. Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

Fig. 1A is a diagram showing an architecture of a next-generation mobile communication system.

Referring to fig. 1A, as shown, a radio access network of a next generation mobile communication system (new radio (NR)) includes new radio node bs (hereinafter, next generation node bs (gnbs)) 1A-10 and new radio core networks (AMFs) 1A-05. The new radio user equipment (hereinafter referred to as NR UE or UE) 1a-15 accesses the external network via gNB 1a-10 and AMF 1a-05.

In fig. 1A, the gNB corresponds to an evolved node B (eNB) of a legacy Long Term Evolution (LTE) system. The gNB may be connected to the NR UE via a wireless channel and may provide superior service compared to the legacy node Bs (1 a-20). All user traffic data may be served through a shared channel in the next generation mobile communication system, and thus, an entity for checking buffer status information, available transmission power status information, and channel status information of the UE and performing scheduling may be required, and the gnbs 1a-10 may operate as such entities. One gNB may typically control multiple cells. NR may have a bandwidth greater than the maximum bandwidth of the conventional LTE system in order to achieve an ultra-high data rate, and an Orthogonal Frequency Division Multiplexing (OFDM) scheme may be used as a radio access technology, and a beamforming technology may be additionally applied to the radio access technology. In addition, the NR may also determine a modulation scheme and a channel coding rate according to a channel state of the UE using Adaptive Modulation and Coding (AMC). The AMFs 1a-05 may perform functions such as mobility support, bearer configuration, and quality of service (QoS) configuration. The AMFs 1a-05 are entities for performing mobility management functions and various control functions for UEs, and are connected to a plurality of Base Stations (BSs). Further, the next generation mobile communication system may cooperate with the legacy LTE system, and the AMFs 1a-05 may be connected to Mobility Management Entities (MMEs) 1a-25 via a network interface. The MME 1a-25 is connected to the eNB 1a-30 as a legacy BS. A UE supporting LTE-NR dual connectivity may send and receive data while maintaining a connection not only with the gNB but also with the enbs (1 a-35).

In the next generation mobile communication system, 3 radio access states (radio resource control (RRC) states) may be defined. The connection mode (rrc_connected) indicates a radio access state in which the UE can transmit and receive data. The IDLE mode (rrc_idle) indicates a radio access state in which the UE monitors whether to send a page to the UE. These two modes are radio access states that are also applied to the conventional LTE system, and detailed technology is the same as that of the conventional LTE system. In the next generation mobile communication system, an INACTIVE radio access state (rrc_inactive) is newly defined. In the radio access state, UE context is maintained for both BS and UE and RAN-based paging is supported. The characteristics of the new radio access state are listed below.

-cell reselection mobility; (cell reselection mobility);

-a CN-NR RAN connection (two C/U planes) has been established for the UE; (CN-NR RAB connection has been established for UE (two C/U faces))

-UE AS context is stored in at least one gNB and UE; (UE AS context is stored in at least one of the gNB and UE)

-paging is initiated by the NR RAN; (paging is initiated by NR RAN)

-the RAN-based notification area is managed by the NR RAN; (the RAN-based notification area is managed by the NR RAN)

-the NR RAN is aware of the RAN-based notification area to which the UE belongs; (NR RAN knows the RAN-based notification area to which the UE belongs)

By using a specific procedure, a new inactive radio access state can be handed over to a connected mode or an idle mode. According to the restoration procedure, the inactive mode may be handed over to the connected mode, and the connected mode may be handed over to the inactive mode by using a release procedure including suspension configuration information. In this procedure, one or more RRC messages may be transmitted and received between the UE and the BS, and the procedure may include one or more steps. Furthermore, via a release procedure after recovery, the inactive mode may be handed over to the idle mode. Handover between connected mode and idle mode follows existing LTE technology. That is, via the setup or release procedure, a handover between modes is performed.

Fig. 1B is a diagram for describing a method of providing system information in a next generation mobile communication system.

The system information broadcast by the gNB 1b-10 in the next generation mobile communication system is broadly classified into minimum System Information (SI) and other system information. The minimum SI is always broadcast periodically (1 b-15) and includes configuration information required for initial access and SI scheduling information required for reception period or optionally other SI broadcast. A Master Information Block (MIB) and a system information block 1 (SIB 1) are included in the minimum SI. The other SI includes substantially all configuration information not included in the minimum SI. Other SIs are broadcast (1 b-20) periodically, or are broadcast based on UE requests or provided to UEs (1 b-25) through dedicated signaling. When receiving other SI based on the UE request, the UE needs to check whether the other SI is valid in the cell or currently broadcast (by the request of another UE) before performing the request. The checking may be performed via specific information provided by the minimum SI. A UE in IDLE mode (rrc_idle) or INACTIVE mode (rrc_inactive) may request other SIs without changing the current RRC state. The UE in the CONNECTED mode (rrc_connected) may request and receive other SIs through dedicated RRC signaling. Other SIs are broadcast at regular intervals within a preset period of time. Public warning system (Public warning system, PWS) information is categorized into other SIs and provided. It is a network implementation whether to broadcast other SI or provide other SI to the UE through dedicated RRC signaling.

Another feature of other SIs in the next generation mobile communication system is that the same information can be broadcast in the neighbor cells of each SIB via SIB1 notification. Since the same information is broadcasted in the neighboring cell for each SIB via SIB1 notification, when the user moves to the neighboring cell and the SIB of the cell before the movement is equal to the SIB of the cell after the movement, an operation of unnecessarily reacquiring the SIB can be prevented. SIB1 indicates that it is an area-based SIB capable of having the same information as a neighboring cell by using an area scope field of each SIB belonging to SI other than MIB and SIB1. Furthermore, using the area scope field, an area ID and a systemiformationareaaid (system information area ID) of the corresponding cell can also be provided. After moving to the neighbor cell, if the region ID provided by SIB1 broadcasted from the neighbor cell has the same value, the UE does not need to reacquire the region-based SIB.

Fig. 1C is a conceptual diagram for describing V-SNPN according to an embodiment of the disclosure.

The release 16NR mobile communication system is enhanced to support a non-public network (NPN). The NPNs are broadly divided into Closed Access Groups (CAGs) and independent non-public networks (SNPN). CAG is also known as public network integrated NPN (PNI-NPN) and indicates NPN provided to interoperate with networks provided by mobile communication providers. To indicate PNI-NPN, the BS may broadcast SIB1 including PNI-NPN ID. The PNI-NPN ID is composed of a Public Land Mobile Network (PLMN) ID and a CAG ID, and the PLMN ID indicates an ID of one of PLMNs of mobile communication providers providing the cell. On the other hand, the SNPN indicates NPN that does not interoperate with a network provided by the mobile communication provider. To indicate the SNPN, the BS may broadcast SIB1 including the SNPN ID. The SNPN ID is composed of a PLMN ID and a Network Identification (NID), and the PLMN ID and the NID are independent of a mobile communication provider. The UE may be configured in the SNPN mode, and in this case, the UE does not perform a normal cell reselection operation. If not configured in SNPN mode, the UE may perform normal cell reselection operations while camping on the SNPN cell.

The UE previously has information of NPN that the UE can access, and determines whether to access the cell in consideration of PNI-NPN or SNPN ID broadcast via SIB 1.

The present disclosure provides a method by which an SNPN cell supports access to a home SP. In the present disclosure, the SNPN may support an external service provider. In this disclosure, this is referred to as home service provider (home SP) 1c-15. For example, an SNPN network may be established to wirelessly control the intelligent plant. Workers working at a factory may want to provide services from external service providers via an SNPN network. The external service provider may indicate an existing wired/wireless communication provider. Here, the AMFs and SMFs in the SNPN in the factory may be connected to network entities of external service providers in order to connect users with the external service providers. SNPN may be described as visited SNPN (V-SNPN) 1c-10. The V-SNPN 1c-10 may broadcast ID information of the home SP supported by itself by using system information. When the UE 1c-05 receives the system information, the UE 1c-05 may determine whether the V-SNPN 1c-10 can be accessed by using the subscription credentials and configuration the UE previously had. The present disclosure describes access as credential access because access uses credentials. For example, the subscription credentials and configuration may include list information of V-SNPN allowed accesses.

Fig. 1D shows a flowchart of a process for accessing a V-SNPN supporting cell according to an embodiment of the disclosure.

In fig. 1D, for convenience of description, the V-SNPN supporting cell is described as V-SNPN gNB 1D-20. The V-SNPN gNB 1d-20 can broadcast the following information (1 d-25) by using the system information.

An indicator a connected to a network entity of the external service provider in order to indicate whether a connection between the user and the external service provider is supported (i.e. whether access using credentials from a separate entity is supported). The information may be broadcast via a preset SIB (e.g., SIB 1).

An indicator B indicating whether a UE that is not configured to select SNPN is allowed to attempt registration (i.e., whether SNPN allows a registration attempt from a UE that is not explicitly configured to select SNPN). The information may be broadcast via a preset SIB (e.g., SIB 1).

-ID list information of one or more home SPs supported by V-SNPN gNB 1d-20. The information may be broadcast via a preset SIB (e.g., SIB 1) and may be provided for each SNPN supported by the respective cell.

-group ID list information of one or more home SPs supported by V-SNPN gNB 1d-20. When V-SNPN gNB 1d-20 supports many home SPs, the amount of information to be broadcast via system information may increase drastically. Thus, to reduce signaling overhead, a preset home SP may be configured as a group. When the V-SNPN gNB 1d-20 supports all or some of the home SPs included in the group, the V-SNPN gNB 1d-20 may broadcast the ID of the group via a preset SIB (e.g., SIB 1). With the group ID list, it is also possible to broadcast the supported ID list of the home SPs. In the present disclosure, the group ID is described as a Group ID (GID). Information may be provided for each SNPN supported by the corresponding cell.

-name information of a human readable home SP or GID. When the V-SNPN gNB 1d-20 supports a plurality of home SPs or GIDs and the UE may support some of the plurality of home SPs or GIDs, the user may manually select one of them. Thus, to support this, it is necessary to identify them with human-readable names. In the present disclosure, the human-readable home SP or GID information may be broadcasted to the UE by using a preset SIB (e.g., SIB 10). Information may be provided for each SNPN supported by the corresponding cell.

The UE AS 1d-15 that has received the information via the SIB may send the received information to the UE NAS 1d-10. That is, home SP and GID information for the indicators A and B and each SNPN may be sent to the UE NAS (1 d-30). The UE NAS 1d-10 having received the information may select an SNPN to be accessed and a home SP or GID to be accessed, and may determine an access identity and an access class (1 d-35) corresponding to the service type. When an ATTACH (atach) or service request is triggered, the UE NAS 1d-10 may send the selected information to the UE AS 1d-15 (1 d-40).

To alleviate network congestion, the V-SNPN gNB 1d-20 may broadcast system information (1 d-45) including forbidden configuration information for each SNPN. The UE having received the information may determine whether to allow an attempt to attempt access via the inhibit check operation (1 d-50).

In the present disclosure, the prohibition check operation may be performed based on the access identification and the access category. The access identity is indication information defined in 3GPP (i.e. standard document). The access identity may be used to indicate a particular access, as shown in the following table. Access, multimedia priority services with priority (multimedia priority service, MPS) and mission critical services (mission critical service, MCS) that are mainly classified into access classes 11 to 15 may be indicated. The access classes 11 to 15 may be used to indicate accesses dedicated to a commercial operator or public purpose.

The access categories may be classified into two types. One type is a standardized access class. The category is defined in the RAN level, i.e. specified in the standard document. Thus, the same standardized access categories may be applied to different commercial operators. In the present disclosure, the category corresponding to the emergency situation may belong to a standardized access category. All accesses may correspond to at least one of the standardized access categories. Another type is an operator specific (non-standardized) access class. The category is defined outside 3GPP and is not specified in the standard document. Thus, the meaning of an access class specific to one operator is different for each commercial operator. This is the same as in the category of existing ACDC. Certain accesses triggered by the UE NAS may not be mapped to operator specific access categories. The great difference from existing ACDC is that the category may correspond not only to the application but also to other factors, which are service type, call type, terminal type, subscriber group, signaling type, slice type or a combination of these factors and the application. That is, for accesses belonging to other factors, whether or not to allow the accesses can be controlled. The access category may be used to indicate a particular access as shown in the following table. The access class numbers 0 to 7 are used to indicate standardized access classes, and the access class numbers 32 to 63 are used to indicate operator specific access classes.

The commercial operator server may provide the UE NAS 1d-10 with information about an operator specific access class (management object (MO)). The information may indicate to which factor each operator specific category corresponds, such as an application. For example, the access class number 32 may indicate in the information that this corresponds to an access corresponding to a Facebook application. The V-SNPN gNB 1d-20 may provide the UE with a category list that provides forbidden configuration information and forbidden configuration information corresponding to each category.

The UE NAS 1d-10 maps the triggered access to one or more of an access identity and an access class. The mapping operation may be performed in all RRC states of a CONNECTED mode (rrc_connected), an IDLE mode (rrc_idle), and an INACTIVE mode (rrc_inactive).

When the UE AS 1d-15 is provided with information of an access identity or an access class with a message received from the UE NAS in all RRC states, the UE AS 1d-15 may perform a barring check operation to determine whether to allow this before performing the message-triggered radio access. Via the inhibit check operation, the UE may request an RRC connection configuration from the network when radio access is allowed.

The UE AS 1d-15 may determine whether to allow access triggered by the UE NAS by using the barring configuration information (barring check).

A commercial operator may want to allow only specific services from the access corresponding to at least one of the access categories 11 to 15. Thus, it may be determined whether to allow access belonging to the access categories 11, 12, 13, 14 and 15 and indicated by the access identities, based on the attributes identified by the access categories. To this end, the present disclosure proposes a method of configuring forbidden configuration information of an access identity or an access class. In the present disclosure, it is assumed that the inhibition configuration information of the access category is configured by ac-barrengfactor and ac-barrengtime as the inhibition configuration information of the existing ACB or ACDC. An example of the asn.1 structure of the inhibit configuration information is as follows, and a detailed description thereof will be provided later.

The UE AS 1d-15 may determine whether to allow the service request by using the information of the access identities and access categories mapped by the NAS and corresponding barring configuration information received from the network. In the present disclosure, the operation of determining whether to allow a service request is referred to as a prohibition check. The UE may receive system information including access control configuration information and may store the configuration information. Forbidden configuration information may be provided for each PLMN/SVPN and each access class. BarringPerCatList IE may be used to provide forbidden configuration information for access categories belonging to one PLMN/SVPN. To this end, PLMN ids (or SNPN ids) and forbidden configuration information for each access class may be included in the IE as a list. The barring configuration information for each access category may include an access category id (or index) indicating a specific access category, uac-barrenforcessidentity (uac-barring for access identification) field, uac-barrenfactor (uac-barring factor) field, and uac-barrengtime (uac-barring time) field. The above-described prohibition check operation is as follows. First, each bit of the configuration uac-barrenforaccessidentity list (uac-forbidden for access identity list) may correspond to one access identity, and when the value of the bit is indicated as "0", access associated with the access identity may be allowed. Access may be allowed when at least one corresponding bit in uac-barrengforaccessidentity is "0" with respect to at least one of the mapped access identities. When at least one corresponding bit in uac-barrengforaccessidentity is not "0" with respect to at least one of the mapped access identities, an additional inhibit check may be performed by additionally using the uac-barrengfactor field. uac-BarringFactor alpha may be in the range of 0.ltoreq.alpha <1.AS 1d-15 derives a random value rand, where 0.ltoreq.rand <1, and when the random value is less than uac-BarringFactor, access may be deemed not to be barred or otherwise barred. When determining that access is barred, the UE AS 1d-15 delays the access attempt by a preset time derived by using equation 1 below. The UE AS 1d-15 runs a timer with a time value. In this disclosure, a timer may be described as a prohibit timer.

"T prohibit" = (0.7+0.6×rand) × uac-barrengtime. [ equation 1]

When access is barred, the UE AS 1d-15 may inform the UE NAS 1d-10 of this. When the derived preset time elapses, the UE AS 1d-15 may notify the UE NAS 1d-10 of the prohibition of mitigation (access request is possible). At this point, the UE NAS 1d-10 may request access again from the UE AS 1d-15.

The V-SNPN gNB 1d-20 may apply different barring configurations to accesses where services must be provided directly by the gNB, accesses to connect to the foreign home SP, and credential accesses. For example, when the network is congested, the V-SNPN gNB 1d-20 may apply a higher priority to accesses that must be serviced directly by the gNB. The present disclosure presents the following options for access control for credential access.

-a first option: when the UE NAS 1d-10 has selected a SNPN and a home SP or GID for access to the V-SNPN gNB 1d-20, the UE NAS 1d-10 may map the access identity with respect to the access to a new access identity corresponding to the credential access. Preset existing access categories may be mapped to the access. The mapping information and information about the selected SNPN and the home SP or GID may be transmitted to the UE AS 1d-15. The V-SNPN gNB 1d-20 may indicate whether the inhibit checking operation may be skipped for the new access identity of each access class as inhibit configuration information corresponding to the selected SNPN. If the inhibit checking operation is indicated to be skipped, the UE may skip the inhibit checking operation and may attempt to access V-SNPN gNB 1d-20. A new access identity corresponding to the credential access may be provided for each SNPN.

-a second option: when the UE NAS 1d-10 has selected the SNPN and the home SP or GID for accessing the V-SNPN gNB 1d-20, the UE NAS 1d-10 may map the access class with respect to the access to the new access class corresponding to the credential access. The preset existing access identities may be mapped to accesses. The mapping information and information about the selected SNPN and the home SP or GID may be transmitted to the UE AS. The gNB may broadcast the forbidden configuration information corresponding to the new access category as forbidden configuration information corresponding to the selected SNPN. A new access category corresponding to the credential access may be provided for each SNPN. The UE may perform the barring check operation by using barring configuration information corresponding to the new access class.

-a third option: the gNB may provide an indicator indicating whether to prohibit credential access for each SNPN supporting credential access. The indicator may be broadcast to the UE by using system information of V-SNPN gNB 1 d-20. If the indicator is provided and the access triggered by the UE NAS is a credential access, then it is considered that access from the corresponding cell is barred. An indicator may be provided for each SNPN and each home SP or GID. Further, an indicator may be provided for each access category.

-a fourth option: the V-SNPN gNB 1d-20 may provide an indicator indicating whether the forbidden configuration information for each access class provided for each SNPN applies only to credential access. If the indicator is provided and the access triggered by the UE NAS is a credential access, the barring check operation may be performed by using barring configuration information mapped to the access class of the access. When the indicator is provided, the UE may not perform a prohibition check operation regarding normal access by using the provided prohibition configuration information. Via the inhibit check operation, when access is allowed, the UE may attempt a random access operation for credential access to the corresponding cell. An indicator may be provided for each SNPN and each home SP or GID. Further, an indicator may be provided for each access category.

-a fifth option: the gNB may provide an indicator indicating whether or not the barring configuration information for each access class provided for each SNPN is also applicable to credential access. If the indicator is not provided and the access triggered by the UE NAS 1d-10 is a credential access, the UE may attempt a random access operation for accessing the corresponding cell without a forbidden check operation with respect to the credential access. If the indicator is provided and the access triggered by the UE NAS 1d-10 is a credential access, the UE may perform a barring check operation by using barring configuration information mapped to the access class of the access. Via the inhibit check operation, the UE may attempt a random access operation to access a corresponding cell when access is allowed. An indicator may be provided for each SNPN and each home SP or GID. Further, an indicator may be provided for each access category.

-a sixth option: individual barring configuration information applied only to credential access may be provided for each access category. The inhibit configuration information may be provided for each home SP or GID.

The operations may be applied in an overlapping manner. When access is allowed via the access control operation, the UE 1d-05 may perform an RRC connection operation to connect to the cell. The UE may send an RRCSetup request message to the V-SNPN gNB 1d-20, and the V-SNPN gNB 1d-20 may send an RRCSetup message corresponding to the RRCSetup request message to the UE. The UE that has received the RRCSetup message may send a RRCSetup complete message to V-SNPN gNB 1d-20. The V-SNPN gNB 1d-20 may be connected to a plurality of AMFs, and each AMF may be connected to a home SP. Thus, the V-SNPN gNB 1d-20 may need to select an appropriate AMF that supports the home SP requested by the UE. To this end, the UE may need to report information (1 d-55) to the V-SNPN gNB 1d-20 about the home SP or GID that the UE NAS selected during the setup procedure. According to embodiments of the present disclosure, information may be reported to V-SNPN gNB 1d-20 by using RRCSetup request or RRCSetup complete message. Further, the rrcsetup request message may include a new establishment cause value or a new indicator indicating that the access is a credential access. The V-SNPN gNB 1d-20 may previously have information on AMFs capable of supporting the home SP or GID, and may select the AMFs capable of supporting the home SP or GID by using the home SP or GID information reported from the UE. If there is no supportable AMF, the V-SNPN gNB 1d-20 can prevent the UE from connecting to the corresponding cell by using an RRCReject (RRC reject) or RRCRelease (RRC release) message. When the rrcsetup request includes information about the home SP or GID selected by the UE NAS, the V-SNPN gNB 1d-20 can reject the UE by using the RRCReject message. On the other hand, when the rrcsetup complete includes information about the home SP or GID selected by the UE NAS, the V-SNPN gNB 1d-20 can release the connection with the UE by using the RRCRelease message. The rrCRject or rrCRelease message may include a cause value (1 d-60) indicating that connection rejection or connection release occurs due to an unsupported home SP or GID. The AMF or home SP may reject the service request even when the appropriate AMF is selected. In this case, the V-SNPN gNB 1d-20 can release the connection with the UE by using the RRCRelease message. The RRCRelease message may include a cause value indicating a connection release due to a rejection in the AMF or home SP.

Fig. 1E is a flowchart of a process for supporting handover in a V-SNPN supporting cell according to an embodiment of the disclosure.

The UE 1e-05 may be connected to the source cell 1e-10 (1 e-20) via an RRCSetup operation. The UE 1e-05 may receive a preset RRC message (1 e-25) including measurement configuration information from the source cell 1 e-10. The UE 1e-05 may measure the signal strengths of the serving cell and the neighboring cells by applying the measurement configuration information (1 e-30) and may report the collected cell measurement information to the source cell 1e-10 periodically or upon occurrence of a preset event (1 e-35). The source cell 1e-10 may determine whether to trigger a normal handover operation (1 e-40) based on the reported cell measurement information. For example, in case event A3 is met (the neighbor becomes offset better than SpCell) and thus cell measurement information is reported, the source cell 1e-10 may determine a normal handover. If it is determined that normal handover is triggered, the source cell 1e-10 may request normal handover from the target cell 1e-15 via a preset inter-node message (1 e-45). According to an embodiment of the present disclosure, the handover request information may include information about the home SP or GID selected by the UE 1 e-05. Alternatively, the source cell 1e-10 may provide home SP or GID information for supporting the UE to the target cell 1 e-15. Here, the source cell 1e-10 must previously have home SP or GID information supporting the UE, and this information may be provided directly from the UE 1e-05 or may be provided via the AMF. If the source cell 1e-10 attempts to obtain home SP or GID information supporting the UE from the UE, the source cell 1e-10 may request the information from the UE by using a ueinformation request message, and the UE having received the request may report the information by using a ueinformation response message. Alternatively, at a preset time, the UE may report information about the home SP or GID supported by the UE to the source cell 1e-10 by using a UE assistance information message.

In consideration of information about the home SP or GID supported by the UE 1e-05, the target cell 1e-15 having received the handover request may accept the handover request by using a preset admission control, and may transmit handover configuration information (1 e-50) required for a normal handover operation to the source cell. For example, when the target cell 1e-15 does not support either the home SP selected by the UE 1e-05 or the home SP supported by the UE 1e-05, the target cell 1e-15 may not accept the handover request. The source cell 1e-10 may include additional configuration information and handover configuration information received from the target cell 1e-15 in a preset RRC message, and may transmit the RRC message to the UE 1e-05 (1 e-55). The configuration information may include an ID of the target cell, frequency information, configuration information (dedicated preamble information, dedicated radio resource information, etc.) required for random access operation with respect to the target cell, transmission power information, cell radio network temporary identifier (C-RNTI) information used in the target cell, and the like.

The UE 1e-05 having received the handover configuration information may immediately perform a random access procedure on the target cell 1e-15 and may run a T304 timer (1 e-60). In addition, the UE 1e-05 may stop the operation of data transmission and reception with the source cell 1 e-10. The UE 1e-05 may send the received preamble. If no dedicated preamble is provided, the UE 1e-05 may transmit one of the contention-based preambles. The target cell 1e-15 having received the preamble may send a Random Access Response (RAR) message to the UE 1 e-05. The UE 1e-05 may transmit msg3 to the target cell 1e-15 by using UL grant information included in the RAR. msg3 may include an RRCRECONfigure complete message (1 e-65). When the random access procedure is successfully completed, the UE 1e-05 considers that the normal handover is successfully completed and stops the running T304 timer. In addition, the UE 1e-05 may perform operations of data transmission and reception with the target cell 1e-15. If the normal handover is not completed successfully until the T304 timer expires, the UE 1e-05 may consider the handover to be failed. Here, the UE 1e-05 may declare a Radio Link Failure (RLF) and may perform a re-establishment operation. When RLF is declared, the UE may record useful information that may be collected at that time, and may report RLF reports when the UE later connects to the cell.

Fig. 1F is a flowchart of a process for collecting and reporting V-SNPN associated information according to an embodiment of the disclosure.

An automatic neighbor relation (automatic neighbor relation, ANR) function may be performed for automatic network optimization as a self-organizing/optimizing network (SON). For network optimization, the gNB needs to collect information about neighboring cells. To this end, the gNB may instruct the UE to collect and report system information broadcast from neighboring cells.

The gNB 11f-10 may configure the UE 1f-05 for cell measurement (1 f-20) by using the RRCRECONfigure message. The cell measurement configuration information may include information required to collect system information broadcast from the neighboring cells 1 f-15. For example, the physical cell ID (PhysCellId) of the target cell from which information has to be collected, whether system information broadcast from the target cell is received using autonomous gaps, whether system information associated with credential access is to be collected, and the like may be included in the configuration information.

The UE having received the configuration information may receive preset system information (1 f-25) broadcasted from the configured cell, and may collect the preset information (1 f-30) from the received system information. The preset system information is SIB1, and system information associated with credential access may be additionally collected. The information that the UE must collect from the received system information and report to the gNB is as follows.

ID list information (PLMN-IdentityInfoList) of PLMN supported by configured cell 1f-15

List information (frequencyBandList) of frequency bands supported by the configured cell

ID list of PNI-NPN and SNPN supported by configured cell (NPN-IdentityInfoList)

Information broadcast from configured cells about indicators A, B

ID list of home SP and GID for configured cell support credential access

Human-readable name information for home SP and GID supporting credential access with respect to configured cells

The UE that has collected information may report the collected information to the gNB 1f-10 (1 f-35) by using a MeasurementReport message. The gNB 1f-10 having received the report of the collected information from the UE may broadcast information on neighbor cells supporting credential access by using preset system information.

Fig. 1G is a conceptual diagram for describing an O-SNPN according to an embodiment of the disclosure.

As described above, the UE 1g-05 that has triggered the credential access may have previously had credential access configuration information, and the V-SNPN may broadcast system information including ID information of the home SP supported by the V-SNPN. The UE 1g-05 may determine whether to access the cell by considering the V-SNPN ID broadcast via SIB1 of the V-SNPN gNB.

However, according to circumstances, the UE 1g-05 may not have credential access configuration information. The SNPN supporting the UE 1g-05 to connect to the gNB and obtain information from the specific server 1g-15 is referred to as a loaded SNPN (O-SNPN) (1 g-10). In this disclosure, attempting to access an O-SNPN in order to obtain credential access configuration information is described as loading access.

Fig. 1H is a flowchart of a process for accessing an O-SNPN supporting cell according to an embodiment of the disclosure.

In FIG. 1H, for ease of description, the O-SNPN supporting cell is described as O-SNPN gNB 1H-20. The O-SNPN gNB 1h-20 may broadcast the information below by using the system information (1 h-25).

An indicator C indicating whether the respective cell supports loading. The information may be broadcast via a particular SIB (e.g., SIB 1).

-ID list information of home SPs supported by O-SNPN gNB 1h-20. The information may be broadcast via a preset SIB (e.g., SIB 1) and may be provided for each SNPN supported by the respective cell.

-group ID list information of home SPs supported by O-SNPN gNB 1h-20. When the O-SNPN gNB 1h-20 supports many home SPs, the amount of information to be broadcast via system information may increase drastically. Thus, to reduce signaling overhead, a preset home SP may be configured as a group. When the O-SNPN gNB 1h-20 supports all or some of the home SPs included in the group, the O-SNPN gNB 1h-20 may broadcast the ID of the group via a particular SIB (e.g., SIB 1). With the group ID list, the supported list of IDs of home SPs may also be broadcast. In the present disclosure, the group ID is described as a Group ID (GID). Information may be provided for each SNPN supported by the corresponding cell.

-name information of a human readable home SP or GID. When the O-SNPN gNB 1h-20 supports a plurality of home SPs or GIDs and the UE may support some of the plurality of home SPs or GIDs, the user may manually select one of them. Thus, to support this, it is necessary to identify an SP or GID having a human-readable name. According to embodiments of the present disclosure, the human-readable home SP or GID information may be broadcast to the UE by using a preset SIB (e.g., SIB 10). Information may be provided for each SNPN supported by the corresponding cell.

The UE AS 1h-15 that has received the information via the SIB may send the received information to the UE NAS 1h-10. That is, the indicator C, home SP, and GID information for each SNPN may be transmitted to the UE NAS 1h-10 (1 h-30). The UE NAS 1h-10 having received the information may select an SNPN to be loaded with access and a home SP or GID to be accessed, and may determine an access identity and an access class (1 h-35) corresponding to the service type. When an attach or service request is triggered, the UE NAS 1h-10 may send the selected information to the UE AS 1h-15 (1 h-40).

To alleviate network congestion, the O-SNPN gNB 1h-20 may broadcast system information (1 h-45) including configuration-disabled information for each SNPN. The UE AS 1h-15 having received the information may determine whether to allow an attempt to attempt access via the inhibit check operation (1 h-50).

The O-SNPN gNB 1h-20 may apply different barring configurations to accesses and loaded accesses where services must be provided directly by the gNB. For example, when the network is congested, the O-SNPN gNB 1h-20 may apply a higher priority to accesses that must be serviced directly by the gNB. The present disclosure presents the following options for access control for credential access.

-a first option: when the UE NAS 1h-10 has selected SNPN and home SP or GID for access to the O-SNPN gNB 1h-20, the UE NAS 1h-10 may map the access identity for the access to a new access identity corresponding to the credential access. Preset existing access categories may be mapped to the access. The mapping information and information about the selected SNPN and the home SP or GID may be transmitted to the UE AS 1h-15. The O-SNPN gNB 1h-20 may indicate whether the inhibit checking operation may be skipped for the new access identities of each access class as inhibit configuration information corresponding to the selected SNPN. If the inhibit check operation is indicated to be skipped, the UE may skip the inhibit check operation and may attempt to access the O-SNPN gNB 1h-20. A new access identity corresponding to the loaded access may be provided for each SNPN.

-a second option: when the UE NAS 1h-10 has selected a SNPN and a home SP or GID for accessing the O-SNPN gNB 1h-20, the UE NAS 1h-10 may map the access class for the access to a new access class corresponding to the credential access. The preset existing access identities may be mapped to accesses. The mapping information and information about the selected SNPN and the home SP or GID may be transmitted to the UE AS 1h-15. The O-SNPN gNB 1h-20 may broadcast the barring configuration information corresponding to the new access class as the barring configuration information corresponding to the selected SNPN. Each SNPN may be provided with a new access class corresponding to the loaded access. The UE may perform the barring check operation by using barring configuration information corresponding to the new access class.

-a third option: the gNB may provide an indicator indicating whether loading access is prohibited for each SNPN supporting credential access. The indicator may be broadcast to the UE by system information using the O-SNPN gNB. If the indicator is provided and the access triggered by the UE NAS 1h-10 is a loaded access, it is considered that access from the corresponding cell is barred. An indicator may be provided for each SNPN and each home SP or GID. Further, an indicator may be provided for each access category.

-a fourth option: the gNB may provide an indicator indicating whether or not the barring configuration information for each access class provided for each SNPN applies only to loading accesses. If the indicator is provided and the access triggered by the UE NAS 1h-10 is a loaded access, the barring check operation may be performed by using barring configuration information mapped to the access class of the access. When the indicator is provided, the UE may not perform a prohibition check operation regarding normal access by using the provided prohibition configuration information. Via the inhibit check operation, the UE may attempt a random access operation for loading access to the corresponding cell when access is allowed. An indicator may be provided for each SNPN and each home SP or GID. Further, an indicator may be provided for each access category.

-a fifth option: the gNB may provide an indicator indicating whether or not the barring configuration information for each access class provided for each SNPN is also applied to loading access. If the indicator is not provided and the access triggered by the UE NAS is a loaded access, the UE may attempt a random access operation to access the corresponding cell without a forbidden check operation with respect to the loaded access. If the indicator is provided and the access triggered by the UE NAS is a loaded access, the UE may perform a barring check operation by using barring configuration information mapped to an access class of the access. Via the inhibit checking operation, when access is allowed, a random access operation for accessing a corresponding cell is attempted. An indicator may be provided for each SNPN and each home SP or GID. Further, an indicator may be provided for each access category.

-a sixth option: individual barring configuration information may be provided for each access class that is only applied to loading access. The inhibit configuration information may be provided for each home SP or GID.

The operations may be applied in an overlapping manner. When loading access is allowed via an access control operation, the UE 1h-05 may perform an RRC connection operation to connect to the cell. The UE 1h-05 may send an RRCSetup request message to the O-SNPN gNB 1h-20, and the O-SNPN gNB 1h-20 may send an RRCSetup message corresponding to the RRCSetup request message to the UE. The UE 1h-05 that has received the RRCSetup message may send the RRCSetup complete message to the O-SNPN gNB 1h-20. The O-SNPN gNB 1h-20 may be connected to a plurality of AMFs, and each AMF is connected to a particular server that provides credential access configuration information or a default home SP. Thus, the O-SNPN gNB 1h-20 may need to select an appropriate AMF that supports the loaded access requested by the UE 1h-05. To this end, the UE 1h-05 may need to report to the O-SNPN gNB 1h-20 whether the access is a loaded access, and information about the home SP or GID selected by the UE NAS 1h-10 during the setup procedure (1 h-55). According to embodiments of the present disclosure, information about the home SP or GID may be reported to the O-SNPN gNB 1h-20 by using a RRCSetup request or RRCSetup complete message. Further, the rrcsetup request message may include a new establishment cause value or a new indicator indicating that the access is a loaded access. The O-SNPN gNB 1h-20 may have information on AMFs capable of supporting the home SP or GID previously, and may select AMFs capable of supporting the home SP or GID by using home SP or GID information reported from the UE 1h-05. If there is no supportable AMF, the O-SNPN gNB 1h-20 can prevent the UE 1h-05 from connecting to the corresponding cell by using RRCRject or RRCRelease messages. When the RRCSetup request includes information about the home SP or GID selected by the UE NAS 1h-10, the O-SNPN gNB 1h-20 can reject the UE 1h-05 by using the RRCRject message. On the other hand, when the RRCSetup complete includes information about the home SP or GID selected by the UE NAS 1h-10, the O-SNPN gNB 1h-20 can release the connection to the UE 1h-05 by using the RRCRelease message. The rrCRject or rrCRelease message may include a cause value (1 h-60) indicating that connection rejection or connection release occurs due to an unsupported home SP or GID. The AMF or a particular server may reject the service request even when an appropriate AMF is selected. In this case, the O-SNPN gNB 1h-20 may release the connection with the UE 1h-05 by using the RRCRelease message. The RRCRelease message may include a cause value indicating a connection release due to a rejection in the AMF or a specific server.

Fig. 1I is a flowchart of a process for supporting handover in an O-SNPN supporting cell according to an embodiment of the disclosure.

The UE 1i-05 may be connected to the source cell 1i-10 (1 i-20) via an RRCSetup operation. The UE 1i-05 may receive a preset RRC message (1 i-25) including measurement configuration information from the source cell 1 i-10. The UE 1i-05 may measure the signal strengths of the serving cell and the neighboring cells by applying the measurement configuration information (1 i-30) and may report the collected cell measurement information (1 i-35) to the source cell 1i-10 periodically or upon occurrence of a preset event. The source cell 1i-10 may determine whether to trigger a normal handover operation (1 i-40) based on the reported cell measurement information. For example, in case event A3 is met (the neighbor becomes offset better than SpCell) and thus cell measurement information is reported, the source cell 1i-10 may determine a normal handover. If it is determined that normal handover is triggered, the source cell 1i-10 may request normal handover to the target cell 1i-15 via a preset inter-node message to support loading access (1 i-45). According to an embodiment of the present disclosure, the handover request information may include a loading indicator and information about a home SP or GID selected by the UE. Alternatively, the source cell 1i-10 may provide information about the home SP or GID supported by the UE 1i-05 to the target cell 1 i-15. Here, the source cell 1i-10 must previously have information about the home SP or GID supported by the UE 1i-05, and this information may be provided directly from the UE or may be provided via the AMF. If the gNB attempts to obtain home SP or GID information supporting the UE from the UE, the gNB may request the information from the UE by using a UEInformationRequest message, and the UE having received the request may report the information by using a UEInformationResponse message. Alternatively, at a preset time, the UE may report information about home SPs or GIDs supported by the UE to the gNB by using a ueassistance information message. In consideration of information about the home SP or GID supported by the UE 1i-05, the target cell 1i-15 having received the request may accept the request by using a preset admission control, and may transmit handover configuration information (1 i-50) required for a normal handover operation to the source cell 1 i-10. For example, when the target cell 1i-15 does not support either the home SP selected by the UE 1i-05 or the home SP supported by the UE 1i-05, the target cell 1i-15 may not accept the handover request. The source cell 1i-10 may include handover configuration information and additional configuration information received from the target cell 1i-15 in a preset RRC message, and may transmit the RRC message to the UE 1i-05 (1 i-55). The configuration information may include an ID of the target cell, frequency information, configuration information (dedicated preamble information, dedicated radio resource information, etc.) required for random access operation with respect to the target cell, transmission power information, C-RNTI information used in the target cell, and the like.

The UE having received the handover configuration information may immediately perform a random access procedure on the target cell 1i-15 and may run a T304 timer (1 i-60). Further, the operation of data transmission and reception with the source cell 1i-10 is stopped. The UE 1i-05 may transmit the received preamble. If no dedicated preamble is provided, the UE may transmit one of the contention-based preambles. The target cell 1i-15 having received the preamble may send a Random Access Response (RAR) message to the UE 1 i-05. The UE 1i-05 may transmit msg3 to the target cell 1i-15 by using UL grant information included in the RAR. msg3 may include an RRCRECONfigure complete message (1 i-65). When the random access procedure is successfully completed, the UE 1i-05 considers that the normal handover is successfully completed, and stops the running T304 timer. In addition, the UE 1i-05 may perform operations of data transmission and reception with the target cell 1i-15. If the normal handover is not completed successfully until the T304 timer expires, the UE 1i-05 may consider the handover to be failed. Here, the UE 1i-05 may declare RLF and may perform a rebuilding operation. When RLF is declared, the UE may record useful information that may be collected at that time, and may report RLF reports when the UE later connects to the cell.

Fig. 1J is a flowchart of a process for collecting and reporting O-SNPN associated information according to an embodiment of the disclosure.

gNB 1j-10 can configure UE 1f-05 for cell measurement (1 j-20) by using the RRCRECONfigure message. The cell measurement configuration information may include information required to collect system information broadcast from the neighboring cells 1 j-15. For example, the physical cell ID (PhysCellId) of the target cell from which information has to be collected, whether system information broadcast from the target cell is received using autonomous gaps, whether system information associated with credential access is to be collected, and the like may be included in the configuration information.

The UE 1j-05 having received the configuration information may receive preset system information (1 j-25) broadcasted from the configured cell and may collect the preset information (1 j-30). The preset system information is SIB1, and system information associated with credential access may be additionally collected. The information that the UE 1i-05 has to collect from the received system information and report to the gNB is as follows.

ID list information (PLMN-IdentityInfoList) of PLMN supported by configured cell 1j-15

List information (frequencyBandList) of frequency bands supported by the configured cell

ID list of PNI-NPN and SNPN supported by configured cell (NPN-IdentityInfoList)

Information on indicator C broadcast from configured cells

ID list of home SP and GID for configured cell support load access

Human-readable name information for home SP and GID of configured cell support loading access

The UE may collect information by using an autonomous gap or a measured measurement gap. The UE may report the collected information to the gNB 1j-10 (1 j-35) by using a MeasurementReport message. The gNB 1j-10 having received the report of the collected information may broadcast information about neighbor cells supporting the loading access by using preset system information.

Fig. 1K is a block diagram showing an internal configuration of a UE to which the present disclosure is applied.

Referring to FIG. 1K, the UE may include a Radio Frequency (RF) processor 1k-10, a baseband processor 1k-20, a memory 1k-30, and a controller 1k-40.

The RF processors 1k-10 perform functions of transmitting and receiving signals via radio channels, such as frequency band conversion and amplification of signals. That is, the RF processors 1k-10 up-convert the baseband signals supplied from the baseband processors 1k-20 into RF band signals, then transmit the RF band signals via the antennas, and down-convert the RF band signals received via the antennas into baseband signals. For example, the RF processors 1k-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, digital-to-analog converters (DACs), analog-to-digital converters (ADCs), and the like. Although only one antenna is shown in the drawings, the UE may include a plurality of antennas. Furthermore, the RF processors 1k-10 may comprise a plurality of RF chains. In addition, the RF processors 1k-10 may perform beamforming. For beamforming, the RF processors 1k-10 may adjust the phase and intensity of signals to be transmitted or received via multiple antennas or antenna elements, respectively. Further, the RF processor may perform MIMO operation and may receive multiple layers in the MIMO operation.

The baseband processors 1k-20 may convert between baseband signals and bit streams based on the physical entity specifications of the system. For example, for data transmission, the baseband processor 1k-20 may generate complex symbols by encoding and modulating the transmitted bit stream. For data reception, the baseband processor 1k-20 may reconstruct the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 1 k-10. For example, according to the OFDM scheme, for data transmission, the baseband processor 1k-20 generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols by performing Inverse Fast Fourier Transform (IFFT) and Cyclic Prefix (CP) insertion. For data reception, the baseband processors 1k-20 may segment the baseband signals provided from the RF processors 1k-10 into OFDM symbol units, may reconstruct the signals mapped to the subcarriers by performing Fast Fourier Transform (FFT) computations, and may then reconstruct the received bit stream by demodulating and decoding the signals.

As described above, the baseband processors 1k-20 and the RF processors 1k-10 transmit and receive signals. Thus, the baseband processors 1k-20 and the RF processors 1k-10 may be described as transmitters, receivers, transceivers, or communicators. In addition, at least one of the baseband processors 1k-20 and the RF processors 1k-10 may include a plurality of communication modules to support a plurality of different radio access technologies. Furthermore, at least one of the baseband processors 1k-20 and the RF processors 1k-10 may comprise different communication modules to process signals of different frequency bands. For example, the different radio access technologies may include wireless LANs (e.g., IEEE 802.11), cellular networks (e.g., LTE), and so on. Further, the different frequency bands may include an ultrahigh frequency (SHF) (e.g., 2.NRhz, NRhz) band and a millimeter wave (mmWave) (e.g., 60 GHz) band.

The memories 1k-30 store basic programs, applications, and data for the operation of the UE, such as configuration information. In particular, the memory 1k-30 may store information associated with a second access node performing wireless communication by using a second radio access technology. The storage 1k-30 provides stored data upon request of the controller 1 k-40.

The controllers 1k-40 may control the overall operation of the UE. For example, the controllers 1k-40 may send and receive signals via the baseband processors 1k-20 and the RF processors 1 k-10. In addition, the controller 1k-40 may record data on the storage 1k-40 and read data from the storage 1 k-40. To this end, the controllers 1k-40 may comprise at least one processor. For example, the controllers 1k-40 may include a Communication Processor (CP) for controlling communication and an Application Processor (AP) for controlling upper layers such as application programs. The controller 1k-40 according to an embodiment may comprise a multi-connection processor 1k-42.

Fig. 1L is a block diagram illustrating a configuration of a BS according to the present disclosure.

As shown in FIG. 1L, the BS includes RF processors 1L-10, baseband processors 1L-20, backhaul communicators 1L-30, storages 1L-40, and controllers 1L-50.

The RF processors 1l-10 may perform functions of transmitting and receiving signals via radio channels, such as frequency band conversion and amplification of signals. That is, the RF processors 1l-10 may up-convert the baseband signals provided from the baseband processors 1l-20 into RF band signals, and then may transmit the RF band signals via the antennas, and may down-convert the RF band signals received via the antennas into baseband signals. For example, the RF processors 1l-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, ADCs, and the like. Although only one antenna is shown in fig. 1L, the first access node may include multiple antennas. Furthermore, the RF processors 1l-10 may comprise a plurality of RF chains. In addition, the RF processors 1l-10 may perform beamforming. For beamforming, the RF processors 1l-10 may adjust the phase and intensity of signals to be transmitted or received via multiple antennas or antenna elements, respectively. The RF processor may perform downlink MIMO operation by transmitting one or more layers.

The baseband processors 1l-20 may convert between baseband signals and bit streams based on the physical entity specifications of the first radio access technology. For example, for data transmission, the baseband processor 1l-20 may generate complex symbols by encoding and modulating the transmitted bit stream. Furthermore, for data reception, the baseband processor 1l-20 may reconstruct the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 1 l-10. For example, according to the OFDM scheme, for data transmission, the baseband processor 1l-20 may generate complex symbols by encoding and modulating a transmission bit stream, may map the complex symbols to subcarriers, and may then configure OFDM symbols by performing IFFT and CP insertion. Further, for data reception, the baseband processor 1l-20 may segment the baseband signal supplied from the RF processor 1l-10 into OFDM symbol units, may reconstruct the signal mapped to the subcarriers by performing FFT, and may then reconstruct the received bit stream by demodulating and decoding the signal. As described above, the baseband processors 1l-20 and the RF processors 1l-10 may transmit and receive signals. Thus, the baseband processor 1l-20 and the RF processor 1l-10 may also be referred to as a transmitter, receiver, transceiver, communicator, or wireless communicator.

Backhaul communicators 1l-30 provide interfaces for communicating with other nodes in the network. That is, the backhaul communicators 1l-30 may convert a bit stream transmitted from the primary BS to another node (e.g., secondary BS, core network, etc.) into a physical signal, and may convert a physical signal received from the other node into a bit stream.

The memories 1l-40 may store basic programs, applications, and data (e.g., configuration information) for the operation of the BS. In particular, the memories 1l-40 may store information about the bearers allocated for the connected UEs and the measurement results reported from the connected UEs. Furthermore, the memories 1l-40 may store standard information for determining whether to provide dual connectivity to the UE or release dual connectivity from the UE. The storage 1l-40 may provide stored data upon request of the controller 1 l-50.

The controllers 1l-50 may control the overall operation of the BS. For example, the controllers 1l-50 may send and receive signals via the baseband processors 1l-20 and the RF processors 1l-10 or the backhaul communicators 1 l-30. In addition, the controller 1l-50 may record data on the storage 1l-40 and read data from the storage 1 l-40. To this end, the controllers 1l-50 may comprise at least one processor. The controller 1l-50 according to an embodiment may comprise a multi-connection processor 1l-52.

The term "credential holder (Credentials Holder, CH)" is used for an external entity that provides a subscription or credential for a SNPN. CH may refer to an external entity that provides subscriptions or credentials for SNPs. That is, in the present disclosure, CH refers to an external server providing configuration information associated with a home SP or credential access.

For the service provider group ID, the term "group ID for network selection (Group IDs for Network Selection, GIN)" is used. That is, in the present disclosure, GIN refers to a group ID list of the home SP.

The BS may provide the UE with a GIN list that can support credential access and loading access for each SNPN via system information.

Each GIN list corresponding to the credential access and the load access may be common or may be provided as separate lists via system information.

When at least one GIN among GINs belonging to each GIN list corresponding to the credential access and the loading access is different, the BS may transmit each GIN list via system information. In another example, the BS may transmit one common GIN list when all GINs belonging to each GIN list corresponding to the credential access and the loading access are equal.

The GIN list is in the form of a bitmap, and bits at corresponding positions in a preset GIN set can be configured.

The cell supporting the SNPN may broadcast PWS information. The PWS is a function of informing the UE of a disaster by broadcasting a preset SIB (i.e., SIB6, 7, 8) including disaster-related information.

The SNPN cell may be installed as a private wireless network among intelligent factors, etc. When a home disaster condition such as a fire occurs in the factory, the PWS may be used to notify UEs in the factory of the disaster condition.

Two types of PWSs may be applied to the SNPN cell. One is the PWS that all UEs have to receive regardless of the SNPN, and the other is the PWS that only UEs belonging to a specific SNPN have to receive. One cell may support multiple SNPs. Here, there may be PWS information associated with only a specific SNPN. For example, the first SNPN is a private purpose of the factory and the second SNPN is used to support credential access or load access. There may be PWS information such as fire that must be shared with all UEs in the factory, and PWS information that is acceptable to be shared with only a particular UE. PWS information that is acceptable to be shared only with a particular UE may be used to notify a particular problem in the factory (e.g., a stop in the production line, etc.).

Accordingly, the present disclosure proposes PWS information to be provided for each SNPN.

The BS may indicate to the UE that the PWS SIB is broadcast by using an etwsandcmaseindication bit in a short message transmitted via a Physical Downlink Control Channel (PDCCH). The UE having received the indicator must receive SIB1 in order to obtain scheduling information of the PWS SIB. Here, the BS may provide information indicating which SNPN is associated with the PWS SIBs (SIB 6, 7, 8) via a preset SIB (e.g., SIB 1). When there is PWS information about the SNPN to which the UE belongs, the UE may perform an operation of receiving the PWS SIB via the information. For example, SIB1 may include SNPN list information that needs to receive broadcast PWS SIBs. As another example, SIB1 may include SNPN list information that does not require reception of broadcast PWS SIBs. If the SNPN to which the UE belongs is included in the list, the UE that has received the SNPN list must receive a broadcast PWS SIB. As another example, if the SNPN to which the UE belongs is not included in the list, the UE does not need to receive the broadcast PWS SIB. The SNPN list may be in the form of a bit map, and the bit order may be matched with the SNPN order in the SNPN list supported by the cell provided via the system information. When all UEs have to receive, the SNPN information may include an indicator indicating that all UEs have to receive the PWS SIB, or alternatively, SIB1 provides scheduling information for the PWS SIB, but the SNPN information is not configured in the system information. For example, a specific bit of the bitmap may be used to indicate that all UEs have to receive.

As another method, PWS information may be provided for each GID. Here, the BS may provide information indicating which GIN is associated with the PWS SIB (SIB 6, 7, 8) via a preset SIB (e.g., SIB 1). When the information includes PWS information about the GIN to which the UE belongs, the UE may perform an operation of receiving the PWS SIB.

In addition, PWS information of each SNPN may be included in each PWS SIB. The UE must decode PWS information corresponding to the SNPN to which the UE belongs. Here, for each PWS information, index information indicating a corresponding SNPN may be included. The PWS SIB may also include information that all UEs must receive.

Claims (15)

1. A method performed by a User Equipment (UE) for supporting a non-public network (NPN) in a wireless communication system, the method comprising:

receiving, by an Access Stratum (AS) of the UE, a loading indicator and a Group Identification (GID) from at least one independent non-public network (SNPN) base station;

reporting a loading indicator and a GID of each of the at least one SNPN base station from the AS of the UE to a non-access stratum (NAS) of the UE; and

when the NAS of the UE selects an SNPN base station from the at least one SNPN base station to perform loading access, an RRC establishment request message is transmitted from the AS of the UE to the selected SNPN.

2. The method of claim 1, wherein a loading indicator and GID are included in a System Information Block (SIB) broadcast from the at least one SNPN base station.

3. The method of claim 1, wherein the GID is included in a list of Group IDs (GINs) transmitted from the at least one SNPN base station for network selection.

4. The method of claim 1, further comprising:

receiving an RRC setup message from the selected SNPN in response to the RRC setup request message; and

an RRC setup complete message including a loading indicator is transmitted to the selected SNPN.

5. A method performed by an independent non-public network (snp) base station for supporting a non-public network (NPN) in a wireless communication system, the method comprising:

broadcast load indicator (GID); and

when the loading indicator and the GID are received by an Access Stratum (AS) of a User Equipment (UE), and the SNPN base station is selected by a non-access stratum (NAS) of the UE that has received the loading indicator and the GID from the AS of the UE, an RRC setup request message is received from the AS of the UE,

wherein the AS of the UE reports the loading indicator and the GID of at least one SNPN base station including the SNPN base station to the NAS of the UE.

6. The method of claim 5, wherein a loading indicator and GID are included in a System Information Block (SIB) broadcast from the at least one SNPN base station.

7. The method of claim 5, wherein the GID is included in a list of Group IDs (GINs) transmitted from the at least one SNPN base station for network selection.

8. A User Equipment (UE) for supporting a non-public network (NPN) in a wireless communication system, the UE comprising:

a transceiver; and

a processor coupled with the transceiver and configured to:

receiving, by an Access Stratum (AS) of the UE, a loading indicator and a Group Identification (GID) from at least one independent non-public network (SNPN) base station,

reporting the loading indicator and GID of each of the at least one SNPN base station from the AS of the UE to a non-access stratum (NAS) of the UE, and

when the NAS of the UE selects an SNPN base station from the at least one SNPN base station to perform loading access, an RRC establishment request message is transmitted from the AS of the UE to the selected SNPN.

9. The UE of claim 8, wherein a loading indicator and GID are included in a System Information Block (SIB) broadcast from the at least one SNPN base station.

10. The UE of claim 8, wherein the GID is included in a list of Group IDs (GINs) for network selection transmitted from the at least one SNPN base station.

11. The UE of claim 8, wherein the processor is configured to:

Receiving an RRC setup message from the selected SNPN in response to the RRC setup request message; and

an RRC setup complete message including a loading indicator is transmitted to the selected SNPN.

12. An independent non-public network (SNPN) base station for supporting a non-public network (NPN) in a wireless communication system, the SNPN base station comprising:

a transceiver; and

a processor coupled with the transceiver and configured to:

broadcast load indicator and Group Identification (GID), and

when the loading indicator and the GID are received by an Access Stratum (AS) of a User Equipment (UE), and the SNPN base station is selected by a non-access stratum (NAS) of the UE that has received the loading indicator and the GID from the AS of the UE, an RRC setup request message is received from the AS of the UE,

wherein the AS of the UE reports the loading indicator and the GID of at least one SNPN base station including the SNPN base station to the NAS of the UE.

13. The SNPN base station of claim 12, wherein the loading indicator and GID are included in a System Information Block (SIB) broadcast from the at least one SNPN base station.

14. The SNPN base station of claim 12, wherein the GID is included in a list of Group IDs (GINs) transmitted from the at least one SNPN base station for network selection.

15. The SNPN base station of claim 12, wherein the processor is configured to:

transmitting an RRC establishment message to the UE in response to the RRC establishment request message; and

an RRC setup complete message including a loading indicator is received from the UE.