Patent Description:
Compared to the legacy <NUM> system, the <NUM> system considers to support various services. For example, the key services may include enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), massive machine type communication (mMTC), evolved multimedia broadcast/multicast service (eMBMS), and so on. A system supporting the URLLC service and a system supporting the eMBB service may be referred to as a URLLC system and an eMBB system, respectively. The terms service and system are interchangeably used with each other.

The URLLC service is a new service under consideration in the <NUM> system, unlike the legacy <NUM> system, and requires ultra-high reliability (e.g., a packet error rate of about <NUM>-<NUM>) and low latency (e.g., about <NUM>. 5msec) relative to other services. To satisfy these strict requirements, the URLLC service may need a shorter transmission time interval (TTI) than the eMBB service, and various operation schemes using the short TTI are considered.

Such an IoT environment may provide intelligent Internet technology (IT) services that create a new value to human life by collecting and analyzing data generated among connected things.

As such, various services are available owing to the development of mobile communication systems. Accordingly, there is a need for a method of efficiently using a non-public network (NPN) to provide such various services in places such as factories, schools, and companies using their own networks.

Document entitled "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Study on enhanced support of non-public networks (Release <NUM>)" discloses a method for onboarding UE and provisioning for an SNPN, when the UEs are deployed without provisioned subscription, it provides a solution on how UE subscription/credentials are afterward provisioned to the UEs. In this regard, the Onboarding SNPN operator has access to a Default Credential Server (DCS) containing a list of unique UE identifiers for UEs that are subject to onboarding and the associated default UE credentials.

The disclosure is intended to provide a method and apparatus for detecting and selecting a server for user equipment (UE) authentication and subscription data transmission in a non-public network (NPN).

Accordingly, an aspect of the disclosure is to provide a method and apparatus for detecting and selecting a server for user equipment (UE) authentication and subscription data transmission in a non-public network (NPN), as set out in the appended set of claims.

A method and apparatus according to an embodiment of the disclosure may effectively select a server for user equipment (UE) authentication and subscription data transmission in a wireless communication system.

Embodiments of the disclosure are described below in detail with reference to the accompanying drawings. It should be noted that like reference numerals denote the same components in the drawings. Further, a detailed description of a generally known function or structure of the disclosure will be avoided lest it should obscure the subject matter of the disclosure.

In describing embodiments of the disclosure, a description of technical ideas which are well known in the technical field to which the disclosure pertains and are not directly related to the disclosure will be omitted. This is intended to make the subject matter of the disclosure more clear by omitting the unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the drawings. The drawn size of each component does not exactly reflect its real size. In each drawing, the same reference numerals are assigned to the same or corresponding components.

The advantages and features of the disclosure, and a method of achieving them will become apparent from reference to embodiments described below in detail in conjunction with the attached drawings. However, the disclosure may be implemented in various manners, not limited to the embodiments set forth herein. Rather, these embodiments are provided such that the disclosure is complete and thorough and its scope is fully conveyed to those skilled in the art, and the disclosure is only defined by the appended claims. The same reference numerals denote the same components throughout the specification. Like reference numerals denote the same components throughout the specification.

It will be understood that each block of the flowchart illustrations and block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams can be implemented by computer program instructions. These computer program instructions may be loaded on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions, which are executed via the processor of the computer or other programmable data processing equipment, create means for implementing the functions specified in the flowchart block(s). These computer program instructions may also be stored in a computer-usable or computer-readable memory that can direct the computer or other programmable data processing equipment to function in a particular manner, such that the instructions stored in the computer-usable or computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block(s). The computer program instructions may also be loaded onto the computer or other programmable data processing equipment to cause a series of operations to be performed on the computer or other programmable data processing equipment to produce a computer implemented process such that the instructions which are executed on the computer or other programmable equipment provide operations for implementing the functions specified in the flowchart and/or block diagram block(s).

Furthermore, the respective block diagrams may illustrate parts of modules, segments, or codes including one or more executable instructions for performing specific logic function(s). Moreover, it should be noted that the functions of the blocks may be performed in a different order in several modifications. For example, two successive blocks may be performed substantially at the same time, or may be performed in reverse order according to their functions.

The term "unit" as used herein means, but is not limited to, a software or hardware component, such as a field programmable gate array (FPGA) or application specific integrated circuit (ASIC), which performs certain tasks. A unit may advantageously be configured to reside on an addressable storage medium and configured to be executed on one or more processors. Thus, a unit may include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality provided in the components and "units" may be combined into fewer components and "units" or further separated into additional components and "units". In addition, the components and "units" may be implemented such that they are executed on one or more central processing units (CPUs) in a device or a secure multimedia card.

In embodiments of the disclosure, a base station (BS), which is an entity to allocate resources to a user equipment (UE), may be at least one of a Node B, a evolved Node B (eNode B or eNB), a next generation Node B (gNode B or gNB), a radio access unit, a base station controller (BSC), or a network node.

A terminal may include a UE, a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of executing a communication function. Embodiments of the disclosure described below are applicable to other communication systems having a similar technical background or channel structure. Further, the disclosure is also applicable to other communication systems through some modifications without greatly departing from the scope of the disclosure as judged by those skilled in the art.

Terms identifying access nodes, terms signifying network entities or network functions (NFs), terms signifying messages, terms signifying interfaces between network entities, and terms signifying various types of identification information as used in the following description are given for convenience of description. Accordingly, the disclosure is not limited to the terms described below, and the terms may be replaced by other equivalent terms in technical meanings.

For convenience of description, some of terms and names defined in the <NUM>rd generation partnership project (3GPP) long term evolution (LTE) and/or 3GPP new radio (NR) standards. However, the disclosure is not limited by the above terms and names, and may be equally applied to systems conforming to other standards.

Embodiments of the disclosure will be described below with reference to the attached drawings.

<FIG> illustrates the structure of a <NUM> network according to an embodiment of the disclosure. Network entities or network nodes included in the <NUM> network will be described below.

Referring to <FIG>, a wireless communication system that forms the <NUM> network may include a UE <NUM> and a plurality of network entities <NUM> to <NUM>.

A (radio) access network ((R)AN) <NUM>, which is an entity allocating radio resources to the UE <NUM>, may be at least one of an eNode B, a gNode B, a Node B, a BS, a next generation radio access network (NG-RAN), a <NUM>-AN, a radio access unit, a BTS, or a network node.

The UE <NUM> may be at least one of a user equipment, a next generation (NG) UE, an MS, a cellular phone, a smartphone, or a computer. Further, the UE <NUM> may include a multimedia system capable of executing a communication function.

While an embodiment of the disclosure is described in the context of a <NUM> system by way of example, the embodiment of the disclosure may be applied to other communication systems having a similar technical background. Further, the disclosure is also applicable to other communication systems through some modifications without greatly departing from the scope of the disclosure as judged by those skilled in the art.

As the wireless communication system evolves from a <NUM> system to a <NUM> system, a new core network, nextgen core (NG core) or <NUM> core network (5GC) is defined. The new core network virtualizes all the existing network entities (NEs) into network functions (NFs). According to an embodiment of the disclosure, an NF may mean a network entity, a network component, and a network resource.

According to an embodiment of the disclosure, the 5GC may include NFs illustrated in <FIG>. Obviously, the 5GC may include more or fewer NFs than the NFs illustrated in <FIG>, not limited to the example of <FIG>.

According to an embodiment of the disclosure, an access and mobility management function (AMF) <NUM> may be an NF that manages the mobility of a UE.

According to an embodiment of the disclosure, a session management function (SMF) <NUM> may be an NF that manages a packet data network (PDN) connection provided to the UE. The PDN connection may be referred to as a protocol data unit (PDU) session.

According to an embodiment of the disclosure, a policy control function (PCF) <NUM> may be an NF that applies a service policy, a charging policy, and a policy for a PDU session of a mobile communication operator to the UE.

According to an embodiment of the disclosure, a unified data management (UDM) <NUM> may be an NF that stores information about a subscriber.

According to an embodiment of the disclosure, an application function (AF) may be an application function operated by a UE manufacturer, a service provider, or a public land mobile network (PLMN) operator. However, even if the AF is not an application function operated by the UE manufacturer, it may mean another application function managing the wireless capability and wireless capability identifier (ID) of the UE.

According to an embodiment of the disclosure, a service communication proxy (SCP) <NUM> may relay communication with an appropriate NF to NFs by serving as a proxy server when delivering a <NUM> core service.

According to an embodiment of the disclosure, a network exposure function (NEF) <NUM> may be a function of providing information about the UE to a server outside the <NUM> network. In addition, the NEF <NUM> may provide a function of providing information required for a service to the <NUM> network and storing the information in a unified data repository (UDR).

According to an embodiment of the disclosure, a user plane function (UPF) <NUM> may be a function that serves as a gateway transmitting user data (a PDU) to a data network (DN) <NUM>.

According to an embodiment of the disclosure, a network repository function (NRF) <NUM> may perform a function of discovering an NF.

According to an embodiment of the disclosure, an authentication server function (AUSF) <NUM> may perform UE authentication in a 3GPP access network and a non-3GPP access network.

According to an embodiment of the disclosure, a network slice selection function (NSSF) <NUM> may perform a function of selecting a network slice instance provided to the UE.

According to an embodiment of the disclosure, the DN <NUM> may be a data network through which the UE <NUM> transmits and receives data in order to use a service of a network operator or a <NUM>rd party service.

<FIG> is a diagram illustrating entities for transmitting a user subscription to a UE according to an embodiment of the disclosure.

Referring to <FIG>, a wireless communication system for transmitting a user subscription to a UE includes a UE <NUM>, an onboarding stand-alone non-public network (O-SNPN) <NUM>, a default credential server (DCS) <NUM>, a provisioning server (PS) <NUM>, and an SNPN <NUM> that keeps user subscription data.

First, it is assumed that the UE <NUM> does not have user subscription data, and has a default UE credential allocated by the DCS <NUM>. In addition, the DCS <NUM> allocates a unique UE ID uniquely identifying the UE <NUM> to the UE <NUM>.

The O-SNPN <NUM> may provide user plane (UP)-based Internet protocol (IP) connectivity (UE onboarding) or control plane (CP)-based non-access stratum (NAS) connectivity (UE onboarding) to the UE <NUM> so that the UE <NUM> without the user subscription data may download the user subscription data. To determine whether to provide the onboarding service to the UE <NUM>, the DCS <NUM> may receive a UE authentication request.

The DCS <NUM> may pre-configure the default UE credential and the unique UE ID for the UE <NUM> and store this information. The DCS <NUM> may receive a request for authentication of the UE <NUM> from the O-SNPN <NUM>, when performing UE registration for onboarding. The UE <NUM> is authenticated using the default UE credential.

Further, when the PS <NUM> transmits subscription data to the UE <NUM>, the DCS <NUM> may receive an authentication/authorization request for the UE <NUM> from the PS <NUM> to determine whether the UE is authorized to receive the subscription data. The DCS <NUM> may be a manufacturer of the UE <NUM> or a <NUM>rd party connected to the manufacturer or an SNPN operator.

The PS <NUM> may receive user subscription data such as a network credential and user configuration information from a network operator and transmit the user subscription data to the UE <NUM>.

The PS <NUM> together with the DCS <NUM> may exist as one server. Like the DCS <NUM>, the PS <NUM> may be a server owned by a <NUM>rd party connected to the manufacturer of the UE or the SNPN operator. The PS <NUM> may communicate with the DCS <NUM> for authentication/authorization of the UE <NUM>.

The SNPN <NUM> having the user subscription data may transmit the user subscription data to the UE <NUM> through the PS <NUM>. In this case, the network operator may have UE ID information about UEs to which user subscription data is to be transmitted.

<FIG> and <FIG> illustrate a UE onboarding procedure for user subscription data reception of a UE according to an embodiment of the disclosure.

Referring to <FIG>, a wireless communication system for performing the UE onboarding procedure may include a UE <NUM>, a <NUM>-AN <NUM>, a 5GC <NUM>, a PS <NUM>, a DCS <NUM>, and a serving network <NUM>.

The <NUM>-AN <NUM> performs radio resource allocation for the UE <NUM> and transmits system information to the UE <NUM>. Further, the 5GC <NUM> may be implemented as an SNPN, and the serving network <NUM> may be implemented as a network (NPN or PLMN) that keeps user subscription data (a network credential and configuration information).

In step S301, the UE <NUM> is pre-configured with a default UE credential and a unique UE ID allocated by the DCS <NUM>. Although the default UE credential is configured for the UE <NUM>, a network credential is not configured for the UE <NUM>. The network credential may be provided to the UE <NUM> as part of the onboarding procedure.

According to an embodiment, when there is an agreement between a UE manufacturer and the SNPN, the UE <NUM> may have an initial default configuration (e.g., PLMN ID and NIF of SNPN, S-NSSAI, DNN, and so on).

The UE ID allocated by the DCS <NUM> should uniquely identify the UE <NUM>. A manufacturer of the UE, mainly an Internet of things (IoT) device or a <NUM>rd party connected to some manufacturers is highly likely to be in charge of the DCS <NUM>.

To allocate a unique ID to a UE without a specific standard organization, the UE ID includes information about the DCS <NUM>. To allocate a unique ID to the UE <NUM>, it is proposed to use a UE ID in the form of a network access identifier (NAI) including the information about the DCS <NUM> in the disclosure.

The NAI is in the form of "user@realm", and the information about the DCS <NUM> is included in the realm to enable an onboarding network to identify a server to be selected for authentication of the corresponding UE from among a plurality of DCSs. Particularly, since an address of the DCS server may be included in realm information, DCS discovery/addressing may be performed at once.

In step S303, upon initial access, the UE <NUM> may detect and select an O-SNPN based on the received broadcast system information. The O-SNPN is not necessarily the same as the SNPN having the network credential.

The UE <NUM> transmits the unique UE ID and the default UE credential of the UE <NUM> to the SNPN <NUM> during the initial access because there is no subscription data for the SNPN <NUM>. The UE <NUM> may transmit additional information such as an application ID or a service provider ID to the SNPN <NUM>.

In the disclosure, the UE <NUM> may use the NAI including the information about the DCS <NUM> as the unique UE ID of the UE <NUM>. The UE <NUM> may transmit the NAI including the information about the DCS <NUM> to the SNPN <NUM>.

In step S305, the SNPN <NUM> receivse the unique UE ID of the UE <NUM> in the form of the NAI, and detects and selects the DCS <NUM> by using the realm information included in the NAI. Particularly, since the realm information may include uniform resource locator (URL) information about the DCS <NUM>, the SNPN <NUM> may transmit a UE authentication message for UE authentication to the DCS <NUM>.

Further, since the DCS <NUM> is likely to make a contract with a specific SNPN for the onboarding service of its UE, the SNPN <NUM> may determine whether to provide connectivity for onboarding to the UE through the realm information included in the NAI.

In step S307, the SNPN <NUM> may transmit the unique UE ID and the default UE credential of the UE to the DCS <NUM> managing the UE <NUM>, thereby requesting authentication of the UE <NUM> as to whether the UE <NUM> is allowed to access the network for onboarding purposes. The authentication may be performed by selecting either primary authentication or network slice specific authentication and authorization (NSSAA).

In step S309, the DCS <NUM> may perform authentication for the UE <NUM>, and when the authentication is successful, receive subscription data from the SNPN <NUM> having the subscription data that the UE <NUM> is to receive, and select the PS <NUM> to transmit the subscription data to the UE <NUM>. In this case, the DCS <NUM> has a list of SNPNs which the UE manufacturer has made a contract with and subscribed to, selects the most appropriate network from among the contracted SNPNs in consideration of the type and current location of the UE, and selects the PS <NUM> supporting the network. Like the SNPNs, the PS <NUM> capable of supporting the selected SNPN may be selected from a list of PSs contracted with the manufacturer. According to an embodiment, when there are multiple selected serving networks, priority information may also be included.

In step S311, the DCS <NUM> may transmit a response indicating success of the UE authentication, address information about the selected PS <NUM>, and the ID (PLMN ID or PLMN ID + NID) of the selected serving network <NUM> to the onboarding network <NUM>.

In step S313, the onboarding network <NUM> should select an SMF and a UPF to create a PDU session that will provide the UE <NUM> with a restricted data connection accessible only to the selected PS <NUM>. For this purpose, the onboarding network <NUM> uses the address of the selected PS received from the DCS <NUM>.

Referring to <FIG>, in step S315, the onboarding network <NUM> may transmit, to the UE <NUM>, the address of the selected PS and S-NSSAI/DNN information for creating the PDU session, received from the DCS <NUM>. The UE <NUM> may create the PDU session by using the received S-NSSAI/DNN information and transmit data to the PS <NUM> by using the address information about the PS <NUM>. PS-related information may be updated in the UE, when it is different from information stored during pre-configuration.

In step S317, the UE <NUM> may create a configuration PDU session. The PDU session is created by using a well-known or pre-configured S-NSSAI/DNN or the S-NSSAI/DNN information received from the DCS <NUM>.

In steps S319 to S323, the subscription data may be requested from the PS <NUM> by using information pre-configured in the UE <NUM> at an application level, or using the address information about the selected PS received from the DCS <NUM>. The PS <NUM> may identify the realm part of the unique UE ID information about the UE, and request UE authentication by transmitting the default UE credential of the UE <NUM> to the DSC <NUM>. In this case, the UE <NUM> may also transmit the serving network ID (PLMN ID or PLMN ID + NID) and the serving network priority information received from the DCS <NUM>.

In step S325, the PS <NUM> may request and receive, from the serving network <NUM>, other UE configuration parameters (e.g. PDU session parameters, such as SNSSAI, DNN, URSPs, QoS rules, and other required parameters to access the SNPN and establish a regular PDU session) as well as network credentials for the future SNPN owning the subscription.

In step S327, the PS <NUM> may transmit the data received from the serving network <NUM> in step S325 to the UE <NUM>.

When receiving the data successfully in step S327, the UE <NUM> may release the configuration PDU session of the onboarding network <NUM> and perform deregistration with the onboarding network <NUM> in step S329.

In step S331, the UE <NUM> may receive a network service by registering to the serving network <NUM> using the received subscription data. The onboarding network <NUM> and the serving network <NUM> may be the same or different.

<FIG> is a diagram illustrating the structure of a network entity or server according to an embodiment of the disclosure.

Each of the network entities or servers described with reference to <FIG> may include the configuration of <FIG>. For example, the structures of an SMF, an NEF, an AF, and so on may correspond to the structure described with reference to <FIG>. For example, structures such as a PS and a DCS may correspond to the structure described with reference to <FIG>.

Referring to <FIG>, a network entity or server according to an embodiment of the disclosure may include a transceiver <NUM>, memory <NUM>, and a processor <NUM>. According to the above-described communication method of the network entity or server, the transceiver <NUM>, the processor <NUM>, and the memory <NUM> of the network entity or server may operate.

However, the components of the network entity or server are not limited to the above-described example. For example, the network entity or server may include more or fewer components than the afore-mentioned components. In addition, the transceiver <NUM>, the processor <NUM>, and the memory <NUM> may be implemented in the form of a single chip. Further, the processor <NUM> may include one or more processors.

The transceiver <NUM> is a generic term for a receiver and a transmitter, and may transmit and receive signals to and from a BS, a UE, a network entity, or a server. The signals transmitted and received to and from the BS, the UE, the network entity, or the server may include control information and data. For this purpose, the transceiver <NUM> may include a radio frequency (RF) transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts a received signal. However, this is only an embodiment of the transceiver <NUM>, and components of the transceiver <NUM> are not limited to the RF transmitter and the RF receiver.

Further, the transceiver <NUM> may receive a signal on a radio channel and output the received signal to the processor <NUM>, and may transmit a signal output from the processor <NUM> on a radio channel.

The memory <NUM> may store a program and data required for the operation of the network entity or server. In addition, the memory <NUM> may store control information or data included in a signal obtained by the network entity or server. The memory <NUM> may be configured as a storage medium or a combination of storage media, such as read only memory (ROM), random access memory (RAM), hard disk, compact disk-ROM (CD-ROM), and digital versatile disk (DVD). Further, the memory <NUM> may be included in the processor <NUM>, not residing separately.

The processor <NUM> may control a series of processes so that the network entity or server may operate according to the above-described embodiment of the disclosure. For example, the processor <NUM> may receive a control signal and a data signal through the transceiver <NUM>, and process the received control signal and data signal. In addition, the processor <NUM> may transmit processed control signal and data signal through the transceiver <NUM>. There may be a plurality of processors <NUM>, and the processor <NUM> may execute the program stored in the memory <NUM> to perform a control operation for a component of the network entity or server.

<FIG> is a diagram illustrating the structure of a UE according to an example not disclosing all the features of the claims.

The UE described with reference to <FIG> may correspond to the UE of <FIG>. Referring to <FIG>, the UE may include a transceiver <NUM>, memory <NUM>, and a processor <NUM>. According to the above-described communication method of the UE, the transceiver <NUM>, the processor <NUM>, and the memory <NUM> of the UE may operate. For example, the UE may include more or fewer components than the afore-mentioned components. In addition, the transceiver <NUM>, the processor <NUM>, and the memory <NUM> may be implemented in the form of a single chip. Further, the processor <NUM> may include one or more processors.

The transceiver <NUM> is a generic term for a receiver and a transmitter of the UE, and may transmit and receive signals to and from a BS, a server, or another UE. The signals transmitted and received to and from the BS, the server, or the other UE may include control information and data. For this purpose, the transceiver <NUM> may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts a received signal. However, this is only an embodiment of the transceiver <NUM>, and the components of the transceiver <NUM> are not limited to the RF transmitter and the RF receiver.

The memory <NUM> may store a program and data required for the operation of the network entity or server. In addition, the memory <NUM> may store control information or data included in a signal obtained by the UE. The memory <NUM> may be configured as a storage medium or a combination of storage media, such as ROM, RAM, hard disk, CD-ROM, and DVD. Further, the memory <NUM> may be included in the processor <NUM>, not residing separately.

The processor <NUM> may control a series of processes so that the UE may operate according to the above-described embodiment of the disclosure. For example, the processor <NUM> may receive a control signal and a data signal through the transceiver <NUM>, and process the received control signal and data signal. In addition, the processor <NUM> may transmit processed control signal and data signal through the transceiver <NUM>. There may be a plurality of processors <NUM>, and the processor <NUM> may execute the program stored in the memory <NUM> to perform a control operation for a component of the UE.

Methods according to the claims of the disclosure or the embodiments described in the specification may be implemented in hardware, software, or a combination of hardware and software.

When the methods are implemented in software, a computer-readable storage medium storing at least one program (software module) may be provided. The at least one program stored in the computer-readable storage medium is configured to be executable by at least one processor in an electronic device. The at least one program includes instructions that cause the electronic device to perform the methods according to the claims or the embodiments of the disclosure.

The program (software module or software) may be stored in RAM, non-volatile memory including flash memory, ROM, electrically erasable programmable ROM (EEPROM), a magnetic disc storage device, CD-ROM, DVD, any other type of optical storage device, or a magnetic cassette. Alternatively, the program may be stored in memory configured as a combination of some or all of them. In addition, each constituent memory may be plural in number.

Further, the program may be stored in an attachable storage device accessible through a communication network such as the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), or a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the disclosure through an external port. Further, a separate storage device on the communication network may be connected to the device implementing the embodiment of the disclosure.

In the specific embodiments of the disclosure described above, elements included in the disclosure are expressed in singular or plural forms according to the specific embodiments. However, the singular or plural expression is appropriately selected in the context for convenience of description, and the disclosure is not limited to the singular or plural components. Even if a component is expressed as plural, it may be singular. Even a component expressed as singular may be plural in number.

Claim 1:
A method by a stand-alone non-public network, SNPN, (<NUM>) to which a user equipment, UE, (<NUM>) is onboarding in a wireless communication system, the method comprising:
receiving, from the UE (<NUM>), a unique identifier of the UE, wherein the unique identifier of the UE takes a form of a network access identifier;
selecting a default credential server (<NUM>) based on information included in realm part of the unique identifier of the UE; and
receiving, from the default credential server (<NUM>), address information of a provisioning server (<NUM>) during authentication procedure for the UE.