Patent Publication Number: US-2023164194-A1

Title: Enhanced Subscriber Identity Module (ESIM) Remote Provisioning Based Solution to Provide IMS Services to a User of a Private Network (NPN)

Description:
RELATED APPLICATIONS 
     The present application claims benefit of U.S. Provisional Application 63/016,590, which was filed Apr. 28, 2020 and U.S. Provisional Application 63/006,279, which was filed Apr. 7, 2020, the disclosures of each of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to communication networks, and more particularly, to providing Internet Protocol Multimedia System (IMS) services to User Equipment (UEs) connected to Standalone Non-Public Networks (SNPN). 
     BACKGROUND 
     Standalone Non-Public Networks (SNPN) using 5G technology will soon be widely deployed. As defined in 3GPP TS 23.501: “System architecture for the 5G System (5GS); Stage 2 (Release 16)” dated March 2020, there are different ways in which such networks can integrate with public 5G networks. However, given the number of ways in which SNPNs can integrate with public 5G networks, there is also a need to enable users in the SNPNs to be able to fully utilize the services provided by the 5G public networks, such as those provided by Internet Protocol Multimedia Systems (IMS) networks. 
     One way to facilitate this capability is to allocate a profile for each user in the IMS domain. Then, for each user in the SNPN, provision the requisite IMS credentials in the user&#39;s device (e.g., a User Equipment (UE)), and setup a subscription for the use in the Home Subscriber Server (HSS). However, such a solution would require each user&#39;s device to contain multiple Universal Subscriber Identity Modules (USIMs). Not only would this make a UE more costly to manufacture, but it would also complicate the handling of user identities. Particularly, every NPN user would have multiple identities—one for the NPN, and the other for the IMS network. And with multiple identities, provisioning the IMS credentials for each user would also be further complicated. 
     SUMMARY 
     In a first aspect, the disclosure provides a method of acquiring User Equipment (UE) configuration/subscription data over an access/core network. The method is implemented by a UE and comprises the steps of establishing a first Protocol Data Unit (PDU) session with a pre-defined Data Network Name (DNN) for remote provisioning, initiating an onboarding procedure over the first PDU session using remote provisioning information that enables the UE to access a remote provisioning system in the pre-defined DNN, receiving, from the remote provisioning system, the UE configuration/subscription data, wherein the UE configuration/subscription data comprises Internet Protocol Multimedia Subsystem (IMS) subscription data for an IMS network associated with a Non-Public Network (NPN), and responsive to determining that a connection to the IMS network associated with the NPN is required, establishing a second PDU session with the IMS network using the IMS subscription data. The pre-defined DNN may, in one embodiment, be a dedicated DNN for remote provisioning. 
     In a second aspect, the disclosure provides a UE comprising communications circuitry and processing circuitry operatively connected to the communications circuitry. The communications circuitry is configured to communicate with one or more network nodes. The processing circuitry is configured to establish a first Protocol Data Unit (PDU) session with a pre-defined Data Network Name (DNN) for remote provisioning, initiate an onboarding procedure over the first PDU session using remote provisioning information that enables the UE to access a remote provisioning system in the pre-defined DNN, receive the UE configuration/subscription data from the remote provisioning system, wherein the UE configuration/subscription data comprises Internet Protocol Multimedia Subsystem (IMS) subscription data for an IMS network associated with a Non-Public Network (NPN), and responsive to determining that a connection to the IMS network associated with the NPN is required, establish a second PDU session with the IMS network using the IMS subscription data. 
     In a third aspect, the disclosure provides a non-transitory computer-readable medium storing a computer program thereon. In this aspect, the computer program comprises instructions that, when executed by processing circuitry of a UE, causes the UE to establish a first Protocol Data Unit (PDU) session with a pre-defined Data Network Name (DNN) for remote provisioning, initiate an onboarding procedure over the first PDU session using remote provisioning information that enables the UE to access a remote provisioning system in the pre-defined DNN, receive the UE configuration/subscription data from the remote provisioning system, wherein the UE configuration/subscription data comprises Internet Protocol Multimedia Subsystem (IMS) subscription data for an IMS network associated with a Non-Public Network (NPN), and responsive to determining that a connection to the IMS network associated with the NPN is required, establish a second PDU session with the IMS network using the IMS subscription data. 
     In a fourth aspect, the present disclosure provides a computer program comprising executable instructions that, when executed by a by processing circuitry of a UE, causes the UE to establish a first Protocol Data Unit (PDU) session with a pre-defined Data Network Name (DNN) for remote provisioning, initiate a an onboarding procedure over the first PDU session using remote provisioning information that enables the UE to access a remote provisioning system in the pre-defined DNN, receive the UE configuration/subscription data from the remote provisioning system, wherein the UE configuration/subscription data comprises Internet Protocol Multimedia Subsystem (IMS) subscription data for an IMS network associated with a Non-Public Network (NPN), and responsive to determining that a connection to the IMS network associated with the NPN is required, establish a second PDU session with the IMS network using the IMS subscription data. 
     In a fifth aspect, the disclosure provides a carrier containing a computer program according to the nineteenth aspect, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium. 
     In a sixth aspect, the disclosure provides a method performed by a Session Management Function (SMF) node and comprises the steps of receiving, from a User Equipment (UE) in a Non Public Network (NPN) via an Access and Mobility Management (AMF) node, a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), wherein the DNN comprises one of a pre-defined DNN used for remotely provisioning the UE, and an internet DNN provided by the Access and Mobility Management Function (AMF), obtaining, for the UE, remote provisioning information associated with the NPN, wherein the remote provisioning information is used by the UE to initiate an onboarding procedure that enables the UE to access the remote provisioning system, and obtaining information associated with the one of the pre-defined DNN and the internet DNN. Then, responsive to obtaining a packet filter, the method comprises selecting and configuring a UPF for the PDU session based on the DNN and the packet filter and sending a session establishment accept message comprising the remote provisioning information used by the UE to initiate the onboarding procedure. 
     In a seventh aspect, the disclosure provides a network node configured to operate as a Session Management Function (SMF). The network node comprises communications circuitry configured to communicate with one or more network nodes and processing circuitry operatively connected to the communications circuitry. Additionally, the processing circuitry is configured to receive, from a User Equipment (UE) in a Non Public Network (NPN) via an Access and Mobility Management (AMF) node, a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), wherein the DNN comprises one of a pre-defined DNN used for remotely provisioning the UE, and an internet DNN provided by an Access and Mobility Management Function (AMF), obtain, for the UE, remote provisioning information associated with the NPN, wherein the remote provisioning information is used by the UE to initiate an onboarding procedure that enables the UE to access the remote provisioning system, and obtain information associated with the one of the pre-defined DNN and the internet DNN. Then, responsive to obtaining a packet filter, the processing circuitry selects and configures a UPF for the PDU session based on the DNN and the packet filter, and sends a session establishment accept message comprising the remote provisioning information used by the UE to initiate the onboarding procedure. 
     In an eighth aspect, the present disclosure provides a non-transitory computer-readable medium storing a computer program thereon. The computer program comprises instructions that, when executed by processing circuitry of a Session Management Function (SMF) node, causes the SMF to receive, from a User Equipment (UE) in a Non Public Network (NPN) via an Access and Mobility Management (AMF) node, a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), wherein the DNN comprises one of a pre-defined DNN used for remotely provisioning the UE, and an internet DNN provided by an Access and Mobility Management Function (AMF), obtain, for the UE, remote provisioning information associated with the NPN, wherein the remote provisioning information is used by the UE to initiate an onboarding procedure that enables the UE to access the remote provisioning system, and obtain information associated with the one of the pre-defined DNN and the internet DNN. Then, responsive to obtaining a packet filter, the processing circuitry selects and configures a UPF for the PDU session based on the DNN and the packet filter and sends a session establishment accept message comprising the remote provisioning information used by the UE to initiate the onboarding procedure. 
     In a ninth aspect, the present disclosure provides a computer program comprising executable instructions that, when executed by a by processing circuitry of a Session Management Function (SMF) node, causes the SMF to receive, from a User Equipment (UE) in a Non Public Network (NPN) via an Access and Mobility Management (AMF) node, a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), wherein the DNN comprises one of a pre-defined DNN used for remotely provisioning the UE, and an internet DNN provided by an Access and Mobility Management Function (AMF), obtain, for the UE, remote provisioning information associated with the NPN, wherein the remote provisioning information is used by the UE to initiate an onboarding procedure that enables the UE to access the remote provisioning system, and obtain information associated with the one of the pre-defined DNN and the internet DNN. Then, responsive to obtaining a packet filter, the instructions cause the SMF to select and configure a UPF for the PDU session based on the DNN and the packet filter and send a session establishment accept message comprising the remote provisioning information used by the UE to initiate the onboarding procedure. 
     In a tenth aspect, the disclosure provides a carrier containing a computer program according to the twenty-fourth aspect, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium. 
     In an eleventh aspect, the disclosure provides a method performed by an Access and Mobility Management Function (AMF) node. In this aspect, the method comprises the steps of receiving, from a User Equipment (UE) in a Non Public Network (NPN), a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), wherein the session establishment request message includes one of a pre-defined DNN and a pre-defined session establishment request type used for remotely provisioning the UE in an onboarding procedure, selecting a Session Management Function (SMF) node, and sending a session establishment create request message to the selected SMF. 
     In a twelfth aspect, the disclosure provides a network node configured to operate as an Access and Mobility Management Function (AMF). In this aspect, the network node comprises communications circuitry configured to communicate with one or more network nodes, and processing circuitry operatively connected to the communications circuitry. The processing circuitry in this aspect is configured to receive, from a User Equipment (UE) in a Non Public Network (NPN), a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), wherein the session establishment request message includes one of a pre-defined DNN and a pre-defined session establishment request type used for remotely provisioning the UE in an onboarding procedure, select a Session Management Function (SMF) node, and then send a session establishment create request message to the selected SMF. 
     In a thirteenth aspect, the disclosure provides a non-transitory computer-readable medium storing a computer program thereon. The computer program comprises instructions that, when executed by processing circuitry of an Access and Mobility Management Function (AMF) node, causes the AMF to receive, from a User Equipment (UE) in a Non Public Network (NPN), a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), wherein the session establishment request message includes one of a pre-defined DNN and a pre-defined session establishment request type used for remotely provisioning the UE in an onboarding procedure, select a Session Management Function (SMF) node, and then send a session establishment create request message to the selected SMF. 
     In a fourteenth aspect, the disclosure provides a computer program comprising executable instructions that, when executed by a by processing circuitry of an Access and Mobility Management Function (AMF) node, causes the AMF receive, from a User Equipment (UE) in a Non Public Network (NPN), a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), wherein the session establishment request message includes one of a pre-defined DNN and a pre-defined session establishment request type used for remotely provisioning the UE in an onboarding procedure, select a Session Management Function (SMF) node, and then send a session establishment create request message to the selected SMF. 
     In a fifteenth aspect, the disclosure provides a carrier containing a computer program according to the twenty-ninth aspect, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium. 
     In a sixteenth aspect, the disclosure provides a method for providing User Equipment (UE) subscription data associated with a Non-Public Network (NPN). In this embodiment, the method implemented by a Unified Data Management (UDM) node and comprises receiving a request for session subscription information for the UE, wherein the request includes a UE identity, and sending, in reply to the request, a response comprising remote provisioning information used by the UE to initiate an onboarding procedure to enable the UE to remotely provision a subscription for a 5GS network and an Internet Protocol Multi-Media Subsystem (IMS) network. 
     In a seventeenth aspect, the disclosure provides a network node configured to operate as a Unified Data Management (UDM) function. The network node comprises communications circuitry configured to communicate with one or more network nodes, and processing circuitry operatively connected to the communications circuitry. According to this aspect, the processing circuitry is configured to receive a request for session subscription information for the UE, wherein the request includes a UE identity, and send, in reply to the request, a response comprising remote provisioning information used by the UE to initiate an onboarding procedure to enable the UE to remotely provision a subscription for a 5GS network and an Internet Protocol Multi-Media Subsystem (IMS) network. 
     In an eighteenth aspect, the disclosure provides a non-transitory computer-readable medium storing a computer program thereon. In this aspect, the computer program comprises instructions that, when executed by processing circuitry of a Unified Data Management (UDM) node, causes the UDM to receive a request for session subscription information for the UE, wherein the request includes a UE identity, and send, in reply to the request, a response comprising remote provisioning information used by the UE to initiate an onboarding procedure to enable the UE to remotely provision a subscription for a 5GS network and an Internet Protocol Multi-Media Subsystem (IMS) network. 
     In a nineteenth aspect, the disclosure provides a computer program comprising executable instructions that, when executed by processing circuitry of a Unified Data Management (UDM) node, causes the UDM to receive a request for session subscription information for the UE, wherein the request includes a UE identity, and send, in reply to the request, a response comprising remote provisioning information used by the UE to initiate an onboarding procedure to enable the UE to remotely provision a subscription for a 5GS network and an Internet Protocol Multi-Media Subsystem (IMS) network. 
     In a twentieth aspect, the disclosure provides a carrier containing a computer program according to the thirty-third aspect, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a functional block diagram illustrating, conceptually, how an IMS network operates with multiple Non-Public Networks (NPNs) according to one embodiment of the present disclosure. 
         FIG.  2    is a functional block diagram illustrating an architecture for providing IMS services to a user of a NPN according to one embodiment of the present disclosure. 
         FIG.  3    is a functional block diagram illustrating an architecture for remotely provisioning UEs with IMS credentials according to one embodiment of the present disclosure. 
         FIG.  4    is a functional block diagram illustrating a method for providing IMS services to a UE according to embodiments of the present disclosure. 
         FIG.  5    is a signaling diagram illustrating a call flow for providing IMS services to a UE according to one embodiment of the present disclosure. 
         FIG.  6    is a signaling diagram illustrating a call flow for providing IMS services to a UE according to another embodiment of the present disclosure. 
         FIGS.  7 A- 7 B  are flow diagrams illustrating a method, implemented at a UE, for acquiring configuration/subscription data over an access/core network according to one embodiment of the present disclosure. 
         FIG.  8    is a flow diagram illustrating a method, implemented at a Session Management Function (SMF), for providing a UE with remote provisioning information according to one embodiment of the present disclosure. 
         FIGS.  9 A- 9 C  are flow diagrams illustrating a method, implemented at a Unified Data Management (UDM) function, for providing an SMF with the remote provisioning information for the UE, and for creating and updating UE subscription data according to embodiments of the present disclosure. 
         FIG.  10    is a signaling diagram illustrating a call flow for providing IMS services to a UE according to another embodiment of the present disclosure. 
         FIG.  11    is a signaling diagram illustrating a call flow for providing IMS services to a UE according to another embodiment of the present disclosure. 
         FIG.  12    is a signaling diagram illustrating a call flow for providing IMS services to a UE according to another embodiment of the present disclosure. 
         FIGS.  13 A- 13 C  are flow diagrams illustrating a method, implemented at a UE, for acquiring configuration/subscription data over an access/core network according to one embodiment of the present disclosure. 
         FIG.  14    is a flow diagram illustrating a method, implemented at a Session Management Function (SMF), for providing a UE with remote provisioning information according to one embodiment of the present disclosure. 
         FIG.  15    is a flow diagram illustrating a method, implemented at Access and Mobility Management Function (AMF), for providing a UE with remote provisioning information according to one embodiment of the present disclosure. 
         FIG.  16    is a flow diagram illustrating a method, implemented at a Unified Data Management (UDM) function, for providing an SMF with the remote provisioning information for the UE, and for modifying the DNN subscription list of the UE, according to embodiments of the present disclosure. 
         FIG.  17    is a functional block diagram of a UE configured according to one embodiment of the present disclosure. 
         FIG.  18    illustrates a computer program product executing on the processing circuitry of a UE according to one embodiment of the present disclosure. 
         FIG.  19    is a functional block diagram of an SMF configured according to one embodiment of the present disclosure. 
         FIG.  20    illustrates a computer program product executing on the processing circuitry of an SMF according to one embodiment of the present disclosure. 
         FIG.  21    is a functional block diagram of a UDM configured according to one embodiment of the present disclosure. 
         FIG.  22    illustrates a computer program product executing on the processing circuitry of a UDM according to one embodiment of the present disclosure. 
         FIG.  23    is a functional block diagram of an AMF configured according to one embodiment of the present disclosure. 
         FIG.  24    illustrates a computer program product executing on the processing circuitry of an AMF according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, an exemplary embodiment of the present disclosure will be described in the context of the 5G standard by the Third Generation Partnership Project (3GPP) communication network. Those skilled in the art will appreciate that the methods and apparatus herein described are not limited to use in 5G networks but may also be used in communication networks operating according to other standards that use a service-based architecture and provide restart notifications. 
     Embodiments of the present disclosure enable UEs connected to an SNPN to receive IMS and emergency services by using eSIM to onboard the IMS credentials needed by the UE for those services. More particularly, the present disclosure describes the support required in the UE for performing eSIM remote provisioning (e.g., based on GSMA specifications “GSMA: “RSP Technical Specification Version 2.2.1 18 Dec. 2018” and “GSMA: “Remote Provisioning Architecture for embedded UICC Technical Specification Version 4.0 25 Feb. 2019”), the requirements for the SNPN 5GC, the subscription profile of SNPN UEs in the 5GC, and the IMS system. 
       FIG.  1    is a functional block diagram illustrating a communications system  10 , and conceptually shows how an IMS network would work with a Non-Public Network (NPN) according to one embodiment of the present disclosure. As seen in  FIG.  1   , system  10  comprises a 5GC Packet Core Non-Public Network (NPN)  12  communicatively interconnecting an IMS network  14  with a plurality of NPN access networks  16   a ,  16   b ,  16   c  (collectively, NPN access networks  16 ). A plurality of UEs  18   a ,  18   b ,  18   c ,  18   d ,  18   e  (collectively, UE  18 ) are connected to corresponding NPN access networks  16 , and access IMS services provided by IMS network  14  via the NPN access networks  16  and NPN  12 . 
       FIG.  2    is a functional block diagram illustrating a reference architecture for providing IMS services to a user of a NPN according to one embodiment of the present disclosure. As seen in  FIG.  2   , system  10  comprises a Standalone NPN (SNPN  20 ) comprising core NPN  12  and IMS network  14 . Additionally, as previously described, UE  18  accesses the services provided by the core NPN  12  and the IMS network  14  via the NPN access network  16 . 
     The core NPN  12  employs a service-based architecture according to the 5G standard by the Third Generation Partnership Project (3GPP). As seen in  FIG.  2   , core NPN  12  comprises a number of network functions (NFs) such as an Access and Mobility Management Function (AMF)  22 , a Session Management Function (SMF)  24 , a Unified Data Management (UDM) function  26 , a Policy Control Function (PCF)  28 , and a User Plane Function ( 30 ). Those of ordinary skill in the art will appreciate that core NPN  12  may have other NFs not specifically shown here, such as an Authentication Server Function, a Network Exposure Function, a Network Slice Selection Function, a Network Repository Function, an Application Function (which may be located in the core NPN  12  or be external to the core NPN  12 ), a Unified Data Repository, a Network Data Analytics Function, and a Charging Function. 
     The NFs shown in  FIG.  2    comprise logical entities that reside in one or more core network nodes, which may be implemented by one or more processors, hardware, firmware, or a combination thereof. The NFs may reside in a single core network node or may be distributed among two or more core network nodes. Further, the core NPN  12  may include multiple instances of the NFs. 
     IMS network  14  also comprises a number of NFs, such as a Proxy-Call Session Control Function (P-CSCF)  32 , an Interrogating/Serving Call Session Control Function (I/S-CSCF)  34 , and a Home Subscriber Server (HSS)-Internet Protocol Multimedia Session (IMS) Function  36 . 
     The P-CSCF  32  is the first contact point for users of IMS network  14 , and functions as a proxy server for UEs  18 . Generally, all Session Initiation Protocol (SIP) signaling traffic to and from the UEs  18  pass through the P-CSCF  32 . The I/S-CSCF  34  is a node that integrates the functions of both an I-CSCF and an S-CSCF, and is the contact point within IMS network  14  for all connections destined to a UE  18  on IMS network  14 . For example, during registration, I/S-CSCF  34  interrogates the HSS to determine where to route the request for registration. I/S-CSCF  34  also provides session set-up, session tear-down, session control and routing functions, and in some situations, may also generate billing records and invoke Application Servers (ASs) based on information received from the HSS. The HSS  36  is a database configured to support the other functions in IMS network  14  that handle user traffic. 
     According to the present disclosure, a node in the IMS network  14  or the remote provisioning manager/eSIM manager sends commands to the UDM  26  in one embodiment to update a UE profile at the UDM based on IMS subscription information, and in other embodiments, to create a subscription for a UE  18  for the NPN access network  16  as well as the core NPN  12 . 
     The architecture illustrated in  FIG.  2    assumes a one-to-one relationship between the core NPN  12  and IMS network  14 . Thus, in this embodiment, IMS network  14  is part of the SNPN  20 . However, those of ordinary skill in the art should readily appreciate that the present embodiments are not so limited and that other deployment options are also possible. In some embodiments, for example, IMS network  14  is owned and operated by a third-party, and as such, comprises an entity that is independent of SNPN  20 . 
     In the embodiment of  FIG.  2   , IMS network  14  is accessed over an N6 reference point as a Data Network offered by SNPN  20 . A Gm reference point extends between UE  18  and P-CSCF  32 , and is managed as user plane traffic via UPF  30 . Additionally, embodiments of the present disclosure require inter-network connectivity between the P-CSCF  32  and the HSS-IMS  36  in IM network  14  with the PCF  28  and UDM  26  in core NPN  12 , respectively. Thus, to gain this connectivity, the present embodiments provide an N5 interface between the P-CSCF  32  and PCF  28 , and an Nxx interface between the UDM  26  and the HSS-IMS  36 . 
     As stated above, IMS network  14  may be owned/operated by a third-party (e.g. a PLMN operator) that is independent of the operator of the core NPN  12 . Thus, in some cases, the interconnectivity provided by the N6, N5 and Nxx reference points implies the use of inter-operator interfaces. In these cases, however, the present embodiments will be able to support additional security requirements over these interfaces. 
     Additionally, embodiments of the present disclosure can be implemented in cases where IMS network  14  supports Service Based Interfaces (SBI) or legacy interfaces. 
     The present embodiments also require that the core NPN  12  enable some relevant functionality to support IMS services, as defined in section 5.16.3.1 of 3GPP TS 23.501. This includes support for:
         Indicating toward the UE  18  whether IMS voice over PS session is supported;   Transporting P-CSCF address(es) to UE (the P-CSCF IP address(es) may be locally configured in the SMF  24  of core NPN  12 , or dynamically discovered by SMF  24  via an NRF (not shown)); and   Support of a P-CSCF restoration procedure.   However, according to the present disclosure, not all the capabilities listed in in section 5.16.3.1 of TS 23.501 are required. For example, support for Terminating Access Domain Selection (TADS) is not required as IMS voice calls to/from users of SNPN  20  are expected to always be managed via New Radio (NR). Similarly, domain selection for UE-originating sessions is set in UEs  18  connected to SNPN  20  to always generate voice calls over IMS.       

     Onboarding and Provisioning of IMS Subscription/Access Related Information 
       FIG.  3    is a functional block diagram illustrating a high-level architecture for remotely provisioning UEs  18  with IMS credentials according to one embodiment of the present disclosure. 
     More specifically, to enable the use of IMS voice and emergency services by UEs  18  connected to SNPN  20 , the present disclosure remotely provisions the UEs  18  for the needed IMS access related information, in one embodiment, or both access network related information and IMS network related information in another embodiment, based on the specifications detailed in GSMA: “RSP Technical Specification Version 2.2.1” and “GSMA: “Remote Provisioning Architecture for embedded UICC Technical Specification.” This process is illustrated in  FIG.  3   . 
     According to the present embodiments, multiple options are possible to effect remote provisioning. The particular option, however, depends on the deployment option chosen by the operator of the SNPN  20 . By way of example only, some of the options that are possible according to the present embodiments are:
         Option 1: If SNPN  20  owns and operates IMS network  14 , the SNPN  20  can use a cloud-based remote provisioning system  50  for the remote provisioning of eSIMs;   Option 2: If SNPN  20  uses the services from an independent IMS provider (i.e., a third-party owner of IMS network  14 ), however, then SNPN  20  can use the remote provisioning of eSIMs of either the cloud-based remote provisioning system  50  or the remote provisioning system  40  owned by the third-party IMS provider.       

     Those skilled in the art should appreciate, however, that these options may require some necessary agreements to be in place between the operators of SPNP  20  and the other entities (e.g., the third-party IMS provider) in accordance with the above-identified GSMA specifications. 
     According to the present disclosure, UE subscription-related information for remote provisioning is provisioned in UDM  26  by the operator of the core NPN  12 . Such data for the remote provisioning of an eSIM for a UE  18  includes:
         UE authorization, referred to as triggering enabling information, to authorize the UE for remote provisioning; and   UE transparent information required by the UE to interact with the remote provisioning system. The information that is needed by the UE depends on which of the options above are selected, as well as the agreements, as previously described.       

     After successful completion of the onboarding process, the core NPN  12  subscription information is updated according to the present embodiments to include the IMS Data Network Name (DNN), and triggering disabling information. 
     It should be noted that, as part of the onboarding process, the selected IMS provider is provisioned with the requisite IMS subscription related information, per subscriber, depending on the agreement in place between the core NPN  12  and the IMS provider. Additionally, an IMS network  14  serving multiple SNPNs  20  will be pre-configured with the information it needs to interact with each SNPN  20  it services. Once the requisite IMS access related information is downloaded to the UE  18 , it can be used for IMS registration and to acquire desired IMS services. 
     IMS Support for Multi-SNPNs (Multi-Tenancy) IMS Support for Multi-SNPNs (Multi-Tenancy) 
     According to the present embodiments, in cases where the operator of SNPN  20  owns and operates the IMS network  14  providing the IMS services to the UE  18 , then there are no additional impacts beyond what has already been previously described. However, in situations where the operator of the IMS network  14  is a different entity, which can potentially interwork with multiple SNPNs  20 , there are additional requirements. 
     More specifically, a single IMS network  14  supporting multiple SNPNs  20  (multi-tenancy) needs to be able to identify each SNPN  20  for multiple reasons, including:
         To interwork with appropriate network functions belonging to the corresponding core NPN  12  for signaling purposes. The NFs at the corresponding SNPN  20  can be pre-configured for each SNPN  20  at the IMS network  14 ;   To statistically distinguish the collected data for different SNPNs  20 ; and   To charge the SNPNs  20 .       

     Additionally, different strategies may be adopted to support multiple SNPNs  20 . In one strategy, for example, the operator of the IMS network  14  can use common IMS NF instances (e.g. P-CSCF or HSS) for all IMS users or deploy separate IMS NF instances for each SNPN  20 . In other strategies, the identification of the corresponding SNPN  20  for these purposes can be based on the home network domain and the IP Multimedia Private Identity/IP Multimedia Public Identity (IMPI/IMPU) identifiers provided by the UE during the IMS registration procedure. This enables HSS to identify the SNPN  20 . 
     Further, the P-CSCF  32  is able to acquire the Public Land Mobile Network Identifier (PLMN-ID) and Network Interface Device (NID) of the SNPN  20  during the IMS registration procedure. 
     Roaming 
     For roaming between an SNPN  20  and a public PLMN supported by a roaming agreement, there is no additional functionality required. Existing procedures are applicable as is, considering that the interface between P-CSCF  32  and PCF  28  may be inter-operator, as previously mentioned. However, support for roaming is subject to an interworking agreement between roaming partners. 
     Remote Provisioning 
       FIG.  4    is a functional block diagram illustrating a method  60  for providing IMS services to a UE  18  according to embodiments of the present disclosure. Particularly, as seen in  FIG.  4   , a UE  18  communicatively connects to a remote provisioning system  50  and/or IMS network  14  via the NPN access network  16  and core NPN  12 . Those of ordinary skill in the art will readily appreciate that, for ease of discussion only, the NPN access network  16  and core NPN  12  are illustrated as a single box  12 ,  16 . Once connected, the UE  18  can establishes a PDU connection with the IMS network  14  and receives IMS services. 
     In more detail, a UE  18  wishing to access IMS services sends a PDU session establishment request message to the core NPN  12  (line  62 ) and receives, in return, a PDU session establishment accept message (line  64 ). The PDU session establishment accept message includes the remote provisioning information needed by the UE  18  to access a remote provisioning system (e.g., remote provisioning system  50  or a system provided by IMS network  14 ). The UE  18  then initiates a remote provisioning procedure at the remote provisioning system  50  and passes the remote provisioning information it received to the remote provisioning system  50  (line  66 ). In return, the UE  18  receives credentials (e.g., eSIM credentials) with which it can access IMS services (line  68 ). The remote provisioning system  50  then creates a subscription with the HSS  36  (line  70 ), and a node in the IMS network  14  (e.g., the HSS  36  or some other node), in turn, updates the UDM  26  (directly or via Network Exposure Function (NEF) in the core NPN  12  to add the IMS services for the UE (line  72 ). Once provisioned, the UE  18  can establish a session with the IMS network  14  and access the desired IMS services. 
     The present disclosure provides at least two methods for enabling UEs  18  to access IMS services. In a first method, seen in the signaling diagram  80  of  FIG.  5   , the UE  18  is assumed to have acquired the information needed to access the NPN access and Core network  16  (e.g., real SUPI, security credentials, etc.). With this method, the credentials provided to the UE  18  as a result of the remote provisioning procedure are used only for IMS purposes. However, in the second method seen in the signaling diagram  90  of  FIG.  6   , the credentials provided to the UE  18  are utilized by the UE  18  to access both the NPN access/core network  16  and for the IMS network  14 . 
     Turning first to the method shown in  FIG.  5   , it is assumed that the UE  18  has already acquired the information it needs to access the NPN access network  16  the onboarding process (box  80 - 1 ). In particular, in this first method, it is assumed that the UE  18  has already been assigned a unique Subscription Permanent Identifier (SUPI) for the NPN access network  16  and the core NPN  12 . 
     In box  80 - 2 , UE  18  performs a 5GC registration in accordance with the procedures specified in 3GPP TS 23.502 V16.4.0: “Procedures for the 5G System (5GS); Stage 2” (Release 16) dated March 2020. 
     In line  80 - 3 , UE  18  initiates a Packet Data Network (PDN) connection for a DNN as specified by the procedures in 3GPP TS 23.502. 
     In line  80 - 4 , AMF  22  selects an SMF  24 , and sends a Nsf_PDUSession_CreateSMContext Request message to the selected SMF  24 . 
     In box  80 - 5 , upon receiving the message from the AMF  22 , SMF  24  fetches the session subscription related information for the UE  18  from UDM  26 . According to the present embodiments, the session subscription related information received from the UDM  26  includes remote provisioning information and eSIM enabling triggering information. The remote provisioning information is sent by UDM  26  to SMF  24  in the UDM session subscription information as transparent information to be transported to UE  18  in the PDU session establishment accept response message. The eSIM enabling triggering information is sent by UDM  26  to allow SMF  24  to determine whether the subscription requires eSIM remote provisioning. If, based on the eSIM enabling triggering information, SMF  24  determines that remote provisioning is required for the subscription SMF  24  includes the remote provisioning information in the PDU session establishment accept response message sent to UE  18 . 
     According to the present disclosure, the remote provisioning information (e.g., eSIM remote provisioning related information) typically includes all the information UE  18  needs to initiate a remote provisioning procedure. However, the particular information included in the remote provisioning procedure can vary depending on factors such as the selected SNPN  20  deployment option, the UE vendor, the remote provisioning service provider, and the IMS provider. In one embodiment, however, the remote provisioning information returned to UE  18  in the PDU session establishment accept response message includes, but is not limited to, NPN subscription information for the UE, authentication credentials for authenticating the UE with the remote provisioning system, enhanced Subscriber Identity Module (eSIM) entitlement server information such as a link to the eSIM entitlement server, and one or more eSIM Information Elements (IE). 
     In line  80 - 6 , the PDU Session Establishment Accept Response, which includes the remote provisioning related information required for UE  18  to initiate the remote provisioning procedure, is sent to UE  18 . 
     In line  80 - 7 , SMF  24  registers the UE context in UDM  26 . 
     In box  80 - 8 , the UE  18  determines that it must initiate a remote provisioning procedure responsive to receiving the remote provisioning information in the PDU Session Establishment Accept Response message. Thus, the receipt of the remote provisioning information in the PDU Session Establishment Accept Response message triggers UE  18  to initiate the remote provisioning procedure. 
     In line  80 - 9 , UE  18  initiates interaction with the remote provisioning system  50  to update its subscription at the HSS  36 . To initiate such interaction, the UE  18 , in one embodiment, sends an Initiate Provisioning Request to an entitlement server associated with the IMS provider. Additionally, the UE  18  includes its SUPI in the request, which as stated above, is unique and assigned to the UE  18 , and is for both the NPN access network  16  and the core NPN  12 . 
     In box  80 - 10 , UE  18  downloads eSIM data in accordance with the previously identified GMSA: “RSP Technical Specification” and “GSMA: “Remote Provisioning Architecture for embedded UICC Technical Specification Version.” 
     In line  80 - 11 , an eSIM manager associated with the IMS provider provisions the HSS  36  with the requisite provisioning information so that it can update the UE subscription. In this embodiment, the provisioning information includes the unique SUPI assigned to UE  18 . 
     In box  80 - 12 , a node in the IMS network  14  sends a message to the UDM  26  via the Nxx interface, or a NEF, to update the UDM subscription for the UE  18 . Upon receiving the message, the UDM  26  updates the UDM subscription by adding the IMS DNN to the UE profile and by disabling the triggering information. 
     At this point, the remote provisioning procedure is complete. Thus, in box  80 - 12 , UE  18  can initiate an IMS PDN connection to establish an IMS PDU session. 
     In box  80 - 13 , UE  18  uses the eSIM credentials it received to initiate IMS procedures based on existing specifications 3GPP TS 23.228 V16.4.0 “IP Multimedia Subsystem (IMS); Stage 2 (Release 16)” dated March 2020. 
       FIG.  6    illustrates the second method using signaling diagram  90 . In this method, the credentials provided to UE  18  are utilized to access both the NPN access network  16  and for authentication and authorization in the IMS network  14 . This differs from the first method seen in signaling diagram  80  of  FIG.  5   , in which the credentials provided to UE  18  are utilized only for IMS purposes. 
     More particularly, the first method illustrated in signaling diagram  80  of  FIG.  5    assumes that UE  18  already has been assigned a unique SUPI. Thus, the UE  18  can already access the NPN access network  16  and core NPN  12  and does not require credentials to obtain a SUPI for those networks. It requires the credentials only for IMS purposes, and thus, the processes described and performed in the embodiment of  FIG.  5    utilize this “actual” SUPI assigned to the UE  18  to provide those credentials. 
     The second method illustrated in signaling diagram  90  of  FIG.  6   , however, covers situations where the UE  18  has not yet been assigned a unique/real SUPI. Thus, as described in more detail below, the second method allows for the use of a “temporary” SUPI by UE  18 . The use of the temporary SUPI by UE  18  allows for at least two things. First, it allows the UE  18  to be assigned an “actual” unique SUPI so it can register with the NPN access network  16  and core NPN  12  using the assigned SUPI. Second, it allows UE  18  to obtain the necessary information for initiating the remote provisioning procedure and to download the data that allows for the establishment of a connection with IMS network  14  to obtain the desired IMS services. Second, 
     As seen in  FIG.  6   , signaling diagram  90  uses the same reference architecture as signaling diagram  80 . 
     In box  90 - 1 , UE  18  registers with the core NPN  12  in accordance with the procedures specified in 3GPP TS 23.502 V16.4.0: “Procedures for the 5G System (5GS); Stage 2” (Release 16) dated March 2020. In this embodiment, to accomplish such registration, UE  18  uses a well-known “temporary” SUPI. In some embodiments, SNPN  20  may have one or more such “temporary” or “default” SUPIs, and the UE  18  can use a selected one of those temporary SUPIs depending on its needs. In this embodiment, the “temporary” SUPI is also used by UE  18  during the remote provisioning process. As part of the registration procedure, the AMF may contact the UDM to retrieve from the UDM the subscription data. As the UE is using a temporary SUPI, the UDM may provide temporary subscription data that may comprise one allowed DNN that the UE is allowed to use when establishing a PDU session and that DNN is a default DNN or a DNN that allows the UE to establish a PDU session with a provisioning system only. 
     In line  90 - 2 , UE  18  initiates a Packet Data Network (PDN) connection for a DNN as specified by the procedures in 3GPP TS 23.502, the UE may include the DNN for the provisioning system or may omit to include the DNN. If the UE has included the DNN, the AMF verifies if the DNN is compatible with the temporary subscription, if not, the AMF overrides with the DNN for remote provisioning. 
     In line  90 - 3 , AMF  22  selects an SMF  24 , and sends a Nsf_PDUSession_CreateSMContext Request message to the selected SMF  24 . If the AMF had provided a DNN for remote provisioning for the temporary SUPI, and optionally an indication that the UE is using a temporary SUPI, the SMF may verify if the DNN is compatible with a configured DNN for remote provisioning if one is configured determines that the UE can only transmit traffic over the PDU session for provisioning and may provide as part of remote provisioning information, packet filters for uplink to the UE in the PDU session establishment accept message and may also provide an identification ?(IP address or similar) of the remote provisioning system server. Additionally, the SMF configures the User plane function (UPF) to only allow traffic between the UE and the remote provisioning system over the PDU session. If the SMF is not configured with the remote provisioning information it proceeds with step  4 , 
     In box  90 - 4 , SMF  24  fetches the session subscription related information associated with the UE&#39;s  18  registered temporary SUPI. The session subscription related information includes eSIM remote provisioning information for the temporary SUPI, and is sent to the SMF  24  by UDM  26  as either transparent information to be transported to UE  18  as remote provisioning information in the PDU Session Establishment Accept response message. The eSIM remote provisioning related information can include any information needed or desired; however, it typically includes all the information needed by UE  18  to initiate the remote provisioning process. The transparent remote provisioning information may include the identification of the remote provisioning system. Such information can vary depending on SNPN chosen deployment option, the UE vendor, the remote provisioning service provider, and/or the IMS provider. However, in one embodiment, the eSIM remote provisioning information returned to UE  18  in the PDU session establishment accept response message includes, but is not limited to, enhanced Subscriber Identity Module (eSIM) entitlement server information such as a link to the eSIM entitlement server, and one or more eSIM Information Elements (IE). The SMF may also use all or part of the remote provisioning information or another indication to determine that the traffic over the PDU session must be limited to provisioning, the SMF may also provide a packet filter for the UE to only allow uplink traffic to the remote provisioning system as part of the PDU session accept message. 
     In line  90 - 5 , the PDU Session Establishment Accept Response message, which includes the remote provisioning related information required for UE  18  to initiate the remote provisioning procedure, is sent to UE  18 . 
     In line  90 - 6 , SMF  24  may register the UE context in UDM  26 , albeit it is based on temporary UE identity. 
     In box  90 - 7 , UE  18  determines that it should initiate a remote provisioning procedure responsive to receiving the remote provisioning information in the PDU Session Establishment Accept Response message if it wants to receive services. That is, the receipt of the remote provisioning information in the PDU Session Establishment Accept Response message may trigger the UE  18  to initiate the remote provisioning procedure. Alternatively, the UE may trigger the procedure when it has uplink data to send (e.g., UE attempting to access any service/internet, etc.), triggering the remote provisioning procedure (automatically or manually by the user) if for example the UE determines that the UL packet filter if provisioned by the SMF does not match the uplink data (e.g., destination IP address does not match the destination IP address (remote provisioning/entitlement server) in the UL packet filter) 
     In line  90 - 8 , UE  18  initiates interaction with the remote provisioning system  50  to update its subscription. To initiate such interaction, the UE  18 , in one embodiment, sends an Initiate Provisioning Request to an entitlement server associated with the NPN. Additionally, the UE  18  includes its temporary SUPI in the request. 
     In box  90 - 9 , UE  18  downloads eSIM data in accordance with the previously identified GMSA: “RSP Technical Specification” and “GSMA: “Remote Provisioning Architecture for embedded UICC Technical Specification Version.” In this embodiment, the UE receives access subscription information and IMS subscription information. 
     In line  90 - 10 , the eSIM manager (which may be the same as provisioning/entitlement server) associated with the NPN provisions the HSS  36  with the requisite provisioning information so that it can create the UE subscription. In this embodiment, the provisioning information includes the actual/real SUPI associated with the temporary SUPI and the credentials needed by the UE to obtain IMS services. 
     In box  90 - 11 , the UDM  26  obtains, from a node in the IMS network  14  (including the eSIM provisioning system), directly or via NEF, real provisioning information that includes creation of an access related subscription associated with the actual/real SUPI of the UE and would enable the UE to perform a new registration with the real SUPI and be authenticated and establishment of PDU sessions to allowed DDNs. The UDM also obtains any relevant subscription data to allow the UE to establish a PDU session to IMS to access IMS services based on the real/actual SUPI, such as IMS DDN at a minimum. 
     At this point, the remote provisioning procedure is complete where both the UE and the UDM have obtained the required subscription data is based on the real SUPI. In box  90 - 12 , UDM  26  creates the UE subscription. Particularly, UDM  26  creates a SUPI profile for UE  18 , and allocates a default profile for that SUPI. This SUPI is unique to the UE  18  and will replace the temporary SUPI. 
     In box  90 - 13 , prior to establishing the IMS session with the IMS provider, UE  18  de-registers from the core NPN  12  using the temporary SUPI. 
     In box  90 - 14 , the UE  18  initiates a new registration with the core NPN  12  using the newly assigned SUPI and performs authentication 
     The UE  18  can initiate an IMS PDN connection to establish an IMS PDU session and use the eSIM credentials to initiate IMS procedures based on existing specifications 3GPP TS 23.228 V16.4.0 “IP Multimedia Subsystem (IMS); Stage 2 (Release 16)” dated March 2020. 
     Thus, embodiments of the present disclosure provide a simple way for allowing NPN users to use IMS network with only minor changes to be made to impacted nodes. Further, the present embodiments accomplish these goals without requiring anything specific from NPNs, and without requiring the provisioning of IMS credentials in any NPN UE device. 
       FIGS.  7 A- 7 B  are flow diagrams illustrating a method  100 , implemented at a UE  18 , for acquiring configuration/subscription data over an access/core network, such as NPN access network  16  and core NPN  12 , according to one embodiment of the present disclosure. In particular,  FIG.  7 A  illustrates method  100  implemented at the UE  18  regardless of whether UE  18  uses its assigned “actual” SUPI or a temporary SUPI.  FIG.  7 B , however, illustrates steps performed by UE  18  in cases where UE  18  uses a temporary SUPI. 
     As seen in  FIG.  7 A , UE  18  sends, to a network node (e.g., AMF  22 ), a PDU session establishment request message to establish a first Protocol Data Unit (PDU) session to a Data Network Name (DNN) (box  102 ). UE  18  then receives, from the network node, a PDU session establishment accept message in response (box  104 ). 
     In this embodiment, the received message comprises remote provisioning information needed by UE  18  to access a remote provisioning system associated with SNPN  20 . The remote provisioning information may comprise any data needed or desired, but will contain all the information UE  18  needs to initiate the remote provisioning procedure. In one embodiment, for example, the remote provisioning information includes, but is not limited to, enhanced Subscriber Identity Module (eSIM) entitlement server information, one or more eSIM Information Elements (IE), NPN subscription information for the UE, authentication credentials for authenticating the UE with the remote provisioning system, and a link to an eSIM manager associated with the IMS provider. 
     UE  18  next determines whether it needs to initiate the remote provisioning procedure (box  106 ). In one embodiment, whether the UE initiates the remote provisioning procedure depends on whether the remote provisioning information is included in the PDU session establishment accept message. If not, method  100  ends and UE  18  operates normally. However, the presence of the remote provisioning information in the PDU session establishment accept message triggers the UE  18  to initiate the remote provisioning procedure (box  108 ). 
     As stated above, the UE  18  may, according to the present disclosure, utilize an “actual” SUPI or a “temporary” SUPI. In both cases, the UE  18  initiates the remote provisioning procedure over the first PDU session by sending a request to update the IMS subscription data for the UE. However, UE  18  will include its “actual” assigned SUPI in the request when it already has a SUPI assigned to it, and the “temporary” SUPI in the request when the UE  18  is using the “temporary” SUPI. 
     UE  18  then receives, from the remote provisioning system, the UE configuration/subscription data (box  110 ), which in one embodiment, comprises IMS subscription data for IMS network  14  associated with SNPN  20 . In cases where the UE  18  is using a temporary SUPI, the UE configuration/subscription data received from the remote provisioning system further comprises access related subscription information for the UE, such as an “actual” SUPI that was assigned to the UE  18  during the remote provisioning process. 
     In at least one embodiment, the IMS subscription data comprises an IMS DNN to access the IMS network  14  of the SNPN  20 . The DNN may, in some embodiments, comprise one or more of a default DNN, a DNN for a packet data network, a DNN for remote provisioning in the NPN, and a DNN for the SNPN  20 . 
     Thereafter, responsive to determining that a connection to the IMS network  14  is required, UE  18  establishes a second PDU session with the IMS network  14  using the IMS subscription data (box  112 ). 
     As seen in  FIG.  7 B , UE  18 , when using a temporary SUPI, UE  18  will also de-register from the NPN access network  16  and core NPN  12  using the temporary SUPI (box  114 ), and then re-register with these networks using the “actual” SUPI returned to it in the UE configuration/subscription data received from the remote provisioning system (box  116 ). 
       FIG.  8    is a flow diagram illustrating a method  120 , implemented at SMF  24 , for providing a UE  18  with remote provisioning information according to one embodiment of the present disclosure. As seen in  FIG.  8   , SMF  24  receives a session establishment request message from UE  18 , via AMF  22 , requesting to establish a PDU session for the UE  18  to a DNN (box  122 ). As previously stated, the DNN may comprise one or more of a default DNN, a DNN for a packet data network, a DNN for remote provisioning in the NPN, and a DNN for the SNPN  20 . Once received, SMF  24  obtains the remote provisioning information for the UE  18  (box  124 ). In one embodiment, the remote provisioning information, which is associated with SNPN  20 , is received in UDM subscription information obtained from the UDM. 
     Next, SMF  24  will determine whether the UE  18  is using a temporary SUPI or its assigned SUPI (box  126 ). Such a determination may be made, for example, based on the SUPI that the UE  18  provided in the session establishment request message. If the UE  18  is using a temporary SUPI, SMF  24  sends a session establishment accept message to the UE including the remote provisioning information it obtained from the UDM  26  (box  130 ). If the UE  18  is using its actual SUPI, however (box  126 ), SMF  24  will determine whether the remote provisioning information is to be sent to the UE  18  (box  128 ). This determination can be based on triggering information received by SMF  24  in the subscription information obtained from the UDM  26 . In one embodiment, the triggering information comprises eSIM enabling information. 
     If the triggering information does not indicate that the remote provisioning information should be sent to the UE  18  (box  128 ), method  120  ends. However, if the triggering information indicates that the remote provisioning information should be sent to the UE  18 , SMF  24  includes the remote provisioning information in the session establishment accept message and sends the message to the UE  18  (box  130 ). Regardless of the SUPI used by UE  18 , however, SMF  24  registers a context for the UE  18  in the UDM  26  (box  132 ). 
       FIGS.  9 A- 9 C  are flow diagrams illustrating a method  140 , implemented at UDM  26 , for providing an SMF with the remote provisioning information for the UE, and for creating and updating UE subscription data according to embodiments of the present disclosure. As seen in  FIG.  9 A , method  140  begins with the UDM  26  receiving a request from SMF  24  for session subscription information for the UE, wherein the request includes a UE identity (box  142 ). In response to the request, UDM  26  sends a response message to SMF  24  comprising the remote provisioning information to enable the UE to remotely provision an IMS subscription (box  144 ). 
     How UDM  26  processes the request depends on whether the UE  18  is using its actual, assigned SUPI or a temporary SUPI. Therefore, as seen in  FIG.  9 B , UDM  26  determines whether the UE identity received with the request is an “actual” SUPI for UE  18  or a temporary SUPI (box  146 ). If it is an actual SUPI, UDM  26  retrieves, based on the UE identity, a UE profile that includes the triggering information and the remote provisioning information for the UE (box  148 ). Then, based on the triggering information in the UE profile, UDM  26  determines that the remote provisioning information should be sent to the UE (box  150 ). So determined, UDM  26  sends the response comprising the remote provisioning information and the triggering information to SMF  24  for delivery to UE  18  (box  152 ). Thereafter, UDM  26  receives IMS subscription data for accessing an IMS network  14  associated with the SNPN  20  and for disabling the triggering information (box  154 ), and updates the UE profile based on the IMS subscription information to add IMS services to the UE profile and disables the triggering information (box  156 ). In one embodiment, updating the UE profile at the UDM includes adding a Data Network Name (DNN) of the IMS network and disabling the triggering information in the UE profile. 
       FIG.  9 C  continues method  140  for cases where the UE identity is the UE&#39;s  18  temporary SUPI. Particularly, UDM  26  retrieves, based on the UE identity, the UE profile including the remote provisioning information (box  158 ). In this embodiment, the remote provisioning information comprises eSIM subscription information for creating a subscription with the NPN access network  16  and core NPN  12 . The eSIM subscription information comprises, in one embodiment, eSIM entitlement server information and one or more eSIM Information Elements (IE). So retrieved, UDM  26  sends the remote provisioning information in the response to SMF  24  for delivery to UE  18  (box  160 ). 
     Thereafter, UDM  26  receives the access/core subscription data needed to create a UE subscription for the NPN access network  16  and core NPN  12 , which includes an actual SUPI for the UE  18 , and the IMS subscription data for accessing IMS network  14  (box  162 ). UDM  26  then creates the UE subscription for the NPN access network  16  and core NPN  12  at the UDM  26  based on the access/core subscription data and the IMS subscription data. In one embodiment, the UE subscription includes IMS subscription information for IMS services (box  164 ). 
     According to embodiments of the present disclosure, the remote provisioning information received by UE  18  can be utilized to provision UE access credentials for the IMS network  14  (e.g., the signaling diagrams of  FIGS.  10 - 11   ), or for both the SNPN  20  and the IMS network  14  (signaling flow diagram of  FIG.  12   ). 
     More particularly, in some embodiments, the UE  18  can be pre-configured with the remote provisioning information needed to access the eSIM Manager, or UE  18  can receive the remote provisioning information in a PDU Session Establishment Accept Response received from AMF  22 . To accomplish this function, one embodiment of the present disclosure provides a pre-defined DDN. The pre-defined DNN, referred to herein as a “RemoteProvisioning DNN,” is a dedicated DNN used only for remotely provisioning UE  18 . Not only does the pre-defined DNN enable UE  18  to interact with the eSIM Manager for purposes of onboarding (i.e., remote provisioning), but it also enables UE  18  to establish connectivity only with the remote provisioning system (i.e., user plane). Such interaction may be enforced by SMF  24  using policies that are either (1) pre-configured in the SMF  24 , or (2) included in an Information Element (IE) associated with the “RemoteProvisioning” DNN, or by using PCF  28 . 
     In some embodiments, the pre-defined “RemoteProvisioning” DNN is configured and stored at UE  18 . However, these are not the only functions for the “RemoteProvisioning” DNN. For example, based on the “RemoteProvisioning” DNN, the AMF  22  may be configured to select a particular SMF  24  that has been dedicated for provisioning. To select a particular SMF  24 , AMF  22  may use Network Repository Function (NRF) discovery procedures, or be locally configured for that purpose. An SMF  24  dedicated for remote provisioning of UE  18 , according to some embodiments, would register such a capability in the NRF as part of its profile. The AMF  22  may also be configured to use Domain Name Servers (DNS) for SMF selection purposes based on the pre-defined DNN. 
     Once the IMS access credentials are successfully provisioned in UE  18 , the “RemoteProvisioning” DNN may be removed from the DNN subscription list of UE  18 . Additionally, the IMS DNN can be inserted into the UE&#39;s DNN subscription list, if it is not already there. As in the previous embodiments, UE  18  initiates remote provisioning by requesting to establish a PDU session to the “RemoteProvisioning” DNN. 
     The information needed by UE  18  to interact with the eSIM Manager can be included in the UE Session Management Subscription data as a new IE associated with the pre-defined “RemoteProvisioning” DNN, or be pre-configured in the SMF  24 . In either case, the information is included in a PDU Session Establishment Accept Response message, and passed transparently to UE  18  via AMF  22 . In some optional embodiments, a network operator may pre-configure the remote provisioning information in UE  18 . In these latter cases, no remote provisioning information is returned to UE  18  in the PDU Session Establishment Accept Response message. 
     To enable the SNPN  20  to provision UE  18  with new IMS access credentials in the event of a change in the IMS provider, or due to other reasons, the SNPN provider, through administrative procedures, may remove the IMS DNN and may re-insert the “RemoteProvisioning” DNN if not there already. UDM issues a UE Update Procedure to request the UE to re-register and initiate onboarding. The network also releases the IMS PDU session if applicable. 
     As previously stated, the pre-defined DNN and the IMS DNN may, in some embodiments, be removed and/or added to the UE&#39;s DNN subscription list. However, with the present embodiments, this is not required. Maintaining one or both of the pre-defined “RemoteProvisioning” DNN and the IMS DNN in the DNN subscription list in the SNPN UE subscriber profile at all times, even after the UE credentials have been successfully downloaded, will not cause an issue if UE tried to download additional credentials. In such cases, the UE  18  will simply be denied for downloading the additional credentials. Further, a UE without valid IMS credentials will simply fail to register with the IMS network  14  even if UE  18  had already successfully established an IMS PDU session. This also applies in the event of a change in IMS providers from an old IMS provider to a new IMS provider. Specifically, credentials that were valid under the old IMS provider will not work with the new IMS provider. This facilitates the management of the UE profile in the SNPN. 
       FIG.  10    illustrates a signaling diagram  170  showing a call flow procedure for onboarding IMS credentials to UE  18  via remote provisioning using a pre-defined “RemoteProvisioning” DNN. 
     In this embodiment, it is assumed that UE  18  has already acquired the information it needs to access NPN access network  16  via the onboarding process (box  170 - 1 ). 
     In box  170 - 2 , UE  18  performs a 5GC registration in accordance with the procedures specified in 3GPP TS 23.502 V16.4.0: “Procedures for the 5G System (5GS); Stage 2” (Release 16) dated March 2020. 
     In box  170 - 3 , UE  18  initiates a PDN connection for the pre-defined “RemoteProvisioning” DNN in accordance with the procedures specified in 3GPP TS 23.502. In this embodiment, the pre-defined “RemoteProvisioning” DNN is pre-configured in the UE. 
     In line  170 - 4 , AMF  22  initiates an Nsf_PDUSession_CreateSMContext Request towards a selected SMF  24 . As previously described, AMF  22  may select a particular SMF  24  using Network Repository Function (NRF) discovery procedures, or it may be locally configured for this purpose, or it may use DNS. 
     In line  170 - 5 , SMF  24  fetches the session subscription related information. Based on the pre-defined “RemoteProvisioning” DNN, and if the UE is not pre-configured with the remote provisioning information, SMF  24  includes the remote provisioning information in a response to UE  18 . Particularly, SMF  24  is configured to include the remote provisioning information as transparent information transported to the UE in a PDU Session Accept response in cases where the remote provisioning information is pre-configured in the SMF  24 , or where the remote provisioning information is received from UDM  26 . In cases where the UE  18  is already pre-configured with the remote provisioning information, then SMF  24  will not include the remote provisioning information in the PDU Session Accept response sent to UE  18 . SMF  24  does, however, fetch the related policies and uses them to ensure that UE  18  will only initiate communication with the remote provisioning system. 
     In box  170 - 6 , the PDU Session Establishment Accept Response is tunneled to UE  18  via AMF  22 . In this embodiment, the PDU Session Establishment Accept Response message includes the remote provisioning related information that UE  18  needs to initiate remote provisioning (i.e., the UE  18  is not already pre-configured with the remote provisioning information). 
     In line  170 - 7 , the SMF registers the UE context in UDM. 
     In line  170 - 8 , the received remote provisioning information triggers the remote provisioning process in UE  18 . In embodiments where UE  18  is already pre-configured with the information, the remote provisioning information still triggers the remote provisioning process in UE  18 . 
     In box  170 - 9 , UE  18  initiates interaction with the remote provisioning system. The UE  18  includes the Information Elements (IEs) required by the remote provisioning system. Such information includes, but is not limited to, identity binding information that enables the IMS provider and the SNPN  20  to identify the same UE  18  for interaction between network nodes, such as the HSS  36 , for example, and the UDM  26 . By way of example only, a SUPI can be binding information. 
     In line  170 - 10 , UE  18  downloads eSIM data in accordance with the previously identified GMSA: “RSP Technical Specification” and “GSMA: “Remote Provisioning Architecture for embedded UICC Technical Specification Version.” 
     In box  170 - 11 , an eSIM manager associated with the IMS provider provisions a network node such as HSS  36  with the requisite provisioning information so that it can update the UE subscription. 
     In line  170 - 12 , the UDM  26  is informed that onboarding has been successfully completed. The UDM  26  then updates the UE subscription to add the IMS DNN. UDM  26  may perform other needed updates as well. By way of example, UDM  26  may remove the pre-defined “RemoteProvisioning” DNN. 
     In this embodiment, line  170 - 12  is optional. Nevertheless, SNPN  20  may provision the IMS DNN in the UE profile after line  170 - 12  or at any time. Such interaction with the IMS network  14  will be successful only if the IMS credentials have been successfully downloaded. 
     At this point, the remote provisioning procedure is complete. Thus, in box  170 - 13 , UE  18  can initiate an IMS PDN connection to establish an IMS PDU session. 
     In box  170 - 14 , UE  18  uses the eSIM credentials it received to initiate IMS procedures based on existing specifications 3GPP TS 23.228 V16.4.0 “IP Multimedia Subsystem (IMS); Stage 2 (Release 16)” dated March 2020. 
       FIG.  11    is a signaling diagram  180  illustrating a variant for the remote provisioning of the IMS access credentials via eSIM remote provisioning. In this embodiment, a new PDU Establishment Request type labelled “Onboarding” is introduced. Additionally, the pre-defined DNN is a dedicated DNN used specifically for onboarding. The pre-defined DNN can be configured in AMF  22 , or in UE  18 , and used for this new PDU Establishment Request Type. UEs authorized to perform onboarding will have this dedicated DNN in their DNN subscription list. The dedicated DNN for onboarding enables connectivity for the UE  18  only to the remote provisioning system. This aspect of the present embodiment is enforced through policies that are either (1) pre-configured in SMF  24 , or (2) included in an IE associated with the dedicated DNN, or by using the PCF. The AMF may select a special SMF dedicated for provisioning, based on the dedicated DNN. The AMF  22  may use NRF discovery procedures, or be locally configured, to perform these functions. An SMF  24  dedicated for provisioning would register such a capability in the NRF as part of its profile. The AMF  22  can also use DNS for SMF selection purposes based on the dedicated DNN. 
     Once the IMS access credentials are successfully provisioned in the UE  18 , the pre-defined dedicated DNN may be removed from the UE DNN subscription list. The new IMS DNN may then be added, if it is not already in the UE DNN subscription list. 
     As previously described, the information needed by the UE to interact with the eSIM Manager can be included in the UE Session Management Subscription data as a new IE associated with the dedicated DNN for onboarding, or it may be pre-configured in SMF  24 . In both cases, the remote provisioning information is included in the PDU Session Establishment Accept Response message and passed transparently to UE  18 . Optionally, in some embodiments, a network operator may pre-configure this information in the UE  18 . In these latter cases, no remote provisioning information will be returned to the UE  18  in the PDU Session Establishment Accept Response message. 
     To enable the SNPN  20  to provision UE  18  with new IMS access credentials, such as may be needed when the IMS provider changes (or due to other reasons), the SNPN  20  provider may remove the IMS DNN from the UE subscription list and re-insert the dedicated DNN into the UE subscription list for onboarding. In such embodiments, UDM  26  may be configured to issue a UE Update Procedure to request UE  18  to re-register and initiate onboarding. 
     As a variant of this embodiment, an internet DNN can be used for onboarding purposes. In these cases, the value of a new parameter—i.e., the PDU establishment Request type—is used to determine whether the internet DNN is used for eSIM remote provisioning or for regular use. Filters controlling internet DNN usage can be either pre-configured in the SMF or in IE associated with the internet DNN, or in the PCF and applied as needed. 
     Additionally, although the PDU Establishment Request type determines the usage of the filter, the PDU Establishment Request type, by itself, is not sufficient. Rather, an additional IE associated with the internet DNN is needed to enable the network to control whether the internet DNN is used for regular usage, or for eSIM remote provisioning, and ensure that the UE is performing the correct procedure. Once the IMS access credentials are successfully provisioned in UE  18 , the IMS DNN is added to the subscription list, provided that it is not already in that list, and the internet DNN is enabled for regular usage. 
     It should be noted that, according to the present disclosure, the internet DNN can also be used in situations where no new Establishment Request type is used, such as the procedure illustrated in signaling diagram  170  of  FIG.  10   , for example. In these cases, an additional IE associated with the internet DNN is used to enable the network to control whether the internet DNN is employed for regular usage or for onboarding and ensures that UE  18  performs the correct procedure accordingly. 
     To provision the UE with new IMS access credentials, in this aspect, the SNPN provider can simply enable, via administrative procedures, the remote provisioning IE associated with the internet DNN. Additionally, the SNPN provider may remove the IMS DNN. Such aspects may be performed, for example, whenever the IMS provider changes, or due to some other reason. Regardless, the UDM  26  issues a UE Update Procedure to request UE  18  to re-register and initiate onboarding. 
     As in the previous embodiment, maintaining a dedicated DNN, if one is used, in the UE subscription list for provisioning after successfully downloading the UE credentials will not cause an issue if the UE  18  tries to download additional credentials. In these cases, UE  18  will simply be denied to download the additional credentials. Similarly, maintaining the IMS DDN in the DNN subscription list in the SNPN UE subscriber profile at all times does not cause any undesirable issues. In these cases, a UE  18  without valid IMS credentials will simply fail to register with the IMS, even in cases where the UE has already successfully established an IMS PDU session. These aspects are also true in the event of a change from one IMS provider to a new IMS provider. In these situations, the old credentials will fail to work with the new IMS provider. This facilitates the UE profile management in the SNPN  20 . 
       FIG.  11    is a signaling diagram  180  illustrating a procedure for the onboarding of IMS credentials via remote provisioning using a new parameter—i.e., the PDU Establishment Request type—and a dedicated DNN described above. Most of the steps in  FIG.  11    (i.e.,  180 - 1 - 180 - 3 ,  180 - 6 - 180 - 11 ,  180 - 13 - 180 - 14 ) are the same as the corresponding steps in  FIG.  10   . Therefore, those steps are not described again. Rather, only those steps that are different are described below with respect to  FIG.  11   . 
     Particularly, in line  180 - 4 , SMF  24  performs the necessary checks to enable the appropriate use of the internet DNN. 
     In box  180 - 5 , the SMF  24  fetches the policies depending on the DNN used. 
     Box  180 - 12  is optional as it was box  170 - 12  in the previous embodiment when the dedicated DNN is used. However, if an internet DNN is used, box  180 - 12  is required to be performed to disable the eSIM provisioning IE element associated with the DNN. Additionally, the SNPN  20  will need to know the SUPI allocated to UE  18  so that UE  18  can de-register the temporary SUPI it used to establish the session, and re-register with the allocated SUPI. 
       FIG.  12    is a signaling diagram  190  illustrating an embodiment where the credentials provided to UE  18  are used to access both the SNPN access network  16  and the IMS network  14 . The call flow illustrated in  FIG.  12    is similar to signaling diagram  80  in  FIG.  5   . In this embodiment, the approaches previously described with respect to the options for including the required provisioning elements and the usage of the DNN, also apply to this embodiment. Thus, steps  190 - 1 - 190 - 10  and  190 - 12   190 - 13  are not described again in detail. 
     Note, however, that in the embodiment of  FIG.  12   , performing box  190 - 11  is not optional, as it is in the embodiments of  FIGS.  10    (i.e., box  170 - 12 ) and  11  (i.e., box  180 - 12 ). Rather, it is mandatory. This is because UE  18  will have de-registered the temporary SUPI it used to establish the session, and re-registered with the allocated SUPI. Thus, the SNPN  20  will need to know the SUPI allocated to UE  18  to create the correct UE subscription. 
     The embodiments described herein provide a simple method for allowing SNPN users to use an IMS network with only minor changes to the impacted nodes, and without requiring anything specific from the SNPNs. Further, the present embodiments advantageously provide such benefits without having to provision the IMS credentials in the UE device. 
       FIGS.  13 A- 13 C  are flow diagrams illustrating methods  200 ,  210 ,  220 , and  230 , respectively, implemented at a UE, for acquiring configuration/subscription data over an access/core network according to one embodiment of the present disclosure. 
     As seen in  FIG.  13 A  method  200  begins with UE  18  establishing a first Protocol Data Unit (PDU) session with a pre-defined Data Network Name (DNN) for remote provisioning (box  202 ). UE  18  then initiates a remote provisioning procedure over the first PDU session using remote provisioning information that enables the UE to access a remote provisioning system in the pre-defined DNN (box  204 ). UE  18  then receives, from the remote provisioning system, the UE configuration/subscription data. In this embodiment, the UE configuration/subscription data comprises Internet Protocol Multimedia Subsystem (IMS) subscription data for an IMS network associated with a Non-Public Network (NPN). Responsive to determining that a connection to the IMS network associated with the NPN is required, UE  18  establishes a second PDU session with the IMS network  14  using the IMS subscription data. 
       FIG.  13 B  illustrates a method  210  in which UE  18  establishes a first Protocol Data Unit (PDU) session with the remote provisioning Data Network Name (DNN). In one embodiment, UE  18  sends, to a network node, a PDU session establishment request message including the pre-defined DNN (box  212 ). In another embodiment, however, UE  18  sends, to a network node, a PDU session establishment request message including a pre-defined PDU session establishment request type used for remote provisioning of the UE  18  (box  214 ). In either case, UE  18  receives a PDU Establishment Accept message that may include the remote provisioning information (box  216 ). 
       FIG.  13 C  is a flow diagram illustrating a method  230  implemented at UE  18  gaining access to both the SNPN access network  16  and the IMS network  14  using the credentials received with the remote provisioning information. As seen in  FIG.  13 D , method  230  begins with UE  18  sending a provisioning request to the remote provisioning system over the first PDU session (box  232 ). In this aspect, as previously described, the provisioning request includes, inter alia, identity binding information that enables both the IMS provider and the SNPN  20  to identify the same UE binding identifier. In response to the provisioning request, UE  18  receives provisioning/subscription information that enables the UE  18  to access the IMS network  14  via a 5GS network (e.g., SNPN  20  and SNPN access network  16 ) (box  234 ). So received, UE  18  can de-register from the access/core network using the temporary SUPI (box  236 ), and register with the access/core network using the SUPI assigned to UE  18  (box  238 ). 
       FIG.  14    is a flow diagram illustrating a method  240 , implemented at SMF  24 , for providing UE  18  with remote provisioning information according to one embodiment of the present disclosure. In some embodiments, SMF  24  is dedicated for provisioning purposes and is selected by AMF  22 . To accomplish selection, AMF  22  may be locally configured to select SMF  24 , or it may use NRF discovery procedures. In such cases, SMF  24  would have registered its capabilities in the NRF as part of its profile. 
     As seen in  FIG.  14   , SMF  24  receives, from UE  18  via AMF  22 , a request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN) (box  242 ). In this embodiment, the request message includes pre-defined triggering information, such as a pre-defined DNN, a session establishment request type, an internet DNN, and the like. SMF  24  then obtains, for UE  18 , remote provisioning information associated with the SNPN  20  (box  244 ). SMF  24  also obtains information associated with the one of the pre-defined DNN and the internet DNN (box  246 ) and, responsive to obtaining a packet filter, selects and configures a UPF for the PDU session based on the DNN and the packet filter (box  248 ). SMF  24  then sends a session establishment accept message to the UE (box  249 ). In this aspect, the session establishment accept message may include the remote provisioning information. 
       FIG.  15    is a flow diagram illustrating a method  250  for providing UE  18  with remote provisioning information according to one embodiment of the present disclosure. In this embodiment, method  250  is implemented at an Access and Mobility Management Function (AMF), such as AMF  22 . 
     As seen in  FIG.  15   , AMF  22  receives, from UE  18  in SNPN  20 , a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN) (box  252 ). In this aspect, the session establishment request message includes pre-defined triggering information, such as a pre-defined DNN, a session establishment request type, an internet DNN, and the like. AMF  22  then selects an SMF  24  (box  254 ) and sends an Nsmf_PDUSession_CreateSMContext Request message to the selected SMF  24  (box  256 ). As stated above, AMF  22  may be locally configured to select SMF  24 , or it may use NRF discovery procedures. In these latter situations, SMF  24  would have registered its capabilities in the NRF as part of its profile. Thereafter, AMF  22  may receive, from SMF  24 , a response message (box  258 ). In this aspect, the response message may include the remote provisioning information for UE  18  to use to initiate the remote provisioning procedure. AMF  22  then forwards the response message received from SMF  24  transparently to UE  18  (box  260 ). As stated previously, an information element (IE) of the response message received from SMF  24  may include the remote provisioning information. 
       FIG.  16    is a flow diagram illustrating a method  270 , implemented at UDM  26 , for providing SMF  24  with the remote provisioning information for UE  18  according to embodiments of the present disclosure. In some embodiments, depending on the pre-configured DNN, UDM  26  may also be configured with additional information used to control the usage of the pre-configured DNN by UE  18 . Particularly, as seen in  FIG.  16   , UDM  26  receives a request for session subscription information for the UE (box  272 ). In this aspect, the request includes a UE identity. In reply to the received request, UDM  26  sends a response that includes the remote provisioning information and other needed information. This information enables UE  18  to remotely provision a UE subscription for a 5GS network (e.g., SNPN  20 ) and an IMS network (e.g., IMS network  14 ). Thereafter, UDM  26  can be configured to remove the pre-defined DNN from a DNN subscription list of the UE, and insert an IMS DNN for the IMS network into the DNN subscription list of the UE (box  276 ). Thereafter, responsive to a change of an IMS provider, UDM  26  may also remove the IMS DNN from the DNN subscription list of the UE, and re-insert the pre-defined DNN into the DNN subscription list of the UE (box  278 ). 
     An apparatus can perform any of the methods herein described by implementing any functional means, modules, units, or circuitry. In one embodiment, for example, the apparatuses comprise respective circuits or circuitry configured to perform the steps shown in the method figures. The circuits or circuitry in this regard may comprise circuits dedicated to performing certain functional processing and/or one or more microprocessors in conjunction with memory. For instance, the circuitry may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory may include program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the methods described herein, in several embodiments. In embodiments that employ memory, the memory stores program code that, when executed by the one or more processors, carries out the methods described herein. 
       FIG.  17   , for example, is a block diagram of some functional components of a UE  18  configured according to one embodiment of the present disclosure. The UE  18  can be configured to implement the signaling procedures and methods as herein described and comprises processing circuitry  280 , memory  282 , and communications circuitry  286 . 
     The communication circuitry  286  comprises interface circuitry for communicating with other core network nodes in SNPN  20  via NPN access network  16 . Processing circuitry  280  controls the overall operation of the UE  18  and is configured to implement the procedures shown in  FIGS.  7 A- 7 B  and in  FIGS.  13 A- 13 D . The processing circuitry  280  may comprise one or more microprocessors, hardware, firmware, or a combination thereof configured to perform method  100  shown in  FIGS.  7 A- 7 B . 
     Memory circuitry  282  comprises both volatile and non-volatile memory for storing computer program code and data needed by the processing circuitry  280  for operation. Memory circuitry  282  may comprise any tangible, non-transitory computer-readable storage medium for storing data including electronic, magnetic, optical, electromagnetic, or semiconductor data storage. Memory circuitry  282  stores a computer program  284  comprising executable instructions that configure the processing circuitry  280  to implement methods  100 ,  200 ,  210 ,  220 , and  230  shown in  FIGS.  7 A- 7 B and  13 A- 13 B . A computer program in this regard may comprise one or more code modules corresponding to the means or units described above. In general, computer program instructions and configuration information are stored in a non-volatile memory, such as a ROM, erasable programmable read only memory (EPROM) or flash memory. Temporary data generated during operation may be stored in a volatile memory, such as a random access memory (RAM). In some embodiments, computer program  284  for configuring the processing circuitry  280  as herein described may be stored in a removable memory, such as a portable compact disc, portable digital video disc, or other removable media. The computer program  284  may also be embodied in a carrier such as an electronic signal, optical signal, radio signal, or computer readable storage medium. 
       FIG.  18    illustrates a computer program product, such as computer program  284 , executing on the processing circuitry  280  of UE  18  according to one embodiment of the present disclosure. As seen in  FIG.  18   , computer program  284  comprises a communications module/unit  290 , a remote provisioning initiation module/unit  292 , a PDU session establishment module/unit  294 , and a registration/deregistration module/unit  296 . 
     The communications module/unit  290  is configured to send and receive messages to core NPN  12  and IMS network  14  via NPN access network  16 , as previously described. The remote provisioning initiation module/unit  292  is configured to determine that a remote provisioning procedure should be performed, and in response, initiate that remote provisioning procedure, as previously described. The PDU session establishment module/unit  294  is configured to establish PDU sessions with the core NPN  12  and IMS network  14 , as previously described. The registration/deregistration module/unit  296  is configured to deregister and reregister UE  18  from NPN access network  16 , as previously described. 
       FIG.  19    is a block diagram of some functional components of an SMF  24  configured according to one embodiment of the present disclosure. The SMF  24  can be configured to implement the signaling procedures and methods as herein described and comprises processing circuitry  300 , memory circuitry  302 , and communications circuitry  306 . 
     The communication circuitry  306  comprises interface circuitry for communicating with other core network nodes in SNPN  20 , such as AMF  22  and UDM  26 . Processing circuitry  300  controls the overall operation of the SMF  24  and is configured to implement the procedures shown in  FIG.  8    and in  FIG.  14   . The processing circuitry  300  may comprise one or more microprocessors, hardware, firmware, or a combination thereof configured to perform method  120  shown in  FIG.  8    and method  240  in  FIG.  14   . 
     Memory circuitry  302  comprises both volatile and non-volatile memory for storing computer program code and data needed by the processing circuitry  300  for operation. Memory circuitry  302  may comprise any tangible, non-transitory computer-readable storage medium for storing data including electronic, magnetic, optical, electromagnetic, or semiconductor data storage. Memory circuitry  302  stores a computer program  304  comprising executable instructions that configure the processing circuitry  300  to implement methods  120  and  240  shown in  FIGS.  8  and  14   , respectively. A computer program in this regard may comprise one or more code modules corresponding to the means or units described above. In general, computer program instructions and configuration information are stored in a non-volatile memory, such as a ROM, erasable programmable read only memory (EPROM) or flash memory. Temporary data generated during operation may be stored in a volatile memory, such as a random access memory (RAM). In some embodiments, computer program  304  for configuring the processing circuitry  300  as herein described may be stored in a removable memory, such as a portable compact disc, portable digital video disc, or other removable media. The computer program  304  may also be embodied in a carrier such as an electronic signal, optical signal, radio signal, or computer readable storage medium. 
       FIG.  20    illustrates a computer program product, such as such as computer program  304 , executing on the processing circuitry  300  of an SMF  24  according to one embodiment of the present disclosure. As seen in  FIG.  20   , computer program  304  comprises a communications module/unit  310 , an information obtaining module/unit  312 , and a provisioning execution determination module/unit  314 . The communications module/unit  310  is configured to communicate messages with other network node in SNPN  20 , such as the AMF  22  and the UDM  26 , as previously described. The information obtaining module/unit  312  is configured to obtain the remote provisioning information from UDM  26  to send to UE  18 , as previously described. The provisioning execution module/unit  314  is configured to determine whether the UE  18  should execute a remote provisioning procedure, and if so, pass the remote provisioning information obtained from UDM  26  to the UE  18 , as previously described. 
       FIG.  21    is a block diagram of some functional components of UDM  26  configured according to one embodiment of the present disclosure. The UDM  26  can be configured to implement the signaling procedures and methods as herein described and comprises processing circuitry  320 , memory circuitry  322 , and communications circuitry  326 . 
     The communication circuitry  326  comprises interface circuitry for communicating with other core network nodes in SNPN  20  and IMS network  14 , such as SMF  24  and HSS  36 . Processing circuitry  320  controls the overall operation of the UDM  26  and is configured to implement the procedures shown in  FIGS.  9 A- 9 C  and in  FIG.  15   . The processing circuitry  320  may comprise one or more microprocessors, hardware, firmware, or a combination thereof configured to perform method  140  shown in  FIGS.  9 A- 9 C and  15   . 
     Memory circuitry  322  comprises both volatile and non-volatile memory for storing computer program code and data needed by the processing circuitry  320  for operation. Memory circuitry  322  may comprise any tangible, non-transitory computer-readable storage medium for storing data including electronic, magnetic, optical, electromagnetic, or semiconductor data storage. Memory circuitry  322  stores a computer program  324  comprising executable instructions that configure the processing circuitry  320  to implement method  140  shown in  FIGS.  9 A- 9 C , and method  250  shown in  FIG.  15   . A computer program in this regard may comprise one or more code modules corresponding to the means or units described above. In general, computer program instructions and configuration information are stored in a non-volatile memory, such as a ROM, erasable programmable read only memory (EPROM) or flash memory. Temporary data generated during operation may be stored in a volatile memory, such as a random access memory (RAM). In some embodiments, computer program  324  for configuring the processing circuitry  320  as herein described may be stored in a removable memory, such as a portable compact disc, portable digital video disc, or other removable media. The computer program  324  may also be embodied in a carrier such as an electronic signal, optical signal, radio signal, or computer readable storage medium. 
       FIG.  22    illustrates a computer program product, such as such as computer program  324 , executing on the processing circuitry  320  of UDM  26  according to one embodiment of the present disclosure. As seen in  FIG.  22   , computer program  324  comprises a communications module/unit  330 , a provisioning information providing determination module/unit  332 , an information obtaining module/unit  334 , and a UE subscription update/creation module/unit  336 . 
     The communications module/unit  330  is configured to communicate messages with other network nodes in SNPN  20 , such as the SMF  24  and other nodes in IMS network  14 , as previously described. The provisioning information providing determination module/unit  332  is configured to determine, based on triggering information, whether the UE should initiate the remote provisioning process, as previously described. The information obtaining module/unit  334  is configured to obtain the remote provisioning information to send to the SMF  24 , as previously described. The UE subscription update/creation module/unit  336  is configured to create a new UE profile, or update an existing UE profile, as previously described. Additionally, the UE subscription update/creation module/unit  336  is also configured to disable the triggering information at the UDM  26 , as previously described. 
       FIG.  23    is a block diagram of some functional components of AMF  22  configured according to one embodiment of the present disclosure. The AMF  22  can be configured to implement the signaling procedures and methods as herein described and comprises processing circuitry  340 , memory circuitry  342 , and communications circuitry  346 . 
     The communication circuitry  346  comprises interface circuitry for communicating with other core network nodes in SNPN  20  and IMS network  14 , such as SMF  24 , and with UE  18 . Processing circuitry  340  controls the overall operation of the UDM  26  and is configured to implement the procedures shown in  FIG.  16   . The processing circuitry  340  may comprise one or more microprocessors, hardware, firmware, or a combination thereof configured to perform method  270  shown in  FIG.  16   . 
     Memory circuitry  342  comprises both volatile and non-volatile memory for storing computer program code and data needed by the processing circuitry  340  for operation. Memory circuitry  342  may comprise any tangible, non-transitory computer-readable storage medium for storing data including electronic, magnetic, optical, electromagnetic, or semiconductor data storage. Memory circuitry  340  stores a computer program  344  comprising executable instructions that configure the processing circuitry  340  to implement method  270  shown in  FIG.  16   . A computer program in this regard may comprise one or more code modules corresponding to the means or units described above. In general, computer program instructions and configuration information are stored in a non-volatile memory, such as a ROM, erasable programmable read only memory (EPROM) or flash memory. Temporary data generated during operation may be stored in a volatile memory, such as a random access memory (RAM). In some embodiments, computer program  344  for configuring the processing circuitry  340  as herein described may be stored in a removable memory, such as a portable compact disc, portable digital video disc, or other removable media. The computer program  344  may also be embodied in a carrier such as an electronic signal, optical signal, radio signal, or computer readable storage medium. 
       FIG.  24    illustrates a computer program product, such as such as computer program  344 , executing on the processing circuitry  340  of AMF  22  according to one embodiment of the present disclosure. As seen in  FIG.  24   , computer program  344  comprises a communications module/unit  350 , and an SMF selection module/unit  352 . 
     The communications module/unit  350  is configured to communicate messages with UE  18 , as well as with other network nodes, such as those in SNPN  20  (e.g., SMF  24 ) and in IMS network  14 , as previously described. The SMF selection module/unit  352  is configured to select an SMF  24  that may be particularly configured for remote provisioning of the UE  18 , as previously described. 
     The present embodiments may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the embodiments. For example, in addition to the previously described aspects, one aspect of the present disclosure provides a method of acquiring User Equipment (UE) configuration/subscription data over an access/core network is provided. The method implemented by a UE and comprises sending, to a network node, a PDU session establishment request message to establish a first Protocol Data Unit (PDU) session to a Data Network Name (DNN), receiving, from the network node, a PDU session establishment accept message comprising remote provisioning information to access a remote provisioning system associated with a Non-Public Network (NPN), initiating a remote provisioning procedure (also referred to herein as an “onboarding” procedure) over the first PDU session using the remote provisioning information, receiving, from the remote provisioning system, the UE configuration/subscription data, wherein the UE configuration/subscription data comprises Internet Protocol Multimedia Subsystem (IMS) subscription data for an IMS network associated with the NPN, and responsive to determining that a connection to the IMS network associated with the NPN is required, establishing a second PDU session with the IMS network using the IMS subscription data. 
     In another aspect, the disclosure provides a User Equipment (UE) comprising communications circuitry and processing circuitry. The communications circuitry is configured to communicate with one or more network nodes. The processing circuitry operatively connected to the communications circuitry and configured to send, to a network node, a PDU session establishment request message to establish a first Protocol Data Unit (PDU) session to a Data Network Name (DNN), receive, from the network node, a PDU session establishment accept message comprising remote provisioning information to access a remote provisioning system associated with a Non-Public Network (NPN), initiate a remote provisioning procedure over the first PDU session using the remote provisioning information, receive, from the remote provisioning system, the UE configuration/subscription data, wherein the UE configuration/subscription data comprises Internet Protocol Multimedia Subsystem (IMS) subscription data for an IMS network associated with the NPN, and responsive to determining that a connection to the IMS network associated with the NPN is required, establish a second PDU session with the IMS network using the IMS subscription data. 
     Additionally, in one aspect, the present disclosure provides a non-transitory computer-readable medium storing a computer program thereon. The computer program comprises instructions that, when executed by processing circuitry of a User Equipment (UE), causes the UE to send, to a network node, a PDU session establishment request message to establish a first Protocol Data Unit (PDU) session to a Data Network Name (DNN), receive, from the network node, a PDU session establishment accept message comprising remote provisioning information to access a remote provisioning system associated with a Non-Public Network (NPN), initiate a remote provisioning procedure over the first PDU session using the remote provisioning information, receive, from the remote provisioning system, the UE configuration/subscription data, wherein the UE configuration/subscription data comprises Internet Protocol Multimedia Subsystem (IMS) subscription data for an IMS network associated with the NPN, and responsive to determining that a connection to the IMS network associated with the NPN is required, establish a second PDU session with the IMS network using the IMS subscription data. 
     In another aspect, the present disclosure provides a computer program comprising executable instructions that, when executed by a by processing circuitry of a User Equipment (UE), causes the UE to send, to a network node, a PDU session establishment request message to establish a first Protocol Data Unit (PDU) session to a Data Network Name (DNN), receive, from the network node, a PDU session establishment accept message comprising remote provisioning information to access a remote provisioning system associated with a Non-Public Network (NPN), initiate a remote provisioning procedure over the first PDU session using the remote provisioning information, receive, from the remote provisioning system, the UE configuration/subscription data, wherein the UE configuration/subscription data comprises Internet Protocol Multimedia Subsystem (IMS) subscription data for an IMS network associated with the NPN, and responsive to determining that a connection to the IMS network associated with the NPN is required, establish a second PDU session with the IMS network using the IMS subscription data. 
     In some aspects, the present disclosure provides a carrier containing a computer program according to the fourth aspect. The carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium. 
     In some aspects, the present disclosure provides a method performed by a Session Management Function (SMF) node. The method comprises receiving, from a User Equipment, a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), obtaining, for the UE, remote provisioning information associated with a Non Public Network (NPN), and sending a session establishment accept message to the UE, wherein the session establishment accept message comprises the remote provisioning information associated with the NPN. 
     In one aspect, the disclosure provides a network node configured to operate as a Session Management Function (SMF). In this aspect, the network node comprises communications circuitry and processing circuitry. The communications circuitry is configured to communicate with one or more network nodes. The processing circuitry is operatively connected to the communications circuitry and configured to receive, from a User Equipment, a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), obtain, for the UE, remote provisioning information associated with a Non Public Network (NPN), and send a session establishment accept message to the UE, wherein the session establishment accept message comprises the remote provisioning information associated with the NPN. 
     In another, the disclosure provides a non-transitory computer-readable medium storing a computer program thereon. The computer program comprises instructions that, when executed by processing circuitry of a Session Management Function (SMF) node, causes the SMF to receive, from a User Equipment, a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), obtain, for the UE, remote provisioning information associated with a Non Public Network (NPN), and send a session establishment accept message to the UE, wherein the session establishment accept message comprises the remote provisioning information associated with the NPN. 
     In yet another, the disclosure provides a computer program comprising executable instructions that, when executed by a by processing circuitry of a Session Management Function (SMF) node, causes the SMF to receive, from a User Equipment, a session establishment request message requesting to establish a Protocol Data Unit (PDU) session for the UE to a Data Network Name (DNN), obtain, for the UE, remote provisioning information associated with a Non Public Network (NPN), and send a session establishment accept message to the UE, wherein the session establishment accept message comprises the remote provisioning information associated with the NPN. 
     In some aspects, the disclosure provides a carrier containing a computer program according to the ninth aspect, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium. 
     In one aspect, the disclosure provides a method for providing User Equipment (UE) subscription data associated with a Non-Public Network (NPN). The method is implemented by a Unified Data Management (UDM) node and comprises receiving a request for session subscription information for the UE, wherein the request includes a UE identity, and sending, in reply to the request, a response comprising the remote provisioning information to enable the UE to remotely provision an IMS subscription. 
     In another aspect, the disclosure provides a network node configured to operate as a Unified Data Management (UDM) node. The network node comprises communications circuitry and processing circuitry. The communications circuitry is configured to communicate with one or more nodes in the NPN network and in an Internet Protocol (IP) Multimedia Subsystem (IMS) network. The processing circuitry is operatively connected to the communications circuitry and configured to receive a request for session subscription information for the UE, wherein the request includes a UE identity, and send, in reply to the request, a response comprising the remote provisioning information to enable the UE to remotely provision an IMS subscription. 
     In some aspects, the disclosure provides a non-transitory computer-readable medium storing a computer program thereon. The computer program comprises instructions that, when executed by processing circuitry of a Unified Data Management (UDM) node, causes the UDM node to receive a request for session subscription information for the UE, and send, in reply to the request, a response comprising the remote provisioning information for the UE. 
     In one aspect, the disclosure provides a computer program comprising executable instructions that, when executed by a by processing circuitry of a Unified Data Management (UDM) node, causes the UDM to receive a request for session subscription information for the UE, and send, in reply to the request, a response comprising the remote provisioning information for the UE. 
     In another aspect, the disclosure provides a carrier containing a computer program according to the fourteenth aspect, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium. 
     Therefore, the present embodiments are therefore to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended embodiments are intended to be embraced therein.