SNPN selection and registration procedure

Abstract

A method for a user equipment (UE) to access an independent non-public network (SNPN) includes registering to a first SNPN and determining whether to initiate a mobility registration update, or performing a registration procedure of local de-registration from the first SNPN and initiating an initial registration for a second SNPN. The UE supports access to the SNPN using credentials from a credential holder, and / or the first SNPN and the second SNPN are equivalent SNPNs.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 487,631, filed on March 1, 2023, the content of which is incorporated herein by reference. Technical field

[0003] The present invention relates to communication systems, and more particularly to the registration process of a Stand - alone Non - Public Network (SNPN). Background art

[0004] A Public Land Mobile Network (PLMN) is a network established and operated by an administrative authority or a recognized operating agency (ROA) for the specific purpose of providing land mobile communication services to the public. The PLMN provides communication possibilities for mobile users. The PLMN can provide services in one frequency band or a combination of multiple frequency bands. Access to PLMN services is achieved through an air interface, which involves wireless communication between a mobile phone with integrated IP network services and a base station. A PLMN can include multiple radio access networks (RANs) that utilize different radio access technologies (RATs) to access mobile services. A radio access network is part of a mobile communication system that implements a radio access technology. Conceptually, the RAN resides between mobile devices and provides a connection to its core network (CN). According to this standard, mobile phones and other wirelessly connected devices are variously referred to as user equipment (UE) (i.e., MS), terminal equipment (TE), mobile station (MS) (i.e., UE), mobile termination (MT), etc. Examples of different RATs include 2G GERAN (GSM) access network, 3G UTRAN (UMTS) radio access network, 4G E - UTRAN (LTE), 5G new radio (NR) radio access network, Next - Generation RAN (NG - RAN), and other non - 3GPP access RATs including Wi - Fi.

[0005] A non-public network (NPN) is a network for non-public use, as compared to a PLMN. An SNPN is a Stand-alone Non-Public Network, i.e., it is operated by an NPN operator and does not rely on network functions provided by a PLMN; or a Public Network Integrated NPN (PNI-NPN), i.e., a non-public network deployed with the support of a PLMN. A Credentials Holder (CH) can authenticate and authorize access to an SNPN that is separate from the Credentials Holder. A combination of a PLMN ID and a Network Identifier (NID) identifies an SNPN. A UE can be supported for an SNPN.

[0006] A PNI-NPN is an NPN that becomes available via a PLMN, e.g., by means of a dedicated DNN or through one or more network slice instances allocated to the NPN. When a PNI-NPN is made available via a PLMN, the UE shall have a subscription to the PLMN to access the PNI-NPN. Since network slicing cannot prevent a UE from attempting to access the network in an area where the UE is not permitted to use the network slice allocated for the NPN, a Closed Access Group (CAG) can be used to apply access control for the PNI-NPN. A CAG identifies a group of subscribers who are permitted to access one or more CAG cells associated with the CAG. The CAG is used for the PNI-NPN to prevent UEs that are not permitted to access the NPN via the associated cells from automatically selecting and accessing the associated CAG cells. The CAG is used for access control, e.g., authorization during cell selection, and is configured in the subscription as part of mobility restrictions. The CAG is identified by a CAG identifier that is uniquely unique within the PLMN ID range.

[0007] A local or localized service is a localized service (e.g., provided in a specific / limited area and / or bounded in time). A localized service provider is an application provider or network operator that localizes its service and provides it to end-users via a hosted network. A hosted network is a network that provides access to a localized service, and the hosted network can be an SNPN or a PNI-NPN, and the home network is the network that owns the current usage subscription or credentials of the UE. The home network can be the home PLMN or the subscribed SNPN. An end-user can allow or prohibit access to a localized service. If the end-user prohibits access to a localized service, the UE (i.e., the MS) cannot access the NPN that provides access to the localized service.

[0008] To provide the User Equipment (UE) with access to localized services, the UE needs to be able to discover, select, and access the NPN that provides access to the localized services (as the home network). Summary of the Invention

[0009] One embodiment provides a method for a User Equipment (UE) to access a Standalone Non-Public Network (SNPN). The method includes: registering to a first SNPN, and determining whether to initiate a mobility registration update, or performing a local deregistration from the first SNPN and initiating a registration process for an initial registration to a second SNPN. The UE supports accessing the SNPN using credentials from a credential holder, and / or the first SNPN and the second SNPN are equivalent SNPNs.

[0010] One embodiment provides a User Equipment (UE) that includes one or more processors. The UE is configured to determine whether to initiate a mobility registration update, or perform a local deregistration from a first SNPN and initiate a registration process for an initial registration to a second SNPN. The UE supports accessing the SNPN using credentials from a credential holder, and / or the first SNPN and the second SNPN are equivalent SNPNs.

[0011] After reading the following detailed description of the preferred embodiments shown in the various figures, these and other objects of the present invention will no doubt become apparent to those skilled in the art. Brief Description of the Drawings

[0012] Figure 1 Schematically shows a communication system with a PLMN, an SNPN, and a PNI-NPN according to a novel aspect, where the PNI-NPN supports (homes) the network and cell selection for localized services.

[0013] Figure 2 Illustrates a simplified block diagram of a user equipment and a network entity according to an embodiment of the present invention.

[0014] Figure 3A Illustrates a first embodiment of a 5G system architecture for accessing an SNPN using credentials from a credential holder.

[0015] Figure 3B Illustrates a second embodiment of a 5G system architecture for accessing an SNPN using credentials from a credential holder.

[0016] Figure 4 Illustrates an example of an NG-RAN pattern for broadcasting certain information to provide access to an SNPN.

[0017] Figure 5AIllustrates an example of an SNPN-capable UE configured with 2 SNPN subscriptions (i.e., 2 subscriptions of SNPN in the "Subscriber Data List").

[0018] Figure 5B Illustrates an example of an SNPN-capable UE configured with 2 PLMN subscriptions (i.e., 2 USIMs).

[0019] Figure 6 Illustrates network selection in the SNPN access mode with automatic SNPN network selection and manual SNPN network selection.

[0020] Figure 7A Illustrates a first embodiment of network and cell selection and access control for CAG cells of PNI-NPN (CAG), where access to the CAG cell is accepted.

[0021] Figure 7B Illustrates a second embodiment of network and cell selection and access control for non-CAG cells (public cells), where access to the PLMN is accepted.

[0022] Figure 8A Illustrates a first embodiment of network and cell selection and access control for CAG cells of PNI-NPN (CAG), where access to the CAG cell is rejected.

[0023] Figure 8B Illustrates a second embodiment of network and cell selection and access control for non-CAG cells (public cells), where access to the PLMN is rejected.

[0024] Figure 9A Illustrates an example where a UE uses validity information to discover, select, and access an NPN (as a home network) that provides access for localized services.

[0025] Figure 9B Illustrates another example where a UE uses validity information associated with an SNPN to discover, select, and access an NPN (as a home network) and receive localized services.

[0026] Figure 9C Illustrates different examples of UEs that use validity information associated with the CAG of a (PLMN) to discover, select, and access an NPN (as a home network) and receive localized services.

[0027] Figure 10A Illustrates a first example of accessing an SNPN (as a home network) that provides access for localized services, where access is accepted.

[0028] Figure 10BIllustrates a second example of accessing an SNPN (as a managed network) that provides access for a localized service, where the access is denied.

[0029] Figure 11A Illustrates a first example of accessing a PNI-NPN / CAG (as a managed network) that provides access for a localized service, where the access is accepted.

[0030] Figure 11B Illustrates a second example of accessing a PNI-NPN / CAG (as a managed network) that provides access for a localized service, where the access is denied.

[0031] Figure 12 Illustrates an embodiment in which a UE receives an updated CAG-related configuration via a CAG cell, enters a LIMITED-SERVICE state, and searches for a suitable cell in the current network.

[0032] Figure 13 Illustrates another embodiment in which a UE receives an updated CAG-related configuration via a CAG cell, enters a LIMITED-SERVICE state, and searches for a suitable cell in the current network.

[0033] Figure 14 Illustrates an embodiment in which, when a UE does not have an emergency PDU session, the UE receives an updated CAG-related configuration via a CAG cell, enters a PLMN-SEARCH state, and applies a network selection process.

[0034] Figure 15 Illustrates an embodiment in which a UE receives an updated CAG-related configuration via a non-CAG cell, enters a LIMITED-SERVICE state, and searches for a suitable cell in the current network.

[0035] Figure 16 Illustrates another embodiment in which a UE receives an updated CAG-related configuration via a non-CAG cell, enters a PLMN-SEARCH state, and applies a network selection process.

[0036] Figure 17 Shows an embodiment of a communication system 1700 having an SNPN. Detailed Description

[0037] In the following detailed description, in order to assist in a comprehensive understanding of the present disclosure, numerous specific details are set forth. However, those skilled in the art should understand that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits are not described in detail to avoid obscuring the present disclosure. It should be understood that the present disclosure is mainly described in the context of wireless networks specified by 3GPP (such as 4G and 5G), but may also be implemented in other forms of cellular or non-cellular wireless networks.

[0038] For terms and technologies not specifically described, reference may be made to wireless communication standard documents previously published in this case (such as 3GPP specifications).

[0039] Figure 1 A communication system 100 according to a novel aspect is schematically illustrated, which has a PLMN 110, a stand-alone SNPN 120, and a PNI-NPN / CAG 130, and the public network integrated NPN / CAG 130 provides access for localized services. The PLMN network 110 includes control plane functions, user plane functions (e.g., UPF), and applications that provide various services by communicating with a plurality of UEs including the UE 101. The serving base station gNB 112 belongs to a part of the radio access network RAN 140. The RAN 140 provides radio access for the UE 101 via a RAT. The access and mobility management function (AMF) in the PLMN 110 communicates with the gNB 112. The UE 101 may be equipped with a radio frequency (RF) transceiver or a plurality of RF transceivers.

[0040] The SNPN network 120 includes control plane functions, user plane functions (e.g., UPF), and applications that provide various services by communicating with multiple UEs including UE 101. The combination of the PLMN ID and the NID identifies the SNPN. The serving base station gNB 122 is part of the RAN 150. The RAN 150 provides radio access to the UE 101 via the RAT. The AMF in the SNPN 120 communicates with the gNB 122. The SNPN 120 is operated by the NPN operator and relies on network functions provided by the public network. The Credential Holder (CH) can authenticate and authorize access to the SNPN that is separate from the Credential Holder. The NG-RAN node that provides access to the SNPN broadcasts the following information: one or more PLMN IDs and a list (123) of NIDs of the non-public network for which the NG-RAN provides access per PLMN ID. The UE that supports the SNPN is configured with the PLMN ID and the NID (SNPN ID) of the subscribed SNPN, and the UE that supports the SNPN and uses the credentials from the Credential Holder to access the SNPN can be additionally configured with information (102) for SNPN selection (SNPN selection information or configuration) and registration (in the SNPN access mode) using the SNPN subscription or the PLMN subscription (USIM).

[0041] The PNI-NPN (CAG) network 130 includes control plane functions (optionally, which can rely on the control plane functions of the PLMN), user plane functions (optionally, which can rely on the user plane functions of the PLMN), and applications that provide various services by communicating with multiple user devices (UEs) including UE 101. The PNI-NPN (CAG) 130 is a non-public network deployed with the support of a PLMN (e.g., PLMN 110) by sharing, for example, the RAN / gNB 112 and, for example, the control plane functions. The CAG identity identifies a group of subscribers who are allowed to access one or more CAG cells associated with the CAG. The CAG is used for the PNI-NPN to prevent UEs that are not allowed to access the NPN via the associated cells from automatically selecting and accessing the associated CAG cells. The CAG is identified by a CAG identifier that is uniquely unique within the PLMN ID range. The CAG cells broadcast one or more CAG identifiers per PLMN (113), and the UE is configured with CAG-related configuration / information (e.g., an (enhanced) CAG information list containing a list of allowed CAGs per PLMN) (102).

[0042] A local or localized service is a service that is localized (i.e., provided at a specific / limited area and / or bounded in time (a specific time period)). A localized service provider is an application provider or a network operator that localizes its services and provides them to end-users via a managed network. A managed network is a network that provides access for the localized service and can be an SNPN or a PNI-NPN, and a home network is a network that owns the current usage subscription or credentials of the UE. In Figure 1 the example of, both the SNPN 120 and the PNI-NPN (CAG) 130 can be managed networks that provide access to the localized service for the UE 101.

[0043] A URSP rule can include an association of a UE application and a DNN or a network slice for a specific localized service. A URSP rule can also include a "routing validity criterion" (time window and / or location criterion validity condition) with a time / location defined for a specific localized service. A LADN (Local Access Data Network) can also be used to enable the UE to access the localized service.

[0044] To enable a PNI-NPN or an SNPN to provide access to a localized service, the PNI-NPN or SNPN operator configures the network with information that enables the UE to access the localized service according to the validity of the localized service, and this information is determined in accordance with the localized service provider, for example: (a) the identification of each localized service to be used in a URSP rule, for example; (b) the validity criteria / limitations for each localized service, for example, the duration and / or the area of the location of the validity.

[0045] When the localized service in the network is completed, all UEs expected to be registered to the network are expected to move to another network or to other cells within the same network. Another network can be an HPLMN, a VPLMN, or another SNPN. For various reasons, a UE can stop using the network resources of the local service, for example: (a) the completion of the localized service in the network; (b) no longer meeting the validity conditions of the network selection information; (c) the user decides to stop using the localized service before the completion of the localized service (for example, the end-user prohibits access to the localized service); (d) the network takes a policy decision whose effect is that the UE is deregistered before the completion of the localized service. The validity information or limitations or criteria or conditions (103) are provided or configured to the UE as part of the localized service information, which is used to restrict the access of the UE to the SNPN / PNI-NPN (as a managed network) that provides access to the localized service. To provide a localized service to the UE, the UE needs to be able to discover, select, and access the SNPN / PNI-NPN (as a managed network) that provides access to the localized service. The discovery mechanism is based on providing or configuring appropriate information to the UE.

[0046] Figure 2 Illustrates a simplified block diagram of a wireless device (e.g., UE 201 and network entity 211) according to an embodiment of the present invention. The network entity 211 may be a base station combined with an AMF. The network entity 211 has an antenna 215 for transmitting and receiving radio signals. The radio frequency (RF) transceiver module 214 coupled to the antenna receives an RF signal from the antenna 215, converts it into a baseband signal and sends the baseband signal to the processor 213. The RF transceiver 214 also converts the baseband signal received from the processor 213, converts it into an RF signal, and sends it out to the antenna 215. The processor 213 processes the received baseband signal and calls different functional modules to perform the features in the base station 211. The memory 212 stores program instructions and data 220 for controlling the operation of the base station 211. In Figure 2 the example of, the network entity 211 further includes a set of control functional modules and circuits 290. The registration circuit 231 is responsible for registration and mobility procedures. The session management circuit 232 is responsible for session management functions. The configuration and control circuit 233 provides different parameters to configure and control the UE.

[0047] Similarly, the UE 201 has a memory 202, a processor 203, and a radio frequency (RF) transceiver module 204. The RF transceiver 204 is coupled to the antenna 205, receives an RF signal from the antenna 205, converts it into a baseband signal, and sends the baseband signal to the processor 203. The RF transceiver 204 also converts the baseband signal received from the processor 203, converts it into an RF signal, and sends it out to the antenna 205. The processor 203 processes the received baseband signal and calls different functional modules and circuits to perform the features in the UE 201. The memory 202 stores data and program instructions 210 to be executed by the processor to control the operation of the UE 201. By way of example, suitable processors include dedicated processors, digital signal processors (DSPs), multiple microprocessors, one or more microprocessors associated with a DSP core, controllers, microcontrollers, application specific integrated circuits (ASICs), field programmable gate array (FPGA) circuits, and other types of integrated circuits (ICs) and / or state machines. Processors associated with software can be used to implement and configure the features of the UE 201.

[0048] The UE 201 also includes a set of functional modules and control circuits for performing the functional tasks of the UE 201. The protocol stack 260 includes a Non-Access-Stratum (NAS) layer that communicates with the AMF entity connected to the core network, a Radio Resource Control (RRC) layer for high-layer configuration and control, a Packet Data Convergence Protocol / Radio Link Control (PDCP / RLC) layer, a Media Access Control (MAC) layer, and a Physical (PHY) layer. The system modules and circuits 270 can be implemented and configured by software, firmware, hardware, and / or combinations thereof. When executed by a processor through program instructions contained in a memory, the functional modules and circuits interact with each other to allow the UE 201 to perform implementation manners, functional tasks, and features in the network. In one example, the system modules and circuits 270 include a registration circuit 221 that performs registration and mobility procedures with the network, a network and cell selection circuit 222 for performing network and cell selection, a PLMN / PNI-NPN (CAG) / SNPN information maintenance circuit 223 that is responsible for adding, removing, and resetting one or more PLMN / PNI-NPN (CAG) / SNPN information in the SIM / USIM and / or the UE (non-volatile) memory (the source of the information can also be from signaling), and a configuration and control circuit 224 that is responsible for configuration and control parameters. Note that network selection and registration-related information, such as the HPLMN, operator-controlled PLMN / SNPN selector list, user-controlled PLMN / SNPN selector list, can be stored in the SIM / USIM 225 and / or the (non-volatile) memory of the UE.

[0049] SNPN

[0050] Figure 3A A first embodiment of a 5G system architecture for accessing an SNPN using a credential from a credential holder is illustrated. Figure 3A A 5G system architecture with an SNPN of a credential holder is depicted, which uses an AAA server for primary authentication and authorization. The AUSF and UDM in the SNPN can use the credential from the AAA server in the credential holder (CH) to support the primary authentication and authorization of the UE. Figure 3A The SNPN in can be the subscribed SNPN for the UE (i.e., the SNPN ID of the subscribed SNPN broadcast by the NG-RAN). As a deployment option, Figure 3AThe SNPN in [the above] can also be another SNPN other than the subscribed SNPN for the UE (i.e., none of the SNPN IDs broadcast by the NG-RAN match the SNPN ID corresponding to the subscribed SNPN). The NSSAAF deployed in the SNPN can use the credentials from the credential holder using the AAA server (as depicted) to support primary authentication in the SNPN and / or the NSSAAF can support network slice-specific authentication and authorization using a network slice-specific AAA server (not depicted).

[0051] Figure 3B Illustrates a second embodiment of a 5G system architecture for accessing an SNPN using credentials from a credential holder. Figure 3B Depicts a 5G system architecture of an SNPN with a credential holder that uses the AUSF and UDM for primary authentication, authorization, and network slicing. The SNPN can support primary authentication and authorization of a UE that uses credentials from a credential holder using the AUSF and UDM. The credential holder can be an SNPN or a PLMN. The credential holder UDM provides subscription data to the SNPN.

[0052] Figure 4 Illustrates an example of an NG-RAN mode for broadcasting certain information to provide access to an SNPN. A credential holder (CH) can authenticate and authorize access to an SNPN separate from the credential holder. For SNPN identification, a combination of a PLMN ID and an NID identifies the SNPN. The NID supports two allocation models. In the self-allocation mode, the NID is individually selected by the SNPN at deployment time (and may thus not be unique), but uses a numbering space different from the coordinated allocation NID. In the coordinated allocation mode, one of the following two options is used to allocate the NID: 1) Allocate the NID such that it is globally unique, regardless of the PLMN ID used; or 2) Allocate the NID such that the combination of the NID and the PLMN ID is globally unique.

[0053] Group IDs for Network Selection (GIN) for network selection support two allocation models. In the self-allocation mode, the GIN is individually selected and may thus not be unique. In the coordinated allocation mode, the GIN uses a combination of a PLMN ID and an NID and is allocated using one of the following two options: 1) Allocate the GIN such that the NID is globally unique (e.g., using an IANA private enterprise number), regardless of the PLMN ID used; or 2) Allocate the GIN such that the combination of the NID and the PLMN ID is globally unique.

[0054] In Figure 4In the example of [[ID=]], the NG-RAN 401 provides access to the SNPN and broadcasts the following information (410): one or more PLMN IDs and a list of NIDs of non-public networks (e.g., SNPN 1 and SNPN 2) to which the NG-RAN provides access for each PLMN ID. Optionally, the broadcast information further includes the following: a human-readable network name (HRNN) for each SNPN; an indication for each SNPN as to whether access using a credential from the credential holder is supported; a list of group IDs (e.g., GIN 1 and GIN 2) for which network selection is supported for each SNPN; and an indication for each SNPN as to whether the SNPN allows registration attempts from UEs that are not explicitly configured to select the SNPN, i.e., the UEs do not have any SNPN ID (PLMN ID + NID) or GIN broadcast by the SNPN in the preferred SNPN / GIN prioritization list controlled by the credential holder.

[0055] Figure 5A An example of a SNPN-capable UE configured with SNPN subscription information for each subscribed SNPN is illustrated. In Figure 5A the example of [[ID=]], the SNPN-capable UE 501 is configured with two SNPN subscriptions, as shown by 510 / 520 for each subscribed SNPN: the SNPN ID (PLMN ID + NID) of the subscribed SNPN (e.g., SNPN 1 in entry 1 of the "subscriber data list", SNPN 2 in entry 2 of the "subscriber data list"); and a subscription identifier (SUPI) and a credential configured for each of the subscribed SNPNs. If the UE supports access to the SNPN using a credential from the credential holder for each subscribed SNPN, the UE is further configured with: 1) a prioritization list of preferred SNPNs controlled by the user (e.g., SNPN 111, SNPN 112 for entry 1; SNPN 211, SNPN 212 for entry 2); 2) a prioritization list of preferred SNPNs controlled by the credential holder (e.g., SNPN 121, SNPN 122 for entry 1; SNPN 221, SNPN 222 for entry 2); and 3) a prioritization list of GINs controlled by the credential holder (e.g., GIN 131, GIN 132 for entry 1; GIN 231, GIN 232 for entry 2).

[0056] Figure 5BAn example of an SNPN - capable UE configured with 2 PLMN subscriptions (i.e., 2 USIMs) is illustrated. An SNPN - capable UE that supports access to the SNPN using credentials from a credential holder and is equipped with a PLMN subscription (USIM) can be additionally configured with information for selecting and registering with an SNPN using the PLMN subscription (in the SNPN access mode). For example, PLMN subscription 1 is associated with the following information 530 for SNPN selection: 1) a prioritized list of user - controlled preferred SNPNs (e.g., SNPN311, SNPN 312); 2) a prioritized list of credential - holder - controlled SNPNs (such as SNPN 321, SNPN 322); and 3) a prioritized list of credential - holder - controlled GINs (e.g., GIN 331, GIN 332). Similarly, PLMN subscription 2 is associated with information 540 for SNPN selection: 1) a prioritized list of user - controlled preferred SNPNs (e.g., SNPN 411, SNPN412); 2) a prioritized list of credential - holder - controlled SNPNs (such as SNPN 421, SNPN 422); and 3) a prioritized list of credential - holder - controlled GINs (e.g., GIN 431, GIN 432).

[0057] The subscription to an SNPN is identified by a SUPI that contains a network - specific identifier in the form of a Network Access Identifier (NAI). The realm part of the NAI can include the NID of the SNPN; or is identified by a SUPI that contains an IMSI. For an SNPN - capable UE with an SNPN subscription, the prioritized list of credential - holder - controlled preferred SNPN / GIN can be updated by the CH using the Steering of Roaming (SoR) procedure. For an SNPN - capable UE with a PLMN subscription, the prioritized list of credential - holder - controlled preferred SNPN / GIN can be updated by the CH using the SoR procedure. When the credential holder updates the UE with the prioritized list of credential - holder - controlled preferred SNPNs and GINs, the UE can perform SNPN selection again, for example, to potentially select an SNPN with a higher priority.

[0058] Figure 6Illustrates network selection in the SNPN access mode with automatic SNPN network selection and manual SNPN network selection. The UE 601 supporting SNPN supports access to the SNPN (in the SNPN access mode). When the UE is set to operate in the SNPN access mode, the UE only selects and registers to the SNPN. When the UE is set to operate in the SNPN access mode, the UE does not perform the normal PLMN selection process. There are two SNPN network selection processes: the automatic SNPN network selection process and the manual SNPN network selection process.

[0059] Under automatic SNPN network selection, the UE selects and attempts to register to an available and permitted SNPN in the following order: 1) the SNPN to which the UE was last registered (if available) or an equivalent SNPN (if available); 2) the subscribed SNPN, which is identified by the SNPN ID (PLMN ID + NID) (the UE has the SUPI and credentials for it); 3) if the UE supports access to the SNPN using the credentials from the credential holder, the UE continues by selecting and attempting to register on an available and allowable SNPN that broadcasts an indication of support for access using the credentials from the credential holder in the following order: a) the SNPNs in the prioritized list of user-controlled preferred SNPNs (in priority order); b) the SNPNs in the prioritized list of credential-holder-controlled preferred SNPNs (in priority order); c) the SNPNs that additionally broadcast a GIN included in the prioritized list of credential-holder-controlled preferred GINs (in priority order); and 4) the SNPN that additionally broadcasts an indication that the SNPN allows registration attempts from UEs not explicitly configured to select the SNPN, i.e., the broadcast SNPN ID or GIN does not exist in the prioritized list of credential-holder-controlled preferred SNPNs / GINs in the UE.

[0060] In Figure 6In the example, UE 601 is registered to SNPN 100, the subscribed SNPN is SNPN 1 and has three lists for credentials. The prioritized list of the user's preferred SNPNs includes SNPN 111, SNPN 112; the prioritized list of the preferred SNPNs controlled by the credential holder includes SNPN 121, SNPN 122; the prioritized list of the GINs controlled by the credential holder includes GIN 131, GIN 132. There is a list of SNPNs / GINs available at the current UE location (broadcast by one or more NG-RANs), such as SNPN 100, SNPN 1, SNPN 111, SNPN 112, SNPN 121, SNPN 300 / GIN 131. UE 601 selects and attempts to register to SNPNs in the following preferred / priority order: SNPN 100, SNPN 1, SNPN 111, SNPN 112, SNPN 121, and SNPN 300 which also broadcasts GIN 131.

[0061] Under manual network selection, a UE operating in SNPN access mode provides the user with a list of SNPNs (identified by PLMN ID and NID respectively) and the relevant human-readable network names of the SNPNs available to the UE with the corresponding SUPI and credentials (if available). If the UE supports access to SNPNs using credentials from the credential holder, the UE also presents the available SNPNs that broadcast the indication "supports access using credentials from the credential holder" and the human-readable names associated with the SNPNs (if available). When the UE performs an initial registration to an SNPN, the UE shall indicate to the NG-RAN the selected PLMNID and NID broadcast by the selected SNPN. The NG-RAN shall notify the selected PLMN ID and NID to the AMF.

[0062] If the UE performs a registration or service request procedure in an SNPN identified by a PLMN ID and a self-assigned NID and there is no subscription for that UE, the AMF shall reject the UE with an appropriate cause code to temporarily prevent the UE from automatically selecting and registering to the same SNPN. If the UE performs a registration or service request procedure in an SNPN identified by a PLMN ID and a co-allocated NID and there is no subscription for the UE, the AMF shall reject the UE with an appropriate cause code to permanently prevent the UE from automatically selecting and registering to the same SNPN. If the UE performs a registration in an SNPN using a credential from a credential holder and the UE is not authorized to access that specific SNPN, the UDM may reject the UE, which results in the AMF rejecting the registration request from the UE with an appropriate cause code to prevent the UE from selecting and registering in the same SNPN using the credential from the credential holder. To prevent one or more authorized UEs from accessing an SNPN in case of network congestion / overload, unified access control information is configured per SNPN (i.e., as part of the subscription information that the UE has for a given SNPN) and provided to the UE.

[0063] PNI-NPN(CAG)

[0064] The PNI-NPN (CAG) is an NPN that is available via a PLMN, for example, by means of a dedicated DNN or via one or more network slice instances allocated to the NPN. Existing network slicing functionality applies. When the PNI-NPN is made available via a PLMN, the UE shall have a subscription to the PLMN to access the PNI-NPN. The CAG identity identifies a group of subscribers that are allowed to access one or more CAG cells associated with that CAG. The CAG is used for the PNI-NPN to prevent UEs that are not allowed to access the NPN via the associated cells from automatically selecting and accessing the associated CAG cells. The CAG is identified by a CAG identifier that is uniquely identified within the PLMN ID scope. The CAG cells broadcast one or more CAG identifiers per PLMN. The CAG cells may also broadcast the HRNN per CAG identifier.

[0065] To use CAG, a UE that supports CAG, which is indicated as part of the UE 5GMM core network capabilities, may be pre-configured or (re)-configured with the following CAG-related information. If a UE supports CAG, the network may provide the UE with a CAG-related configuration consisting of zero or more entries (e.g., (enhanced) CAG information (list) that contains a list of allowed CAGs per PLMN), and each entry contains: a) PLMN ID, b) an "allowed CAG list" with zero or more CAG-IDs, and c) an optional "indication that the UE is only allowed to access 5GS via CAG cells". The HPLMN may use the UE configuration update procedure or other 5GMM procedures (e.g., registration procedure or service procedure) to pre-configure or re-configure the UE with the above CAG-related configuration. The above CAG-related configuration is provided by the HPLMN per PLMN. In a PLMN, the UE shall only consider the CAG information provided for that PLMN.

[0066] When the relevant configuration of the subscribed CAG changes, the UDM sets the CAG information subscription change indication and sends it to the AMF. When the UDM indicates that the CAG-related configuration within the access and mobility subscription data has changed, the AMF shall provide the UE with the CAG-related configuration. When the AMF receives an indication from the UDM that the CAG-related configuration within the access and mobility subscription has changed, the AMF uses the CAG-related configuration received from the UDM to update the UE. When the AMF updates the UE and obtains confirmation from the UE, the AMF notifies the UDM about the successful update, and the UDM clears the CAG information subscription change indication flag. The AMF may use the UE configuration update procedure to update the UE after the registration procedure is completed, or update the UE by including the new CAG-related configuration in the registration acceptance or registration rejection or deregistration request or service rejection.

[0067] When the UE is roaming and the serving PLMN provides the CAG-related configuration, the UE shall update only the CAG-related configuration provided for the serving PLMN, without updating the CAG-related configurations stored for other PLMNs. When the UE is not roaming and the HPLMN provides the CAG-related configuration, the UE shall update the CAG-related configurations stored in the UE with the received CAG-related configurations for all PLMNs. The UE shall store the latest available CAG-related configuration provided for each PLMN and retain its storage when the UE deregisters or is powered off. The CAG-related configuration only applies to 5GS.

[0068] For network and cell selection, CAG cells shall broadcast information such that only UEs supporting CAG are allowed to access the cell; the cell is either a CAG cell or a normal PLMN cell (non-CAG cell). For access control, in order to prevent authorized UEs from accessing the NPN in case of network congestion or overload, existing mechanisms defined for control plane load control, congestion and overload control, as well as access control and barring functions can be used, or a unified access control leveraging access categories can be used. Mobility restrictions shall be able to restrict the mobility of the UE according to the allowed CAG list (if configured in the subscription), and include an indication on whether the UE is only allowed to access the 5GS via CAG cells (if configured in the subscription).

[0069] During the transition from CM-IDLE to CM-CONNECTED, and during registration after connection-mode mobility from E-UTRAN to NG-RAN, the AMF shall verify whether the UE access is allowed by the mobility restrictions. If the UE accesses the 5GS via a CAG cell and if at least one of the CAG identifiers received from the NG-RAN is part of the allowed CAG list of the UE, the AMF accepts the NAS request. If the UE accesses the 5GS via a CAG cell and if none of the CAG identifiers received from the NG-RAN is part of the allowed CAG list of the UE, the AMF rejects the NAS request, and the AMF may include (carry) CAG-related configuration in the NAS rejection message. Then, the AMF releases the NAS signaling connection for the UE by triggering an AN release procedure. If the UE accesses the 5GS via a non-CAG cell and the subscription of the UE contains an indication that the UE is only allowed to access the 5GS via CAG cells, the AMF rejects the NAS request, and the AMF shall include (carry) CAG-related configuration in the NAS rejection message. Then, the AMF releases the NAS signaling connection for the UE by triggering an AN release procedure.

[0070] During the transition from RRC_INACTIVE to RRC_CONNECTED state, when the UE initiates an RRC resume procedure for the RRC_INACTIVE to RRC_CONNECTED state transition in a CAG cell, if none of the CAG identifiers supported by the CAG cell is part of the allowed CAG list of the UE according to the mobility restrictions received from the AMF, or if no allowed CAG list is received from the AMF, the NG-RAN shall reject the RRC resume request from the UE. When the UE initiates an RRC resume procedure for the RRC_INACTIVE to RRC_CONNECTED state transition in a non-CAG cell, if the mobility restrictions received from the AMF only allow the UE to access CAG cells, the NG-RAN shall reject the resume request of the UE.

[0071] During the connected mode mobility procedure (i.e., handover procedure) within the NG-RAN, if the target is a CAG cell and none of the CAG identifiers supported by the target CAG cell are part of the allowed CAG list of the UE in the mobility restriction list, or if no allowed CAG list is received from the AMF, the source NG-RAN shall not hand over the UE to the target NG-RAN node. If the UE is only allowed to access CAG cells based on the mobility restriction list, the source NG-RAN does not hand over the UE to a non-CAG cell. If the target cell is a CAG cell and none of the CAG identifiers supported by the CAG cell are part of the allowed CAG list of the UE in the mobility restriction list, or if no allowed CAG list is received from the AMF, the target NG-RAN shall reject the N2-based handover procedure. If the target cell is a non-CAG cell, then if the UE is only allowed to access CAG cells based on the mobility restriction list, the target NG-RAN shall reject the N2-based handover procedure. When the AMF receives Nudm_SDM_Notification from the UDM and the AMF determines that the indication of the allowed CAG list or whether the UE is only allowed to access CAG cells has changed, the AMF shall update the mobility restrictions in the UE and the NG-RAN accordingly under this condition.

[0072] Figure 7A Illustrates a first embodiment of network and cell selection and access control for a CAG cell of a PNI-NPN (CAG), where access to the CAG cell is accepted. In Figure 7A the example, UE 711 is configured with a CAG-related configuration (e.g., CAG information list 710) including a list of entries. For each entry, it includes a) a PLMN ID, b) an "allowed CAG list" with zero or more CAG-IDs, and c) an optional "indication that the UE is only allowed to access the 5GS via CAG cells". For example, entry 1 includes PLMN 111 and an allowed CAG list with CAG-IDs AAA and BBB. Via the 5G core network (5G corenetwork, 5GC) / AMF and the NG-RAN, one or more CAG-IDs per PLMN are broadcast by the CAG cell, e.g., CAG-IDs AAA and CCC can be accessed via CAG cell 712. Thus, UE 711 can access CAG cell 712 in PLMN 111.

[0073] Figure 7B Illustrates a second embodiment of network and cell selection and access control for a non-CAG cell, where access to the PLMN is accepted. In Figure 7BIn the example, UE 721 is configured with a CAG-related configuration including a list of entries (e.g., CAG information list 720). For each entry, it includes a) a PLMN ID, b) an "allowed CAG list" with zero or more CAG-IDs, and c) an optional "indication that the UE is only allowed to access 5GS via CAG cells". For example, entry 1 includes PLMN 111 and an allowed CAG list with CAG-IDs AAA and BBB. Additionally, there is no indication in entry 1 that the UE is only allowed to access 5GS via CAG cells. Through 5GC / AMF and NG-RAN 722, UE 721 discovers a non-CAG cell in PLMN 111 (i.e., cell 722 does not broadcast a CAG ID). Since the UE 721 is allowed to access 5GS via non-CAG cells, the UE 721 can access the non-CAG cell 722 in PLMN 111.

[0074] Figure 8A Illustrates a first embodiment of network and cell selection and access control for CAG cells of a PNI-NPN (CAG), where access to the CAG cell is denied. In Figure 8A In the example, UE 811 is configured with a CAG-related configuration including a list of entries (e.g., CAG information list 810). For each entry, it includes a) a PLMN ID, b) an "allowed CAG list" with zero or more CAG-IDs, and c) an optional "indication that the UE is only allowed to access 5GS via CAG cells". For example, entry 1 includes PLMN 111 and an allowed CAG list with CAG-IDs AAA and BBB. Through 5GC / AMF and NG-RAN 812, the CAG cell broadcasts one or more CAG-IDs per PLMN, such as CAG-IDs CCC and DDD. However, neither CAG-ID CCC nor CAG-ID DDD is in the "allowed CAG list". Therefore, UE 811 cannot access this CAG cell CCC / DDD of PLMN 111.

[0075] Figure 8B Illustrates a second embodiment of network and cell selection and access control for CAG cells of a PNI-NPN (CAG), where access to the PLMN is denied. In Figure 8BIn the example, the UE 821 is configured with a CAG-related configuration (CAG information list 820) that includes a list of entries. For each entry, it includes a) a PLMN ID, b) an "Allowed CAG list" with zero or more CAG-IDs, and c) an optional "Indication that the UE is only allowed to access the 5GS via CAG cells". For example, entry 1 includes PLMN 111 and an allowed CAG list with CAG-IDs AAA and BBB. In addition, in entry 1, there is an indication that the UE is only allowed to access the 5GS via CAG cells. Through the 5GC / AMF and the NG-RAN 822, the UE 821 discovers a non-CAG cell in PLMN 111 (i.e., cell 822 does not broadcast a CAG cell ID). Since the UE 821 is not allowed to access the 5GS via non-CAG cells, the UE 821 cannot access the non-CAG cell 822 in PLMN 111.

[0076] Provision of NPN (as a managed network) for access to localized services

[0077] Local or localized services are localized (i.e., provided at a specific / limited area and / or can be time-bounded). The service can be realized via an application (e.g., live or on-demand audio / video streaming, video games, IMS, etc.) or connectivity (e.g., UE-to-UE, UE-to-data network, etc.). A localized service provider is an application provider or network operator that localizes its services and provides them to end-users via a hosting network, where the hosting network is a network that provides access to local or localized services. A home network is a network that owns the current usage subscription or credentials of the UE. The home network can be a home PLMN or a subscribed SNPN. The SNPN can support the primary authentication and authorization of the UE, which uses credentials from the credential holder of the AUSF and UDM. The credential holder can be the home PLMN or the subscribed SNPN. For an SNPN acting as a hosting network, the home network can be regarded as the CH. For a PNI-NPN (CAG) acting as a hosting network, the home network can be regarded as the (home) PLMN. To provide a localized service to the UE, the UE needs to be able to discover, select, and access the NPN (acting as a hosting network) that provides access to the localized service. The discovery mechanism is based on providing / (pre-)configuring / signaling appropriate information to the UE.

[0078] Figure 9AIllustrated is an example where a UE uses availability information to discover, select, and access an NPN (as a managed network) and receive localized services. When a UE uses the subscription / credentials of its home network to access an NPN (as a managed network), only two cases are considered. If the home network (or CH) is a PLMN, the managed network can be a PNI-NPN or an SNPN. If the home network (or CH) is an SNPN, the managed network can be only an SNPN. If a UE uses a subscription or credentials from its UE home network to access a managed network and the UE has multiple credentials or subscriptions, the UE needs to determine which credential or subscription to use to access the managed network. The availability information or conditional information provided to the UE as part of the localized service information can be used to restrict the UE's access to the managed network, including: (time and / or location) availability information or conditional information ((time and / or location) duration, criteria, or restrictions) associated with an SNPN (ID) or a GIN; and (time and / or location) availability information / conditions ((time and / or location) duration, criteria, or restrictions) associated with a PNI-NPN / CAG-ID.

[0079] As shown in 910, a UE supporting an SNPN is configured with the following information for each subscribed SNPN: the PLMN ID and NID (SNPN ID) of the subscribed SNPN (e.g., SNPN 1); and the subscription identifier (SUPI) and credentials for the subscribed SNPN. If the UE supports access to an SNPN using credentials from a credential holder, the UE is also configured with: 1) a prioritized list of user-controlled preferred SNPNs (e.g., SNPN 111, SNPN 112); 2) a prioritized list of credential-holder-controlled preferred SNPNs (such as SNPN 121, SNPN 122, SNPN 123); and 3) a prioritized list of credential-holder-controlled GINs (e.g., GIN 131, GIN 132).

[0080] Figure 9BAnother example of a UE that uses validity information to discover, select, and access an NPN (as a managed network) and receive localized services is shown. For automatic network selection, in the case of an SNPN (as a managed network) for localized services, there may be associated (time (duration) and / or location (restriction)) validity information for the SNPN or GIN. For example, as shown in 910, (1) a prioritized list of preferred SNPNs (and GINs) controlled by an existing credential holder can be extended with (time and / or location) validity information or conditional information for each entry in the list; or as another example depicted by 911, (2) there may be one or more new list types defined to provide entries with validity information for SNPNs (and GINs) (e.g., defining a prioritized list of preferred SNPNs / GINs controlled by a new CH that includes (optional) validity information / conditions (for accessing localized services, where each entry contains an SNPN and / or GIN identifier)).

[0081] As shown in 910 or 911, SNPN 121 has an associated time (duration) validity condition from January 1st to January 2nd (the duration allowing the UE to access SNPN 121 (e.g., start and end times)), SNPN 123 has an associated time validity condition from January 1st to January 3rd, and GIN 131 has an associated time (duration) validity condition from January 1st to January 3rd. This time (duration) validity / condition information is provided to the UE as part of the localized service information to restrict the UE's access to the (managed network) localized services. The validity / condition information can also optionally include location validity / condition information, which can be in the form of (geolocation of the serving network (serving PLMN / PNI-NPN or serving SNPN) and / or TAI / cell), and this location validity / condition information can be used to help the UE know where to start searching for the SNPN managed network.

[0082] Figure 9CAnother example of a UE that uses validity / condition information to discover, select, and access an NPN (as a managed network) and receive localized services is illustrated. For automatic network selection, in the case of a PNI-NPN with a CAG, the CAG-ID (in the (enhanced / extended (permitted)) CAG list) can optionally be associated with time validity / condition or restriction information (the duration for which the UE is permitted to access the PNI-NPN / CAG (e.g., start and end times)) and / or location validity / condition or restriction information. This duration and / or location validity / condition or restriction can be provided together with the CAG identifier. For example, the ((enhanced / extended) permitted) CAG list can be provided to the UE and the AMF for implementation to ensure that the UE does not access CAG cells outside the duration and / or outside the permitted location. The location validity / condition information can be in the form of (geolocation and / or TAI / cell of the serving network (serving PLMN / PNI-NPN or serving SNPN)), and this location validity / condition or restriction information can be used to help the UE know where to start searching for the PNI-NPN managed network.

[0083] Note that, as shown in 920, the (time and / or location) validity information can be stored beside the CAG-ID (e.g., enhanced / extended original permitted CAG list), or stored independently in the UE and associated with one or more CAG-IDs; or as shown in 921, there can be one or more new list types that are defined to provide entries with validity information for the CAG. For example, as shown in 920, the ((enhanced / extended) permitted) CAG list for PLMN 111 includes CAGs AAA, BBB, and CCC. CAG-ID AAA is associated with time validity information from January 1st to January 3rd, and CAG-ID CCC is associated with time validity information from January 1st to January 2nd. Similar logic applies to location validity (if any). Such (time and location) validity conditions are provided to the UE as part of the localized service information to restrict the UE's access to the localized service (managed network).

[0084] Figure 10A The first example of accessing localized services via an SNPN (as a managed network) is illustrated, where the access is accepted. In Figure 10AIn the example, UE 1001 is configured with the following SNPN subscriptions: Subscribed SNPN = SNPN 1, a prioritized list of preferred SNPNs controlled by the credential holder, which includes SNPN 121, SNPN 122, and SNPN 123. SNPN 121 is associated with a time validity condition from January 1 to January 2, and SNPN 123 is associated with a time validity condition from January 1 to January 3. Through 5GC / AMF and NG-RAN 1002, SNPN 123 broadcasts its SNPN ID == 123, along with an indication of support for access using a credential from the credential holder. Since UE 1001 has subscribed to SNPN 1 and SNPN 123 is included as a preferred SNPN in the entry of the "subscriber data list" for SNPN 1, UE 1001 can attempt to use the credential from SNPN 1 to access SNPN 123. Since the time validity condition is associated with SNPN 123, UE 1001 needs to determine whether this time validity condition is met before access. UE 1001 checks that the current time is January 2, which is within the time period from January 1 to January 3. As a result, UE 1001 can use the credential from (the subscribed) SNPN 1 to access SNPN 123. SNPN 123 is a localized service provider. SNPN 123 is a managed network. SNPN 1 is the credential holder. (If location validity information is available, in this example, we assume that the location validity is met according to the location validity information).

[0085] Figure 10B Illustrates a second example of accessing a localized service via an SNPN (as a managed network), where access is not allowed (if the UE attempts to access, the network will reject). In Figure 10BIn the example, UE 1001 is configured with the following SNPN subscriptions: Subscribed SNPN = SNPN 1, a prioritized list of preferred SNPNs controlled by the credential holder, which includes SNPN 121, SNPN 122, and SNPN 123. SNPN 121 is associated with a time validity condition from January 1 to January 2, and SNPN 123 is associated with a time validity condition from January 1 to January 3. Through 5GC / AMF and NG-RAN 1002, the home network SNPN 123 broadcasts its SNPN ID == 123, along with an indication of support for access using a credential from the credential holder. Since UE1001 has subscribed to SNPN 1 and SNPN 123 is included as a preferred SNPN in the entry of the "subscriber data list" for SNPN 1, UE 1001 can attempt to access SNPN 123. However, due to the time validity condition associated with SNPN 123, UE 1001 also needs to additionally determine whether this time validity condition is met before access. UE 1001 checks that the current time is January 4, which is outside the time period from January 1 to January 3. As a result, UE 1001 cannot use the credential from SNPN 1 to access SNPN 123.

[0086] Figure 11A Illustrates a first example of accessing a localized service via a PNI-NPN access with a CAG (as the home network), where the access is accepted. In Figure 11AIn the example, UE 1101 is configured with a CAG-related configuration 1110 that includes a list of entries. For example, entry 1 includes PLMN 111 and an enhanced or extended allowed CAG list with CAG-IDs AAA, BBB, and CCC. CAG AAA is associated with a time validity condition from January 1st to January 3rd, and CAG CCC is associated with a time validity condition from January 1st to January 2nd. Through 5GC / AMF and NG-RAN 1102, the CAG cell broadcasts one or more CAG-IDs per PLMN, such as CAG-ID AAA for PLMN 111. Since the time validity condition is associated with CAG AAA, UE 1101 needs to determine whether this time validity condition is met before accessing. UE 1101 checks that the current time is January 2nd, which is within the time period from January 1st to January 3rd associated with CAG AAA. Therefore, UE 1101 can access CAG AAA of PLMN 111 via this cell. (PNI-NPN / CAG-AAA is the service provider, PNI-NPN / CAG-AAA is the hosting network, the home PLMN of the currently used USIM is the home network, and the home PLMN is the credential holder.) (If location validity information is available, in this example, we assume that the location validity is met according to the location validity information.)

[0087] Figure 11B Illustrates a second example of accessing a localized service via a PNI-NPN with a CAG (as the hosting network), where access is denied. In Figure 11B In the example, UE 1101 is configured with a CAG-related configuration 1110 that includes a list of entries. For example, entry 1 includes PLMN 111 and an enhanced or extended allowed CAG list with CAG-IDs AAA, BBB, and CCC. CAG AAA is associated with a time validity condition from January 1st to January 3rd, and CAG CCC is associated with a time validity condition from January 1st to January 2nd. Through 5GC / AMF and NG-RAN 1102, the CAG cell broadcasts one or more CAG-IDs per PLMN, such as CAG-ID AAA and CAG-ID CCC for PLMN 111. Since the time validity conditions are associated with CAG AAA and CCC, UE 1101 needs to determine whether these time validity conditions are met before accessing. UE 1101 checks that the current time is January 4th, which is outside the time period from January 1st to January 3rd associated with CAG AAA and outside the time period from January 1st to January 2nd associated with CAG CCC. Therefore, UE 1101 cannot access CAG cell AAA or CCC.

[0088] Processing of updated CAG configuration

[0089] When the PNI-NPN is available via a PLMN, the UE must subscribe to that PLMN to access the PNI-NPN. A CAG identifies a group of users allowed to access one or more CAG cells associated with that CAG. The CAG can be used for access control of the PNI-NPN. When the PNI-NPN (home network) provides localized services, the CAG cells of the PNI-NPN home network broadcast one or more CAG identifiers for each PLMN, and each CAG-ID may be associated with validity information (e.g., time and / or location validity criteria).

[0090] To use the CAG, a UE that supports the CAG as part of its UE 5GMM core network functionality can configure and / or reconfigure or update the CAG-related configuration. The CAG-related configuration (e.g., the (enhanced) CAG information (list) containing the list of allowed CAGs for each PLMN) consists of zero or more entries, each entry containing: a) a PLMN ID; b) an "allowed CAG list" containing zero or more CAG-IDs; and c) an optional indication "indicating that the UE is only allowed to access the 5GS via CAG cells".

[0091] When the subscribed CAG-related configuration changes, the UDM sets a CAG information subscription change indication and sends it to the AMF. When the UDM indicates that the CAG-related configuration in the access and mobility subscription data has changed, the AMF shall provide the updated CAG-related configuration to the UE. When the UE receives the updated CAG-related configuration, the operation of the UE needs to consider the configured "one or more CAG validity information".

[0092] According to a first novel aspect, the UE receives the updated CAG-related configuration in a DL NAS message via a CAG cell that broadcasts a list of CAG-IDs supported by the current network. The updated CAG-related configuration contains the list of CAG-IDs allowed by the current network, and an indication as to whether the UE is only allowed to access the 5GS via CAG cells. The UE checks the list of allowed CAG-IDs in the updated CAG-related configuration to determine whether the CAG cell supports these CAG-IDs, whether these CAG-IDs are associated with validity information, whether the validity criteria are met, whether the UE is only allowed to access the 5GS via CAG cells, and whether the UE has any emergency PDU sessions. Based on the determined results, the UE either enters the LIMITED-SERVICE state and searches for a suitable cell in the current network, or enters the PLMN-SEARCH state and applies the PLMN selection process.

[0093] According to the second novelty aspect, the UE receives updated CAG-related configuration in a DL NAS message via a non-CAG cell of the current network. The updated CAG-related configuration includes a list of CAG-IDs permitted by the current network and an indication of whether the UE is only permitted to access the 5GS via CAG cells. The UE checks the list of permitted CAG-IDs in the updated CAG-related configuration to determine whether they are associated with validity information, whether the validity criteria are met, whether the UE is only permitted to access the 5GS via CAG cells, and whether the UE has any emergency PDU sessions. Based on the determined results, the UE either enters the LIMITED-SERVICE state and searches for a suitable cell in the current network or enters the PLMN-SEARCH state and applies the PLMN selection process.

[0094] In one example, the validity information only includes time validity information, where the validity criteria are met if the time validity information matches the UE's current time; the validity criteria are not met if the time validity information does not match the UE's current time. In another example, the validity information only includes location validity information, where the validity criteria are met if the location validity information matches the UE's current location; the validity criteria are not met if the location validity information does not match the UE's current location. In yet another example, the validity information includes both time validity information and location validity information, where the validity criteria are met if the time validity information matches the UE's current time and the location validity information matches the UE's current location; the validity criteria are not met if the time validity information does not match the UE's current time or the location validity information does not match the UE's current location.

[0095] Figure 12 An embodiment is illustrated in which the UE receives updated CA-related configuration via a CAG cell, enters the LIMITED-SERVICE state, and searches for a suitable cell in the current network. In Figure 12In the example, UE 1201 is accessing PLMN 111 via 5GC / NG-RAN 1202. The current CAG cell broadcasts a list of CAG IDs supported by PLMN 111, which includes CAGBBB, CCC, and DDD. Subsequently, UE 1201 configures an updated CAG-related configuration 1210 via a downlink NAS signaling message. This configuration contains multiple entries, and one entry contains PLMN ID 111 and an (enhanced) (allowed) CAG list. This (enhanced) (allowed) CAG list also contains multiple allowed CAG IDs of PLMN 111, including CAG AAA, BBB, and CCC. Among the allowed CAG-IDs, the current CAG cell does not support CAG AAA. The current CAG cell supports CAG BBB and CCC, but they are associated with the validity information of accessing local services. For local services, CAG BBB is associated with the time validity / limitation information / criteria from January 3 to January 5, and CAG CCC is associated with the time validity / limitation information and criteria from January 3 to January 5. If the current time is January 2, the validity / limitation criteria / conditions of CAG BBB and CCC are not met. Therefore, UE1201 cannot access CAG AAA, BBB, or CCC of the current CAG cell.

[0096] However, the updated CAG-related configuration 1210 contains the allowed CAG AAA but is not associated with any validity information. In addition, the updated CAG-related configuration 1210 does not contain an indication that the UE is only allowed to access 5GS via CAG cells. Therefore, the UE can stay on the current PLMN 111 and search for other suitable cells (CAG / non-CAG cells). In one example, UE1201 can enter the LIMITED-SERVICE state and search for another CAG cell in PLMN 111 that supports CAG AAA. In another example, UE 1201 can enter the limited service state and search for non-CAG cells in PLMN 111. If UE1201 has an emergency PDU session, UE 1201 can enter the LIMITED-SERVICE state and perform a local release of all other PDU sessions related to 3GPP access.

[0097] Figure 13 Illustrates another embodiment in which the UE receives an updated CAG-related configuration via a CAG cell, enters the LIMITED-SERVICE state, and searches for a suitable cell in the current network. In Figure 13In the example, UE 1301 is accessing PLMN 111 via 5GC / NG-RAN 1302. The current CAG cell broadcast includes a list of supported CAG IDs including CAG DDD. Subsequently, UE 1301 configures an updated CAG-related configuration 1310 via a downlink NAS signaling message. This configuration contains multiple entries, one of which contains PLMN ID 111 and a (enhanced)(permitted) CAG list. The (enhanced)(permitted) CAG list also contains multiple (permitted) CAG IDs of PLMN 111 including CAG BBB and CCC. Among the permitted CAG IDs, the current CAG cell does not support CAG BBB and CCC. Therefore, UE 1301 cannot access the current CAG cell via CAG BBB or CAG CCC.

[0098] In addition, the updated CAG-related configuration 1310 also contains an indication that the UE is only allowed to access the 5GS network via CAG cells, which means that UE 1301 can only search for CAG cells. However, for localized services, CAG BBB is associated with time validity / limitation information and criteria from January 1st to January 5th, while CAG CCC is associated with time validity / limitation information / criteria from January 3rd to January 5th. If the current time is January 2nd, the validity criteria for CAG BBB are met, but the validity criteria for CAG CCC are not met. Therefore, the UE can stay on the current PLMN 111 and search for other suitable cells. In one example, since the validity criteria for CAG BBB have been met, UE 1301 can enter the LIMITED-SERVICE state and search for another CAG cell in PLMN 111 that supports CAG BBB. If UE 1301 has an emergency PDU session, UE1301 can enter the LIMITED-SERVICE state and perform a local release of all other PDU sessions related to 3GPP access.

[0099] Figure 14 Illustrates an embodiment in which, when the UE does not have an emergency PDU session, the UE receives an updated CAG-related configuration via a CAG cell, enters the PLMN-SEARCH state, and applies the network selection process. In Figure 14In the example, UE 1401 is accessing PLMN 111 via 5GC / NG-RAN 1402. The current CAG cell broadcasts a list of supported CAG IDs that includes CAG DDD. Subsequently, UE 1401 configures an updated CAG-related configuration 1410 via a downlink NAS signaling message. This configuration contains multiple entries, and one of the entries contains PLMN ID 111 and an (enhanced) (allowed) CAG list. This (enhanced) (allowed) CAG list also contains multiple (allowed) CAG IDs of PLMN 111, including CAG BBB and CCC. Among the allowed CAG-IDs, the current CAG cell does not support CAG BBB and CCC. Therefore, UE 1401 cannot access the current CAG cell via CAG BBB or CAG CCC.

[0100] In addition, the updated CAG-related configuration 1410 also contains an indication that the UE is only allowed to access 5GS via CAG cells, which means that UE 1401 can only search for CAG cells. However, for localized services, CAG BBB is associated with time validity / limitation information and criteria for (January 3 to January 5), and CAG CCC is associated with time validity / limitation information / criteria for (January 3 to January 5). If the current time is January 2, the validity / limitation criteria or conditions for the allowed CAG BBB and CAG CCC are not met. Therefore, if UE 1401 does not have an emergency PDU session, UE 1401 should not stay in the current PLMN 111 because UE 140 will not be able to find any suitable cells in the current PLMN 111. Therefore, UE 1401 enters the PLMN-SEARCH state and applies a PLMN selection process using the updated CAG-related configuration to search for another network. However, if UE 1401 has an emergency PDU session, UE 1401 should (1) perform a local release of all PDU sessions related to 3GPP access except for the emergency PDU session and enter the LIMITED-SERVICE state in PLMN 111, or (2) (a) perform a local release of all non-emergency (single access) PDU sessions related to 3GPP access; (b) perform a local release of the 3GPP access user plane resources of the MAPDU that has user plane resources on both 3GPP access and non-3GPP access; (c) perform a local release of the MAPDU that has user plane resources only on 3GPP access.

[0101] Figure 15 An embodiment is illustrated in which the UE receives an updated CAG-related configuration via a non-CAG cell, enters the LIMITED-SERVICE state, and searches for a suitable cell in the current network. In Figure 15In the example, UE 1501 is accessing a non-CAG cell in PLMN 111 via 5GC / NG-RAN 1502. Subsequently, UE 1501 configures updated CAG-related configuration 1510 via a downlink NAS signaling message. This configuration contains multiple entries, one of which contains PLMN ID 111 and an (enhanced) (permitted) CAG list. This (enhanced) (permitted) CAG list also contains multiple permitted CAG IDs of PLMN 111 including CAG BBB and CCC. The updated CAG-related configuration 1510 also contains an indication that the UE is only allowed to access 5GS via CAG cells, which means that UE 1501 can only access CAG cells on PLMN 111. Therefore, UE 1501 can no longer access the current non-CAG cell in PLMN 111.

[0102] In addition, for localized services, CAG BBB is associated with time validity / limitation information / criteria from January 1st to January 5th, and CAG CCC is associated with time validity / limitation information / criteria from January 3rd to January 5th. If the current time is January 2nd, the validity / limitation criteria / conditions of CAG BBB are met, while the validity / limitation criteria / conditions of CAG CCC are not met. Therefore, UE 1501 can continue to search for other suitable CAG cells on the current PLMN 111. In one example, UE 1501 can enter the LIMITED-SERVICE state and search for another CAG cell on PLMN 111 that supports CAG BBB.

[0103] Figure 16 Illustrates another embodiment in which the UE receives updated CAG-related configuration via a non-CAG cell, enters the PLMN-SEARCH state, and applies the network selection process. In Figure 16 the example, UE 1601 is accessing a non-CAG cell in PLMN 111 via 5GC / NG-RAN 1602. Subsequently, UE 1601 configures updated CAG-related configuration 1610 via a downlink NAS signaling message. This configuration contains multiple entries, one of which contains PLMN ID 111 and an (enhanced) (permitted) CAG list. This (enhanced) (permitted) CAG list also contains multiple permitted CAG IDs of PLMN 111 including CAG BBB and CCC. The updated CAG-related configuration 1610 also contains an indication that the UE is only allowed to access 5GS via CAG cells, which means that UE 1601 can only access CAG cells in PLMN 111. Therefore, UE 1601 can no longer access the current non-CAG cell in PLMN 111.

[0104] In addition, for the localized service, CAG BBB is associated with the time validity / limitation information / criteria for (January 3 to January 5), and CAG CCC is associated with the time validity / limitation information / criteria for (January 3 to January 5). If the current time is January 2, neither the validity / limitation criteria / conditions of the (permitted) CAG BBB and CAG CCC are met. Therefore, if UE 1601 does not have an emergency PDU session, UE 1601 should not stay in the current PLMN 111 because UE 1601 will not be able to find any suitable cell in the current PLMN 111. Therefore, UE 1601 enters the PLMN-SEARCH state and applies the PLMN selection process with the updated CAG-related configuration to search for another network. However, if UE 1601 has an emergency PDU session, UE 1601 should (1) perform a local release of all PDU sessions other than the emergency PDU session associated with 3GPP access and enter the LIMITED-SERVICE state in PLMN 111, or (2) (a) perform a local release of all non-emergency (single access) PDU sessions associated with 3GPP access (b) perform a local release of the 3GPP access user plane resources for the MA PDU with user plane resources on 3GPP access and non-3GPP access, and (c) perform a local release of the MAPDU with user plane resources only on 3GPP access, and (d) enter the LIMITED-SERVICE state in PLMN 111.

[0105] SNPN registration process

[0106] Based on the above description, UE 101 can switch from one SNPN to the next by initiating a mobility registration update. Figure 17 An embodiment of a communication system 1700 with SNPN 1710 and SNPN 1720 is illustrated.

[0107] The SNPN 1710 includes control plane functions, user plane functions (such as UPF), and application programs that provide various services by communicating with user equipment (such as UE 101). The SNPN 1710 can be identified by a globally unique SNPN identifier. The serving base station gNB 1712 is part of the RAN 1750. The RAN 1750 provides wireless access to the UE 101 via the RAT. The AMF in the SNPN 1710 communicates with the gNB 1712. The SNPN 1720 is operated by an NPN operator and does not rely on network functions provided by the public network. A Credentials Holder (CH) can authenticate and authorize access to an SNPN independent of the Credentials Holder. The NG-RAN node providing SNPN access broadcasts the following information: one or more PLMN IDs, and a list of NIDs for each PLMN ID used to identify the non-public network. The SNPN-enabled UE is configured with the SNPN ID of the subscribed SNPN. The SNPN-enabled UE that supports accessing the SNPN using the Credentials Holder credentials can also be additionally configured with information for SNPN selection (SNPN selection information or configuration) and registration using the SNPN subscription or using the PLMN subscription (USIM).

[0108] The SNPN 1720 includes control plane functions, user plane functions (such as UPF), and application programs that provide various services by communicating with user equipment (such as UE 101). The SNPN 1720 can be identified by a globally unique SNPN identifier. The serving base station gNB 1722 is part of the RAN 1760. The RAN 1760 provides wireless access to the UE 101 via the RAT. The AMF in the SNPN 1720 communicates with the gNB 1722. The SNPN 1720 is operated by an NPN operator and does not rely on network functions provided by the public network. A Credentials Holder (CH) can authenticate and authorize access to an SNPN independent of the Credentials Holder. The NG-RAN node providing SNPN access broadcasts the following information: one or more PLMN IDs, and a list of NIDs corresponding to each PLMN ID used to identify the non-public network NG-RAN. The SNPN-enabled UE is configured with the SNPN ID of the subscribed SNPN. The SNPN-enabled UE that supports accessing the SNPN using the Credentials Holder credentials can also be additionally configured with information for SNPN selection (SNPN selection information or configuration) and registration using the SNPN subscription or using the PLMN subscription (USIM).

[0109] In other words, the UE 101 supports accessing the SNPN 1710 and the second SNPN 1720 using the credentials of the credential holder. Additionally, the SNPN 1710 and the SNPN 1720 can be equivalent SNPNs.

[0110] Generally, in the PLMN-SEARCH state, the UE shall perform PLMN selection or SNPN selection. If a new PLMN is selected, the UE 101 shall reset the registration attempt counter and initiate the mobility registration procedure and periodic registration update. If a new SNPN is selected, the UE shall reset the registration attempt counter, be able to perform local deregistration, and initiate the registration procedure for initial registration.

[0111] In this embodiment, if both the SNPN 1710 and the SNPN 1720 are identified by a globally unique SNPN identifier, the UE 101 may initiate a mobility registration update when switching from the SNPN 1710 to the SNPN 1720 (i.e., a new SNPN is selected). The registration procedure for the mobility registration update is described as follows.

[0112] The UE 101 may enter the 5GMM-REGISTERED PLMN-SEARCH state and initiate a mobility registration update by sending a REGISTRATION REQUEST message to the AMF. The UE 101 may set the 5GS update type IE in the REGISTRATION REQUEST message to "mobility registration update". The complete procedure for the mobility registration update can be found in 3GPP TS 24.501 version 18.4. Therefore, for the sake of brevity, it will not be elaborated in this invention. Finally, after the UE 101 performs the mobility registration update to the SNPN 1720, it can register to the SNPN 1720.

[0113] In addition, it should be noted that the UE 101 holds a valid 5G globally unique temporary identifier (5G-GUTI), which was previously assigned by the SNPN 1710 via 3GPP access or non-3GPP access, and the SNPN 1710 is identified by a globally unique SNPN identifier. In this case, the UE 101 may indicate the 5G-GUTI in the 5GS mobility identity IE.

[0114] Conversely, if either the SNPN 1710 or the SNPN 1720 is not identified by a globally unique SNPN identifier, the UE 101 will perform local deregistration of the SNPN 1710 and initiate the registration procedure for the initial registration of the SNPN 1720.

[0115] For UE 101, performing local deregistration means that UE 101 locally releases the established NAS signaling connection (if any) and enters the 5GMM-DEREGISTERED state. Then, UE 101 can initiate the registration process for the initial registration of SNPN 1720 by sending a REGISTRATION REQUEST message to the AMF.

[0116] In addition, if UE 101 holds a valid 5G-GUTI, UE 101 shall include the 5G-GUTI in the additional GUTI IE of the registration request (REGISTRATION REQUEST) message in the following order: 1) a valid 5G-GUTI allocated by the same PLMN for which UE 101 previously performed registration; 2) a valid 5G-GUTI allocated by an equivalent PLMN; 3) a valid 5G-GUTI allocated by any other PLMN.

[0117] The complete procedures for local deregistration and initial registration can also be found in 3GPP TS 24.501, version 18.4. Therefore, for the sake of brevity, they are not elaborated in this invention. Finally, after completing the mobility registration update procedure, UE 101 is registered to SNPN 1720.

[0118] Therefore, initiating a mobility registration update for registration to SNPN 1720 can reduce the steps (e.g., messages) required within the 5G system and may be more preferable than performing local deregistration from SNPN 1710 and initiating the registration process for the initial registration of SNPN 1720, because both SNPN 1710 and SNPN 1720 are identified by a globally unique SNPN identifier.

[0119] Supplementary Note

[0120] The terms used in describing the various embodiments in this invention are only for describing specific embodiments and are not intended to be limiting. In describing the various embodiments and the appended claims, the singular forms "a", "an", and "the" also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" used in this invention refers to and encompasses any and all possible combinations of one or more of the related listed items. Further, it should be understood that the terms "includes", "including", "comprises", and / or "comprising" used in this specification specify the presence of the described features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or their combinations.

[0121] Terms such as "coupled", "connected", "connecting", and "electrically connected" are used interchangeably in the present invention and generally refer to the state of electrical / electronic connection. Similarly, when a first entity sends and / or receives information signals (whether containing voice information or non-voice data / control information) to / from a second entity in an electrical manner (either wired or wirelessly), regardless of the type of these signals (analog or digital), the first entity is considered to be in a "communication" state with the second entity (or multiple entities). It should be further noted that the various drawings (including component diagrams) shown and discussed in the present invention are for illustrative purposes only and are not drawn to scale.

[0122] Various illustrative logic blocks, modules, functions, and circuits related to the aspects disclosed in the present invention can be implemented or executed by a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof, which are designed to perform the functions described in the present invention. The processor can be a microprocessor, or alternatively, any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration.

[0123] Aspects of the present disclosure may be embodied in hardware and instructions stored in hardware, and may reside in, for example, Random Access Memory (RAM), flash memory, Read Only Memory (ROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), registers, hard disk, removable disk, CD-ROM, or any other form of computer-readable medium known in the art. The exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In alternative, the storage medium may be integrated into the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a remote station. In alternative, the processor and the storage medium may reside as discrete components in a remote station, base station, or server.

[0124] It should also be noted that the operation steps described in any exemplary aspect of the present invention are provided only for examples and discussions. The described operations may be performed in many different orders other than the shown order. In addition, the operations described in a single operation step may actually be performed in multiple different steps. In addition, one or more operation steps discussed in the exemplary aspects may be used in combination. It should be understood that various different modifications can be made to the operation steps shown in the flowcharts, which will be obvious to those skilled in the art. Those skilled in the art will also understand that information and signals can be represented using any of a variety of different technologies and methods. For example, the data, instructions, commands, information, signals, bits, symbols, and chipsets referred to in the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0125] In some embodiments, the computing instructions may be executed by an operating system, such as Microsoft Windows TM , Apple Mac OS / X or iOS operating systems, certain variants of the Linux operating system, Google Android TM operating systems, etc.

[0126] In some embodiments, the computer may be located on a distributed computing network, such as a network having any number of clients and / or servers. Each client may run software for implementing the client portion of the embodiments. Additionally, any number of servers may be provided to process requests received from one or more clients. The clients and servers may communicate with each other via one or more electronic networks, which may be the Internet, a wide area network, a mobile phone network, a wireless network (e.g., Wi-Fi, 5G, etc.), or a local area network in various embodiments. The network may be implemented using any known network protocol.

[0127] Various embodiments have been described in detail, examples of which are illustrated in the accompanying drawings. In the above detailed description, numerous specific details have been set forth in order to provide a thorough understanding of the various described embodiments. However, it will be apparent to one of ordinary skill in the art that the various described embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail so as not to unnecessarily obscure certain aspects of the embodiments.

[0128] For the case where the above system collects user information, the user may choose to opt in / out of programs or features that may collect personal information (e.g., information about user preferences or smart device usage). Additionally, in certain embodiments, certain data may be anonymized in one or more ways before storage or use, thereby removing personally identifiable information. For example, the user identity may be anonymized such that personally identifiable information cannot be determined or associated with the user, and user preferences or user interactions are generalized (e.g., generalized based on user demographics) rather than associated with a specific user.

[0129] Although some of the figures show multiple logical stages in a particular order, stages that are not order-dependent may be reordered, and other stages may be combined or split. Although the present invention specifically mentions some reordering or other grouping, other such reordering or grouping will be apparent to those skilled in the art, and thus the orderings and groupings described herein are not an exhaustive list of alternatives. Additionally, it should be recognized that these stages may be implemented in hardware, firmware, software, or any combination thereof.

[0130] It will be readily apparent to those skilled in the art that various modifications and variations can be made to the device and method while retaining the teachings of the present invention. Accordingly, the above disclosure should be understood as being limited only by the bounds and scope of the appended claims.

Claims

1. A user equipment (UE) includes one or more processors and is configured to determine whether to initiate a mobility registration update or a registration procedure of performing a local deregistration from a first standalone non-public network (SNPN) and initiating an initial registration to a second SNPN, wherein, The UE supports accessing the SNPN using a credential from a credential holder, and / or the first SNPN and the second SNPN are equivalent SNPNs.

2. The UE according to claim 1, wherein If both the first SNPN and the second SNPN are identified by a globally unique SNPN identifier, the UE determines to initiate the mobility registration update.

3. The UE according to claim 1, wherein The UE initially registers to the first SNPN.

4. The UE according to claim 1, wherein, The UE has entered the Public Land Mobile Network Search (PLMN-SEARCH) sub-state.

5. The UE according to claim 4, wherein the PLMN-SEARCH state is a sub-state of the 5GMM-REGISTERED state.

6. The UE according to claim 2, wherein, After the mobility registration update, the UE registers to the second SNPN.

7. The UE according to claim 1, wherein After the registration process in which the processor performs local deregistration from the first SNPN and initiates an initial registration to the second SNPN, the UE registers to the second SNPN.

8. A method for a User Equipment (UE) to access a Standalone Non-Public Network (SNPN), comprising: Registering to a first SNPN; And Determining whether to initiate a mobility registration update, or a registration process of performing local deregistration from the first SNPN and initiating an initial registration to a second SNPN, wherein the UE supports accessing the SNPN using a credential from a credential holder, and / or the first SNPN and the second SNPN are equivalent SNPNs.

9. The method according to claim 8, further comprising: If both the first SNPN and the second SNPN are identified by a globally unique SNPN identifier, initiate the mobility registration update.

10. The method according to claim 9, wherein, After the mobility registration update, the UE registers to the second SNPN.

11. The method according to claim 8 further comprises: If the first SNPN or the second SNPN is not identified by a globally unique SNPN identifier, perform a registration process of local deregistration from the first SNPN and initiate an initial registration to the second SNPN.

12. The method according to claim 11, wherein The UE registers to the second SNPN after the registration process of performing local deregistration from the first SNPN and initiating an initial registration to the second SNPN.

13. The method according to claim 8, further comprising entering the Public Land Mobile Network Search (PLMN-SEARCH) sub-state.

14. The method according to claim 13, wherein, The PLMN-SEARCH state is a sub-state of the 5GMM-REGISTERED state.

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