Disabling n1 mode upon receiving a 5gmm cause value message

Abstract

A method includes a user equipment (UE) transmitting a registration request message to a network node according to a non-access stratum (NAS) protocol. The registration request message includes a request for one or more Single Network Slice Selection Assist Information (S-NSSAI) in a first network. The UE receives a registration rejection message from the network node, the registration rejection message including a 5G System Mobility Management (5GMM) reason value #62 "No network slice available" indication. Based on receiving the registration rejection message, the UE disables N1 mode capability for the first network, stores an identifier for the first network, and subsequently utilizes the stored identifier for the first network during a network selection process.

Description

Technical Field

[0001] Field of the Invention

[0002] Various exemplary embodiments generally relate to wireless networks, and more particularly, to deactivating N1 mode after receiving a 5G Mobility Management (5GMM) cause value message. Prior Art

[0003] Background of the Invention

[0004] To participate in 5G Mobility Management (5GMM), a User Equipment (UE) registers with the network by transmitting a registration request message using the non-access stratum (NAS) protocol. The network notifies the UE whether a network slice is available, and if there is an available network slice, the UE is allowed to register. If no network slice is available, the network responds to the UE's registration request with a registration rejection message, in which case the UE may deactivate its N1 mode capability. However, unless another Radio Access Technology (RAT) is provided to the UE, the UE will continue to reactivate its N1 mode capability and send registration requests to the same network indefinitely, potentially causing the utilization of excessive resources. Summary of the Invention

[0005] Abstract of the Invention

[0006] In one aspect of the present disclosure, a method includes a User Equipment (UE) transmitting a registration request message to a network node according to a non-access stratum (NAS) protocol, the registration request message including a request for one or more single network slice selection assistance information (S-NSSAI) in a first network. The UE receives a registration rejection message from the network node, the registration rejection message including a 5G System Mobility Management (5GMM) cause value No. 62 (#62) "no network slice available" indication. The UE deactivates its N1 mode capability for the first network based on the receipt of the registration rejection message, stores an identity of the first network, and after storage, the UE utilizes the stored identity of the first network during a network selection process.

[0007] In one aspect of the method, the 5GMM cause value #62 "no network slice available" indication includes a cause "S-NSSAI is not available due to failed or deregistered network slice specific authentication" indication.

[0008] In one aspect of the method, the first network is a public land mobile network (PLMN) or a stand-alone public network (SNPN).

[0009] In one aspect of the method, the 5GMM cause value #62 "no network slice available" indicates a cause "S-NSSAI not available in the current PLMN or SNPN".

[0010] In one aspect of the method, the method further includes: the UE adding the identifier of the PLMN to a list listing the PLMNs for which the UE deactivates the N1 mode capability.

[0011] In one aspect of the method, the method further includes: starting a timer after deactivating the N1 mode capability.

[0012] In one aspect of the method, the timer is a TNSU timer.

[0013] In one aspect of the method, a value of the timer TNSU does not exceed a background timer value.

[0014] In one aspect of the method, the method further includes: the UE discarding the PLMN for which the identifier was previously added to the list during the network selection process.

[0015] In one aspect of the method, the method further includes: the UE removing the identifier of the PLMN when the UE is powered off.

[0016] In one aspect of the method, the method further includes: the UE deleting the identifier of the PLMN from the list after a universal subscriber identity module is removed from the UE.

[0017] In one aspect of the method, the method further includes: the UE deleting the identifier of the PLMN from the list after receiving a registration acceptance message.

[0018] In one aspect of the method, the method further includes: by the UE, deleting the identifier of the PLMN from the list after removing an S-NSSAI from a rejected NSSAI due to a failed or deregistered network slice specific authentication and authorization (NSSAA) service.

[0019] In one aspect of the method, the method further includes: by the UE, adding the identifier of the SNPN to a list listing the SNPNs for which the UE deactivates the N1 mode capability.

[0020] In one aspect of the method, the method further includes: starting a timer after deactivating the N1 mode capability.

[0021] In one aspect of the method, the timer is a T_NSU_SNPN timer.

[0022] In one aspect of the method, a value of the timer T_NSU_SNPN does not exceed a background timer value.

[0023] In one aspect of the method, the method further includes: by the UE, discarding the SNPN for which the identifier was previously added to the list during the network selection process.

[0024] In one aspect of the method, the method further includes: by the UE, deleting the identifier of the SNPN from the list when the UE is turned off.

[0025] In one aspect of the method, the method further includes: by the UE, deleting the identifier of the SNPN from the list after a universal subscriber identity module is removed from the UE.

[0026] In one aspect of the method, the method further includes: by the UE, deleting the identifier of the SNPN from the list after receiving a registration acceptance message.

[0027] In one aspect of the method, the method further includes: by the UE, deleting the identifier of the SNPN from the list after removing an S-NSSAI from a rejected NSSAI due to a failed or deregistered network slice specific authentication and authorization (NSSAA) service.

[0028] In one aspect of the method, the network node includes an Access and Mobility Function (AMF).

[0029] In one aspect of the present disclosure, a user equipment includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to perform at least any one of the foregoing methods.

[0030] In one aspect of the present disclosure, a processor-readable medium stores instructions that, when executed by at least one processor of a device, cause the device to perform at least any one of the foregoing methods.

[0031] According to some aspects, there is provided the subject matter of independent technical solutions. Some other aspects are defined in the dependent technical solutions. Brief Description of the Drawings

[0032] Some exemplary embodiments will now be described with reference to the accompanying drawings.

[0033] FIG. 1 is a diagram of an exemplary embodiment of a wireless network connection between a network system and a user equipment (UE) according to one illustrated aspect of the present disclosure;

[0034] FIG. 2 is a diagram of exemplary components of a network system according to one illustrated aspect of the present disclosure;

[0035] FIG. 3 is a diagram of an exemplary embodiment of signals and operations in a UE and an AMF according to one illustrated aspect of the present disclosure; and

[0036] FIG. 4 is a diagram of an exemplary embodiment of components of a UE or a network device according to one illustrated aspect of the present disclosure. Embodiments

[0037] Detailed Description of the Preferred Embodiment

[0038] In the following description, certain specific details are set forth in order to provide a thorough understanding of the disclosed aspects. However, those skilled in the relevant art will recognize that the aspects may be practiced without one or more of these specific details or by other methods, components, materials, etc. In other instances, well-known structures associated with transmitters, receivers, or transceivers have not been shown or described in detail to avoid unnecessarily obscuring the description of the aspects.

[0039] References to "one aspect" or "an aspect" throughout this specification mean that the particular features, structures, or characteristics described in connection with that aspect are included in at least one aspect. Thus, the phrases "in one aspect" or "in an aspect" that appear throughout this specification do not necessarily all refer to the same aspect. Additionally, in one or more aspects, the particular features, structures, or characteristics may be combined in any suitable manner.

[0040] The embodiments described in this disclosure may be implemented in wireless network connection devices, such as but not limited to those utilizing Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile Communications (GSM, 2G), GSM EDGE Radio Access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunications System (UMTS, 3G) based on Wideband Code Division Multiple Access (W-CDMA), High-Speed Packet Access (HSPA), Long-Term Evolution (LTE), Advanced LTE, Enhanced LTE (eLTE), 5G New Radio (5G NR), 5G Advance, 6G (and higher versions), and 802.11ax (Wi-Fi 6), as well as other wireless network connection systems. Here, the term 'eLTE' indicates the evolution of LTE connected to the 5G core. LTE is also known as Evolved UMTS Terrestrial Radio Access (EUTRA) or Evolved UMTS Terrestrial Radio Access Network (EUTRAN).

[0041] This disclosure may use the term "serving network device" to refer to a network node or network device (or a part thereof) that serves a UE. As used herein, the terms "transmitted to", "received from", and "cooperates with" (and their variants) include communications that may or may not involve communication through one or more intermediate devices or nodes. The term "obtain" (and its variants) includes obtaining a first instance or re-obtaining after the first instance. The term "connection" may mean a physical connection or a logical connection.

[0042] This disclosure uses 5G NR as an example of a wireless network and may use a smartphone and / or an extended reality headset as examples of UEs. It is desired and should be understood that these examples are merely illustrative, and this disclosure is applicable to other wireless networks and user equipment.

[0043] FIG. 1 is a diagram depicting an example of a wireless network connection between a network system 100 and a user equipment (UE) 150. The network system 100 may include one or more network nodes 120, one or more servers 110, and / or one or more network equipment 130 (e.g., test equipment). The network nodes 120 will be described in more detail below. As used herein, the term "network device" may refer to any component of the network system 100, such as the server 110, the network node 120, the network equipment 130, any one or more components of the foregoing, and / or any one or more other components of the network system 100. Examples of network devices include, but are not limited to, devices implementing aspects of 5G NR and other devices. This disclosure describes embodiments related to 5G NR and embodiments related to aspects defined by the 3rd Generation Partnership Project (3GPP). However, embodiments related to other wireless network connection technologies are contemplated to be within the scope of this disclosure.

[0044] The following description provides further details of an example of a network node. In a 5G NR network, a gNodeB (also referred to as gNB) may include, for example, a node that provides new radio (NR) user plane and control plane protocol terminations to a UE and is connected to a 5G core (5GC) via an NG interface, for example, according to section 3.2 of 3GPP TS 38.300 V16.6.0 (2021-06), which is hereby incorporated herein by reference.

[0045] The gNB supports various protocol layers, such as layer 1 (L1) - the physical layer, layer 2 (L2), and layer 3 (L3).

[0046] Layer 2 (L2) of NR is split into the following sublayers: Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Service Data Adaptation Protocol (SDAP), where, for example: ○ The physical layer provides a transport channel to the MAC sublayer; ○ The MAC sublayer provides a logical channel to the RLC sublayer; ○ The RLC sublayer provides an RLC channel to the PDCP sublayer; ○ The PDCP sublayer provides a radio bearer to the SDAP sublayer; ○ The SDAP sublayer provides a Quality of Service (QoS) flow to the 5GC; ○ The control channels include a Broadcast Control Channel (BCCH) and a Paging Control Channel (PCCH).

[0047] Layer 3 (L3) includes, for example, Radio Resource Control (RRC) according to Section 6 of 3GPP TS 38.300 V16.6.0 (2021-06), which is hereby incorporated by reference in its entirety.

[0048] The gNB Central Unit (gNB-CU) includes, for example, a logical node that hosts the Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) protocols of a gNB, or the RRC and PDCP protocols of an en-gNB. The gNB-CU controls the operation of one or more gNB Distributed Units (gNB-DUs). The gNB-CU terminates the F1 interface connected to the gNB-DU. The gNB-CU may also be referred to as the CU, Central Unit, Centralized Unit, or Control Unit in this document.

[0049] The gNB Distributed Unit (gNB-DU) includes, for example, a logical node that hosts the Radio Link Control (RLC), Medium Access Control (MAC), and Physical (PHY) layers of a gNB or en-gNB, and the operation of the gNB-DU is partially controlled by the gNB-CU. One gNB-DU supports one or more cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface connected to the gNB-CU. The gNB-DU may also be referred to as the DU or Distributed Unit in this document.

[0050] As used herein, the term "network node" may refer to any one or any combination of a gNB, gNB-CU, or gNB-DU. A Radio Access Network (RAN) node or a network node such as, for example, a gNB, gNB-CU, or gNB-DU or a part thereof may be implemented using, for example, a device having at least one processor and / or at least one memory having processor-readable instructions ("program") configured to support and / or provide and / or process CU and / or DU related functionality and / or features, and / or at least one protocol (sub)layer of the Radio Access Network (RAN), such as, for example, Layer 2 and / or Layer 3. There may be different functional partitions between the central unit and the distributed unit. Examples of such devices and components will be described in connection with Figure 4 below.

[0051] The gNB-CU and gNB-DU parts may be, for example, co-located or physically separated. The gNB-DU may even be further split into, for example, two parts, such as a part including processing equipment and a part including antennas. The Central Unit (CU) may also be referred to as the Baseband Unit / Radio Equipment Controller / Cloud-RAN / Virtual-RAN (BBU / REC / C-RAN / V-RAN), Open RAN (O-RAN), or a part thereof. The Distributed Unit (DU) may also be referred to as the Remote Radio Head / Remote Radio Unit / Radio Equipment / Radio Unit (RRH / RRU / RE / RU), or a part thereof. Hereinafter, in various exemplary embodiments of the present disclosure, a network node supporting at least one of the Central Unit functionality or the Layer 3 protocol of the radio access network may be, for example, the gNB-CU. Similarly, a network node supporting at least one of the Distributed Unit functionality or the Layer 2 protocol of the radio access network may be, for example, the gNB-DU.

[0052] The gNB-CU may support one or more gNB-DUs. The gNB-DU may support one or more cells and may thus support the serving cell for the User Equipment (UE) or candidate cells for handover, dual connectivity, and / or carrier aggregation, as well as other procedures.

[0053] The User Equipment (UE) 150 may be or include a wireless or mobile device, a device with a radio interface for interacting with a Radio Access Network (RAN), a smartphone, an in-vehicle device, an IoT device, or an M2M device, and other types of user equipment. This UE 150 may include: at least one processor; and at least one memory including code; wherein the at least one memory and the computer code are configured to use the at least one processor to cause the device to perform at least certain operations, such as, for example, an RRC connection with the RAN. Examples of the components of the UE will be described in connection with FIG. 4. In an embodiment, the UE 150 may be configured to generate a message (e.g., including a cell ID) to be transmitted wirelessly towards the RAN (e.g., to reach the serving cell and communicate with the serving cell). In an embodiment, the UE 150 may generate, transmit, and receive an RRC message containing one or more RRC packet data units (PDUs). Those skilled in the art should understand that the UE may execute the RRC protocol and other procedures.

[0054] Continuing to refer to FIG. 1, in an example of a 5G NR network, the network system 100 provides one or more cells that define the coverage area of the network system 100. As described above, the network system 100 may include a gNB of a 5G NR network or may include any other device configured to control radio communications and manage radio resources within a cell. As used herein, the term "resource" may refer to radio resources such as resource blocks (RBs), physical resource blocks (PRBs), radio frames, subframes, time slots, sub-bands, frequency regions, subcarriers, beams, etc. In an embodiment, the network node 120 may be referred to as a base station.

[0055] FIG. 1 provides an example and only illustrates the network system 100 and the UE 150. Those skilled in the art should understand that the network system 100 includes components not shown in FIG. 1 and should understand that other user equipment may communicate with the network system 100.

[0056] FIG. 2 is a block diagram of exemplary components of the network system 100 of FIG. 1. The 5G NR network may be described as an example of the network system 100, and it is intended that the aspects described below should equally apply to other types of network systems. The network system may operate according to the signals and connections shown in FIG. 1 such that the UE 150 communicates with the network system 100 via the radio access network 225. Additionally, the network system may be divided into user plane components and functions and control plane components and functions, as shown and described herein. Unless otherwise indicated, the terms "component", "function", and "service" may be used interchangeably herein, and these terms may refer to instructions executed by one or more processors and implemented by those instructions.

[0057] Exemplary functions of the components are described below. The exemplary functions are only illustrative, and it should be understood that additional operations and functions may be performed by the components described herein. Additionally, the connections between components may be virtual connections on a service-based interface such that any component may communicate with any other component. In this way, any component may act as a service "producer" for any other component that is a service "consumer" to provide services for network functions.

[0058] For example, the core network 210 is described in the control plane of the network system. The core network 210 may include an Authentication Server Function (AUSF) 211, an Access and Mobility Function (AMF) 212, and a Session Management Function (SMF) 213. The core network 210 may also include a Network Slice Selection Function (NSSF) 214, a Network Exposure Function (NEF) 215, a Network Repository Function (NRF) 216, and a Unified Data Management Function (UDM) 217, and the Unified Data Management Function may include a Schema Data Repository (UDR) 224.

[0059] Additional components and functions of the core network 210 may include an Application Function 218, a Policy Control Function (PCF) 219, a Network Data Analytics Function (NWDAF) 220, an Analytics Data Repository Function (ADRF) 221, a Management Data Analytics Function (MDAF) 222, and an Operation and Administration Function (OAM) 223.

[0060] The user plane includes a UE 150, a Radio Access Network (RAN) 225, a User Plane Function (UPF) 226, and a Data Network (DN) 227. The RAN 225 may include one or more components described in connection with FIG. 1, such as one or more network nodes. However, the RAN 225 may not be limited to these components. The UPF 226 provides a connection for data transmitted via the RAN 225. The DN 226 identifies services, Internet access, and third-party services, for example, from a service provider.

[0061] The AMF 212 processes connection and mobility tasks. The AUSF 211 receives an authentication request from the AMF 212 and interacts with the UDM 217 to authenticate and verify a network response for a successful authentication determination. The SMF 213 performs Packet Data Unit (PDU) session management and manages the session context with the UPF 226.

[0062] The NSSF 214 may select a Network Slice Instance (NSI) and determine a Permitted Network Slice Selection Assistance Information (NSSAI). This selection and determination are used to configure the AMF 212 to provide services to the UE 150. The NEF 215 ensures third-party access to network services to establish dedicated network services. The NRF 216 acts as a repository for storing network functions to allow registration of these functions and discovery of each other.

[0063] The UDM 217 generates authentication vectors for use by the AUSF 211 and the ADM 212 and provides user identification handling. The UDM 217 can be connected to the UDR 224 that stores data related to authentication, applications, or the like. The AF 218 provides application services to users (e.g., streaming services, etc.). The PCF 219 provides policy control functionality. For example, the PCF 219 can assist in network slicing and mobility management, and provide quality of service (QoS) and charging functionality.

[0064] The NWDAF 220 collects data (e.g., from the UE 150 and the network system) to perform network analysis and provide insights into functions that utilize the analysis in providing services. The ADRF 221 allows consumers to store, retrieve, and remove data and analysis. The MDAF 222 provides additional data analysis services for network functions. The OAM 223 provides provisioning and management processing functions to manage components in the network or connected to the network (e.g., the UE 150, network nodes, etc.).

[0065] FIG. 2 is only an example of the components of the network system, and variations are contemplated within the scope of this disclosure. In an embodiment, the network system may include other components not shown in FIG. 2. In an embodiment, the network system may not include every component shown in FIG. 2. In an embodiment, the components and connections may be implemented with connections different from the connections shown in FIG. 2. These and other embodiments are contemplated within the scope of this disclosure.

[0066] Although further details are provided below, as mentioned above, in various embodiments, the UE may be able to operate in N1 mode, where "N1" refers to the interface between the UE and the AMF. Therefore, in order to operate in N1 mode, the UE needs to support the non-access stratum (NAS) protocol in the 5G system (5GS) (e.g., the 5G mobility management (5GMM) protocol). To establish communication, the UE attempts to transmit a registration request to register to the network (e.g., the first network) by using a non-access stratum (NAS) protocol such as the 5GMM protocol. After receiving the registration request message from the UE, the network can reject the request via a network component (e.g., the AMF) in the case where no network slice is available and transmit a registration rejection message to the UE (e.g., via a network node). In various embodiments, the registration rejection message may include a 5GMM cause value #62 message (e.g., indicating that all single network slice selection assistance information (S-NSSAI) is rejected or unavailable).

[0067] In various embodiments, after receiving a registration rejection message, the UE may disable the N1 mode capability. However, if no other radio access technology (RAT) is provided or a network selection procedure is not initiated, the UE may re-enable the N1 mode capability and continue to send registration request messages to the same network to establish communication. In various embodiments, this may create a type of ping-pong effect, where the UE and the network continue to send unnecessary registration requests and registration rejection messages to each other respectively, resulting in overuse of network resources.

[0068] That is, if the UE disables the N1 mode capability for the network because all S-NSSAIs in the configured NSSAI are rejected due to cause value #62 (e.g., "S-NSSAI is not available in the current public land mobile network (PLMN) or stand-alone public network (SNPN)" or "S-NSSAI is not available due to failed or deregistered network slice specific authentication and authorization"), the UE may re-enable the N1 mode capability for the network and the UE may continue to repeatedly transmit registration requests to the same network (e.g., via the RAN), as shown in the current procedures in TS 24.501 for example.

[0069] Therefore, the UE will continue to receive either of the two variant messages described above regarding the 5GMM cause value #62 message of no network slice available, which will continue to trigger the UE to disable the N1 mode capability and, in the case where the network repeatedly does not provide an appropriate RAT, the UE to re-enable the N1 mode capability for the network, thus entering a potential loop.

[0070] Therefore, although further details are provided below, a method is provided herein for the UE to remember (e.g., record) the identifier of the network where no network slice is available to avoid continuously retransmitting registration request messages until an event (e.g., a first event) occurs.

[0071] As used herein, communicating with a radio access network (RAN) may refer to and mean communicating with a part of the RAN, such as communicating with a network node (e.g., DU and / or CU) or another part of the RAN. As used herein, communicating with the core network may refer to and mean communicating with one or more services / applications of the core network, such as the AMF or another service of the core network.

[0072] As used herein, in various embodiments, the term "user equipment" or "UE" may be interchangeable with the term "mobile station" or "MS". For example, in various embodiments, the term user equipment or UE may be used to identify a mobile station or MS connected to a network, or the term mobile station or MS may be used to identify a user equipment or UE connected to a network.

[0073] According to the brief description, FIG. 3 is a diagram of an exemplary embodiment of signals and operations 300 among a UE and an AMF according to one illustrative aspect of the present disclosure. The following paragraphs will describe various signals and operations. It should be understood that the described signals may have associated operations, and the described operations may have associated signals.

[0074] At operation 301, the UE transmits a registration request to the AMF, and the AMF receives the registration request. The registration request includes a request for a NSSAI (S-NSSAI). In various embodiments, those skilled in the art will understand that the registration request is transmitted according to, for example, TS 24.501.

[0075] After receiving the registration request message from the UE, the AMF determines whether the network slice is available and the S-NSSAI is acceptable. If the network slice is not available, then at operation 302, the AMF transmits a registration rejection message to the UE and the UE receives the registration rejection message. In various embodiments, the registration rejection message may include a 5GMM cause #62 "No network slice available" message. In various embodiments, the registration rejection message includes all S-NSSAIs included in the requested NSSAI in the rejected NSSAI of the registration rejection message. In various embodiments, the registration rejection message may include a cause "S-NSSAI is not available in the current PLMN or SNPN" or a cause "S-NSSAI is not available due to failed or deregistered network slice specific authentication and authorization" as the cause of no network slice available. In various embodiments, the cause "S-NSSAI is not available in the current PLMN or SNPN" or the cause "S-NSSAI is not available due to failed or deregistered network slice specific authentication and authorization" may be regarded as a semi-permanent cause.

[0076] Therefore, once the UE receives a registration rejection message from the AMF and meets one or more conditions (e.g., the UE detects that all S-NSSAIs that the UE can request are rejected due to, for example, semi-permanent causes), then at operation 303, the UE deactivates the N1 mode capability.

[0077] At operation 304, unless there is a change, the UE takes an action to avoid accessing the same network. In various embodiments, the change may include an event that causes the UE to start accessing the network (e.g., a first event), and the UE receives an indication that no network slice is available for the network.

[0078] In various embodiments, at operation 304, the UE may maintain a list of PLMNs in which the N1 mode capability is deactivated after receiving a registration rejection message with 5GMM cause #62 "No network slice available" from the network as the PLMNs for which the N1 mode is not allowed due to network slice unavailability. In various embodiments, when the UE deactivates its N1 mode capability after receiving a registration rejection message with 5GMM cause #62 "No network slice available" from the network, the UE may add the identifier or identifier of the PLMN to the list of PLMNs for which the N1 mode is not allowed due to network slice unavailability and may start a timer (which may be referred to as TNSU) if the timer has not been running. In various embodiments, the timer TNSU may be started after the N1 mode capability is deactivated (e.g., based on the deactivation). The number of PLMNs that the UE may store for which the N1 mode is not allowed due to network slice unavailability may be specific to a particular implementation and may include one or more. Additionally, in various embodiments, the value of the timer TNSU may be specific to the UE's implementation, but in various embodiments does not exceed the maximum possible value of the background scanning timer T (e.g., the background scanning timer T as defined in 3GPP TS 23.122).

[0079] In various embodiments, in automatic PLMN selection, unless no other PLMN is available, the UE may utilize the stored information by not considering (e.g., discarding / ignoring) the PLMNs for which the N1 mode is not allowed due to network slice unavailability as PLMN selection candidates for the NG-RAN access technology. In various embodiments, if a PLMN is available for another RAT, the PLMN may be selected as a PLMN candidate for the NG-RAN access technology.

[0080] In various embodiments, when the UE is turned off, the UE may delete the stored information about the PLMN that does not allow the N1 mode due to network slice unavailability, remove the Universal Subscriber Identity Module (USIM) from the UE, the timer TNSU expires, the UE receives a registration acceptance message containing a network slice indication information element (IE), the network slice indication information element includes a network slice subscription change indication set to "network slice subscription change", or the UE removes the S-NSSAI from the rejected NSSAI for the failed or deregistered network slice specific authentication and authorization (NSSAA) service.

[0081] In various embodiments, the UE performs network selection only for PLMNs that are not in the list of PLMNs that do not allow the N1 mode due to network slice unavailability.

[0082] In various embodiments, if the UE does not support either retrieving the SNPN using a certificate from the certificate retainer or retrieving the equivalent SNPN, the UE may maintain the list of SNPNs for which the N1 mode capability is deactivated after receiving a registration rejection message from the network with 5GMM cause #62 "no network slice available". In various embodiments, if the UE supports retrieving the SNPN using a certificate from the certificate retainer that is not a PLMN, supports retrieving the equivalent SNPN, or both, the UE may maintain one or more lists of SNPNs for which the N1 mode capability is deactivated after receiving a registration rejection message from the network with 5GMM cause #62 "no network slice available", where each entry in the list is associated with an entry in the "user profile list".

[0083] In various embodiments, if the UE supports retrieving the SNPN using a certificate from the certificate retainer as a PLMN, the UE may maintain the list of SNPNs for which the N1 mode capability is deactivated after receiving a registration rejection message from the network with 5GMM cause #62 "no network slice available" associated with the PLMN subscription. In various embodiments, if the UE supports retrieving the SNPN using a certificate from the certificate retainer, supports retrieving the equivalent SNPN, or both, the UE may use the list associated with the selected entry or selected PLMN subscription in the "user profile list". When the UE deactivates its N1 mode capability after receiving a registration rejection message from the network with 5GMM cause #62 "no network slice available", the UE may perform operations according to the following.

[0084] In various embodiments, the UE may add the identifier of the SNPN to the list of SNPNs for which the N1 mode is not allowed due to network slice unavailability and start a timer, which may be referred to as T NSU_SNPN, when the timer has stopped running. In various embodiments, the timer T NSU_SNPN may be started after the N1 mode capability is deactivated. The number of identifiers of the SNPNs for which the N1 mode is not allowed due to network slice unavailability that the UE may store may be implementation-specific, but in various embodiments, the number is at least one. In various embodiments, the value of the timer T NSU_SNPN may be specific to the UE implementation.

[0085] In various embodiments, in automatic SNPN selection, unless no other SNPN is available, the UE may utilize the stored information by not considering (e.g., discarding / ignoring) the SNPNs for which the N1 mode is not allowed due to network slice unavailability as candidates for SNPN selection for NG-RAN access technology.

[0086] In various embodiments, when the UE is powered off, the UE may delete the stored information about the SNPNs for which the N1 mode is not allowed due to network slice unavailability, the USIM is removed, the entry in the "Subscriber Data List" for the SNPN is updated, the timer T NSU_SNPN expires, the UE receives a registration acceptance message containing a network slice indication IE that includes a network slice subscription change indication set to "Network slice subscription change", or the MS removes the S-NSSAI from the rejected NSSAI for the failed or deregistered NSSAA service.

[0087] The operations in Figure 3 are illustrative only, and variations are contemplated within the scope of this disclosure. In an embodiment, the operations may include other operations not shown in Figure 3. In an embodiment, the operations may not include every operation shown in Figure 3. In an embodiment, the operations may be performed in an order different from the order shown in Figure 3. These and other embodiments are contemplated within the scope of this disclosure. Those skilled in the art will understand that although various exemplary components are described as performing various functions, other components may perform those functions described in method 300. Additionally, although the above embodiments are described based on the 5G system (5GS), these embodiments may be applied to systems of different generations.

[0088] The operations from the perspective of the UE are described below. From such perspectives, the method includes transmitting, by the UE, a first message to a network node, the first message including a request to access a first network according to the NAS protocol. The UE may receive a second message from the network node, the second message including an indication that no network slice is available to serve the access to the first network requested by the UE. The UE may deactivate the ability to access the network using the NAS protocol based on receiving the second message, store the identifier of the first network, and after storing, utilize the stored identifier of the first network by the UE during a network selection process.

[0089] Referring now to FIG. 4, a block diagram showing exemplary components of a UE or network device (e.g., of a RAN or core network) is presented. The device includes an electronic storage 410, a processor 420, a network interface 440, and a memory 450. The various components may be communicatively coupled to each other. The processor 420 may be and may include any type of processor, such as a single-core central processing unit (CPU), a multi-core CPU, a microprocessor, a digital signal processor (DSP), a system-on-a-chip (SoC), or any other type of processor. The memory 450 may be a volatile type of memory, such as RAM, or a non-volatile type of memory, such as NAND flash memory. The memory 450 includes processor-readable instructions executable by the processor 420 to cause the device to perform various operations, including those operations mentioned herein, such as the operations of FIG. 3.

[0090] The electronic storage 410 may be and include any type of electronic storage for storing data, such as a hard disk drive, a solid-state drive, an optical disk, and / or other non-transitory computer-readable media, as well as other types of electronic storage. The electronic storage 410 stores processor-readable instructions for causing or configured to cause the device to perform its operations and store data associated with such operations, such as storing data related to the 5G NR standard and other data. The network interface 440 may implement wireless network connection technologies, such as 5G NR and / or other wireless network connection technologies.

[0091] The components shown in FIG. 4 are merely examples, and those skilled in the art should understand that the device includes other components not shown and may include multiples of any of the components shown. These and other embodiments are contemplated within the scope of the present disclosure.

[0092] Other embodiments of the present disclosure include the following examples.

[0093] Example 1.1. A device comprising: Components for a user equipment (UE) to transmit a registration request message to a network node according to a non-access stratum (NAS) protocol, the registration request message including a request for one or more single network slice selection assistance information (S-NSSAIs) in a first network; Components for the UE to receive a registration rejection message from the network node, the registration rejection message including a 5G system mobility management (5GMM) cause value #62 "no network slice available" indication; Components for the UE to deactivate N1 mode capability for the first network based on the reception of the registration rejection message; Components for the UE to store an identifier of the first network; and Components for the UE to utilize the stored identifier of the first network during a network selection process after storage.

[0094] Example 1.2. The apparatus as in Example 1.1, wherein the 5GMM cause value #62 "no network slice available" indication includes a cause "S-NSSAI not available due to failed or deregistered network slice specific authentication" indication.

[0095] Example 1.3. The apparatus as in Example 1.1, wherein the first network is a public land mobile network (PLMN) or a stand-alone public network (SNPN).

[0096] Example 1.4. The apparatus as in Example 1.3, wherein the 5GMM cause value #62 "no network slice available" indication includes a cause "S-NSSAI not available in the current PLMN or SNPN" indication.

[0097] Example 1.5. The apparatus as in any one of Examples 1.3 to 1.4, further comprising: the UE adding the identifier of the PLMN to a list listing the PLMNs for which the UE deactivates N1 mode capability.

[0098] Example 1.6. The apparatus as in Example 1.5, further comprising: starting a timer after deactivating N1 mode capability.

[0099] Example 1.7. The apparatus as in Example 1.6, wherein the timer is a TNSU timer.

[0100] Example 1.8. The device as in Example 1.7, wherein a value of the timer T NSU does not exceed a background timer value.

[0101] Example 1.9. The device as in any one of Examples 1.3 to 1.8, further comprising: the UE discarding the PLMN for which the identifier was previously added to the list during the network selection process.

[0102] Example 1.10. The device as in any one of Examples 1.5 to 1.8, further comprising: the UE deleting the identifier of the PLMN from the list when the UE is turned off.

[0103] Example 1.11. The device as in any one of Examples 1.5 to 1.8, further comprising: the UE deleting the identifier of the PLMN from the list after a universal subscriber identity module is removed from the UE.

[0104] Example 1.12. The device as in any one of Examples 1.5 to 1.8, further comprising: the UE deleting the identifier of the PLMN from the list after receiving a registration acceptance message.

[0105] Example 1.13. The device as in any one of Examples 1.5 to 1.8, further comprising: the UE deleting the identifier of the PLMN from the list after a single network slice selection assistance information (S-NSSAI) is removed from a rejected NSSAI due to a failed or deregistered network slice specific authentication and authorization (NSSAA) service.

[0106] Example 1.14. The device as in any one of Examples 1.3 to 1.4, further comprising: the UE adding the identifier of the SNPN to a list listing the SNPNs for which the UE deactivates the N1 mode capability.

[0107] Example 1.15. The device as in Example 1.14, further comprising: starting a timer after deactivating the N1 mode capability.

[0108] Example 1.16. The device as in Example 1.15, wherein the timer is a T NSU_SNPN timer.

[0109] Example 1.17. The device as in Example 1.16, wherein a value of the timer T NSU_SNPN does not exceed a background timer value.

[0110] Example 1.18. The device as in any one of Examples 1.15 to 1.17, further comprising: the UE discards the SNPN for which the identifier was previously added to the list during the network selection process.

[0111] Example 1.19. The device as in any one of Examples 1.15 to 1.17, further comprising: when the UE is turned off, the UE deletes the identifier of the SNPN from the list.

[0112] Example 1.20. The device as in any one of Examples 1.15 to 1.17, further comprising: the UE deletes the identifier of the SNPN from the list after a universal subscriber identity module is removed from the UE.

[0113] Example 1.21. The device as in any one of Examples 1.15 to 1.17, further comprising: the UE deletes the identifier of the SNPN from the list after receiving a registration acceptance message.

[0114] Example 1.22. The device as in any one of Examples 1.15 to 1.17, further comprising: the UE deletes the identifier of the SNPN from the list after a single-network slice selection assistance information (S-NSSAI) is removed from a rejected NSSAI due to a failed or deregistered network slice-specific authentication and authorization (NSSAA) service.

[0115] Example 1.23. The device as in Example 1.1, wherein the network node includes an access and mobility management function (AMF).

[0116] The embodiments and aspects disclosed herein are examples of the present disclosure and can be embodied in various forms. For example, although some embodiments herein are described as separate embodiments, each embodiment herein can be combined with one or more of the other embodiments herein. The specific structural and functional details disclosed herein should not be construed as restrictive, but rather as a basis for the claims and as a representative basis for teaching those skilled in the art to apply the present disclosure in various ways to almost any appropriate detailed structure. In the description of the figures, like reference numerals may refer to like or identical elements.

[0117] According to the present disclosure, the phrases "in one aspect", "in aspects", "in various aspects", "in some aspects", or "in other aspects" may each refer to one or more of the same or different aspects. The phrase "a plurality of" may refer to two or more.

[0118] The phrases "in one embodiment", "in embodiments", "in various embodiments", "in some embodiments", or "in other embodiments" may each refer to one or more of the same or different embodiments according to the present disclosure. A phrase in the form of "A or B" means "(A), (B), or (A and B)". A phrase in the form of "at least one of A, B, or C" means "(A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C)".

[0119] Any of the methods, procedures, algorithms, or code described herein may be converted into a programming language or computer program, or expressed in a programming language or computer program. As used herein, the terms "programming language" and "computer program" each include any language for specifying instructions to a computer, and include (but are not limited to) the following languages and their derivatives: assembler, Basic, batch file, BCPL, C, C+, C++, Delphi, Fortran, Java, JavaScript, machine code, operating system command language, Pascal, Perl, PL1, Python, scripting language, Visual Basic, a meta-language that specifies procedures itself, and all first-generation, second-generation, third-generation, fourth-generation, fifth-generation, or more-generation computer languages. Also included are databases and other data schematics, and any other meta-language. No distinction is made between interpreted, compiled, or both compiled and interpreted methods of the language. No distinction is made between the interpreted version and the compiled version of the program. Thus, a reference to a program that may exist in more than one state (such as source, compiled, object, or linked) for a programming language is a reference to any and all such states. A reference to a program may cover the actual instructions and / or the intent of those instructions.

[0120] Although aspects of the present disclosure have been shown in the drawings, it is not intended that the present disclosure be limited thereto, because it is desired that the present disclosure be as broad as possible within the scope permitted by the art and that this specification be so understood. Thus, the above description should not be construed as restrictive, but only as illustrative of particular aspects. Those skilled in the art will envision other modifications within the scope and spirit of the appended claims hereto.

[0121] 100: Network system 110: Server 120: Network node 130: Network equipment 150: User equipment 210: Core network 211: Authentication server function 212: Access and mobility function 213: Session management function 214: Network slice selection function 215: Network exposure function 216: Network repository function 217: Unified data management function 218: Application function 219: Policy control function 220: Network data analysis function 221: Analysis data repository function 222: Management data analysis function 223: Operation and management function 224: Unified data repository 225: Radio access network 226: User plane function 227: Data network 300: Operation, method 301,302,303,304: Operation 410: Electronic storage 420: Processor 440: Network interface 450: Memory

Claims

1. A method for communication, comprising: transmitting a registration request message from a user equipment (UE) to a network node according to a non-access stratum (NAS) protocol, wherein, The network node includes an Access and Mobility Function (AMF), and the registration request message includes a request for one or more Single Network Slice Selection Assistance Information (S-NSSAI) in a first network, wherein the first network is a Public Mobile Network (PLMN) or a Standalone Non-Public Network (SNPN); the UE receives a registration rejection message from the network node, the registration rejection message including a 5G System Mobility Management (5GMM) reason value 62 (#62) "No network slice available" indication, wherein the registration rejection message includes the reason "S-NSSAI is unavailable in the current PLMN or SNPN" as the reason for no network slice available; the UE disables N1 mode capability for the first network based on the receipt of the registration rejection message; the UE stores an identification code of the first network; after storage, the UE uses the stored identification code of the first network during a network selection process; The UE adds the identifier of the PLMN or SNPN to a list of PLMNs or SNPNs for which the N1 mode capability is disabled; and the UE removes the identifier of the PLMN or SNPN from the list after receiving a registration acceptance message containing a network slice indication information element (IE), the network slice indication information element including a network slice subscription change indication set to "network slice subscription change".

2. As in request item 1, where, The use of this network selection process includes: not considering the first network as a candidate for PLMN and / or SNPN selection for NG-RAN access technology in the automatic PLMN and / or SNPN selection.

3. The method of request item 1 further includes: starting a timer after disabling the N1 mode capability.

4. As in request item 3, where, This timer is a TNSU timer.

5. As in request item 4, where, One of the values ​​of the timer TNSU does not exceed a background timer value.

6. The method of any one of requests 1 to 5 further includes: the PLMN whose identifier was previously targeted and added to the list by the UE during the network selection process.

7. The method of any one of requests 1 to 5 further includes: when the UE is turned off, the UE removes the identifier of the PLMN from the list.

8. The method of any one of requests 1 to 5 further comprises: by the UE, after a general user identification module is removed from the list, the identification code of the PLMN is removed.

9. The method of any one of requests 1 to 5 further comprises: the UE removing the identifier of the PLMN from the list after removing an S-NSSAI from a rejected NSSAI due to a failed or deregistered Network Slice Specific Authentication and Authorization (NSSAA) service.

10. As in request item 3, wherein, This timer is a TNSU_SNPN timer.

11. As in request item 10, wherein, One of the values ​​of the timer TNSU_SNPN does not exceed a background timer value.

12. The method of any of requests 3, 10 or 11, further comprising: the UE discarding the previously targeted SNPN by adding the identifier to the list during the network selection process.

13. The method of any of requests 3, 10 or 11 further comprises: the UE removing the identifier of the SNPN from the list when the UE is turned off.

14. The method of any of requests 3, 10 or 11 further comprises: by the UE, removing the identifier of the SNPN from the list after a general user identification module is removed from the UE.

15. The method of any of requests 3, 10 or 11 further comprises: the UE removing the identifier of the SNPN from the list after removing an S-NSSAI from a rejected NSSAI due to a failed or deregistered Network Slice Specific Authentication and Authorization (NSSAA) service.

16. A user equipment (UE) comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the user equipment to perform at least one of the methods claimed in claims 1 to 15.

17. A processor-readable medium storing instructions that, when executed by at least one processor of a device, cause the device to perform at least one of the methods described in claims 1 to 15.

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