Method, wireless device and system for wireless device paging over a wireless network

Abstract

The wireless device sends a first request to an access and mobility management function (AMF). The first request includes a paging cause value in a paging message. The paging message is received by the wireless device and includes the paging cause value. A second request to establish a connection is sent based on the paging message.

Description

[0001] Divisional application

[0002] This application is a continuation of Chinese Patent Application No. 202080020564.5, titled “WIRELESS DEVICE PAGING OVER A WIRELESS NETWORK,” filed on March 11, 2020, which claims priority to U.S. Provisional Application No. 62 / 816,414, filed on March 11, 2019, which is hereby incorporated by reference in its entirety.

[0003] Cross Reference to Related Applications

[0004] This application claims the benefit of U.S. Provisional Application No. 62 / 816,414, filed on March 11, 2019, which is hereby incorporated by reference in its entirety. BRIEF DESCRIPTION OF DRAWINGS

[0005] Examples of several different embodiments of the present application are described herein with reference to the accompanying drawings.

[0006] Figure 1 is a diagram of an exemplary 5G system architecture according to an aspect of embodiments of the present disclosure;

[0007] Figure 2 is a diagram of an exemplary 5G system architecture according to an aspect of embodiments of the present disclosure;

[0008] Figure 3 is a system diagram of exemplary wireless devices and network nodes in a 5G system according to an aspect of embodiments of the present disclosure;

[0009] Figure 4 is a system diagram of an exemplary wireless device according to an aspect of embodiments of the present disclosure;

[0010] Figure 5A and Figure 5B depicts two registration management state models in a UE 100 and an AMF 155 according to an aspect of embodiments of the present disclosure;

[0011] Figure 6A and Figure 6B depicts two connection management state models in a UE 100 and an AMF 155 according to an aspect of embodiments of the present disclosure;

[0012] Figure 7 is a diagram of classifying and marking traffic according to an aspect of embodiments of the present disclosure;

[0013] Figure 8 is an exemplary call flow according to an aspect of embodiments of the present disclosure;

[0014] Figure 9 is an exemplary call flow according to an aspect of embodiments of the present disclosure;

[0015] Figure 10 is an exemplary call flow according to an aspect of embodiments of the present disclosure;

[0016] Figure 11 is an exemplary call flow according to an aspect of embodiments of the present disclosure;

[0017] Figure 12 is an exemplary call flow according to an aspect of embodiments of the present disclosure;

[0018] Figure 13 is an exemplary call flow according to an aspect of embodiments of the present disclosure;

[0019] Figure 14 is an exemplary radio resource control (RRC) state transition aspect according to an aspect of embodiments of the present disclosure;

[0020] Figure 15 is an exemplary call flow for RRC state transition according to an aspect of embodiments of the present disclosure;

[0021] Figure 16 is an exemplary call flow for RRC state transition reporting to the core network;

[0022] Figure 17 is a diagram of an exemplary 5G system architecture for 3GPP and non-3GPP simultaneous access according to an aspect of embodiments of the present disclosure;

[0023] Figure 18 is an exemplary call flow illustrating simultaneous registration to the same AMF via 3GPP and non-3GPP;

[0024] Figure 19 is a diagram of an exemplary multi-subscriber identity module (SIM) device architecture;

[0025] Figure 20 is a diagram of an exemplary 5G system architecture for dual-SIM devices;

[0026] Figure 21 is a diagram of an exemplary 4G and 5G network architecture for dual-SIM devices;

[0027] Figure 22 is an exemplary call flow for a network triggered service request procedure;

[0028] Figure 23 is an exemplary call flow for a paging procedure in idle state by the core network;

[0029] Figure 24 is an exemplary call flow for a paging procedure in connected mode (RRC-INACTIVE) by the radio access network;

[0030] Figure 25A is an exemplary call flow for downlink packet data unit (PDU) session information transfer;

[0031] Figure 25B is an exemplary format for downlink PDU session information;

[0032] Figure 26A is an exemplary call flow for downlink NAS transfer;

[0033] Figure 26B is an exemplary format for downlink NAS transfer;

[0034] Figure 27 illustrates an exemplary embodiment of the present disclosure;

[0035] Figure 28 illustrates an exemplary embodiment of the present disclosure;

[0036] Figure 29 illustrates an exemplary embodiment of the present disclosure;

[0037] Figure 30 illustrates an exemplary embodiment of the present disclosure;

[0038] Figure 31 illustrates an exemplary embodiment of the present disclosure;

[0039] Figure 32 illustrates an exemplary embodiment of the present disclosure;

[0040] Figure 33A illustrates an exemplary embodiment of the present disclosure;

[0041] Figure 33B illustrates an exemplary embodiment of the present disclosure;

[0042] Figure 34 illustrates an exemplary embodiment of the present disclosure;

[0043] Figure 35 is a flow diagram of an aspect of an exemplary embodiment of the present disclosure;

[0044] Figure 36 is a flow diagram of an aspect of an exemplary embodiment of the present disclosure;

[0045] Figure 37 is a flow diagram of an aspect of an exemplary embodiment of the present disclosure;

[0046] Figure 38 is a flow diagram of an aspect of an exemplary embodiment of the present disclosure;

[0047] Figure 39 is a flow diagram of an aspect of an exemplary embodiment of the present disclosure;

[0048] Figure 40 a flow diagram of one aspect of the exemplary embodiments of the present disclosure;

[0049] Figure 41 a flow diagram of one aspect of the exemplary embodiments of the present disclosure;

[0050] Figure 42 a flow diagram of one aspect of the exemplary embodiments of the present disclosure;

[0051] Figure 43 a flow diagram of one aspect of the exemplary embodiments of the present disclosure. DETAILED DESCRIPTION

[0052] Exemplary embodiments of the present application can implement enhanced features and functions in 4G / 5G systems. Embodiments of the technology disclosed herein can apply to the field of network slicing for 4G / 5G systems and communication systems. More specifically, embodiments of the technology disclosed herein can relate to a 5G core network and 5G system for network slicing in a communication system. Throughout the present disclosure, UE, wireless device, and mobile device can be used interchangeably.

[0053] The following acronyms are used throughout the present disclosure:

[0054] 5G Fifth Generation mobile network

[0055] 5GC 5G Core Network

[0056] 5GS 5G System

[0057] 5G-AN 5G Access Network

[0058] 5QI 5G QoS Indicator

[0059] ACK Acknowledgement

[0060] AF Application Function

[0061] AMF Access and Mobility Management Function

[0062] AN Access Network

[0063] CDR Charging Data Record

[0064] CCNF Common Control Network Function

[0065] CIoT Cellular Internet of Things

[0066] CN Core Network

[0067] CP Control Plane

[0068] DDN Downlink Data Notification

[0069] DL Downlink

[0070] CN data network

[0071] CN data network name

[0072] DRX discontinuous reception

[0073] F-TEID fully qualified TEID

[0074] gNB next generation Node B

[0075] GPSI generic public subscription identifier

[0076] GTP GPRS tunneling protocol

[0077] GUTI global unique temporary identifier

[0078] HPLMN home public land mobile network

[0079] IMSI international mobile subscriber identity

[0080] LADN local area data network

[0081] LI lawful interception

[0082] MEI mobile equipment identifier

[0083] MICO mobile originated connection only

[0084] MME mobility management entity

[0085] MO mobile originating

[0086] MSISDN mobile subscriber ISDN

[0087] MT mobile terminated

[0088] N3IWF non-3GPP interworking function

[0089] NAI network access identifier

[0090] NAS non-access stratum

[0091] NB-IoT narrow band internet of things

[0092] NEF network exposure function

[0093] NF network function

[0094] NGAP next generation application protocol

[0095] NR new radio

[0096] NRF network repository function

[0097] NSI network slice instance

[0098] NSSAI network slice selection assistance information

[0099] NSSF network slice selection function

[0100] OCS online charging system

[0101] OFCS offline charging system

[0102] PCF policy control function

[0103] PDU packet / protocol data unit

[0104] PEI permanent equipment identifier

[0105] PLMN public land mobile network

[0106] PRACH physical random access channel

[0107] RAN radio access network

[0108] QFI QoS flow identity

[0109] RM registration management

[0110] S1-AP S1 application protocol

[0111] SBA service-based architecture

[0112] SEA security anchor function

[0113] SCM security context management

[0114] SI system information

[0115] SIB system information block

[0116] SMF session management function

[0117] SMS short message service

[0118] SMSF SMS function

[0119] S-NSSAI single network slice selection assistance information

[0120] SUCI served user association ID

[0121] SUPI subscriber permanent identifier

[0122] TEID tunnel endpoint identifier

[0123] UE user equipment

[0124] UL uplink

[0125] UL CL uplink classifier

[0126] UPF user plane function

[0127] VPLMN visited public land mobile network

[0128] exemplary Figure 1 and Figure 2 A 5G system is depicted consisting of an access network and a 5G core network. An exemplary 5G access network can include an access network connected to a 5G core network. The access network can include an NG-RAN 105 and / or a non-3GPP AN 165. An exemplary 5G core network can be connected to one or more 5G access networks 5G-AN and / or NG-RANs. The 5G core network can include functional elements or network functions as depicted in exemplary Figure 1 and exemplary Figure 2 The interfaces can be used for communication between functional elements and / or network elements.

[0129] In one example, a network function can be a processing function in a network, which network can have functional behavior and / or interfaces. The network function can be implemented as a network element on dedicated hardware, and / or as a software instance running on dedicated hardware and / or shared hardware, or as a virtualized function instantiated on an appropriate platform. Figure 3 and Figure 4 The network nodes as depicted in

[0130] In one example, an access and mobility management function AMF 155 can include the following functions (some of the AMF 155 functions can be supported in a single instance of the AMF 155): termination of RAN 105 CP interface (N2), termination of NAS (N1), NAS ciphering and integrity protection, registration management, connection management, reachability management, mobility management, lawful intercept (interface to LI system for AMF 155 events), provide transport for access authentication, access authorization, provide transport for session management, SM messages between the UE 100 and the SMF 160, transparent proxy for routing SM messages, access authentication, access authorization, provide transport for SMS messages between the UE 100 and the SMSF, provide transport for interaction with the AUSF 150 and the security anchor function SEA for the UE 100, receive intermediate keys established as a result of the UE 100 authentication process, security context management SCM receives keys from the SEA for the derivation of access network specific keys, and the like.

[0131] In one example, the AMF 155 can support non-3GPP access networks through an N2 interface with the N3IWF 170, through NAS signaling with the UE 100 over the N3IWF 170, authentication of the UE connected through the N3IWF 170, mobility management, authentication, and separate security context state for the UE 100 connected via non-3GPP access 165 or simultaneously connected via 3GPP access 105 and non-3GPP access 165, support of a coordinated RM context valid through 3GPP access 105 and non-3GPP access 165, support of a CM management context for the UE 100 for connection through non-3GPP access, and the like.

[0132] In one example, an AMF 155 region can include one or more AMF 155 sets. An AMF 155 set can include some AMF 155 that serve a given region and / or network slice. In one example, multiple AMF 155 sets can be based on AMF 155 regions and / or network slices. An application identifier can be an identifier that can be mapped to a specific application traffic detection rule. A configured NSSAI can be an NSSAI that can be provided in the UE 100. For a DNN, a DN 115 access identifier (DNAI) can be an identifier of a user plane access DN 115. An initial registration can relate to a UE 100 registration in an RM-DEREGISTERED 500, 520 state. An N2AP UE 100 association can be a logical based UE 100 association between a 5G AN node and an AMF 155. An N2AP UE-TNLA binding can be a binding between an N2AP UE 100 association and a TNL association of a specific transport network layer for a given UE 100.

[0133] In one example, the Session Management Function, SMF 160, can include one or more of the following functions (one or more of the SMF 160 functions can be supported in a single instance of the SMF 160): session management (e.g., session establishment, modify, and release, including tunnel maintenance between UPF 110 and AN 105 nodes), UE 100 IP address allocation and management (including optional authorization), selection and control of UP function, configuration of traffic steering at the UPF 110 to route traffic to proper destination, termination of policy control function interface, policy enforcement and QoS control, lawful intercept (interfaces to SM events and LI system), termination of SM part of NAS messages, downlink data notification, initiation of AN specific SM information, transmission to (R)AN 105 over N2 via AMF 155, determination of SSC mode of a session, roaming functions, handling of local enforcement to apply QoS SLAs (VPLMN), charging data collection and charging interface (VPLMN), lawful intercept (interfaces to SM events and LI system in VPLMN), support for interaction with external DN 115 for transport of signaling via external DN 115, etc. for PDU session authorization / authentication.

[0134] In one example, the User Plane Function, UPF 110, can include one or more of the following functions (some of the UPF 110 functions can be supported in a single instance of the UPF 110): anchor point for Intra- / Inter-RAT mobility (as applicable), external PDU session point of interconnect to DN 115, packet routing and forwarding, user plane part of packet inspection and policy rule enforcement, lawful intercept (UP collection), traffic usage reporting, uplink classifier to support routing traffic flows to the data network, branching point to support multi-homed PDU session, QoS handling for user plane, uplink traffic verification (SDF to QoS flow mapping), transport level packet marking in uplink and downlink, downlink packet buffering, downlink data notification triggering, etc.

[0135] In one example, UE 100 IP address management can include allocation and release of UE 100 IP addresses and / or update of allocated IP addresses. The UE 100 can set the requested PDU type during the PDU session establishment procedure based on its IP stack capabilities and / or configuration. In one example, the SMF 160 can select the PDU type for the PDU session. In one example, if the SMF 160 receives a request with PDU type set to IP, the SMF 160 can select the PDU type IPv4 or IPv6 based on the DNN configuration and / or operator policy. In one example, the SMF 160 can provide a cause value to the UE 100 to indicate whether the other IP version is supported on the DNN. In one example, if the SMF 160 receives a request for PDU type IPv4 or IPv6 and the requested IP version is supported by the DNN, the SMF 160 can select the requested PDU type.

[0136] In example embodiments, 5GC elements and the UE 100 can support the following mechanisms: during the PDU session establishment procedure, the SMF 160 can send an IP address to the UE 100 via SM NAS signaling. Once the PDU session can be established, IPv4 address allocation and / or IPv4 parameter configuration via DHCPv4 can be employed. If IPv6 is supported, IPv6 prefix allocation can be supported via IPv6 stateless auto-configuration. For example, 5GC network elements can support IPv6 parameter configuration via stateless DHCPv6.

[0137] The 5GC can support allocation of static IPv4 addresses and / or static IPv6 prefixes based on subscription information in the UDM 140 and / or per-subscriber, per-DNN configured.

[0138] The User Plane Function (UPF 110) can handle the user plane path of the PDU session. The UPF 110 that provides an interface towards data networks can support the function of a PDU session anchor point.

[0139] In one example, the Policy Control Function, PCF 135, can support a unified policy framework to govern network behavior, provide policy rules to control plane functions to enforce policy rules, implement a front end to access subscription information related to policy decisions in a user data repository (UDR), and / or the like.

[0140] The Network Exposure Function, NEF 125, can provide a means to securely expose services and capabilities offered by 3GPP network functions, translate between information exchanged with AFs 145 and information exchanged with internal network functions, receive information from other network functions, and / or the like.

[0141] In one example, the network repository function, NRF 130, can support a service discovery function that can receive NF discovery requests from NF instances, provide information about discovered NF instances (discovered) to NF instances, and maintain information about available NF instances and their supported services, etc.

[0142] In one example, the NSSF 120 can select a set of network slice instances that serve the UE 100, can determine allowed NSSAI. In one example, the NSSF 120 can determine a set of AMF 155 for providing service for the UE 100 and / or determine a list of candidate AMF 155 155 by querying the NRF 130 based on a configuration.

[0143] In one example, data stored in the UDR can include at least user subscription data including at least subscription identifier, security credentials, access and mobility related subscription data, session related subscription data, policy data, etc.

[0144] In one example, the AUSF 150 can support an authentication server function (AUSF 150).

[0145] In one example, the application function, AF 145, can interact with the 3GPP core network to provide services. In one example, based on operator deployment, an application function can gain operator trust to directly interact with relevant network functions. An application function that is not allowed direct access to network functions can interact with relevant network functions using an external exposure framework (e.g., via the NEF 125).

[0146] In one example, the control plane interface between the (R)AN 105 and the 5G core can support connecting multiple different types of ANs (e.g., 3GPP RAN 105, N3IWF 170 for untrusted access 165) to the 5GC via the control plane protocol. In one example, the N2 AP protocol can be used for both 3GPP access 105 and non-3GPP access 165. In one example, the control plane interface between the (R)AN 105 and the 5G core can support decoupling between the AMF 155 and other functions such as the SMF 160 that can need to control services supported by the AN (e.g., control resources in the UP AN 105 for a PDU session).

[0147] In one example, 5GC can provide policy information from PCF 135 to UE 100. In one example, policy information may include: Access Network Discovery and Selection Policy, UE 100 Routing Selection Policy (URSP), SSC Mode Selection Policy (SSCMSP), Network Slice Selection Policy (NSSP), DNN Selection Policy, Non-Seamless Offload Policy, etc.

[0148] In one example, as exemplary Figure 5A and Figure 5B As described, the Registration Management (RM) can be used to register or deregister UE / User 100 with the network and establish user contexts within the network. Connection Management can be used to establish and release signaling connections between UE100 and AMF 155.

[0149] In one example, UE 100 may register with the network to receive services that require registration. In another example, UE 100 may periodically update its registration with the network to maintain reachability (periodic registration update), or based on mobility (e.g., mobility registration update), or update its capabilities or renegotiate protocol parameters.

[0150] In one example, as exemplary Figure 8 and Figure 9 The described initial registration process may involve the execution of network access control functions (e.g., user authentication and access authorization based on subscription profiles in UDM 140). Example Figure 9 yes Figure 8 This is a continuation of the initial registration process described in [the document]. As a result of the initial registration process, the AMF 155 identifier for the service can be registered in UDM 140.

[0151] In one example, the Registration Management (RM) process can be applied to both 3GPP Access 105 and non-3GPP Access 165.

[0152] Example Figure 5AThe RM state of UE 100 as observed by UE 100 and AMF 155 can be depicted. In an exemplary embodiment, two RM states that can reflect the registration status of UE 100 in the selected PLMN can be employed in UE 100 and AMF 155: RM-DEREGISTERED 500 and RM-REGISTERED 510. In one example, in RM-DEREGISTERED state 500, UE 100 may not be registered with the network. The UE 100 context in AMF 155 may not maintain valid location or routing information for UE 100, therefore UE 100 may be unreachable from AMF 155. In one example, the UE 100 context may be stored in both UE 100 and AMF 155. In one example, in RM-DEREGISTERED state 510, UE 100 may not be registered with the network. In RM-REGISTERED state 510, UE 100 can receive services that may require registration with the network.

[0153] In an exemplary embodiment, two RM states that can reflect the registration status of the UE 100 in the selected PLMN can be adopted in the AMF 155 for the UE 100: RM-DEREGISTERED 520 and RM-REGISTERED 530.

[0154] As exemplary Figure 6A and Figure 6B As described, the connection management CM may include establishing and releasing signaling connections between UE 100 and AMF 155 via the N1 interface. Signaling connections may be used to implement NAS signaling exchange between UE 100 and the core network. The signaling connection between UE 100 and AMF 155 may include an AN signaling connection between UE 100 and (R)AN 105 (e.g., an RRC connection via 3GPP access) and an N2 connection between AN for UE 100 and AMF 155.

[0155] As exemplary Figure 6A and Figure 6BAs depicted, two CM states can be used for UE 100 NAS signaling connectivity with AMF 155, CM-IDLE 600, 620 and CM-CONNECTED 610, 630. A UE 100 in CM-IDLE 600 state can be in RM-REGISTERED 510 state and can not have a NAS signaling connection established with AMF 155 over N1. UE 100 can perform cell selection, cell reselection, PLMN selection, etc. A UE 100 in CM-CONNECTED 610 state can have a NAS signaling connection with AMF 155 over N1.

[0156] In an example embodiment, two CM states can be employed for UE 100 at AMF 155, CM-IDLE 620 and CM-CONNECTED 630.

[0157] In one example, an RRC inactive state can be applied for NG-RAN (e.g., it can be applied for NR and E-UTRA connected to 5G CN). Based on network configuration, AMF 155 can provide assistance information to NG RAN 105 to help NG RAN 105 decide whether UE 100 can be sent to RRC inactive state. When UE 100 is in CM-CONNECTED 610 in RRC inactive state, UE 100 can resume RRC connection due to uplink data pending, mobile originated signaling procedure, in response to RAN 105 paging to inform the network that it has left the RAN 105 notification area, etc.

[0158] In one example, NAS signaling connection management can include establishment and release of NAS signaling connection. NAS signaling connection establishment function can be provided by UE 100 and AMF 155 in order to establish a NAS signaling connection for UE 100 in CM-IDLE 600 state. The procedure to release a NAS signaling connection can be initiated by a 5G (R)AN 105 node or AMF 155.

[0159] In one example, UE 100 reachability management can detect whether UE 100 is reachable and can provide the network with a UE 100 location (e.g., access node) to reach UE 100. Reachability management can be accomplished by paging UE 100 and UE 100 location tracking. UE 100 location tracking can include both UE 100 registration area tracking and UE 100 reachability tracking. UE 100 and AMF 155 can negotiate UE 100 reachability characteristics for UE 100 in CM-IDLE 600, 620 state during registration and registration update procedures.

[0160] In one example, for CM-IDLE 600, 620 state, two UE 100 reachability categories can be negotiated between the UE 100 and the AMF 155. 1) UE 100 reachability allows mobile device termination of data when the UE 100 is in CM-IDLE 600 mode. 2) Mobile initiated connection only (MICO) mode. The 5GC can support a PDU connectivity service that provides exchange of PDUs between the UE 100 and a data network identified by a DNN. The PDU connectivity service can be supported via a PDU session established upon request from the UE 100.

[0161] In one example, a PDU session can support one or more PDU session types. The PDU session 160 can be established (e.g., upon request from the UE 100), modified (e.g., upon request from the UE 100 and the 5GC), and / or released (e.g., upon request from the UE 100 and the 5GC) using NAS SM signaling exchanged between the UE 100 and the SMF over N1. Upon request from an application server, the 5GC can be able to trigger a specific application in the UE 100. Upon receiving the trigger, the UE 100 can send it to an application identified in the UE 100. The application represented in the UE 100 can establish a PDU session with a specific DNN.

[0162] In one example, the 5G QoS model can support a QoS flow based framework, as exemplified in FIG. 7. The 5G QoS model can support QoS flows that require guaranteed flow bit rates and QoS flows that can not require guaranteed flow bit rates. In one example, the 5G QoS model can support reflective QoS. The QoS model can include flow mapping or packet marking at the UPF 110 (CN_UP) 110, the AN 105, and / or the UE 100. In one example, the packets can be from and / or to the application / service layer 730 of the UE 100, the UPF 110 (CN_UP) 110, and / or the AF 145. Figure 7

[0163] In one example, a QoS flow can be a granularity of QoS differentiation in a PDU session. A QoS flow ID, QFI, can be used to identify a QoS flow in the 5G system. In one example, user plane traffic with the same QFI within a PDU session can receive the same traffic forwarding treatment. The QFI can be carried in encapsulation headers over N3 and / or N9 (e.g., without any changes to the end-to-end packet header). In one example, the QFI can be applied to PDUs with different types of payloads. The QFI can be unique in a PDU session.

[0164] ​In one example, QoS parameters for a QoS flow can be provided to the (R)AN 105 as a QoS profile at PDU session establishment time, at QoS flow establishment time, or at each time the user plane is activated using NG-RAN over N2. In one example, each PDU session can need a default QoS rule. The SMF 160 can allocate a QFI for a QoS flow and can derive QoS parameters from information provided by the PCF 135. In one example, the SMF 160 can provide the QFI to the (R)AN 105 together with a QoS profile containing QoS parameters for the QoS flow.

[0165] In one example, a 5G QoS flow can be the granularity of QoS forwarding treatment in a 5G system. Traffic mapped to the same 5G QoS flow can receive the same forwarding treatment (e.g., scheduling policy, queue management policy, rate shaping policy, RLC configuration, etc.). In one example, providing different QoS forwarding treatment can require separate 5G QoS flows.

[0166] In one example, a 5G QoS indicator can be a scalar that can be used as a reference to a specific QoS forwarding behavior (e.g., packet loss rate, packet delay budget) that will be provided to a 5G QoS flow. In one example, a 5G QoS indicator can be implemented in an access network through node-specific parameters that can control QoS forwarding treatment (e.g., scheduling weight, admission threshold, queue management threshold, link layer protocol configuration, etc.) referenced by a 5QI.

[0167] In one example, the 5GC can support edge computing and can enable operator and 3rd party services to be hosted close to the UE's 100 point of attachment. The 5G core network can select a UPF 110 close to the UE 100 and can perform traffic steering from the UPF 110 to local data networks via the N6 interface. In one example, the selection and traffic steering can be based on the UE 100 location, subscription data of the UE 100, information from application functions AF 145, policies, other relevant traffic rules, etc. In one example, the 5G core network can expose network information and capabilities to edge computing application functions. The functional support for edge computing can include: local breakout where the 5G core network can select a UPF 110 to route user traffic to a local data network; traffic steering where the 5G core network can select traffic to be routed to applications in a local data network; session and service continuity to enable UE 100 and application mobility; user plane selection and reselection, e.g., based on input from application functions; network capability exposure where the 5G core network and application functions can provide information for each other via NEf 125; QoS and charging where the PCF 135 can provide rules for QoS control and charging for traffic routed to a local data network; support for local area data networks where the 5G core network can support LADN connected to a certain area where applications are deployed, etc.

[0168] An example 5G system can be a 3GPP system including a 5G access network 105, a 5G core network, and a UE 100. Allowed NSSAI can be NSSAI provided by a serving PLMN during, for example, a registration procedure, indicating a network allowed NSSAI for the UE 100 in the serving PLMN for the current registration area.

[0169] In one example, a PDU connection service can provide exchange of PDUs between the UE 100 and a data network. A PDU session can be an association between the UE 100 and a data network DN 115 that can provide a PDU connection service. The association type can be IP, Ethernet, and / or unstructured.

[0170] Establishing a user plane connection to a data network via a network slice instance can include the following operations: performing a RM procedure to select an AMF 155 that supports a required network slice, and establishing one or more PDU sessions to a required data network via the network slice instance.

[0171] In one example, the set of network slices for the UE 100 can change at any time when the UE 100 can be registered with the network, and can be initiated by the network or the UE 100.

[0172] In one example, a periodic registration update can be a re-registration of the UE 100 upon expiry of a periodic registration timer. The requested NSSAI can be the NSSAI that the UE 100 can provide to the network.

[0173] In one example, a service-based interface can represent the way a given NF can provide / expose a set of services.

[0174] In one example, service continuity can be an uninterrupted user experience of a service, including cases where IP address and / or anchor point can change. In one example, session continuity can refer to continuity of a PDU session. For IP type of PDU session, session continuity can mean that the IP address is preserved for the lifetime of the PDU session. An uplink classifier can be a UPF 110 function that aims to divert uplink traffic towards a data network, DN 115, based on filter rules provided by the SMF 160.

[0175] In one example, a 5G system architecture can support data connectivity and services, enabling deployments to use technologies such as network function virtualization and / or software defined networking. The 5G system architecture can utilize service-based interaction among identified control plane (CP) network functions. In the 5G system architecture, it can be considered to separate user plane (UP) functions from control plane functions. If needed, the 5G system can enable network functions to directly interact with other NFs.

[0176] In one example, a 5G system can reduce dependencies between an access network (AN) and a core network (CN). The architecture can include an aggregated access agnostic core network with a generic AN-CN interface that can integrate different 3GPP and non-3GPP access types.

[0177] In one example, a 5G system can support a unified authentication framework, stateless NFs, where compute resources are separated from storage resources, capability exposure, and concurrent access to local and centralized services. To support low latency services and access to local data networks, UP functions can be deployed close to the access network.

[0178] In one example, a 5G system can support the use of home network routing traffic and / or local breakout traffic roaming in visited PLMNs. An example 5G architecture can be service-based, and interactions between network functions can be represented in two ways. (1) As service-based representation (in example Figure 1(1) Face representation, depicting the network functions within the control plane that can enable other authorized network functions to access their services. This representation can also include point-to-point reference points, if necessary. (2) Reference point representation, showing the interactions between NF services in network functions described by point-to-point reference points (e.g., N11) between any two network functions.

[0179] In one example, a network slice can include core network control plane and user plane network functions, 5G radio access network; N3IWF acting on non-3GPP access networks and / or the like. Network slices can differ in supported features and network function implementations. An operator can deploy multiple network slice instances providing the same features but targeted for different groups of UEs, e.g., because they offer different committed services and / or because they can be committed to serve customers. The NSSF 120 can store mapping information between slice instance IDs and NF IDs (or NF addresses).

[0180] In one example, a UE 100 can be simultaneously served by one or more network slice instances via a 5G-AN. In one example, a UE 100 can be served by k network slices at a time (e.g., k = 8, 16, etc.). An AMF 155 instance logically serving the UE 100 can belong to a network slice instance serving the UE 100.

[0181] In one example, a PDU session can belong to one specific network slice instance based on a PLMN. In one example, different network slice instances can not share a PDU session. Different slices can have slice-specific PDU sessions using the same DNN.

[0182] An S-NSSAI (Single-Network Slice Selection Assistance Information) can identify a network slice. An S-NSSAI can include a slice / service type (SST), which can refer to the intended network slice behavior in terms of features and services; and / or a slice differentiator (SD). The slice differentiator can be optional information that can complement the slice / service type to allow further differentiation to select a network slice instance from possibly multiple network slice instances conforming to the indicated slice / service type. In one example, different S-NSSAIs can be employed to select the same network slice instance. The CN part of the network slice instance serving the UE 100 can be selected by the CN.

[0183] In one example, the subscription data can include S-NSSAI of network slices to which the UE 100 is subscribed. One or more S-NSSAI can be marked as a default S-NSSAI. In one example, k S-NSSAI can be marked as a default S-NSSAI (e.g., k = 8, 16, etc.). In one example, the UE 100 can subscribe to more than 8 S-NSSAI.

[0184] In one example, the UE 100 can be configured by the HPLMN with a PLMN based configured NSSAI. Upon successful completion of the registration procedure of the UE, the UE 100 can obtain from the AMF 155 allowed NSSAI for the PLMN, which can include one or more S-NSSAI.

[0185] In one example, the priority of the allowed NSSAI can be higher than the configured NSSAI of the PLMN. The UE 100 can use the S-NSSAI in the allowed NSSAI corresponding to a network slice for subsequent network slice selection related procedures in the PLMN of the service.

[0186] In one example, establishing a user plane connection to a data network via a network slice instance can include performing a RM procedure to select an AMF 155 that can support a required network slice, establishing one or more PDU sessions with a required data network via a network slice instance, etc.

[0187] In one example, when the UE 100 registers with a PLMN, if the UE 100 has a configured NSSAI or an allowed NSSAI for the PLMN, the UE 100 can provide to the network in RRC and NAS layers a requested NSSAI including S-NSSAI corresponding to slices that the UE 100 attempts to register, a temporary user ID if the UE is assigned one, etc. The requested NSSAI can be a configured NSSAI, an allowed NSSAI, etc.

[0188] In one example, when the UE 100 registers with a PLMN, if the UE 100 has no configured NSSAI or allowed NSSAI for the PLMN, the RAN 105 can route NAS signaling from the UE 100 to a default AMF 155 or from the default AMF to the UE.

[0189] In one example, based on local policy, subscription changes, and / or UE 100 mobility, the network can change the set of allowed network slices to which the UE 100 is registered. In one example, the network can perform the change during a registration procedure or trigger a change to the UE 100 to be informed of the supported network slices using a RM procedure (which can trigger a registration procedure). The network can provide the UE 100 with a new allowed NSSAI and a list of tracking areas.

[0190] In one example, during a registration procedure in a PLMN, if the network decides based on network slice aspects that the UE 100 should be served by a different AMF 155, the AMF 155 that first receives the registration request can redirect the registration request to another AMF 155 via the RAN 105 or via direct signaling between the initial AMF 155 and the target AMF 155.

[0191] In one example, a network operator can provide a UE 100 with a network slice selection policy (NSSP). The NSSP can include one or more NSSP rules.

[0192] In one example, if the UE 100 has one or more PDU sessions established corresponding to a particular S-NSSAI, the UE 100 can route user data for an application in one of the PDU sessions unless other conditions in the UE 100 can prohibit the use of the PDU session. If the application provides a DNN, the UE 100 can consider the DNN to determine which PDU session to use. In one example, if the UE 100 does not have a PDU session established with a particular S-NSSAI, the UE 100 can request a new PDU session corresponding to the S-NSSAI and with a DNN that can be provided by the application. In one example, for the RAN 105 to select appropriate resources to support network slices in the RAN 105, the RAN 105 can be aware of the network slices used by the UE 100.

[0193] In one example, when the UE 100 triggers establishment of a PDU session, the AMF 155 can select an SMF 160 in a network slice instance based on the S-NSSAI, the DNN, and / or other information such as UE 100 subscription and local operator policy. The selected SMF 160 can establish the PDU session based on the S-NSSAI and the DNN.

[0194] In one example, to support network-controlled privacy of slice information that the UE 100 can access, the UE 100 can not include the NSSAI in NAS signaling when the UE 100 knows or is configured that privacy considerations can apply to the NSSAI, unless the UE 100 has a NAS security context, and the UE 100 can not include the NSSAI in unprotected RRC signaling.

[0195] In one example, for roaming scenarios, network slice-specific network functions in the VPLMN and HPLMN can be selected based on the S-NSSAI provided by the UE 100 during PDU connection establishment. If standardized S-NSSAI is used, the selection of slice-specific NF instances can be done by each PLMN based on the provided S-NSSAI. In one example, the VPLMN can map the S-NSSAI of the HPLMN to S-NSSAI of the VPLMN based on roaming agreements (e.g., including mapping to a default S-NSSAI of the VPLMN). In one example, the selection of slice-specific NF instances in the VPLMN can be done based on the S-NSSAI of the VPLMN. In one example, the selection of any slice-specific NF instances in the HPLMN can be based on the S-NSSAI of the HPLMN.

[0196] As depicted in example Figure 8 and Figure 9 The registration procedure can be performed by the UE 100 to be authorized to receive services, enable mobility tracking, enable reachability, etc.

[0197] In one example, the UE 100 can send an AN message 805 (including AN parameters, RM-NAS registration request (registration type, SUCI or SUPI or 5G-GUTI, last visited TAI (if available), security parameters, requested NSSAI, mapping of requested NSSAI, UE 100 5GC capabilities, PDU session status, PDU sessions to be reactivated, follow on request, MICO mode preference, etc.), etc.) to the (R)AN 105. In one example, in the case of NG-RAN, the AN parameters can include, for example, SUCI or SUPI or 5G-GUTI, selected PLMN ID and requested NSSAI, etc. In one example, the AN parameters can include an establishment cause. The establishment cause can provide a reason for requesting establishment of an RRC connection. In one example, the registration type can indicate whether the UE 100 wants to perform an initial registration (i.e., the UE 100 is in an RM-DEREGISTERED state), a mobility registration update (e.g., the UE 100 is in an RM-REGISTERED state and initiates the registration procedure due to mobility), a periodic registration update (e.g., the UE 100 is in an RM-REGISTERED state and can initiate the registration procedure due to periodic registration update timer expiry), or an emergency registration (e.g., the UE 100 is in a limited service state). In one example, if the UE 100 performs an initial registration to a PLMN for which the UE 100 does not yet have a 5G-GUTI (i.e., the UE 100 is in an RM-DEREGISTERED state), the UE 100 can include its SUCI or the SUPI in the registration request. The SUCI can be included if the home network has provided a public key to protect the SUPI in the UE. If the UE 100 receives a UE 100 configuration update command indicating that the UE 100 needs to re-register and the 5G-GUTI is invalid, the UE 100 can perform an initial registration and can include the SUPI in the registration request message. For an emergency registration, the SUPI can be included if the UE 100 does not have a valid 5G-GUTI available; the PEI can be included when the UE 100 does not have a SUPI and no valid 5G-GUTI. In other cases, the 5G-GUTI can be included and it can indicate the last serving AMF 155. If the UE 100 has registered in a PLMN (e.g., not the registered PLMN or an equivalent PLMN of the registered PLMN) via non-3GPP access different from 3GPP access, the UE 100 can not provide the 5G-GUTI assigned by the AMF 155 through 3GPP access during the registration procedure over non-3GPP access.If the UE 100 has registered in a PLMN (e.g., a registered PLMN) different from the new PLMN of the non-3GPP access (i.e., not the registered PLMN or the equivalent PLMN of the registered PLMN) via 3GPP access, the UE 100 can not provide the 5G-GUTI assigned by the AMF 155 over the non-3GPP access during the registration procedure over 3GPP access. The UE 100 can provide the UE's usage settings based on its configuration. In case of initial registration or mobility registration update, the UE 100 can include a mapping of the requested NSSAI, which can be each S-NSSAI of the requested NSSAI to an S-NSSAI of the configured NSSAI for the HPLMN, to ensure that the network is able to verify whether the S-NSSAI in the requested NSSAI is permitted based on the subscribed S-NSSAI. If available, the last visited TAI can be included in order to help the AMF 155 to produce the registration area for the UE. In one example, security parameters can be used for authentication and integrity protection. The requested NSSAI can indicate the network slice selection assistance information. The PDU session status can indicate the previously established PDU sessions in the UE. When the UE 100 is connected to two AMFs 155 belonging to different PLMNs via 3GPP access and non-3GPP access, the PDU session status can indicate the established PDU sessions for the current PLMN in the UE. The PDU sessions to be reactivated can be included to indicate that the UE 100 can intend to activate the PDU sessions for UP connectivity. When the UE 100 is outside the available area of a LADN, the PDU session corresponding to the LADN can not be included in the PDU sessions to be reactivated. When the UE 100 can have pending uplink signaling and the UE 100 can not include the PDU sessions to be reactivated, the subsequent request can be included, or the registration type can indicate that the UE 100 can want to perform an emergency registration.

[0198] In one example, if the SUPI or the 5G-GUTI is included or does not indicate a valid AMF 155, the (R)AN 105 can select 808 an AMF 155 based on the (R)AT and the requested NSSAI, if available. If the UE 100 is in CM-CONNECTED state, the (R)AN 105 can forward the registration request message to the AMF 155 based on the UE's N2 connection. If the (R)AN 105 can not select a suitable AMF 155, it can forward the registration request to an AMF 155 configured in the (R)AN 105 to perform the AMF 155 selection 808.

[0199] In one example, the (R)AN 105 can send an N2 message 810 (including: N2 parameters, RM-NAS registration request (registration type, SUPI or 5G-GUTI, last visited TAI (if available), security parameters, requested NSSAI, mapping of requested NSSAI, UE 1005 GC capability, PDU session status, PDU sessions to be reactivated, follow-up request, and MICO mode preference), etc.) to the new AMF 155. In one example, when NG-RAN is used, the N2 parameters can include the selected PLMN ID, location information, cell identity, and RAT type related to the cell in which the UE 100 is camped. In one example, when NG-RAN is used, the N2 parameters can include the establishment cause.

[0200] In one example, the new AMF 155 can send a Namf_Communication_UEContextTransfer (full registration request) 815 to the old AMF 155. In one example, if the UE’s 5G-GUTI is included in the registration request and the serving AMF 155 has changed since the last registration procedure, the new AMF 155 can invoke the Namf_Communication_UEContextTransfer service operation 815 on the old AMF 155 including the full registration request IE, which can be integrity protected, for requesting the UE’s SUPI and MM context. The old AMF 155 can use the integrity protected full registration request IE to verify that the context transfer service operation invocation corresponds to the requesting UE 100. In one example, the old AMF 155 can transfer the event subscription information for the UE to the new AMF 155 by per NF consumer. In one example, the SUPI request can be skipped if the UE 100 identifies itself with a PEI.

[0201] In one example, the old AMF 155 can send a response 815 to Namf_Communication_UEContextTransfer (SUPI, MM context, SMF 160 information, PCF ID) to the new AMF 155. In one example, the old AMF 155 can respond to the new AMF 155 invoking Namf_Communication_UEContextTransfer by including the SUPI of the UE and the MM context. In one example, if the old AMF 155 keeps information about established PDU Sessions, the old AMF 155 can include SMF 160 information including S-NSSAI, SMF 160 identity, and PDU Session ID. In one example, if the old AMF 155 keeps information about active NGAP UE-TNLA bindings to N3IWF, the old AMF 155 can include information about the NGAP UE-TNLA bindings.

[0202] In one example, if the SUPI is not provided by the UE 100 nor retrieved from the old AMF 155, the identity request procedure 820 can be initiated by the AMF 155 sending an identity request message to the UE 100 to request a SUCI.

[0203] In one example, the UE 100 can respond with an identity response message 820 including a SUCI. The UE 100 can derive the SUCI by using the provided public key of the HPLMN.

[0204] In one example, the AMF 155 can decide to initiate UE 100 authentication 825 by invoking the AUSF 150. The AMF 155 can select the AUSF 150 based on the SUPI or the SUCI. In one example, if the AMF 155 is configured to support emergency registration of unauthenticated SUPI and the UE 100 indicates a registration type of emergency registration, the AMF 155 can skip authentication and security setup, or the AMF 155 can accept that authentication can fail and can continue the registration procedure.

[0205] In one example, authentication 830 can be performed by the Nudm_UEAuthenticate_Get operation. The AUSF 150 can discover the UDM 140. In case the AMF 155 provided the SUCI to the AUSF 150, the AUSF 150 can return the SUPI to the AMF 155 after the authentication is successful. In one example, if network slicing is used, the AMF 155 can decide if the registration request needs to be rerouted, where the initial AMF 155 refers to the AMF 155. In one example, the AMF 155 can initiate NAS security functions. In one example, after completing the NAS security function setup, the AMF 155 can initiate an NGAP procedure to enable the 5G-AN to use it to protect procedures with the UE. In one example, the 5G-AN can store the security context and can acknowledge to the AMF 155. The 5G-AN can use the security context to protect messages exchanged with the UE.

[0206] In one example, the new AMF 155 can send a Namf_Communication_RegistrationCompleteNotify 835 to the old AMF 155. If the AMF 155 has changed, the new AMF 155 can notify the old AMF 155 that the registration of the UE 100 in the new AMF 155 can be completed by invoking the Namf_Communication_RegistrationCompleteNotify service operation. If the authentication / security procedure failed, the registration can be rejected and the new AMF 155 can invoke the Namf_Communication_RegistrationCompleteNotify service operation with a rejection indication cause code to the old AMF 155. The old AMF 155 can continue as if it never received the UE 100 context transfer service operation. If one or more S-NSSAI that was in use in the old registration area can not be served in the target registration area, the new AMF 155 can determine which PDU sessions can not be supported in the new registration area. The new AMF 155 can invoke the Namf_Communication_RegistrationCompleteNotify service operation including the rejected PDU session IDs and the rejection reason to the old AMF 155 (e.g., S-NSSAI became unavailable). The new AMF 155 can modify the PDU session status accordingly. The old AMF 155 can notify the corresponding SMF 160 to release the UE’s SM context locally by invoking the Nsmf_PDUSession_ReleaseSMContext service operation.

[0207] In one example, the new AMF 155 can send an identity request / response 840 (e.g., PEI) to the UE 100. If the PEI is neither provided by the UE 100 nor retrieved from the old AMF 155, the identity request procedure can be initiated by the AMF 155 sending an identity request message to the UE 100 to retrieve the PEI. The PEI can be transmitted encrypted unless the UE 100 performs emergency registration and can not be authenticated. For emergency registration, the UE 100 can have included the PEI in the registration request.

[0208] In one example, the new AMF 155 can initiate the ME identity check 845 by invoking the N5g-eir_EquipmentIdentityCheck_Get service operation 845.

[0209] In one example, the new AMF 155 can select 905 the UDM 140 based on the SUPI. The UDM 140 can select a UDR instance. In one example, the AMF 155 can select the UDM 140.

[0210] In one example, if the AMF 155 has changed since the last registration procedure, or if the SUPI provided by the UE 100 can not refer to a valid context in the AMF 155, or if the UE 100 registers to the same AMF 155 that it has registered to for non-3GPP access (e.g., the UE 100 is registered over non-3GPP access and can initiate the registration procedure to add 3GPP access), the new AMF 155 can register to the UDM 140 using Nudm_UECM_Registration 910 and can subscribe to be notified when the UDM 140 can deregister the AMF 155. The UDM 140 can store the AMF 155 identity associated with the access type and can not remove the AMF 155 identities associated with other access types. The UDM 140 can store the information provided at registration in the UDR through Nudr_UDM_Update. In one example, the AMF 155 can use Nudm_SDM_Get 915 to retrieve the access and mobile subscription data and the SMF 160 selection subscription data. The UDM 140 can retrieve this information from the UDR through Nudr_UDM_Query (Access and Mobile Subscription Data). Upon receiving a success response, the AMF 155 can subscribe to notifications using Nudm_SDM_Subscribe 920 when the requested data can be modified. The UDM 140 can subscribe to the UDR through Nudr_UDM_Subscribe. If the GPSI is available in the UE 100 subscription data, the GPSI can be provided to the AMF 155 in the subscription data from the UDM 140. In one example, the new AMF 155 can provide the UDM 140 the access type it serves for the UE 100 and the access type can be set to 3GPP access. The UDM 140 can store the associated access type in the UDR with the serving AMF 155 through Nudr_UDM_Update. After obtaining the mobile subscription data from the UDM 140, the new AMF 155 can create an MM context for the UE 100. In one example, when the UDM 140 stores the associated access type with the serving AMF 155, the UDM 140 can initiate Nudm_UECM_DeregistrationNotification 921 to the old AMF 155 corresponding to 3GPP access. The old AMF 155 can remove the MM context for the UE. If the serving NF removal reason indicated by the UDM 140 is initial registration, the old AMF 155 can invoke the Namf_EventExposure_Notify service operation for all associated SMF 160 for the UE 100 to notify the UE 100 deregistered from the old AMF 155.The SMF 160 can release the PDU session upon obtaining the notification. In one example, the old AMF 155 can unsubscribe from the subscription data using Nudm_SDM_unsubscribe 922 to the UDM 140.

[0211] In one example, the AMF 155 can select 925 a PCF 135 if the AMF 155 decides to initiate PCF 135 communication, for example, the AMF 155 has not obtained the access and mobility policy for the UE 100, or if the access and mobility policy in the AMF 155 is no longer valid. The AMF 155 can select the PCF 135 identified by the PCF ID if the new AMF 155 receives the PCF ID from the old AMF 155 and successfully contacts the PCF 135 identified by the PCF ID. The AMF 155 can select 925 the PCF 135 identified by the PCF ID if the PCF 135 identified by the PCF ID can not be used (e.g., no response from the PCF 135) or if the PCF ID is not received from the old AMF 155.

[0212] In one example, the new AMF 155 can perform policy association establishment 930 during the registration procedure. The new AMF 155 can include the PCF-ID in the Npcf AMPolicyControl Get operation if the new AMF 155 contacts the PCF 135 identified by the (V-)PCF ID received during the inter-AMF 155 mobility. The PCF 135 can provide the updated mobility restrictions to the AMF 155 if the AMF 155 informs the mobility restrictions (e.g., UE 100 location) to the PCF 135 for adjustment, or if the PCF 135 updates the mobility restrictions itself due to certain conditions (e.g., applications in use, time and date).

[0213] In one example, the PCF 135 can invoke the Namf EventExposure Subscribe service operation 935 for UE 100 event subscription.

[0214] In one example, the AMF 155 can send an Nsmf_PDUSession_UpdateSMContext 936 to the SMF 160. In one example, the AMF 155 can invoke Nsmf_PDUSession_UpdateSMContext if the PDU sessions to be reactivated are included in the registration request. The AMF 155 can send an Nsmf_PDUSession_UpdateSMContext request to the SMF 160 associated with the PDU session to activate the user plane connection of the PDU session. The SMF 160 can decide to trigger intermediate UPF 110 insertion, removal, or change of e.g. PSA. In case of intermediate UPF 110 insertion, removal, or relocation for PDU sessions not included in the PDU sessions to be reactivated, this flow can be performed without N11 and N2 interaction to update the N3 user plane between the (R)AN 105 and 5GC. If any PDU session status indicates that it is released at the UE 100, the AMF 155 can invoke the Nsmf_PDUSession_ReleaseSMContext service operation to the SMF 160. The AMF 155 can invoke the Nsmf_PDUSession_ReleaseSMContext service operation to the SMF 160 in order to release any network resources related to the PDU session.

[0215] In one example, the new AMF 155 can send an N2 AMF 155 mobility request 940 to the N3IWF. If the AMF 155 has changed, the new AMF 155 can create an NGAP UE 100 association with the N3IWF to which the UE 100 is connected. In one example, the N3IWF can respond to the new AMF 155 with an N2 AMF 155 mobility response 940.

[0216] In one example, the new AMF 155 can send a registration accept 955 to the UE 100 (including: 5G-GUTI, registration area, mobility restrictions, PDU session status, allowed NSSAI, [mapping of allowed NSSAI], periodic registration update timer, LADN information, and accepted MICO mode, indication of support of IMS voice over PS session based, emergency service support indicator, etc.). In one example, the AMF 155 can send a registration accept message to the UE 100 indicating that the registration request has been accepted. If the AMF 155 allocates a new 5G-GUTI, it can include the 5G-GUTI. If the AMF 155 allocates a new registration area, it can send the registration area to the UE 100 via the registration accept message 955. If the registration area is not included in the registration accept message, the UE 100 can consider the old registration area valid. In one example, the mobility restrictions can be included in case the mobility restrictions can apply to the UE 100 and the registration type can not be an emergency registration. The AMF 155 can indicate to the UE 100 the established PDU sessions in the PDU session status. The UE 100 can locally remove any internal resources related to PDU sessions not marked as established in the received PDU session status. In one example, when the UE 100 is connected to two AMFs 155 belonging to different PLMNs via 3GPP access and non-3GPP access, the UE 100 can then locally remove any internal resources related to PDU sessions of the current PLMN not marked as established in the received PDU session status. If the PDU session status information is in the registration request, the AMF 155 can indicate the PDU session status to the UE. The mapping of allowed NSSAI can be a mapping of each S-NSSAI of the allowed NSSAI to an S-NSSAI of the configured NSSAI of the HPLMN. The AMF 155 can include in the registration accept message 955 the LADN information of the LADNs available within the registration area determined by the AMF 155 for the UE. If the UE 100 included a MICO mode in the request, the AMF 155 can respond whether the MICO mode can be used. The AMF 155 can set the indication of support of IMS voice over PS session based. In one example, to set the indication of support of IMS voice over PS session based, the AMF 155 can perform a UE / RAN radio information and compatibility request procedure to check the compatibility of the UE 100 and RAN radio capabilities related to IMS voice over PS based. In one example, the emergency service support indicator can inform the UE 100 that emergency services are supported, e.g., the UE 100 can request a PDU session for emergency services. In one example, the handover restriction list and the UE-AMBR can be provided by the AMF 155 to the NG-RAN.

[0217] In one example, the UE 100 can send a registration complete 960 message to the new AMF 155. In one example, the UE 100 can send a registration complete message 960 to the AMF 155 to confirm that a new 5G-GUTI can be allocated. In one example, the AMF 155 can release the signaling connection with the UE 100 when information about PDU sessions to be reactivated is not included in the registration request. In one example, the AMF 155 can not release the signaling connection after the registration procedure is completed when a subsequent request is included in the registration request. In one example, the AMF 155 can not release the signaling connection after the completion of the registration procedure if the AMF 155 is aware that there is some outstanding signaling in the AMF 155 or between the UE 100 and the 5GC.

[0218] Example Figure 10 and Figure 11 As depicted in FIG. 10, a service request procedure, e.g., a service request procedure triggered by the UE 100, can be used by the UE 100 in the CM-IDLE state to request establishment of a secure connection with the AMF 155. Figure 11 is a continuation of Figure 10 depicts a service request procedure. The service request procedure can be used to activate user plane connections for established PDU sessions. The service request procedure can be triggered by the UE 100 or the 5GC, and can be used when the UE 100 is in CM-IDLE and / or CM-CONNECTED, and can allow selective activation of user plane connections for some established PDU sessions.

[0219] In one example, the UE 100 in the CM IDLE state can initiate the service request procedure to send uplink signaling messages, user data, etc., in response to a network paging request, etc. In one example, the AMF 155 can perform authentication after receiving the service request message. In one example, after establishing a signaling connection to the AMF 155, the UE 100 or the network can send signaling messages, e.g., PDU session establishment, from the UE 100 to the SMF 160 via the AMF 155.

[0220] In one example, for any service request, the AMF 155 can respond with a service accept message to synchronize the PDU session state between the UE 100 and the network. If the service request can not be accepted by the network, the AMF 155 can respond to the UE 100 with a service reject message. The service reject message can include an indication or a cause code that requests the UE 100 to perform a registration update procedure. In one example, for a service request due to user data, the network can take further actions if the user plane connection activation can not be successful. In one example, the network can send a service accept message to the UE 100 to activate the user plane connection for the PDU session. Figure 10 andFigure 11 In an example, multiple UPFs can be involved, e.g., old UPF 110-2 and PDU Session Anchor, PSA, UPF 110-3.

[0221] In one example, UE 100 can send an AN message including AN parameters, mobility management, MM NAS service request 1005 (e.g., list of PDU sessions to activate, list of PDU sessions allowed, security parameters, PDU session status, etc.), etc., to (R)AN 105. In one example, UE 100 can provide a list of PDU sessions to activate when UE 100 can reactivate PDU sessions. The list of PDU sessions allowed can be provided by UE 100 when the service request can be a response to a paging or NAS notification, and can identify PDU sessions that can be transferred or associated to an access that can send the service request. In one example, for the case of NG-RAN, the AN parameters can include a selected PLMN ID and an establishment cause. The establishment cause can provide a reason for requesting establishment of an RRC connection. UE 100 can send the NAS service request message encapsulated in an RRC message to RAN 105 to AMF 155.

[0222] In one example, if the service request can be triggered for user data, UE 100 can use the list of PDU sessions to activate to identify PDU sessions that will activate UP connections in the NAS service request message. If the service request can be triggered for signaling, UE 100 can not identify any PDU sessions. If the procedure can be triggered for a paging response, and / or UE 100 can have user data to transmit simultaneously, UE 100 can identify PDU sessions that can activate UP connections in the MM NAS service request message through the list of PDU sessions to activate.

[0223] In one example, if the service request through 3GPP access can be triggered in response to a paging indicating non-3GPP access, the NAS service request message can identify a list of PDU sessions associated with non-3GPP access that can be reactivated through 3GPP in the list of PDU sessions allowed. In one example, the PDU session status can indicate PDU sessions available in UE 100. In one example, UE 100 can not trigger the service request procedure for a PDU session corresponding to a LADN when UE 100 can be outside the available area of the LADN. UE 100 can not identify such PDU sessions in the list of PDU sessions to activate if the service request can be triggered for other reasons.

[0224] In one example, the (R)AN 105 can send an N2 message 1010 (e.g., Service Request) including N2 parameters, MM NAS Service Request, etc. to the AMF 155. If the AMF 155 can not be able to handle the service request, it can reject the N2 message. In one example, the N2 parameters can include 5G-GUTI, selected PLMN ID, location information, RAT type, establishment cause, etc. if NG-RAN can be used. In one example, the 5G-GUTI can be obtained in the RRC procedure and the (R)AN 105 can select the AMF 155 according to the 5G-GUTI. In one example, the location information and RAT type can be related to the cell in which the UE 100 can camp. In one example, based on the PDU session status, the AMF 155 can initiate a PDU session release procedure in the network for the PDU session, the PDU session ID of which can be indicated by the UE 100 as not available.

[0225] In one example, the AMF 155 can initiate a NAS authentication / security procedure 1015 if the service request is not sent with integrity protection or integrity protection verification fails.

[0226] In one example, if the UE 100 triggers a service request to establish a signaling connection, the UE 100 and the network can exchange NAS signaling after the signaling connection is successfully established.

[0227] In one example, the AMF 155 can send a PDU session update context request 1020, e.g., Nsmf_PDUSession_UpdateSMContext request, to the SMF 160 including PDU session ID, cause, UE 100 location information, access type, etc.

[0228] In one example, the Nsmf_PDUSession_UpdateSMContext request can be invoked by the AMF 155 if the UE 100 can identify a PDU session to be activated in the NAS service request message. In one example, the Nsmf_PDUSession_UpdateSMContext request can be triggered by the SMF 160 where the PDU session identified by the UE 100 can be related to another PDU session ID other than the PDU session ID that triggers the procedure. In one example, the Nsmf_PDUSession_UpdateSMContext request can be triggered by the SMF 160 where the current UE 100 location can be outside the validity area of the N2 information provided by the SMF 160 during the network triggered service request procedure. The AMF 155 can not send the N2 information provided by the SMF 160 during the network triggered service request procedure.

[0229] In one example, the AMF 155 can determine the PDU session to be activated and can send an Nsmf_PDUSession_UpdateSMContext request to the SMF 160 associated with the PDU session with the cause set to indicate user plane resources are established for the PDU session.

[0230] In one example, if the procedure can be triggered in response to a paging indicating non-3GPP access and the allowed PDU session list provided by the UE 100 can not include the PDU session for which the UE 100 is paged, the AMF 155 can inform the SMF 160 that the user plane for the PDU session can not be reactivated. The service request procedure can be successful without reactivating the user plane of any PDU session and the AMF 155 can inform the UE 100.

[0231] In one example, if the PDU session ID can correspond to a LADN and the SMF 160 can determine based on the UE 100 location report from the AMF 155 that the UE 100 can be outside the available area of the LADN, the SMF 160 can decide (based on local policy) to keep the PDU session, can reject the activation of the user plane connection of the PDU session, and can inform the AMF 155. In one example, if the procedure can be triggered by a service request triggered by the network, the SMF 160 can inform the UPF 110 initiating the data notification to discard downlink data for the PDU session and / or not provide further data notification messages. The SMF 160 can respond to the AMF 155 with an appropriate rejection cause and can stop the user plane activation of the PDU session.

[0232] In one example, if the PDU session ID can correspond to a LADN and the SMF 160 can determine based on the UE 100 location report from the AMF 155 that the UE 100 can be outside the available area of the LADN, the SMF 160 can decide (based on local policy) to release the PDU session. The SMF 160 can release the PDU session locally and can inform the AMF 155 that the PDU session can be released. The SMF 160 can respond to the AMF 155 with an appropriate rejection cause and can stop the user plane activation of the PDU session.

[0233] In one example, if the UP activation of the PDU session can be accepted by the SMF 160, based on the location information received from the AMF 155, the SMF 160 can check the UPF 110 selection 1025 criteria (e.g., slice isolation requirements, slice coexistence requirements, UPF 110 dynamic load, UPF 110 relative static capacity among UPFs supporting the same DNN, UPF 110 location available at the SMF 160, UE 100 location information, capabilities of the UPF 110 and functionalities required for the specific UE 100 session. In one example, a proper UPF 110 can be selected by matching the functionalities and features required by the following: UE 100, DNN, PDU session type (i.e., IPv4, IPv6, Ethernet type or unstructured type) and, if applicable, static IP address / prefix, SSC mode selected for the PDU session, UE 100 subscription profile in the UDM 140, DNAI included in PCC rules, local operator policies, S-NSSAI, access technology used by the UE 100, UPF 110 logical topology, etc.), and can decide to perform one or more of the following: continue using the current UPF; select a new intermediate UPF 110 (or add / remove intermediate UPF 110) if the UE 100 has moved out of the service area of the UPF 110 previously connected to the (R)AN 105 while keeping the UPF acting as a PDU session anchor point; can trigger a re-establishment of the PDU session to perform a relocation / re-allocation of the UPF 110 acting as a PDU session anchor point, e.g., the UE 100 has moved out of the service area of the anchor UPF 110 connected to the RAN 105.

[0234] In one example, the SMF 160 can send a N4 session establishment request 1030 to the UPF 110 (e.g., a new intermediate UPF 110). In one example, if the SMF 160 can select a new UPF 110 as an intermediate UPF 110-2 for the PDU session, or if the SMF 160 can select to insert an intermediate UPF 110 for a PDU session that can not have an intermediate UPF 110-2, the N4 session establishment request 1030 message can be sent to the new UPF 110 providing packet detection, data forwarding, enforcement and reporting rules installed on the new intermediate UPF. The PDU session anchor point addressing information (over N9) for this PDU session can be provided to the intermediate UPF 110-2.

[0235] In one example, if a new UPF 110 is selected by the SMF 160 to replace the old (intermediate) UPF 110-2, the SMF 160 can include a data forwarding indication. The data forwarding indication can indicate to the UPF 110 that a second tunnel endpoint can be reserved for buffered DL data from the old I-UPF.

[0236] In one example, the new UPF 110 (intermediate) can send an N4 session establishment response message 1030 to the SMF 160. In case the UPF 110 can allocate CN tunnel information, the UPF 110 can provide the SMF 160 with DL CN tunnel information and UL CN tunnel information (e.g., CN N3 tunnel information) for the UPF 110 acting as a PDU session anchor point. If a data forwarding indication can be received, the new (intermediate) UPF 110 acting as a N3 termination point can send the DL CN tunnel information of the old (intermediate) UPF 110-2 to the SMF 160. The SMF 160 can start a timer to release resources in the old intermediate UPF 110-2.

[0237] In one example, if the SMF 160 can select a new intermediate UPF 110 for a PDU session or can remove the old I-UPF 110-2, the SMF 160 can send an N4 session modification request message 1035 to the PDU session anchor point, PSA UPF 110-3, providing a data forwarding indication and DL tunnel information from the new intermediate UPF 110.

[0238] In one example, if a new intermediate UPF 110 can be added for a PDU session, the (PSA) UPF 110-3 can start sending DL data to the new I-UPF 110 as indicated in the DL tunnel information.

[0239] In one example, if a service request can be triggered by the network and the SMF 160 can remove the old I-UPF 110-2 and can not replace the old I-UPF 110-2 with a new I-UPF 110, the SMF 160 can include a data forwarding indication in the request. The data forwarding indication can indicate to the (PSA) UPF 110-3 that a second tunnel endpoint can be reserved for buffered DL data from the old I-UPF 110-2. In this case, the PSA UPF 110-3 can start buffering DL data that it can receive from the N6 interface at the same time.

[0240] In one example, the PSA UPF 110-3 (PSA) can send an N4 session modification response 1035 to the SMF 160. In one example, if a data forwarding indication can be received, the PSA UPF 110-3 can become an N3 termination point and can send the CN DL tunnel information of the old (intermediate) UPF 110-2 to the SMF 160. The SMF 160 can start a timer to release resources in the old intermediate UPF 110-2 (if any).

[0241] In one example, the SMF 160 can send an N4 session modification request 1045 to the old UPF 110-2 (e.g., can include a new UPF 110 address, a new UPF 110 DL tunnel ID, etc.). In one example, if a service request can be triggered by the network and / or the SMF 160 can remove the old (intermediate) UPF 110-2, the SMF 160 can send an N4 session modification request message to the old (intermediate) UPF 110-2 and can provide DL tunnel information for the buffered DL data. If the SMF 160 can allocate a new I-UPF 110, the DL tunnel information can be from the new (intermediate) UPF 110 that can act as an N3 termination point. If the SMF 160 can not allocate a new I-UPF 110, the DL tunnel information can be from the new UPF 110 (PSA) 110-3 that acts as an N3 termination point. The SMF 160 can start a timer to monitor the forwarding tunnel. In one example, the old (intermediate) UPF 110-2 can send an N4 session modification response message to the SMF 160.

[0242] In one example, if the I-UPF 110-2 can be relocated and a forwarding tunnel is established to a new I-UPF 110, the old (intermediate) UPF 110-2 can forward its buffered data to the new (intermediate) UPF 110 as an N3 termination point. In one example, if the old I-UPF 110-2 can be removed and a new I-UPF 110 can not be allocated to the PDU session and a forwarding tunnel can be established to the UPF 110 (PSA) 110-3, the old (intermediate) UPF 110-2 can forward its buffered data to the UPF 110 (PSA) 110-3 that acts as an N3 termination point.

[0243] In one example, the SMF 160 can send an N11 message 1060, e.g., Nsmf_PDUSession_UpdateSMContext response (including: N1 SM container (PDU session ID, PDU session re-establishment indication), N2 SM information (PDU session ID, QoS profile, CN N3 tunnel information, S-NSSAI), cause) to the AMF 155 upon receiving the Nsmf_PDUSession_UpdateSMContext request with a cause including, for example, establishment of user plane resources. The SMF 160 can determine whether UPF 110 reallocation can be performed based on UE 100 location information, UPF 110 service area, and operator policy. In one example, for PDU sessions that the SMF 160 can determine are served by the current UPF 110, e.g., PDU session anchor or intermediate UPF, the SMF 160 can generate N2 SM information and can send an Nsmf_PDUSession_UpdateSMContext response 1060 155 to the AMF to establish the user plane. The N2 SM information can contain information that the AMF 155 can provide to the RAN 105. In one example, for PDU sessions that the SMF 160 can determine require UPF 110 relocation for the PDU session anchor UPF, the SMF 160 can reject the activation of the UP of the PDU session by sending an Nsmf_PDUSession_UpdateSMContext response to the UE 100 via the AMF 155 that can contain an N1 SM container. The N1 SM container can include the corresponding PDU session ID and PDU session re-establishment indication.

[0244] Upon receiving the Namf_EventExposure_Notify from the AMF 155 to the SMF 160 with an indication that the UE 100 is reachable, the SMF 160 can invoke the Namf_Communication_N1N2MessageTransfer service operation to the AMF 155 to establish the user plane of the PDU session if the SMF 160 can have pending DL data. In one example, the SMF 160 can resume sending DL data notifications to the AMF 155 in case of DL data.

[0245] In one example, if the PDU session can correspond to a LADN and the UE 100 can be outside the available area of the LADN, or if the AMF 155 can inform the SMF 160 that the UE 100 can be reachable for regulatory priority service and the PDU session to be activated can not be for regulatory priority service; or if the SMF 160 can decide to perform PSA UPF 110-3 relocation for the requested PDU session, the SMF 160 can send a message to the AMF 155 to reject the activation of the UP of the PDU session by including a cause in the Nsmf_PDUSession_UpdateSMContext response.

[0246] In one example, the AMF 155 can send a N2 request message 1065 (e.g., N2 SM information received from the SMF 160, security context, AMF 155 signaling connection ID, handover restriction list, MM NAS service accept, recommended cell / TA / NG-RAN node identifier list) to the (R)AN 105. In one example, the RAN 105 can store the security context, AMF 155 signaling connection Id, QoS information for the QoS flows of the PDU session that can be activated, and N3 tunnel IDs in the UE 100 RAN 105 context. In one example, the MM NAS service accept can include the PDU session status in the AMF 155. If the UP activation of the PDU session can be rejected by the SMF 160, the MM NAS service accept can include the PDU session ID and the cause that the user plane resources can not be activated (e.g., LADN not available). The local PDU session release during the session request procedure can be indicated to the UE 100 via the session status.

[0247] In one example, if there are multiple PDU sessions that can involve multiple SMFs 160, the AMF 155 can not wait for responses from all SMFs 160 before it can send the N2 SM information to the UE 100. The AMF 155 can wait for all responses from the SMFs 160 before it can send the MM NAS service accept message to the UE 100.

[0248] In one example, if the procedure can be triggered for PDU session user plane activation, the AMF 155 can include at least one N2 SM information from the SMF 160. The AMF 155 can send additional N2 SM information from the SMF 160 in separate N2 messages (e.g., N2 Tunnel Setup Request) if any. Alternatively, if multiple SMFs 160 can be involved, the AMF 155 can send one N2 request message to the (R)AN 105 after all Nsmf_PDUSession_UpdateSMContext response service operations from all SMFs 160 associated with the UE 100 can be received. In this case, the N2 request message can include the N2 SM information received in each of the Nsmf_PDUSession_UpdateSMContext responses and PDU session IDs to enable the AMF 155 to associate the responses with the relevant SMF 160.

[0249] In one example, if the RAN 105 (e.g., NG RAN) node can provide a list of recommended cell / TA / NG-RAN node identifiers during the AN release procedure, the AMF 155 can include information from the list in the N2 request. The RAN 105 can use this information to allocate a RAN 105 notification area when the RAN 105 can decide to enable the RRC Inactive state for the UE 100.

[0250] If, for any of the PDU sessions established for the UE 100, the AMF 155 can receive an indication from the SMF 160 during the PDU session establishment procedure that the UE 100 can be using a PDU session related to a delay sensitive service, and the AMF 155 has received an indication from the UE 100 that the CM-CONNECTED can support the RRC Inactive state, the AMF 155 can include the UE’s RRC Inactive assistance information. In one example, the AMF 155 based on network configuration can include the UE’s RRC Inactive assistance information.

[0251] In one example, the (R)AN 105 can send a message to the UE 100 to perform an RRC connection reconfiguration 1070 with the UE 100 according to the QoS information and data radio bearers for all QoS flows of the PDU session for which the UP connection can be activated. In one example, user plane security can be established.

[0252] In one example, if the N2 request can include an MM NAS service accept message, the RAN 105 can forward the MM NAS service accept to the UE 100. The UE 100 can locally delete the context of the PDU session that can not be available in the 5GC.

[0253] In one example, if the N1 SM information can be transmitted to the UE 100 and can indicate that some PDU sessions can be re-established, the UE 100 can initiate PDU session re-establishment for the PDU sessions, which can re-establish the PDU sessions after the service request procedure is completed.

[0254] In one example, after the user plane radio resources can be set up, uplink data from the UE 100 can be forwarded to the RAN 105. The RAN 105 (e.g., NG-RAN) can send the uplink data to the UPF 110 address and the provided tunnel ID.

[0255] In one example, the (R)AN 105 can send a N2 Request Ack 1105 (e.g., N2 SM information (including: AN tunnel information, list of accepted QoS flows for PDU sessions for which UP connection is activated, list of rejected QoS flows for PDU sessions for which UP connection is activated)) to the AMF 155. In one example, the N2 request message can include N2 SM information, such as AN tunnel information. The RAN 105 can respond to the N2 SM information with a separate N2 message (e.g., N2 tunnel setup response). In one example, if multiple N2 SM information is included in the N2 request message, the N2 request acknowledgement can include multiple N2 SM information and information that enables the AMF 155 to associate the response with the related SMF 160.

[0256] In one example, the AMF 155 can send a PDU session based Nsmf_PDUSession_UpdateSMContext request 1110 (N2 SM information (AN tunnel information), RAT type) to the SMF 160. If the AMF 155 can receive N2 SM information(s) from the RAN 105, the AMF 155 can forward the N2 SM information to the related SMF 160. If the UE 100 time zone can change compared to the last reported UE 100 time zone, the AMF 155 can include the UE 100 time zone IE in the Nsmf_PDUSession_UpdateSMContext request message.

[0257] In one example, if dynamic PCC is deployed, the SMF 160 can initiate a notification about the new location information to the PCF 135 (if subscribed) by invoking the Event Exposure Notify operation (e.g., Nsmf_EventExposure_Notify service operation). The PCF 135 can provide the updated policy by invoking the Policy Control Update Notify message 1115 (e.g., Npcf_SMPolicyControl_UpdateNotify operation).

[0258] In one example, if the SMF 160 can select a new UPF 110 as an intermediate UPF 110 for the PDU session, the SMF 160 can initiate a N4 session modification procedure 1120 to the new I-UPF 110 and can provide the AN tunnel information. Downlink data from the new I-UPF 110 can be forwarded to the RAN 105 and the UE 100. In one example, the UPF 110 can send a N4 session modification response 1120 to the SMF 160. In one example, the SMF 160 can send a Nsmf_PDUSession_UpdateSMContext response 1140 to the AMF 155.

[0259] In one example, if a forwarding tunnel to the new I-UPF 110 can be established, and if a timer set for the forwarding tunnel can expire, the SMF 160 can send a N4 session modification request 1145 to the new (intermediate) UPF 110 acting as the N3 termination point to release the forwarding tunnel. In one example, the new (intermediate) UPF 110 can send a N4 session modification response 1145 to the SMF 160. In one example, the SMF 160 can send a N4 session modification request 1150 or a N4 session release request to the PSA UPF 110-3. In one example, if the SMF 160 can continue to use the old UPF 110-2, the SMF 160 can send a N4 session modification request 1155 providing the AN tunnel information. In one example, if the SMF 160 can select a new UPF 110 as an intermediate UPF 110 and the old UPF 110-2 can not be the PSA UPF 110-3, the SMF 160 can initiate resource release after the timer expires by sending a N4 session release request (release cause) to the old intermediate UPF 110-2.

[0260] In one example, the old intermediate UPF 110-2 can send an N4 session modification response or N4 session release response 1155 to the SMF 160. The old UPF 110-2 can acknowledge the N4 session modification response or N4 session release response message to acknowledge the modification or release of resources. The AMF 155 can invoke the Namf_EventExposure_Notify service operation to notify the mobility related event to NFs that can have subscribed to the event after this procedure is completed. In one example, the AMF 155 can invoke the Namf_EventExposure_Notify to the SMF 160 if the SMF 160 has subscribed to the UE 100 moving into or out of an area of interest and if the current location of the UE can indicate that it can be moving into or out of the subscribed area of interest, or if the SMF 160 has subscribed to a LADN DNN and if the UE 100 can be moving into or out of an area where the LADN is available, or if the UE 100 can be in MICO mode and the AMF 155 has informed the SMF 160 that the UE 100 is unreachable and the SMF 160 can not send DL data notification to the AMF 155, and the AMF 155 can inform the SMF 160 that the UE 100 is reachable, or if the SMF 160 has subscribed to the UE 100 reachability status, the AMF 155 can inform the UE 100 reachability.

[0261] Figure 12 and Figure 13An example PDU session establishment procedure is depicted. In an example embodiment, when a PDU session establishment procedure can be employed, the UE 100 can send a NAS message 1205 (or SM NAS message) including NSSAI, S-NSSAI (e.g., requested S-NSSAI, allowed S-NSSAI, subscribed S-NSSAI, etc.), DNN, PDU session ID, request type, old PDU session ID, N1 SM container (PDU session establishment request), etc. to the AMF 155. In one example, to establish a new PDU session, the UE 100 can generate a new PDU session ID. In one example, when emergency services can be required and an emergency PDU session can not have been established, the UE 100 can initiate a UE 100 requested PDU session establishment procedure with a request type indicating an emergency request. In one example, the UE 100 can initiate a UE 100 requested PDU session establishment procedure by transmitting a NAS message containing a PDU session establishment request within a N1 SM container. The PDU session establishment request can include a PDU type, SSC mode, protocol configuration options, etc. In one example, if the PDU session establishment is a request to establish a new PDU session, the request type can indicate an initial request, and if the request relates to an existing PDU session between 3GPP access and non-3GPP access or an existing PDN connection in EPC, the request type can indicate an existing PDU session. In one example, if the PDU session establishment can be a request to establish a PDU session for emergency services, the request type can indicate an emergency request. If the request relates to an existing PDU session for emergency services between 3GPP access and non-3GPP access, the request type can indicate an existing emergency PDU session. In one example, the NAS message sent by the UE 100 can be encapsulated by the AN in a N2 message to the AMF 155, which can include user location information and access technology type information. In one example, the PDU session establishment request message can contain an SM PDU DN request container containing information for external DN to PDU session authorization. In one example, if the procedure can be triggered for SSC mode 3 operation, the UE 100 can include an old PDU session ID in the NAS message that can indicate an ongoing PDU session to be released. The old PDU session ID can be an optional parameter, which can be included in this case. In one example, the AMF 155 can receive the NAS message (e.g., NAS SM message) from the AN along with user location information (e.g., cell ID in the case of RAN 105). In one example, when the UE 100 is outside the available area of a LADN, the UE 100 can not trigger PDU session establishment for a PDU session corresponding to the LADN.

[0262] In one example, the AMF 155 can determine that the NAS message or SM NAS message can correspond to a request for a new PDU session and that the PDU session ID can not be used for any existing PDU session of the UE 100 based on the request type indicating an initial request. If the NAS message does not contain an S-NSSAI, the AMF 155 can determine a default S-NSSAI for the requested PDU session according to the UE 100 subscription, if the NAS message can contain only one default S-NSSAI, based on operator policy. In one example, the AMF 155 can perform SMF 160 selection 1210 and select an SMF 160. If the request type can indicate an initial request or the request can be caused by a handover from EPS, the AMF 155 can store an association of the S-NSSAI, the PDU session ID, and the SMF 160 ID. In one example, if the request type is an initial request and if an old PDU session ID indicating an existing PDU session can be contained in the message, the AMF 155 can select an SMF 160 and can store an association of the new PDU session ID and the selected SMF 160 ID.

[0263] In one example, the AMF 155 can send an N11 message 1215, e.g., a Nsmf_PDUSession_CreateSMContext request (including: SUPI or PEI, DNN, S-NSSAI, PDU Session ID, AMF 155 ID, Request Type, N1 SM Container (PDU Session Establishment Request), User Location Information, Access Type, PEI, GPSI) or a Nsmf_PDUSession_UpdateSMContext request (SUPI, DNN, S-NSSAI, PDU Session ID, AMF 155 ID, Request Type, N1 SM Container (PDU Session Establishment Request), User Location Information, Access Type, RAT Type, PEI) to the SMF 160. In one example, if the AMF 155 can not have an association with the SMF 160 for the PDU Session ID provided by the UE 100 (e.g., when the Request Type indicates an initial request), the AMF 155 can invoke the Nsmf_PDUSession_CreateSMContext request, but if the AMF 155 is already associated with the SMF 160 for the PDU Session ID provided by the UE 100 (e.g., when the Request Type indicates an existing PDU Session), the AMF 155 can invoke the Nsmf_PDUSession_UpdateSMContext request. In one example, the AMF 155 ID can be the GUAMI that uniquely identifies the UE for the AMF 155 serving the UE 100. The AMF 155 can forward the PDU Session ID with the N1 SM container containing the PDU Session Establishment Request received from the UE 100. When the UE 100 has registered for emergency services without providing a SUPI, the AMF 155 can provide a PEI instead of a SUPI. In the case that the UE 100 has registered for emergency services but has not yet been authenticated, the AMF 155 can indicate that the SUPI has not yet been authenticated.

[0264] In one example, if the request type indicates neither an emergency request nor an existing emergency PDU session, and if the SMF 160 is not already registered and subscription data can not be available, the SMF 160 can register with the UDM 140 and can retrieve subscription data 1225 and subscribe to be notified when subscription data can be modified. In one example, if the request type can indicate an existing PDU session or an existing emergency PDU session, the SMF 160 can determine that the request can be caused by a handover between 3GPP access and non-3GPP access or by a handover from EPS. The SMF 160 can identify the existing PDU session based on the PDU session ID. The SMF 160 can not create a new SM context but can update the existing SM context and can provide an indication of the updated SM context in the response to the AMF 155. If the request type can be an initial request and if an old PDU session ID can be included in the Nsmf_PDUSession_CreateSMContext request, the SMF 160 can identify the existing PDU session to be released based on the old PDU session ID.

[0265] In one example, the SMF 160 can send an N11 message response 1220, e.g., a PDU session create / update response, a Nsmf_PDUSession_CreateSMContext response 1220 (cause, SM context ID or N1 SM container (PDU session reject (cause))), or a Nsmf_PDUSession_UpdateSMContext response, to the AMF 155.

[0266] In one example, if the SMF 160 can perform a secondary authorization / authentication 1230 during the DN-AAA server establishes the PDU session, the SMF 160 can select a UPF 110 and can trigger PDU session establishment authentication / authorization.

[0267] In one example, if the request type can indicate an initial request, the SMF 160 can select an SSC mode for the PDU session. The SMF 160 can select one or more UPFs as needed. In case of PDU type IPv4 or IPv6, the SMF 160 can allocate an IP address / prefix for the PDU session. In case of PDU type IPv6, the SMF 160 can allocate an interface identifier to the UE 100 in order for the UE 100 to establish its link-local address. For unstructured PDU type, the SMF 160 can allocate an IPv6 prefix for the PDU session and N6 point-to-point tunnel (based on UDP / IPv6).

[0268] In one example, if dynamic PCC is deployed, the SMF 160 can perform PCF 135 selection 1235. If the request type indicates an existing PDU session or an existing emergency PDU session, the SMF 160 can use the PCF 135 already selected for the PDU session. If dynamic PCC is not deployed, the SMF 160 can apply local policy.

[0269] In one example, the SMF 160 can perform a session management policy establishment procedure 1240 to establish a PDU session with the PCF 135 and can obtain default PCC rules for the PDU session. The GPSI can be included if available in the SMF 160. If the request type in 1215 indicates an existing PDU session, the SMF 160 can inform the PCF 135 of previously subscribed events through a session management policy modification procedure, and the PCF 135 can update policy information in the SMF 160. The PCF 135 can provide authorized Session-AMBR and authorized 5QI and ARP to the SMF 160. The PCF 135 can subscribe to IP allocation / release events (and can subscribe to other events) in the SMF 160.

[0270] In one example, the PCF 135 can set the ARP of the PCC rules to a value that can be reserved for emergency services based on the emergency DNN.

[0271] In one example, if the request type in 1215 indicates an initial request, the SMF 160 can select an SSC mode for the PDU session. The SMF 160 can select one or more UPFs 1245 as needed. In the case of a PDU type IPv4 or IPv6, the SMF 160 can allocate an IP address / prefix for the PDU session. In the case of a PDU type IPv6, the SMF 160 can allocate an interface identifier to the UE 100 so that the UE 100 establishes its link-local address. For an unstructured PDU type, the SMF 160 can allocate an IPv6 prefix for the PDU session and the N6 point-to-point tunnel (e.g., based on UDP / IPv6). In one example, for a PDU session of Ethernet PDU type, the SMF 160 can neither allocate a MAC address nor an IP address to the UE 100 for that PDU session.

[0272] In one example, if the request type in 1215 is an existing PDU session, the SMF 160 can maintain the same IP address / prefix that can be allocated to the UE 100 in the source network.

[0273] In one example, if the request type in 1215 indicates that the existing PDU session is moving between 3GPP access and non-3GPP access, the SMF 160 can keep the SSC mode of the PDU session, e.g., the current PDU session anchor and IP address. In one example, the SMF 160 can trigger, e.g., a new intermediate UPF 110 insertion or allocation of a new UPF 110. In one example, if the request type indicates an emergency request, the SMF 160 can select 1245 a UPF 110 and can select SSC mode 1.

[0274] In one example, the SMF 160 can perform a session management policy modification 1250 procedure to report certain events to a previously subscribed PCF 135. If the request type is an initial request and dynamic PCC is deployed and the PDU type is IPv4 or IPv6, the SMF 160 can inform the (previously subscribed) PCF 135 with the allocated UE 100 IP address / prefix.

[0275] In one example, the PCF 135 can provide updated policies to the SMF 160. The PCF 135 can provide the authorized Session-AMBR and authorized 5QI and ARP to the SMF 160.

[0276] In one example, if the request type indicates an initial request, the SMF 160 can initiate a N4 session establishment procedure 1255 with the selected UPF 110. The SMF 160 can initiate a N4 session modification procedure with the selected UPF 110. In one example, the SMF 160 can send a N4 session establishment / modification request 1255 to the UPF 110 and can provide packet detection, enforcement, reporting rules, etc. to be installed on the UPF 110 for this PDU session. If CN tunnel information is allocated by the SMF 160, the CN tunnel information can be provided to the UPF 110. If the PDU session requires selective user plane deactivation, the SMF 160 can determine the inactivity timer and can provide it to the UPF 110. In one example, the UPF 110 can acknowledge by sending a N4 session establishment / modification response 1255. If CN tunnel information is allocated by the UPF, the CN tunnel information can be provided to the SMF 160. In one example, if multiple UPFs are selected for the PDU session, the SMF 160 can initiate a N4 session establishment / modification procedure 1255 with each UPF 110 of the PDU session.

[0277] In one example, the SMF 160 can send a Namf_Communication_N1N2MessageTransfer 1305 message to the AMF 155 (including PDU Session ID, Access Type, N2 SM Information (PDU Session ID, QFI, QoS Profile, CN Tunnel Info, S-NSSAI, Session-AMBR, PDU Session Type, etc.), N1 SM Container (PDU Session Establishment Accept (QoS Rules, Selected SSC Mode, S-NSSAI, Allocated IPv4 Address, Interface Identifier, Session-AMBR, Selected PDU Session Type, etc.))). In case of multiple UPFs for a PDU Session, the CN Tunnel Info can include tunnel information related to the UPF 110 that terminates the N3. In one example, the N2 SM Information can carry information that the AMF 155 can forward to the (R)AN 105 (e.g., CN Tunnel Info corresponding to a core network address of the N3 tunnel corresponding to the PDU Session, one or more QoS Profiles and corresponding QFIs can be provided to the (R)AN 105, the PDU Session ID can be used by AN signaling with the UE 100 to indicate the association between the AN resources and the PDU Session of the UE 100, etc.). In one example, the PDU Session can be associated with an S-NSSAI and a DNN. In one example, the N1 SM Container can contain the PDU Session Establishment Accept that the AMF 155 can provide to the UE 100. In one example, multiple QoS Rules and QoS Profiles can be included in the PDU Session Establishment Accept within the N1 SM and the N2 SM Information. In one example, the Namf_Communication_N1N2MessageTransfer 1305 can also include the PDU Session ID and information that allows the AMF 155 to know which access to the UE 100 to use.

[0278] In one example, the AMF 155 can send a N2 PDU Session Request 1310 to the (R)AN 105 (including N2 SM Information, NAS Message (PDU Session ID, N1 SM Container (PDU Session Establishment Accept, etc.))). In one example, the AMF 155 can send a NAS Message 1310 to the (R)AN 105 that can include a PDU Session ID and a PDU Session Establishment Accept targeted to the UE 100 and the N2 SM Information received from the SMF 160 within the N2 PDU Session Request 1310.

[0279] In one example, the (R)AN 105 can initiate AN specific signaling exchange 1315 with the UE 100 that can be related to the information received from the SMF 160. In one example, in case of a 3GPP RAN 105, an RRC connection reconfiguration procedure can be conducted with the UE 100 to establish the necessary RAN 105 resources related to the QoS rules of the PDU Session Request 1310. In one example, the (R)AN 105 can allocate (R)AN 105 N3 tunnel information for the PDU Session. In case of dual connectivity, the master RAN 105 node can allocate some (zero or more) QFIs to be setup to the master RAN 105 node and other QFIs to the secondary RAN 105 node. The AN tunnel information can include the tunnel endpoint of each involved RAN 105 node and the QFIs allocated to each tunnel endpoint. The QFIs can be allocated to the master RAN 105 node or the secondary RAN 105 node. In one example, the (R)AN 105 can forward the NAS message 1310 (PDU Session ID, N1 SM Container (PDU Session Establishment Accept)) to the UE 100. If the necessary RAN 105 resources are established and the allocation of the (R)AN 105 tunnel information is successful, the (R)AN 105 can provide a NAS message to the UE 100.

[0280] In one example, the N2 PDU Session Response 1320 can include the PDU Session ID, cause, N2 SM information (PDU Session ID, AN tunnel information, list of accepted / rejected QFIs), etc. In one example, the AN tunnel information can correspond to the access network address of the N3 tunnel corresponding to the PDU Session.

[0281] In one example, the AMF 155 can forward the N2 SM information received from the (R)AN 105 to the SMF 160 via a Nsmf_PDUSession_UpdateSMContext request 1330 (including: N2 SM information, request type, etc.). In one example, if the list of rejected QFIs is included in the N2 SM information, the SMF 160 can release the QoS profiles associated with the rejected QFIs.

[0282] In one example, the SMF 160 can initiate a N4 Session Modification procedure 1335 with the UPF 110. The SMF 160 can provide the AN tunnel information to the UPF 110 along with the corresponding forwarding rules. In one example, the UPF 110 can provide a N4 Session Modification Response 1335 to the SMF 160 160.

[0283] In one example, the SMF 160 can send an Nsmf_PDUSession_UpdateSMContext response 1340 (cause) to the AMF 155. In one example, after this step, the SMF 160 can subscribe to UE 100 mobility event notifications (e.g., location reporting, UE 100 moving in or out of an area of interest) from the AMF 155 by invoking the Namf_EventExposure_Subscribe service operation. For LADN, the SMF 160 can subscribe to UE 100 moving in or out of the LADN service area event notifications by providing the LADN DNN as an indicator of the area of interest. The AMF 155 can forward the relevant events subscribed by the SMF 160.

[0284] In one example, the SMF 160 can send an Nsmf_PDUSession_SMContextStatusNotify (release) 1345 to the AMF 155. In one example, the SMF 160 can notify the AMF 155 by invoking the Nsmf_PDUSession_SMContextStatusNotify (release) 1345 whenever the PDU session establishment is not successful during the procedure. The SMF 160 can release any N4 session created, any allocated PDU session address (e.g., IP address) and can release the association with the PCF 135.

[0285] In one example, in case of PDU type IPv6, the SMF 160 can generate an IPv6 router advertisement 1350 and can send it to the UE 100 via N4 and UPF 110.

[0286] In one example, the SMF 160 can unsubscribe 1360 from the modification of the session management subscription data for the corresponding (SUPI, DNN, S-NSSAI) using Nudm_SDM_Unsubscribe (SUPI, DNN, S-NSSAI) if the PDU session can not be established (if the SMF 160 is no longer handling the PDU session for the UE 100 for this (DNN, S-NSSAI)). In one example, the SMF 160 can deregister 1360 for a given PDU session using Nudm_UECM_Deregistration (SUPI, DNN, PDU Session ID) if the PDU session can not be established.

[0287] As Figure 14As depicted, a connection management (CM) state can be related to a radio resource control (RRC) state. RRC-INACTIVE (e.g., RRC inactive) can be a state in which a UE (e.g., wireless device, device) remains in CM-CONNECTED (e.g., CM connected). In one example, a UE can move within an area, referred to as a RAN notification area (RNA), configured by a RAN (e.g., NG-RAN) without notifying the RAN. In the RRC_INACTIVE state, a last base station (e.g., gNB) of the RAN serving the UE can keep the UE context as well as the connection (e.g., N2 connection, N3 connection) associated with the UE to the serving AMF and UPF. In one example, a UE in CM-IDLE can be in RRC-IDLE. In one example, a UE in CM-CONNECTED can be in RRC-CONNECTED. Mobility behavior of a UE in RRC-INACTIVE can be similar to RRC-IDLE state behavior (e.g., cell reselection based on serving cell quality, paging monitoring, periodic system information acquisition) and different parameters can be applied for RRC-IDLE and RRC-INACTIVE.

[0288] Figure 15 An example call flow for four RRC state transitions is illustrated in accordance with an embodiment of the present disclosure. The four RRC state transitions include: RRC-IDLE to RRC-CONNECTED; RRC-CONNECTED to RRC-INACTIVE; RRC-INACTIVE to RRC-CONNECTED; and RRC_CONNECTED to RRC-IDLE. It should be noted that while the four RRC state transitions are shown as part of a single call flow diagram, each RRC state transition call flow can be executed independently of one another.

[0289] With the RRC state transition from RRC-IDLE to RRC-CONNECTED, a UE in RRC-IDLE can send an RRC setup request message to an NG-RAN node (e.g., gNB) to request RRC connection setup with the NG-RAN. The UE can receive an RRC setup message from the NG-RAN node in response to the RRC setup request message. In response to the RRC setup message from the NG-RAN node, the UE can transition from RRC-IDLE to RRC-CONNECTED. After the state transition, the RRC state maintained at the UE can be updated to reflect the current RRC state of the UE as RRC-CONNECTED. The UE can respond to the RRC setup message by sending an RRC setup complete message to the NG-RAN. Upon receiving the RRC setup complete message, the RRC state maintained at the NG-RAN node can be updated to reflect the current RRC state of the UE as RRC-CONNECTED.

[0290] For the RRC state transition from RRC-CONNECTED to RRC-INACTIVE, the NG-RAN node can send an RRC release message to the UE requesting suspension of the RRC connection. In one example, the RRC release message can include suspension information indicating to the UE that the RRC release message is for suspension rather than release of the RRC connection. The suspension information can include a radio network temporary identity (RNTI) value, a radio access network (RAN) paging cycle, RAN notification area information, and the like. In response to the RRC release message from the NG-RAN node, the UE can transition from RRC-CONNECTED to RRC-INACTIVE. The RRC state maintained at both the UE and the NG-RAN node can be updated to reflect the current RRC state of the UE as RRC-INACTIVE.

[0291] For the RRC state transition from RRC-INACTIVE to RRC-CONNECTED, the UE can send an RRC resume request message to the NG-RAN node requesting resumption of the suspended RRC connection. The UE can receive an RRC resume message from the NG-RAN node in response to the RRC resume request message. In response to the RRC resume message from the NG-RAN node, the UE can transition from RRC-INANCTIVE to RRC-CONNECTED state and can send an RRC resume complete message to the NG-RAN node. After the state transition, the RRC state maintained at the UE can be updated to reflect the current RRC state of the UE as RRC-CONNECTED. Upon receiving the RRC resume complete message from the UE, the RRC state maintained at the NG-RAN node can be updated to reflect the current RRC state of the UE as RRC-CONNECTED.

[0292] Finally, for RRC state transition from RRC-CONNECTED to RRC-IDLE, the NG-RAN node can send an RRC release message to the UE to request to release the RRC connection. Upon receiving the RRC release message from the NG-RAN node, the UE can transition from RRC-CONNECTED to RRC-IDLE. The RRC state maintained at both the UE and the NG-RAN node can be updated to reflect the current RRC state of the UE as RRC-IDLE.

[0293] The 5G core network node can query the NG-RAN node for the RRC state transition information of the UE. In one example, the core network can be an AMF. The AMF can send a UE state transition notification request message (e.g., a UE state transition notification request message, an RRC state notification message) to the NG-RAN node to request reporting of the RRC state transition information, such as Figure 16The UE state transition notification request message can include an AMF UE NGAP ID, a RAN UE NGAP ID, an RRC Inactivity Transition Reporting Request information element (IE), and the like. The AMF UE NGAP ID can uniquely identify the UE association on the NG interface (e.g., N2 interface) within the AMF side. The RAN UE NGAP ID can uniquely identify the UE association on the NG interface within the NG-RAN side. The RRC Inactivity Transition Reporting Request IE can indicate the condition for RRC state transition reporting and can include a Subsequent State Transition Reporting, a Single RRC Connection State Reporting, a Cancel Reporting, and the like. In case the RRC Inactivity Transition Reporting Request information element (IE) is set to “Subsequent State Transition Reporting”, the NG-RAN can report to the AMF by sending a UE notification message (e.g., RRC INACTIVE TRANSITION REPORT, RRC State Information message) containing the RRC state of the UE if the UE transitions from RRC-INACTIVE to RRC-CONNECTED, and vice versa. In one example, if the UE is in RRC_CONNECTED state and the RRC Inactivity Transition Reporting Request IE is set to “Single RRC Connection State Reporting”, the NG-RAN can report to the AMF by sending a UE notification message but no subsequent UE notification message. In one example, if the UE is in RRC_INACTIVE state and the RRC Inactivity Transition Reporting Request IE is set to “Single RRC Connection State Reporting”, the NG-RAN can report to the AMF one UE notification message plus one subsequent UE notification message when the RRC state transitions to RRC_CONNECTED state. In one example, in case the RRC Inactivity Transition Reporting Request IE is set to “Cancel Reporting”, the NG-RAN can stop reporting the RRC state of the UE to the AMF. In one example, the UE notification message can also include an AMF UE NGAP ID, a RAN UE NGAP ID, a user location information, and the like. The user location information can include a tracking area identity, a cell global identity, an age of location of location information (e.g., a time stamp information as defined in IETF RFC 5905), and the like. The AMF can request the reporting of RRC state transition for each UE. The continuous reporting by setting “Subsequent State Transition Reporting” for all RRC state transitions can be enabled by the operator local configuration.

[0294] In one example, a UE can be registered to the same AMF through a Third Generation Partnership Project (3GPP) access network and a non-3GPP access network. The 3GPP access network can be a 5G access network (e.g., NG-RAN) or a 4G access network (e.g., LTE). The non-3GPP access network can be a wireless local area network (WLAN), such as a WLAN implemented according to one of the IEEE 802.11 specifications, or a wired LAN.

[0295] As Figure 17 depicted in Figure 17 , a 5G core network can support connectivity to a UE through a non-3GPP access network. The 5G core network can include, for example, an AMF, an SMF, a UPF, and a non-3GPP interworking function (N3IWF), as shown in Figure 17 . In one example, a non-3GPP access network can be connected to a 5G core network through the N3IWF. In one example, the interface between the N3IWF and a 5G core network CP (e.g., AMF) can be an N2 interface. In one example, the interface between the N3IWF and a 5G core network UP function (e.g., UPF) can be one or more N3 interfaces. The 5G core network can connect a non-3GPP access network using the N2 and N3 reference points. In one example, a UE accessing a 5G core network through a non-3GPP access network can use an N1 reference point to send NAS signaling to a 5G core network CP function.

[0296] In one example, a UE can be connected to an AMF via an NG-RAN (e.g., 3GPP access) and via a non-3GPP access network. In one example, there can be two N1 instances for the UE. There can be one N1 instance between the NG-RAN and the UE, and one N1 instance between the non-3GPP access and the UE.

[0297] In one example, a UE connected to the same 5G core network of a PLMN through a 3GPP access network and a non-3GPP access network can be registered through a single AMF.

[0298] In one example, a Y1 reference point can be used as an interface between a UE and a non-3GPP access network. In one example, a Y2 reference point between a non-3GPP access network and a N3IWF can be used for transport of NWu traffic. In one example, a NWu reference point can be used between a UE and a N3IWF to establish a secure tunnel between the UE and the N3IWF.

[0299] Referring now to Figure 18 , a registration call flow for registration to the same AMF through a first access network (e.g., a 3GPP access network) and through a second access network (e.g., a non-3GPP access network) is illustrated in accordance with the disclosed embodiments. As Figure 18As shown, the UE can send a registration request message to the AMF via the first access network. The UE may include a UE identifier (e.g., a 5G Globally Unique Temporary Identifier (GUTI) and / or a User Hidden Identifier (SUCI)) used for initial registration via the first access network. The AMF can accept the registration request by sending a registration acceptance message to the UE via the first access network. The registration acceptance message may include the UE temporary identifier (e.g., a 5G-GUTI). After the registration message exchange, the UE may be in an RM-REGISTERED state for the first access network. The UE can register with the same AMF via the second access network by sending a registration request message including the UE identifier. In one example, the UE can use the 5G-GUTI assigned by the AMF during the first access network registration process to route to the same AMF.

[0300] In one example, the UE can use more than one Subscriber Identity Module (SIM), such as Figure 19 As shown. The UE may also include a communication interface, speaker / microphone, keyboard, display / touchpad, processor, database, power supply, Global Positioning System (GPS) chipset, peripherals, etc. In one example, the UE may also include a single transmitter and one or more receivers. In one example, the UE may be a Dual SIM Dual Standby (DSDS) UE. In one example, a DSDS UE may be a dual SIM UE. The UE can register to different PLMNs simultaneously and can be prepared to place and receive voice calls on both PLMNs.

[0301] like Figure 19 As shown, during the period when the UE is connected to wireless network 1 using SIM 1, the UE may attempt to receive paging messages from wireless network 2 using SIM 2. The UE may create a gap in its active connection to wireless network 1 to listen for paging messages from another connection (wireless network 2). In one example, the UE may be unreachable / available by wireless network 1 during the gap period.

[0302] Figure 20 and Figure 21 The illustration shows an example architecture with a dual-SIM UE and two wireless networks. In one example, Figure 20 The diagram illustrates a scenario where both the wireless network / PLMN uses a 5G system, and Figure 21 This illustrates a scenario where one wireless network / PLMN uses a 4G network while another data network / PLMN uses a 5G network.

[0303] like Figure 20 and Figure 21As depicted, during the time period when the UE is actively communicating over the 3GPP access of wireless network 1, the UE can simultaneously communicate over the non-3GPP access of wireless network 2. In one example, a dual-SIM UE with single transmission for 3GPP access can simultaneously activate non-3GPP transmission.

[0304] The explanation of the present disclosure is specific to 5G systems and network functions. However, the same functions can be applicable to 4G systems and network functions. In one example, the functions of AMF can be adopted by MME and S-GW in 4G networks.

[0305] In one example, the 5G core network can adopt 5G access technology (e.g., New Radio) and enhanced 4G access technology (e.g., EUTRA / LTE). In one example, the base station supporting 4G access technology can be enhanced to support N2 / N3 interfaces of the 5G core network.

[0306] In one example, the 5G / 4G system can support AMF / MME / S-GW and / or base station to apply different paging strategies for different types of traffic according to the operator's configuration. For the UE in CM-IDLE state, different paging strategies can be configured in the AMF for different combinations of DNN, paging policy indicator (PPI), ARP, 5QI, etc. For the UE in CM-CONNECTED / RRC-INACTIVE state, different paging strategies can be configured in the base station for different combinations of PPI, ARP, and 5QI.

[0307] In one example, the paging strategy can include a paging retransmission scheme, determining whether to send a paging message to the base station in certain AMF high load situations, whether to apply sub-area based paging, etc. In one example, the paging retransmission scheme can be the frequency or time interval of paging repetition. In one example, the paging retransmission scheme can be the maximum number of paging retransmission attempts when there is no response from the UE. In one example, the sub-area based paging is the first paging in the last known cell ID or tracking area (TA) and retransmission in all registered TAs.

[0308] In one example, the AMF can apply different paging strategies for IMS DNN and Internet DNN of the same UE. In one example, in response to paging for IMS DNN, the AMF can send a paging message to the entire tracking area of the UE for the first paging transmission. At the same time, in response to paging for Internet DNN, the AMF can send a paging message to the last known cell of the UE for the first paging transmission. Different paging strategies can solve different connection setup time and connection success rate. In one example, the AMF can not perform paging retransmission for a specific DNN to save the paging resources of the system.

[0309] In case the UE is in CM-IDLE state, the AMF can perform paging and determine the paging strategy based on, for example, local configuration, type of network node triggering the paging, information available in the request triggering the paging (e.g., data notification message), etc. In case the UE is in CM-CONNECTED / RRC-INACTIVE state, the base station can perform the paging procedure and determine the paging strategy based on, for example, local configuration and information received from the AMF or SMF.

[0310] In case of network triggered service request from SMF, as depicted in FIG. 22, the SMF can determine 5QI and ARP based on the downlink data received from UPF or data notification of downlink data. In one example, the SMF can include the 5QI and ARP corresponding to the received downlink data in the request (e.g., communication request) sent to the AMF. If the UE is in CM IDLE, the AMF uses, for example, the 5QI and ARP to derive different paging strategies for the paging procedure.

[0311] Paging policy differentiation

[0312] Paging policy differentiation (PPD) functionality can allow the AMF to apply different paging strategies for different traffic or service types provided within the same PDU session based on operator configuration. In one example, the paging policy differentiation can be applied to IP type PDU session. When the 5GS supports PPD feature, the application server sets the DSCP value (TOS in IPv4 / TC in IPv6) of the user IP packet to indicate to the 5G system which paging strategy should be adopted for a certain IP packet. The Differentiated Services Code Point (DSCP) is a packet header value that can be used to request high priority or best effort traffic transmission.

[0313] As shown in FIG. 23, the application server can be an IP Multimedia Subsystem Proxy Server (e.g., P-CSCF), and the P-CSCF can support the PPD feature by using DSCP marking for packets related to a specific IMS service to be sent to the UE. In one example, the specific IMS service can indicate at least one of IMS voice, IMS video, IMS SMS, IMS signaling, other PS services, etc. The UPF can include the DSCP in the TOS (IPv4) / TC (IPv6) value of the IP header of the downlink data packet from the application server and include an indication of the corresponding QoS flow in the Data Notification message sent to the SMF. The SMF can determine the Paging Policy Index (PPI) based on the DSCP in the Data Notification message received from the UPF. In one example, the SMF can include the PPI, ARP, and 5QI of the corresponding QoS flow in the N11 message sent to the AMF. If the UE is in CM-IDLE state, the AMF uses this information to derive the paging policy and send a paging message to the base station. In one example, the AMF can apply different paging policies for IMS voice and IMS SMS.

[0314] In one example, for a UE in CM-CONNECTED / RRC-INACTIVE state, the base station can implement a specific paging policy for RAN paging based on the 5QI, ARP, and PPI associated with the incoming DL PDU, as shown in FIG. 24. To achieve this, the SMF can indicate to the UPF to detect the DSCP in the TOS (IPv4) / TC (IPv6) value of the IP header of the DL PDU (by using a Downlink Packet Detection Rule (DL PDR) with the DSCP of this traffic) and transmit the corresponding PPI in the Core Network (CN) tunnel header (by using a Forwarding Action Rule (FAR) with the PPI value). Figure 24 Figure 25A An example call flow of downlink (DL) PDU session information transfer from the sUPF and sBase station is illustrated. In one example, the DL PDU session information transfer flow can be used to send control information elements related to a PDU session from the UPF to the base station (NG-RAN). In one example, the DL PDU session information transfer flow can be invoked whenever packets of that PDU session need to be transferred across the relevant interface instances. The base station can utilize the PPI received in the CN tunnel header of the incoming DL PDU in order to apply the corresponding paging policy in case the UE is in RRC-INACTIVE state and needs to be paged. Figure 25B ​An example frame format depicting DL PDU session information is depicted. In one example, the DL PDU session information frame can include a QoS flow identifier (QFI) field associated with the transmitted packet. In one example, the base station can use the received QFI to determine the QoS flow and QoS profile associated with the received packet. The DL PDU session information frame can include a reflective QoS indicator (RQI) field to indicate that user plane reflective QoS should be activated or not activated. The DL PDU session information frame can include a paging policy indicator (PPI) field associated with the transmitted packet. The base station can use the received PPI to determine the paging policy differentiation associated with the received packet.

[0315] Figure 22 An example call flow of a network triggered service request procedure is illustrated. The network triggered service request can be used by the network when the network needs to signal to the UE (e.g., send N1 signaling to the UE, mobile terminated SMS, user plane connection activation of a PDU session to transmit mobile terminated user data). When the procedure is triggered by the SMSF, PCF, NEF, or UDM, Figure 22 The SMF in may be replaced by the corresponding network function. If the UE is in CM-IDLE state or CM-CONNECTED state in 3GPP access, the network can initiate the network triggered service request procedure. If the UE is in CM-IDLE state and no asynchronous type communication is activated, the network triggered service request procedure can trigger a paging procedure (i.e., the AMF sends a paging request message to the UE through the base station). In one example, the paging request message can be a paging message. In one example, the paging procedure can trigger the UE triggered service request procedure in the UE as shown in Figure 10 and Figure 11 If asynchronous type communication is activated, when the UE enters CM-CONNECTED state, the network can store the received message and forward the message to the base station and / or the UE.

[0316] If the UE is in CM-IDLE state in 3GPP access, in CM-CONNECTED state in non-3GPP access, and if the UE is registered in the same PLMN through 3GPP and non-3GPP access at the same time, the network can initiate the network triggered service request procedure for 3GPP access via non-3GPP access by sending a notification message.

[0317] In one example, the SMF can need to establish an N3 tunnel (i.e., a tunnel between the UPF and the base station) to transmit downlink data packets to the UE for a PDU session, and the UE is in CM-IDLE state. In one example, the SMF can send a communication request message (e.g., Namf_communication_N1N2message transfer) to the AMF, and thus the AMF can perform a paging procedure.

[0318] In one example, a network function (e.g., SMF, SMSF, PCF, or NEF) can need to send an N1 message to the UE. In this case, the NF can use the Namf_communication_N1N2message transfer service operation (e.g., send Namf_communication_N1N2message transfer). When the UE is in CM-IDLE state, the AMF can respond to the NF by sending a communication request response message (Namf_communication_N1N2transfer response message) that can contain the cause “Attempting to reach UE,” and the AMF can perform a paging procedure. In one example, the N1 message can be a non-access stratum message. In one example, the N1 message can be a control signaling message from the network function to the UE, such as a PDU session modification command message.

[0319] In existing wireless technologies, a UE can simultaneously monitor two different paging messages from two different systems. For example, a dual-subscriber identity module (SIM) dual- standby (DSDS) UE can monitor two different paging messages from two different public land mobile networks (PLMNs) of two different subscriptions. Adding a paging cause value in the paging message can help the DSDS UE to selectively respond to terminating services. In one example, the paging cause value (or more simply, the paging cause) in the paging message can help the DSDS UE to selectively ignore less important terminating services compared to other terminating services. In one example, the UE can be actively communicating with a first PLMN (PLMN1) and can want to respond to a paging message for IMS voice service from a second PLMN (PLMN2). In another example, the UE can be actively communicating with the PLMN1 and can not want to respond to a paging message for a non-IMS terminating service.

[0320] In the existing wireless technologies described above, paging resources may be wasted on both the RAN and core network sides. For example, existing wireless technologies may include a paging reason in every paging message for the UE, even if the UE does not need a paging reason. This can lead to a waste of paging resources. Furthermore, existing technologies may retransmit paging messages from the network without knowing that the UE might ignore the paging message. This can also lead to a waste of paging resources.

[0321] In one embodiment of this disclosure, the UE can determine whether a paging cause value (or paging cause) needs to be included in the paging message. Based on this determination, the UE can send a request to the AMF to provide a paging cause value in the paging message. If the AMF accepts the request, the AMF can add one or more paging cause values ​​to the paging message used by the UE. In another embodiment of this disclosure, the above-described paging cause request procedure and paging cause addition procedure can be extended to RAN paging. In one example, the AMF may not include a paging cause value in the paging message. This can be based on the AMF rejecting a request from the UE, based on the UE not sending a request, or sending a request not to include a paging cause value in the paging message. Embodiments of this disclosure can improve paging resource efficiency for RAN paging and core network paging by providing a paging cause value in the paging message to the UE based on, for example, the UE's need. Embodiments of this disclosure can alternatively or additionally improve paging resource efficiency by controlling paging message retransmission based on UE behavior (e.g., whether the UE ignores the paging message).

[0322] Figure 27 An exemplary call flow is illustrated, comprising a paging reason value request flow and a paging reason determination flow according to embodiments of the present disclosure. Figure 27As shown, the UE can determine whether a paging cause parameter / value / indication can be needed. In one example, the determination can be based on a device type (e.g., dual-SIM UE, multi-SIM UE), a roaming status of the UE (UE registered with a visited PLMN or a home PLMN), an indication from the network that the network supports dual-SIM UE optimization, and / or the like. In one example, the UE can be a multi-SIM device. The multi-SIM device can include more than one SIM. In one example, the UE can be a dual-SIM device. The dual-SIM device can include two / dual SIMs. In one example, the UE can be previously registered with a first PLMN (PLMN A). In one example, PLMN A can be a primary PLMN. The UE can register with a second PLMN (PLMN B). In one example, PLMN B can be a secondary PLMN. In another example, PLMN B can be a primary PLMN. In one example, the UE can request, during registration with PLMN B, to include a paging cause value in a paging message to the UE. The UE can send a registration request message to an AMF of PLMN B through a base station, requesting to register with PLMN B. The registration request message can include: a request to include a paging cause value in a paging message to the UE, a UE identity (e.g., SUCI, 5G-GUTI), a location of the UE (e.g., last visited TAI), a requested NSSAI, UE mobility management context information, PDU session status, MICO mode usage information, and / or the like. In one example, the UE can include a dual-SIM UE capability in the registration request message instead of the request to include a paging cause value in a paging message. In one example, the AMF can interpret the dual-SIM UE capability as the same as the request to include a paging cause value in a paging message.

[0323] In one example, the UE can request to include a paging cause value if the UE is registered in a visited PLMN and attempts / tries to reselect and / or register to a home PLMN.

[0324] In one example, the AMF can determine whether to include a paging cause value in a paging message to the UE based on one or more of: the request to include a paging cause value, a local policy of the AMF, subscription information of the UE in a UDM, an overload situation of the system, a dual-SIM UE capability, and / or the like. In one example, the AMF can not include a paging cause value if the local policy of the AMF does not allow. In one example, the AMF can not include a paging cause value if the subscription information of the UE does not indicate / allow to include a paging cause value in a paging message to the UE. In one example, the AMF can not include a paging cause value if an overload / congestion situation does not allow. In one example, the AMF can detect an overload / congestion of paging resource usage. The AMF can not allow UE selective paging response based on a paging cause value.

[0325] In one example, the AMF can send a notification message over the non-3GPP access (if the UE is in CM-CONNECTED for the non-3GPP access) instead of sending a paging message over the 3GPP access of the UE in response to receiving and accepting the request including the paging cause value. In one example, for a UE in CM-CONNECTED for the non-3GPP access, the AMF can send a notification message instead of a paging message.

[0326] In one example, the AMF can send a registration accept message to the UE indicating that the registration is successful. In one example, the registration accept message can include a 5G-GUTI, a registration area, a periodic registration area update time value, an MICO mode indication, and the like. In one example, the registration accept message can also include a result of the request (e.g., whether the AMF accepted that the paging message for the UE includes the paging cause value).

[0327] In one example, the AMF and the base station can determine a release of the connection with the 3GPP access of the UE. In one example, the determination of the release of the connection with the UE can be based on inactivity detection of the UE for a period of time (e.g., when there is no transmission or reception from the UE for 10 seconds).

[0328] In one example, for a UE in a CM-IDLE state for the 3GPP access, a network triggered service request can be performed between the AMF and a network function, as shown in Figure 22 and Figure 23 .

[0329] In one example, the network triggered service request can be triggered by the UPF in response to receiving downlink data. In one example, the network triggered service request can be triggered by one or more network functions (e.g., NEF, SMSF, PCF, and the like) to request sending control signaling to the UE. In one example, the PCF can request the network triggered service request due to a change in the UE policy. In one example, the network triggered service request can be triggered by the AMF due to a change in the UE configuration (e.g., configuration for access and mobility management, MICO disable, slice information update, and the like).

[0330] In one example, the UPF can receive downlink data for a PDU session and there is no AN tunnel information stored in the UPF for the PDU session. In one example, the UPF can send a data notification message to the SMF requesting to establish a user plane connection for the PDU session with the UE in response to receiving the downlink data. In one example, the data notification message can include an N4 session identity, a Differentiated Services Code Point (DSCP) value (TOS in IPv4 / TC in IPv6), information identifying a QoS flow of the DL data packet, etc. In one example, the N4 session identity can be used by the SMF to identify the PDU session. In one example, the SMF can derive an Allocation Retention Priority (ARP) and a 5QI based on the information identifying the QoS flow of the DL data packet. The SMF can derive a Paging Policy Indicator (PPI) from the DSCP value. In one example, if the UPF and an IP Multimedia System (IMS) support Paging Policy Differentiation (PPD), an Application Server (e.g., P-CSCF) can set the DSCP (TOS in IPv4 / TC in IPv6) to indicate to the 5G system which paging policy should be applied for a certain IP data packet by marking the data packet related to a specific IMS service to be sent to the UE using the DSCP. In one example, the specific IMS service can indicate at least one of IMS voice, IMS video, IMS SMS, IMS signaling, other PS services, etc. In one example, the SMF can send a data notification acknowledgement message to the UPF in response to receiving the data notification message. In one example, the SMF can send a communication request message to the AMF requesting to establish a communication with the UE in response to receiving the downlink data notification from the UPF. The communication request message can be a Namf_Communication_N1N2MessageTransfer. In one example, the communication request message can include a UE identity, a PDU session identity, a session management container, a QFI, a QoS profile, a 5QI, an ARP, a PPI, an N1 message, etc. In one example, the UE is in a CM-IDLE state at the AMF. If the AMF is able to page the UE, the AMF can immediately send a communication request response message to the SMF with a cause “Attempting to reach UE” in response to the communication request message.

[0331] If the AMF accepts the paging cause value included in the previous step in Figure 27 , and the UE is in a CM-IDLE state at the AMF, the AMF can determine the paging cause value for the paging message of the UE. In one example, the determination of the paging cause value can be based on at least one of the PPI, the 5QI, the network node / function triggering the paging procedure, the paging resource load condition of the system, etc.

[0332] In one example, the paging cause value can indicate at least one of non-access stratum (NAS) signaling for mobility management, NAS signaling for slice change, UE context / configuration update, UE policy update, indication of request for registration, IMS voice, IMS video, IMS SMS, IMS signaling, other IMS, other, etc.

[0333] In one example, the network node triggering the paging procedure can be a UPF, and the communication request message from the SMF does not contain PPI. The AMF can determine the paging cause value based on the PPI.

[0334] In one example, the network node triggering the paging procedure can be a UPF, and the communication request message from the SMF does not contain PPI (the network does not support PPD feature). The AMF can determine the paging cause value based on the 5QI and session information. For example, if the 5QI value indicates 5 (i.e., IMS signaling), the AMF can determine the paging cause as IMS service. If the 5QI indicates other than 5, the AMF can determine the paging cause as non-IMS service.

[0335] In one example, the network node triggering the paging procedure can be a PCF. The AMF can determine the paging cause value as “UE policy update”.

[0336] In one example, the network node triggering the paging procedure can be an AMF. The AMF can determine the paging cause value according to the message content. If the AMF triggers the paging procedure to update slice information, the AMF can indicate the paging cause value as NAS signaling for slice change. If the AMF triggers the paging procedure to update UE configuration, the AMF can indicate the paging cause value as NAS signaling for UE configuration update.

[0337] In one example, the AMF can send a paging message to the UE through a base station. The paging message can include the paging cause value, the UE identity, the access type, etc. In one example, the UE identity can indicate a 5G S-TMSI. In one example, the access type can indicate a third generation partnership project (3GPP) access technology. In one example, the paging message can not include the paging cause value for a UE for which the paging cause value is not requested, or the request is not accepted by the AMF. This procedure improves paging resource efficiency by not sending the paging cause value for certain UEs.

[0338] In one example, the UE can receive a paging message. In response to receiving the paging message, the UE can determine to send a radio resource control (RRC) message to request establishment of a connection with PLMN B. The determination can be based on a paging cause value, a 3GPP connection state of the UE, a roaming status of the UE, and / or the like. In one example, the 3GPP connection state can indicate an active connection with a base station belonging to PLMN A or for a UE in CM-CONNECTED for PLMN A. The roaming status of the UE can indicate whether the UE is registered in a visited PLMN or a home PLMN.

[0339] In one example, the UE can send the RRC request message in response to a paging cause value indicating IMS voice. The UE can abandon any active communication with PLMN A in order to send the RRC request message and continue a terminated service with PLMN B. In one example, the UE can not send the RRC request message in response to a paging cause value indicating other terminated services (e.g., in addition to IMS voice). In another example, the UE can not send the RRC request message in response to a paging cause value indicating other terminated services when the UE is actively communicating with PLMN A. However, if the UE is not actively communicating with PLMN A, the UE can send the RRC request message in response to a paging cause value indicating other terminated services.

[0340] In one example, in response to sending the RRC request message, the UE can receive an RRC request response message. The UE can send an RRC request complete message to the base station. The RRC request complete message can include a NAS service request message. By sending the NAS service request message from the UE, the UE triggered service request procedure can be invoked as described above in Figure 10 and Figure 11 .

[0341] In one example, the AMF can retransmit the paging message in response to expiration of a wait response message (e.g., service request message) and a wait timer. In one example, the AMF can use the request including the paging cause value for paging policy. In one example, the AMF can reduce the number of paging retransmission attempts (or change the time interval, time offset, etc. between subsequent paging retransmissions) if the UE previously requested including the paging cause and the AMF includes the paging cause value in the paging message. In one example, the AMF can consider whether the UE intentionally does not respond to the paging. In one example, the AMF can know that there is no coverage blind spot in the registration area of the UE location so that the UE can respond to the paging message. The coverage blind spot can be an area where the UE cannot receive a signal from a base station. In one example, if the paging cause included in the paging message has a relatively low priority, the AMF can know that the UE is likely to ignore the paging message and not send a paging response (e.g., service request) (e.g., the AMF can determine that the UE has ignored the paging message based on the priority associated with the paging cause). In one example, if the AMF knows that there is no coverage blind spot and the UE does not respond to the paging message, the AMF can not retransmit the paging message based on, for example, paging resource usage. In one example, the AMF can not retransmit the paging message to the UE if the paging message includes the paging cause.

[0342] Figure 28 FIG. illustrates an example of a paging cause value request procedure and paging cause determination between a UE and an MME with respect to a 4G system case according to an embodiment of the disclosure. In this example, the UE can previously register a different PLMN that does not include the base station. Figure 28 In this example, the AMF is replaced by the MME, and the SMF is replaced by the S-GW compared to the previous example of Figure 27

[0343] Figure 29 FIG. illustrates an example of a paging cause value request procedure and paging cause determination between a UE and a base station for an RRC-INACTIVE state with respect to a 5G system case according to an embodiment of the disclosure. In this example, the UE can previously register a different PLMN that does not include the base station. The UE and the AMF can negotiate to include the paging cause value in the paging message during a registration procedure based on a request including the paging cause value from the UE, a local policy of the AMF, subscription information of the UE in the UDM, overload situation of the system, etc.

[0344] ​In one example, if the AMF determines to include a paging cause for the UE, the AMF can provide the corresponding information to the base station during a connection establishment procedure so that the base station can properly configure the paging cause for RAN paging during the RRC-INACTIVE state. In one example, the AMF can send a context setup request message to the base station to request connection establishment for the UE. In one example, the context setup request message can include a request to include a paging cause value for the UE. The base station can respond to receiving the context setup request message by sending a context setup response message to the AMF.

[0345] In one example, the base station can detect that the UE is inactive for a period of time (e.g., no transmission or reception from the UE for 10 seconds) and determine to suspend the RRC connection with the UE. In one example, the base station can send an RRC release message to the UE in response to the determination. In one example, the RRC release message can include suspend / suspend configuration information.

[0346] In one example, the suspend / suspend configuration information can include a radio network temporary identifier (RNTI), a radio access network (RAN) paging cycle, RAN notification area (RNA) information, a periodic RNA update time value, and / or the like. In one example, the periodic RNA update time value can be 10 minutes. In one example, the RAN notification area information can include a cell list, a PLMN identity, a tracking area code list, a RAN area code list, and / or the like.

[0347] In one example, the UE can enter the RRC-INACTIVE state in response to receiving the RRC release message. The UE can listen for paging messages in response to entering the RRC-INACTIVE state. In one example, the UE can perform a RAN notification area update procedure in response to entering a cell that does not belong to the RNA. In one example, the UE can perform a RAN notification area update procedure in response to entering a new RNA. In one example, the base station can determine the periodic RNA update time value according to the periodic registration area update time value. In one example, the periodic RNA update time value (e.g., 30 minutes or 1 hour) can be less than the periodic registration area update time value (e.g., 3 hours or 12 hours).

[0348] In one example, the base station can receive user NAS data (e.g., downlink NAS transport) from the AMF for the UE. In one example, the base station can receive user packet data (e.g., DL PDU session information) from the UPF.

[0349] In one example, the user packet data can be downlink PDU session information as described in Figure 25A In one example, the base station can send a downlink data notification message to the UE in response to receiving the user packet data. In one example, the downlink data notification message can include the RNTI, the RAN paging cycle, the RNA information, and / or the like.Figure 25B As shown, the downlink PDU session information can include RQI, PPI, QoS flow identifiers, etc.

[0350] In one example, the base station can receive a downlink NAS transport message from the AMF, as Figure 26A depicted. In one example, the NAS transport message, as Figure 26B depicted, can include a message type, an AMF UE NGAP identity, a RAN UE NGAP identity, an old AMF address, a RAN paging priority, a NAS-PDU, a NAS PDU type, an allowed NSSAI, etc. In one example, the AMF UE NGAP ID can uniquely identify the UE association over the NG interface (e.g., N2 interface) within the AMF side. The RAN UE NGAP ID can uniquely identify the UE association over the NG interface within the NG-RAN side. In one example, the NAS PDU type can indicate at least one of mobility management, UE policy update, UE context / configuration update, indication of request for registration, etc.

[0351] In one example, the base station can determine a paging cause value based on information received from the UPF and the AMF. In one example, the information can be a NAS PDU type, a PPI, a QoS flow identifier, etc.

[0352] In one example, the base station can transmit a RAN paging message in response to receiving the downlink PDU session information or the downlink NAS transport message. In one example, the RAN paging message can include a paging cause value, a UE identity, an access type, etc. In one example, the UE identity can indicate a 5G S-TMSI or an I-RNTI. In one example, the access type can indicate a third generation partnership project (3GPP) access technology. The paging cause value can indicate at least one of non-access stratum (NAS) signaling for mobility management, NAS signaling for slice change, UE context / configuration update, UE policy update, indication of request for registration, IMS voice, IMS video, IMS SMS, IMS signaling, other IMS, other, etc.

[0353] In one example, the base station can not transmit a RAN paging message in response to detecting resource congestion and the paging cause is a relatively low priority. In one example, a non-IMS paging can be a relatively low priority.

[0354] In one example, the base station can retransmit the RAN paging message in response to the wait for response message (e.g., RRC resume request message) and expiration of the wait timer. In one example, the base station can use the request for paging policy including the paging cause value. In one example, if the UE previously requested including the paging cause and the base station RAN includes the paging cause value in the paging message, the base station can reduce the number of paging retransmission attempts (or change the time interval, time offset, etc. between subsequent paging retransmissions).

[0355] In one example, the base station can consider whether the UE intentionally did not respond to the paging message. In one example, the base station can know that there are no coverage holes in the RAN notification area of the UE location so the UE can respond to the RAN paging message. In one example, if the paging cause included in the paging message has a relatively low priority, the base station can know that the UE likely ignored the paging message and did not send a paging response (e.g., the base station can determine that the UE ignored the paging message based on the priority associated with the paging cause). In one example, if the paging message includes a paging cause and the paging cause has a relatively low priority, the base station can determine not to retransmit the paging message to the UE.

[0356] Figure 30 、 Figure 31 、 Figure 32 、 Figure 33A and Figure 33B Figure illustrates an example when the user packet includes a paging cause value instead of the base station determining the paging cause value. This example embodiment shows how the information such as the paging cause value and PPI can be selectively included in the downlink PDU session information. In one example, the PPI and paging cause value can only be used when the UE is in the RRC-INACTIVE state. In one example, if the UE is in the RRC-CONNECTED state, the base station can not use the PPI and paging cause.

[0357] Figure 30 Figure illustrates how the paging cause value and PPI are communicated to the base station according to embodiments of the disclosure. In one example, the base station can use the paging cause value in the user packet (i.e., downlink PDU session information) and can include the same paging cause value in the RAN paging message. The behavior of the UE and base station after the base station sends the paging message can be the same as the example embodiments of Figure 29 .

[0358] Figure 31 Figure shows a downlink PDU session information format according to embodiments of the disclosure that also includes a paging cause value.

[0359] In the above existing wireless technologies, a paging cause value or PPI can be included in a packet data unit header. The paging cause value or PPI can be used for RAN paging of a wireless device in an RRC inactive state by an access network. The paging cause value or PPI cannot be used for a wireless device in an RRC connected state. A session management function and / or user plane function can not know whether a wireless device is in an RRC inactive state or an RRC connected state. A user plane packet header can include a paging cause value or PPI even if a base station does not need this information. Including a paging cause value or PPI without considering an RRC state can waste user plane resources. Therefore, a mechanism can be needed for a SMF or UPF to know an RRC state.

[0360] Figure 32 It is shown how a SMF knows an RRC state of a UE and how the SMF reports an RRC state change to a UPF. In one example, a UPF can include a paging cause value or PPI value based on an RRC state of a UE. In one example, the UPF can include the paging cause value or PPI if the UE is in an RRC-INACTIVE state. In one example, the UPF can not include a paging cause value or PPI if the UE is in an RRC-CONNECTED state. In one example, the UPF can include a paging cause value or PPI value based on an explicit indication from a SMF.

[0361] As Figure 32 depicted, a SMF can send a Namf_EventExposure_Subscribe message to an AMF. The Namf_EvenExposure_Subscribe message can include an event type, a UE type, a reporting type, a UE identity, as shown in Figure 33A and Figure 33B Figure 33A For a connected state reporting event type. Figure 33B For an RRC connected state reporting event. In one example, the event type can be an RRC connected state reporting. In one example, the reporting type can be a continuous reporting. Again referring to Figure 32 ​In response to receiving the Namf_EventExposure_Subscribe message with event type as RRC connection status report, the AMF can subscribe to the event type of RRC connection status for the UE. In one example, in response to receiving the Namf_EventExposure_Subscribe message with event type as RRC connection status report, the AMF can send a UE state transition notification request message to the base station. In one example, the base station can monitor the change of RRC state of the UE and the base station can report the change of RRC state (e.g. RRC-CONNECTED to RRC-INACTIVE or RRC-INACTIVE to RRC-CONNECTED) to the AMF through the sent UE notification message, as shown in Figure 16 In one example, in response to receiving the UE notification message from the base station, the AMF can send a Namf_EventExposure_Notify message including the RRC state. In one example, the SMF can report the change of RRC state and the current RRC state to the UPF. In one example, the SMF can request the UPF to include the paging cause value or PPI based on the RRC state being RRC-INACTIVE state. In one example, in response to the implicit or explicit indication from the SMF, the UPF can include any additional information for the RAN paging procedure.

[0362] Figure 34 An example embodiment illustrating per-PDU paging cause request procedure is shown. The UE can request the paging cause requirement during the PDU session establishment request procedure. Thus, if the PDU session is configured to include the paging cause, the AMF includes the paging cause value of the paging message.

[0363] Figure 35 、 Figure 36 and Figure 37 are flowcharts of the present disclosure.

[0364] Figure 35 UE behavior when or how the UE determines the need for paging cause and requests from the network is shown. In one example, the UE can be a dual-SIM UE and has previously registered in a PLMN 1 different from the serving PLMN. In one example, the serving PLMN can be the secondary PLMN. Thus, the UE can want to know the type of terminated service of the serving PLMN by asking the paging cause of the terminated service. Thus, for the terminated service with a paging cause value indicating less importance than the active service of the PLMN 1, the UE can ignore (not respond to) the paging of the terminated service.

[0365] In one example, the serving PLMN can be a visited PLMN, and thus the UE can want to prioritize searching for or camping on the home PLMN. In one example, the UE can want to know the reason for the service termination in the visited PLMN so that the UE can selectively respond to the service termination by the visited PLMN.

[0366] Figure 36 FIGURE illustrates how an AMF determines to include a paging cause in a paging message. In one example, the AMF can determine based on a request from the UE, subscription information of the UE, local policy of the AMF, etc. If the UE does not request to include the paging cause value, the AMF can not include the paging cause value in the paging message to the UE.

[0367] Figure 37 FIGURE illustrates how a UE determines to respond to a paging message based on a paging cause value in the paging message.

[0368] In one example, a wireless device can send a registration request message to an access and mobility management function (AMF) to request registration to a public land mobile network (PLMN). In one example, the registration request message can include a request to include a paging cause value in a paging message to the wireless device.

[0369] In one example, the wireless device can receive a registration accept message from the AMF indicating that the registration to the PLMN is successful.

[0370] In one example, the wireless device can receive a paging message from a base station. The paging message can include a paging cause value.

[0371] In one example, the wireless device can determine to send a radio resource control (RRC) request message requesting to establish a connection with the PLMN and can send the RRC request message.

[0372] In one example, the wireless device can send the request in response to the wireless device being a multi-subscriber identity module (SIM) device.

[0373] In one example, the multi-SIM device can be a dual-SIM device.

[0374] In one example, the wireless device can send the request in response to the PLMN being a low priority PLMN for the wireless device.

[0375] In one example, the wireless device can send the request in response to the wireless device using dual registration for interworking.

[0376] In one example, interworking can be a UE functionality to interwork between different generations of wireless communication technologies (e.g., 4G or 5G).

[0377] In one example, the wireless device can simultaneously register the fourth generation network of the PLMN and the fifth generation network of the PLMN.

[0378] In one example, the wireless device can transmit the request in response to the PLMN being a visited PLMN.

[0379] In one example, the paging message can further include a 5G S-TMSI, an I-RNTI, an access type.

[0380] In one example, the access type can indicate a third generation partnership project (3GPP) access technology, a non-third generation partnership project (Non-3GPP) access technology, and / or the like.

[0381] In one example, the paging cause value can indicate at least one of NAS signaling for mobility management, NAS signaling for policy update, UE context / configuration update, UE policy update, indication of registration request, IMS voice, IMS video, IMS SMS, IMS MMS, IMS signaling, other IMS, other, and / or the like.

[0382] In one example, the wireless device can transmit the RRC request message in response to the paging cause value indicating IMS voice.

[0383] In one example, the wireless device can not transmit the RRC request message in response to the paging cause value indicating other.

[0384] In one example, the paging cause value can indicate at least one of high priority, medium priority, low priority.

[0385] In one example, the wireless device can transmit the RRC request message in response to the paging cause value indicating high priority.

[0386] In one example, the wireless device can not transmit the RRC request message in response to the paging cause value indicating low priority.

[0387] In one example, the registration request message can further include at least one of a registration type, a UE identity, a last visited tracking area identity, a requested NSSAI, a mobile initiated connection only (MICO) mode indication, a UE mobility management core network capability, packet data session related information, and / or the like.

[0388] In one example, the registration type can indicate at least one of initial registration, mobility registration update, periodic registration update, emergency registration.

[0389] In one example, the UE identity can indicate at least one of a subscriber concealed identifier (SUCI), a 5G globally unique temporary identity (GUTI), a permanent equipment identifier (PEI), and / or the like.

[0390] In one example, the RRC request message can be an RRC setup request message.

[0391] In one example, the RRC request message can be an RRC resume request message.

[0392] In one example, a wireless device can transmit, to a session management function (SMF), a session establishment request message requesting establishment of a packet data unit (PDU) session with a public land mobile network (PLMN), the session establishment request message can include a request that a paging message to the wireless device include a paging cause value.

[0393] In one example, the wireless device can receive, from the SMF, a session establishment accept message indicating that the session establishment with the PLMN was successful.

[0394] In one example, the wireless device can receive a paging message including a paging cause value.

[0395] In one example, the wireless device can determine, based on the paging cause value, to transmit a radio resource control (RRC) request message requesting establishment of a connection with the PLMN.

[0396] In one example, in response to the determination, the wireless device can transmit the RRC request message.

[0397] In one example, the session establishment request message can further include at least one of a data network name (DNN), a PDU session ID, a requested PDU session type, a requested session and service continuity (SSC) mode, a session management capability PCO, a number of data packet filters, a requested always-on PDU session, and / or the like.

[0398] In one example, the DNN can indicate an IP multimedia subsystem (IMS).

[0399] In one example, an access and mobility management function (AMF) can receive, from a wireless device, a registration request message requesting registration to a public land mobile network (PLMN), the registration request message can include a request that a paging message to the wireless device include a paging cause value.

[0400] In one example, the AMF can transmit, to the wireless device, a registration accept message indicating successful registration to the PLMN.

[0401] In one example, the AMF can determine a paging cause value for a paging message to the wireless device.

[0402] In one example, the AMF can transmit a paging message to the base station, which can include a paging cause.

[0403] In one example, determining to include the paging cause value in the paging message packet can be based on at least one of a request, a local policy of the AMF, subscription information of the wireless device, an overload situation of the system.

[0404] In one example, determining to transmit the paging message can be based on at least one of receiving a connection establishment request message from a network node of the wireless device, a change in UE configuration, a change in UE policy, etc.

[0405] In one example, the network node can be a session management function, a policy control function, a network exposure function, a user data management function, etc.

[0406] In one example, the determination of the paging cause value can be based on at least one of a paging policy indication, a QoS parameter of a corresponding user data packet (5QI), a local policy, a network node triggered / triggered paging procedure, a paging resource load situation of the system, etc.

[0407] In one example, the paging policy indication can be based on a type of IMS service.

[0408] In one example, the paging policy indication can be based on a type of application service.

[0409] In one example, the AMF can perform multiple retransmissions of the paging message. The number of retransmissions can be based on at least one of the paging cause value, an assigned and reserved priority, a local policy, a load / congestion situation of the AMF, a load / congestion situation of the RAN, etc.

[0410] In one example, the AMF can perform the retransmission of the paging message based on a retransmission timer.

[0411] In one example, the AMF can prioritize a notification procedure via a non-Third Generation Partnership Project (3GPP) access network over a paging procedure via a 3GPP access network based on a request.

[0412] In one example, the base station can receive a context setup message from an Access and Mobility Management Function (AMF) requesting to establish a user plane connection, which can include a request to include a paging cause value in a paging message to a wireless device.

[0413] In one example, the base station can transmit a radio resource control (RRC) message to the wireless device to transition the wireless device from an RRC connected state to an RRC inactive state.

[0414] In one example, a base station can determine a paging cause value for a paging message to a wireless device and can transmit to the wireless device. The paging message can include the paging cause value.

[0415] In one example, the base station can also determine to include the paging cause value in the paging message based on at least one of a request, a local policy of the base station, an overload condition of the system, and / or the like.

[0416] In one example, the base station can also determine to transmit the paging message based on at least one of receiving a downlink NAS transport message from an AMF for the wireless device, receiving a downlink packet data unit (PDU) session from a user plane function (UPF), and / or the like.

[0417] In one example, the downlink NAS transport message can include a non-access stratum (NAS) PDU type.

[0418] In one example, the NAS PDU type can indicate at least one of an update of a UE mobility management, an update of a UE policy, an update of a UE context, a request for registration, and / or the like.

[0419] In one example, the determination of the paging cause value can be based on the NAS PDU type.

[0420] In one example, the downlink packet data unit (PDU) session information can include at least one of a paging policy indication (PPI), a QoS flow identifier (5QI), a paging cause value, and / or the like.

[0421] In one example, the determination of the paging cause value can be based on at least one of the PPI, the QoS flow identifier, the paging cause value, and / or the like.

[0422] In one example, the paging policy indication (PPI) can be based on a type of IMS service.

[0423] In one example, the base station can perform multiple retransmissions of the paging message. The number of retransmissions is based on at least one of the paging cause value, an assigned and reserved priority, a local policy, a load / congestion condition of the base station, and / or the like.

[0424] In one example, the base station can perform the retransmission of the paging message based on a retransmission timer.

[0425] According to various embodiments, devices such as wireless devices, off-network wireless devices, base stations, and / or the like can include one or more processors and memory. The memory can store instructions that, when executed by the one or more processors, cause the device to perform a series of actions. Embodiments of example actions are described in the drawings and specification. Features from the various embodiments can be combined to create additional embodiments.

[0426] Figure 38 is a flow diagram of one aspect of the example embodiments of the present disclosure. At 3810, a wireless device can send a first request to an access and mobility management function (AMF) to include a paging cause value in a paging message. At 3820, a paging message can be received. The paging message can include the paging cause value. At 3830, based on the paging message, a second request to establish a connection can be sent.

[0427] According to one embodiment, the paging message can include the paging cause value in response to the first request. According to one embodiment, the first request can be a registration request message. According to one embodiment, the second request can be a radio resource control (RRC) setup message. According to one embodiment, the RRC setup message can be an RRC setup request message. According to one embodiment, the RRC setup message can be an RRC resume request message. According to one embodiment, the first request can include a user equipment identity of the wireless device. According to one embodiment, the first request can include at least one parameter indicating that the wireless device requests that the paging message can include the paging cause value.

[0428] According to one embodiment, a first public land mobile network (PLMN) can include the AMF. According to one embodiment, the first PLMN can be a visited PLMN. According to one embodiment, further comprising registering by the wireless device with a second PLMN. According to one embodiment, the first request can be based on the first PLMN being a lower priority PLMN than the second PLMN. According to one embodiment, the first request can be based on the wireless device being a multi-subscriber identity module (SIM) device. According to one embodiment, the multi-SIM device can be a dual-SIM device. According to one embodiment, the first request can be based on the wireless device using dual registration. According to one embodiment, the wireless device can further register with a mobility management entity (MME). According to one embodiment, the fourth generation network can include the MME.

[0429] According to one embodiment, the paging message can include the paging cause value. According to one embodiment, the paging message can include a user equipment identity. According to one embodiment, the paging message can include an access type.

[0430] According to one embodiment, the access type indicates a third generation partnership project (3GPP) access technology. According to one embodiment, the access type indicates a non-3GPP access technology.

[0431] According to one embodiment, the user equipment identity can indicate a fifth generation service temporary mobile subscriber identity. According to one embodiment, the user equipment identity is an inactive rate network temporary identifier.

[0432] According to an embodiment, the paging cause value can indicate that the paging message can be for non-access stratum (NAS) signaling for mobility management. According to an embodiment, the paging cause value can indicate that the paging message can be for NAS signaling for policy update. According to an embodiment, the paging cause value can indicate that the paging message can be for user equipment (UE) configuration update. According to an embodiment, the paging cause value can indicate that the paging message can be for UE policy update. According to an embodiment, the paging cause value can indicate that the paging message can be for an indication of a request for registration. According to an embodiment, the paging cause value can indicate that the paging message can be for internet protocol multimedia subsystem (IMS) voice. According to an embodiment, the paging cause value can indicate that the paging message can be for IMS video. According to an embodiment, the paging cause value can indicate that the paging message can be for IMS short message service. According to an embodiment, the paging cause value can indicate that the paging message can be for IMS multimedia message service. According to an embodiment, the paging cause value can indicate that the paging message can be for IMS signaling. According to an embodiment, the paging cause value can indicate that the paging message can be for other IMS.

[0433] According to an embodiment, the sending of the second request can be based on the paging cause value indicating IMS voice. According to an embodiment, the paging cause value can indicate high priority. According to an embodiment, the paging cause value can indicate medium priority. According to an embodiment, the paging cause value can indicate low priority. According to an embodiment, the sending of the second request can be based on the paging cause value indicating high priority. According to an embodiment, the first request can include the paging cause value in a paging message to the wireless device.

[0434] According to an embodiment, a wireless device can send a first request to an access and mobility management function (AMF) of a public land mobile network (PLMN) to include a paging cause value in a paging message to the wireless device. The paging message can be received from a base station. The paging cause value in the paging message can be based on the first request. The wireless device can send a second request to establish a connection with the PLMN based on the paging cause value in the paging message.

[0435] According to an embodiment, a wireless device can send a registration request message to an access and mobility management function (AMF) requesting: registration to a public land mobile network (PLMN); and inclusion of a paging cause value in a paging message to the wireless device. The paging message can be received from a base station. The paging cause value of the paging message can be based on the registration request message. A radio resource control (RRC) request message can be sent requesting establishment of a connection with the PLMN based on the paging cause value in the paging message.

[0436] Figure 39is a flow diagram of an aspect of the example embodiments of the present disclosure. At 3910, an access and mobility management function (AMF) can receive, from a wireless device, a request to include a paging cause value in a paging message. At 3920, the AMF can determine the paging cause value for the paging message. At 3930, the AMF can transmit the paging message based on the request. The paging message can include the paging cause value.

[0437] According to an embodiment, the determining can be further based on a local policy of the AMF. The determining can be further based on subscription information of the wireless device. The determining can be further based on an overload situation of the system. The determining can be further based on a paging policy indication. The determining can be further based on a quality of service parameter of a corresponding user data packet. The determining can be further based on a network node triggered paging procedure. The determining can be further based on a paging resource load situation of the system.

[0438] According to an embodiment, the paging policy indication can be based on a type of an internet protocol multimedia subsystem service. According to an embodiment, the paging policy indication can be based on a type of an application service. According to an embodiment, the subscription information can indicate whether the wireless device can be allowed to request the paging cause value. According to an embodiment, the transmitting can be based on at least one of: receiving a connection establishment request message for the wireless device from a network node; a change of a user equipment configuration; or a change of a user equipment policy.

[0439] According to an embodiment, the network node can be at least one of: a session management function; a policy control function; a network exposure function; or a user data management function. According to an embodiment, the AMF can further determine a number of retransmissions of the paging message. The number of retransmissions can be based on at least one of: the request; the paging cause value; an allocated and reserved priority; a local policy; a load status of the AMF; or a load status of a RAN.

[0440] According to an embodiment, the AMF can further perform the retransmission of the paging message based on a retransmission timer. According to an embodiment, the AMF can prioritize a notification procedure via a non-third generation partnership project (3GPP) access network over a paging procedure via a 3GPP access network based on the request. According to an embodiment, a public land mobile network (PLMN) can include the AMF. According to an embodiment, the PLMN can be a visited PLMN of the wireless device.

[0441] According to an embodiment, an access and mobility management function (AMF) can receive, from a wireless device, a registration request message requesting to register to a PLMN. The registration request message can include a request for a paging message to the wireless device to include a paging cause value. The AMF can determine the paging cause value for the paging message to the wireless device based on the request. The AMF can transmit, to a base station, the paging message including the paging cause value based on the request.

[0442] Figure 40 is a flow diagram of an aspect of example embodiments of the present disclosure. At 4010, a base station can receive a message from a wireless device, the message including a request for a paging message to include a paging cause value. At 4020, the base station can receive a paging message from an access and mobility management function (AMF). At 4030, the base station can transmit a page to the wireless device based on the paging message.

[0443] According to one embodiment, the paging message can include the paging cause value based on the request. According to one embodiment, the page can include the paging cause value.

[0444] Figure 41 is a flow diagram of an aspect of example embodiments of the present disclosure. At 4110, a base station can receive a first request message from an access and mobility management function (AMF) to include a paging cause value in a paging message to a wireless device. At 4120, the base station can determine the paging cause value. At 4130, the base station can transmit the paging message to the wireless device. The paging message can include the paging cause value based on the first request message.

[0445] According to one embodiment, the base station can transmit a second request message to the wireless device to transition the wireless device from a radio resource connected (RRC) connected state to an RRC inactive state.

[0446] According to one embodiment, the first request message can be a context setup request message requesting establishment of a user plane connection with the wireless device.

[0447] According to one embodiment, the base station can receive a downlink non-access stratum (NAS) transport message for the wireless device from the AMF. The base station NAS transport message can include: a NAS packet data unit (PDU); and a NAS PDU type associated with the NAS PDU. The base station NAS PDU type can include at least one of: an update of a user equipment (UE) mobility management parameter; an update of a UE policy; an update of a UE context; or a registration request. According to one embodiment, the determination by the base station can be further based on the NAS PDU type.

[0448] According to one embodiment, a base station can receive downlink packet data unit session information from a user plane function. According to one embodiment, the downlink packet data unit session information can include at least one of: a paging policy indication (PPI); a quality of service flow identifier; or a second paging cause value. According to one embodiment, the PPI can be based on a type of internet protocol multimedia subsystem service. According to one embodiment, determining the paging cause value can be further based on the downlink packet data unit session information. According to one embodiment, the base station can perform multiple retransmissions of a paging message. The number of retransmissions can be based on at least one of: the paging cause value; an allocation and retention priority of the wireless device; a local policy; or a load status of the base station.

[0449] According to one embodiment, a wireless device can send a first request to a session management function (SMF) to include a paging cause value in a paging message for a packet data unit (PDU) session. A paging message for the PDU session can be received. The wireless device can send a second request to establish a connection based on the paging message. According to one embodiment, the first request can be a session establishment request message. According to one embodiment, the first request can include: a PDU session identification of the PDU session; and at least one parameter indicating that the paging cause value is included in a paging message for the PDU session identified by the PDU session identification. According to one embodiment, the first request further includes at least one of: a data network name (DNN) of the PDU session; a PDU session identification of the PDU session; a requested PDU session type of the PDU session; a requested session and service continuity mode of the PDU session; a session management capability protocol configuration option of the PDU session; or a number of data packet filters. According to one embodiment, the DNN can indicate an internet protocol multimedia subsystem.

[0450] According to one embodiment, a session management function (SMF) can receive a request from a wireless device to include a paging cause value in a paging message for a packet data unit (PDU) session. The SMF can determine a paging cause value for the paging message for the PDU session. The SMF can send a connection establishment request message including the paging cause value to an access and mobility management function (AMF) based on the request.

[0451] According to one embodiment, a wireless device can send a session establishment request message to a session management function (SMF) requesting establishment of a packet data unit (PDU) session to a public land mobile network (PLMN). The session establishment request message can include a request that a paging cause value for the PDU session be included in a paging message to the wireless device. The paging message can be received from a base station. The paging message can include the paging cause value for the PDU session based on the request. The wireless device can send a radio resource control (RRC) request message based on the paging cause value requesting establishment of a connection with the PLMN for the PDU session. According to one embodiment, the session establishment request message can include: a PDU session identity of the PDU session; and at least one parameter indicating that the paging cause value is to be included in a paging message for the PDU session identified by the PDU identity. According to one embodiment, the session establishment request message can further include at least one of: a data network name (DNN); the PDU session identity; a requested PDU session type; a requested session and service continuity mode; a session management capability protocol configuration option; or a number of data packet filters. According to one embodiment, the DNN can indicate an internet protocol multimedia subsystem.

[0452] Figure 42 is a flow diagram of an aspect of example embodiments of the present disclosure. At 4210, a session management function (SMF) can send a request to an access and mobility management function (AMF) to notify the SMF of a transition of a radio resource control (RRC) connection state of a wireless device. At 4220, the SMF can receive a second message from the AMF notifying of a change in the RRC state of the wireless device. At 4230, the SMF can send a third message to a user plane function (UPF) requesting that a paging cause be included in a user plane packet header of the wireless device.

[0453] According to one embodiment, a session management function (SMF) can send an event reporting request message to an access and mobility management function (AMF) requesting radio resource control (RRC) connection state change reporting for a wireless device. The SMF can receive a notification message from the AMF indicating that the wireless device transitioned from an RRC connected state to an RRC inactive state. The SMF can send a message to a user plane function (UPF) requesting that a paging cause be included into a user plane packet header of the wireless device.

[0454] Figure 43is a flow diagram of an aspect of the example embodiments of the present disclosure. At 4310, an access and mobility management function (AMF) can receive, from a network function, a first request message requesting notification of a transition of a radio resource control (RRC) state of a wireless device. At 4320, the AMF can receive, from a base station, a notification message indicating the transition of the RRC state of the wireless device. At 4330, the AMF can send, to the network function, an event report message indicating the RRC state of the wireless device. According to an embodiment, the AMF can send, to the base station, a second request message requesting notification of the transition of the RRC state of the wireless device. According to an embodiment, the second request message can be based on the first request message. According to an embodiment, the network function can be a session management function. According to an embodiment, the first request message can be an event report request message. According to an embodiment, the first request message can include at least one of: an event type; a reporting type; or a user equipment identity. According to an embodiment, the event type can include at least one of: a report of an RRC connected state; or a report of a connected state. According to an embodiment, the connected state can indicate at least one of: an idle state; or a connected state. According to an embodiment, the transition of the RRC state can indicate at least one of: a transition from the RRC connected state to an RRC inactive state; or a transition from the RRC inactive state to the RRC connected state.

[0455] According to an embodiment, an access and mobility management function (AMF) can receive, from a network function, an event report request message requesting a radio resource control (RRC) connected state change report of a wireless device. According to an embodiment, the AMF can send, to a base station, a notification request message requesting notification of a state transition of the wireless device based on the event report request message. According to an embodiment, the AMF can receive, from the base station, a notification response message indicating a RRC state change of the wireless device. According to an embodiment, the AMF can send, to the network function, an event report response message indicating the RRC state change.

[0456] According to an embodiment, an access and mobility management function (AMF) receives, from a network function, an event report request message requesting a radio resource control (RRC) connected state change of a wireless device. The AMF can send, to a base station, a notification request message requesting a state change of the wireless device based on the receiving. The AMF can receive, from the base station, a notification response message indicating a RRC state change of the wireless device. The change of the RRC state can include at least one of: a transition from an RRC connected state to an RRC inactive state; or a transition from the RRC inactive state to the RRC connected state. The AMF can send, to the network function, an event report response message indicating the RRC state change.

[0457] In this specification, "a" and "an" and similar phrases are to be interpreted as "at least one" and "one or more." In this specification, the term "may" is to be interpreted as "may, for example." In other words, the term "may" indicates that a phrase following the term "may" is an example of one of a number of suitable possibilities that can be used in one or more embodiments. If A and B are sets, and every element of A is also an element of B, then A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B = {celll, cell2} are: {celll}, {cell2}, and {celll, cell2}.

[0458] In this specification, a parameter (information element: IE) can include one or more objects, and each of the objects can include one or more other objects. For example, if a parameter (IE) N includes a parameter (IE) M, and the parameter (IE) M includes a parameter (IE) K, and the parameter (IE) K includes a parameter (information element) J, then, for example, N includes K, and N includes J. In an example embodiment, when one or more messages include a plurality of parameters, this means that one of the plurality of parameters is in at least one of the one or more messages, but not necessarily in each of the one or more messages.

[0459] Many of the elements described in the disclosed embodiments can be implemented as modules. Herein, a module can be interpreted as a tangible element that performs a defined function and has a defined interface to other elements. Modules described in this disclosure can be implemented in hardware, software in combination with hardware, firmware, wetware (i.e., hardware with a biological element) or a combination thereof, which can be behaviorally equivalent. For example, a module can be implemented as a software routine in a computer language (e.g., C, C++, Fortran, Java, Basic, Matlab, etc.) that is configured to execute on a hardware machine (e.g., a computer, a micro-processor, an ASIC, etc.) or a modeling / simulation program (e.g., Simulink, Stateflow, GNU Octave, or LabVIEWMathScript). Furthermore, it is possible for a module to be implemented as a physical hardware that incorporates discrete or programmable analog, digital and / or quantum hardware. Examples of programmable hardware include computers, microcontrollers, microprocessors, application specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers and microprocessors use languages such as assembly, C, C++ and the like to program them. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDLs), such as VHDL or Verilog, which configure the connections between less functional internal hardware modules on the programmable devices. Finally, it is important to note that the above technologies are often used in combination to achieve the results of a functional module.

[0460] Exemplary embodiments of the present invention can be implemented using various physical and / or virtual network elements, software defined networks, virtual network functions.

[0461] The disclosure of this patent document incorporates material that is copyrighted. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

[0462] While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Numerous changes to the disclosed embodiments can be made in the details of construction and arrangement without departing from the spirit and scope of the disclosure. Indeed, various embodiments of the application can be practiced without some or all of the specific details set forth herein. Further, although the disclosed embodiments have been described specifically, those skilled in the art will understand that various modifications can be made to the process and system described and that features from one embodiment can be incorporated into other embodiments. Accordingly, the present embodiments are not to be seen as limited to the examples described herein. In particular, it should be noted that the above explanation has focused on examples using a 5G AN. However, those skilled in the art will recognize that embodiments of the present application can also be implemented in systems including one or more legacy systems or LTE. The disclosed methods and systems can be implemented in wireless or wired systems. Features of the various embodiments presented in this disclosure can be combined. One or more features (methods or systems) of one embodiment can be implemented in other embodiments. Only a limited number of example combinations have been shown to indicate the possibilities of combining features to create enhanced transmitting and receiving systems and methods in the various embodiments.

[0463] In addition, it should be understood that any figures which highlight the functionality and advantages are presented for example purposes only. The architecture disclosed is sufficiently flexible and configurable, such that it can utilize different modes of implementation, in different environments, with different schedules, etc. For example, the actions delineated in any flow chart can be reordered or optionally utilized in some embodiments.

[0464] Furthermore, the purpose of the Abstract of the Disclosure is to enable the United States Patent and Trademark Office and the public generally, especially scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure. The Abstract is not intended to be limiting as to the scope of the application in any way.

[0465] Finally, it is the applicant's intent that only claims which include the explicit language "means for" or "step for" are to be interpreted under 35 U.S.C. 112, paragraph 6. It is the applicant's intent that claims not including the explicit language "means for" or "step for" are not to be interpreted under 35 U.S.C. 112, paragraph 6.

Claims

1. A method of communication comprising: sending, by a multi-Universal Subscriber Identity Module (multi-USIM) wireless device, a registration request message to a mobility management function, the registration request message including a capability of the multi-USIM wireless device for a network to include a paging cause value in a paging message; receiving a first paging message including the paging cause value; and based on the first paging message, sending a radio resource control (RRC) message requesting connection setup.

2. The method of claim 1, wherein the registration request message includes an identifier of the wireless device.

3. The method of claim 1, wherein the RRC message is an RRC setup message.

4. The method of claim 3, wherein the RRC setup message is an RRC setup request message.

5. The method of claim 3, wherein the RRC setup message is an RRC resume request message.

6. The method of claim 1, wherein sending the registration request message is based on the wireless device being a multi-USIM device.

7. The method of claim 1, wherein the paging cause value indicates that the paging message is for Internet Protocol Multimedia Subsystem (IMS) voice.

8. The method of claim 1, wherein the mobility management function is one or more of: a mobility management entity; and a mobility management function.

9. The method of claim 1, wherein the mobility management function is a mobility management function of a visited Public Land Mobile Network (PLMN).

10. The method of claim 9, further comprising: registering, by the wireless device, with a second PLMN; wherein the registration request message is based on the visited PLMN being a lower priority PLMN than the second PLMN.

11. A multi-Universal Subscriber Identity Module (multi-USIM) wireless device comprising: one or more processors; and memory storing instructions that, when executed by the one or more processors, cause the wireless device to: send, to a mobility management function, a registration request message including a capability of the multi-USIM wireless device for a network to include a paging cause value in a paging message; receive a first paging message including the paging cause value; and based on the first paging message, send a radio resource control (RRC) message requesting connection setup.

12. The wireless device of claim 11, wherein the registration request message includes an identifier of the wireless device.

13. The wireless device of claim 11, wherein the RRC message is an RRC setup message.

14. The wireless device of claim 13, wherein the RRC setup message is an RRC setup request message.

15. The wireless device of claim 13, wherein the RRC setup message is an RRC resume request message.

16. The wireless device of claim 11, wherein sending the registration request message is based on the wireless device being a multi-USIM device. ​ 17. The wireless device of claim 11, wherein the paging cause value indicates that the paging message is for Internet Protocol Multimedia Subsystem (IMS) voice.

18. The wireless device of claim 11, wherein the mobility management function is one or more of: a mobility management entity; and a mobility management function.

19. The wireless device of claim 11, wherein the mobility management function is a mobility management function of a visited public land mobile network (PLMN).

20. A communication system comprising: a multi-Universal Subscriber Identity Module (multi-USIM) wireless device comprising: one or more processors; and memory storing instructions that, when executed by the instructions by the one or more processors, cause the wireless device to: send a registration request message to a mobility management function, the registration request message comprising a capability of the multi-USIM wireless device for a network to include a paging cause value in a paging message; receive a first paging message comprising a paging cause value; and based on the first paging message, send a radio resource control (RRC) message requesting connection setup; and a mobility management function, wherein the mobility management function comprises: one or more processors; and memory storing instructions that, when executed by the instructions by the one or more processors, cause the mobility management function to: receive the registration request message; and send the first paging message; and receive the RRC message.

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